Add the flags parameter to struct_ops functions, to distinguish between read-like and write-like operations on struct_ops maps.
Also, always perform the search with read-only permission, and eventually obtain a new file descriptor if the requested permission is different.
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com --- tools/bpf/bpftool/struct_ops.c | 39 +++++++++++++++++++++++----------- 1 file changed, 27 insertions(+), 12 deletions(-)
diff --git a/tools/bpf/bpftool/struct_ops.c b/tools/bpf/bpftool/struct_ops.c index 2535f079ed67..e8252a76e115 100644 --- a/tools/bpf/bpftool/struct_ops.c +++ b/tools/bpf/bpftool/struct_ops.c @@ -130,7 +130,8 @@ static struct bpf_map_info *map_info_alloc(__u32 *alloc_len) * -1: Error and the caller should abort the iteration. */ static int get_next_struct_ops_map(const char *name, int *res_fd, - struct bpf_map_info *info, __u32 info_len) + struct bpf_map_info *info, __u32 info_len, + __u32 flags) { __u32 id = info->id; int err, fd; @@ -144,7 +145,7 @@ static int get_next_struct_ops_map(const char *name, int *res_fd, return -1; }
- fd = bpf_map_get_fd_by_id(id); + fd = bpf_map_get_fd_by_id_flags(id, BPF_F_RDONLY); if (fd < 0) { if (errno == ENOENT) continue; @@ -162,6 +163,19 @@ static int get_next_struct_ops_map(const char *name, int *res_fd,
if (info->type == BPF_MAP_TYPE_STRUCT_OPS && (!name || !strcmp(name, info->name))) { + if (flags != BPF_F_RDONLY) { + close(fd); + + fd = bpf_map_get_fd_by_id_flags(id, flags); + if (fd < 0) { + if (errno == ENOENT) + continue; + p_err("can't get map by id (%u): %s", + id, strerror(errno)); + return -1; + } + } + *res_fd = fd; return 1; } @@ -186,7 +200,7 @@ typedef int (*work_func)(int fd, const struct bpf_map_info *info, void *data, * Then call "func(fd, info, data, wtr)" on each struct_ops map found. */ static struct res do_search(const char *name, work_func func, void *data, - struct json_writer *wtr) + struct json_writer *wtr, __u32 flags) { struct bpf_map_info *info; struct res res = {}; @@ -201,7 +215,8 @@ static struct res do_search(const char *name, work_func func, void *data,
if (wtr) jsonw_start_array(wtr); - while ((err = get_next_struct_ops_map(name, &fd, info, info_len)) == 1) { + while ((err = get_next_struct_ops_map(name, &fd, info, info_len, + flags)) == 1) { res.nr_maps++; err = func(fd, info, data, wtr); if (err) @@ -235,7 +250,7 @@ static struct res do_search(const char *name, work_func func, void *data, }
static struct res do_one_id(const char *id_str, work_func func, void *data, - struct json_writer *wtr) + struct json_writer *wtr, __u32 flags) { struct bpf_map_info *info; struct res res = {}; @@ -251,7 +266,7 @@ static struct res do_one_id(const char *id_str, work_func func, void *data, return res; }
- fd = bpf_map_get_fd_by_id(id); + fd = bpf_map_get_fd_by_id_flags(id, flags); if (fd < 0) { p_err("can't get map by id (%lu): %s", id, strerror(errno)); res.nr_errs++; @@ -300,16 +315,16 @@ static struct res do_one_id(const char *id_str, work_func func, void *data, static struct res do_work_on_struct_ops(const char *search_type, const char *search_term, work_func func, void *data, - struct json_writer *wtr) + struct json_writer *wtr, __u32 flags) { if (search_type) { if (is_prefix(search_type, "id")) - return do_one_id(search_term, func, data, wtr); + return do_one_id(search_term, func, data, wtr, flags); else if (!is_prefix(search_type, "name")) usage(); }
- return do_search(search_term, func, data, wtr); + return do_search(search_term, func, data, wtr, flags); }
static int __do_show(int fd, const struct bpf_map_info *info, void *data, @@ -344,7 +359,7 @@ static int do_show(int argc, char **argv) }
res = do_work_on_struct_ops(search_type, search_term, __do_show, - NULL, json_wtr); + NULL, json_wtr, 0);
return cmd_retval(&res, !!search_term); } @@ -433,7 +448,7 @@ static int do_dump(int argc, char **argv) d.prog_id_as_func_ptr = true;
res = do_work_on_struct_ops(search_type, search_term, __do_dump, &d, - wtr); + wtr, 0);
if (!json_output) jsonw_destroy(&wtr); @@ -472,7 +487,7 @@ static int do_unregister(int argc, char **argv) search_term = GET_ARG();
res = do_work_on_struct_ops(search_type, search_term, - __do_unregister, NULL, NULL); + __do_unregister, NULL, NULL, 0);
return cmd_retval(&res, true); }