Commit | Line | Data |
---|---|---|
1da177e4 LT |
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) output module. | |
7 | * | |
02c30a84 | 8 | * Authors: Ross Biro |
1da177e4 LT |
9 | * 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. | |
e905a9ed | 23 | * Bradford Johnson: Fix faulty handling of some frames when |
1da177e4 LT |
24 | * 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. | |
e905a9ed YH |
34 | * Andi Kleen : Split fast and slow ip_build_xmit path |
35 | * for decreased register pressure on x86 | |
36 | * and more readibility. | |
1da177e4 LT |
37 | * 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> | |
1da177e4 LT |
46 | #include <linux/module.h> |
47 | #include <linux/types.h> | |
48 | #include <linux/kernel.h> | |
1da177e4 LT |
49 | #include <linux/mm.h> |
50 | #include <linux/string.h> | |
51 | #include <linux/errno.h> | |
a1f8e7f7 | 52 | #include <linux/highmem.h> |
5a0e3ad6 | 53 | #include <linux/slab.h> |
1da177e4 LT |
54 | |
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> | |
cfacb057 | 69 | #include <net/xfrm.h> |
1da177e4 LT |
70 | #include <linux/skbuff.h> |
71 | #include <net/sock.h> | |
72 | #include <net/arp.h> | |
73 | #include <net/icmp.h> | |
1da177e4 LT |
74 | #include <net/checksum.h> |
75 | #include <net/inetpeer.h> | |
1da177e4 LT |
76 | #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> | |
6cbb0df7 | 81 | #include <linux/tcp.h> |
1da177e4 | 82 | |
ab32ea5d | 83 | int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; |
323e126f | 84 | EXPORT_SYMBOL(sysctl_ip_default_ttl); |
1da177e4 LT |
85 | |
86 | /* Generate a checksum for an outgoing IP datagram. */ | |
87 | __inline__ void ip_send_check(struct iphdr *iph) | |
88 | { | |
89 | iph->check = 0; | |
90 | iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); | |
91 | } | |
4bc2f18b | 92 | EXPORT_SYMBOL(ip_send_check); |
1da177e4 | 93 | |
c439cb2e HX |
94 | int __ip_local_out(struct sk_buff *skb) |
95 | { | |
96 | struct iphdr *iph = ip_hdr(skb); | |
97 | ||
98 | iph->tot_len = htons(skb->len); | |
99 | ip_send_check(iph); | |
9bbc768a JE |
100 | return nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, skb, NULL, |
101 | skb_dst(skb)->dev, dst_output); | |
c439cb2e HX |
102 | } |
103 | ||
104 | int ip_local_out(struct sk_buff *skb) | |
105 | { | |
106 | int err; | |
107 | ||
108 | err = __ip_local_out(skb); | |
109 | if (likely(err == 1)) | |
110 | err = dst_output(skb); | |
111 | ||
112 | return err; | |
113 | } | |
114 | EXPORT_SYMBOL_GPL(ip_local_out); | |
115 | ||
1da177e4 LT |
116 | static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) |
117 | { | |
118 | int ttl = inet->uc_ttl; | |
119 | ||
120 | if (ttl < 0) | |
323e126f | 121 | ttl = ip4_dst_hoplimit(dst); |
1da177e4 LT |
122 | return ttl; |
123 | } | |
124 | ||
e905a9ed | 125 | /* |
1da177e4 LT |
126 | * Add an ip header to a skbuff and send it out. |
127 | * | |
128 | */ | |
129 | int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, | |
f6d8bd05 | 130 | __be32 saddr, __be32 daddr, struct ip_options_rcu *opt) |
1da177e4 LT |
131 | { |
132 | struct inet_sock *inet = inet_sk(sk); | |
511c3f92 | 133 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
134 | struct iphdr *iph; |
135 | ||
136 | /* Build the IP header. */ | |
f6d8bd05 | 137 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0)); |
8856dfa3 | 138 | skb_reset_network_header(skb); |
eddc9ec5 | 139 | iph = ip_hdr(skb); |
1da177e4 LT |
140 | iph->version = 4; |
141 | iph->ihl = 5; | |
142 | iph->tos = inet->tos; | |
d8d1f30b | 143 | if (ip_dont_fragment(sk, &rt->dst)) |
1da177e4 LT |
144 | iph->frag_off = htons(IP_DF); |
145 | else | |
146 | iph->frag_off = 0; | |
d8d1f30b | 147 | iph->ttl = ip_select_ttl(inet, &rt->dst); |
dd927a26 DM |
148 | iph->daddr = (opt && opt->opt.srr ? opt->opt.faddr : daddr); |
149 | iph->saddr = saddr; | |
1da177e4 | 150 | iph->protocol = sk->sk_protocol; |
d8d1f30b | 151 | ip_select_ident(iph, &rt->dst, sk); |
1da177e4 | 152 | |
f6d8bd05 ED |
153 | if (opt && opt->opt.optlen) { |
154 | iph->ihl += opt->opt.optlen>>2; | |
155 | ip_options_build(skb, &opt->opt, daddr, rt, 0); | |
1da177e4 | 156 | } |
1da177e4 LT |
157 | |
158 | skb->priority = sk->sk_priority; | |
4a19ec58 | 159 | skb->mark = sk->sk_mark; |
1da177e4 LT |
160 | |
161 | /* Send it out. */ | |
c439cb2e | 162 | return ip_local_out(skb); |
1da177e4 | 163 | } |
d8c97a94 ACM |
164 | EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); |
165 | ||
1da177e4 LT |
166 | static inline int ip_finish_output2(struct sk_buff *skb) |
167 | { | |
adf30907 | 168 | struct dst_entry *dst = skb_dst(skb); |
80787ebc | 169 | struct rtable *rt = (struct rtable *)dst; |
1da177e4 | 170 | struct net_device *dev = dst->dev; |
c2636b4d | 171 | unsigned int hh_len = LL_RESERVED_SPACE(dev); |
f6b72b62 | 172 | struct neighbour *neigh; |
1da177e4 | 173 | |
edf391ff NH |
174 | if (rt->rt_type == RTN_MULTICAST) { |
175 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len); | |
176 | } else if (rt->rt_type == RTN_BROADCAST) | |
177 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTBCAST, skb->len); | |
80787ebc | 178 | |
1da177e4 | 179 | /* Be paranoid, rather than too clever. */ |
3b04ddde | 180 | if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { |
1da177e4 LT |
181 | struct sk_buff *skb2; |
182 | ||
183 | skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); | |
184 | if (skb2 == NULL) { | |
185 | kfree_skb(skb); | |
186 | return -ENOMEM; | |
187 | } | |
188 | if (skb->sk) | |
189 | skb_set_owner_w(skb2, skb->sk); | |
5d0ba55b | 190 | consume_skb(skb); |
1da177e4 LT |
191 | skb = skb2; |
192 | } | |
193 | ||
f2c31e32 | 194 | rcu_read_lock(); |
27217455 | 195 | neigh = dst_get_neighbour_noref(dst); |
f2c31e32 ED |
196 | if (neigh) { |
197 | int res = neigh_output(neigh, skb); | |
198 | ||
199 | rcu_read_unlock(); | |
200 | return res; | |
201 | } | |
202 | rcu_read_unlock(); | |
05e3aa09 | 203 | |
e87cc472 JP |
204 | net_dbg_ratelimited("%s: No header cache and no neighbour!\n", |
205 | __func__); | |
1da177e4 LT |
206 | kfree_skb(skb); |
207 | return -EINVAL; | |
208 | } | |
209 | ||
628a5c56 JH |
210 | static inline int ip_skb_dst_mtu(struct sk_buff *skb) |
211 | { | |
212 | struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; | |
213 | ||
214 | return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? | |
adf30907 | 215 | skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); |
628a5c56 JH |
216 | } |
217 | ||
861d0486 | 218 | static int ip_finish_output(struct sk_buff *skb) |
1da177e4 | 219 | { |
5c901daa PM |
220 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
221 | /* Policy lookup after SNAT yielded a new policy */ | |
adf30907 | 222 | if (skb_dst(skb)->xfrm != NULL) { |
48d5cad8 PM |
223 | IPCB(skb)->flags |= IPSKB_REROUTED; |
224 | return dst_output(skb); | |
225 | } | |
5c901daa | 226 | #endif |
628a5c56 | 227 | if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) |
1bd9bef6 PM |
228 | return ip_fragment(skb, ip_finish_output2); |
229 | else | |
230 | return ip_finish_output2(skb); | |
1da177e4 LT |
231 | } |
232 | ||
233 | int ip_mc_output(struct sk_buff *skb) | |
234 | { | |
235 | struct sock *sk = skb->sk; | |
511c3f92 | 236 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 237 | struct net_device *dev = rt->dst.dev; |
1da177e4 LT |
238 | |
239 | /* | |
240 | * If the indicated interface is up and running, send the packet. | |
241 | */ | |
edf391ff | 242 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
1da177e4 LT |
243 | |
244 | skb->dev = dev; | |
245 | skb->protocol = htons(ETH_P_IP); | |
246 | ||
247 | /* | |
248 | * Multicasts are looped back for other local users | |
249 | */ | |
250 | ||
251 | if (rt->rt_flags&RTCF_MULTICAST) { | |
7ad6848c | 252 | if (sk_mc_loop(sk) |
1da177e4 LT |
253 | #ifdef CONFIG_IP_MROUTE |
254 | /* Small optimization: do not loopback not local frames, | |
255 | which returned after forwarding; they will be dropped | |
256 | by ip_mr_input in any case. | |
257 | Note, that local frames are looped back to be delivered | |
258 | to local recipients. | |
259 | ||
260 | This check is duplicated in ip_mr_input at the moment. | |
261 | */ | |
9d4fb27d JP |
262 | && |
263 | ((rt->rt_flags & RTCF_LOCAL) || | |
264 | !(IPCB(skb)->flags & IPSKB_FORWARDED)) | |
1da177e4 | 265 | #endif |
9d4fb27d | 266 | ) { |
1da177e4 LT |
267 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
268 | if (newskb) | |
9bbc768a JE |
269 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
270 | newskb, NULL, newskb->dev, | |
95603e22 | 271 | dev_loopback_xmit); |
1da177e4 LT |
272 | } |
273 | ||
274 | /* Multicasts with ttl 0 must not go beyond the host */ | |
275 | ||
eddc9ec5 | 276 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
277 | kfree_skb(skb); |
278 | return 0; | |
279 | } | |
280 | } | |
281 | ||
282 | if (rt->rt_flags&RTCF_BROADCAST) { | |
283 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
284 | if (newskb) | |
9bbc768a | 285 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, newskb, |
95603e22 | 286 | NULL, newskb->dev, dev_loopback_xmit); |
1da177e4 LT |
287 | } |
288 | ||
9bbc768a JE |
289 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, |
290 | skb->dev, ip_finish_output, | |
48d5cad8 | 291 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
292 | } |
293 | ||
294 | int ip_output(struct sk_buff *skb) | |
295 | { | |
adf30907 | 296 | struct net_device *dev = skb_dst(skb)->dev; |
1bd9bef6 | 297 | |
edf391ff | 298 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
1da177e4 | 299 | |
1bd9bef6 PM |
300 | skb->dev = dev; |
301 | skb->protocol = htons(ETH_P_IP); | |
302 | ||
9bbc768a | 303 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, dev, |
e905a9ed | 304 | ip_finish_output, |
48d5cad8 | 305 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
306 | } |
307 | ||
84f9307c ED |
308 | /* |
309 | * copy saddr and daddr, possibly using 64bit load/stores | |
310 | * Equivalent to : | |
311 | * iph->saddr = fl4->saddr; | |
312 | * iph->daddr = fl4->daddr; | |
313 | */ | |
314 | static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4) | |
315 | { | |
316 | BUILD_BUG_ON(offsetof(typeof(*fl4), daddr) != | |
317 | offsetof(typeof(*fl4), saddr) + sizeof(fl4->saddr)); | |
318 | memcpy(&iph->saddr, &fl4->saddr, | |
319 | sizeof(fl4->saddr) + sizeof(fl4->daddr)); | |
320 | } | |
321 | ||
d9d8da80 | 322 | int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl) |
1da177e4 | 323 | { |
e89862f4 | 324 | struct sock *sk = skb->sk; |
1da177e4 | 325 | struct inet_sock *inet = inet_sk(sk); |
f6d8bd05 | 326 | struct ip_options_rcu *inet_opt; |
b57ae01a | 327 | struct flowi4 *fl4; |
1da177e4 LT |
328 | struct rtable *rt; |
329 | struct iphdr *iph; | |
ab6e3feb | 330 | int res; |
1da177e4 LT |
331 | |
332 | /* Skip all of this if the packet is already routed, | |
333 | * f.e. by something like SCTP. | |
334 | */ | |
ab6e3feb | 335 | rcu_read_lock(); |
f6d8bd05 | 336 | inet_opt = rcu_dereference(inet->inet_opt); |
ea4fc0d6 | 337 | fl4 = &fl->u.ip4; |
511c3f92 | 338 | rt = skb_rtable(skb); |
1da177e4 LT |
339 | if (rt != NULL) |
340 | goto packet_routed; | |
341 | ||
342 | /* Make sure we can route this packet. */ | |
343 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
344 | if (rt == NULL) { | |
3ca3c68e | 345 | __be32 daddr; |
1da177e4 LT |
346 | |
347 | /* Use correct destination address if we have options. */ | |
c720c7e8 | 348 | daddr = inet->inet_daddr; |
f6d8bd05 ED |
349 | if (inet_opt && inet_opt->opt.srr) |
350 | daddr = inet_opt->opt.faddr; | |
1da177e4 | 351 | |
78fbfd8a DM |
352 | /* If this fails, retransmit mechanism of transport layer will |
353 | * keep trying until route appears or the connection times | |
354 | * itself out. | |
355 | */ | |
b57ae01a | 356 | rt = ip_route_output_ports(sock_net(sk), fl4, sk, |
78fbfd8a DM |
357 | daddr, inet->inet_saddr, |
358 | inet->inet_dport, | |
359 | inet->inet_sport, | |
360 | sk->sk_protocol, | |
361 | RT_CONN_FLAGS(sk), | |
362 | sk->sk_bound_dev_if); | |
363 | if (IS_ERR(rt)) | |
364 | goto no_route; | |
d8d1f30b | 365 | sk_setup_caps(sk, &rt->dst); |
1da177e4 | 366 | } |
d8d1f30b | 367 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
368 | |
369 | packet_routed: | |
ea4fc0d6 | 370 | if (inet_opt && inet_opt->opt.is_strictroute && fl4->daddr != rt->rt_gateway) |
1da177e4 LT |
371 | goto no_route; |
372 | ||
373 | /* OK, we know where to send it, allocate and build IP header. */ | |
f6d8bd05 | 374 | skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0)); |
8856dfa3 | 375 | skb_reset_network_header(skb); |
eddc9ec5 | 376 | iph = ip_hdr(skb); |
714e85be | 377 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); |
d8d1f30b | 378 | if (ip_dont_fragment(sk, &rt->dst) && !skb->local_df) |
1da177e4 LT |
379 | iph->frag_off = htons(IP_DF); |
380 | else | |
381 | iph->frag_off = 0; | |
d8d1f30b | 382 | iph->ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 | 383 | iph->protocol = sk->sk_protocol; |
84f9307c ED |
384 | ip_copy_addrs(iph, fl4); |
385 | ||
1da177e4 LT |
386 | /* Transport layer set skb->h.foo itself. */ |
387 | ||
f6d8bd05 ED |
388 | if (inet_opt && inet_opt->opt.optlen) { |
389 | iph->ihl += inet_opt->opt.optlen >> 2; | |
390 | ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); | |
1da177e4 LT |
391 | } |
392 | ||
d8d1f30b | 393 | ip_select_ident_more(iph, &rt->dst, sk, |
7967168c | 394 | (skb_shinfo(skb)->gso_segs ?: 1) - 1); |
1da177e4 | 395 | |
1da177e4 | 396 | skb->priority = sk->sk_priority; |
4a19ec58 | 397 | skb->mark = sk->sk_mark; |
1da177e4 | 398 | |
ab6e3feb ED |
399 | res = ip_local_out(skb); |
400 | rcu_read_unlock(); | |
401 | return res; | |
1da177e4 LT |
402 | |
403 | no_route: | |
ab6e3feb | 404 | rcu_read_unlock(); |
5e38e270 | 405 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
1da177e4 LT |
406 | kfree_skb(skb); |
407 | return -EHOSTUNREACH; | |
408 | } | |
4bc2f18b | 409 | EXPORT_SYMBOL(ip_queue_xmit); |
1da177e4 LT |
410 | |
411 | ||
412 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) | |
413 | { | |
414 | to->pkt_type = from->pkt_type; | |
415 | to->priority = from->priority; | |
416 | to->protocol = from->protocol; | |
adf30907 | 417 | skb_dst_drop(to); |
fe76cda3 | 418 | skb_dst_copy(to, from); |
1da177e4 | 419 | to->dev = from->dev; |
82e91ffe | 420 | to->mark = from->mark; |
1da177e4 LT |
421 | |
422 | /* Copy the flags to each fragment. */ | |
423 | IPCB(to)->flags = IPCB(from)->flags; | |
424 | ||
425 | #ifdef CONFIG_NET_SCHED | |
426 | to->tc_index = from->tc_index; | |
427 | #endif | |
e7ac05f3 | 428 | nf_copy(to, from); |
ba9dda3a JK |
429 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ |
430 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) | |
431 | to->nf_trace = from->nf_trace; | |
432 | #endif | |
c98d80ed JA |
433 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
434 | to->ipvs_property = from->ipvs_property; | |
1da177e4 | 435 | #endif |
984bc16c | 436 | skb_copy_secmark(to, from); |
1da177e4 LT |
437 | } |
438 | ||
439 | /* | |
440 | * This IP datagram is too large to be sent in one piece. Break it up into | |
441 | * smaller pieces (each of size equal to IP header plus | |
442 | * a block of the data of the original IP data part) that will yet fit in a | |
443 | * single device frame, and queue such a frame for sending. | |
444 | */ | |
445 | ||
d9319100 | 446 | int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) |
1da177e4 LT |
447 | { |
448 | struct iphdr *iph; | |
1da177e4 LT |
449 | int ptr; |
450 | struct net_device *dev; | |
451 | struct sk_buff *skb2; | |
c893b806 | 452 | unsigned int mtu, hlen, left, len, ll_rs; |
1da177e4 | 453 | int offset; |
76ab608d | 454 | __be16 not_last_frag; |
511c3f92 | 455 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
456 | int err = 0; |
457 | ||
d8d1f30b | 458 | dev = rt->dst.dev; |
1da177e4 LT |
459 | |
460 | /* | |
461 | * Point into the IP datagram header. | |
462 | */ | |
463 | ||
eddc9ec5 | 464 | iph = ip_hdr(skb); |
1da177e4 LT |
465 | |
466 | if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { | |
5e38e270 | 467 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 468 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
628a5c56 | 469 | htonl(ip_skb_dst_mtu(skb))); |
1da177e4 LT |
470 | kfree_skb(skb); |
471 | return -EMSGSIZE; | |
472 | } | |
473 | ||
474 | /* | |
475 | * Setup starting values. | |
476 | */ | |
477 | ||
478 | hlen = iph->ihl * 4; | |
d8d1f30b | 479 | mtu = dst_mtu(&rt->dst) - hlen; /* Size of data space */ |
6c79bf0f BDS |
480 | #ifdef CONFIG_BRIDGE_NETFILTER |
481 | if (skb->nf_bridge) | |
482 | mtu -= nf_bridge_mtu_reduction(skb); | |
483 | #endif | |
89cee8b1 | 484 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
1da177e4 LT |
485 | |
486 | /* When frag_list is given, use it. First, check its validity: | |
487 | * some transformers could create wrong frag_list or break existing | |
488 | * one, it is not prohibited. In this case fall back to copying. | |
489 | * | |
490 | * LATER: this step can be merged to real generation of fragments, | |
491 | * we can switch to copy when see the first bad fragment. | |
492 | */ | |
21dc3301 | 493 | if (skb_has_frag_list(skb)) { |
3d13008e | 494 | struct sk_buff *frag, *frag2; |
1da177e4 LT |
495 | int first_len = skb_pagelen(skb); |
496 | ||
497 | if (first_len - hlen > mtu || | |
498 | ((first_len - hlen) & 7) || | |
56f8a75c | 499 | ip_is_fragment(iph) || |
1da177e4 LT |
500 | skb_cloned(skb)) |
501 | goto slow_path; | |
502 | ||
d7fcf1a5 | 503 | skb_walk_frags(skb, frag) { |
1da177e4 LT |
504 | /* Correct geometry. */ |
505 | if (frag->len > mtu || | |
506 | ((frag->len & 7) && frag->next) || | |
507 | skb_headroom(frag) < hlen) | |
3d13008e | 508 | goto slow_path_clean; |
1da177e4 LT |
509 | |
510 | /* Partially cloned skb? */ | |
511 | if (skb_shared(frag)) | |
3d13008e | 512 | goto slow_path_clean; |
2fdba6b0 HX |
513 | |
514 | BUG_ON(frag->sk); | |
515 | if (skb->sk) { | |
2fdba6b0 HX |
516 | frag->sk = skb->sk; |
517 | frag->destructor = sock_wfree; | |
2fdba6b0 | 518 | } |
3d13008e | 519 | skb->truesize -= frag->truesize; |
1da177e4 LT |
520 | } |
521 | ||
522 | /* Everything is OK. Generate! */ | |
523 | ||
524 | err = 0; | |
525 | offset = 0; | |
526 | frag = skb_shinfo(skb)->frag_list; | |
d7fcf1a5 | 527 | skb_frag_list_init(skb); |
1da177e4 LT |
528 | skb->data_len = first_len - skb_headlen(skb); |
529 | skb->len = first_len; | |
530 | iph->tot_len = htons(first_len); | |
531 | iph->frag_off = htons(IP_MF); | |
532 | ip_send_check(iph); | |
533 | ||
534 | for (;;) { | |
535 | /* Prepare header of the next frame, | |
536 | * before previous one went down. */ | |
537 | if (frag) { | |
538 | frag->ip_summed = CHECKSUM_NONE; | |
badff6d0 | 539 | skb_reset_transport_header(frag); |
e2d1bca7 ACM |
540 | __skb_push(frag, hlen); |
541 | skb_reset_network_header(frag); | |
d56f90a7 | 542 | memcpy(skb_network_header(frag), iph, hlen); |
eddc9ec5 | 543 | iph = ip_hdr(frag); |
1da177e4 LT |
544 | iph->tot_len = htons(frag->len); |
545 | ip_copy_metadata(frag, skb); | |
546 | if (offset == 0) | |
547 | ip_options_fragment(frag); | |
548 | offset += skb->len - hlen; | |
549 | iph->frag_off = htons(offset>>3); | |
550 | if (frag->next != NULL) | |
551 | iph->frag_off |= htons(IP_MF); | |
552 | /* Ready, complete checksum */ | |
553 | ip_send_check(iph); | |
554 | } | |
555 | ||
556 | err = output(skb); | |
557 | ||
dafee490 | 558 | if (!err) |
5e38e270 | 559 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 LT |
560 | if (err || !frag) |
561 | break; | |
562 | ||
563 | skb = frag; | |
564 | frag = skb->next; | |
565 | skb->next = NULL; | |
566 | } | |
567 | ||
568 | if (err == 0) { | |
5e38e270 | 569 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
570 | return 0; |
571 | } | |
572 | ||
573 | while (frag) { | |
574 | skb = frag->next; | |
575 | kfree_skb(frag); | |
576 | frag = skb; | |
577 | } | |
5e38e270 | 578 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 579 | return err; |
3d13008e ED |
580 | |
581 | slow_path_clean: | |
582 | skb_walk_frags(skb, frag2) { | |
583 | if (frag2 == frag) | |
584 | break; | |
585 | frag2->sk = NULL; | |
586 | frag2->destructor = NULL; | |
587 | skb->truesize += frag2->truesize; | |
588 | } | |
1da177e4 LT |
589 | } |
590 | ||
591 | slow_path: | |
592 | left = skb->len - hlen; /* Space per frame */ | |
49085bd7 | 593 | ptr = hlen; /* Where to start from */ |
1da177e4 | 594 | |
1da177e4 | 595 | /* for bridged IP traffic encapsulated inside f.e. a vlan header, |
9bcfcaf5 SH |
596 | * we need to make room for the encapsulating header |
597 | */ | |
c893b806 | 598 | ll_rs = LL_RESERVED_SPACE_EXTRA(rt->dst.dev, nf_bridge_pad(skb)); |
9bcfcaf5 | 599 | |
1da177e4 LT |
600 | /* |
601 | * Fragment the datagram. | |
602 | */ | |
603 | ||
604 | offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
605 | not_last_frag = iph->frag_off & htons(IP_MF); | |
606 | ||
607 | /* | |
608 | * Keep copying data until we run out. | |
609 | */ | |
610 | ||
132adf54 | 611 | while (left > 0) { |
1da177e4 LT |
612 | len = left; |
613 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
614 | if (len > mtu) | |
615 | len = mtu; | |
25985edc | 616 | /* IF: we are not sending up to and including the packet end |
1da177e4 LT |
617 | then align the next start on an eight byte boundary */ |
618 | if (len < left) { | |
619 | len &= ~7; | |
620 | } | |
621 | /* | |
622 | * Allocate buffer. | |
623 | */ | |
624 | ||
625 | if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { | |
64ce2073 | 626 | NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); |
1da177e4 LT |
627 | err = -ENOMEM; |
628 | goto fail; | |
629 | } | |
630 | ||
631 | /* | |
632 | * Set up data on packet | |
633 | */ | |
634 | ||
635 | ip_copy_metadata(skb2, skb); | |
636 | skb_reserve(skb2, ll_rs); | |
637 | skb_put(skb2, len + hlen); | |
c1d2bbe1 | 638 | skb_reset_network_header(skb2); |
b0e380b1 | 639 | skb2->transport_header = skb2->network_header + hlen; |
1da177e4 LT |
640 | |
641 | /* | |
642 | * Charge the memory for the fragment to any owner | |
643 | * it might possess | |
644 | */ | |
645 | ||
646 | if (skb->sk) | |
647 | skb_set_owner_w(skb2, skb->sk); | |
648 | ||
649 | /* | |
650 | * Copy the packet header into the new buffer. | |
651 | */ | |
652 | ||
d626f62b | 653 | skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); |
1da177e4 LT |
654 | |
655 | /* | |
656 | * Copy a block of the IP datagram. | |
657 | */ | |
bff9b61c | 658 | if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) |
1da177e4 LT |
659 | BUG(); |
660 | left -= len; | |
661 | ||
662 | /* | |
663 | * Fill in the new header fields. | |
664 | */ | |
eddc9ec5 | 665 | iph = ip_hdr(skb2); |
1da177e4 LT |
666 | iph->frag_off = htons((offset >> 3)); |
667 | ||
668 | /* ANK: dirty, but effective trick. Upgrade options only if | |
669 | * the segment to be fragmented was THE FIRST (otherwise, | |
670 | * options are already fixed) and make it ONCE | |
671 | * on the initial skb, so that all the following fragments | |
672 | * will inherit fixed options. | |
673 | */ | |
674 | if (offset == 0) | |
675 | ip_options_fragment(skb); | |
676 | ||
677 | /* | |
678 | * Added AC : If we are fragmenting a fragment that's not the | |
679 | * last fragment then keep MF on each bit | |
680 | */ | |
681 | if (left > 0 || not_last_frag) | |
682 | iph->frag_off |= htons(IP_MF); | |
683 | ptr += len; | |
684 | offset += len; | |
685 | ||
686 | /* | |
687 | * Put this fragment into the sending queue. | |
688 | */ | |
1da177e4 LT |
689 | iph->tot_len = htons(len + hlen); |
690 | ||
691 | ip_send_check(iph); | |
692 | ||
693 | err = output(skb2); | |
694 | if (err) | |
695 | goto fail; | |
dafee490 | 696 | |
5e38e270 | 697 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 | 698 | } |
5d0ba55b | 699 | consume_skb(skb); |
5e38e270 | 700 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
701 | return err; |
702 | ||
703 | fail: | |
e905a9ed | 704 | kfree_skb(skb); |
5e38e270 | 705 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
706 | return err; |
707 | } | |
2e2f7aef PM |
708 | EXPORT_SYMBOL(ip_fragment); |
709 | ||
1da177e4 LT |
710 | int |
711 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
712 | { | |
713 | struct iovec *iov = from; | |
714 | ||
84fa7933 | 715 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
1da177e4 LT |
716 | if (memcpy_fromiovecend(to, iov, offset, len) < 0) |
717 | return -EFAULT; | |
718 | } else { | |
44bb9363 | 719 | __wsum csum = 0; |
1da177e4 LT |
720 | if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) |
721 | return -EFAULT; | |
722 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
723 | } | |
724 | return 0; | |
725 | } | |
4bc2f18b | 726 | EXPORT_SYMBOL(ip_generic_getfrag); |
1da177e4 | 727 | |
44bb9363 | 728 | static inline __wsum |
1da177e4 LT |
729 | csum_page(struct page *page, int offset, int copy) |
730 | { | |
731 | char *kaddr; | |
44bb9363 | 732 | __wsum csum; |
1da177e4 LT |
733 | kaddr = kmap(page); |
734 | csum = csum_partial(kaddr + offset, copy, 0); | |
735 | kunmap(page); | |
736 | return csum; | |
737 | } | |
738 | ||
4b30b1c6 | 739 | static inline int ip_ufo_append_data(struct sock *sk, |
1470ddf7 | 740 | struct sk_buff_head *queue, |
e89e9cf5 AR |
741 | int getfrag(void *from, char *to, int offset, int len, |
742 | int odd, struct sk_buff *skb), | |
743 | void *from, int length, int hh_len, int fragheaderlen, | |
d9be4f7a | 744 | int transhdrlen, int maxfraglen, unsigned int flags) |
e89e9cf5 AR |
745 | { |
746 | struct sk_buff *skb; | |
747 | int err; | |
748 | ||
749 | /* There is support for UDP fragmentation offload by network | |
750 | * device, so create one single skb packet containing complete | |
751 | * udp datagram | |
752 | */ | |
1470ddf7 | 753 | if ((skb = skb_peek_tail(queue)) == NULL) { |
e89e9cf5 AR |
754 | skb = sock_alloc_send_skb(sk, |
755 | hh_len + fragheaderlen + transhdrlen + 20, | |
756 | (flags & MSG_DONTWAIT), &err); | |
757 | ||
758 | if (skb == NULL) | |
759 | return err; | |
760 | ||
761 | /* reserve space for Hardware header */ | |
762 | skb_reserve(skb, hh_len); | |
763 | ||
764 | /* create space for UDP/IP header */ | |
d9319100 | 765 | skb_put(skb, fragheaderlen + transhdrlen); |
e89e9cf5 AR |
766 | |
767 | /* initialize network header pointer */ | |
c1d2bbe1 | 768 | skb_reset_network_header(skb); |
e89e9cf5 AR |
769 | |
770 | /* initialize protocol header pointer */ | |
b0e380b1 | 771 | skb->transport_header = skb->network_header + fragheaderlen; |
e89e9cf5 | 772 | |
84fa7933 | 773 | skb->ip_summed = CHECKSUM_PARTIAL; |
e89e9cf5 | 774 | skb->csum = 0; |
e89e9cf5 | 775 | |
be9164e7 | 776 | /* specify the length of each IP datagram fragment */ |
d9be4f7a | 777 | skb_shinfo(skb)->gso_size = maxfraglen - fragheaderlen; |
f83ef8c0 | 778 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
1470ddf7 | 779 | __skb_queue_tail(queue, skb); |
e89e9cf5 | 780 | } |
be9164e7 K |
781 | |
782 | return skb_append_datato_frags(sk, skb, getfrag, from, | |
783 | (length - transhdrlen)); | |
e89e9cf5 AR |
784 | } |
785 | ||
f5fca608 DM |
786 | static int __ip_append_data(struct sock *sk, |
787 | struct flowi4 *fl4, | |
788 | struct sk_buff_head *queue, | |
1470ddf7 HX |
789 | struct inet_cork *cork, |
790 | int getfrag(void *from, char *to, int offset, | |
791 | int len, int odd, struct sk_buff *skb), | |
792 | void *from, int length, int transhdrlen, | |
793 | unsigned int flags) | |
1da177e4 LT |
794 | { |
795 | struct inet_sock *inet = inet_sk(sk); | |
796 | struct sk_buff *skb; | |
797 | ||
07df5294 | 798 | struct ip_options *opt = cork->opt; |
1da177e4 LT |
799 | int hh_len; |
800 | int exthdrlen; | |
801 | int mtu; | |
802 | int copy; | |
803 | int err; | |
804 | int offset = 0; | |
805 | unsigned int maxfraglen, fragheaderlen; | |
806 | int csummode = CHECKSUM_NONE; | |
1470ddf7 | 807 | struct rtable *rt = (struct rtable *)cork->dst; |
1da177e4 | 808 | |
96d7303e SK |
809 | skb = skb_peek_tail(queue); |
810 | ||
811 | exthdrlen = !skb ? rt->dst.header_len : 0; | |
07df5294 | 812 | mtu = cork->fragsize; |
1da177e4 | 813 | |
d8d1f30b | 814 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
1da177e4 LT |
815 | |
816 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
817 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
818 | ||
1470ddf7 | 819 | if (cork->length + length > 0xFFFF - fragheaderlen) { |
f5fca608 | 820 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, |
c720c7e8 | 821 | mtu-exthdrlen); |
1da177e4 LT |
822 | return -EMSGSIZE; |
823 | } | |
824 | ||
825 | /* | |
826 | * transhdrlen > 0 means that this is the first fragment and we wish | |
827 | * it won't be fragmented in the future. | |
828 | */ | |
829 | if (transhdrlen && | |
830 | length + fragheaderlen <= mtu && | |
d8d1f30b | 831 | rt->dst.dev->features & NETIF_F_V4_CSUM && |
1da177e4 | 832 | !exthdrlen) |
84fa7933 | 833 | csummode = CHECKSUM_PARTIAL; |
1da177e4 | 834 | |
1470ddf7 | 835 | cork->length += length; |
26cde9f7 | 836 | if (((length > mtu) || (skb && skb_is_gso(skb))) && |
be9164e7 | 837 | (sk->sk_protocol == IPPROTO_UDP) && |
c146066a | 838 | (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len) { |
1470ddf7 HX |
839 | err = ip_ufo_append_data(sk, queue, getfrag, from, length, |
840 | hh_len, fragheaderlen, transhdrlen, | |
d9be4f7a | 841 | maxfraglen, flags); |
baa829d8 | 842 | if (err) |
e89e9cf5 | 843 | goto error; |
e89e9cf5 AR |
844 | return 0; |
845 | } | |
1da177e4 LT |
846 | |
847 | /* So, what's going on in the loop below? | |
848 | * | |
849 | * We use calculated fragment length to generate chained skb, | |
850 | * each of segments is IP fragment ready for sending to network after | |
851 | * adding appropriate IP header. | |
852 | */ | |
853 | ||
26cde9f7 | 854 | if (!skb) |
1da177e4 LT |
855 | goto alloc_new_skb; |
856 | ||
857 | while (length > 0) { | |
858 | /* Check if the remaining data fits into current packet. */ | |
859 | copy = mtu - skb->len; | |
860 | if (copy < length) | |
861 | copy = maxfraglen - skb->len; | |
862 | if (copy <= 0) { | |
863 | char *data; | |
864 | unsigned int datalen; | |
865 | unsigned int fraglen; | |
866 | unsigned int fraggap; | |
867 | unsigned int alloclen; | |
868 | struct sk_buff *skb_prev; | |
869 | alloc_new_skb: | |
870 | skb_prev = skb; | |
871 | if (skb_prev) | |
872 | fraggap = skb_prev->len - maxfraglen; | |
873 | else | |
874 | fraggap = 0; | |
875 | ||
876 | /* | |
877 | * If remaining data exceeds the mtu, | |
878 | * we know we need more fragment(s). | |
879 | */ | |
880 | datalen = length + fraggap; | |
881 | if (datalen > mtu - fragheaderlen) | |
882 | datalen = maxfraglen - fragheaderlen; | |
883 | fraglen = datalen + fragheaderlen; | |
884 | ||
e905a9ed | 885 | if ((flags & MSG_MORE) && |
d8d1f30b | 886 | !(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 LT |
887 | alloclen = mtu; |
888 | else | |
59104f06 | 889 | alloclen = fraglen; |
1da177e4 | 890 | |
353e5c9a SK |
891 | alloclen += exthdrlen; |
892 | ||
1da177e4 LT |
893 | /* The last fragment gets additional space at tail. |
894 | * Note, with MSG_MORE we overallocate on fragments, | |
895 | * because we have no idea what fragment will be | |
896 | * the last. | |
897 | */ | |
33f99dc7 | 898 | if (datalen == length + fraggap) |
d8d1f30b | 899 | alloclen += rt->dst.trailer_len; |
33f99dc7 | 900 | |
1da177e4 | 901 | if (transhdrlen) { |
e905a9ed | 902 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
903 | alloclen + hh_len + 15, |
904 | (flags & MSG_DONTWAIT), &err); | |
905 | } else { | |
906 | skb = NULL; | |
907 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
908 | 2 * sk->sk_sndbuf) | |
e905a9ed | 909 | skb = sock_wmalloc(sk, |
1da177e4 LT |
910 | alloclen + hh_len + 15, 1, |
911 | sk->sk_allocation); | |
912 | if (unlikely(skb == NULL)) | |
913 | err = -ENOBUFS; | |
51f31cab PO |
914 | else |
915 | /* only the initial fragment is | |
916 | time stamped */ | |
1470ddf7 | 917 | cork->tx_flags = 0; |
1da177e4 LT |
918 | } |
919 | if (skb == NULL) | |
920 | goto error; | |
921 | ||
922 | /* | |
923 | * Fill in the control structures | |
924 | */ | |
925 | skb->ip_summed = csummode; | |
926 | skb->csum = 0; | |
927 | skb_reserve(skb, hh_len); | |
1470ddf7 | 928 | skb_shinfo(skb)->tx_flags = cork->tx_flags; |
1da177e4 LT |
929 | |
930 | /* | |
931 | * Find where to start putting bytes. | |
932 | */ | |
353e5c9a | 933 | data = skb_put(skb, fraglen + exthdrlen); |
c14d2450 | 934 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
935 | skb->transport_header = (skb->network_header + |
936 | fragheaderlen); | |
353e5c9a | 937 | data += fragheaderlen + exthdrlen; |
1da177e4 LT |
938 | |
939 | if (fraggap) { | |
940 | skb->csum = skb_copy_and_csum_bits( | |
941 | skb_prev, maxfraglen, | |
942 | data + transhdrlen, fraggap, 0); | |
943 | skb_prev->csum = csum_sub(skb_prev->csum, | |
944 | skb->csum); | |
945 | data += fraggap; | |
e9fa4f7b | 946 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
947 | } |
948 | ||
949 | copy = datalen - transhdrlen - fraggap; | |
950 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
951 | err = -EFAULT; | |
952 | kfree_skb(skb); | |
953 | goto error; | |
954 | } | |
955 | ||
956 | offset += copy; | |
957 | length -= datalen - fraggap; | |
958 | transhdrlen = 0; | |
959 | exthdrlen = 0; | |
960 | csummode = CHECKSUM_NONE; | |
961 | ||
962 | /* | |
963 | * Put the packet on the pending queue. | |
964 | */ | |
1470ddf7 | 965 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
966 | continue; |
967 | } | |
968 | ||
969 | if (copy > length) | |
970 | copy = length; | |
971 | ||
d8d1f30b | 972 | if (!(rt->dst.dev->features&NETIF_F_SG)) { |
1da177e4 LT |
973 | unsigned int off; |
974 | ||
975 | off = skb->len; | |
e905a9ed | 976 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
977 | offset, copy, off, skb) < 0) { |
978 | __skb_trim(skb, off); | |
