From ae0f7d5f83236a43c572a744e4bbb30e8702d821 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Wed, 11 Jan 2006 15:53:04 -0800 Subject: [PATCH] [IPV6]: Avoid calling ip6_xmit() with NULL sk The ip6_xmit() function now assumes that its sk argument is non-NULL, which isn't currently true when TCPv6 code is sending RST or ACK packets. This fixes that code to use a socket of its own for sending such packets, as TCPv4 does. (Thanks Andi for the pointer). Signed-off-by: David Woodhouse Signed-off-by: David S. Miller --- net/ipv6/tcp_ipv6.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index a25f4e8..66d0400 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -67,6 +67,9 @@ #include #include +/* Socket used for sending RSTs and ACKs */ +static struct socket *tcp6_socket; + static void tcp_v6_send_reset(struct sk_buff *skb); static void tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req); static void tcp_v6_send_check(struct sock *sk, int len, @@ -611,7 +614,7 @@ static void tcp_v6_send_reset(struct sk_buff *skb) if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) { if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) { - ip6_xmit(NULL, buff, &fl, NULL, 0); + ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0); TCP_INC_STATS_BH(TCP_MIB_OUTSEGS); TCP_INC_STATS_BH(TCP_MIB_OUTRSTS); return; @@ -675,7 +678,7 @@ static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) { if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) { - ip6_xmit(NULL, buff, &fl, NULL, 0); + ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0); TCP_INC_STATS_BH(TCP_MIB_OUTSEGS); return; } @@ -1600,8 +1603,21 @@ static struct inet_protosw tcpv6_protosw = { void __init tcpv6_init(void) { + int err; + /* register inet6 protocol */ if (inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP) < 0) printk(KERN_ERR "tcpv6_init: Could not register protocol\n"); inet6_register_protosw(&tcpv6_protosw); + + err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_TCP, &tcp6_socket); + if (err < 0) + panic("Failed to create the TCPv6 control socket.\n"); + tcp6_socket->sk->sk_allocation = GFP_ATOMIC; + + /* Unhash it so that IP input processing does not even + * see it, we do not wish this socket to see incoming + * packets. + */ + tcp6_socket->sk->sk_prot->unhash(tcp6_socket->sk); } -- 2.7.4