Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * The Internet Protocol (IP) output module. | |
7 | * | |
8 | * Version: $Id: ip_output.c,v 1.100 2002/02/01 22:01:03 davem Exp $ | |
9 | * | |
02c30a84 | 10 | * Authors: Ross Biro |
1da177e4 LT |
11 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
12 | * Donald Becker, <becker@super.org> | |
13 | * Alan Cox, <Alan.Cox@linux.org> | |
14 | * Richard Underwood | |
15 | * Stefan Becker, <stefanb@yello.ping.de> | |
16 | * Jorge Cwik, <jorge@laser.satlink.net> | |
17 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> | |
18 | * Hirokazu Takahashi, <taka@valinux.co.jp> | |
19 | * | |
20 | * See ip_input.c for original log | |
21 | * | |
22 | * Fixes: | |
23 | * Alan Cox : Missing nonblock feature in ip_build_xmit. | |
24 | * Mike Kilburn : htons() missing in ip_build_xmit. | |
e905a9ed | 25 | * Bradford Johnson: Fix faulty handling of some frames when |
1da177e4 LT |
26 | * no route is found. |
27 | * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit | |
28 | * (in case if packet not accepted by | |
29 | * output firewall rules) | |
30 | * Mike McLagan : Routing by source | |
31 | * Alexey Kuznetsov: use new route cache | |
32 | * Andi Kleen: Fix broken PMTU recovery and remove | |
33 | * some redundant tests. | |
34 | * Vitaly E. Lavrov : Transparent proxy revived after year coma. | |
35 | * Andi Kleen : Replace ip_reply with ip_send_reply. | |
e905a9ed YH |
36 | * Andi Kleen : Split fast and slow ip_build_xmit path |
37 | * for decreased register pressure on x86 | |
38 | * and more readibility. | |
1da177e4 LT |
39 | * Marc Boucher : When call_out_firewall returns FW_QUEUE, |
40 | * silently drop skb instead of failing with -EPERM. | |
41 | * Detlev Wengorz : Copy protocol for fragments. | |
42 | * Hirokazu Takahashi: HW checksumming for outgoing UDP | |
43 | * datagrams. | |
44 | * Hirokazu Takahashi: sendfile() on UDP works now. | |
45 | */ | |
46 | ||
47 | #include <asm/uaccess.h> | |
48 | #include <asm/system.h> | |
49 | #include <linux/module.h> | |
50 | #include <linux/types.h> | |
51 | #include <linux/kernel.h> | |
1da177e4 LT |
52 | #include <linux/mm.h> |
53 | #include <linux/string.h> | |
54 | #include <linux/errno.h> | |
a1f8e7f7 | 55 | #include <linux/highmem.h> |
1da177e4 LT |
56 | |
57 | #include <linux/socket.h> | |
58 | #include <linux/sockios.h> | |
59 | #include <linux/in.h> | |
60 | #include <linux/inet.h> | |
61 | #include <linux/netdevice.h> | |
62 | #include <linux/etherdevice.h> | |
63 | #include <linux/proc_fs.h> | |
64 | #include <linux/stat.h> | |
65 | #include <linux/init.h> | |
66 | ||
67 | #include <net/snmp.h> | |
68 | #include <net/ip.h> | |
69 | #include <net/protocol.h> | |
70 | #include <net/route.h> | |
cfacb057 | 71 | #include <net/xfrm.h> |
1da177e4 LT |
72 | #include <linux/skbuff.h> |
73 | #include <net/sock.h> | |
74 | #include <net/arp.h> | |
75 | #include <net/icmp.h> | |
1da177e4 LT |
76 | #include <net/checksum.h> |
77 | #include <net/inetpeer.h> | |
1da177e4 LT |
78 | #include <linux/igmp.h> |
79 | #include <linux/netfilter_ipv4.h> | |
80 | #include <linux/netfilter_bridge.h> | |
81 | #include <linux/mroute.h> | |
82 | #include <linux/netlink.h> | |
6cbb0df7 | 83 | #include <linux/tcp.h> |
1da177e4 | 84 | |
ab32ea5d | 85 | int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; |
1da177e4 LT |
86 | |
87 | /* Generate a checksum for an outgoing IP datagram. */ | |
88 | __inline__ void ip_send_check(struct iphdr *iph) | |
89 | { | |
90 | iph->check = 0; | |
91 | iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); | |
92 | } | |
93 | ||
94 | /* dev_loopback_xmit for use with netfilter. */ | |
95 | static int ip_dev_loopback_xmit(struct sk_buff *newskb) | |
96 | { | |
459a98ed | 97 | skb_reset_mac_header(newskb); |
bbe735e4 | 98 | __skb_pull(newskb, skb_network_offset(newskb)); |
1da177e4 LT |
99 | newskb->pkt_type = PACKET_LOOPBACK; |
100 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
101 | BUG_TRAP(newskb->dst); | |
1da177e4 LT |
102 | netif_rx(newskb); |
103 | return 0; | |
104 | } | |
105 | ||
106 | static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) | |
107 | { | |
108 | int ttl = inet->uc_ttl; | |
109 | ||
110 | if (ttl < 0) | |
111 | ttl = dst_metric(dst, RTAX_HOPLIMIT); | |
112 | return ttl; | |
113 | } | |
114 | ||
e905a9ed | 115 | /* |
1da177e4 LT |
116 | * Add an ip header to a skbuff and send it out. |
117 | * | |
118 | */ | |
119 | int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, | |
13d8eaa0 | 120 | __be32 saddr, __be32 daddr, struct ip_options *opt) |
1da177e4 LT |
121 | { |
122 | struct inet_sock *inet = inet_sk(sk); | |
123 | struct rtable *rt = (struct rtable *)skb->dst; | |
124 | struct iphdr *iph; | |
125 | ||
126 | /* Build the IP header. */ | |
8856dfa3 ACM |
127 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
128 | skb_reset_network_header(skb); | |
eddc9ec5 | 129 | iph = ip_hdr(skb); |
1da177e4 LT |
130 | iph->version = 4; |
131 | iph->ihl = 5; | |
132 | iph->tos = inet->tos; | |
133 | if (ip_dont_fragment(sk, &rt->u.dst)) | |
134 | iph->frag_off = htons(IP_DF); | |
135 | else | |
136 | iph->frag_off = 0; | |
137 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); | |
138 | iph->daddr = rt->rt_dst; | |
139 | iph->saddr = rt->rt_src; | |
140 | iph->protocol = sk->sk_protocol; | |
141 | iph->tot_len = htons(skb->len); | |
142 | ip_select_ident(iph, &rt->u.dst, sk); | |
1da177e4 LT |
143 | |
144 | if (opt && opt->optlen) { | |
145 | iph->ihl += opt->optlen>>2; | |
146 | ip_options_build(skb, opt, daddr, rt, 0); | |
147 | } | |
148 | ip_send_check(iph); | |
149 | ||
150 | skb->priority = sk->sk_priority; | |
151 | ||
152 | /* Send it out. */ | |
153 | return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev, | |
154 | dst_output); | |
155 | } | |
156 | ||
d8c97a94 ACM |
157 | EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); |
158 | ||
1da177e4 LT |
159 | static inline int ip_finish_output2(struct sk_buff *skb) |
160 | { | |
161 | struct dst_entry *dst = skb->dst; | |
80787ebc | 162 | struct rtable *rt = (struct rtable *)dst; |
1da177e4 | 163 | struct net_device *dev = dst->dev; |
