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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 | 242 | { |
88bebdf5 | 243 | struct sk_buff *segs, *nskb; |
c7ba65d7 | 244 | netdev_features_t features; |
c7ba65d7 FW |
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 | ||
88bebdf5 | 275 | skb_list_walk_safe(segs, segs, nskb) { |
c7ba65d7 FW |
276 | int err; |
277 | ||
a8305bff | 278 | skb_mark_not_on_list(segs); |
694869b3 | 279 | err = ip_fragment(net, sk, segs, mtu, ip_finish_output2); |
c7ba65d7 FW |
280 | |
281 | if (err && ret == 0) | |
282 | ret = err; | |
88bebdf5 | 283 | } |
c7ba65d7 FW |
284 | |
285 | return ret; | |
286 | } | |
287 | ||
956fe219 | 288 | static int __ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 289 | { |
c5501eb3 FW |
290 | unsigned int mtu; |
291 | ||
5c901daa PM |
292 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
293 | /* Policy lookup after SNAT yielded a new policy */ | |
00db4124 | 294 | if (skb_dst(skb)->xfrm) { |
48d5cad8 | 295 | IPCB(skb)->flags |= IPSKB_REROUTED; |
13206b6b | 296 | return dst_output(net, sk, skb); |
48d5cad8 | 297 | } |
5c901daa | 298 | #endif |
fedbb6b4 | 299 | mtu = ip_skb_dst_mtu(sk, skb); |
c7ba65d7 | 300 | if (skb_is_gso(skb)) |
694869b3 | 301 | return ip_finish_output_gso(net, sk, skb, mtu); |
c7ba65d7 | 302 | |
d6b915e2 | 303 | if (skb->len > mtu || (IPCB(skb)->flags & IPSKB_FRAG_PMTU)) |
694869b3 | 304 | return ip_fragment(net, sk, skb, mtu, ip_finish_output2); |
c7ba65d7 | 305 | |
694869b3 | 306 | return ip_finish_output2(net, sk, skb); |
1da177e4 LT |
307 | } |
308 | ||
956fe219 | 309 | static int ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
310 | { | |
311 | int ret; | |
312 | ||
313 | ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); | |
314 | switch (ret) { | |
315 | case NET_XMIT_SUCCESS: | |
316 | return __ip_finish_output(net, sk, skb); | |
317 | case NET_XMIT_CN: | |
318 | return __ip_finish_output(net, sk, skb) ? : ret; | |
319 | default: | |
320 | kfree_skb(skb); | |
321 | return ret; | |
322 | } | |
323 | } | |
324 | ||
33b48679 DM |
325 | static int ip_mc_finish_output(struct net *net, struct sock *sk, |
326 | struct sk_buff *skb) | |
327 | { | |
5b18f128 | 328 | struct rtable *new_rt; |
d96ff269 DM |
329 | bool do_cn = false; |
330 | int ret, err; | |
33b48679 DM |
331 | |
332 | ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); | |
956fe219 | 333 | switch (ret) { |
956fe219 | 334 | case NET_XMIT_CN: |
d96ff269 DM |
335 | do_cn = true; |
336 | /* fall through */ | |
337 | case NET_XMIT_SUCCESS: | |
338 | break; | |
956fe219 | 339 | default: |
33b48679 DM |
340 | kfree_skb(skb); |
341 | return ret; | |
342 | } | |
343 | ||
5b18f128 SS |
344 | /* Reset rt_iif so that inet_iif() will return skb->skb_iif. Setting |
345 | * this to non-zero causes ipi_ifindex in in_pktinfo to be overwritten, | |
346 | * see ipv4_pktinfo_prepare(). | |
347 | */ | |
348 | new_rt = rt_dst_clone(net->loopback_dev, skb_rtable(skb)); | |
349 | if (new_rt) { | |
350 | new_rt->rt_iif = 0; | |
351 | skb_dst_drop(skb); | |
352 | skb_dst_set(skb, &new_rt->dst); | |
353 | } | |
354 | ||
d96ff269 DM |
355 | err = dev_loopback_xmit(net, sk, skb); |
356 | return (do_cn && err) ? ret : err; | |
33b48679 DM |
357 | } |
358 | ||
ede2059d | 359 | int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 360 | { |
511c3f92 | 361 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 362 | struct net_device *dev = rt->dst.dev; |
1da177e4 LT |
363 | |
364 | /* | |
365 | * If the indicated interface is up and running, send the packet. | |
366 | */ | |
88f5cc24 | 367 | IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); |
1da177e4 LT |
368 | |
369 | skb->dev = dev; | |
370 | skb->protocol = htons(ETH_P_IP); | |
371 | ||
372 | /* | |
373 | * Multicasts are looped back for other local users | |
374 | */ | |
375 | ||
376 | if (rt->rt_flags&RTCF_MULTICAST) { | |
7ad6848c | 377 | if (sk_mc_loop(sk) |
1da177e4 LT |
378 | #ifdef CONFIG_IP_MROUTE |
379 | /* Small optimization: do not loopback not local frames, | |
380 | which returned after forwarding; they will be dropped | |
381 | by ip_mr_input in any case. | |
382 | Note, that local frames are looped back to be delivered | |
383 | to local recipients. | |
384 | ||
385 | This check is duplicated in ip_mr_input at the moment. | |
386 | */ | |
9d4fb27d JP |
387 | && |
388 | ((rt->rt_flags & RTCF_LOCAL) || | |
389 | !(IPCB(skb)->flags & IPSKB_FORWARDED)) | |
1da177e4 | 390 | #endif |
9d4fb27d | 391 | ) { |
1da177e4 LT |
392 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
393 | if (newskb) | |
9bbc768a | 394 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
29a26a56 | 395 | net, sk, newskb, NULL, newskb->dev, |
33b48679 | 396 | ip_mc_finish_output); |
1da177e4 LT |
397 | } |
398 | ||
399 | /* Multicasts with ttl 0 must not go beyond the host */ | |
400 | ||
eddc9ec5 | 401 | if (ip_hdr(skb)->ttl == 0) { |
1da177e4 LT |
402 | kfree_skb(skb); |
403 | return 0; | |
404 | } | |
405 | } | |
406 | ||
407 | if (rt->rt_flags&RTCF_BROADCAST) { | |
408 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
409 | if (newskb) | |
29a26a56 EB |
410 | NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
411 | net, sk, newskb, NULL, newskb->dev, | |
33b48679 | 412 | ip_mc_finish_output); |
1da177e4 LT |
413 | } |
414 | ||
29a26a56 EB |
415 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
416 | net, sk, skb, NULL, skb->dev, | |
417 | ip_finish_output, | |
48d5cad8 | 418 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
419 | } |
420 | ||
ede2059d | 421 | int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 422 | { |
28f8bfd1 | 423 | struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev; |
1bd9bef6 | 424 | |
88f5cc24 | 425 | IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); |
1da177e4 | 426 | |
1bd9bef6 PM |
427 | skb->dev = dev; |
428 | skb->protocol = htons(ETH_P_IP); | |
429 | ||
29a26a56 | 430 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
28f8bfd1 | 431 | net, sk, skb, indev, dev, |
e905a9ed | 432 | ip_finish_output, |
48d5cad8 | 433 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
1da177e4 LT |
434 | } |
435 | ||
84f9307c ED |
436 | /* |
437 | * copy saddr and daddr, possibly using 64bit load/stores | |
438 | * Equivalent to : | |
439 | * iph->saddr = fl4->saddr; | |
440 | * iph->daddr = fl4->daddr; | |
441 | */ | |
442 | static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4) | |
443 | { | |
444 | BUILD_BUG_ON(offsetof(typeof(*fl4), daddr) != | |
445 | offsetof(typeof(*fl4), saddr) + sizeof(fl4->saddr)); | |
446 | memcpy(&iph->saddr, &fl4->saddr, | |
447 | sizeof(fl4->saddr) + sizeof(fl4->daddr)); | |
448 | } | |
449 | ||
b0270e91 | 450 | /* Note: skb->sk can be different from sk, in case of tunnels */ |
69b9e1e0 XL |
451 | int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, |