979 | err = -EFAULT; | |
980 | goto error; | |
981 | } | |
982 | } else { | |
983 | int i = skb_shinfo(skb)->nr_frags; | |
984 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; | |
1470ddf7 HX |
985 | struct page *page = cork->page; |
986 | int off = cork->off; | |
1da177e4 LT |
987 | unsigned int left; |
988 | ||
989 | if (page && (left = PAGE_SIZE - off) > 0) { | |
990 | if (copy >= left) | |
991 | copy = left; | |
aff65da0 | 992 | if (page != skb_frag_page(frag)) { |
1da177e4 LT |
993 | if (i == MAX_SKB_FRAGS) { |
994 | err = -EMSGSIZE; | |
995 | goto error; | |
996 | } | |
1470ddf7 | 997 | skb_fill_page_desc(skb, i, page, off, 0); |
aff65da0 | 998 | skb_frag_ref(skb, i); |
1da177e4 LT |
999 | frag = &skb_shinfo(skb)->frags[i]; |
1000 | } | |
1001 | } else if (i < MAX_SKB_FRAGS) { | |
1002 | if (copy > PAGE_SIZE) | |
1003 | copy = PAGE_SIZE; | |
1004 | page = alloc_pages(sk->sk_allocation, 0); | |
1005 | if (page == NULL) { | |
1006 | err = -ENOMEM; | |
1007 | goto error; | |
1008 | } | |
1470ddf7 HX |
1009 | cork->page = page; |
1010 | cork->off = 0; | |
1da177e4 LT |
1011 | |
1012 | skb_fill_page_desc(skb, i, page, 0, 0); | |
1013 | frag = &skb_shinfo(skb)->frags[i]; | |
1da177e4 LT |
1014 | } else { |
1015 | err = -EMSGSIZE; | |
1016 | goto error; | |
1017 | } | |
9e903e08 | 1018 | if (getfrag(from, skb_frag_address(frag)+skb_frag_size(frag), |
aff65da0 | 1019 | offset, copy, skb->len, skb) < 0) { |
1da177e4 LT |
1020 | err = -EFAULT; |
1021 | goto error; | |
1022 | } | |
1470ddf7 | 1023 | cork->off += copy; |
9e903e08 | 1024 | skb_frag_size_add(frag, copy); |
1da177e4 LT |
1025 | skb->len += copy; |
1026 | skb->data_len += copy; | |
f945fa7a HX |
1027 | skb->truesize += copy; |
1028 | atomic_add(copy, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1029 | } |
1030 | offset += copy; | |
1031 | length -= copy; | |
1032 | } | |
1033 | ||
1034 | return 0; | |
1035 | ||
1036 | error: | |
1470ddf7 | 1037 | cork->length -= length; |
5e38e270 | 1038 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
e905a9ed | 1039 | return err; |
1da177e4 LT |
1040 | } |
1041 | ||
1470ddf7 HX |
1042 | static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, |
1043 | struct ipcm_cookie *ipc, struct rtable **rtp) | |
1044 | { | |
1045 | struct inet_sock *inet = inet_sk(sk); | |
f6d8bd05 | 1046 | struct ip_options_rcu *opt; |
1470ddf7 HX |
1047 | struct rtable *rt; |
1048 | ||
1049 | /* | |
1050 | * setup for corking. | |
1051 | */ | |
1052 | opt = ipc->opt; | |
1053 | if (opt) { | |
1054 | if (cork->opt == NULL) { | |
1055 | cork->opt = kmalloc(sizeof(struct ip_options) + 40, | |
1056 | sk->sk_allocation); | |
1057 | if (unlikely(cork->opt == NULL)) | |
1058 | return -ENOBUFS; | |
1059 | } | |
f6d8bd05 | 1060 | memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen); |
1470ddf7 HX |
1061 | cork->flags |= IPCORK_OPT; |
1062 | cork->addr = ipc->addr; | |
1063 | } | |
1064 | rt = *rtp; | |
1065 | if (unlikely(!rt)) | |
1066 | return -EFAULT; | |
1067 | /* | |
1068 | * We steal reference to this route, caller should not release it | |
1069 | */ | |
1070 | *rtp = NULL; | |
1071 | cork->fragsize = inet->pmtudisc == IP_PMTUDISC_PROBE ? | |
353e5c9a | 1072 | rt->dst.dev->mtu : dst_mtu(&rt->dst); |
1470ddf7 HX |
1073 | cork->dst = &rt->dst; |
1074 | cork->length = 0; | |
1075 | cork->tx_flags = ipc->tx_flags; | |
1076 | cork->page = NULL; | |
1077 | cork->off = 0; | |
1078 | ||
1079 | return 0; | |
1080 | } | |
1081 | ||
1082 | /* | |
1083 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
1084 | * from many pieces of data. Each pieces will be holded on the socket | |
1085 | * until ip_push_pending_frames() is called. Each piece can be a page | |
1086 | * or non-page data. | |
1087 | * | |
1088 | * Not only UDP, other transport protocols - e.g. raw sockets - can use | |
1089 | * this interface potentially. | |
1090 | * | |
1091 | * LATER: length must be adjusted by pad at tail, when it is required. | |
1092 | */ | |
f5fca608 | 1093 | int ip_append_data(struct sock *sk, struct flowi4 *fl4, |
1470ddf7 HX |
1094 | int getfrag(void *from, char *to, int offset, int len, |
1095 | int odd, struct sk_buff *skb), | |
1096 | void *from, int length, int transhdrlen, | |
1097 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1098 | unsigned int flags) | |
1099 | { | |
1100 | struct inet_sock *inet = inet_sk(sk); | |
1101 | int err; | |
1102 | ||
1103 | if (flags&MSG_PROBE) | |
1104 | return 0; | |
1105 | ||
1106 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
bdc712b4 | 1107 | err = ip_setup_cork(sk, &inet->cork.base, ipc, rtp); |
1470ddf7 HX |
1108 | if (err) |
1109 | return err; | |
1110 | } else { | |
1111 | transhdrlen = 0; | |
1112 | } | |
1113 | ||
f5fca608 | 1114 | return __ip_append_data(sk, fl4, &sk->sk_write_queue, &inet->cork.base, getfrag, |
1470ddf7 HX |
1115 | from, length, transhdrlen, flags); |
1116 | } | |
1117 | ||
f5fca608 | 1118 | ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, |
1da177e4 LT |
1119 | int offset, size_t size, int flags) |
1120 | { | |
1121 | struct inet_sock *inet = inet_sk(sk); | |
1122 | struct sk_buff *skb; | |
1123 | struct rtable *rt; | |
1124 | struct ip_options *opt = NULL; | |
bdc712b4 | 1125 | struct inet_cork *cork; |
1da177e4 LT |
1126 | int hh_len; |
1127 | int mtu; | |
1128 | int len; | |
1129 | int err; | |
1130 | unsigned int maxfraglen, fragheaderlen, fraggap; | |
1131 | ||
1132 | if (inet->hdrincl) | |
1133 | return -EPERM; | |
1134 | ||
1135 | if (flags&MSG_PROBE) | |
1136 | return 0; | |
1137 | ||
1138 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1139 | return -EINVAL; | |
1140 | ||
bdc712b4 DM |
1141 | cork = &inet->cork.base; |
1142 | rt = (struct rtable *)cork->dst; | |
1143 | if (cork->flags & IPCORK_OPT) | |
1144 | opt = cork->opt; | |
1da177e4 | 1145 | |
d8d1f30b | 1146 | if (!(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 LT |
1147 | return -EOPNOTSUPP; |
1148 | ||
d8d1f30b | 1149 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
bdc712b4 | 1150 | mtu = cork->fragsize; |
1da177e4 LT |
1151 | |
1152 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1153 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
1154 | ||
bdc712b4 | 1155 | if (cork->length + size > 0xFFFF - fragheaderlen) { |
f5fca608 | 1156 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, mtu); |
1da177e4 LT |
1157 | return -EMSGSIZE; |
1158 | } | |
1159 | ||
1160 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1161 | return -EINVAL; | |
1162 | ||
bdc712b4 | 1163 | cork->length += size; |
26cde9f7 HX |
1164 | if ((size + skb->len > mtu) && |
1165 | (sk->sk_protocol == IPPROTO_UDP) && | |
d8d1f30b | 1166 | (rt->dst.dev->features & NETIF_F_UFO)) { |
7967168c | 1167 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
f83ef8c0 | 1168 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
7967168c | 1169 | } |
e89e9cf5 | 1170 | |
1da177e4 LT |
1171 | |
1172 | while (size > 0) { | |
1173 | int i; | |
1174 | ||
89114afd | 1175 | if (skb_is_gso(skb)) |
e89e9cf5 AR |
1176 | len = size; |
1177 | else { | |
1178 | ||
1179 | /* Check if the remaining data fits into current packet. */ | |
1180 | len = mtu - skb->len; | |
1181 | if (len < size) | |
1182 | len = maxfraglen - skb->len; | |
1183 | } | |
1da177e4 LT |
1184 | if (len <= 0) { |
1185 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1186 | int alloclen; |
1187 | ||
1188 | skb_prev = skb; | |
0d0d2bba | 1189 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1190 | |
1191 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1192 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1193 | if (unlikely(!skb)) { | |
1194 | err = -ENOBUFS; | |
1195 | goto error; | |
1196 | } | |
1197 | ||
1198 | /* | |
1199 | * Fill in the control structures | |
1200 | */ | |
1201 | skb->ip_summed = CHECKSUM_NONE; | |
1202 | skb->csum = 0; | |
1203 | skb_reserve(skb, hh_len); | |
1204 | ||
1205 | /* | |
1206 | * Find where to start putting bytes. | |
1207 | */ | |
967b05f6 | 1208 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1209 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1210 | skb->transport_header = (skb->network_header + |
1211 | fragheaderlen); | |
1da177e4 | 1212 | if (fraggap) { |
967b05f6 ACM |
1213 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1214 | maxfraglen, | |
9c70220b | 1215 | skb_transport_header(skb), |
967b05f6 | 1216 | fraggap, 0); |
1da177e4 LT |
1217 | skb_prev->csum = csum_sub(skb_prev->csum, |
1218 | skb->csum); | |
e9fa4f7b | 1219 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1220 | } |
1221 | ||
1222 | /* | |
1223 | * Put the packet on the pending queue. | |
1224 | */ | |
1225 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1226 | continue; | |
1227 | } | |
1228 | ||
1229 | i = skb_shinfo(skb)->nr_frags; | |
1230 | if (len > size) | |
1231 | len = size; | |
1232 | if (skb_can_coalesce(skb, i, page, offset)) { | |
9e903e08 | 1233 | skb_frag_size_add(&skb_shinfo(skb)->frags[i-1], len); |
1da177e4 LT |
1234 | } else if (i < MAX_SKB_FRAGS) { |
1235 | get_page(page); | |
1236 | skb_fill_page_desc(skb, i, page, offset, len); | |
1237 | } else { | |
1238 | err = -EMSGSIZE; | |
1239 | goto error; | |
1240 | } | |
1241 | ||
1242 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1243 | __wsum csum; |
1da177e4 LT |
1244 | csum = csum_page(page, offset, len); |
1245 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1246 | } | |
1247 | ||
1248 | skb->len += len; | |
1249 | skb->data_len += len; | |
1e34a11d DM |
1250 | skb->truesize += len; |
1251 | atomic_add(len, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1252 | offset += len; |
1253 | size -= len; | |
1254 | } | |
1255 | return 0; | |
1256 | ||
1257 | error: | |
bdc712b4 | 1258 | cork->length -= size; |
5e38e270 | 1259 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1260 | return err; |
1261 | } | |
1262 | ||
1470ddf7 | 1263 | static void ip_cork_release(struct inet_cork *cork) |
429f08e9 | 1264 | { |
1470ddf7 HX |
1265 | cork->flags &= ~IPCORK_OPT; |
1266 | kfree(cork->opt); | |
1267 | cork->opt = NULL; | |
1268 | dst_release(cork->dst); | |
1269 | cork->dst = NULL; | |
429f08e9 PE |
1270 | } |
1271 | ||
1da177e4 LT |
1272 | /* |
1273 | * Combined all pending IP fragments on the socket as one IP datagram | |
1274 | * and push them out. | |
1275 | */ | |
1c32c5ad | 1276 | struct sk_buff *__ip_make_skb(struct sock *sk, |
77968b78 | 1277 | struct flowi4 *fl4, |
1c32c5ad HX |
1278 | struct sk_buff_head *queue, |
1279 | struct inet_cork *cork) | |
1da177e4 LT |
1280 | { |
1281 | struct sk_buff *skb, *tmp_skb; | |
1282 | struct sk_buff **tail_skb; | |
1283 | struct inet_sock *inet = inet_sk(sk); | |
0388b004 | 1284 | struct net *net = sock_net(sk); |
1da177e4 | 1285 | struct ip_options *opt = NULL; |
1470ddf7 | 1286 | struct rtable *rt = (struct rtable *)cork->dst; |
1da177e4 | 1287 | struct iphdr *iph; |
76ab608d | 1288 | __be16 df = 0; |
1da177e4 | 1289 | __u8 ttl; |
1da177e4 | 1290 | |
1470ddf7 | 1291 | if ((skb = __skb_dequeue(queue)) == NULL) |
1da177e4 LT |
1292 | goto out; |
1293 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1294 | ||
1295 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1296 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1297 | __skb_pull(skb, skb_network_offset(skb)); |
1470ddf7 | 1298 | while ((tmp_skb = __skb_dequeue(queue)) != NULL) { |
cfe1fc77 | 1299 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1300 | *tail_skb = tmp_skb; |
1301 | tail_skb = &(tmp_skb->next); | |
1302 | skb->len += tmp_skb->len; | |
1303 | skb->data_len += tmp_skb->len; | |
1304 | skb->truesize += tmp_skb->truesize; | |
1da177e4 LT |
1305 | tmp_skb->destructor = NULL; |
1306 | tmp_skb->sk = NULL; | |
1307 | } | |
1308 | ||
1309 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1310 | * to fragment the frame generated here. No matter, what transforms | |
1311 | * how transforms change size of the packet, it will come out. | |
1312 | */ | |
628a5c56 | 1313 | if (inet->pmtudisc < IP_PMTUDISC_DO) |
1da177e4 LT |
1314 | skb->local_df = 1; |
1315 | ||
1316 | /* DF bit is set when we want to see DF on outgoing frames. | |
1317 | * If local_df is set too, we still allow to fragment this frame | |
1318 | * locally. */ | |
628a5c56 | 1319 | if (inet->pmtudisc >= IP_PMTUDISC_DO || |
d8d1f30b CG |
1320 | (skb->len <= dst_mtu(&rt->dst) && |
1321 | ip_dont_fragment(sk, &rt->dst))) | |
1da177e4 LT |
1322 | df = htons(IP_DF); |
1323 | ||
1470ddf7 HX |
1324 | if (cork->flags & IPCORK_OPT) |
1325 | opt = cork->opt; | |
1da177e4 LT |
1326 | |
1327 | if (rt->rt_type == RTN_MULTICAST) | |
1328 | ttl = inet->mc_ttl; | |
1329 | else | |
d8d1f30b | 1330 | ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 LT |
1331 | |
1332 | iph = (struct iphdr *)skb->data; | |
1333 | iph->version = 4; | |
1334 | iph->ihl = 5; | |
1da177e4 | 1335 | iph->tos = inet->tos; |
1da177e4 | 1336 | iph->frag_off = df; |
d8d1f30b | 1337 | ip_select_ident(iph, &rt->dst, sk); |
1da177e4 LT |
1338 | iph->ttl = ttl; |
1339 | iph->protocol = sk->sk_protocol; | |
84f9307c | 1340 | ip_copy_addrs(iph, fl4); |
1da177e4 | 1341 | |
22f728f8 DM |
1342 | if (opt) { |
1343 | iph->ihl += opt->optlen>>2; | |
1344 | ip_options_build(skb, opt, cork->addr, rt, 0); | |
1345 | } | |
1346 | ||
1da177e4 | 1347 | skb->priority = sk->sk_priority; |
4a19ec58 | 1348 | skb->mark = sk->sk_mark; |
a21bba94 ED |
1349 | /* |
1350 | * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec | |
1351 | * on dst refcount | |
1352 | */ | |
1470ddf7 | 1353 | cork->dst = NULL; |
