Commit | Line | Data |
---|---|---|
7c657876 ACM |
1 | /* |
2 | * net/dccp/input.c | |
8109b02b | 3 | * |
7c657876 ACM |
4 | * An implementation of the DCCP protocol |
5 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | */ | |
12 | ||
7c657876 ACM |
13 | #include <linux/dccp.h> |
14 | #include <linux/skbuff.h> | |
15 | ||
16 | #include <net/sock.h> | |
17 | ||
ae31c339 | 18 | #include "ackvec.h" |
7c657876 ACM |
19 | #include "ccid.h" |
20 | #include "dccp.h" | |
21 | ||
22 | static void dccp_fin(struct sock *sk, struct sk_buff *skb) | |
23 | { | |
24 | sk->sk_shutdown |= RCV_SHUTDOWN; | |
25 | sock_set_flag(sk, SOCK_DONE); | |
26 | __skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4); | |
27 | __skb_queue_tail(&sk->sk_receive_queue, skb); | |
28 | skb_set_owner_r(skb, sk); | |
29 | sk->sk_data_ready(sk, 0); | |
30 | } | |
31 | ||
32 | static void dccp_rcv_close(struct sock *sk, struct sk_buff *skb) | |
33 | { | |
017487d7 | 34 | dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); |
7ad07e7c ACM |
35 | dccp_fin(sk, skb); |
36 | dccp_set_state(sk, DCCP_CLOSED); | |
331968bd | 37 | sk_wake_async(sk, 1, POLL_HUP); |
7c657876 ACM |
38 | } |
39 | ||
40 | static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) | |
41 | { | |
42 | /* | |
43 | * Step 7: Check for unexpected packet types | |
44 | * If (S.is_server and P.type == CloseReq) | |
45 | * Send Sync packet acknowledging P.seqno | |
46 | * Drop packet and return | |
47 | */ | |
48 | if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) { | |
e92ae93a | 49 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); |
7c657876 ACM |
50 | return; |
51 | } | |
52 | ||
811265b8 ACM |
53 | if (sk->sk_state != DCCP_CLOSING) |
54 | dccp_set_state(sk, DCCP_CLOSING); | |
7ad07e7c | 55 | dccp_send_close(sk, 0); |
7c657876 ACM |
56 | } |
57 | ||
c25a18ba | 58 | static void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
59 | { |
60 | struct dccp_sock *dp = dccp_sk(sk); | |
61 | ||
a4bf3902 | 62 | if (dccp_msk(sk)->dccpms_send_ack_vector) |
ae31c339 ACM |
63 | dccp_ackvec_check_rcv_ackno(dp->dccps_hc_rx_ackvec, sk, |
64 | DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
7c657876 ACM |
65 | } |
66 | ||
67 | static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb) | |
68 | { | |
69 | const struct dccp_hdr *dh = dccp_hdr(skb); | |
70 | struct dccp_sock *dp = dccp_sk(sk); | |
cbe1f5f8 GR |
71 | u64 lswl, lawl, seqno = DCCP_SKB_CB(skb)->dccpd_seq, |
72 | ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; | |
7c657876 ACM |
73 | |
74 | /* | |
75 | * Step 5: Prepare sequence numbers for Sync | |
76 | * If P.type == Sync or P.type == SyncAck, | |
77 | * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL, | |
78 | * / * P is valid, so update sequence number variables | |
79 | * accordingly. After this update, P will pass the tests | |
80 | * in Step 6. A SyncAck is generated if necessary in | |
81 | * Step 15 * / | |
82 | * Update S.GSR, S.SWL, S.SWH | |
83 | * Otherwise, | |
84 | * Drop packet and return | |
85 | */ | |
8109b02b | 86 | if (dh->dccph_type == DCCP_PKT_SYNC || |
7c657876 | 87 | dh->dccph_type == DCCP_PKT_SYNCACK) { |
cbe1f5f8 GR |
88 | if (between48(ackno, dp->dccps_awl, dp->dccps_awh) && |
89 | dccp_delta_seqno(dp->dccps_swl, seqno) >= 0) | |
90 | dccp_update_gsr(sk, seqno); | |
7c657876 ACM |
91 | else |
92 | return -1; | |
e92ae93a | 93 | } |
c9eaf173 | 94 | |
7c657876 ACM |
95 | /* |
96 | * Step 6: Check sequence numbers | |
