From 74f312ef847f006aadbe5061eeefe375200e3207 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Wed, 16 Jan 2019 11:10:04 -0800 Subject: bpftool: add pop and dequeue commands This is intended to be used with queues and stacks, it pops and prints the last element via bpf_map_lookup_and_delete_elem. Example: bpftool map create /sys/fs/bpf/q type queue value 4 entries 10 name q bpftool map push pinned /sys/fs/bpf/q value 0 1 2 3 bpftool map pop pinned /sys/fs/bpf/q value: 00 01 02 03 bpftool map pop pinned /sys/fs/bpf/q Error: empty map bpftool map create /sys/fs/bpf/s type stack value 4 entries 10 name s bpftool map enqueue pinned /sys/fs/bpf/s value 0 1 2 3 bpftool map dequeue pinned /sys/fs/bpf/s value: 00 01 02 03 bpftool map dequeue pinned /sys/fs/bpf/s Error: empty map Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/Documentation/bpftool-map.rst | 8 ++ tools/bpf/bpftool/map.c | 125 +++++++++++++++++------- 2 files changed, 98 insertions(+), 35 deletions(-) (limited to 'tools/bpf') diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index 435a79d2eed5..0584c31d3fe2 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-map.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -33,7 +33,9 @@ MAP COMMANDS | **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*] | **bpftool** **map peek** *MAP* | **bpftool** **map push** *MAP* **value** *VALUE* +| **bpftool** **map pop** *MAP* | **bpftool** **map enqueue** *MAP* **value** *VALUE* +| **bpftool** **map dequeue** *MAP* | **bpftool** **map help** | | *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } @@ -116,9 +118,15 @@ DESCRIPTION **bpftool map push** *MAP* **value** *VALUE* Push **value** onto the stack. + **bpftool map pop** *MAP* + Pop and print **value** from the stack. + **bpftool map enqueue** *MAP* **value** *VALUE* Enqueue **value** into the queue. + **bpftool map dequeue** *MAP* + Dequeue and print **value** from the queue. + **bpftool map help** Print short help message. diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index 6b5fcbe2d9d4..850c99ac980f 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -857,12 +857,51 @@ exit_free: return err; } +static void print_key_value(struct bpf_map_info *info, void *key, + void *value) +{ + json_writer_t *btf_wtr; + struct btf *btf = NULL; + int err; + + err = btf__get_from_id(info->btf_id, &btf); + if (err) { + p_err("failed to get btf"); + return; + } + + if (json_output) { + print_entry_json(info, key, value, btf); + } else if (btf) { + /* if here json_wtr wouldn't have been initialised, + * so let's create separate writer for btf + */ + btf_wtr = get_btf_writer(); + if (!btf_wtr) { + p_info("failed to create json writer for btf. falling back to plain output"); + btf__free(btf); + btf = NULL; + print_entry_plain(info, key, value); + } else { + struct btf_dumper d = { + .btf = btf, + .jw = btf_wtr, + .is_plain_text = true, + }; + + do_dump_btf(&d, info, key, value); + jsonw_destroy(&btf_wtr); + } + } else { + print_entry_plain(info, key, value); + } + btf__free(btf); +} + static int do_lookup(int argc, char **argv) { struct bpf_map_info info = {}; __u32 len = sizeof(info); - json_writer_t *btf_wtr; - struct btf *btf = NULL; void *key, *value; int err; int fd; @@ -900,43 +939,12 @@ static int do_lookup(int argc, char **argv) } /* here means bpf_map_lookup_elem() succeeded */ - err = btf__get_from_id(info.btf_id, &btf); - if (err) { - p_err("failed to get btf"); - goto exit_free; - } - - if (json_output) { - print_entry_json(&info, key, value, btf); - } else if (btf) { - /* if here json_wtr wouldn't have been initialised, - * so let's create separate writer for btf - */ - btf_wtr = get_btf_writer(); - if (!btf_wtr) { - p_info("failed to create json writer for btf. falling back to plain output"); - btf__free(btf); - btf = NULL; - print_entry_plain(&info, key, value); - } else { - struct btf_dumper d = { - .btf = btf, - .jw = btf_wtr, - .is_plain_text = true, - }; - - do_dump_btf(&d, &info, key, value); - jsonw_destroy(&btf_wtr); - } - } else { - print_entry_plain(&info, key, value); - } + print_key_value(&info, key, value); exit_free: free(key); free(value); close(fd); - btf__free(btf); return err; } @@ -1149,6 +1157,49 @@ static int do_create(int argc, char **argv) return 0; } +static int do_pop_dequeue(int argc, char **argv) +{ + struct bpf_map_info info = {}; + __u32 len = sizeof(info); + void *key, *value; + int err; + int fd; + + if (argc < 2) + usage(); + + fd = map_parse_fd_and_info(&argc, &argv, &info, &len); + if (fd < 0) + return -1; + + err = alloc_key_value(&info, &key, &value); + if (err) + goto exit_free; + + err = bpf_map_lookup_and_delete_elem(fd, key, value); + if (err) { + if (errno == ENOENT) { + if (json_output) + jsonw_null(json_wtr); + else + printf("Error: empty map\n"); + } else { + p_err("pop failed: %s", strerror(errno)); + } + + goto exit_free; + } + + print_key_value(&info, key, value); + +exit_free: + free(key); + free(value); + close(fd); + + return err; +} + static int do_help(int argc, char **argv) { if (json_output) { @@ -1170,7 +1221,9 @@ static int do_help(int argc, char **argv) " %s %s event_pipe MAP [cpu N index M]\n" " %s %s peek MAP\n" " %s %s push MAP value VALUE\n" + " %s %s pop MAP\n" " %s %s enqueue MAP value VALUE\n" + " %s %s dequeue MAP\n" " %s %s help\n" "\n" " " HELP_SPEC_MAP "\n" @@ -1189,7 +1242,7 @@ static int do_help(int argc, char **argv) bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], - bin_name, argv[-2]); + bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]); return 0; } @@ -1209,6 +1262,8 @@ static const struct cmd cmds[] = { { "peek", do_lookup }, { "push", do_update }, { "enqueue", do_update }, + { "pop", do_pop_dequeue }, + { "dequeue", do_pop_dequeue }, { 0 } }; -- cgit v1.2.3-59-g8ed1b