From f367540c8c13d65603c431e29a0b87a7db893d6c Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Thu, 26 Jan 2017 13:19:56 -0800 Subject: tools lib bpf: Add BPF program pinning APIs Add new APIs to pin a BPF program (or specific instances) to the filesystem. The user can specify the path full path within a BPF filesystem to pin the program. bpf_program__pin_instance(prog, path, n) will pin the nth instance of 'prog' to the specified path. bpf_program__pin(prog, path) will create the directory 'path' (if it does not exist) and pin each instance within that directory. For instance, path/0, path/1, path/2. Committer notes: - Add missing headers for mkdir() - Check strdup() for failure - Check snprintf >= size, not >, as == also means truncated, see 'man snprintf', return value. - Conditionally define BPF_FS_MAGIC, as it isn't in magic.h in older systems and we're not yet having a tools/include/uapi/linux/magic.h copy. - Do not include linux/magic.h, not present in older distros. Signed-off-by: Joe Stringer Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Wang Nan Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170126212001.14103-2-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/libbpf.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 3 ++ 2 files changed, 123 insertions(+) (limited to 'tools/lib') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e6cd62b1264b..c4465b2fddf6 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4,6 +4,7 @@ * Copyright (C) 2013-2015 Alexei Starovoitov * Copyright (C) 2015 Wang Nan * Copyright (C) 2015 Huawei Inc. + * Copyright (C) 2017 Nicira, Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -22,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -32,6 +34,10 @@ #include #include #include +#include +#include +#include +#include #include #include @@ -42,6 +48,10 @@ #define EM_BPF 247 #endif +#ifndef BPF_FS_MAGIC +#define BPF_FS_MAGIC 0xcafe4a11 +#endif + #define __printf(a, b) __attribute__((format(printf, a, b))) __printf(1, 2) @@ -1237,6 +1247,116 @@ out: return err; } +static int check_path(const char *path) +{ + struct statfs st_fs; + char *dname, *dir; + int err = 0; + + if (path == NULL) + return -EINVAL; + + dname = strdup(path); + if (dname == NULL) + return -ENOMEM; + + dir = dirname(dname); + if (statfs(dir, &st_fs)) { + pr_warning("failed to statfs %s: %s\n", dir, strerror(errno)); + err = -errno; + } + free(dname); + + if (!err && st_fs.f_type != BPF_FS_MAGIC) { + pr_warning("specified path %s is not on BPF FS\n", path); + err = -EINVAL; + } + + return err; +} + +int bpf_program__pin_instance(struct bpf_program *prog, const char *path, + int instance) +{ + int err; + + err = check_path(path); + if (err) + return err; + + if (prog == NULL) { + pr_warning("invalid program pointer\n"); + return -EINVAL; + } + + if (instance < 0 || instance >= prog->instances.nr) { + pr_warning("invalid prog instance %d of prog %s (max %d)\n", + instance, prog->section_name, prog->instances.nr); + return -EINVAL; + } + + if (bpf_obj_pin(prog->instances.fds[instance], path)) { + pr_warning("failed to pin program: %s\n", strerror(errno)); + return -errno; + } + pr_debug("pinned program '%s'\n", path); + + return 0; +} + +static int make_dir(const char *path) +{ + int err = 0; + + if (mkdir(path, 0700) && errno != EEXIST) + err = -errno; + + if (err) + pr_warning("failed to mkdir %s: %s\n", path, strerror(-err)); + return err; +} + +int bpf_program__pin(struct bpf_program *prog, const char *path) +{ + int i, err; + + err = check_path(path); + if (err) + return err; + + if (prog == NULL) { + pr_warning("invalid program pointer\n"); + return -EINVAL; + } + + if (prog->instances.nr <= 0) { + pr_warning("no instances of prog %s to pin\n", + prog->section_name); + return -EINVAL; + } + + err = make_dir(path); + if (err) + return err; + + for (i = 0; i < prog->instances.nr; i++) { + char buf[PATH_MAX]; + int len; + + len = snprintf(buf, PATH_MAX, "%s/%d", path, i); + if (len < 0) + return -EINVAL; + else if (len >= PATH_MAX) + return -ENAMETOOLONG; + + err = bpf_program__pin_instance(prog, buf, i); + if (err) + return err; + } + + return 0; +} + void bpf_object__close(struct bpf_object *obj) { size_t i; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 4014d1ba5e3d..9f8aa63b95f4 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -106,6 +106,9 @@ void *bpf_program__priv(struct bpf_program *prog); const char *bpf_program__title(struct bpf_program *prog, bool needs_copy); int bpf_program__fd(struct bpf_program *prog); +int bpf_program__pin_instance(struct bpf_program *prog, const char *path, + int instance); +int bpf_program__pin(struct bpf_program *prog, const char *path); struct bpf_insn; -- cgit v1.3-14-g43fede From b6989f35e80bf830f8dc97b74128d619faef0273 Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Thu, 26 Jan 2017 13:19:57 -0800 Subject: tools lib bpf: Add bpf_map__pin() Add a new API to pin a BPF map to the filesystem. The user can specify the path full path within a BPF filesystem to pin the map. Signed-off-by: Joe Stringer Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Wang Nan Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170126212001.14103-3-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/libbpf.c | 22 ++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 1 + 2 files changed, 23 insertions(+) (limited to 'tools/lib') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index c4465b2fddf6..6a8c8beeb291 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1357,6 +1357,28 @@ int bpf_program__pin(struct bpf_program *prog, const char *path) return 0; } +int bpf_map__pin(struct bpf_map *map, const char *path) +{ + int err; + + err = check_path(path); + if (err) + return err; + + if (map == NULL) { + pr_warning("invalid map pointer\n"); + return -EINVAL; + } + + if (bpf_obj_pin(map->fd, path)) { + pr_warning("failed to pin map: %s\n", strerror(errno)); + return -errno; + } + + pr_debug("pinned map '%s'\n", path); + return 0; +} + void bpf_object__close(struct bpf_object *obj) { size_t i; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 9f8aa63b95f4..2addf9d5b13c 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -236,6 +236,7 @@ typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); int bpf_map__set_priv(struct bpf_map *map, void *priv, bpf_map_clear_priv_t clear_priv); void *bpf_map__priv(struct bpf_map *map); +int bpf_map__pin(struct bpf_map *map, const char *path); long libbpf_get_error(const void *ptr); -- cgit v1.3-14-g43fede From d5148d8554d08f03b3e34ecc286ab1729c35c24c Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Thu, 26 Jan 2017 13:19:58 -0800 Subject: tools lib bpf: Add bpf_object__pin() Add a new API to pin a BPF object to the filesystem. The user can specify the path within a BPF filesystem to pin the object. Programs will be pinned under a subdirectory named the same as the program, with each instance appearing as a numbered file under that directory, and maps will be pinned under the path using the name of the map as the file basename. For example, with the directory '/sys/fs/bpf/foo' and a BPF object which contains two instances of a program named 'bar', and a map named 'baz': /sys/fs/bpf/foo/bar/0 /sys/fs/bpf/foo/bar/1 /sys/fs/bpf/foo/baz Signed-off-by: Joe Stringer Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Wang Nan Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170126212001.14103-4-joe@ovn.org [ Check snprintf >= for truncation, as snprintf(bf, size, ...) == size also means truncation ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/libbpf.