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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * The Internet Protocol (IP) output module. | |
7 | * | |
02c30a84 | 8 | * Authors: Ross Biro |
1da177e4 LT |
9 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
10 | * Donald Becker, <becker@super.org> | |
11 | * Alan Cox, <Alan.Cox@linux.org> | |
12 | * Richard Underwood | |
13 | * Stefan Becker, <stefanb@yello.ping.de> | |
14 | * Jorge Cwik, <jorge@laser.satlink.net> | |
15 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> | |
16 | * Hirokazu Takahashi, <taka@valinux.co.jp> | |
17 | * | |
18 | * See ip_input.c for original log | |
19 | * | |
20 | * Fixes: | |
21 | * Alan Cox : Missing nonblock feature in ip_build_xmit. | |
22 | * Mike Kilburn : htons() missing in ip_build_xmit. | |
e905a9ed | 23 | * Bradford Johnson: Fix faulty handling of some frames when |
1da177e4 LT |
24 | * no route is found. |
25 | * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit | |
26 | * (in case if packet not accepted by | |
27 | * output firewall rules) | |
28 | * Mike McLagan : Routing by source | |
29 | * Alexey Kuznetsov: use new route cache | |
30 | * Andi Kleen: Fix broken PMTU recovery and remove | |
31 | * some redundant tests. | |
32 | * Vitaly E. Lavrov : Transparent proxy revived after year coma. | |
33 | * Andi Kleen : Replace ip_reply with ip_send_reply. | |
e905a9ed YH |
34 | * Andi Kleen : Split fast and slow ip_build_xmit path |
35 | * for decreased register pressure on x86 | |
36 | * and more readibility. | |
1da177e4 LT |
37 | * Marc Boucher : When call_out_firewall returns FW_QUEUE, |
38 | * silently drop skb instead of failing with -EPERM. | |
39 | * Detlev Wengorz : Copy protocol for fragments. | |
40 | * Hirokazu Takahashi: HW checksumming for outgoing UDP | |
41 | * datagrams. | |
42 | * Hirokazu Takahashi: sendfile() on UDP works now. | |
43 | */ | |
44 | ||
45 | #include <asm/uaccess.h> | |
1da177e4 LT |
46 | #include <linux/module.h> |
47 | #include <linux/types.h> | |
48 | #include <linux/kernel.h> | |
1da177e4 LT |
49 | #include <linux/mm.h> |
50 | #include <linux/string.h> | |
51 | #include <linux/errno.h> | |
a1f8e7f7 | 52 | #include <linux/highmem.h> |
5a0e3ad6 | 53 | #include <linux/slab.h> |
1da177e4 LT |
54 | |
55 | #include <linux/socket.h> | |
56 | #include <linux/sockios.h> | |
57 | #include <linux/in.h> | |
58 | #include <linux/inet.h> | |
59 | #include <linux/netdevice.h> | |
60 | #include <linux/etherdevice.h> | |
61 | #include <linux/proc_fs.h> | |
62 | #include <linux/stat.h> | |
63 | #include <linux/init.h> | |
64 | ||
65 | #include <net/snmp.h> | |
66 | #include <net/ip.h> | |
67 | #include <net/protocol.h> | |
68 | #include <net/route.h> | |
cfacb057 | 69 | #include <net/xfrm.h> |
1da177e4 LT |
70 | #include <linux/skbuff.h> |
71 | #include <net/sock.h> | |
72 | #include <net/arp.h> | |
73 | #include <net/icmp.h> | |
1da177e4 LT |
74 | #include <net/checksum.h> |
75 | #include <net/inetpeer.h> | |
1da177e4 LT |
76 | #include <linux/igmp.h> |
77 | #include <linux/netfilter_ipv4.h> | |
78 | #include <linux/netfilter_bridge.h> | |
79 | #include <linux/mroute.h> | |
80 | #include <linux/netlink.h> | |
6cbb0df7 | 81 | #include <linux/tcp.h> |
1da177e4 | 82 | |
ab32ea5d | 83 | int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; |
323e126f | 84 | EXPORT_SYMBOL(sysctl_ip_default_ttl); |
1da177e4 LT |
85 | |
86 | /* Generate a checksum for an outgoing IP datagram. */ | |
2fbd9679 | 87 | void ip_send_check(struct iphdr *iph) |
1da177e4 LT |
88 | { |
89 | iph->check = 0; | |
90 | iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); | |
91 | } | |
4bc2f18b | 92 | EXPORT_SYMBOL(ip_send_check); |
1da177e4 | 93 | |
c439cb2e HX |
94 | int __ip_local_out(struct sk_buff *skb) |
95 | { | |
96 | struct iphdr *iph = ip_hdr(skb); | |
97 | ||
98 | iph->tot_len = htons(skb->len); | |
99 | ip_send_check(iph); | |
9bbc768a JE |
100 | return nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, skb, NULL, |
101 | skb_dst(skb)->dev, dst_output); | |
c439cb2e HX |
102 | } |
103 | ||
104 | int ip_local_out(struct sk_buff *skb) | |
105 | { | |
106 | int err; | |
107 | ||
108 | err = __ip_local_out(skb); | |
109 | if (likely(err == 1)) | |
110 | err = dst_output(skb); | |
111 | ||
112 | return err; | |
113 | } | |
114 | EXPORT_SYMBOL_GPL(ip_local_out); | |
115 | ||
1da177e4 LT |
116 | static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) |
117 | { | |
118 | int ttl = inet->uc_ttl; | |
119 | ||
120 | if (ttl < 0) | |
323e126f | 121 | ttl = ip4_dst_hoplimit(dst); |
1da177e4 LT |
122 | return ttl; |
123 | } | |
124 | ||
e905a9ed | 125 | /* |
1da177e4 LT |
126 | * Add an ip header to a skbuff and send it out. |
127 | * | |
128 | */ | |
129 | int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, | |
f6d8bd05 | 130 | __be32 saddr, __be32 daddr, struct ip_options_rcu *opt) |
1da177e4 LT |
131 | { |
132 | struct inet_sock *inet = inet_sk(sk); | |
511c3f92 | 133 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
134 | struct iphdr *iph; |
135 | ||
136 | /* Build the IP header. */ | |
f6d8bd05 | 137 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0)); |
8856dfa3 | 138 | skb_reset_network_header(skb); |
eddc9ec5 | 139 | iph = ip_hdr(skb); |
1da177e4 LT |
140 | iph->version = 4; |
141 | iph->ihl = 5; | |
142 | iph->tos = inet->tos; | |
d8d1f30b | 143 | if (ip_dont_fragment(sk, &rt->dst)) |
1da177e4 LT |
144 | iph->frag_off = htons(IP_DF); |
145 | else | |
146 | iph->frag_off = 0; | |
d8d1f30b | 147 | iph->ttl = ip_select_ttl(inet, &rt->dst); |
dd927a26 DM |
148 | iph->daddr = (opt && opt->opt.srr ? opt->opt.faddr : daddr); |
149 | iph->saddr = saddr; | |
1da177e4 | 150 | iph->protocol = sk->sk_protocol; |
703133de | 151 | ip_select_ident(skb, &rt->dst, sk); |
1da177e4 | 152 | |
f6d8bd05 ED |
153 | if (opt && opt->opt.optlen) { |
154 | iph->ihl += opt->opt.optlen>>2; | |
155 | ip_options_build(skb, &opt->opt, daddr, rt, 0); | |
1da177e4 | 156 | } |
1da177e4 LT |
157 | |
158 | skb->priority = sk->sk_priority; | |
4a19ec58 | 159 | skb->mark = sk->sk_mark; |
1da177e4 LT |
160 | |
161 | /* Send it out. */ | |
c439cb2e | 162 | return ip_local_out(skb); |
1da177e4 | 163 | } |
d8c97a94 ACM |
164 | EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); |
165 | ||
1da177e4 LT |
166 | static inline int ip_finish_output2(struct sk_buff *skb) |
167 | { | |
adf30907 | 168 | struct dst_entry *dst = skb_dst(skb); |
80787ebc | 169 | struct rtable *rt = (struct rtable *)dst; |
1da177e4 | 170 | struct net_device *dev = dst->dev; |
c2636b4d | 171 | unsigned int hh_len = LL_RESERVED_SPACE(dev); |
f6b72b62 | 172 | struct neighbour *neigh; |
a263b309 | 173 | u32 nexthop; |
1da177e4 | 174 | |
edf391ff NH |
175 | if (rt->rt_type == RTN_MULTICAST) { |
176 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len); | |
177 | } else if (rt->rt_type == RTN_BROADCAST) | |
178 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTBCAST, skb->len); | |
80787ebc | 179 | |
1da177e4 | 180 | /* Be paranoid, rather than too clever. */ |
3b04ddde | 181 | if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { |
1da177e4 LT |
182 | struct sk_buff *skb2; |
183 | ||
184 | skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); | |
185 | if (skb2 == NULL) { | |
186 | kfree_skb(skb); | |
187 | return -ENOMEM; | |
188 | } | |
189 | if (skb->sk) | |
190 | skb_set_owner_w(skb2, skb->sk); | |
5d0ba55b | 191 | consume_skb(skb); |
1da177e4 LT |
192 | skb = skb2; |
193 | } | |
194 | ||
a263b309 | 195 | rcu_read_lock_bh(); |
155e8336 | 196 | nexthop = (__force u32) rt_nexthop(rt, ip_hdr(skb)->daddr); |
a263b309 DM |
197 | neigh = __ipv4_neigh_lookup_noref(dev, nexthop); |
198 | if (unlikely(!neigh)) | |
199 | neigh = __neigh_create(&arp_tbl, &nexthop, dev, false); | |
9871f1ad | 200 | if (!IS_ERR(neigh)) { |
5110effe | 201 | int res = dst_neigh_output(dst, neigh, skb); |
f2c31e32 | 202 | |
a263b309 | 203 | rcu_read_unlock_bh(); |
f2c31e32 ED |
204 | return res; |
205 | } | |
a263b309 | 206 | rcu_read_unlock_bh(); |
05e3aa09 | 207 | |
e87cc472 JP |
208 | net_dbg_ratelimited("%s: No header cache and no neighbour!\n", |
209 | __func__); | |
1da177e4 LT |
210 | kfree_skb(skb); |
211 | return -EINVAL; | |
212 | } | |
213 | ||
861d0486 | 214 | static int ip_finish_output(struct sk_buff *skb) |
1da177e4 | 215 | { |
5c901daa PM |
216 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
217 | /* Policy lookup after SNAT yielded a new policy */ | |
adf30907 | 218 | if (skb_dst(skb)->xfrm != NULL) { |
48d5cad8 PM |
219 | IPCB(skb)->flags |= IPSKB_REROUTED; |
220 | return dst_output(skb); | |
221 | } | |
5c901daa | 222 | #endif |
628a5c56 | 223 | if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) |
1bd9bef6 PM |
224 | return ip_fragment(skb, ip_finish_output2); |
225 | else | |
226 | return ip_finish_output2(skb); | |
1da177e4 LT |
227 | } |
228 | ||
229 | int ip_mc_output(struct sk_buff *skb) | |
230 | { | |
231 | struct sock *sk = skb->sk; | |
511c3f92 | 232 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 233 | struct net_device *dev = rt->dst.dev; |
1da177e4 LT |
234 | |
235 | /* | |
236 | * If the indicated interface is up and running, send the packet. | |
237 | */ | |
edf391ff | 238 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
1da177e4 LT |
239 | |
240 | skb->dev = dev; | |
241 | skb->protocol = htons(ETH_P_IP); | |
242 | ||
243 | /* | |
244 | * Multicasts are looped back for other local users | |
245 | */ | |
246 | ||
247 | if (rt->rt_flags&RTCF_MULTICAST) { | |
7ad6848c | 248 | if (sk_mc_loop(sk) |
1da177e4 LT |
249 | #ifdef CONFIG_IP_MROUTE |
250 | /* Small optimization: do not loopback not local frames, | |
251 | which returned after forwarding; they will be dropped | |
252 | by ip_mr_input in any case. | |
253 | Note, that local frames are looped back to be delivered | |
254 | to local recipients. | |
255 | ||
256 | This check is duplicated in ip_mr_input at the moment. | |
257 | */ | |
9d4fb27d JP |
258 | && |
259 | ((rt->rt_flags & RTCF_LOCAL) || | |
260 | !(IPCB(skb)->flags & IPSKB_FORWARDED)) | |
1da177e4 | 261 | #endif |
9d4fb27d | 262 | ) { |
1da177e4 LT |
263 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
264 | if (newskb) | |
9bbc768a JE |
265 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
266 | newskb, NULL, newskb->dev, | |
95603e22 | 267 | dev_loopback_xmit); |
1da177e4 LT |
268 | } |
269 | ||
270 | /* Multicasts with ttl 0 must not go beyond the host */ | |
271 | ||
eddc9ec5 | 272 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
273 | kfree_skb(skb); |
274 | return 0; | |
275 | } | |
276 | } | |
277 | ||
278 | if (rt->rt_flags&RTCF_BROADCAST) { | |
279 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
280 | if (newskb) | |
9bbc768a | 281 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, newskb, |
95603e22 | 282 | NULL, newskb->dev, dev_loopback_xmit); |
1da177e4 LT |
283 | } |
284 | ||
9bbc768a JE |
285 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, |
286 | skb->dev, ip_finish_output, | |
48d5cad8 | 287 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
288 | } |
289 | ||
290 | int ip_output(struct sk_buff *skb) | |
291 | { | |
adf30907 | 292 | struct net_device *dev = skb_dst(skb)->dev; |
1bd9bef6 | 293 | |
edf391ff | 294 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
1da177e4 | 295 | |
1bd9bef6 PM |
296 | skb->dev = dev; |
297 | skb->protocol = htons(ETH_P_IP); | |
298 | ||
9bbc768a | 299 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, dev, |
e905a9ed | 300 | ip_finish_output, |
48d5cad8 | 301 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
302 | } |
303 | ||
84f9307c ED |
304 | /* |
305 | * copy saddr and daddr, possibly using 64bit load/stores | |
306 | * Equivalent to : | |
307 | * iph->saddr = fl4->saddr; | |
308 | * iph->daddr = fl4->daddr; | |
309 | */ | |
310 | static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4) | |
311 | { | |
312 | BUILD_BUG_ON(offsetof(typeof(*fl4), daddr) != | |
313 | offsetof(typeof(*fl4), saddr) + sizeof(fl4->saddr)); | |
314 | memcpy(&iph->saddr, &fl4->saddr, | |
315 | sizeof(fl4->saddr) + sizeof(fl4->daddr)); | |
316 | } | |
317 | ||
d9d8da80 | 318 | int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl) |
1da177e4 | 319 | { |
e89862f4 | 320 | struct sock *sk = skb->sk; |
1da177e4 | 321 | struct inet_sock *inet = inet_sk(sk); |
f6d8bd05 | 322 | struct ip_options_rcu *inet_opt; |
b57ae01a | 323 | struct flowi4 *fl4; |
1da177e4 LT |
324 | struct rtable *rt; |
325 | struct iphdr *iph; | |
ab6e3feb | 326 | int res; |
1da177e4 LT |
327 | |
328 | /* Skip all of this if the packet is already routed, | |
329 | * f.e. by something like SCTP. | |
330 | */ | |
ab6e3feb | 331 | rcu_read_lock(); |
f6d8bd05 | 332 | inet_opt = rcu_dereference(inet->inet_opt); |
ea4fc0d6 | 333 | fl4 = &fl->u.ip4; |
511c3f92 | 334 | rt = skb_rtable(skb); |
1da177e4 LT |
335 | if (rt != NULL) |
336 | goto packet_routed; | |
337 | ||
338 | /* Make sure we can route this packet. */ | |
339 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
340 | if (rt == NULL) { | |
3ca3c68e | 341 | __be32 daddr; |
1da177e4 LT |
342 | |
343 | /* Use correct destination address if we have options. */ | |
c720c7e8 | 344 | daddr = inet->inet_daddr; |
f6d8bd05 ED |
345 | if (inet_opt && inet_opt->opt.srr) |
346 | daddr = inet_opt->opt.faddr; | |
1da177e4 | 347 | |
78fbfd8a DM |
348 | /* If this fails, retransmit mechanism of transport layer will |
349 | * keep trying until route appears or the connection times | |
350 | * itself out. | |
351 | */ | |
b57ae01a | 352 | rt = ip_route_output_ports(sock_net(sk), fl4, sk, |
78fbfd8a DM |
353 | daddr, inet->inet_saddr, |
354 | inet->inet_dport, | |
355 | inet->inet_sport, | |
356 | sk->sk_protocol, | |
357 | RT_CONN_FLAGS(sk), | |
358 | sk->sk_bound_dev_if); | |
359 | if (IS_ERR(rt)) | |
360 | goto no_route; | |
d8d1f30b | 361 | sk_setup_caps(sk, &rt->dst); |
1da177e4 | 362 | } |
d8d1f30b | 363 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
364 | |
365 | packet_routed: | |
155e8336 | 366 | if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_uses_gateway) |
1da177e4 LT |
367 | goto no_route; |
368 | ||
369 | /* OK, we know where to send it, allocate and build IP header. */ | |
f6d8bd05 | 370 | skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0)); |
8856dfa3 | 371 | skb_reset_network_header(skb); |
eddc9ec5 | 372 | iph = ip_hdr(skb); |
714e85be | 373 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); |
d8d1f30b | 374 | if (ip_dont_fragment(sk, &rt->dst) && !skb->local_df) |
1da177e4 LT |
375 | iph->frag_off = htons(IP_DF); |
376 | else | |
377 | iph->frag_off = 0; | |
d8d1f30b | 378 | iph->ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 | 379 | iph->protocol = sk->sk_protocol; |
84f9307c ED |
380 | ip_copy_addrs(iph, fl4); |
381 | ||
1da177e4 LT |
382 | /* Transport layer set skb->h.foo itself. */ |
383 | ||
f6d8bd05 ED |
384 | if (inet_opt && inet_opt->opt.optlen) { |
385 | iph->ihl += inet_opt->opt.optlen >> 2; | |
386 | ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); | |
1da177e4 LT |
387 | } |
388 | ||
703133de | 389 | ip_select_ident_more(skb, &rt->dst, sk, |
7967168c | 390 | (skb_shinfo(skb)->gso_segs ?: 1) - 1); |
1da177e4 | 391 | |
1da177e4 | 392 | skb->priority = sk->sk_priority; |
4a19ec58 | 393 | skb->mark = sk->sk_mark; |
1da177e4 | 394 | |
ab6e3feb ED |
395 | res = ip_local_out(skb); |
396 | rcu_read_unlock(); | |
397 | return res; | |
1da177e4 LT |
398 | |
399 | no_route: | |
ab6e3feb | 400 | rcu_read_unlock(); |
5e38e270 | 401 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
1da177e4 LT |
402 | kfree_skb(skb); |
403 | return -EHOSTUNREACH; | |
404 | } | |
4bc2f18b | 405 | EXPORT_SYMBOL(ip_queue_xmit); |
1da177e4 LT |
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 | 413 | skb_dst_drop(to); |
fe76cda3 | 414 | skb_dst_copy(to, 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); |
f0165888 | 425 | #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) |
ba9dda3a JK |
426 | to->nf_trace = from->nf_trace; |
427 | #endif | |
c98d80ed JA |
428 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
429 | to->ipvs_property = from->ipvs_property; | |
1da177e4 | 430 | #endif |
984bc16c | 431 | skb_copy_secmark(to, from); |
1da177e4 LT |
432 | } |
433 | ||
434 | /* | |
435 | * This IP datagram is too large to be sent in one piece. Break it up into | |
436 | * smaller pieces (each of size equal to IP header plus | |
437 | * a block of the data of the original IP data part) that will yet fit in a | |
438 | * single device frame, and queue such a frame for sending. | |
439 | */ | |
440 | ||
d9319100 | 441 | int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) |
1da177e4 LT |
442 | { |
443 | struct iphdr *iph; | |
1da177e4 LT |
444 | int ptr; |
445 | struct net_device *dev; | |
446 | struct sk_buff *skb2; | |
c893b806 | 447 | unsigned int mtu, hlen, left, len, ll_rs; |
1da177e4 | 448 | int offset; |
76ab608d | 449 | __be16 not_last_frag; |
511c3f92 | 450 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
451 | int err = 0; |
452 | ||
d8d1f30b | 453 | dev = rt->dst.dev; |
1da177e4 LT |
454 | |
455 | /* | |
456 | * Point into the IP datagram header. | |
457 | */ | |
458 | ||
eddc9ec5 | 459 | iph = ip_hdr(skb); |
1da177e4 | 460 | |
5f2d04f1 PM |
461 | if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->local_df) || |
462 | (IPCB(skb)->frag_max_size && | |
463 | IPCB(skb)->frag_max_size > dst_mtu(&rt->dst)))) { | |
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; | |
d8d1f30b | 476 | mtu = dst_mtu(&rt->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 | */ | |
21dc3301 | 490 | if (skb_has_frag_list(skb)) { |
3d13008e | 491 | struct sk_buff *frag, *frag2; |
1da177e4 LT |
492 | int first_len = skb_pagelen(skb); |
493 | ||
494 | if (first_len - hlen > mtu || | |
495 | ((first_len - hlen) & 7) || | |
56f8a75c | 496 | ip_is_fragment(iph) || |
1da177e4 LT |
497 | skb_cloned(skb)) |
498 | goto slow_path; | |
499 | ||
d7fcf1a5 | 500 | skb_walk_frags(skb, frag) { |
1da177e4 LT |
501 | /* Correct geometry. */ |
502 | if (frag->len > mtu || | |
503 | ((frag->len & 7) && frag->next) || | |
504 | skb_headroom(frag) < hlen) | |
3d13008e | 505 | goto slow_path_clean; |
1da177e4 LT |
506 | |
507 | /* Partially cloned skb? */ | |
508 | if (skb_shared(frag)) | |
3d13008e | 509 | goto slow_path_clean; |
2fdba6b0 HX |
510 | |
511 | BUG_ON(frag->sk); | |
512 | if (skb->sk) { | |
2fdba6b0 HX |
513 | frag->sk = skb->sk; |
514 | frag->destructor = sock_wfree; | |
2fdba6b0 | 515 | } |
3d13008e | 516 | skb->truesize -= frag->truesize; |
1da177e4 LT |
517 | } |
518 | ||
519 | /* Everything is OK. Generate! */ | |
520 | ||
521 | err = 0; | |
522 | offset = 0; | |
523 | frag = skb_shinfo(skb)->frag_list; | |
d7fcf1a5 | 524 | skb_frag_list_init(skb); |
1da177e4 LT |
525 | skb->data_len = first_len - skb_headlen(skb); |
526 | skb->len = first_len; | |
527 | iph->tot_len = htons(first_len); | |
528 | iph->frag_off = htons(IP_MF); | |
529 | ip_send_check(iph); | |
530 | ||
531 | for (;;) { | |
532 | /* Prepare header of the next frame, | |
533 | * before previous one went down. */ | |
534 | if (frag) { | |
535 | frag->ip_summed = CHECKSUM_NONE; | |
badff6d0 | 536 | skb_reset_transport_header(frag); |
e2d1bca7 ACM |
537 | __skb_push(frag, hlen); |
538 | skb_reset_network_header(frag); | |
d56f90a7 | 539 | memcpy(skb_network_header(frag), iph, hlen); |
eddc9ec5 | 540 | iph = ip_hdr(frag); |
1da177e4 LT |
541 | iph->tot_len = htons(frag->len); |
542 | ip_copy_metadata(frag, skb); | |
543 | if (offset == 0) | |
544 | ip_options_fragment(frag); | |
545 | offset += skb->len - hlen; | |
546 | iph->frag_off = htons(offset>>3); | |
547 | if (frag->next != NULL) | |
548 | iph->frag_off |= htons(IP_MF); | |
549 | /* Ready, complete checksum */ | |
550 | ip_send_check(iph); | |
551 | } | |
552 | ||
553 | err = output(skb); | |
554 | ||
dafee490 | 555 | if (!err) |
5e38e270 | 556 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 LT |
557 | if (err || !frag) |
558 | break; | |
559 | ||
560 | skb = frag; | |
561 | frag = skb->next; | |
562 | skb->next = NULL; | |
563 | } | |
564 | ||
565 | if (err == 0) { | |
5e38e270 | 566 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
567 | return 0; |
568 | } | |
569 | ||
570 | while (frag) { | |
571 | skb = frag->next; | |
572 | kfree_skb(frag); | |
573 | frag = skb; | |
574 | } | |
5e38e270 | 575 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 576 | return err; |
3d13008e ED |
577 | |
578 | slow_path_clean: | |
579 | skb_walk_frags(skb, frag2) { | |
580 | if (frag2 == frag) | |
581 | break; | |
582 | frag2->sk = NULL; | |
583 | frag2->destructor = NULL; | |
584 | skb->truesize += frag2->truesize; | |
585 | } | |
1da177e4 LT |
586 | } |
587 | ||
588 | slow_path: | |
fc70fb64 AD |
589 | /* for offloaded checksums cleanup checksum before fragmentation */ |
590 | if ((skb->ip_summed == CHECKSUM_PARTIAL) && skb_checksum_help(skb)) | |
591 | goto fail; | |
c9af6db4 | 592 | iph = ip_hdr(skb); |
fc70fb64 | 593 | |
1da177e4 | 594 | left = skb->len - hlen; /* Space per frame */ |
49085bd7 | 595 | ptr = hlen; /* Where to start from */ |
1da177e4 | 596 | |
1da177e4 | 597 | /* for bridged IP traffic encapsulated inside f.e. a vlan header, |
9bcfcaf5 SH |
598 | * we need to make room for the encapsulating header |
599 | */ | |
c893b806 | 600 | ll_rs = LL_RESERVED_SPACE_EXTRA(rt->dst.dev, nf_bridge_pad(skb)); |
9bcfcaf5 | 601 | |
1da177e4 LT |
602 | /* |
603 | * Fragment the datagram. | |
604 | */ | |
605 | ||
606 | offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
607 | not_last_frag = iph->frag_off & htons(IP_MF); | |
608 | ||
609 | /* | |
610 | * Keep copying data until we run out. | |
611 | */ | |
612 | ||
132adf54 | 613 | while (left > 0) { |
1da177e4 LT |
614 | len = left; |
615 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
616 | if (len > mtu) | |
617 | len = mtu; | |
25985edc | 618 | /* IF: we are not sending up to and including the packet end |
1da177e4 LT |
619 | then align the next start on an eight byte boundary */ |
620 | if (len < left) { | |
621 | len &= ~7; | |
622 | } | |
623 | /* | |
624 | * Allocate buffer. | |
625 | */ | |
626 | ||
627 | if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { | |
64ce2073 | 628 | NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); |
1da177e4 LT |
629 | err = -ENOMEM; |
630 | goto fail; | |
631 | } | |
632 | ||
633 | /* | |
634 | * Set up data on packet | |
635 | */ | |
636 | ||
637 | ip_copy_metadata(skb2, skb); | |
638 | skb_reserve(skb2, ll_rs); | |
639 | skb_put(skb2, len + hlen); | |
c1d2bbe1 | 640 | skb_reset_network_header(skb2); |
b0e380b1 | 641 | skb2->transport_header = skb2->network_header + hlen; |
1da177e4 LT |
642 | |
643 | /* | |
644 | * Charge the memory for the fragment to any owner | |
645 | * it might possess | |
646 | */ | |
647 | ||
648 | if (skb->sk) | |
649 | skb_set_owner_w(skb2, skb->sk); | |
650 | ||
651 | /* | |
652 | * Copy the packet header into the new buffer. | |
653 | */ | |
654 | ||
d626f62b | 655 | skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); |
1da177e4 LT |
656 | |
657 | /* | |
658 | * Copy a block of the IP datagram. | |
659 | */ | |
bff9b61c | 660 | if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) |
1da177e4 LT |
661 | BUG(); |
662 | left -= len; | |
663 | ||
664 | /* | |
665 | * Fill in the new header fields. | |
666 | */ | |
eddc9ec5 | 667 | iph = ip_hdr(skb2); |
1da177e4 LT |
668 | iph->frag_off = htons((offset >> 3)); |
669 | ||
670 | /* ANK: dirty, but effective trick. Upgrade options only if | |
671 | * the segment to be fragmented was THE FIRST (otherwise, | |
672 | * options are already fixed) and make it ONCE | |
673 | * on the initial skb, so that all the following fragments | |
674 | * will inherit fixed options. | |
675 | */ | |
676 | if (offset == 0) | |
677 | ip_options_fragment(skb); | |
678 | ||
679 | /* | |
680 | * Added AC : If we are fragmenting a fragment that's not the | |
681 | * last fragment then keep MF on each bit | |
682 | */ | |
683 | if (left > 0 || not_last_frag) | |
684 | iph->frag_off |= htons(IP_MF); | |
685 | ptr += len; | |
686 | offset += len; | |
687 | ||
688 | /* | |
689 | * Put this fragment into the sending queue. | |
690 | */ | |
1da177e4 LT |
691 | iph->tot_len = htons(len + hlen); |
692 | ||
693 | ip_send_check(iph); | |
694 | ||
695 | err = output(skb2); | |
696 | if (err) | |
697 | goto fail; | |
dafee490 | 698 | |
5e38e270 | 699 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
1da177e4 | 700 | } |
5d0ba55b | 701 | consume_skb(skb); |
5e38e270 | 702 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
703 | return err; |
704 | ||
705 | fail: | |
e905a9ed | 706 | kfree_skb(skb); |
5e38e270 | 707 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
708 | return err; |
709 | } | |
2e2f7aef PM |
710 | EXPORT_SYMBOL(ip_fragment); |
711 | ||
1da177e4 LT |
712 | int |
713 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
714 | { | |
715 | struct iovec *iov = from; | |
716 | ||
84fa7933 | 717 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
1da177e4 LT |
718 | if (memcpy_fromiovecend(to, iov, offset, len) < 0) |
719 | return -EFAULT; | |
720 | } else { | |
44bb9363 | 721 | __wsum csum = 0; |
1da177e4 LT |
722 | if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) |
723 | return -EFAULT; | |
724 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
725 | } | |
726 | return 0; | |
727 | } | |
4bc2f18b | 728 | EXPORT_SYMBOL(ip_generic_getfrag); |
1da177e4 | 729 | |
44bb9363 | 730 | static inline __wsum |
1da177e4 LT |
731 | csum_page(struct page *page, int offset, int copy) |
732 | { | |
733 | char *kaddr; | |
44bb9363 | 734 | __wsum csum; |
1da177e4 LT |
735 | kaddr = kmap(page); |
736 | csum = csum_partial(kaddr + offset, copy, 0); | |
737 | kunmap(page); | |
738 | return csum; | |
739 | } | |
740 | ||
4b30b1c6 | 741 | static inline int ip_ufo_append_data(struct sock *sk, |
1470ddf7 | 742 | struct sk_buff_head *queue, |
e89e9cf5 AR |
743 | int getfrag(void *from, char *to, int offset, int len, |
744 | int odd, struct sk_buff *skb), | |
745 | void *from, int length, int hh_len, int fragheaderlen, | |
d9be4f7a | 746 | int transhdrlen, int maxfraglen, unsigned int flags) |
e89e9cf5 AR |
747 | { |
748 | struct sk_buff *skb; | |
749 | int err; | |
750 | ||
751 | /* There is support for UDP fragmentation offload by network | |
752 | * device, so create one single skb packet containing complete | |
753 | * udp datagram | |
754 | */ | |
1470ddf7 | 755 | if ((skb = skb_peek_tail(queue)) == NULL) { |
e89e9cf5 AR |
756 | skb = sock_alloc_send_skb(sk, |
757 | hh_len + fragheaderlen + transhdrlen + 20, | |
758 | (flags & MSG_DONTWAIT), &err); | |
759 | ||
760 | if (skb == NULL) | |
761 | return err; | |
762 | ||
763 | /* reserve space for Hardware header */ | |
764 | skb_reserve(skb, hh_len); | |
765 | ||
766 | /* create space for UDP/IP header */ | |
d9319100 | 767 | skb_put(skb, fragheaderlen + transhdrlen); |
e89e9cf5 AR |
768 | |
769 | /* initialize network header pointer */ | |
c1d2bbe1 | 770 | skb_reset_network_header(skb); |
e89e9cf5 AR |
771 | |
772 | /* initialize protocol header pointer */ | |
b0e380b1 | 773 | skb->transport_header = skb->network_header + fragheaderlen; |
e89e9cf5 | 774 | |
e89e9cf5 | 775 | skb->csum = 0; |
e89e9cf5 | 776 | |
e93b7d74 | 777 | |
1470ddf7 | 778 | __skb_queue_tail(queue, skb); |
e93b7d74 JP |
779 | } else if (skb_is_gso(skb)) { |
780 | goto append; | |
e89e9cf5 | 781 | } |
be9164e7 | 782 | |
e93b7d74 JP |
783 | skb->ip_summed = CHECKSUM_PARTIAL; |
784 | /* specify the length of each IP datagram fragment */ | |
785 | skb_shinfo(skb)->gso_size = maxfraglen - fragheaderlen; | |
786 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; | |
787 | ||
788 | append: | |
be9164e7 K |
789 | return skb_append_datato_frags(sk, skb, getfrag, from, |
790 | (length - transhdrlen)); | |
e89e9cf5 AR |
791 | } |
792 | ||
f5fca608 DM |
