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Commit | Line | Data |
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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; |
a263b309 | 173 | u32 nexthop; |
1da177e4 | 174 | |
edf391ff NH |
175 | if (rt->rt_type == RTN_MULTICAST) { |
176 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len); | |
177 | } else if (rt->rt_type == RTN_BROADCAST) | |
178 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTBCAST, skb->len); | |
80787ebc | 179 | |
1da177e4 | 180 | /* Be paranoid, rather than too clever. */ |
3b04ddde | 181 | if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { |
1da177e4 LT |
182 | struct sk_buff *skb2; |
183 | ||
184 | skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); | |
185 | if (skb2 == NULL) { | |
186 | kfree_skb(skb); | |
187 | return -ENOMEM; | |
188 | } | |
189 | if (skb->sk) | |
190 | skb_set_owner_w(skb2, skb->sk); | |
5d0ba55b | 191 | consume_skb(skb); |
1da177e4 LT |
192 | skb = skb2; |
193 | } | |
194 | ||
a263b309 DM |
195 | rcu_read_lock_bh(); |
196 | nexthop = rt->rt_gateway ? rt->rt_gateway : ip_hdr(skb)->daddr; | |
197 | neigh = __ipv4_neigh_lookup_noref(dev, nexthop); | |
198 | if (unlikely(!neigh)) | |
199 | neigh = __neigh_create(&arp_tbl, &nexthop, dev, false); | |
9871f1ad | 200 | if (!IS_ERR(neigh)) { |
5110effe | 201 | int res = dst_neigh_output(dst, neigh, skb); |
f2c31e32 | 202 | |
a263b309 | 203 | rcu_read_unlock_bh(); |
f2c31e32 ED |
204 | return res; |
205 | } | |
a263b309 | 206 | rcu_read_unlock_bh(); |
05e3aa09 | 207 | |
e87cc472 JP |
208 | net_dbg_ratelimited("%s: No header cache and no neighbour!\n", |
209 | __func__); | |
1da177e4 LT |
210 | kfree_skb(skb); |
211 | return -EINVAL; | |
212 | } | |
213 | ||
628a5c56 JH |
214 | static inline int ip_skb_dst_mtu(struct sk_buff *skb) |
215 | { | |
216 | struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; | |
217 | ||
218 | return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? | |
adf30907 | 219 | skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); |
628a5c56 JH |
220 | } |
221 | ||
861d0486 | 222 | static int ip_finish_output(struct sk_buff *skb) |
1da177e4 | 223 | { |
5c901daa PM |
224 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
225 | /* Policy lookup after SNAT yielded a new policy */ | |
adf30907 | 226 | if (skb_dst(skb)->xfrm != NULL) { |
48d5cad8 PM |
227 | IPCB(skb)->flags |= IPSKB_REROUTED; |
228 | return dst_output(skb); | |
229 | } | |
5c901daa | 230 | #endif |
628a5c56 | 231 | if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) |
1bd9bef6 PM |
232 | return ip_fragment(skb, ip_finish_output2); |
233 | else | |
234 | return ip_finish_output2(skb); | |
1da177e4 LT |
235 | } |
236 | ||
237 | int ip_mc_output(struct sk_buff *skb) | |
238 | { | |
239 | struct sock *sk = skb->sk; | |
511c3f92 | 240 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 241 | struct net_device *dev = rt->dst.dev; |
1da177e4 LT |
242 | |
243 | /* | |
244 | * If the indicated interface is up and running, send the packet. | |
245 | */ | |
edf391ff | 246 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
1da177e4 LT |
247 | |
248 | skb->dev = dev; | |
249 | skb->protocol = htons(ETH_P_IP); | |
250 | ||
251 | /* | |
252 | * Multicasts are looped back for other local users | |
253 | */ | |
254 | ||
255 | if (rt->rt_flags&RTCF_MULTICAST) { | |
7ad6848c | 256 | if (sk_mc_loop(sk) |
1da177e4 LT |
257 | #ifdef CONFIG_IP_MROUTE |
258 | /* Small optimization: do not loopback not local frames, | |
259 | which returned after forwarding; they will be dropped | |
260 | by ip_mr_input in any case. | |
261 | Note, that local frames are looped back to be delivered | |
262 | to local recipients. | |
263 | ||
264 | This check is duplicated in ip_mr_input at the moment. | |
265 | */ | |
9d4fb27d JP |
266 | && |
267 | ((rt->rt_flags & RTCF_LOCAL) || | |
268 | !(IPCB(skb)->flags & IPSKB_FORWARDED)) | |
1da177e4 | 269 | #endif |
9d4fb27d | 270 | ) { |
1da177e4 LT |
271 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
272 | if (newskb) | |
9bbc768a JE |
273 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
274 | newskb, NULL, newskb->dev, | |
95603e22 | 275 | dev_loopback_xmit); |
1da177e4 LT |
276 | } |
277 | ||
278 | /* Multicasts with ttl 0 must not go beyond the host */ | |
279 | ||
eddc9ec5 | 280 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
281 | kfree_skb(skb); |
282 | return 0; | |
283 | } | |
284 | } | |
285 | ||
286 | if (rt->rt_flags&RTCF_BROADCAST) { | |
287 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
288 | if (newskb) | |
9bbc768a | 289 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, newskb, |
95603e22 | 290 | NULL, newskb->dev, dev_loopback_xmit); |
1da177e4 LT |
291 | } |
292 | ||
9bbc768a JE |
293 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, |
294 | skb->dev, ip_finish_output, | |
48d5cad8 | 295 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
296 | } |
297 | ||
298 | int ip_output(struct sk_buff *skb) | |
299 | { | |
adf30907 | 300 | struct net_device *dev = skb_dst(skb)->dev; |
1bd9bef6 | 301 | |
edf391ff | 302 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
1da177e4 | 303 | |
1bd9bef6 PM |
304 | skb->dev = dev; |
305 | skb->protocol = htons(ETH_P_IP); | |
306 | ||
9bbc768a | 307 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, dev, |
e905a9ed | 308 | ip_finish_output, |
48d5cad8 | 309 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
310 | } |
311 | ||
84f9307c ED |
312 | /* |
313 | * copy saddr and daddr, possibly using 64bit load/stores | |
314 | * Equivalent to : | |
315 | * iph->saddr = fl4->saddr; | |
316 | * iph->daddr = fl4->daddr; | |
317 | */ | |
318 | static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4) | |
319 | { | |
320 | BUILD_BUG_ON(offsetof(typeof(*fl4), daddr) != | |
321 | offsetof(typeof(*fl4), saddr) + sizeof(fl4->saddr)); | |
322 | memcpy(&iph->saddr, &fl4->saddr, | |
323 | sizeof(fl4->saddr) + sizeof(fl4->daddr)); | |
324 | } | |
325 | ||
d9d8da80 | 326 | int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl) |
1da177e4 | 327 | { |
e89862f4 | 328 | struct sock *sk = skb->sk; |
1da177e4 | 329 | struct inet_sock *inet = inet_sk(sk); |
f6d8bd05 | 330 | struct ip_options_rcu *inet_opt; |
b57ae01a | 331 | struct flowi4 *fl4; |