97 | * Let LSWL = S.SWL and LAWL = S.AWL | |
98 | * If P.type == CloseReq or P.type == Close or P.type == Reset, | |
99 | * LSWL := S.GSR + 1, LAWL := S.GAR | |
100 | * If LSWL <= P.seqno <= S.SWH | |
101 | * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH), | |
102 | * Update S.GSR, S.SWL, S.SWH | |
103 | * If P.type != Sync, | |
104 | * Update S.GAR | |
7c657876 | 105 | */ |
e92ae93a ACM |
106 | lswl = dp->dccps_swl; |
107 | lawl = dp->dccps_awl; | |
108 | ||
109 | if (dh->dccph_type == DCCP_PKT_CLOSEREQ || | |
c59eab46 ACM |
110 | dh->dccph_type == DCCP_PKT_CLOSE || |
111 | dh->dccph_type == DCCP_PKT_RESET) { | |
cbe1f5f8 | 112 | lswl = ADD48(dp->dccps_gsr, 1); |
7c657876 ACM |
113 | lawl = dp->dccps_gar; |
114 | } | |
115 | ||
cbe1f5f8 GR |
116 | if (between48(seqno, lswl, dp->dccps_swh) && |
117 | (ackno == DCCP_PKT_WITHOUT_ACK_SEQ || | |
118 | between48(ackno, lawl, dp->dccps_awh))) { | |
119 | dccp_update_gsr(sk, seqno); | |
7c657876 ACM |
120 | |
121 | if (dh->dccph_type != DCCP_PKT_SYNC && | |
cbe1f5f8 GR |
122 | (ackno != DCCP_PKT_WITHOUT_ACK_SEQ)) |
123 | dp->dccps_gar = ackno; | |
7c657876 | 124 | } else { |
59348b19 GR |
125 | DCCP_WARN("DCCP: Step 6 failed for %s packet, " |
126 | "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and " | |
127 | "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), " | |
128 | "sending SYNC...\n", dccp_packet_name(dh->dccph_type), | |
cbe1f5f8 | 129 | (unsigned long long) lswl, (unsigned long long) seqno, |
59348b19 | 130 | (unsigned long long) dp->dccps_swh, |
cbe1f5f8 GR |
131 | (ackno == DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist" |
132 | : "exists", | |
133 | (unsigned long long) lawl, (unsigned long long) ackno, | |
59348b19 | 134 | (unsigned long long) dp->dccps_awh); |
e155d769 GR |
135 | /* |
136 | * Step 6: Check sequence numbers | |
137 | * Otherwise, | |
138 | * If P.type == Reset, | |
139 | * Send Sync packet acknowledging S.GSR | |
140 | * Otherwise, | |
141 | * Send Sync packet acknowledging P.seqno | |
142 | * Drop packet and return | |
143 | */ | |
144 | if (dh->dccph_type == DCCP_PKT_RESET) | |
145 | seqno = dp->dccps_gsr; | |
cbe1f5f8 | 146 | dccp_send_sync(sk, seqno, DCCP_PKT_SYNC); |
7c657876 ACM |
147 | return -1; |
148 | } | |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
c25a18ba ACM |
153 | static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, |
154 | const struct dccp_hdr *dh, const unsigned len) | |
7c657876 ACM |
155 | { |
156 | struct dccp_sock *dp = dccp_sk(sk); | |
157 | ||
7c657876 ACM |
158 | switch (dccp_hdr(skb)->dccph_type) { |
159 | case DCCP_PKT_DATAACK: | |
160 | case DCCP_PKT_DATA: | |
161 | /* | |
7690af3f ACM |
162 | * FIXME: check if sk_receive_queue is full, schedule DATA_DROPPED |
163 | * option if it is. | |
7c657876 ACM |
164 | */ |
165 | __skb_pull(skb, dh->dccph_doff * 4); | |
166 | __skb_queue_tail(&sk->sk_receive_queue, skb); | |
167 | skb_set_owner_r(skb, sk); | |
168 | sk->sk_data_ready(sk, 0); | |
169 | return 0; | |
170 | case DCCP_PKT_ACK: | |
171 | goto discard; | |
172 | case DCCP_PKT_RESET: | |
173 | /* | |
174 | * Step 9: Process Reset | |
175 | * If P.type == Reset, | |
176 | * Tear down connection | |
177 | * S.state := TIMEWAIT | |
178 | * Set TIMEWAIT timer | |
179 | * Drop packet and return | |
180 | */ | |
181 | dccp_fin(sk, skb); | |
182 | dccp_time_wait(sk, DCCP_TIME_WAIT, 0); | |
183 | return 0; | |
184 | case DCCP_PKT_CLOSEREQ: | |
185 | dccp_rcv_closereq(sk, skb); | |
186 | goto discard; | |
187 | case DCCP_PKT_CLOSE: | |
188 | dccp_rcv_close(sk, skb); | |
189 | return 0; | |
190 | case DCCP_PKT_REQUEST: | |
8109b02b ACM |
191 | /* Step 7 |
192 | * or (S.is_server and P.type == Response) | |
7c657876 ACM |
193 | * or (S.is_client and P.type == Request) |
194 | * or (S.state >= OPEN and P.type == Request | |
195 | * and P.seqno >= S.OSR) | |
196 | * or (S.state >= OPEN and P.type == Response | |
197 | * and P.seqno >= S.OSR) | |
198 | * or (S.state == RESPOND and P.type == Data), | |
199 | * Send Sync packet acknowledging P.seqno | |
200 | * Drop packet and return | |
201 | */ | |
202 | if (dp->dccps_role != DCCP_ROLE_LISTEN) | |
203 | goto send_sync; | |
204 | goto check_seq; | |
205 | case DCCP_PKT_RESPONSE: | |
206 | if (dp->dccps_role != DCCP_ROLE_CLIENT) | |
207 | goto send_sync; | |
208 | check_seq: | |
8d13bf9a GR |
209 | if (dccp_delta_seqno(dp->dccps_osr, |
210 | DCCP_SKB_CB(skb)->dccpd_seq) >= 0) { | |
7c657876 | 211 | send_sync: |
e92ae93a ACM |
212 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, |
213 | DCCP_PKT_SYNC); | |
7c657876 ACM |
214 | } |
215 | break; | |
e92ae93a ACM |
216 | case DCCP_PKT_SYNC: |
217 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, | |
218 | DCCP_PKT_SYNCACK); | |
219 | /* | |
0e64e94e | 220 | * From RFC 4340, sec. 5.7 |
e92ae93a ACM |
221 | * |
222 | * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets | |
223 | * MAY have non-zero-length application data areas, whose | |
0e64e94e | 224 | * contents receivers MUST ignore. |
e92ae93a ACM |
225 | */ |
226 | goto discard; | |
7c657876 ACM |
227 | } |
228 | ||
229 | DCCP_INC_STATS_BH(DCCP_MIB_INERRS); | |
230 | discard: | |
231 | __kfree_skb(skb); | |
232 | return 0; | |
233 | } | |
234 | ||
709dd3aa AB |
235 | int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, |
236 | const struct dccp_hdr *dh, const unsigned len) | |
237 | { | |
238 | struct dccp_sock *dp = dccp_sk(sk); | |
239 | ||
240 | if (dccp_check_seqno(sk, skb)) | |
241 | goto discard; | |
242 | ||
243 | if (dccp_parse_options(sk, skb)) | |
244 | goto discard; | |
245 | ||
246 | if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) | |
247 | dccp_event_ack_recv(sk, skb); | |
248 | ||
a4bf3902 | 249 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
709dd3aa AB |
250 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, |
251 | DCCP_SKB_CB(skb)->dccpd_seq, | |
252 | DCCP_ACKVEC_STATE_RECEIVED)) | |
253 | goto discard; | |
254 | ||
151a9931 GR |
255 | ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); |
256 | ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); | |
709dd3aa AB |
257 | |
258 | return __dccp_rcv_established(sk, skb, dh, len); | |
259 | discard: | |
260 | __kfree_skb(skb); | |
261 | return 0; | |
262 | } | |
263 | ||
f21e68ca ACM |
264 | EXPORT_SYMBOL_GPL(dccp_rcv_established); |
265 | ||
7c657876 ACM |
266 | static int dccp_rcv_request_sent_state_process(struct sock *sk, |
267 | struct sk_buff *skb, | |
268 | const struct dccp_hdr *dh, | |
269 | const unsigned len) | |
270 | { | |
8109b02b | 271 | /* |
7c657876 ACM |
272 | * Step 4: Prepare sequence numbers in REQUEST |
273 | * If S.state == REQUEST, | |
274 | * If (P.type == Response or P.type == Reset) | |
275 | * and S.AWL <= P.ackno <= S.AWH, | |
276 | * / * Set sequence number variables corresponding to the | |
277 | * other endpoint, so P will pass the tests in Step 6 * / | |
278 | * Set S.GSR, S.ISR, S.SWL, S.SWH | |
