diff mbox series

[net-next,v2,2/3] net: ipv4: use consistent txhash in TIME_WAIT and SYN_RECV

Message ID 20230523161453.196094-3-atenart@kernel.org (mailing list archive)
State Accepted
Commit c0a8966e2bc7d31f77a7246947ebc09c1ff06066
Delegated to: Netdev Maintainers
Headers show
Series net: tcp: make txhash use consistent for IPv4 | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1747 this patch: 1747
netdev/cc_maintainers warning 1 maintainers not CCed: dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 231 this patch: 231
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1887 this patch: 1887
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 80 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Antoine Tenart May 23, 2023, 4:14 p.m. UTC 
When using IPv4/TCP, skb->hash comes from sk->sk_txhash except in
TIME_WAIT and SYN_RECV where it's not set in the reply skb from
ip_send_unicast_reply. Those packets will have a mismatched hash with
others from the same flow as their hashes will be 0. IPv6 does not have
the same issue as the hash is set from the socket txhash in those cases.

This commits sets the hash in the reply skb from ip_send_unicast_reply,
which makes the IPv4 code behaving like IPv6.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
---
 include/net/ip.h     |  2 +-
 net/ipv4/ip_output.c |  4 +++-
 net/ipv4/tcp_ipv4.c  | 14 +++++++++-----
 3 files changed, 13 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/include/net/ip.h b/include/net/ip.h
index c3fffaa92d6e..749735171e2c 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -280,7 +280,7 @@  void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 			   const struct ip_options *sopt,
 			   __be32 daddr, __be32 saddr,
 			   const struct ip_reply_arg *arg,
-			   unsigned int len, u64 transmit_time);
+			   unsigned int len, u64 transmit_time, u32 txhash);
 
 #define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
 #define __IP_INC_STATS(net, field)	__SNMP_INC_STATS64((net)->mib.ip_statistics, field)
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 61892268e8a6..a1bead441026 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1692,7 +1692,7 @@  void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 			   const struct ip_options *sopt,
 			   __be32 daddr, __be32 saddr,
 			   const struct ip_reply_arg *arg,
-			   unsigned int len, u64 transmit_time)
+			   unsigned int len, u64 transmit_time, u32 txhash)
 {
 	struct ip_options_data replyopts;
 	struct ipcm_cookie ipc;
@@ -1755,6 +1755,8 @@  void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 								arg->csum));
 		nskb->ip_summed = CHECKSUM_NONE;
 		nskb->mono_delivery_time = !!transmit_time;
+		if (txhash)
+			skb_set_hash(nskb, txhash, PKT_HASH_TYPE_L4);
 		ip_push_pending_frames(sk, &fl4);
 	}
 out:
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index af043f063a73..a50bd782f91f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -692,6 +692,7 @@  static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 	u64 transmit_time = 0;
 	struct sock *ctl_sk;
 	struct net *net;
+	u32 txhash = 0;
 
 	/* Never send a reset in response to a reset. */
 	if (th->rst)
@@ -829,6 +830,8 @@  static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 				   inet_twsk(sk)->tw_priority : sk->sk_priority;
 		transmit_time = tcp_transmit_time(sk);
 		xfrm_sk_clone_policy(ctl_sk, sk);
+		txhash = (sk->sk_state == TCP_TIME_WAIT) ?
+			 inet_twsk(sk)->tw_txhash : sk->sk_txhash;
 	} else {
 		ctl_sk->sk_mark = 0;
 		ctl_sk->sk_priority = 0;
@@ -837,7 +840,7 @@  static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 			      skb, &TCP_SKB_CB(skb)->header.h4.opt,
 			      ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 			      &arg, arg.iov[0].iov_len,
-			      transmit_time);
+			      transmit_time, txhash);
 
 	xfrm_sk_free_policy(ctl_sk);
 	sock_net_set(ctl_sk, &init_net);
@@ -859,7 +862,7 @@  static void tcp_v4_send_ack(const struct sock *sk,
 			    struct sk_buff *skb, u32 seq, u32 ack,
 			    u32 win, u32 tsval, u32 tsecr, int oif,
 			    struct tcp_md5sig_key *key,
-			    int reply_flags, u8 tos)
+			    int reply_flags, u8 tos, u32 txhash)
 {
 	const struct tcphdr *th = tcp_hdr(skb);
 	struct {
@@ -935,7 +938,7 @@  static void tcp_v4_send_ack(const struct sock *sk,
 			      skb, &TCP_SKB_CB(skb)->header.h4.opt,
 			      ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 			      &arg, arg.iov[0].iov_len,
-			      transmit_time);
+			      transmit_time, txhash);
 
 	sock_net_set(ctl_sk, &init_net);
 	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
@@ -955,7 +958,8 @@  static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
 			tw->tw_bound_dev_if,
 			tcp_twsk_md5_key(tcptw),
 			tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0,
-			tw->tw_tos
+			tw->tw_tos,
+			tw->tw_txhash
 			);
 
 	inet_twsk_put(tw);
@@ -988,7 +992,7 @@  static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 			0,
 			tcp_md5_do_lookup(sk, l3index, addr, AF_INET),
 			inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
-			ip_hdr(skb)->tos);
+			ip_hdr(skb)->tos, tcp_rsk(req)->txhash);
 }
 
 /*