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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> | |
46 | #include <asm/system.h> | |
47 | #include <linux/module.h> | |
48 | #include <linux/types.h> | |
49 | #include <linux/kernel.h> | |
1da177e4 LT |
50 | #include <linux/mm.h> |
51 | #include <linux/string.h> | |
52 | #include <linux/errno.h> | |
a1f8e7f7 | 53 | #include <linux/highmem.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; |
1da177e4 LT |
84 | |
85 | /* Generate a checksum for an outgoing IP datagram. */ | |
86 | __inline__ void ip_send_check(struct iphdr *iph) | |
87 | { | |
88 | iph->check = 0; | |
89 | iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); | |
90 | } | |
91 | ||
c439cb2e HX |
92 | int __ip_local_out(struct sk_buff *skb) |
93 | { | |
94 | struct iphdr *iph = ip_hdr(skb); | |
95 | ||
96 | iph->tot_len = htons(skb->len); | |
97 | ip_send_check(iph); | |
6e23ae2a | 98 | return nf_hook(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, skb->dst->dev, |
c439cb2e HX |
99 | dst_output); |
100 | } | |
101 | ||
102 | int ip_local_out(struct sk_buff *skb) | |
103 | { | |
104 | int err; | |
105 | ||
106 | err = __ip_local_out(skb); | |
107 | if (likely(err == 1)) | |
108 | err = dst_output(skb); | |
109 | ||
110 | return err; | |
111 | } | |
112 | EXPORT_SYMBOL_GPL(ip_local_out); | |
113 | ||
1da177e4 LT |
114 | /* dev_loopback_xmit for use with netfilter. */ |
115 | static int ip_dev_loopback_xmit(struct sk_buff *newskb) | |
116 | { | |
459a98ed | 117 | skb_reset_mac_header(newskb); |
bbe735e4 | 118 | __skb_pull(newskb, skb_network_offset(newskb)); |
1da177e4 LT |
119 | newskb->pkt_type = PACKET_LOOPBACK; |
120 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
547b792c | 121 | WARN_ON(!newskb->dst); |
1da177e4 LT |
122 | netif_rx(newskb); |
123 | return 0; | |
124 | } | |
125 | ||
126 | static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) | |
127 | { | |
128 | int ttl = inet->uc_ttl; | |
129 | ||
130 | if (ttl < 0) | |
131 | ttl = dst_metric(dst, RTAX_HOPLIMIT); | |
132 | return ttl; | |
133 | } | |
134 | ||
e905a9ed | 135 | /* |
1da177e4 LT |
136 | * Add an ip header to a skbuff and send it out. |
137 | * | |
138 | */ | |
139 | int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, | |
13d8eaa0 | 140 | __be32 saddr, __be32 daddr, struct ip_options *opt) |
1da177e4 LT |
141 | { |
142 | struct inet_sock *inet = inet_sk(sk); | |
ee6b9673 | 143 | struct rtable *rt = skb->rtable; |
1da177e4 LT |
144 | struct iphdr *iph; |
145 | ||
146 | /* Build the IP header. */ | |
8856dfa3 ACM |
147 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
148 | skb_reset_network_header(skb); | |
eddc9ec5 | 149 | iph = ip_hdr(skb); |
1da177e4 LT |
150 | iph->version = 4; |
151 | iph->ihl = 5; | |
152 | iph->tos = inet->tos; | |
153 | if (ip_dont_fragment(sk, &rt->u.dst)) | |
154 | iph->frag_off = htons(IP_DF); | |
155 | else | |
156 | iph->frag_off = 0; | |
157 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); | |
158 | iph->daddr = rt->rt_dst; | |
159 | iph->saddr = rt->rt_src; | |
160 | iph->protocol = sk->sk_protocol; | |
1da177e4 | 161 | ip_select_ident(iph, &rt->u.dst, sk); |
1da177e4 LT |
162 | |
163 | if (opt && opt->optlen) { | |
164 | iph->ihl += opt->optlen>>2; | |
165 | ip_options_build(skb, opt, daddr, rt, 0); | |
166 | } | |
1da177e4 LT |
167 | |
168 | skb->priority = sk->sk_priority; | |
4a19ec58 | 169 | skb->mark = sk->sk_mark; |
1da177e4 LT |
170 | |
171 | /* Send it out. */ | |
c439cb2e | 172 | return ip_local_out(skb); |
1da177e4 LT |
173 | } |
174 | ||
d8c97a94 ACM |
175 | EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); |
176 | ||
1da177e4 LT |
177 | static inline int ip_finish_output2(struct sk_buff *skb) |
178 | { | |
179 | struct dst_entry *dst = skb->dst; | |
80787ebc | 180 | struct rtable *rt = (struct rtable *)dst; |
1da177e4 | 181 | struct net_device *dev = dst->dev; |
c2636b4d | 182 | unsigned int hh_len = LL_RESERVED_SPACE(dev); |
1da177e4 | 183 | |
80787ebc | 184 | if (rt->rt_type == RTN_MULTICAST) |
5e38e270 | 185 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTMCASTPKTS); |
80787ebc | 186 | else if (rt->rt_type == RTN_BROADCAST) |
5e38e270 | 187 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTBCASTPKTS); |
80787ebc | 188 | |
1da177e4 | 189 | /* Be paranoid, rather than too clever. */ |
3b04ddde | 190 | if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { |
1da177e4 LT |
191 | struct sk_buff *skb2; |
192 | ||
193 | skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); | |
194 | if (skb2 == NULL) { | |
195 | kfree_skb(skb); | |
196 | return -ENOMEM; | |
197 | } | |
198 | if (skb->sk) | |
199 | skb_set_owner_w(skb2, skb->sk); | |
200 | kfree_skb(skb); | |
201 | skb = skb2; | |
202 | } | |
203 | ||
3644f0ce SH |
204 | if (dst->hh) |
205 | return neigh_hh_output(dst->hh, skb); | |
206 | else if (dst->neighbour) | |
1da177e4 LT |
207 | return dst->neighbour->output(skb); |
208 | ||
209 | if (net_ratelimit()) | |
210 | printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); | |
211 | kfree_skb(skb); | |
212 | return -EINVAL; | |
213 | } | |
214 | ||
628a5c56 JH |
215 | static inline int ip_skb_dst_mtu(struct sk_buff *skb) |
216 | { | |
217 | struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; | |
218 | ||
219 | return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? | |
220 | skb->dst->dev->mtu : dst_mtu(skb->dst); | |
221 | } | |
222 | ||
861d0486 | 223 | static int ip_finish_output(struct sk_buff *skb) |
1da177e4 | 224 | { |
5c901daa PM |
225 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
226 | /* Policy lookup after SNAT yielded a new policy */ | |
48d5cad8 PM |
227 | if (skb->dst->xfrm != NULL) { |
228 | IPCB(skb)->flags |= IPSKB_REROUTED; | |
229 | return dst_output(skb); | |
230 | } | |
5c901daa | 231 | #endif |
628a5c56 | 232 | if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) |
1bd9bef6 PM |
233 | return ip_fragment(skb, ip_finish_output2); |
234 | else | |
235 | return ip_finish_output2(skb); | |
1da177e4 LT |
236 | } |
237 | ||
238 | int ip_mc_output(struct sk_buff *skb) | |
239 | { | |
240 | struct sock *sk = skb->sk; | |
ee6b9673 | 241 | struct rtable *rt = skb->rtable; |
1da177e4 LT |
242 | struct net_device *dev = rt->u.dst.dev; |
243 | ||
244 | /* | |
245 | * If the indicated interface is up and running, send the packet. | |
246 | */ | |
5e38e270 | 247 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTREQUESTS); |
1da177e4 LT |
248 | |
249 | skb->dev = dev; | |
250 | skb->protocol = htons(ETH_P_IP); | |
251 | ||
252 | /* | |
253 | * Multicasts are looped back for other local users | |
254 | */ | |
255 | ||
256 | if (rt->rt_flags&RTCF_MULTICAST) { | |
257 | if ((!sk || inet_sk(sk)->mc_loop) | |
258 | #ifdef CONFIG_IP_MROUTE | |
259 | /* Small optimization: do not loopback not local frames, | |
260 | which returned after forwarding; they will be dropped | |
261 | by ip_mr_input in any case. | |
262 | Note, that local frames are looped back to be delivered | |
263 | to local recipients. | |
264 | ||
265 | This check is duplicated in ip_mr_input at the moment. | |
266 | */ | |
267 | && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED)) | |
268 | #endif | |
269 | ) { | |
270 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
271 | if (newskb) | |
6e23ae2a PM |
272 | NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, |
273 | NULL, newskb->dev, | |
1da177e4 LT |
274 | ip_dev_loopback_xmit); |
275 | } | |
276 | ||
277 | /* Multicasts with ttl 0 must not go beyond the host */ | |
278 | ||
eddc9ec5 | 279 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
280 | kfree_skb(skb); |
281 | return 0; | |
282 | } | |
283 | } | |
284 | ||
285 | if (rt->rt_flags&RTCF_BROADCAST) { | |
286 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
287 | if (newskb) | |
6e23ae2a | 288 | NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, NULL, |
1da177e4 LT |
289 | newskb->dev, ip_dev_loopback_xmit); |
290 | } | |
291 | ||
6e23ae2a | 292 | return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, skb->dev, |
48d5cad8 PM |
293 | ip_finish_output, |
294 | !(IPCB(skb)->flags & IPSKB_REROUTED)); | |
1da177e4 LT |
295 | } |
296 | ||
297 | int ip_output(struct sk_buff *skb) | |
298 | { | |
1bd9bef6 PM |
299 | struct net_device *dev = skb->dst->dev; |
300 | ||
5e38e270 | 301 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTREQUESTS); |
1da177e4 | 302 | |
1bd9bef6 PM |
303 | skb->dev = dev; |
304 | skb->protocol = htons(ETH_P_IP); | |
305 | ||
6e23ae2a | 306 | return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, dev, |
e905a9ed | 307 | ip_finish_output, |
48d5cad8 | 308 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
309 | } |
310 | ||
e89862f4 | 311 | int ip_queue_xmit(struct sk_buff *skb, int ipfragok) |
1da177e4 | 312 | { |
e89862f4 | 313 | struct sock *sk = skb->sk; |
1da177e4 LT |
314 | struct inet_sock *inet = inet_sk(sk); |
315 | struct ip_options *opt = inet->opt; | |
316 | struct rtable *rt; | |
317 | struct iphdr *iph; | |
318 | ||
319 | /* Skip all of this if the packet is already routed, | |
320 | * f.e. by something like SCTP. | |
321 | */ | |
ee6b9673 | 322 | rt = skb->rtable; |
1da177e4 LT |
323 | if (rt != NULL) |
324 | goto packet_routed; | |
325 | ||
326 | /* Make sure we can route this packet. */ | |
327 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
328 | if (rt == NULL) { | |
3ca3c68e | 329 | __be32 daddr; |
1da177e4 LT |
330 | |
331 | /* Use correct destination address if we have options. */ | |
332 | daddr = inet->daddr; | |
333 | if(opt && opt->srr) | |
334 | daddr = opt->faddr; | |
335 | ||
336 | { | |
337 | struct flowi fl = { .oif = sk->sk_bound_dev_if, | |
338 | .nl_u = { .ip4_u = | |
339 | { .daddr = daddr, | |
340 | .saddr = inet->saddr, | |
341 | .tos = RT_CONN_FLAGS(sk) } }, | |
342 | .proto = sk->sk_protocol, | |
86b08d86 | 343 | .flags = inet_sk_flowi_flags(sk), |
1da177e4 LT |
344 | .uli_u = { .ports = |
345 | { .sport = inet->sport, | |
346 | .dport = inet->dport } } }; | |
347 | ||
348 | /* If this fails, retransmit mechanism of transport layer will | |
349 | * keep trying until route appears or the connection times | |
350 | * itself out. | |
351 | */ | |
beb8d13b | 352 | security_sk_classify_flow(sk, &fl); |
3b1e0a65 | 353 | if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0)) |
1da177e4 LT |
354 | goto no_route; |
355 | } | |
6cbb0df7 | 356 | sk_setup_caps(sk, &rt->u.dst); |
1da177e4 LT |
357 | } |
358 | skb->dst = dst_clone(&rt->u.dst); | |
359 | ||
360 | packet_routed: | |
361 | if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) | |
362 | goto no_route; | |
363 | ||
364 | /* OK, we know where to send it, allocate and build IP header. */ | |
8856dfa3 ACM |
365 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
366 | skb_reset_network_header(skb); | |
eddc9ec5 | 367 | iph = ip_hdr(skb); |
714e85be | 368 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); |
1da177e4 LT |
369 | if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok) |
370 | iph->frag_off = htons(IP_DF); | |
371 | else | |
372 | iph->frag_off = 0; | |
373 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); | |
374 | iph->protocol = sk->sk_protocol; | |
375 | iph->saddr = rt->rt_src; | |
376 | iph->daddr = rt->rt_dst; | |
1da177e4 LT |
377 | /* Transport layer set skb->h.foo itself. */ |
378 | ||
379 | if (opt && opt->optlen) { | |
380 | iph->ihl += opt->optlen >> 2; | |
381 | ip_options_build(skb, opt, inet->daddr, rt, 0); | |
382 | } | |
383 | ||
89f5f0ae | 384 | ip_select_ident_more(iph, &rt->u.dst, sk, |
7967168c | 385 | (skb_shinfo(skb)->gso_segs ?: 1) - 1); |
1da177e4 | 386 | |
1da177e4 | 387 | skb->priority = sk->sk_priority; |
4a19ec58 | 388 | skb->mark = sk->sk_mark; |
1da177e4 | 389 | |
c439cb2e | 390 | return ip_local_out(skb); |
1da177e4 LT |
391 | |
392 | no_route: | |
5e38e270 | 393 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
1da177e4 LT |
394 | kfree_skb(skb); |
