]>
Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
4 | * operating system. INET is implemented using the BSD Socket | |
5 | * interface as the means of communication with the user level. | |
6 | * | |
7 | * The Internet Protocol (IP) output module. | |
8 | * | |
02c30a84 | 9 | * Authors: Ross Biro |
1da177e4 LT |
10 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
11 | * Donald Becker, <becker@super.org> | |
12 | * Alan Cox, <Alan.Cox@linux.org> | |
13 | * Richard Underwood | |
14 | * Stefan Becker, <stefanb@yello.ping.de> | |
15 | * Jorge Cwik, <jorge@laser.satlink.net> | |
16 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> | |
17 | * Hirokazu Takahashi, <taka@valinux.co.jp> | |
18 | * | |
19 | * See ip_input.c for original log | |
20 | * | |
21 | * Fixes: | |
22 | * Alan Cox : Missing nonblock feature in ip_build_xmit. | |
23 | * Mike Kilburn : htons() missing in ip_build_xmit. | |
e905a9ed | 24 | * Bradford Johnson: Fix faulty handling of some frames when |
1da177e4 LT |
25 | * no route is found. |
26 | * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit | |
27 | * (in case if packet not accepted by | |
28 | * output firewall rules) | |
29 | * Mike McLagan : Routing by source | |
30 | * Alexey Kuznetsov: use new route cache | |
31 | * Andi Kleen: Fix broken PMTU recovery and remove | |
32 | * some redundant tests. | |
33 | * Vitaly E. Lavrov : Transparent proxy revived after year coma. | |
34 | * Andi Kleen : Replace ip_reply with ip_send_reply. | |
e905a9ed YH |
35 | * Andi Kleen : Split fast and slow ip_build_xmit path |
36 | * for decreased register pressure on x86 | |
37 | * and more readibility. | |
1da177e4 LT |
38 | * Marc Boucher : When call_out_firewall returns FW_QUEUE, |
39 | * silently drop skb instead of failing with -EPERM. | |
40 | * Detlev Wengorz : Copy protocol for fragments. | |
41 | * Hirokazu Takahashi: HW checksumming for outgoing UDP | |
42 | * datagrams. | |
43 | * Hirokazu Takahashi: sendfile() on UDP works now. | |
44 | */ | |
45 | ||
7c0f6ba6 | 46 | #include <linux/uaccess.h> |
1da177e4 LT |
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> | |
14972cbd | 77 | #include <net/lwtunnel.h> |
33b48679 | 78 | #include <linux/bpf-cgroup.h> |
1da177e4 LT |
79 | #include <linux/igmp.h> |
80 | #include <linux/netfilter_ipv4.h> | |
81 | #include <linux/netfilter_bridge.h> | |
1da177e4 | 82 | #include <linux/netlink.h> |
6cbb0df7 | 83 | #include <linux/tcp.h> |
1da177e4 | 84 | |
694869b3 EB |
85 | static int |
86 | ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, | |
87 | unsigned int mtu, | |
88 | int (*output)(struct net *, struct sock *, struct sk_buff *)); | |
49d16b23 | 89 | |
1da177e4 | 90 | /* Generate a checksum for an outgoing IP datagram. */ |
2fbd9679 | 91 | void ip_send_check(struct iphdr *iph) |
1da177e4 LT |
92 | { |
93 | iph->check = 0; | |
94 | iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); | |
95 | } | |
4bc2f18b | 96 | EXPORT_SYMBOL(ip_send_check); |
1da177e4 | 97 | |
cf91a99d | 98 | int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb) |
c439cb2e HX |
99 | { |
100 | struct iphdr *iph = ip_hdr(skb); | |
101 | ||
102 | iph->tot_len = htons(skb->len); | |
103 | ip_send_check(iph); | |
a8e3e1a9 DA |
104 | |
105 | /* if egress device is enslaved to an L3 master device pass the | |
106 | * skb to its handler for processing | |
107 | */ | |
108 | skb = l3mdev_ip_out(sk, skb); | |
109 | if (unlikely(!skb)) | |
110 | return 0; | |
111 | ||
f4180439 EC |
112 | skb->protocol = htons(ETH_P_IP); |
113 | ||
29a26a56 EB |
114 | return nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, |
115 | net, sk, skb, NULL, skb_dst(skb)->dev, | |
13206b6b | 116 | dst_output); |
7026b1dd DM |
117 | } |
118 | ||
33224b16 | 119 | int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb) |
c439cb2e HX |
120 | { |
121 | int err; | |
122 | ||
cf91a99d | 123 | err = __ip_local_out(net, sk, skb); |
c439cb2e | 124 | if (likely(err == 1)) |
13206b6b | 125 | err = dst_output(net, sk, skb); |
c439cb2e HX |
126 | |
127 | return err; | |
128 | } | |
e2cb77db | 129 | EXPORT_SYMBOL_GPL(ip_local_out); |
c439cb2e | 130 | |
1da177e4 LT |
131 | static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) |
132 | { | |
133 | int ttl = inet->uc_ttl; | |
134 | ||
135 | if (ttl < 0) | |
323e126f | 136 | ttl = ip4_dst_hoplimit(dst); |
1da177e4 LT |
137 | return ttl; |
138 | } | |
139 | ||
e905a9ed | 140 | /* |
1da177e4 LT |
141 | * Add an ip header to a skbuff and send it out. |
142 | * | |
143 | */ | |
cfe673b0 | 144 | int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, |
f6d8bd05 | 145 | __be32 saddr, __be32 daddr, struct ip_options_rcu *opt) |
1da177e4 LT |
146 | { |
147 | struct inet_sock *inet = inet_sk(sk); | |
511c3f92 | 148 | struct rtable *rt = skb_rtable(skb); |
77589ce0 | 149 | struct net *net = sock_net(sk); |
1da177e4 LT |
150 | struct iphdr *iph; |
151 | ||
152 | /* Build the IP header. */ | |
f6d8bd05 | 153 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0)); |
8856dfa3 | 154 | skb_reset_network_header(skb); |
eddc9ec5 | 155 | iph = ip_hdr(skb); |
1da177e4 LT |
156 | iph->version = 4; |
157 | iph->ihl = 5; | |
158 | iph->tos = inet->tos; | |
d8d1f30b | 159 | iph->ttl = ip_select_ttl(inet, &rt->dst); |
dd927a26 DM |
160 | iph->daddr = (opt && opt->opt.srr ? opt->opt.faddr : daddr); |
161 | iph->saddr = saddr; | |
1da177e4 | 162 | iph->protocol = sk->sk_protocol; |
cfe673b0 ED |
163 | if (ip_dont_fragment(sk, &rt->dst)) { |
164 | iph->frag_off = htons(IP_DF); | |
165 | iph->id = 0; | |
166 | } else { | |
167 | iph->frag_off = 0; | |
77589ce0 | 168 | __ip_select_ident(net, iph, 1); |
cfe673b0 | 169 | } |
1da177e4 | 170 | |
f6d8bd05 ED |
171 | if (opt && opt->opt.optlen) { |
172 | iph->ihl += opt->opt.optlen>>2; | |
173 | ip_options_build(skb, &opt->opt, daddr, rt, 0); | |
1da177e4 | 174 | } |
1da177e4 LT |
175 | |
176 | skb->priority = sk->sk_priority; | |
e05a90ec JHS |
177 | if (!skb->mark) |
178 | skb->mark = sk->sk_mark; | |
1da177e4 LT |
179 | |
180 | /* Send it out. */ | |
33224b16 | 181 | return ip_local_out(net, skb->sk, skb); |
1da177e4 | 182 | } |
d8c97a94 ACM |
183 | EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); |
184 | ||
694869b3 | 185 | static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 186 | { |
adf30907 | 187 | struct dst_entry *dst = skb_dst(skb); |
80787ebc | 188 | struct rtable *rt = (struct rtable *)dst; |
1da177e4 | 189 | struct net_device *dev = dst->dev; |
c2636b4d | 190 | unsigned int hh_len = LL_RESERVED_SPACE(dev); |
f6b72b62 | 191 | struct neighbour *neigh; |
5c9f7c1d | 192 | bool is_v6gw = false; |
1da177e4 | 193 | |
edf391ff | 194 | if (rt->rt_type == RTN_MULTICAST) { |
4ba1bf42 | 195 | IP_UPD_PO_STATS(net, IPSTATS_MIB_OUTMCAST, skb->len); |
edf391ff | 196 | } else if (rt->rt_type == RTN_BROADCAST) |
4ba1bf42 | 197 | IP_UPD_PO_STATS(net, IPSTATS_MIB_OUTBCAST, skb->len); |
80787ebc | 198 | |
1da177e4 | 199 | /* Be paranoid, rather than too clever. */ |
3b04ddde | 200 | if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { |
1da177e4 LT |
201 | struct sk_buff *skb2; |
202 | ||
203 | skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); | |
51456b29 | 204 | if (!skb2) { |
1da177e4 LT |
205 | kfree_skb(skb); |
206 | return -ENOMEM; | |
207 | } | |
208 | if (skb->sk) | |
209 | skb_set_owner_w(skb2, skb->sk); | |
5d0ba55b | 210 | consume_skb(skb); |
1da177e4 LT |
211 | skb = skb2; |
212 | } | |
213 | ||
14972cbd RP |
214 | if (lwtunnel_xmit_redirect(dst->lwtstate)) { |
215 | int res = lwtunnel_xmit(skb); | |
216 | ||
217 | if (res < 0 || res == LWTUNNEL_XMIT_DONE) | |
218 | return res; | |
219 | } | |
220 | ||
a263b309 | 221 | rcu_read_lock_bh(); |
5c9f7c1d | 222 | neigh = ip_neigh_for_gw(rt, skb, &is_v6gw); |
9871f1ad | 223 | if (!IS_ERR(neigh)) { |
4ff06203 JA |
224 | int res; |
225 | ||
226 | sock_confirm_neigh(skb, neigh); | |
5c9f7c1d DA |
227 | /* if crossing protocols, can not use the cached header */ |
228 | res = neigh_output(neigh, skb, is_v6gw); | |
a263b309 | 229 | rcu_read_unlock_bh(); |