c2636b4d | 164 | unsigned int hh_len = LL_RESERVED_SPACE(dev); |
1da177e4 | 165 | |
80787ebc MC |
166 | if (rt->rt_type == RTN_MULTICAST) |
167 | IP_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS); | |
168 | else if (rt->rt_type == RTN_BROADCAST) | |
169 | IP_INC_STATS(IPSTATS_MIB_OUTBCASTPKTS); | |
170 | ||
1da177e4 | 171 | /* Be paranoid, rather than too clever. */ |
3b04ddde | 172 | if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { |
1da177e4 LT |
173 | struct sk_buff *skb2; |
174 | ||
175 | skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); | |
176 | if (skb2 == NULL) { | |
177 | kfree_skb(skb); | |
178 | return -ENOMEM; | |
179 | } | |
180 | if (skb->sk) | |
181 | skb_set_owner_w(skb2, skb->sk); | |
182 | kfree_skb(skb); | |
183 | skb = skb2; | |
184 | } | |
185 | ||
3644f0ce SH |
186 | if (dst->hh) |
187 | return neigh_hh_output(dst->hh, skb); | |
188 | else if (dst->neighbour) | |
1da177e4 LT |
189 | return dst->neighbour->output(skb); |
190 | ||
191 | if (net_ratelimit()) | |
192 | printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); | |
193 | kfree_skb(skb); | |
194 | return -EINVAL; | |
195 | } | |
196 | ||
628a5c56 JH |
197 | static inline int ip_skb_dst_mtu(struct sk_buff *skb) |
198 | { | |
199 | struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; | |
200 | ||
201 | return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? | |
202 | skb->dst->dev->mtu : dst_mtu(skb->dst); | |
203 | } | |
204 | ||
861d0486 | 205 | static int ip_finish_output(struct sk_buff *skb) |
1da177e4 | 206 | { |
5c901daa PM |
207 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
208 | /* Policy lookup after SNAT yielded a new policy */ | |
48d5cad8 PM |
209 | if (skb->dst->xfrm != NULL) { |
210 | IPCB(skb)->flags |= IPSKB_REROUTED; | |
211 | return dst_output(skb); | |
212 | } | |
5c901daa | 213 | #endif |
628a5c56 | 214 | if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) |
1bd9bef6 PM |
215 | return ip_fragment(skb, ip_finish_output2); |
216 | else | |
217 | return ip_finish_output2(skb); | |
1da177e4 LT |
218 | } |
219 | ||
220 | int ip_mc_output(struct sk_buff *skb) | |
221 | { | |
222 | struct sock *sk = skb->sk; | |
223 | struct rtable *rt = (struct rtable*)skb->dst; | |
224 | struct net_device *dev = rt->u.dst.dev; | |
225 | ||
226 | /* | |
227 | * If the indicated interface is up and running, send the packet. | |
228 | */ | |
229 | IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); | |
230 | ||
231 | skb->dev = dev; | |
232 | skb->protocol = htons(ETH_P_IP); | |
233 | ||
234 | /* | |
235 | * Multicasts are looped back for other local users | |
236 | */ | |
237 | ||
238 | if (rt->rt_flags&RTCF_MULTICAST) { | |
239 | if ((!sk || inet_sk(sk)->mc_loop) | |
240 | #ifdef CONFIG_IP_MROUTE | |
241 | /* Small optimization: do not loopback not local frames, | |
242 | which returned after forwarding; they will be dropped | |
243 | by ip_mr_input in any case. | |
244 | Note, that local frames are looped back to be delivered | |
245 | to local recipients. | |
246 | ||
247 | This check is duplicated in ip_mr_input at the moment. | |
248 | */ | |
249 | && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED)) | |
250 | #endif | |
251 | ) { | |
252 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
253 | if (newskb) | |
254 | NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL, | |
e905a9ed | 255 | newskb->dev, |
1da177e4 LT |
256 | ip_dev_loopback_xmit); |
257 | } | |
258 | ||
259 | /* Multicasts with ttl 0 must not go beyond the host */ | |
260 | ||
eddc9ec5 | 261 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
262 | kfree_skb(skb); |
263 | return 0; | |
264 | } | |
265 | } | |
266 | ||
267 | if (rt->rt_flags&RTCF_BROADCAST) { | |
268 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
269 | if (newskb) | |
270 | NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL, | |
271 | newskb->dev, ip_dev_loopback_xmit); | |
272 | } | |
273 | ||
48d5cad8 PM |
274 | return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dev, |
275 | ip_finish_output, | |
276 | !(IPCB(skb)->flags & IPSKB_REROUTED)); | |
1da177e4 LT |
277 | } |
278 | ||
279 | int ip_output(struct sk_buff *skb) | |
280 | { | |
1bd9bef6 PM |
281 | struct net_device *dev = skb->dst->dev; |
282 | ||
1da177e4 LT |
283 | IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); |
284 | ||
1bd9bef6 PM |
285 | skb->dev = dev; |
286 | skb->protocol = htons(ETH_P_IP); | |
287 | ||
48d5cad8 | 288 | return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev, |
e905a9ed | 289 | ip_finish_output, |
48d5cad8 | 290 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
291 | } |
292 | ||
e89862f4 | 293 | int ip_queue_xmit(struct sk_buff *skb, int ipfragok) |
1da177e4 | 294 | { |
e89862f4 | 295 | struct sock *sk = skb->sk; |
1da177e4 LT |
296 | struct inet_sock *inet = inet_sk(sk); |
297 | struct ip_options *opt = inet->opt; | |
298 | struct rtable *rt; | |
299 | struct iphdr *iph; | |
300 | ||
301 | /* Skip all of this if the packet is already routed, | |
302 | * f.e. by something like SCTP. | |
303 | */ | |
304 | rt = (struct rtable *) skb->dst; | |
305 | if (rt != NULL) | |
306 | goto packet_routed; | |
307 | ||
308 | /* Make sure we can route this packet. */ | |
309 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
310 | if (rt == NULL) { | |
3ca3c68e | 311 | __be32 daddr; |
1da177e4 LT |
312 | |
313 | /* Use correct destination address if we have options. */ | |
314 | daddr = inet->daddr; | |
315 | if(opt && opt->srr) | |
316 | daddr = opt->faddr; | |
317 | ||
318 | { | |
319 | struct flowi fl = { .oif = sk->sk_bound_dev_if, | |
320 | .nl_u = { .ip4_u = | |
321 | { .daddr = daddr, | |
322 | .saddr = inet->saddr, | |
323 | .tos = RT_CONN_FLAGS(sk) } }, | |
324 | .proto = sk->sk_protocol, | |
325 | .uli_u = { .ports = | |
326 | { .sport = inet->sport, | |
327 | .dport = inet->dport } } }; | |
328 | ||
329 | /* If this fails, retransmit mechanism of transport layer will | |
330 | * keep trying until route appears or the connection times | |
331 | * itself out. | |
332 | */ | |
beb8d13b | 333 | security_sk_classify_flow(sk, &fl); |
1da177e4 LT |
