Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 3 | * operating system. INET is implemented using the BSD Socket |
| 4 | * interface as the means of communication with the user level. |
| 5 | * |
| 6 | * The Internet Protocol (IP) module. |
| 7 | * |
Jesper Juhl | 02c30a8 | 2005-05-05 16:16:16 -0700 | [diff] [blame] | 8 | * Authors: Ross Biro |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| 10 | * Donald Becker, <becker@super.org> |
Alan Cox | 113aa83 | 2008-10-13 19:01:08 -0700 | [diff] [blame] | 11 | * Alan Cox, <alan@lxorguk.ukuu.org.uk> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * Richard Underwood |
| 13 | * Stefan Becker, <stefanb@yello.ping.de> |
| 14 | * Jorge Cwik, <jorge@laser.satlink.net> |
| 15 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 16 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | * |
| 18 | * Fixes: |
| 19 | * Alan Cox : Commented a couple of minor bits of surplus code |
| 20 | * Alan Cox : Undefining IP_FORWARD doesn't include the code |
| 21 | * (just stops a compiler warning). |
| 22 | * Alan Cox : Frames with >=MAX_ROUTE record routes, strict routes or loose routes |
| 23 | * are junked rather than corrupting things. |
| 24 | * Alan Cox : Frames to bad broadcast subnets are dumped |
| 25 | * We used to process them non broadcast and |
| 26 | * boy could that cause havoc. |
| 27 | * Alan Cox : ip_forward sets the free flag on the |
| 28 | * new frame it queues. Still crap because |
| 29 | * it copies the frame but at least it |
| 30 | * doesn't eat memory too. |
| 31 | * Alan Cox : Generic queue code and memory fixes. |
| 32 | * Fred Van Kempen : IP fragment support (borrowed from NET2E) |
| 33 | * Gerhard Koerting: Forward fragmented frames correctly. |
| 34 | * Gerhard Koerting: Fixes to my fix of the above 8-). |
| 35 | * Gerhard Koerting: IP interface addressing fix. |
| 36 | * Linus Torvalds : More robustness checks |
| 37 | * Alan Cox : Even more checks: Still not as robust as it ought to be |
| 38 | * Alan Cox : Save IP header pointer for later |
| 39 | * Alan Cox : ip option setting |
| 40 | * Alan Cox : Use ip_tos/ip_ttl settings |
| 41 | * Alan Cox : Fragmentation bogosity removed |
| 42 | * (Thanks to Mark.Bush@prg.ox.ac.uk) |
| 43 | * Dmitry Gorodchanin : Send of a raw packet crash fix. |
| 44 | * Alan Cox : Silly ip bug when an overlength |
| 45 | * fragment turns up. Now frees the |
| 46 | * queue. |
| 47 | * Linus Torvalds/ : Memory leakage on fragmentation |
| 48 | * Alan Cox : handling. |
| 49 | * Gerhard Koerting: Forwarding uses IP priority hints |
| 50 | * Teemu Rantanen : Fragment problems. |
| 51 | * Alan Cox : General cleanup, comments and reformat |
| 52 | * Alan Cox : SNMP statistics |
| 53 | * Alan Cox : BSD address rule semantics. Also see |
| 54 | * UDP as there is a nasty checksum issue |
| 55 | * if you do things the wrong way. |
| 56 | * Alan Cox : Always defrag, moved IP_FORWARD to the config.in file |
| 57 | * Alan Cox : IP options adjust sk->priority. |
| 58 | * Pedro Roque : Fix mtu/length error in ip_forward. |
| 59 | * Alan Cox : Avoid ip_chk_addr when possible. |
| 60 | * Richard Underwood : IP multicasting. |
| 61 | * Alan Cox : Cleaned up multicast handlers. |
| 62 | * Alan Cox : RAW sockets demultiplex in the BSD style. |
| 63 | * Gunther Mayer : Fix the SNMP reporting typo |
| 64 | * Alan Cox : Always in group 224.0.0.1 |
| 65 | * Pauline Middelink : Fast ip_checksum update when forwarding |
| 66 | * Masquerading support. |
| 67 | * Alan Cox : Multicast loopback error for 224.0.0.1 |
| 68 | * Alan Cox : IP_MULTICAST_LOOP option. |
| 69 | * Alan Cox : Use notifiers. |
| 70 | * Bjorn Ekwall : Removed ip_csum (from slhc.c too) |
| 71 | * Bjorn Ekwall : Moved ip_fast_csum to ip.h (inline!) |
| 72 | * Stefan Becker : Send out ICMP HOST REDIRECT |
| 73 | * Arnt Gulbrandsen : ip_build_xmit |
| 74 | * Alan Cox : Per socket routing cache |
