projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 2cc7d573 | 1 | /* IPv4 specific functions of netfilter core */ |
| 020b4c12 | 2 | |
| 2cc7d573 | 3 | #include <linux/config.h> |
| 020b4c12 HW |
4 | #ifdef CONFIG_NETFILTER |
| 5 | ||
| 020b4c12 HW |
6 | #include <linux/kernel.h> |
| 7 | #include <linux/netfilter.h> | |
| 2cc7d573 | 8 | #include <linux/netfilter_ipv4.h> |
| 020b4c12 HW |
9 | |
| 10 | #include <linux/tcp.h> | |
| 11 | #include <linux/udp.h> | |
| 12 | #include <linux/icmp.h> | |
| 13 | #include <net/route.h> | |
| 14 | #include <linux/ip.h> | |
| 15 | ||
| 16 | /* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */ | |
| 17 | int ip_route_me_harder(struct sk_buff **pskb) | |
| 18 | { | |
| 19 | struct iphdr *iph = (*pskb)->nh.iph; | |
| 20 | struct rtable *rt; | |
| 21 | struct flowi fl = {}; | |
| 22 | struct dst_entry *odst; | |
| 23 | unsigned int hh_len; | |
| 24 | ||
| 25 | /* some non-standard hacks like ipt_REJECT.c:send_reset() can cause | |
| 26 | * packets with foreign saddr to appear on the NF_IP_LOCAL_OUT hook. | |
| 27 | */ | |
| 28 | if (inet_addr_type(iph->saddr) == RTN_LOCAL) { | |
| 29 | fl.nl_u.ip4_u.daddr = iph->daddr; | |
| 30 | fl.nl_u.ip4_u.saddr = iph->saddr; | |
| 31 | fl.nl_u.ip4_u.tos = RT_TOS(iph->tos); | |
| 32 | fl.oif = (*pskb)->sk ? (*pskb)->sk->sk_bound_dev_if : 0; | |
| 33 | #ifdef CONFIG_IP_ROUTE_FWMARK | |
| 34 | fl.nl_u.ip4_u.fwmark = (*pskb)->nfmark; | |
| 35 | #endif | |
| 36 | fl.proto = iph->protocol; | |
| 37 | if (ip_route_output_key(&rt, &fl) != 0) | |
| 38 | return -1; | |
| 39 | ||
| 40 | /* Drop old route. */ | |
| 41 | dst_release((*pskb)->dst); | |
| 42 | (*pskb)->dst = &rt->u.dst; | |
| 43 | } else { | |
| 44 | /* non-local src, find valid iif to satisfy | |
| 45 | * rp-filter when calling ip_route_input. */ | |
| 46 | fl.nl_u.ip4_u.daddr = iph->saddr; | |
| 47 | if (ip_route_output_key(&rt, &fl) != 0) | |
| 48 | return -1; | |
| 49 | ||
| 50 | odst = (*pskb)->dst; | |
| 51 | if (ip_route_input(*pskb, iph->daddr, iph->saddr, | |
| 52 | RT_TOS(iph->tos), rt->u.dst.dev) != 0) { | |
| 53 | dst_release(&rt->u.dst); | |
| 54 | return -1; | |
| 55 | } | |
| 56 | dst_release(&rt->u.dst); | |
| 57 | dst_release(odst); | |
| 58 | } | |
| 59 | ||
| 60 | if ((*pskb)->dst->error) | |
| 61 | return -1; | |
| 62 | ||
| 63 | /* Change in oif may mean change in hh_len. */ | |
| 64 | hh_len = (*pskb)->dst->dev->hard_header_len; | |
| 65 | if (skb_headroom(*pskb) < hh_len) { | |
| 66 | struct sk_buff *nskb; | |
| 67 | ||
| 68 | nskb = skb_realloc_headroom(*pskb, hh_len); | |
| 69 | if (!nskb) | |
| 70 | return -1; | |
| 71 | if ((*pskb)->sk) | |
| 72 | skb_set_owner_w(nskb, (*pskb)->sk); | |
| 73 | kfree_skb(*pskb); | |
| 74 | *pskb = nskb; | |
| 75 | } | |
| 76 | ||
| 77 | return 0; | |
| 78 | } | |
| 79 | EXPORT_SYMBOL(ip_route_me_harder); | |
| 2cc7d573 HW |
80 | |
| 81 | /* | |
| 82 | * Extra routing may needed on local out, as the QUEUE target never | |
| 83 | * returns control to the table. | |
| 84 | */ | |
| 85 | ||
| 86 | struct ip_rt_info { | |
| 87 | u_int32_t daddr; | |
| 88 | u_int32_t saddr; | |
| 89 | u_int8_t tos; | |
| 90 | }; | |
| 91 | ||
| 92 | static void queue_save(const struct sk_buff *skb, struct nf_info *info) | |
| 93 | { | |
| 94 | struct ip_rt_info *rt_info = nf_info_reroute(info); | |
| 95 | ||
| 96 | if (info->hook == NF_IP_LOCAL_OUT) { | |
| 97 | const struct iphdr *iph = skb->nh.iph; | |
| 98 | ||
| 99 | rt_info->tos = iph->tos; | |
| 100 | rt_info->daddr = iph->daddr; | |
| 101 | rt_info->saddr = iph->saddr; | |
| 102 | } | |
| 103 | } | |
| 104 | ||
| 105 | static int queue_reroute(struct sk_buff **pskb, const struct nf_info *info) | |
| 106 | { | |
| 107 | const struct ip_rt_info *rt_info = nf_info_reroute(info); | |
| 108 | ||
| 109 | if (info->hook == NF_IP_LOCAL_OUT) { | |
| 110 | struct iphdr *iph = (*pskb)->nh.iph; | |
| 111 | ||
| 112 | if (!(iph->tos == rt_info->tos | |
| 113 | && iph->daddr == rt_info->daddr | |
| 114 | && iph->saddr == rt_info->saddr)) | |
| 115 | return ip_route_me_harder(pskb); | |
| 116 | } | |
| 117 | return 0; | |
| 118 | } | |
| 119 | ||
| 120 | static struct nf_queue_rerouter ip_reroute = { | |
| 121 | .rer_size = sizeof(struct ip_rt_info), | |
| 122 | .save = queue_save, | |
| 123 | .reroute = queue_reroute, | |
| 124 | }; | |
| 125 | ||
| 126 | static int init(void) | |
| 127 | { | |
| 128 | return nf_register_queue_rerouter(PF_INET, &ip_reroute); | |
| 129 | } | |
| 130 | ||
| 131 | static void fini(void) | |
| 132 | { | |
| 133 | nf_unregister_queue_rerouter(PF_INET); | |
| 134 | } | |
| 135 | ||
| 136 | module_init(init); | |
| 137 | module_exit(fini); | |
| 138 | ||
| 020b4c12 | 139 | #endif /* CONFIG_NETFILTER */ |