793 | static int __ip_append_data(struct sock *sk, |
794 | struct flowi4 *fl4, | |
795 | struct sk_buff_head *queue, | |
1470ddf7 | 796 | struct inet_cork *cork, |
5640f768 | 797 | struct page_frag *pfrag, |
1470ddf7 HX |
798 | int getfrag(void *from, char *to, int offset, |
799 | int len, int odd, struct sk_buff *skb), | |
800 | void *from, int length, int transhdrlen, | |
801 | unsigned int flags) | |
1da177e4 LT |
802 | { |
803 | struct inet_sock *inet = inet_sk(sk); | |
804 | struct sk_buff *skb; | |
805 | ||
07df5294 | 806 | struct ip_options *opt = cork->opt; |
1da177e4 LT |
807 | int hh_len; |
808 | int exthdrlen; | |
809 | int mtu; | |
810 | int copy; | |
811 | int err; | |
812 | int offset = 0; | |
daba287b | 813 | unsigned int maxfraglen, fragheaderlen, maxnonfragsize; |
1da177e4 | 814 | int csummode = CHECKSUM_NONE; |
1470ddf7 | 815 | struct rtable *rt = (struct rtable *)cork->dst; |
1da177e4 | 816 | |
96d7303e SK |
817 | skb = skb_peek_tail(queue); |
818 | ||
819 | exthdrlen = !skb ? rt->dst.header_len : 0; | |
07df5294 | 820 | mtu = cork->fragsize; |
1da177e4 | 821 | |
d8d1f30b | 822 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
1da177e4 LT |
823 | |
824 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
825 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
daba287b HFS |
826 | maxnonfragsize = (inet->pmtudisc >= IP_PMTUDISC_DO) ? |
827 | mtu : 0xFFFF; | |
1da177e4 | 828 | |
daba287b | 829 | if (cork->length + length > maxnonfragsize - fragheaderlen) { |
f5fca608 | 830 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, |
61e7f09d | 831 | mtu - (opt ? opt->optlen : 0)); |
1da177e4 LT |
832 | return -EMSGSIZE; |
833 | } | |
834 | ||
835 | /* | |
836 | * transhdrlen > 0 means that this is the first fragment and we wish | |
837 | * it won't be fragmented in the future. | |
838 | */ | |
839 | if (transhdrlen && | |
840 | length + fragheaderlen <= mtu && | |
d8d1f30b | 841 | rt->dst.dev->features & NETIF_F_V4_CSUM && |
1da177e4 | 842 | !exthdrlen) |
84fa7933 | 843 | csummode = CHECKSUM_PARTIAL; |
1da177e4 | 844 | |
1470ddf7 | 845 | cork->length += length; |
26cde9f7 | 846 | if (((length > mtu) || (skb && skb_is_gso(skb))) && |
be9164e7 | 847 | (sk->sk_protocol == IPPROTO_UDP) && |
c146066a | 848 | (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len) { |
1470ddf7 HX |
849 | err = ip_ufo_append_data(sk, queue, getfrag, from, length, |
850 | hh_len, fragheaderlen, transhdrlen, | |
d9be4f7a | 851 | maxfraglen, flags); |
baa829d8 | 852 | if (err) |
e89e9cf5 | 853 | goto error; |
e89e9cf5 AR |
854 | return 0; |
855 | } | |
1da177e4 LT |
856 | |
857 | /* So, what's going on in the loop below? | |
858 | * | |
859 | * We use calculated fragment length to generate chained skb, | |
860 | * each of segments is IP fragment ready for sending to network after | |
861 | * adding appropriate IP header. | |
862 | */ | |
863 | ||
26cde9f7 | 864 | if (!skb) |
1da177e4 LT |
865 | goto alloc_new_skb; |
866 | ||
867 | while (length > 0) { | |
868 | /* Check if the remaining data fits into current packet. */ | |
869 | copy = mtu - skb->len; | |
870 | if (copy < length) | |
871 | copy = maxfraglen - skb->len; | |
872 | if (copy <= 0) { | |
873 | char *data; | |
874 | unsigned int datalen; | |
875 | unsigned int fraglen; | |
876 | unsigned int fraggap; | |
877 | unsigned int alloclen; | |
878 | struct sk_buff *skb_prev; | |
879 | alloc_new_skb: | |
880 | skb_prev = skb; | |
881 | if (skb_prev) | |
882 | fraggap = skb_prev->len - maxfraglen; | |
883 | else | |
884 | fraggap = 0; | |
885 | ||
886 | /* | |
887 | * If remaining data exceeds the mtu, | |
888 | * we know we need more fragment(s). | |
889 | */ | |
890 | datalen = length + fraggap; | |
891 | if (datalen > mtu - fragheaderlen) | |
892 | datalen = maxfraglen - fragheaderlen; | |
893 | fraglen = datalen + fragheaderlen; | |
894 | ||
e905a9ed | 895 | if ((flags & MSG_MORE) && |
d8d1f30b | 896 | !(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 LT |
897 | alloclen = mtu; |
898 | else | |
59104f06 | 899 | alloclen = fraglen; |
1da177e4 | 900 | |
353e5c9a SK |
901 | alloclen += exthdrlen; |
902 | ||
1da177e4 LT |
903 | /* The last fragment gets additional space at tail. |
904 | * Note, with MSG_MORE we overallocate on fragments, | |
905 | * because we have no idea what fragment will be | |
906 | * the last. | |
907 | */ | |
33f99dc7 | 908 | if (datalen == length + fraggap) |
d8d1f30b | 909 | alloclen += rt->dst.trailer_len; |
33f99dc7 | 910 | |
1da177e4 | 911 | if (transhdrlen) { |
e905a9ed | 912 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
913 | alloclen + hh_len + 15, |
914 | (flags & MSG_DONTWAIT), &err); | |
915 | } else { | |
916 | skb = NULL; | |
917 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
918 | 2 * sk->sk_sndbuf) | |
e905a9ed | 919 | skb = sock_wmalloc(sk, |
1da177e4 LT |
920 | alloclen + hh_len + 15, 1, |
921 | sk->sk_allocation); | |
922 | if (unlikely(skb == NULL)) | |
923 | err = -ENOBUFS; | |
51f31cab PO |
924 | else |
925 | /* only the initial fragment is | |
926 | time stamped */ | |
1470ddf7 | 927 | cork->tx_flags = 0; |
1da177e4 LT |
928 | } |
929 | if (skb == NULL) | |
930 | goto error; | |
931 | ||
932 | /* | |
933 | * Fill in the control structures | |
934 | */ | |
935 | skb->ip_summed = csummode; | |
936 | skb->csum = 0; | |
937 | skb_reserve(skb, hh_len); | |
1470ddf7 | 938 | skb_shinfo(skb)->tx_flags = cork->tx_flags; |
1da177e4 LT |
939 | |
940 | /* | |
941 | * Find where to start putting bytes. | |
942 | */ | |
353e5c9a | 943 | data = skb_put(skb, fraglen + exthdrlen); |
c14d2450 | 944 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
945 | skb->transport_header = (skb->network_header + |
946 | fragheaderlen); | |
353e5c9a | 947 | data += fragheaderlen + exthdrlen; |
1da177e4 LT |
948 | |
949 | if (fraggap) { | |
950 | skb->csum = skb_copy_and_csum_bits( | |
951 | skb_prev, maxfraglen, | |
952 | data + transhdrlen, fraggap, 0); | |
953 | skb_prev->csum = csum_sub(skb_prev->csum, | |
954 | skb->csum); | |
955 | data += fraggap; | |
e9fa4f7b | 956 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
957 | } |
958 | ||
959 | copy = datalen - transhdrlen - fraggap; | |
960 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
961 | err = -EFAULT; | |
962 | kfree_skb(skb); | |
963 | goto error; | |
964 | } | |
965 | ||
966 | offset += copy; | |
967 | length -= datalen - fraggap; | |
968 | transhdrlen = 0; | |
969 | exthdrlen = 0; | |
970 | csummode = CHECKSUM_NONE; | |
971 | ||
972 | /* | |
973 | * Put the packet on the pending queue. | |
974 | */ | |
1470ddf7 | 975 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
976 | continue; |
977 | } | |
978 | ||
979 | if (copy > length) | |
980 | copy = length; | |
981 | ||
d8d1f30b | 982 | if (!(rt->dst.dev->features&NETIF_F_SG)) { |
1da177e4 LT |
983 | unsigned int off; |
984 | ||
985 | off = skb->len; | |
e905a9ed | 986 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
987 | offset, copy, off, skb) < 0) { |
988 | __skb_trim(skb, off); | |
