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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 | * | |
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 | ||
c439cb2e HX |
94 | int __ip_local_out(struct sk_buff *skb) |
95 | { | |
96 | struct iphdr *iph = ip_hdr(skb); | |
97 | ||
98 | iph->tot_len = htons(skb->len); | |
99 | ip_send_check(iph); | |
6e23ae2a | 100 | return nf_hook(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, skb->dst->dev, |
c439cb2e HX |
101 | dst_output); |
102 | } | |
103 | ||
104 | int ip_local_out(struct sk_buff *skb) | |
105 | { | |
106 | int err; | |
107 | ||
108 | err = __ip_local_out(skb); | |
109 | if (likely(err == 1)) | |
110 | err = dst_output(skb); | |
111 | ||
112 | return err; | |
113 | } | |
114 | EXPORT_SYMBOL_GPL(ip_local_out); | |
115 | ||
1da177e4 LT |
116 | /* dev_loopback_xmit for use with netfilter. */ |
117 | static int ip_dev_loopback_xmit(struct sk_buff *newskb) | |
118 | { | |
459a98ed | 119 | skb_reset_mac_header(newskb); |
bbe735e4 | 120 | __skb_pull(newskb, skb_network_offset(newskb)); |
1da177e4 LT |
121 | newskb->pkt_type = PACKET_LOOPBACK; |
122 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
123 | BUG_TRAP(newskb->dst); | |
1da177e4 LT |
124 | netif_rx(newskb); |
125 | return 0; | |
126 | } | |
127 | ||
128 | static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) | |
129 | { | |
130 | int ttl = inet->uc_ttl; | |
131 | ||
132 | if (ttl < 0) | |
133 | ttl = dst_metric(dst, RTAX_HOPLIMIT); | |
134 | return ttl; | |
135 | } | |
136 | ||
e905a9ed | 137 | /* |
1da177e4 LT |
138 | * Add an ip header to a skbuff and send it out. |
139 | * | |
140 | */ | |
141 | int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, | |
13d8eaa0 | 142 | __be32 saddr, __be32 daddr, struct ip_options *opt) |
1da177e4 LT |
143 | { |
144 | struct inet_sock *inet = inet_sk(sk); | |
145 | struct rtable *rt = (struct rtable *)skb->dst; | |
146 | struct iphdr *iph; | |
147 | ||
148 | /* Build the IP header. */ | |
8856dfa3 ACM |
149 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
150 | skb_reset_network_header(skb); | |
eddc9ec5 | 151 | iph = ip_hdr(skb); |
1da177e4 LT |
152 | iph->version = 4; |
153 | iph->ihl = 5; | |
154 | iph->tos = inet->tos; | |
155 | if (ip_dont_fragment(sk, &rt->u.dst)) | |
156 | iph->frag_off = htons(IP_DF); | |
157 | else | |
158 | iph->frag_off = 0; | |
159 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); | |
160 | iph->daddr = rt->rt_dst; | |
161 | iph->saddr = rt->rt_src; | |
162 | iph->protocol = sk->sk_protocol; | |
1da177e4 | 163 | ip_select_ident(iph, &rt->u.dst, sk); |
1da177e4 LT |
164 | |
165 | if (opt && opt->optlen) { | |
166 | iph->ihl += opt->optlen>>2; | |
167 | ip_options_build(skb, opt, daddr, rt, 0); | |
168 | } | |
1da177e4 LT |
169 | |
170 | skb->priority = sk->sk_priority; | |
171 | ||
172 | /* Send it out. */ | |
c439cb2e | 173 | return ip_local_out(skb); |
1da177e4 LT |
174 | } |
175 | ||
d8c97a94 ACM |
176 | EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); |
177 | ||
1da177e4 LT |
178 | static inline int ip_finish_output2(struct sk_buff *skb) |
179 | { | |
180 | struct dst_entry *dst = skb->dst; | |
80787ebc | 181 | struct rtable *rt = (struct rtable *)dst; |
1da177e4 | 182 | struct net_device *dev = dst->dev; |
c2636b4d | 183 | unsigned int hh_len = LL_RESERVED_SPACE(dev); |
1da177e4 | 184 | |
80787ebc MC |
185 | if (rt->rt_type == RTN_MULTICAST) |
186 | IP_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS); | |
187 | else if (rt->rt_type == RTN_BROADCAST) | |
188 | IP_INC_STATS(IPSTATS_MIB_OUTBCASTPKTS); | |
189 | ||
1da177e4 | 190 | /* Be paranoid, rather than too clever. */ |
3b04ddde | 191 | if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { |
1da177e4 LT |
192 | struct sk_buff *skb2; |
193 | ||
194 | skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); | |
195 | if (skb2 == NULL) { | |
196 | kfree_skb(skb); | |
197 | return -ENOMEM; | |
198 | } | |
199 | if (skb->sk) | |
200 | skb_set_owner_w(skb2, skb->sk); | |
201 | kfree_skb(skb); | |
202 | skb = skb2; | |
203 | } | |
204 | ||
3644f0ce SH |
205 | if (dst->hh) |
206 | return neigh_hh_output(dst->hh, skb); | |
207 | else if (dst->neighbour) | |
1da177e4 LT |
208 | return dst->neighbour->output(skb); |
209 | ||
210 | if (net_ratelimit()) | |
211 | printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); | |
212 | kfree_skb(skb); | |
213 | return -EINVAL; | |
214 | } | |
215 | ||
628a5c56 JH |
216 | static inline int ip_skb_dst_mtu(struct sk_buff *skb) |
217 | { | |
218 | struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; | |
219 | ||
220 | return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? | |
221 | skb->dst->dev->mtu : dst_mtu(skb->dst); | |
222 | } | |
223 | ||
861d0486 | 224 | static int ip_finish_output(struct sk_buff *skb) |
1da177e4 | 225 | { |
5c901daa PM |
226 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
227 | /* Policy lookup after SNAT yielded a new policy */ | |
48d5cad8 PM |
228 | if (skb->dst->xfrm != NULL) { |
229 | IPCB(skb)->flags |= IPSKB_REROUTED; | |
230 | return dst_output(skb); | |
231 | } | |
5c901daa | 232 | #endif |
628a5c56 | 233 | if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) |
1bd9bef6 PM |
234 | return ip_fragment(skb, ip_finish_output2); |
235 | else | |
236 | return ip_finish_output2(skb); | |
1da177e4 LT |
237 | } |
238 | ||
239 | int ip_mc_output(struct sk_buff *skb) | |
240 | { | |
241 | struct sock *sk = skb->sk; | |
242 | struct rtable *rt = (struct rtable*)skb->dst; | |
243 | struct net_device *dev = rt->u.dst.dev; | |
244 | ||