334 | if (ip_route_output_flow(&rt, &fl, sk, 0)) |
335 | goto no_route; | |
336 | } | |
6cbb0df7 | 337 | sk_setup_caps(sk, &rt->u.dst); |
1da177e4 LT |
338 | } |
339 | skb->dst = dst_clone(&rt->u.dst); | |
340 | ||
341 | packet_routed: | |
342 | if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) | |
343 | goto no_route; | |
344 | ||
345 | /* OK, we know where to send it, allocate and build IP header. */ | |
8856dfa3 ACM |
346 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
347 | skb_reset_network_header(skb); | |
eddc9ec5 | 348 | iph = ip_hdr(skb); |
714e85be | 349 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); |
1da177e4 LT |
350 | iph->tot_len = htons(skb->len); |
351 | if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok) | |
352 | iph->frag_off = htons(IP_DF); | |
353 | else | |
354 | iph->frag_off = 0; | |
355 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); | |
356 | iph->protocol = sk->sk_protocol; | |
357 | iph->saddr = rt->rt_src; | |
358 | iph->daddr = rt->rt_dst; | |
1da177e4 LT |
359 | /* Transport layer set skb->h.foo itself. */ |
360 | ||
361 | if (opt && opt->optlen) { | |
362 | iph->ihl += opt->optlen >> 2; | |
363 | ip_options_build(skb, opt, inet->daddr, rt, 0); | |
364 | } | |
365 | ||
89f5f0ae | 366 | ip_select_ident_more(iph, &rt->u.dst, sk, |
7967168c | 367 | (skb_shinfo(skb)->gso_segs ?: 1) - 1); |
1da177e4 LT |
368 | |
369 | /* Add an IP checksum. */ | |
370 | ip_send_check(iph); | |
371 | ||
372 | skb->priority = sk->sk_priority; | |
373 | ||
374 | return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev, | |
375 | dst_output); | |
376 | ||
377 | no_route: | |
378 | IP_INC_STATS(IPSTATS_MIB_OUTNOROUTES); | |
379 | kfree_skb(skb); | |
380 | return -EHOSTUNREACH; | |
381 | } | |
382 | ||
383 | ||
384 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) | |
385 | { | |
386 | to->pkt_type = from->pkt_type; | |
387 | to->priority = from->priority; | |
388 | to->protocol = from->protocol; | |
1da177e4 LT |
389 | dst_release(to->dst); |
390 | to->dst = dst_clone(from->dst); | |
391 | to->dev = from->dev; | |
82e91ffe | 392 | to->mark = from->mark; |
1da177e4 LT |
393 | |
394 | /* Copy the flags to each fragment. */ | |
395 | IPCB(to)->flags = IPCB(from)->flags; | |
396 | ||
397 | #ifdef CONFIG_NET_SCHED | |
398 | to->tc_index = from->tc_index; | |
399 | #endif | |
e7ac05f3 | 400 | nf_copy(to, from); |
ba9dda3a JK |
401 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ |
402 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) | |
403 | to->nf_trace = from->nf_trace; | |
404 | #endif | |
c98d80ed JA |
405 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
406 | to->ipvs_property = from->ipvs_property; | |
1da177e4 | 407 | #endif |
984bc16c | 408 | skb_copy_secmark(to, from); |
1da177e4 LT |
409 | } |
410 | ||
411 | /* | |
412 | * This IP datagram is too large to be sent in one piece. Break it up into | |
413 | * smaller pieces (each of size equal to IP header plus | |
414 | * a block of the data of the original IP data part) that will yet fit in a | |
415 | * single device frame, and queue such a frame for sending. | |
416 | */ | |
417 | ||
2e2f7aef | 418 | int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) |
1da177e4 LT |
419 | { |
420 | struct iphdr *iph; | |
421 | int raw = 0; | |
422 | int ptr; | |
423 | struct net_device *dev; | |
424 | struct sk_buff *skb2; | |
9bcfcaf5 | 425 | unsigned int mtu, hlen, left, len, ll_rs, pad; |
1da177e4 | 426 | int offset; |
76ab608d | 427 | __be16 not_last_frag; |
1da177e4 LT |
428 | struct rtable *rt = (struct rtable*)skb->dst; |
429 | int err = 0; | |
430 | ||
431 | dev = rt->u.dst.dev; | |
432 | ||
433 | /* | |
434 | * Point into the IP datagram header. | |
435 | */ | |
436 | ||
eddc9ec5 | 437 | iph = ip_hdr(skb); |
1da177e4 LT |
438 | |
439 | if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { | |
0668b472 | 440 | IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 441 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
628a5c56 | 442 | htonl(ip_skb_dst_mtu(skb))); |
1da177e4 LT |
443 | kfree_skb(skb); |
444 | return -EMSGSIZE; | |
445 | } | |
446 | ||
447 | /* | |
448 | * Setup starting values. | |
449 | */ | |
450 | ||
451 | hlen = iph->ihl * 4; | |
452 | mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ | |
89cee8b1 | 453 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
1da177e4 LT |
454 | |
455 | /* When frag_list is given, use it. First, check its validity: | |
456 | * some transformers could create wrong frag_list or break existing | |
457 | * one, it is not prohibited. In this case fall back to copying. | |
458 | * | |
459 | * LATER: this step can be merged to real generation of fragments, | |
460 | * we can switch to copy when see the first bad fragment. | |
461 | */ | |
462 | if (skb_shinfo(skb)->frag_list) { | |
463 | struct sk_buff *frag; | |
464 | int first_len = skb_pagelen(skb); | |
465 | ||
466 | if (first_len - hlen > mtu || | |
467 | ((first_len - hlen) & 7) || | |
468 | (iph->frag_off & htons(IP_MF|IP_OFFSET)) || | |
469 | skb_cloned(skb)) | |
470 | goto slow_path; | |
471 | ||
472 | for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { | |
473 | /* Correct geometry. */ | |
474 | if (frag->len > mtu || | |
475 | ((frag->len & 7) && frag->next) || | |
476 | skb_headroom(frag) < hlen) | |
477 | goto slow_path; | |
478 | ||
479 | /* Partially cloned skb? */ | |
480 | if (skb_shared(frag)) | |
481 | goto slow_path; | |
2fdba6b0 HX |
482 | |
483 | BUG_ON(frag->sk); | |
484 | if (skb->sk) { | |
485 | sock_hold(skb->sk); | |
486 | frag->sk = skb->sk; | |
487 | frag->destructor = sock_wfree; | |
488 | skb->truesize -= frag->truesize; | |
489 | } | |
1da177e4 LT |
490 | } |
491 | ||
492 | /* Everything is OK. Generate! */ | |
493 | ||
494 | err = 0; | |
495 | offset = 0; | |
496 | frag = skb_shinfo(skb)->frag_list; | |
497 | skb_shinfo(skb)->frag_list = NULL; | |
498 | skb->data_len = first_len - skb_headlen(skb); | |
499 | skb->len = first_len; | |
500 | iph->tot_len = htons(first_len); | |
501 | iph->frag_off = htons(IP_MF); | |
502 | ip_send_check(iph); | |
503 | ||
504 | for (;;) { | |
505 | /* Prepare header of the next frame, | |
