[ 25/73] ipv4: Save nexthop address of LSRR/SSRR option to IPCB.
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-02-28 01:39:46
Also in:
lkml
3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Wei <redacted> [ Upstream commit ac8a48106be49c422575ddc7531b776f8eb49610 ] We can not update iph->daddr in ip_options_rcv_srr(), It is too early. When some exception ocurred later (eg. in ip_forward() when goto sr_failed) we need the ip header be identical to the original one as ICMP need it. Add a field 'nexthop' in struct ip_options to save nexthop of LSRR or SSRR option. Signed-off-by: Li Wei <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- include/net/inet_sock.h | 2 ++ net/ipv4/ip_forward.c | 2 +- net/ipv4/ip_options.c | 5 +++-- 3 files changed, 6 insertions(+), 3 deletions(-)
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h@@ -31,6 +31,7 @@ /** struct ip_options - IP Options * * @faddr - Saved first hop address + * @nexthop - Saved nexthop address in LSRR and SSRR * @is_data - Options in __data, rather than skb * @is_strictroute - Strict source route * @srr_is_hit - Packet destination addr was our one
@@ -41,6 +42,7 @@ */ struct ip_options { __be32 faddr; + __be32 nexthop; unsigned char optlen; unsigned char srr; unsigned char rr; --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c
@@ -84,7 +84,7 @@ int ip_forward(struct sk_buff *skb) rt = skb_rtable(skb); - if (opt->is_strictroute && ip_hdr(skb)->daddr != rt->rt_gateway) + if (opt->is_strictroute && opt->nexthop != rt->rt_gateway) goto sr_failed; if (unlikely(skb->len > dst_mtu(&rt->dst) && !skb_is_gso(skb) && --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c
@@ -568,12 +568,13 @@ void ip_forward_options(struct sk_buff * ) { if (srrptr + 3 > srrspace) break; - if (memcmp(&ip_hdr(skb)->daddr, &optptr[srrptr-1], 4) == 0) + if (memcmp(&opt->nexthop, &optptr[srrptr-1], 4) == 0) break; } if (srrptr + 3 <= srrspace) { opt->is_changed = 1; ip_rt_get_source(&optptr[srrptr-1], skb, rt); + ip_hdr(skb)->daddr = opt->nexthop; optptr[2] = srrptr+4; } else if (net_ratelimit()) printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
@@ -640,7 +641,7 @@ int ip_options_rcv_srr(struct sk_buff *s } if (srrptr <= srrspace) { opt->srr_is_hit = 1; - iph->daddr = nexthop; + opt->nexthop = nexthop; opt->is_changed = 1; } return 0;