395 | return -EHOSTUNREACH; | |
396 | } | |
397 | ||
398 | ||
399 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) | |
400 | { | |
401 | to->pkt_type = from->pkt_type; | |
402 | to->priority = from->priority; | |
403 | to->protocol = from->protocol; | |
1da177e4 LT |
404 | dst_release(to->dst); |
405 | to->dst = dst_clone(from->dst); | |
406 | to->dev = from->dev; | |
82e91ffe | 407 | to->mark = from->mark; |
1da177e4 LT |
408 | |
409 | /* Copy the flags to each fragment. */ | |
410 | IPCB(to)->flags = IPCB(from)->flags; | |
411 | ||
412 | #ifdef CONFIG_NET_SCHED | |
413 | to->tc_index = from->tc_index; | |
414 | #endif | |
e7ac05f3 | 415 | nf_copy(to, from); |
ba9dda3a JK |
416 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ |
417 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) | |
418 | to->nf_trace = from->nf_trace; | |
419 | #endif | |
c98d80ed JA |
420 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
421 | to->ipvs_property = from->ipvs_property; | |
1da177e4 | 422 | #endif |
984bc16c | 423 | skb_copy_secmark(to, from); |
1da177e4 LT |
424 | } |
425 | ||
426 | /* | |
427 | * This IP datagram is too large to be sent in one piece. Break it up into | |
428 | * smaller pieces (each of size equal to IP header plus | |
429 | * a block of the data of the original IP data part) that will yet fit in a | |
430 | * single device frame, and queue such a frame for sending. | |
431 | */ | |
432 | ||
d9319100 | 433 | int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) |
1da177e4 LT |
434 | { |
435 | struct iphdr *iph; | |
436 | int raw = 0; | |
437 | int ptr; | |
438 | struct net_device *dev; | |
439 | struct sk_buff *skb2; | |
9bcfcaf5 | 440 | unsigned int mtu, hlen, left, len, ll_rs, pad; |
1da177e4 | 441 | int offset; |
76ab608d | 442 | __be16 not_last_frag; |
ee6b9673 | 443 | struct rtable *rt = skb->rtable; |
1da177e4 LT |
444 | int err = 0; |
445 | ||
446 | dev = rt->u.dst.dev; | |
447 | ||
448 | /* | |
449 | * Point into the IP datagram header. | |
450 | */ | |
451 | ||
eddc9ec5 | 452 | iph = ip_hdr(skb); |
1da177e4 LT |
453 | |
454 | if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { | |
5e38e270 | 455 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 456 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
628a5c56 | 457 | htonl(ip_skb_dst_mtu(skb))); |
1da177e4 LT |
458 | kfree_skb(skb); |
459 | return -EMSGSIZE; | |
460 | } | |
461 | ||
462 | /* | |
463 | * Setup starting values. | |
464 | */ | |
465 | ||
466 | hlen = iph->ihl * 4; | |
467 | mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ | |
89cee8b1 | 468 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
1da177e4 LT |
469 | |
470 | /* When frag_list is given, use it. First, check its validity: | |
471 | * some transformers could create wrong frag_list or break existing | |
472 | * one, it is not prohibited. In this case fall back to copying. | |
473 | * | |
474 | * LATER: this step can be merged to real generation of fragments, | |
475 | * we can switch to copy when see the first bad fragment. | |
476 | */ | |
477 | if (skb_shinfo(skb)->frag_list) { | |
478 | struct sk_buff *frag; | |
479 | int first_len = skb_pagelen(skb); | |
29ffe1a5 | 480 | int truesizes = 0; |
1da177e4 LT |
481 | |
482 | if (first_len - hlen > mtu || | |
483 | ((first_len - hlen) & 7) || | |
484 | (iph->frag_off & htons(IP_MF|IP_OFFSET)) || | |
485 | skb_cloned(skb)) | |
486 | goto slow_path; | |
487 | ||
488 | for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { | |
489 | /* Correct geometry. */ | |
490 | if (frag->len > mtu || | |
491 | ((frag->len & 7) && frag->next) || | |
492 | skb_headroom(frag) < hlen) | |
493 | goto slow_path; | |
494 | ||
495 | /* Partially cloned skb? */ | |
496 | if (skb_shared(frag)) | |
497 | goto slow_path; | |
2fdba6b0 HX |
498 | |
499 | BUG_ON(frag->sk); | |
500 | if (skb->sk) { | |
501 | sock_hold(skb->sk); | |
502 | frag->sk = skb->sk; | |
503 | frag->destructor = sock_wfree; | |
29ffe1a5 | 504 | truesizes += frag->truesize; |
2fdba6b0 | 505 | } |
1da177e4 LT |
506 | } |
507 | ||
508 | /* Everything is OK. Generate! */ | |
509 | ||
510 | err = 0; | |
511 | offset = 0; | |
512 | frag = skb_shinfo(skb)->frag_list; | |
513 | skb_shinfo(skb)->frag_list = NULL; | |
514 | skb->data_len = first_len - skb_headlen(skb); | |
29ffe1a5 | 515 | skb->truesize -= truesizes; |
1da177e4 LT |
516 | skb->len = first_len; |
517 | iph->tot_len = htons(first_len); | |
518 | iph->frag_off = htons(IP_MF); | |
519 | ip_send_check(iph); | |
520 | ||
521 | for (;;) { | |
522 | /* Prepare header of the next frame, | |
523 | * before previous one went down. */ | |
524 | if (frag) { | |
525 | frag->ip_summed = CHECKSUM_NONE; | |
badff6d0 | 526 | skb_reset_transport_header(frag); |
e2d1bca7 ACM |
527 | __skb_push(frag, hlen); |
528 | skb_reset_network_header(frag); | |
d56f90a7 | 529 | memcpy(skb_network_header(frag), iph, hlen); |
eddc9ec5 | 530 | iph = ip_hdr(frag); |
1da177e4 LT |
531 | iph->tot_len = htons(frag->len); |
532 | ip_copy_metadata(frag, skb); | |
533 | if (offset == 0) | |
534 | ip_options_fragment(frag); | |
535 | offset += skb->len - hlen; | |
536 | iph->frag_off = htons(offset>>3); | |
537 | if (frag->next != NULL) | |
538 | iph->frag_off |= htons(IP_MF); | |
539 | /* Ready, complete checksum */ | |
540 | ip_send_check(iph); | |
541 | } | |
542 | ||
543 | err = output(skb); | |
544 | ||
dafee490 | 545 | if (!err) |
5e38e270 | 546 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 LT |
547 | if (err || !frag) |
548 | break; | |
549 | ||
550 | skb = frag; | |
551 | frag = skb->next; | |
552 | skb->next = NULL; | |
553 | } | |
554 | ||
555 | if (err == 0) { | |
5e38e270 | 556 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
557 | return 0; |
558 | } | |
559 | ||
560 | while (frag) { | |
561 | skb = frag->next; | |
562 | kfree_skb(frag); | |
563 | frag = skb; | |
564 | } | |
5e38e270 | 565 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
566 | return err; |
567 | } | |
568 | ||
569 | slow_path: | |
570 | left = skb->len - hlen; /* Space per frame */ | |
571 | ptr = raw + hlen; /* Where to start from */ | |
572 | ||
1da177e4 | 573 | /* for bridged IP traffic encapsulated inside f.e. a vlan header, |
9bcfcaf5 SH |
574 | * we need to make room for the encapsulating header |
575 | */ | |
576 | pad = nf_bridge_pad(skb); | |
577 | ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad); | |
578 | mtu -= pad; | |
579 | ||
1da177e4 LT |
580 | /* |
581 | * Fragment the datagram. | |
582 | */ | |
583 | ||
584 | offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
585 | not_last_frag = iph->frag_off & htons(IP_MF); | |
586 | ||
587 | /* | |
588 | * Keep copying data until we run out. | |
589 | */ | |
590 | ||
132adf54 | 591 | while (left > 0) { |
1da177e4 LT |
592 | len = left; |
593 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
594 | if (len > mtu) | |
595 | len = mtu; | |
596 | /* IF: we are not sending upto and including the packet end | |
597 | then align the next start on an eight byte boundary */ | |
598 | if (len < left) { | |
599 | len &= ~7; | |
600 | } | |
601 | /* | |
602 | * Allocate buffer. | |
603 | */ | |
604 | ||
605 | if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { | |
64ce2073 | 606 | NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); |
1da177e4 LT |
607 | err = -ENOMEM; |
608 | goto fail; | |
609 | } | |
610 | ||
611 | /* | |
612 | * Set up data on packet | |
613 | */ | |
614 | ||
615 | ip_copy_metadata(skb2, skb); | |
616 | skb_reserve(skb2, ll_rs); | |
617 | skb_put(skb2, len + hlen); | |
c1d2bbe1 | 618 | skb_reset_network_header(skb2); |
b0e380b1 | 619 | skb2->transport_header = skb2->network_header + hlen; |
1da177e4 LT |
620 | |
621 | /* | |
622 | * Charge the memory for the fragment to any owner | |
623 | * it might possess | |
624 | */ | |
625 | ||
626 | if (skb->sk) | |
627 | skb_set_owner_w(skb2, skb->sk); | |
628 | ||
629 | /* | |
630 | * Copy the packet header into the new buffer. | |
631 | */ | |
632 | ||
d626f62b | 633 | skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); |
1da177e4 LT |
634 | |
635 | /* | |
636 | * Copy a block of the IP datagram. | |
637 | */ | |
bff9b61c | 638 | if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) |
1da177e4 LT |
639 | BUG(); |
640 | left -= len; | |
641 | ||
642 | /* | |
643 | * Fill in the new header fields. | |
644 | */ | |
eddc9ec5 | 645 | iph = ip_hdr(skb2); |
1da177e4 LT |
646 | iph->frag_off = htons((offset >> 3)); |
647 | ||
648 | /* ANK: dirty, but effective trick. Upgrade options only if | |
649 | * the segment to be fragmented was THE FIRST (otherwise, | |
650 | * options are already fixed) and make it ONCE | |
651 | * on the initial skb, so that all the following fragments | |
652 | * will inherit fixed options. | |
653 | */ | |
654 | if (offset == 0) | |
655 | ip_options_fragment(skb); | |
656 | ||
657 | /* | |
658 | * Added AC : If we are fragmenting a fragment that's not the | |
659 | * last fragment then keep MF on each bit | |
660 | */ | |
661 | if (left > 0 || not_last_frag) | |
662 | iph->frag_off |= htons(IP_MF); | |
663 | ptr += len; | |
664 | offset += len; | |
665 | ||
666 | /* | |
667 | * Put this fragment into the sending queue. | |
668 | */ | |
1da177e4 LT |
669 | iph->tot_len = htons(len + hlen); |
670 | ||
671 | ip_send_check(iph); | |
672 | ||
673 | err = output(skb2); | |
674 | if (err) | |
675 | goto fail; | |
dafee490 | 676 | |
5e38e270 | 677 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 LT |
678 | } |
679 | kfree_skb(skb); | |
5e38e270 | 680 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
681 | return err; |
682 | ||
683 | fail: | |
e905a9ed | 684 | kfree_skb(skb); |
5e38e270 | 685 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
686 | return err; |
687 | } | |
688 | ||
2e2f7aef PM |
689 | EXPORT_SYMBOL(ip_fragment); |
690 | ||
1da177e4 LT |
691 | int |
692 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
693 | { | |
694 | struct iovec *iov = from; | |
695 | ||
84fa7933 | 696 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
1da177e4 LT |
697 | if (memcpy_fromiovecend(to, iov, offset, len) < 0) |
698 | return -EFAULT; | |
699 | } else { | |
44bb9363 | 700 | __wsum csum = 0; |
1da177e4 LT |
701 | if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) |
702 | return -EFAULT; | |
703 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
704 | } | |
705 | return 0; | |
706 | } | |
707 | ||
44bb9363 | 708 | static inline __wsum |
1da177e4 LT |
709 | csum_page(struct page *page, int offset, int copy) |
710 | { | |
711 | char *kaddr; | |
44bb9363 | 712 | __wsum csum; |
1da177e4 LT |
713 | kaddr = kmap(page); |
714 | csum = csum_partial(kaddr + offset, copy, 0); | |
715 | kunmap(page); | |
716 | return csum; | |
717 | } | |
718 | ||
4b30b1c6 | 719 | static inline int ip_ufo_append_data(struct sock *sk, |
e89e9cf5 AR |
720 | int getfrag(void *from, char *to, int offset, int len, |
721 | int odd, struct sk_buff *skb), | |
722 | void *from, int length, int hh_len, int fragheaderlen, | |
d9319100 | 723 | int transhdrlen, int mtu, unsigned int flags) |
e89e9cf5 AR |
724 | { |
725 | struct sk_buff *skb; | |
726 | int err; | |
727 | ||
728 | /* There is support for UDP fragmentation offload by network | |
729 | * device, so create one single skb packet containing complete | |
730 | * udp datagram | |
731 | */ | |
732 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { | |
733 | skb = sock_alloc_send_skb(sk, | |
734 | hh_len + fragheaderlen + transhdrlen + 20, | |
735 | (flags & MSG_DONTWAIT), &err); | |
736 | ||
737 | if (skb == NULL) | |
738 | return err; | |
739 | ||
740 | /* reserve space for Hardware header */ | |
741 | skb_reserve(skb, hh_len); | |
742 | ||
743 | /* create space for UDP/IP header */ | |
d9319100 | 744 | skb_put(skb, fragheaderlen + transhdrlen); |
e89e9cf5 AR |
745 | |
746 | /* initialize network header pointer */ | |
c1d2bbe1 | 747 | skb_reset_network_header(skb); |
e89e9cf5 AR |
748 | |
749 | /* initialize protocol header pointer */ | |
b0e380b1 | 750 | skb->transport_header = skb->network_header + fragheaderlen; |
e89e9cf5 | 751 | |
84fa7933 | 752 | skb->ip_summed = CHECKSUM_PARTIAL; |
e89e9cf5 AR |
753 | skb->csum = 0; |
754 | sk->sk_sndmsg_off = 0; | |
e89e9cf5 | 755 | |
be9164e7 | 756 | /* specify the length of each IP datagram fragment */ |
7967168c | 757 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
f83ef8c0 | 758 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
e89e9cf5 | 759 | __skb_queue_tail(&sk->sk_write_queue, skb); |
e89e9cf5 | 760 | } |
be9164e7 K |
761 | |
762 | return skb_append_datato_frags(sk, skb, getfrag, from, | |
763 | (length - transhdrlen)); | |
e89e9cf5 AR |
764 | } |
765 | ||
1da177e4 LT |
766 | /* |
767 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
768 | * from many pieces of data. Each pieces will be holded on the socket | |
769 | * until ip_push_pending_frames() is called. Each piece can be a page | |
770 | * or non-page data. | |
e905a9ed | 771 | * |
1da177e4 LT |
772 | * Not only UDP, other transport protocols - e.g. raw sockets - can use |
773 | * this interface potentially. | |
774 | * | |
775 | * LATER: length must be adjusted by pad at tail, when it is required. | |
776 | */ | |
777 | int ip_append_data(struct sock *sk, | |
778 | int getfrag(void *from, char *to, int offset, int len, | |
779 | int odd, struct sk_buff *skb), | |
780 | void *from, int length, int transhdrlen, | |
2e77d89b | 781 | struct ipcm_cookie *ipc, struct rtable **rtp, |
1da177e4 LT |
782 | unsigned int flags) |
783 | { | |
784 | struct inet_sock *inet = inet_sk(sk); | |
785 | struct sk_buff *skb; | |
786 | ||
787 | struct ip_options *opt = NULL; | |
788 | int hh_len; | |
789 | int exthdrlen; | |
790 | int mtu; | |
791 | int copy; | |
792 | int err; | |
793 | int offset = 0; | |
794 | unsigned int maxfraglen, fragheaderlen; | |
795 | int csummode = CHECKSUM_NONE; | |
2e77d89b | 796 | struct rtable *rt; |
1da177e4 LT |
797 | |
798 | if (flags&MSG_PROBE) | |
799 | return 0; | |
800 | ||
801 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
802 | /* | |
803 | * setup for corking. | |
804 | */ | |
805 | opt = ipc->opt; | |
806 | if (opt) { | |
807 | if (inet->cork.opt == NULL) { | |
808 | inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation); | |
809 | if (unlikely(inet->cork.opt == NULL)) | |
810 | return -ENOBUFS; | |
811 | } | |
812 | memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen); | |
813 | inet->cork.flags |= IPCORK_OPT; | |
814 | inet->cork.addr = ipc->addr; | |
815 | } | |
2e77d89b ED |
816 | rt = *rtp; |
817 | /* | |
818 | * We steal reference to this route, caller should not release it | |
819 | */ | |
820 | *rtp = NULL; | |
628a5c56 JH |
821 | inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ? |
822 | rt->u.dst.dev->mtu : | |
823 | dst_mtu(rt->u.dst.path); | |
c8cdaf99 | 824 | inet->cork.dst = &rt->u.dst; |
1da177e4 LT |
825 | inet->cork.length = 0; |
826 | sk->sk_sndmsg_page = NULL; | |
827 | sk->sk_sndmsg_off = 0; | |
828 | if ((exthdrlen = rt->u.dst.header_len) != 0) { | |
829 | length += exthdrlen; | |
830 | transhdrlen += exthdrlen; | |
831 | } | |
832 | } else { | |
c8cdaf99 | 833 | rt = (struct rtable *)inet->cork.dst; |
1da177e4 LT |
834 | if (inet->cork.flags & IPCORK_OPT) |
835 | opt = inet->cork.opt; | |
836 | ||
837 | transhdrlen = 0; | |
838 | exthdrlen = 0; | |
839 | mtu = inet->cork.fragsize; | |
840 | } | |
841 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
842 | ||
843 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
844 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
845 | ||
846 | if (inet->cork.length + length > 0xFFFF - fragheaderlen) { | |
847 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen); | |
848 | return -EMSGSIZE; | |
849 | } | |
850 | ||
851 | /* | |
852 | * transhdrlen > 0 means that this is the first fragment and we wish | |
853 | * it won't be fragmented in the future. | |
854 | */ | |
855 | if (transhdrlen && | |
856 | length + fragheaderlen <= mtu && | |
d212f87b | 857 | rt->u.dst.dev->features & NETIF_F_V4_CSUM && |
1da177e4 | 858 | !exthdrlen) |
84fa7933 | 859 | csummode = CHECKSUM_PARTIAL; |
1da177e4 LT |
860 | |
861 | inet->cork.length += length; | |
be9164e7 K |
862 | if (((length> mtu) || !skb_queue_empty(&sk->sk_write_queue)) && |
863 | (sk->sk_protocol == IPPROTO_UDP) && | |
864 | (rt->u.dst.dev->features & NETIF_F_UFO)) { | |
baa829d8 PM |
865 | err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, |
866 | fragheaderlen, transhdrlen, mtu, | |
867 | flags); | |
868 | if (err) | |
e89e9cf5 | 869 | goto error; |
e89e9cf5 AR |
870 | return 0; |
871 | } | |
1da177e4 LT |
872 | |
873 | /* So, what's going on in the loop below? | |
874 | * | |
875 | * We use calculated fragment length to generate chained skb, | |
876 | * each of segments is IP fragment ready for sending to network after | |
877 | * adding appropriate IP header. | |
878 | */ | |
879 | ||
880 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
881 | goto alloc_new_skb; | |
882 | ||
883 | while (length > 0) { | |
884 | /* Check if the remaining data fits into current packet. */ | |
885 | copy = mtu - skb->len; | |
886 | if (copy < length) | |
887 | copy = maxfraglen - skb->len; | |
888 | if (copy <= 0) { | |
889 | char *data; | |
890 | unsigned int datalen; | |
891 | unsigned int fraglen; | |
892 | unsigned int fraggap; | |
893 | unsigned int alloclen; | |
894 | struct sk_buff *skb_prev; | |
895 | alloc_new_skb: | |
896 | skb_prev = skb; | |
897 | if (skb_prev) | |
898 | fraggap = skb_prev->len - maxfraglen; | |
899 | else | |
900 | fraggap = 0; | |
901 | ||
902 | /* | |
903 | * If remaining data exceeds the mtu, | |
904 | * we know we need more fragment(s). | |
905 | */ | |
906 | datalen = length + fraggap; | |
907 | if (datalen > mtu - fragheaderlen) | |
908 | datalen = maxfraglen - fragheaderlen; | |
909 | fraglen = datalen + fragheaderlen; | |
910 | ||
e905a9ed | 911 | if ((flags & MSG_MORE) && |
1da177e4 LT |
912 | !(rt->u.dst.dev->features&NETIF_F_SG)) |
913 | alloclen = mtu; | |
914 | else | |
915 | alloclen = datalen + fragheaderlen; | |
916 | ||
917 | /* The last fragment gets additional space at tail. | |
918 | * Note, with MSG_MORE we overallocate on fragments, | |
919 | * because we have no idea what fragment will be | |
920 | * the last. | |
921 | */ | |
3d9dd756 | 922 | if (datalen == length + fraggap) |
1da177e4 LT |
923 | alloclen += rt->u.dst.trailer_len; |
924 | ||
925 | if (transhdrlen) { | |
e905a9ed | 926 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
927 | alloclen + hh_len + 15, |
928 | (flags & MSG_DONTWAIT), &err); | |
929 | } else { | |
930 | skb = NULL; | |
931 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
932 | 2 * sk->sk_sndbuf) | |
e905a9ed | 933 | skb = sock_wmalloc(sk, |
1da177e4 LT |
934 | alloclen + hh_len + 15, 1, |
935 | sk->sk_allocation); | |
936 | if (unlikely(skb == NULL)) | |
937 | err = -ENOBUFS; | |
938 | } | |
939 | if (skb == NULL) | |
940 | goto error; | |
941 | ||
942 | /* | |
943 | * Fill in the control structures | |
944 | */ | |
945 | skb->ip_summed = csummode; | |
946 | skb->csum = 0; | |
947 | skb_reserve(skb, hh_len); | |
948 | ||
949 | /* | |
950 | * Find where to start putting bytes. | |
951 | */ | |
952 | data = skb_put(skb, fraglen); | |
c14d2450 | 953 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
954 | skb->transport_header = (skb->network_header + |
955 | fragheaderlen); | |
1da177e4 | 956 | data += fragheaderlen; |
1da177e4 LT |
957 | |
958 | if (fraggap) { | |
959 | skb->csum = skb_copy_and_csum_bits( | |
960 | skb_prev, maxfraglen, | |
961 | data + transhdrlen, fraggap, 0); | |
962 | skb_prev->csum = csum_sub(skb_prev->csum, | |
963 | skb->csum); | |
964 | data += fraggap; | |
e9fa4f7b | 965 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
966 | } |
967 | ||
968 | copy = datalen - transhdrlen - fraggap; | |
969 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
970 | err = -EFAULT; | |
971 | kfree_skb(skb); | |
972 | goto error; | |
973 | } | |
974 | ||
975 | offset += copy; | |
976 | length -= datalen - fraggap; | |
977 | transhdrlen = 0; | |
978 | exthdrlen = 0; | |
979 | csummode = CHECKSUM_NONE; | |
980 | ||
981 | /* | |
982 | * Put the packet on the pending queue. | |
983 | */ | |
984 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
985 | continue; | |
986 | } | |
987 | ||
988 | if (copy > length) | |
989 | copy = length; | |
990 | ||
991 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) { | |
992 | unsigned int off; | |
993 | ||
994 | off = skb->len; | |
e905a9ed | 995 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
996 | offset, copy, off, skb) < 0) { |
997 | __skb_trim(skb, off); | |
998 | err = -EFAULT; | |
999 | goto error; | |
1000 | } | |
1001 | } else { | |
1002 | int i = skb_shinfo(skb)->nr_frags; | |
1003 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; | |
1004 | struct page *page = sk->sk_sndmsg_page; | |
1005 | int off = sk->sk_sndmsg_off; | |
1006 | unsigned int left; | |
1007 | ||
1008 | if (page && (left = PAGE_SIZE - off) > 0) { | |
1009 | if (copy >= left) | |
1010 | copy = left; | |
1011 | if (page != frag->page) { | |
1012 | if (i == MAX_SKB_FRAGS) { | |
1013 | err = -EMSGSIZE; | |
1014 | goto error; | |
1015 | } | |
1016 | get_page(page); | |
e905a9ed | 1017 | skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); |
1da177e4 LT |
1018 | frag = &skb_shinfo(skb)->frags[i]; |
1019 | } | |
1020 | } else if (i < MAX_SKB_FRAGS) { | |
1021 | if (copy > PAGE_SIZE) | |
1022 | copy = PAGE_SIZE; | |
1023 | page = alloc_pages(sk->sk_allocation, 0); | |
1024 | if (page == NULL) { | |
1025 | err = -ENOMEM; | |
1026 | goto error; | |
1027 | } | |
1028 | sk->sk_sndmsg_page = page; | |
1029 | sk->sk_sndmsg_off = 0; | |
1030 | ||
1031 | skb_fill_page_desc(skb, i, page, 0, 0); | |
1032 | frag = &skb_shinfo(skb)->frags[i]; | |
1da177e4 LT |
1033 | } else { |
1034 | err = -EMSGSIZE; | |
1035 | goto error; | |
1036 | } | |
1037 | if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { | |
1038 | err = -EFAULT; | |
1039 | goto error; | |
1040 | } | |
1041 | sk->sk_sndmsg_off += copy; | |
1042 | frag->size += copy; | |
1043 | skb->len += copy; | |
1044 | skb->data_len += copy; | |
f945fa7a HX |
1045 | skb->truesize += copy; |
1046 | atomic_add(copy, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1047 | } |
1048 | offset += copy; | |
1049 | length -= copy; | |
1050 | } | |
1051 | ||
1052 | return 0; | |
1053 | ||
1054 | error: | |
1055 | inet->cork.length -= length; | |
5e38e270 | 1056 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
e905a9ed | 1057 | return err; |
1da177e4 LT |
1058 | } |
1059 | ||
1060 | ssize_t ip_append_page(struct sock *sk, struct page *page, | |
1061 | int offset, size_t size, int flags) | |
1062 | { | |
1063 | struct inet_sock *inet = inet_sk(sk); | |
1064 | struct sk_buff *skb; | |
1065 | struct rtable *rt; | |
1066 | struct ip_options *opt = NULL; | |
1067 | int hh_len; | |
1068 | int mtu; | |
1069 | int len; | |
1070 | int err; | |
1071 | unsigned int maxfraglen, fragheaderlen, fraggap; | |
1072 | ||
1073 | if (inet->hdrincl) | |
1074 | return -EPERM; | |
1075 | ||
1076 | if (flags&MSG_PROBE) | |
1077 | return 0; | |
1078 | ||
1079 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1080 | return -EINVAL; | |
1081 | ||
c8cdaf99 | 1082 | rt = (struct rtable *)inet->cork.dst; |
1da177e4 LT |
1083 | if (inet->cork.flags & IPCORK_OPT) |
1084 | opt = inet->cork.opt; | |
1085 | ||
1086 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) | |
1087 | return -EOPNOTSUPP; | |
1088 | ||
1089 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
1090 | mtu = inet->cork.fragsize; | |
1091 | ||
1092 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1093 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
1094 | ||
1095 | if (inet->cork.length + size > 0xFFFF - fragheaderlen) { | |
1096 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu); | |
1097 | return -EMSGSIZE; | |
1098 | } | |
1099 | ||
1100 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1101 | return -EINVAL; | |
1102 | ||
1103 | inet->cork.length += size; | |
e89e9cf5 | 1104 | if ((sk->sk_protocol == IPPROTO_UDP) && |
7967168c HX |
1105 | (rt->u.dst.dev->features & NETIF_F_UFO)) { |
1106 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; | |
f83ef8c0 | 1107 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
7967168c | 1108 | } |
e89e9cf5 | 1109 | |
1da177e4 LT |
1110 | |
1111 | while (size > 0) { | |
1112 | int i; | |
1113 | ||
89114afd | 1114 | if (skb_is_gso(skb)) |
e89e9cf5 AR |
1115 | len = size; |
1116 | else { | |
1117 | ||
1118 | /* Check if the remaining data fits into current packet. */ | |
1119 | len = mtu - skb->len; | |
1120 | if (len < size) | |
1121 | len = maxfraglen - skb->len; | |
1122 | } | |
1da177e4 LT |
1123 | if (len <= 0) { |
1124 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1125 | int alloclen; |
1126 | ||
1127 | skb_prev = skb; | |
0d0d2bba | 1128 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1129 | |
1130 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1131 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1132 | if (unlikely(!skb)) { | |
1133 | err = -ENOBUFS; | |
1134 | goto error; | |
1135 | } | |
1136 | ||
1137 | /* | |
1138 | * Fill in the control structures | |
1139 | */ | |
1140 | skb->ip_summed = CHECKSUM_NONE; | |
1141 | skb->csum = 0; | |
1142 | skb_reserve(skb, hh_len); | |
1143 | ||
1144 | /* | |
1145 | * Find where to start putting bytes. | |
1146 | */ | |
967b05f6 | 1147 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1148 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1149 | skb->transport_header = (skb->network_header + |
1150 | fragheaderlen); | |
1da177e4 | 1151 | if (fraggap) { |
967b05f6 ACM |
1152 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1153 | maxfraglen, | |
9c70220b | 1154 | skb_transport_header(skb), |
967b05f6 | 1155 | fraggap, 0); |
1da177e4 LT |
1156 | skb_prev->csum = csum_sub(skb_prev->csum, |
1157 | skb->csum); | |
e9fa4f7b | 1158 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1159 | } |
1160 | ||
1161 | /* | |
1162 | * Put the packet on the pending queue. | |
1163 | */ | |
1164 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1165 | continue; | |
1166 | } | |
1167 | ||
1168 | i = skb_shinfo(skb)->nr_frags; | |
1169 | if (len > size) | |
1170 | len = size; | |
1171 | if (skb_can_coalesce(skb, i, page, offset)) { | |
1172 | skb_shinfo(skb)->frags[i-1].size += len; | |
1173 | } else if (i < MAX_SKB_FRAGS) { | |
1174 | get_page(page); | |
1175 | skb_fill_page_desc(skb, i, page, offset, len); | |
1176 | } else { | |
1177 | err = -EMSGSIZE; | |
1178 | goto error; | |
1179 | } | |
1180 | ||
1181 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1182 | __wsum csum; |
1da177e4 LT |
1183 | csum = csum_page(page, offset, len); |
1184 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1185 | } | |
1186 | ||
1187 | skb->len += len; | |
1188 | skb->data_len += len; | |
1e34a11d DM |
1189 | skb->truesize += len; |
1190 | atomic_add(len, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1191 | offset += len; |
1192 | size -= len; | |
1193 | } | |
1194 | return 0; | |
1195 | ||
1196 | error: | |
1197 | inet->cork.length -= size; | |
5e38e270 | 1198 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1199 | return err; |
1200 | } | |
1201 | ||
429f08e9 PE |
1202 | static void ip_cork_release(struct inet_sock *inet) |
1203 | { | |
1204 | inet->cork.flags &= ~IPCORK_OPT; | |
1205 | kfree(inet->cork.opt); | |
1206 | inet->cork.opt = NULL; | |
c8cdaf99 YH |
1207 | dst_release(inet->cork.dst); |
1208 | inet->cork.dst = NULL; | |
429f08e9 PE |
1209 | } |
1210 | ||
1da177e4 LT |
1211 | /* |
1212 | * Combined all pending IP fragments on the socket as one IP datagram | |
1213 | * and push them out. | |
1214 | */ | |
1215 | int ip_push_pending_frames(struct sock *sk) | |
1216 | { | |
1217 | struct sk_buff *skb, *tmp_skb; | |
1218 | struct sk_buff **tail_skb; | |
1219 | struct inet_sock *inet = inet_sk(sk); | |
0388b004 | 1220 | struct net *net = sock_net(sk); |
1da177e4 | 1221 | struct ip_options *opt = NULL; |
c8cdaf99 | 1222 | struct rtable *rt = (struct rtable *)inet->cork.dst; |
1da177e4 | 1223 | struct iphdr *iph; |
76ab608d | 1224 | __be16 df = 0; |
1da177e4 LT |
1225 | __u8 ttl; |
1226 | int err = 0; | |
1227 | ||
1228 | if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) | |
1229 | goto out; | |
1230 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1231 | ||
1232 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1233 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1234 | __skb_pull(skb, skb_network_offset(skb)); |
1da177e4 | 1235 | while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { |
cfe1fc77 | 1236 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1237 | *tail_skb = tmp_skb; |
1238 | tail_skb = &(tmp_skb->next); | |
1239 | skb->len += tmp_skb->len; | |
1240 | skb->data_len += tmp_skb->len; | |
1241 | skb->truesize += tmp_skb->truesize; | |
1242 | __sock_put(tmp_skb->sk); | |
1243 | tmp_skb->destructor = NULL; | |
1244 | tmp_skb->sk = NULL; | |
1245 | } | |
1246 | ||
1247 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1248 | * to fragment the frame generated here. No matter, what transforms | |
1249 | * how transforms change size of the packet, it will come out. | |
1250 | */ | |
628a5c56 | 1251 | if (inet->pmtudisc < IP_PMTUDISC_DO) |
1da177e4 LT |
1252 | skb->local_df = 1; |
1253 | ||
1254 | /* DF bit is set when we want to see DF on outgoing frames. | |
1255 | * If local_df is set too, we still allow to fragment this frame | |
1256 | * locally. */ | |
628a5c56 | 1257 | if (inet->pmtudisc >= IP_PMTUDISC_DO || |
1da177e4 LT |
1258 | (skb->len <= dst_mtu(&rt->u.dst) && |
1259 | ip_dont_fragment(sk, &rt->u.dst))) | |
1260 | df = htons(IP_DF); | |
1261 | ||
1262 | if (inet->cork.flags & IPCORK_OPT) | |
1263 | opt = inet->cork.opt; | |
1264 | ||
1265 | if (rt->rt_type == RTN_MULTICAST) | |
1266 | ttl = inet->mc_ttl; | |
1267 | else | |
1268 | ttl = ip_select_ttl(inet, &rt->u.dst); | |
1269 | ||
1270 | iph = (struct iphdr *)skb->data; | |
1271 | iph->version = 4; | |
1272 | iph->ihl = 5; | |
1273 | if (opt) { | |
1274 | iph->ihl += opt->optlen>>2; | |
1275 | ip_options_build(skb, opt, inet->cork.addr, rt, 0); | |
1276 | } | |
1277 | iph->tos = inet->tos; | |
1da177e4 | 1278 | iph->frag_off = df; |
1a55d57b | 1279 | ip_select_ident(iph, &rt->u.dst, sk); |
1da177e4 LT |
1280 | iph->ttl = ttl; |
1281 | iph->protocol = sk->sk_protocol; | |
1282 | iph->saddr = rt->rt_src; | |
1283 | iph->daddr = rt->rt_dst; | |
1da177e4 LT |
1284 | |
1285 | skb->priority = sk->sk_priority; | |
4a19ec58 | 1286 | skb->mark = sk->sk_mark; |
a21bba94 ED |
1287 | /* |
1288 | * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec | |
1289 | * on dst refcount | |
1290 | */ | |
1291 | inet->cork.dst = NULL; | |
1292 | skb->dst = &rt->u.dst; | |
1da177e4 | 1293 | |
96793b48 | 1294 | if (iph->protocol == IPPROTO_ICMP) |
0388b004 | 1295 | icmp_out_count(net, ((struct icmphdr *) |
96793b48 DS |
1296 | skb_transport_header(skb))->type); |
1297 | ||
1da177e4 | 1298 | /* Netfilter gets whole the not fragmented skb. */ |
c439cb2e | 1299 | err = ip_local_out(skb); |
1da177e4 LT |
1300 | if (err) { |
1301 | if (err > 0) | |
1302 | err = inet->recverr ? net_xmit_errno(err) : 0; | |
1303 | if (err) | |
1304 | goto error; | |
1305 | } | |
1306 | ||
1307 | out: | |
429f08e9 | 1308 | ip_cork_release(inet); |
1da177e4 LT |
1309 | return err; |
1310 | ||
1311 | error: | |
5e38e270 | 1312 | IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1313 | goto out; |
1314 | } | |
1315 | ||
1316 | /* | |
1317 | * Throw away all pending data on the socket. | |
1318 | */ | |
1319 | void ip_flush_pending_frames(struct sock *sk) | |
1320 | { | |
1da177e4 LT |
1321 | struct sk_buff *skb; |
1322 | ||
1323 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) | |
1324 | kfree_skb(skb); | |
1325 | ||
429f08e9 | 1326 | ip_cork_release(inet_sk(sk)); |
1da177e4 LT |
1327 | } |
1328 | ||
1329 | ||
1330 | /* | |
1331 | * Fetch data from kernel space and fill in checksum if needed. | |
1332 | */ | |
e905a9ed | 1333 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1334 | int len, int odd, struct sk_buff *skb) |
1335 | { | |
5084205f | 1336 | __wsum csum; |
1da177e4 LT |
1337 | |
1338 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1339 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1340 | return 0; |
1da177e4 LT |
1341 | } |
1342 | ||
e905a9ed | 1343 | /* |
1da177e4 LT |
1344 | * Generic function to send a packet as reply to another packet. |
1345 | * Used to send TCP resets so far. ICMP should use this function too. | |
1346 | * | |
e905a9ed | 1347 | * Should run single threaded per socket because it uses the sock |
1da177e4 | 1348 | * structure to pass arguments. |
1da177e4 LT |
1349 | */ |
1350 | void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, | |
1351 | unsigned int len) | |
1352 | { | |
1353 | struct inet_sock *inet = inet_sk(sk); | |
1354 | struct { | |
1355 | struct ip_options opt; | |
1356 | char data[40]; | |
1357 | } replyopts; | |
1358 | struct ipcm_cookie ipc; | |
3ca3c68e | 1359 | __be32 daddr; |
ee6b9673 | 1360 | struct rtable *rt = skb->rtable; |
1da177e4 LT |
1361 | |
1362 | if (ip_options_echo(&replyopts.opt, skb)) | |
1363 | return; | |
1364 | ||
1365 | daddr = ipc.addr = rt->rt_src; | |
1366 | ipc.opt = NULL; | |
1367 | ||
1368 | if (replyopts.opt.optlen) { | |
1369 | ipc.opt = &replyopts.opt; | |
1370 | ||
1371 | if (ipc.opt->srr) | |
1372 | daddr = replyopts.opt.faddr; | |
1373 | } | |
1374 | ||
1375 | { | |
f0e48dbf PM |
1376 | struct flowi fl = { .oif = arg->bound_dev_if, |
1377 | .nl_u = { .ip4_u = | |
1da177e4 LT |
1378 | { .daddr = daddr, |
1379 | .saddr = rt->rt_spec_dst, | |
eddc9ec5 | 1380 | .tos = RT_TOS(ip_hdr(skb)->tos) } }, |
1da177e4 LT |
1381 | /* Not quite clean, but right. */ |
1382 | .uli_u = { .ports = | |
aa8223c7 ACM |
1383 | { .sport = tcp_hdr(skb)->dest, |
1384 | .dport = tcp_hdr(skb)->source } }, | |
86b08d86 KK |
1385 | .proto = sk->sk_protocol, |
1386 | .flags = ip_reply_arg_flowi_flags(arg) }; | |
beb8d13b | 1387 | security_skb_classify_flow(skb, &fl); |
3b1e0a65 | 1388 | if (ip_route_output_key(sock_net(sk), &rt, &fl)) |
1da177e4 LT |
1389 | return; |
1390 | } | |
1391 | ||
1392 | /* And let IP do all the hard work. | |
1393 | ||
1394 | This chunk is not reenterable, hence spinlock. | |
1395 | Note that it uses the fact, that this function is called | |
1396 | with locally disabled BH and that sk cannot be already spinlocked. | |
1397 | */ | |
1398 | bh_lock_sock(sk); | |
eddc9ec5 | 1399 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 | 1400 | sk->sk_priority = skb->priority; |
eddc9ec5 | 1401 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1402 | sk->sk_bound_dev_if = arg->bound_dev_if; |
1da177e4 | 1403 | ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, |
2e77d89b | 1404 | &ipc, &rt, MSG_DONTWAIT); |
1da177e4 LT |
1405 | if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
1406 | if (arg->csumoffset >= 0) | |
9c70220b ACM |
1407 | *((__sum16 *)skb_transport_header(skb) + |
1408 | arg->csumoffset) = csum_fold(csum_add(skb->csum, | |
1409 | arg->csum)); | |
1da177e4 LT |
1410 | skb->ip_summed = CHECKSUM_NONE; |
1411 | ip_push_pending_frames(sk); | |
1412 | } | |
1413 | ||
1414 | bh_unlock_sock(sk); | |
1415 | ||
1416 | ip_rt_put(rt); | |
1417 | } | |
1418 | ||
1da177e4 LT |
1419 | void __init ip_init(void) |
1420 | { | |
1da177e4 LT |
1421 | ip_rt_init(); |
1422 | inet_initpeers(); | |
1423 | ||
1424 | #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) | |
1425 | igmp_mc_proc_init(); | |
1426 | #endif | |
1427 | } | |
1428 | ||
1da177e4 LT |
1429 | EXPORT_SYMBOL(ip_generic_getfrag); |
1430 | EXPORT_SYMBOL(ip_queue_xmit); | |
1431 | EXPORT_SYMBOL(ip_send_check); |