f2c31e32 ED |
230 | return res; |
231 | } | |
a263b309 | 232 | rcu_read_unlock_bh(); |
05e3aa09 | 233 | |
e87cc472 JP |
234 | net_dbg_ratelimited("%s: No header cache and no neighbour!\n", |
235 | __func__); | |
1da177e4 LT |
236 | kfree_skb(skb); |
237 | return -EINVAL; | |
238 | } | |
239 | ||
694869b3 EB |
240 | static int ip_finish_output_gso(struct net *net, struct sock *sk, |
241 | struct sk_buff *skb, unsigned int mtu) | |
c7ba65d7 FW |
242 | { |
243 | netdev_features_t features; | |
244 | struct sk_buff *segs; | |
245 | int ret = 0; | |
246 | ||
9ee6c5dc | 247 | /* common case: seglen is <= mtu |
359ebda2 | 248 | */ |
779b7931 | 249 | if (skb_gso_validate_network_len(skb, mtu)) |
694869b3 | 250 | return ip_finish_output2(net, sk, skb); |
c7ba65d7 | 251 | |
0ace81ec | 252 | /* Slowpath - GSO segment length exceeds the egress MTU. |
c7ba65d7 | 253 | * |
0ace81ec LR |
254 | * This can happen in several cases: |
255 | * - Forwarding of a TCP GRO skb, when DF flag is not set. | |
256 | * - Forwarding of an skb that arrived on a virtualization interface | |
257 | * (virtio-net/vhost/tap) with TSO/GSO size set by other network | |
258 | * stack. | |
259 | * - Local GSO skb transmitted on an NETIF_F_TSO tunnel stacked over an | |
260 | * interface with a smaller MTU. | |
261 | * - Arriving GRO skb (or GSO skb in a virtualized environment) that is | |
262 | * bridged to a NETIF_F_TSO tunnel stacked over an interface with an | |
263 | * insufficent MTU. | |
c7ba65d7 FW |
264 | */ |
265 | features = netif_skb_features(skb); | |
9207f9d4 | 266 | BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET); |
c7ba65d7 | 267 | segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK); |
330966e5 | 268 | if (IS_ERR_OR_NULL(segs)) { |
c7ba65d7 FW |
269 | kfree_skb(skb); |
270 | return -ENOMEM; | |
271 | } | |
272 | ||
273 | consume_skb(skb); | |
274 | ||
275 | do { | |
276 | struct sk_buff *nskb = segs->next; | |
277 | int err; | |
278 | ||
a8305bff | 279 | skb_mark_not_on_list(segs); |
694869b3 | 280 | err = ip_fragment(net, sk, segs, mtu, ip_finish_output2); |
c7ba65d7 FW |
281 | |
282 | if (err && ret == 0) | |
283 | ret = err; | |
284 | segs = nskb; | |
285 | } while (segs); | |
286 | ||
287 | return ret; | |
288 | } | |
289 | ||
956fe219 | 290 | static int __ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 291 | { |
c5501eb3 FW |
292 | unsigned int mtu; |
293 | ||
5c901daa PM |
294 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
295 | /* Policy lookup after SNAT yielded a new policy */ | |
00db4124 | 296 | if (skb_dst(skb)->xfrm) { |
48d5cad8 | 297 | IPCB(skb)->flags |= IPSKB_REROUTED; |
13206b6b | 298 | return dst_output(net, sk, skb); |
48d5cad8 | 299 | } |
5c901daa | 300 | #endif |
fedbb6b4 | 301 | mtu = ip_skb_dst_mtu(sk, skb); |
c7ba65d7 | 302 | if (skb_is_gso(skb)) |
694869b3 | 303 | return ip_finish_output_gso(net, sk, skb, mtu); |
c7ba65d7 | 304 | |
d6b915e2 | 305 | if (skb->len > mtu || (IPCB(skb)->flags & IPSKB_FRAG_PMTU)) |
694869b3 | 306 | return ip_fragment(net, sk, skb, mtu, ip_finish_output2); |
c7ba65d7 | 307 | |
694869b3 | 308 | return ip_finish_output2(net, sk, skb); |
1da177e4 LT |
309 | } |
310 | ||
956fe219 | 311 | static int ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
312 | { | |
313 | int ret; | |
314 | ||
315 | ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); | |
316 | switch (ret) { | |
317 | case NET_XMIT_SUCCESS: | |
318 | return __ip_finish_output(net, sk, skb); | |
319 | case NET_XMIT_CN: | |
320 | return __ip_finish_output(net, sk, skb) ? : ret; | |
321 | default: | |
322 | kfree_skb(skb); | |
323 | return ret; | |
324 | } | |
325 | } | |
326 | ||
33b48679 DM |
327 | static int ip_mc_finish_output(struct net *net, struct sock *sk, |
328 | struct sk_buff *skb) | |
329 | { | |
5b18f128 | 330 | struct rtable *new_rt; |
d96ff269 DM |
331 | bool do_cn = false; |
332 | int ret, err; | |
33b48679 DM |
333 | |
334 | ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); | |
956fe219 | 335 | switch (ret) { |
956fe219 | 336 | case NET_XMIT_CN: |
d96ff269 DM |
337 | do_cn = true; |
338 | /* fall through */ | |
339 | case NET_XMIT_SUCCESS: | |
340 | break; | |
956fe219 | 341 | default: |
33b48679 DM |
342 | kfree_skb(skb); |
343 | return ret; | |
344 | } | |
345 | ||
5b18f128 SS |
346 | /* Reset rt_iif so that inet_iif() will return skb->skb_iif. Setting |
347 | * this to non-zero causes ipi_ifindex in in_pktinfo to be overwritten, | |
348 | * see ipv4_pktinfo_prepare(). | |
349 | */ | |
350 | new_rt = rt_dst_clone(net->loopback_dev, skb_rtable(skb)); | |
351 | if (new_rt) { | |
352 | new_rt->rt_iif = 0; | |
353 | skb_dst_drop(skb); | |
354 | skb_dst_set(skb, &new_rt->dst); | |
355 | } | |
356 | ||
d96ff269 DM |
357 | err = dev_loopback_xmit(net, sk, skb); |
358 | return (do_cn && err) ? ret : err; | |
33b48679 DM |
359 | } |
360 | ||
ede2059d | 361 | int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 362 | { |
511c3f92 | 363 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 364 | struct net_device *dev = rt->dst.dev; |
1da177e4 LT |
365 | |
366 | /* | |
367 | * If the indicated interface is up and running, send the packet. | |
368 | */ | |
88f5cc24 | 369 | IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); |
1da177e4 LT |
370 | |
371 | skb->dev = dev; | |
372 | skb->protocol = htons(ETH_P_IP); | |
373 | ||
374 | /* | |
375 | * Multicasts are looped back for other local users | |
376 | */ | |
377 | ||
378 | if (rt->rt_flags&RTCF_MULTICAST) { | |
7ad6848c | 379 | if (sk_mc_loop(sk) |
1da177e4 LT |
380 | #ifdef CONFIG_IP_MROUTE |
381 | /* Small optimization: do not loopback not local frames, | |
382 | which returned after forwarding; they will be dropped | |
383 | by ip_mr_input in any case. | |
384 | Note, that local frames are looped back to be delivered | |
385 | to local recipients. | |
386 | ||
387 | This check is duplicated in ip_mr_input at the moment. | |
388 | */ | |
9d4fb27d JP |
389 | && |
390 | ((rt->rt_flags & RTCF_LOCAL) || | |
391 | !(IPCB(skb)->flags & IPSKB_FORWARDED)) | |
1da177e4 | 392 | #endif |
9d4fb27d | 393 | ) { |
1da177e4 LT |
394 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
395 | if (newskb) | |
9bbc768a | 396 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
29a26a56 | 397 | net, sk, newskb, NULL, newskb->dev, |
33b48679 | 398 | ip_mc_finish_output); |
1da177e4 LT |
399 | } |
400 | ||
401 | /* Multicasts with ttl 0 must not go beyond the host */ | |
402 | ||
eddc9ec5 | 403 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
404 | kfree_skb(skb); |
405 | return 0; | |
406 | } | |
407 | } | |
408 | ||
409 | if (rt->rt_flags&RTCF_BROADCAST) { | |
410 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
411 | if (newskb) | |
29a26a56 EB |
412 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
413 | net, sk, newskb, NULL, newskb->dev, | |
33b48679 | 414 | ip_mc_finish_output); |
1da177e4 LT |
415 | } |
416 | ||
29a26a56 EB |
417 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
418 | net, sk, skb, NULL, skb->dev, | |
419 | ip_finish_output, | |
48d5cad8 | 420 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
421 | } |
422 | ||
ede2059d | 423 | int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 424 | { |
28f8bfd1 | 425 | struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev; |
1bd9bef6 | 426 | |
88f5cc24 | 427 | IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); |
1da177e4 | 428 | |
1bd9bef6 PM |
429 | skb->dev = dev; |
430 | skb->protocol = htons(ETH_P_IP); | |
431 | ||
29a26a56 | 432 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
28f8bfd1 | 433 | net, sk, skb, indev, dev, |
e905a9ed | 434 | ip_finish_output, |
48d5cad8 | 435 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
436 | } |
437 | ||
84f9307c ED |
438 | /* |
439 | * copy saddr and daddr, possibly using 64bit load/stores | |
440 | * Equivalent to : | |
441 | * iph->saddr = fl4->saddr; | |
442 | * iph->daddr = fl4->daddr; | |
443 | */ | |
444 | static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4) | |