| 75 | * Alan Cox : Fixed routing cache, added header cache. |
| 76 | * Alan Cox : Loopback didn't work right in original ip_build_xmit - fixed it. |
| 77 | * Alan Cox : Only send ICMP_REDIRECT if src/dest are the same net. |
| 78 | * Alan Cox : Incoming IP option handling. |
| 79 | * Alan Cox : Set saddr on raw output frames as per BSD. |
| 80 | * Alan Cox : Stopped broadcast source route explosions. |
| 81 | * Alan Cox : Can disable source routing |
| 82 | * Takeshi Sone : Masquerading didn't work. |
| 83 | * Dave Bonn,Alan Cox : Faster IP forwarding whenever possible. |
| 84 | * Alan Cox : Memory leaks, tramples, misc debugging. |
| 85 | * Alan Cox : Fixed multicast (by popular demand 8)) |
| 86 | * Alan Cox : Fixed forwarding (by even more popular demand 8)) |
| 87 | * Alan Cox : Fixed SNMP statistics [I think] |
| 88 | * Gerhard Koerting : IP fragmentation forwarding fix |
| 89 | * Alan Cox : Device lock against page fault. |
| 90 | * Alan Cox : IP_HDRINCL facility. |
| 91 | * Werner Almesberger : Zero fragment bug |
| 92 | * Alan Cox : RAW IP frame length bug |
| 93 | * Alan Cox : Outgoing firewall on build_xmit |
| 94 | * A.N.Kuznetsov : IP_OPTIONS support throughout the kernel |
| 95 | * Alan Cox : Multicast routing hooks |
| 96 | * Jos Vos : Do accounting *before* call_in_firewall |
| 97 | * Willy Konynenberg : Transparent proxying support |
| 98 | * |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 99 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | * |
| 101 | * To Fix: |
| 102 | * IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient |
| 103 | * and could be made very efficient with the addition of some virtual memory hacks to permit |
| 104 | * the allocation of a buffer that can then be 'grown' by twiddling page tables. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 105 | * Output fragmentation wants updating along with the buffer management to use a single |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | * interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet |
| 107 | * output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause |
| 108 | * fragmentation anyway. |
| 109 | * |
| 110 | * This program is free software; you can redistribute it and/or |
| 111 | * modify it under the terms of the GNU General Public License |
| 112 | * as published by the Free Software Foundation; either version |
| 113 | * 2 of the License, or (at your option) any later version. |
| 114 | */ |
| 115 | |
| 116 | #include <asm/system.h> |
| 117 | #include <linux/module.h> |
| 118 | #include <linux/types.h> |
| 119 | #include <linux/kernel.h> |
| 120 | #include <linux/string.h> |
| 121 | #include <linux/errno.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
| 123 | #include <linux/net.h> |
| 124 | #include <linux/socket.h> |
| 125 | #include <linux/sockios.h> |
| 126 | #include <linux/in.h> |
| 127 | #include <linux/inet.h> |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 128 | #include <linux/inetdevice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | #include <linux/netdevice.h> |
| 130 | #include <linux/etherdevice.h> |
| 131 | |
| 132 | #include <net/snmp.h> |
| 133 | #include <net/ip.h> |
| 134 | #include <net/protocol.h> |
| 135 | #include <net/route.h> |
| 136 | #include <linux/skbuff.h> |
| 137 | #include <net/sock.h> |
| 138 | #include <net/arp.h> |
| 139 | #include <net/icmp.h> |
| 140 | #include <net/raw.h> |
| 141 | #include <net/checksum.h> |
| 142 | #include <linux/netfilter_ipv4.h> |
| 143 | #include <net/xfrm.h> |
| 144 | #include <linux/mroute.h> |
| 145 | #include <linux/netlink.h> |
| 146 | |
| 147 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | * Process Router Attention IP option |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 149 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | int ip_call_ra_chain(struct sk_buff *skb) |
| 151 | { |
| 152 | struct ip_ra_chain *ra; |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 153 | u8 protocol = ip_hdr(skb)->protocol; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | struct sock *last = NULL; |
Denis V. Lunev | cb84663 | 2008-03-24 15:31:00 -0700 | [diff] [blame] | 155 | struct net_device *dev = skb->dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | |
| 157 | read_lock(&ip_ra_lock); |
| 158 | for (ra = ip_ra_chain; ra; ra = ra->next) { |
| 159 | struct sock *sk = ra->sk; |
| 160 | |
| 161 | /* If socket is bound to an interface, only report |
| 162 | * the packet if it came from that interface. |
| 163 | */ |
| 164 | if (sk && inet_sk(sk)->num == protocol && |
| 165 | (!sk->sk_bound_dev_if || |
Denis V. Lunev | cb84663 | 2008-03-24 15:31:00 -0700 | [diff] [blame] | 166 | sk->sk_bound_dev_if == dev->ifindex) && |
YOSHIFUJI Hideaki | 3b1e0a6 | 2008-03-26 02:26:21 +0900 | [diff] [blame] | 167 | sock_net(sk) == dev_net(dev)) { |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 168 | if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { |
Herbert Xu | 776c729 | 2007-10-14 00:38:32 -0700 | [diff] [blame] | 169 | if (ip_defrag(skb, IP_DEFRAG_CALL_RA_CHAIN)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | read_unlock(&ip_ra_lock); |
| 171 | return 1; |
| 172 | } |
| 173 | } |
| 174 | if (last) { |
| 175 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); |
| 176 | if (skb2) |
| 177 | raw_rcv(last, skb2); |
| 178 | } |
| 179 | last = sk; |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | if (last) { |
| 184 | raw_rcv(last, skb); |
| 185 | read_unlock(&ip_ra_lock); |
| 186 | return 1; |
| 187 | } |
| 188 | read_unlock(&ip_ra_lock); |
| 189 | return 0; |
| 190 | } |
| 191 | |
Patrick McHardy | 861d048 | 2007-10-15 01:48:39 -0700 | [diff] [blame] | 192 | static int ip_local_deliver_finish(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | { |
YOSHIFUJI Hideaki | c346dca | 2008-03-25 21:47:49 +0900 | [diff] [blame] | 194 | struct net *net = dev_net(skb->dev); |
Denis V. Lunev | f145049 | 2008-03-24 15:33:00 -0700 | [diff] [blame] | 195 | |
Arnaldo Carvalho de Melo | c9bdd4b | 2007-03-12 20:09:15 -0300 | [diff] [blame] | 196 | __skb_pull(skb, ip_hdrlen(skb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 198 | /* Point into the IP datagram, just past the header. */ |
Arnaldo Carvalho de Melo | badff6d | 2007-03-13 13:06:52 -0300 | [diff] [blame] | 199 | skb_reset_transport_header(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | |
| 201 | rcu_read_lock(); |
| 202 | { |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 203 | int protocol = ip_hdr(skb)->protocol; |
Pavel Emelyanov | 7bc54c9 | 2007-11-19 22:35:07 -0800 | [diff] [blame] | 204 | int hash, raw; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | struct net_protocol *ipprot; |
| 206 | |
| 207 | resubmit: |
Pavel Emelyanov | 7bc54c9 | 2007-11-19 22:35:07 -0800 | [diff] [blame] | 208 | raw = raw_local_deliver(skb, protocol); |
| 209 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | hash = protocol & (MAX_INET_PROTOS - 1); |
Denis V. Lunev | f145049 | 2008-03-24 15:33:00 -0700 | [diff] [blame] | 211 | ipprot = rcu_dereference(inet_protos[hash]); |
| 212 | if (ipprot != NULL && (net == &init_net || ipprot->netns_ok)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | int ret; |
| 214 | |
Patrick McHardy | b59c270 | 2006-01-06 23:06:10 -0800 | [diff] [blame] | 215 | if (!ipprot->no_policy) { |
| 216 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| 217 | kfree_skb(skb); |
| 218 | goto out; |
| 219 | } |
| 220 | nf_reset(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | } |
| 222 | ret = ipprot->handler(skb); |
| 223 | if (ret < 0) { |
| 224 | protocol = -ret; |
| 225 | goto resubmit; |
| 226 | } |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 227 | IP_INC_STATS_BH(net, IPSTATS_MIB_INDELIVERS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | } else { |
Pavel Emelyanov | 7bc54c9 | 2007-11-19 22:35:07 -0800 | [diff] [blame] | 229 | if (!raw) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | if (xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 231 | IP_INC_STATS_BH(net, IPSTATS_MIB_INUNKNOWNPROTOS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | icmp_send(skb, ICMP_DEST_UNREACH, |
| 233 | ICMP_PROT_UNREACH, 0); |
| 234 | } |
| 235 | } else |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 236 | IP_INC_STATS_BH(net, IPSTATS_MIB_INDELIVERS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | kfree_skb(skb); |
| 238 | } |
| 239 | } |
| 240 | out: |
| 241 | rcu_read_unlock(); |
| 242 | |
| 243 | return 0; |
| 244 | } |
| 245 | |
| 246 | /* |
| 247 | * Deliver IP Packets to the higher protocol layers. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 248 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | int ip_local_deliver(struct sk_buff *skb) |
| 250 | { |
| 251 | /* |
| 252 | * Reassemble IP fragments. |
| 253 | */ |
| 254 | |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 255 | if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { |
Herbert Xu | 776c729 | 2007-10-14 00:38:32 -0700 | [diff] [blame] | 256 | if (ip_defrag(skb, IP_DEFRAG_LOCAL_DELIVER)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | return 0; |
| 258 | } |
| 259 | |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 260 | return NF_HOOK(PF_INET, NF_INET_LOCAL_IN, skb, skb->dev, NULL, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | ip_local_deliver_finish); |
| 262 | } |
| 263 | |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 264 | static inline int ip_rcv_options(struct sk_buff *skb) |
| 265 | { |
| 266 | struct ip_options *opt; |
| 267 | struct iphdr *iph; |
| 268 | struct net_device *dev = skb->dev; |
| 269 | |
| 270 | /* It looks as overkill, because not all |
| 271 | IP options require packet mangling. |
| 272 | But it is the easiest for now, especially taking |
| 273 | into account that combination of IP options |
| 274 | and running sniffer is extremely rare condition. |
| 275 | --ANK (980813) |
| 276 | */ |
| 277 | if (skb_cow(skb, skb_headroom(skb))) { |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 278 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS); |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 279 | goto drop; |
| 280 | } |
| 281 | |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 282 | iph = ip_hdr(skb); |
Denis V. Lunev | 22aba38 | 2008-03-22 16:36:20 -0700 | [diff] [blame] | 283 | opt = &(IPCB(skb)->opt); |
| 284 | opt->optlen = iph->ihl*4 - sizeof(struct iphdr); |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 285 | |
YOSHIFUJI Hideaki | c346dca | 2008-03-25 21:47:49 +0900 | [diff] [blame] | 286 | if (ip_options_compile(dev_net(dev), opt, skb)) { |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 287 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS); |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 288 | goto drop; |
| 289 | } |
| 290 | |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 291 | if (unlikely(opt->srr)) { |
| 292 | struct in_device *in_dev = in_dev_get(dev); |
| 293 | if (in_dev) { |
| 294 | if (!IN_DEV_SOURCE_ROUTE(in_dev)) { |
| 295 | if (IN_DEV_LOG_MARTIANS(in_dev) && |
| 296 | net_ratelimit()) |
Harvey Harrison | 673d57e | 2008-10-31 00:53:57 -0700 | [diff] [blame] | 297 | printk(KERN_INFO "source route option %pI4 -> %pI4\n", |
| 298 | &iph->saddr, &iph->daddr); |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 299 | in_dev_put(in_dev); |
| 300 | goto drop; |
| 301 | } |
| 302 | |
| 303 | in_dev_put(in_dev); |
| 304 | } |
| 305 | |
| 306 | if (ip_options_rcv_srr(skb)) |
| 307 | goto drop; |
| 308 | } |
| 309 | |
| 310 | return 0; |
| 311 | drop: |