452 | __u8 tos) | |
1da177e4 | 453 | { |
1da177e4 | 454 | struct inet_sock *inet = inet_sk(sk); |
77589ce0 | 455 | struct net *net = sock_net(sk); |
f6d8bd05 | 456 | struct ip_options_rcu *inet_opt; |
b57ae01a | 457 | struct flowi4 *fl4; |
1da177e4 LT |
458 | struct rtable *rt; |
459 | struct iphdr *iph; | |
ab6e3feb | 460 | int res; |
1da177e4 LT |
461 | |
462 | /* Skip all of this if the packet is already routed, | |
463 | * f.e. by something like SCTP. | |
464 | */ | |
ab6e3feb | 465 | rcu_read_lock(); |
f6d8bd05 | 466 | inet_opt = rcu_dereference(inet->inet_opt); |
ea4fc0d6 | 467 | fl4 = &fl->u.ip4; |
511c3f92 | 468 | rt = skb_rtable(skb); |
00db4124 | 469 | if (rt) |
1da177e4 LT |
470 | goto packet_routed; |
471 | ||
472 | /* Make sure we can route this packet. */ | |
473 | rt = (struct rtable *)__sk_dst_check(sk, 0); | |
51456b29 | 474 | if (!rt) { |
3ca3c68e | 475 | __be32 daddr; |
1da177e4 LT |
476 | |
477 | /* Use correct destination address if we have options. */ | |
c720c7e8 | 478 | daddr = inet->inet_daddr; |
f6d8bd05 ED |
479 | if (inet_opt && inet_opt->opt.srr) |
480 | daddr = inet_opt->opt.faddr; | |
1da177e4 | 481 | |
78fbfd8a DM |
482 | /* If this fails, retransmit mechanism of transport layer will |
483 | * keep trying until route appears or the connection times | |
484 | * itself out. | |
485 | */ | |
77589ce0 | 486 | rt = ip_route_output_ports(net, fl4, sk, |
78fbfd8a DM |
487 | daddr, inet->inet_saddr, |
488 | inet->inet_dport, | |
489 | inet->inet_sport, | |
490 | sk->sk_protocol, | |
69b9e1e0 | 491 | RT_CONN_FLAGS_TOS(sk, tos), |
78fbfd8a DM |
492 | sk->sk_bound_dev_if); |
493 | if (IS_ERR(rt)) | |
494 | goto no_route; | |
d8d1f30b | 495 | sk_setup_caps(sk, &rt->dst); |
1da177e4 | 496 | } |
d8d1f30b | 497 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
498 | |
499 | packet_routed: | |
77d5bc7e | 500 | if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_uses_gateway) |
1da177e4 LT |
501 | goto no_route; |
502 | ||
503 | /* OK, we know where to send it, allocate and build IP header. */ | |
f6d8bd05 | 504 | skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0)); |
8856dfa3 | 505 | skb_reset_network_header(skb); |
eddc9ec5 | 506 | iph = ip_hdr(skb); |
69b9e1e0 | 507 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (tos & 0xff)); |
60ff7467 | 508 | if (ip_dont_fragment(sk, &rt->dst) && !skb->ignore_df) |
1da177e4 LT |
509 | iph->frag_off = htons(IP_DF); |
510 | else | |
511 | iph->frag_off = 0; | |
d8d1f30b | 512 | iph->ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 | 513 | iph->protocol = sk->sk_protocol; |
84f9307c ED |
514 | ip_copy_addrs(iph, fl4); |
515 | ||
1da177e4 LT |
516 | /* Transport layer set skb->h.foo itself. */ |
517 | ||
f6d8bd05 ED |
518 | if (inet_opt && inet_opt->opt.optlen) { |
519 | iph->ihl += inet_opt->opt.optlen >> 2; | |
520 | ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); | |
1da177e4 LT |
521 | } |
522 | ||
77589ce0 | 523 | ip_select_ident_segs(net, skb, sk, |
b6a7719a | 524 | skb_shinfo(skb)->gso_segs ?: 1); |
1da177e4 | 525 | |
b0270e91 | 526 | /* TODO : should we use skb->sk here instead of sk ? */ |
1da177e4 | 527 | skb->priority = sk->sk_priority; |
4a19ec58 | 528 | skb->mark = sk->sk_mark; |
1da177e4 | 529 | |
33224b16 | 530 | res = ip_local_out(net, sk, skb); |
ab6e3feb ED |
531 | rcu_read_unlock(); |
532 | return res; | |
1da177e4 LT |
533 | |
534 | no_route: | |
ab6e3feb | 535 | rcu_read_unlock(); |
77589ce0 | 536 | IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); |
1da177e4 LT |
537 | kfree_skb(skb); |
538 | return -EHOSTUNREACH; | |
539 | } | |
69b9e1e0 | 540 | EXPORT_SYMBOL(__ip_queue_xmit); |
1da177e4 | 541 | |
1da177e4 LT |
542 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) |
543 | { | |
544 | to->pkt_type = from->pkt_type; | |
545 | to->priority = from->priority; | |
546 | to->protocol = from->protocol; | |
d2f0c961 | 547 | to->skb_iif = from->skb_iif; |
adf30907 | 548 | skb_dst_drop(to); |
fe76cda3 | 549 | skb_dst_copy(to, from); |
1da177e4 | 550 | to->dev = from->dev; |
82e91ffe | 551 | to->mark = from->mark; |
1da177e4 | 552 | |
3dd1c9a1 PA |
553 | skb_copy_hash(to, from); |
554 | ||
1da177e4 LT |
555 | #ifdef CONFIG_NET_SCHED |
556 | to->tc_index = from->tc_index; | |
557 | #endif | |
e7ac05f3 | 558 | nf_copy(to, from); |
df5042f4 | 559 | skb_ext_copy(to, from); |
6ca40d4e | 560 | #if IS_ENABLED(CONFIG_IP_VS) |
c98d80ed | 561 | to->ipvs_property = from->ipvs_property; |
1da177e4 | 562 | #endif |
984bc16c | 563 | skb_copy_secmark(to, from); |
1da177e4 LT |
564 | } |
565 | ||
694869b3 | 566 | static int ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
c5501eb3 | 567 | unsigned int mtu, |
694869b3 | 568 | int (*output)(struct net *, struct sock *, struct sk_buff *)) |
49d16b23 AZ |
569 | { |
570 | struct iphdr *iph = ip_hdr(skb); | |
49d16b23 | 571 | |
d6b915e2 | 572 | if ((iph->frag_off & htons(IP_DF)) == 0) |
694869b3 | 573 | return ip_do_fragment(net, sk, skb, output); |
d6b915e2 FW |
574 | |
575 | if (unlikely(!skb->ignore_df || | |
49d16b23 AZ |
576 | (IPCB(skb)->frag_max_size && |
577 | IPCB(skb)->frag_max_size > mtu))) { | |
9479b0af | 578 | IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); |
49d16b23 AZ |
579 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
580 | htonl(mtu)); | |
581 | kfree_skb(skb); | |
582 | return -EMSGSIZE; | |
583 | } | |
584 | ||
694869b3 | 585 | return ip_do_fragment(net, sk, skb, output); |
49d16b23 AZ |
586 | } |
587 | ||
c8b17be0 PNA |
588 | void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, |
589 | unsigned int hlen, struct ip_fraglist_iter *iter) | |
590 | { | |
591 | unsigned int first_len = skb_pagelen(skb); | |
592 | ||
b7034146 | 593 | iter->frag = skb_shinfo(skb)->frag_list; |
c8b17be0 PNA |
594 | skb_frag_list_init(skb); |
595 | ||
596 | iter->offset = 0; | |
597 | iter->iph = iph; | |
598 | iter->hlen = hlen; | |
599 | ||
600 | skb->data_len = first_len - skb_headlen(skb); | |
601 | skb->len = first_len; | |
602 | iph->tot_len = htons(first_len); | |
603 | iph->frag_off = htons(IP_MF); | |
604 | ip_send_check(iph); | |
605 | } | |
606 | EXPORT_SYMBOL(ip_fraglist_init); | |
607 | ||
19c3401a PNA |
608 | static void ip_fraglist_ipcb_prepare(struct sk_buff *skb, |
609 | struct ip_fraglist_iter *iter) | |
610 | { | |
611 | struct sk_buff *to = iter->frag; | |
612 | ||
613 | /* Copy the flags to each fragment. */ | |
614 | IPCB(to)->flags = IPCB(skb)->flags; | |
615 | ||
616 | if (iter->offset == 0) | |
617 | ip_options_fragment(to); | |
618 | } | |
619 | ||
c8b17be0 PNA |
620 | void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter) |
621 | { | |
622 | unsigned int hlen = iter->hlen; | |
623 | struct iphdr *iph = iter->iph; | |
624 | struct sk_buff *frag; | |
625 | ||
626 | frag = iter->frag; | |
627 | frag->ip_summed = CHECKSUM_NONE; | |
