diff options
Diffstat (limited to 'net/ipv4/ip_forward.c')
| -rw-r--r-- | net/ipv4/ip_forward.c | 48 |
1 files changed, 17 insertions, 31 deletions
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index e136a16ca..8cd0d5962 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -5,7 +5,7 @@ * * The IP forwarding functionality. * - * Version: $Id: ip_forward.c,v 1.40 1998/03/08 05:56:20 davem Exp $ + * Version: $Id: ip_forward.c,v 1.41 1998/08/26 12:03:42 davem Exp $ * * Authors: see ip.c * @@ -79,10 +79,8 @@ int ip_forward(struct sk_buff *skb) int fw_res = 0; #endif - if (IPCB(skb)->opt.router_alert) { - if (ip_call_ra_chain(skb)) - return 0; - } + if (IPCB(skb)->opt.router_alert && ip_call_ra_chain(skb)) + return 0; if (skb->pkt_type != PACKET_HOST) goto drop; @@ -110,7 +108,7 @@ int ip_forward(struct sk_buff *skb) goto local_pkt; #endif - if (ip_decrease_ttl(iph) <= 0) + if (iph->ttl <= 1) goto too_many_hops; if (opt->is_strictroute && rt->rt_dst != rt->rt_gateway) @@ -121,22 +119,30 @@ int ip_forward(struct sk_buff *skb) * after asking the firewall permission to do so. */ - skb->priority = rt->u.dst.priority; + skb->priority = rt_tos2priority(iph->tos); dev2 = rt->u.dst.dev; - mtu = dev2->mtu; + mtu = rt->u.dst.pmtu; #ifdef CONFIG_NET_SECURITY call_fw_firewall(PF_SECURITY, dev2, NULL, &mtu, NULL); #endif /* - * In IP you never have to forward a frame on the interface that it - * arrived upon. We now generate an ICMP HOST REDIRECT giving the route + * We now generate an ICMP HOST REDIRECT giving the route * we calculated. */ if (rt->rt_flags&RTCF_DOREDIRECT && !opt->srr) ip_rt_send_redirect(skb); - + + /* We are about to mangle packet. Copy it! */ + if ((skb = skb_cow(skb, dev2->hard_header_len)) == NULL) + return -1; + iph = skb->nh.iph; + opt = &(IPCB(skb)->opt); + + /* Decrease ttl after skb cow done */ + ip_decrease_ttl(iph); + /* * We now may allocate a new buffer, and copy the datagram into it. * If the indicated interface is up and running, kick it. @@ -147,14 +153,6 @@ int ip_forward(struct sk_buff *skb) #ifdef CONFIG_IP_ROUTE_NAT if (rt->rt_flags & RTCF_NAT) { - if (skb_headroom(skb) < dev2->hard_header_len || skb_cloned(skb)) { - struct sk_buff *skb2; - skb2 = skb_realloc_headroom(skb, (dev2->hard_header_len + 15)&~15); - kfree_skb(skb); - if (skb2 == NULL) - return -1; - skb = skb2; - } if (ip_do_nat(skb)) { kfree_skb(skb); return -1; @@ -243,18 +241,6 @@ skip_call_fw_firewall: } #endif - if (skb_headroom(skb) < dev2->hard_header_len || skb_cloned(skb)) { - struct sk_buff *skb2; - skb2 = skb_realloc_headroom(skb, (dev2->hard_header_len + 15)&~15); - kfree_skb(skb); - - if (skb2 == NULL) { - NETDEBUG(printk(KERN_ERR "\nIP: No memory available for IP forward\n")); - return -1; - } - skb = skb2; - iph = skb2->nh.iph; - } #ifdef CONFIG_FIREWALL if ((fw_res = call_out_firewall(PF_INET, dev2, iph, NULL,&skb)) < FW_ACCEPT) { |