| 312 | return -1; |
| 313 | } |
| 314 | |
Patrick McHardy | 861d048 | 2007-10-15 01:48:39 -0700 | [diff] [blame] | 315 | static int ip_rcv_finish(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | { |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 317 | const struct iphdr *iph = ip_hdr(skb); |
Mitsuru Chinen | 5506b54 | 2007-04-30 00:48:10 -0700 | [diff] [blame] | 318 | struct rtable *rt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | |
| 320 | /* |
| 321 | * Initialise the virtual path cache for the packet. It describes |
| 322 | * how the packet travels inside Linux networking. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 323 | */ |
Hua Zhong | 0182bd2 | 2006-05-06 18:11:39 -0700 | [diff] [blame] | 324 | if (skb->dst == NULL) { |
Thomas Graf | 3e192be | 2005-08-20 17:26:30 -0700 | [diff] [blame] | 325 | int err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, |
| 326 | skb->dev); |
| 327 | if (unlikely(err)) { |
Dietmar Eggemann | 2c2910a | 2005-06-28 13:06:23 -0700 | [diff] [blame] | 328 | if (err == -EHOSTUNREACH) |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 329 | IP_INC_STATS_BH(dev_net(skb->dev), |
| 330 | IPSTATS_MIB_INADDRERRORS); |
Mitsuru Chinen | e91a47e | 2007-04-30 00:45:49 -0700 | [diff] [blame] | 331 | else if (err == -ENETUNREACH) |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 332 | IP_INC_STATS_BH(dev_net(skb->dev), |
| 333 | IPSTATS_MIB_INNOROUTES); |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 334 | goto drop; |
Dietmar Eggemann | 2c2910a | 2005-06-28 13:06:23 -0700 | [diff] [blame] | 335 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | } |
| 337 | |
| 338 | #ifdef CONFIG_NET_CLS_ROUTE |
Thomas Graf | 3e192be | 2005-08-20 17:26:30 -0700 | [diff] [blame] | 339 | if (unlikely(skb->dst->tclassid)) { |
Eric Dumazet | 8dbde28 | 2007-11-16 03:32:10 -0800 | [diff] [blame] | 340 | struct ip_rt_acct *st = per_cpu_ptr(ip_rt_acct, smp_processor_id()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | u32 idx = skb->dst->tclassid; |
| 342 | st[idx&0xFF].o_packets++; |
| 343 | st[idx&0xFF].o_bytes+=skb->len; |
| 344 | st[(idx>>16)&0xFF].i_packets++; |
| 345 | st[(idx>>16)&0xFF].i_bytes+=skb->len; |
| 346 | } |
| 347 | #endif |
| 348 | |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 349 | if (iph->ihl > 5 && ip_rcv_options(skb)) |
| 350 | goto drop; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | |
Eric Dumazet | ee6b967 | 2008-03-05 18:30:47 -0800 | [diff] [blame] | 352 | rt = skb->rtable; |
Mitsuru Chinen | 5506b54 | 2007-04-30 00:48:10 -0700 | [diff] [blame] | 353 | if (rt->rt_type == RTN_MULTICAST) |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 354 | IP_INC_STATS_BH(dev_net(rt->u.dst.dev), IPSTATS_MIB_INMCASTPKTS); |
Mitsuru Chinen | 5506b54 | 2007-04-30 00:48:10 -0700 | [diff] [blame] | 355 | else if (rt->rt_type == RTN_BROADCAST) |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 356 | IP_INC_STATS_BH(dev_net(rt->u.dst.dev), IPSTATS_MIB_INBCASTPKTS); |
Mitsuru Chinen | 5506b54 | 2007-04-30 00:48:10 -0700 | [diff] [blame] | 357 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | return dst_input(skb); |
| 359 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | drop: |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 361 | kfree_skb(skb); |
| 362 | return NET_RX_DROP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | } |
| 364 | |
| 365 | /* |
| 366 | * Main IP Receive routine. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 367 | */ |
David S. Miller | f2ccd8f | 2005-08-09 19:34:12 -0700 | [diff] [blame] | 368 | int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | { |
| 370 | struct iphdr *iph; |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 371 | u32 len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | |
| 373 | /* When the interface is in promisc. mode, drop all the crap |
