From efce3d1fdff53ef45b11ff407f16bc2f6f292b93 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Tue, 28 Nov 2023 18:29:21 -0800 Subject: [PATCH] tcp: Don't initialise tp->tsoffset in tcp_get_cookie_sock(). When we create a full socket from SYN Cookie, we initialise tcp_sk(sk)->tsoffset redundantly in tcp_get_cookie_sock() as the field is inherited from tcp_rsk(req)->ts_off. cookie_v[46]_check |- treq->ts_off = 0 `- tcp_get_cookie_sock |- tcp_v[46]_syn_recv_sock | `- tcp_create_openreq_child | `- newtp->tsoffset = treq->ts_off `- tcp_sk(child)->tsoffset = tsoff Let's initialise tcp_rsk(req)->ts_off with the correct offset and remove the second initialisation of tcp_sk(sk)->tsoffset. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20231129022924.96156-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- include/net/tcp.h | 2 +- net/ipv4/syncookies.c | 7 +++---- net/ipv6/syncookies.c | 4 ++-- 3 files changed, 6 insertions(+), 7 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 2b2c79c7bbcd..cc7143a781da 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -490,7 +490,7 @@ void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); /* From syncookies.c */ struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, struct request_sock *req, - struct dst_entry *dst, u32 tsoff); + struct dst_entry *dst); int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th); struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index c08428d63d11..de051eb08db8 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -204,7 +204,7 @@ EXPORT_SYMBOL_GPL(__cookie_v4_check); struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, struct request_sock *req, - struct dst_entry *dst, u32 tsoff) + struct dst_entry *dst) { struct inet_connection_sock *icsk = inet_csk(sk); struct sock *child; @@ -214,7 +214,6 @@ struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, NULL, &own_req); if (child) { refcount_set(&req->rsk_refcnt, 1); - tcp_sk(child)->tsoffset = tsoff; sock_rps_save_rxhash(child, skb); if (rsk_drop_req(req)) { @@ -386,7 +385,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) treq = tcp_rsk(req); treq->rcv_isn = ntohl(th->seq) - 1; treq->snt_isn = ntohl(th->ack_seq) - 1; - treq->ts_off = 0; + treq->ts_off = tsoff; treq->txhash = net_tx_rndhash(); req->mss = mss; ireq->ir_num = ntohs(th->dest); @@ -452,7 +451,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) ireq->rcv_wscale = rcv_wscale; ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, net, &rt->dst); - ret = tcp_get_cookie_sock(sk, skb, req, &rt->dst, tsoff); + ret = tcp_get_cookie_sock(sk, skb, req, &rt->dst); /* ip_queue_xmit() depends on our flow being setup * Normal sockets get it right from inet_csk_route_child_sock() */ diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index 4cd26c481168..18c2e3c1677b 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -215,7 +215,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) treq->snt_synack = 0; treq->rcv_isn = ntohl(th->seq) - 1; treq->snt_isn = ntohl(th->ack_seq) - 1; - treq->ts_off = 0; + treq->ts_off = tsoff; treq->txhash = net_tx_rndhash(); l3index = l3mdev_master_ifindex_by_index(net, ireq->ir_iif); @@ -264,7 +264,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) ireq->rcv_wscale = rcv_wscale; ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, net, dst); - ret = tcp_get_cookie_sock(sk, skb, req, dst, tsoff); + ret = tcp_get_cookie_sock(sk, skb, req, dst); out: return ret; out_free: