blob: d533a89e08de14d2e7417b41dddcb99d8e9c881b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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) output module.
7 *
Jesper Juhl02c30a82005-05-05 16:16:16 -07008 * Authors: Ross Biro
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Donald Becker, <becker@super.org>
11 * Alan Cox, <Alan.Cox@linux.org>
12 * Richard Underwood
13 * Stefan Becker, <stefanb@yello.ping.de>
14 * Jorge Cwik, <jorge@laser.satlink.net>
15 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
16 * Hirokazu Takahashi, <taka@valinux.co.jp>
17 *
18 * See ip_input.c for original log
19 *
20 * Fixes:
21 * Alan Cox : Missing nonblock feature in ip_build_xmit.
22 * Mike Kilburn : htons() missing in ip_build_xmit.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090023 * Bradford Johnson: Fix faulty handling of some frames when
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 * no route is found.
25 * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit
26 * (in case if packet not accepted by
27 * output firewall rules)
28 * Mike McLagan : Routing by source
29 * Alexey Kuznetsov: use new route cache
30 * Andi Kleen: Fix broken PMTU recovery and remove
31 * some redundant tests.
32 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
33 * Andi Kleen : Replace ip_reply with ip_send_reply.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090034 * Andi Kleen : Split fast and slow ip_build_xmit path
35 * for decreased register pressure on x86
36 * and more readibility.
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 * Marc Boucher : When call_out_firewall returns FW_QUEUE,
38 * silently drop skb instead of failing with -EPERM.
39 * Detlev Wengorz : Copy protocol for fragments.
40 * Hirokazu Takahashi: HW checksumming for outgoing UDP
41 * datagrams.
42 * Hirokazu Takahashi: sendfile() on UDP works now.
43 */
44
45#include <asm/uaccess.h>
46#include <asm/system.h>
47#include <linux/module.h>
48#include <linux/types.h>
49#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#include <linux/mm.h>
51#include <linux/string.h>
52#include <linux/errno.h>
Al Viroa1f8e7f72006-10-19 16:08:53 -040053#include <linux/highmem.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55#include <linux/socket.h>
56#include <linux/sockios.h>
57#include <linux/in.h>
58#include <linux/inet.h>
59#include <linux/netdevice.h>
60#include <linux/etherdevice.h>
61#include <linux/proc_fs.h>
62#include <linux/stat.h>
63#include <linux/init.h>
64
65#include <net/snmp.h>
66#include <net/ip.h>
67#include <net/protocol.h>
68#include <net/route.h>
Patrick McHardycfacb052006-01-08 22:36:54 -080069#include <net/xfrm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070070#include <linux/skbuff.h>
71#include <net/sock.h>
72#include <net/arp.h>
73#include <net/icmp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070074#include <net/checksum.h>
75#include <net/inetpeer.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070076#include <linux/igmp.h>
77#include <linux/netfilter_ipv4.h>
78#include <linux/netfilter_bridge.h>
79#include <linux/mroute.h>
80#include <linux/netlink.h>
Arnaldo Carvalho de Melo6cbb0df2005-08-09 19:49:02 -070081#include <linux/tcp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Brian Haleyab32ea52006-09-22 14:15:41 -070083int sysctl_ip_default_ttl __read_mostly = IPDEFTTL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85/* Generate a checksum for an outgoing IP datagram. */
86__inline__ void ip_send_check(struct iphdr *iph)
87{
88 iph->check = 0;
89 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
90}
91
Herbert Xuc439cb22008-01-11 19:14:00 -080092int __ip_local_out(struct sk_buff *skb)
93{
94 struct iphdr *iph = ip_hdr(skb);
95
96 iph->tot_len = htons(skb->len);
97 ip_send_check(iph);
Patrick McHardy6e23ae22007-11-19 18:53:30 -080098 return nf_hook(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, skb->dst->dev,
Herbert Xuc439cb22008-01-11 19:14:00 -080099 dst_output);
100}
101
102int ip_local_out(struct sk_buff *skb)
103{
104 int err;
105
106 err = __ip_local_out(skb);
107 if (likely(err == 1))
108 err = dst_output(skb);
109
110 return err;
111}
112EXPORT_SYMBOL_GPL(ip_local_out);
113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114/* dev_loopback_xmit for use with netfilter. */
115static int ip_dev_loopback_xmit(struct sk_buff *newskb)
116{
Arnaldo Carvalho de Melo459a98e2007-03-19 15:30:44 -0700117 skb_reset_mac_header(newskb);
Arnaldo Carvalho de Melobbe735e2007-03-10 22:16:10 -0300118 __skb_pull(newskb, skb_network_offset(newskb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 newskb->pkt_type = PACKET_LOOPBACK;
120 newskb->ip_summed = CHECKSUM_UNNECESSARY;
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700121 WARN_ON(!newskb->dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 netif_rx(newskb);
123 return 0;
124}
125
126static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
127{
128 int ttl = inet->uc_ttl;
129
130 if (ttl < 0)
131 ttl = dst_metric(dst, RTAX_HOPLIMIT);
132 return ttl;
133}
134
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900135/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 * Add an ip header to a skbuff and send it out.
137 *
138 */
139int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
Al Viro13d8eaa2006-09-26 22:27:30 -0700140 __be32 saddr, __be32 daddr, struct ip_options *opt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141{
142 struct inet_sock *inet = inet_sk(sk);
Eric Dumazetee6b9672008-03-05 18:30:47 -0800143 struct rtable *rt = skb->rtable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 struct iphdr *iph;
145
146 /* Build the IP header. */
Arnaldo Carvalho de Melo8856dfa2007-03-10 19:40:39 -0300147 skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
148 skb_reset_network_header(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700149 iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 iph->version = 4;
151 iph->ihl = 5;
152 iph->tos = inet->tos;
153 if (ip_dont_fragment(sk, &rt->u.dst))
154 iph->frag_off = htons(IP_DF);
155 else
156 iph->frag_off = 0;
157 iph->ttl = ip_select_ttl(inet, &rt->u.dst);
158 iph->daddr = rt->rt_dst;
159 iph->saddr = rt->rt_src;
160 iph->protocol = sk->sk_protocol;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 ip_select_ident(iph, &rt->u.dst, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163 if (opt && opt->optlen) {
164 iph->ihl += opt->optlen>>2;
165 ip_options_build(skb, opt, daddr, rt, 0);
166 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168 skb->priority = sk->sk_priority;
Laszlo Attila Toth4a19ec52008-01-30 19:08:16 -0800169 skb->mark = sk->sk_mark;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
171 /* Send it out. */
Herbert Xuc439cb22008-01-11 19:14:00 -0800172 return ip_local_out(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173}
174
Arnaldo Carvalho de Melod8c97a92005-08-09 20:12:12 -0700175EXPORT_SYMBOL_GPL(ip_build_and_send_pkt);
176
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177static inline int ip_finish_output2(struct sk_buff *skb)
178{
179 struct dst_entry *dst = skb->dst;
Mitsuru Chinen80787eb2007-04-30 00:48:20 -0700180 struct rtable *rt = (struct rtable *)dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 struct net_device *dev = dst->dev;
Chuck Leverc2636b42007-10-23 21:07:32 -0700182 unsigned int hh_len = LL_RESERVED_SPACE(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Mitsuru Chinen80787eb2007-04-30 00:48:20 -0700184 if (rt->rt_type == RTN_MULTICAST)
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700185 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTMCASTPKTS);
Mitsuru Chinen80787eb2007-04-30 00:48:20 -0700186 else if (rt->rt_type == RTN_BROADCAST)
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700187 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTBCASTPKTS);
Mitsuru Chinen80787eb2007-04-30 00:48:20 -0700188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 /* Be paranoid, rather than too clever. */
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700190 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 struct sk_buff *skb2;
192
193 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
194 if (skb2 == NULL) {
195 kfree_skb(skb);
196 return -ENOMEM;
197 }
198 if (skb->sk)
199 skb_set_owner_w(skb2, skb->sk);
200 kfree_skb(skb);
201 skb = skb2;
202 }
203
Stephen Hemminger3644f0c2006-12-07 15:08:17 -0800204 if (dst->hh)
205 return neigh_hh_output(dst->hh, skb);
206 else if (dst->neighbour)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 return dst->neighbour->output(skb);
208
209 if (net_ratelimit())
210 printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n");
211 kfree_skb(skb);
212 return -EINVAL;
213}
214
John Heffner628a5c52007-04-20 15:53:27 -0700215static inline int ip_skb_dst_mtu(struct sk_buff *skb)
216{
217 struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL;
218
219 return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ?
220 skb->dst->dev->mtu : dst_mtu(skb->dst);
221}
222
Patrick McHardy861d0482007-10-15 01:48:39 -0700223static int ip_finish_output(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
Patrick McHardy5c901da2006-01-06 23:05:36 -0800225#if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
226 /* Policy lookup after SNAT yielded a new policy */
Patrick McHardy48d5cad2006-02-15 15:10:22 -0800227 if (skb->dst->xfrm != NULL) {
228 IPCB(skb)->flags |= IPSKB_REROUTED;
229 return dst_output(skb);
230 }
Patrick McHardy5c901da2006-01-06 23:05:36 -0800231#endif
John Heffner628a5c52007-04-20 15:53:27 -0700232 if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb))
Patrick McHardy1bd9bef2006-01-05 12:20:59 -0800233 return ip_fragment(skb, ip_finish_output2);
234 else
235 return ip_finish_output2(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236}
237
238int ip_mc_output(struct sk_buff *skb)
239{
240 struct sock *sk = skb->sk;
Eric Dumazetee6b9672008-03-05 18:30:47 -0800241 struct rtable *rt = skb->rtable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 struct net_device *dev = rt->u.dst.dev;
243
244 /*
245 * If the indicated interface is up and running, send the packet.
246 */
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700247 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTREQUESTS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249 skb->dev = dev;
250 skb->protocol = htons(ETH_P_IP);
251
252 /*
253 * Multicasts are looped back for other local users
254 */
255
256 if (rt->rt_flags&RTCF_MULTICAST) {
257 if ((!sk || inet_sk(sk)->mc_loop)
258#ifdef CONFIG_IP_MROUTE
259 /* Small optimization: do not loopback not local frames,
260 which returned after forwarding; they will be dropped
261 by ip_mr_input in any case.
262 Note, that local frames are looped back to be delivered
263 to local recipients.
264
265 This check is duplicated in ip_mr_input at the moment.
266 */
267 && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED))
268#endif
269 ) {
270 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
271 if (newskb)
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800272 NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb,
273 NULL, newskb->dev,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 ip_dev_loopback_xmit);
275 }
276
277 /* Multicasts with ttl 0 must not go beyond the host */
278
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700279 if (ip_hdr(skb)->ttl == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 kfree_skb(skb);
281 return 0;
282 }
283 }
284
285 if (rt->rt_flags&RTCF_BROADCAST) {
286 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
287 if (newskb)
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800288 NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, NULL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 newskb->dev, ip_dev_loopback_xmit);
290 }
291
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800292 return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, skb->dev,
Patrick McHardy48d5cad2006-02-15 15:10:22 -0800293 ip_finish_output,
294 !(IPCB(skb)->flags & IPSKB_REROUTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295}
296
297int ip_output(struct sk_buff *skb)
298{
Patrick McHardy1bd9bef2006-01-05 12:20:59 -0800299 struct net_device *dev = skb->dst->dev;
300
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700301 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTREQUESTS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
Patrick McHardy1bd9bef2006-01-05 12:20:59 -0800303 skb->dev = dev;
304 skb->protocol = htons(ETH_P_IP);
305
Patrick McHardy6e23ae22007-11-19 18:53:30 -0800306 return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, dev,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900307 ip_finish_output,
Patrick McHardy48d5cad2006-02-15 15:10:22 -0800308 !(IPCB(skb)->flags & IPSKB_REROUTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309}
310
David S. Millere89862f2007-01-26 01:04:55 -0800311int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312{
David S. Millere89862f2007-01-26 01:04:55 -0800313 struct sock *sk = skb->sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 struct inet_sock *inet = inet_sk(sk);
315 struct ip_options *opt = inet->opt;
316 struct rtable *rt;
317 struct iphdr *iph;
318
319 /* Skip all of this if the packet is already routed,
320 * f.e. by something like SCTP.
321 */
Eric Dumazetee6b9672008-03-05 18:30:47 -0800322 rt = skb->rtable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 if (rt != NULL)
324 goto packet_routed;
325
326 /* Make sure we can route this packet. */
327 rt = (struct rtable *)__sk_dst_check(sk, 0);
328 if (rt == NULL) {
Al Viro3ca3c682006-09-27 18:28:07 -0700329 __be32 daddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330
331 /* Use correct destination address if we have options. */
332 daddr = inet->daddr;
333 if(opt && opt->srr)
334 daddr = opt->faddr;
335
336 {
337 struct flowi fl = { .oif = sk->sk_bound_dev_if,
338 .nl_u = { .ip4_u =
339 { .daddr = daddr,
340 .saddr = inet->saddr,
341 .tos = RT_CONN_FLAGS(sk) } },
342 .proto = sk->sk_protocol,
343 .uli_u = { .ports =
344 { .sport = inet->sport,
345 .dport = inet->dport } } };
346
347 /* If this fails, retransmit mechanism of transport layer will
348 * keep trying until route appears or the connection times
349 * itself out.
350 */
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700351 security_sk_classify_flow(sk, &fl);
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900352 if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 goto no_route;
354 }
Arnaldo Carvalho de Melo6cbb0df2005-08-09 19:49:02 -0700355 sk_setup_caps(sk, &rt->u.dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 }
357 skb->dst = dst_clone(&rt->u.dst);
358
359packet_routed:
360 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
361 goto no_route;
362
363 /* OK, we know where to send it, allocate and build IP header. */
Arnaldo Carvalho de Melo8856dfa2007-03-10 19:40:39 -0300364 skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
365 skb_reset_network_header(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700366 iph = ip_hdr(skb);
Al Viro714e85b2006-11-14 20:51:49 -0800367 *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok)
369 iph->frag_off = htons(IP_DF);
370 else
371 iph->frag_off = 0;
372 iph->ttl = ip_select_ttl(inet, &rt->u.dst);
373 iph->protocol = sk->sk_protocol;
374 iph->saddr = rt->rt_src;
375 iph->daddr = rt->rt_dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 /* Transport layer set skb->h.foo itself. */
377
378 if (opt && opt->optlen) {
379 iph->ihl += opt->optlen >> 2;
380 ip_options_build(skb, opt, inet->daddr, rt, 0);
381 }
382
Herbert Xu89f5f0a2005-11-08 09:41:56 -0800383 ip_select_ident_more(iph, &rt->u.dst, sk,
Herbert Xu79671682006-06-22 02:40:14 -0700384 (skb_shinfo(skb)->gso_segs ?: 1) - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 skb->priority = sk->sk_priority;
Laszlo Attila Toth4a19ec52008-01-30 19:08:16 -0800387 skb->mark = sk->sk_mark;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
Herbert Xuc439cb22008-01-11 19:14:00 -0800389 return ip_local_out(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390
391no_route:
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700392 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 kfree_skb(skb);
394 return -EHOSTUNREACH;
395}
396
397
398static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
399{
400 to->pkt_type = from->pkt_type;
401 to->priority = from->priority;
402 to->protocol = from->protocol;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 dst_release(to->dst);
404 to->dst = dst_clone(from->dst);
405 to->dev = from->dev;
Thomas Graf82e91ff2006-11-09 15:19:14 -0800406 to->mark = from->mark;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
408 /* Copy the flags to each fragment. */
409 IPCB(to)->flags = IPCB(from)->flags;
410
411#ifdef CONFIG_NET_SCHED
412 to->tc_index = from->tc_index;
413#endif
Yasuyuki Kozakaie7ac05f2007-03-14 16:44:01 -0700414 nf_copy(to, from);
Jozsef Kadlecsikba9dda32007-07-07 22:21:23 -0700415#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
416 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
417 to->nf_trace = from->nf_trace;
418#endif
Julian Anastasovc98d80e2005-10-22 13:39:21 +0300419#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
420 to->ipvs_property = from->ipvs_property;
421#endif
James Morris984bc162006-06-09 00:29:17 -0700422 skb_copy_secmark(to, from);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423}
424
425/*
426 * This IP datagram is too large to be sent in one piece. Break it up into
427 * smaller pieces (each of size equal to IP header plus
428 * a block of the data of the original IP data part) that will yet fit in a
429 * single device frame, and queue such a frame for sending.
430 */
431
Patrick McHardy2e2f7ae2006-04-04 13:42:35 -0700432int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433{
434 struct iphdr *iph;
435 int raw = 0;
436 int ptr;
437 struct net_device *dev;
438 struct sk_buff *skb2;
Stephen Hemminger9bcfcaf2006-08-29 17:48:57 -0700439 unsigned int mtu, hlen, left, len, ll_rs, pad;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 int offset;
Alexey Dobriyan76ab6082006-01-06 13:24:29 -0800441 __be16 not_last_frag;
Eric Dumazetee6b9672008-03-05 18:30:47 -0800442 struct rtable *rt = skb->rtable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 int err = 0;
444
445 dev = rt->u.dst.dev;
446
447 /*
448 * Point into the IP datagram header.
449 */
450
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700451 iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
453 if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) {
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700454 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
John Heffner628a5c52007-04-20 15:53:27 -0700456 htonl(ip_skb_dst_mtu(skb)));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 kfree_skb(skb);
458 return -EMSGSIZE;
459 }
460
461 /*
462 * Setup starting values.
463 */
464
465 hlen = iph->ihl * 4;
466 mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */
Herbert Xu89cee8b2005-12-13 23:14:27 -0800467 IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468
469 /* When frag_list is given, use it. First, check its validity:
470 * some transformers could create wrong frag_list or break existing
471 * one, it is not prohibited. In this case fall back to copying.
472 *
473 * LATER: this step can be merged to real generation of fragments,
474 * we can switch to copy when see the first bad fragment.
475 */
476 if (skb_shinfo(skb)->frag_list) {
477 struct sk_buff *frag;
478 int first_len = skb_pagelen(skb);
Herbert Xu29ffe1a2008-01-28 20:45:20 -0800479 int truesizes = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480
481 if (first_len - hlen > mtu ||
482 ((first_len - hlen) & 7) ||
483 (iph->frag_off & htons(IP_MF|IP_OFFSET)) ||
484 skb_cloned(skb))
485 goto slow_path;
486
487 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
488 /* Correct geometry. */
489 if (frag->len > mtu ||
490 ((frag->len & 7) && frag->next) ||
491 skb_headroom(frag) < hlen)
492 goto slow_path;
493
494 /* Partially cloned skb? */
495 if (skb_shared(frag))
496 goto slow_path;
Herbert Xu2fdba6b2005-05-18 22:52:33 -0700497
498 BUG_ON(frag->sk);
499 if (skb->sk) {
500 sock_hold(skb->sk);
501 frag->sk = skb->sk;
502 frag->destructor = sock_wfree;
Herbert Xu29ffe1a2008-01-28 20:45:20 -0800503 truesizes += frag->truesize;
Herbert Xu2fdba6b2005-05-18 22:52:33 -0700504 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 }
506
507 /* Everything is OK. Generate! */
508
509 err = 0;
510 offset = 0;
511 frag = skb_shinfo(skb)->frag_list;
512 skb_shinfo(skb)->frag_list = NULL;
513 skb->data_len = first_len - skb_headlen(skb);
Herbert Xu29ffe1a2008-01-28 20:45:20 -0800514 skb->truesize -= truesizes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 skb->len = first_len;
516 iph->tot_len = htons(first_len);
517 iph->frag_off = htons(IP_MF);
518 ip_send_check(iph);
519
520 for (;;) {
521 /* Prepare header of the next frame,
522 * before previous one went down. */
523 if (frag) {
524 frag->ip_summed = CHECKSUM_NONE;
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -0300525 skb_reset_transport_header(frag);
Arnaldo Carvalho de Meloe2d1bca2007-04-10 20:46:21 -0700526 __skb_push(frag, hlen);
527 skb_reset_network_header(frag);
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700528 memcpy(skb_network_header(frag), iph, hlen);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700529 iph = ip_hdr(frag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 iph->tot_len = htons(frag->len);
531 ip_copy_metadata(frag, skb);
532 if (offset == 0)
533 ip_options_fragment(frag);
534 offset += skb->len - hlen;
535 iph->frag_off = htons(offset>>3);
536 if (frag->next != NULL)
537 iph->frag_off |= htons(IP_MF);
538 /* Ready, complete checksum */
539 ip_send_check(iph);
540 }
541
542 err = output(skb);
543
Wei Dongdafee492006-08-02 13:41:21 -0700544 if (!err)
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700545 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 if (err || !frag)
547 break;
548
549 skb = frag;
550 frag = skb->next;
551 skb->next = NULL;
552 }
553
554 if (err == 0) {
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700555 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 return 0;
557 }
558
559 while (frag) {
560 skb = frag->next;
561 kfree_skb(frag);
562 frag = skb;
563 }
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700564 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 return err;
566 }
567
568slow_path:
569 left = skb->len - hlen; /* Space per frame */
570 ptr = raw + hlen; /* Where to start from */
571
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 /* for bridged IP traffic encapsulated inside f.e. a vlan header,
Stephen Hemminger9bcfcaf2006-08-29 17:48:57 -0700573 * we need to make room for the encapsulating header
574 */
575 pad = nf_bridge_pad(skb);
576 ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad);
577 mtu -= pad;
578
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 /*
580 * Fragment the datagram.
581 */
582
583 offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3;
584 not_last_frag = iph->frag_off & htons(IP_MF);
585
586 /*
587 * Keep copying data until we run out.
588 */
589
Stephen Hemminger132adf52007-03-08 20:44:43 -0800590 while (left > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 len = left;
592 /* IF: it doesn't fit, use 'mtu' - the data space left */
593 if (len > mtu)
594 len = mtu;
595 /* IF: we are not sending upto and including the packet end
596 then align the next start on an eight byte boundary */
597 if (len < left) {
598 len &= ~7;
599 }
600 /*
601 * Allocate buffer.
602 */
603
604 if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) {
Patrick McHardy64ce2072005-08-09 20:50:53 -0700605 NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 err = -ENOMEM;
607 goto fail;
608 }
609
610 /*
611 * Set up data on packet
612 */
613
614 ip_copy_metadata(skb2, skb);
615 skb_reserve(skb2, ll_rs);
616 skb_put(skb2, len + hlen);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700617 skb_reset_network_header(skb2);
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700618 skb2->transport_header = skb2->network_header + hlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619
620 /*
621 * Charge the memory for the fragment to any owner
622 * it might possess
623 */
624
625 if (skb->sk)
626 skb_set_owner_w(skb2, skb->sk);
627
628 /*
629 * Copy the packet header into the new buffer.
630 */
631
Arnaldo Carvalho de Melod626f622007-03-27 18:55:52 -0300632 skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
634 /*
635 * Copy a block of the IP datagram.
636 */
Arnaldo Carvalho de Melobff9b612007-03-16 17:19:57 -0300637 if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 BUG();
639 left -= len;
640
641 /*
642 * Fill in the new header fields.
643 */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700644 iph = ip_hdr(skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 iph->frag_off = htons((offset >> 3));
646
647 /* ANK: dirty, but effective trick. Upgrade options only if
648 * the segment to be fragmented was THE FIRST (otherwise,
649 * options are already fixed) and make it ONCE
650 * on the initial skb, so that all the following fragments
651 * will inherit fixed options.
652 */
653 if (offset == 0)
654 ip_options_fragment(skb);
655
656 /*
657 * Added AC : If we are fragmenting a fragment that's not the
658 * last fragment then keep MF on each bit
659 */
660 if (left > 0 || not_last_frag)
661 iph->frag_off |= htons(IP_MF);
662 ptr += len;
663 offset += len;
664
665 /*
666 * Put this fragment into the sending queue.
667 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 iph->tot_len = htons(len + hlen);
669
670 ip_send_check(iph);
671
672 err = output(skb2);
673 if (err)
674 goto fail;
Wei Dongdafee492006-08-02 13:41:21 -0700675
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700676 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 }
678 kfree_skb(skb);
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700679 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 return err;
681
682fail:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900683 kfree_skb(skb);
Pavel Emelyanov5e38e272008-07-16 20:19:49 -0700684 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 return err;
686}
687
Patrick McHardy2e2f7ae2006-04-04 13:42:35 -0700688EXPORT_SYMBOL(ip_fragment);
689
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690int
691ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
692{
693 struct iovec *iov = from;
694
Patrick McHardy84fa7932006-08-29 16:44:56 -0700695 if (skb->ip_summed == CHECKSUM_PARTIAL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 if (memcpy_fromiovecend(to, iov, offset, len) < 0)
697 return -EFAULT;
698 } else {
Al Viro44bb9362006-11-14 21:36:14 -0800699 __wsum csum = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0)
701 return -EFAULT;
702 skb->csum = csum_block_add(skb->csum, csum, odd);
703 }
704 return 0;
705}
706
Al Viro44bb9362006-11-14 21:36:14 -0800707static inline __wsum
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708csum_page(struct page *page, int offset, int copy)
709{
710 char *kaddr;
Al Viro44bb9362006-11-14 21:36:14 -0800711 __wsum csum;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 kaddr = kmap(page);
713 csum = csum_partial(kaddr + offset, copy, 0);
714 kunmap(page);
715 return csum;
716}
717
Adrian Bunk4b30b1c2005-11-29 16:27:20 -0800718static inline int ip_ufo_append_data(struct sock *sk,
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700719 int getfrag(void *from, char *to, int offset, int len,
720 int odd, struct sk_buff *skb),
721 void *from, int length, int hh_len, int fragheaderlen,
722 int transhdrlen, int mtu,unsigned int flags)
723{
724 struct sk_buff *skb;
725 int err;
726
727 /* There is support for UDP fragmentation offload by network
728 * device, so create one single skb packet containing complete
729 * udp datagram
730 */
731 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
732 skb = sock_alloc_send_skb(sk,
733 hh_len + fragheaderlen + transhdrlen + 20,
734 (flags & MSG_DONTWAIT), &err);
735
736 if (skb == NULL)
737 return err;
738
739 /* reserve space for Hardware header */
740 skb_reserve(skb, hh_len);
741
742 /* create space for UDP/IP header */
743 skb_put(skb,fragheaderlen + transhdrlen);
744
745 /* initialize network header pointer */
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700746 skb_reset_network_header(skb);
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700747
748 /* initialize protocol header pointer */
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700749 skb->transport_header = skb->network_header + fragheaderlen;
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700750
Patrick McHardy84fa7932006-08-29 16:44:56 -0700751 skb->ip_summed = CHECKSUM_PARTIAL;
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700752 skb->csum = 0;
753 sk->sk_sndmsg_off = 0;
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700754
Kostya Bbe9164e2008-04-29 22:36:30 -0700755 /* specify the length of each IP datagram fragment */
Herbert Xu79671682006-06-22 02:40:14 -0700756 skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
Herbert Xuf83ef8c2006-06-30 13:37:03 -0700757 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700758 __skb_queue_tail(&sk->sk_write_queue, skb);
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700759 }
Kostya Bbe9164e2008-04-29 22:36:30 -0700760
761 return skb_append_datato_frags(sk, skb, getfrag, from,
762 (length - transhdrlen));
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700763}
764
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765/*
766 * ip_append_data() and ip_append_page() can make one large IP datagram
767 * from many pieces of data. Each pieces will be holded on the socket
768 * until ip_push_pending_frames() is called. Each piece can be a page
769 * or non-page data.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900770 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 * Not only UDP, other transport protocols - e.g. raw sockets - can use
772 * this interface potentially.