245 | /* | |
246 | * If the indicated interface is up and running, send the packet. | |
247 | */ | |
248 | IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); | |
249 | ||
250 | skb->dev = dev; | |
251 | skb->protocol = htons(ETH_P_IP); | |
252 | ||
253 | /* | |
254 | * Multicasts are looped back for other local users | |
255 | */ | |
256 | ||
257 | if (rt->rt_flags&RTCF_MULTICAST) { | |
258 | if ((!sk || inet_sk(sk)->mc_loop) | |
259 | #ifdef CONFIG_IP_MROUTE | |
260 | /* Small optimization: do not loopback not local frames, | |
261 | which returned after forwarding; they will be dropped | |
262 | by ip_mr_input in any case. | |
263 | Note, that local frames are looped back to be delivered | |
264 | to local recipients. | |
265 | ||
266 | This check is duplicated in ip_mr_input at the moment. | |
267 | */ | |
268 | && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED)) | |
269 | #endif | |
270 | ) { | |
271 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
272 | if (newskb) | |
6e23ae2a PM |
273 | NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, |
274 | NULL, newskb->dev, | |
1da177e4 LT |
275 | ip_dev_loopback_xmit); |
276 | } | |
277 | ||
278 | /* Multicasts with ttl 0 must not go beyond the host */ | |
279 | ||
eddc9ec5 | 280 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
281 | kfree_skb(skb); |
282 | return 0; | |
283 | } | |
284 | } | |
285 | ||
286 | if (rt->rt_flags&RTCF_BROADCAST) { | |
287 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
288 | if (newskb) | |
6e23ae2a | 289 | NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, NULL, |
1da177e4 LT |
290 | newskb->dev, ip_dev_loopback_xmit); |
291 | } | |
292 | ||
6e23ae2a | 293 | return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, skb->dev, |
48d5cad8 PM |
294 | ip_finish_output, |
295 | !(IPCB(skb)->flags & IPSKB_REROUTED)); | |
1da177e4 LT |
296 | } |
297 | ||
298 | int ip_output(struct sk_buff *skb) | |
299 | { | |
1bd9bef6 PM |
300 | struct net_device *dev = skb->dst->dev; |
301 | ||
1da177e4 LT |
302 | IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); |
303 | ||
1bd9bef6 PM |
304 | skb->dev = dev; |
305 | skb->protocol = htons(ETH_P_IP); | |
306 | ||
6e23ae2a | 307 | return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, dev, |
e905a9ed | 308 | ip_finish_output, |
48d5cad8 | 309 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
310 | } |
311 | ||
e89862f4 | 312 | int ip_queue_xmit(struct sk_buff *skb, int ipfragok) |
1da177e4 | 313 | { |
e89862f4 | 314 | struct sock *sk = skb->sk; |
1da177e4 LT |
315 | struct inet_sock *inet = inet_sk(sk); |
316 | struct ip_options *opt = inet->opt; | |
317 | struct rtable *rt; | |
318 | struct iphdr *iph; | |
319 | ||
320 | /* Skip all of this if the packet is already routed, | |
321 | * f.e. by something like SCTP. | |
322 | */ | |
323 | rt = (struct rtable *) skb->dst; | |
324 | if (rt != NULL) | |
325 | goto packet_routed; | |
326 | ||
327 | /* Make sure we can route this packet. */ | |
328 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
329 | if (rt == NULL) { | |
3ca3c68e | 330 | __be32 daddr; |
1da177e4 LT |
331 | |
332 | /* Use correct destination address if we have options. */ | |
333 | daddr = inet->daddr; | |
334 | if(opt && opt->srr) | |
335 | daddr = opt->faddr; | |
336 | ||
337 | { | |
338 | struct flowi fl = { .oif = sk->sk_bound_dev_if, | |
339 | .nl_u = { .ip4_u = | |
340 | { .daddr = daddr, | |
341 | .saddr = inet->saddr, | |
342 | .tos = RT_CONN_FLAGS(sk) } }, | |
343 | .proto = sk->sk_protocol, | |
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); |
f1b050bf | 353 | if (ip_route_output_flow(&init_net, &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 LT |
387 | skb->priority = sk->sk_priority; |
388 | ||
c439cb2e | 389 | return ip_local_out(skb); |
1da177e4 LT |
390 | |
391 | no_route: | |
392 | IP_INC_STATS(IPSTATS_MIB_OUTNOROUTES); | |
393 | kfree_skb(skb); | |
394 | return -EHOSTUNREACH; | |
395 | } | |
396 | ||
397 | ||
398 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) | |
399 | { | |
400 | to->pkt_type = from->pkt_type; | |
401 | to->priority = from->priority; | |
402 | to->protocol = from->protocol; | |
1da177e4 LT |
403 | dst_release(to->dst); |
404 | to->dst = dst_clone(from->dst); | |
405 | to->dev = from->dev; | |
82e91ffe | 406 | to->mark = from->mark; |
1da177e4 LT |
407 | |
408 | /* Copy the flags to each fragment. */ | |
409 | IPCB(to)->flags = IPCB(from)->flags; | |
410 | ||
411 | #ifdef CONFIG_NET_SCHED | |
412 | to->tc_index = from->tc_index; | |
413 | #endif | |
e7ac05f3 | 414 | nf_copy(to, from); |
ba9dda3a JK |
415 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ |
416 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) | |
417 | to->nf_trace = from->nf_trace; | |
418 | #endif | |
c98d80ed JA |
419 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
420 | to->ipvs_property = from->ipvs_property; | |
1da177e4 | 421 | #endif |
984bc16c | 422 | skb_copy_secmark(to, from); |
1da177e4 LT |
423 | } |
424 | ||
425 | /* | |
426 | * This IP datagram is too large to be sent in one piece. Break it up into | |
427 | * smaller pieces (each of size equal to IP header plus | |
428 | * a block of the data of the original IP data part) that will yet fit in a | |
429 | * single device frame, and queue such a frame for sending. | |
430 | */ | |
431 | ||
2e2f7aef | 432 | int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) |
1da177e4 LT |
433 | { |
434 | struct iphdr *iph; | |
435 | int raw = 0; | |
436 | int ptr; | |
437 | struct net_device *dev; | |
438 | struct sk_buff *skb2; | |
