Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * The Internet Protocol (IP) output module. | |
7 | * | |
02c30a84 | 8 | * Authors: Ross Biro |
1da177e4 LT |
9 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
10 | * Donald Becker, <becker@super.org> | |
11 | * Alan Cox, <Alan.Cox@linux.org> | |
12 | * Richard Underwood | |
13 | * Stefan Becker, <stefanb@yello.ping.de> | |
14 | * Jorge Cwik, <jorge@laser.satlink.net> | |
15 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> | |
16 | * Hirokazu Takahashi, <taka@valinux.co.jp> | |
17 | * | |
18 | * See ip_input.c for original log | |
19 | * | |
20 | * Fixes: | |
21 | * Alan Cox : Missing nonblock feature in ip_build_xmit. | |
22 | * Mike Kilburn : htons() missing in ip_build_xmit. | |
e905a9ed | 23 | * Bradford Johnson: Fix faulty handling of some frames when |
1da177e4 LT |
24 | * no route is found. |
25 | * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit | |
26 | * (in case if packet not accepted by | |
27 | * output firewall rules) | |
28 | * Mike McLagan : Routing by source | |
29 | * Alexey Kuznetsov: use new route cache | |
30 | * Andi Kleen: Fix broken PMTU recovery and remove | |
31 | * some redundant tests. | |
32 | * Vitaly E. Lavrov : Transparent proxy revived after year coma. | |
33 | * Andi Kleen : Replace ip_reply with ip_send_reply. | |
e905a9ed YH |
34 | * Andi Kleen : Split fast and slow ip_build_xmit path |
35 | * for decreased register pressure on x86 | |
36 | * and more readibility. | |
1da177e4 LT |
37 | * Marc Boucher : When call_out_firewall returns FW_QUEUE, |
38 | * silently drop skb instead of failing with -EPERM. | |
39 | * Detlev Wengorz : Copy protocol for fragments. | |
40 | * Hirokazu Takahashi: HW checksumming for outgoing UDP | |
41 | * datagrams. | |
42 | * Hirokazu Takahashi: sendfile() on UDP works now. | |
43 | */ | |
44 | ||
45 | #include <asm/uaccess.h> | |
46 | #include <asm/system.h> | |
47 | #include <linux/module.h> | |
48 | #include <linux/types.h> | |
49 | #include <linux/kernel.h> | |
1da177e4 LT |
50 | #include <linux/mm.h> |
51 | #include <linux/string.h> | |
52 | #include <linux/errno.h> | |
a1f8e7f7 | 53 | #include <linux/highmem.h> |
5a0e3ad6 | 54 | #include <linux/slab.h> |
1da177e4 LT |
55 | |
56 | #include <linux/socket.h> | |
57 | #include <linux/sockios.h> | |
58 | #include <linux/in.h> | |
59 | #include <linux/inet.h> | |
60 | #include <linux/netdevice.h> | |
61 | #include <linux/etherdevice.h> | |
62 | #include <linux/proc_fs.h> | |
63 | #include <linux/stat.h> | |
64 | #include <linux/init.h> | |
65 | ||
66 | #include <net/snmp.h> | |
67 | #include <net/ip.h> | |
68 | #include <net/protocol.h> | |
69 | #include <net/route.h> | |
cfacb057 | 70 | #include <net/xfrm.h> |
1da177e4 LT |
71 | #include <linux/skbuff.h> |
72 | #include <net/sock.h> | |
73 | #include <net/arp.h> | |
74 | #include <net/icmp.h> | |
1da177e4 LT |
75 | #include <net/checksum.h> |
76 | #include <net/inetpeer.h> | |
1da177e4 LT |
77 | #include <linux/igmp.h> |
78 | #include <linux/netfilter_ipv4.h> | |
79 | #include <linux/netfilter_bridge.h> | |
80 | #include <linux/mroute.h> | |
81 | #include <linux/netlink.h> | |
6cbb0df7 | 82 | #include <linux/tcp.h> |
1da177e4 | 83 | |
ab32ea5d | 84 | int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; |
1da177e4 LT |
85 | |
86 | /* Generate a checksum for an outgoing IP datagram. */ | |
87 | __inline__ void ip_send_check(struct iphdr *iph) | |
88 | { | |
89 | iph->check = 0; | |
90 | iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); | |
91 | } | |
92 | ||
c439cb2e HX |
93 | int __ip_local_out(struct sk_buff *skb) |
94 | { | |
95 | struct iphdr *iph = ip_hdr(skb); | |
96 | ||
97 | iph->tot_len = htons(skb->len); | |
98 | ip_send_check(iph); | |
9bbc768a JE |
99 | return nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, skb, NULL, |
100 | skb_dst(skb)->dev, dst_output); | |
c439cb2e HX |
101 | } |
102 | ||
103 | int ip_local_out(struct sk_buff *skb) | |
104 | { | |
105 | int err; | |
106 | ||
107 | err = __ip_local_out(skb); | |
108 | if (likely(err == 1)) | |
109 | err = dst_output(skb); | |
110 | ||
111 | return err; | |
112 | } | |
113 | EXPORT_SYMBOL_GPL(ip_local_out); | |
114 | ||
1da177e4 LT |
115 | /* dev_loopback_xmit for use with netfilter. */ |
116 | static int ip_dev_loopback_xmit(struct sk_buff *newskb) | |
117 | { | |
459a98ed | 118 | skb_reset_mac_header(newskb); |
bbe735e4 | 119 | __skb_pull(newskb, skb_network_offset(newskb)); |
1da177e4 LT |
120 | newskb->pkt_type = PACKET_LOOPBACK; |
121 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
adf30907 | 122 | WARN_ON(!skb_dst(newskb)); |
e30b38c2 | 123 | netif_rx_ni(newskb); |
1da177e4 LT |
124 | return 0; |
125 | } | |
126 | ||
127 | static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) | |
128 | { | |
129 | int ttl = inet->uc_ttl; | |
130 | ||
131 | if (ttl < 0) | |
132 | ttl = dst_metric(dst, RTAX_HOPLIMIT); | |
133 | return ttl; | |
134 | } | |
135 | ||
e905a9ed | 136 | /* |
1da177e4 LT |
137 | * Add an ip header to a skbuff and send it out. |
138 | * | |
139 | */ | |
140 | int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, | |
13d8eaa0 | 141 | __be32 saddr, __be32 daddr, struct ip_options *opt) |
1da177e4 LT |
142 | { |
143 | struct inet_sock *inet = inet_sk(sk); | |
511c3f92 | 144 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
145 | struct iphdr *iph; |
146 | ||
147 | /* Build the IP header. */ | |
8856dfa3 ACM |
148 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
149 | skb_reset_network_header(skb); | |
eddc9ec5 | 150 | iph = ip_hdr(skb); |
1da177e4 LT |
151 | iph->version = 4; |
152 | iph->ihl = 5; | |
153 | iph->tos = inet->tos; | |
154 | if (ip_dont_fragment(sk, &rt->u.dst)) | |
155 | iph->frag_off = htons(IP_DF); | |
156 | else | |
157 | iph->frag_off = 0; | |
158 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); | |
159 | iph->daddr = rt->rt_dst; | |
160 | iph->saddr = rt->rt_src; | |
161 | iph->protocol = sk->sk_protocol; | |
1da177e4 | 162 | ip_select_ident(iph, &rt->u.dst, sk); |
1da177e4 LT |
163 | |
164 | if (opt && opt->optlen) { | |
165 | iph->ihl += opt->optlen>>2; | |
166 | ip_options_build(skb, opt, daddr, rt, 0); | |
