From c8aa703822bf811269975cf7251b5eaad4c38e9c Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 28 Jan 2019 08:53:53 -0800 Subject: net/flow_dissector: move bpf case into __skb_flow_bpf_dissect This way, we can reuse it for flow dissector in BPF_PROG_TEST_RUN. No functional changes. Signed-off-by: Stanislav Fomichev Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- include/linux/skbuff.h | 5 +++ net/core/flow_dissector.c | 92 +++++++++++++++++++++++++++-------------------- 2 files changed, 59 insertions(+), 38 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 93f56fddd92a..be762fc34ff3 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1221,6 +1221,11 @@ static inline int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr) } #endif +struct bpf_flow_keys; +bool __skb_flow_bpf_dissect(struct bpf_prog *prog, + const struct sk_buff *skb, + struct flow_dissector *flow_dissector, + struct bpf_flow_keys *flow_keys); bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_dissector *flow_dissector, void *target_container, diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 9f2840510e63..bb1a54747d64 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -683,6 +683,46 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, } } +bool __skb_flow_bpf_dissect(struct bpf_prog *prog, + const struct sk_buff *skb, + struct flow_dissector *flow_dissector, + struct bpf_flow_keys *flow_keys) +{ + struct bpf_skb_data_end cb_saved; + struct bpf_skb_data_end *cb; + u32 result; + + /* Note that even though the const qualifier is discarded + * throughout the execution of the BPF program, all changes(the + * control block) are reverted after the BPF program returns. + * Therefore, __skb_flow_dissect does not alter the skb. + */ + + cb = (struct bpf_skb_data_end *)skb->cb; + + /* Save Control Block */ + memcpy(&cb_saved, cb, sizeof(cb_saved)); + memset(cb, 0, sizeof(*cb)); + + /* Pass parameters to the BPF program */ + memset(flow_keys, 0, sizeof(*flow_keys)); + cb->qdisc_cb.flow_keys = flow_keys; + flow_keys->nhoff = skb_network_offset(skb); + flow_keys->thoff = flow_keys->nhoff; + + bpf_compute_data_pointers((struct sk_buff *)skb); + result = BPF_PROG_RUN(prog, skb); + + /* Restore state */ + memcpy(cb, &cb_saved, sizeof(cb_saved)); + + flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, 0, skb->len); + flow_keys->thoff = clamp_t(u16, flow_keys->thoff, + flow_keys->nhoff, skb->len); + + return result == BPF_OK; +} + /** * __skb_flow_dissect - extract the flow_keys struct and return it * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified @@ -714,7 +754,6 @@ bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_dissector_key_vlan *key_vlan; enum flow_dissect_ret fdret; enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX; - struct bpf_prog *attached = NULL; int num_hdrs = 0; u8 ip_proto = 0; bool ret; @@ -754,53 +793,30 @@ bool __skb_flow_dissect(const struct sk_buff *skb, FLOW_DISSECTOR_KEY_BASIC, target_container); - rcu_read_lock(); if (skb) { + struct bpf_flow_keys flow_keys; + struct bpf_prog *attached = NULL; + + rcu_read_lock(); + if (skb->dev) attached = rcu_dereference(dev_net(skb->dev)->flow_dissector_prog); else if (skb->sk) attached = rcu_dereference(sock_net(skb->sk)->flow_dissector_prog); else WARN_ON_ONCE(1); - } - if (attached) { - /* Note that even though the const qualifier is discarded - * throughout the execution of the BPF program, all changes(the - * control block) are reverted after the BPF program returns. - * Therefore, __skb_flow_dissect does not alter the skb. - */ - struct bpf_flow_keys flow_keys = {}; - struct bpf_skb_data_end cb_saved; - struct bpf_skb_data_end *cb; - u32 result; - - cb = (struct bpf_skb_data_end *)skb->cb; - - /* Save Control Block */ - memcpy(&cb_saved, cb, sizeof(cb_saved)); - memset(cb, 0, sizeof(cb_saved)); - /* Pass parameters to the BPF program */ - cb->qdisc_cb.flow_keys = &flow_keys; - flow_keys.nhoff = nhoff; - flow_keys.thoff = nhoff; - - bpf_compute_data_pointers((struct sk_buff *)skb); - result = BPF_PROG_RUN(attached, skb); - - /* Restore state */ - memcpy(cb, &cb_saved, sizeof(cb_saved)); - - flow_keys.nhoff = clamp_t(u16, flow_keys.nhoff, 0, skb->len); - flow_keys.thoff = clamp_t(u16, flow_keys.thoff, - flow_keys.nhoff, skb->len); - - __skb_flow_bpf_to_target(&flow_keys, flow_dissector, - target_container); + if (attached) { + ret = __skb_flow_bpf_dissect(attached, skb, + flow_dissector, + &flow_keys); + __skb_flow_bpf_to_target(&flow_keys, flow_dissector, + target_container); + rcu_read_unlock(); + return ret; + } rcu_read_unlock(); - return result == BPF_OK; } - rcu_read_unlock(); if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ETH_ADDRS)) { -- cgit v1.2.3-59-g8ed1b From b7a1848e8398b8396c990279e6a10272d818577e Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 28 Jan 2019 08:53:54 -0800 Subject: bpf: add BPF_PROG_TEST_RUN support for flow dissector The input is packet data, the output is struct bpf_flow_key. This should make it easy to test flow dissector programs without elaborate setup. Signed-off-by: Stanislav Fomichev Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- include/linux/bpf.h | 3 ++ net/bpf/test_run.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++ net/core/filter.c | 1 + 3 files changed, 86 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 3851529062ec..0394f1f9213b 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -404,6 +404,9 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, union bpf_attr __user *uattr); int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, union bpf_attr __user *uattr); +int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, + const union bpf_attr *kattr, + union bpf_attr __user *uattr); /* an array of programs to be executed under rcu_lock. * diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index fa2644d276ef..2c5172b33209 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -240,3 +240,85 @@ out: kfree(data); return ret; } + +int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, + const union bpf_attr *kattr, + union bpf_attr __user *uattr) +{ + u32 size = kattr->test.data_size_in; + u32 repeat = kattr->test.repeat; + struct bpf_flow_keys flow_keys; + u64 time_start, time_spent = 0; + struct bpf_skb_data_end *cb; + u32 retval, duration; + struct sk_buff *skb; + struct sock *sk; + void *data; + int ret; + u32 i; + + if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR) + return -EINVAL; + + data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN, + SKB_DATA_ALIGN(sizeof(struct skb_shared_info))); + if (IS_ERR(data)) + return PTR_ERR(data); + + sk = kzalloc(sizeof(*sk), GFP_USER); + if (!sk) { + kfree(data); + return -ENOMEM; + } + sock_net_set(sk, current->nsproxy->net_ns); + sock_init_data(NULL, sk); + + skb = build_skb(data, 0); + if (!skb) { + kfree(data); + kfree(sk); + return -ENOMEM; + } + skb->sk = sk; + + skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); + __skb_put(skb, size); + skb->protocol = eth_type_trans(skb, + current->nsproxy->net_ns->loopback_dev); + skb_reset_network_header(skb); + + cb = (struct bpf_skb_data_end *)skb->cb; + cb->qdisc_cb.flow_keys = &flow_keys; + + if (!repeat) + repeat = 1; + + time_start = ktime_get_ns(); + for (i = 0; i < repeat; i++) { + preempt_disable(); + rcu_read_lock(); + retval = __skb_flow_bpf_dissect(prog, skb, + &flow_keys_dissector, + &flow_keys); + rcu_read_unlock(); + preempt_enable(); + + if (need_resched()) { + if (signal_pending(current)) + break; + time_spent += ktime_get_ns() - time_start; + cond_resched(); + time_start = ktime_get_ns(); + } + } + time_spent += ktime_get_ns() - time_start; + do_div(time_spent, repeat); + duration = time_spent > U32_MAX ? U32_MAX : (u32)time_spent; + + ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys), + retval, duration); + + kfree_skb(skb); + kfree(sk); + return ret; +} diff --git a/net/core/filter.c b/net/core/filter.c index 8e587dd1da20..8ce421796ac6 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7711,6 +7711,7 @@ const struct bpf_verifier_ops flow_dissector_verifier_ops = { }; const struct bpf_prog_ops flow_dissector_prog_ops = { + .test_run = bpf_prog_test_run_flow_dissector, }; int sk_detach_filter(struct sock *sk) -- cgit