| 374 | * that it receives, do not try to analyse it. |
| 375 | */ |
| 376 | if (skb->pkt_type == PACKET_OTHERHOST) |
| 377 | goto drop; |
| 378 | |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 379 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INRECEIVES); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | |
| 381 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) { |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 382 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | goto out; |
| 384 | } |
| 385 | |
| 386 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) |
| 387 | goto inhdr_error; |
| 388 | |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 389 | iph = ip_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | |
| 391 | /* |
J.H.M. Dassen (Ray) | c67fa02 | 2008-05-08 01:11:04 -0700 | [diff] [blame] | 392 | * RFC1122: 3.2.1.2 MUST silently discard any IP frame that fails the checksum. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | * |
| 394 | * Is the datagram acceptable? |
| 395 | * |
| 396 | * 1. Length at least the size of an ip header |
| 397 | * 2. Version of 4 |
| 398 | * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums] |
| 399 | * 4. Doesn't have a bogus length |
| 400 | */ |
| 401 | |
| 402 | if (iph->ihl < 5 || iph->version != 4) |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 403 | goto inhdr_error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | |
| 405 | if (!pskb_may_pull(skb, iph->ihl*4)) |
| 406 | goto inhdr_error; |
| 407 | |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 408 | iph = ip_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | |
Thomas Graf | e9c6042 | 2005-08-20 17:25:52 -0700 | [diff] [blame] | 410 | if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 411 | goto inhdr_error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 413 | len = ntohs(iph->tot_len); |
Mitsuru Chinen | 704aed5 | 2007-04-30 00:46:30 -0700 | [diff] [blame] | 414 | if (skb->len < len) { |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 415 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS); |
Mitsuru Chinen | 704aed5 | 2007-04-30 00:46:30 -0700 | [diff] [blame] | 416 | goto drop; |
| 417 | } else if (len < (iph->ihl*4)) |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 418 | goto inhdr_error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 420 | /* Our transport medium may have padded the buffer out. Now we know it |
| 421 | * is IP we can trim to the true length of the frame. |
| 422 | * Note this now means skb->len holds ntohs(iph->tot_len). |
| 423 | */ |
| 424 | if (pskb_trim_rcsum(skb, len)) { |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 425 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS); |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 426 | goto drop; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | } |
| 428 | |
Stephen Hemminger | 53602f9 | 2006-07-14 14:49:32 -0700 | [diff] [blame] | 429 | /* Remove any debris in the socket control block */ |
Guillaume Chazarain | d569f1d | 2006-07-24 23:45:16 -0700 | [diff] [blame] | 430 | memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); |
Stephen Hemminger | 53602f9 | 2006-07-14 14:49:32 -0700 | [diff] [blame] | 431 | |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 432 | return NF_HOOK(PF_INET, NF_INET_PRE_ROUTING, skb, dev, NULL, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | ip_rcv_finish); |
| 434 | |
| 435 | inhdr_error: |
Pavel Emelyanov | 7c73a6f | 2008-07-16 20:20:11 -0700 | [diff] [blame] | 436 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | drop: |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 438 | kfree_skb(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | out: |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 440 | return NET_RX_DROP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | } |