Commit | Line | Data |
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47505b8b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
60c778b2 | 2 | /* SCTP kernel implementation |
1da177e4 LT |
3 | * (C) Copyright IBM Corp. 2001, 2004 |
4 | * Copyright (c) 1999-2000 Cisco, Inc. | |
5 | * Copyright (c) 1999-2001 Motorola, Inc. | |
6 | * | |
60c778b2 | 7 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
8 | * |
9 | * These functions handle output processing. | |
10 | * | |
1da177e4 LT |
11 | * Please send any bug reports or fixes you make to the |
12 | * email address(es): | |
91705c61 | 13 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 14 | * |
1da177e4 LT |
15 | * Written or modified by: |
16 | * La Monte H.P. Yarroll <piggy@acm.org> | |
17 | * Karl Knutson <karl@athena.chicago.il.us> | |
18 | * Jon Grimm <jgrimm@austin.ibm.com> | |
19 | * Sridhar Samudrala <sri@us.ibm.com> | |
1da177e4 LT |
20 | */ |
21 | ||
145ce502 JP |
22 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
23 | ||
1da177e4 LT |
24 | #include <linux/types.h> |
25 | #include <linux/kernel.h> | |
26 | #include <linux/wait.h> | |
27 | #include <linux/time.h> | |
28 | #include <linux/ip.h> | |
29 | #include <linux/ipv6.h> | |
30 | #include <linux/init.h> | |
5a0e3ad6 | 31 | #include <linux/slab.h> |
1da177e4 | 32 | #include <net/inet_ecn.h> |
8d2f9e81 | 33 | #include <net/ip.h> |
1da177e4 | 34 | #include <net/icmp.h> |
7c73a6fa | 35 | #include <net/net_namespace.h> |
1da177e4 | 36 | |
1da177e4 LT |
37 | #include <linux/socket.h> /* for sa_family_t */ |
38 | #include <net/sock.h> | |
39 | ||
40 | #include <net/sctp/sctp.h> | |
41 | #include <net/sctp/sm.h> | |
9ad0977f | 42 | #include <net/sctp/checksum.h> |
1da177e4 LT |
43 | |
44 | /* Forward declarations for private helpers. */ | |
86b36f2a XL |
45 | static enum sctp_xmit __sctp_packet_append_chunk(struct sctp_packet *packet, |
46 | struct sctp_chunk *chunk); | |
47 | static enum sctp_xmit sctp_packet_can_append_data(struct sctp_packet *packet, | |
48 | struct sctp_chunk *chunk); | |
e83963b7 | 49 | static void sctp_packet_append_data(struct sctp_packet *packet, |
86b36f2a XL |
50 | struct sctp_chunk *chunk); |
51 | static enum sctp_xmit sctp_packet_will_fit(struct sctp_packet *packet, | |
52 | struct sctp_chunk *chunk, | |
53 | u16 chunk_len); | |
1da177e4 | 54 | |
be297143 WY |
55 | static void sctp_packet_reset(struct sctp_packet *packet) |
56 | { | |
b7e10c25 RH |
57 | /* sctp_packet_transmit() relies on this to reset size to the |
58 | * current overhead after sending packets. | |
59 | */ | |
be297143 | 60 | packet->size = packet->overhead; |
b7e10c25 | 61 | |
be297143 WY |
62 | packet->has_cookie_echo = 0; |
63 | packet->has_sack = 0; | |
64 | packet->has_data = 0; | |
65 | packet->has_auth = 0; | |
66 | packet->ipfragok = 0; | |
67 | packet->auth = NULL; | |
68 | } | |
69 | ||
1da177e4 LT |
70 | /* Config a packet. |
71 | * This appears to be a followup set of initializations. | |
72 | */ | |
66b91d2c MRL |
73 | void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, |
74 | int ecn_capable) | |
1da177e4 | 75 | { |
90017acc MRL |
76 | struct sctp_transport *tp = packet->transport; |
77 | struct sctp_association *asoc = tp->asoc; | |
feddd6c1 | 78 | struct sctp_sock *sp = NULL; |
df2729c3 | 79 | struct sock *sk; |
1da177e4 | 80 | |
bb33381d | 81 | pr_debug("%s: packet:%p vtag:0x%x\n", __func__, packet, vtag); |
1da177e4 | 82 | packet->vtag = vtag; |
1da177e4 | 83 | |
df2729c3 XL |
84 | /* do the following jobs only once for a flush schedule */ |
85 | if (!sctp_packet_empty(packet)) | |
86 | return; | |
90017acc | 87 | |
b7e10c25 | 88 | /* set packet max_size with pathmtu, then calculate overhead */ |
df2729c3 | 89 | packet->max_size = tp->pathmtu; |
feddd6c1 | 90 | |
b7e10c25 | 91 | if (asoc) { |
feddd6c1 MRL |
92 | sk = asoc->base.sk; |
93 | sp = sctp_sk(sk); | |
94 | } | |
95 | packet->overhead = sctp_mtu_payload(sp, 0, 0); | |
96 | packet->size = packet->overhead; | |
b7e10c25 | 97 | |
feddd6c1 | 98 | if (!asoc) |
df2729c3 | 99 | return; |
90017acc | 100 | |
df2729c3 | 101 | /* update dst or transport pathmtu if in need */ |
df2729c3 | 102 | if (!sctp_transport_dst_check(tp)) { |
feddd6c1 | 103 | sctp_transport_route(tp, NULL, sp); |
df2729c3 | 104 | if (asoc->param_flags & SPP_PMTUD_ENABLE) |
3ebfdf08 | 105 | sctp_assoc_sync_pmtu(asoc); |
7307e4fa | 106 | } else if (!sctp_transport_pl_enabled(tp) && |
02dc2ee7 XL |
107 | asoc->param_flags & SPP_PMTUD_ENABLE) { |
108 | if (!sctp_transport_pmtu_check(tp)) | |
69fec325 | 109 | sctp_assoc_sync_pmtu(asoc); |
90017acc MRL |
110 | } |
111 | ||
d805397c XL |
112 | if (asoc->pmtu_pending) { |
113 | if (asoc->param_flags & SPP_PMTUD_ENABLE) | |
114 | sctp_assoc_sync_pmtu(asoc); | |
115 | asoc->pmtu_pending = 0; | |
116 | } | |
117 | ||
df2729c3 XL |
118 | /* If there a is a prepend chunk stick it on the list before |
119 | * any other chunks get appended. | |
120 | */ | |
121 | if (ecn_capable) { | |
122 | struct sctp_chunk *chunk = sctp_get_ecne_prepend(asoc); | |
1da177e4 | 123 | |
1da177e4 LT |
124 | if (chunk) |
125 | sctp_packet_append_chunk(packet, chunk); | |
126 | } | |
df2729c3 XL |
127 | |
128 | if (!tp->dst) | |
129 | return; | |
130 | ||
131 | /* set packet max_size with gso_max_size if gso is enabled*/ | |
132 | rcu_read_lock(); | |
133 | if (__sk_dst_get(sk) != tp->dst) { | |
134 | dst_hold(tp->dst); | |
135 | sk_setup_caps(sk, tp->dst); | |
136 | } | |
7c4e983c AD |
137 | packet->max_size = sk_can_gso(sk) ? min(READ_ONCE(tp->dst->dev->gso_max_size), |
138 | GSO_LEGACY_MAX_SIZE) | |
df2729c3 XL |
139 | : asoc->pathmtu; |
140 | rcu_read_unlock(); | |
1da177e4 LT |
141 | } |
142 | ||
143 | /* Initialize the packet structure. */ | |
66b91d2c MRL |
144 | void sctp_packet_init(struct sctp_packet *packet, |
145 | struct sctp_transport *transport, | |
146 | __u16 sport, __u16 dport) | |
1da177e4 | 147 | { |
bb33381d | 148 | pr_debug("%s: packet:%p transport:%p\n", __func__, packet, transport); |
1da177e4 LT |
149 | |
150 | packet->transport = transport; | |
151 | packet->source_port = sport; | |
152 | packet->destination_port = dport; | |
79af02c2 | 153 | INIT_LIST_HEAD(&packet->chunk_list); |
b7e10c25 RH |
154 | /* The overhead will be calculated by sctp_packet_config() */ |
155 | packet->overhead = 0; | |
be297143 | 156 | sctp_packet_reset(packet); |
1da177e4 | 157 | packet->vtag = 0; |
1da177e4 LT |
158 | } |
159 | ||
160 | /* Free a packet. */ | |
161 | void sctp_packet_free(struct sctp_packet *packet) | |
162 | { | |
79af02c2 | 163 | struct sctp_chunk *chunk, *tmp; |
1da177e4 | 164 | |
bb33381d | 165 | pr_debug("%s: packet:%p\n", __func__, packet); |
1da177e4 | 166 | |
79af02c2 DM |
167 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
168 | list_del_init(&chunk->list); | |
1da177e4 | 169 | sctp_chunk_free(chunk); |
79af02c2 | 170 | } |
1da177e4 LT |
171 | } |
172 | ||
173 | /* This routine tries to append the chunk to the offered packet. If adding | |
174 | * the chunk causes the packet to exceed the path MTU and COOKIE_ECHO chunk | |
175 | * is not present in the packet, it transmits the input packet. | |
176 | * Data can be bundled with a packet containing a COOKIE_ECHO chunk as long | |
177 | * as it can fit in the packet, but any more data that does not fit in this | |
178 | * packet can be sent only after receiving the COOKIE_ACK. | |
179 | */ | |
86b36f2a XL |
180 | enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet, |
181 | struct sctp_chunk *chunk, | |
182 | int one_packet, gfp_t gfp) | |
1da177e4 | 183 | { |
86b36f2a | 184 | enum sctp_xmit retval; |
1da177e4 | 185 | |
5b5e0928 | 186 | pr_debug("%s: packet:%p size:%zu chunk:%p size:%d\n", __func__, |
942b3235 | 187 | packet, packet->size, chunk, chunk->skb ? chunk->skb->len : -1); |
1da177e4 LT |
188 | |
189 | switch ((retval = (sctp_packet_append_chunk(packet, chunk)))) { | |
190 | case SCTP_XMIT_PMTU_FULL: | |
191 | if (!packet->has_cookie_echo) { | |
64519440 XL |
192 | int error = 0; |
193 | ||
cea8768f | 194 | error = sctp_packet_transmit(packet, gfp); |
1da177e4 LT |
195 | if (error < 0) |
196 | chunk->skb->sk->sk_err = -error; | |
197 | ||
198 | /* If we have an empty packet, then we can NOT ever | |
199 | * return PMTU_FULL. | |
200 | */ | |
2e3216cd VY |
201 | if (!one_packet) |
202 | retval = sctp_packet_append_chunk(packet, | |
203 | chunk); | |
1da177e4 LT |
204 | } |
205 | break; | |
206 | ||
207 | case SCTP_XMIT_RWND_FULL: | |
208 | case SCTP_XMIT_OK: | |
526cbef7 | 209 | case SCTP_XMIT_DELAY: |
1da177e4 | 210 | break; |
3ff50b79 | 211 | } |
1da177e4 LT |
212 | |
213 | return retval; | |
214 | } | |
215 | ||
fe59379b XL |
216 | /* Try to bundle a pad chunk into a packet with a heartbeat chunk for PLPMTUTD probe */ |
217 | static enum sctp_xmit sctp_packet_bundle_pad(struct sctp_packet *pkt, struct sctp_chunk *chunk) | |
218 | { | |
219 | struct sctp_transport *t = pkt->transport; | |
220 | struct sctp_chunk *pad; | |
221 | int overhead = 0; | |
222 | ||
223 | if (!chunk->pmtu_probe) | |
224 | return SCTP_XMIT_OK; | |
225 | ||
226 | /* calculate the Padding Data size for the pad chunk */ | |
227 | overhead += sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr); | |
228 | overhead += sizeof(struct sctp_sender_hb_info) + sizeof(struct sctp_pad_chunk); | |
229 | pad = sctp_make_pad(t->asoc, t->pl.probe_size - overhead); | |
230 | if (!pad) | |
231 | return SCTP_XMIT_DELAY; | |
232 | ||
233 | list_add_tail(&pad->list, &pkt->chunk_list); | |
234 | pkt->size += SCTP_PAD4(ntohs(pad->chunk_hdr->length)); | |
235 | chunk->transport = t; | |
236 | ||
237 | return SCTP_XMIT_OK; | |
238 | } | |
239 | ||
4cd57c80 | 240 | /* Try to bundle an auth chunk into the packet. */ |
86b36f2a XL |
241 | static enum sctp_xmit sctp_packet_bundle_auth(struct sctp_packet *pkt, |
242 | struct sctp_chunk *chunk) | |
4cd57c80 VY |
243 | { |
244 | struct sctp_association *asoc = pkt->transport->asoc; | |
86b36f2a | 245 | enum sctp_xmit retval = SCTP_XMIT_OK; |
4cd57c80 | 246 | struct sctp_chunk *auth; |
4cd57c80 VY |
247 | |
248 | /* if we don't have an association, we can't do authentication */ | |
249 | if (!asoc) | |
250 | return retval; | |
251 | ||
252 | /* See if this is an auth chunk we are bundling or if | |
253 | * auth is already bundled. | |
254 | */ | |
4007cc88 | 255 | if (chunk->chunk_hdr->type == SCTP_CID_AUTH || pkt->has_auth) |
4cd57c80 VY |
256 | return retval; |
257 | ||
258 | /* if the peer did not request this chunk to be authenticated, | |
259 | * don't do it | |
260 | */ | |
261 | if (!chunk->auth) | |
262 | return retval; | |
263 | ||
1b1e0bc9 | 264 | auth = sctp_make_auth(asoc, chunk->shkey->key_id); |
4cd57c80 VY |
265 | if (!auth) |
266 | return retval; | |
267 | ||
1b1e0bc9 XL |
268 | auth->shkey = chunk->shkey; |
269 | sctp_auth_shkey_hold(auth->shkey); | |
270 | ||
ed106277 NH |
271 | retval = __sctp_packet_append_chunk(pkt, auth); |
272 | ||
273 | if (retval != SCTP_XMIT_OK) | |
274 | sctp_chunk_free(auth); | |
4cd57c80 VY |
275 | |
276 | return retval; | |
277 | } | |
278 | ||
1da177e4 | 279 | /* Try to bundle a SACK with the packet. */ |
86b36f2a XL |
280 | static enum sctp_xmit sctp_packet_bundle_sack(struct sctp_packet *pkt, |
281 | struct sctp_chunk *chunk) | |
1da177e4 | 282 | { |
86b36f2a | 283 | enum sctp_xmit retval = SCTP_XMIT_OK; |
1da177e4 LT |
284 | |
285 | /* If sending DATA and haven't aleady bundled a SACK, try to | |
286 | * bundle one in to the packet. | |
287 | */ | |
288 | if (sctp_chunk_is_data(chunk) && !pkt->has_sack && | |
289 | !pkt->has_cookie_echo) { | |
290 | struct sctp_association *asoc; | |
af87b823 | 291 | struct timer_list *timer; |
1da177e4 | 292 | asoc = pkt->transport->asoc; |
af87b823 | 293 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; |
1da177e4 | 294 | |
af87b823 DG |
295 | /* If the SACK timer is running, we have a pending SACK */ |
296 | if (timer_pending(timer)) { | |
1da177e4 | 297 | struct sctp_chunk *sack; |
4244854d NH |
298 | |
299 | if (pkt->transport->sack_generation != | |
300 | pkt->transport->asoc->peer.sack_generation) | |
301 | return retval; | |
302 | ||
1da177e4 LT |
303 | asoc->a_rwnd = asoc->rwnd; |
304 | sack = sctp_make_sack(asoc); | |
305 | if (sack) { | |
ed106277 NH |
306 | retval = __sctp_packet_append_chunk(pkt, sack); |
307 | if (retval != SCTP_XMIT_OK) { | |
308 | sctp_chunk_free(sack); | |
309 | goto out; | |
310 | } | |
4e7696d9 | 311 | SCTP_INC_STATS(asoc->base.net, |
7af03301 XL |
312 | SCTP_MIB_OUTCTRLCHUNKS); |
313 | asoc->stats.octrlchunks++; | |
1da177e4 | 314 | asoc->peer.sack_needed = 0; |
af87b823 | 315 | if (del_timer(timer)) |
1da177e4 LT |
316 | sctp_association_put(asoc); |
317 | } | |
318 | } | |
319 | } | |
ed106277 | 320 | out: |
1da177e4 LT |
321 | return retval; |
322 | } | |
323 | ||
ed106277 | 324 | |
1da177e4 LT |
325 | /* Append a chunk to the offered packet reporting back any inability to do |
326 | * so. | |
327 | */ | |
86b36f2a XL |
328 | static enum sctp_xmit __sctp_packet_append_chunk(struct sctp_packet *packet, |
329 | struct sctp_chunk *chunk) | |
1da177e4 | 330 | { |
e2f036a9 | 331 | __u16 chunk_len = SCTP_PAD4(ntohs(chunk->chunk_hdr->length)); |
86b36f2a | 332 | enum sctp_xmit retval = SCTP_XMIT_OK; |
1da177e4 | 333 | |
e83963b7 VY |
334 | /* Check to see if this chunk will fit into the packet */ |
335 | retval = sctp_packet_will_fit(packet, chunk, chunk_len); | |
336 | if (retval != SCTP_XMIT_OK) | |
337 | goto finish; | |
1da177e4 | 338 | |
e83963b7 | 339 | /* We believe that this chunk is OK to add to the packet */ |
4cd57c80 | 340 | switch (chunk->chunk_hdr->type) { |
f7010e61 | 341 | case SCTP_CID_DATA: |
668c9beb | 342 | case SCTP_CID_I_DATA: |
e83963b7 VY |
343 | /* Account for the data being in the packet */ |
344 | sctp_packet_append_data(packet, chunk); | |
1da177e4 LT |
345 | /* Disallow SACK bundling after DATA. */ |
346 | packet->has_sack = 1; | |
4cd57c80 VY |
347 | /* Disallow AUTH bundling after DATA */ |
348 | packet->has_auth = 1; | |
349 | /* Let it be knows that packet has DATA in it */ | |
350 | packet->has_data = 1; | |
759af00e VY |
351 | /* timestamp the chunk for rtx purposes */ |
352 | chunk->sent_at = jiffies; | |
a6c2f792 XL |
353 | /* Mainly used for prsctp RTX policy */ |
354 | chunk->sent_count++; | |
4cd57c80 | 355 | break; |
f7010e61 | 356 | case SCTP_CID_COOKIE_ECHO: |
1da177e4 | 357 | packet->has_cookie_echo = 1; |
4cd57c80 VY |
358 | break; |
359 | ||
f7010e61 | 360 | case SCTP_CID_SACK: |
1da177e4 | 361 | packet->has_sack = 1; |
196d6759 MB |
362 | if (chunk->asoc) |
363 | chunk->asoc->stats.osacks++; | |
4cd57c80 VY |
364 | break; |
365 | ||
f7010e61 | 366 | case SCTP_CID_AUTH: |
4cd57c80 VY |
367 | packet->has_auth = 1; |
368 | packet->auth = chunk; | |
369 | break; | |
370 | } | |
1da177e4 LT |
371 | |
372 | /* It is OK to send this chunk. */ | |
79af02c2 | 373 | list_add_tail(&chunk->list, &packet->chunk_list); |
1da177e4 LT |
374 | packet->size += chunk_len; |
375 | chunk->transport = packet->transport; | |
376 | finish: | |
377 | return retval; | |
378 | } | |
379 | ||
ed106277 NH |
380 | /* Append a chunk to the offered packet reporting back any inability to do |
381 | * so. | |
382 | */ | |
86b36f2a XL |
383 | enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet, |
384 | struct sctp_chunk *chunk) | |
ed106277 | 385 | { |
86b36f2a | 386 | enum sctp_xmit retval = SCTP_XMIT_OK; |
ed106277 | 387 | |
bb33381d | 388 | pr_debug("%s: packet:%p chunk:%p\n", __func__, packet, chunk); |
ed106277 NH |
389 | |
390 | /* Data chunks are special. Before seeing what else we can | |
391 | * bundle into this packet, check to see if we are allowed to | |
392 | * send this DATA. | |
393 | */ | |
394 | if (sctp_chunk_is_data(chunk)) { | |
395 | retval = sctp_packet_can_append_data(packet, chunk); | |
396 | if (retval != SCTP_XMIT_OK) | |
397 | goto finish; | |
398 | } | |
399 | ||
400 | /* Try to bundle AUTH chunk */ | |
401 | retval = sctp_packet_bundle_auth(packet, chunk); | |
402 | if (retval != SCTP_XMIT_OK) | |
403 | goto finish; | |
404 | ||
405 | /* Try to bundle SACK chunk */ | |
406 | retval = sctp_packet_bundle_sack(packet, chunk); | |
407 | if (retval != SCTP_XMIT_OK) | |
408 | goto finish; | |
409 | ||
410 | retval = __sctp_packet_append_chunk(packet, chunk); | |
fe59379b XL |
411 | if (retval != SCTP_XMIT_OK) |
412 | goto finish; | |
413 | ||
414 | retval = sctp_packet_bundle_pad(packet, chunk); | |
ed106277 NH |
415 | |
416 | finish: | |
417 | return retval; | |
418 | } | |
419 | ||
99519122 XL |
420 | static void sctp_packet_gso_append(struct sk_buff *head, struct sk_buff *skb) |
421 | { | |
422 | if (SCTP_OUTPUT_CB(head)->last == head) | |
423 | skb_shinfo(head)->frag_list = skb; | |
424 | else | |
425 | SCTP_OUTPUT_CB(head)->last->next = skb; | |
426 | SCTP_OUTPUT_CB(head)->last = skb; | |
427 | ||
428 | head->truesize += skb->truesize; | |
429 | head->data_len += skb->len; | |
430 | head->len += skb->len; | |
0d32f177 | 431 | refcount_add(skb->truesize, &head->sk->sk_wmem_alloc); |
99519122 XL |
432 | |
433 | __skb_header_release(skb); | |
434 | } | |
435 | ||
e4ff952a XL |
436 | static int sctp_packet_pack(struct sctp_packet *packet, |
437 | struct sk_buff *head, int gso, gfp_t gfp) | |
1da177e4 LT |
438 | { |
439 | struct sctp_transport *tp = packet->transport; | |
e4ff952a | 440 | struct sctp_auth_chunk *auth = NULL; |
79af02c2 | 441 | struct sctp_chunk *chunk, *tmp; |
e4ff952a XL |
442 | int pkt_count = 0, pkt_size; |
443 | struct sock *sk = head->sk; | |
444 | struct sk_buff *nskb; | |
ecc515d7 | 445 | int auth_len = 0; |
1da177e4 | 446 | |
90017acc | 447 | if (gso) { |
90017acc | 448 | skb_shinfo(head)->gso_type = sk->sk_gso_type; |
99519122 | 449 | SCTP_OUTPUT_CB(head)->last = head; |
e4ff952a XL |
450 | } else { |
451 | nskb = head; | |
452 | pkt_size = packet->size; | |
453 | goto merge; | |
90017acc | 454 | } |
1da177e4 | 455 | |
90017acc | 456 | do { |
e4ff952a XL |
457 | /* calculate the pkt_size and alloc nskb */ |
458 | pkt_size = packet->overhead; | |
459 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, | |
460 | list) { | |
461 | int padded = SCTP_PAD4(chunk->skb->len); | |
6eabca54 | 462 | |
e4ff952a XL |
463 | if (chunk == packet->auth) |
464 | auth_len = padded; | |
465 | else if (auth_len + padded + packet->overhead > | |
466 | tp->pathmtu) | |
467 | return 0; | |
468 | else if (pkt_size + padded > tp->pathmtu) | |
469 | break; | |
470 | pkt_size += padded; | |
90017acc | 471 | } |
e4ff952a XL |
472 | nskb = alloc_skb(pkt_size + MAX_HEADER, gfp); |
473 | if (!nskb) | |
474 | return 0; | |
475 | skb_reserve(nskb, packet->overhead + MAX_HEADER); | |
1da177e4 | 476 | |
e4ff952a XL |
477 | merge: |
478 | /* merge chunks into nskb and append nskb into head list */ | |
90017acc MRL |
479 | pkt_size -= packet->overhead; |
480 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { | |
e4ff952a XL |
481 | int padding; |
482 | ||
90017acc MRL |
483 | list_del_init(&chunk->list); |
484 | if (sctp_chunk_is_data(chunk)) { | |
cc6ac9bc XL |
485 | if (!sctp_chunk_retransmitted(chunk) && |
486 | !tp->rto_pending) { | |
90017acc MRL |
487 | chunk->rtt_in_progress = 1; |
488 | tp->rto_pending = 1; | |
489 | } | |
90017acc MRL |
490 | } |
491 | ||
e2f036a9 | 492 | padding = SCTP_PAD4(chunk->skb->len) - chunk->skb->len; |
90017acc | 493 | if (padding) |
b080db58 | 494 | skb_put_zero(chunk->skb, padding); |
90017acc | 495 | |
90017acc | 496 | if (chunk == packet->auth) |
e4ff952a XL |
497 | auth = (struct sctp_auth_chunk *) |
498 | skb_tail_pointer(nskb); | |
90017acc | 499 | |
59ae1d12 | 500 | skb_put_data(nskb, chunk->skb->data, chunk->skb->len); |
1da177e4 | 501 | |
90017acc MRL |
502 | pr_debug("*** Chunk:%p[%s] %s 0x%x, length:%d, chunk->skb->len:%d, rtt_in_progress:%d\n", |
503 | chunk, | |
504 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)), | |
505 | chunk->has_tsn ? "TSN" : "No TSN", | |
506 | chunk->has_tsn ? ntohl(chunk->subh.data_hdr->tsn) : 0, | |
507 | ntohs(chunk->chunk_hdr->length), chunk->skb->len, | |
508 | chunk->rtt_in_progress); | |
509 | ||
e2f036a9 | 510 | pkt_size -= SCTP_PAD4(chunk->skb->len); |
1da177e4 | 511 | |
f1533cce | 512 | if (!sctp_chunk_is_data(chunk) && chunk != packet->auth) |
90017acc MRL |
513 | sctp_chunk_free(chunk); |
514 | ||
515 | if (!pkt_size) | |
516 | break; | |
517 | } | |
518 | ||
e4ff952a | 519 | if (auth) { |
1b1e0bc9 XL |
520 | sctp_auth_calculate_hmac(tp->asoc, nskb, auth, |
521 | packet->auth->shkey, gfp); | |
e4ff952a XL |
522 | /* free auth if no more chunks, or add it back */ |
523 | if (list_empty(&packet->chunk_list)) | |
524 | sctp_chunk_free(packet->auth); | |
525 | else | |
1aa25ec2 XL |
526 | list_add(&packet->auth->list, |
527 | &packet->chunk_list); | |
f1533cce MRL |
528 | } |
529 | ||
99519122 XL |
530 | if (gso) |
531 | sctp_packet_gso_append(head, nskb); | |
e4ff952a XL |
532 | |
533 | pkt_count++; | |
90017acc | 534 | } while (!list_empty(&packet->chunk_list)); |
4cd57c80 | 535 | |
e4ff952a XL |
536 | if (gso) { |
537 | memset(head->cb, 0, max(sizeof(struct inet_skb_parm), | |
538 | sizeof(struct inet6_skb_parm))); | |
539 | skb_shinfo(head)->gso_segs = pkt_count; | |
540 | skb_shinfo(head)->gso_size = GSO_BY_FRAGS; | |
e4ff952a | 541 | goto chksum; |
8dc92f7e | 542 | } |
1da177e4 | 543 | |
e4ff952a XL |
544 | if (sctp_checksum_disable) |
545 | return 1; | |
1da177e4 | 546 | |
600af7fd XL |
547 | if (!(tp->dst->dev->features & NETIF_F_SCTP_CRC) || |
548 | dst_xfrm(tp->dst) || packet->ipfragok || tp->encap_port) { | |
e4ff952a XL |
549 | struct sctphdr *sh = |
550 | (struct sctphdr *)skb_transport_header(head); | |
1da177e4 | 551 | |
e4ff952a XL |
552 | sh->checksum = sctp_compute_cksum(head, 0); |
553 | } else { | |
554 | chksum: | |
555 | head->ip_summed = CHECKSUM_PARTIAL; | |
dba00306 | 556 | head->csum_not_inet = 1; |
e4ff952a XL |
557 | head->csum_start = skb_transport_header(head) - head->head; |
558 | head->csum_offset = offsetof(struct sctphdr, checksum); | |
1da177e4 LT |
559 | } |
560 | ||
e4ff952a XL |
561 | return pkt_count; |
562 | } | |
563 | ||
564 | /* All packets are sent to the network through this function from | |
565 | * sctp_outq_tail(). | |
566 | * | |
567 | * The return value is always 0 for now. | |
568 | */ | |
569 | int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp) | |
570 | { | |
571 | struct sctp_transport *tp = packet->transport; | |
572 | struct sctp_association *asoc = tp->asoc; | |
573 | struct sctp_chunk *chunk, *tmp; | |
574 | int pkt_count, gso = 0; | |
e4ff952a XL |
575 | struct sk_buff *head; |
576 | struct sctphdr *sh; | |
577 | struct sock *sk; | |
1da177e4 | 578 | |
e4ff952a XL |
579 | pr_debug("%s: packet:%p\n", __func__, packet); |
580 | if (list_empty(&packet->chunk_list)) | |
581 | return 0; | |
582 | chunk = list_entry(packet->chunk_list.next, struct sctp_chunk, list); | |
583 | sk = chunk->skb->sk; | |
1da177e4 | 584 | |
fe59379b | 585 | if (packet->size > tp->pathmtu && !packet->ipfragok && !chunk->pmtu_probe) { |
40171248 XL |
586 | if (tp->pl.state == SCTP_PL_ERROR) { /* do IP fragmentation if in Error state */ |
587 | packet->ipfragok = 1; | |
588 | } else { | |
589 | if (!sk_can_gso(sk)) { /* check gso */ | |
590 | pr_err_once("Trying to GSO but underlying device doesn't support it."); | |
591 | goto out; | |
592 | } | |
593 | gso = 1; | |
1da177e4 | 594 | } |
e4ff952a XL |
595 | } |
596 | ||
597 | /* alloc head skb */ | |
598 | head = alloc_skb((gso ? packet->overhead : packet->size) + | |
599 | MAX_HEADER, gfp); | |
600 | if (!head) | |
601 | goto out; | |
602 | skb_reserve(head, packet->overhead + MAX_HEADER); | |
02968ccf | 603 | skb_set_owner_w(head, sk); |
e4ff952a XL |
604 | |
605 | /* set sctp header */ | |
d58ff351 | 606 | sh = skb_push(head, sizeof(struct sctphdr)); |
e4ff952a XL |
607 | skb_reset_transport_header(head); |
608 | sh->source = htons(packet->source_port); | |
609 | sh->dest = htons(packet->destination_port); | |
610 | sh->vtag = htonl(packet->vtag); | |
611 | sh->checksum = 0; | |
612 | ||
df2729c3 | 613 | /* drop packet if no dst */ |
600af7fd | 614 | if (!tp->dst) { |
e4ff952a XL |
615 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
616 | kfree_skb(head); | |
617 | goto out; | |
618 | } | |
1da177e4 | 619 | |
e4ff952a XL |
620 | /* pack up chunks */ |
621 | pkt_count = sctp_packet_pack(packet, head, gso, gfp); | |
622 | if (!pkt_count) { | |
623 | kfree_skb(head); | |
624 | goto out; | |
625 | } | |
90017acc MRL |
626 | pr_debug("***sctp_transmit_packet*** skb->len:%d\n", head->len); |
627 | ||
e4ff952a XL |
628 | /* start autoclose timer */ |
629 | if (packet->has_data && sctp_state(asoc, ESTABLISHED) && | |
630 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { | |
631 | struct timer_list *timer = | |
632 | &asoc->timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]; | |
633 | unsigned long timeout = | |
634 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]; | |
1da177e4 | 635 | |
e4ff952a XL |
636 | if (!mod_timer(timer, jiffies + timeout)) |
637 | sctp_association_hold(asoc); | |
638 | } | |
90017acc | 639 | |
e4ff952a XL |
640 | /* sctp xmit */ |
641 | tp->af_specific->ecn_capable(sk); | |
642 | if (asoc) { | |
643 | asoc->stats.opackets += pkt_count; | |
644 | if (asoc->peer.last_sent_to != tp) | |
645 | asoc->peer.last_sent_to = tp; | |
90017acc MRL |
646 | } |
647 | head->ignore_df = packet->ipfragok; | |
486a43db | 648 | if (tp->dst_pending_confirm) |
c86a773c JA |
649 | skb_set_dst_pending_confirm(head, 1); |
650 | /* neighbour should be confirmed on successful transmission or | |
651 | * positive error | |
652 | */ | |
486a43db XL |
653 | if (tp->af_specific->sctp_xmit(head, tp) >= 0 && |
654 | tp->dst_pending_confirm) | |
c86a773c | 655 | tp->dst_pending_confirm = 0; |
1da177e4 | 656 | |
e4ff952a | 657 | out: |
79af02c2 DM |
658 | list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { |
659 | list_del_init(&chunk->list); | |
1da177e4 | 660 | if (!sctp_chunk_is_data(chunk)) |
d808ad9a | 661 | sctp_chunk_free(chunk); |
1da177e4 | 662 | } |
41001faf | 663 | sctp_packet_reset(packet); |
e4ff952a | 664 | return 0; |
1da177e4 LT |
665 | } |
666 | ||
667 | /******************************************************************** | |
668 | * 2nd Level Abstractions | |
669 | ********************************************************************/ | |
670 | ||
e83963b7 | 671 | /* This private function check to see if a chunk can be added */ |
86b36f2a XL |
672 | static enum sctp_xmit sctp_packet_can_append_data(struct sctp_packet *packet, |
673 | struct sctp_chunk *chunk) | |
1da177e4 | 674 | { |
e83963b7 | 675 | size_t datasize, rwnd, inflight, flight_size; |
1da177e4 | 676 | struct sctp_transport *transport = packet->transport; |
1da177e4 | 677 | struct sctp_association *asoc = transport->asoc; |
1da177e4 LT |
678 | struct sctp_outq *q = &asoc->outqueue; |
679 | ||
680 | /* RFC 2960 6.1 Transmission of DATA Chunks | |
681 | * | |
682 | * A) At any given time, the data sender MUST NOT transmit new data to | |
683 | * any destination transport address if its peer's rwnd indicates | |
684 | * that the peer has no buffer space (i.e. rwnd is 0, see Section | |
685 | * 6.2.1). However, regardless of the value of rwnd (including if it | |
686 | * is 0), the data sender can always have one DATA chunk in flight to | |
687 | * the receiver if allowed by cwnd (see rule B below). This rule | |
688 | * allows the sender to probe for a change in rwnd that the sender | |
689 | * missed due to the SACK having been lost in transit from the data | |
690 | * receiver to the data sender. | |
691 | */ | |
692 | ||
693 | rwnd = asoc->peer.rwnd; | |
e83963b7 VY |
694 | inflight = q->outstanding_bytes; |
695 | flight_size = transport->flight_size; | |
1da177e4 LT |
696 | |
697 | datasize = sctp_data_size(chunk); | |
698 | ||
723189fa DL |
699 | if (datasize > rwnd && inflight > 0) |
700 | /* We have (at least) one data chunk in flight, | |
701 | * so we can't fall back to rule 6.1 B). | |
702 | */ | |
703 | return SCTP_XMIT_RWND_FULL; | |
1da177e4 | 704 | |
1da177e4 LT |
705 | /* RFC 2960 6.1 Transmission of DATA Chunks |
706 | * | |
707 | * B) At any given time, the sender MUST NOT transmit new data | |
708 | * to a given transport address if it has cwnd or more bytes | |
709 | * of data outstanding to that transport address. | |
710 | */ | |
711 | /* RFC 7.2.4 & the Implementers Guide 2.8. | |
712 | * | |
713 | * 3) ... | |
714 | * When a Fast Retransmit is being performed the sender SHOULD | |
715 | * ignore the value of cwnd and SHOULD NOT delay retransmission. | |
716 | */ | |
723189fa DL |
717 | if (chunk->fast_retransmit != SCTP_NEED_FRTX && |
718 | flight_size >= transport->cwnd) | |
719 | return SCTP_XMIT_RWND_FULL; | |
1da177e4 LT |
720 | |
721 | /* Nagle's algorithm to solve small-packet problem: | |
722 | * Inhibit the sending of new chunks when new outgoing data arrives | |
723 | * if any previously transmitted data on the connection remains | |
724 | * unacknowledged. | |
725 | */ | |
1da177e4 | 726 | |
4ea0c32f | 727 | if ((sctp_sk(asoc->base.sk)->nodelay || inflight == 0) && |
f9ba3501 | 728 | !asoc->force_delay) |
4ea0c32f | 729 | /* Nothing unacked */ |
723189fa DL |
730 | return SCTP_XMIT_OK; |
731 | ||
732 | if (!sctp_packet_empty(packet)) | |
733 | /* Append to packet */ | |
734 | return SCTP_XMIT_OK; | |
735 | ||
723189fa DL |
736 | if (!sctp_state(asoc, ESTABLISHED)) |
737 | return SCTP_XMIT_OK; | |
738 | ||
739 | /* Check whether this chunk and all the rest of pending data will fit | |
740 | * or delay in hopes of bundling a full sized packet. | |
741 | */ | |
9f8d3147 | 742 | if (chunk->skb->len + q->out_qlen > transport->pathmtu - |
668c9beb | 743 | packet->overhead - sctp_datachk_len(&chunk->asoc->stream) - 4) |
723189fa DL |
744 | /* Enough data queued to fill a packet */ |
745 | return SCTP_XMIT_OK; | |
746 | ||
747 | /* Don't delay large message writes that may have been fragmented */ | |
748 | if (!chunk->msg->can_delay) | |
749 | return SCTP_XMIT_OK; | |
750 | ||
751 | /* Defer until all data acked or packet full */ | |
526cbef7 | 752 | return SCTP_XMIT_DELAY; |
e83963b7 VY |
753 | } |
754 | ||
755 | /* This private function does management things when adding DATA chunk */ | |
756 | static void sctp_packet_append_data(struct sctp_packet *packet, | |
757 | struct sctp_chunk *chunk) | |
758 | { | |
759 | struct sctp_transport *transport = packet->transport; | |
760 | size_t datasize = sctp_data_size(chunk); | |