v1.2.3-59-g8ed1b From bf0f0fd939451a88e8b021ad8829da2815651980 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 28 Jan 2019 08:53:55 -0800 Subject: selftests/bpf: add simple BPF_PROG_TEST_RUN examples for flow dissector Use existing pkt_v4 and pkt_v6 to make sure flow_keys are what we want. Also, add new bpf_flow_load routine (and flow_dissector_load.h header) that loads bpf_flow.o program and does all required setup. Signed-off-by: Stanislav Fomichev Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/Makefile | 3 + tools/testing/selftests/bpf/flow_dissector_load.c | 43 ++----------- tools/testing/selftests/bpf/flow_dissector_load.h | 55 ++++++++++++++++ tools/testing/selftests/bpf/test_progs.c | 78 ++++++++++++++++++++++- 4 files changed, 139 insertions(+), 40 deletions(-) create mode 100644 tools/testing/selftests/bpf/flow_dissector_load.h diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 89b0d1799ff3..c566090e5657 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -148,6 +148,9 @@ $(OUTPUT)/test_xdp_noinline.o: CLANG_FLAGS += -fno-inline $(OUTPUT)/test_queue_map.o: test_queue_stack_map.h $(OUTPUT)/test_stack_map.o: test_queue_stack_map.h +$(OUTPUT)/flow_dissector_load.o: flow_dissector_load.h +$(OUTPUT)/test_progs.o: flow_dissector_load.h + BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris) BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF) BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm') diff --git a/tools/testing/selftests/bpf/flow_dissector_load.c b/tools/testing/selftests/bpf/flow_dissector_load.c index ae8180b11d5f..77cafa66d048 100644 --- a/tools/testing/selftests/bpf/flow_dissector_load.c +++ b/tools/testing/selftests/bpf/flow_dissector_load.c @@ -12,6 +12,7 @@ #include #include "bpf_rlimit.h" +#include "flow_dissector_load.h" const char *cfg_pin_path = "/sys/fs/bpf/flow_dissector"; const char *cfg_map_name = "jmp_table"; @@ -21,46 +22,13 @@ char *cfg_path_name; static void load_and_attach_program(void) { - struct bpf_program *prog, *main_prog; - struct bpf_map *prog_array; - int i, fd, prog_fd, ret; + int prog_fd, ret; struct bpf_object *obj; - int prog_array_fd; - ret = bpf_prog_load(cfg_path_name, BPF_PROG_TYPE_FLOW_DISSECTOR, &obj, - &prog_fd); + ret = bpf_flow_load(&obj, cfg_path_name, cfg_section_name, + cfg_map_name, &prog_fd); if (ret) - error(1, 0, "bpf_prog_load %s", cfg_path_name); - - main_prog = bpf_object__find_program_by_title(obj, cfg_section_name); - if (!main_prog) - error(1, 0, "bpf_object__find_program_by_title %s", - cfg_section_name); - - prog_fd = bpf_program__fd(main_prog); - if (prog_fd < 0) - error(1, 0, "bpf_program__fd"); - - prog_array = bpf_object__find_map_by_name(obj, cfg_map_name); - if (!prog_array) - error(1, 0, "bpf_object__find_map_by_name %s", cfg_map_name); - - prog_array_fd = bpf_map__fd(prog_array); - if (prog_array_fd < 0) - error(1, 0, "bpf_map__fd %s", cfg_map_name); - - i = 0; - bpf_object__for_each_program(prog, obj) { - fd = bpf_program__fd(prog); - if (fd < 0) - error(1, 0, "bpf_program__fd"); - - if (fd != prog_fd) { - printf("%d: %s\n", i, bpf_program__title(prog, false)); - bpf_map_update_elem(prog_array_fd, &i, &fd, BPF_ANY); - ++i; - } - } + error(1, 0, "bpf_flow_load %s", cfg_path_name); ret = bpf_prog_attach(prog_fd, 0 /* Ignore */, BPF_FLOW_DISSECTOR, 0); if (ret) @@ -69,7 +37,6 @@ static void load_and_attach_program(void) ret = bpf_object__pin(obj, cfg_pin_path); if (ret) error(1, 0, "bpf_object__pin %s", cfg_pin_path); - } static void detach_program(void) diff --git a/tools/testing/selftests/bpf/flow_dissector_load.h b/tools/testing/selftests/bpf/flow_dissector_load.h new file mode 100644 index 000000000000..41dd6959feb0 --- /dev/null +++ b/tools/testing/selftests/bpf/flow_dissector_load.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ +#ifndef FLOW_DISSECTOR_LOAD +#define FLOW_DISSECTOR_LOAD + +#include +#include + +static inline int bpf_flow_load(struct bpf_object **obj, + const char *path, + const char *section_name, + const char *map_name, + int *prog_fd) +{ + struct bpf_program *prog, *main_prog; + struct bpf_map *prog_array; + int prog_array_fd; + int ret, fd, i; + + ret = bpf_prog_load(path, BPF_PROG_TYPE_FLOW_DISSECTOR, obj, + prog_fd); + if (ret) + return ret; + + main_prog = bpf_object__find_program_by_title(*obj, section_name); + if (!main_prog) + return ret; + + *prog_fd = bpf_program__fd(main_prog); + if (*prog_fd < 0) + return ret; + + prog_array = bpf_object__find_map_by_name(*obj, map_name); + if (!prog_array) + return ret; + + prog_array_fd = bpf_map__fd(prog_array); + if (prog_array_fd < 0) + return ret; + + i = 0; + bpf_object__for_each_program(prog, *obj) { + fd = bpf_program__fd(prog); + if (fd < 0) + return fd; + + if (fd != *prog_fd) { + bpf_map_update_elem(prog_array_fd, &i, &fd, BPF_ANY); + ++i; + } + } + + return 0; +} + +#endif /* FLOW_DISSECTOR_LOAD */ diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index 126fc624290d..5f46680d4ad4 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -39,6 +39,7 @@ typedef __u16 __sum16; #include "bpf_endian.h" #include "bpf_rlimit.h" #include "trace_helpers.h" +#include "flow_dissector_load.h" static int error_cnt, pass_cnt; static bool jit_enabled; @@ -53,9 +54,10 @@ static struct { } __packed pkt_v4 = { .eth.h_proto = __bpf_constant_htons(ETH_P_IP), .iph.ihl = 5, - .iph.protocol = 6, + .iph.protocol = IPPROTO_TCP, .iph.tot_len = __bpf_constant_htons(MAGIC_BYTES), .tcp.urg_ptr = 123, + .tcp.doff = 5, }; /* ipv6 test vector */ @@ -65,9 +67,10 @@ static struct { struct tcphdr tcp; } __packed pkt_v6 = { .eth.h_proto = __bpf_constant_htons(ETH_P_IPV6), - .iph.nexthdr = 6, + .iph.nexthdr = IPPROTO_TCP, .iph.payload_len = __bpf_constant_htons(MAGIC_BYTES), .tcp.urg_ptr = 123, + .tcp.doff = 5, }; #define _CHECK(condition, tag, duration, format...) ({ \ @@ -1882,6 +1885,76 @@ out: bpf_object__close(obj); } +#define CHECK_FLOW_KEYS(desc, got, expected) \ + CHECK(memcmp(&got, &expected, sizeof(got)) != 0, \ + desc, \ + "nhoff=%u/%u " \ + "thoff=%u/%u " \ + "addr_proto=0x%x/0x%x " \ + "is_frag=%u/%u " \ + "is_first_frag=%u/%u " \ + "is_encap=%u/%u " \ + "n_proto=0x%x/0x%x " \ + "sport=%u/%u " \ + "dport=%u/%u\n", \ + got.nhoff, expected.nhoff, \ + got.thoff, expected.thoff, \ + got.addr_proto, expected.addr_proto, \ + got.is_frag, expected.is_frag, \ + got.is_first_frag, expected.is_first_frag, \ + got.is_encap, expected.is_encap, \ + got.n_proto, expected.n_proto, \ + got.sport, expected.sport, \ + got.dport, expected.dport) + +static struct bpf_flow_keys pkt_v4_flow_keys = { + .nhoff = 0, + .thoff = sizeof(struct iphdr), + .addr_proto = ETH_P_IP, + .ip_proto = IPPROTO_TCP, + .n_proto = bpf_htons(ETH_P_IP), +}; + +static struct bpf_flow_keys pkt_v6_flow_keys = { + .nhoff = 0, + .thoff = sizeof(struct ipv6hdr), + .addr_proto = ETH_P_IPV6, + .ip_proto = IPPROTO_TCP, + .n_proto = bpf_htons(ETH_P_IPV6), +}; + +static void test_flow_dissector(void) +{ + struct bpf_flow_keys flow_keys; + struct bpf_object *obj; + __u32 duration, retval; + int err, prog_fd; + __u32 size; + + err = bpf_flow_load(&obj, "./bpf_flow.o", "flow_dissector", + "jmp_table", &prog_fd); + if (err) { + error_cnt++; + return; + } + + err = bpf_prog_test_run(prog_fd, 10, &pkt_v4, sizeof(pkt_v4), + &flow_keys, &size, &retval, &duration); + CHECK(size != sizeof(flow_keys) || err || retval != 1, "ipv4", + "err %d errno %d retval %d duration %d size %u/%lu\n", + err, errno, retval, duration, size, sizeof(flow_keys)); + CHECK_FLOW_KEYS("ipv4_flow_keys", flow_keys, pkt_v4_flow_keys); + + err = bpf_prog_test_run(prog_fd, 10, &pkt_v6, sizeof(pkt_v6), + &flow_keys, &size, &retval, &duration); + CHECK(size != sizeof(flow_keys) || err || retval != 1, "ipv6", + "err %d errno %d retval %d duration %d size %u/%lu\n", + err, errno, retval, duration, size, sizeof(flow_keys)); + CHECK_FLOW_KEYS("ipv6_flow_keys", flow_keys, pkt_v6_flow_keys); + + bpf_object__close(obj); +} + int main(void) { srand(time(NULL)); @@ -1909,6 +1982,7 @@ int main(void) test_reference_tracking(); test_queue_stack_map(QUEUE); test_queue_stack_map(STACK); + test_flow_dissector(); printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt); return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS; -- cgit v1.2.3-59-g8ed1b