167 | } | |
1da177e4 LT |
168 | |
169 | skb->priority = sk->sk_priority; | |
4a19ec58 | 170 | skb->mark = sk->sk_mark; |
1da177e4 LT |
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 | { | |
adf30907 | 180 | struct dst_entry *dst = skb_dst(skb); |
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 | |
edf391ff NH |
185 | if (rt->rt_type == RTN_MULTICAST) { |
186 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len); | |
187 | } else if (rt->rt_type == RTN_BROADCAST) | |
188 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTBCAST, skb->len); | |
80787ebc | 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) ? | |
adf30907 | 221 | skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); |
628a5c56 JH |
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 */ | |
adf30907 | 228 | if (skb_dst(skb)->xfrm != NULL) { |
48d5cad8 PM |
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; | |
511c3f92 | 242 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
243 | struct net_device *dev = rt->u.dst.dev; |
244 | ||
245 | /* | |
246 | * If the indicated interface is up and running, send the packet. | |
247 | */ | |
edf391ff | 248 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
1da177e4 LT |
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) { | |
7ad6848c | 258 | if (sk_mc_loop(sk) |
1da177e4 LT |
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 | */ | |
9d4fb27d JP |
268 | && |
269 | ((rt->rt_flags & RTCF_LOCAL) || | |
270 | !(IPCB(skb)->flags & IPSKB_FORWARDED)) | |
1da177e4 | 271 | #endif |
9d4fb27d | 272 | ) { |
1da177e4 LT |
273 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
274 | if (newskb) | |
9bbc768a JE |
275 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
276 | newskb, NULL, newskb->dev, | |
1da177e4 LT |
277 | ip_dev_loopback_xmit); |
278 | } | |
279 | ||
280 | /* Multicasts with ttl 0 must not go beyond the host */ | |
281 | ||
eddc9ec5 | 282 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
283 | kfree_skb(skb); |
284 | return 0; | |
285 | } | |
286 | } | |
287 | ||
288 | if (rt->rt_flags&RTCF_BROADCAST) { | |
289 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
290 | if (newskb) | |
9bbc768a JE |
291 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, newskb, |
292 | NULL, newskb->dev, ip_dev_loopback_xmit); | |
1da177e4 LT |
293 | } |
294 | ||
9bbc768a JE |
295 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, |
296 | skb->dev, ip_finish_output, | |
48d5cad8 | 297 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
298 | } |
299 | ||
300 | int ip_output(struct sk_buff *skb) | |
301 | { | |
adf30907 | 302 | struct net_device *dev = skb_dst(skb)->dev; |
1bd9bef6 | 303 | |
edf391ff | 304 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
1da177e4 | 305 | |
1bd9bef6 PM |
306 | skb->dev = dev; |
307 | skb->protocol = htons(ETH_P_IP); | |
308 | ||
9bbc768a | 309 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, dev, |
e905a9ed | 310 | ip_finish_output, |
48d5cad8 | 311 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
312 | } |
313 | ||
4e15ed4d | 314 | int ip_queue_xmit(struct sk_buff *skb) |
1da177e4 | 315 | { |
e89862f4 | 316 | struct sock *sk = skb->sk; |
1da177e4 LT |
317 | struct inet_sock *inet = inet_sk(sk); |
318 | struct ip_options *opt = inet->opt; | |
319 | struct rtable *rt; | |
320 | struct iphdr *iph; | |
ab6e3feb | 321 | int res; |
1da177e4 LT |
322 | |
323 | /* Skip all of this if the packet is already routed, | |
324 | * f.e. by something like SCTP. | |
325 | */ | |
ab6e3feb | 326 | rcu_read_lock(); |
511c3f92 | 327 | rt = skb_rtable(skb); |
1da177e4 LT |
328 | if (rt != NULL) |
329 | goto packet_routed; | |
330 | ||
331 | /* Make sure we can route this packet. */ | |
332 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
333 | if (rt == NULL) { | |
3ca3c68e | 334 | __be32 daddr; |
1da177e4 LT |
335 | |
336 | /* Use correct destination address if we have options. */ | |
c720c7e8 | 337 | daddr = inet->inet_daddr; |
1da177e4 LT |
338 | if(opt && opt->srr) |
339 | daddr = opt->faddr; | |
340 | ||
341 | { | |
342 | struct flowi fl = { .oif = sk->sk_bound_dev_if, | |
914a9ab3 | 343 | .mark = sk->sk_mark, |
1da177e4 LT |
344 | .nl_u = { .ip4_u = |
345 | { .daddr = daddr, | |
c720c7e8 | 346 | .saddr = inet->inet_saddr, |
1da177e4 LT |
347 | .tos = RT_CONN_FLAGS(sk) } }, |
348 | .proto = sk->sk_protocol, | |
86b08d86 | 349 | .flags = inet_sk_flowi_flags(sk), |
1da177e4 | 350 | .uli_u = { .ports = |
c720c7e8 ED |
351 | { .sport = inet->inet_sport, |
352 | .dport = inet->inet_dport } } }; | |
1da177e4 LT |
353 | |
354 | /* If this fails, retransmit mechanism of transport layer will | |
355 | * keep trying until route appears or the connection times | |
356 | * itself out. | |
357 | */ | |
beb8d13b | 358 | security_sk_classify_flow(sk, &fl); |
3b1e0a65 | 359 | if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0)) |
1da177e4 LT |
360 | goto no_route; |
361 | } | |
6cbb0df7 | 362 | sk_setup_caps(sk, &rt->u.dst); |
1da177e4 | 363 | } |
ab6e3feb | 364 | skb_dst_set_noref(skb, &rt->u.dst); |
1da177e4 LT |
365 | |
366 | packet_routed: | |
367 | if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) | |
368 | goto no_route; | |
369 | ||
370 | /* OK, we know where to send it, allocate and build IP header. */ | |
8856dfa3 ACM |
371 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
372 | skb_reset_network_header(skb); | |
eddc9ec5 | 373 | iph = ip_hdr(skb); |
714e85be | 374 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); |
4e15ed4d | 375 | if (ip_dont_fragment(sk, &rt->u.dst) && !skb->local_df) |
1da177e4 LT |
376 | iph->frag_off = htons(IP_DF); |
377 | else | |
378 | iph->frag_off = 0; | |
379 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); | |
380 | iph->protocol = sk->sk_protocol; | |
381 | iph->saddr = rt->rt_src; | |
382 | iph->daddr = rt->rt_dst; | |
1da177e4 LT |
383 | /* Transport layer set skb->h.foo itself. */ |
384 | ||
385 | if (opt && opt->optlen) { | |
386 | iph->ihl += opt->optlen >> 2; | |
c720c7e8 | 387 | ip_options_build(skb, opt, inet->inet_daddr, rt, 0); |
1da177e4 LT |
388 | } |
389 | ||
89f5f0ae | 390 | ip_select_ident_more(iph, &rt->u.dst, sk, |