9bcfcaf5 | 439 | unsigned int mtu, hlen, left, len, ll_rs, pad; |
1da177e4 | 440 | int offset; |
76ab608d | 441 | __be16 not_last_frag; |
1da177e4 LT |
442 | struct rtable *rt = (struct rtable*)skb->dst; |
443 | int err = 0; | |
444 | ||
445 | dev = rt->u.dst.dev; | |
446 | ||
447 | /* | |
448 | * Point into the IP datagram header. | |
449 | */ | |
450 | ||
eddc9ec5 | 451 | iph = ip_hdr(skb); |
1da177e4 LT |
452 | |
453 | if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { | |
0668b472 | 454 | IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 455 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
628a5c56 | 456 | htonl(ip_skb_dst_mtu(skb))); |
1da177e4 LT |
457 | kfree_skb(skb); |
458 | return -EMSGSIZE; | |
459 | } | |
460 | ||
461 | /* | |
462 | * Setup starting values. | |
463 | */ | |
464 | ||
465 | hlen = iph->ihl * 4; | |
466 | mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ | |
89cee8b1 | 467 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
1da177e4 LT |
468 | |
469 | /* When frag_list is given, use it. First, check its validity: | |
470 | * some transformers could create wrong frag_list or break existing | |
471 | * one, it is not prohibited. In this case fall back to copying. | |
472 | * | |
473 | * LATER: this step can be merged to real generation of fragments, | |
474 | * we can switch to copy when see the first bad fragment. | |
475 | */ | |
476 | if (skb_shinfo(skb)->frag_list) { | |
477 | struct sk_buff *frag; | |
478 | int first_len = skb_pagelen(skb); | |
29ffe1a5 | 479 | int truesizes = 0; |
1da177e4 LT |
480 | |
481 | if (first_len - hlen > mtu || | |
482 | ((first_len - hlen) & 7) || | |
483 | (iph->frag_off & htons(IP_MF|IP_OFFSET)) || | |
484 | skb_cloned(skb)) | |
485 | goto slow_path; | |
486 | ||
487 | for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { | |
488 | /* Correct geometry. */ | |
489 | if (frag->len > mtu || | |
490 | ((frag->len & 7) && frag->next) || | |
491 | skb_headroom(frag) < hlen) | |
492 | goto slow_path; | |
493 | ||
494 | /* Partially cloned skb? */ | |
495 | if (skb_shared(frag)) | |
496 | goto slow_path; | |
2fdba6b0 HX |
497 | |
498 | BUG_ON(frag->sk); | |
499 | if (skb->sk) { | |
500 | sock_hold(skb->sk); | |
501 | frag->sk = skb->sk; | |
502 | frag->destructor = sock_wfree; | |
29ffe1a5 | 503 | truesizes += frag->truesize; |
2fdba6b0 | 504 | } |
1da177e4 LT |
505 | } |
506 | ||
507 | /* Everything is OK. Generate! */ | |
508 | ||
509 | err = 0; | |
510 | offset = 0; | |
511 | frag = skb_shinfo(skb)->frag_list; | |
512 | skb_shinfo(skb)->frag_list = NULL; | |
513 | skb->data_len = first_len - skb_headlen(skb); | |
29ffe1a5 | 514 | skb->truesize -= truesizes; |
1da177e4 LT |
515 | skb->len = first_len; |
516 | iph->tot_len = htons(first_len); | |
517 | iph->frag_off = htons(IP_MF); | |
518 | ip_send_check(iph); | |
519 | ||
520 | for (;;) { | |
521 | /* Prepare header of the next frame, | |
522 | * before previous one went down. */ | |
523 | if (frag) { | |
524 | frag->ip_summed = CHECKSUM_NONE; | |
badff6d0 | 525 | skb_reset_transport_header(frag); |
e2d1bca7 ACM |
526 | __skb_push(frag, hlen); |
527 | skb_reset_network_header(frag); | |
d56f90a7 | 528 | memcpy(skb_network_header(frag), iph, hlen); |
eddc9ec5 | 529 | iph = ip_hdr(frag); |
1da177e4 LT |
530 | iph->tot_len = htons(frag->len); |
531 | ip_copy_metadata(frag, skb); | |
532 | if (offset == 0) | |
533 | ip_options_fragment(frag); | |
534 | offset += skb->len - hlen; | |
535 | iph->frag_off = htons(offset>>3); | |
536 | if (frag->next != NULL) | |
537 | iph->frag_off |= htons(IP_MF); | |
538 | /* Ready, complete checksum */ | |
539 | ip_send_check(iph); | |
540 | } | |
541 | ||
542 | err = output(skb); | |
543 | ||
dafee490 WD |
544 | if (!err) |
545 | IP_INC_STATS(IPSTATS_MIB_FRAGCREATES); | |
1da177e4 LT |
546 | if (err || !frag) |
547 | break; | |
548 | ||
549 | skb = frag; | |
550 | frag = skb->next; | |
551 | skb->next = NULL; | |
552 | } | |
553 | ||
554 | if (err == 0) { | |
555 | IP_INC_STATS(IPSTATS_MIB_FRAGOKS); | |
556 | return 0; | |
557 | } | |
558 | ||
559 | while (frag) { | |
560 | skb = frag->next; | |
561 | kfree_skb(frag); | |
562 | frag = skb; | |
563 | } | |
564 | IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); | |
565 | return err; | |
566 | } | |
567 | ||
568 | slow_path: | |
569 | left = skb->len - hlen; /* Space per frame */ | |
570 | ptr = raw + hlen; /* Where to start from */ | |
571 | ||
1da177e4 | 572 | /* for bridged IP traffic encapsulated inside f.e. a vlan header, |
9bcfcaf5 SH |
573 | * we need to make room for the encapsulating header |
574 | */ | |
575 | pad = nf_bridge_pad(skb); | |
576 | ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad); | |
577 | mtu -= pad; | |
578 | ||
1da177e4 LT |
579 | /* |
580 | * Fragment the datagram. | |
581 | */ | |
582 | ||
583 | offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
584 | not_last_frag = iph->frag_off & htons(IP_MF); | |
585 | ||
586 | /* | |
587 | * Keep copying data until we run out. | |
588 | */ | |
589 | ||
132adf54 | 590 | while (left > 0) { |
1da177e4 LT |
591 | len = left; |
592 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
593 | if (len > mtu) | |
594 | len = mtu; | |
595 | /* IF: we are not sending upto and including the packet end | |
596 | then align the next start on an eight byte boundary */ | |
597 | if (len < left) { | |
598 | len &= ~7; | |
599 | } | |
600 | /* | |
601 | * Allocate buffer. | |
602 | */ | |
603 | ||
604 | if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { | |
64ce2073 | 605 | NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); |