506 | * before previous one went down. */ | |
507 | if (frag) { | |
508 | frag->ip_summed = CHECKSUM_NONE; | |
badff6d0 | 509 | skb_reset_transport_header(frag); |
e2d1bca7 ACM |
510 | __skb_push(frag, hlen); |
511 | skb_reset_network_header(frag); | |
d56f90a7 | 512 | memcpy(skb_network_header(frag), iph, hlen); |
eddc9ec5 | 513 | iph = ip_hdr(frag); |
1da177e4 LT |
514 | iph->tot_len = htons(frag->len); |
515 | ip_copy_metadata(frag, skb); | |
516 | if (offset == 0) | |
517 | ip_options_fragment(frag); | |
518 | offset += skb->len - hlen; | |
519 | iph->frag_off = htons(offset>>3); | |
520 | if (frag->next != NULL) | |
521 | iph->frag_off |= htons(IP_MF); | |
522 | /* Ready, complete checksum */ | |
523 | ip_send_check(iph); | |
524 | } | |
525 | ||
526 | err = output(skb); | |
527 | ||
dafee490 WD |
528 | if (!err) |
529 | IP_INC_STATS(IPSTATS_MIB_FRAGCREATES); | |
1da177e4 LT |
530 | if (err || !frag) |
531 | break; | |
532 | ||
533 | skb = frag; | |
534 | frag = skb->next; | |
535 | skb->next = NULL; | |
536 | } | |
537 | ||
538 | if (err == 0) { | |
539 | IP_INC_STATS(IPSTATS_MIB_FRAGOKS); | |
540 | return 0; | |
541 | } | |
542 | ||
543 | while (frag) { | |
544 | skb = frag->next; | |
545 | kfree_skb(frag); | |
546 | frag = skb; | |
547 | } | |
548 | IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); | |
549 | return err; | |
550 | } | |
551 | ||
552 | slow_path: | |
553 | left = skb->len - hlen; /* Space per frame */ | |
554 | ptr = raw + hlen; /* Where to start from */ | |
555 | ||
1da177e4 | 556 | /* for bridged IP traffic encapsulated inside f.e. a vlan header, |
9bcfcaf5 SH |
557 | * we need to make room for the encapsulating header |
558 | */ | |
559 | pad = nf_bridge_pad(skb); | |
560 | ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad); | |
561 | mtu -= pad; | |
562 | ||
1da177e4 LT |
563 | /* |
564 | * Fragment the datagram. | |
565 | */ | |
566 | ||
567 | offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
568 | not_last_frag = iph->frag_off & htons(IP_MF); | |
569 | ||
570 | /* | |
571 | * Keep copying data until we run out. | |
572 | */ | |
573 | ||
132adf54 | 574 | while (left > 0) { |
1da177e4 LT |
575 | len = left; |
576 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
577 | if (len > mtu) | |
578 | len = mtu; | |
579 | /* IF: we are not sending upto and including the packet end | |
580 | then align the next start on an eight byte boundary */ | |
581 | if (len < left) { | |
582 | len &= ~7; | |
583 | } | |
584 | /* | |
585 | * Allocate buffer. | |
586 | */ | |
587 | ||
588 | if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { | |
64ce2073 | 589 | NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); |
1da177e4 LT |
590 | err = -ENOMEM; |
591 | goto fail; | |
592 | } | |
593 | ||
594 | /* | |
595 | * Set up data on packet | |
596 | */ | |
597 | ||
598 | ip_copy_metadata(skb2, skb); | |
599 | skb_reserve(skb2, ll_rs); | |
600 | skb_put(skb2, len + hlen); | |
c1d2bbe1 | 601 | skb_reset_network_header(skb2); |
b0e380b1 | 602 | skb2->transport_header = skb2->network_header + hlen; |
1da177e4 LT |
603 | |
604 | /* | |
605 | * Charge the memory for the fragment to any owner | |
606 | * it might possess | |
607 | */ | |
608 | ||
609 | if (skb->sk) | |
610 | skb_set_owner_w(skb2, skb->sk); | |
611 | ||
612 | /* | |
613 | * Copy the packet header into the new buffer. | |
614 | */ | |
615 | ||
d626f62b | 616 | skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); |
1da177e4 LT |
617 | |
618 | /* | |
619 | * Copy a block of the IP datagram. | |
620 | */ | |
bff9b61c | 621 | if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) |
1da177e4 LT |
622 | BUG(); |
623 | left -= len; | |
624 | ||
625 | /* | |
626 | * Fill in the new header fields. | |
627 | */ | |
eddc9ec5 | 628 | iph = ip_hdr(skb2); |
1da177e4 LT |
629 | iph->frag_off = htons((offset >> 3)); |
630 | ||
631 | /* ANK: dirty, but effective trick. Upgrade options only if | |
632 | * the segment to be fragmented was THE FIRST (otherwise, | |
633 | * options are already fixed) and make it ONCE | |
634 | * on the initial skb, so that all the following fragments | |
635 | * will inherit fixed options. | |
636 | */ | |
637 | if (offset == 0) | |
638 | ip_options_fragment(skb); | |
639 | ||
640 | /* | |
641 | * Added AC : If we are fragmenting a fragment that's not the | |
642 | * last fragment then keep MF on each bit | |
643 | */ | |
644 | if (left > 0 || not_last_frag) | |
645 | iph->frag_off |= htons(IP_MF); | |
646 | ptr += len; | |
647 | offset += len; | |
648 | ||
649 | /* | |
650 | * Put this fragment into the sending queue. | |
651 | */ | |
1da177e4 LT |
652 | iph->tot_len = htons(len + hlen); |
653 | ||
654 | ip_send_check(iph); | |
655 | ||
656 | err = output(skb2); | |
657 | if (err) | |
658 | goto fail; | |
dafee490 WD |
659 | |
660 | IP_INC_STATS(IPSTATS_MIB_FRAGCREATES); | |
1da177e4 LT |
661 | } |
662 | kfree_skb(skb); | |
663 | IP_INC_STATS(IPSTATS_MIB_FRAGOKS); | |
664 | return err; | |
665 | ||
666 | fail: | |
e905a9ed | 667 | kfree_skb(skb); |
1da177e4 LT |
668 | IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); |
669 | return err; | |
670 | } | |
671 | ||
2e2f7aef PM |
672 | EXPORT_SYMBOL(ip_fragment); |
673 | ||
1da177e4 LT |
674 | int |
675 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
676 | { | |
677 | struct iovec *iov = from; | |
678 | ||
84fa7933 | 679 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
1da177e4 LT |
680 | if (memcpy_fromiovecend(to, iov, offset, len) < 0) |
681 | return -EFAULT; | |
682 | } else { | |
44bb9363 | 683 | __wsum csum = 0; |
1da177e4 LT |
684 | if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) |
685 | return -EFAULT; | |
686 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
687 | } | |
688 | return 0; | |
689 | } | |
690 | ||
44bb9363 | 691 | static inline __wsum |
1da177e4 LT |
692 | csum_page(struct page *page, int offset, int copy) |
693 | { | |
694 | char *kaddr; | |
44bb9363 | 695 | __wsum csum; |
1da177e4 LT |
696 | kaddr = kmap(page); |
697 | csum = csum_partial(kaddr + offset, copy, 0); | |
698 | kunmap(page); | |
699 | return csum; | |
700 | } | |
701 | ||