7967168c | 391 | (skb_shinfo(skb)->gso_segs ?: 1) - 1); |
1da177e4 | 392 | |
1da177e4 | 393 | skb->priority = sk->sk_priority; |
4a19ec58 | 394 | skb->mark = sk->sk_mark; |
1da177e4 | 395 | |
ab6e3feb ED |
396 | res = ip_local_out(skb); |
397 | rcu_read_unlock(); | |
398 | return res; | |
1da177e4 LT |
399 | |
400 | no_route: | |
ab6e3feb | 401 | rcu_read_unlock(); |
5e38e270 | 402 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
1da177e4 LT |
403 | kfree_skb(skb); |
404 | return -EHOSTUNREACH; | |
405 | } | |
406 | ||
407 | ||
408 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) | |
409 | { | |
410 | to->pkt_type = from->pkt_type; | |
411 | to->priority = from->priority; | |
412 | to->protocol = from->protocol; | |
adf30907 ED |
413 | skb_dst_drop(to); |
414 | skb_dst_set(to, dst_clone(skb_dst(from))); | |
1da177e4 | 415 | to->dev = from->dev; |
82e91ffe | 416 | to->mark = from->mark; |
1da177e4 LT |
417 | |
418 | /* Copy the flags to each fragment. */ | |
419 | IPCB(to)->flags = IPCB(from)->flags; | |
420 | ||
421 | #ifdef CONFIG_NET_SCHED | |
422 | to->tc_index = from->tc_index; | |
423 | #endif | |
e7ac05f3 | 424 | nf_copy(to, from); |
ba9dda3a JK |
425 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ |
426 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) | |
427 | to->nf_trace = from->nf_trace; | |
428 | #endif | |
c98d80ed JA |
429 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
430 | to->ipvs_property = from->ipvs_property; | |
1da177e4 | 431 | #endif |
984bc16c | 432 | skb_copy_secmark(to, from); |
1da177e4 LT |
433 | } |
434 | ||
435 | /* | |
436 | * This IP datagram is too large to be sent in one piece. Break it up into | |
437 | * smaller pieces (each of size equal to IP header plus | |
438 | * a block of the data of the original IP data part) that will yet fit in a | |
439 | * single device frame, and queue such a frame for sending. | |
440 | */ | |
441 | ||
d9319100 | 442 | int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) |
1da177e4 LT |
443 | { |
444 | struct iphdr *iph; | |
445 | int raw = 0; | |
446 | int ptr; | |
447 | struct net_device *dev; | |
448 | struct sk_buff *skb2; | |
9bcfcaf5 | 449 | unsigned int mtu, hlen, left, len, ll_rs, pad; |
1da177e4 | 450 | int offset; |
76ab608d | 451 | __be16 not_last_frag; |
511c3f92 | 452 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
453 | int err = 0; |
454 | ||
455 | dev = rt->u.dst.dev; | |
456 | ||
457 | /* | |
458 | * Point into the IP datagram header. | |
459 | */ | |
460 | ||
eddc9ec5 | 461 | iph = ip_hdr(skb); |
1da177e4 LT |
462 | |
463 | if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { | |
5e38e270 | 464 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 465 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
628a5c56 | 466 | htonl(ip_skb_dst_mtu(skb))); |
1da177e4 LT |
467 | kfree_skb(skb); |
468 | return -EMSGSIZE; | |
469 | } | |
470 | ||
471 | /* | |
472 | * Setup starting values. | |
473 | */ | |
474 | ||
475 | hlen = iph->ihl * 4; | |
476 | mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ | |
6c79bf0f BDS |
477 | #ifdef CONFIG_BRIDGE_NETFILTER |
478 | if (skb->nf_bridge) | |
479 | mtu -= nf_bridge_mtu_reduction(skb); | |
480 | #endif | |
89cee8b1 | 481 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
1da177e4 LT |
482 | |
483 | /* When frag_list is given, use it. First, check its validity: | |
484 | * some transformers could create wrong frag_list or break existing | |
485 | * one, it is not prohibited. In this case fall back to copying. | |
486 | * | |
487 | * LATER: this step can be merged to real generation of fragments, | |
488 | * we can switch to copy when see the first bad fragment. | |
489 | */ | |
d7fcf1a5 | 490 | if (skb_has_frags(skb)) { |
1da177e4 LT |
491 | struct sk_buff *frag; |
492 | int first_len = skb_pagelen(skb); | |
29ffe1a5 | 493 | int truesizes = 0; |
1da177e4 LT |
494 | |
495 | if (first_len - hlen > mtu || | |
496 | ((first_len - hlen) & 7) || | |
497 | (iph->frag_off & htons(IP_MF|IP_OFFSET)) || | |
498 | skb_cloned(skb)) | |
499 | goto slow_path; | |
500 | ||
d7fcf1a5 | 501 | skb_walk_frags(skb, frag) { |
1da177e4 LT |
502 | /* Correct geometry. */ |
503 | if (frag->len > mtu || | |
504 | ((frag->len & 7) && frag->next) || | |
505 | skb_headroom(frag) < hlen) | |
506 | goto slow_path; | |
507 | ||
508 | /* Partially cloned skb? */ | |
509 | if (skb_shared(frag)) | |
510 | goto slow_path; | |
2fdba6b0 HX |
511 | |
512 | BUG_ON(frag->sk); | |
513 | if (skb->sk) { | |
2fdba6b0 HX |
514 | frag->sk = skb->sk; |
515 | frag->destructor = sock_wfree; | |
2fdba6b0 | 516 | } |
b2722b1c | 517 | truesizes += frag->truesize; |
1da177e4 LT |
518 | } |
519 | ||
520 | /* Everything is OK. Generate! */ | |
521 | ||
522 | err = 0; | |
523 | offset = 0; | |
524 | frag = skb_shinfo(skb)->frag_list; | |
d7fcf1a5 | 525 | skb_frag_list_init(skb); |
1da177e4 | 526 | skb->data_len = first_len - skb_headlen(skb); |
29ffe1a5 | 527 | skb->truesize -= truesizes; |
1da177e4 LT |
528 | skb->len = first_len; |
529 | iph->tot_len = htons(first_len); | |
530 | iph->frag_off = htons(IP_MF); | |
531 | ip_send_check(iph); | |
532 | ||
533 | for (;;) { | |
534 | /* Prepare header of the next frame, | |
535 | * before previous one went down. */ | |
536 | if (frag) { | |
537 | frag->ip_summed = CHECKSUM_NONE; | |
badff6d0 | 538 | skb_reset_transport_header(frag); |
e2d1bca7 ACM |
539 | __skb_push(frag, hlen); |
540 | skb_reset_network_header(frag); | |
d56f90a7 | 541 | memcpy(skb_network_header(frag), iph, hlen); |
eddc9ec5 | 542 | iph = ip_hdr(frag); |
1da177e4 LT |
543 | iph->tot_len = htons(frag->len); |
544 | ip_copy_metadata(frag, skb); | |
545 | if (offset == 0) | |
546 | ip_options_fragment(frag); | |
547 | offset += skb->len - hlen; | |
548 | iph->frag_off = htons(offset>>3); | |
549 | if (frag->next != NULL) | |
550 | iph->frag_off |= htons(IP_MF); | |
551 | /* Ready, complete checksum */ | |
552 | ip_send_check(iph); | |
553 | } | |
554 | ||
555 | err = output(skb); | |
556 | ||
dafee490 | 557 | if (!err) |
5e38e270 | 558 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 LT |
559 | if (err || !frag) |
560 | break; | |
561 | ||
562 | skb = frag; | |
563 | frag = skb->next; | |
564 | skb->next = NULL; | |
565 | } | |
566 | ||
567 | if (err == 0) { | |
5e38e270 | 568 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
569 | return 0; |
570 | } | |
571 | ||
572 | while (frag) { | |
573 | skb = frag->next; | |
574 | kfree_skb(frag); | |
575 | frag = skb; | |
576 | } | |
5e38e270 | 577 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
578 | return err; |
579 | } | |
580 | ||
581 | slow_path: | |
582 | left = skb->len - hlen; /* Space per frame */ | |
583 | ptr = raw + hlen; /* Where to start from */ | |
584 | ||
1da177e4 | 585 | /* for bridged IP traffic encapsulated inside f.e. a vlan header, |
9bcfcaf5 SH |
586 | * we need to make room for the encapsulating header |
587 | */ | |
588 | pad = nf_bridge_pad(skb); | |
589 | ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad); | |
590 | mtu -= pad; | |
591 | ||
1da177e4 LT |
592 | /* |
593 | * Fragment the datagram. | |
594 | */ | |
595 | ||
596 | offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
597 | not_last_frag = iph->frag_off & htons(IP_MF); | |
598 | ||
599 | /* | |
600 | * Keep copying data until we run out. | |
601 | */ | |
602 | ||
132adf54 | 603 | while (left > 0) { |
1da177e4 LT |
604 | len = left; |
605 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
606 | if (len > mtu) | |
607 | len = mtu; | |
608 | /* IF: we are not sending upto and including the packet end | |
609 | then align the next start on an eight byte boundary */ | |
610 | if (len < left) { | |
611 | len &= ~7; | |
612 | } | |
613 | /* | |
614 | * Allocate buffer. | |
615 | */ | |
616 | ||
617 | if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { | |
64ce2073 | 618 | NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); |
1da177e4 LT |
619 | err = -ENOMEM; |
620 | goto fail; | |
621 | } | |
622 | ||
623 | /* | |
624 | * Set up data on packet | |
625 | */ | |
626 | ||
627 | ip_copy_metadata(skb2, skb); | |
628 | skb_reserve(skb2, ll_rs); | |
629 | skb_put(skb2, len + hlen); | |
c1d2bbe1 | 630 | skb_reset_network_header(skb2); |
b0e380b1 | 631 | skb2->transport_header = skb2->network_header + hlen; |
1da177e4 LT |
632 | |
633 | /* | |
634 | * Charge the memory for the fragment to any owner | |
635 | * it might possess | |
636 | */ | |
637 | ||
638 | if (skb->sk) | |
639 | skb_set_owner_w(skb2, skb->sk); | |
640 | ||
641 | /* | |
642 | * Copy the packet header into the new buffer. | |
643 | */ | |
644 | ||
d626f62b | 645 | skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); |
1da177e4 LT |
646 | |
647 | /* | |
648 | * Copy a block of the IP datagram. | |
649 | */ | |
bff9b61c | 650 | if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) |
1da177e4 LT |
651 | BUG(); |
652 | left -= len; | |
653 | ||
654 | /* | |
655 | * Fill in the new header fields. | |
656 | */ | |
eddc9ec5 | 657 | iph = ip_hdr(skb2); |
1da177e4 LT |
658 | iph->frag_off = htons((offset >> 3)); |
659 | ||
660 | /* ANK: dirty, but effective trick. Upgrade options only if | |
661 | * the segment to be fragmented was THE FIRST (otherwise, | |
662 | * options are already fixed) and make it ONCE | |
663 | * on the initial skb, so that all the following fragments | |
664 | * will inherit fixed options. | |
665 | */ | |
666 | if (offset == 0) | |
667 | ip_options_fragment(skb); | |
668 | ||
669 | /* | |
670 | * Added AC : If we are fragmenting a fragment that's not the | |
671 | * last fragment then keep MF on each bit | |
672 | */ | |
673 | if (left > 0 || not_last_frag) | |
674 | iph->frag_off |= htons(IP_MF); | |
675 | ptr += len; | |
676 | offset += len; | |
677 | ||
678 | /* | |
679 | * Put this fragment into the sending queue. | |
680 | */ | |
1da177e4 LT |
681 | iph->tot_len = htons(len + hlen); |
682 | ||
683 | ip_send_check(iph); | |
684 | ||
685 | err = output(skb2); | |
686 | if (err) | |
687 | goto fail; | |
dafee490 | 688 | |
5e38e270 | 689 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 LT |
690 | } |
691 | kfree_skb(skb); | |
5e38e270 | 692 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
693 | return err; |
694 | ||
695 | fail: | |
e905a9ed | 696 | kfree_skb(skb); |
5e38e270 | 697 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
698 | return err; |
699 | } | |
700 | ||
2e2f7aef PM |
701 | EXPORT_SYMBOL(ip_fragment); |
702 | ||
1da177e4 LT |
703 | int |
704 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
705 | { | |
706 | struct iovec *iov = from; | |
707 | ||
84fa7933 | 708 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
1da177e4 LT |
709 | if (memcpy_fromiovecend(to, iov, offset, len) < 0) |
710 | return -EFAULT; | |
711 | } else { | |
44bb9363 | 712 | __wsum csum = 0; |
1da177e4 LT |
713 | if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) |
714 | return -EFAULT; | |
715 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
716 | } | |
717 | return 0; | |
718 | } | |
719 | ||
44bb9363 | 720 | static inline __wsum |
1da177e4 LT |
721 | csum_page(struct page *page, int offset, int copy) |
722 | { | |
723 | char *kaddr; | |
44bb9363 | 724 | __wsum csum; |
1da177e4 LT |
725 | kaddr = kmap(page); |
726 | csum = csum_partial(kaddr + offset, copy, 0); | |
727 | kunmap(page); | |
728 | return csum; | |
729 | } | |
730 | ||
4b30b1c6 | 731 | static inline int ip_ufo_append_data(struct sock *sk, |
e89e9cf5 AR |
732 | int getfrag(void *from, char *to, int offset, int len, |
733 | int odd, struct sk_buff *skb), | |
734 | void *from, int length, int hh_len, int fragheaderlen, | |
d9319100 | 735 | int transhdrlen, int mtu, unsigned int flags) |
e89e9cf5 AR |
736 | { |
737 | struct sk_buff *skb; | |
738 | int err; | |
739 | ||
740 | /* There is support for UDP fragmentation offload by network | |
741 | * device, so create one single skb packet containing complete | |
742 | * udp datagram | |
743 | */ | |
744 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { | |
745 | skb = sock_alloc_send_skb(sk, | |
746 | hh_len + fragheaderlen + transhdrlen + 20, | |
747 | (flags & MSG_DONTWAIT), &err); | |
748 | ||
749 | if (skb == NULL) | |
750 | return err; | |
751 | ||
752 | /* reserve space for Hardware header */ | |
