This patch renames reuseport_select_sock() to __reuseport_select_sock() and adds two wrapper function of it to pass the migration type defined in the previous commit.
reuseport_select_sock : BPF_SK_REUSEPORT_MIGRATE_NO reuseport_select_migrated_sock : BPF_SK_REUSEPORT_MIGRATE_REQUEST As mentioned before, we have to select a new listener for TCP_NEW_SYN_RECV requests at receiving the final ACK or sending a SYN+ACK. Therefore, this patch also changes the code to call reuseport_select_migrated_sock() even if the listening socket is TCP_CLOSE. If we can pick out a listening socket from the reuseport group, we rewrite request_sock.rsk_listener and resume processing the request. Link: https://lore.kernel.org/bpf/202012020136.bf0z4guu-...@intel.com/ Reported-by: kernel test robot <l...@intel.com> Reviewed-by: Benjamin Herrenschmidt <b...@amazon.com> Signed-off-by: Kuniyuki Iwashima <kun...@amazon.co.jp> --- include/net/inet_connection_sock.h | 11 ++++++++ include/net/request_sock.h | 13 ++++++++++ include/net/sock_reuseport.h | 8 +++--- net/core/sock_reuseport.c | 40 ++++++++++++++++++++++++------ net/ipv4/inet_connection_sock.c | 13 ++++++++-- net/ipv4/tcp_ipv4.c | 9 +++++-- net/ipv6/tcp_ipv6.c | 9 +++++-- 7 files changed, 86 insertions(+), 17 deletions(-) diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 2ea2d743f8fc..d8c3be31e987 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -272,6 +272,17 @@ static inline void inet_csk_reqsk_queue_added(struct sock *sk) reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); } +static inline void inet_csk_reqsk_queue_migrated(struct sock *sk, + struct sock *nsk, + struct request_sock *req) +{ + reqsk_queue_migrated(&inet_csk(sk)->icsk_accept_queue, + &inet_csk(nsk)->icsk_accept_queue, + req); + sock_put(sk); + req->rsk_listener = nsk; +} + static inline int inet_csk_reqsk_queue_len(const struct sock *sk) { return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 29e41ff3ec93..d18ba0b857cc 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -226,6 +226,19 @@ static inline void reqsk_queue_added(struct request_sock_queue *queue) atomic_inc(&queue->qlen); } +static inline void reqsk_queue_migrated(struct request_sock_queue *old_accept_queue, + struct request_sock_queue *new_accept_queue, + const struct request_sock *req) +{ + atomic_dec(&old_accept_queue->qlen); + atomic_inc(&new_accept_queue->qlen); + + if (req->num_timeout == 0) { + atomic_dec(&old_accept_queue->young); + atomic_inc(&new_accept_queue->young); + } +} + static inline int reqsk_queue_len(const struct request_sock_queue *queue) { return atomic_read(&queue->qlen); diff --git a/include/net/sock_reuseport.h b/include/net/sock_reuseport.h index 09a1b1539d4c..a48259a974be 100644 --- a/include/net/sock_reuseport.h +++ b/include/net/sock_reuseport.h @@ -32,10 +32,10 @@ extern int reuseport_alloc(struct sock *sk, bool bind_inany); extern int reuseport_add_sock(struct sock *sk, struct sock *sk2, bool bind_inany); extern struct sock *reuseport_detach_sock(struct sock *sk); -extern struct sock *reuseport_select_sock(struct sock *sk, - u32 hash, - struct sk_buff *skb, - int hdr_len); +extern struct sock *reuseport_select_sock(struct sock *sk, u32 hash, + struct sk_buff *skb, int hdr_len); +extern struct sock *reuseport_select_migrated_sock(struct sock *sk, u32 hash, + struct sk_buff *skb); extern int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog); extern int reuseport_detach_prog(struct sock *sk); diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c index 2de42f8103ea..1011c3756c92 100644 --- a/net/core/sock_reuseport.c +++ b/net/core/sock_reuseport.c @@ -170,7 +170,7 @@ int reuseport_add_sock(struct sock *sk, struct sock *sk2, bool bind_inany) } reuse->socks[reuse->num_socks] = sk; - /* paired with smp_rmb() in reuseport_select_sock() */ + /* paired with smp_rmb() in __reuseport_select_sock() */ smp_wmb(); reuse->num_socks++; rcu_assign_pointer(sk->sk_reuseport_cb, reuse); @@ -277,12 +277,13 @@ static struct sock *run_bpf_filter(struct sock_reuseport *reuse, u16 