1da177e4 LT |
606 | err = -ENOMEM; |
607 | goto fail; | |
608 | } | |
609 | ||
610 | /* | |
611 | * Set up data on packet | |
612 | */ | |
613 | ||
614 | ip_copy_metadata(skb2, skb); | |
615 | skb_reserve(skb2, ll_rs); | |
616 | skb_put(skb2, len + hlen); | |
c1d2bbe1 | 617 | skb_reset_network_header(skb2); |
b0e380b1 | 618 | skb2->transport_header = skb2->network_header + hlen; |
1da177e4 LT |
619 | |
620 | /* | |
621 | * Charge the memory for the fragment to any owner | |
622 | * it might possess | |
623 | */ | |
624 | ||
625 | if (skb->sk) | |
626 | skb_set_owner_w(skb2, skb->sk); | |
627 | ||
628 | /* | |
629 | * Copy the packet header into the new buffer. | |
630 | */ | |
631 | ||
d626f62b | 632 | skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); |
1da177e4 LT |
633 | |
634 | /* | |
635 | * Copy a block of the IP datagram. | |
636 | */ | |
bff9b61c | 637 | if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) |
1da177e4 LT |
638 | BUG(); |
639 | left -= len; | |
640 | ||
641 | /* | |
642 | * Fill in the new header fields. | |
643 | */ | |
eddc9ec5 | 644 | iph = ip_hdr(skb2); |
1da177e4 LT |
645 | iph->frag_off = htons((offset >> 3)); |
646 | ||
647 | /* ANK: dirty, but effective trick. Upgrade options only if | |
648 | * the segment to be fragmented was THE FIRST (otherwise, | |
649 | * options are already fixed) and make it ONCE | |
650 | * on the initial skb, so that all the following fragments | |
651 | * will inherit fixed options. | |
652 | */ | |
653 | if (offset == 0) | |
654 | ip_options_fragment(skb); | |
655 | ||
656 | /* | |
657 | * Added AC : If we are fragmenting a fragment that's not the | |
658 | * last fragment then keep MF on each bit | |
659 | */ | |
660 | if (left > 0 || not_last_frag) | |
661 | iph->frag_off |= htons(IP_MF); | |
662 | ptr += len; | |
663 | offset += len; | |
664 | ||
665 | /* | |
666 | * Put this fragment into the sending queue. | |
667 | */ | |
1da177e4 LT |
668 | iph->tot_len = htons(len + hlen); |
669 | ||
670 | ip_send_check(iph); | |
671 | ||
672 | err = output(skb2); | |
673 | if (err) | |
674 | goto fail; | |
dafee490 WD |
675 | |
676 | IP_INC_STATS(IPSTATS_MIB_FRAGCREATES); | |
1da177e4 LT |
677 | } |
678 | kfree_skb(skb); | |
679 | IP_INC_STATS(IPSTATS_MIB_FRAGOKS); | |
680 | return err; | |
681 | ||
682 | fail: | |
e905a9ed | 683 | kfree_skb(skb); |
1da177e4 LT |
684 | IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); |
685 | return err; | |
686 | } | |
687 | ||
2e2f7aef PM |
688 | EXPORT_SYMBOL(ip_fragment); |
689 | ||
1da177e4 LT |
690 | int |
691 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
692 | { | |
693 | struct iovec *iov = from; | |
694 | ||
84fa7933 | 695 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
1da177e4 LT |
696 | if (memcpy_fromiovecend(to, iov, offset, len) < 0) |
697 | return -EFAULT; | |
698 | } else { | |
44bb9363 | 699 | __wsum csum = 0; |
1da177e4 LT |
700 | if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) |
701 | return -EFAULT; | |
702 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
703 | } | |
704 | return 0; | |
705 | } | |
706 | ||
44bb9363 | 707 | static inline __wsum |
1da177e4 LT |
708 | csum_page(struct page *page, int offset, int copy) |
709 | { | |
710 | char *kaddr; | |
44bb9363 | 711 | __wsum csum; |
1da177e4 LT |
712 | kaddr = kmap(page); |
713 | csum = csum_partial(kaddr + offset, copy, 0); | |
714 | kunmap(page); | |
715 | return csum; | |
716 | } | |
717 | ||
4b30b1c6 | 718 | static inline int ip_ufo_append_data(struct sock *sk, |
e89e9cf5 AR |
719 | int getfrag(void *from, char *to, int offset, int len, |
720 | int odd, struct sk_buff *skb), | |
721 | void *from, int length, int hh_len, int fragheaderlen, | |
722 | int transhdrlen, int mtu,unsigned int flags) | |
723 | { | |
724 | struct sk_buff *skb; | |
725 | int err; | |
726 | ||
727 | /* There is support for UDP fragmentation offload by network | |
728 | * device, so create one single skb packet containing complete | |
729 | * udp datagram | |
730 | */ | |
731 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { | |
732 | skb = sock_alloc_send_skb(sk, | |
733 | hh_len + fragheaderlen + transhdrlen + 20, | |
734 | (flags & MSG_DONTWAIT), &err); | |
735 | ||
736 | if (skb == NULL) | |
737 | return err; | |
738 | ||
739 | /* reserve space for Hardware header */ | |
740 | skb_reserve(skb, hh_len); | |
741 | ||
742 | /* create space for UDP/IP header */ | |
743 | skb_put(skb,fragheaderlen + transhdrlen); | |
744 | ||
745 | /* initialize network header pointer */ | |
c1d2bbe1 | 746 | skb_reset_network_header(skb); |
e89e9cf5 AR |
747 | |
748 | /* initialize protocol header pointer */ | |
b0e380b1 | 749 | skb->transport_header = skb->network_header + fragheaderlen; |
e89e9cf5 | 750 | |
84fa7933 | 751 | skb->ip_summed = CHECKSUM_PARTIAL; |
e89e9cf5 AR |
752 | skb->csum = 0; |
753 | sk->sk_sndmsg_off = 0; | |
754 | } | |
755 | ||
756 | err = skb_append_datato_frags(sk,skb, getfrag, from, | |
757 | (length - transhdrlen)); | |
758 | if (!err) { | |
759 | /* specify the length of each IP datagram fragment*/ | |
7967168c | 760 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
f83ef8c0 | 761 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
e89e9cf5 AR |
762 | __skb_queue_tail(&sk->sk_write_queue, skb); |
763 | ||
764 | return 0; | |
765 | } | |
766 | /* There is not enough support do UFO , | |
767 | * so follow normal path | |
768 | */ | |
769 | kfree_skb(skb); | |
770 | return err; | |
771 | } | |
772 | ||
1da177e4 LT |
773 | /* |
774 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