4b30b1c6 | 702 | static inline int ip_ufo_append_data(struct sock *sk, |
e89e9cf5 AR |
703 | int getfrag(void *from, char *to, int offset, int len, |
704 | int odd, struct sk_buff *skb), | |
705 | void *from, int length, int hh_len, int fragheaderlen, | |
706 | int transhdrlen, int mtu,unsigned int flags) | |
707 | { | |
708 | struct sk_buff *skb; | |
709 | int err; | |
710 | ||
711 | /* There is support for UDP fragmentation offload by network | |
712 | * device, so create one single skb packet containing complete | |
713 | * udp datagram | |
714 | */ | |
715 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { | |
716 | skb = sock_alloc_send_skb(sk, | |
717 | hh_len + fragheaderlen + transhdrlen + 20, | |
718 | (flags & MSG_DONTWAIT), &err); | |
719 | ||
720 | if (skb == NULL) | |
721 | return err; | |
722 | ||
723 | /* reserve space for Hardware header */ | |
724 | skb_reserve(skb, hh_len); | |
725 | ||
726 | /* create space for UDP/IP header */ | |
727 | skb_put(skb,fragheaderlen + transhdrlen); | |
728 | ||
729 | /* initialize network header pointer */ | |
c1d2bbe1 | 730 | skb_reset_network_header(skb); |
e89e9cf5 AR |
731 | |
732 | /* initialize protocol header pointer */ | |
b0e380b1 | 733 | skb->transport_header = skb->network_header + fragheaderlen; |
e89e9cf5 | 734 | |
84fa7933 | 735 | skb->ip_summed = CHECKSUM_PARTIAL; |
e89e9cf5 AR |
736 | skb->csum = 0; |
737 | sk->sk_sndmsg_off = 0; | |
738 | } | |
739 | ||
740 | err = skb_append_datato_frags(sk,skb, getfrag, from, | |
741 | (length - transhdrlen)); | |
742 | if (!err) { | |
743 | /* specify the length of each IP datagram fragment*/ | |
7967168c | 744 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
f83ef8c0 | 745 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
e89e9cf5 AR |
746 | __skb_queue_tail(&sk->sk_write_queue, skb); |
747 | ||
748 | return 0; | |
749 | } | |
750 | /* There is not enough support do UFO , | |
751 | * so follow normal path | |
752 | */ | |
753 | kfree_skb(skb); | |
754 | return err; | |
755 | } | |
756 | ||
1da177e4 LT |
757 | /* |
758 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
759 | * from many pieces of data. Each pieces will be holded on the socket | |
760 | * until ip_push_pending_frames() is called. Each piece can be a page | |
761 | * or non-page data. | |
e905a9ed | 762 | * |
1da177e4 LT |
763 | * Not only UDP, other transport protocols - e.g. raw sockets - can use |
764 | * this interface potentially. | |
765 | * | |
766 | * LATER: length must be adjusted by pad at tail, when it is required. | |
767 | */ | |
768 | int ip_append_data(struct sock *sk, | |
769 | int getfrag(void *from, char *to, int offset, int len, | |
770 | int odd, struct sk_buff *skb), | |
771 | void *from, int length, int transhdrlen, | |
772 | struct ipcm_cookie *ipc, struct rtable *rt, | |
773 | unsigned int flags) | |
774 | { | |
775 | struct inet_sock *inet = inet_sk(sk); | |
776 | struct sk_buff *skb; | |
777 | ||
778 | struct ip_options *opt = NULL; | |
779 | int hh_len; | |
780 | int exthdrlen; | |
781 | int mtu; | |
782 | int copy; | |
783 | int err; | |
784 | int offset = 0; | |
785 | unsigned int maxfraglen, fragheaderlen; | |
786 | int csummode = CHECKSUM_NONE; | |
787 | ||
788 | if (flags&MSG_PROBE) | |
789 | return 0; | |
790 | ||
791 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
792 | /* | |
793 | * setup for corking. | |
794 | */ | |
795 | opt = ipc->opt; | |
796 | if (opt) { | |
797 | if (inet->cork.opt == NULL) { | |
798 | inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation); | |
799 | if (unlikely(inet->cork.opt == NULL)) | |
800 | return -ENOBUFS; | |
801 | } | |
802 | memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen); | |
803 | inet->cork.flags |= IPCORK_OPT; | |
804 | inet->cork.addr = ipc->addr; | |
805 | } | |
806 | dst_hold(&rt->u.dst); | |
628a5c56 JH |
807 | inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ? |
808 | rt->u.dst.dev->mtu : | |
809 | dst_mtu(rt->u.dst.path); | |
1da177e4 LT |
810 | inet->cork.rt = rt; |
811 | inet->cork.length = 0; | |
812 | sk->sk_sndmsg_page = NULL; | |
813 | sk->sk_sndmsg_off = 0; | |
814 | if ((exthdrlen = rt->u.dst.header_len) != 0) { | |
815 | length += exthdrlen; | |
816 | transhdrlen += exthdrlen; | |
817 | } | |
818 | } else { | |
819 | rt = inet->cork.rt; | |
820 | if (inet->cork.flags & IPCORK_OPT) | |
821 | opt = inet->cork.opt; | |
822 | ||
823 | transhdrlen = 0; | |
824 | exthdrlen = 0; | |
825 | mtu = inet->cork.fragsize; | |
826 | } | |
827 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
828 | ||
829 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
830 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
831 | ||
832 | if (inet->cork.length + length > 0xFFFF - fragheaderlen) { | |
833 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen); | |
834 | return -EMSGSIZE; | |
835 | } | |
836 | ||
837 | /* | |
838 | * transhdrlen > 0 means that this is the first fragment and we wish | |
839 | * it won't be fragmented in the future. | |
840 | */ | |
841 | if (transhdrlen && | |
842 | length + fragheaderlen <= mtu && | |
d212f87b | 843 | rt->u.dst.dev->features & NETIF_F_V4_CSUM && |
1da177e4 | 844 | !exthdrlen) |
84fa7933 | 845 | csummode = CHECKSUM_PARTIAL; |
1da177e4 LT |
846 | |
847 | inet->cork.length += length; | |
e89e9cf5 AR |
848 | if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) && |
849 | (rt->u.dst.dev->features & NETIF_F_UFO)) { | |
850 | ||
baa829d8 PM |
851 | err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, |
852 | fragheaderlen, transhdrlen, mtu, | |
853 | flags); | |
854 | if (err) | |
e89e9cf5 | 855 | goto error; |
e89e9cf5 AR |
856 | return 0; |
857 | } | |
1da177e4 LT |
858 | |
859 | /* So, what's going on in the loop below? | |
860 | * | |
861 | * We use calculated fragment length to generate chained skb, | |
862 | * each of segments is IP fragment ready for sending to network after | |
863 | * adding appropriate IP header. | |
864 | */ | |
865 | ||
866 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
867 | goto alloc_new_skb; | |
868 | ||
869 | while (length > 0) { | |
870 | /* Check if the remaining data fits into current packet. */ | |
