| Message ID | 20230313041619.394914-1-xiyou.wangcong@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v2] sock_map: dump socket map id via diag | expand |
On 03/12, Cong Wang wrote: > From: Cong Wang <cong.wang@bytedance.com> > Currently there is no way to know which sockmap a socket has been added > to from outside, especially for that a socket can be added to multiple > sockmap's. We could dump this via socket diag, as shown below. > Sample output: > # ./iproute2/misc/ss -tnaie --sockmap > ESTAB 0 344329 127.0.0.1:1234 127.0.0.1:40912 ino:21098 > sk:5 cgroup:/user.slice/user-0.slice/session-c1.scope <-> sockmap: 1 > # bpftool map > 1: sockmap flags 0x0 > key 4B value 4B max_entries 2 memlock 4096B > pids echo-sockmap(549) > 4: array name pid_iter.rodata flags 0x480 > key 4B value 4B max_entries 1 memlock 4096B > btf_id 10 frozen > pids bpftool(624) > In the future, we could dump other sockmap related stats too, hence I > make it a nested attribute. > Cc: John Fastabend <john.fastabend@gmail.com> > Cc: Jakub Sitnicki <jakub@cloudflare.com> > Signed-off-by: Cong Wang <cong.wang@bytedance.com> > --- > v2: rename enum's with more generic names > sock_map_idiag_dump -> sock_map_diag_dump() > make sock_map_diag_dump() return number of maps > include/linux/bpf.h | 1 + > include/uapi/linux/inet_diag.h | 1 + > include/uapi/linux/sock_diag.h | 8 ++++++ > include/uapi/linux/unix_diag.h | 1 + > net/core/sock_map.c | 51 ++++++++++++++++++++++++++++++++++ > net/ipv4/inet_diag.c | 5 ++++ > net/unix/diag.c | 6 ++++ > 7 files changed, 73 insertions(+) > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index 6792a7940e1e..4cc315ce26a9 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -2638,6 +2638,7 @@ int sock_map_bpf_prog_query(const union bpf_attr > *attr, > void sock_map_unhash(struct sock *sk); > void sock_map_destroy(struct sock *sk); > void sock_map_close(struct sock *sk, long timeout); > +int sock_map_diag_dump(struct sock *sk, struct sk_buff *skb, int attr); > #else > static inline int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log, > struct bpf_prog_aux *prog_aux) > diff --git a/include/uapi/linux/inet_diag.h > b/include/uapi/linux/inet_diag.h > index 50655de04c9b..d1f1e4522633 100644 > --- a/include/uapi/linux/inet_diag.h > +++ b/include/uapi/linux/inet_diag.h > @@ -161,6 +161,7 @@ enum { > INET_DIAG_SK_BPF_STORAGES, > INET_DIAG_CGROUP_ID, > INET_DIAG_SOCKOPT, > + INET_DIAG_BPF_MAP, > __INET_DIAG_MAX, > }; > diff --git a/include/uapi/linux/sock_diag.h > b/include/uapi/linux/sock_diag.h > index 5f74a5f6091d..7c961940b408 100644 > --- a/include/uapi/linux/sock_diag.h > +++ b/include/uapi/linux/sock_diag.h > @@ -62,4 +62,12 @@ enum { > #define SK_DIAG_BPF_STORAGE_MAX (__SK_DIAG_BPF_STORAGE_MAX - 1) > +enum { > + SK_DIAG_BPF_MAP_NONE, > + SK_DIAG_BPF_MAP_IDS, > + __SK_DIAG_BPF_MAP_MAX, > +}; > + > +#define SK_DIAG_BPF_MAP_MAX (__SK_DIAG_BPF_MAP_MAX - 1) > + > #endif /* _UAPI__SOCK_DIAG_H__ */ > diff --git a/include/uapi/linux/unix_diag.h > b/include/uapi/linux/unix_diag.h > index a1988576fa8a..b95a2b33521d 100644 > --- a/include/uapi/linux/unix_diag.h > +++ b/include/uapi/linux/unix_diag.h > @@ -42,6 +42,7 @@ enum { > UNIX_DIAG_MEMINFO, > UNIX_DIAG_SHUTDOWN, > UNIX_DIAG_UID, > + UNIX_DIAG_BPF_MAP, > __UNIX_DIAG_MAX, > }; > diff --git a/net/core/sock_map.c b/net/core/sock_map.c > index 9b854e236d23..8c4b3044e7a9 100644 > --- a/net/core/sock_map.c > +++ b/net/core/sock_map.c > @@ -1656,6 +1656,57 @@ void sock_map_close(struct sock *sk, long timeout) > } > EXPORT_SYMBOL_GPL(sock_map_close); > +int sock_map_diag_dump(struct sock *sk, struct sk_buff *skb, int > attrtype) > +{ > + struct sk_psock_link *link; > + struct nlattr *nla, *attr; > + int nr_links = 0, ret = 0; > + struct sk_psock *psock; > + u32 *ids; > + [..] > + rcu_read_lock(); Looks like sk_psock_get already starts RCU read section and returns a refcnt'ed psock. So maybe drop rcu_read_lock/rcu_read_unlock? > + psock = sk_psock_get(sk); > + if (unlikely(!psock)) { > + rcu_read_unlock(); > + return 0; > + } > + > + nla = nla_nest_start_noflag(skb, attrtype); > + if (!nla) { > + sk_psock_put(sk, psock); > + rcu_read_unlock(); > + return -EMSGSIZE; > + } > + spin_lock_bh(&psock->link_lock); > + list_for_each_entry(link, &psock->link, list) > + nr_links++; > + > + attr = nla_reserve(skb, SK_DIAG_BPF_MAP_IDS, > + sizeof(link->map->id) * nr_links); > + if (!attr) { > + ret = -EMSGSIZE; > + goto unlock; > + } > + > + ids = nla_data(attr); > + list_for_each_entry(link, &psock->link, list) { > + *ids = link->map->id; > + ids++; > + } > +unlock: > + spin_unlock_bh(&psock->link_lock); > + sk_psock_put(sk, psock); > + rcu_read_unlock(); > + if (ret) { > + nla_nest_cancel(skb, nla); > + } else { > + ret = nr_links; > + nla_nest_end(skb, nla); > + } > + return ret; > +} > +EXPORT_SYMBOL_GPL(sock_map_diag_dump); > + > static int sock_map_iter_attach_target(struct bpf_prog *prog, > union bpf_iter_link_info *linfo, > struct bpf_iter_aux_info *aux) > diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c > index b812eb36f0e3..0949909d5b46 100644 > --- a/net/ipv4/inet_diag.c > +++ b/net/ipv4/inet_diag.c > @@ -197,6 +197,11 @@ int inet_diag_msg_attrs_fill(struct sock *sk, struct > sk_buff *skb, > &inet_sockopt)) > goto errout; > +#ifdef CONFIG_BPF_SYSCALL > + if (sock_map_diag_dump(sk, skb, INET_DIAG_BPF_MAP) < 0) > + goto errout; > +#endif > + > return 0; > errout: > return 1; > diff --git a/net/unix/diag.c b/net/unix/diag.c > index 616b55c5b890..54aa8da2831e 100644 > --- a/net/unix/diag.c > +++ b/net/unix/diag.c > @@ -6,6 +6,7 @@ > #include <linux/skbuff.h> > #include <linux/module.h> > #include <linux/uidgid.h> > +#include <linux/bpf.h> > #include <net/netlink.h> > #include <net/af_unix.h> > #include <net/tcp_states.h> > @@ -172,6 +173,11 @@ static int sk_diag_fill(struct sock *sk, struct > sk_buff *skb, struct unix_diag_r > sk_diag_dump_uid(sk, skb, user_ns)) > goto out_nlmsg_trim; > +#ifdef CONFIG_BPF_SYSCALL > + if (sock_map_diag_dump(sk, skb, UNIX_DIAG_BPF_MAP) < 0) > + goto out_nlmsg_trim; > +#endif > + > nlmsg_end(skb, nlh); > return 0; > -- > 2.34.1