753 | skb_reserve(skb, hh_len); | |
754 | ||
755 | /* create space for UDP/IP header */ | |
d9319100 | 756 | skb_put(skb, fragheaderlen + transhdrlen); |
e89e9cf5 AR |
757 | |
758 | /* initialize network header pointer */ | |
c1d2bbe1 | 759 | skb_reset_network_header(skb); |
e89e9cf5 AR |
760 | |
761 | /* initialize protocol header pointer */ | |
b0e380b1 | 762 | skb->transport_header = skb->network_header + fragheaderlen; |
e89e9cf5 | 763 | |
84fa7933 | 764 | skb->ip_summed = CHECKSUM_PARTIAL; |
e89e9cf5 AR |
765 | skb->csum = 0; |
766 | sk->sk_sndmsg_off = 0; | |
e89e9cf5 | 767 | |
be9164e7 | 768 | /* specify the length of each IP datagram fragment */ |
7967168c | 769 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
f83ef8c0 | 770 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
e89e9cf5 | 771 | __skb_queue_tail(&sk->sk_write_queue, skb); |
e89e9cf5 | 772 | } |
be9164e7 K |
773 | |
774 | return skb_append_datato_frags(sk, skb, getfrag, from, | |
775 | (length - transhdrlen)); | |
e89e9cf5 AR |
776 | } |
777 | ||
1da177e4 LT |
778 | /* |
779 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
780 | * from many pieces of data. Each pieces will be holded on the socket | |
781 | * until ip_push_pending_frames() is called. Each piece can be a page | |
782 | * or non-page data. | |
e905a9ed | 783 | * |
1da177e4 LT |
784 | * Not only UDP, other transport protocols - e.g. raw sockets - can use |
785 | * this interface potentially. | |
786 | * | |
787 | * LATER: length must be adjusted by pad at tail, when it is required. | |
788 | */ | |
789 | int ip_append_data(struct sock *sk, | |
790 | int getfrag(void *from, char *to, int offset, int len, | |
791 | int odd, struct sk_buff *skb), | |
792 | void *from, int length, int transhdrlen, | |
2e77d89b | 793 | struct ipcm_cookie *ipc, struct rtable **rtp, |
1da177e4 LT |
794 | unsigned int flags) |
795 | { | |
796 | struct inet_sock *inet = inet_sk(sk); | |
797 | struct sk_buff *skb; | |
798 | ||
799 | struct ip_options *opt = NULL; | |
800 | int hh_len; | |
801 | int exthdrlen; | |
802 | int mtu; | |
803 | int copy; | |
804 | int err; | |
805 | int offset = 0; | |
806 | unsigned int maxfraglen, fragheaderlen; | |
807 | int csummode = CHECKSUM_NONE; | |
2e77d89b | 808 | struct rtable *rt; |
1da177e4 LT |
809 | |
810 | if (flags&MSG_PROBE) | |
811 | return 0; | |
812 | ||
813 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
814 | /* | |
815 | * setup for corking. | |
816 | */ | |
817 | opt = ipc->opt; | |
818 | if (opt) { | |
819 | if (inet->cork.opt == NULL) { | |
820 | inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation); | |
821 | if (unlikely(inet->cork.opt == NULL)) | |
822 | return -ENOBUFS; | |
823 | } | |
824 | memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen); | |
825 | inet->cork.flags |= IPCORK_OPT; | |
826 | inet->cork.addr = ipc->addr; | |
827 | } | |
2e77d89b | 828 | rt = *rtp; |
788d908f JT |
829 | if (unlikely(!rt)) |
830 | return -EFAULT; | |
2e77d89b ED |
831 | /* |
832 | * We steal reference to this route, caller should not release it | |
833 | */ | |
834 | *rtp = NULL; | |
628a5c56 JH |
835 | inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ? |
836 | rt->u.dst.dev->mtu : | |
837 | dst_mtu(rt->u.dst.path); | |
c8cdaf99 | 838 | inet->cork.dst = &rt->u.dst; |
1da177e4 LT |
839 | inet->cork.length = 0; |
840 | sk->sk_sndmsg_page = NULL; | |
841 | sk->sk_sndmsg_off = 0; | |
842 | if ((exthdrlen = rt->u.dst.header_len) != 0) { | |
843 | length += exthdrlen; | |
844 | transhdrlen += exthdrlen; | |
845 | } | |
846 | } else { | |
c8cdaf99 | 847 | rt = (struct rtable *)inet->cork.dst; |
1da177e4 LT |
848 | if (inet->cork.flags & IPCORK_OPT) |
849 | opt = inet->cork.opt; | |
850 | ||
851 | transhdrlen = 0; | |
852 | exthdrlen = 0; | |
853 | mtu = inet->cork.fragsize; | |
854 | } | |
855 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
856 | ||
857 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
858 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
859 | ||
860 | if (inet->cork.length + length > 0xFFFF - fragheaderlen) { | |
c720c7e8 ED |
861 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->inet_dport, |
862 | mtu-exthdrlen); | |
1da177e4 LT |
863 | return -EMSGSIZE; |
864 | } | |
865 | ||
866 | /* | |
867 | * transhdrlen > 0 means that this is the first fragment and we wish | |
868 | * it won't be fragmented in the future. | |
869 | */ | |
870 | if (transhdrlen && | |
871 | length + fragheaderlen <= mtu && | |
d212f87b | 872 | rt->u.dst.dev->features & NETIF_F_V4_CSUM && |
1da177e4 | 873 | !exthdrlen) |
84fa7933 | 874 | csummode = CHECKSUM_PARTIAL; |
1da177e4 LT |
875 | |
876 | inet->cork.length += length; | |
be9164e7 K |
877 | if (((length> mtu) || !skb_queue_empty(&sk->sk_write_queue)) && |
878 | (sk->sk_protocol == IPPROTO_UDP) && | |
879 | (rt->u.dst.dev->features & NETIF_F_UFO)) { | |
baa829d8 PM |
880 | err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, |
881 | fragheaderlen, transhdrlen, mtu, | |
882 | flags); | |
883 | if (err) | |
e89e9cf5 | 884 | goto error; |
e89e9cf5 AR |
885 | return 0; |
886 | } | |
1da177e4 LT |
887 | |
888 | /* So, what's going on in the loop below? | |
889 | * | |
890 | * We use calculated fragment length to generate chained skb, | |
891 | * each of segments is IP fragment ready for sending to network after | |
892 | * adding appropriate IP header. | |
893 | */ | |
894 | ||
895 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
896 | goto alloc_new_skb; | |
897 | ||
898 | while (length > 0) { | |
899 | /* Check if the remaining data fits into current packet. */ | |
900 | copy = mtu - skb->len; | |
901 | if (copy < length) | |
902 | copy = maxfraglen - skb->len; | |
903 | if (copy <= 0) { | |
904 | char *data; | |
905 | unsigned int datalen; | |
906 | unsigned int fraglen; | |
907 | unsigned int fraggap; | |
908 | unsigned int alloclen; | |
909 | struct sk_buff *skb_prev; | |
910 | alloc_new_skb: | |
911 | skb_prev = skb; | |
912 | if (skb_prev) | |
913 | fraggap = skb_prev->len - maxfraglen; | |
914 | else | |
915 | fraggap = 0; | |
916 | ||
917 | /* | |
918 | * If remaining data exceeds the mtu, | |
919 | * we know we need more fragment(s). | |
