From 9d02002d2dc2c7423e5891b97727fde4d667adf1 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 2 Oct 2006 16:12:20 -0700 Subject: [PATCH] [NETFILTER]: ipt_REJECT: remove largely duplicate route_reverse function Use ip_route_me_harder instead, which now allows to specify how we wish the packet to be routed. Based on patch by Simon Horman . Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/ipt_REJECT.c | 97 +++++++-------------------------- 1 file changed, 19 insertions(+), 78 deletions(-) diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c index fd0c05efed..ad0312d0e4 100644 --- a/net/ipv4/netfilter/ipt_REJECT.c +++ b/net/ipv4/netfilter/ipt_REJECT.c @@ -38,76 +38,16 @@ MODULE_DESCRIPTION("iptables REJECT target module"); #define DEBUGP(format, args...) #endif -static inline struct rtable *route_reverse(struct sk_buff *skb, - struct tcphdr *tcph, int hook) -{ - struct iphdr *iph = skb->nh.iph; - struct dst_entry *odst; - struct flowi fl = {}; - struct rtable *rt; - - /* We don't require ip forwarding to be enabled to be able to - * send a RST reply for bridged traffic. */ - if (hook != NF_IP_FORWARD -#ifdef CONFIG_BRIDGE_NETFILTER - || (skb->nf_bridge && skb->nf_bridge->mask & BRNF_BRIDGED) -#endif - ) { - fl.nl_u.ip4_u.daddr = iph->saddr; - if (hook == NF_IP_LOCAL_IN) - fl.nl_u.ip4_u.saddr = iph->daddr; - fl.nl_u.ip4_u.tos = RT_TOS(iph->tos); - - if (ip_route_output_key(&rt, &fl) != 0) - return NULL; - } else { - /* non-local src, find valid iif to satisfy - * rp-filter when calling ip_route_input. */ - fl.nl_u.ip4_u.daddr = iph->daddr; - if (ip_route_output_key(&rt, &fl) != 0) - return NULL; - - odst = skb->dst; - if (ip_route_input(skb, iph->saddr, iph->daddr, - RT_TOS(iph->tos), rt->u.dst.dev) != 0) { - dst_release(&rt->u.dst); - return NULL; - } - dst_release(&rt->u.dst); - rt = (struct rtable *)skb->dst; - skb->dst = odst; - - fl.nl_u.ip4_u.daddr = iph->saddr; - fl.nl_u.ip4_u.saddr = iph->daddr; - fl.nl_u.ip4_u.tos = RT_TOS(iph->tos); - } - - if (rt->u.dst.error) { - dst_release(&rt->u.dst); - return NULL; - } - - fl.proto = IPPROTO_TCP; - fl.fl_ip_sport = tcph->dest; - fl.fl_ip_dport = tcph->source; - security_skb_classify_flow(skb, &fl); - - xfrm_lookup((struct dst_entry **)&rt, &fl, NULL, 0); - - return rt; -} - /* Send RST reply */ static void send_reset(struct sk_buff *oldskb, int hook) { struct sk_buff *nskb; struct iphdr *iph = oldskb->nh.iph; struct tcphdr _otcph, *oth, *tcph; - struct rtable *rt; __be16 tmp_port; __be32 tmp_addr; int needs_ack; - int hh_len; + unsigned int addr_type; /* IP header checks: fragment. */ if (oldskb->nh.iph->frag_off & htons(IP_OFFSET)) @@ -126,23 +66,13 @@ static void send_reset(struct sk_buff *oldskb, int hook) if (nf_ip_checksum(oldskb, hook, iph->ihl * 4, IPPROTO_TCP)) return; - if ((rt = route_reverse(oldskb, oth, hook)) == NULL) - return; - - hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); - /* We need a linear, writeable skb. We also need to expand headroom in case hh_len of incoming interface < hh_len of outgoing interface */ - nskb = skb_copy_expand(oldskb, hh_len, skb_tailroom(oldskb), + nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb), GFP_ATOMIC); - if (!nskb) { - dst_release(&rt->u.dst); + if (!nskb) return; - } - - dst_release(nskb->dst); - nskb->dst = &rt->u.dst; /* This packet will not be the same as the other: clear nf fields */ nf_reset(nskb); @@ -184,6 +114,21 @@ static void send_reset(struct sk_buff *oldskb, int hook) tcph->window = 0; tcph->urg_ptr = 0; + /* Set DF, id = 0 */ + nskb->nh.iph->frag_off = htons(IP_DF); + nskb->nh.iph->id = 0; + + addr_type = RTN_UNSPEC; + if (hook != NF_IP_FORWARD +#ifdef CONFIG_BRIDGE_NETFILTER + || (nskb->nf_bridge && nskb->nf_bridge->mask & BRNF_BRIDGED) +#endif + ) + addr_type = RTN_LOCAL; + + if (ip_route_me_harder(&nskb, addr_type)) + goto free_nskb; + /* Adjust TCP checksum */ nskb->ip_summed = CHECKSUM_NONE; tcph->check = 0; @@ -192,12 +137,8 @@ static void send_reset(struct sk_buff *oldskb, int hook) nskb->nh.iph->daddr, csum_partial((char *)tcph, sizeof(struct tcphdr), 0)); - - /* Adjust IP TTL, DF */ + /* Adjust IP TTL */ nskb->nh.iph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT); - /* Set DF, id = 0 */ - nskb->nh.iph->frag_off = htons(IP_DF); - nskb->nh.iph->id = 0; /* Adjust IP checksum */ nskb->nh.iph->check = 0; -- 2.39.5