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 1 + 2 files changed, 54 insertions(+) (limited to 'tools/lib') diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6a8c8beeb291..ac6eb863b2a4 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1379,6 +1379,59 @@ int bpf_map__pin(struct bpf_map *map, const char *path) return 0; } +int bpf_object__pin(struct bpf_object *obj, const char *path) +{ + struct bpf_program *prog; + struct bpf_map *map; + int err; + + if (!obj) + return -ENOENT; + + if (!obj->loaded) { + pr_warning("object not yet loaded; load it first\n"); + return -ENOENT; + } + + err = make_dir(path); + if (err) + return err; + + bpf_map__for_each(map, obj) { + char buf[PATH_MAX]; + int len; + + len = snprintf(buf, PATH_MAX, "%s/%s", path, + bpf_map__name(map)); + if (len < 0) + return -EINVAL; + else if (len >= PATH_MAX) + return -ENAMETOOLONG; + + err = bpf_map__pin(map, buf); + if (err) + return err; + } + + bpf_object__for_each_program(prog, obj) { + char buf[PATH_MAX]; + int len; + + len = snprintf(buf, PATH_MAX, "%s/%s", path, + prog->section_name); + if (len < 0) + return -EINVAL; + else if (len >= PATH_MAX) + return -ENAMETOOLONG; + + err = bpf_program__pin(prog, buf); + if (err) + return err; + } + + return 0; +} + void bpf_object__close(struct bpf_object *obj) { size_t i; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 2addf9d5b13c..b30394f9947a 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -65,6 +65,7 @@ struct bpf_object *bpf_object__open(const char *path); struct bpf_object *bpf_object__open_buffer(void *obj_buf, size_t obj_buf_sz, const char *name); +int bpf_object__pin(struct bpf_object *object, const char *path); void bpf_object__close(struct bpf_object *object); /* Load/unload object into/from kernel */ -- cgit v1.3-14-g43fede From 71dc4c30680fa7e7fd4b82352a845e2fb4d86b2b Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Thu, 26 Jan 2017 13:20:00 -0800 Subject: tools lib api fs: Add bpf_fs filesystem detector Allow mounting of the BPF filesystem at /sys/fs/bpf. Signed-off-by: Joe Stringer Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Wang Nan Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20170126212001.14103-6-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/api/fs/fs.c | 16 ++++++++++++++++ tools/lib/api/fs/fs.h | 1 + 2 files changed, 17 insertions(+) (limited to 'tools/lib') diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c index f99f49e4a31e..4b6bfc43cccf 100644 --- a/tools/lib/api/fs/fs.c +++ b/tools/lib/api/fs/fs.c @@ -38,6 +38,10 @@ #define HUGETLBFS_MAGIC 0x958458f6 #endif +#ifndef BPF_FS_MAGIC +#define BPF_FS_MAGIC 0xcafe4a11 +#endif + static const char * const sysfs__fs_known_mountpoints[] = { "/sys", 0, @@ -75,6 +79,11 @@ static const char * const hugetlbfs__known_mountpoints[] = { 0, }; +static const char * const bpf_fs__known_mountpoints[] = { + "/sys/fs/bpf", + 0, +}; + struct fs { const char *name; const char * const *mounts; @@ -89,6 +98,7 @@ enum { FS__DEBUGFS = 2, FS__TRACEFS = 3, FS__HUGETLBFS = 4, + FS__BPF_FS = 5, }; #ifndef TRACEFS_MAGIC @@ -121,6 +131,11 @@ static struct fs fs__entries[] = { .mounts = hugetlbfs__known_mountpoints, .magic = HUGETLBFS_MAGIC, }, + [FS__BPF_FS] = { + .name = "bpf", + .mounts = bpf_fs__known_mountpoints, + .magic = BPF_FS_MAGIC, + }, }; static bool fs__read_mounts(struct fs *fs) @@ -280,6 +295,7 @@ FS(procfs, FS__PROCFS); FS(debugfs, FS__DEBUGFS); FS(tracefs, FS__TRACEFS); FS(hugetlbfs, FS__HUGETLBFS); +FS(bpf_fs, FS__BPF_FS); int filename__read_int(const char *filename, int *value) { diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h index a63269f5d20c..6b332dc74498 100644 --- a/tools/lib/api/fs/fs.h +++ b/tools/lib/api/fs/fs.h @@ -22,6 +22,7 @@ FS(procfs) FS(debugfs) FS(tracefs) FS(hugetlbfs) +FS(bpf_fs) #undef FS -- cgit v1.3-14-g43fede