920 | */ | |
921 | datalen = length + fraggap; | |
922 | if (datalen > mtu - fragheaderlen) | |
923 | datalen = maxfraglen - fragheaderlen; | |
924 | fraglen = datalen + fragheaderlen; | |
925 | ||
e905a9ed | 926 | if ((flags & MSG_MORE) && |
1da177e4 LT |
927 | !(rt->u.dst.dev->features&NETIF_F_SG)) |
928 | alloclen = mtu; | |
929 | else | |
930 | alloclen = datalen + fragheaderlen; | |
931 | ||
932 | /* The last fragment gets additional space at tail. | |
933 | * Note, with MSG_MORE we overallocate on fragments, | |
934 | * because we have no idea what fragment will be | |
935 | * the last. | |
936 | */ | |
3d9dd756 | 937 | if (datalen == length + fraggap) |
1da177e4 LT |
938 | alloclen += rt->u.dst.trailer_len; |
939 | ||
940 | if (transhdrlen) { | |
e905a9ed | 941 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
942 | alloclen + hh_len + 15, |
943 | (flags & MSG_DONTWAIT), &err); | |
944 | } else { | |
945 | skb = NULL; | |
946 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
947 | 2 * sk->sk_sndbuf) | |
e905a9ed | 948 | skb = sock_wmalloc(sk, |
1da177e4 LT |
949 | alloclen + hh_len + 15, 1, |
950 | sk->sk_allocation); | |
951 | if (unlikely(skb == NULL)) | |
952 | err = -ENOBUFS; | |
51f31cab PO |
953 | else |
954 | /* only the initial fragment is | |
955 | time stamped */ | |
956 | ipc->shtx.flags = 0; | |
1da177e4 LT |
957 | } |
958 | if (skb == NULL) | |
959 | goto error; | |
960 | ||
961 | /* | |
962 | * Fill in the control structures | |
963 | */ | |
964 | skb->ip_summed = csummode; | |
965 | skb->csum = 0; | |
966 | skb_reserve(skb, hh_len); | |
51f31cab | 967 | *skb_tx(skb) = ipc->shtx; |
1da177e4 LT |
968 | |
969 | /* | |
970 | * Find where to start putting bytes. | |
971 | */ | |
972 | data = skb_put(skb, fraglen); | |
c14d2450 | 973 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
974 | skb->transport_header = (skb->network_header + |
975 | fragheaderlen); | |
1da177e4 | 976 | data += fragheaderlen; |
1da177e4 LT |
977 | |
978 | if (fraggap) { | |
979 | skb->csum = skb_copy_and_csum_bits( | |
980 | skb_prev, maxfraglen, | |
981 | data + transhdrlen, fraggap, 0); | |
982 | skb_prev->csum = csum_sub(skb_prev->csum, | |
983 | skb->csum); | |
984 | data += fraggap; | |
e9fa4f7b | 985 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
986 | } |
987 | ||
988 | copy = datalen - transhdrlen - fraggap; | |
989 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
990 | err = -EFAULT; | |
991 | kfree_skb(skb); | |
992 | goto error; | |
993 | } | |
994 | ||
995 | offset += copy; | |
996 | length -= datalen - fraggap; | |
997 | transhdrlen = 0; | |
998 | exthdrlen = 0; | |
999 | csummode = CHECKSUM_NONE; | |
1000 | ||
1001 | /* | |
1002 | * Put the packet on the pending queue. | |
1003 | */ | |
1004 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1005 | continue; | |
1006 | } | |
1007 | ||
1008 | if (copy > length) | |
1009 | copy = length; | |
1010 | ||
1011 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) { | |
1012 | unsigned int off; | |
1013 | ||
1014 | off = skb->len; | |
e905a9ed | 1015 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
1016 | offset, copy, off, skb) < 0) { |
1017 | __skb_trim(skb, off); | |
1018 | err = -EFAULT; | |
1019 | goto error; | |
1020 | } | |
1021 | } else { | |
1022 | int i = skb_shinfo(skb)->nr_frags; | |
1023 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; | |
1024 | struct page *page = sk->sk_sndmsg_page; | |
1025 | int off = sk->sk_sndmsg_off; | |
1026 | unsigned int left; | |
1027 | ||
1028 | if (page && (left = PAGE_SIZE - off) > 0) { | |
1029 | if (copy >= left) | |
1030 | copy = left; | |
1031 | if (page != frag->page) { | |
1032 | if (i == MAX_SKB_FRAGS) { | |
1033 | err = -EMSGSIZE; | |
1034 | goto error; | |
1035 | } | |
1036 | get_page(page); | |
e905a9ed | 1037 | skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); |
1da177e4 LT |
1038 | frag = &skb_shinfo(skb)->frags[i]; |
1039 | } | |
1040 | } else if (i < MAX_SKB_FRAGS) { | |
1041 | if (copy > PAGE_SIZE) | |
1042 | copy = PAGE_SIZE; | |
1043 | page = alloc_pages(sk->sk_allocation, 0); | |
1044 | if (page == NULL) { | |
1045 | err = -ENOMEM; | |
1046 | goto error; | |
1047 | } | |
1048 | sk->sk_sndmsg_page = page; | |
1049 | sk->sk_sndmsg_off = 0; | |
1050 | ||
1051 | skb_fill_page_desc(skb, i, page, 0, 0); | |
1052 | frag = &skb_shinfo(skb)->frags[i]; | |
1da177e4 LT |
1053 | } else { |
1054 | err = -EMSGSIZE; | |
1055 | goto error; | |
1056 | } | |
1057 | if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { | |
1058 | err = -EFAULT; | |
1059 | goto error; | |
1060 | } | |
1061 | sk->sk_sndmsg_off += copy; | |
1062 | frag->size += copy; | |
1063 | skb->len += copy; | |
1064 | skb->data_len += copy; | |
f945fa7a HX |
1065 | skb->truesize += copy; |
1066 | atomic_add(copy, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1067 | } |
1068 | offset += copy; | |
1069 | length -= copy; | |
1070 | } | |
1071 | ||
1072 | return 0; | |
1073 | ||
1074 | error: | |
1075 | inet->cork.length -= length; | |
5e38e270 | 1076 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
e905a9ed | 1077 | return err; |
1da177e4 LT |
1078 | } |
1079 | ||
1080 | ssize_t ip_append_page(struct sock *sk, struct page *page, | |
1081 | int offset, size_t size, int flags) | |
1082 | { | |
1083 | struct inet_sock *inet = inet_sk(sk); | |
1084 | struct sk_buff *skb; | |
1085 | struct rtable *rt; | |
1086 | struct ip_options *opt = NULL; | |
1087 | int hh_len; | |
1088 | int mtu; | |
1089 | int len; | |
1090 | int err; | |
1091 | unsigned int maxfraglen, fragheaderlen, fraggap; | |
1092 | ||
1093 | if (inet->hdrincl) | |
1094 | return -EPERM; | |
1095 | ||
1096 | if (flags&MSG_PROBE) | |
1097 | return 0; | |
1098 | ||
1099 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1100 | return -EINVAL; | |
1101 | ||
c8cdaf99 | 1102 | rt = (struct rtable *)inet->cork.dst; |
1da177e4 LT |
1103 | if (inet->cork.flags & IPCORK_OPT) |
1104 | opt = inet->cork.opt; | |
1105 | ||
1106 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) | |
1107 | return -EOPNOTSUPP; | |
1108 | ||
1109 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
