diff options
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/Build | 2 | ||||
| -rw-r--r-- | tools/lib/bpf/Makefile | 26 | ||||
| -rw-r--r-- | tools/lib/bpf/README.rst | 15 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf.c | 80 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf.h | 3 | ||||
| -rw-r--r-- | tools/lib/bpf/btf.c | 2198 | ||||
| -rw-r--r-- | tools/lib/bpf/btf.h | 46 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 210 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 44 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.map | 30 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf_probes.c | 242 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf_util.h | 30 | ||||
| -rw-r--r-- | tools/lib/bpf/netlink.c | 85 | ||||
| -rw-r--r-- | tools/lib/bpf/test_libbpf.cpp | 4 | ||||
| -rw-r--r-- | tools/lib/bpf/xsk.c | 723 | ||||
| -rw-r--r-- | tools/lib/bpf/xsk.h | 203 |
16 files changed, 3594 insertions, 347 deletions
diff --git a/tools/lib/bpf/Build b/tools/lib/bpf/Build index 197b40f5b5c6..ee9d5362f35b 100644 --- a/tools/lib/bpf/Build +++ b/tools/lib/bpf/Build @@ -1 +1 @@ -libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o netlink.o bpf_prog_linfo.o +libbpf-y := libbpf.o bpf.o nlattr.o btf.o libbpf_errno.o str_error.o netlink.o bpf_prog_linfo.o libbpf_probes.o xsk.o diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 34d9c3619c96..a05c43468bd0 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -14,21 +14,6 @@ srctree := $(patsubst %/,%,$(dir $(srctree))) #$(info Determined 'srctree' to be $(srctree)) endif -# Makefiles suck: This macro sets a default value of $(2) for the -# variable named by $(1), unless the variable has been set by -# environment or command line. This is necessary for CC and AR -# because make sets default values, so the simpler ?= approach -# won't work as expected. -define allow-override - $(if $(or $(findstring environment,$(origin $(1))),\ - $(findstring command line,$(origin $(1)))),,\ - $(eval $(1) = $(2))) -endef - -# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix. -$(call allow-override,CC,$(CROSS_COMPILE)gcc) -$(call allow-override,AR,$(CROSS_COMPILE)ar) - INSTALL = install # Use DESTDIR for installing into a different root directory. @@ -54,7 +39,7 @@ man_dir_SQ = '$(subst ','\'',$(man_dir))' export man_dir man_dir_SQ INSTALL export DESTDIR DESTDIR_SQ -include ../../scripts/Makefile.include +include $(srctree)/tools/scripts/Makefile.include # copy a bit from Linux kbuild @@ -147,9 +132,9 @@ BPF_IN := $(OUTPUT)libbpf-in.o LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) VERSION_SCRIPT := libbpf.map -GLOBAL_SYM_COUNT = $(shell readelf -s $(BPF_IN) | \ +GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {s++} END{print s}') -VERSIONED_SYM_COUNT = $(shell readelf -s $(OUTPUT)libbpf.so | \ +VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) CMD_TARGETS = $(LIB_FILE) @@ -179,6 +164,9 @@ $(BPF_IN): force elfdep bpfdep @(test -f ../../include/uapi/linux/if_link.h -a -f ../../../include/uapi/linux/if_link.h && ( \ (diff -B ../../include/uapi/linux/if_link.h ../../../include/uapi/linux/if_link.h >/dev/null) || \ echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_link.h' differs from latest version at 'include/uapi/linux/if_link.h'" >&2 )) || true + @(test -f ../../include/uapi/linux/if_xdp.h -a -f ../../../include/uapi/linux/if_xdp.h && ( \ + (diff -B ../../include/uapi/linux/if_xdp.h ../../../include/uapi/linux/if_xdp.h >/dev/null) || \ + echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true $(Q)$(MAKE) $(build)=libbpf $(OUTPUT)libbpf.so: $(BPF_IN) @@ -189,7 +177,7 @@ $(OUTPUT)libbpf.a: $(BPF_IN) $(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^ $(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a - $(QUIET_LINK)$(CXX) $^ -lelf -o $@ + $(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@ check: check_abi diff --git a/tools/lib/bpf/README.rst b/tools/lib/bpf/README.rst index 607aae40f4ed..5788479384ca 100644 --- a/tools/lib/bpf/README.rst +++ b/tools/lib/bpf/README.rst @@ -9,7 +9,7 @@ described here. It's recommended to follow these conventions whenever a new function or type is added to keep libbpf API clean and consistent. All types and functions provided by libbpf API should have one of the -following prefixes: ``bpf_``, ``btf_``, ``libbpf_``. +following prefixes: ``bpf_``, ``btf_``, ``libbpf_``, ``xsk_``. System call wrappers -------------------- @@ -62,6 +62,19 @@ Auxiliary functions and types that don't fit well in any of categories described above should have ``libbpf_`` prefix, e.g. ``libbpf_get_error`` or ``libbpf_prog_type_by_name``. +AF_XDP functions +------------------- + +AF_XDP functions should have an ``xsk_`` prefix, e.g. +``xsk_umem__get_data`` or ``xsk_umem__create``. The interface consists +of both low-level ring access functions and high-level configuration +functions. These can be mixed and matched. Note that these functions +are not reentrant for performance reasons. + +Please take a look at Documentation/networking/af_xdp.rst in the Linux +kernel source tree on how to use XDP sockets and for some common +mistakes in case you do not get any traffic up to user space. + libbpf ABI ========== diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 88cbd110ae58..9cd015574e83 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -22,6 +22,7 @@ */ #include <stdlib.h> +#include <string.h> #include <memory.h> #include <unistd.h> #include <asm/unistd.h> @@ -214,23 +215,35 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, { void *finfo = NULL, *linfo = NULL; union bpf_attr attr; + __u32 log_level; __u32 name_len; int fd; - if (!load_attr) + if (!load_attr || !log_buf != !log_buf_sz) + return -EINVAL; + + log_level = load_attr->log_level; + if (log_level > 2 || (log_level && !log_buf)) return -EINVAL; name_len = load_attr->name ? strlen(load_attr->name) : 0; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.prog_type = load_attr->prog_type; attr.expected_attach_type = load_attr->expected_attach_type; attr.insn_cnt = (__u32)load_attr->insns_cnt; attr.insns = ptr_to_u64(load_attr->insns); attr.license = ptr_to_u64(load_attr->license); - attr.log_buf = ptr_to_u64(NULL); - attr.log_size = 0; - attr.log_level = 0; + + attr.log_level = log_level; + if (log_level) { + attr.log_buf = ptr_to_u64(log_buf); + attr.log_size = log_buf_sz; + } else { + attr.log_buf = ptr_to_u64(NULL); + attr.log_size = 0; + } + attr.kern_version = load_attr->kern_version; attr.prog_ifindex = load_attr->prog_ifindex; attr.prog_btf_fd = load_attr->prog_btf_fd; @@ -286,7 +299,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, goto done; } - if (!log_buf || !log_buf_sz) + if (log_level || !log_buf) goto done; /* Try again with log */ @@ -327,7 +340,7 @@ int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.prog_type = type; attr.insn_cnt = (__u32)insns_cnt; attr.insns = ptr_to_u64(insns); @@ -347,7 +360,7 @@ int bpf_map_update_elem(int fd, const void *key, const void *value, { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); @@ -360,7 +373,7 @@ int bpf_map_lookup_elem(int fd, const void *key, void *value) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); @@ -368,11 +381,24 @@ int bpf_map_lookup_elem(int fd, const void *key, void *value) return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); } +int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags) +{ + union bpf_attr attr; + + memset(&attr, 0, sizeof(attr)); + attr.map_fd = fd; + attr.key = ptr_to_u64(key); + attr.value = ptr_to_u64(value); + attr.flags = flags; + + return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); +} + int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.value = ptr_to_u64(value); @@ -384,7 +410,7 @@ int bpf_map_delete_elem(int fd, const void *key) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); @@ -395,7 +421,7 @@ int bpf_map_get_next_key(int fd, const void *key, void *next_key) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.map_fd = fd; attr.key = ptr_to_u64(key); attr.next_key = ptr_to_u64(next_key); @@ -407,7 +433,7 @@ int bpf_obj_pin(int fd, const char *pathname) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.pathname = ptr_to_u64((void *)pathname); attr.bpf_fd = fd; @@ -418,7 +444,7 @@ int bpf_obj_get(const char *pathname) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.pathname = ptr_to_u64((void *)pathname); return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); @@ -429,7 +455,7 @@ int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.target_fd = target_fd; attr.attach_bpf_fd = prog_fd; attr.attach_type = type; @@ -442,7 +468,7 @@ int bpf_prog_detach(int target_fd, enum bpf_attach_type type) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.target_fd = target_fd; attr.attach_type = type; @@ -453,7 +479,7 @@ int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.target_fd = target_fd; attr.attach_bpf_fd = prog_fd; attr.attach_type = type; @@ -467,7 +493,7 @@ int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, union bpf_attr attr; int ret; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.query.target_fd = target_fd; attr.query.attach_type = type; attr.query.query_flags = query_flags; @@ -488,7 +514,7 @@ int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, union bpf_attr attr; int ret; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.test.prog_fd = prog_fd; attr.test.data_in = ptr_to_u64(data); attr.test.data_out = ptr_to_u64(data_out); @@ -513,7 +539,7 @@ int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr) if (!test_attr->data_out && test_attr->data_size_out > 0) return -EINVAL; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.test.prog_fd = test_attr->prog_fd; attr.test.data_in = ptr_to_u64(test_attr->data_in); attr.test.data_out = ptr_to_u64(test_attr->data_out); @@ -533,7 +559,7 @@ int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) union bpf_attr attr; int err; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.start_id = start_id; err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr)); @@ -548,7 +574,7 @@ int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) union bpf_attr attr; int err; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.start_id = start_id; err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr)); @@ -562,7 +588,7 @@ int bpf_prog_get_fd_by_id(__u32 id) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.prog_id = id; return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); @@ -572,7 +598,7 @@ int bpf_map_get_fd_by_id(__u32 id) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.map_id = id; return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); @@ -582,7 +608,7 @@ int bpf_btf_get_fd_by_id(__u32 id) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.btf_id = id; return sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr)); @@ -593,7 +619,7 @@ int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len) union bpf_attr attr; int err; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.info.bpf_fd = prog_fd; attr.info.info_len = *info_len; attr.info.info = ptr_to_u64(info); @@ -609,7 +635,7 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd) { union bpf_attr attr; - bzero(&attr, sizeof(attr)); + memset(&attr, 0, sizeof(attr)); attr.raw_tracepoint.name = ptr_to_u64(name); attr.raw_tracepoint.prog_fd = prog_fd; diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 8f09de482839..6ffdd79bea89 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -85,6 +85,7 @@ struct bpf_load_program_attr { __u32 line_info_rec_size; const void *line_info; __u32 line_info_cnt; + __u32 log_level; }; /* Flags to direct loading requirements */ @@ -110,6 +111,8 @@ LIBBPF_API int bpf_map_update_elem(int fd, const void *key, const void *value, __u64 flags); LIBBPF_API int bpf_map_lookup_elem(int fd, const void *key, void *value); +LIBBPF_API int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, + __u64 flags); LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value); LIBBPF_API int bpf_map_delete_elem(int fd, const void *key); diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index d682d3b8f7b9..1b8d8cdd3575 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) /* Copyright (c) 2018 Facebook */ +#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> @@ -9,12 +10,14 @@ #include <linux/btf.h> #include "btf.h" #include "bpf.h" +#include "libbpf.h" +#include "libbpf_util.h" -#define elog(fmt, ...) { if (err_log) err_log(fmt, ##__VA_ARGS__); } #define max(a, b) ((a) > (b) ? (a) : (b)) #define min(a, b) ((a) < (b) ? (a) : (b)) -#define BTF_MAX_NR_TYPES 65535 +#define BTF_MAX_NR_TYPES 0x7fffffff +#define BTF_MAX_STR_OFFSET 0x7fffffff #define IS_MODIFIER(k) (((k) == BTF_KIND_TYPEDEF) || \ ((k) == BTF_KIND_VOLATILE) || \ @@ -39,9 +42,8 @@ struct btf { struct btf_ext_info { /* - * info points to a deep copy of the individual info section - * (e.g. func_info and line_info) from the .BTF.ext. - * It does not include the __u32 rec_size. + * info points to the individual info section (e.g. func_info and + * line_info) from the .BTF.ext. It does not include the __u32 rec_size. */ void *info; __u32 rec_size; @@ -49,8 +51,13 @@ struct btf_ext_info { }; struct btf_ext { + union { + struct btf_ext_header *hdr; + void *data; + }; struct btf_ext_info func_info; struct btf_ext_info line_info; + __u32 data_size; }; struct btf_ext_info_sec { @@ -107,54 +114,54 @@ static int btf_add_type(struct btf *btf, struct btf_type *t) return 0; } -static int btf_parse_hdr(struct btf *btf, btf_print_fn_t err_log) +static int btf_parse_hdr(struct btf *btf) { const struct btf_header *hdr = btf->hdr; __u32 meta_left; if (btf->data_size < sizeof(struct btf_header)) { - elog("BTF header not found\n"); + pr_debug("BTF header not found\n"); return -EINVAL; } if (hdr->magic != BTF_MAGIC) { - elog("Invalid BTF magic:%x\n", hdr->magic); + pr_debug("Invalid BTF magic:%x\n", hdr->magic); return -EINVAL; } if (hdr->version != BTF_VERSION) { - elog("Unsupported BTF version:%u\n", hdr->version); + pr_debug("Unsupported BTF version:%u\n", hdr->version); return -ENOTSUP; } if (hdr->flags) { - elog("Unsupported BTF flags:%x\n", hdr->flags); + pr_debug("Unsupported BTF flags:%x\n", hdr->flags); return -ENOTSUP; } meta_left = btf->data_size - sizeof(*hdr); if (!meta_left) { - elog("BTF has no data\n"); + pr_debug("BTF has no data\n"); return -EINVAL; } if (meta_left < hdr->type_off) { - elog("Invalid BTF type section offset:%u\n", hdr->type_off); + pr_debug("Invalid BTF type section offset:%u\n", hdr->type_off); return -EINVAL; } if (meta_left < hdr->str_off) { - elog("Invalid BTF string section offset:%u\n", hdr->str_off); + pr_debug("Invalid BTF string section offset:%u\n", hdr->str_off); return -EINVAL; } if (hdr->type_off >= hdr->str_off) { - elog("BTF type section offset >= string section offset. No type?\n"); + pr_debug("BTF type section offset >= string section offset. No type?\n"); return -EINVAL; } if (hdr->type_off & 0x02) { - elog("BTF type section is not aligned to 4 bytes\n"); + pr_debug("BTF type section is not aligned to 4 bytes\n"); return -EINVAL; } @@ -163,15 +170,15 @@ static int btf_parse_hdr(struct btf *btf, btf_print_fn_t err_log) return 0; } -static int btf_parse_str_sec(struct btf *btf, btf_print_fn_t err_log) +static int btf_parse_str_sec(struct btf *btf) { const struct btf_header *hdr = btf->hdr; const char *start = btf->nohdr_data + hdr->str_off; const char *end = start + btf->hdr->str_len; - if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || + if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET || start[0] || end[-1]) { - elog("Invalid BTF string section\n"); + pr_debug("Invalid BTF string section\n"); return -EINVAL; } @@ -180,7 +187,38 @@ static int btf_parse_str_sec(struct btf *btf, btf_print_fn_t err_log) return 0; } -static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log) +static int btf_type_size(struct btf_type *t) +{ + int base_size = sizeof(struct btf_type); + __u16 vlen = BTF_INFO_VLEN(t->info); + + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_FWD: + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_PTR: + case BTF_KIND_TYPEDEF: + case BTF_KIND_FUNC: + return base_size; + case BTF_KIND_INT: + return base_size + sizeof(__u32); + case BTF_KIND_ENUM: + return base_size + vlen * sizeof(struct btf_enum); + case BTF_KIND_ARRAY: + return base_size + sizeof(struct btf_array); + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + return base_size + vlen * sizeof(struct btf_member); + case BTF_KIND_FUNC_PROTO: + return base_size + vlen * sizeof(struct btf_param); + default: + pr_debug("Unsupported BTF_KIND:%u\n", BTF_INFO_KIND(t->info)); + return -EINVAL; + } +} + +static int btf_parse_type_sec(struct btf *btf) { struct btf_header *hdr = btf->hdr; void *nohdr_data = btf->nohdr_data; @@ -189,41 +227,13 @@ static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log) while (next_type < end_type) { struct btf_type *t = next_type; - __u16 vlen = BTF_INFO_VLEN(t->info); + int type_size; int err; - next_type += sizeof(*t); - switch (BTF_INFO_KIND(t->info)) { - case BTF_KIND_INT: - next_type += sizeof(int); - break; - case BTF_KIND_ARRAY: - next_type += sizeof(struct btf_array); - break; - case BTF_KIND_STRUCT: - case BTF_KIND_UNION: - next_type += vlen * sizeof(struct btf_member); - break; - case BTF_KIND_ENUM: - next_type += vlen * sizeof(struct btf_enum); - break; - case BTF_KIND_FUNC_PROTO: - next_type += vlen * sizeof(struct btf_param); - break; - case BTF_KIND_FUNC: - case BTF_KIND_TYPEDEF: - case BTF_KIND_PTR: - case BTF_KIND_FWD: - case BTF_KIND_VOLATILE: - case BTF_KIND_CONST: - case BTF_KIND_RESTRICT: - break; - default: - elog("Unsupported BTF_KIND:%u\n", - BTF_INFO_KIND(t->info)); - return -EINVAL; - } - + type_size = btf_type_size(t); + if (type_size < 0) + return type_size; + next_type += type_size; err = btf_add_type(btf, t); if (err) return err; @@ -232,6 +242,11 @@ static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log) return 0; } +__u32 btf__get_nr_types(const struct btf *btf) +{ + return btf->nr_types; +} + const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id) { if (type_id > btf->nr_types) @@ -250,21 +265,6 @@ static bool btf_type_is_void_or_null(const struct btf_type *t) return !t || btf_type_is_void(t); } -static __s64 btf_type_size(const struct btf_type *t) -{ - switch (BTF_INFO_KIND(t->info)) { - case BTF_KIND_INT: - case BTF_KIND_STRUCT: - case BTF_KIND_UNION: - case BTF_KIND_ENUM: - return t->size; - case BTF_KIND_PTR: - return sizeof(void *); - default: - return -EINVAL; - } -} - #define MAX_RESOLVE_DEPTH 32 __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) @@ -278,11 +278,16 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) t = btf__type_by_id(btf, type_id); for (i = 0; i < MAX_RESOLVE_DEPTH && !btf_type_is_void_or_null(t); i++) { - size = btf_type_size(t); - if (size >= 0) - break; - switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_INT: + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + case BTF_KIND_ENUM: + size = t->size; + goto done; + case BTF_KIND_PTR: + size = sizeof(void *); + goto done; case BTF_KIND_TYPEDEF: case BTF_KIND_VOLATILE: case BTF_KIND_CONST: @@ -306,6 +311,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) if (size < 0) return -EINVAL; +done: if (nelems && size > UINT32_MAX / nelems) return -E2BIG; @@ -363,10 +369,8 @@ void btf__free(struct btf *btf) free(btf); } -struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log) +struct btf *btf__new(__u8 *data, __u32 size) { - __u32 log_buf_size = 0; - char *log_buf = NULL; struct btf *btf; int err; @@ -376,16 +380,6 @@ struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log) btf->fd = -1; - if (err_log) { - log_buf = malloc(BPF_LOG_BUF_SIZE); - if (!log_buf) { - err = -ENOMEM; - goto done; - } - *log_buf = 0; - log_buf_size = BPF_LOG_BUF_SIZE; - } - btf->data = malloc(size); if (!btf->data) { err = -ENOMEM; @@ -395,30 +389,17 @@ struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log) memcpy(btf->data, data, size); btf->data_size = size; - btf->fd = bpf_load_btf(btf->data, btf->data_size, - log_buf, log_buf_size, false); - - if (btf->fd == -1) { - err = -errno; - elog("Error loading BTF: %s(%d)\n", strerror(errno), errno); - if (log_buf && *log_buf) - elog("%s\n", log_buf); - goto done; - } - - err = btf_parse_hdr(btf, err_log); + err = btf_parse_hdr(btf); if (err) goto done; - err = btf_parse_str_sec(btf, err_log); + err = btf_parse_str_sec(btf); if (err) goto done; - err = btf_parse_type_sec(btf, err_log); + err = btf_parse_type_sec(btf); done: - free(log_buf); - if (err) { btf__free(btf); return ERR_PTR(err); @@ -427,11 +408,47 @@ done: return btf; } +int btf__load(struct btf *btf) +{ + __u32 log_buf_size = BPF_LOG_BUF_SIZE; + char *log_buf = NULL; + int err = 0; + + if (btf->fd >= 0) + return -EEXIST; + + log_buf = malloc(log_buf_size); + if (!log_buf) + return -ENOMEM; + + *log_buf = 0; + + btf->fd = bpf_load_btf(btf->data, btf->data_size, + log_buf, log_buf_size, false); + if (btf->fd < 0) { + err = -errno; + pr_warning("Error loading BTF: %s(%d)\n", strerror(errno), errno); + if (*log_buf) + pr_warning("%s\n", log_buf); + goto done; + } + +done: + free(log_buf); + return err; +} + int btf__fd(const struct btf *btf) { return btf->fd; } +const void *btf__get_raw_data(const struct btf *btf, __u32 *size) +{ + *size = btf->data_size; + return btf->data; +} + const char *btf__name_by_offset(const struct btf *btf, __u32 offset) { if (offset < btf->hdr->str_len) @@ -467,7 +484,7 @@ int btf__get_from_id(__u32 id, struct btf **btf) goto exit_free; } - bzero(ptr, last_size); + memset(ptr, 0, last_size); btf_info.btf = ptr_to_u64(ptr); err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); @@ -481,7 +498,7 @@ int btf__get_from_id(__u32 id, struct btf **btf) goto exit_free; } ptr = temp_ptr; - bzero(ptr, last_size); + memset(ptr, 0, last_size); btf_info.btf = ptr_to_u64(ptr); err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); } @@ -491,7 +508,7 @@ int btf__get_from_id(__u32 id, struct btf **btf) goto exit_free; } - *btf = btf__new((__u8 *)(long)btf_info.btf, btf_info.btf_size, NULL); + *btf = btf__new((__u8 *)(long)btf_info.btf, btf_info.btf_size); if (IS_ERR(*btf)) { err = PTR_ERR(*btf); *btf = NULL; @@ -504,7 +521,79 @@ exit_free: return err; } -struct btf_ext_sec_copy_param { +int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, + __u32 expected_key_size, __u32 expected_value_size, + __u32 *key_type_id, __u32 *value_type_id) +{ + const struct btf_type *container_type; + const struct btf_member *key, *value; + const size_t max_name = 256; + char container_name[max_name]; + __s64 key_size, value_size; + __s32 container_id; + + if (snprintf(container_name, max_name, "____btf_map_%s", map_name) == + max_name) { + pr_warning("map:%s length of '____btf_map_%s' is too long\n", + map_name, map_name); + return -EINVAL; + } + + container_id = btf__find_by_name(btf, container_name); + if (container_id < 0) { + pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n", + map_name, container_name); + return container_id; + } + + container_type = btf__type_by_id(btf, container_id); + if (!container_type) { + pr_warning("map:%s cannot find BTF type for container_id:%u\n", + map_name, container_id); + return -EINVAL; + } + + if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT || + BTF_INFO_VLEN(container_type->info) < 2) { + pr_warning("map:%s container_name:%s is an invalid container struct\n", + map_name, container_name); + return -EINVAL; + } + + key = (struct btf_member *)(container_type + 1); + value = key + 1; + + key_size = btf__resolve_size(btf, key->type); + if (key_size < 0) { + pr_warning("map:%s invalid BTF key_type_size\n", map_name); + return key_size; + } + + if (expected_key_size != key_size) { + pr_warning("map:%s btf_key_type_size:%u != map_def_key_size:%u\n", + map_name, (__u32)key_size, expected_key_size); + return -EINVAL; + } + + value_size = btf__resolve_size(btf, value->type); + if (value_size < 0) { + pr_warning("map:%s invalid BTF value_type_size\n", map_name); + return value_size; + } + + if (expected_value_size != value_size) { + pr_warning("map:%s btf_value_type_size:%u != map_def_value_size:%u\n", + map_name, (__u32)value_size, expected_value_size); + return -EINVAL; + } + + *key_type_id = key->type; + *value_type_id = value->type; + + return 0; +} + +struct btf_ext_sec_setup_param { __u32 off; __u32 len; __u32 min_rec_size; @@ -512,41 +601,33 @@ struct btf_ext_sec_copy_param { const char *desc; }; -static int btf_ext_copy_info(struct btf_ext *btf_ext, - __u8 *data, __u32 data_size, - struct btf_ext_sec_copy_param *ext_sec, - btf_print_fn_t err_log) +static int btf_ext_setup_info(struct btf_ext *btf_ext, + struct btf_ext_sec_setup_param *ext_sec) { - const struct btf_ext_header *hdr = (struct btf_ext_header *)data; const struct btf_ext_info_sec *sinfo; struct btf_ext_info *ext_info; __u32 info_left, record_size; /* The start of the info sec (including the __u32 record_size). */ - const void *info; - - /* data and data_size do not include btf_ext_header from now on */ - data = data + hdr->hdr_len; - data_size -= hdr->hdr_len; + void *info; if (ext_sec->off & 0x03) { - elog(".BTF.ext %s section is not aligned to 4 bytes\n", + pr_debug(".BTF.ext %s section is not aligned to 4 bytes\n", ext_sec->desc); return -EINVAL; } - if (data_size < ext_sec->off || - ext_sec->len > data_size - ext_sec->off) { - elog("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n", - ext_sec->desc, ext_sec->off, ext_sec->len); + info = btf_ext->data + btf_ext->hdr->hdr_len + ext_sec->off; + info_left = ext_sec->len; + + if (btf_ext->data + btf_ext->data_size < info + ext_sec->len) { + pr_debug("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n", + ext_sec->desc, ext_sec->off, ext_sec->len); return -EINVAL; } - info = data + ext_sec->off; - info_left = ext_sec->len; - /* At least a record size */ if (info_left < sizeof(__u32)) { - elog(".BTF.ext %s record size not found\n", ext_sec->desc); + pr_debug(".BTF.ext %s record size not found\n", ext_sec->desc); return -EINVAL; } @@ -554,8 +635,8 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext, record_size = *(__u32 *)info; if (record_size < ext_sec->min_rec_size || record_size & 0x03) { - elog("%s section in .BTF.ext has invalid record size %u\n", - ext_sec->desc, record_size); + pr_debug("%s section in .BTF.ext has invalid record size %u\n", + ext_sec->desc, record_size); return -EINVAL; } @@ -564,7 +645,7 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext, /* If no records, return failure now so .BTF.ext won't be used. */ if (!info_left) { - elog("%s section in .BTF.ext has no records", ext_sec->desc); + pr_debug("%s section in .BTF.ext has no records", ext_sec->desc); return -EINVAL; } @@ -574,14 +655,14 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext, __u32 num_records; if (info_left < sec_hdrlen) { - elog("%s section header is not found in .BTF.ext\n", + pr_debug("%s section header is not found in .BTF.ext\n", ext_sec->desc); return -EINVAL; } num_records = sinfo->num_info; if (num_records == 0) { - elog("%s section has incorrect num_records in .BTF.ext\n", + pr_debug("%s section has incorrect num_records in .BTF.ext\n", ext_sec->desc); return -EINVAL; } @@ -589,7 +670,7 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext, total_record_size = sec_hdrlen + (__u64)num_records * record_size; if (info_left < total_record_size) { - elog("%s section has incorrect num_records in .BTF.ext\n", + pr_debug("%s section has incorrect num_records in .BTF.ext\n", ext_sec->desc); return -EINVAL; } @@ -601,74 +682,64 @@ static int btf_ext_copy_info(struct btf_ext *btf_ext, ext_info = ext_sec->ext_info; ext_info->len = ext_sec->len - sizeof(__u32); ext_info->rec_size = record_size; - ext_info->info = malloc(ext_info->len); - if (!ext_info->info) - return -ENOMEM; - memcpy(ext_info->info, info + sizeof(__u32), ext_info->len); + ext_info->info = info + sizeof(__u32); return 0; } -static int btf_ext_copy_func_info(struct btf_ext *btf_ext, - __u8 *data, __u32 data_size, - btf_print_fn_t err_log) +static int btf_ext_setup_func_info(struct btf_ext *btf_ext) { - const struct btf_ext_header *hdr = (struct btf_ext_header *)data; - struct btf_ext_sec_copy_param param = { - .off = hdr->func_info_off, - .len = hdr->func_info_len, + struct btf_ext_sec_setup_param param = { + .off = btf_ext->hdr->func_info_off, + .len = btf_ext->hdr->func_info_len, .min_rec_size = sizeof(struct bpf_func_info_min), .ext_info = &btf_ext->func_info, .desc = "func_info" }; - return btf_ext_copy_info(btf_ext, data, data_size, ¶m, err_log); + return btf_ext_setup_info(btf_ext, ¶m); } -static int btf_ext_copy_line_info(struct btf_ext *btf_ext, - __u8 *data, __u32 data_size, - btf_print_fn_t err_log) +static int btf_ext_setup_line_info(struct btf_ext *btf_ext) { - const struct btf_ext_header *hdr = (struct btf_ext_header *)data; - struct btf_ext_sec_copy_param param = { - .off = hdr->line_info_off, - .len = hdr->line_info_len, + struct btf_ext_sec_setup_param param = { + .off = btf_ext->hdr->line_info_off, + .len = btf_ext->hdr->line_info_len, .min_rec_size = sizeof(struct bpf_line_info_min), .ext_info = &btf_ext->line_info, .desc = "line_info", }; - return btf_ext_copy_info(btf_ext, data, data_size, ¶m, err_log); + return btf_ext_setup_info(btf_ext, ¶m); } -static int btf_ext_parse_hdr(__u8 *data, __u32 data_size, - btf_print_fn_t err_log) +static int btf_ext_parse_hdr(__u8 *data, __u32 data_size) { const struct btf_ext_header *hdr = (struct btf_ext_header *)data; if (data_size < offsetof(struct btf_ext_header, func_info_off) || data_size < hdr->hdr_len) { - elog("BTF.ext header not found"); + pr_debug("BTF.ext header not found"); return -EINVAL; } if (hdr->magic != BTF_MAGIC) { - elog("Invalid BTF.ext magic:%x\n", hdr->magic); + pr_debug("Invalid BTF.ext magic:%x\n", hdr->magic); return -EINVAL; } if (hdr->version != BTF_VERSION) { - elog("Unsupported BTF.ext version:%u\n", hdr->version); + pr_debug("Unsupported BTF.ext version:%u\n", hdr->version); return -ENOTSUP; } if (hdr->flags) { - elog("Unsupported BTF.ext flags:%x\n", hdr->flags); + pr_debug("Unsupported BTF.ext flags:%x\n", hdr->flags); return -ENOTSUP; } if (data_size == hdr->hdr_len) { - elog("BTF.ext has no data\n"); + pr_debug("BTF.ext has no data\n"); return -EINVAL; } @@ -679,18 +750,16 @@ void btf_ext__free(struct btf_ext *btf_ext) { if (!btf_ext) return; - - free(btf_ext->func_info.info); - free(btf_ext->line_info.info); + free(btf_ext->data); free(btf_ext); } -struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log) +struct btf_ext *btf_ext__new(__u8 *data, __u32 size) { struct btf_ext *btf_ext; int err; - err = btf_ext_parse_hdr(data, size, err_log); + err = btf_ext_parse_hdr(data, size); if (err) return ERR_PTR(err); @@ -698,13 +767,23 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log) if (!btf_ext) return ERR_PTR(-ENOMEM); - err = btf_ext_copy_func_info(btf_ext, data, size, err_log); - if (err) { - btf_ext__free(btf_ext); - return ERR_PTR(err); + btf_ext->data_size = size; + btf_ext->data = malloc(size); + if (!btf_ext->data) { + err = -ENOMEM; + goto done; } + memcpy(btf_ext->data, data, size); + + err = btf_ext_setup_func_info(btf_ext); + if (err) + goto done; + + err = btf_ext_setup_line_info(btf_ext); + if (err) + goto done; - err = btf_ext_copy_line_info(btf_ext, data, size, err_log); +done: if (err) { btf_ext__free(btf_ext); return ERR_PTR(err); @@ -713,6 +792,12 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log) return btf_ext; } +const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size) +{ + *size = btf_ext->data_size; + return btf_ext->data; +} + static int btf_ext_reloc_info(const struct btf *btf, const struct btf_ext_info *ext_info, const char *sec_name, __u32 insns_cnt, @@ -761,7 +846,8 @@ static int btf_ext_reloc_info(const struct btf *btf, return -ENOENT; } -int btf_ext__reloc_func_info(const struct btf *btf, const struct btf_ext *btf_ext, +int btf_ext__reloc_func_info(const struct btf *btf, + const struct btf_ext *btf_ext, const char *sec_name, __u32 insns_cnt, void **func_info, __u32 *cnt) { @@ -769,7 +855,8 @@ int btf_ext__reloc_func_info(const struct btf *btf, const struct btf_ext *btf_ex insns_cnt, func_info, cnt); } -int btf_ext__reloc_line_info(const struct btf *btf, const struct btf_ext *btf_ext, +int btf_ext__reloc_line_info(const struct btf *btf, + const struct btf_ext *btf_ext, const char *sec_name, __u32 insns_cnt, void **line_info, __u32 *cnt) { @@ -786,3 +873,1778 @@ __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext) { return btf_ext->line_info.rec_size; } + +struct btf_dedup; + +static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext, + const struct btf_dedup_opts *opts); +static void btf_dedup_free(struct btf_dedup *d); +static int btf_dedup_strings(struct btf_dedup *d); +static int btf_dedup_prim_types(struct btf_dedup *d); +static int btf_dedup_struct_types(struct btf_dedup *d); +static int btf_dedup_ref_types(struct btf_dedup *d); +static int btf_dedup_compact_types(struct btf_dedup *d); +static int btf_dedup_remap_types(struct btf_dedup *d); + +/* + * Deduplicate BTF types and strings. + * + * BTF dedup algorithm