775 | * from many pieces of data. Each pieces will be holded on the socket | |
776 | * until ip_push_pending_frames() is called. Each piece can be a page | |
777 | * or non-page data. | |
e905a9ed | 778 | * |
1da177e4 LT |
779 | * Not only UDP, other transport protocols - e.g. raw sockets - can use |
780 | * this interface potentially. | |
781 | * | |
782 | * LATER: length must be adjusted by pad at tail, when it is required. | |
783 | */ | |
784 | int ip_append_data(struct sock *sk, | |
785 | int getfrag(void *from, char *to, int offset, int len, | |
786 | int odd, struct sk_buff *skb), | |
787 | void *from, int length, int transhdrlen, | |
788 | struct ipcm_cookie *ipc, struct rtable *rt, | |
789 | unsigned int flags) | |
790 | { | |
791 | struct inet_sock *inet = inet_sk(sk); | |
792 | struct sk_buff *skb; | |
793 | ||
794 | struct ip_options *opt = NULL; | |
795 | int hh_len; | |
796 | int exthdrlen; | |
797 | int mtu; | |
798 | int copy; | |
799 | int err; | |
800 | int offset = 0; | |
801 | unsigned int maxfraglen, fragheaderlen; | |
802 | int csummode = CHECKSUM_NONE; | |
803 | ||
804 | if (flags&MSG_PROBE) | |
805 | return 0; | |
806 | ||
807 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
808 | /* | |
809 | * setup for corking. | |
810 | */ | |
811 | opt = ipc->opt; | |
812 | if (opt) { | |
813 | if (inet->cork.opt == NULL) { | |
814 | inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation); | |
815 | if (unlikely(inet->cork.opt == NULL)) | |
816 | return -ENOBUFS; | |
817 | } | |
818 | memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen); | |
819 | inet->cork.flags |= IPCORK_OPT; | |
820 | inet->cork.addr = ipc->addr; | |
821 | } | |
822 | dst_hold(&rt->u.dst); | |
628a5c56 JH |
823 | inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ? |
824 | rt->u.dst.dev->mtu : | |
825 | dst_mtu(rt->u.dst.path); | |
1da177e4 LT |
826 | inet->cork.rt = rt; |
827 | inet->cork.length = 0; | |
828 | sk->sk_sndmsg_page = NULL; | |
829 | sk->sk_sndmsg_off = 0; | |
830 | if ((exthdrlen = rt->u.dst.header_len) != 0) { | |
831 | length += exthdrlen; | |
832 | transhdrlen += exthdrlen; | |
833 | } | |
834 | } else { | |
835 | rt = inet->cork.rt; | |
836 | if (inet->cork.flags & IPCORK_OPT) | |
837 | opt = inet->cork.opt; | |
838 | ||
839 | transhdrlen = 0; | |
840 | exthdrlen = 0; | |
841 | mtu = inet->cork.fragsize; | |
842 | } | |
843 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
844 | ||
845 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
846 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
847 | ||
848 | if (inet->cork.length + length > 0xFFFF - fragheaderlen) { | |
849 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen); | |
850 | return -EMSGSIZE; | |
851 | } | |
852 | ||
853 | /* | |
854 | * transhdrlen > 0 means that this is the first fragment and we wish | |
855 | * it won't be fragmented in the future. | |
856 | */ | |
857 | if (transhdrlen && | |
858 | length + fragheaderlen <= mtu && | |
d212f87b | 859 | rt->u.dst.dev->features & NETIF_F_V4_CSUM && |
1da177e4 | 860 | !exthdrlen) |
84fa7933 | 861 | csummode = CHECKSUM_PARTIAL; |
1da177e4 LT |
862 | |
863 | inet->cork.length += length; | |
e89e9cf5 AR |
864 | if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) && |
865 | (rt->u.dst.dev->features & NETIF_F_UFO)) { | |
866 | ||
baa829d8 PM |
867 | err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, |
868 | fragheaderlen, transhdrlen, mtu, | |
869 | flags); | |
870 | if (err) | |
e89e9cf5 | 871 | goto error; |
e89e9cf5 AR |
872 | return 0; |
873 | } | |
1da177e4 LT |
874 | |
875 | /* So, what's going on in the loop below? | |
876 | * | |
877 | * We use calculated fragment length to generate chained skb, | |
878 | * each of segments is IP fragment ready for sending to network after | |
879 | * adding appropriate IP header. | |
880 | */ | |
881 | ||
882 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
883 | goto alloc_new_skb; | |
884 | ||
885 | while (length > 0) { | |
886 | /* Check if the remaining data fits into current packet. */ | |
887 | copy = mtu - skb->len; | |
888 | if (copy < length) | |
889 | copy = maxfraglen - skb->len; | |
890 | if (copy <= 0) { | |
891 | char *data; | |
892 | unsigned int datalen; | |
893 | unsigned int fraglen; | |
894 | unsigned int fraggap; | |
895 | unsigned int alloclen; | |
896 | struct sk_buff *skb_prev; | |
897 | alloc_new_skb: | |
898 | skb_prev = skb; | |
899 | if (skb_prev) | |
900 | fraggap = skb_prev->len - maxfraglen; | |
901 | else | |
902 | fraggap = 0; | |
903 | ||
904 | /* | |
905 | * If remaining data exceeds the mtu, | |
906 | * we know we need more fragment(s). | |
907 | */ | |
908 | datalen = length + fraggap; | |
909 | if (datalen > mtu - fragheaderlen) | |
910 | datalen = maxfraglen - fragheaderlen; | |
911 | fraglen = datalen + fragheaderlen; | |
912 | ||
e905a9ed | 913 | if ((flags & MSG_MORE) && |
1da177e4 LT |
914 | !(rt->u.dst.dev->features&NETIF_F_SG)) |
915 | alloclen = mtu; | |
916 | else | |
917 | alloclen = datalen + fragheaderlen; | |
918 | ||
919 | /* The last fragment gets additional space at tail. | |
920 | * Note, with MSG_MORE we overallocate on fragments, | |
921 | * because we have no idea what fragment will be | |
922 | * the last. | |
923 | */ | |
3d9dd756 | 924 | if (datalen == length + fraggap) |
1da177e4 LT |
925 | alloclen += rt->u.dst.trailer_len; |
926 | ||
927 | if (transhdrlen) { | |
e905a9ed | 928 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
929 | alloclen + hh_len + 15, |
930 | (flags & MSG_DONTWAIT), &err); | |
931 | } else { | |
932 | skb = NULL; | |
933 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