d8d1f30b | 1354 | skb_dst_set(skb, &rt->dst); |
1da177e4 | 1355 | |
96793b48 | 1356 | if (iph->protocol == IPPROTO_ICMP) |
0388b004 | 1357 | icmp_out_count(net, ((struct icmphdr *) |
96793b48 DS |
1358 | skb_transport_header(skb))->type); |
1359 | ||
1c32c5ad HX |
1360 | ip_cork_release(cork); |
1361 | out: | |
1362 | return skb; | |
1363 | } | |
1364 | ||
1365 | int ip_send_skb(struct sk_buff *skb) | |
1366 | { | |
1367 | struct net *net = sock_net(skb->sk); | |
1368 | int err; | |
1369 | ||
c439cb2e | 1370 | err = ip_local_out(skb); |
1da177e4 LT |
1371 | if (err) { |
1372 | if (err > 0) | |
6ce9e7b5 | 1373 | err = net_xmit_errno(err); |
1da177e4 | 1374 | if (err) |
1c32c5ad | 1375 | IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1376 | } |
1377 | ||
1da177e4 | 1378 | return err; |
1da177e4 LT |
1379 | } |
1380 | ||
77968b78 | 1381 | int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4) |
1470ddf7 | 1382 | { |
1c32c5ad HX |
1383 | struct sk_buff *skb; |
1384 | ||
77968b78 | 1385 | skb = ip_finish_skb(sk, fl4); |
1c32c5ad HX |
1386 | if (!skb) |
1387 | return 0; | |
1388 | ||
1389 | /* Netfilter gets whole the not fragmented skb. */ | |
1390 | return ip_send_skb(skb); | |
1470ddf7 HX |
1391 | } |
1392 | ||
1da177e4 LT |
1393 | /* |
1394 | * Throw away all pending data on the socket. | |
1395 | */ | |
1470ddf7 HX |
1396 | static void __ip_flush_pending_frames(struct sock *sk, |
1397 | struct sk_buff_head *queue, | |
1398 | struct inet_cork *cork) | |
1da177e4 | 1399 | { |
1da177e4 LT |
1400 | struct sk_buff *skb; |
1401 | ||
1470ddf7 | 1402 | while ((skb = __skb_dequeue_tail(queue)) != NULL) |
1da177e4 LT |
1403 | kfree_skb(skb); |
1404 | ||
1470ddf7 HX |
1405 | ip_cork_release(cork); |
1406 | } | |
1407 | ||
1408 | void ip_flush_pending_frames(struct sock *sk) | |
1409 | { | |
bdc712b4 | 1410 | __ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base); |
1da177e4 LT |
1411 | } |
1412 | ||
1c32c5ad | 1413 | struct sk_buff *ip_make_skb(struct sock *sk, |
77968b78 | 1414 | struct flowi4 *fl4, |
1c32c5ad HX |
1415 | int getfrag(void *from, char *to, int offset, |
1416 | int len, int odd, struct sk_buff *skb), | |
1417 | void *from, int length, int transhdrlen, | |
1418 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1419 | unsigned int flags) | |
1420 | { | |
b80d7226 | 1421 | struct inet_cork cork; |
1c32c5ad HX |
1422 | struct sk_buff_head queue; |
1423 | int err; | |
1424 | ||
1425 | if (flags & MSG_PROBE) | |
1426 | return NULL; | |
1427 | ||
1428 | __skb_queue_head_init(&queue); | |
1429 | ||
b80d7226 DM |
1430 | cork.flags = 0; |
1431 | cork.addr = 0; | |
70652728 | 1432 | cork.opt = NULL; |
1c32c5ad HX |
1433 | err = ip_setup_cork(sk, &cork, ipc, rtp); |
1434 | if (err) | |
1435 | return ERR_PTR(err); | |
1436 | ||
f5fca608 | 1437 | err = __ip_append_data(sk, fl4, &queue, &cork, getfrag, |
1c32c5ad HX |
1438 | from, length, transhdrlen, flags); |
1439 | if (err) { | |
1440 | __ip_flush_pending_frames(sk, &queue, &cork); | |
1441 | return ERR_PTR(err); | |
1442 | } | |
1443 | ||
77968b78 | 1444 | return __ip_make_skb(sk, fl4, &queue, &cork); |
1c32c5ad | 1445 | } |
1da177e4 LT |
1446 | |
1447 | /* | |
1448 | * Fetch data from kernel space and fill in checksum if needed. | |
1449 | */ | |
e905a9ed | 1450 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1451 | int len, int odd, struct sk_buff *skb) |
1452 | { | |
5084205f | 1453 | __wsum csum; |
1da177e4 LT |
1454 | |
1455 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1456 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1457 | return 0; |
1da177e4 LT |
1458 | } |
1459 | ||
e905a9ed | 1460 | /* |
1da177e4 | 1461 | * Generic function to send a packet as reply to another packet. |
70e73416 | 1462 | * Used to send TCP resets so far. |
1da177e4 | 1463 | * |
e905a9ed | 1464 | * Should run single threaded per socket because it uses the sock |
1da177e4 | 1465 | * structure to pass arguments. |
1da177e4 | 1466 | */ |
70e73416 DM |
1467 | void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr, |
1468 | __be32 saddr, const struct ip_reply_arg *arg, | |
1469 | unsigned int len) | |
1da177e4 LT |
1470 | { |
1471 | struct inet_sock *inet = inet_sk(sk); | |
f6d8bd05 | 1472 | struct ip_options_data replyopts; |
1da177e4 | 1473 | struct ipcm_cookie ipc; |
77968b78 | 1474 | struct flowi4 fl4; |
511c3f92 | 1475 | struct rtable *rt = skb_rtable(skb); |
1da177e4 | 1476 | |
f6d8bd05 | 1477 | if (ip_options_echo(&replyopts.opt.opt, skb)) |
1da177e4 LT |
1478 | return; |
1479 | ||
0a5ebb80 | 1480 | ipc.addr = daddr; |
1da177e4 | 1481 | ipc.opt = NULL; |
2244d07b | 1482 | ipc.tx_flags = 0; |
1da177e4 | 1483 | |
f6d8bd05 | 1484 | if (replyopts.opt.opt.optlen) { |
1da177e4 LT |
1485 | ipc.opt = &replyopts.opt; |
1486 | ||
f6d8bd05 ED |
1487 | if (replyopts.opt.opt.srr) |
1488 | daddr = replyopts.opt.opt.faddr; | |
1da177e4 LT |
1489 | } |
1490 | ||
77968b78 | 1491 | flowi4_init_output(&fl4, arg->bound_dev_if, 0, |
66b13d99 | 1492 | RT_TOS(arg->tos), |
77968b78 DM |
1493 | RT_SCOPE_UNIVERSE, sk->sk_protocol, |
1494 | ip_reply_arg_flowi_flags(arg), | |
70e73416 | 1495 | daddr, saddr, |
77968b78 DM |
1496 | tcp_hdr(skb)->source, tcp_hdr(skb)->dest); |
1497 | security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); | |
1498 | rt = ip_route_output_key(sock_net(sk), &fl4); | |
1499 | if (IS_ERR(rt)) | |
1500 | return; | |
1da177e4 LT |
1501 | |
1502 | /* And let IP do all the hard work. | |
1503 | ||
1504 | This chunk is not reenterable, hence spinlock. | |
1505 | Note that it uses the fact, that this function is called | |
1506 | with locally disabled BH and that sk cannot be already spinlocked. | |
1507 | */ | |
1508 | bh_lock_sock(sk); | |
66b13d99 | 1509 | inet->tos = arg->tos; |
1da177e4 | 1510 | sk->sk_priority = skb->priority; |
eddc9ec5 | 1511 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1512 | sk->sk_bound_dev_if = arg->bound_dev_if; |
f5fca608 | 1513 | ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, len, 0, |
2e77d89b | 1514 | &ipc, &rt, MSG_DONTWAIT); |
1da177e4 LT |
1515 | if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
1516 | if (arg->csumoffset >= 0) | |
9c70220b ACM |
1517 | *((__sum16 *)skb_transport_header(skb) + |
1518 | arg->csumoffset) = csum_fold(csum_add(skb->csum, | |
1519 | arg->csum)); | |
1da177e4 | 1520 | skb->ip_summed = CHECKSUM_NONE; |
77968b78 | 1521 | ip_push_pending_frames(sk, &fl4); |
1da177e4 LT |
1522 | } |
1523 | ||
1524 | bh_unlock_sock(sk); | |
1525 | ||
1526 | ip_rt_put(rt); | |
1527 | } | |
1528 | ||
1da177e4 LT |
1529 | void __init ip_init(void) |
1530 | { | |
1da177e4 LT |
1531 | ip_rt_init(); |
1532 | inet_initpeers(); | |
1533 | ||
1534 | #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) | |
1535 | igmp_mc_proc_init(); | |
1536 | #endif | |
1537 | } |