From 79636038d37e7bd4d078238f2a3f002cab4423bc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 10 Oct 2024 17:48:17 +0000 Subject: [PATCH] ipv4: tcp: give socket pointer to control skbs ip_send_unicast_reply() send orphaned 'control packets'. These are RST packets and also ACK packets sent from TIME_WAIT. Some eBPF programs would prefer to have a meaningful skb->sk pointer as much as possible. This means that TCP can now attach TIME_WAIT sockets to outgoing skbs. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Reviewed-by: Brian Vazquez Link: https://patch.msgid.link/20241010174817.1543642-6-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/net/ip.h | 3 ++- net/ipv4/ip_output.c | 5 ++++- net/ipv4/tcp_ipv4.c | 4 ++-- 3 files changed, 8 insertions(+), 4 deletions(-) diff --git a/include/net/ip.h b/include/net/ip.h index bab084df15677..4be0a6a603b2b 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -288,7 +288,8 @@ static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; } -void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, +void ip_send_unicast_reply(struct sock *sk, const struct sock *orig_sk, + struct sk_buff *skb, const struct ip_options *sopt, __be32 daddr, __be32 saddr, const struct ip_reply_arg *arg, diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index e5c55a95063dd..0065b1996c947 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1596,7 +1596,8 @@ static int ip_reply_glue_bits(void *dptr, char *to, int offset, * Generic function to send a packet as reply to another packet. * Used to send some TCP resets/acks so far. */ -void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, +void ip_send_unicast_reply(struct sock *sk, const struct sock *orig_sk, + struct sk_buff *skb, const struct ip_options *sopt, __be32 daddr, __be32 saddr, const struct ip_reply_arg *arg, @@ -1662,6 +1663,8 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, arg->csumoffset) = csum_fold(csum_add(nskb->csum, arg->csum)); nskb->ip_summed = CHECKSUM_NONE; + if (orig_sk) + skb_set_owner_edemux(nskb, (struct sock *)orig_sk); if (transmit_time) nskb->tstamp_type = SKB_CLOCK_MONOTONIC; if (txhash) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 985028434f644..9d3dd101ea713 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -907,7 +907,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb, ctl_sk->sk_mark = 0; ctl_sk->sk_priority = 0; } - ip_send_unicast_reply(ctl_sk, + ip_send_unicast_reply(ctl_sk, sk, skb, &TCP_SKB_CB(skb)->header.h4.opt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len, @@ -1021,7 +1021,7 @@ static void tcp_v4_send_ack(const struct sock *sk, ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? inet_twsk(sk)->tw_priority : READ_ONCE(sk->sk_priority); transmit_time = tcp_transmit_time(sk); - ip_send_unicast_reply(ctl_sk, + ip_send_unicast_reply(ctl_sk, sk, skb, &TCP_SKB_CB(skb)->header.h4.opt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len, -- 2.50.1