1da177e4 LT |
332 | struct rtable *rt; |
333 | struct iphdr *iph; | |
ab6e3feb | 334 | int res; |
1da177e4 LT |
335 | |
336 | /* Skip all of this if the packet is already routed, | |
337 | * f.e. by something like SCTP. | |
338 | */ | |
ab6e3feb | 339 | rcu_read_lock(); |
f6d8bd05 | 340 | inet_opt = rcu_dereference(inet->inet_opt); |
ea4fc0d6 | 341 | fl4 = &fl->u.ip4; |
511c3f92 | 342 | rt = skb_rtable(skb); |
1da177e4 LT |
343 | if (rt != NULL) |
344 | goto packet_routed; | |
345 | ||
346 | /* Make sure we can route this packet. */ | |
347 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
348 | if (rt == NULL) { | |
3ca3c68e | 349 | __be32 daddr; |
1da177e4 LT |
350 | |
351 | /* Use correct destination address if we have options. */ | |
c720c7e8 | 352 | daddr = inet->inet_daddr; |
f6d8bd05 ED |
353 | if (inet_opt && inet_opt->opt.srr) |
354 | daddr = inet_opt->opt.faddr; | |
1da177e4 | 355 | |
78fbfd8a DM |
356 | /* If this fails, retransmit mechanism of transport layer will |
357 | * keep trying until route appears or the connection times | |
358 | * itself out. | |
359 | */ | |
b57ae01a | 360 | rt = ip_route_output_ports(sock_net(sk), fl4, sk, |
78fbfd8a DM |
361 | daddr, inet->inet_saddr, |
362 | inet->inet_dport, | |
363 | inet->inet_sport, | |
364 | sk->sk_protocol, | |
365 | RT_CONN_FLAGS(sk), | |
366 | sk->sk_bound_dev_if); | |
367 | if (IS_ERR(rt)) | |
368 | goto no_route; | |
d8d1f30b | 369 | sk_setup_caps(sk, &rt->dst); |
1da177e4 | 370 | } |
d8d1f30b | 371 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
372 | |
373 | packet_routed: | |
f8126f1d | 374 | if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_gateway) |
1da177e4 LT |
375 | goto no_route; |
376 | ||
377 | /* OK, we know where to send it, allocate and build IP header. */ | |
f6d8bd05 | 378 | skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0)); |
8856dfa3 | 379 | skb_reset_network_header(skb); |
eddc9ec5 | 380 | iph = ip_hdr(skb); |
714e85be | 381 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); |
d8d1f30b | 382 | if (ip_dont_fragment(sk, &rt->dst) && !skb->local_df) |
1da177e4 LT |
383 | iph->frag_off = htons(IP_DF); |
384 | else | |
385 | iph->frag_off = 0; | |
d8d1f30b | 386 | iph->ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 | 387 | iph->protocol = sk->sk_protocol; |
84f9307c ED |
388 | ip_copy_addrs(iph, fl4); |
389 | ||
1da177e4 LT |
390 | /* Transport layer set skb->h.foo itself. */ |
391 | ||
f6d8bd05 ED |
392 | if (inet_opt && inet_opt->opt.optlen) { |
393 | iph->ihl += inet_opt->opt.optlen >> 2; | |
394 | ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); | |
1da177e4 LT |
395 | } |
396 | ||
d8d1f30b | 397 | ip_select_ident_more(iph, &rt->dst, sk, |
7967168c | 398 | (skb_shinfo(skb)->gso_segs ?: 1) - 1); |
1da177e4 | 399 | |
1da177e4 | 400 | skb->priority = sk->sk_priority; |
4a19ec58 | 401 | skb->mark = sk->sk_mark; |
1da177e4 | 402 | |
ab6e3feb ED |
403 | res = ip_local_out(skb); |
404 | rcu_read_unlock(); | |
405 | return res; | |
1da177e4 LT |
406 | |
407 | no_route: | |
ab6e3feb | 408 | rcu_read_unlock(); |
5e38e270 | 409 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
1da177e4 LT |
410 | kfree_skb(skb); |
411 | return -EHOSTUNREACH; | |
412 | } | |
4bc2f18b | 413 | EXPORT_SYMBOL(ip_queue_xmit); |
1da177e4 LT |
414 | |
415 | ||
416 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) | |
417 | { | |
418 | to->pkt_type = from->pkt_type; | |
419 | to->priority = from->priority; | |
420 | to->protocol = from->protocol; | |
adf30907 | 421 | skb_dst_drop(to); |
fe76cda3 | 422 | skb_dst_copy(to, from); |
1da177e4 | 423 | to->dev = from->dev; |
82e91ffe | 424 | to->mark = from->mark; |
1da177e4 LT |
425 | |
426 | /* Copy the flags to each fragment. */ | |
427 | IPCB(to)->flags = IPCB(from)->flags; | |
428 | ||
429 | #ifdef CONFIG_NET_SCHED | |
430 | to->tc_index = from->tc_index; | |
431 | #endif | |
e7ac05f3 | 432 | nf_copy(to, from); |
ba9dda3a JK |
433 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ |
434 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) | |
435 | to->nf_trace = from->nf_trace; | |
436 | #endif | |
c98d80ed JA |
437 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
438 | to->ipvs_property = from->ipvs_property; | |
1da177e4 | 439 | #endif |
984bc16c | 440 | skb_copy_secmark(to, from); |
1da177e4 LT |
441 | } |
442 | ||
443 | /* | |
444 | * This IP datagram is too large to be sent in one piece. Break it up into | |
445 | * smaller pieces (each of size equal to IP header plus | |
446 | * a block of the data of the original IP data part) that will yet fit in a | |
447 | * single device frame, and queue such a frame for sending. | |
448 | */ | |
449 | ||
d9319100 | 450 | int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) |
1da177e4 LT |
451 | { |
452 | struct iphdr *iph; | |
1da177e4 LT |
453 | int ptr; |
454 | struct net_device *dev; | |
455 | struct sk_buff *skb2; | |
c893b806 | 456 | unsigned int mtu, hlen, left, len, ll_rs; |
1da177e4 | 457 | int offset; |
76ab608d | 458 | __be16 not_last_frag; |
511c3f92 | 459 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
460 | int err = 0; |
461 | ||
d8d1f30b | 462 | dev = rt->dst.dev; |
1da177e4 LT |
463 | |
464 | /* | |
465 | * Point into the IP datagram header. | |
466 | */ | |
467 | ||
eddc9ec5 | 468 | iph = ip_hdr(skb); |
1da177e4 LT |
469 | |
470 | if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { | |
5e38e270 | 471 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 472 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
628a5c56 | 473 | htonl(ip_skb_dst_mtu(skb))); |
1da177e4 LT |
474 | kfree_skb(skb); |
475 | return -EMSGSIZE; | |
476 | } | |
477 | ||
478 | /* | |
479 | * Setup starting values. | |
480 | */ | |
481 | ||
482 | hlen = iph->ihl * 4; | |
d8d1f30b | 483 | mtu = dst_mtu(&rt->dst) - hlen; /* Size of data space */ |
6c79bf0f BDS |
484 | #ifdef CONFIG_BRIDGE_NETFILTER |
485 | if (skb->nf_bridge) | |
486 | mtu -= nf_bridge_mtu_reduction(skb); | |
487 | #endif | |
89cee8b1 | 488 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
1da177e4 LT |
489 | |
490 | /* When frag_list is given, use it. First, check its validity: | |
491 | * some transformers could create wrong frag_list or break existing | |
492 | * one, it is not prohibited. In this case fall back to copying. | |
493 | * | |
494 | * LATER: this step can be merged to real generation of fragments, | |
495 | * we can switch to copy when see the first bad fragment. | |
496 | */ | |
21dc3301 | 497 | if (skb_has_frag_list(skb)) { |
3d13008e | 498 | struct sk_buff *frag, *frag2; |
1da177e4 LT |
499 | int first_len = skb_pagelen(skb); |
500 | ||
501 | if (first_len - hlen > mtu || | |
502 | ((first_len - hlen) & 7) || | |
56f8a75c | 503 | ip_is_fragment(iph) || |
1da177e4 LT |
504 | skb_cloned(skb)) |
505 | goto slow_path; | |
506 | ||
d7fcf1a5 | 507 | skb_walk_frags(skb, frag) { |
1da177e4 LT |
508 | /* Correct geometry. */ |
509 | if (frag->len > mtu || | |
510 | ((frag->len & 7) && frag->next) || | |
511 | skb_headroom(frag) < hlen) | |
3d13008e | 512 | goto slow_path_clean; |
1da177e4 LT |
513 | |
514 | /* Partially cloned skb? */ | |
515 | if (skb_shared(frag)) | |
3d13008e | 516 | goto slow_path_clean; |
2fdba6b0 HX |
517 | |
518 | BUG_ON(frag->sk); | |
519 | if (skb->sk) { | |
2fdba6b0 HX |
520 | frag->sk = skb->sk; |
521 | frag->destructor = sock_wfree; | |
2fdba6b0 | 522 | } |
3d13008e | 523 | skb->truesize -= frag->truesize; |
1da177e4 LT |
524 | } |
525 | ||
526 | /* Everything is OK. Generate! */ | |
527 | ||
528 | err = 0; | |
529 | offset = 0; | |
530 | frag = skb_shinfo(skb)->frag_list; | |
d7fcf1a5 | 531 | skb_frag_list_init(skb); |
1da177e4 LT |
532 | skb->data_len = first_len - skb_headlen(skb); |
533 | skb->len = first_len; | |
534 | iph->tot_len = htons(first_len); | |
535 | iph->frag_off = htons(IP_MF); | |
536 | ip_send_check(iph); | |
537 | ||
538 | for (;;) { | |
539 | /* Prepare header of the next frame, | |
540 | * before previous one went down. */ | |
541 | if (frag) { | |
542 | frag->ip_summed = CHECKSUM_NONE; | |
badff6d0 | 543 | skb_reset_transport_header(frag); |
e2d1bca7 ACM |
544 | __skb_push(frag, hlen); |
545 | skb_reset_network_header(frag); | |
d56f90a7 | 546 | memcpy(skb_network_header(frag), iph, hlen); |
eddc9ec5 | 547 | iph = ip_hdr(frag); |
1da177e4 LT |
548 | iph->tot_len = htons(frag->len); |
549 | ip_copy_metadata(frag, skb); | |
550 | if (offset == 0) | |
551 | ip_options_fragment(frag); | |
552 | offset += skb->len - hlen; | |
553 | iph->frag_off = htons(offset>>3); | |
554 | if (frag->next != NULL) | |
555 | iph->frag_off |= htons(IP_MF); | |
556 | /* Ready, complete checksum */ | |
557 | ip_send_check(iph); | |
558 | } | |
559 | ||
560 | err = output(skb); | |
561 | ||
dafee490 | 562 | if (!err) |
5e38e270 | 563 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 LT |
564 | if (err || !frag) |
565 | break; | |
566 | ||
567 | skb = frag; | |
568 | frag = skb->next; | |
569 | skb->next = NULL; | |
570 | } | |
571 | ||
572 | if (err == 0) { | |
5e38e270 | 573 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
574 | return 0; |
575 | } | |
576 | ||
577 | while (frag) { | |
578 | skb = frag->next; | |
579 | kfree_skb(frag); | |
580 | frag = skb; | |
581 | } | |
5e38e270 | 582 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 583 | return err; |
3d13008e ED |
584 | |
585 | slow_path_clean: | |
586 | skb_walk_frags(skb, frag2) { | |
587 | if (frag2 == frag) | |
588 | break; | |
589 | frag2->sk = NULL; | |
590 | frag2->destructor = NULL; | |
591 | skb->truesize += frag2->truesize; | |
592 | } | |
1da177e4 LT |
593 | } |
594 | ||
595 | slow_path: | |
596 | left = skb->len - hlen; /* Space per frame */ | |
49085bd7 | 597 | ptr = hlen; /* Where to start from */ |
1da177e4 | 598 | |
1da177e4 | 599 | /* for bridged IP traffic encapsulated inside f.e. a vlan header, |
9bcfcaf5 SH |
600 | * we need to make room for the encapsulating header |
601 | */ | |
c893b806 | 602 | ll_rs = LL_RESERVED_SPACE_EXTRA(rt->dst.dev, nf_bridge_pad(skb)); |
9bcfcaf5 | 603 | |
1da177e4 LT |
604 | /* |
605 | * Fragment the datagram. | |
606 | */ | |
607 | ||
608 | offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
609 | not_last_frag = iph->frag_off & htons(IP_MF); | |
610 | ||
611 | /* | |
612 | * Keep copying data until we run out. | |
613 | */ | |
614 | ||
132adf54 | 615 | while (left > 0) { |
1da177e4 LT |
616 | len = left; |
617 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
618 | if (len > mtu) | |
619 | len = mtu; | |
25985edc | 620 | /* IF: we are not sending up to and including the packet end |
1da177e4 LT |
621 | then align the next start on an eight byte boundary */ |
622 | if (len < left) { | |
623 | len &= ~7; | |
624 | } | |
625 | /* | |
626 | * Allocate buffer. | |
627 | */ | |
628 | ||
629 | if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { | |
64ce2073 | 630 | NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); |
1da177e4 LT |
631 | err = -ENOMEM; |
632 | goto fail; | |
633 | } | |
634 | ||
635 | /* | |
636 | * Set up data on packet | |
637 | */ | |
638 | ||
639 | ip_copy_metadata(skb2, skb); | |
640 | skb_reserve(skb2, ll_rs); | |
641 | skb_put(skb2, len + hlen); | |
c1d2bbe1 | 642 | skb_reset_network_header(skb2); |
b0e380b1 | 643 | skb2->transport_header = skb2->network_header + hlen; |
1da177e4 LT |
644 | |
645 | /* | |
646 | * Charge the memory for the fragment to any owner | |
647 | * it might possess | |
648 | */ | |
649 | ||
650 | if (skb->sk) | |
651 | skb_set_owner_w(skb2, skb->sk); | |
652 | ||
653 | /* | |
654 | * Copy the packet header into the new buffer. | |
655 | */ | |
656 | ||
d626f62b | 657 | skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); |
1da177e4 LT |
658 | |
659 | /* | |
660 | * Copy a block of the IP datagram. | |
661 | */ | |
bff9b61c | 662 | if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) |
1da177e4 LT |
663 | BUG(); |
664 | left -= len; | |
665 | ||
666 | /* | |
667 | * Fill in the new header fields. | |
668 | */ | |
eddc9ec5 | 669 | iph = ip_hdr(skb2); |
1da177e4 LT |
670 | iph->frag_off = htons((offset >> 3)); |
671 | ||
672 | /* ANK: dirty, but effective trick. Upgrade options only if | |
673 | * the segment to be fragmented was THE FIRST (otherwise, | |
674 | * options are already fixed) and make it ONCE | |
675 | * on the initial skb, so that all the following fragments | |
676 | * will inherit fixed options. | |
677 | */ | |
678 | if (offset == 0) | |
679 | ip_options_fragment(skb); | |
680 | ||
681 | /* | |
682 | * Added AC : If we are fragmenting a fragment that's not the | |
683 | * last fragment then keep MF on each bit | |
684 | */ | |
685 | if (left > 0 || not_last_frag) | |
686 | iph->frag_off |= htons(IP_MF); | |
687 | ptr += len; | |
688 | offset += len; | |
689 | ||
690 | /* | |
691 | * Put this fragment into the sending queue. | |
692 | */ | |
1da177e4 LT |
693 | iph->tot_len = htons(len + hlen); |
694 | ||
695 | ip_send_check(iph); | |
696 | ||
697 | err = output(skb2); | |
698 | if (err) | |
699 | goto fail; | |
dafee490 | 700 | |
5e38e270 | 701 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 | 702 | } |
5d0ba55b | 703 | consume_skb(skb); |
5e38e270 | 704 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
705 | return err; |
706 | ||
707 | fail: | |
e905a9ed | 708 | kfree_skb(skb); |
5e38e270 | 709 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
710 | return err; |
711 | } | |
2e2f7aef PM |
712 | EXPORT_SYMBOL(ip_fragment); |
713 | ||
1da177e4 LT |
714 | int |
715 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
716 | { | |
717 | struct iovec *iov = from; | |
718 | ||
84fa7933 | 719 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
1da177e4 LT |
720 | if (memcpy_fromiovecend(to, iov, offset, len) < 0) |
721 | return -EFAULT; | |
722 | } else { | |
44bb9363 | 723 | __wsum csum = 0; |
1da177e4 LT |
724 | if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) |
725 | return -EFAULT; | |
726 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
727 | } | |
728 | return 0; | |
729 | } | |
4bc2f18b | 730 | EXPORT_SYMBOL(ip_generic_getfrag); |
1da177e4 | 731 | |
44bb9363 | 732 | static inline __wsum |
1da177e4 LT |
733 | csum_page(struct page *page, int offset, int copy) |
734 | { | |
735 | char *kaddr; | |
44bb9363 | 736 | __wsum csum; |
1da177e4 LT |
737 | kaddr = kmap(page); |
738 | csum = csum_partial(kaddr + offset, copy, 0); | |
739 | kunmap(page); | |
740 | return csum; | |
741 | } | |
742 | ||
4b30b1c6 | 743 | static inline int ip_ufo_append_data(struct sock *sk, |
1470ddf7 | 744 | struct sk_buff_head *queue, |
e89e9cf5 AR |
745 | int getfrag(void *from, char *to, int offset, int len, |
746 | int odd, struct sk_buff *skb), | |
747 | void *from, int length, int hh_len, int fragheaderlen, | |
d9be4f7a | 748 | int transhdrlen, int maxfraglen, unsigned int flags) |
e89e9cf5 AR |
749 | { |
750 | struct sk_buff *skb; | |
751 | int err; | |
752 | ||
753 | /* There is support for UDP fragmentation offload by network | |
754 | * device, so create one single skb packet containing complete | |
755 | * udp datagram | |
756 | */ | |
1470ddf7 | 757 | if ((skb = skb_peek_tail(queue)) == NULL) { |
e89e9cf5 AR |
758 | skb = sock_alloc_send_skb(sk, |
759 | hh_len + fragheaderlen + transhdrlen + 20, | |
760 | (flags & MSG_DONTWAIT), &err); | |
761 | ||
762 | if (skb == NULL) | |
763 | return err; | |
764 | ||
765 | /* reserve space for Hardware header */ | |
766 | skb_reserve(skb, hh_len); | |
767 | ||
768 | /* create space for UDP/IP header */ | |
d9319100 | 769 | skb_put(skb, fragheaderlen + transhdrlen); |
e89e9cf5 AR |
770 | |
771 | /* initialize network header pointer */ | |
c1d2bbe1 | 772 | skb_reset_network_header(skb); |
e89e9cf5 AR |
773 | |
774 | /* initialize protocol header pointer */ | |
b0e380b1 | 775 | skb->transport_header = skb->network_header + fragheaderlen; |
e89e9cf5 | 776 | |
84fa7933 | 777 | skb->ip_summed = CHECKSUM_PARTIAL; |
e89e9cf5 | 778 | skb->csum = 0; |
e89e9cf5 | 779 | |
be9164e7 | 780 | /* specify the length of each IP datagram fragment */ |
d9be4f7a | 781 | skb_shinfo(skb)->gso_size = maxfraglen - fragheaderlen; |
f83ef8c0 | 782 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
1470ddf7 | 783 | __skb_queue_tail(queue, skb); |
e89e9cf5 | 784 | } |
be9164e7 K |
785 | |
786 | return skb_append_datato_frags(sk, skb, getfrag, from, | |
787 | (length - transhdrlen)); | |
e89e9cf5 AR |
788 | } |
789 | ||
f5fca608 DM |
790 | static int __ip_append_data(struct sock *sk, |
791 | struct flowi4 *fl4, | |
792 | struct sk_buff_head *queue, | |
1470ddf7 HX |
793 | struct inet_cork *cork, |
794 | int getfrag(void *from, char *to, int offset, | |
795 | int len, int odd, struct sk_buff *skb), | |
796 | void *from, int length, int transhdrlen, | |
797 | unsigned int flags) | |
1da177e4 LT |
798 | { |
799 | struct inet_sock *inet = inet_sk(sk); | |
800 | struct sk_buff *skb; | |
801 | ||
07df5294 | 802 | struct ip_options *opt = cork->opt; |
1da177e4 LT |
803 | int hh_len; |
804 | int exthdrlen; | |
805 | int mtu; | |
806 | int copy; | |
807 | int err; | |
808 | int offset = 0; | |
809 | unsigned int maxfraglen, fragheaderlen; | |
810 | int csummode = CHECKSUM_NONE; | |
1470ddf7 | 811 | struct rtable *rt = (struct rtable *)cork->dst; |
1da177e4 | 812 | |
96d7303e SK |
813 | skb = skb_peek_tail(queue); |
814 | ||
815 | exthdrlen = !skb ? rt->dst.header_len : 0; | |
07df5294 | 816 | mtu = cork->fragsize; |
1da177e4 | 817 | |
d8d1f30b | 818 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
1da177e4 LT |
819 | |
820 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
821 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
822 | ||
1470ddf7 | 823 | if (cork->length + length > 0xFFFF - fragheaderlen) { |
f5fca608 | 824 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, |
c720c7e8 | 825 | mtu-exthdrlen); |
1da177e4 LT |
826 | return -EMSGSIZE; |
827 | } | |
828 | ||
829 | /* | |
830 | * transhdrlen > 0 means that this is the first fragment and we wish | |
831 | * it won't be fragmented in the future. | |
832 | */ | |
833 | if (transhdrlen && | |
834 | length + fragheaderlen <= mtu && | |
d8d1f30b | 835 | rt->dst.dev->features & NETIF_F_V4_CSUM && |
1da177e4 | 836 | !exthdrlen) |
84fa7933 | 837 | csummode = CHECKSUM_PARTIAL; |
1da177e4 | 838 | |
1470ddf7 | 839 | cork->length += length; |
26cde9f7 | 840 | if (((length > mtu) || (skb && skb_is_gso(skb))) && |
be9164e7 | 841 | (sk->sk_protocol == IPPROTO_UDP) && |
c146066a | 842 | (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len) { |
1470ddf7 HX |
843 | err = ip_ufo_append_data(sk, queue, getfrag, from, length, |
844 | hh_len, fragheaderlen, transhdrlen, | |
d9be4f7a | 845 | maxfraglen, flags); |
baa829d8 | 846 | if (err) |
e89e9cf5 | 847 | goto error; |
e89e9cf5 AR |
848 | return 0; |
849 | } | |
1da177e4 LT |
850 | |
851 | /* So, what's going on in the loop below? | |
852 | * | |
853 | * We use calculated fragment length to generate chained skb, | |
854 | * each of segments is IP fragment ready for sending to network after | |
855 | * adding appropriate IP header. | |
856 | */ | |
857 | ||
26cde9f7 | 858 | if (!skb) |
1da177e4 LT |
859 | goto alloc_new_skb; |
860 | ||
861 | while (length > 0) { | |
862 | /* Check if the remaining data fits into current packet. */ | |
863 | copy = mtu - skb->len; | |
864 | if (copy < length) | |
865 | copy = maxfraglen - skb->len; | |
866 | if (copy <= 0) { | |
867 | char *data; | |
868 | unsigned int datalen; | |
869 | unsigned int fraglen; | |
870 | unsigned int fraggap; | |
871 | unsigned int alloclen; | |
872 | struct sk_buff *skb_prev; | |
873 | alloc_new_skb: | |
874 | skb_prev = skb; | |
875 | if (skb_prev) | |
876 | fraggap = skb_prev->len - maxfraglen; | |
877 | else | |
878 | fraggap = 0; | |
879 | ||
880 | /* | |
881 | * If remaining data exceeds the mtu, | |
882 | * we know we need more fragment(s). | |
883 | */ | |
884 | datalen = length + fraggap; | |
885 | if (datalen > mtu - fragheaderlen) | |
886 | datalen = maxfraglen - fragheaderlen; | |
887 | fraglen = datalen + fragheaderlen; | |
888 | ||
e905a9ed | 889 | if ((flags & MSG_MORE) && |
d8d1f30b | 890 | !(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 LT |
891 | alloclen = mtu; |
892 | else | |
59104f06 | 893 | alloclen = fraglen; |
1da177e4 | 894 | |
353e5c9a SK |
895 | alloclen += exthdrlen; |
896 | ||
1da177e4 LT |
897 | /* The last fragment gets additional space at tail. |
898 | * Note, with MSG_MORE we overallocate on fragments, | |
899 | * because we have no idea what fragment will be | |
900 | * the last. | |
901 | */ | |
33f99dc7 | 902 | if (datalen == length + fraggap) |
d8d1f30b | 903 | alloclen += rt->dst.trailer_len; |
33f99dc7 | 904 | |
1da177e4 | 905 | if (transhdrlen) { |
e905a9ed | 906 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
907 | alloclen + hh_len + 15, |
908 | (flags & MSG_DONTWAIT), &err); | |
909 | } else { | |
910 | skb = NULL; | |
911 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
912 | 2 * sk->sk_sndbuf) | |
e905a9ed | 913 | skb = sock_wmalloc(sk, |
1da177e4 LT |
914 | alloclen + hh_len + 15, 1, |
915 | sk->sk_allocation); | |
916 | if (unlikely(skb == NULL)) | |
917 | err = -ENOBUFS; | |
51f31cab PO |
918 | else |
919 | /* only the initial fragment is | |
920 | time stamped */ | |
1470ddf7 | 921 | cork->tx_flags = 0; |
1da177e4 LT |
922 | } |
923 | if (skb == NULL) | |
924 | goto error; | |
925 | ||
926 | /* | |
927 | * Fill in the control structures | |
928 | */ | |
929 | skb->ip_summed = csummode; | |
930 | skb->csum = 0; | |
931 | skb_reserve(skb, hh_len); | |
1470ddf7 | 932 | skb_shinfo(skb)->tx_flags = cork->tx_flags; |
1da177e4 LT |
933 | |
934 | /* | |
935 | * Find where to start putting bytes. | |
936 | */ | |
353e5c9a | 937 | data = skb_put(skb, fraglen + exthdrlen); |
c14d2450 | 938 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
939 | skb->transport_header = (skb->network_header + |
940 | fragheaderlen); | |
353e5c9a | 941 | data += fragheaderlen + exthdrlen; |
1da177e4 LT |
942 | |
943 | if (fraggap) { | |
944 | skb->csum = skb_copy_and_csum_bits( | |
945 | skb_prev, maxfraglen, | |
946 | data + transhdrlen, fraggap, 0); | |
947 | skb_prev->csum = csum_sub(skb_prev->csum, | |
948 | skb->csum); | |
949 | data += fraggap; | |
e9fa4f7b | 950 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
951 | } |
952 | ||
953 | copy = datalen - transhdrlen - fraggap; | |
954 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
955 | err = -EFAULT; | |
956 | kfree_skb(skb); | |
957 | goto error; | |
958 | } | |
959 | ||
960 | offset += copy; | |
961 | length -= datalen - fraggap; | |
962 | transhdrlen = 0; | |
963 | exthdrlen = 0; | |
964 | csummode = CHECKSUM_NONE; | |
965 | ||
966 | /* | |
967 | * Put the packet on the pending queue. | |
968 | */ | |
1470ddf7 | 969 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
970 | continue; |
971 | } | |
972 | ||
973 | if (copy > length) | |
974 | copy = length; | |
975 | ||
d8d1f30b | 976 | if (!(rt->dst.dev->features&NETIF_F_SG)) { |
1da177e4 LT |
977 | unsigned int off; |
978 | ||
979 | off = skb->len; | |
e905a9ed | 980 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
981 | offset, copy, off, skb) < 0) { |
982 | __skb_trim(skb, off); | |
983 | err = -EFAULT; | |
984 | goto error; | |
985 | } | |
986 | } else { | |
987 | int i = skb_shinfo(skb)->nr_frags; | |
988 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; | |
1470ddf7 HX |
989 | struct page *page = cork->page; |
990 | int off = cork->off; | |
1da177e4 LT |
991 | unsigned int left; |
992 | ||
993 | if (page && (left = PAGE_SIZE - off) > 0) { | |
994 | if (copy >= left) | |
995 | copy = left; | |
aff65da0 | 996 | if (page != skb_frag_page(frag)) { |
1da177e4 LT |
997 | if (i == MAX_SKB_FRAGS) { |
998 | err = -EMSGSIZE; | |
999 | goto error; | |
1000 | } | |
1470ddf7 | 1001 | skb_fill_page_desc(skb, i, page, off, 0); |
aff65da0 | 1002 | skb_frag_ref(skb, i); |
1da177e4 LT |
1003 | frag = &skb_shinfo(skb)->frags[i]; |
1004 | } | |
1005 | } else if (i < MAX_SKB_FRAGS) { | |
1006 | if (copy > PAGE_SIZE) | |
1007 | copy = PAGE_SIZE; | |
1008 | page = alloc_pages(sk->sk_allocation, 0); | |
1009 | if (page == NULL) { | |
1010 | err = -ENOMEM; | |
1011 | goto error; | |
1012 | } | |
1470ddf7 HX |
1013 | cork->page = page; |
1014 | cork->off = 0; | |
1da177e4 LT |
1015 | |
1016 | skb_fill_page_desc(skb, i, page, 0, 0); | |
1017 | frag = &skb_shinfo(skb)->frags[i]; | |
1da177e4 LT |
1018 | } else { |
1019 | err = -EMSGSIZE; | |
1020 | goto error; | |
1021 | } | |
9e903e08 | 1022 | if (getfrag(from, skb_frag_address(frag)+skb_frag_size(frag), |
aff65da0 | 1023 | offset, copy, skb->len, skb) < 0) { |
1da177e4 LT |
1024 | err = -EFAULT; |
1025 | goto error; | |
1026 | } | |
1470ddf7 | 1027 | cork->off += copy; |
9e903e08 | 1028 | skb_frag_size_add(frag, copy); |
1da177e4 LT |
1029 | skb->len += copy; |
1030 | skb->data_len += copy; | |
f945fa7a HX |
1031 | skb->truesize += copy; |
1032 | atomic_add(copy, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1033 | } |
1034 | offset += copy; | |
1035 | length -= copy; | |
1036 | } | |
1037 | ||
1038 | return 0; | |
1039 | ||
1040 | error: | |
1470ddf7 | 1041 | cork->length -= length; |
5e38e270 | 1042 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
e905a9ed | 1043 | return err; |
1da177e4 LT |
1044 | } |
1045 | ||
1470ddf7 HX |
1046 | static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, |
1047 | struct ipcm_cookie *ipc, struct rtable **rtp) | |
1048 | { | |
1049 | struct inet_sock *inet = inet_sk(sk); | |
f6d8bd05 | 1050 | struct ip_options_rcu *opt; |
1470ddf7 HX |
1051 | struct rtable *rt; |
1052 | ||
1053 | /* | |
1054 | * setup for corking. | |
1055 | */ | |
1056 | opt = ipc->opt; | |
1057 | if (opt) { | |
1058 | if (cork->opt == NULL) { | |
1059 | cork->opt = kmalloc(sizeof(struct ip_options) + 40, | |
1060 | sk->sk_allocation); | |
1061 | if (unlikely(cork->opt == NULL)) | |
1062 | return -ENOBUFS; | |
1063 | } | |
f6d8bd05 | 1064 | memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen); |
1470ddf7 HX |
1065 | cork->flags |= IPCORK_OPT; |
1066 | cork->addr = ipc->addr; | |
1067 | } | |
1068 | rt = *rtp; | |
1069 | if (unlikely(!rt)) | |
1070 | return -EFAULT; | |
1071 | /* | |
1072 | * We steal reference to this route, caller should not release it | |
1073 | */ | |
1074 | *rtp = NULL; | |
1075 | cork->fragsize = inet->pmtudisc == IP_PMTUDISC_PROBE ? | |
353e5c9a | 1076 | rt->dst.dev->mtu : dst_mtu(&rt->dst); |
1470ddf7 HX |
1077 | cork->dst = &rt->dst; |
1078 | cork->length = 0; | |
1079 | cork->tx_flags = ipc->tx_flags; | |
1080 | cork->page = NULL; | |
1081 | cork->off = 0; | |
1082 | ||
1083 | return 0; | |
1084 | } | |
1085 | ||
1086 | /* | |
1087 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
1088 | * from many pieces of data. Each pieces will be holded on the socket | |
1089 | * until ip_push_pending_frames() is called. Each piece can be a page | |
1090 | * or non-page data. | |
1091 | * | |
1092 | * Not only UDP, other transport protocols - e.g. raw sockets - can use | |
1093 | * this interface potentially. | |
1094 | * | |
1095 | * LATER: length must be adjusted by pad at tail, when it is required. | |
1096 | */ | |
f5fca608 | 1097 | int ip_append_data(struct sock *sk, struct flowi4 *fl4, |
1470ddf7 HX |
1098 | int getfrag(void *from, char *to, int offset, int len, |
1099 | int odd, struct sk_buff *skb), | |
1100 | void *from, int length, int transhdrlen, | |
1101 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1102 | unsigned int flags) | |
1103 | { | |
1104 | struct inet_sock *inet = inet_sk(sk); | |
1105 | int err; | |
1106 | ||
1107 | if (flags&MSG_PROBE) | |
1108 | return 0; | |
1109 | ||
1110 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
bdc712b4 | 1111 | err = ip_setup_cork(sk, &inet->cork.base, ipc, rtp); |
1470ddf7 HX |
1112 | if (err) |
1113 | return err; | |
1114 | } else { | |
1115 | transhdrlen = 0; | |
1116 | } | |
1117 | ||
f5fca608 | 1118 | return __ip_append_data(sk, fl4, &sk->sk_write_queue, &inet->cork.base, getfrag, |
1470ddf7 HX |
1119 | from, length, transhdrlen, flags); |
1120 | } | |
1121 | ||
f5fca608 | 1122 | ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, |
1da177e4 LT |
1123 | int offset, size_t size, int flags) |
1124 | { | |
1125 | struct inet_sock *inet = inet_sk(sk); | |
1126 | struct sk_buff *skb; | |
1127 | struct rtable *rt; | |
1128 | struct ip_options *opt = NULL; | |
bdc712b4 | 1129 | struct inet_cork *cork; |
1da177e4 LT |
1130 | int hh_len; |
1131 | int mtu; | |
1132 | int len; | |
1133 | int err; | |
1134 | unsigned int maxfraglen, fragheaderlen, fraggap; | |
1135 | ||
1136 | if (inet->hdrincl) | |
1137 | return -EPERM; | |
1138 | ||
1139 | if (flags&MSG_PROBE) | |
1140 | return 0; | |
1141 | ||
1142 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1143 | return -EINVAL; | |
1144 | ||
bdc712b4 DM |
1145 | cork = &inet->cork.base; |
1146 | rt = (struct rtable *)cork->dst; | |
1147 | if (cork->flags & IPCORK_OPT) | |
1148 | opt = cork->opt; | |
1da177e4 | 1149 | |
d8d1f30b | 1150 | if (!(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 LT |
1151 | return -EOPNOTSUPP; |
1152 | ||
d8d1f30b | 1153 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
bdc712b4 | 1154 | mtu = cork->fragsize; |
1da177e4 LT |
1155 | |
1156 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1157 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
1158 | ||
bdc712b4 | 1159 | if (cork->length + size > 0xFFFF - fragheaderlen) { |
f5fca608 | 1160 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, mtu); |
1da177e4 LT |
1161 | return -EMSGSIZE; |
1162 | } | |
1163 | ||
1164 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1165 | return -EINVAL; | |
1166 | ||
bdc712b4 | 1167 | cork->length += size; |
26cde9f7 HX |
1168 | if ((size + skb->len > mtu) && |
1169 | (sk->sk_protocol == IPPROTO_UDP) && | |
d8d1f30b | 1170 | (rt->dst.dev->features & NETIF_F_UFO)) { |
7967168c | 1171 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
f83ef8c0 | 1172 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
7967168c | 1173 | } |
e89e9cf5 | 1174 | |
1da177e4 LT |
1175 | |
1176 | while (size > 0) { | |
1177 | int i; | |
1178 | ||
89114afd | 1179 | if (skb_is_gso(skb)) |
e89e9cf5 AR |
1180 | len = size; |
1181 | else { | |
1182 | ||
1183 | /* Check if the remaining data fits into current packet. */ | |
1184 | len = mtu - skb->len; | |
1185 | if (len < size) | |
1186 | len = maxfraglen - skb->len; | |
1187 | } | |
1da177e4 LT |
1188 | if (len <= 0) { |
1189 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1190 | int alloclen; |
1191 | ||
1192 | skb_prev = skb; | |
0d0d2bba | 1193 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1194 | |
1195 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1196 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1197 | if (unlikely(!skb)) { | |
1198 | err = -ENOBUFS; | |
1199 | goto error; | |
1200 | } | |
1201 | ||
1202 | /* | |
1203 | * Fill in the control structures | |
1204 | */ | |
1205 | skb->ip_summed = CHECKSUM_NONE; | |
1206 | skb->csum = 0; | |
1207 | skb_reserve(skb, hh_len); | |
1208 | ||
1209 | /* | |
1210 | * Find where to start putting bytes. | |
1211 | */ | |
967b05f6 | 1212 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1213 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1214 | skb->transport_header = (skb->network_header + |
1215 | fragheaderlen); | |
1da177e4 | 1216 | if (fraggap) { |
967b05f6 ACM |
1217 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1218 | maxfraglen, | |
9c70220b | 1219 | skb_transport_header(skb), |
967b05f6 | 1220 | fraggap, 0); |
1da177e4 LT |
1221 | skb_prev->csum = csum_sub(skb_prev->csum, |
1222 | skb->csum); | |
e9fa4f7b | 1223 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1224 | } |
1225 | ||
1226 | /* | |
1227 | * Put the packet on the pending queue. | |
1228 | */ | |
1229 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1230 | continue; | |
1231 | } | |
1232 | ||
1233 | i = skb_shinfo(skb)->nr_frags; | |
1234 | if (len > size) | |
1235 | len = size; | |
1236 | if (skb_can_coalesce(skb, i, page, offset)) { | |
9e903e08 | 1237 | skb_frag_size_add(&skb_shinfo(skb)->frags[i-1], len); |
1da177e4 LT |
1238 | } else if (i < MAX_SKB_FRAGS) { |
1239 | get_page(page); | |
1240 | skb_fill_page_desc(skb, i, page, offset, len); | |
1241 | } else { | |
1242 | err = -EMSGSIZE; | |
1243 | goto error; | |
1244 | } | |
1245 | ||
1246 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1247 | __wsum csum; |
1da177e4 LT |
1248 | csum = csum_page(page, offset, len); |
1249 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1250 | } | |
1251 | ||
1252 | skb->len += len; | |
1253 | skb->data_len += len; | |
1e34a11d DM |
1254 | skb->truesize += len; |
1255 | atomic_add(len, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1256 | offset += len; |
1257 | size -= len; | |
1258 | } | |
1259 | return 0; | |
1260 | ||
1261 | error: | |
bdc712b4 | 1262 | cork->length -= size; |
5e38e270 | 1263 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1264 | return err; |
1265 | } | |
1266 | ||
1470ddf7 | 1267 | static void ip_cork_release(struct inet_cork *cork) |
429f08e9 | 1268 | { |
1470ddf7 HX |
1269 | cork->flags &= ~IPCORK_OPT; |
1270 | kfree(cork->opt); | |
1271 | cork->opt = NULL; | |
1272 | dst_release(cork->dst); | |
1273 | cork->dst = NULL; | |
429f08e9 PE |
1274 | } |
1275 | ||
1da177e4 LT |
1276 | /* |
1277 | * Combined all pending IP fragments on the socket as one IP datagram | |
1278 | * and push them out. | |
1279 | */ | |
1c32c5ad | 1280 | struct sk_buff *__ip_make_skb(struct sock *sk, |
77968b78 | 1281 | struct flowi4 *fl4, |
1c32c5ad HX |
1282 | struct sk_buff_head *queue, |
1283 | struct inet_cork *cork) | |
1da177e4 LT |
1284 | { |
1285 | struct sk_buff *skb, *tmp_skb; | |
1286 | struct sk_buff **tail_skb; | |
1287 | struct inet_sock *inet = inet_sk(sk); | |
0388b004 | 1288 | struct net *net = sock_net(sk); |
1da177e4 | 1289 | struct ip_options *opt = NULL; |
1470ddf7 | 1290 | struct rtable *rt = (struct rtable *)cork->dst; |
1da177e4 | 1291 | struct iphdr *iph; |
76ab608d | 1292 | __be16 df = 0; |
1da177e4 | 1293 | __u8 ttl; |
1da177e4 | 1294 | |
1470ddf7 | 1295 | if ((skb = __skb_dequeue(queue)) == NULL) |
1da177e4 LT |
1296 | goto out; |
1297 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1298 | ||
1299 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1300 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1301 | __skb_pull(skb, skb_network_offset(skb)); |
1470ddf7 | 1302 | while ((tmp_skb = __skb_dequeue(queue)) != NULL) { |
cfe1fc77 | 1303 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1304 | *tail_skb = tmp_skb; |
1305 | tail_skb = &(tmp_skb->next); | |
1306 | skb->len += tmp_skb->len; | |
1307 | skb->data_len += tmp_skb->len; | |
1308 | skb->truesize += tmp_skb->truesize; | |
1da177e4 LT |
1309 | tmp_skb->destructor = NULL; |
1310 | tmp_skb->sk = NULL; | |
1311 | } | |
1312 | ||
1313 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1314 | * to fragment the frame generated here. No matter, what transforms | |
1315 | * how transforms change size of the packet, it will come out. | |
1316 | */ | |
628a5c56 | 1317 | if (inet->pmtudisc < IP_PMTUDISC_DO) |
1da177e4 LT |
1318 | skb->local_df = 1; |
1319 | ||
1320 | /* DF bit is set when we want to see DF on outgoing frames. | |
1321 | * If local_df is set too, we still allow to fragment this frame | |
1322 | * locally. */ | |
628a5c56 | 1323 | if (inet->pmtudisc >= IP_PMTUDISC_DO || |
d8d1f30b CG |
1324 | (skb->len <= dst_mtu(&rt->dst) && |
1325 | ip_dont_fragment(sk, &rt->dst))) | |
1da177e4 LT |
1326 | df = htons(IP_DF); |
1327 | ||
1470ddf7 HX |
1328 | if (cork->flags & IPCORK_OPT) |
1329 | opt = cork->opt; | |
1da177e4 LT |
1330 | |
1331 | if (rt->rt_type == RTN_MULTICAST) | |
1332 | ttl = inet->mc_ttl; | |
1333 | else | |
d8d1f30b | 1334 | ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 LT |
1335 | |
1336 | iph = (struct iphdr *)skb->data; | |
1337 | iph->version = 4; | |
1338 | iph->ihl = 5; | |
1da177e4 | 1339 | iph->tos = inet->tos; |
1da177e4 | 1340 | iph->frag_off = df; |
d8d1f30b | 1341 | ip_select_ident(iph, &rt->dst, sk); |
1da177e4 LT |
1342 | iph->ttl = ttl; |
1343 | iph->protocol = sk->sk_protocol; | |
84f9307c | 1344 | ip_copy_addrs(iph, fl4); |
1da177e4 | 1345 | |
22f728f8 DM |
1346 | if (opt) { |
1347 | iph->ihl += opt->optlen>>2; | |
1348 | ip_options_build(skb, opt, cork->addr, rt, 0); | |
1349 | } | |
1350 | ||
1da177e4 | 1351 | skb->priority = sk->sk_priority; |
4a19ec58 | 1352 | skb->mark = sk->sk_mark; |
a21bba94 ED |
1353 | /* |
1354 | * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec | |
1355 | * on dst refcount | |
1356 | */ | |
1470ddf7 | 1357 | cork->dst = NULL; |
d8d1f30b | 1358 | skb_dst_set(skb, &rt->dst); |
1da177e4 | 1359 | |
96793b48 | 1360 | if (iph->protocol == IPPROTO_ICMP) |
0388b004 | 1361 | icmp_out_count(net, ((struct icmphdr *) |
96793b48 DS |
1362 | skb_transport_header(skb))->type); |
1363 | ||
1c32c5ad HX |
1364 | ip_cork_release(cork); |
1365 | out: | |
1366 | return skb; | |
1367 | } | |
1368 | ||
1369 | int ip_send_skb(struct sk_buff *skb) | |
1370 | { | |
1371 | struct net *net = sock_net(skb->sk); | |
1372 | int err; | |
1373 | ||
c439cb2e | 1374 | err = ip_local_out(skb); |
1da177e4 LT |
1375 | if (err) { |
1376 | if (err > 0) | |
6ce9e7b5 | 1377 | err = net_xmit_errno(err); |
1da177e4 | 1378 | if (err) |
1c32c5ad | 1379 | IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1380 | } |
1381 | ||
1da177e4 | 1382 | return err; |
1da177e4 LT |
1383 | } |
1384 | ||
77968b78 | 1385 | int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4) |
1470ddf7 | 1386 | { |
1c32c5ad HX |
1387 | struct sk_buff *skb; |
1388 | ||
77968b78 | 1389 | skb = ip_finish_skb(sk, fl4); |
1c32c5ad HX |
1390 | if (!skb) |
1391 | return 0; | |
1392 | ||
1393 | /* Netfilter gets whole the not fragmented skb. */ | |
1394 | return ip_send_skb(skb); | |
1470ddf7 HX |
1395 | } |
1396 | ||
1da177e4 LT |
1397 | /* |
1398 | * Throw away all pending data on the socket. | |
1399 | */ | |
1470ddf7 HX |
1400 | static void __ip_flush_pending_frames(struct sock *sk, |
1401 | struct sk_buff_head *queue, | |
1402 | struct inet_cork *cork) | |
1da177e4 | 1403 | { |
1da177e4 LT |
1404 | struct sk_buff *skb; |
1405 | ||
1470ddf7 | 1406 | while ((skb = __skb_dequeue_tail(queue)) != NULL) |
1da177e4 LT |
1407 | kfree_skb(skb); |
1408 | ||
1470ddf7 HX |
1409 | ip_cork_release(cork); |
1410 | } | |
1411 | ||
1412 | void ip_flush_pending_frames(struct sock *sk) | |
1413 | { | |
bdc712b4 | 1414 | __ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base); |
1da177e4 LT |
1415 | } |
1416 | ||
1c32c5ad | 1417 | struct sk_buff *ip_make_skb(struct sock *sk, |
77968b78 | 1418 | struct flowi4 *fl4, |
1c32c5ad HX |
1419 | int getfrag(void *from, char *to, int offset, |
1420 | int len, int odd, struct sk_buff *skb), | |
1421 | void *from, int length, int transhdrlen, | |
1422 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1423 | unsigned int flags) | |
1424 | { | |
b80d7226 | 1425 | struct inet_cork cork; |
1c32c5ad HX |
1426 | struct sk_buff_head queue; |
1427 | int err; | |
1428 | ||
1429 | if (flags & MSG_PROBE) | |
1430 | return NULL; | |
1431 | ||
1432 | __skb_queue_head_init(&queue); | |
1433 | ||
b80d7226 DM |
1434 | cork.flags = 0; |
1435 | cork.addr = 0; | |
70652728 | 1436 | cork.opt = NULL; |
1c32c5ad HX |
1437 | err = ip_setup_cork(sk, &cork, ipc, rtp); |
1438 | if (err) | |
1439 | return ERR_PTR(err); | |
1440 | ||
f5fca608 | 1441 | err = __ip_append_data(sk, fl4, &queue, &cork, getfrag, |
1c32c5ad HX |
1442 | from, length, transhdrlen, flags); |
1443 | if (err) { | |
1444 | __ip_flush_pending_frames(sk, &queue, &cork); | |
1445 | return ERR_PTR(err); | |
1446 | } | |
1447 | ||
77968b78 | 1448 | return __ip_make_skb(sk, fl4, &queue, &cork); |
1c32c5ad | 1449 | } |
1da177e4 LT |
1450 | |
1451 | /* | |
1452 | * Fetch data from kernel space and fill in checksum if needed. | |
1453 | */ | |
e905a9ed | 1454 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1455 | int len, int odd, struct sk_buff *skb) |
1456 | { | |
5084205f | 1457 | __wsum csum; |
1da177e4 LT |
1458 | |
1459 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1460 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1461 | return 0; |
1da177e4 LT |
1462 | } |
1463 | ||
e905a9ed | 1464 | /* |
1da177e4 | 1465 | * Generic function to send a packet as reply to another packet. |
be9f4a44 | 1466 | * Used to send some TCP resets/acks so far. |
1da177e4 | 1467 | * |
be9f4a44 | 1468 | * Use a fake percpu inet socket to avoid false sharing and contention. |
1da177e4 | 1469 | */ |
be9f4a44 ED |
1470 | static DEFINE_PER_CPU(struct inet_sock, unicast_sock) = { |
1471 | .sk = { | |
1472 | .__sk_common = { | |
1473 | .skc_refcnt = ATOMIC_INIT(1), | |
1474 | }, | |
1475 | .sk_wmem_alloc = ATOMIC_INIT(1), | |
1476 | .sk_allocation = GFP_ATOMIC, | |
1477 | .sk_flags = (1UL << SOCK_USE_WRITE_QUEUE), | |
1478 | }, | |
0980e56e ED |
1479 | .pmtudisc = IP_PMTUDISC_WANT, |
1480 | .uc_ttl = -1, | |
be9f4a44 ED |
1481 | }; |
1482 | ||
1483 | void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, | |
70e73416 DM |
1484 | __be32 saddr, const struct ip_reply_arg *arg, |
1485 | unsigned int len) | |
1da177e4 | 1486 | { |
f6d8bd05 | 1487 | struct ip_options_data replyopts; |
1da177e4 | 1488 | struct ipcm_cookie ipc; |
77968b78 | 1489 | struct flowi4 fl4; |
511c3f92 | 1490 | struct rtable *rt = skb_rtable(skb); |
be9f4a44 ED |
1491 | struct sk_buff *nskb; |
1492 | struct sock *sk; | |
1493 | struct inet_sock *inet; | |
1da177e4 | 1494 | |
f6d8bd05 | 1495 | if (ip_options_echo(&replyopts.opt.opt, skb)) |
1da177e4 LT |
1496 | return; |
1497 | ||
0a5ebb80 | 1498 | ipc.addr = daddr; |
1da177e4 | 1499 | ipc.opt = NULL; |
2244d07b | 1500 | ipc.tx_flags = 0; |
1da177e4 | 1501 | |
f6d8bd05 | 1502 | if (replyopts.opt.opt.optlen) { |
1da177e4 LT |
1503 | ipc.opt = &replyopts.opt; |
1504 | ||
f6d8bd05 ED |
1505 | if (replyopts.opt.opt.srr) |
1506 | daddr = replyopts.opt.opt.faddr; | |
1da177e4 LT |
1507 | } |
1508 | ||
77968b78 | 1509 | flowi4_init_output(&fl4, arg->bound_dev_if, 0, |
66b13d99 | 1510 | RT_TOS(arg->tos), |
be9f4a44 | 1511 | RT_SCOPE_UNIVERSE, ip_hdr(skb)->protocol, |
77968b78 | 1512 | ip_reply_arg_flowi_flags(arg), |
70e73416 | 1513 | daddr, saddr, |
77968b78 DM |
1514 | tcp_hdr(skb)->source, tcp_hdr(skb)->dest); |
1515 | security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); | |
be9f4a44 | 1516 | rt = ip_route_output_key(net, &fl4); |
77968b78 DM |
1517 | if (IS_ERR(rt)) |
1518 | return; | |
1da177e4 | 1519 | |
be9f4a44 | 1520 | inet = &get_cpu_var(unicast_sock); |
1da177e4 | 1521 | |
66b13d99 | 1522 | inet->tos = arg->tos; |
be9f4a44 | 1523 | sk = &inet->sk; |
1da177e4 | 1524 | sk->sk_priority = skb->priority; |
eddc9ec5 | 1525 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1526 | sk->sk_bound_dev_if = arg->bound_dev_if; |
be9f4a44 ED |
1527 | sock_net_set(sk, net); |
1528 | __skb_queue_head_init(&sk->sk_write_queue); | |
1529 | sk->sk_sndbuf = sysctl_wmem_default; | |
f5fca608 | 1530 | ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, len, 0, |
2e77d89b | 1531 | &ipc, &rt, MSG_DONTWAIT); |
be9f4a44 ED |
1532 | nskb = skb_peek(&sk->sk_write_queue); |
1533 | if (nskb) { | |
1da177e4 | 1534 | if (arg->csumoffset >= 0) |
be9f4a44 ED |
1535 | *((__sum16 *)skb_transport_header(nskb) + |
1536 | arg->csumoffset) = csum_fold(csum_add(nskb->csum, | |
9c70220b | 1537 | arg->csum)); |
be9f4a44 ED |
1538 | nskb->ip_summed = CHECKSUM_NONE; |
1539 | skb_set_queue_mapping(nskb, skb_get_queue_mapping(skb)); | |
77968b78 | 1540 | ip_push_pending_frames(sk, &fl4); |
1da177e4 LT |
1541 | } |
1542 | ||
be9f4a44 | 1543 | put_cpu_var(unicast_sock); |
1da177e4 LT |
1544 | |
1545 | ip_rt_put(rt); | |
1546 | } | |
1547 | ||
1da177e4 LT |
1548 | void __init ip_init(void) |
1549 | { | |
1da177e4 LT |
1550 | ip_rt_init(); |
1551 | inet_initpeers(); | |
1552 | ||
1553 | #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) | |
1554 | igmp_mc_proc_init(); | |
1555 | #endif | |
1556 | } |