934 | 2 * sk->sk_sndbuf) | |
e905a9ed | 935 | skb = sock_wmalloc(sk, |
1da177e4 LT |
936 | alloclen + hh_len + 15, 1, |
937 | sk->sk_allocation); | |
938 | if (unlikely(skb == NULL)) | |
939 | err = -ENOBUFS; | |
940 | } | |
941 | if (skb == NULL) | |
942 | goto error; | |
943 | ||
944 | /* | |
945 | * Fill in the control structures | |
946 | */ | |
947 | skb->ip_summed = csummode; | |
948 | skb->csum = 0; | |
949 | skb_reserve(skb, hh_len); | |
950 | ||
951 | /* | |
952 | * Find where to start putting bytes. | |
953 | */ | |
954 | data = skb_put(skb, fraglen); | |
c14d2450 | 955 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
956 | skb->transport_header = (skb->network_header + |
957 | fragheaderlen); | |
1da177e4 | 958 | data += fragheaderlen; |
1da177e4 LT |
959 | |
960 | if (fraggap) { | |
961 | skb->csum = skb_copy_and_csum_bits( | |
962 | skb_prev, maxfraglen, | |
963 | data + transhdrlen, fraggap, 0); | |
964 | skb_prev->csum = csum_sub(skb_prev->csum, | |
965 | skb->csum); | |
966 | data += fraggap; | |
e9fa4f7b | 967 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
968 | } |
969 | ||
970 | copy = datalen - transhdrlen - fraggap; | |
971 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
972 | err = -EFAULT; | |
973 | kfree_skb(skb); | |
974 | goto error; | |
975 | } | |
976 | ||
977 | offset += copy; | |
978 | length -= datalen - fraggap; | |
979 | transhdrlen = 0; | |
980 | exthdrlen = 0; | |
981 | csummode = CHECKSUM_NONE; | |
982 | ||
983 | /* | |
984 | * Put the packet on the pending queue. | |
985 | */ | |
986 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
987 | continue; | |
988 | } | |
989 | ||
990 | if (copy > length) | |
991 | copy = length; | |
992 | ||
993 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) { | |
994 | unsigned int off; | |
995 | ||
996 | off = skb->len; | |
e905a9ed | 997 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
998 | offset, copy, off, skb) < 0) { |
999 | __skb_trim(skb, off); | |
1000 | err = -EFAULT; | |
1001 | goto error; | |
1002 | } | |
1003 | } else { | |
1004 | int i = skb_shinfo(skb)->nr_frags; | |
1005 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; | |
1006 | struct page *page = sk->sk_sndmsg_page; | |
1007 | int off = sk->sk_sndmsg_off; | |
1008 | unsigned int left; | |
1009 | ||
1010 | if (page && (left = PAGE_SIZE - off) > 0) { | |
1011 | if (copy >= left) | |
1012 | copy = left; | |
1013 | if (page != frag->page) { | |
1014 | if (i == MAX_SKB_FRAGS) { | |
1015 | err = -EMSGSIZE; | |
1016 | goto error; | |
1017 | } | |
1018 | get_page(page); | |
e905a9ed | 1019 | skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); |
1da177e4 LT |
1020 | frag = &skb_shinfo(skb)->frags[i]; |
1021 | } | |
1022 | } else if (i < MAX_SKB_FRAGS) { | |
1023 | if (copy > PAGE_SIZE) | |
1024 | copy = PAGE_SIZE; | |
1025 | page = alloc_pages(sk->sk_allocation, 0); | |
1026 | if (page == NULL) { | |
1027 | err = -ENOMEM; | |
1028 | goto error; | |
1029 | } | |
1030 | sk->sk_sndmsg_page = page; | |
1031 | sk->sk_sndmsg_off = 0; | |
1032 | ||
1033 | skb_fill_page_desc(skb, i, page, 0, 0); | |
1034 | frag = &skb_shinfo(skb)->frags[i]; | |
1da177e4 LT |
1035 | } else { |
1036 | err = -EMSGSIZE; | |
1037 | goto error; | |
1038 | } | |
1039 | if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { | |
1040 | err = -EFAULT; | |
1041 | goto error; | |
1042 | } | |
1043 | sk->sk_sndmsg_off += copy; | |
1044 | frag->size += copy; | |
1045 | skb->len += copy; | |
1046 | skb->data_len += copy; | |
f945fa7a HX |
1047 | skb->truesize += copy; |
1048 | atomic_add(copy, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1049 | } |
1050 | offset += copy; | |
1051 | length -= copy; | |
1052 | } | |
1053 | ||
1054 | return 0; | |
1055 | ||
1056 | error: | |
1057 | inet->cork.length -= length; | |
1058 | IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); | |
e905a9ed | 1059 | return err; |
1da177e4 LT |
1060 | } |
1061 | ||
1062 | ssize_t ip_append_page(struct sock *sk, struct page *page, | |
1063 | int offset, size_t size, int flags) | |
1064 | { | |
1065 | struct inet_sock *inet = inet_sk(sk); | |
1066 | struct sk_buff *skb; | |
1067 | struct rtable *rt; | |
1068 | struct ip_options *opt = NULL; | |
1069 | int hh_len; | |
1070 | int mtu; | |
1071 | int len; | |
1072 | int err; | |
1073 | unsigned int maxfraglen, fragheaderlen, fraggap; | |
1074 | ||
1075 | if (inet->hdrincl) | |
1076 | return -EPERM; | |
1077 | ||
1078 | if (flags&MSG_PROBE) | |
1079 | return 0; | |
1080 | ||
1081 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1082 | return -EINVAL; | |
1083 | ||
1084 | rt = inet->cork.rt; | |
1085 | if (inet->cork.flags & IPCORK_OPT) | |
1086 | opt = inet->cork.opt; | |
1087 | ||
1088 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) | |
1089 | return -EOPNOTSUPP; | |
1090 | ||
1091 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
1092 | mtu = inet->cork.fragsize; | |
1093 | ||
1094 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1095 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
1096 | ||
1097 | if (inet->cork.length + size > 0xFFFF - fragheaderlen) { | |
1098 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu); | |
1099 | return -EMSGSIZE; | |
1100 | } | |
1101 | ||
1102 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1103 | return -EINVAL; | |
1104 | ||
1105 | inet->cork.length += size; | |
e89e9cf5 | 1106 | if ((sk->sk_protocol == IPPROTO_UDP) && |
7967168c HX |
1107 | (rt->u.dst.dev->features & NETIF_F_UFO)) { |
1108 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; | |