Cong Wang wrote: > From: Cong Wang <cong.wang@bytedance.com> > > Currently there is no way to know which sockmap a socket has been added > to from outside, especially for that a socket can be added to multiple > sockmap's. We could dump this via socket diag, as shown below. > > Sample output: > > # ./iproute2/misc/ss -tnaie --sockmap > ESTAB 0 344329 127.0.0.1:1234 127.0.0.1:40912 ino:21098 sk:5 cgroup:/user.slice/user-0.slice/session-c1.scope <-> sockmap: 1 > > # bpftool map > 1: sockmap flags 0x0 > key 4B value 4B max_entries 2 memlock 4096B > pids echo-sockmap(549) > 4: array name pid_iter.rodata flags 0x480 > key 4B value 4B max_entries 1 memlock 4096B > btf_id 10 frozen > pids bpftool(624) > > In the future, we could dump other sockmap related stats too, hence I > make it a nested attribute. > > Cc: John Fastabend <john.fastabend@gmail.com> > Cc: Jakub Sitnicki <jakub@cloudflare.com> > Signed-off-by: Cong Wang <cong.wang@bytedance.com> > --- > v2: rename enum's with more generic names > sock_map_idiag_dump -> sock_map_diag_dump() > make sock_map_diag_dump() return number of maps > > include/linux/bpf.h | 1 + > include/uapi/linux/inet_diag.h | 1 + > include/uapi/linux/sock_diag.h | 8 ++++++ > include/uapi/linux/unix_diag.h | 1 + > net/core/sock_map.c | 51 ++++++++++++++++++++++++++++++++++ > net/ipv4/inet_diag.c | 5 ++++ > net/unix/diag.c | 6 ++++ > 7 files changed, 73 insertions(+) > [...] > +int sock_map_diag_dump(struct sock *sk, struct sk_buff *skb, int attrtype) > +{ > + struct sk_psock_link *link; > + struct nlattr *nla, *attr; > + int nr_links = 0, ret = 0; > + struct sk_psock *psock; > + u32 *ids; > + > + rcu_read_lock(); > + psock = sk_psock_get(sk); > + if (unlikely(!psock)) { wont this be the common case because we call this for any sk from inet_diag_msg_attrs_fill(sk, ...)? Probably drop the unlikely? > + rcu_read_unlock(); > + return 0; > + }
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 6792a7940e1e..4cc315ce26a9 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2638,6 +2638,7 @@ int sock_map_bpf_prog_query(const union bpf_attr *attr, void sock_map_unhash(struct sock *sk); void sock_map_destroy(struct sock *sk); void sock_map_close(struct sock *sk, long timeout); +int sock_map_diag_dump(struct sock *sk, struct sk_buff *skb, int attr); #else static inline int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log, struct bpf_prog_aux *prog_aux) diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h index 50655de04c9b..d1f1e4522633 100644 --- a/include/uapi/linux/inet_diag.h +++ b/include/uapi/linux/inet_diag.h @@ -161,6 +161,7 @@ enum { INET_DIAG_SK_BPF_STORAGES, INET_DIAG_CGROUP_ID, INET_DIAG_SOCKOPT, + INET_DIAG_BPF_MAP, __INET_DIAG_MAX, }; diff --git a/include/uapi/linux/sock_diag.h b/include/uapi/linux/sock_diag.h index 5f74a5f6091d..7c961940b408 100644 --- a/include/uapi/linux/sock_diag.h +++ b/include/uapi/linux/sock_diag.h @@ -62,4 +62,12 @@ enum { #define SK_DIAG_BPF_STORAGE_MAX (__SK_DIAG_BPF_STORAGE_MAX - 1) +enum { + SK_DIAG_BPF_MAP_NONE, + SK_DIAG_BPF_MAP_IDS, + __SK_DIAG_BPF_MAP_MAX, +}; + +#define SK_DIAG_BPF_MAP_MAX (__SK_DIAG_BPF_MAP_MAX - 1) + #endif /* _UAPI__SOCK_DIAG_H__ */ diff --git a/include/uapi/linux/unix_diag.h b/include/uapi/linux/unix_diag.h index a1988576fa8a..b95a2b33521d 100644 --- a/include/uapi/linux/unix_diag.h +++ b/include/uapi/linux/unix_diag.h @@ -42,6 +42,7 @@ enum { UNIX_DIAG_MEMINFO, UNIX_DIAG_SHUTDOWN, UNIX_DIAG_UID, + UNIX_DIAG_BPF_MAP, __UNIX_DIAG_MAX, }; diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 9b854e236d23..8c4b3044e7a9 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -1656,6 +1656,57 @@ void sock_map_close(struct sock *sk, long timeout) } EXPORT_SYMBOL_GPL(sock_map_close); +int sock_map_diag_dump(struct sock *sk, struct sk_buff *skb, int attrtype) +{ + struct sk_psock_link *link; + struct nlattr *nla, *attr; + int nr_links = 0, ret = 0; + struct sk_psock *psock; + u32 *ids; + + rcu_read_lock(); + psock = sk_psock_get(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + return 0; + } + + nla = nla_nest_start_noflag(skb, attrtype); + if (!nla) { + sk_psock_put(sk, psock); + rcu_read_unlock(); + return -EMSGSIZE; + } + spin_lock_bh(&psock->link_lock); + list_for_each_entry(link, &psock->link, list) + nr_links++; + + attr = nla_reserve(skb, SK_DIAG_BPF_MAP_IDS, + sizeof(link->map->id) * nr_links); + if (!attr) { + ret = -EMSGSIZE; + goto unlock; + } + + ids = nla_data(attr); + list_for_each_entry(link, &psock->link, list) { + *ids = link->map->id; + ids++; + } +unlock: + spin_unlock_bh(&psock->link_lock); + sk_psock_put(sk, psock); + rcu_read_unlock(); + if (ret) { + nla_nest_cancel(skb, nla); + } else { + ret = nr_links; + nla_nest_end(skb, nla); + } + return ret; +} +EXPORT_SYMBOL_GPL(sock_map_diag_dump); + static int sock_map_iter_attach_target(struct bpf_prog *prog, union bpf_iter_link_info *linfo, struct bpf_iter_aux_info *aux) diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index b812eb36f0e3..0949909d5b46 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -197,6 +197,11 @@ int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb, &inet_sockopt)) goto errout; +#ifdef CONFIG_BPF_SYSCALL + if (sock_map_diag_dump(sk, skb, INET_DIAG_BPF_MAP) < 0) + goto errout; +#endif + return 0; errout: return 1; diff --git a/net/unix/diag.c b/net/unix/diag.c index 616b55c5b890..54aa8da2831e 100644 --- a/net/unix/diag.c +++ b/net/unix/diag.c @@ -6,6 +6,7 @@ #include <linux/skbuff.h> #include <linux/module.h> #include <linux/uidgid.h> +#include <linux/bpf.h> #include <net/netlink.h> #include <net/af_unix.h> #include <net/tcp_states.h> @@ -172,6 +173,11 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_r sk_diag_dump_uid(sk, skb, user_ns)) goto out_nlmsg_trim; +#ifdef CONFIG_BPF_SYSCALL + if (sock_map_diag_dump(sk, skb, UNIX_DIAG_BPF_MAP) < 0) + goto out_nlmsg_trim; +#endif + nlmsg_end(skb, nlh); return 0;