628 | skb_reset_transport_header(frag); | |
629 | __skb_push(frag, hlen); | |
630 | skb_reset_network_header(frag); | |
631 | memcpy(skb_network_header(frag), iph, hlen); | |
632 | iter->iph = ip_hdr(frag); | |
633 | iph = iter->iph; | |
634 | iph->tot_len = htons(frag->len); | |
635 | ip_copy_metadata(frag, skb); | |
c8b17be0 PNA |
636 | iter->offset += skb->len - hlen; |
637 | iph->frag_off = htons(iter->offset >> 3); | |
638 | if (frag->next) | |
639 | iph->frag_off |= htons(IP_MF); | |
640 | /* Ready, complete checksum */ | |
641 | ip_send_check(iph); | |
642 | } | |
643 | EXPORT_SYMBOL(ip_fraglist_prepare); | |
644 | ||
065ff79f | 645 | void ip_frag_init(struct sk_buff *skb, unsigned int hlen, |
e7a409c3 | 646 | unsigned int ll_rs, unsigned int mtu, bool DF, |
065ff79f PNA |
647 | struct ip_frag_state *state) |
648 | { | |
649 | struct iphdr *iph = ip_hdr(skb); | |
650 | ||
e7a409c3 | 651 | state->DF = DF; |
065ff79f PNA |
652 | state->hlen = hlen; |
653 | state->ll_rs = ll_rs; | |
654 | state->mtu = mtu; | |
655 | ||
656 | state->left = skb->len - hlen; /* Space per frame */ | |
657 | state->ptr = hlen; /* Where to start from */ | |
658 | ||
659 | state->offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; | |
660 | state->not_last_frag = iph->frag_off & htons(IP_MF); | |
661 | } | |
662 | EXPORT_SYMBOL(ip_frag_init); | |
663 | ||
19c3401a PNA |
664 | static void ip_frag_ipcb(struct sk_buff *from, struct sk_buff *to, |
665 | bool first_frag, struct ip_frag_state *state) | |
666 | { | |
667 | /* Copy the flags to each fragment. */ | |
668 | IPCB(to)->flags = IPCB(from)->flags; | |
669 | ||
19c3401a PNA |
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 (first_frag) | |
677 | ip_options_fragment(from); | |
678 | } | |
679 | ||
065ff79f PNA |
680 | struct sk_buff *ip_frag_next(struct sk_buff *skb, struct ip_frag_state *state) |
681 | { | |
682 | unsigned int len = state->left; | |
683 | struct sk_buff *skb2; | |
684 | struct iphdr *iph; | |
685 | ||
686 | len = state->left; | |
687 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
688 | if (len > state->mtu) | |
689 | len = state->mtu; | |
690 | /* IF: we are not sending up to and including the packet end | |
691 | then align the next start on an eight byte boundary */ | |
692 | if (len < state->left) { | |
693 | len &= ~7; | |
694 | } | |
695 | ||
696 | /* Allocate buffer */ | |
697 | skb2 = alloc_skb(len + state->hlen + state->ll_rs, GFP_ATOMIC); | |
698 | if (!skb2) | |
699 | return ERR_PTR(-ENOMEM); | |
700 | ||
701 | /* | |
702 | * Set up data on packet | |
703 | */ | |
704 | ||
705 | ip_copy_metadata(skb2, skb); | |
706 | skb_reserve(skb2, state->ll_rs); | |
707 | skb_put(skb2, len + state->hlen); | |
708 | skb_reset_network_header(skb2); | |
709 | skb2->transport_header = skb2->network_header + state->hlen; | |
710 | ||
711 | /* | |
712 | * Charge the memory for the fragment to any owner | |
713 | * it might possess | |
714 | */ | |
715 | ||
716 | if (skb->sk) | |
717 | skb_set_owner_w(skb2, skb->sk); | |
718 | ||
719 | /* | |
720 | * Copy the packet header into the new buffer. | |
721 | */ | |
722 | ||
723 | skb_copy_from_linear_data(skb, skb_network_header(skb2), state->hlen); | |
724 | ||
725 | /* | |
726 | * Copy a block of the IP datagram. | |
727 | */ | |
728 | if (skb_copy_bits(skb, state->ptr, skb_transport_header(skb2), len)) | |
729 | BUG(); | |
730 | state->left -= len; | |
731 | ||
732 | /* | |
733 | * Fill in the new header fields. | |
734 | */ | |
735 | iph = ip_hdr(skb2); | |
736 | iph->frag_off = htons((state->offset >> 3)); | |
e7a409c3 ED |
737 | if (state->DF) |
738 | iph->frag_off |= htons(IP_DF); | |
065ff79f | 739 | |
065ff79f PNA |
740 | /* |
741 | * Added AC : If we are fragmenting a fragment that's not the | |
742 | * last fragment then keep MF on each bit | |
743 | */ | |
744 | if (state->left > 0 || state->not_last_frag) | |
745 | iph->frag_off |= htons(IP_MF); | |
746 | state->ptr += len; | |
747 | state->offset += len; | |
748 | ||
749 | iph->tot_len = htons(len + state->hlen); | |
750 | ||
751 | ip_send_check(iph); | |
752 | ||
753 | return skb2; | |
754 | } | |
755 | EXPORT_SYMBOL(ip_frag_next); | |
756 | ||
1da177e4 LT |
757 | /* |
758 | * This IP datagram is too large to be sent in one piece. Break it up into | |
759 | * smaller pieces (each of size equal to IP header plus | |
760 | * a block of the data of the original IP data part) that will yet fit in a | |
761 | * single device frame, and queue such a frame for sending. | |
762 | */ | |
763 | ||
694869b3 EB |
764 | int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
765 | int (*output)(struct net *, struct sock *, struct sk_buff *)) | |
1da177e4 LT |
766 | { |
767 | struct iphdr *iph; | |
1da177e4 | 768 | struct sk_buff *skb2; |
511c3f92 | 769 | struct rtable *rt = skb_rtable(skb); |
065ff79f | 770 | unsigned int mtu, hlen, ll_rs; |
c8b17be0 | 771 | struct ip_fraglist_iter iter; |
9669fffc | 772 | ktime_t tstamp = skb->tstamp; |
065ff79f | 773 | struct ip_frag_state state; |
1da177e4 LT |
774 | int err = 0; |
775 | ||
dbd3393c HFS |
776 | /* for offloaded checksums cleanup checksum before fragmentation */ |
777 | if (skb->ip_summed == CHECKSUM_PARTIAL && | |
778 | (err = skb_checksum_help(skb))) | |
779 | goto fail; | |
780 | ||
1da177e4 LT |
781 | /* |
782 | * Point into the IP datagram header. | |
783 | */ | |
784 | ||
eddc9ec5 | 785 | iph = ip_hdr(skb); |
1da177e4 | 786 | |
fedbb6b4 | 787 | mtu = ip_skb_dst_mtu(sk, skb); |
d6b915e2 FW |
788 | if (IPCB(skb)->frag_max_size && IPCB(skb)->frag_max_size < mtu) |
789 | mtu = IPCB(skb)->frag_max_size; | |
1da177e4 LT |
790 | |
791 | /* | |
792 | * Setup starting values. | |
793 | */ | |
794 | ||
795 | hlen = iph->ihl * 4; | |
f87c10a8 | 796 | mtu = mtu - hlen; /* Size of data space */ |
89cee8b1 | 797 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
254d900b | 798 | ll_rs = LL_RESERVED_SPACE(rt->dst.dev); |
1da177e4 LT |
799 | |
800 | /* When frag_list is given, use it. First, check its validity: | |
801 | * some transformers could create wrong frag_list or break existing | |
802 | * one, it is not prohibited. In this case fall back to copying. | |
803 | * | |
804 | * LATER: this step can be merged to real generation of fragments, | |
805 | * we can switch to copy when see the first bad fragment. | |
806 | */ | |
21dc3301 | 807 | if (skb_has_frag_list(skb)) { |
3d13008e | 808 | struct sk_buff *frag, *frag2; |
c72d8cda | 809 | unsigned int first_len = skb_pagelen(skb); |
1da177e4 LT |
810 | |
811 | if (first_len - hlen > mtu || | |
812 | ((first_len - hlen) & 7) || | |
56f8a75c | 813 | ip_is_fragment(iph) || |
254d900b VA |
814 | skb_cloned(skb) || |
815 | skb_headroom(skb) < ll_rs) | |
1da177e4 LT |
816 | goto slow_path; |
817 | ||
d7fcf1a5 | 818 | skb_walk_frags(skb, frag) { |
1da177e4 LT |
819 | /* Correct geometry. */ |
820 | if (frag->len > mtu || | |
821 | ((frag->len & 7) && frag->next) || | |
254d900b | 822 | skb_headroom(frag) < hlen + ll_rs) |
3d13008e | 823 | goto slow_path_clean; |
1da177e4 LT |
824 | |
825 | /* Partially cloned skb? */ | |
826 | if (skb_shared(frag)) | |
3d13008e | 827 | goto slow_path_clean; |
2fdba6b0 HX |
828 | |
829 | BUG_ON(frag->sk); | |
830 | if (skb->sk) { | |
2fdba6b0 HX |
831 | frag->sk = skb->sk; |
832 | frag->destructor = sock_wfree; | |
2fdba6b0 | 833 | } |
3d13008e | 834 | skb->truesize -= frag->truesize; |
1da177e4 LT |
835 | } |
836 | ||
837 | /* Everything is OK. Generate! */ | |
c8b17be0 | 838 | ip_fraglist_init(skb, iph, hlen, &iter); |
1da177e4 LT |
839 | |
840 | for (;;) { | |
841 | /* Prepare header of the next frame, | |
842 | * before previous one went down. */ | |
19c3401a PNA |
843 | if (iter.frag) { |
844 | ip_fraglist_ipcb_prepare(skb, &iter); | |
c8b17be0 | 845 | ip_fraglist_prepare(skb, &iter); |
19c3401a | 846 | } |
1da177e4 | 847 | |
9669fffc | 848 | skb->tstamp = tstamp; |
694869b3 | 849 | err = output(net, sk, skb); |
1da177e4 | 850 | |
dafee490 | 851 | if (!err) |
26a949db | 852 | IP_INC_STATS(net, IPSTATS_MIB_FRAGCREATES); |
c8b17be0 | 853 | if (err || !iter.frag) |
1da177e4 LT |
854 | break; |
855 | ||
c8b17be0 | 856 | skb = ip_fraglist_next(&iter); |
1da177e4 LT |
857 | } |
858 | ||
859 | if (err == 0) { | |
26a949db | 860 | IP_INC_STATS(net, IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
861 | return 0; |
862 | } | |
863 | ||
b7034146 | 864 | kfree_skb_list(iter.frag); |
942f146a | 865 | |
26a949db | 866 | IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); |
1da177e4 | 867 | return err; |
3d13008e ED |
868 | |
869 | slow_path_clean: | |
870 | skb_walk_frags(skb, frag2) { | |
871 | if (frag2 == frag) | |
872 | break; | |
873 | frag2->sk = NULL; | |
874 | frag2->destructor = NULL; | |
875 | skb->truesize += frag2->truesize; | |
876 | } | |
1da177e4 LT |
877 | } |
878 | ||
879 | slow_path: | |
1da177e4 LT |
880 | /* |
881 | * Fragment the datagram. | |
882 | */ | |
883 | ||
e7a409c3 ED |
884 | ip_frag_init(skb, hlen, ll_rs, mtu, IPCB(skb)->flags & IPSKB_FRAG_PMTU, |
885 | &state); | |
1da177e4 LT |
886 | |
887 | /* | |
888 | * Keep copying data until we run out. | |
889 | */ | |
890 | ||
065ff79f | 891 | while (state.left > 0) { |
19c3401a PNA |
892 | bool first_frag = (state.offset == 0); |
893 | ||
065ff79f PNA |
894 | skb2 = ip_frag_next(skb, &state); |
895 | if (IS_ERR(skb2)) { | |
896 | err = PTR_ERR(skb2); | |
1da177e4 LT |
897 | goto fail; |
898 | } | |
19c3401a | 899 | ip_frag_ipcb(skb, skb2, first_frag, &state); |
1da177e4 | 900 | |
1da177e4 LT |
901 | /* |
902 | * Put this fragment into the sending queue. | |
903 | */ | |
9669fffc | 904 | skb2->tstamp = tstamp; |
694869b3 | 905 | err = output(net, sk, skb2); |
1da177e4 LT |
906 | if (err) |
907 | goto fail; | |
dafee490 | 908 | |
26a949db | 909 | IP_INC_STATS(net, IPSTATS_MIB_FRAGCREATES); |
1da177e4 | 910 | } |
5d0ba55b | 911 | consume_skb(skb); |
26a949db | 912 | IP_INC_STATS(net, IPSTATS_MIB_FRAGOKS); |
1da177e4 LT |
913 | return err; |
914 | ||
915 | fail: | |
e905a9ed | 916 | kfree_skb(skb); |
26a949db | 917 | IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); |
1da177e4 LT |
918 | return err; |
919 | } | |
49d16b23 | 920 | EXPORT_SYMBOL(ip_do_fragment); |
2e2f7aef | 921 | |
1da177e4 LT |
922 | int |
923 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
924 | { | |
f69e6d13 | 925 | struct msghdr *msg = from; |
1da177e4 | 926 | |
84fa7933 | 927 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
0b62fca2 | 928 | if (!copy_from_iter_full(to, len, &msg->msg_iter)) |
1da177e4 LT |
929 | return -EFAULT; |
930 | } else { | |
44bb9363 | 931 | __wsum csum = 0; |
0b62fca2 | 932 | if (!csum_and_copy_from_iter_full(to, len, &csum, &msg->msg_iter)) |
1da177e4 LT |
933 | return -EFAULT; |
934 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
935 | } | |
936 | return 0; | |
937 | } | |
4bc2f18b | 938 | EXPORT_SYMBOL(ip_generic_getfrag); |
1da177e4 | 939 | |
44bb9363 | 940 | static inline __wsum |
1da177e4 LT |
941 | csum_page(struct page *page, int offset, int copy) |
942 | { | |
943 | char *kaddr; | |
44bb9363 | 944 | __wsum csum; |
1da177e4 LT |
945 | kaddr = kmap(page); |
946 | csum = csum_partial(kaddr + offset, copy, 0); | |
947 | kunmap(page); | |
948 | return csum; | |
949 | } | |
950 | ||
f5fca608 DM |
951 | static int __ip_append_data(struct sock *sk, |
952 | struct flowi4 *fl4, | |
953 | struct sk_buff_head *queue, | |
1470ddf7 | 954 | struct inet_cork *cork, |
5640f768 | 955 | struct page_frag *pfrag, |
1470ddf7 HX |
956 | int getfrag(void *from, char *to, int offset, |
957 | int len, int odd, struct sk_buff *skb), | |
958 | void *from, int length, int transhdrlen, | |
959 | unsigned int flags) | |
1da177e4 LT |
960 | { |
961 | struct inet_sock *inet = inet_sk(sk); | |
b5947e5d | 962 | struct ubuf_info *uarg = NULL; |
1da177e4 LT |
963 | struct sk_buff *skb; |
964 | ||
07df5294 | 965 | struct ip_options *opt = cork->opt; |
1da177e4 LT |
966 | int hh_len; |
967 | int exthdrlen; | |
968 | int mtu; | |
969 | int copy; | |
970 | int err; | |
971 | int offset = 0; | |
daba287b | 972 | unsigned int maxfraglen, fragheaderlen, maxnonfragsize; |
1da177e4 | 973 | int csummode = CHECKSUM_NONE; |
1470ddf7 | 974 | struct rtable *rt = (struct rtable *)cork->dst; |
694aba69 | 975 | unsigned int wmem_alloc_delta = 0; |
100f6d8e | 976 | bool paged, extra_uref = false; |
09c2d251 | 977 | u32 tskey = 0; |
1da177e4 | 978 | |
96d7303e SK |
979 | skb = skb_peek_tail(queue); |
980 | ||
981 | exthdrlen = !skb ? rt->dst.header_len : 0; | |
bec1f6f6 | 982 | mtu = cork->gso_size ? IP_MAX_MTU : cork->fragsize; |
15e36f5b | 983 | paged = !!cork->gso_size; |
bec1f6f6 | 984 | |
09c2d251 WB |
985 | if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && |
986 | sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) | |
987 | tskey = sk->sk_tskey++; | |
1da177e4 | 988 | |
d8d1f30b | 989 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
1da177e4 LT |
990 | |
991 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
992 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
60ff7467 | 993 | maxnonfragsize = ip_sk_ignore_df(sk) ? 0xFFFF : mtu; |
1da177e4 | 994 | |
daba287b | 995 | if (cork->length + length > maxnonfragsize - fragheaderlen) { |
f5fca608 | 996 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, |
61e7f09d | 997 | mtu - (opt ? opt->optlen : 0)); |
1da177e4 LT |
998 | return -EMSGSIZE; |
999 | } | |
1000 | ||
1001 | /* | |
1002 | * transhdrlen > 0 means that this is the first fragment and we wish | |
1003 | * it won't be fragmented in the future. | |
1004 | */ | |
1005 | if (transhdrlen && | |
1006 | length + fragheaderlen <= mtu && | |
c8cd0989 | 1007 | rt->dst.dev->features & (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM) && |
bec1f6f6 | 1008 | (!(flags & MSG_MORE) || cork->gso_size) && |
cd027a54 | 1009 | (!exthdrlen || (rt->dst.dev->features & NETIF_F_HW_ESP_TX_CSUM))) |
84fa7933 | 1010 | csummode = CHECKSUM_PARTIAL; |
1da177e4 | 1011 | |
b5947e5d WB |
1012 | if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { |
1013 | uarg = sock_zerocopy_realloc(sk, length, skb_zcopy(skb)); | |
1014 | if (!uarg) | |
1015 | return -ENOBUFS; | |
522924b5 | 1016 | extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ |
b5947e5d WB |
1017 | if (rt->dst.dev->features & NETIF_F_SG && |
1018 | csummode == CHECKSUM_PARTIAL) { | |
1019 | paged = true; | |
1020 | } else { | |
1021 | uarg->zerocopy = 0; | |
52900d22 | 1022 | skb_zcopy_set(skb, uarg, &extra_uref); |
b5947e5d WB |
1023 | } |
1024 | } | |
1025 | ||
1470ddf7 | 1026 | cork->length += length; |
1da177e4 LT |
1027 | |
1028 | /* So, what's going on in the loop below? | |
1029 | * | |
1030 | * We use calculated fragment length to generate chained skb, | |
1031 | * each of segments is IP fragment ready for sending to network after | |
1032 | * adding appropriate IP header. | |
1033 | */ | |
1034 | ||
26cde9f7 | 1035 | if (!skb) |
1da177e4 LT |
1036 | goto alloc_new_skb; |
1037 | ||
1038 | while (length > 0) { | |
1039 | /* Check if the remaining data fits into current packet. */ | |
1040 | copy = mtu - skb->len; | |
1041 | if (copy < length) | |
1042 | copy = maxfraglen - skb->len; | |
1043 | if (copy <= 0) { | |
1044 | char *data; | |
1045 | unsigned int datalen; | |
1046 | unsigned int fraglen; | |
1047 | unsigned int fraggap; | |
1048 | unsigned int alloclen; | |
aba36930 | 1049 | unsigned int pagedlen; |
1da177e4 LT |
1050 | struct sk_buff *skb_prev; |
1051 | alloc_new_skb: | |
1052 | skb_prev = skb; | |
1053 | if (skb_prev) | |
1054 | fraggap = skb_prev->len - maxfraglen; | |
1055 | else | |
1056 | fraggap = 0; | |
1057 | ||
1058 | /* | |
1059 | * If remaining data exceeds the mtu, | |
1060 | * we know we need more fragment(s). | |
1061 | */ | |
1062 | datalen = length + fraggap; | |
1063 | if (datalen > mtu - fragheaderlen) | |
1064 | datalen = maxfraglen - fragheaderlen; | |
1065 | fraglen = datalen + fragheaderlen; | |
aba36930 | 1066 | pagedlen = 0; |
1da177e4 | 1067 | |
e905a9ed | 1068 | if ((flags & MSG_MORE) && |
d8d1f30b | 1069 | !(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 | 1070 | alloclen = mtu; |
15e36f5b | 1071 | else if (!paged) |
59104f06 | 1072 | alloclen = fraglen; |
15e36f5b WB |
1073 | else { |
1074 | alloclen = min_t(int, fraglen, MAX_HEADER); | |
1075 | pagedlen = fraglen - alloclen; | |
1076 | } | |
1da177e4 | 1077 | |
353e5c9a SK |
1078 | alloclen += exthdrlen; |
1079 | ||
1da177e4 LT |
1080 | /* The last fragment gets additional space at tail. |
1081 | * Note, with MSG_MORE we overallocate on fragments, | |
1082 | * because we have no idea what fragment will be | |
1083 | * the last. | |
1084 | */ | |
33f99dc7 | 1085 | if (datalen == length + fraggap) |
d8d1f30b | 1086 | alloclen += rt->dst.trailer_len; |
33f99dc7 | 1087 | |
1da177e4 | 1088 | if (transhdrlen) { |
e905a9ed | 1089 | skb = sock_alloc_send_skb(sk, |
1da177e4 LT |
1090 | alloclen + hh_len + 15, |
1091 | (flags & MSG_DONTWAIT), &err); | |
1092 | } else { | |
1093 | skb = NULL; | |
694aba69 | 1094 | if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= |
1da177e4 | 1095 | 2 * sk->sk_sndbuf) |
694aba69 ED |
1096 | skb = alloc_skb(alloclen + hh_len + 15, |
1097 | sk->sk_allocation); | |
51456b29 | 1098 | if (unlikely(!skb)) |
1da177e4 LT |
1099 | err = -ENOBUFS; |
1100 | } | |
51456b29 | 1101 | if (!skb) |
1da177e4 LT |
1102 | goto error; |
1103 | ||
1104 | /* | |
1105 | * Fill in the control structures | |
1106 | */ | |
1107 | skb->ip_summed = csummode; | |
1108 | skb->csum = 0; | |
1109 | skb_reserve(skb, hh_len); | |
11878b40 | 1110 | |
1da177e4 LT |
1111 | /* |
1112 | * Find where to start putting bytes. | |
1113 | */ | |
15e36f5b | 1114 | data = skb_put(skb, fraglen + exthdrlen - pagedlen); |
c14d2450 | 1115 | skb_set_network_header(skb, exthdrlen); |
b0e380b1 ACM |
1116 | skb->transport_header = (skb->network_header + |
1117 | fragheaderlen); | |
353e5c9a | 1118 | data += fragheaderlen + exthdrlen; |
1da177e4 LT |
1119 | |
1120 | if (fraggap) { | |
1121 | skb->csum = skb_copy_and_csum_bits( | |
1122 | skb_prev, maxfraglen, | |
1123 | data + transhdrlen, fraggap, 0); | |
1124 | skb_prev->csum = csum_sub(skb_prev->csum, | |
1125 | skb->csum); | |
1126 | data += fraggap; | |
e9fa4f7b | 1127 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1128 | } |
1129 | ||
15e36f5b | 1130 | copy = datalen - transhdrlen - fraggap - pagedlen; |
1da177e4 LT |
1131 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { |
1132 | err = -EFAULT; | |
1133 | kfree_skb(skb); | |
1134 | goto error; | |
1135 | } | |
1136 | ||
1137 | offset += copy; | |
15e36f5b | 1138 | length -= copy + transhdrlen; |
1da177e4 LT |
1139 | transhdrlen = 0; |
1140 | exthdrlen = 0; | |
1141 | csummode = CHECKSUM_NONE; | |
1142 | ||
52900d22 WB |
1143 | /* only the initial fragment is time stamped */ |
1144 | skb_shinfo(skb)->tx_flags = cork->tx_flags; | |
1145 | cork->tx_flags = 0; | |
1146 | skb_shinfo(skb)->tskey = tskey; | |
1147 | tskey = 0; | |
1148 | skb_zcopy_set(skb, uarg, &extra_uref); | |
1149 | ||
0dec879f JA |
1150 | if ((flags & MSG_CONFIRM) && !skb_prev) |
1151 | skb_set_dst_pending_confirm(skb, 1); | |
1152 | ||
1da177e4 LT |
1153 | /* |
1154 | * Put the packet on the pending queue. | |
1155 | */ | |
694aba69 ED |
1156 | if (!skb->destructor) { |
1157 | skb->destructor = sock_wfree; | |
1158 | skb->sk = sk; | |
1159 | wmem_alloc_delta += skb->truesize; | |
1160 | } | |
1470ddf7 | 1161 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
1162 | continue; |
1163 | } | |
1164 | ||
1165 | if (copy > length) | |
1166 | copy = length; | |
1167 | ||
113f99c3 WB |
1168 | if (!(rt->dst.dev->features&NETIF_F_SG) && |
1169 | skb_tailroom(skb) >= copy) { | |
1da177e4 LT |
1170 | unsigned int off; |
1171 | ||
1172 | off = skb->len; | |
e905a9ed | 1173 | if (getfrag(from, skb_put(skb, copy), |
1da177e4 LT |
1174 | offset, copy, off, skb) < 0) { |
1175 | __skb_trim(skb, off); | |
1176 | err = -EFAULT; | |
1177 | goto error; | |
1178 | } | |
b5947e5d | 1179 | } else if (!uarg || !uarg->zerocopy) { |
1da177e4 | 1180 | int i = skb_shinfo(skb)->nr_frags; |
1da177e4 | 1181 | |
5640f768 ED |
1182 | err = -ENOMEM; |
1183 | if (!sk_page_frag_refill(sk, pfrag)) | |
1da177e4 | 1184 | goto error; |
5640f768 ED |
1185 | |
1186 | if (!skb_can_coalesce(skb, i, pfrag->page, | |
1187 | pfrag->offset)) { | |
1188 | err = -EMSGSIZE; | |
1189 | if (i == MAX_SKB_FRAGS) | |
1190 | goto error; | |
1191 | ||
1192 | __skb_fill_page_desc(skb, i, pfrag->page, | |
1193 | pfrag->offset, 0); | |
1194 | skb_shinfo(skb)->nr_frags = ++i; | |
1195 | get_page(pfrag->page); | |
1da177e4 | 1196 | } |
5640f768 ED |
1197 | copy = min_t(int, copy, pfrag->size - pfrag->offset); |
1198 | if (getfrag(from, | |
1199 | page_address(pfrag->page) + pfrag->offset, | |
1200 | offset, copy, skb->len, skb) < 0) | |
1201 | goto error_efault; | |
1202 | ||
1203 | pfrag->offset += copy; | |
1204 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); | |
1da177e4 LT |
1205 | skb->len += copy; |
1206 | skb->data_len += copy; | |
f945fa7a | 1207 | skb->truesize += copy; |
694aba69 | 1208 | wmem_alloc_delta += copy; |
b5947e5d WB |
1209 | } else { |
1210 | err = skb_zerocopy_iter_dgram(skb, from, copy); | |
1211 | if (err < 0) | |
1212 | goto error; | |
1da177e4 LT |
1213 | } |
1214 | offset += copy; | |
1215 | length -= copy; | |
1216 | } | |
1217 | ||
9e8445a5 PA |
1218 | if (wmem_alloc_delta) |
1219 | refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); | |
1da177e4 LT |
1220 | return 0; |
1221 | ||
5640f768 ED |
1222 | error_efault: |
1223 | err = -EFAULT; | |
1da177e4 | 1224 | error: |
97ef7b4c WB |
1225 | if (uarg) |
1226 | sock_zerocopy_put_abort(uarg, extra_uref); | |
1470ddf7 | 1227 | cork->length -= length; |
5e38e270 | 1228 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
694aba69 | 1229 | refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); |
e905a9ed | 1230 | return err; |
1da177e4 LT |
1231 | } |
1232 | ||
1470ddf7 HX |
1233 | static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, |
1234 | struct ipcm_cookie *ipc, struct rtable **rtp) | |
1235 | { | |
f6d8bd05 | 1236 | struct ip_options_rcu *opt; |
1470ddf7 HX |
1237 | struct rtable *rt; |
1238 | ||
9783ccd0 GF |
1239 | rt = *rtp; |
1240 | if (unlikely(!rt)) | |
1241 | return -EFAULT; | |
1242 | ||
1470ddf7 HX |
1243 | /* |
1244 | * setup for corking. | |
1245 | */ | |
1246 | opt = ipc->opt; | |
1247 | if (opt) { | |
51456b29 | 1248 | if (!cork->opt) { |
1470ddf7 HX |
1249 | cork->opt = kmalloc(sizeof(struct ip_options) + 40, |
1250 | sk->sk_allocation); | |
51456b29 | 1251 | if (unlikely(!cork->opt)) |
1470ddf7 HX |
1252 | return -ENOBUFS; |
1253 | } | |
f6d8bd05 | 1254 | memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen); |
1470ddf7 HX |
1255 | cork->flags |= IPCORK_OPT; |
1256 | cork->addr = ipc->addr; | |
1257 | } | |
9783ccd0 | 1258 | |
482fc609 | 1259 | cork->fragsize = ip_sk_use_pmtu(sk) ? |
501a90c9 ED |
1260 | dst_mtu(&rt->dst) : READ_ONCE(rt->dst.dev->mtu); |
1261 | ||
1262 | if (!inetdev_valid_mtu(cork->fragsize)) | |
1263 | return -ENETUNREACH; | |
bec1f6f6 | 1264 | |
fbf47813 | 1265 | cork->gso_size = ipc->gso_size; |
501a90c9 | 1266 | |
1470ddf7 | 1267 | cork->dst = &rt->dst; |
501a90c9 ED |
1268 | /* We stole this route, caller should not release it. */ |
1269 | *rtp = NULL; | |
1270 | ||
1470ddf7 | 1271 | cork->length = 0; |
aa661581 FF |
1272 | cork->ttl = ipc->ttl; |
1273 | cork->tos = ipc->tos; | |
c6af0c22 | 1274 | cork->mark = ipc->sockc.mark; |
aa661581 | 1275 | cork->priority = ipc->priority; |
bc969a97 | 1276 | cork->transmit_time = ipc->sockc.transmit_time; |
678ca42d WB |
1277 | cork->tx_flags = 0; |
1278 | sock_tx_timestamp(sk, ipc->sockc.tsflags, &cork->tx_flags); | |
1470ddf7 HX |
1279 | |
1280 | return 0; | |
1281 | } | |
1282 | ||
1283 | /* | |
1284 | * ip_append_data() and ip_append_page() can make one large IP datagram | |
1285 | * from many pieces of data. Each pieces will be holded on the socket | |
1286 | * until ip_push_pending_frames() is called. Each piece can be a page | |
1287 | * or non-page data. | |
1288 | * | |
1289 | * Not only UDP, other transport protocols - e.g. raw sockets - can use | |
1290 | * this interface potentially. | |
1291 | * | |
1292 | * LATER: length must be adjusted by pad at tail, when it is required. | |
1293 | */ | |
f5fca608 | 1294 | int ip_append_data(struct sock *sk, struct flowi4 *fl4, |
1470ddf7 HX |
1295 | int getfrag(void *from, char *to, int offset, int len, |
1296 | int odd, struct sk_buff *skb), | |
1297 | void *from, int length, int transhdrlen, | |
1298 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1299 | unsigned int flags) | |
1300 | { | |
1301 | struct inet_sock *inet = inet_sk(sk); | |
1302 | int err; | |
1303 | ||
1304 | if (flags&MSG_PROBE) | |
1305 | return 0; | |
1306 | ||
1307 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
bdc712b4 | 1308 | err = ip_setup_cork(sk, &inet->cork.base, ipc, rtp); |
1470ddf7 HX |
1309 | if (err) |
1310 | return err; | |
1311 | } else { | |
1312 | transhdrlen = 0; | |
1313 | } | |
1314 | ||
5640f768 ED |
1315 | return __ip_append_data(sk, fl4, &sk->sk_write_queue, &inet->cork.base, |
1316 | sk_page_frag(sk), getfrag, | |
1470ddf7 HX |
1317 | from, length, transhdrlen, flags); |
1318 | } | |
1319 | ||
f5fca608 | 1320 | ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, |
1da177e4 LT |
1321 | int offset, size_t size, int flags) |
1322 | { | |
1323 | struct inet_sock *inet = inet_sk(sk); | |
1324 | struct sk_buff *skb; | |
1325 | struct rtable *rt; | |
1326 | struct ip_options *opt = NULL; | |
bdc712b4 | 1327 | struct inet_cork *cork; |
1da177e4 LT |
1328 | int hh_len; |
1329 | int mtu; | |
1330 | int len; | |
1331 | int err; | |
daba287b | 1332 | unsigned int maxfraglen, fragheaderlen, fraggap, maxnonfragsize; |
1da177e4 LT |
1333 | |
1334 | if (inet->hdrincl) | |
1335 | return -EPERM; | |
1336 | ||
1337 | if (flags&MSG_PROBE) | |
1338 | return 0; | |
1339 | ||
1340 | if (skb_queue_empty(&sk->sk_write_queue)) | |
1341 | return -EINVAL; | |
1342 | ||
bdc712b4 DM |
1343 | cork = &inet->cork.base; |
1344 | rt = (struct rtable *)cork->dst; | |
1345 | if (cork->flags & IPCORK_OPT) | |
1346 | opt = cork->opt; | |
1da177e4 | 1347 | |
d8d1f30b | 1348 | if (!(rt->dst.dev->features&NETIF_F_SG)) |
1da177e4 LT |
1349 | return -EOPNOTSUPP; |
1350 | ||
d8d1f30b | 1351 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
bec1f6f6 | 1352 | mtu = cork->gso_size ? IP_MAX_MTU : cork->fragsize; |
1da177e4 LT |
1353 | |
1354 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); | |
1355 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; | |
60ff7467 | 1356 | maxnonfragsize = ip_sk_ignore_df(sk) ? 0xFFFF : mtu; |
1da177e4 | 1357 | |
daba287b | 1358 | if (cork->length + size > maxnonfragsize - fragheaderlen) { |
61e7f09d HFS |
1359 | ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, |
1360 | mtu - (opt ? opt->optlen : 0)); | |
1da177e4 LT |
1361 | return -EMSGSIZE; |
1362 | } | |
1363 | ||
51456b29 IM |
1364 | skb = skb_peek_tail(&sk->sk_write_queue); |
1365 | if (!skb) | |
1da177e4 LT |
1366 | return -EINVAL; |
1367 | ||
a8c4a252 | 1368 | cork->length += size; |
e89e9cf5 | 1369 | |
1da177e4 | 1370 | while (size > 0) { |
ab2fb7e3 WB |
1371 | /* Check if the remaining data fits into current packet. */ |
1372 | len = mtu - skb->len; | |