773 *
774 * LATER: length must be adjusted by pad at tail, when it is required.
775 */
776int ip_append_data(struct sock *sk,
777 int getfrag(void *from, char *to, int offset, int len,
778 int odd, struct sk_buff *skb),
779 void *from, int length, int transhdrlen,
780 struct ipcm_cookie *ipc, struct rtable *rt,
781 unsigned int flags)
782{
783 struct inet_sock *inet = inet_sk(sk);
784 struct sk_buff *skb;
785
786 struct ip_options *opt = NULL;
787 int hh_len;
788 int exthdrlen;
789 int mtu;
790 int copy;
791 int err;
792 int offset = 0;
793 unsigned int maxfraglen, fragheaderlen;
794 int csummode = CHECKSUM_NONE;
795
796 if (flags&MSG_PROBE)
797 return 0;
798
799 if (skb_queue_empty(&sk->sk_write_queue)) {
800 /*
801 * setup for corking.
802 */
803 opt = ipc->opt;
804 if (opt) {
805 if (inet->cork.opt == NULL) {
806 inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation);
807 if (unlikely(inet->cork.opt == NULL))
808 return -ENOBUFS;
809 }
810 memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen);
811 inet->cork.flags |= IPCORK_OPT;
812 inet->cork.addr = ipc->addr;
813 }
814 dst_hold(&rt->u.dst);
John Heffner628a5c52007-04-20 15:53:27 -0700815 inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ?
816 rt->u.dst.dev->mtu :
817 dst_mtu(rt->u.dst.path);
YOSHIFUJI Hideakic8cdaf92008-03-10 04:30:37 -0400818 inet->cork.dst = &rt->u.dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 inet->cork.length = 0;
820 sk->sk_sndmsg_page = NULL;
821 sk->sk_sndmsg_off = 0;
822 if ((exthdrlen = rt->u.dst.header_len) != 0) {
823 length += exthdrlen;
824 transhdrlen += exthdrlen;
825 }
826 } else {
YOSHIFUJI Hideakic8cdaf92008-03-10 04:30:37 -0400827 rt = (struct rtable *)inet->cork.dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 if (inet->cork.flags & IPCORK_OPT)
829 opt = inet->cork.opt;
830
831 transhdrlen = 0;
832 exthdrlen = 0;
833 mtu = inet->cork.fragsize;
834 }
835 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
836
837 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
838 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
839
840 if (inet->cork.length + length > 0xFFFF - fragheaderlen) {
841 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen);
842 return -EMSGSIZE;
843 }
844
845 /*
846 * transhdrlen > 0 means that this is the first fragment and we wish
847 * it won't be fragmented in the future.
848 */
849 if (transhdrlen &&
850 length + fragheaderlen <= mtu &&
Stephen Hemmingerd212f872007-06-27 00:47:37 -0700851 rt->u.dst.dev->features & NETIF_F_V4_CSUM &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 !exthdrlen)
Patrick McHardy84fa7932006-08-29 16:44:56 -0700853 csummode = CHECKSUM_PARTIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854
855 inet->cork.length += length;
Kostya Bbe9164e2008-04-29 22:36:30 -0700856 if (((length> mtu) || !skb_queue_empty(&sk->sk_write_queue)) &&
857 (sk->sk_protocol == IPPROTO_UDP) &&
858 (rt->u.dst.dev->features & NETIF_F_UFO)) {
Patrick McHardybaa829d2006-03-12 20:35:12 -0800859 err = ip_ufo_append_data(sk, getfrag, from, length, hh_len,
860 fragheaderlen, transhdrlen, mtu,
861 flags);
862 if (err)
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700863 goto error;
Ananda Rajue89e9cf2005-10-18 15:46:41 -0700864 return 0;
865 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866
867 /* So, what's going on in the loop below?
868 *
869 * We use calculated fragment length to generate chained skb,
870 * each of segments is IP fragment ready for sending to network after
871 * adding appropriate IP header.
872 */
873
874 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
875 goto alloc_new_skb;
876
877 while (length > 0) {
878 /* Check if the remaining data fits into current packet. */
879 copy = mtu - skb->len;
880 if (copy < length)
881 copy = maxfraglen - skb->len;
882 if (copy <= 0) {
883 char *data;
884 unsigned int datalen;
885 unsigned int fraglen;
886 unsigned int fraggap;
887 unsigned int alloclen;
888 struct sk_buff *skb_prev;
889alloc_new_skb:
890 skb_prev = skb;
891 if (skb_prev)
892 fraggap = skb_prev->len - maxfraglen;
893 else
894 fraggap = 0;
895
896 /*
897 * If remaining data exceeds the mtu,
898 * we know we need more fragment(s).
899 */
900 datalen = length + fraggap;
901 if (datalen > mtu - fragheaderlen)
902 datalen = maxfraglen - fragheaderlen;
903 fraglen = datalen + fragheaderlen;
904
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900905 if ((flags & MSG_MORE) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 !(rt->u.dst.dev->features&NETIF_F_SG))
907 alloclen = mtu;
908 else
909 alloclen = datalen + fragheaderlen;
910
911 /* The last fragment gets additional space at tail.
912 * Note, with MSG_MORE we overallocate on fragments,
913 * because we have no idea what fragment will be
914 * the last.
915 */
Zach Brown3d9dd752006-04-14 16:04:18 -0700916 if (datalen == length + fraggap)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 alloclen += rt->u.dst.trailer_len;
918
919 if (transhdrlen) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900920 skb = sock_alloc_send_skb(sk,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 alloclen + hh_len + 15,
922 (flags & MSG_DONTWAIT), &err);
923 } else {
924 skb = NULL;
925 if (atomic_read(&sk->sk_wmem_alloc) <=
926 2 * sk->sk_sndbuf)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900927 skb = sock_wmalloc(sk,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928 alloclen + hh_len + 15, 1,
929 sk->sk_allocation);
930 if (unlikely(skb == NULL))
931 err = -ENOBUFS;
932 }
933 if (skb == NULL)
934 goto error;
935
936 /*
937 * Fill in the control structures
938 */
939 skb->ip_summed = csummode;
940 skb->csum = 0;
941 skb_reserve(skb, hh_len);
942
943 /*
944 * Find where to start putting bytes.
945 */
946 data = skb_put(skb, fraglen);
Arnaldo Carvalho de Meloc14d2452007-03-11 22:39:41 -0300947 skb_set_network_header(skb, exthdrlen);
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700948 skb->transport_header = (skb->network_header +
949 fragheaderlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 data += fragheaderlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951
952 if (fraggap) {
953 skb->csum = skb_copy_and_csum_bits(
954 skb_prev, maxfraglen,
955 data + transhdrlen, fraggap, 0);
956 skb_prev->csum = csum_sub(skb_prev->csum,
957 skb->csum);
958 data += fraggap;
Herbert Xue9fa4f72006-08-13 20:12:58 -0700959 pskb_trim_unique(skb_prev, maxfraglen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 }
961
962 copy = datalen - transhdrlen - fraggap;
963 if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
964 err = -EFAULT;
965 kfree_skb(skb);
966 goto error;
967 }
968
969 offset += copy;
970 length -= datalen - fraggap;
971 transhdrlen = 0;
972 exthdrlen = 0;
973 csummode = CHECKSUM_NONE;
974
975 /*
976 * Put the packet on the pending queue.
977 */
978 __skb_queue_tail(&sk->sk_write_queue, skb);
979 continue;
980 }
981
982 if (copy > length)
983 copy = length;
984
985 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
986 unsigned int off;
987
988 off = skb->len;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900989 if (getfrag(from, skb_put(skb, copy),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 offset, copy, off, skb) < 0) {
991 __skb_trim(skb, off);
992 err = -EFAULT;
993 goto error;
994 }
995 } else {
996 int i = skb_shinfo(skb)->nr_frags;
997 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
998 struct page *page = sk->sk_sndmsg_page;
999 int off = sk->sk_sndmsg_off;
1000 unsigned int left;
1001
1002 if (page && (left = PAGE_SIZE - off) > 0) {
1003 if (copy >= left)
1004 copy = left;
1005 if (page != frag->page) {
1006 if (i == MAX_SKB_FRAGS) {
1007 err = -EMSGSIZE;
1008 goto error;
1009 }
1010 get_page(page);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001011 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 frag = &skb_shinfo(skb)->frags[i];
1013 }
1014 } else if (i < MAX_SKB_FRAGS) {
1015 if (copy > PAGE_SIZE)
1016 copy = PAGE_SIZE;
1017 page = alloc_pages(sk->sk_allocation, 0);
1018 if (page == NULL) {
1019 err = -ENOMEM;
1020 goto error;
1021 }
1022 sk->sk_sndmsg_page = page;
1023 sk->sk_sndmsg_off = 0;
1024
1025 skb_fill_page_desc(skb, i, page, 0, 0);
1026 frag = &skb_shinfo(skb)->frags[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 } else {
1028 err = -EMSGSIZE;
1029 goto error;
1030 }
1031 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1032 err = -EFAULT;
1033 goto error;
1034 }
1035 sk->sk_sndmsg_off += copy;
1036 frag->size += copy;
1037 skb->len += copy;
1038 skb->data_len += copy;
Herbert Xuf945fa72008-01-22 22:39:26 -08001039 skb->truesize += copy;
1040 atomic_add(copy, &sk->sk_wmem_alloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 }
1042 offset += copy;
1043 length -= copy;
1044 }
1045
1046 return 0;
1047
1048error:
1049 inet->cork.length -= length;
Pavel Emelyanov5e38e272008-07-16 20:19:49 -07001050 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001051 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052}
1053
1054ssize_t ip_append_page(struct sock *sk, struct page *page,
1055 int offset, size_t size, int flags)
1056{
1057 struct inet_sock *inet = inet_sk(sk);
1058 struct sk_buff *skb;
1059 struct rtable *rt;
1060 struct ip_options *opt = NULL;
1061 int hh_len;
1062 int mtu;
1063 int len;
1064 int err;
1065 unsigned int maxfraglen, fragheaderlen, fraggap;
1066
1067 if (inet->hdrincl)
1068 return -EPERM;
1069
1070 if (flags&MSG_PROBE)
1071 return 0;
1072
1073 if (skb_queue_empty(&sk->sk_write_queue))
1074 return -EINVAL;
1075
YOSHIFUJI Hideakic8cdaf92008-03-10 04:30:37 -04001076 rt = (struct rtable *)inet->cork.dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077 if (inet->cork.flags & IPCORK_OPT)
1078 opt = inet->cork.opt;
1079
1080 if (!(rt->u.dst.dev->features&NETIF_F_SG))
1081 return -EOPNOTSUPP;
1082
1083 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1084 mtu = inet->cork.fragsize;
1085
1086 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
1087 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
1088
1089 if (inet->cork.length + size > 0xFFFF - fragheaderlen) {
1090 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu);
1091 return -EMSGSIZE;
1092 }
1093
1094 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1095 return -EINVAL;
1096
1097 inet->cork.length += size;
Ananda Rajue89e9cf2005-10-18 15:46:41 -07001098 if ((sk->sk_protocol == IPPROTO_UDP) &&
Herbert Xu79671682006-06-22 02:40:14 -07001099 (rt->u.dst.dev->features & NETIF_F_UFO)) {
1100 skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
Herbert Xuf83ef8c2006-06-30 13:37:03 -07001101 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
Herbert Xu79671682006-06-22 02:40:14 -07001102 }
Ananda Rajue89e9cf2005-10-18 15:46:41 -07001103
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104
1105 while (size > 0) {
1106 int i;
1107
Herbert Xu89114af2006-07-08 13:34:32 -07001108 if (skb_is_gso(skb))
Ananda Rajue89e9cf2005-10-18 15:46:41 -07001109 len = size;
1110 else {
1111
1112 /* Check if the remaining data fits into current packet. */
1113 len = mtu - skb->len;
1114 if (len < size)
1115 len = maxfraglen - skb->len;
1116 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 if (len <= 0) {
1118 struct sk_buff *skb_prev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 int alloclen;
1120
1121 skb_prev = skb;
Jayachandran C0d0d2bb2005-10-13 11:43:02 -07001122 fraggap = skb_prev->len - maxfraglen;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123
1124 alloclen = fragheaderlen + hh_len + fraggap + 15;
1125 skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation);
1126 if (unlikely(!skb)) {
1127 err = -ENOBUFS;
1128 goto error;
1129 }
1130
1131 /*
1132 * Fill in the control structures
1133 */
1134 skb->ip_summed = CHECKSUM_NONE;
1135 skb->csum = 0;
1136 skb_reserve(skb, hh_len);
1137
1138 /*
1139 * Find where to start putting bytes.
1140 */
Arnaldo Carvalho de Melo967b05f2007-03-13 13:51:52 -03001141 skb_put(skb, fragheaderlen + fraggap);
Arnaldo Carvalho de Melo2ca9e6f2007-03-10 19:15:25 -03001142 skb_reset_network_header(skb);
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -07001143 skb->transport_header = (skb->network_header +
1144 fragheaderlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 if (fraggap) {
Arnaldo Carvalho de Melo967b05f2007-03-13 13:51:52 -03001146 skb->csum = skb_copy_and_csum_bits(skb_prev,
1147 maxfraglen,
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07001148 skb_transport_header(skb),
Arnaldo Carvalho de Melo967b05f2007-03-13 13:51:52 -03001149 fraggap, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 skb_prev->csum = csum_sub(skb_prev->csum,
1151 skb->csum);
Herbert Xue9fa4f72006-08-13 20:12:58 -07001152 pskb_trim_unique(skb_prev, maxfraglen);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 }
1154
1155 /*
1156 * Put the packet on the pending queue.
1157 */
1158 __skb_queue_tail(&sk->sk_write_queue, skb);
1159 continue;
1160 }
1161
1162 i = skb_shinfo(skb)->nr_frags;
1163 if (len > size)
1164 len = size;
1165 if (skb_can_coalesce(skb, i, page, offset)) {
1166 skb_shinfo(skb)->frags[i-1].size += len;
1167 } else if (i < MAX_SKB_FRAGS) {
1168 get_page(page);
1169 skb_fill_page_desc(skb, i, page, offset, len);
1170 } else {
1171 err = -EMSGSIZE;
1172 goto error;
1173 }
1174
1175 if (skb->ip_summed == CHECKSUM_NONE) {
Al Viro44bb9362006-11-14 21:36:14 -08001176 __wsum csum;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 csum = csum_page(page, offset, len);
1178 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1179 }
1180
1181 skb->len += len;
1182 skb->data_len += len;
David S. Miller1e34a112008-01-22 23:44:31 -08001183 skb->truesize += len;
1184 atomic_add(len, &sk->sk_wmem_alloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 offset += len;
1186 size -= len;
1187 }
1188 return 0;
1189
1190error:
1191 inet->cork.length -= size;
Pavel Emelyanov5e38e272008-07-16 20:19:49 -07001192 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 return err;
1194}
1195
Pavel Emelyanov429f08e2007-11-05 21:03:24 -08001196static void ip_cork_release(struct inet_sock *inet)
1197{
1198 inet->cork.flags &= ~IPCORK_OPT;
1199 kfree(inet->cork.opt);
1200 inet->cork.opt = NULL;
YOSHIFUJI Hideakic8cdaf92008-03-10 04:30:37 -04001201 dst_release(inet->cork.dst);
1202 inet->cork.dst = NULL;
Pavel Emelyanov429f08e2007-11-05 21:03:24 -08001203}
1204
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205/*
1206 * Combined all pending IP fragments on the socket as one IP datagram
1207 * and push them out.
1208 */
1209int ip_push_pending_frames(struct sock *sk)
1210{
1211 struct sk_buff *skb, *tmp_skb;
1212 struct sk_buff **tail_skb;
1213 struct inet_sock *inet = inet_sk(sk);
Pavel Emelyanov0388b002008-07-14 23:00:43 -07001214 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 struct ip_options *opt = NULL;
YOSHIFUJI Hideakic8cdaf92008-03-10 04:30:37 -04001216 struct rtable *rt = (struct rtable *)inet->cork.dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 struct iphdr *iph;
Alexey Dobriyan76ab6082006-01-06 13:24:29 -08001218 __be16 df = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219 __u8 ttl;
1220 int err = 0;
1221
1222 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1223 goto out;
1224 tail_skb = &(skb_shinfo(skb)->frag_list);
1225
1226 /* move skb->data to ip header from ext header */
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -07001227 if (skb->data < skb_network_header(skb))
Arnaldo Carvalho de Melobbe735e2007-03-10 22:16:10 -03001228 __skb_pull(skb, skb_network_offset(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
Arnaldo Carvalho de Melocfe1fc72007-03-16 17:26:39 -03001230 __skb_pull(tmp_skb, skb_network_header_len(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 *tail_skb = tmp_skb;
1232 tail_skb = &(tmp_skb->next);
1233 skb->len += tmp_skb->len;
1234 skb->data_len += tmp_skb->len;
1235 skb->truesize += tmp_skb->truesize;
1236 __sock_put(tmp_skb->sk);
1237 tmp_skb->destructor = NULL;
1238 tmp_skb->sk = NULL;
1239 }
1240
1241 /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow
1242 * to fragment the frame generated here. No matter, what transforms
1243 * how transforms change size of the packet, it will come out.
1244 */
John Heffner628a5c52007-04-20 15:53:27 -07001245 if (inet->pmtudisc < IP_PMTUDISC_DO)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 skb->local_df = 1;
1247
1248 /* DF bit is set when we want to see DF on outgoing frames.
1249 * If local_df is set too, we still allow to fragment this frame
1250 * locally. */
John Heffner628a5c52007-04-20 15:53:27 -07001251 if (inet->pmtudisc >= IP_PMTUDISC_DO ||
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 (skb->len <= dst_mtu(&rt->u.dst) &&
1253 ip_dont_fragment(sk, &rt->u.dst)))
1254 df = htons(IP_DF);
1255
1256 if (inet->cork.flags & IPCORK_OPT)
1257 opt = inet->cork.opt;
1258
1259 if (rt->rt_type == RTN_MULTICAST)
1260 ttl = inet->mc_ttl;
1261 else
1262 ttl = ip_select_ttl(inet, &rt->u.dst);
1263
1264 iph = (struct iphdr *)skb->data;
1265 iph->version = 4;
1266 iph->ihl = 5;
1267 if (opt) {
1268 iph->ihl += opt->optlen>>2;
1269 ip_options_build(skb, opt, inet->cork.addr, rt, 0);
1270 }
1271 iph->tos = inet->tos;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 iph->frag_off = df;
Alexey Kuznetsov1a55d572006-03-22 14:27:59 -08001273 ip_select_ident(iph, &rt->u.dst, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 iph->ttl = ttl;
1275 iph->protocol = sk->sk_protocol;
1276 iph->saddr = rt->rt_src;
1277 iph->daddr = rt->rt_dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278
1279 skb->priority = sk->sk_priority;
Laszlo Attila Toth4a19ec52008-01-30 19:08:16 -08001280 skb->mark = sk->sk_mark;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 skb->dst = dst_clone(&rt->u.dst);
1282
David L Stevens96793b42007-09-17 09:57:33 -07001283 if (iph->protocol == IPPROTO_ICMP)
Pavel Emelyanov0388b002008-07-14 23:00:43 -07001284 icmp_out_count(net, ((struct icmphdr *)
David L Stevens96793b42007-09-17 09:57:33 -07001285 skb_transport_header(skb))->type);
1286
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 /* Netfilter gets whole the not fragmented skb. */
Herbert Xuc439cb22008-01-11 19:14:00 -08001288 err = ip_local_out(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289 if (err) {
1290 if (err > 0)
1291 err = inet->recverr ? net_xmit_errno(err) : 0;
1292 if (err)
1293 goto error;
1294 }
1295
1296out:
Pavel Emelyanov429f08e2007-11-05 21:03:24 -08001297 ip_cork_release(inet);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298 return err;
1299
1300error:
Pavel Emelyanov5e38e272008-07-16 20:19:49 -07001301 IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 goto out;
1303}
1304
1305/*
1306 * Throw away all pending data on the socket.
1307 */
1308void ip_flush_pending_frames(struct sock *sk)
1309{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001310 struct sk_buff *skb;
1311
1312 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
1313 kfree_skb(skb);
1314
Pavel Emelyanov429f08e2007-11-05 21:03:24 -08001315 ip_cork_release(inet_sk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316}
1317
1318
1319/*
1320 * Fetch data from kernel space and fill in checksum if needed.
1321 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001322static int ip_reply_glue_bits(void *dptr, char *to, int offset,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 int len, int odd, struct sk_buff *skb)
1324{
Al Viro50842052006-11-14 21:36:34 -08001325 __wsum csum;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326
1327 csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0);
1328 skb->csum = csum_block_add(skb->csum, csum, odd);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001329 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330}
1331
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001332/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 * Generic function to send a packet as reply to another packet.
1334 * Used to send TCP resets so far. ICMP should use this function too.
1335 *
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001336 * Should run single threaded per socket because it uses the sock
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 * structure to pass arguments.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338 */
1339void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
1340 unsigned int len)
1341{
1342 struct inet_sock *inet = inet_sk(sk);
1343 struct {
1344 struct ip_options opt;
1345 char data[40];
1346 } replyopts;
1347 struct ipcm_cookie ipc;
Al Viro3ca3c682006-09-27 18:28:07 -07001348 __be32 daddr;
Eric Dumazetee6b9672008-03-05 18:30:47 -08001349 struct rtable *rt = skb->rtable;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350
1351 if (ip_options_echo(&replyopts.opt, skb))
1352 return;
1353
1354 daddr = ipc.addr = rt->rt_src;
1355 ipc.opt = NULL;
1356
1357 if (replyopts.opt.optlen) {
1358 ipc.opt = &replyopts.opt;
1359
1360 if (ipc.opt->srr)
1361 daddr = replyopts.opt.faddr;
1362 }
1363
1364 {
Patrick McHardyf0e48db2007-06-04 21:32:46 -07001365 struct flowi fl = { .oif = arg->bound_dev_if,
1366 .nl_u = { .ip4_u =
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 { .daddr = daddr,
1368 .saddr = rt->rt_spec_dst,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001369 .tos = RT_TOS(ip_hdr(skb)->tos) } },
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370 /* Not quite clean, but right. */
1371 .uli_u = { .ports =
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001372 { .sport = tcp_hdr(skb)->dest,
1373 .dport = tcp_hdr(skb)->source } },
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374 .proto = sk->sk_protocol };
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -07001375 security_skb_classify_flow(skb, &fl);
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001376 if (ip_route_output_key(sock_net(sk), &rt, &fl))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 return;
1378 }
1379
1380 /* And let IP do all the hard work.
1381
1382 This chunk is not reenterable, hence spinlock.
1383 Note that it uses the fact, that this function is called
1384 with locally disabled BH and that sk cannot be already spinlocked.
1385 */
1386 bh_lock_sock(sk);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001387 inet->tos = ip_hdr(skb)->tos;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388 sk->sk_priority = skb->priority;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001389 sk->sk_protocol = ip_hdr(skb)->protocol;
Patrick McHardyf0e48db2007-06-04 21:32:46 -07001390 sk->sk_bound_dev_if = arg->bound_dev_if;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391 ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0,
1392 &ipc, rt, MSG_DONTWAIT);
1393 if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
1394 if (arg->csumoffset >= 0)
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -07001395 *((__sum16 *)skb_transport_header(skb) +
1396 arg->csumoffset) = csum_fold(csum_add(skb->csum,
1397 arg->csum));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 skb->ip_summed = CHECKSUM_NONE;
1399 ip_push_pending_frames(sk);
1400 }
1401
1402 bh_unlock_sock(sk);
1403
1404 ip_rt_put(rt);
1405}
1406
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407void __init ip_init(void)
1408{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 ip_rt_init();
1410 inet_initpeers();
1411
1412#if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS)
1413 igmp_mc_proc_init();
1414#endif
1415}
1416
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417EXPORT_SYMBOL(ip_generic_getfrag);
1418EXPORT_SYMBOL(ip_queue_xmit);
1419EXPORT_SYMBOL(ip_send_check);