f83ef8c0 | 1109 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
7967168c | 1110 | } |
e89e9cf5 | 1111 | |
1da177e4 LT |
1112 | |
1113 | while (size > 0) { | |
1114 | int i; | |
1115 | ||
89114afd | 1116 | if (skb_is_gso(skb)) |
e89e9cf5 AR |
1117 | len = size; |
1118 | else { | |
1119 | ||
1120 | /* Check if the remaining data fits into current packet. */ | |
1121 | len = mtu - skb->len; | |
1122 | if (len < size) | |
1123 | len = maxfraglen - skb->len; | |
1124 | } | |
1da177e4 LT |
1125 | if (len <= 0) { |
1126 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1127 | int alloclen; |
1128 | ||
1129 | skb_prev = skb; | |
0d0d2bba | 1130 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1131 | |
1132 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1133 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1134 | if (unlikely(!skb)) { | |
1135 | err = -ENOBUFS; | |
1136 | goto error; | |
1137 | } | |
1138 | ||
1139 | /* | |
1140 | * Fill in the control structures | |
1141 | */ | |
1142 | skb->ip_summed = CHECKSUM_NONE; | |
1143 | skb->csum = 0; | |
1144 | skb_reserve(skb, hh_len); | |
1145 | ||
1146 | /* | |
1147 | * Find where to start putting bytes. | |
1148 | */ | |
967b05f6 | 1149 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1150 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1151 | skb->transport_header = (skb->network_header + |
1152 | fragheaderlen); | |
1da177e4 | 1153 | if (fraggap) { |
967b05f6 ACM |
1154 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1155 | maxfraglen, | |
9c70220b | 1156 | skb_transport_header(skb), |
967b05f6 | 1157 | fraggap, 0); |
1da177e4 LT |
1158 | skb_prev->csum = csum_sub(skb_prev->csum, |
1159 | skb->csum); | |
e9fa4f7b | 1160 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1161 | } |
1162 | ||
1163 | /* | |
1164 | * Put the packet on the pending queue. | |
1165 | */ | |
1166 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1167 | continue; | |
1168 | } | |
1169 | ||
1170 | i = skb_shinfo(skb)->nr_frags; | |
1171 | if (len > size) | |
1172 | len = size; | |
1173 | if (skb_can_coalesce(skb, i, page, offset)) { | |
1174 | skb_shinfo(skb)->frags[i-1].size += len; | |
1175 | } else if (i < MAX_SKB_FRAGS) { | |
1176 | get_page(page); | |
1177 | skb_fill_page_desc(skb, i, page, offset, len); | |
1178 | } else { | |
1179 | err = -EMSGSIZE; | |
1180 | goto error; | |
1181 | } | |
1182 | ||
1183 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1184 | __wsum csum; |
1da177e4 LT |
1185 | csum = csum_page(page, offset, len); |
1186 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1187 | } | |
1188 | ||
1189 | skb->len += len; | |
1190 | skb->data_len += len; | |
1e34a11d DM |
1191 | skb->truesize += len; |
1192 | atomic_add(len, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1193 | offset += len; |
1194 | size -= len; | |
1195 | } | |
1196 | return 0; | |
1197 | ||
1198 | error: | |
1199 | inet->cork.length -= size; | |
1200 | IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); | |
1201 | return err; | |
1202 | } | |
1203 | ||
429f08e9 PE |
1204 | static void ip_cork_release(struct inet_sock *inet) |
1205 | { | |
1206 | inet->cork.flags &= ~IPCORK_OPT; | |
1207 | kfree(inet->cork.opt); | |
1208 | inet->cork.opt = NULL; | |
1209 | if (inet->cork.rt) { | |
1210 | ip_rt_put(inet->cork.rt); | |
1211 | inet->cork.rt = NULL; | |
1212 | } | |
1213 | } | |
1214 | ||
1da177e4 LT |
1215 | /* |
1216 | * Combined all pending IP fragments on the socket as one IP datagram | |
1217 | * and push them out. | |
1218 | */ | |
1219 | int ip_push_pending_frames(struct sock *sk) | |
1220 | { | |
1221 | struct sk_buff *skb, *tmp_skb; | |
1222 | struct sk_buff **tail_skb; | |
1223 | struct inet_sock *inet = inet_sk(sk); | |
1224 | struct ip_options *opt = NULL; | |
1225 | struct rtable *rt = inet->cork.rt; | |
1226 | struct iphdr *iph; | |
76ab608d | 1227 | __be16 df = 0; |
1da177e4 LT |
1228 | __u8 ttl; |
1229 | int err = 0; | |
1230 | ||
1231 | if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) | |
1232 | goto out; | |
1233 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1234 | ||
1235 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1236 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1237 | __skb_pull(skb, skb_network_offset(skb)); |
1da177e4 | 1238 | while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { |
cfe1fc77 | 1239 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1240 | *tail_skb = tmp_skb; |
1241 | tail_skb = &(tmp_skb->next); | |
1242 | skb->len += tmp_skb->len; | |
1243 | skb->data_len += tmp_skb->len; | |
1244 | skb->truesize += tmp_skb->truesize; | |
1245 | __sock_put(tmp_skb->sk); | |
1246 | tmp_skb->destructor = NULL; | |
1247 | tmp_skb->sk = NULL; | |
1248 | } | |
1249 | ||
1250 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1251 | * to fragment the frame generated here. No matter, what transforms | |
1252 | * how transforms change size of the packet, it will come out. | |
1253 | */ | |
628a5c56 | 1254 | if (inet->pmtudisc < IP_PMTUDISC_DO) |
1da177e4 LT |
1255 | skb->local_df = 1; |
1256 | ||
1257 | /* DF bit is set when we want to see DF on outgoing frames. | |
1258 | * If local_df is set too, we still allow to fragment this frame | |
1259 | * locally. */ | |
628a5c56 | 1260 | if (inet->pmtudisc >= IP_PMTUDISC_DO || |
1da177e4 LT |
1261 | (skb->len <= dst_mtu(&rt->u.dst) && |
1262 | ip_dont_fragment(sk, &rt->u.dst))) | |
1263 | df = htons(IP_DF); | |
1264 | ||
1265 | if (inet->cork.flags & IPCORK_OPT) | |
1266 | opt = inet->cork.opt; | |
1267 | ||
1268 | if (rt->rt_type == RTN_MULTICAST) | |