445 | { | |
446 | BUILD_BUG_ON(offsetof(typeof(*fl4), daddr) != | |
447 | offsetof(typeof(*fl4), saddr) + sizeof(fl4->saddr)); | |
448 | memcpy(&iph->saddr, &fl4->saddr, | |
449 | sizeof(fl4->saddr) + sizeof(fl4->daddr)); | |
450 | } | |
451 | ||
b0270e91 | 452 | /* Note: skb->sk can be different from sk, in case of tunnels */ |
69b9e1e0 XL |
453 | int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, |
454 | __u8 tos) | |
1da177e4 | 455 | { |
1da177e4 | 456 | struct inet_sock *inet = inet_sk(sk); |
77589ce0 | 457 | struct net *net = sock_net(sk); |
f6d8bd05 | 458 | struct ip_options_rcu *inet_opt; |
b57ae01a | 459 | struct flowi4 *fl4; |
1da177e4 LT |
460 | struct rtable *rt; |
461 | struct iphdr *iph; | |
ab6e3feb | 462 | int res; |
1da177e4 LT |
463 | |
464 | /* Skip all of this if the packet is already routed, | |
465 | * f.e. by something like SCTP. | |
466 | */ | |
ab6e3feb | 467 | rcu_read_lock(); |
f6d8bd05 | 468 | inet_opt = rcu_dereference(inet->inet_opt); |
ea4fc0d6 | 469 | fl4 = &fl->u.ip4; |
511c3f92 | 470 | rt = skb_rtable(skb); |
00db4124 | 471 | if (rt) |
1da177e4 LT |
472 | goto packet_routed; |
473 | ||
474 | /* Make sure we can route this packet. */ | |
475 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
51456b29 | 476 | if (!rt) { |
3ca3c68e | 477 | __be32 daddr; |
1da177e4 LT |
478 | |
479 | /* Use correct destination address if we have options. */ | |
c720c7e8 | 480 | daddr = inet->inet_daddr; |
f6d8bd05 ED |
481 | if (inet_opt && inet_opt->opt.srr) |
482 | daddr = inet_opt->opt.faddr; | |
1da177e4 | 483 | |
78fbfd8a DM |
484 | /* If this fails, retransmit mechanism of transport layer will |
485 | * keep trying until route appears or the connection times | |
486 | * itself out. | |
487 | */ | |
77589ce0 | 488 | rt = ip_route_output_ports(net, fl4, sk, |
78fbfd8a DM |
489 | daddr, inet->inet_saddr, |
490 | inet->inet_dport, | |
491 | inet->inet_sport, | |
492 | sk->sk_protocol, | |
69b9e1e0 | 493 | RT_CONN_FLAGS_TOS(sk, tos), |
78fbfd8a DM |
494 | sk->sk_bound_dev_if); |
495 | if (IS_ERR(rt)) | |
496 | goto no_route; | |
d8d1f30b | 497 | sk_setup_caps(sk, &rt->dst); |
1da177e4 | 498 | } |
d8d1f30b | 499 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
500 | |
501 | packet_routed: | |
77d5bc7e | 502 | if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_uses_gateway) |
1da177e4 LT |
503 | goto no_route; |
504 | ||
505 | /* OK, we know where to send it, allocate and build IP header. */ | |
f6d8bd05 | 506 | skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0)); |
8856dfa3 | 507 | skb_reset_network_header(skb); |
eddc9ec5 | 508 | iph = ip_hdr(skb); |
69b9e1e0 | 509 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (tos & 0xff)); |
60ff7467 | 510 | if (ip_dont_fragment(sk, &rt->dst) && !skb->ignore_df) |
1da177e4 LT |
511 | iph->frag_off = htons(IP_DF); |
512 | else | |
513 | iph->frag_off = 0; | |
d8d1f30b | 514 | iph->ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 | 515 | iph->protocol = sk->sk_protocol; |
84f9307c ED |
516 | ip_copy_addrs(iph, fl4); |
517 | ||
1da177e4 LT |
518 | /* Transport layer set skb->h.foo itself. */ |
519 | ||
f6d8bd05 ED |
520 | if (inet_opt && inet_opt->opt.optlen) { |
521 | iph->ihl += inet_opt->opt.optlen >> 2; | |
522 | ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); | |
1da177e4 LT |
523 | } |
524 | ||
77589ce0 | 525 | ip_select_ident_segs(net, skb, sk, |
b6a7719a | 526 | skb_shinfo(skb)->gso_segs ?: 1); |
1da177e4 | 527 | |
b0270e91 | 528 | /* TODO : should we use skb->sk here instead of sk ? */ |
1da177e4 | 529 | skb->priority = sk->sk_priority; |
4a19ec58 | 530 | skb->mark = sk->sk_mark; |
1da177e4 | 531 | |
33224b16 | 532 | res = ip_local_out(net, sk, skb); |
ab6e3feb ED |
533 | rcu_read_unlock(); |
534 | return res; | |
1da177e4 LT |
535 | |
536 | no_route: | |
ab6e3feb | 537 | rcu_read_unlock(); |
77589ce0 | 538 | IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); |
1da177e4 LT |
539 | kfree_skb(skb); |
540 | return -EHOSTUNREACH; | |
541 | } | |
69b9e1e0 | 542 | EXPORT_SYMBOL(__ip_queue_xmit); |
1da177e4 | 543 | |
1da177e4 LT |
544 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) |
545 | { | |
546 | to->pkt_type = from->pkt_type; | |
547 | to->priority = from->priority; | |
548 | to->protocol = from->protocol; | |
d2f0c961 | 549 | to->skb_iif = from->skb_iif; |
adf30907 | 550 | skb_dst_drop(to); |
fe76cda3 | 551 | skb_dst_copy(to, from); |
1da177e4 | 552 | to->dev = from->dev; |
82e91ffe | 553 | to->mark = from->mark; |
1da177e4 | 554 | |
3dd1c9a1 PA |
555 | skb_copy_hash(to, from); |
556 | ||
1da177e4 LT |
557 | #ifdef CONFIG_NET_SCHED |
558 | to->tc_index = from->tc_index; | |
559 | #endif | |
e7ac05f3 | 560 | nf_copy(to, from); |
df5042f4 | 561 | skb_ext_copy(to, from); |
6ca40d4e | 562 | #if IS_ENABLED(CONFIG_IP_VS) |
c98d80ed | 563 | to->ipvs_property = from->ipvs_property; |
1da177e4 | 564 | #endif |
984bc16c | 565 | skb_copy_secmark(to, from); |
1da177e4 LT |
566 | } |
567 | ||
694869b3 | 568 | static int ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
c5501eb3 | 569 | unsigned int mtu, |
694869b3 | 570 | int (*output)(struct net *, struct sock *, struct sk_buff *)) |
49d16b23 AZ |
571 | { |
572 | struct iphdr *iph = ip_hdr(skb); | |
49d16b23 | 573 | |
d6b915e2 | 574 | if ((iph->frag_off & htons(IP_DF)) == 0) |
694869b3 | 575 | return ip_do_fragment(net, sk, skb, output); |
d6b915e2 FW |
576 | |
577 | if (unlikely(!skb->ignore_df || | |
49d16b23 AZ |
578 | (IPCB(skb)->frag_max_size && |
579 | IPCB(skb)->frag_max_size > mtu))) { | |
9479b0af | 580 | IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); |
49d16b23 AZ |
581 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
582 | htonl(mtu)); | |
583 | kfree_skb(skb); | |
584 | return -EMSGSIZE; | |
585 | } | |
586 | ||
694869b3 | 587 | return ip_do_fragment(net, sk, skb, output); |
49d16b23 AZ |
588 | } |
589 | ||
c8b17be0 PNA |
590 | void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, |
591 | unsigned int hlen, struct ip_fraglist_iter *iter) | |
592 | { | |
593 | unsigned int first_len = skb_pagelen(skb); | |
594 | ||
b7034146 | 595 | iter->frag = skb_shinfo(skb)->frag_list; |
c8b17be0 PNA |
596 | skb_frag_list_init(skb); |
597 | ||
598 | iter->offset = 0; | |
599 | iter->iph = iph; | |
600 | iter->hlen = hlen; | |
601 | ||
602 | skb->data_len = first_len - skb_headlen(skb); | |
603 | skb->len = first_len; | |
604 | iph->tot_len = htons(first_len); | |
605 | iph->frag_off = htons(IP_MF); | |
606 | ip_send_check(iph); | |
607 | } | |
608 | EXPORT_SYMBOL(ip_fraglist_init); | |
609 | ||
19c3401a PNA |
610 | static void ip_fraglist_ipcb_prepare(struct sk_buff *skb, |
611 | struct ip_fraglist_iter *iter) | |
612 | { | |
613 | struct sk_buff *to = iter->frag; | |
614 | ||
615 | /* Copy the flags to each fragment. */ | |
616 | IPCB(to)->flags = IPCB(skb)->flags; | |
617 | ||
618 | if (iter->offset == 0) | |
619 | ip_options_fragment(to); | |
620 | } | |
621 | ||
c8b17be0 PNA |
622 | void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter) |
623 | { | |
624 | unsigned int hlen = iter->hlen; | |
625 | struct iphdr *iph = iter->iph; | |
626 | struct sk_buff *frag; | |
627 | ||
628 | frag = iter->frag; | |
629 | frag->ip_summed = CHECKSUM_NONE; | |
630 | skb_reset_transport_header(frag); | |
631 | __skb_push(frag, hlen); | |
632 | skb_reset_network_header(frag); | |
633 | memcpy(skb_network_header(frag), iph, hlen); | |
634 | iter->iph = ip_hdr(frag); | |
635 | iph = iter->iph; | |
636 | iph->tot_len = htons(frag->len); | |
637 | ip_copy_metadata(frag, skb); | |
c8b17be0 PNA |
638 | iter->offset += skb->len - hlen; |
639 | iph->frag_off = htons(iter->offset >> 3); | |
640 | if (frag->next) | |
641 | iph->frag_off |= htons(IP_MF); | |
642 | /* Ready, complete checksum */ | |
643 | ip_send_check(iph); | |
644 | } | |
645 | EXPORT_SYMBOL(ip_fraglist_prepare); | |
646 | ||
065ff79f | 647 | void ip_frag_init(struct sk_buff *skb, unsigned int hlen, |
e7a409c3 | 648 | unsigned int ll_rs, unsigned int mtu, bool DF, |
065ff79f PNA |
