From cfe673b0ae4754ffc051482f4a948b67ddbeec10 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 25 Sep 2015 07:39:16 -0700 Subject: [PATCH] ip: constify ip_build_and_send_pkt() socket argument This function is used to build and send SYNACK packets, possibly on behalf of unlocked listener socket. Make sure we did not miss a write by making this socket const. We no longer can use ip_select_ident() and have to either set iph->id to 0 or directly call __ip_select_ident() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/ip.h | 2 +- net/ipv4/ip_output.c | 14 ++++++++------ 2 files changed, 9 insertions(+), 7 deletions(-) diff --git a/include/net/ip.h b/include/net/ip.h index 525dc0778926..91a6b2c88341 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -100,7 +100,7 @@ int igmp_mc_init(void); * Functions provided by ip.c */ -int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, +int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, __be32 saddr, __be32 daddr, struct ip_options_rcu *opt); int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 09a6b7bb7ea3..06d2c87ed505 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -137,7 +137,7 @@ static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) * Add an ip header to a skbuff and send it out. * */ -int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, +int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, __be32 saddr, __be32 daddr, struct ip_options_rcu *opt) { struct inet_sock *inet = inet_sk(sk); @@ -151,15 +151,17 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, iph->version = 4; iph->ihl = 5; iph->tos = inet->tos; - if (ip_dont_fragment(sk, &rt->dst)) - iph->frag_off = htons(IP_DF); - else - iph->frag_off = 0; iph->ttl = ip_select_ttl(inet, &rt->dst); iph->daddr = (opt && opt->opt.srr ? opt->opt.faddr : daddr); iph->saddr = saddr; iph->protocol = sk->sk_protocol; - ip_select_ident(sock_net(sk), skb, sk); + if (ip_dont_fragment(sk, &rt->dst)) { + iph->frag_off = htons(IP_DF); + iph->id = 0; + } else { + iph->frag_off = 0; + __ip_select_ident(sock_net(sk), iph, 1); + } if (opt && opt->opt.optlen) { iph->ihl += opt->opt.optlen>>2; -- 2.20.1