socks, * @hdr_len: BPF filter expects skb data pointer at payload data. If * the skb does not yet point at the payload, this parameter represents * how far the pointer needs to advance to reach the payload. + * @migration: represents if it is selecting a listener for SYN or + * migrating ESTABLISHED/SYN_RECV sockets or NEW_SYN_RECV socket. * Returns a socket that should receive the packet (or NULL on error). */ -struct sock *reuseport_select_sock(struct sock *sk, - u32 hash, - struct sk_buff *skb, - int hdr_len) +static struct sock *__reuseport_select_sock(struct sock *sk, u32 hash, + struct sk_buff *skb, int hdr_len, + u8 migration) { struct sock_reuseport *reuse; struct bpf_prog *prog; @@ -296,13 +297,19 @@ struct sock *reuseport_select_sock(struct sock *sk, if (!reuse) goto out; - prog = rcu_dereference(reuse->prog); socks = READ_ONCE(reuse->num_socks); if (likely(socks)) { /* paired with smp_wmb() in reuseport_add_sock() */ smp_rmb(); - if (!prog || !skb) + prog = rcu_dereference(reuse->prog); + if (!prog) + goto select_by_hash; + + if (migration) + goto out; + + if (!skb) goto select_by_hash; if (prog->type == BPF_PROG_TYPE_SK_REUSEPORT) @@ -331,8 +338,27 @@ struct sock *reuseport_select_sock(struct sock *sk, rcu_read_unlock(); return sk2; } + +struct sock *reuseport_select_sock(struct sock *sk, u32 hash, + struct sk_buff *skb, int hdr_len) +{ + return __reuseport_select_sock(sk, hash, skb, hdr_len, BPF_SK_REUSEPORT_MIGRATE_NO); +} EXPORT_SYMBOL(reuseport_select_sock); +struct sock *reuseport_select_migrated_sock(struct sock *sk, u32 hash, + struct sk_buff *skb) +{ + struct sock *nsk; + + nsk = __reuseport_select_sock(sk, hash, skb, 0, BPF_SK_REUSEPORT_MIGRATE_REQUEST); + if (nsk && likely(refcount_inc_not_zero(&nsk->sk_refcnt))) + return nsk; + + return NULL; +} +EXPORT_SYMBOL(reuseport_select_migrated_sock); + int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog) { struct sock_reuseport *reuse; diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 143590858c2e..f042e9122074 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -743,8 +743,17 @@ static void reqsk_timer_handler(struct timer_list *t) struct request_sock_queue *queue = &icsk->icsk_accept_queue; int max_syn_ack_retries, qlen, expire = 0, resend = 0; - if (inet_sk_state_load(sk_listener) != TCP_LISTEN) - goto drop; + if (inet_sk_state_load(sk_listener) != TCP_LISTEN) { + sk_listener = reuseport_select_migrated_sock(sk_listener, + req_to_sk(req)->sk_hash, NULL); + if (!sk_listener) { + sk_listener = req->rsk_listener; + goto drop; + } + inet_csk_reqsk_queue_migrated(req->rsk_listener, sk_listener, req); + icsk = inet_csk(sk_listener); + queue = &icsk->icsk_accept_queue; + } max_syn_ack_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries; /* Normally all the openreqs are young and become mature diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index af2338294598..a4eea6b36795 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1978,8 +1978,13 @@ int tcp_v4_rcv(struct sk_buff *skb) goto csum_error; } if (unlikely(sk->sk_state != TCP_LISTEN)) { - inet_csk_reqsk_queue_drop_and_put(sk, req); - goto lookup; + nsk = reuseport_select_migrated_sock(sk, req_to_sk(req)->sk_hash, skb); + if (!nsk) { + inet_csk_reqsk_queue_drop_and_put(sk, req); + goto lookup; + } + inet_csk_reqsk_queue_migrated(sk, nsk, req); + sk = nsk; } /* We own a reference on the listener, increase it again * as we might lose it too soon. diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 1a1510513739..61b8c5855735 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1640,8 +1640,13 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) goto csum_error; } if (unlikely(sk->sk_state != TCP_LISTEN)) { - inet_csk_reqsk_queue_drop_and_put(sk, req); - goto lookup; + nsk = reuseport_select_migrated_sock(sk, req_to_sk(req)->sk_hash, skb); + if (!nsk) { + inet_csk_reqsk_queue_drop_and_put(sk, req); + goto lookup; + } + inet_csk_reqsk_queue_migrated(sk, nsk, req); + sk = nsk; } sock_hold(sk); refcounted = true; -- 2.17.2 (Apple Git-113)