takes as an input `struct btf` representing `.BTF` ELF + * section with all BTF type descriptors and string data. It overwrites that + * memory in-place with deduplicated types and strings without any loss of + * information. If optional `struct btf_ext` representing '.BTF.ext' ELF section + * is provided, all the strings referenced from .BTF.ext section are honored + * and updated to point to the right offsets after deduplication. + * + * If function returns with error, type/string data might be garbled and should + * be discarded. + * + * More verbose and detailed description of both problem btf_dedup is solving, + * as well as solution could be found at: + * https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html + * + * Problem description and justification + * ===================================== + * + * BTF type information is typically emitted either as a result of conversion + * from DWARF to BTF or directly by compiler. In both cases, each compilation + * unit contains information about a subset of all the types that are used + * in an application. These subsets are frequently overlapping and contain a lot + * of duplicated information when later concatenated together into a single + * binary. This algorithm ensures that each unique type is represented by single + * BTF type descriptor, greatly reducing resulting size of BTF data. + * + * Compilation unit isolation and subsequent duplication of data is not the only + * problem. The same type hierarchy (e.g., struct and all the type that struct + * references) in different compilation units can be represented in BTF to + * various degrees of completeness (or, rather, incompleteness) due to + * struct/union forward declarations. + * + * Let's take a look at an example, that we'll use to better understand the + * problem (and solution). Suppose we have two compilation units, each using + * same `struct S`, but each of them having incomplete type information about + * struct's fields: + * + * // CU #1: + * struct S; + * struct A { + * int a; + * struct A* self; + * struct S* parent; + * }; + * struct B; + * struct S { + * struct A* a_ptr; + * struct B* b_ptr; + * }; + * + * // CU #2: + * struct S; + * struct A; + * struct B { + * int b; + * struct B* self; + * struct S* parent; + * }; + * struct S { + * struct A* a_ptr; + * struct B* b_ptr; + * }; + * + * In case of CU #1, BTF data will know only that `struct B` exist (but no + * more), but will know the complete type information about `struct A`. While + * for CU #2, it will know full type information about `struct B`, but will + * only know about forward declaration of `struct A` (in BTF terms, it will + * have `BTF_KIND_FWD` type descriptor with name `B`). + * + * This compilation unit isolation means that it's possible that there is no + * single CU with complete type information describing structs `S`, `A`, and + * `B`. Also, we might get tons of duplicated and redundant type information. + * + * Additional complication we need to keep in mind comes from the fact that + * types, in general, can form graphs containing cycles, not just DAGs. + * + * While algorithm does deduplication, it also merges and resolves type + * information (unless disabled throught `struct btf_opts`), whenever possible. + * E.g., in the example above with two compilation units having partial type + * information for structs `A` and `B`, the output of algorithm will emit + * a single copy of each BTF type that describes structs `A`, `B`, and `S` + * (as well as type information for `int` and pointers), as if they were defined + * in a single compilation unit as: + * + * struct A { + * int a; + * struct A* self; + * struct S* parent; + * }; + * struct B { + * int b; + * struct B* self; + * struct S* parent; + * }; + * struct S { + * struct A* a_ptr; + * struct B* b_ptr; + * }; + * + * Algorithm summary + * ================= + * + * Algorithm completes its work in 6 separate passes: + * + * 1. Strings deduplication. + * 2. Primitive types deduplication (int, enum, fwd). + * 3. Struct/union types deduplication. + * 4. Reference types deduplication (pointers, typedefs, arrays, funcs, func + * protos, and const/volatile/restrict modifiers). + * 5. Types compaction. + * 6. Types remapping. + * + * Algorithm determines canonical type descriptor, which is a single + * representative type for each truly unique type. This canonical type is the + * one that will go into final deduplicated BTF type information. For + * struct/unions, it is also the type that algorithm will merge additional type + * information into (while resolving FWDs), as it discovers it from data in + * other CUs. Each input BTF type eventually gets either mapped to itself, if + * that type is canonical, or to some other type, if that type is equivalent + * and was chosen as canonical representative. This mapping is stored in + * `btf_dedup->map` array. This map is also used to record STRUCT/UNION that + * FWD type got resolved to. + * + * To facilitate fast discovery of canonical types, we also maintain canonical + * index (`btf_dedup->dedup_table`), which maps type descriptor's signature hash + * (i.e., hashed kind, name, size, fields, etc) into a list of canonical types + * that match that signature. With sufficiently good choice of type signature + * hashing function, we can limit number of canonical types for each unique type + * signature to a very small number, allowing to find canonical type for any + * duplicated type very quickly. + * + * Struct/union deduplication is the most critical part and algorithm for + * deduplicating structs/unions is described in greater details in comments for + * `btf_dedup_is_equiv` function. + */ +int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, + const struct btf_dedup_opts *opts) +{ + struct btf_dedup *d = btf_dedup_new(btf, btf_ext, opts); + int err; + + if (IS_ERR(d)) { + pr_debug("btf_dedup_new failed: %ld", PTR_ERR(d)); + return -EINVAL; + } + + err = btf_dedup_strings(d); + if (err < 0) { + pr_debug("btf_dedup_strings failed:%d\n", err); + goto done; + } + err = btf_dedup_prim_types(d); + if (err < 0) { + pr_debug("btf_dedup_prim_types failed:%d\n", err); + goto done; + } + err = btf_dedup_struct_types(d); + if (err < 0) { + pr_debug("btf_dedup_struct_types failed:%d\n", err); + goto done; + } + err = btf_dedup_ref_types(d); + if (err < 0) { + pr_debug("btf_dedup_ref_types failed:%d\n", err); + goto done; + } + err = btf_dedup_compact_types(d); + if (err < 0) { + pr_debug("btf_dedup_compact_types failed:%d\n", err); + goto done; + } + err = btf_dedup_remap_types(d); + if (err < 0) { + pr_debug("btf_dedup_remap_types failed:%d\n", err); + goto done; + } + +done: + btf_dedup_free(d); + return err; +} + +#define BTF_DEDUP_TABLE_DEFAULT_SIZE (1 << 14) +#define BTF_DEDUP_TABLE_MAX_SIZE_LOG 31 +#define BTF_UNPROCESSED_ID ((__u32)-1) +#define BTF_IN_PROGRESS_ID ((__u32)-2) + +struct btf_dedup_node { + struct btf_dedup_node *next; + __u32 type_id; +}; + +struct btf_dedup { + /* .BTF section to be deduped in-place */ + struct btf *btf; + /* + * Optional .BTF.ext section. When provided, any strings referenced + * from it will be taken into account when deduping strings + */ + struct btf_ext *btf_ext; + /* + * This is a map from any type's signature hash to a list of possible + * canonical representative type candidates. Hash collisions are + * ignored, so even types of various kinds can share same list of + * candidates, which is fine because we rely on subsequent + * btf_xxx_equal() checks to authoritatively verify type equality. + */ + struct btf_dedup_node **dedup_table; + /* Canonical types map */ + __u32 *map; + /* Hypothetical mapping, used during type graph equivalence checks */ + __u32 *hypot_map; + __u32 *hypot_list; + size_t hypot_cnt; + size_t hypot_cap; + /* Various option modifying behavior of algorithm */ + struct btf_dedup_opts opts; +}; + +struct btf_str_ptr { + const char *str; + __u32 new_off; + bool used; +}; + +struct btf_str_ptrs { + struct btf_str_ptr *ptrs; + const char *data; + __u32 cnt; + __u32 cap; +}; + +static inline __u32 hash_combine(__u32 h, __u32 value) +{ +/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */ +#define GOLDEN_RATIO_PRIME 0x9e370001UL + return h * 37 + value * GOLDEN_RATIO_PRIME; +#undef GOLDEN_RATIO_PRIME +} + +#define for_each_dedup_cand(d, hash, node) \ + for (node = d->dedup_table[hash & (d->opts.dedup_table_size - 1)]; \ + node; \ + node = node->next) + +static int btf_dedup_table_add(struct btf_dedup *d, __u32 hash, __u32 type_id) +{ + struct btf_dedup_node *node = malloc(sizeof(struct btf_dedup_node)); + int bucket = hash & (d->opts.dedup_table_size - 1); + + if (!node) + return -ENOMEM; + node->type_id = type_id; + node->next = d->dedup_table[bucket]; + d->dedup_table[bucket] = node; + return 0; +} + +static int btf_dedup_hypot_map_add(struct btf_dedup *d, + __u32 from_id, __u32 to_id) +{ + if (d->hypot_cnt == d->hypot_cap) { + __u32 *new_list; + + d->hypot_cap += max(16, d->hypot_cap / 2); + new_list = realloc(d->hypot_list, sizeof(__u32) * d->hypot_cap); + if (!new_list) + return -ENOMEM; + d->hypot_list = new_list; + } + d->hypot_list[d->hypot_cnt++] = from_id; + d->hypot_map[from_id] = to_id; + return 0; +} + +static void btf_dedup_clear_hypot_map(struct btf_dedup *d) +{ + int i; + + for (i = 0; i < d->hypot_cnt; i++) + d->hypot_map[d->hypot_list[i]] = BTF_UNPROCESSED_ID; + d->hypot_cnt = 0; +} + +static void btf_dedup_table_free(struct btf_dedup *d) +{ + struct btf_dedup_node *head, *tmp; + int i; + + if (!d->dedup_table) + return; + + for (i = 0; i < d->opts.dedup_table_size; i++) { + while (d->dedup_table[i]) { + tmp = d->dedup_table[i]; + d->dedup_table[i] = tmp->next; + free(tmp); + } + + head = d->dedup_table[i]; + while (head) { + tmp = head; + head = head->next; + free(tmp); + } + } + + free(d->dedup_table); + d->dedup_table = NULL; +} + +static void btf_dedup_free(struct btf_dedup *d) +{ + btf_dedup_table_free(d); + + free(d->map); + d->map = NULL; + + free(d->hypot_map); + d->hypot_map = NULL; + + free(d->hypot_list); + d->hypot_list = NULL; + + free(d); +} + +/* Find closest power of two >= to size, capped at 2^max_size_log */ +static __u32 roundup_pow2_max(__u32 size, int max_size_log) +{ + int i; + + for (i = 0; i < max_size_log && (1U << i) < size; i++) + ; + return 1U << i; +} + + +static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext, + const struct btf_dedup_opts *opts) +{ + struct btf_dedup *d = calloc(1, sizeof(struct btf_dedup)); + int i, err = 0; + __u32 sz; + + if (!d) + return ERR_PTR(-ENOMEM); + + d->opts.dont_resolve_fwds = opts && opts->dont_resolve_fwds; + sz = opts && opts->dedup_table_size ? opts->dedup_table_size + : BTF_DEDUP_TABLE_DEFAULT_SIZE; + sz = roundup_pow2_max(sz, BTF_DEDUP_TABLE_MAX_SIZE_LOG); + d->opts.dedup_table_size = sz; + + d->btf = btf; + d->btf_ext = btf_ext; + + d->dedup_table = calloc(d->opts.dedup_table_size, + sizeof(struct btf_dedup_node *)); + if (!d->dedup_table) { + err = -ENOMEM; + goto done; + } + + d->map = malloc(sizeof(__u32) * (1 + btf->nr_types)); + if (!d->map) { + err = -ENOMEM; + goto done; + } + /* special BTF "void" type is made canonical immediately */ + d->map[0] = 0; + for (i = 1; i <= btf->nr_types; i++) + d->map[i] = BTF_UNPROCESSED_ID; + + d->hypot_map = malloc(sizeof(__u32) * (1 + btf->nr_types)); + if (!d->hypot_map) { + err = -ENOMEM; + goto done; + } + for (i = 0; i <= btf->nr_types; i++) + d->hypot_map[i] = BTF_UNPROCESSED_ID; + +done: + if (err) { + btf_dedup_free(d); + return ERR_PTR(err); + } + + return d; +} + +typedef int (*str_off_fn_t)(__u32 *str_off_ptr, void *ctx); + +/* + * Iterate over all possible places in .BTF and .BTF.ext that can reference + * string and pass pointer to it to a provided callback `fn`. + */ +static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx) +{ + void *line_data_cur, *line_data_end; + int i, j, r, rec_size; + struct btf_type *t; + + for (i = 1; i <= d->btf->nr_types; i++) { + t = d->btf->types[i]; + r = fn(&t->name_off, ctx); + if (r) + return r; + + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: { + struct btf_member *m = (struct btf_member *)(t + 1); + __u16 vlen = BTF_INFO_VLEN(t->info); + + for (j = 0; j < vlen; j++) { + r = fn(&m->name_off, ctx); + if (r) + return r; + m++; + } + break; + } + case BTF_KIND_ENUM: { + struct btf_enum *m = (struct btf_enum *)(t + 1); + __u16 vlen = BTF_INFO_VLEN(t->info); + + for (j = 0; j < vlen; j++) { + r = fn(&m->name_off, ctx); + if (r) + return r; + m++; + } + break; + } + case BTF_KIND_FUNC_PROTO: { + struct btf_param *m = (struct btf_param *)(t + 1); + __u16 vlen = BTF_INFO_VLEN(t->info); + + for (j = 0; j < vlen; j++) { + r = fn(&m->name_off, ctx); + if (r) + return r; + m++; + } + break; + } + default: + break; + } + } + + if (!d->btf_ext) + return 0; + + line_data_cur = d->btf_ext->line_info.info; + line_data_end = d->btf_ext->line_info.info + d->btf_ext->line_info.len; + rec_size = d->btf_ext->line_info.rec_size; + + while (line_data_cur < line_data_end) { + struct btf_ext_info_sec *sec = line_data_cur; + struct bpf_line_info_min *line_info; + __u32 num_info = sec->num_info; + + r = fn(&sec->sec_name_off, ctx); + if (r) + return r; + + line_data_cur += sizeof(struct btf_ext_info_sec); + for (i = 0; i < num_info; i++) { + line_info = line_data_cur; + r = fn(&line_info->file_name_off, ctx); + if (r) + return r; + r = fn(&line_info->line_off, ctx); + if (r) + return r; + line_data_cur += rec_size; + } + } + + return 0; +} + +static int str_sort_by_content(const void *a1, const void *a2) +{ + const struct btf_str_ptr *p1 = a1; + const struct btf_str_ptr *p2 = a2; + + return strcmp(p1->str, p2->str); +} + +static int str_sort_by_offset(const void *a1, const void *a2) +{ + const struct btf_str_ptr *p1 = a1; + const struct btf_str_ptr *p2 = a2; + + if (p1->str != p2->str) + return p1->str < p2->str ? -1 : 1; + return 0; +} + +static int btf_dedup_str_ptr_cmp(const void *str_ptr, const void *pelem) +{ + const struct btf_str_ptr *p = pelem; + + if (str_ptr != p->str) + return (const char *)str_ptr < p->str ? -1 : 1; + return 0; +} + +static int btf_str_mark_as_used(__u32 *str_off_ptr, void *ctx) +{ + struct btf_str_ptrs *strs; + struct btf_str_ptr *s; + + if (*str_off_ptr == 0) + return 0; + + strs = ctx; + s = bsearch(strs->data + *str_off_ptr, strs->ptrs, strs->cnt, + sizeof(struct btf_str_ptr), btf_dedup_str_ptr_cmp); + if (!s) + return -EINVAL; + s->used = true; + return 0; +} + +static int btf_str_remap_offset(__u32 *str_off_ptr, void *ctx) +{ + struct btf_str_ptrs *strs; + struct btf_str_ptr *s; + + if (*str_off_ptr == 0) + return 0; + + strs = ctx; + s = bsearch(strs->data + *str_off_ptr, strs->ptrs, strs->cnt, + sizeof(struct btf_str_ptr), btf_dedup_str_ptr_cmp); + if (!s) + return -EINVAL; + *str_off_ptr = s->new_off; + return 0; +} + +/* + * Dedup string and filter out those that are not referenced from either .BTF + * or .BTF.ext (if provided) sections. + * + * This is done by building index of all strings in BTF's string section, + * then iterating over all entities that can reference strings (e.g., type + * names, struct field names, .BTF.ext line info, etc) and marking corresponding + * strings as used. After that all used strings are deduped and compacted into + * sequential blob of memory and new offsets are calculated. Then all the string + * references are iterated again and rewritten using new offsets. + */ +static int btf_dedup_strings(struct btf_dedup *d) +{ + const struct btf_header *hdr = d->btf->hdr; + char *start = (char *)d->btf->nohdr_data + hdr->str_off; + char *end = start + d->btf->hdr->str_len; + char *p = start, *tmp_strs = NULL; + struct btf_str_ptrs strs = { + .cnt = 0, + .cap = 0, + .ptrs = NULL, + .data = start, + }; + int i, j, err = 0, grp_idx; + bool grp_used; + + /* build index of all strings */ + while (p < end) { + if (strs.cnt + 1 > strs.cap) { + struct btf_str_ptr *new_ptrs; + + strs.cap += max(strs.cnt / 2, 16); + new_ptrs = realloc(strs.ptrs, + sizeof(strs.ptrs[0]) * strs.cap); + if (!new_ptrs) { + err = -ENOMEM; + goto done; + } + strs.ptrs = new_ptrs; + } + + strs.ptrs[strs.cnt].str = p; + strs.ptrs[strs.cnt].used = false; + + p += strlen(p) + 1; + strs.cnt++; + } + + /* temporary storage for deduplicated strings */ + tmp_strs = malloc(d->btf->hdr->str_len); + if (!tmp_strs) { + err = -ENOMEM; + goto done; + } + + /* mark all used strings */ + strs.ptrs[0].used = true; + err = btf_for_each_str_off(d, btf_str_mark_as_used, &strs); + if (err) + goto done; + + /* sort strings by context, so that we can identify duplicates */ + qsort(strs.ptrs, strs.cnt, sizeof(strs.ptrs[0]), str_sort_by_content); + + /* + * iterate groups of equal strings and if any instance in a group was + * referenced, emit single instance and remember new offset + */ + p = tmp_strs; + grp_idx = 0; + grp_used = strs.ptrs[0].used; + /* iterate past end to avoid code duplication after loop */ + for (i = 1; i <= strs.cnt; i++) { + /* + * when i == strs.cnt, we want to skip string comparison and go + * straight to handling last group of strings (otherwise we'd + * need to handle last group after the loop w/ duplicated code) + */ + if (i < strs.cnt && + !strcmp(strs.ptrs[i].str, strs.ptrs[grp_idx].str)) { + grp_used = grp_used || strs.ptrs[i].used; + continue; + } + + /* + * this check would have been required after the loop to handle + * last group of strings, but due to <= condition in a loop + * we avoid that duplication + */ + if (grp_used) { + int new_off = p - tmp_strs; + __u32 len = strlen(strs.ptrs[grp_idx].str); + + memmove(p, strs.ptrs[grp_idx].str, len + 1); + for (j = grp_idx; j < i; j++) + strs.ptrs[j].new_off = new_off; + p += len + 1; + } + + if (i < strs.cnt) { + grp_idx = i; + grp_used = strs.ptrs[i].used; + } + } + + /* replace original strings with deduped ones */ + d->btf->hdr->str_len = p - tmp_strs; + memmove(start, tmp_strs, d->btf->hdr->str_len); + end = start + d->btf->hdr->str_len; + + /* restore original order for further binary search lookups */ + qsort(strs.ptrs, strs.cnt, sizeof(strs.ptrs[0]), str_sort_by_offset); + + /* remap string offsets */ + err = btf_for_each_str_off(d, btf_str_remap_offset, &strs); + if (err) + goto done; + + d->btf->hdr->str_len = end - start; + +done: + free(tmp_strs); + free(strs.ptrs); + return err; +} + +static __u32 btf_hash_common(struct btf_type *t) +{ + __u32 h; + + h = hash_combine(0, t->name_off); + h = hash_combine(h, t->info); + h = hash_combine(h, t->size); + return h; +} + +static bool btf_equal_common(struct btf_type *t1, struct btf_type *t2) +{ + return t1->name_off == t2->name_off && + t1->info == t2->info && + t1->size == t2->size; +} + +/* Calculate type signature hash of INT. */ +static __u32 btf_hash_int(struct btf_type *t) +{ + __u32 info = *(__u32 *)(t + 1); + __u32 h; + + h = btf_hash_common(t); + h = hash_combine(h, info); + return h; +} + +/* Check structural equality of two INTs. */ +static bool btf_equal_int(struct btf_type *t1, struct btf_type *t2) +{ + __u32 info1, info2; + + if (!btf_equal_common(t1, t2)) + return false; + info1 = *(__u32 *)(t1 + 1); + info2 = *(__u32 *)(t2 + 1); + return info1 == info2; +} + +/* Calculate type signature hash of ENUM. */ +static __u32 btf_hash_enum(struct btf_type *t) +{ + struct btf_enum *member = (struct btf_enum *)(t + 1); + __u32 vlen = BTF_INFO_VLEN(t->info); + __u32 h = btf_hash_common(t); + int i; + + for (i = 0; i < vlen; i++) { + h = hash_combine(h, member->name_off); + h = hash_combine(h, member->val); + member++; + } + return h; +} + +/* Check structural equality of two ENUMs. */ +static bool btf_equal_enum(struct btf_type *t1, struct btf_type *t2) +{ + struct btf_enum *m1, *m2; + __u16 vlen; + int i; + + if (!btf_equal_common(t1, t2)) + return false; + + vlen = BTF_INFO_VLEN(t1->info); + m1 = (struct btf_enum *)(t1 + 1); + m2 = (struct btf_enum *)(t2 + 1); + for (i = 0; i < vlen; i++) { + if (m1->name_off != m2->name_off || m1->val != m2->val) + return false; + m1++; + m2++; + } + return true; +} + +/* + * Calculate type signature hash of STRUCT/UNION, ignoring referenced type IDs, + * as referenced type IDs equivalence is established separately during type + * graph equivalence check algorithm. + */ +static __u32 btf_hash_struct(struct btf_type *t) +{ + struct btf_member *member = (struct btf_member *)(t + 1); + __u32 vlen = BTF_INFO_VLEN(t->info); + __u32 h = btf_hash_common(t); + int i; + + for (i = 0; i < vlen; i++) { + h = hash_combine(h, member->name_off); + h = hash_combine(h, member->offset); + /* no hashing of referenced type ID, it can be unresolved yet */ + member++; + } + return h; +} + +/* + * Check structural compatibility of two FUNC_PROTOs, ignoring referenced type + * IDs. This check is performed during type graph equivalence check and + * referenced types equivalence is checked separately. + */ +static bool btf_shallow_equal_struct(struct btf_type *t1, struct btf_type *t2) +{ + struct btf_member *m1, *m2; + __u16 vlen; + int i; + + if (!btf_equal_common(t1, t2)) + return false; + + vlen = BTF_INFO_VLEN(t1->info); + m1 = (struct btf_member *)(t1 + 1); + m2 = (struct btf_member *)(t2 + 1); + for (i = 0; i < vlen; i++) { + if (m1->name_off != m2->name_off || m1->offset != m2->offset) + return false; + m1++; + m2++; + } + return true; +} + +/* + * Calculate type signature hash of ARRAY, including referenced type IDs, + * under assumption that they were already resolved to canonical type IDs and + * are not going to change. + */ +static __u32 btf_hash_array(struct btf_type *t) +{ + struct btf_array *info = (struct btf_array *)(t + 1); + __u32 h = btf_hash_common(t); + + h = hash_combine(h, info->type); + h = hash_combine(h, info->index_type); + h = hash_combine(h, info->nelems); + return h; +} + +/* + * Check exact equality of two ARRAYs, taking into account referenced + * type IDs, under assumption that they were already resolved to canonical + * type IDs and are not going to change. + * This function is called during reference types deduplication to compare + * ARRAY to potential canonical representative. + */ +static bool btf_equal_array(struct btf_type *t1, struct btf_type *t2) +{ + struct btf_array *info1, *info2; + + if (!btf_equal_common(t1, t2)) + return false; + + info1 = (struct btf_array *)(t1 + 1); + info2 = (struct btf_array *)(t2 + 1); + return info1->type == info2->type && + info1->index_type == info2->index_type && + info1->nelems == info2->nelems; +} + +/* + * Check structural compatibility of two ARRAYs, ignoring referenced type + * IDs. This check is performed during type graph equivalence check and + * referenced types equivalence is checked separately. + */ +static bool btf_compat_array(struct btf_type *t1, struct btf_type *t2) +{ + struct btf_array *info1, *info2; + + if (!btf_equal_common(t1, t2)) + return false; + + info1 = (struct btf_array *)(t1 + 1); + info2 = (struct btf_array *)(t2 + 1); + return info1->nelems == info2->nelems; +} + +/* + * Calculate type signature hash of FUNC_PROTO, including referenced type IDs, + * under assumption that they were already resolved to canonical type IDs and + * are not going to change. + */ +static inline __u32 btf_hash_fnproto(struct btf_type *t) +{ + struct btf_param *member = (struct btf_param *)(t + 1); + __u16 vlen = BTF_INFO_VLEN(t->info); + __u32 h = btf_hash_common(t); + int i; + + for (i = 0; i < vlen; i++) { + h = hash_combine(h, member->name_off); + h = hash_combine(h, member->type); + member++; + } + return h; +} + +/* + * Check exact equality of two FUNC_PROTOs, taking into account referenced + * type IDs, under assumption that they were already resolved to canonical + * type IDs and are not going to change. + * This function is called during reference types deduplication to compare + * FUNC_PROTO to potential canonical representative. + */ +static inline bool btf_equal_fnproto(struct btf_type *t1, struct btf_type *t2) +{ + struct btf_param *m1, *m2; + __u16 vlen; + int i; + + if (!btf_equal_common(t1, t2)) + return false; + + vlen = BTF_INFO_VLEN(t1->info); + m1 = (struct btf_param *)(t1 + 1); + m2 = (struct btf_param *)(t2 + 1); + for (i = 0; i < vlen; i++) { + if (m1->name_off != m2->name_off || m1->type != m2->type) + return false; + m1++; + m2++; + } + return true; +} + +/* + * Check structural compatibility of two FUNC_PROTOs, ignoring referenced type + * IDs. This check is performed during type graph equivalence check and + * referenced types equivalence is checked separately. + */ +static inline bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2) +{ + struct btf_param *m1, *m2; + __u16 vlen; + int i; + + /* skip return type ID */ + if (t1->name_off != t2->name_off || t1->info != t2->info) + return false; + + vlen = BTF_INFO_VLEN(t1->info); + m1 = (struct btf_param *)(t1 + 1); + m2 = (struct btf_param *)(t2 + 1); + for (i = 0; i < vlen; i++) { + if (m1->name_off != m2->name_off) + return false; + m1++; + m2++; + } + return true; +} + +/* + * Deduplicate primitive types, that can't reference other types, by calculating + * their type signature hash and comparing them with any possible canonical + * candidate. If no canonical candidate matches, type itself is marked as + * canonical and is added into `btf_dedup->dedup_table` as another candidate. + */ +static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) +{ + struct btf_type *t = d->btf->types[type_id]; + struct btf_type *cand; + struct btf_dedup_node *cand_node; + /* if we don't find equivalent type, then we are canonical */ + __u32 new_id = type_id; + __u32 h; + + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_PTR: + case BTF_KIND_TYPEDEF: + case BTF_KIND_ARRAY: + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + case BTF_KIND_FUNC: + case BTF_KIND_FUNC_PROTO: + return 0; + + case BTF_KIND_INT: + h = btf_hash_int(t); + for_each_dedup_cand(d, h, cand_node) { + cand = d->btf->types[cand_node->type_id]; + if (btf_equal_int(t, cand)) { + new_id = cand_node->type_id; + break; + } + } + break; + + case BTF_KIND_ENUM: + h = btf_hash_enum(t); + for_each_dedup_cand(d, h, cand_node) { + cand = d->btf->types[cand_node->type_id]; + if (btf_equal_enum(t, cand)) { + new_id = cand_node->type_id; + break; + } + } + break; + + case BTF_KIND_FWD: + h = btf_hash_common(t); + for_each_dedup_cand(d, h, cand_node) { + cand = d->btf->types[cand_node->type_id]; + if (btf_equal_common(t, cand)) { + new_id = cand_node->type_id; + break; + } + } + break; + + default: + return -EINVAL; + } + + d->map[type_id] = new_id; + if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) + return -ENOMEM; + + return 0; +} + +static int btf_dedup_prim_types(struct btf_dedup *d) +{ + int i, err; + + for (i = 1; i <= d->btf->nr_types; i++) { + err = btf_dedup_prim_type(d, i); + if (err) + return err; + } + return 0; +} + +/* + * Check whether type is already mapped into canonical one (could be to itself). + */ +static inline bool is_type_mapped(struct btf_dedup *d, uint32_t type_id) +{ + return d->map[type_id] <= BTF_MAX_NR_TYPES; +} + +/* + * Resolve type ID into its canonical type ID, if any; otherwise return original + * type ID. If type is FWD and is resolved into STRUCT/UNION already, follow + * STRUCT/UNION link and resolve it into canonical type ID as well. + */ +static inline __u32 resolve_type_id(struct btf_dedup *d, __u32 type_id) +{ + while (is_type_mapped(d, type_id) && d->map[type_id] != type_id) + type_id = d->map[type_id]; + return type_id; +} + +/* + * Resolve FWD to underlying STRUCT/UNION, if any; otherwise return original + * type ID. + */ +static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id) +{ + __u32 orig_type_id = type_id; + + if (BTF_INFO_KIND(d->btf->types[type_id]->info) != BTF_KIND_FWD) + return type_id; + + while (is_type_mapped(d, type_id) && d->map[type_id] != type_id) + type_id = d->map[type_id]; + + if (BTF_INFO_KIND(d->btf->types[type_id]->info) != BTF_KIND_FWD) + return type_id; + + return orig_type_id; +} + + +static inline __u16 btf_fwd_kind(struct btf_type *t) +{ + return BTF_INFO_KFLAG(t->info) ? BTF_KIND_UNION : BTF_KIND_STRUCT; +} + +/* + * Check equivalence of BTF type graph formed by candidate struct/union (we'll + * call it "candidate graph" in this description for brevity) to a type graph + * formed by (potential) canonical struct/union ("canonical graph" for brevity + * here, though keep in mind that not all types in canonical graph are + * necessarily canonical representatives themselves, some of them might be + * duplicates or its uniqueness might not have been established yet). + * Returns: + * - >0, if type graphs are equivalent; + * - 0, if not equivalent; + * - <0, on error. + * + * Algorithm performs side-by-side DFS traversal of both type graphs and checks + * equivalence of BTF types at each step. If at any point BTF types in candidate + * and canonical graphs are not compatible structurally, whole graphs are + * incompatible. If types are structurally equivalent (i.e., all information + * except referenced type IDs is exactly the same), a mapping from `canon_id` to + * a `cand_id` is recored in hypothetical mapping (`btf_dedup->hypot_map`). + * If a type references other types, then those referenced types are checked + * for equivalence recursively. + * + * During DFS traversal, if we find that for current `canon_id` type we + * already have some mapping in hypothetical map, we check for two possible + * situations: + * - `canon_id` is mapped to exactly the same type as `cand_id`. This will + * happen when type graphs have cycles. In this case we assume those two + * types are equivalent. + * - `canon_id` is mapped to different type. This is contradiction in our + * hypothetical mapping, because same graph in canonical graph corresponds + * to two different types in candidate graph, which for equivalent type + * graphs shouldn't happen. This condition terminates equivalence check + * with negative result. + * + * If type graphs traversal exhausts types to check and find no contradiction, + * then type graphs are equivalent. + * + * When checking types for equivalence, there is one special case: FWD types. + * If FWD type resolution is allowed and one of the types (either from canonical + * or candidate graph) is FWD and other is STRUCT/UNION (depending on FWD's kind + * flag) and their names match, hypothetical mapping is updated to point from + * FWD to STRUCT/UNION. If graphs will be determined as equivalent successfully, + * this mapping will be used to record FWD -> STRUCT/UNION mapping permanently. + * + * Technically, this could lead to incorrect FWD to STRUCT/UNION resolution, + * if there are two exactly named (or anonymous) structs/unions that are + * compatible structurally, one of which has FWD field, while other is concrete + * STRUCT/UNION, but according to C sources they are different structs/unions + * that are referencing different types with the same name. This is extremely + * unlikely to happen, but btf_dedup API allows to disable FWD resolution if + * this logic is causing problems. + * + * Doing FWD resolution means that both candidate and/or canonical graphs can + * consists of portions of the graph that come from multiple compilation units. + * This is due to the fact that types within single compilation unit are always + * deduplicated and FWDs are already resolved, if referenced struct/union + * definiton is available. So, if we had unresolved FWD and found corresponding + * STRUCT/UNION, they will be from different compilation units. This + * consequently means that when we "link" FWD to corresponding STRUCT/UNION, + * type graph will likely have at least two different BTF types that describe + * same type (e.g., most probably there will be two different BTF types for the + * same 'int' primitive type) and could even have "overlapping" parts of type + * graph that describe same subset of types. + * + * This in turn means that our assumption that each type in canonical graph + * must correspond to exactly one type in candidate graph might not hold + * anymore and will make it harder to detect contradictions using hypothetical + * map. To handle this problem, we allow to follow FWD -> STRUCT/UNION + * resolution only in canonical graph. FWDs in candidate graphs are never + * resolved. To see why it's OK, let's check all possible situations w.r.t. FWDs + * that can occur: + * - Both types in canonical and candidate graphs are FWDs. If they are + * structurally equivalent, then they can either be both resolved to the + * same STRUCT/UNION or not resolved at all. In both cases they are + * equivalent and there is no need to resolve FWD on candidate side. + * - Both types in canonical and candidate graphs are concrete STRUCT/UNION, + * so nothing to resolve as well, algorithm will check equivalence anyway. + * - Type in canonical graph is FWD, while type in candidate is concrete + * STRUCT/UNION. In this case candidate graph comes from single compilation + * unit, so there is exactly one BTF type for each unique C type. After + * resolving FWD into STRUCT/UNION, there might be more than one BTF type + * in canonical graph mapping to single BTF type in candidate graph, but + * because hypothetical mapping maps from canonical to candidate types, it's + * alright, and we still maintain the property of having single `canon_id` + * mapping to single `cand_id` (there could be two different `canon_id` + * mapped to the same `cand_id`, but it's not contradictory). + * - Type in canonical graph is concrete STRUCT/UNION, while type in candidate + * graph is FWD. In this case we are just going to check compatibility of + * STRUCT/UNION and corresponding FWD, and if they are compatible, we'll + * assume that whatever STRUCT/UNION FWD resolves to must be equivalent to + * a concrete STRUCT/UNION from canonical graph. If the rest of type graphs + * turn out equivalent, we'll re-resolve FWD to concrete STRUCT/UNION from + * canonical graph. + */ +static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, + __u32 canon_id) +{ + struct btf_type *cand_type; + struct btf_type *canon_type; + __u32 hypot_type_id; + __u16 cand_kind; + __u16 canon_kind; + int i, eq; + + /* if both resolve to the same canonical, they must be equivalent */ + if (resolve_type_id(d, cand_id) == resolve_type_id(d, canon_id)) + return 1; + + canon_id = resolve_fwd_id(d, canon_id); + + hypot_type_id = d->hypot_map[canon_id]; + if (hypot_type_id <= BTF_MAX_NR_TYPES) + return hypot_type_id == cand_id; + + if (btf_dedup_hypot_map_add(d, canon_id, cand_id)) + return -ENOMEM; + + cand_type = d->btf->types[cand_id]; + canon_type = d->btf->types[canon_id]; + cand_kind = BTF_INFO_KIND(cand_type->info); + canon_kind = BTF_INFO_KIND(canon_type->info); + + if (cand_type->name_off != canon_type->name_off) + return 0; + + /* FWD <--> STRUCT/UNION equivalence check, if enabled */ + if (!d->opts.dont_resolve_fwds + && (cand_kind == BTF_KIND_FWD || canon_kind == BTF_KIND_FWD) + && cand_kind != canon_kind) { + __u16 real_kind; + __u16 fwd_kind; + + if (cand_kind == BTF_KIND_FWD) { + real_kind = canon_kind; + fwd_kind = btf_fwd_kind(cand_type); + } else { + real_kind = cand_kind; + fwd_kind = btf_fwd_kind(canon_type); + } + return fwd_kind == real_kind; + } + + if (cand_type->info != canon_type->info) + return 0; + + switch (cand_kind) { + case BTF_KIND_INT: + return btf_equal_int(cand_type, canon_type); + + case BTF_KIND_ENUM: + return btf_equal_enum(cand_type, canon_type); + + case BTF_KIND_FWD: + return btf_equal_common(cand_type, canon_type); + + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_PTR: + case BTF_KIND_TYPEDEF: + case BTF_KIND_FUNC: + return btf_dedup_is_equiv(d, cand_type->type, canon_type->type); + + case BTF_KIND_ARRAY: { + struct btf_array *cand_arr, *canon_arr; + + if (!btf_compat_array(cand_type, canon_type)) + return 0; + cand_arr = (struct btf_array *)(cand_type + 1); + canon_arr = (struct btf_array *)(canon_type + 1); + eq = btf_dedup_is_equiv(d, + cand_arr->index_type, canon_arr->index_type); + if (eq <= 0) + return eq; + return btf_dedup_is_equiv(d, cand_arr->type, canon_arr->type); + } + + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: { + struct btf_member *cand_m, *canon_m; + __u16 vlen; + + if (!btf_shallow_equal_struct(cand_type, canon_type)) + return 0; + vlen = BTF_INFO_VLEN(cand_type->info); + cand_m = (struct btf_member *)(cand_type + 1); + canon_m = (struct btf_member *)(canon_type + 1); + for (i = 0; i < vlen; i++) { + eq = btf_dedup_is_equiv(d, cand_m->type, canon_m->type); + if (eq <= 0) + return eq; + cand_m++; + canon_m++; + } + + return 1; + } + + case BTF_KIND_FUNC_PROTO: { + struct btf_param *cand_p, *canon_p; + __u16 vlen; + + if (!btf_compat_fnproto(cand_type, canon_type)) + return 0; + eq = btf_dedup_is_equiv(d, cand_type->type, canon_type->type); + if (eq <= 0) + return eq; + vlen = BTF_INFO_VLEN(cand_type->info); + cand_p = (struct btf_param *)(cand_type + 1); + canon_p = (struct btf_param *)(canon_type + 1); + for (i = 0; i < vlen; i++) { + eq = btf_dedup_is_equiv(d, cand_p->type, canon_p->type); + if (eq <= 0) + return eq; + cand_p++; + canon_p++; + } + return 1; + } + + default: + return -EINVAL; + } + return 0; +} + +/* + * Use hypothetical mapping, produced by successful type graph equivalence + * check, to augment existing struct/union canonical mapping, where possible. + * + * If BTF_KIND_FWD resolution is allowed, this mapping is also used to record + * FWD -> STRUCT/UNION correspondence as well. FWD resolution is bidirectional: + * it doesn't matter if FWD type was part of canonical graph or candidate one, + * we are recording the mapping anyway. As opposed to carefulness required + * for struct/union correspondence mapping (described below), for FWD resolution + * it's not important, as by the time that FWD type (reference type) will be + * deduplicated all structs/unions will be deduped already anyway. + * + * Recording STRUCT/UNION mapping is purely a performance optimization and is + * not required for correctness. It needs to be done carefully to ensure that + * struct/union from candidate's type graph is not mapped into corresponding + * struct/union from canonical type graph that itself hasn't been resolved into + * canonical representative. The only guarantee we have is that canonical + * struct/union was determined as canonical and that won't change. But any + * types referenced through that struct/union fields could have been not yet + * resolved, so in case like that it's too early to establish any kind of + * correspondence between structs/unions. + * + * No canonical correspondence is derived for primitive types (they are already + * deduplicated completely already anyway) or reference types (they rely on + * stability of struct/union canonical relationship for equivalence checks). + */ +static void btf_dedup_merge_hypot_map(struct btf_dedup *d) +{ + __u32 cand_type_id, targ_type_id; + __u16 t_kind, c_kind; + __u32 t_id, c_id; + int i; + + for (i = 0; i < d->hypot_cnt; i++) { + cand_type_id = d->hypot_list[i]; + targ_type_id = d->hypot_map[cand_type_id]; + t_id = resolve_type_id(d, targ_type_id); + c_id = resolve_type_id(d, cand_type_id); + t_kind = BTF_INFO_KIND(d->btf->types[t_id]->info); + c_kind = BTF_INFO_KIND(d->btf->types[c_id]->info); + /* + * Resolve FWD into STRUCT/UNION. + * It's ok to resolve FWD into STRUCT/UNION that's not yet + * mapped to canonical representative (as opposed to + * STRUCT/UNION <--> STRUCT/UNION mapping logic below), because + * eventually that struct is going to be mapped and all resolved + * FWDs will automatically resolve to correct canonical + * representative. This will happen before ref type deduping, + * which critically depends on stability of these mapping. This + * stability is not a requirement for STRUCT/UNION equivalence + * checks, though. + */ + if (t_kind != BTF_KIND_FWD && c_kind == BTF_KIND_FWD) + d->map[c_id] = t_id; + else if (t_kind == BTF_KIND_FWD && c_kind != BTF_KIND_FWD) + d->map[t_id] = c_id; + + if ((t_kind == BTF_KIND_STRUCT || t_kind == BTF_KIND_UNION) && + c_kind != BTF_KIND_FWD && + is_type_mapped(d, c_id) && + !is_type_mapped(d, t_id)) { + /* + * as a perf optimization, we can map struct/union + * that's part of type graph we just verified for + * equivalence. We can do that for struct/union that has + * canonical representative only, though. + */ + d->map[t_id] = c_id; + } + } +} + +/* + * Deduplicate struct/union types. + * + * For each struct/union type its type signature hash is calculated, taking + * into account type's name, size, number, order and names of fields, but + * ignoring type ID's referenced from fields, because they might not be deduped + * completely until after reference types deduplication phase. This type hash + * is used to iterate over all potential canonical types, sharing same hash. + * For each canonical candidate we check whether type graphs that they form + * (through referenced types in fields and so on) are equivalent using algorithm + * implemented in `btf_dedup_is_equiv`. If such equivalence is found and + * BTF_KIND_FWD resolution is allowed, then hypothetical mapping + * (btf_dedup->hypot_map) produced by aforementioned type graph equivalence + * algorithm is used to record FWD -> STRUCT/UNION mapping. It's also used to + * potentially map other structs/unions to their canonical representatives, + * if such relationship hasn't yet been established. This speeds up algorithm + * by eliminating some of the duplicate work. + * + * If no matching canonical representative was found, struct/union is marked + * as canonical for itself and is added into btf_dedup->dedup_table hash map + * for further look ups. + */ +static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id) +{ + struct btf_dedup_node *cand_node; + struct btf_type *cand_type, *t; + /* if we don't find equivalent type, then we are canonical */ + __u32 new_id = type_id; + __u16 kind; + __u32 h; + + /* already deduped or is in process of deduping (loop detected) */ + if (d->map[type_id] <= BTF_MAX_NR_TYPES) + return 0; + + t = d->btf->types[type_id]; + kind = BTF_INFO_KIND(t->info); + + if (kind != BTF_KIND_STRUCT && kind != BTF_KIND_UNION) + return 0; + + h = btf_hash_struct(t); + for_each_dedup_cand(d, h, cand_node) { + int eq; + + /* + * Even though btf_dedup_is_equiv() checks for + * btf_shallow_equal_struct() internally when checking two + * structs (unions) for equivalence, we need to guard here + * from picking matching FWD type as a dedup candidate. + * This can happen due to hash collision. In such case just + * relying on btf_dedup_is_equiv() would lead to potentially + * creating a loop (FWD -> STRUCT and STRUCT -> FWD), because + * FWD and compatible STRUCT/UNION are considered equivalent. + */ + cand_type = d->btf->types[cand_node->type_id]; + if (!btf_shallow_equal_struct(t, cand_type)) + continue; + + btf_dedup_clear_hypot_map(d); + eq = btf_dedup_is_equiv(d, type_id, cand_node->type_id); + if (eq < 0) + return eq; + if (!eq) + continue; + new_id = cand_node->type_id; + btf_dedup_merge_hypot_map(d); + break; + } + + d->map[type_id] = new_id; + if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) + return -ENOMEM; + + return 0; +} + +static int btf_dedup_struct_types(struct btf_dedup *d) +{ + int i, err; + + for (i = 1; i <= d->btf->nr_types; i++) { + err = btf_dedup_struct_type(d, i); + if (err) + return err; + } + return 0; +} + +/* + * Deduplicate reference type. + * + * Once all primitive and struct/union types got deduplicated, we can easily + * deduplicate all other (reference) BTF types. This is done in two steps: + * + * 1. Resolve all referenced type IDs into their canonical type IDs. This + * resolution can be done either immediately for primitive or struct/union types + * (because they were deduped in previous two phases) or recursively for + * reference types. Recursion will always terminate at either primitive or + * struct/union type, at which point we can "unwind" chain of reference types + * one by one. There is no danger of encountering cycles because in C type + * system the only way to form type cycle is through struct/union, so any chain + * of reference types, even those taking part in a type cycle, will inevitably + * reach struct/union at some point. + * + * 2. Once all referenced type IDs are resolved into canonical ones, BTF type + * becomes "stable", in the sense that no further deduplication will cause + * any changes to it. With that, it's now possible to calculate type's signature + * hash (this time taking into account referenced type IDs) and loop over all + * potential canonical representatives. If no match was found, current type + * will become canonical representative of itself and will be added into + * btf_dedup->dedup_table as another possible canonical representative. + */ +static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) +{ + struct btf_dedup_node *cand_node; + struct btf_type *t, *cand; + /* if we don't find equivalent type, then we are representative type */ + __u32 new_id = type_id; + int ref_type_id; + __u32 h; + + if (d->map[type_id] == BTF_IN_PROGRESS_ID) + return -ELOOP; + if (d->map[type_id] <= BTF_MAX_NR_TYPES) + return resolve_type_id(d, type_id); + + t = d->btf->types[type_id]; + d->map[type_id] = BTF_IN_PROGRESS_ID; + + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_PTR: + case BTF_KIND_TYPEDEF: + case BTF_KIND_FUNC: + ref_type_id = btf_dedup_ref_type(d, t->type); + if (ref_type_id < 0) + return ref_type_id; + t->type = ref_type_id; + + h = btf_hash_common(t); + for_each_dedup_cand(d, h, cand_node) { + cand = d->btf->types[cand_node->type_id]; + if (btf_equal_common(t, cand)) { + new_id = cand_node->type_id; + break; + } + } + break; + + case BTF_KIND_ARRAY: { + struct btf_array *info = (struct btf_array *)(t + 1); + + ref_type_id = btf_dedup_ref_type(d, info->type); + if (ref_type_id < 0) + return ref_type_id; + info->type = ref_type_id; + + ref_type_id = btf_dedup_ref_type(d, info->index_type); + if (ref_type_id < 0) + return ref_type_id; + info->index_type = ref_type_id; + + h = btf_hash_array(t); + for_each_dedup_cand(d, h, cand_node) { + cand = d->btf->types[cand_node->type_id]; + if (btf_equal_array(t, cand)) { + new_id = cand_node->type_id; + break; + } + } + break; + } + + case BTF_KIND_FUNC_PROTO: { + struct btf_param *param; + __u16 vlen; + int i; + + ref_type_id = btf_dedup_ref_type(d, t->type); + if (ref_type_id < 0) + return ref_type_id; + t->type = ref_type_id; + + vlen = BTF_INFO_VLEN(t->info); + param = (struct btf_param *)(t + 1); + for (i = 0; i < vlen; i++) { + ref_type_id = btf_dedup_ref_type(d, param->type); + if (ref_type_id < 0) + return ref_type_id; + param->type = ref_type_id; + param++; + } + + h = btf_hash_fnproto(t); + for_each_dedup_cand(d, h, cand_node) { + cand = d->btf->types[cand_node->type_id]; + if (btf_equal_fnproto(t, cand)) { + new_id = cand_node->type_id; + break; + } + } + break; + } + + default: + return -EINVAL; + } + + d->map[type_id] = new_id; + if (type_id == new_id && btf_dedup_table_add(d, h, type_id)) + return -ENOMEM; + + return new_id; +} + +static int btf_dedup_ref_types(struct btf_dedup *d) +{ + int i, err; + + for (i = 1; i <= d->btf->nr_types; i++) { + err = btf_dedup_ref_type(d, i); + if (err < 0) + return err; + } + btf_dedup_table_free(d); + return 0; +} + +/* + * Compact types. + * + * After we established for each type its corresponding canonical representative + * type, we now can eliminate types that are not canonical and leave only + * canonical ones layed out sequentially in memory by copying them over + * duplicates. During compaction btf_dedup->hypot_map array is reused to store + * a map from original type ID to a new compacted type ID, which will be used + * during next phase to "fix up" type IDs, referenced from struct/union and + * reference types. + */ +static int btf_dedup_compact_types(struct btf_dedup *d) +{ + struct btf_type **new_types; + __u32 next_type_id = 1; + char *types_start, *p; + int i, len; + + /* we are going to reuse hypot_map to store compaction remapping */ + d->hypot_map[0] = 0; + for (i = 1; i <= d->btf->nr_types; i++) + d->hypot_map[i] = BTF_UNPROCESSED_ID; + + types_start = d->btf->nohdr_data + d->btf->hdr->type_off; + p = types_start; + + for (i = 1; i <= d->btf->nr_types; i++) { + if (d->map[i] != i) + continue; + + len = btf_type_size(d->btf->types[i]); + if (len < 0) + return len; + + memmove(p, d->btf->types[i], len); + d->hypot_map[i] = next_type_id; + d->btf->types[next_type_id] = (struct btf_type *)p; + p += len; + next_type_id++; + } + + /* shrink struct btf's internal types index and update btf_header */ + d->btf->nr_types = next_type_id - 1; + d->btf->types_size = d->btf->nr_types; + d->btf->hdr->type_len = p - types_start; + new_types = realloc(d->btf->types, + (1 + d->btf->nr_types) * sizeof(struct btf_type *)); + if (!new_types) + return -ENOMEM; + d->btf->types = new_types; + + /* make sure string section follows type information without gaps */ + d->btf->hdr->str_off = p - (char *)d->btf->nohdr_data; + memmove(p, d->btf->strings, d->btf->hdr->str_len); + d->btf->strings = p; + p += d->btf->hdr->str_len; + + d->btf->data_size = p - (char *)d->btf->data; + return 0; +} + +/* + * Figure out final (deduplicated and compacted) type ID for provided original + * `type_id` by first resolving it into corresponding canonical type ID and + * then mapping it to a deduplicated type ID, stored in btf_dedup->hypot_map, + * which is populated during compaction phase. + */ +static int btf_dedup_remap_type_id(struct btf_dedup *d, __u32 type_id) +{ + __u32 resolved_type_id, new_type_id; + + resolved_type_id = resolve_type_id(d, type_id); + new_type_id = d->hypot_map[resolved_type_id]; + if (new_type_id > BTF_MAX_NR_TYPES) + return -EINVAL; + return new_type_id; +} + +/* + * Remap referenced type IDs into deduped type IDs. + * + * After BTF types are deduplicated and compacted, their