649 | struct ip_frag_state *state) |
650 | { | |
651 | struct iphdr *iph = ip_hdr(skb); | |
652 | ||
e7a409c3 | 653 | state->DF = DF; |
065ff79f PNA |
654 | state->hlen = hlen; |
655 | state->ll_rs = ll_rs; | |
656 | state->mtu = mtu; | |
657 | ||
658 | state->left = skb->len - hlen; /* Space per frame */ | |
659 | state->ptr = hlen; /* Where to start from */ | |
660 | ||
661 | state->offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
662 | state->not_last_frag = iph->frag_off & htons(IP_MF); | |
663 | } | |
664 | EXPORT_SYMBOL(ip_frag_init); | |
665 | ||
19c3401a PNA |
666 | static void ip_frag_ipcb(struct sk_buff *from, struct sk_buff *to, |
667 | bool first_frag, struct ip_frag_state *state) | |
668 | { | |
669 | /* Copy the flags to each fragment. */ | |
670 | IPCB(to)->flags = IPCB(from)->flags; | |
671 | ||
19c3401a PNA |
672 | /* ANK: dirty, but effective trick. Upgrade options only if |
673 | * the segment to be fragmented was THE FIRST (otherwise, | |
674 | * options are already fixed) and make it ONCE | |
675 | * on the initial skb, so that all the following fragments | |
676 | * will inherit fixed options. | |
677 | */ | |
678 | if (first_frag) | |
679 | ip_options_fragment(from); | |
680 | } | |
681 | ||
065ff79f PNA |
682 | struct sk_buff *ip_frag_next(struct sk_buff *skb, struct ip_frag_state *state) |
683 | { | |
684 | unsigned int len = state->left; | |
685 | struct sk_buff *skb2; | |
686 | struct iphdr *iph; | |
687 | ||
688 | len = state->left; | |
689 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
690 | if (len > state->mtu) | |
691 | len = state->mtu; | |
692 | /* IF: we are not sending up to and including the packet end | |
693 | then align the next start on an eight byte boundary */ | |
694 | if (len < state->left) { | |
695 | len &= ~7; | |
696 | } | |
697 | ||
698 | /* Allocate buffer */ | |
699 | skb2 = alloc_skb(len + state->hlen + state->ll_rs, GFP_ATOMIC); | |
700 | if (!skb2) | |
701 | return ERR_PTR(-ENOMEM); | |
702 | ||
703 | /* | |
704 | * Set up data on packet | |
705 | */ | |
706 | ||
707 | ip_copy_metadata(skb2, skb); | |
708 | skb_reserve(skb2, state->ll_rs); | |
709 | skb_put(skb2, len + state->hlen); | |
710 | skb_reset_network_header(skb2); | |
711 | skb2->transport_header = skb2->network_header + state->hlen; | |
712 | ||
713 | /* | |
714 | * Charge the memory for the fragment to any owner | |
715 | * it might possess | |
716 | */ | |
717 | ||
718 | if (skb->sk) | |
719 | skb_set_owner_w(skb2, skb->sk); | |
720 | ||
721 | /* | |
722 | * Copy the packet header into the new buffer. | |
723 | */ | |
724 | ||
725 | skb_copy_from_linear_data(skb, skb_network_header(skb2), state->hlen); | |
726 | ||
727 | /* | |
728 | * Copy a block of the IP datagram. | |
729 | */ | |
730 | if (skb_copy_bits(skb, state->ptr, skb_transport_header(skb2), len)) | |
731 | BUG(); | |
732 | state->left -= len; | |
733 | ||
734 | /* | |
735 | * Fill in the new header fields. | |
736 | */ | |
737 | iph = ip_hdr(skb2); | |
738 | iph->frag_off = htons((state->offset >> 3)); | |
e7a409c3 ED |
739 | if (state->DF) |
740 | iph->frag_off |= htons(IP_DF); | |
065ff79f | 741 | |
065ff79f PNA |
742 | /* |
743 | * Added AC : If we are fragmenting a fragment that's not the | |
744 | * last fragment then keep MF on each bit | |
745 | */ | |
746 | if (state->left > 0 || state->not_last_frag) | |
747 | iph->frag_off |= htons(IP_MF); | |
748 | state->ptr += len; | |
749 | state->offset += len; | |
750 | ||
751 | iph->tot_len = htons(len + state->hlen); | |
752 | ||
753 | ip_send_check(iph); | |
754 | ||
755 | return skb2; | |
756 | } | |
757 | EXPORT_SYMBOL(ip_frag_next); | |
758 | ||
1da177e4 LT |
759 | /* |
760 | * This IP datagram is too large to be sent in one piece. Break it up into | |
761 | * smaller pieces (each of size equal to IP header plus | |
762 | * a block of the data of the original IP data part) that will yet fit in a | |
763 | * single device frame, and queue such a frame for sending. | |
764 | */ | |
765 | ||
694869b3 EB |
766 | int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
767 | int (*output)(struct net *, struct sock *, struct sk_buff *)) | |
1da177e4 LT |
768 | { |
769 | struct iphdr *iph; | |
1da177e4 | 770 | struct sk_buff *skb2; |
511c3f92 | 771 | struct rtable *rt = skb_rtable(skb); |
065ff79f | 772 | unsigned int mtu, hlen, ll_rs; |
c8b17be0 | 773 | struct ip_fraglist_iter iter; |
9669fffc | 774 | ktime_t tstamp = skb->tstamp; |
065ff79f | 775 | struct ip_frag_state state; |
1da177e4 LT |
776 | int err = 0; |
777 | ||
dbd3393c HFS |
778 | /* for offloaded checksums cleanup checksum before fragmentation */ |
779 | if (skb->ip_summed == CHECKSUM_PARTIAL && | |
780 | (err = skb_checksum_help(skb))) | |
781 | goto fail; | |
782 | ||
1da177e4 LT |
783 | /* |
784 | * Point into the IP datagram header. | |
785 | */ | |
786 | ||
eddc9ec5 | 787 | iph = ip_hdr(skb); |
1da177e4 | 788 | |
fedbb6b4 | 789 | mtu = ip_skb_dst_mtu(sk, skb); |
d6b915e2 FW |
790 | if (IPCB(skb)->frag_max_size && IPCB(skb)->frag_max_size < mtu) |
791 | mtu = IPCB(skb)->frag_max_size; | |
1da177e4 LT |
792 | |
793 | /* | |
794 | * Setup starting values. | |
795 | */ | |
796 | ||
797 | hlen = iph->ihl * 4; | |
f87c10a8 | 798 | mtu = mtu - hlen; /* Size of data space */ |
89cee8b1 | 799 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
254d900b | 800 | ll_rs = LL_RESERVED_SPACE(rt->dst.dev); |
1da177e4 LT |
801 | |
802 | /* When frag_list is given, use it. First, check its validity: | |
803 | * some transformers could create wrong frag_list or break existing | |
804 | * one, it is not prohibited. In this case fall back to copying. | |
805 | * | |
806 | * LATER: this step can be merged to real generation of fragments, | |
807 | * we can switch to copy when see the first bad fragment. | |
808 | */ | |
21dc3301 | 809 | if (skb_has_frag_list(skb)) { |
3d13008e | 810 | struct sk_buff *frag, *frag2; |
c72d8cda | 811 | unsigned int first_len = skb_pagelen(skb); |
1da177e4 LT |
812 | |
813 | if (first_len - hlen > mtu || | |
814 | ((first_len - hlen) & 7) || | |
56f8a75c | 815 | ip_is_fragment(iph) || |
254d900b VA |
816 | skb_cloned(skb) || |
817 | skb_headroom(skb) < ll_rs) | |
1da177e4 LT |
818 | goto slow_path; |
819 | ||
d7fcf1a5 | 820 | skb_walk_frags(skb, frag) { |
1da177e4 LT |
821 | /* Correct geometry. */ |
822 | if (frag->len > mtu || | |
823 | ((frag->len & 7) && frag->next) || | |
254d900b | 824 | skb_headroom(frag) < hlen + ll_rs) |
3d13008e | 825 | goto slow_path_clean; |
1da177e4 LT |
826 | |
827 | /* Partially cloned skb? */ | |
828 | if (skb_shared(frag)) | |
3d13008e | 829 | goto slow_path_clean; |
2fdba6b0 HX |
830 | |
831 | BUG_ON(frag->sk); | |
832 | if (skb->sk) { | |
2fdba6b0 HX |
833 | frag->sk = skb->sk; |
834 | frag->destructor = sock_wfree; | |
2fdba6b0 | 835 | } |
3d13008e | 836 | skb->truesize -= frag->truesize; |
1da177e4 LT |
837 | } |
838 | ||
839 | /* Everything is OK. Generate! */ | |
c8b17be0 | 840 | ip_fraglist_init(skb, iph, hlen, &iter); |
1da177e4 LT |
841 | |
842 | for (;;) { | |
843 | /* Prepare header of the next frame, | |
844 | * before previous one went down. */ | |
19c3401a PNA |
845 | if (iter.frag) { |
846 | ip_fraglist_ipcb_prepare(skb, &iter); | |
c8b17be0 | 847 | ip_fraglist_prepare(skb, &iter); |
19c3401a | 848 | } |
1da177e4 | 849 | |
9669fffc | 850 | skb->tstamp = tstamp; |
694869b3 | 851 | err = output(net, sk, skb); |
1da177e4 | 852 | |
dafee490 | 853 | if (!err) |
26a949db | 854 | IP_INC_STATS(net, IPSTATS_MIB_FRAGCREATES); |
c8b17be0 | 855 | if (err || !iter.frag) |
1da177e4 LT |
856 | break; |
857 | ||
c8b17be0 | 858 | skb = ip_fraglist_next(&iter); |
1da177e4 LT |
859 | } |
860 | ||
861 | if (err == 0) { | |
26a949db | 862 | IP_INC_STATS(net, IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
863 | return 0; |
864 | } | |
865 | ||
b7034146 | 866 | kfree_skb_list(iter.frag); |
942f146a | 867 | |
26a949db | 868 | IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 869 | return err; |
3d13008e ED |
870 | |
871 | slow_path_clean: | |