1373 | if (len < size) | |
1374 | len = maxfraglen - skb->len; | |
e89e9cf5 | 1375 | |
1da177e4 LT |
1376 | if (len <= 0) { |
1377 | struct sk_buff *skb_prev; | |
1da177e4 LT |
1378 | int alloclen; |
1379 | ||
1380 | skb_prev = skb; | |
0d0d2bba | 1381 | fraggap = skb_prev->len - maxfraglen; |
1da177e4 LT |
1382 | |
1383 | alloclen = fragheaderlen + hh_len + fraggap + 15; | |
1384 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); | |
1385 | if (unlikely(!skb)) { | |
1386 | err = -ENOBUFS; | |
1387 | goto error; | |
1388 | } | |
1389 | ||
1390 | /* | |
1391 | * Fill in the control structures | |
1392 | */ | |
1393 | skb->ip_summed = CHECKSUM_NONE; | |
1394 | skb->csum = 0; | |
1395 | skb_reserve(skb, hh_len); | |
1396 | ||
1397 | /* | |
1398 | * Find where to start putting bytes. | |
1399 | */ | |
967b05f6 | 1400 | skb_put(skb, fragheaderlen + fraggap); |
2ca9e6f2 | 1401 | skb_reset_network_header(skb); |
b0e380b1 ACM |
1402 | skb->transport_header = (skb->network_header + |
1403 | fragheaderlen); | |
1da177e4 | 1404 | if (fraggap) { |
967b05f6 ACM |
1405 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
1406 | maxfraglen, | |
9c70220b | 1407 | skb_transport_header(skb), |
967b05f6 | 1408 | fraggap, 0); |
1da177e4 LT |
1409 | skb_prev->csum = csum_sub(skb_prev->csum, |
1410 | skb->csum); | |
e9fa4f7b | 1411 | pskb_trim_unique(skb_prev, maxfraglen); |
1da177e4 LT |
1412 | } |
1413 | ||
1414 | /* | |
1415 | * Put the packet on the pending queue. | |
1416 | */ | |
1417 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1418 | continue; | |
1419 | } | |
1420 | ||
1da177e4 LT |
1421 | if (len > size) |
1422 | len = size; | |
be12a1fe HFS |
1423 | |
1424 | if (skb_append_pagefrags(skb, page, offset, len)) { | |
1da177e4 LT |
1425 | err = -EMSGSIZE; |
1426 | goto error; | |
1427 | } | |
1428 | ||
1429 | if (skb->ip_summed == CHECKSUM_NONE) { | |
44bb9363 | 1430 | __wsum csum; |
1da177e4 LT |
1431 | csum = csum_page(page, offset, len); |
1432 | skb->csum = csum_block_add(skb->csum, csum, skb->len); | |
1433 | } | |
1434 | ||
1435 | skb->len += len; | |
1436 | skb->data_len += len; | |
1e34a11d | 1437 | skb->truesize += len; |
14afee4b | 1438 | refcount_add(len, &sk->sk_wmem_alloc); |
1da177e4 LT |
1439 | offset += len; |
1440 | size -= len; | |
1441 | } | |
1442 | return 0; | |
1443 | ||
1444 | error: | |
bdc712b4 | 1445 | cork->length -= size; |
5e38e270 | 1446 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1447 | return err; |
1448 | } | |
1449 | ||
1470ddf7 | 1450 | static void ip_cork_release(struct inet_cork *cork) |
429f08e9 | 1451 | { |
1470ddf7 HX |
1452 | cork->flags &= ~IPCORK_OPT; |
1453 | kfree(cork->opt); | |
1454 | cork->opt = NULL; | |
1455 | dst_release(cork->dst); | |
1456 | cork->dst = NULL; | |
429f08e9 PE |
1457 | } |
1458 | ||
1da177e4 LT |
1459 | /* |
1460 | * Combined all pending IP fragments on the socket as one IP datagram | |
1461 | * and push them out. | |
1462 | */ | |
1c32c5ad | 1463 | struct sk_buff *__ip_make_skb(struct sock *sk, |
77968b78 | 1464 | struct flowi4 *fl4, |
1c32c5ad HX |
1465 | struct sk_buff_head *queue, |
1466 | struct inet_cork *cork) | |
1da177e4 LT |
1467 | { |
1468 | struct sk_buff *skb, *tmp_skb; | |
1469 | struct sk_buff **tail_skb; | |
1470 | struct inet_sock *inet = inet_sk(sk); | |
0388b004 | 1471 | struct net *net = sock_net(sk); |
1da177e4 | 1472 | struct ip_options *opt = NULL; |
1470ddf7 | 1473 | struct rtable *rt = (struct rtable *)cork->dst; |
1da177e4 | 1474 | struct iphdr *iph; |
76ab608d | 1475 | __be16 df = 0; |
1da177e4 | 1476 | __u8 ttl; |
1da177e4 | 1477 | |
51456b29 IM |
1478 | skb = __skb_dequeue(queue); |
1479 | if (!skb) | |
1da177e4 LT |
1480 | goto out; |
1481 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1482 | ||
1483 | /* move skb->data to ip header from ext header */ | |
d56f90a7 | 1484 | if (skb->data < skb_network_header(skb)) |
bbe735e4 | 1485 | __skb_pull(skb, skb_network_offset(skb)); |
1470ddf7 | 1486 | while ((tmp_skb = __skb_dequeue(queue)) != NULL) { |
cfe1fc77 | 1487 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1da177e4 LT |
1488 | *tail_skb = tmp_skb; |
1489 | tail_skb = &(tmp_skb->next); | |
1490 | skb->len += tmp_skb->len; | |
1491 | skb->data_len += tmp_skb->len; | |
1492 | skb->truesize += tmp_skb->truesize; | |
1da177e4 LT |
1493 | tmp_skb->destructor = NULL; |
1494 | tmp_skb->sk = NULL; | |
1495 | } | |
1496 | ||
1497 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow | |
1498 | * to fragment the frame generated here. No matter, what transforms | |
1499 | * how transforms change size of the packet, it will come out. | |
1500 | */ | |
60ff7467 | 1501 | skb->ignore_df = ip_sk_ignore_df(sk); |
1da177e4 LT |
1502 | |
1503 | /* DF bit is set when we want to see DF on outgoing frames. | |
60ff7467 | 1504 | * If ignore_df is set too, we still allow to fragment this frame |
1da177e4 | 1505 | * locally. */ |
482fc609 HFS |
1506 | if (inet->pmtudisc == IP_PMTUDISC_DO || |
1507 | inet->pmtudisc == IP_PMTUDISC_PROBE || | |
d8d1f30b CG |
1508 | (skb->len <= dst_mtu(&rt->dst) && |
1509 | ip_dont_fragment(sk, &rt->dst))) | |
1da177e4 LT |
1510 | df = htons(IP_DF); |
1511 | ||
1470ddf7 HX |
1512 | if (cork->flags & IPCORK_OPT) |
1513 | opt = cork->opt; | |
1da177e4 | 1514 | |
aa661581 FF |
1515 | if (cork->ttl != 0) |
1516 | ttl = cork->ttl; | |
1517 | else if (rt->rt_type == RTN_MULTICAST) | |
1da177e4 LT |
1518 | ttl = inet->mc_ttl; |
1519 | else | |
d8d1f30b | 1520 | ttl = ip_select_ttl(inet, &rt->dst); |
1da177e4 | 1521 | |
749154aa | 1522 | iph = ip_hdr(skb); |
1da177e4 LT |
1523 | iph->version = 4; |
1524 | iph->ihl = 5; | |
aa661581 | 1525 | iph->tos = (cork->tos != -1) ? cork->tos : inet->tos; |
1da177e4 | 1526 | iph->frag_off = df; |
1da177e4 LT |
1527 | iph->ttl = ttl; |
1528 | iph->protocol = sk->sk_protocol; | |
84f9307c | 1529 | ip_copy_addrs(iph, fl4); |
b6a7719a | 1530 | ip_select_ident(net, skb, sk); |
1da177e4 | 1531 | |
22f728f8 DM |
1532 | if (opt) { |
1533 | iph->ihl += opt->optlen>>2; | |
1534 | ip_options_build(skb, opt, cork->addr, rt, 0); | |
1535 | } | |
1536 | ||
aa661581 | 1537 | skb->priority = (cork->tos != -1) ? cork->priority: sk->sk_priority; |
c6af0c22 | 1538 | skb->mark = cork->mark; |
bc969a97 | 1539 | skb->tstamp = cork->transmit_time; |
a21bba94 ED |
1540 | /* |
1541 | * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec | |
1542 | * on dst refcount | |
1543 | */ | |
1470ddf7 | 1544 | cork->dst = NULL; |
d8d1f30b | 1545 | skb_dst_set(skb, &rt->dst); |
1da177e4 | 1546 | |
96793b48 | 1547 | if (iph->protocol == IPPROTO_ICMP) |
0388b004 | 1548 | icmp_out_count(net, ((struct icmphdr *) |
96793b48 DS |
1549 | skb_transport_header(skb))->type); |
1550 | ||
1c32c5ad HX |
1551 | ip_cork_release(cork); |
1552 | out: | |
1553 | return skb; | |
1554 | } | |
1555 | ||