final type IDs may + * differ from original ones. The map from original to a corresponding + * deduped type ID is stored in btf_dedup->hypot_map and is populated during + * compaction phase. During remapping phase we are rewriting all type IDs + * referenced from any BTF type (e.g., struct fields, func proto args, etc) to + * their final deduped type IDs. + */ +static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id) +{ + struct btf_type *t = d->btf->types[type_id]; + int i, r; + + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_INT: + case BTF_KIND_ENUM: + break; + + case BTF_KIND_FWD: + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_PTR: + case BTF_KIND_TYPEDEF: + case BTF_KIND_FUNC: + r = btf_dedup_remap_type_id(d, t->type); + if (r < 0) + return r; + t->type = r; + break; + + case BTF_KIND_ARRAY: { + struct btf_array *arr_info = (struct btf_array *)(t + 1); + + r = btf_dedup_remap_type_id(d, arr_info->type); + if (r < 0) + return r; + arr_info->type = r; + r = btf_dedup_remap_type_id(d, arr_info->index_type); + if (r < 0) + return r; + arr_info->index_type = r; + break; + } + + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: { + struct btf_member *member = (struct btf_member *)(t + 1); + __u16 vlen = BTF_INFO_VLEN(t->info); + + for (i = 0; i < vlen; i++) { + r = btf_dedup_remap_type_id(d, member->type); + if (r < 0) + return r; + member->type = r; + member++; + } + break; + } + + case BTF_KIND_FUNC_PROTO: { + struct btf_param *param = (struct btf_param *)(t + 1); + __u16 vlen = BTF_INFO_VLEN(t->info); + + r = btf_dedup_remap_type_id(d, t->type); + if (r < 0) + return r; + t->type = r; + + for (i = 0; i < vlen; i++) { + r = btf_dedup_remap_type_id(d, param->type); + if (r < 0) + return r; + param->type = r; + param++; + } + break; + } + + default: + return -EINVAL; + } + + return 0; +} + +static int btf_dedup_remap_types(struct btf_dedup *d) +{ + int i, r; + + for (i = 1; i <= d->btf->nr_types; i++) { + r = btf_dedup_remap_type(d, i); + if (r < 0) + return r; + } + return 0; +} diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index b0610dcdae6b..28a1e1e59861 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -55,33 +55,47 @@ struct btf_ext_header { __u32 line_info_len; }; -typedef int (*btf_print_fn_t)(const char *, ...) - __attribute__((format(printf, 1, 2))); - LIBBPF_API void btf__free(struct btf *btf); -LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log); +LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size); +LIBBPF_API int btf__load(struct btf *btf); LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, const char *type_name); +LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf); LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 id); LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); LIBBPF_API int btf__fd(const struct btf *btf); +LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size); LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); +LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, + __u32 expected_key_size, + __u32 expected_value_size, + __u32 *key_type_id, __u32 *value_type_id); + +LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size); +LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext); +LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, + __u32 *size); +LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf, + const struct btf_ext *btf_ext, + const char *sec_name, __u32 insns_cnt, + void **func_info, __u32 *cnt); +LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf, + const struct btf_ext *btf_ext, + const char *sec_name, __u32 insns_cnt, + void **line_info, __u32 *cnt); +LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); +LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); + +struct btf_dedup_opts { + unsigned int dedup_table_size; + bool dont_resolve_fwds; +}; -struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log); -void btf_ext__free(struct btf_ext *btf_ext); -int btf_ext__reloc_func_info(const struct btf *btf, - const struct btf_ext *btf_ext, - const char *sec_name, __u32 insns_cnt, - void **func_info, __u32 *func_info_len); -int btf_ext__reloc_line_info(const struct btf *btf, - const struct btf_ext *btf_ext, - const char *sec_name, __u32 insns_cnt, - void **line_info, __u32 *cnt); -__u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); -__u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); +LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, + const struct btf_dedup_opts *opts); #ifdef __cplusplus } /* extern "C" */ diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 169e347c76f6..f5eb60379c8d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -42,6 +42,7 @@ #include "bpf.h" #include "btf.h" #include "str_error.h" +#include "libbpf_util.h" #ifndef EM_BPF #define EM_BPF 247 @@ -53,39 +54,33 @@ #define __printf(a, b) __attribute__((format(printf, a, b))) -__printf(1, 2) -static int __base_pr(const char *format, ...) +static int __base_pr(enum libbpf_print_level level, const char *format, + va_list args) { - va_list args; - int err; + if (level == LIBBPF_DEBUG) + return 0; - va_start(args, format); - err = vfprintf(stderr, format, args); - va_end(args); - return err; + return vfprintf(stderr, format, args); } -static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr; -static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr; -static __printf(1, 2) libbpf_print_fn_t __pr_debug; - -#define __pr(func, fmt, ...) \ -do { \ - if ((func)) \ - (func)("libbpf: " fmt, ##__VA_ARGS__); \ -} while (0) +static libbpf_print_fn_t __libbpf_pr = __base_pr; -#define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__) -#define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__) -#define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__) +void libbpf_set_print(libbpf_print_fn_t fn) +{ + __libbpf_pr = fn; +} -void libbpf_set_print(libbpf_print_fn_t warn, - libbpf_print_fn_t info, - libbpf_print_fn_t debug) +__printf(2, 3) +void libbpf_print(enum libbpf_print_level level, const char *format, ...) { - __pr_warning = warn; - __pr_info = info; - __pr_debug = debug; + va_list args; + + if (!__libbpf_pr) + return; + + va_start(args, format); + __libbpf_pr(level, format, args); + va_end(args); } #define STRERR_BUFSIZE 128 @@ -312,7 +307,7 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx, return -EINVAL; } - bzero(prog, sizeof(*prog)); + memset(prog, 0, sizeof(*prog)); prog->section_name = strdup(section_name); if (!prog->section_name) { @@ -839,9 +834,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) else if (strcmp(name, "maps") == 0) obj->efile.maps_shndx = idx; else if (strcmp(name, BTF_ELF_SEC) == 0) { - obj->btf = btf__new(data->d_buf, data->d_size, - __pr_debug); - if (IS_ERR(obj->btf)) { + obj->btf = btf__new(data->d_buf, data->d_size); + if (IS_ERR(obj->btf) || btf__load(obj->btf)) { pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", BTF_ELF_SEC, PTR_ERR(obj->btf)); obj->btf = NULL; @@ -915,8 +909,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) BTF_EXT_ELF_SEC, BTF_ELF_SEC); } else { obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, - btf_ext_data->d_size, - __pr_debug); + btf_ext_data->d_size); if (IS_ERR(obj->btf_ext)) { pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", BTF_EXT_ELF_SEC, @@ -1057,72 +1050,18 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf) { - const struct btf_type *container_type; - const struct btf_member *key, *value; struct bpf_map_def *def = &map->def; - const size_t max_name = 256; - char container_name[max_name]; - __s64 key_size, value_size; - __s32 container_id; - - if (snprintf(container_name, max_name, "____btf_map_%s", map->name) == - max_name) { - pr_warning("map:%s length of '____btf_map_%s' is too long\n", - map->name, map->name); - return -EINVAL; - } - - container_id = btf__find_by_name(btf, container_name); - if (container_id < 0) { - pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n", - map->name, container_name); - return container_id; - } - - container_type = btf__type_by_id(btf, container_id); - if (!container_type) { - pr_warning("map:%s cannot find BTF type for container_id:%u\n", - map->name, container_id); - return -EINVAL; - } - - if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT || - BTF_INFO_VLEN(container_type->info) < 2) { - pr_warning("map:%s container_name:%s is an invalid container struct\n", - map->name, container_name); - return -EINVAL; - } - - key = (struct btf_member *)(container_type + 1); - value = key + 1; - - key_size = btf__resolve_size(btf, key->type); - if (key_size < 0) { - pr_warning("map:%s invalid BTF key_type_size\n", - map->name); - return key_size; - } - - if (def->key_size != key_size) { - pr_warning("map:%s btf_key_type_size:%u != map_def_key_size:%u\n", - map->name, (__u32)key_size, def->key_size); - return -EINVAL; - } - - value_size = btf__resolve_size(btf, value->type); - if (value_size < 0) { - pr_warning("map:%s invalid BTF value_type_size\n", map->name); - return value_size; - } + __u32 key_type_id, value_type_id; + int ret; - if (def->value_size != value_size) { - pr_warning("map:%s btf_value_type_size:%u != map_def_value_size:%u\n", - map->name, (__u32)value_size, def->value_size); - return -EINVAL; - } + ret = btf__get_map_kv_tids(btf, map->name, def->key_size, + def->value_size, &key_type_id, + &value_type_id); + if (ret) + return ret; - map->btf_key_type_id = key->type; - map->btf_value_type_id = value->type; + map->btf_key_type_id = key_type_id; + map->btf_value_type_id = value_type_id; return 0; } @@ -1174,6 +1113,20 @@ err_free_new_name: return -errno; } +int bpf_map__resize(struct bpf_map *map, __u32 max_entries) +{ + if (!map || !max_entries) + return -EINVAL; + + /* If map already created, its attributes can't be changed. */ + if (map->fd >= 0) + return -EBUSY; + + map->def.max_entries = max_entries; + + return 0; +} + static int bpf_object__probe_name(struct bpf_object *obj) { @@ -1637,7 +1590,7 @@ bpf_program__load(struct bpf_program *prog, struct bpf_prog_prep_result result; bpf_program_prep_t preprocessor = prog->preprocessor; - bzero(&result, sizeof(result)); + memset(&result, 0, sizeof(result)); err = preprocessor(prog, i, prog->insns, prog->insns_cnt, &result); if (err) { @@ -2147,7 +2100,7 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path) if (err) return err; - bpf_map__for_each(map, obj) { + bpf_object__for_each_map(map, obj) { char buf[PATH_MAX]; int len; @@ -2194,7 +2147,7 @@ int bpf_object__unpin_maps(struct bpf_object *obj, const char *path) if (!obj) return -ENOENT; - bpf_map__for_each(map, obj) { + bpf_object__for_each_map(map, obj) { char buf[PATH_MAX]; int len; @@ -2378,6 +2331,11 @@ unsigned int bpf_object__kversion(struct bpf_object *obj) return obj ? obj->kern_version : 0; } +struct btf *bpf_object__btf(struct bpf_object *obj) +{ + return obj ? obj->btf : NULL; +} + int bpf_object__btf_fd(const struct bpf_object *obj) { return obj->btf ? btf__fd(obj->btf) : -1; @@ -2667,9 +2625,38 @@ static const struct { #undef BPF_EAPROG_SEC #undef BPF_APROG_COMPAT +#define MAX_TYPE_NAME_SIZE 32 + +static char *libbpf_get_type_names(bool attach_type) +{ + int i, len = ARRAY_SIZE(section_names) * MAX_TYPE_NAME_SIZE; + char *buf; + + buf = malloc(len); + if (!buf) + return NULL; + + buf[0] = '\0'; + /* Forge string buf with all available names */ + for (i = 0; i < ARRAY_SIZE(section_names); i++) { + if (attach_type && !section_names[i].is_attachable) + continue; + + if (strlen(buf) + strlen(section_names[i].sec) + 2 > len) { + free(buf); + return NULL; + } + strcat(buf, " "); + strcat(buf, section_names[i].sec); + } + + return buf; +} + int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, enum bpf_attach_type *expected_attach_type) { + char *type_names; int i; if (!name) @@ -2682,12 +2669,20 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, *expected_attach_type = section_names[i].expected_attach_type; return 0; } + pr_warning("failed to guess program type based on ELF section name '%s'\n", name); + type_names = libbpf_get_type_names(false); + if (type_names != NULL) { + pr_info("supported section(type) names are:%s\n", type_names); + free(type_names); + } + return -EINVAL; } int libbpf_attach_type_by_name(const char *name, enum bpf_attach_type *attach_type) { + char *type_names; int i; if (!name) @@ -2701,6 +2696,13 @@ int libbpf_attach_type_by_name(const char *name, *attach_type = section_names[i].attach_type; return 0; } + pr_warning("failed to guess attach type based on ELF section name '%s'\n", name); + type_names = libbpf_get_type_names(true); + if (type_names != NULL) { + pr_info("attachable section(type) names are:%s\n", type_names); + free(type_names); + } + return -EINVAL; } @@ -2833,13 +2835,19 @@ bpf_object__find_map_by_name(struct bpf_object *obj, const char *name) { struct bpf_map *pos; - bpf_map__for_each(pos, obj) { + bpf_object__for_each_map(pos, obj) { if (pos->name && !strcmp(pos->name, name)) return pos; } return NULL; } +int +bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name) +{ + return bpf_map__fd(bpf_object__find_map_by_name(obj, name)); +} + struct bpf_map * bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) { @@ -2907,8 +2915,6 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, err = bpf_program__identify_section(prog, &prog_type, &expected_attach_type); if (err < 0) { - pr_warning("failed to guess program type based on section name %s\n", - prog->section_name); bpf_object__close(obj); return -EINVAL; } @@ -2922,7 +2928,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, first_prog = prog; } - bpf_map__for_each(map, obj) { + bpf_object__for_each_map(map, obj) { if (!bpf_map__is_offload_neutral(map)) map->map_ifindex = attr->ifindex; } diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 5f68d7b75215..b4652aa1a58a 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -47,17 +47,16 @@ enum libbpf_errno { LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); -/* - * __printf is defined in include/linux/compiler-gcc.h. However, - * it would be better if libbpf.h didn't depend on Linux header files. - * So instead of __printf, here we use gcc attribute directly. - */ -typedef int (*libbpf_print_fn_t)(const char *, ...) - __attribute__((format(printf, 1, 2))); +enum libbpf_print_level { + LIBBPF_WARN, + LIBBPF_INFO, + LIBBPF_DEBUG, +}; -LIBBPF_API void libbpf_set_print(libbpf_print_fn_t warn, - libbpf_print_fn_t info, - libbpf_print_fn_t debug); +typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level, + const char *, va_list ap); + +LIBBPF_API void libbpf_set_print(libbpf_print_fn_t fn); /* Hide internal to user */ struct bpf_object; @@ -90,6 +89,9 @@ LIBBPF_API int bpf_object__load(struct bpf_object *obj); LIBBPF_API int bpf_object__unload(struct bpf_object *obj); LIBBPF_API const char *bpf_object__name(struct bpf_object *obj); LIBBPF_API unsigned int bpf_object__kversion(struct bpf_object *obj); + +struct btf; +LIBBPF_API struct btf *bpf_object__btf(struct bpf_object *obj); LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); LIBBPF_API struct bpf_program * @@ -264,6 +266,9 @@ struct bpf_map; LIBBPF_API struct bpf_map * bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); +LIBBPF_API int +bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name); + /* * Get bpf_map through the offset of corresponding struct bpf_map_def * in the BPF object file. @@ -273,10 +278,11 @@ bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); LIBBPF_API struct bpf_map * bpf_map__next(struct bpf_map *map, struct bpf_object *obj); -#define bpf_map__for_each(pos, obj) \ +#define bpf_object__for_each_map(pos, obj) \ for ((pos) = bpf_map__next(NULL, (obj)); \ (pos) != NULL; \ (pos) = bpf_map__next((pos), (obj))) +#define bpf_map__for_each bpf_object__for_each_map LIBBPF_API struct bpf_map * bpf_map__prev(struct bpf_map *map, struct bpf_object *obj); @@ -292,6 +298,7 @@ LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv, bpf_map_clear_priv_t clear_priv); LIBBPF_API void *bpf_map__priv(struct bpf_map *map); LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); +LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries); LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map); LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); @@ -314,6 +321,7 @@ LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type, struct bpf_object **pobj, int *prog_fd); LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); +LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags); enum bpf_perf_event_ret { LIBBPF_PERF_EVENT_DONE = 0, @@ -355,6 +363,20 @@ LIBBPF_API const struct bpf_line_info * bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, __u32 insn_off, __u32 nr_skip); +/* + * Probe for supported system features + * + * Note that running many of these probes in a short amount of time can cause + * the kernel to reach the maximal size of lockable memory allowed for the + * user, causing subsequent probes to fail. In this case, the caller may want + * to adjust that limit with setrlimit(). + */ +LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type, + __u32 ifindex); +LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex); +LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id, + enum bpf_prog_type prog_type, __u32 ifindex); + #ifdef __cplusplus } /* extern "C" */ #endif diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index cd02cd4e2cc3..778a26702a70 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -124,3 +124,33 @@ LIBBPF_0.0.1 { local: *; }; + +LIBBPF_0.0.2 { + global: + bpf_probe_helper; + bpf_probe_map_type; + bpf_probe_prog_type; + bpf_map__resize; + bpf_map_lookup_elem_flags; + bpf_object__btf; + bpf_object__find_map_fd_by_name; + bpf_get_link_xdp_id; + btf__dedup; + btf__get_map_kv_tids; + btf__get_nr_types; + btf__get_raw_data; + btf__load; + btf_ext__free; + btf_ext__func_info_rec_size; + btf_ext__get_raw_data; + btf_ext__line_info_rec_size; + btf_ext__new; + btf_ext__reloc_func_info; + btf_ext__reloc_line_info; + xsk_umem__create; + xsk_socket__create; + xsk_umem__delete; + xsk_socket__delete; + xsk_umem__fd; + xsk_socket__fd; +} LIBBPF_0.0.1; diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c new file mode 100644 index 000000000000..8c3a1c04dcb2 --- /dev/null +++ b/tools/lib/bpf/libbpf_probes.