872 | skb_walk_frags(skb, frag2) { | |
873 | if (frag2 == frag) | |
874 | break; | |
875 | frag2->sk = NULL; | |
876 | frag2->destructor = NULL; | |
877 | skb->truesize += frag2->truesize; | |
878 | } | |
1da177e4 LT |
879 | } |
880 | ||
881 | slow_path: | |
1da177e4 LT |
882 | /* |
883 | * Fragment the datagram. | |
884 | */ | |
885 | ||
e7a409c3 ED |
886 | ip_frag_init(skb, hlen, ll_rs, mtu, IPCB(skb)->flags & IPSKB_FRAG_PMTU, |
887 | &state); | |
1da177e4 LT |
888 | |
889 | /* | |
890 | * Keep copying data until we run out. | |
891 | */ | |
892 | ||
065ff79f | 893 | while (state.left > 0) { |
19c3401a PNA |
894 | bool first_frag = (state.offset == 0); |
895 | ||
065ff79f PNA |
896 | skb2 = ip_frag_next(skb, &state); |
897 | if (IS_ERR(skb2)) { | |
898 | err = PTR_ERR(skb2); | |
1da177e4 LT |
899 | goto fail; |
900 | } | |
19c3401a | 901 | ip_frag_ipcb(skb, skb2, first_frag, &state); |
1da177e4 | 902 | |
1da177e4 LT |
903 | /* |
904 | * Put this fragment into the sending queue. | |
905 | */ | |
9669fffc | 906 | skb2->tstamp = tstamp; |
694869b3 | 907 | err = output(net, sk, skb2); |
1da177e4 LT |
908 | if (err) |
909 | goto fail; | |
dafee490 | 910 | |
26a949db | 911 | IP_INC_STATS(net, IPSTATS_MIB_FRAGCREATES); |
1da177e4 | 912 | } |
5d0ba55b | 913 | consume_skb(skb); |
26a949db | 914 | IP_INC_STATS(net, IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
915 | return err; |
916 | ||
917 | fail: | |
e905a9ed | 918 | kfree_skb(skb); |
26a949db | 919 | IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
920 | return err; |
921 | } | |
49d16b23 | 922 | EXPORT_SYMBOL(ip_do_fragment); |
2e2f7aef | 923 | |
1da177e4 LT |
924 | int |
925 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
926 | { | |
f69e6d13 | 927 | struct msghdr *msg = from; |
1da177e4 | 928 | |
84fa7933 | 929 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
0b62fca2 | 930 | if (!copy_from_iter_full(to, len, &msg->msg_iter)) |
1da177e4 LT |
931 | return -EFAULT; |
932 | } else { | |
44bb9363 | 933 | __wsum csum = 0; |
0b62fca2 | 934 | if (!csum_and_copy_from_iter_full(to, len, &csum, &msg->msg_iter)) |
1da177e4 LT |
935 | return -EFAULT; |
936 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
937 | } | |
938 | return 0; | |
939 | } | |
4bc2f18b | 940 | EXPORT_SYMBOL(ip_generic_getfrag); |
1da177e4 | 941 | |
44bb9363 | 942 | static inline __wsum |
1da177e4 LT |
943 | csum_page(struct page *page, int offset, int copy) |
944 | { | |
945 | char *kaddr; | |
44bb9363 | 946 | __wsum csum; |
1da177e4 LT |
947 | kaddr = kmap(page); |
948 | csum = csum_partial(kaddr + offset, copy, 0); | |
949 | kunmap(page); | |
950 | return csum; | |
951 | } | |
952 | ||
f5fca608 DM |
953 | static int __ip_append_data(struct sock *sk, |
954 | struct flowi4 *fl4, | |
955 | struct sk_buff_head *queue, | |
1470ddf7 | 956 | struct inet_cork *cork, |
5640f768 | 957 | struct page_frag *pfrag, |
1470ddf7 HX |
958 | int getfrag(void *from, char *to, int offset, |
959 | int len, int odd, struct sk_buff *skb), | |
960 | void *from, int length, int transhdrlen, | |
961 | unsigned int flags) | |
1da177e4 LT |
962 | { |
963 | struct inet_sock *inet = inet_sk(sk); | |
b5947e5d | 964 | struct ubuf_info *uarg = NULL; |
1da177e4 LT |
965 | struct sk_buff *skb; |
966 | ||
07df5294 | 967 | struct ip_options *opt = cork->opt; |
1da177e4 LT |
968 | int hh_len; |
969 | int exthdrlen; | |
970 | int mtu; | |
971 | int copy; | |
972 | int err; | |
973 | int offset = 0; | |
daba287b | 974 | unsigned int maxfraglen, fragheaderlen, maxnonfragsize; |
1da177e4 | 975 | int csummode = CHECKSUM_NONE; |
1470ddf7 | 976 | struct rtable *rt = (struct rtable *)cork->dst; |
694aba69 | 977 | unsigned int wmem_alloc_delta = 0; |
100f6d8e | 978 | bool paged, extra_uref = false; |
09c2d251 | 979 | u32 tskey = 0; |
1da177e4 | 980 | |
96d7303e SK |
981 | skb = skb_peek_tail(queue); |
982 | ||
983 | exthdrlen = !skb ? rt->dst.header_len : 0; | |
bec1f6f6 | 984 | mtu = cork->gso_size ? IP_MAX_MTU : cork->fragsize; |
15e36f5b | 985 | paged = !!cork->gso_size; |
bec1f6f6 | 986 | |
09c2d251 WB |
987 | if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && |
988 | sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) | |
989 | tskey = sk->sk_tskey++; | |
1da177e4 | 990 | |
d8d1f30b | 991 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
1da177e4 LT |
992 | |
993 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
994 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
60ff7467 | 995 | maxnonfragsize = ip_sk_ignore_df(sk) ? 0xFFFF : mtu; |
1da177e4 | 996 | |
daba287b | 997 | if (cork->length + length > maxnonfragsize - fragheaderlen) { |
f5fca608 | 998 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, |
61e7f09d | 999 | mtu - (opt ? opt->optlen : 0)); |
1da177e4 LT |
1000 | return -EMSGSIZE; |
1001 | } | |
1002 | ||
1003 | /* | |
1004 | * transhdrlen > 0 means that this is the first fragment and we wish | |
1005 | * it won't be fragmented in the future. | |
1006 | */ | |
1007 | if (transhdrlen && | |
1008 | length + fragheaderlen <= mtu && | |
c8cd0989 | 1009 | rt->dst.dev->features & (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM) && |
bec1f6f6 | 1010 | (!(flags & MSG_MORE) || cork->gso_size) && |
cd027a54 | 1011 | (!exthdrlen || (rt->dst.dev->features & NETIF_F_HW_ESP_TX_CSUM))) |
84fa7933 | 1012 | csummode = CHECKSUM_PARTIAL; |
1da177e4 | 1013 | |
b5947e5d WB |
1014 | if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { |
1015 | uarg = sock_zerocopy_realloc(sk, length, skb_zcopy(skb)); | |
1016 | if (!uarg) | |
1017 | return -ENOBUFS; | |
522924b5 | 1018 | extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ |
b5947e5d WB |
1019 | if (rt->dst.dev->features & NETIF_F_SG && |
1020 | csummode == CHECKSUM_PARTIAL) { | |
1021 | paged = true; | |
1022 | } else { | |
1023 | uarg->zerocopy = 0; | |
52900d22 | 1024 | skb_zcopy_set(skb, uarg, &extra_uref); |
b5947e5d WB |
1025 | } |
1026 | } | |
1027 | ||
1470ddf7 | 1028 | cork->length += length; |
1da177e4 LT |
1029 | |
1030 | /* So, what's going on in the loop below? | |
1031 | * | |
1032 | * We use calculated fragment length to generate chained skb, | |
1033 | * each of segments is IP fragment ready for sending to network after | |
1034 | * adding appropriate IP header. | |
1035 | */ | |
1036 | ||
26cde9f7 | 1037 | if (!skb) |
1da177e4 LT |
1038 | goto alloc_new_skb; |
1039 | ||
1040 | while (length > 0) { | |
1041 | /* Check if the remaining data fits into current packet. */ | |
1042 | copy = mtu - skb->len; | |
1043 | if (copy < length) | |
1044 | copy = maxfraglen - skb->len; | |
1045 | if (copy <= 0) { | |
1046 | char *data; | |
1047 | unsigned int datalen; | |
1048 | unsigned int fraglen; | |
1049 | unsigned int fraggap; | |
1050 | unsigned int alloclen; | |
aba36930 | 1051 | unsigned int pagedlen; |
1da177e4 LT |
1052 | struct sk_buff *skb_prev; |
1053 | alloc_new_skb: | |
1054 | skb_prev = skb; | |
1055 | if (skb_prev) | |
1056 | fraggap = skb_prev->len - maxfraglen; | |
1057 | else | |
1058 | fraggap = 0; | |
1059 | ||
1060 | /* | |
1061 | * If remaining data exceeds the mtu, | |
1062 | * we know we need more fragment(s). | |
1063 | */ | |
1064 | datalen = length + fraggap; | |
1065 | if (datalen > mtu - fragheaderlen) | |
1066 | datalen = maxfraglen - fragheaderlen; | |
1067 | fraglen = datalen + fragheaderlen; | |
aba36930 | 1068 | pagedlen = 0; |
1da177e4 | 1069 | |
e905a9ed | 1070 | if ((flags & MSG_MORE) && |
d8d1f30b | 1071 | !(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 | 1072 | alloclen = mtu; |
15e36f5b | 1073 | else if (!paged) |
59104f06 | 1074 | alloclen = fraglen; |
15e36f5b WB |
1075 | else { |
1076 | alloclen = min_t(int, fraglen, MAX_HEADER); | |
1077 | pagedlen = fraglen - alloclen; | |
1078 | } | |
1da177e4 | 1079 | |
353e5c9a SK |
1080 | alloclen += exthdrlen; |
1081 | ||
1da177e4 LT |
1082 | /* The last fragment gets additional space at tail. |
1083 | * Note, with MSG_MORE we overallocate on fragments, | |
1084 | * because we have no idea what fragment will be | |
1085 | * the last. | |
