[PATCH net-next 5/7] icmp: reflect tos through ip cookie rather than updating inet_sk
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2025-02-06 19:35:31
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
From: Willem de Bruijn <willemb@google.com>
Do not modify socket fields if it can be avoided.
The current code predates the introduction of ip cookies in commit
aa6615814533 ("ipv4: processing ancillary IP_TOS or IP_TTL"). Now that
cookies exist and support tos, update that field directly.
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
Tested with ping -Q 32 127.0.0.1 and tcpdump
The existing logic works because inet->tos is read if ipc.tos (and
with that cork->tos) is left unitialized:
iph->tos = (cork->tos != -1) ? cork->tos : READ_ONCE(inet->tos);
---
net/ipv4/icmp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 094084b61bff..9c5e052a7802 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c@@ -429,7 +429,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) icmp_param->data.icmph.checksum = 0; ipcm_init(&ipc); - inet->tos = ip_hdr(skb)->tos; + ipc.tos = ip_hdr(skb)->tos; ipc.sockc.mark = mark; daddr = ipc.addr = ip_hdr(skb)->saddr; saddr = fib_compute_spec_dst(skb);
@@ -735,8 +735,8 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, icmp_param.data.icmph.checksum = 0; icmp_param.skb = skb_in; icmp_param.offset = skb_network_offset(skb_in); - inet_sk(sk)->tos = tos; ipcm_init(&ipc); + ipc.tos = tos; ipc.addr = iph->saddr; ipc.opt = &icmp_param.replyopts.opt; ipc.sockc.mark = mark;
--
2.48.1.502.g6dc24dfdaf-goog