989 | err = -EFAULT; | |
990 | goto error; | |
991 | } | |
992 | } else { | |
993 | int i = skb_shinfo(skb)->nr_frags; | |
1da177e4 | 994 | |
5640f768 ED |
995 | err = -ENOMEM; |
996 | if (!sk_page_frag_refill(sk, pfrag)) | |
1da177e4 | 997 | goto error; |
5640f768 ED |
998 | |
999 | if (!skb_can_coalesce(skb, i, pfrag->page, | |
1000 | pfrag->offset)) { | |
1001 | err = -EMSGSIZE; | |
1002 | if (i == MAX_SKB_FRAGS) | |
1003 | goto error; | |
1004 | ||
1005 | __skb_fill_page_desc(skb, i, pfrag->page, | |
1006 | pfrag->offset, 0); | |
1007 | skb_shinfo(skb)->nr_frags = ++i; | |
1008 | get_page(pfrag->page); | |
1da177e4 | 1009 | } |
5640f768 ED |
1010 | copy = min_t(int, copy, pfrag->size - pfrag->offset); |
1011 | if (getfrag(from, | |
1012 | page_address(pfrag->page) + pfrag->offset, | |
1013 | offset, copy, skb->len, skb) < 0) | |
1014 | goto error_efault; | |
1015 | ||
1016 | pfrag->offset += copy; | |
1017 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); | |
1da177e4 LT |
1018 | skb->len += copy; |
1019 | skb->data_len += copy; | |
f945fa7a HX |
1020 | skb->truesize += copy; |
1021 | atomic_add(copy, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1022 | } |
1023 | offset += copy; | |
1024 | length -= copy; | |
1025 | } | |
1026 | ||
1027 | return 0; | |
1028 | ||
5640f768 ED |
1029 | error_efault: |
1030 | err = -EFAULT; | |
1da177e4 | 1031 | error: |
1470ddf7 | 1032 | cork->length -= length; |
5e38e270 | 1033 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
e905a9ed | 1034 | return err; |
1da177e4 LT |
1035 | } |
1036 | ||
1470ddf7 HX |
1037 | static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, |
1038 | struct ipcm_cookie *ipc, struct rtable **rtp) | |
1039 | { | |
f6d8bd05 | 1040 | struct ip_options_rcu *opt; |
1470ddf7 HX |
1041 | struct rtable *rt; |
1042 | ||
1043 | /* | |
1044 | * setup for corking. | |
1045 | */ | |
1046 | opt = ipc->opt; | |
1047 | if (opt) { | |
1048 | if (cork->opt == NULL) { | |
1049 | cork->opt = kmalloc(sizeof(struct ip_options) + 40, | |
1050 | sk->sk_allocation); | |
1051 | if (unlikely(cork->opt == NULL)) | |
1052 | return -ENOBUFS; | |
1053 | } | |
f6d8bd05 | 1054 | memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen); |
1470ddf7 HX |
1055 | cork->flags |= IPCORK_OPT; |
1056 | cork->addr = ipc->addr; | |
1057 | } | |
1058 | rt = *rtp; | |
1059 | if (unlikely(!rt)) | |
1060 | return -EFAULT; | |
1061 | /* | |
1062 | * We steal reference to this route, caller should not release it | |
1063 | */ | |
1064 | *rtp = NULL; | |
482fc609 HFS |
1065 | cork->fragsize = ip_sk_use_pmtu(sk) ? |
1066 | dst_mtu(&rt->dst) : rt->dst.dev->mtu; | |
1470ddf7 HX |
1067 | cork->dst = &rt->dst; |
1068 | cork->length = 0; | |
aa661581 FF |
1069 | cork->ttl = ipc->ttl; |
1070 | cork->tos = ipc->tos; | |
1071 | cork->priority = ipc->priority; | |
1470ddf7 | 1072 | cork->tx_flags = ipc->tx_flags; |
1470ddf7 HX |
1073 | |
1074 | return 0; | |
1075 | } | |
1076 | ||
1077 | /* | |
1078 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
1079 | * from many pieces of data. Each pieces will be holded on the socket | |
1080 | * until ip_push_pending_frames() is called. Each piece can be a page | |
1081 | * or non-page data. | |
1082 | * | |
1083 | * Not only UDP, other transport protocols - e.g. raw sockets - can use | |
1084 | * this interface potentially. | |
1085 | * | |
1086 | * LATER: length must be adjusted by pad at tail, when it is required. | |
1087 | */ | |
f5fca608 | 1088 | int ip_append_data(struct sock *sk, struct flowi4 *fl4, |
1470ddf7 HX |
1089 | int getfrag(void *from, char *to, int offset, int len, |
1090 | int odd, struct sk_buff *skb), | |
1091 | void *from, int length, int transhdrlen, | |
1092 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1093 | unsigned int flags) | |
1094 | { | |
1095 | struct inet_sock *inet = inet_sk(sk); | |
1096 | int err; | |
1097 | ||
1098 | if (flags&MSG_PROBE) | |
1099 | return 0; | |
1100 | ||
1101 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
bdc712b4 | 1102 | err = ip_setup_cork(sk, &inet->cork.base, ipc, rtp); |
1470ddf7 HX |
1103 | if (err) |
1104 | return err; | |
1105 | } else { | |
1106 | transhdrlen = 0; | |
1107 | } | |
1108 | ||
5640f768 ED |
1109 | return __ip_append_data(sk, fl4, &sk->sk_write_queue, &inet->cork.base, |
1110 | sk_page_frag(sk), getfrag, | |
1470ddf7 HX |
1111 | from, length, transhdrlen, flags); |
1112 | } | |
1113 | ||
f5fca608 | 1114 | ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, |
1da177e4 LT |
1115 | int offset, size_t size, int flags) |
1116 | { | |
1117 | struct inet_sock *inet = inet_sk(sk); | |
1118 | struct sk_buff *skb; | |
1119 | struct rtable *rt; | |
1120 | struct ip_options *opt = NULL; | |
bdc712b4 | 1121 | struct inet_cork *cork; |
1da177e4 LT |
1122 | int hh_len; |
1123 | int mtu; | |
1124 | int len; | |
1125 | int err; | |
daba287b | 1126 | unsigned int maxfraglen, fragheaderlen, fraggap, maxnonfragsize; |
1da177e4 LT |
1127 | |
1128 | if (inet->hdrincl) | |
1129 | return -EPERM; | |
1130 | ||
1131 | if (flags&MSG_PROBE) | |
1132 | return 0; | |
1133 | ||
1134 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1135 | return -EINVAL; | |
1136 | ||
bdc712b4 DM |
1137 | cork = &inet->cork.base; |
1138 | rt = (struct rtable *)cork->dst; | |
1139 | if (cork->flags & IPCORK_OPT) | |
1140 | opt = cork->opt; | |
1da177e4 | 1141 | |
d8d1f30b | 1142 | if (!(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 LT |
1143 | return -EOPNOTSUPP; |
1144 | ||
d8d1f30b | 1145 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
bdc712b4 | 1146 | mtu = cork->fragsize; |
1da177e4 LT |
1147 | |
1148 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1149 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
daba287b HFS |
1150 | maxnonfragsize = (inet->pmtudisc >= IP_PMTUDISC_DO) ? |
1151 | mtu : 0xFFFF; | |
1da177e4 | 1152 | |
daba287b | 1153 | if (cork->length + size > maxnonfragsize - fragheaderlen) { |
61e7f09d HFS |
1154 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, |
1155 | mtu - (opt ? opt->optlen : 0)); | |
1da177e4 LT |
1156 | return -EMSGSIZE; |
1157 | } | |
1158 | ||
1159 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1160 | return -EINVAL; | |
1161 | ||
bdc712b4 | 1162 | cork->length += size; |
26cde9f7 HX |
1163 | if ((size + skb->len > mtu) && |
1164 | (sk->sk_protocol == IPPROTO_UDP) && | |
d8d1f30b | 1165 | (rt->dst.dev->features & NETIF_F_UFO)) { |
7967168c | 1166 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
f83ef8c0 | 1167 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
7967168c | 1168 | } |
e89e9cf5 | 1169 | |
1da177e4 LT |
1170 | |
1171 | while (size > 0) { | |
1172 | int i; | |
1173 | ||
89114afd | 1174 | if (skb_is_gso(skb)) |
e89e9cf5 AR |
1175 | len = size; |
1176 | else { | |
1177 | ||
1178 | /* Check if the remaining data fits into current packet. */ | |
1179 | len = mtu - skb->len; | |
1180 | if (len < size) | |
1181 | len = maxfraglen - skb->len; | |
1182 | } | |
1da177e4 LT |