1086 | */ | |
33f99dc7 | 1087 | if (datalen == length + fraggap) |
d8d1f30b | 1088 | alloclen += rt->dst.trailer_len; |
33f99dc7 | 1089 | |
1da177e4 | 1090 | if (transhdrlen) { |
e905a9ed | 1091 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
1092 | alloclen + hh_len + 15, |
1093 | (flags & MSG_DONTWAIT), &err); | |
1094 | } else { | |
1095 | skb = NULL; | |
694aba69 | 1096 | if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= |
1da177e4 | 1097 | 2 * sk->sk_sndbuf) |
694aba69 ED |
1098 | skb = alloc_skb(alloclen + hh_len + 15, |
1099 | sk->sk_allocation); | |
51456b29 | 1100 | if (unlikely(!skb)) |
1da177e4 LT |
1101 | err = -ENOBUFS; |
1102 | } | |
51456b29 | 1103 | if (!skb) |
1da177e4 LT |
1104 | goto error; |
1105 | ||
1106 | /* | |
1107 | * Fill in the control structures | |
1108 | */ | |
1109 | skb->ip_summed = csummode; | |
1110 | skb->csum = 0; | |
1111 | skb_reserve(skb, hh_len); | |
11878b40 | 1112 | |
1da177e4 LT |
1113 | /* |
1114 | * Find where to start putting bytes. | |
1115 | */ | |
15e36f5b | 1116 | data = skb_put(skb, fraglen + exthdrlen - pagedlen); |
c14d2450 | 1117 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
1118 | skb->transport_header = (skb->network_header + |
1119 | fragheaderlen); | |
353e5c9a | 1120 | data += fragheaderlen + exthdrlen; |
1da177e4 LT |
1121 | |
1122 | if (fraggap) { | |
1123 | skb->csum = skb_copy_and_csum_bits( | |
1124 | skb_prev, maxfraglen, | |
1125 | data + transhdrlen, fraggap, 0); | |
1126 | skb_prev->csum = csum_sub(skb_prev->csum, | |
1127 | skb->csum); | |
1128 | data += fraggap; | |
e9fa4f7b | 1129 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1130 | } |
1131 | ||
15e36f5b | 1132 | copy = datalen - transhdrlen - fraggap - pagedlen; |
1da177e4 LT |
1133 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { |
1134 | err = -EFAULT; | |
1135 | kfree_skb(skb); | |
1136 | goto error; | |
1137 | } | |
1138 | ||
1139 | offset += copy; | |
15e36f5b | 1140 | length -= copy + transhdrlen; |
1da177e4 LT |
1141 | transhdrlen = 0; |
1142 | exthdrlen = 0; | |
1143 | csummode = CHECKSUM_NONE; | |
1144 | ||
52900d22 WB |
1145 | /* only the initial fragment is time stamped */ |
1146 | skb_shinfo(skb)->tx_flags = cork->tx_flags; | |
1147 | cork->tx_flags = 0; | |
1148 | skb_shinfo(skb)->tskey = tskey; | |
1149 | tskey = 0; | |
1150 | skb_zcopy_set(skb, uarg, &extra_uref); | |
1151 | ||
0dec879f JA |
1152 | if ((flags & MSG_CONFIRM) && !skb_prev) |
1153 | skb_set_dst_pending_confirm(skb, 1); | |
1154 | ||
1da177e4 LT |
1155 | /* |
1156 | * Put the packet on the pending queue. | |
1157 | */ | |
694aba69 ED |
1158 | if (!skb->destructor) { |
1159 | skb->destructor = sock_wfree; | |
1160 | skb->sk = sk; | |
1161 | wmem_alloc_delta += skb->truesize; | |
1162 | } | |
1470ddf7 | 1163 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
1164 | continue; |
1165 | } | |
1166 | ||
1167 | if (copy > length) | |
1168 | copy = length; | |
1169 | ||
113f99c3 WB |
1170 | if (!(rt->dst.dev->features&NETIF_F_SG) && |
1171 | skb_tailroom(skb) >= copy) { | |
1da177e4 LT |
1172 | unsigned int off; |
1173 | ||
1174 | off = skb->len; | |
e905a9ed | 1175 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
1176 | offset, copy, off, skb) < 0) { |
1177 | __skb_trim(skb, off); | |
1178 | err = -EFAULT; | |
1179 | goto error; | |
1180 | } | |
b5947e5d | 1181 | } else if (!uarg || !uarg->zerocopy) { |
1da177e4 | 1182 | int i = skb_shinfo(skb)->nr_frags; |
1da177e4 | 1183 | |
5640f768 ED |
1184 | err = -ENOMEM; |
1185 | if (!sk_page_frag_refill(sk, pfrag)) | |
1da177e4 | 1186 | goto error; |
5640f768 ED |
1187 | |
1188 | if (!skb_can_coalesce(skb, i, pfrag->page, | |
1189 | pfrag->offset)) { | |
1190 | err = -EMSGSIZE; | |
1191 | if (i == MAX_SKB_FRAGS) | |
1192 | goto error; | |
1193 | ||
1194 | __skb_fill_page_desc(skb, i, pfrag->page, | |
1195 | pfrag->offset, 0); | |
1196 | skb_shinfo(skb)->nr_frags = ++i; | |
1197 | get_page(pfrag->page); | |
1da177e4 | 1198 | } |
5640f768 ED |
1199 | copy = min_t(int, copy, pfrag->size - pfrag->offset); |
1200 | if (getfrag(from, | |
1201 | page_address(pfrag->page) + pfrag->offset, | |
1202 | offset, copy, skb->len, skb) < 0) | |
1203 | goto error_efault; | |
1204 | ||
1205 | pfrag->offset += copy; | |
1206 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); | |
1da177e4 LT |
1207 | skb->len += copy; |
1208 | skb->data_len += copy; | |
f945fa7a | 1209 | skb->truesize += copy; |
694aba69 | 1210 | wmem_alloc_delta += copy; |
b5947e5d WB |
1211 | } else { |
1212 | err = skb_zerocopy_iter_dgram(skb, from, copy); | |
1213 | if (err < 0) | |
1214 | goto error; | |
1da177e4 LT |
1215 | } |
1216 | offset += copy; | |
1217 | length -= copy; | |
1218 | } | |
1219 | ||
9e8445a5 PA |
1220 | if (wmem_alloc_delta) |
1221 | refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1222 | return 0; |
1223 | ||
5640f768 ED |
1224 | error_efault: |
1225 | err = -EFAULT; | |
1da177e4 | 1226 | error: |
97ef7b4c WB |
1227 | if (uarg) |
1228 | sock_zerocopy_put_abort(uarg, extra_uref); | |
1470ddf7 | 1229 | cork->length -= length; |
5e38e270 | 1230 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
694aba69 | 1231 | refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); |
e905a9ed | 1232 | return err; |
1da177e4 LT |
1233 | } |
1234 | ||
1470ddf7 HX |
1235 | static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, |
1236 | struct ipcm_cookie *ipc, struct rtable **rtp) | |
1237 | { | |
f6d8bd05 | 1238 | struct ip_options_rcu *opt; |
1470ddf7 HX |
1239 | struct rtable *rt; |
1240 | ||
9783ccd0 GF |
1241 | rt = *rtp; |
1242 | if (unlikely(!rt)) | |
1243 | return -EFAULT; | |
1244 | ||
1470ddf7 HX |
1245 | /* |
1246 | * setup for corking. | |
1247 | */ | |
1248 | opt = ipc->opt; | |
1249 | if (opt) { | |
51456b29 | 1250 | if (!cork->opt) { |
1470ddf7 HX |
1251 | cork->opt = kmalloc(sizeof(struct ip_options) + 40, |
1252 | sk->sk_allocation); | |
51456b29 | 1253 | if (unlikely(!cork->opt)) |
1470ddf7 HX |
1254 | return -ENOBUFS; |
1255 | } | |
f6d8bd05 | 1256 | memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen); |
1470ddf7 HX |
1257 | cork->flags |= IPCORK_OPT; |
1258 | cork->addr = ipc->addr; | |
1259 | } | |
9783ccd0 | 1260 | |
1470ddf7 HX |
1261 | /* |
1262 | * We steal reference to this route, caller should not release it | |
1263 | */ | |
1264 | *rtp = NULL; | |
482fc609 HFS |
1265 | cork->fragsize = ip_sk_use_pmtu(sk) ? |
1266 | dst_mtu(&rt->dst) : rt->dst.dev->mtu; | |
bec1f6f6 | 1267 | |
fbf47813 | 1268 | cork->gso_size = ipc->gso_size; |
1470ddf7 HX |
1269 | cork->dst = &rt->dst; |
1270 | cork->length = 0; | |
aa661581 FF |
1271 | cork->ttl = ipc->ttl; |
1272 | cork->tos = ipc->tos; | |
c6af0c22 | 1273 | cork->mark = ipc->sockc.mark; |
aa661581 | 1274 | cork->priority = ipc->priority; |
bc969a97 | 1275 | cork->transmit_time = ipc->sockc.transmit_time; |
678ca42d WB |
1276 | cork->tx_flags = 0; |
1277 | sock_tx_timestamp(sk, ipc->sockc.tsflags, &cork->tx_flags); | |
1470ddf7 HX |
1278 | |
1279 | return 0; | |
1280 | } | |
1281 | ||
1282 | /* | |
1283 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
1284 | * from many pieces of data. Each pieces will be holded on the socket | |
1285 | * until ip_push_pending_frames() is called. Each piece can be a page | |
1286 | * or non-page data. | |
1287 | * | |
1288 | * Not only UDP, other transport protocols - e.g. raw sockets - can use | |
1289 | * this interface potentially. | |
1290 | * | |
1291 | * LATER: length must be adjusted by pad at tail, when it is required. | |
1292 | */ | |
f5fca608 | 1293 | int ip_append_data(struct sock *sk, struct flowi4 *fl4, |
1470ddf7 HX |
1294 | int getfrag(void *from, char *to, int offset, int len, |
1295 | int odd, struct sk_buff *skb), | |
1296 | void *from, int length, int transhdrlen, | |
1297 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1298 | unsigned int flags) | |
1299 | { | |
1300 | struct inet_sock *inet = inet_sk(sk); | |
1301 | int err; | |
1302 | ||
1303 | if (flags&MSG_PROBE) | |
1304 | return 0; | |
1305 | ||