871 | copy = mtu - skb->len; | |
872 | if (copy < length) | |
873 | copy = maxfraglen - skb->len; | |
874 | if (copy <= 0) { | |
875 | char *data; | |
876 | unsigned int datalen; | |
877 | unsigned int fraglen; | |
878 | unsigned int fraggap; | |
879 | unsigned int alloclen; | |
880 | struct sk_buff *skb_prev; | |
881 | alloc_new_skb: | |
882 | skb_prev = skb; | |
883 | if (skb_prev) | |
884 | fraggap = skb_prev->len - maxfraglen; | |
885 | else | |
886 | fraggap = 0; | |
887 | ||
888 | /* | |
889 | * If remaining data exceeds the mtu, | |
890 | * we know we need more fragment(s). | |
891 | */ | |
892 | datalen = length + fraggap; | |
893 | if (datalen > mtu - fragheaderlen) | |
894 | datalen = maxfraglen - fragheaderlen; | |
895 | fraglen = datalen + fragheaderlen; | |
896 | ||
e905a9ed | 897 | if ((flags & MSG_MORE) && |
1da177e4 LT |
898 | !(rt->u.dst.dev->features&NETIF_F_SG)) |
899 | alloclen = mtu; | |
900 | else | |
901 | alloclen = datalen + fragheaderlen; | |
902 | ||
903 | /* The last fragment gets additional space at tail. | |
904 | * Note, with MSG_MORE we overallocate on fragments, | |
905 | * because we have no idea what fragment will be | |
906 | * the last. | |
907 | */ | |
3d9dd756 | 908 | if (datalen == length + fraggap) |
1da177e4 LT |
909 | alloclen += rt->u.dst.trailer_len; |
910 | ||
911 | if (transhdrlen) { | |
e905a9ed | 912 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
913 | alloclen + hh_len + 15, |
914 | (flags & MSG_DONTWAIT), &err); | |
915 | } else { | |
916 | skb = NULL; | |
917 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
918 | 2 * sk->sk_sndbuf) | |
e905a9ed | 919 | skb = sock_wmalloc(sk, |
1da177e4 LT |
920 | alloclen + hh_len + 15, 1, |
921 | sk->sk_allocation); | |
922 | if (unlikely(skb == NULL)) | |
923 | err = -ENOBUFS; | |
924 | } | |
925 | if (skb == NULL) | |
926 | goto error; | |
927 | ||
928 | /* | |
929 | * Fill in the control structures | |
930 | */ | |
931 | skb->ip_summed = csummode; | |
932 | skb->csum = 0; | |
933 | skb_reserve(skb, hh_len); | |
934 | ||
935 | /* | |
936 | * Find where to start putting bytes. | |
937 | */ | |
938 | data = skb_put(skb, fraglen); | |
c14d2450 | 939 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
940 | skb->transport_header = (skb->network_header + |
941 | fragheaderlen); | |
1da177e4 | 942 | data += fragheaderlen; |
1da177e4 LT |
943 | |
944 | if (fraggap) { | |
945 | skb->csum = skb_copy_and_csum_bits( | |
946 | skb_prev, maxfraglen, | |
947 | data + transhdrlen, fraggap, 0); | |
948 | skb_prev->csum = csum_sub(skb_prev->csum, | |
949 | skb->csum); | |
950 | data += fraggap; | |
e9fa4f7b | 951 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
952 | } |
953 | ||
954 | copy = datalen - transhdrlen - fraggap; | |
955 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
956 | err = -EFAULT; | |
957 | kfree_skb(skb); | |
958 | goto error; | |
959 | } | |
960 | ||
961 | offset += copy; | |
962 | length -= datalen - fraggap; | |
963 | transhdrlen = 0; | |
964 | exthdrlen = 0; | |
965 | csummode = CHECKSUM_NONE; | |
966 | ||
967 | /* | |
968 | * Put the packet on the pending queue. | |
969 | */ | |
970 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
971 | continue; | |
972 | } | |
973 | ||
974 | if (copy > length) | |
975 | copy = length; | |
976 | ||
977 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) { | |
978 | unsigned int off; | |
979 | ||
980 | off = skb->len; | |
e905a9ed | 981 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
982 | offset, copy, off, skb) < 0) { |
983 | __skb_trim(skb, off); | |
984 | err = -EFAULT; | |
985 | goto error; | |
986 | } | |
987 | } else { | |
988 | int i = skb_shinfo(skb)->nr_frags; | |
989 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; | |
990 | struct page *page = sk->sk_sndmsg_page; | |
991 | int off = sk->sk_sndmsg_off; | |
992 | unsigned int left; | |
993 | ||
994 | if (page && (left = PAGE_SIZE - off) > 0) { | |
995 | if (copy >= left) | |
996 | copy = left; | |
997 | if (page != frag->page) { | |
998 | if (i == MAX_SKB_FRAGS) { | |
999 | err = -EMSGSIZE; | |
1000 | goto error; | |
1001 | } | |
1002 | get_page(page); | |
e905a9ed | 1003 | skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); |
1da177e4 LT |
1004 | frag = &skb_shinfo(skb)->frags[i]; |
1005 | } | |
1006 | } else if (i < MAX_SKB_FRAGS) { | |
1007 | if (copy > PAGE_SIZE) | |
1008 | copy = PAGE_SIZE; | |
1009 | page = alloc_pages(sk->sk_allocation, 0); | |
1010 | if (page == NULL) { | |
1011 | err = -ENOMEM; | |
1012 | goto error; | |
1013 | } | |
1014 | sk->sk_sndmsg_page = page; | |
1015 | sk->sk_sndmsg_off = 0; | |
1016 | ||
1017 | skb_fill_page_desc(skb, i, page, 0, 0); | |
1018 | frag = &skb_shinfo(skb)->frags[i]; | |
1019 | skb->truesize += PAGE_SIZE; | |
1020 | atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc); | |
1021 | } else { | |
1022 | err = -EMSGSIZE; | |
1023 | goto error; | |
1024 | } | |
1025 | if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { | |
1026 | err = -EFAULT; | |
1027 | goto error; | |
1028 | } | |
1029 | sk->sk_sndmsg_off += copy; | |
1030 | frag->size += copy; | |
1031 | skb->len += copy; | |
1032 | skb->data_len += copy; | |
1033 | } | |
1034 | offset += copy; | |
1035 | length -= copy; | |
1036 | } | |
1037 | ||
1038 | return 0; | |
1039 | ||
1040 | error: | |
1041 | inet->cork.length -= length; | |
1042 | IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); | |
e905a9ed | 1043 | return err; |
1da177e4 LT |
1044 | } |
1045 | ||
1046 | ssize_t ip_append_page(struct sock *sk, struct page *page, | |
1047 | int offset, size_t size, int flags) | |
1048 | { | |
1049 | struct inet_sock *inet = inet_sk(sk); | |
1050 | struct sk_buff *skb; | |
1051 | struct rtable *rt; | |
1052 | struct ip_options *opt = NULL; | |
1053 | int hh_len; | |
1054 | int mtu; | |
1055 | int len; | |
1056 | int err; | |
1057 | unsigned int maxfraglen, fragheaderlen, fraggap; | |
1058 | ||
1059 | if (inet->hdrincl) | |
1060 | return -EPERM; | |
1061 | ||
1062 | if (flags&MSG_PROBE) | |
1063 | return 0; | |
1064 | ||
1065 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1066 | return -EINVAL; | |
1067 | ||
