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author | Stanislav Fomichev <sdf@google.com> | 2019-04-25 14:37:24 -0700 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-04-25 23:49:06 +0200 |
commit | 7f0c57fec80f198ae9fcd06e5bbca13196815a4b (patch) | |
tree | 85308388727bfaabda0dc9487b2c036b02284a96 /tools/bpf | |
parent | 118c8e9ae629d35fa9b3d27a7b9d59298b1b4183 (diff) | |
download | linux-7f0c57fec80f198ae9fcd06e5bbca13196815a4b.tar.bz2 |
bpftool: show flow_dissector attachment status
Right now there is no way to query whether BPF flow_dissector program
is attached to a network namespace or not. In previous commit, I added
support for querying that info, show it when doing `bpftool net`:
$ bpftool prog loadall ./bpf_flow.o \
/sys/fs/bpf/flow type flow_dissector \
pinmaps /sys/fs/bpf/flow
$ bpftool prog
3: flow_dissector name _dissect tag 8c9e917b513dd5cc gpl
loaded_at 2019-04-23T16:14:48-0700 uid 0
xlated 656B jited 461B memlock 4096B map_ids 1,2
btf_id 1
...
$ bpftool net -j
[{"xdp":[],"tc":[],"flow_dissector":[]}]
$ bpftool prog attach pinned \
/sys/fs/bpf/flow/flow_dissector flow_dissector
$ bpftool net -j
[{"xdp":[],"tc":[],"flow_dissector":["id":3]}]
Doesn't show up in a different net namespace:
$ ip netns add test
$ ip netns exec test bpftool net -j
[{"xdp":[],"tc":[],"flow_dissector":[]}]
Non-json output:
$ bpftool net
xdp:
tc:
flow_dissector:
id 3
v2:
* initialization order (Jakub Kicinski)
* clear errno for batch mode (Quentin Monnet)
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/bpf')
-rw-r--r-- | tools/bpf/bpftool/net.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/net.c b/tools/bpf/bpftool/net.c index db0e7de49d49..67e99c56bc88 100644 --- a/tools/bpf/bpftool/net.c +++ b/tools/bpf/bpftool/net.c @@ -3,6 +3,7 @@ #define _GNU_SOURCE #include <errno.h> +#include <fcntl.h> #include <stdlib.h> #include <string.h> #include <unistd.h> @@ -12,6 +13,8 @@ #include <linux/rtnetlink.h> #include <linux/tc_act/tc_bpf.h> #include <sys/socket.h> +#include <sys/stat.h> +#include <sys/types.h> #include <bpf.h> #include <nlattr.h> @@ -48,6 +51,10 @@ struct bpf_filter_t { int ifindex; }; +struct bpf_attach_info { + __u32 flow_dissector_id; +}; + static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb) { struct bpf_netdev_t *netinfo = cookie; @@ -180,8 +187,45 @@ out: return 0; } +static int query_flow_dissector(struct bpf_attach_info *attach_info) +{ + __u32 attach_flags; + __u32 prog_ids[1]; + __u32 prog_cnt; + int err; + int fd; + + fd = open("/proc/self/ns/net", O_RDONLY); + if (fd < 0) { + p_err("can't open /proc/self/ns/net: %d", + strerror(errno)); + return -1; + } + prog_cnt = ARRAY_SIZE(prog_ids); + err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0, + &attach_flags, prog_ids, &prog_cnt); + close(fd); + if (err) { + if (errno == EINVAL) { + /* Older kernel's don't support querying + * flow dissector programs. + */ + errno = 0; + return 0; + } + p_err("can't query prog: %s", strerror(errno)); + return -1; + } + + if (prog_cnt == 1) + attach_info->flow_dissector_id = prog_ids[0]; + + return 0; +} + static int do_show(int argc, char **argv) { + struct bpf_attach_info attach_info = {}; int i, sock, ret, filter_idx = -1; struct bpf_netdev_t dev_array; unsigned int nl_pid; @@ -199,6 +243,10 @@ static int do_show(int argc, char **argv) usage(); } + ret = query_flow_dissector(&attach_info); + if (ret) + return -1; + sock = libbpf_netlink_open(&nl_pid); if (sock < 0) { fprintf(stderr, "failed to open netlink sock\n"); @@ -227,6 +275,12 @@ static int do_show(int argc, char **argv) } NET_END_ARRAY("\n"); } + + NET_START_ARRAY("flow_dissector", "%s:\n"); + if (attach_info.flow_dissector_id > 0) + NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id); + NET_END_ARRAY("\n"); + NET_END_OBJECT; if (json_output) jsonw_end_array(json_wtr); |