bpftool will use bpf_object__pin in the next commit to pin all programs
and maps from the file; in case of a partial failure, we need to get
back to the clean state (undo previous program/map pins).
Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
---
tools/lib/bpf/libbpf.c | 248 ++++++++++++++++++++++++++++++++++++-----
tools/lib/bpf/libbpf.h | 11 ++
2 files changed, 230 insertions(+), 29 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index d6e62e90e8d4..db84c85554e7 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1699,6 +1699,34 @@ int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
return 0;
}
+int bpf_program__unpin_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;
+ }
+
+ err = unlink(path);
+ if (err != 0)
+ return -errno;
+ pr_debug("unpinned program '%s'\n", path);
+
+ return 0;
+}
+
static int make_dir(const char *path)
{
char *cp, errmsg[STRERR_BUFSIZE];
@@ -1737,6 +1765,64 @@ int bpf_program__pin(struct bpf_program *prog, const char *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) {
+ err = -EINVAL;
+ goto err_unpin;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin;
+ }
+
+ err = bpf_program__pin_instance(prog, buf, i);
+ if (err)
+ goto err_unpin;
+ }
+
+ return 0;
+
+err_unpin:
+ for (i = i - 1; i >= 0; i--) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
+ if (len < 0)
+ continue;
+ else if (len >= PATH_MAX)
+ continue;
+
+ bpf_program__unpin_instance(prog, buf, i);
+ }
+
+ rmdir(path);
+
+ return err;
+}
+
+int bpf_program__unpin(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;
+ }
+
for (i = 0; i < prog->instances.nr; i++) {
char buf[PATH_MAX];
int len;
@@ -1747,11 +1833,15 @@ int bpf_program__pin(struct bpf_program *prog, const char *path)
else if (len >= PATH_MAX)
return -ENAMETOOLONG;
- err = bpf_program__pin_instance(prog, buf, i);
+ err = bpf_program__unpin_instance(prog, buf, i);
if (err)
return err;
}
+ err = rmdir(path);
+ if (err)
+ return -errno;
+
return 0;
}
@@ -1776,6 +1866,28 @@ int bpf_map__pin(struct bpf_map *map, const char *path)
}
pr_debug("pinned map '%s'\n", path);
+
+ return 0;
+}
+
+int bpf_map__unpin(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;
+ }
+
+ err = unlink(path);
+ if (err != 0)
+ return -errno;
+ pr_debug("unpinned map '%s'\n", path);
+
return 0;
}
@@ -1803,14 +1915,17 @@ int bpf_object__pin(struct bpf_object *obj, const char *path)
len = snprintf(buf, PATH_MAX, "%s/%s", path,
bpf_map__name(map));
- if (len < 0)
- return -EINVAL;
- else if (len >= PATH_MAX)
- return -ENAMETOOLONG;
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin_maps;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin_maps;
+ }
err = bpf_map__pin(map, buf);
if (err)
- return err;
+ goto err_unpin_maps;
}
bpf_object__for_each_program(prog, obj) {
@@ -1819,17 +1934,56 @@ int bpf_object__pin(struct bpf_object *obj, const char *path)
len = snprintf(buf, PATH_MAX, "%s/%s", path,
prog->section_name);
- if (len < 0)
- return -EINVAL;
- else if (len >= PATH_MAX)
- return -ENAMETOOLONG;
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin_programs;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin_programs;
+ }
err = bpf_program__pin(prog, buf);
if (err)
- return err;
+ goto err_unpin_programs;
}
return 0;
+
+err_unpin_programs:
+ for (prog = bpf_program__prev(prog, obj);
+ prog != NULL;
+ prog = bpf_program__prev(prog, obj)) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ prog->section_name);
+ if (len < 0)
+ continue;
+ else if (len >= PATH_MAX)
+ continue;
+
+ bpf_program__unpin(prog, buf);
+ }
+
+err_unpin_maps:
+ for (map = bpf_map__prev(map, obj);
+ map != NULL;
+ map = bpf_map__prev(map, obj)) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ bpf_map__name(map));
+ if (len < 0)
+ continue;
+ else if (len >= PATH_MAX)
+ continue;
+
+ bpf_map__unpin(map, buf);
+ }
+
+ return err;
}
void bpf_object__close(struct bpf_object *obj)
@@ -1918,23 +2072,20 @@ void *bpf_object__priv(struct bpf_object *obj)
}
static struct bpf_program *
-__bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
