* [PATCH bpf-next v3 1/2] bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_type @ 2019-04-24 18:52 Stanislav Fomichev 2019-04-24 18:52 ` [PATCH bpf-next v3 2/2] bpftool: show flow_dissector attachment status Stanislav Fomichev 0 siblings, 1 reply; 3+ messages in thread From: Stanislav Fomichev @ 2019-04-24 18:52 UTC (permalink / raw) To: netdev, bpf Cc: davem, ast, daniel, jakub.kicinski, quentin.monnet, Stanislav Fomichev target_fd is target namespace. If there is a flow dissector BPF program attached to that namespace, its (single) id is returned. v3: * add missing inline to skb_flow_dissector_prog_query static def (kbuild test robot <lkp@intel.com>) v2: * don't sleep in rcu critical section (Jakub Kicinski) * check input prog_cnt (exit early) Signed-off-by: Stanislav Fomichev <sdf@google.com> --- include/linux/skbuff.h | 8 ++++++++ kernel/bpf/syscall.c | 2 ++ net/core/flow_dissector.c | 37 +++++++++++++++++++++++++++++++++++++ 3 files changed, 47 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 998256c2820b..6d58fa8a65fd 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1258,11 +1258,19 @@ void skb_flow_dissector_init(struct flow_dissector *flow_dissector, unsigned int key_count); #ifdef CONFIG_NET +int skb_flow_dissector_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr); int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog); int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr); #else +static inline int skb_flow_dissector_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + return -EOPNOTSUPP; +} + static inline int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 92c9b8a32b50..b0de49598341 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2009,6 +2009,8 @@ static int bpf_prog_query(const union bpf_attr *attr, break; case BPF_LIRC_MODE2: return lirc_prog_query(attr, uattr); + case BPF_FLOW_DISSECTOR: + return skb_flow_dissector_prog_query(attr, uattr); default: return -EINVAL; } diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index fac712cee9d5..12b92c7d1eae 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -65,6 +65,43 @@ void skb_flow_dissector_init(struct flow_dissector *flow_dissector, } EXPORT_SYMBOL(skb_flow_dissector_init); +int skb_flow_dissector_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); + u32 prog_id, prog_cnt = 0, flags = 0; + struct bpf_prog *attached; + struct net *net; + + if (attr->query.query_flags) + return -EINVAL; + + net = get_net_ns_by_fd(attr->query.target_fd); + if (IS_ERR(net)) + return PTR_ERR(net); + + rcu_read_lock(); + attached = rcu_dereference(net->flow_dissector_prog); + if (attached) { + prog_cnt = 1; + prog_id = attached->aux->id; + } + rcu_read_unlock(); + + if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags))) + return -EFAULT; + if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt))) + return -EFAULT; + + if (!attr->query.prog_cnt || !prog_ids || !prog_cnt) + return 0; + + if (copy_to_user(prog_ids, &prog_id, sizeof(u32))) + return -EFAULT; + + return 0; +} + int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) { -- 2.21.0.593.g511ec345e18-goog ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH bpf-next v3 2/2] bpftool: show flow_dissector attachment status 2019-04-24 18:52 [PATCH bpf-next v3 1/2] bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_type Stanislav Fomichev @ 2019-04-24 18:52 ` Stanislav Fomichev 2019-04-24 19:02 ` Quentin Monnet 0 siblings, 1 reply; 3+ messages in thread From: Stanislav Fomichev @ 2019-04-24 18:52 UTC (permalink / raw) To: netdev, bpf Cc: davem, ast, daniel, jakub.kicinski, quentin.monnet, Stanislav Fomichev 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> --- tools/bpf/bpftool/net.c | 54 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) 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 @@ static int show_dev_tc_bpf(int sock, unsigned int nl_pid, 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); -- 2.21.0.593.g511ec345e18-goog ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH bpf-next v3 2/2] bpftool: show flow_dissector attachment status 2019-04-24 18:52 ` [PATCH bpf-next v3 2/2] bpftool: show flow_dissector attachment status Stanislav Fomichev @ 2019-04-24 19:02 ` Quentin Monnet 0 siblings, 0 replies; 3+ messages in thread From: Quentin Monnet @ 2019-04-24 19:02 UTC (permalink / raw) To: Stanislav Fomichev, netdev, bpf; +Cc: davem, ast, daniel, jakub.kicinski 2019-04-24 11:52 UTC-0700 ~ Stanislav Fomichev <sdf@google.com> > 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> Thanks! ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-04-24 19:02 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-04-24 18:52 [PATCH bpf-next v3 1/2] bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_type Stanislav Fomichev 2019-04-24 18:52 ` [PATCH bpf-next v3 2/2] bpftool: show flow_dissector attachment status Stanislav Fomichev 2019-04-24 19:02 ` Quentin Monnet
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