1110 | mtu = inet->cork.fragsize; | |
1111 | ||
1112 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1113 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
1114 | ||
1115 | if (inet->cork.length + size > 0xFFFF - fragheaderlen) { | |
c720c7e8 | 1116 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->inet_dport, mtu); |
1da177e4 LT |
1117 | return -EMSGSIZE; |
1118 | } | |
1119 | ||
1120 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1121 | return -EINVAL; | |
1122 | ||
1123 | inet->cork.length += size; | |
e89e9cf5 | 1124 | if ((sk->sk_protocol == IPPROTO_UDP) && |
7967168c HX |
1125 | (rt->u.dst.dev->features & NETIF_F_UFO)) { |
1126 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; | |
f83ef8c0 | 1127 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
7967168c | 1128 | } |
e89e9cf5 | 1129 | |
1da177e4 LT |
1130 | |
1131 | while (size > 0) { | |
1132 | int i; | |
1133 | ||
89114afd | 1134 | if (skb_is_gso(skb)) |
e89e9cf5 AR |
1135 | len = size; |
1136 | else { | |
1137 | ||
1138 | /* Check if the remaining data fits into current packet. */ | |
1139 | len = mtu - skb->len; | |
1140 | if (len < size) | |
1141 | len = maxfraglen - skb->len; | |
1142 | } | |
1da177e4 LT |
1143 | if (len <= 0) { |
1144 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1145 | int alloclen; |
1146 | ||
1147 | skb_prev = skb; | |
0d0d2bba | 1148 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1149 | |
1150 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1151 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1152 | if (unlikely(!skb)) { | |
1153 | err = -ENOBUFS; | |
1154 | goto error; | |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Fill in the control structures | |
1159 | */ | |
1160 | skb->ip_summed = CHECKSUM_NONE; | |
1161 | skb->csum = 0; | |
1162 | skb_reserve(skb, hh_len); | |
1163 | ||
1164 | /* | |
1165 | * Find where to start putting bytes. | |
1166 | */ | |
967b05f6 | 1167 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1168 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1169 | skb->transport_header = (skb->network_header + |
1170 | fragheaderlen); | |
1da177e4 | 1171 | if (fraggap) { |
967b05f6 ACM |
1172 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1173 | maxfraglen, | |
9c70220b | 1174 | skb_transport_header(skb), |
967b05f6 | 1175 | fraggap, 0); |
1da177e4 LT |
1176 | skb_prev->csum = csum_sub(skb_prev->csum, |
1177 | skb->csum); | |
e9fa4f7b | 1178 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1179 | } |
1180 | ||
1181 | /* | |
1182 | * Put the packet on the pending queue. | |
1183 | */ | |
1184 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1185 | continue; | |
1186 | } | |
1187 | ||
1188 | i = skb_shinfo(skb)->nr_frags; | |
1189 | if (len > size) | |
1190 | len = size; | |
1191 | if (skb_can_coalesce(skb, i, page, offset)) { | |
1192 | skb_shinfo(skb)->frags[i-1].size += len; | |
1193 | } else if (i < MAX_SKB_FRAGS) { | |
1194 | get_page(page); | |
1195 | skb_fill_page_desc(skb, i, page, offset, len); | |
1196 | } else { | |
1197 | err = -EMSGSIZE; | |
1198 | goto error; | |
1199 | } | |
1200 | ||
1201 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1202 | __wsum csum; |
1da177e4 LT |
1203 | csum = csum_page(page, offset, len); |
1204 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1205 | } | |
1206 | ||
1207 | skb->len += len; | |
1208 | skb->data_len += len; | |
1e34a11d DM |
1209 | skb->truesize += len; |
1210 | atomic_add(len, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1211 | offset += len; |
1212 | size -= len; | |
1213 | } | |
1214 | return 0; | |
1215 | ||
1216 | error: | |
1217 | inet->cork.length -= size; | |
5e38e270 | 1218 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1219 | return err; |
1220 | } | |
1221 | ||
429f08e9 PE |
1222 | static void ip_cork_release(struct inet_sock *inet) |
1223 | { | |
1224 | inet->cork.flags &= ~IPCORK_OPT; | |
1225 | kfree(inet->cork.opt); | |
1226 | inet->cork.opt = NULL; | |
c8cdaf99 YH |
1227 | dst_release(inet->cork.dst); |
1228 | inet->cork.dst = NULL; | |
429f08e9 PE |
1229 | } |
1230 | ||
1da177e4 LT |
1231 | /* |
1232 | * Combined all pending IP fragments on the socket as one IP datagram | |
1233 | * and push them out. | |
1234 | */ | |
1235 | int ip_push_pending_frames(struct sock *sk) | |
1236 | { | |
1237 | struct sk_buff *skb, *tmp_skb; | |
1238 | struct sk_buff **tail_skb; | |
1239 | struct inet_sock *inet = inet_sk(sk); | |
0388b004 | 1240 | struct net *net = sock_net(sk); |
1da177e4 | 1241 | struct ip_options *opt = NULL; |
c8cdaf99 | 1242 | struct rtable *rt = (struct rtable *)inet->cork.dst; |
1da177e4 | 1243 | struct iphdr *iph; |
76ab608d | 1244 | __be16 df = 0; |
1da177e4 LT |
1245 | __u8 ttl; |
1246 | int err = 0; | |
1247 | ||
1248 | if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) | |
1249 | goto out; | |
1250 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1251 | ||
1252 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1253 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1254 | __skb_pull(skb, skb_network_offset(skb)); |
1da177e4 | 1255 | while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { |
cfe1fc77 | 1256 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1257 | *tail_skb = tmp_skb; |
1258 | tail_skb = &(tmp_skb->next); | |
1259 | skb->len += tmp_skb->len; | |
1260 | skb->data_len += tmp_skb->len; | |
1261 | skb->truesize += tmp_skb->truesize; | |
1da177e4 LT |
1262 | tmp_skb->destructor = NULL; |
1263 | tmp_skb->sk = NULL; | |
1264 | } | |
1265 | ||
1266 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1267 | * to fragment the frame generated here. No matter, what transforms | |
1268 | * how transforms change size of the packet, it will come out. | |
1269 | */ | |
628a5c56 | 1270 | if (inet->pmtudisc < IP_PMTUDISC_DO) |
1da177e4 LT |
1271 | skb->local_df = 1; |
1272 | ||
1273 | /* DF bit is set when we want to see DF on outgoing frames. | |
1274 | * If local_df is set too, we still allow to fragment this frame | |
1275 | * locally. */ | |
628a5c56 | 1276 | if (inet->pmtudisc >= IP_PMTUDISC_DO || |
1da177e4 LT |
1277 | (skb->len <= dst_mtu(&rt->u.dst) && |
1278 | ip_dont_fragment(sk, &rt->u.dst))) | |
