diff options
Diffstat (limited to 'net/ipv4/netfilter/ipt_REJECT.c')
| -rw-r--r-- | net/ipv4/netfilter/ipt_REJECT.c | 45 |
1 files changed, 21 insertions, 24 deletions
diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c index 80f739e2182..9041e0741f6 100644 --- a/net/ipv4/netfilter/ipt_REJECT.c +++ b/net/ipv4/netfilter/ipt_REJECT.c @@ -1,7 +1,5 @@ /* * This is a module which is used for rejecting packets. - * Added support for customized reject packets (Jozsef Kadlecsik). - * Added support for ICMP type-3-code-13 (Maciej Soltysiak). [RFC 1812] */ /* (C) 1999-2001 Paul `Rusty' Russell @@ -43,7 +41,7 @@ MODULE_DESCRIPTION("iptables REJECT target module"); static void send_reset(struct sk_buff *oldskb, int hook) { struct sk_buff *nskb; - struct iphdr *iph = oldskb->nh.iph; + struct iphdr *niph; struct tcphdr _otcph, *oth, *tcph; __be16 tmp_port; __be32 tmp_addr; @@ -51,10 +49,10 @@ static void send_reset(struct sk_buff *oldskb, int hook) unsigned int addr_type; /* IP header checks: fragment. */ - if (oldskb->nh.iph->frag_off & htons(IP_OFFSET)) + if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET)) return; - oth = skb_header_pointer(oldskb, oldskb->nh.iph->ihl * 4, + oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb), sizeof(_otcph), &_otcph); if (oth == NULL) return; @@ -64,7 +62,7 @@ static void send_reset(struct sk_buff *oldskb, int hook) return; /* Check checksum */ - if (nf_ip_checksum(oldskb, hook, iph->ihl * 4, IPPROTO_TCP)) + if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP)) return; /* We need a linear, writeable skb. We also need to expand @@ -84,20 +82,21 @@ static void send_reset(struct sk_buff *oldskb, int hook) skb_shinfo(nskb)->gso_segs = 0; skb_shinfo(nskb)->gso_type = 0; - tcph = (struct tcphdr *)((u_int32_t*)nskb->nh.iph + nskb->nh.iph->ihl); + tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb)); /* Swap source and dest */ - tmp_addr = nskb->nh.iph->saddr; - nskb->nh.iph->saddr = nskb->nh.iph->daddr; - nskb->nh.iph->daddr = tmp_addr; + niph = ip_hdr(nskb); + tmp_addr = niph->saddr; + niph->saddr = niph->daddr; + niph->daddr = tmp_addr; tmp_port = tcph->source; tcph->source = tcph->dest; tcph->dest = tmp_port; /* Truncate to length (no data) */ tcph->doff = sizeof(struct tcphdr)/4; - skb_trim(nskb, nskb->nh.iph->ihl*4 + sizeof(struct tcphdr)); - nskb->nh.iph->tot_len = htons(nskb->len); + skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr)); + niph->tot_len = htons(nskb->len); if (tcph->ack) { needs_ack = 0; @@ -105,9 +104,9 @@ static void send_reset(struct sk_buff *oldskb, int hook) tcph->ack_seq = 0; } else { needs_ack = 1; - tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin - + oldskb->len - oldskb->nh.iph->ihl*4 - - (oth->doff<<2)); + tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin + + oldskb->len - ip_hdrlen(oldskb) - + (oth->doff << 2)); tcph->seq = 0; } @@ -122,14 +121,13 @@ static void send_reset(struct sk_buff *oldskb, int hook) /* Adjust TCP checksum */ tcph->check = 0; tcph->check = tcp_v4_check(sizeof(struct tcphdr), - nskb->nh.iph->saddr, - nskb->nh.iph->daddr, + niph->saddr, niph->daddr, csum_partial((char *)tcph, sizeof(struct tcphdr), 0)); /* Set DF, id = 0 */ - nskb->nh.iph->frag_off = htons(IP_DF); - nskb->nh.iph->id = 0; + niph->frag_off = htons(IP_DF); + niph->id = 0; addr_type = RTN_UNSPEC; if (hook != NF_IP_FORWARD @@ -145,12 +143,11 @@ static void send_reset(struct sk_buff *oldskb, int hook) nskb->ip_summed = CHECKSUM_NONE; /* Adjust IP TTL */ - nskb->nh.iph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT); + niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT); /* Adjust IP checksum */ - nskb->nh.iph->check = 0; - nskb->nh.iph->check = ip_fast_csum((unsigned char *)nskb->nh.iph, - nskb->nh.iph->ihl); + niph->check = 0; + niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl); /* "Never happens" */ if (nskb->len > dst_mtu(nskb->dst)) @@ -182,7 +179,7 @@ static unsigned int reject(struct sk_buff **pskb, /* Our naive response construction doesn't deal with IP options, and probably shouldn't try. */ - if ((*pskb)->nh.iph->ihl<<2 != sizeof(struct iphdr)) + if (ip_hdrlen(*pskb) != sizeof(struct iphdr)) return NF_DROP; /* WARNING: This code causes reentry within iptables. |