1269 | ttl = inet->mc_ttl; | |
1270 | else | |
1271 | ttl = ip_select_ttl(inet, &rt->u.dst); | |
1272 | ||
1273 | iph = (struct iphdr *)skb->data; | |
1274 | iph->version = 4; | |
1275 | iph->ihl = 5; | |
1276 | if (opt) { | |
1277 | iph->ihl += opt->optlen>>2; | |
1278 | ip_options_build(skb, opt, inet->cork.addr, rt, 0); | |
1279 | } | |
1280 | iph->tos = inet->tos; | |
1da177e4 | 1281 | iph->frag_off = df; |
1a55d57b | 1282 | ip_select_ident(iph, &rt->u.dst, sk); |
1da177e4 LT |
1283 | iph->ttl = ttl; |
1284 | iph->protocol = sk->sk_protocol; | |
1285 | iph->saddr = rt->rt_src; | |
1286 | iph->daddr = rt->rt_dst; | |
1da177e4 LT |
1287 | |
1288 | skb->priority = sk->sk_priority; | |
1289 | skb->dst = dst_clone(&rt->u.dst); | |
1290 | ||
96793b48 DS |
1291 | if (iph->protocol == IPPROTO_ICMP) |
1292 | icmp_out_count(((struct icmphdr *) | |
1293 | skb_transport_header(skb))->type); | |
1294 | ||
1da177e4 | 1295 | /* Netfilter gets whole the not fragmented skb. */ |
c439cb2e | 1296 | err = ip_local_out(skb); |
1da177e4 LT |
1297 | if (err) { |
1298 | if (err > 0) | |
1299 | err = inet->recverr ? net_xmit_errno(err) : 0; | |
1300 | if (err) | |
1301 | goto error; | |
1302 | } | |
1303 | ||
1304 | out: | |
429f08e9 | 1305 | ip_cork_release(inet); |
1da177e4 LT |
1306 | return err; |
1307 | ||
1308 | error: | |
1309 | IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); | |
1310 | goto out; | |
1311 | } | |
1312 | ||
1313 | /* | |
1314 | * Throw away all pending data on the socket. | |
1315 | */ | |
1316 | void ip_flush_pending_frames(struct sock *sk) | |
1317 | { | |
1da177e4 LT |
1318 | struct sk_buff *skb; |
1319 | ||
1320 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) | |
1321 | kfree_skb(skb); | |
1322 | ||
429f08e9 | 1323 | ip_cork_release(inet_sk(sk)); |
1da177e4 LT |
1324 | } |
1325 | ||
1326 | ||
1327 | /* | |
1328 | * Fetch data from kernel space and fill in checksum if needed. | |
1329 | */ | |
e905a9ed | 1330 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1331 | int len, int odd, struct sk_buff *skb) |
1332 | { | |
5084205f | 1333 | __wsum csum; |
1da177e4 LT |
1334 | |
1335 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1336 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1337 | return 0; |
1da177e4 LT |
1338 | } |
1339 | ||
e905a9ed | 1340 | /* |
1da177e4 LT |
1341 | * Generic function to send a packet as reply to another packet. |
1342 | * Used to send TCP resets so far. ICMP should use this function too. | |
1343 | * | |
e905a9ed | 1344 | * Should run single threaded per socket because it uses the sock |
1da177e4 | 1345 | * structure to pass arguments. |
1da177e4 LT |
1346 | */ |
1347 | void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, | |
1348 | unsigned int len) | |
1349 | { | |
1350 | struct inet_sock *inet = inet_sk(sk); | |
1351 | struct { | |
1352 | struct ip_options opt; | |
1353 | char data[40]; | |
1354 | } replyopts; | |
1355 | struct ipcm_cookie ipc; | |
3ca3c68e | 1356 | __be32 daddr; |
1da177e4 LT |
1357 | struct rtable *rt = (struct rtable*)skb->dst; |
1358 | ||
1359 | if (ip_options_echo(&replyopts.opt, skb)) | |
1360 | return; | |
1361 | ||
1362 | daddr = ipc.addr = rt->rt_src; | |
1363 | ipc.opt = NULL; | |
1364 | ||
1365 | if (replyopts.opt.optlen) { | |
1366 | ipc.opt = &replyopts.opt; | |
1367 | ||
1368 | if (ipc.opt->srr) | |
1369 | daddr = replyopts.opt.faddr; | |
1370 | } | |
1371 | ||
1372 | { | |
f0e48dbf PM |
1373 | struct flowi fl = { .oif = arg->bound_dev_if, |
1374 | .nl_u = { .ip4_u = | |
1da177e4 LT |
1375 | { .daddr = daddr, |
1376 | .saddr = rt->rt_spec_dst, | |
eddc9ec5 | 1377 | .tos = RT_TOS(ip_hdr(skb)->tos) } }, |
1da177e4 LT |
1378 | /* Not quite clean, but right. */ |
1379 | .uli_u = { .ports = | |
aa8223c7 ACM |
1380 | { .sport = tcp_hdr(skb)->dest, |
1381 | .dport = tcp_hdr(skb)->source } }, | |
1da177e4 | 1382 | .proto = sk->sk_protocol }; |
beb8d13b | 1383 | security_skb_classify_flow(skb, &fl); |
dde1bc0e | 1384 | if (ip_route_output_key(sk->sk_net, &rt, &fl)) |
1da177e4 LT |
1385 | return; |
1386 | } | |
1387 | ||
1388 | /* And let IP do all the hard work. | |
1389 | ||
1390 | This chunk is not reenterable, hence spinlock. | |
1391 | Note that it uses the fact, that this function is called | |
1392 | with locally disabled BH and that sk cannot be already spinlocked. | |
1393 | */ | |
1394 | bh_lock_sock(sk); | |
eddc9ec5 | 1395 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 | 1396 | sk->sk_priority = skb->priority; |
eddc9ec5 | 1397 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1398 | sk->sk_bound_dev_if = arg->bound_dev_if; |
1da177e4 LT |
1399 | ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, |
1400 | &ipc, rt, MSG_DONTWAIT); | |
1401 | if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { | |
1402 | if (arg->csumoffset >= 0) | |
9c70220b ACM |
1403 | *((__sum16 *)skb_transport_header(skb) + |
1404 | arg->csumoffset) = csum_fold(csum_add(skb->csum, | |
1405 | arg->csum)); | |
1da177e4 LT |
1406 | skb->ip_summed = CHECKSUM_NONE; |
1407 | ip_push_pending_frames(sk); | |
1408 | } | |
1409 | ||
1410 | bh_unlock_sock(sk); | |
1411 | ||
1412 | ip_rt_put(rt); | |
1413 | } | |
1414 | ||
1da177e4 LT |
1415 | void __init ip_init(void) |
1416 | { | |
1da177e4 LT |
1417 | ip_rt_init(); |
1418 | inet_initpeers(); | |
1419 | ||
1420 | #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) | |
1421 | igmp_mc_proc_init(); | |
1422 | #endif | |
1423 | } | |
1424 | ||
1da177e4 LT |
1425 | EXPORT_SYMBOL(ip_generic_getfrag); |
1426 | EXPORT_SYMBOL(ip_queue_xmit); | |
1427 | EXPORT_SYMBOL(ip_send_check); |