1068 | rt = inet->cork.rt; | |
1069 | if (inet->cork.flags & IPCORK_OPT) | |
1070 | opt = inet->cork.opt; | |
1071 | ||
1072 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) | |
1073 | return -EOPNOTSUPP; | |
1074 | ||
1075 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
1076 | mtu = inet->cork.fragsize; | |
1077 | ||
1078 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1079 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
1080 | ||
1081 | if (inet->cork.length + size > 0xFFFF - fragheaderlen) { | |
1082 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu); | |
1083 | return -EMSGSIZE; | |
1084 | } | |
1085 | ||
1086 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1087 | return -EINVAL; | |
1088 | ||
1089 | inet->cork.length += size; | |
e89e9cf5 | 1090 | if ((sk->sk_protocol == IPPROTO_UDP) && |
7967168c HX |
1091 | (rt->u.dst.dev->features & NETIF_F_UFO)) { |
1092 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; | |
f83ef8c0 | 1093 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
7967168c | 1094 | } |
e89e9cf5 | 1095 | |
1da177e4 LT |
1096 | |
1097 | while (size > 0) { | |
1098 | int i; | |
1099 | ||
89114afd | 1100 | if (skb_is_gso(skb)) |
e89e9cf5 AR |
1101 | len = size; |
1102 | else { | |
1103 | ||
1104 | /* Check if the remaining data fits into current packet. */ | |
1105 | len = mtu - skb->len; | |
1106 | if (len < size) | |
1107 | len = maxfraglen - skb->len; | |
1108 | } | |
1da177e4 LT |
1109 | if (len <= 0) { |
1110 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1111 | int alloclen; |
1112 | ||
1113 | skb_prev = skb; | |
0d0d2bba | 1114 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1115 | |
1116 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1117 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1118 | if (unlikely(!skb)) { | |
1119 | err = -ENOBUFS; | |
1120 | goto error; | |
1121 | } | |
1122 | ||
1123 | /* | |
1124 | * Fill in the control structures | |
1125 | */ | |
1126 | skb->ip_summed = CHECKSUM_NONE; | |
1127 | skb->csum = 0; | |
1128 | skb_reserve(skb, hh_len); | |
1129 | ||
1130 | /* | |
1131 | * Find where to start putting bytes. | |
1132 | */ | |
967b05f6 | 1133 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1134 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1135 | skb->transport_header = (skb->network_header + |
1136 | fragheaderlen); | |
1da177e4 | 1137 | if (fraggap) { |
967b05f6 ACM |
1138 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1139 | maxfraglen, | |
9c70220b | 1140 | skb_transport_header(skb), |
967b05f6 | 1141 | fraggap, 0); |
1da177e4 LT |
1142 | skb_prev->csum = csum_sub(skb_prev->csum, |
1143 | skb->csum); | |
e9fa4f7b | 1144 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1145 | } |
1146 | ||
1147 | /* | |
1148 | * Put the packet on the pending queue. | |
1149 | */ | |
1150 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1151 | continue; | |
1152 | } | |
1153 | ||
1154 | i = skb_shinfo(skb)->nr_frags; | |
1155 | if (len > size) | |
1156 | len = size; | |
1157 | if (skb_can_coalesce(skb, i, page, offset)) { | |
1158 | skb_shinfo(skb)->frags[i-1].size += len; | |
1159 | } else if (i < MAX_SKB_FRAGS) { | |
1160 | get_page(page); | |
1161 | skb_fill_page_desc(skb, i, page, offset, len); | |
1162 | } else { | |
1163 | err = -EMSGSIZE; | |
1164 | goto error; | |
1165 | } | |
1166 | ||
1167 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1168 | __wsum csum; |
1da177e4 LT |
1169 | csum = csum_page(page, offset, len); |
1170 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1171 | } | |
1172 | ||
1173 | skb->len += len; | |
1174 | skb->data_len += len; | |
1e34a11d DM |
1175 | skb->truesize += len; |
1176 | atomic_add(len, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1177 | offset += len; |
1178 | size -= len; | |
1179 | } | |
1180 | return 0; | |
1181 | ||
1182 | error: | |
1183 | inet->cork.length -= size; | |
1184 | IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); | |
1185 | return err; | |
1186 | } | |
1187 | ||
429f08e9 PE |
1188 | static void ip_cork_release(struct inet_sock *inet) |
1189 | { | |
1190 | inet->cork.flags &= ~IPCORK_OPT; | |
1191 | kfree(inet->cork.opt); | |
1192 | inet->cork.opt = NULL; | |
1193 | if (inet->cork.rt) { | |
1194 | ip_rt_put(inet->cork.rt); | |
1195 | inet->cork.rt = NULL; | |
1196 | } | |
1197 | } | |
1198 | ||
1da177e4 LT |
1199 | /* |
1200 | * Combined all pending IP fragments on the socket as one IP datagram | |
1201 | * and push them out. | |
1202 | */ | |
1203 | int ip_push_pending_frames(struct sock *sk) | |
1204 | { | |
1205 | struct sk_buff *skb, *tmp_skb; | |
1206 | struct sk_buff **tail_skb; | |
1207 | struct inet_sock *inet = inet_sk(sk); | |
1208 | struct ip_options *opt = NULL; | |
1209 | struct rtable *rt = inet->cork.rt; | |
1210 | struct iphdr *iph; | |
76ab608d | 1211 | __be16 df = 0; |
1da177e4 LT |
1212 | __u8 ttl; |
1213 | int err = 0; | |
1214 | ||
1215 | if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) | |
1216 | goto out; | |
1217 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1218 | ||
1219 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1220 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1221 | __skb_pull(skb, skb_network_offset(skb)); |
1da177e4 | 1222 | while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { |
cfe1fc77 | 1223 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1224 | *tail_skb = tmp_skb; |
1225 | tail_skb = &(tmp_skb->next); | |
1226 | skb->len += tmp_skb->len; | |
1227 | skb->data_len += tmp_skb->len; | |
1228 | skb->truesize += tmp_skb->truesize; | |
1229 | __sock_put(tmp_skb->sk); | |
1230 | tmp_skb->destructor = NULL; | |
1231 | tmp_skb->sk = NULL; | |
1232 | } | |
1233 | ||
1234 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1235 | * to fragment the frame generated here. No matter, what transforms | |
1236 | * how transforms change size of the packet, it will come out. | |
1237 | */ | |
628a5c56 | 1238 | if (inet->pmtudisc < IP_PMTUDISC_DO) |
1da177e4 LT |
1239 | skb->local_df = 1; |
1240 | ||
1241 | /* DF bit is set when we want to see DF on outgoing frames. | |
1242 | * If local_df is set too, we still allow to fragment this frame | |
1243 | * locally. */ | |
628a5c56 | 1244 | if (inet->pmtudisc >= IP_PMTUDISC_DO || |
1da177e4 LT |
1245 | (skb->len <= dst_mtu(&rt->u.dst) && |
1246 | ip_dont_fragment(sk, &rt->u.dst))) | |
1247 | df = htons(IP_DF); | |
1248 | ||
1249 | if (inet->cork.flags & IPCORK_OPT) | |
1250 | opt = inet->cork.opt; | |
1251 | ||
1252 | if (rt->rt_type == RTN_MULTICAST) | |
1253 | ttl = inet->mc_ttl; | |
1254 | else | |
1255 | ttl = ip_select_ttl(inet, &rt->u.dst); | |
1256 | ||
1257 | iph = (struct iphdr *)skb->data; | |
1258 | iph->version = 4; | |
1259 | iph->ihl = 5; | |
1260 | if (opt) { | |
1261 | iph->ihl += opt->optlen>>2; | |
1262 | ip_options_build(skb, opt, inet->cork.addr, rt, 0); | |
1263 | } | |
1264 | iph->tos = inet->tos; | |
1265 | iph->tot_len = htons(skb->len); | |
1266 | iph->frag_off = df; | |
1a55d57b | 1267 | ip_select_ident(iph, &rt->u.dst, sk); |
1da177e4 LT |
1268 | iph->ttl = ttl; |
1269 | iph->protocol = sk->sk_protocol; | |
1270 | iph->saddr = rt->rt_src; | |
1271 | iph->daddr = rt->rt_dst; | |
1272 | ip_send_check(iph); | |
1273 | ||
1274 | skb->priority = sk->sk_priority; | |
1275 | skb->dst = dst_clone(&rt->u.dst); | |
1276 | ||
96793b48 DS |
1277 | if (iph->protocol == IPPROTO_ICMP) |
1278 | icmp_out_count(((struct icmphdr *) | |
1279 | skb_transport_header(skb))->type); | |
1280 | ||
1da177e4 | 1281 | /* Netfilter gets whole the not fragmented skb. */ |
e905a9ed | 1282 | err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, |
1da177e4 LT |
1283 | skb->dst->dev, dst_output); |
1284 | if (err) { | |
1285 | if (err > 0) | |
1286 | err = inet->recverr ? net_xmit_errno(err) : 0; | |
1287 | if (err) | |
1288 | goto error; | |
1289 | } | |
1290 | ||
1291 | out: | |
429f08e9 | 1292 | ip_cork_release(inet); |
1da177e4 LT |
1293 | return err; |
1294 | ||
1295 | error: | |
1296 | IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); | |
1297 | goto out; | |
1298 | } | |
1299 | ||
1300 | /* | |
1301 | * Throw away all pending data on the socket. | |
1302 | */ | |
1303 | void ip_flush_pending_frames(struct sock *sk) | |
1304 | { | |
1da177e4 LT |
1305 | struct sk_buff *skb; |
1306 | ||
1307 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) | |
1308 | kfree_skb(skb); | |
1309 | ||
429f08e9 | 1310 | ip_cork_release(inet_sk(sk)); |
1da177e4 LT |
1311 | } |
1312 | ||
1313 | ||
1314 | /* | |
1315 | * Fetch data from kernel space and fill in checksum if needed. | |
1316 | */ | |
e905a9ed | 1317 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1318 | int len, int odd, struct sk_buff *skb) |
1319 | { | |
5084205f | 1320 | __wsum csum; |
1da177e4 LT |
1321 | |
1322 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1323 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1324 | return 0; |
1da177e4 LT |
1325 | } |
1326 | ||
e905a9ed | 1327 | /* |
1da177e4 LT |
1328 | * Generic function to send a packet as reply to another packet. |
1329 | * Used to send TCP resets so far. ICMP should use this function too. | |
1330 | * | |
e905a9ed | 1331 | * Should run single threaded per socket because it uses the sock |
1da177e4 LT |
1332 | * structure to pass arguments. |
1333 | * | |
1334 | * LATER: switch from ip_build_xmit to ip_append_* | |
1335 | */ | |
1336 | void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, | |
1337 | unsigned int len) | |
1338 | { | |
1339 | struct inet_sock *inet = inet_sk(sk); | |
1340 | struct { | |
1341 | struct ip_options opt; | |
1342 | char data[40]; | |
1343 | } replyopts; | |
1344 | struct ipcm_cookie ipc; | |
3ca3c68e | 1345 | __be32 daddr; |
1da177e4 LT |
1346 | struct rtable *rt = (struct rtable*)skb->dst; |
1347 | ||
1348 | if (ip_options_echo(&replyopts.opt, skb)) | |
1349 | return; | |
1350 | ||
1351 | daddr = ipc.addr = rt->rt_src; | |
1352 | ipc.opt = NULL; | |
1353 | ||
1354 | if (replyopts.opt.optlen) { | |
1355 | ipc.opt = &replyopts.opt; | |
1356 | ||
1357 | if (ipc.opt->srr) | |
1358 | daddr = replyopts.opt.faddr; | |
1359 | } | |
1360 | ||
1361 | { | |
f0e48dbf PM |
1362 | struct flowi fl = { .oif = arg->bound_dev_if, |
1363 | .nl_u = { .ip4_u = | |
1da177e4 LT |
1364 | { .daddr = daddr, |
1365 | .saddr = rt->rt_spec_dst, | |
eddc9ec5 | 1366 | .tos = RT_TOS(ip_hdr(skb)->tos) } }, |
1da177e4 LT |
1367 | /* Not quite clean, but right. */ |
1368 | .uli_u = { .ports = | |
aa8223c7 ACM |
1369 | { .sport = tcp_hdr(skb)->dest, |
1370 | .dport = tcp_hdr(skb)->source } }, | |
1da177e4 | 1371 | .proto = sk->sk_protocol }; |
beb8d13b | 1372 | security_skb_classify_flow(skb, &fl); |
1da177e4 LT |
1373 | if (ip_route_output_key(&rt, &fl)) |
1374 | return; | |
1375 | } | |
1376 | ||
1377 | /* And let IP do all the hard work. | |
1378 | ||
1379 | This chunk is not reenterable, hence spinlock. | |
1380 | Note that it uses the fact, that this function is called | |
1381 | with locally disabled BH and that sk cannot be already spinlocked. | |
1382 | */ | |
1383 | bh_lock_sock(sk); | |
eddc9ec5 | 1384 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 | 1385 | sk->sk_priority = skb->priority; |
eddc9ec5 | 1386 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1387 | sk->sk_bound_dev_if = arg->bound_dev_if; |
1da177e4 LT |
1388 | ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, |
1389 | &ipc, rt, MSG_DONTWAIT); | |
1390 | if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { | |
1391 | if (arg->csumoffset >= 0) | |
9c70220b ACM |
1392 | *((__sum16 *)skb_transport_header(skb) + |
1393 | arg->csumoffset) = csum_fold(csum_add(skb->csum, | |
1394 | arg->csum)); | |
1da177e4 LT |
1395 | skb->ip_summed = CHECKSUM_NONE; |
1396 | ip_push_pending_frames(sk); | |
1397 | } | |
1398 | ||
1399 | bh_unlock_sock(sk); | |
1400 | ||
1401 | ip_rt_put(rt); | |
1402 | } | |
1403 | ||
1da177e4 LT |
1404 | void __init ip_init(void) |
1405 | { | |
1da177e4 LT |
1406 | ip_rt_init(); |
1407 | inet_initpeers(); | |
1408 | ||
1409 | #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) | |
1410 | igmp_mc_proc_init(); | |
1411 | #endif | |
1412 | } | |
1413 | ||
1da177e4 LT |
1414 | EXPORT_SYMBOL(ip_generic_getfrag); |
1415 | EXPORT_SYMBOL(ip_queue_xmit); | |
1416 | EXPORT_SYMBOL(ip_send_check); |