1279 | df = htons(IP_DF); | |
1280 | ||
1281 | if (inet->cork.flags & IPCORK_OPT) | |
1282 | opt = inet->cork.opt; | |
1283 | ||
1284 | if (rt->rt_type == RTN_MULTICAST) | |
1285 | ttl = inet->mc_ttl; | |
1286 | else | |
1287 | ttl = ip_select_ttl(inet, &rt->u.dst); | |
1288 | ||
1289 | iph = (struct iphdr *)skb->data; | |
1290 | iph->version = 4; | |
1291 | iph->ihl = 5; | |
1292 | if (opt) { | |
1293 | iph->ihl += opt->optlen>>2; | |
1294 | ip_options_build(skb, opt, inet->cork.addr, rt, 0); | |
1295 | } | |
1296 | iph->tos = inet->tos; | |
1da177e4 | 1297 | iph->frag_off = df; |
1a55d57b | 1298 | ip_select_ident(iph, &rt->u.dst, sk); |
1da177e4 LT |
1299 | iph->ttl = ttl; |
1300 | iph->protocol = sk->sk_protocol; | |
1301 | iph->saddr = rt->rt_src; | |
1302 | iph->daddr = rt->rt_dst; | |
1da177e4 LT |
1303 | |
1304 | skb->priority = sk->sk_priority; | |
4a19ec58 | 1305 | skb->mark = sk->sk_mark; |
a21bba94 ED |
1306 | /* |
1307 | * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec | |
1308 | * on dst refcount | |
1309 | */ | |
1310 | inet->cork.dst = NULL; | |
adf30907 | 1311 | skb_dst_set(skb, &rt->u.dst); |
1da177e4 | 1312 | |
96793b48 | 1313 | if (iph->protocol == IPPROTO_ICMP) |
0388b004 | 1314 | icmp_out_count(net, ((struct icmphdr *) |
96793b48 DS |
1315 | skb_transport_header(skb))->type); |
1316 | ||
1da177e4 | 1317 | /* Netfilter gets whole the not fragmented skb. */ |
c439cb2e | 1318 | err = ip_local_out(skb); |
1da177e4 LT |
1319 | if (err) { |
1320 | if (err > 0) | |
6ce9e7b5 | 1321 | err = net_xmit_errno(err); |
1da177e4 LT |
1322 | if (err) |
1323 | goto error; | |
1324 | } | |
1325 | ||
1326 | out: | |
429f08e9 | 1327 | ip_cork_release(inet); |
1da177e4 LT |
1328 | return err; |
1329 | ||
1330 | error: | |
5e38e270 | 1331 | IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1332 | goto out; |
1333 | } | |
1334 | ||
1335 | /* | |
1336 | * Throw away all pending data on the socket. | |
1337 | */ | |
1338 | void ip_flush_pending_frames(struct sock *sk) | |
1339 | { | |
1da177e4 LT |
1340 | struct sk_buff *skb; |
1341 | ||
1342 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) | |
1343 | kfree_skb(skb); | |
1344 | ||
429f08e9 | 1345 | ip_cork_release(inet_sk(sk)); |
1da177e4 LT |
1346 | } |
1347 | ||
1348 | ||
1349 | /* | |
1350 | * Fetch data from kernel space and fill in checksum if needed. | |
1351 | */ | |
e905a9ed | 1352 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1353 | int len, int odd, struct sk_buff *skb) |
1354 | { | |
5084205f | 1355 | __wsum csum; |
1da177e4 LT |
1356 | |
1357 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1358 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1359 | return 0; |
1da177e4 LT |
1360 | } |
1361 | ||
e905a9ed | 1362 | /* |
1da177e4 LT |
1363 | * Generic function to send a packet as reply to another packet. |
1364 | * Used to send TCP resets so far. ICMP should use this function too. | |
1365 | * | |
e905a9ed | 1366 | * Should run single threaded per socket because it uses the sock |
1da177e4 | 1367 | * structure to pass arguments. |
1da177e4 LT |
1368 | */ |
1369 | void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, | |
1370 | unsigned int len) | |
1371 | { | |
1372 | struct inet_sock *inet = inet_sk(sk); | |
1373 | struct { | |
1374 | struct ip_options opt; | |
1375 | char data[40]; | |
1376 | } replyopts; | |
1377 | struct ipcm_cookie ipc; | |
3ca3c68e | 1378 | __be32 daddr; |
511c3f92 | 1379 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
1380 | |
1381 | if (ip_options_echo(&replyopts.opt, skb)) | |
1382 | return; | |
1383 | ||
1384 | daddr = ipc.addr = rt->rt_src; | |
1385 | ipc.opt = NULL; | |
51f31cab | 1386 | ipc.shtx.flags = 0; |
1da177e4 LT |
1387 | |
1388 | if (replyopts.opt.optlen) { | |
1389 | ipc.opt = &replyopts.opt; | |
1390 | ||
1391 | if (ipc.opt->srr) | |
1392 | daddr = replyopts.opt.faddr; | |
1393 | } | |
1394 | ||
1395 | { | |
f0e48dbf PM |
1396 | struct flowi fl = { .oif = arg->bound_dev_if, |
1397 | .nl_u = { .ip4_u = | |
1da177e4 LT |
1398 | { .daddr = daddr, |
1399 | .saddr = rt->rt_spec_dst, | |
eddc9ec5 | 1400 | .tos = RT_TOS(ip_hdr(skb)->tos) } }, |
1da177e4 LT |
1401 | /* Not quite clean, but right. */ |
1402 | .uli_u = { .ports = | |
aa8223c7 ACM |
1403 | { .sport = tcp_hdr(skb)->dest, |
1404 | .dport = tcp_hdr(skb)->source } }, | |
86b08d86 KK |
1405 | .proto = sk->sk_protocol, |
1406 | .flags = ip_reply_arg_flowi_flags(arg) }; | |
beb8d13b | 1407 | security_skb_classify_flow(skb, &fl); |
3b1e0a65 | 1408 | if (ip_route_output_key(sock_net(sk), &rt, &fl)) |
1da177e4 LT |
1409 | return; |
1410 | } | |
1411 | ||
1412 | /* And let IP do all the hard work. | |
1413 | ||
1414 | This chunk is not reenterable, hence spinlock. | |
1415 | Note that it uses the fact, that this function is called | |
1416 | with locally disabled BH and that sk cannot be already spinlocked. | |
1417 | */ | |
1418 | bh_lock_sock(sk); | |
eddc9ec5 | 1419 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 | 1420 | sk->sk_priority = skb->priority; |
eddc9ec5 | 1421 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1422 | sk->sk_bound_dev_if = arg->bound_dev_if; |
1da177e4 | 1423 | ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, |
2e77d89b | 1424 | &ipc, &rt, MSG_DONTWAIT); |
1da177e4 LT |
1425 | if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
1426 | if (arg->csumoffset >= 0) | |
9c70220b ACM |
1427 | *((__sum16 *)skb_transport_header(skb) + |
1428 | arg->csumoffset) = csum_fold(csum_add(skb->csum, | |
1429 | arg->csum)); | |
1da177e4 LT |
1430 | skb->ip_summed = CHECKSUM_NONE; |
1431 | ip_push_pending_frames(sk); | |
1432 | } | |
1433 | ||
1434 | bh_unlock_sock(sk); | |
1435 | ||
1436 | ip_rt_put(rt); | |
1437 | } | |
1438 | ||
1da177e4 LT |
1439 | void __init ip_init(void) |
1440 | { | |
1da177e4 LT |
1441 | ip_rt_init(); |
1442 | inet_initpeers(); | |
1443 | ||
1444 | #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) | |
1445 | igmp_mc_proc_init(); | |
1446 | #endif | |
1447 | } | |
1448 | ||
1da177e4 LT |
1449 | EXPORT_SYMBOL(ip_generic_getfrag); |
1450 | EXPORT_SYMBOL(ip_queue_xmit); | |
1451 | EXPORT_SYMBOL(ip_send_check); |