b5ec8eea | 1556 | int ip_send_skb(struct net *net, struct sk_buff *skb) |
1c32c5ad | 1557 | { |
1c32c5ad HX |
1558 | int err; |
1559 | ||
33224b16 | 1560 | err = ip_local_out(net, skb->sk, skb); |
1da177e4 LT |
1561 | if (err) { |
1562 | if (err > 0) | |
6ce9e7b5 | 1563 | err = net_xmit_errno(err); |
1da177e4 | 1564 | if (err) |
1c32c5ad | 1565 | IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); |
1da177e4 LT |
1566 | } |
1567 | ||
1da177e4 | 1568 | return err; |
1da177e4 LT |
1569 | } |
1570 | ||
77968b78 | 1571 | int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4) |
1470ddf7 | 1572 | { |
1c32c5ad HX |
1573 | struct sk_buff *skb; |
1574 | ||
77968b78 | 1575 | skb = ip_finish_skb(sk, fl4); |
1c32c5ad HX |
1576 | if (!skb) |
1577 | return 0; | |
1578 | ||
1579 | /* Netfilter gets whole the not fragmented skb. */ | |
b5ec8eea | 1580 | return ip_send_skb(sock_net(sk), skb); |
1470ddf7 HX |
1581 | } |
1582 | ||
1da177e4 LT |
1583 | /* |
1584 | * Throw away all pending data on the socket. | |
1585 | */ | |
1470ddf7 HX |
1586 | static void __ip_flush_pending_frames(struct sock *sk, |
1587 | struct sk_buff_head *queue, | |
1588 | struct inet_cork *cork) | |
1da177e4 | 1589 | { |
1da177e4 LT |
1590 | struct sk_buff *skb; |
1591 | ||
1470ddf7 | 1592 | while ((skb = __skb_dequeue_tail(queue)) != NULL) |
1da177e4 LT |
1593 | kfree_skb(skb); |
1594 | ||
1470ddf7 HX |
1595 | ip_cork_release(cork); |
1596 | } | |
1597 | ||
1598 | void ip_flush_pending_frames(struct sock *sk) | |
1599 | { | |
bdc712b4 | 1600 | __ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base); |
1da177e4 LT |
1601 | } |
1602 | ||
1c32c5ad | 1603 | struct sk_buff *ip_make_skb(struct sock *sk, |
77968b78 | 1604 | struct flowi4 *fl4, |
1c32c5ad HX |
1605 | int getfrag(void *from, char *to, int offset, |
1606 | int len, int odd, struct sk_buff *skb), | |
1607 | void *from, int length, int transhdrlen, | |
1608 | struct ipcm_cookie *ipc, struct rtable **rtp, | |
1cd7884d | 1609 | struct inet_cork *cork, unsigned int flags) |
1c32c5ad | 1610 | { |
1c32c5ad HX |
1611 | struct sk_buff_head queue; |
1612 | int err; | |
1613 | ||
1614 | if (flags & MSG_PROBE) | |
1615 | return NULL; | |
1616 | ||
1617 | __skb_queue_head_init(&queue); | |
1618 | ||
1cd7884d WB |
1619 | cork->flags = 0; |
1620 | cork->addr = 0; | |
1621 | cork->opt = NULL; | |
1622 | err = ip_setup_cork(sk, cork, ipc, rtp); | |
1c32c5ad HX |
1623 | if (err) |
1624 | return ERR_PTR(err); | |
1625 | ||
1cd7884d | 1626 | err = __ip_append_data(sk, fl4, &queue, cork, |
5640f768 | 1627 | ¤t->task_frag, getfrag, |
1c32c5ad HX |
1628 | from, length, transhdrlen, flags); |
1629 | if (err) { | |
1cd7884d | 1630 | __ip_flush_pending_frames(sk, &queue, cork); |
1c32c5ad HX |
1631 | return ERR_PTR(err); |
1632 | } | |
1633 | ||
1cd7884d | 1634 | return __ip_make_skb(sk, fl4, &queue, cork); |
1c32c5ad | 1635 | } |
1da177e4 LT |
1636 | |
1637 | /* | |
1638 | * Fetch data from kernel space and fill in checksum if needed. | |
1639 | */ | |
e905a9ed | 1640 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
1da177e4 LT |
1641 | int len, int odd, struct sk_buff *skb) |
1642 | { | |
5084205f | 1643 | __wsum csum; |
1da177e4 LT |
1644 | |
1645 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); | |
1646 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
e905a9ed | 1647 | return 0; |
1da177e4 LT |
1648 | } |
1649 | ||
e905a9ed | 1650 | /* |
1da177e4 | 1651 | * Generic function to send a packet as reply to another packet. |
be9f4a44 | 1652 | * Used to send some TCP resets/acks so far. |
1da177e4 | 1653 | */ |
bdbbb852 | 1654 | void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, |
24a2d43d ED |
1655 | const struct ip_options *sopt, |
1656 | __be32 daddr, __be32 saddr, | |
1657 | const struct ip_reply_arg *arg, | |
d6fb396c | 1658 | unsigned int len, u64 transmit_time) |
1da177e4 | 1659 | { |
f6d8bd05 | 1660 | struct ip_options_data replyopts; |
1da177e4 | 1661 | struct ipcm_cookie ipc; |
77968b78 | 1662 | struct flowi4 fl4; |
511c3f92 | 1663 | struct rtable *rt = skb_rtable(skb); |
bdbbb852 | 1664 | struct net *net = sock_net(sk); |
be9f4a44 | 1665 | struct sk_buff *nskb; |
4062090e | 1666 | int err; |
f7ba868b | 1667 | int oif; |
1da177e4 | 1668 | |
91ed1e66 | 1669 | if (__ip_options_echo(net, &replyopts.opt.opt, skb, sopt)) |
1da177e4 LT |
1670 | return; |
1671 | ||
35178206 | 1672 | ipcm_init(&ipc); |
0a5ebb80 | 1673 | ipc.addr = daddr; |
d6fb396c | 1674 | ipc.sockc.transmit_time = transmit_time; |
1da177e4 | 1675 | |
f6d8bd05 | 1676 | if (replyopts.opt.opt.optlen) { |
1da177e4 LT |
1677 | ipc.opt = &replyopts.opt; |
1678 | ||
f6d8bd05 ED |
1679 | if (replyopts.opt.opt.srr) |
1680 | daddr = replyopts.opt.opt.faddr; | |
1da177e4 LT |
1681 | } |
1682 | ||
f7ba868b | 1683 | oif = arg->bound_dev_if; |
9b6c14d5 DA |
1684 | if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) |
1685 | oif = skb->skb_iif; | |
f7ba868b DA |
1686 | |
1687 | flowi4_init_output(&fl4, oif, | |
00483690 | 1688 | IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark, |
66b13d99 | 1689 | RT_TOS(arg->tos), |
be9f4a44 | 1690 | RT_SCOPE_UNIVERSE, ip_hdr(skb)->protocol, |
77968b78 | 1691 | ip_reply_arg_flowi_flags(arg), |
70e73416 | 1692 | daddr, saddr, |
e2d118a1 LC |
1693 | tcp_hdr(skb)->source, tcp_hdr(skb)->dest, |
1694 | arg->uid); | |
77968b78 | 1695 | security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); |
be9f4a44 | 1696 | rt = ip_route_output_key(net, &fl4); |
77968b78 DM |
1697 | if (IS_ERR(rt)) |
1698 | return; | |
1da177e4 | 1699 | |
bdbbb852 | 1700 | inet_sk(sk)->tos = arg->tos; |
1da177e4 | 1701 | |
eddc9ec5 | 1702 | sk->sk_protocol = ip_hdr(skb)->protocol; |
f0e48dbf | 1703 | sk->sk_bound_dev_if = arg->bound_dev_if; |
be9f4a44 | 1704 | sk->sk_sndbuf = sysctl_wmem_default; |
bf99b4de | 1705 | sk->sk_mark = fl4.flowi4_mark; |
4062090e VA |
1706 | err = ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, |
1707 | len, 0, &ipc, &rt, MSG_DONTWAIT); | |
1708 | if (unlikely(err)) { | |
1709 | ip_flush_pending_frames(sk); | |
1710 | goto out; | |
1711 | } | |
1712 | ||
be9f4a44 ED |
1713 | nskb = skb_peek(&sk->sk_write_queue); |
1714 | if (nskb) { | |
1da177e4 | 1715 | if (arg->csumoffset >= 0) |
be9f4a44 ED |
1716 | *((__sum16 *)skb_transport_header(nskb) + |
1717 | arg->csumoffset) = csum_fold(csum_add(nskb->csum, | |
9c70220b | 1718 | arg->csum)); |
be9f4a44 | 1719 | nskb->ip_summed = CHECKSUM_NONE; |
77968b78 | 1720 | ip_push_pending_frames(sk, &fl4); |
1da177e4 | 1721 | } |
4062090e | 1722 | out: |
1da177e4 LT |
1723 | ip_rt_put(rt); |
1724 | } | |
1725 | ||
1da177e4 LT |
1726 | void __init ip_init(void) |
1727 | { | |
1da177e4 LT |
1728 | ip_rt_init(); |
1729 | inet_initpeers(); | |
1730 | ||
72c1d3bd WC |
1731 | #if defined(CONFIG_IP_MULTICAST) |
1732 | igmp_mc_init(); | |
1da177e4 LT |
1733 | #endif |
1734 | } |