1306 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
bdc712b4 | 1307 | err = ip_setup_cork(sk, &inet->cork.base, ipc, rtp); |
1470ddf7 HX |
1308 | if (err) |
1309 | return err; | |
1310 | } else { | |
1311 | transhdrlen = 0; | |
1312 | } | |
1313 | ||
5640f768 ED |
1314 | return __ip_append_data(sk, fl4, &sk->sk_write_queue, &inet->cork.base, |
1315 | sk_page_frag(sk), getfrag, | |
1470ddf7 HX |
1316 | from, length, transhdrlen, flags); |
1317 | } | |
1318 | ||
f5fca608 | 1319 | ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, |
1da177e4 LT |
1320 | int offset, size_t size, int flags) |
1321 | { | |
1322 | struct inet_sock *inet = inet_sk(sk); | |
1323 | struct sk_buff *skb; | |
1324 | struct rtable *rt; | |
1325 | struct ip_options *opt = NULL; | |
bdc712b4 | 1326 | struct inet_cork *cork; |
1da177e4 LT |
1327 | int hh_len; |
1328 | int mtu; | |
1329 | int len; | |
1330 | int err; | |
daba287b | 1331 | unsigned int maxfraglen, fragheaderlen, fraggap, maxnonfragsize; |
1da177e4 LT |
1332 | |
1333 | if (inet->hdrincl) | |
1334 | return -EPERM; | |
1335 | ||
1336 | if (flags&MSG_PROBE) | |
1337 | return 0; | |
1338 | ||
1339 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1340 | return -EINVAL; | |
1341 | ||
bdc712b4 DM |
1342 | cork = &inet->cork.base; |
1343 | rt = (struct rtable *)cork->dst; | |
1344 | if (cork->flags & IPCORK_OPT) | |
1345 | opt = cork->opt; | |
1da177e4 | 1346 | |
d8d1f30b | 1347 | if (!(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 LT |
1348 | return -EOPNOTSUPP; |
1349 | ||
d8d1f30b | 1350 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
bec1f6f6 | 1351 | mtu = cork->gso_size ? IP_MAX_MTU : cork->fragsize; |
1da177e4 LT |
1352 | |
1353 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1354 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
60ff7467 | 1355 | maxnonfragsize = ip_sk_ignore_df(sk) ? 0xFFFF : mtu; |
1da177e4 | 1356 | |
daba287b | 1357 | if (cork->length + size > maxnonfragsize - fragheaderlen) { |
61e7f09d HFS |
1358 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, |
1359 | mtu - (opt ? opt->optlen : 0)); | |
1da177e4 LT |
1360 | return -EMSGSIZE; |
1361 | } | |
1362 | ||
51456b29 IM |
1363 | skb = skb_peek_tail(&sk->sk_write_queue); |
1364 | if (!skb) | |
1da177e4 LT |
1365 | return -EINVAL; |
1366 | ||
a8c4a252 | 1367 | cork->length += size; |
e89e9cf5 | 1368 | |
1da177e4 | 1369 | while (size > 0) { |
ab2fb7e3 WB |
1370 | /* Check if the remaining data fits into current packet. */ |
1371 | len = mtu - skb->len; | |
1372 | if (len < size) | |
1373 | len = maxfraglen - skb->len; | |
e89e9cf5 | 1374 | |
1da177e4 LT |
1375 | if (len <= 0) { |
1376 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1377 | int alloclen; |
1378 | ||
1379 | skb_prev = skb; | |
0d0d2bba | 1380 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1381 | |
1382 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1383 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1384 | if (unlikely(!skb)) { | |
1385 | err = -ENOBUFS; | |
1386 | goto error; | |
1387 | } | |
1388 | ||
1389 | /* | |
1390 | * Fill in the control structures | |
1391 | */ | |
1392 | skb->ip_summed = CHECKSUM_NONE; | |
1393 | skb->csum = 0; | |
1394 | skb_reserve(skb, hh_len); | |
1395 | ||
1396 | /* | |
1397 | * Find where to start putting bytes. | |
1398 | */ | |
967b05f6 | 1399 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1400 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1401 | skb->transport_header = (skb->network_header + |
1402 | fragheaderlen); | |
1da177e4 | 1403 | if (fraggap) { |
967b05f6 ACM |
1404 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1405 | maxfraglen, | |
9c70220b | 1406 | skb_transport_header(skb), |
967b05f6 | 1407 | fraggap, 0); |
1da177e4 LT |
1408 | skb_prev->csum = csum_sub(skb_prev->csum, |
1409 | skb->csum); | |
e9fa4f7b | 1410 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1411 | } |
1412 | ||
1413 | /* | |
1414 | * Put the packet on the pending queue. | |
1415 | */ | |
1416 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1417 | continue; | |
1418 | } | |
1419 | ||
1da177e4 LT |
1420 | if (len > size) |
1421 | len = size; | |
be12a1fe HFS |
1422 | |
1423 | if (skb_append_pagefrags(skb, page, offset, len)) { | |
1da177e4 LT |
1424 | err = -EMSGSIZE; |
1425 | goto error; | |
1426 | } | |
1427 | ||
1428 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1429 | __wsum csum; |
1da177e4 LT |
1430 | csum = csum_page(page, offset, len); |
1431 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1432 | } | |
1433 | ||
1434 | skb->len += len; | |
1435 | skb->data_len += len; | |
1e34a11d | 1436 | skb->truesize += len; |
14afee4b | 1437 | refcount_add(len, &sk->sk_wmem_alloc); |
1da177e4 LT |
1438 | offset += len; |
1439 | size -= len; | |
1440 | } | |
1441 | return 0; | |
1442 | ||
1443 | error: | |
bdc712b4 | 1444 | cork->length -= size; |
5e38e270 | 1445 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1446 | return err; |
1447 | } | |
1448 | ||
1470ddf7 | 1449 | static void ip_cork_release(struct inet_cork *cork) |
429f08e9 | 1450 | { |
1470ddf7 HX |
1451 | cork->flags &= ~IPCORK_OPT; |
1452 | kfree(cork->opt); | |
1453 | cork->opt = NULL; | |
1454 | dst_release(cork->dst); | |
1455 | cork->dst = NULL; | |
429f08e9 PE |
1456 | } |
1457 | ||
1da177e4 LT |
1458 | /* |
1459 | * Combined all pending IP fragments on the socket as one IP datagram | |
1460 | * and push them out. | |
1461 | */ | |
1c32c5ad | 1462 | struct sk_buff *__ip_make_skb(struct sock *sk, |
77968b78 | 1463 | struct flowi4 *fl4, |
1c32c5ad HX |
1464 | struct sk_buff_head *queue, |
1465 | struct inet_cork *cork) | |
1da177e4 LT |
1466 | { |
1467 | struct sk_buff *skb, *tmp_skb; | |
1468 | struct sk_buff **tail_skb; | |
1469 | struct inet_sock *inet = inet_sk(sk); | |
0388b004 | 1470 | struct net *net = sock_net(sk); |
1da177e4 | 1471 | struct ip_options *opt = NULL; |
1470ddf7 | 1472 | struct rtable *rt = (struct rtable *)cork->dst; |
1da177e4 | 1473 | struct iphdr *iph; |
76ab608d | 1474 | __be16 df = 0; |
1da177e4 | 1475 | __u8 ttl; |
1da177e4 | 1476 | |
51456b29 IM |
1477 | skb = __skb_dequeue(queue); |
1478 | if (!skb) | |
1da177e4 LT |
1479 | goto out; |
1480 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1481 | ||
1482 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1483 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1484 | __skb_pull(skb, skb_network_offset(skb)); |
1470ddf7 | 1485 | while ((tmp_skb = __skb_dequeue(queue)) != NULL) { |
cfe1fc77 | 1486 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1487 | *tail_skb = tmp_skb; |
1488 | tail_skb = &(tmp_skb->next); | |
1489 | skb->len += tmp_skb->len; | |
1490 | skb->data_len += tmp_skb->len; | |
1491 | skb->truesize += tmp_skb->truesize; | |
1da177e4 LT |
1492 | tmp_skb->destructor = NULL; |
1493 | tmp_skb->sk = NULL; | |
1494 | } | |
1495 | ||
1496 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1497 | * to fragment the frame generated here. No matter, what transforms | |
1498 | * how transforms change size of the packet, it will come out. | |
1499 | */ | |
60ff7467 | 1500 | skb->ignore_df = ip_sk_ignore_df(sk); |
1da177e4 LT |
1501 | |
1502 | /* DF bit is set when we want to see DF on outgoing frames. | |
60ff7467 | 1503 | * If ignore_df is set too, we still allow to fragment this frame |
1da177e4 | 1504 | * locally. */ |
482fc609 HFS |
1505 | if (inet->pmtudisc == IP_PMTUDISC_DO || |
1506 | inet->pmtudisc == IP_PMTUDISC_PROBE || | |
d8d1f30b CG |
1507 | (skb->len <= dst_mtu(&rt->dst) && |
1508 | ip_dont_fragment(sk, &rt->dst))) | |
1da177e4 LT |
1509 | df = htons(IP_DF); |
1510 | ||
1470ddf7 HX |
1511 | if (cork->flags & IPCORK_OPT) |
1512 | opt = cork->opt; | |
1da177e4 | 1513 | |
aa661581 FF |
1514 | if (cork->ttl != 0) |
1515 | ttl = cork->ttl; | |
1516 | else if (rt->rt_type == RTN_MULTICAST) | |
1da177e4 LT |
1517 | ttl = inet->mc_ttl; |
1518 | else | |
d8d1f30b | 1519 | ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 | 1520 | |
749154aa | 1521 | iph = ip_hdr(skb); |
1da177e4 LT |