761 | struct sctp_association *asoc = transport->asoc; | |
762 | u32 rwnd = asoc->peer.rwnd; | |
763 | ||
1da177e4 LT |
764 | /* Keep track of how many bytes are in flight over this transport. */ |
765 | transport->flight_size += datasize; | |
766 | ||
767 | /* Keep track of how many bytes are in flight to the receiver. */ | |
768 | asoc->outqueue.outstanding_bytes += datasize; | |
769 | ||
a76c0adf | 770 | /* Update our view of the receiver's rwnd. */ |
1da177e4 LT |
771 | if (datasize < rwnd) |
772 | rwnd -= datasize; | |
773 | else | |
774 | rwnd = 0; | |
775 | ||
776 | asoc->peer.rwnd = rwnd; | |
d8dd1578 | 777 | sctp_chunk_assign_tsn(chunk); |
668c9beb | 778 | asoc->stream.si->assign_number(chunk); |
e83963b7 VY |
779 | } |
780 | ||
86b36f2a XL |
781 | static enum sctp_xmit sctp_packet_will_fit(struct sctp_packet *packet, |
782 | struct sctp_chunk *chunk, | |
783 | u16 chunk_len) | |
e83963b7 | 784 | { |
86b36f2a | 785 | enum sctp_xmit retval = SCTP_XMIT_OK; |
7303a147 | 786 | size_t psize, pmtu, maxsize; |
e83963b7 | 787 | |
1b1e0bc9 XL |
788 | /* Don't bundle in this packet if this chunk's auth key doesn't |
789 | * match other chunks already enqueued on this packet. Also, | |
790 | * don't bundle the chunk with auth key if other chunks in this | |
791 | * packet don't have auth key. | |
792 | */ | |
793 | if ((packet->auth && chunk->shkey != packet->auth->shkey) || | |
794 | (!packet->auth && chunk->shkey && | |
795 | chunk->chunk_hdr->type != SCTP_CID_AUTH)) | |
796 | return SCTP_XMIT_PMTU_FULL; | |
797 | ||
e83963b7 | 798 | psize = packet->size; |
90017acc MRL |
799 | if (packet->transport->asoc) |
800 | pmtu = packet->transport->asoc->pathmtu; | |
801 | else | |
802 | pmtu = packet->transport->pathmtu; | |
e83963b7 VY |
803 | |
804 | /* Decide if we need to fragment or resubmit later. */ | |
90017acc MRL |
805 | if (psize + chunk_len > pmtu) { |
806 | /* It's OK to fragment at IP level if any one of the following | |
e83963b7 | 807 | * is true: |
90017acc MRL |
808 | * 1. The packet is empty (meaning this chunk is greater |
809 | * the MTU) | |
810 | * 2. The packet doesn't have any data in it yet and data | |
811 | * requires authentication. | |
e83963b7 | 812 | */ |
90017acc | 813 | if (sctp_packet_empty(packet) || |
e83963b7 VY |
814 | (!packet->has_data && chunk->auth)) { |
815 | /* We no longer do re-fragmentation. | |
816 | * Just fragment at the IP layer, if we | |
817 | * actually hit this condition | |
818 | */ | |
819 | packet->ipfragok = 1; | |
90017acc | 820 | goto out; |
e83963b7 | 821 | } |
90017acc | 822 | |
7303a147 MRL |
823 | /* Similarly, if this chunk was built before a PMTU |
824 | * reduction, we have to fragment it at IP level now. So | |
825 | * if the packet already contains something, we need to | |
826 | * flush. | |
827 | */ | |
828 | maxsize = pmtu - packet->overhead; | |
829 | if (packet->auth) | |
e2f036a9 | 830 | maxsize -= SCTP_PAD4(packet->auth->skb->len); |
7303a147 MRL |
831 | if (chunk_len > maxsize) |
832 | retval = SCTP_XMIT_PMTU_FULL; | |
833 | ||
90017acc MRL |
834 | /* It is also okay to fragment if the chunk we are |
835 | * adding is a control chunk, but only if current packet | |
836 | * is not a GSO one otherwise it causes fragmentation of | |
837 | * a large frame. So in this case we allow the | |
838 | * fragmentation by forcing it to be in a new packet. | |
839 | */ | |
840 | if (!sctp_chunk_is_data(chunk) && packet->has_data) | |
841 | retval = SCTP_XMIT_PMTU_FULL; | |
842 | ||
843 | if (psize + chunk_len > packet->max_size) | |
844 | /* Hit GSO/PMTU limit, gotta flush */ | |
845 | retval = SCTP_XMIT_PMTU_FULL; | |
846 | ||
847 | if (!packet->transport->burst_limited && | |
848 | psize + chunk_len > (packet->transport->cwnd >> 1)) | |
849 | /* Do not allow a single GSO packet to use more | |
850 | * than half of cwnd. | |
851 | */ | |
852 | retval = SCTP_XMIT_PMTU_FULL; | |
853 | ||
854 | if (packet->transport->burst_limited && | |
855 | psize + chunk_len > (packet->transport->burst_limited >> 1)) | |
856 | /* Do not allow a single GSO packet to use more | |
857 | * than half of original cwnd. | |
858 | */ | |
859 | retval = SCTP_XMIT_PMTU_FULL; | |
860 | /* Otherwise it will fit in the GSO packet */ | |
e83963b7 | 861 | } |
1da177e4 | 862 | |
90017acc | 863 | out: |
1da177e4 LT |
864 | return retval; |
865 | } |