1183 | if (len <= 0) { |
1184 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1185 | int alloclen; |
1186 | ||
1187 | skb_prev = skb; | |
0d0d2bba | 1188 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1189 | |
1190 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1191 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1192 | if (unlikely(!skb)) { | |
1193 | err = -ENOBUFS; | |
1194 | goto error; | |
1195 | } | |
1196 | ||
1197 | /* | |
1198 | * Fill in the control structures | |
1199 | */ | |
1200 | skb->ip_summed = CHECKSUM_NONE; | |
1201 | skb->csum = 0; | |
1202 | skb_reserve(skb, hh_len); | |
1203 | ||
1204 | /* | |
1205 | * Find where to start putting bytes. | |
1206 | */ | |
967b05f6 | 1207 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1208 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1209 | skb->transport_header = (skb->network_header + |
1210 | fragheaderlen); | |
1da177e4 | 1211 | if (fraggap) { |
967b05f6 ACM |
1212 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1213 | maxfraglen, | |
9c70220b | 1214 | skb_transport_header(skb), |
967b05f6 | 1215 | fraggap, 0); |
1da177e4 LT |
1216 | skb_prev->csum = csum_sub(skb_prev->csum, |
1217 | skb->csum); | |
e9fa4f7b | 1218 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1219 | } |
1220 | ||
1221 | /* | |
1222 | * Put the packet on the pending queue. | |
1223 | */ | |
1224 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1225 | continue; | |
1226 | } | |
1227 | ||
1228 | i = skb_shinfo(skb)->nr_frags; | |
1229 | if (len > size) | |
1230 | len = size; | |
1231 | if (skb_can_coalesce(skb, i, page, offset)) { | |
9e903e08 | 1232 | skb_frag_size_add(&skb_shinfo(skb)->frags[i-1], len); |
1da177e4 LT |
1233 | } else if (i < MAX_SKB_FRAGS) { |
1234 | get_page(page); | |
1235 | skb_fill_page_desc(skb, i, page, offset, len); | |
1236 | } else { | |
1237 | err = -EMSGSIZE; | |
1238 | goto error; | |
1239 | } | |
1240 | ||
1241 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1242 | __wsum csum; |
1da177e4 LT |
1243 | csum = csum_page(page, offset, len); |
1244 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1245 | } | |
1246 | ||
1247 | skb->len += len; | |
1248 | skb->data_len += len; | |
1e34a11d DM |
1249 | skb->truesize += len; |
1250 | atomic_add(len, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1251 | offset += len; |
1252 | size -= len; | |
1253 | } | |
1254 | return 0; | |
1255 | ||
1256 | error: | |
bdc712b4 | 1257 | cork->length -= size; |
5e38e270 | 1258 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1259 | return err; |
1260 | } | |
1261 | ||
1470ddf7 | 1262 | static void ip_cork_release(struct inet_cork *cork) |
429f08e9 | 1263 | { |
1470ddf7 HX |
1264 | cork->flags &= ~IPCORK_OPT; |
1265 | kfree(cork->opt); | |
1266 | cork->opt = NULL; | |
1267 | dst_release(cork->dst); | |
1268 | cork->dst = NULL; | |
429f08e9 PE |
1269 | } |
1270 | ||
1da177e4 LT |
1271 | /* |
1272 | * Combined all pending IP fragments on the socket as one IP datagram | |
1273 | * and push them out. | |
1274 | */ | |
1c32c5ad | 1275 | struct sk_buff *__ip_make_skb(struct sock *sk, |
77968b78 | 1276 | struct flowi4 *fl4, |
1c32c5ad HX |
1277 | struct sk_buff_head *queue, |
1278 | struct inet_cork *cork) | |
1da177e4 LT |
1279 | { |
1280 | struct sk_buff *skb, *tmp_skb; | |
1281 | struct sk_buff **tail_skb; | |
1282 | struct inet_sock *inet = inet_sk(sk); | |
0388b004 | 1283 | struct net *net = sock_net(sk); |
1da177e4 | 1284 | struct ip_options *opt = NULL; |
1470ddf7 | 1285 | struct rtable *rt = (struct rtable *)cork->dst; |
1da177e4 | 1286 | struct iphdr *iph; |
76ab608d | 1287 | __be16 df = 0; |
1da177e4 | 1288 | __u8 ttl; |
1da177e4 | 1289 | |
1470ddf7 | 1290 | if ((skb = __skb_dequeue(queue)) == NULL) |
1da177e4 LT |
1291 | goto out; |
1292 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1293 | ||
1294 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1295 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1296 | __skb_pull(skb, skb_network_offset(skb)); |
1470ddf7 | 1297 | while ((tmp_skb = __skb_dequeue(queue)) != NULL) { |
cfe1fc77 | 1298 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1299 | *tail_skb = tmp_skb; |
1300 | tail_skb = &(tmp_skb->next); | |
1301 | skb->len += tmp_skb->len; | |
1302 | skb->data_len += tmp_skb->len; | |
1303 | skb->truesize += tmp_skb->truesize; | |
1da177e4 LT |
1304 | tmp_skb->destructor = NULL; |
1305 | tmp_skb->sk = NULL; | |
1306 | } | |
1307 | ||
1308 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1309 | * to fragment the frame generated here. No matter, what transforms | |
1310 | * how transforms change size of the packet, it will come out. | |
1311 | */ | |
628a5c56 | 1312 | if (inet->pmtudisc < IP_PMTUDISC_DO) |
1da177e4 LT |
1313 | skb->local_df = 1; |
1314 | ||
1315 | /* DF bit is set when we want to see DF on outgoing frames. | |
1316 | * If local_df is set too, we still allow to fragment this frame | |
1317 | * locally. */ | |
482fc609 HFS |
1318 | if (inet->pmtudisc == IP_PMTUDISC_DO || |
1319 | inet->pmtudisc == IP_PMTUDISC_PROBE || | |
d8d1f30b CG |
1320 | (skb->len <= dst_mtu(&rt->dst) && |
1321 | ip_dont_fragment(sk, &rt->dst))) | |
1da177e4 LT |
1322 | df = htons(IP_DF); |
1323 | ||
1470ddf7 HX |
1324 | if (cork->flags & IPCORK_OPT) |
1325 | opt = cork->opt; | |
1da177e4 | 1326 | |
aa661581 FF |
1327 | if (cork->ttl != 0) |
1328 | ttl = cork->ttl; | |
1329 | else if (rt->rt_type == RTN_MULTICAST) | |
1da177e4 LT |
1330 | ttl = inet->mc_ttl; |
1331 | else | |
d8d1f30b | 1332 | ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 | 1333 | |
749154aa | 1334 | iph = ip_hdr(skb); |
1da177e4 LT |
1335 | iph->version = 4; |
1336 | iph->ihl = 5; | |
aa661581 | 1337 | iph->tos = (cork->tos != -1) ? cork->tos : inet->tos; |
1da177e4 | 1338 | iph->frag_off = df; |
1da177e4 LT |
1339 | iph->ttl = ttl; |
1340 | iph->protocol = sk->sk_protocol; | |
84f9307c | 1341 | ip_copy_addrs(iph, fl4); |
703133de | 1342 | ip_select_ident(skb, &rt->dst, sk); |
1da177e4 | 1343 | |
22f728f8 DM |
1344 | if (opt) { |
1345 | iph->ihl += opt->optlen>>2; | |
1346 | ip_options_build(skb, opt, cork->addr, rt, 0); | |
1347 | } | |
1348 | ||
aa661581 | 1349 | skb->priority = (cork->tos != -1) ? cork->priority: sk->sk_priority; |
4a19ec58 | 1350 | skb->mark = sk->sk_mark; |
a21bba94 ED |
1351 | /* |
1352 | * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec | |
1353 | * on dst refcount | |
1354 | */ | |
1470ddf7 | 1355 | cork->dst = NULL; |
d8d1f30b | 1356 | skb_dst_set(skb, &rt->dst); |
1da177e4 | 1357 | |
96793b48 | 1358 | if (iph->protocol == IPPROTO_ICMP) |
0388b004 | 1359 | icmp_out_count(net, ((struct icmphdr *) |
96793b48 DS |
1360 | skb_transport_header(skb))->type); |
1361 | ||
1c32c5ad HX |
1362 | ip_cork_release(cork); |
1363 | out: | |
1364 | return skb; | |
1365 | } | |
1366 | ||
b5ec8eea | 1367 | int ip_send_skb(struct net *net, struct sk_buff *skb) |
1c32c5ad | 1368 | { |
1c32c5ad HX |
1369 | int err; |
1370 | ||
c439cb2e | 1371 | err = ip_local_out(skb); |