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) +/* Copyright (c) 2019 Netronome Systems, Inc. */ + +#include <errno.h> +#include <fcntl.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <net/if.h> +#include <sys/utsname.h> + +#include <linux/filter.h> +#include <linux/kernel.h> + +#include "bpf.h" +#include "libbpf.h" + +static bool grep(const char *buffer, const char *pattern) +{ + return !!strstr(buffer, pattern); +} + +static int get_vendor_id(int ifindex) +{ + char ifname[IF_NAMESIZE], path[64], buf[8]; + ssize_t len; + int fd; + + if (!if_indextoname(ifindex, ifname)) + return -1; + + snprintf(path, sizeof(path), "/sys/class/net/%s/device/vendor", ifname); + + fd = open(path, O_RDONLY); + if (fd < 0) + return -1; + + len = read(fd, buf, sizeof(buf)); + close(fd); + if (len < 0) + return -1; + if (len >= (ssize_t)sizeof(buf)) + return -1; + buf[len] = '\0'; + + return strtol(buf, NULL, 0); +} + +static int get_kernel_version(void) +{ + int version, subversion, patchlevel; + struct utsname utsn; + + /* Return 0 on failure, and attempt to probe with empty kversion */ + if (uname(&utsn)) + return 0; + + if (sscanf(utsn.release, "%d.%d.%d", + &version, &subversion, &patchlevel) != 3) + return 0; + + return (version << 16) + (subversion << 8) + patchlevel; +} + +static void +probe_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, + size_t insns_cnt, char *buf, size_t buf_len, __u32 ifindex) +{ + struct bpf_load_program_attr xattr = {}; + int fd; + + switch (prog_type) { + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + xattr.expected_attach_type = BPF_CGROUP_INET4_CONNECT; + break; + case BPF_PROG_TYPE_KPROBE: + xattr.kern_version = get_kernel_version(); + break; + case BPF_PROG_TYPE_UNSPEC: + case BPF_PROG_TYPE_SOCKET_FILTER: + case BPF_PROG_TYPE_SCHED_CLS: + case BPF_PROG_TYPE_SCHED_ACT: + case BPF_PROG_TYPE_TRACEPOINT: + case BPF_PROG_TYPE_XDP: + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_CGROUP_SKB: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_LWT_IN: + case BPF_PROG_TYPE_LWT_OUT: + case BPF_PROG_TYPE_LWT_XMIT: + case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_SK_SKB: + case BPF_PROG_TYPE_CGROUP_DEVICE: + case BPF_PROG_TYPE_SK_MSG: + case BPF_PROG_TYPE_RAW_TRACEPOINT: + case BPF_PROG_TYPE_LWT_SEG6LOCAL: + case BPF_PROG_TYPE_LIRC_MODE2: + case BPF_PROG_TYPE_SK_REUSEPORT: + case BPF_PROG_TYPE_FLOW_DISSECTOR: + default: + break; + } + + xattr.prog_type = prog_type; + xattr.insns = insns; + xattr.insns_cnt = insns_cnt; + xattr.license = "GPL"; + xattr.prog_ifindex = ifindex; + + fd = bpf_load_program_xattr(&xattr, buf, buf_len); + if (fd >= 0) + close(fd); +} + +bool bpf_probe_prog_type(enum bpf_prog_type prog_type, __u32 ifindex) +{ + struct bpf_insn insns[2] = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN() + }; + + if (ifindex && prog_type == BPF_PROG_TYPE_SCHED_CLS) + /* nfp returns -EINVAL on exit(0) with TC offload */ + insns[0].imm = 2; + + errno = 0; + probe_load(prog_type, insns, ARRAY_SIZE(insns), NULL, 0, ifindex); + + return errno != EINVAL && errno != EOPNOTSUPP; +} + +bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex) +{ + int key_size, value_size, max_entries, map_flags; + struct bpf_create_map_attr attr = {}; + int fd = -1, fd_inner; + + key_size = sizeof(__u32); + value_size = sizeof(__u32); + max_entries = 1; + map_flags = 0; + + switch (map_type) { + case BPF_MAP_TYPE_STACK_TRACE: + value_size = sizeof(__u64); + break; + case BPF_MAP_TYPE_LPM_TRIE: + key_size = sizeof(__u64); + value_size = sizeof(__u64); + map_flags = BPF_F_NO_PREALLOC; + break; + case BPF_MAP_TYPE_CGROUP_STORAGE: + case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: + key_size = sizeof(struct bpf_cgroup_storage_key); + value_size = sizeof(__u64); + max_entries = 0; + break; + case BPF_MAP_TYPE_QUEUE: + case BPF_MAP_TYPE_STACK: + key_size = 0; + break; + case BPF_MAP_TYPE_UNSPEC: + case BPF_MAP_TYPE_HASH: + case BPF_MAP_TYPE_ARRAY: + case BPF_MAP_TYPE_PROG_ARRAY: + case BPF_MAP_TYPE_PERF_EVENT_ARRAY: + case BPF_MAP_TYPE_PERCPU_HASH: + case BPF_MAP_TYPE_PERCPU_ARRAY: + case BPF_MAP_TYPE_CGROUP_ARRAY: + case BPF_MAP_TYPE_LRU_HASH: + case BPF_MAP_TYPE_LRU_PERCPU_HASH: + case BPF_MAP_TYPE_ARRAY_OF_MAPS: + case BPF_MAP_TYPE_HASH_OF_MAPS: + case BPF_MAP_TYPE_DEVMAP: + case BPF_MAP_TYPE_SOCKMAP: + case BPF_MAP_TYPE_CPUMAP: + case BPF_MAP_TYPE_XSKMAP: + case BPF_MAP_TYPE_SOCKHASH: + case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: + default: + break; + } + + if (map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS || + map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { + /* TODO: probe for device, once libbpf has a function to create + * map-in-map for offload + */ + if (ifindex) + return false; + + fd_inner = bpf_create_map(BPF_MAP_TYPE_HASH, + sizeof(__u32), sizeof(__u32), 1, 0); + if (fd_inner < 0) + return false; + fd = bpf_create_map_in_map(map_type, NULL, sizeof(__u32), + fd_inner, 1, 0); + close(fd_inner); + } else { + /* Note: No other restriction on map type probes for offload */ + attr.map_type = map_type; + attr.key_size = key_size; + attr.value_size = value_size; + attr.max_entries = max_entries; + attr.map_flags = map_flags; + attr.map_ifindex = ifindex; + + fd = bpf_create_map_xattr(&attr); + } + if (fd >= 0) + close(fd); + + return fd >= 0; +} + +bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type, + __u32 ifindex) +{ + struct bpf_insn insns[2] = { + BPF_EMIT_CALL(id), + BPF_EXIT_INSN() + }; + char buf[4096] = {}; + bool res; + + probe_load(prog_type, insns, ARRAY_SIZE(insns), buf, sizeof(buf), + ifindex); + res = !grep(buf, "invalid func ") && !grep(buf, "unknown func "); + + if (ifindex) { + switch (get_vendor_id(ifindex)) { + case 0x19ee: /* Netronome specific */ + res = res && !grep(buf, "not supported by FW") && + !grep(buf, "unsupported function id"); + break; + default: + break; + } + } + + return res; +} diff --git a/tools/lib/bpf/libbpf_util.h b/tools/lib/bpf/libbpf_util.h new file mode 100644 index 000000000000..81ecda0cb9c9 --- /dev/null +++ b/tools/lib/bpf/libbpf_util.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ +/* Copyright (c) 2019 Facebook */ + +#ifndef __LIBBPF_LIBBPF_UTIL_H +#define __LIBBPF_LIBBPF_UTIL_H + +#include <stdbool.h> + +#ifdef __cplusplus +extern "C" { +#endif + +extern void libbpf_print(enum libbpf_print_level level, + const char *format, ...) + __attribute__((format(printf, 2, 3))); + +#define __pr(level, fmt, ...) \ +do { \ + libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \ +} while (0) + +#define pr_warning(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__) +#define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) +#define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__) + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c index 0ce67aea8f3b..ce3ec81b71c0 100644 --- a/tools/lib/bpf/netlink.c +++ b/tools/lib/bpf/netlink.c @@ -21,6 +21,12 @@ typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t, void *cookie); +struct xdp_id_md { + int ifindex; + __u32 flags; + __u32 id; +}; + int libbpf_netlink_open(__u32 *nl_pid) { struct sockaddr_nl sa; @@ -196,6 +202,85 @@ static int __dump_link_nlmsg(struct nlmsghdr *nlh, return dump_link_nlmsg(cookie, ifi, tb); } +static unsigned char get_xdp_id_attr(unsigned char mode, __u32 flags) +{ + if (mode != XDP_ATTACHED_MULTI) + return IFLA_XDP_PROG_ID; + if (flags & XDP_FLAGS_DRV_MODE) + return IFLA_XDP_DRV_PROG_ID; + if (flags & XDP_FLAGS_HW_MODE) + return IFLA_XDP_HW_PROG_ID; + if (flags & XDP_FLAGS_SKB_MODE) + return IFLA_XDP_SKB_PROG_ID; + + return IFLA_XDP_UNSPEC; +} + +static int get_xdp_id(void *cookie, void *msg, struct nlattr **tb) +{ + struct nlattr *xdp_tb[IFLA_XDP_MAX + 1]; + struct xdp_id_md *xdp_id = cookie; + struct ifinfomsg *ifinfo = msg; + unsigned char mode, xdp_attr; + int ret; + + if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index) + return 0; + + if (!tb[IFLA_XDP]) + return 0; + + ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL); + if (ret) + return ret; + + if (!xdp_tb[IFLA_XDP_ATTACHED]) + return 0; + + mode = libbpf_nla_getattr_u8(xdp_tb[IFLA_XDP_ATTACHED]); + if (mode == XDP_ATTACHED_NONE) + return 0; + + xdp_attr = get_xdp_id_attr(mode, xdp_id->flags); + if (!xdp_attr || !xdp_tb[xdp_attr]) + return 0; + + xdp_id->id = libbpf_nla_getattr_u32(xdp_tb[xdp_attr]); + + return 0; +} + +int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags) +{ + struct xdp_id_md xdp_id = {}; + int sock, ret; + __u32 nl_pid; + __u32 mask; + + if (flags & ~XDP_FLAGS_MASK) + return -EINVAL; + + /* Check whether the single {HW,DRV,SKB} mode is set */ + flags &= (XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE); + mask = flags - 1; + if (flags && flags & mask) + return -EINVAL; + + sock = libbpf_netlink_open(&nl_pid); + if (sock < 0) + return sock; + + xdp_id.ifindex = ifindex; + xdp_id.flags = flags; + + ret = libbpf_nl_get_link(sock, nl_pid, get_xdp_id, &xdp_id); + if (!ret) + *prog_id = xdp_id.id; + + close(sock); + return ret; +} + int libbpf_nl_get_link(int sock, unsigned int nl_pid, libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie) { diff --git a/tools/lib/bpf/test_libbpf.cpp b/tools/lib/bpf/test_libbpf.cpp index abf3fc25c9fa..fc134873bb6d 100644 --- a/tools/lib/bpf/test_libbpf.cpp +++ b/tools/lib/bpf/test_libbpf.cpp @@ -8,11 +8,11 @@ int main(int argc, char *argv[]) { /* libbpf.h */ - libbpf_set_print(NULL, NULL, NULL); + libbpf_set_print(NULL); /* bpf.h */ bpf_prog_get_fd_by_id(0); /* btf.h */ - btf__new(NULL, 0, NULL); + btf__new(NULL, 0); } diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c new file mode 100644 index 000000000000..f98ac82c9aea --- /dev/null +++ b/tools/lib/bpf/xsk.c @@ -0,0 +1,723 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) + +/* + * AF_XDP user-space access library. + * + * Copyright(c) 2018 - 2019 Intel Corporation. + * + * Author(s): Magnus Karlsson <magnus.karlsson@intel.com> + */ + +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <arpa/inet.h> +#include <asm/barrier.h> +#include <linux/compiler.h> +#include <linux/ethtool.h> +#include <linux/filter.h> +#include <linux/if_ether.h> +#include <linux/if_packet.h> +#include <linux/if_xdp.h> +#include <linux/sockios.h> +#include <net/if.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/socket.h> +#include <sys/types.h> + +#include "bpf.h" +#include "libbpf.h" +#include "libbpf_util.h" +#include "xsk.h" + +#ifndef SOL_XDP + #define SOL_XDP 283 +#endif + +#ifndef AF_XDP + #define AF_XDP 44 +#endif + +#ifndef PF_XDP + #define PF_XDP AF_XDP +#endif + +struct xsk_umem { + struct xsk_ring_prod *fill; + struct xsk_ring_cons *comp; + char *umem_area; + struct xsk_umem_config config; + int fd; + int refcount; +}; + +struct xsk_socket { + struct xsk_ring_cons *rx; + struct xsk_ring_prod *tx; + __u64 outstanding_tx; + struct xsk_umem *umem; + struct xsk_socket_config config; + int fd; + int xsks_map; + int ifindex; + int prog_fd; + int qidconf_map_fd; + int xsks_map_fd; + __u32 queue_id; + char ifname[IFNAMSIZ]; +}; + +struct xsk_nl_info { + bool xdp_prog_attached; + int ifindex; + int fd; +}; + +/* For 32-bit systems, we need to use mmap2 as the offsets are 64-bit. + * Unfortunately, it is not part of glibc. + */ +static inline void *xsk_mmap(void *addr, size_t length, int prot, int flags, + int fd, __u64 offset) +{ +#ifdef __NR_mmap2 + unsigned int page_shift = __builtin_ffs(getpagesize()) - 1; + long ret = syscall(__NR_mmap2, addr, length, prot, flags, fd, + (off_t)(offset >> page_shift)); + + return (void *)ret; +#else + return mmap(addr, length, prot, flags, fd, offset); +#endif +} + +int xsk_umem__fd(const struct xsk_umem *umem) +{ + return umem ? umem->fd : -EINVAL; +} + +int xsk_socket__fd(const struct xsk_socket *xsk) +{ + return xsk ? xsk->fd : -EINVAL; +} + +static bool xsk_page_aligned(void *buffer) +{ + unsigned long addr = (unsigned long)buffer; + + return !(addr & (getpagesize() - 1)); +} + +static void xsk_set_umem_config(struct xsk_umem_config *cfg, + const struct xsk_umem_config *usr_cfg) +{ + if (!usr_cfg) { + cfg->fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS; + cfg->comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS; + cfg->frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE; + cfg->frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM; + return; + } + + cfg->fill_size = usr_cfg->fill_size; + cfg->comp_size = usr_cfg->comp_size; + cfg->frame_size = usr_cfg->frame_size; + cfg->frame_headroom = usr_cfg->frame_headroom; +} + +static void xsk_set_xdp_socket_config(struct xsk_socket_config *cfg, + const struct xsk_socket_config *usr_cfg) +{ + if (!usr_cfg) { + cfg->rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS; + cfg->tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS; + cfg->libbpf_flags = 0; + cfg->xdp_flags = 0; + cfg->bind_flags = 0; + return; + } + + cfg->rx_size = usr_cfg->rx_size; + cfg->tx_size = usr_cfg->tx_size; + cfg->libbpf_flags = usr_cfg->libbpf_flags; + cfg->xdp_flags = usr_cfg->xdp_flags; + cfg->bind_flags = usr_cfg->bind_flags; +} + +int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size, + struct xsk_ring_prod *fill, struct xsk_ring_cons *comp, + const struct xsk_umem_config *usr_config) +{ + struct xdp_mmap_offsets off; + struct xdp_umem_reg mr; + struct xsk_umem *umem; + socklen_t optlen; + void *map; + int err; + + if (!umem_area || !umem_ptr || !fill || !comp) + return -EFAULT; + if (!size && !xsk_page_aligned(umem_area)) + return -EINVAL; + + umem = calloc(1, sizeof(*umem)); + if (!umem) + return -ENOMEM; + + umem->fd = socket(AF_XDP, SOCK_RAW, 0); + if (umem->fd < 0) { + err = -errno; + goto out_umem_alloc; + } + + umem->umem_area = umem_area; + xsk_set_umem_config(&umem->config, usr_config); + + mr.addr = (uintptr_t)umem_area; + mr.len = size; + mr.chunk_size = umem->config.frame_size; + mr.headroom = umem->config.frame_headroom; + + err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr)); + if (err) { + err = -errno; + goto out_socket; + } + err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_FILL_RING, + &umem->config.fill_size, + sizeof(umem->config.fill_size)); + if (err) { + err = -errno; + goto out_socket; + } + err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_COMPLETION_RING, + &umem->config.comp_size, + sizeof(umem->config.comp_size)); + if (err) { + err = -errno; + goto out_socket; + } + + optlen = sizeof(off); + err = getsockopt(umem->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen); + if (err) { + err = -errno; + goto out_socket; + } + + map = xsk_mmap(NULL, off.fr.desc + + umem->config.fill_size * sizeof(__u64), + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, + umem->fd, XDP_UMEM_PGOFF_FILL_RING); + if (map == MAP_FAILED) { + err = -errno; + goto out_socket; + } + + umem->fill = fill; + fill->mask = umem->config.fill_size - 1; + fill->size = umem->config.fill_size; + fill->producer = map + off.fr.producer; + fill->consumer = map + off.fr.consumer; + fill->ring = map + off.fr.desc; + fill->cached_cons = umem->config.fill_size; + + map = xsk_mmap(NULL, + off.cr.desc + umem->config.comp_size * sizeof(__u64), + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, + umem->fd, XDP_UMEM_PGOFF_COMPLETION_RING); + if (map == MAP_FAILED) { + err = -errno; + goto out_mmap; + } + + umem->comp = comp; + comp->mask = umem->config.comp_size - 1; + comp->size = umem->config.comp_size; + comp->producer = map + off.cr.producer; + comp->consumer = map + off.cr.consumer; + comp->ring = map + off.cr.desc; + + *umem_ptr = umem; + return 0; + +out_mmap: + munmap(umem->fill, + off.fr.desc + umem->config.fill_size * sizeof(__u64)); +out_socket: + close(umem->fd); +out_umem_alloc: + free(umem); + return err; +} + +static int xsk_load_xdp_prog(struct xsk_socket *xsk) +{ + char bpf_log_buf[BPF_LOG_BUF_SIZE]; + int err, prog_fd; + + /* This is the C-program: + * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx) + * { + * int *qidconf, index = ctx->rx_queue_index; + * + * // A set entry here means that the correspnding queue_id + * // has an active AF_XDP socket bound to it. + * qidconf = bpf_map_lookup_elem(&qidconf_map, &index); + * if (!qidconf) + * return XDP_ABORTED; + * + * if (*qidconf) + * return bpf_redirect_map(&xsks_map, index, 0); + * + * return XDP_PASS; + * } + */ + struct bpf_insn prog[] = { + /* r1 = *(u32 *)(r1 + 16) */ + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 16), + /* *(u32 *)(r10 - 4) = r1 */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_1, -4), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), + BPF_LD_MAP_FD(BPF_REG_1, xsk->qidconf_map_fd), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV32_IMM(BPF_REG_0, 0), + /* if r1 == 0 goto +8 */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 8), + BPF_MOV32_IMM(BPF_REG_0, 2), + /* r1 = *(u32 *)(r1 + 0) */ + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 0), + /* if r1 == 0 goto +5 */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5), + /* r2 = *(u32 *)(r10 - 4) */ + BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd), + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_10, -4), + BPF_MOV32_IMM(BPF_REG_3, 0), + BPF_EMIT_CALL(BPF_FUNC_redirect_map), + /* The jumps are to this instruction */ + BPF_EXIT_INSN(), + }; + size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn); + + prog_fd = bpf_load_program(BPF_PROG_TYPE_XDP, prog, insns_cnt, + "LGPL-2.1 or BSD-2-Clause", 0, bpf_log_buf, + BPF_LOG_BUF_SIZE); + if (prog_fd < 0) { + pr_warning("BPF log buffer:\n%s", bpf_log_buf); + return prog_fd; + } + + err = bpf_set_link_xdp_fd(xsk->ifindex, prog_fd, xsk->config.xdp_flags); + if (err) { + close(prog_fd); + return err; + } + + xsk->prog_fd = prog_fd; + return 0; +} + +static int xsk_get_max_queues(struct xsk_socket *xsk) +{ + struct ethtool_channels channels; + struct ifreq ifr; + int fd, err, ret; + + fd = socket(AF_INET, SOCK_DGRAM, 0); + if (fd < 0) + return -errno; + + channels.cmd = ETHTOOL_GCHANNELS; + ifr.ifr_data = (void *)&channels; + strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ); + err = ioctl(fd, SIOCETHTOOL, &ifr); + if (err && errno != EOPNOTSUPP) { + ret = -errno; + goto out; + } + + if (channels.max_combined == 0 || errno == EOPNOTSUPP) + /* If the device says it has no channels, then all traffic + * is sent to a single stream, so max queues = 1. + */ + ret = 1; + else + ret = channels.max_combined; + +out: + close(fd); + return ret; +} + +static int xsk_create_bpf_maps(struct xsk_socket *xsk) +{ + int max_queues; + int fd; + + max_queues = xsk_get_max_queues(xsk); + if (max_queues < 0) + return max_queues; + + fd = bpf_create_map_name(BPF_MAP_TYPE_ARRAY, "qidconf_map", + sizeof(int), sizeof(int), max_queues, 0); + if (fd < 0) + return fd; + xsk->qidconf_map_fd = fd; + + fd = bpf_create_map_name(BPF_MAP_TYPE_XSKMAP, "xsks_map", + sizeof(int), sizeof(int), max_queues, 0); + if (fd < 0) { + close(xsk->qidconf_map_fd); + return fd; + } + xsk->xsks_map_fd = fd; + + return 0; +} + +static void xsk_delete_bpf_maps(struct xsk_socket *xsk) +{ + close(xsk->qidconf_map_fd); + close(xsk->xsks_map_fd); +} + +static int xsk_update_bpf_maps(struct xsk_socket *xsk, int qidconf_value, + int xsks_value) +{ + bool qidconf_map_updated = false, xsks_map_updated = false; + struct bpf_prog_info prog_info = {}; + __u32 prog_len = sizeof(prog_info); + struct bpf_map_info map_info; + __u32 map_len = sizeof(map_info); + __u32 *map_ids; + int reset_value = 0; + __u32 num_maps; + unsigned int i; + int err; + + err = bpf_obj_get_info_by_fd(xsk->prog_fd, &prog_info, &prog_len); + if (err) + return err; + + num_maps = prog_info.nr_map_ids; + + map_ids = calloc(prog_info.nr_map_ids, sizeof(*map_ids)); + if (!map_ids) + return -ENOMEM; + + memset(&prog_info, 0, prog_len); + prog_info.nr_map_ids = num_maps; + prog_info.map_ids = (__u64)(unsigned long)map_ids; + + err = bpf_obj_get_info_by_fd(xsk->prog_fd, &prog_info, &prog_len); + if (err) + goto out_map_ids; + + for (i = 0; i < prog_info.nr_map_ids; i++) { + int fd; + + fd = bpf_map_get_fd_by_id(map_ids[i]); + if (fd < 0) { + err = -errno; + goto out_maps; + } + + err = bpf_obj_get_info_by_fd(fd, &map_info, &map_len); + if (err) + goto out_maps; + + if (!strcmp(map_info.name, "qidconf_map")) { + err = bpf_map_update_elem(fd, &xsk->queue_id, + &qidconf_value, 0); + if (err) + goto out_maps; + qidconf_map_updated = true; + xsk->qidconf_map_fd = fd; + } else if (!strcmp(map_info.name, "xsks_map")) { + err = bpf_map_update_elem(fd, &xsk->queue_id, + &xsks_value, 0); + if (err) + goto out_maps; + xsks_map_updated = true; + xsk->xsks_map_fd = fd; + } + + if (qidconf_map_updated && xsks_map_updated) + break; + } + + if (!(qidconf_map_updated && xsks_map_updated)) { + err = -ENOENT; + goto out_maps; + } + + err = 0; + goto out_success; + +out_maps: + if (qidconf_map_updated) + (void)bpf_map_update_elem(xsk->qidconf_map_fd, &xsk->queue_id, + &reset_value, 0); + if (xsks_map_updated) + (void)bpf_map_update_elem(xsk->xsks_map_fd, &xsk->queue_id, + &reset_value, 0); +out_success: + if (qidconf_map_updated) + close(xsk->qidconf_map_fd); + if (xsks_map_updated) + close(xsk->xsks_map_fd); +out_map_ids: + free(map_ids); + return err; +} + +static int xsk_setup_xdp_prog(struct xsk_socket *xsk) +{ + bool prog_attached = false; + __u32 prog_id = 0; + int err; + + err = bpf_get_link_xdp_id(xsk->ifindex, &prog_id, + xsk->config.xdp_flags); + if (err) + return err; + + if (!prog_id) { + prog_attached = true; + err = xsk_create_bpf_maps(xsk); + if (err) + return err; + + err = xsk_load_xdp_prog(xsk); + if (err) + goto out_maps; + } else { + xsk->prog_fd = bpf_prog_get_fd_by_id(prog_id); + } + + err = xsk_update_bpf_maps(xsk, true, xsk->fd); + if (err) + goto out_load; + + return 0; + +out_load: + if (prog_attached) + close(xsk->prog_fd); +out_maps: + if (prog_attached) + xsk_delete_bpf_maps(xsk); + return err; +} + +int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, + __u32 queue_id, struct xsk_umem *umem, + struct xsk_ring_cons *rx, struct xsk_ring_prod *tx, + const struct xsk_socket_config *usr_config) +{ + struct sockaddr_xdp sxdp = {}; + struct xdp_mmap_offsets off; + struct xsk_socket *xsk; + socklen_t optlen; + void *map; + int err; + + if (!umem || !xsk_ptr || !rx || !tx) + return -EFAULT; + + if (umem->refcount) { + pr_warning("Error: shared umems not supported by libbpf.\n"); + return -EBUSY; + } + + xsk = calloc(1, sizeof(*xsk)); + if (!xsk) + return -ENOMEM; + + if (umem->refcount++ > 0) { + xsk->fd = socket(AF_XDP, SOCK_RAW, 0); + if (xsk->fd < 0) { + err = -errno; + goto out_xsk_alloc; + } + } else { + xsk->fd = umem->fd; + } + + xsk->outstanding_tx = 0; + xsk->queue_id = queue_id; + xsk->umem = umem; + xsk->ifindex = if_nametoindex(ifname); + if (!xsk->ifindex) { + err = -errno; + goto out_socket; + } + strncpy(xsk->ifname, ifname, IFNAMSIZ); + + xsk_set_xdp_socket_config(&xsk->config, usr_config); + + if (rx) { + err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING, + &xsk->config.rx_size, + sizeof(xsk->config.rx_size)); + if (err) { + err = -errno; + goto out_socket; + } + } + if (tx) { + err = setsockopt(xsk->fd, SOL_XDP, XDP_TX_RING, + &xsk->config.tx_size, + sizeof(xsk->config.tx_size)); + if (err) { + err = -errno; + goto out_socket; + } + } + + optlen = sizeof(off); + err = getsockopt(xsk->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen); + if (err) { + err = -errno; + goto out_socket; + } + + if (rx) { + map = xsk_mmap(NULL, off.rx.desc + + xsk->config.rx_size * sizeof(struct xdp_desc), + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, + xsk->fd, XDP_PGOFF_RX_RING); + if (map == MAP_FAILED) { + err = -errno; + goto out_socket; + } + + rx->mask = xsk->config.rx_size - 1; + rx->size = xsk->config.rx_size; + rx->producer = map + off.rx.producer; + rx->consumer = map + off.rx.consumer; + rx->ring = map + off.rx.desc; + } + xsk->rx = rx; + + if (tx) { + map = xsk_mmap(NULL, off.tx.desc + + xsk->config.tx_size * sizeof(struct xdp_desc), + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, + xsk->fd, XDP_PGOFF_TX_RING); + if (map == MAP_FAILED) { + err = -errno; + goto out_mmap_rx; + } + + tx->mask = xsk->config.tx_size - 1; + tx->size = xsk->config.tx_size; + tx->producer = map + off.tx.producer; + tx->consumer = map + off.tx.consumer; + tx->ring = map + off.tx.desc; + tx->cached_cons = xsk->config.tx_size; + } + xsk->tx = tx; + + sxdp.sxdp_family = PF_XDP; + sxdp.sxdp_ifindex = xsk->ifindex; + sxdp.sxdp_queue_id = xsk->queue_id; + sxdp.sxdp_flags = xsk->config.bind_flags; + + err = bind(xsk->fd, (struct sockaddr *)&sxdp, sizeof(sxdp)); + if (err) { + err = -errno; + goto out_mmap_tx; + } + + if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) { + err = xsk_setup_xdp_prog(xsk); + if (err) + goto out_mmap_tx; + } + + *xsk_ptr = xsk; + return 0; + +out_mmap_tx: + if (tx) + munmap(xsk->tx, + off.tx.desc + + xsk->config.tx_size * sizeof(struct xdp_desc)); +out_mmap_rx: + if (rx) + munmap(xsk->rx, + off.rx.desc + + xsk->config.rx_size * sizeof(struct xdp_desc)); +out_socket: + if (--umem->refcount) + close(xsk->fd); +out_xsk_alloc: + free(xsk); + return err; +} + +int xsk_umem__delete(struct xsk_umem *umem) +{ + struct xdp_mmap_offsets off; + socklen_t optlen; + int err; + + if (!umem) + return 0; + + if (umem->refcount) + return -EBUSY; + + optlen = sizeof(off); + err = getsockopt(umem->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen); + if (!err) { + munmap(umem->fill->ring, + off.fr.desc + umem->config.fill_size * sizeof(__u64)); + munmap(umem->comp->ring, + off.cr.desc + umem->config.comp_size * sizeof(__u64)); + } + + close(umem->fd); + free(umem); + + return 0; +} + +void xsk_socket__delete(struct xsk_socket *xsk) +{ + struct xdp_mmap_offsets off; + socklen_t optlen; + int err; + + if (!xsk) + return; + + (void)xsk_update_bpf_maps(xsk, 0, 0); + + optlen = sizeof(off); + err = getsockopt(xsk->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen); + if (!err) { + if (xsk->rx) + munmap(xsk->rx->ring, + off.rx.desc + + xsk->config.rx_size * sizeof(struct xdp_desc)); + if (xsk->tx) + munmap(xsk->tx->ring, + off.tx.desc + + xsk->config.tx_size * sizeof(struct xdp_desc)); + } + + xsk->umem->refcount--; + /* Do not close an fd that also has an associated umem connected + * to it. + */ + if (xsk->fd != xsk->umem->fd) + close(xsk->fd); + free(xsk); +} diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h new file mode 100644 index 000000000000..a497f00e2962 --- /dev/null +++ b/tools/lib/bpf/xsk.h @@ -0,0 +1,203 @@ +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ + +/* + * AF_XDP user-space access library. + * + * Copyright(c) 2018 - 2019 Intel Corporation. + * + * Author(s): Magnus Karlsson <magnus.karlsson@intel.com> + */ + +#ifndef __LIBBPF_XSK_H +#define __LIBBPF_XSK_H + +#include <stdio.h> +#include <stdint.h> +#include <linux/if_xdp.h> + +#include "libbpf.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Do not access these members directly. Use the functions below. */ +#define DEFINE_XSK_RING(name) \ +struct name { \ + __u32 cached_prod; \ + __u32 cached_cons; \ + __u32 mask; \ + __u32 size; \ + __u32 *producer; \ + __u32 *consumer; \ + void *ring; \ +} + +DEFINE_XSK_RING(xsk_ring_prod); +DEFINE_XSK_RING(xsk_ring_cons); + +struct xsk_umem; +struct xsk_socket; + +static inline __u64 *xsk_ring_prod__fill_addr(struct xsk_ring_prod *fill, + __u32 idx) +{ + __u64 *addrs = (__u64 *)fill->ring; + + return &addrs[idx & fill->mask]; +} + +static inline const __u64 * +xsk_ring_cons__comp_addr(const struct xsk_ring_cons *comp, __u32 idx) +{ + const __u64 *addrs = (const __u64 *)comp->ring; + + return &addrs[idx & comp->mask]; +} + +static inline struct xdp_desc *xsk_ring_prod__tx_desc(struct xsk_ring_prod *tx, + __u32 idx) +{ + struct xdp_desc *descs = (struct xdp_desc *)tx->ring; + + return &descs[idx & tx->mask]; +} + +static inline const struct xdp_desc * +xsk_ring_cons__rx_desc(const struct xsk_ring_cons *rx, __u32 idx) +{ + const struct xdp_desc *descs = (const struct xdp_desc *)rx->ring; + + return &descs[idx & rx->mask]; +} + +static inline __u32 xsk_prod_nb_free(struct xsk_ring_prod *r, __u32 nb) +{ + __u32 free_entries = r->cached_cons - r->cached_prod; + + if (free_entries >= nb) + return free_entries; + + /* Refresh the local tail pointer. + * cached_cons is r->size bigger than the real consumer pointer so + * that this addition can be avoided in the more frequently + * executed code that computs free_entries in the beginning of + * this function. Without this optimization it whould have been + * free_entries = r->cached_prod - r->cached_cons + r->size. + */ + r->cached_cons = *r->consumer + r->size; + + return r->cached_cons - r->cached_prod; +} + +static inline __u32 xsk_cons_nb_avail(struct xsk_ring_cons *r, __u32 nb) +{ + __u32 entries = r->cached_prod - r->cached_cons; + + if (entries == 0) { + r->cached_prod = *r->producer; + entries = r->cached_prod - r->cached_cons; + } + + return (entries > nb) ? nb : entries; +} + +static inline size_t xsk_ring_prod__reserve(struct xsk_ring_prod *prod, + size_t nb, __u32 *idx) +{ + if (unlikely(xsk_prod_nb_free(prod, nb) < nb)) + return 0; + + *idx = prod->cached_prod; + prod->cached_prod += nb; + + return nb; +} + +static inline void xsk_ring_prod__submit(struct xsk_ring_prod *prod, size_t nb) +{ + /* Make sure everything has been written to the ring before signalling + * this to the kernel. + */ + smp_wmb(); + + *prod->producer += nb; +} + +static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons, + size_t nb, __u32 *idx) +{ + size_t entries = xsk_cons_nb_avail(cons, nb); + + if (likely(entries > 0)) { + /* Make sure we do not speculatively read the data before + * we have received the packet buffers from the ring. + */ + smp_rmb(); + + *idx = cons->cached_cons; + cons->cached_cons += entries; + } + + return entries; +} + +static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, size_t nb) +{ + *cons->consumer += nb; +} + +static inline void *xsk_umem__get_data(void *umem_area, __u64 addr) +{ + return &((char *)umem_area)[addr]; +} + +LIBBPF_API int xsk_umem__fd(const struct xsk_umem *umem); +LIBBPF_API int xsk_socket__fd(const struct xsk_socket *xsk); + +#define XSK_RING_CONS__DEFAULT_NUM_DESCS 2048 +#define XSK_RING_PROD__DEFAULT_NUM_DESCS 2048 +#define XSK_UMEM__DEFAULT_FRAME_SHIFT 11 /* 2048 bytes */ +#define XSK_UMEM__DEFAULT_FRAME_SIZE (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT) +#define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0 + +struct xsk_umem_config { + __u32 fill_size; + __u32 comp_size; + __u32 frame_size; + __u32 frame_headroom; +}; + +/* Flags for the libbpf_flags field. */ +#define XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD (1 << 0) + +struct xsk_socket_config { + __u32 rx_size; + __u32 tx_size; + __u32 libbpf_flags; + __u32 xdp_flags; + __u16 bind_flags; +}; + +/* Set config to NULL to get the default configuration. */ +LIBBPF_API int xsk_umem__create(struct xsk_umem **umem, + void *umem_area, __u64 size, + struct xsk_ring_prod *fill, + struct xsk_ring_cons *comp, + const struct xsk_umem_config *config); +LIBBPF_API int xsk_socket__create(struct xsk_socket **xsk, + const char *ifname, __u32 queue_id, + struct xsk_umem *umem, + struct xsk_ring_cons *rx, + struct xsk_ring_prod *tx, + const struct xsk_socket_config *config); + +/* Returns 0 for success and -EBUSY if the umem is still in use. */ +LIBBPF_API int xsk_umem__delete(struct xsk_umem *umem); +LIBBPF_API void xsk_socket__delete(struct xsk_socket *xsk); + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif /* __LIBBPF_XSK_H */ |