1522 | iph->version = 4; |
1523 | iph->ihl = 5; | |
aa661581 | 1524 | iph->tos = (cork->tos != -1) ? cork->tos : inet->tos; |
1da177e4 | 1525 | iph->frag_off = df; |
1da177e4 LT |
1526 | iph->ttl = ttl; |
1527 | iph->protocol = sk->sk_protocol; | |
84f9307c | 1528 | ip_copy_addrs(iph, fl4); |
b6a7719a | 1529 | ip_select_ident(net, skb, sk); |
1da177e4 | 1530 | |
22f728f8 DM |
1531 | if (opt) { |
1532 | iph->ihl += opt->optlen>>2; | |
1533 | ip_options_build(skb, opt, cork->addr, rt, 0); | |
1534 | } | |
1535 | ||
aa661581 | 1536 | skb->priority = (cork->tos != -1) ? cork->priority: sk->sk_priority; |
c6af0c22 | 1537 | skb->mark = cork->mark; |
bc969a97 | 1538 | skb->tstamp = cork->transmit_time; |
a21bba94 ED |
1539 | /* |
1540 | * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec | |
1541 | * on dst refcount | |
1542 | */ | |
1470ddf7 | 1543 | cork->dst = NULL; |
d8d1f30b | 1544 | skb_dst_set(skb, &rt->dst); |
1da177e4 | 1545 | |
96793b48 | 1546 | if (iph->protocol == IPPROTO_ICMP) |
0388b004 | 1547 | icmp_out_count(net, ((struct icmphdr *) |
96793b48 DS |
1548 | skb_transport_header(skb))->type); |
1549 | ||
1c32c5ad HX |
1550 | ip_cork_release(cork); |
1551 | out: | |
1552 | return skb; | |
1553 | } | |
1554 | ||
b5ec8eea | 1555 | int ip_send_skb(struct net *net, struct sk_buff *skb) |
1c32c5ad | 1556 | { |
1c32c5ad HX |
1557 | int err; |
1558 | ||
33224b16 | 1559 | err = ip_local_out(net, skb->sk, skb); |
1da177e4 LT |
1560 | if (err) { |
1561 | if (err > 0) | |
6ce9e7b5 | 1562 | err = net_xmit_errno(err); |
1da177e4 | 1563 | if (err) |
1c32c5ad | 1564 | IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1565 | } |
1566 | ||
1da177e4 | 1567 | return err; |
1da177e4 LT |
1568 | } |
1569 | ||
77968b78 | 1570 | int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4) |
1470ddf7 | 1571 | { |
1c32c5ad HX |
1572 | struct sk_buff *skb; |
1573 | ||
77968b78 | 1574 | skb = ip_finish_skb(sk, fl4); |
1c32c5ad HX |
1575 | if (!skb) |
1576 | return 0; | |
1577 | ||
1578 | /* Netfilter gets whole the not fragmented skb. */ | |
b5ec8eea | 1579 | return ip_send_skb(sock_net(sk), skb); |
1470ddf7 HX |
1580 | } |
1581 | ||
1da177e4 LT |
1582 | /* |
1583 | * Throw away all pending data on the socket. | |
1584 | */ | |
1470ddf7 HX |
1585 | static void __ip_flush_pending_frames(struct sock *sk, |
1586 | struct sk_buff_head *queue, | |
1587 | struct inet_cork *cork) | |
1da177e4 | 1588 | { |
1da177e4 LT |
1589 | struct sk_buff *skb; |
1590 | ||
1470ddf7 | 1591 | while ((skb = __skb_dequeue_tail(queue)) != NULL) |
1da177e4 LT |
1592 | kfree_skb(skb); |
1593 | ||
1470ddf7 HX |
1594 | ip_cork_release(cork); |
1595 | } | |
1596 | ||
1597 | void ip_flush_pending_frames(struct sock *sk) | |
1598 | { | |
bdc712b4 | 1599 | __ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base); |
1da177e4 LT |
1600 | } |
1601 | ||
1c32c5ad | 1602 | struct sk_buff *ip_make_skb(struct sock *sk, |
77968b78 | 1603 | struct flowi4 *fl4, |
1c32c5ad HX |
1604 | int getfrag(void *from, char *to, int offset, |
1605 | int len, int odd, struct sk_buff *skb), | |
1606 | void *from, int length, int transhdrlen, | |
1607 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1cd7884d | 1608 | struct inet_cork *cork, unsigned int flags) |
1c32c5ad | 1609 | { |
1c32c5ad HX |
1610 | struct sk_buff_head queue; |
1611 | int err; | |
1612 | ||
1613 | if (flags & MSG_PROBE) | |
1614 | return NULL; | |
1615 | ||
1616 | __skb_queue_head_init(&queue); | |
1617 | ||
1cd7884d WB |
1618 | cork->flags = 0; |
1619 | cork->addr = 0; | |
1620 | cork->opt = NULL; | |
1621 | err = ip_setup_cork(sk, cork, ipc, rtp); | |
1c32c5ad HX |
1622 | if (err) |
1623 | return ERR_PTR(err); | |
1624 | ||
1cd7884d | 1625 | err = __ip_append_data(sk, fl4, &queue, cork, |
5640f768 | 1626 | ¤t->task_frag, getfrag, |
1c32c5ad HX |
1627 | from, length, transhdrlen, flags); |
1628 | if (err) { | |
1cd7884d | 1629 | __ip_flush_pending_frames(sk, &queue, cork); |
1c32c5ad HX |
1630 | return ERR_PTR(err); |
1631 | } | |
1632 | ||
1cd7884d | 1633 | return __ip_make_skb(sk, fl4, &queue, cork); |
1c32c5ad | 1634 | } |
1da177e4 LT |
1635 | |
1636 | /* | |
1637 | * Fetch data from kernel space and fill in checksum if needed. | |
1638 | */ | |
e905a9ed | 1639 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1640 | int len, int odd, struct sk_buff *skb) |
1641 | { | |
5084205f | 1642 | __wsum csum; |
1da177e4 LT |
1643 | |
1644 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1645 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1646 | return 0; |
1da177e4 LT |
1647 | } |
1648 | ||
e905a9ed | 1649 | /* |
1da177e4 | 1650 | * Generic function to send a packet as reply to another packet. |
be9f4a44 | 1651 | * Used to send some TCP resets/acks so far. |
1da177e4 | 1652 | */ |
bdbbb852 | 1653 | void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, |
24a2d43d ED |
1654 | const struct ip_options *sopt, |
1655 | __be32 daddr, __be32 saddr, | |
1656 | const struct ip_reply_arg *arg, | |
d6fb396c | 1657 | unsigned int len, u64 transmit_time) |
1da177e4 | 1658 | { |
f6d8bd05 | 1659 | struct ip_options_data replyopts; |
1da177e4 | 1660 | struct ipcm_cookie ipc; |
77968b78 | 1661 | struct flowi4 fl4; |
511c3f92 | 1662 | struct rtable *rt = skb_rtable(skb); |
bdbbb852 | 1663 | struct net *net = sock_net(sk); |
be9f4a44 | 1664 | struct sk_buff *nskb; |
4062090e | 1665 | int err; |
f7ba868b | 1666 | int oif; |
1da177e4 | 1667 | |
91ed1e66 | 1668 | if (__ip_options_echo(net, &replyopts.opt.opt, skb, sopt)) |
1da177e4 LT |
1669 | return; |
1670 | ||
35178206 | 1671 | ipcm_init(&ipc); |
0a5ebb80 | 1672 | ipc.addr = daddr; |
d6fb396c | 1673 | ipc.sockc.transmit_time = transmit_time; |
1da177e4 | 1674 | |
f6d8bd05 | 1675 | if (replyopts.opt.opt.optlen) { |
1da177e4 LT |
1676 | ipc.opt = &replyopts.opt; |
1677 | ||
f6d8bd05 ED |
1678 | if (replyopts.opt.opt.srr) |
1679 | daddr = replyopts.opt.opt.faddr; | |
1da177e4 LT |
1680 | } |
1681 | ||
f7ba868b | 1682 | oif = arg->bound_dev_if; |
9b6c14d5 DA |
1683 | if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) |
1684 | oif = skb->skb_iif; | |
f7ba868b DA |
1685 | |
1686 | flowi4_init_output(&fl4, oif, | |
00483690 | 1687 | IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark, |
66b13d99 | 1688 | RT_TOS(arg->tos), |
be9f4a44 | 1689 | RT_SCOPE_UNIVERSE, ip_hdr(skb)->protocol, |
77968b78 | 1690 | ip_reply_arg_flowi_flags(arg), |
70e73416 | 1691 | daddr, saddr, |
e2d118a1 LC |
1692 | tcp_hdr(skb)->source, tcp_hdr(skb)->dest, |
1693 | arg->uid); | |
77968b78 | 1694 | security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); |
be9f4a44 | 1695 | rt = ip_route_output_key(net, &fl4); |
77968b78 DM |
1696 | if (IS_ERR(rt)) |
1697 | return; | |
1da177e4 | 1698 | |
bdbbb852 | 1699 | inet_sk(sk)->tos = arg->tos; |
1da177e4 | 1700 | |
eddc9ec5 | 1701 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1702 | sk->sk_bound_dev_if = arg->bound_dev_if; |
be9f4a44 | 1703 | sk->sk_sndbuf = sysctl_wmem_default; |
bf99b4de | 1704 | sk->sk_mark = fl4.flowi4_mark; |
4062090e VA |
1705 | err = ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, |
1706 | len, 0, &ipc, &rt, MSG_DONTWAIT); | |
1707 | if (unlikely(err)) { | |
1708 | ip_flush_pending_frames(sk); | |
1709 | goto out; | |
1710 | } | |
1711 | ||
be9f4a44 ED |
1712 | nskb = skb_peek(&sk->sk_write_queue); |
1713 | if (nskb) { | |
1da177e4 | 1714 | if (arg->csumoffset >= 0) |
be9f4a44 ED |
1715 | *((__sum16 *)skb_transport_header(nskb) + |
1716 | arg->csumoffset) = csum_fold(csum_add(nskb->csum, | |
9c70220b | 1717 | arg->csum)); |
be9f4a44 | 1718 | nskb->ip_summed = CHECKSUM_NONE; |
77968b78 | 1719 | ip_push_pending_frames(sk, &fl4); |
1da177e4 | 1720 | } |
4062090e | 1721 | out: |
1da177e4 LT |
1722 | ip_rt_put(rt); |
1723 | } | |
1724 | ||
1da177e4 LT |
1725 | void __init ip_init(void) |
1726 | { | |
1da177e4 LT |
1727 | ip_rt_init(); |
1728 | inet_initpeers(); | |
1729 | ||
72c1d3bd WC |
1730 | #if defined(CONFIG_IP_MULTICAST) |
1731 | igmp_mc_init(); | |
1da177e4 LT |
1732 | #endif |
1733 | } |