1da177e4 LT |
1372 | if (err) { |
1373 | if (err > 0) | |
6ce9e7b5 | 1374 | err = net_xmit_errno(err); |
1da177e4 | 1375 | if (err) |
1c32c5ad | 1376 | IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1377 | } |
1378 | ||
1da177e4 | 1379 | return err; |
1da177e4 LT |
1380 | } |
1381 | ||
77968b78 | 1382 | int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4) |
1470ddf7 | 1383 | { |
1c32c5ad HX |
1384 | struct sk_buff *skb; |
1385 | ||
77968b78 | 1386 | skb = ip_finish_skb(sk, fl4); |
1c32c5ad HX |
1387 | if (!skb) |
1388 | return 0; | |
1389 | ||
1390 | /* Netfilter gets whole the not fragmented skb. */ | |
b5ec8eea | 1391 | return ip_send_skb(sock_net(sk), skb); |
1470ddf7 HX |
1392 | } |
1393 | ||
1da177e4 LT |
1394 | /* |
1395 | * Throw away all pending data on the socket. | |
1396 | */ | |
1470ddf7 HX |
1397 | static void __ip_flush_pending_frames(struct sock *sk, |
1398 | struct sk_buff_head *queue, | |
1399 | struct inet_cork *cork) | |
1da177e4 | 1400 | { |
1da177e4 LT |
1401 | struct sk_buff *skb; |
1402 | ||
1470ddf7 | 1403 | while ((skb = __skb_dequeue_tail(queue)) != NULL) |
1da177e4 LT |
1404 | kfree_skb(skb); |
1405 | ||
1470ddf7 HX |
1406 | ip_cork_release(cork); |
1407 | } | |
1408 | ||
1409 | void ip_flush_pending_frames(struct sock *sk) | |
1410 | { | |
bdc712b4 | 1411 | __ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base); |
1da177e4 LT |
1412 | } |
1413 | ||
1c32c5ad | 1414 | struct sk_buff *ip_make_skb(struct sock *sk, |
77968b78 | 1415 | struct flowi4 *fl4, |
1c32c5ad HX |
1416 | int getfrag(void *from, char *to, int offset, |
1417 | int len, int odd, struct sk_buff *skb), | |
1418 | void *from, int length, int transhdrlen, | |
1419 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1420 | unsigned int flags) | |
1421 | { | |
b80d7226 | 1422 | struct inet_cork cork; |
1c32c5ad HX |
1423 | struct sk_buff_head queue; |
1424 | int err; | |
1425 | ||
1426 | if (flags & MSG_PROBE) | |
1427 | return NULL; | |
1428 | ||
1429 | __skb_queue_head_init(&queue); | |
1430 | ||
b80d7226 DM |
1431 | cork.flags = 0; |
1432 | cork.addr = 0; | |
70652728 | 1433 | cork.opt = NULL; |
1c32c5ad HX |
1434 | err = ip_setup_cork(sk, &cork, ipc, rtp); |
1435 | if (err) | |
1436 | return ERR_PTR(err); | |
1437 | ||
5640f768 ED |
1438 | err = __ip_append_data(sk, fl4, &queue, &cork, |
1439 | ¤t->task_frag, getfrag, | |
1c32c5ad HX |
1440 | from, length, transhdrlen, flags); |
1441 | if (err) { | |
1442 | __ip_flush_pending_frames(sk, &queue, &cork); | |
1443 | return ERR_PTR(err); | |
1444 | } | |
1445 | ||
77968b78 | 1446 | return __ip_make_skb(sk, fl4, &queue, &cork); |
1c32c5ad | 1447 | } |
1da177e4 LT |
1448 | |
1449 | /* | |
1450 | * Fetch data from kernel space and fill in checksum if needed. | |
1451 | */ | |
e905a9ed | 1452 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1453 | int len, int odd, struct sk_buff *skb) |
1454 | { | |
5084205f | 1455 | __wsum csum; |
1da177e4 LT |
1456 | |
1457 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1458 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1459 | return 0; |
1da177e4 LT |
1460 | } |
1461 | ||
e905a9ed | 1462 | /* |
1da177e4 | 1463 | * Generic function to send a packet as reply to another packet. |
be9f4a44 | 1464 | * Used to send some TCP resets/acks so far. |
1da177e4 | 1465 | * |
be9f4a44 | 1466 | * Use a fake percpu inet socket to avoid false sharing and contention. |
1da177e4 | 1467 | */ |
be9f4a44 ED |
1468 | static DEFINE_PER_CPU(struct inet_sock, unicast_sock) = { |
1469 | .sk = { | |
1470 | .__sk_common = { | |
1471 | .skc_refcnt = ATOMIC_INIT(1), | |
1472 | }, | |
1473 | .sk_wmem_alloc = ATOMIC_INIT(1), | |
1474 | .sk_allocation = GFP_ATOMIC, | |
1475 | .sk_flags = (1UL << SOCK_USE_WRITE_QUEUE), | |
1476 | }, | |
0980e56e ED |
1477 | .pmtudisc = IP_PMTUDISC_WANT, |
1478 | .uc_ttl = -1, | |
be9f4a44 ED |
1479 | }; |
1480 | ||
1481 | void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, | |
70e73416 DM |
1482 | __be32 saddr, const struct ip_reply_arg *arg, |
1483 | unsigned int len) | |
1da177e4 | 1484 | { |
f6d8bd05 | 1485 | struct ip_options_data replyopts; |
1da177e4 | 1486 | struct ipcm_cookie ipc; |
77968b78 | 1487 | struct flowi4 fl4; |
511c3f92 | 1488 | struct rtable *rt = skb_rtable(skb); |
be9f4a44 ED |
1489 | struct sk_buff *nskb; |
1490 | struct sock *sk; | |
1491 | struct inet_sock *inet; | |
1da177e4 | 1492 | |
f6d8bd05 | 1493 | if (ip_options_echo(&replyopts.opt.opt, skb)) |
1da177e4 LT |
1494 | return; |
1495 | ||
0a5ebb80 | 1496 | ipc.addr = daddr; |
1da177e4 | 1497 | ipc.opt = NULL; |
2244d07b | 1498 | ipc.tx_flags = 0; |
aa661581 FF |
1499 | ipc.ttl = 0; |
1500 | ipc.tos = -1; | |
1da177e4 | 1501 | |
f6d8bd05 | 1502 | if (replyopts.opt.opt.optlen) { |
1da177e4 LT |
1503 | ipc.opt = &replyopts.opt; |
1504 | ||
f6d8bd05 ED |
1505 | if (replyopts.opt.opt.srr) |
1506 | daddr = replyopts.opt.opt.faddr; | |
1da177e4 LT |
1507 | } |
1508 | ||
77968b78 | 1509 | flowi4_init_output(&fl4, arg->bound_dev_if, 0, |
66b13d99 | 1510 | RT_TOS(arg->tos), |
be9f4a44 | 1511 | RT_SCOPE_UNIVERSE, ip_hdr(skb)->protocol, |
77968b78 | 1512 | ip_reply_arg_flowi_flags(arg), |
70e73416 | 1513 | daddr, saddr, |
77968b78 DM |
1514 | tcp_hdr(skb)->source, tcp_hdr(skb)->dest); |
1515 | security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); | |
be9f4a44 | 1516 | rt = ip_route_output_key(net, &fl4); |
77968b78 DM |
1517 | if (IS_ERR(rt)) |
1518 | return; | |
1da177e4 | 1519 | |
be9f4a44 | 1520 | inet = &get_cpu_var(unicast_sock); |
1da177e4 | 1521 | |
66b13d99 | 1522 | inet->tos = arg->tos; |
be9f4a44 | 1523 | sk = &inet->sk; |
1da177e4 | 1524 | sk->sk_priority = skb->priority; |
eddc9ec5 | 1525 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1526 | sk->sk_bound_dev_if = arg->bound_dev_if; |
be9f4a44 ED |
1527 | sock_net_set(sk, net); |
1528 | __skb_queue_head_init(&sk->sk_write_queue); | |
1529 | sk->sk_sndbuf = sysctl_wmem_default; | |
f5fca608 | 1530 | ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, len, 0, |
2e77d89b | 1531 | &ipc, &rt, MSG_DONTWAIT); |
be9f4a44 ED |
1532 | nskb = skb_peek(&sk->sk_write_queue); |
1533 | if (nskb) { | |
1da177e4 | 1534 | if (arg->csumoffset >= 0) |
be9f4a44 ED |
1535 | *((__sum16 *)skb_transport_header(nskb) + |
1536 | arg->csumoffset) = csum_fold(csum_add(nskb->csum, | |
9c70220b | 1537 | arg->csum)); |
be9f4a44 | 1538 | nskb->ip_summed = CHECKSUM_NONE; |
3a7c384f | 1539 | skb_orphan(nskb); |
be9f4a44 | 1540 | skb_set_queue_mapping(nskb, skb_get_queue_mapping(skb)); |
77968b78 | 1541 | ip_push_pending_frames(sk, &fl4); |
1da177e4 LT |
1542 | } |
1543 | ||
be9f4a44 | 1544 | put_cpu_var(unicast_sock); |
1da177e4 LT |
1545 | |
1546 | ip_rt_put(rt); | |
1547 | } | |
1548 | ||
1da177e4 LT |
1549 | void __init ip_init(void) |
1550 | { | |
1da177e4 LT |
1551 | ip_rt_init(); |
1552 | inet_initpeers(); | |
1553 | ||
1554 | #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) | |
1555 | igmp_mc_proc_init(); | |
1556 | #endif | |
1557 | } |