+__bpf_program__iter(struct bpf_program *p, struct bpf_object *obj, int i)
{
- size_t idx;
+ ssize_t idx;
if (!obj->programs)
return NULL;
- /* First handler */
- if (prev == NULL)
- return &obj->programs[0];
- if (prev->obj != obj) {
+ if (p->obj != obj) {
pr_warning("error: program handler doesn't match object\n");
return NULL;
}
- idx = (prev - obj->programs) + 1;
- if (idx >= obj->nr_programs)
+ idx = (p - obj->programs) + i;
+ if (idx >= obj->nr_programs || idx < 0)
return NULL;
return &obj->programs[idx];
}
@@ -1944,8 +2095,29 @@ bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
{
struct bpf_program *prog = prev;
+ if (prev == NULL)
+ return obj->programs;
+
+ do {
+ prog = __bpf_program__iter(prog, obj, 1);
+ } while (prog && bpf_program__is_function_storage(prog, obj));
+
+ return prog;
+}
+
+struct bpf_program *
+bpf_program__prev(struct bpf_program *next, struct bpf_object *obj)
+{
+ struct bpf_program *prog = next;
+
+ if (next == NULL) {
+ if (!obj->nr_programs)
+ return NULL;
+ return obj->programs + obj->nr_programs - 1;
+ }
+
do {
- prog = __bpf_program__next(prog, obj);
+ prog = __bpf_program__iter(prog, obj, -1);
} while (prog && bpf_program__is_function_storage(prog, obj));
return prog;
@@ -2272,10 +2444,10 @@ void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
map->map_ifindex = ifindex;
}
-struct bpf_map *
-bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
+static struct bpf_map *
+__bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i)
{
- size_t idx;
+ ssize_t idx;
struct bpf_map *s, *e;
if (!obj || !obj->maps)
@@ -2284,21 +2456,39 @@ bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
s = obj->maps;
e = obj->maps + obj->nr_maps;
- if (prev == NULL)
- return s;
-
- if ((prev < s) || (prev >= e)) {
+ if ((m < s) || (m >= e)) {
pr_warning("error in %s: map handler doesn't belong to object\n",
__func__);
return NULL;
}
- idx = (prev - obj->maps) + 1;
- if (idx >= obj->nr_maps)
+ idx = (m - obj->maps) + i;
+ if (idx >= obj->nr_maps || idx < 0)
return NULL;
return &obj->maps[idx];
}
+struct bpf_map *
+bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
+{
+ if (prev == NULL)
+ return obj->maps;
+
+ return __bpf_map__iter(prev, obj, 1);
+}
+
+struct bpf_map *
+bpf_map__prev(struct bpf_map *next, struct bpf_object *obj)
+{
+ if (next == NULL) {
+ if (!obj->nr_maps)
+ return NULL;
+ return obj->maps + obj->nr_maps - 1;
+ }
+
+ return __bpf_map__iter(next, obj, -1);
+}
+
struct bpf_map *
bpf_object__find_map_by_name(struct bpf_object *obj, const char *name)
{
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 1f3468dad8b2..785b27f761de 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -112,6 +112,9 @@ LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
(pos) != NULL; \
(pos) = bpf_program__next((pos), (obj)))
+LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
+ struct bpf_object *obj);
+
typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
void *);
@@ -131,7 +134,11 @@ LIBBPF_API int bpf_program__fd(struct bpf_program *prog);
LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
const char *path,
int instance);
+LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
+ const char *path,
+ int instance);
LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
+LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
struct bpf_insn;
@@ -260,6 +267,9 @@ bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
(pos) != NULL; \
(pos) = bpf_map__next((pos), (obj)))
+LIBBPF_API struct bpf_map *
+bpf_map__prev(struct bpf_map *map, struct bpf_object *obj);
+
LIBBPF_API int bpf_map__fd(struct bpf_map *map);
LIBBPF_API const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
LIBBPF_API const char *bpf_map__name(struct bpf_map *map);
@@ -274,6 +284,7 @@ LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
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);
+LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
LIBBPF_API long libbpf_get_error(const void *ptr);
--
2.19.1.930.g4563a0d9d0-goog