279 | * / * Response processing continues in Step 10; Reset | |
280 | * processing continues in Step 9 * / | |
281 | */ | |
282 | if (dh->dccph_type == DCCP_PKT_RESPONSE) { | |
283 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
284 | struct dccp_sock *dp = dccp_sk(sk); | |
3393da82 | 285 | long tstamp = dccp_timestamp(); |
7c657876 ACM |
286 | |
287 | /* Stop the REQUEST timer */ | |
288 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); | |
289 | BUG_TRAP(sk->sk_send_head != NULL); | |
290 | __kfree_skb(sk->sk_send_head); | |
291 | sk->sk_send_head = NULL; | |
292 | ||
7690af3f ACM |
293 | if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, |
294 | dp->dccps_awl, dp->dccps_awh)) { | |
295 | dccp_pr_debug("invalid ackno: S.AWL=%llu, " | |
296 | "P.ackno=%llu, S.AWH=%llu \n", | |
297 | (unsigned long long)dp->dccps_awl, | |
298 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, | |
299 | (unsigned long long)dp->dccps_awh); | |
7c657876 ACM |
300 | goto out_invalid_packet; |
301 | } | |
9e377202 | 302 | |
afe00251 AB |
303 | if (dccp_parse_options(sk, skb)) |
304 | goto out_invalid_packet; | |
305 | ||
3393da82 GR |
306 | /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */ |
307 | if (likely(dp->dccps_options_received.dccpor_timestamp_echo)) | |
308 | dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp - | |
309 | dp->dccps_options_received.dccpor_timestamp_echo)); | |
89560b53 | 310 | |
c9eaf173 YH |
311 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
312 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, | |
313 | DCCP_SKB_CB(skb)->dccpd_seq, | |
314 | DCCP_ACKVEC_STATE_RECEIVED)) | |
315 | goto out_invalid_packet; /* FIXME: change error code */ | |
7c657876 ACM |
316 | |
317 | dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; | |
03ace394 ACM |
318 | dccp_update_gsr(sk, dp->dccps_isr); |
319 | /* | |
320 | * SWL and AWL are initially adjusted so that they are not less than | |
321 | * the initial Sequence Numbers received and sent, respectively: | |
322 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
323 | * AWL := max(GSS - W' + 1, ISS). | |
324 | * These adjustments MUST be applied only at the beginning of the | |
325 | * connection. | |
326 | * | |
327 | * AWL was adjusted in dccp_v4_connect -acme | |
328 | */ | |
329 | dccp_set_seqno(&dp->dccps_swl, | |
330 | max48(dp->dccps_swl, dp->dccps_isr)); | |
7c657876 | 331 | |
d83d8461 | 332 | dccp_sync_mss(sk, icsk->icsk_pmtu_cookie); |
7c657876 ACM |
333 | |
334 | /* | |
335 | * Step 10: Process REQUEST state (second part) | |
336 | * If S.state == REQUEST, | |
7690af3f ACM |
337 | * / * If we get here, P is a valid Response from the |
338 | * server (see Step 4), and we should move to | |
339 | * PARTOPEN state. PARTOPEN means send an Ack, | |
340 | * don't send Data packets, retransmit Acks | |
341 | * periodically, and always include any Init Cookie | |
342 | * from the Response * / | |
7c657876 ACM |
343 | * S.state := PARTOPEN |
344 | * Set PARTOPEN timer | |
8109b02b | 345 | * Continue with S.state == PARTOPEN |
7690af3f ACM |
346 | * / * Step 12 will send the Ack completing the |
347 | * three-way handshake * / | |
7c657876 ACM |
348 | */ |
349 | dccp_set_state(sk, DCCP_PARTOPEN); | |
350 | ||
351 | /* Make sure socket is routed, for correct metrics. */ | |
57cca05a | 352 | icsk->icsk_af_ops->rebuild_header(sk); |
7c657876 ACM |
353 | |
354 | if (!sock_flag(sk, SOCK_DEAD)) { | |
355 | sk->sk_state_change(sk); | |
356 | sk_wake_async(sk, 0, POLL_OUT); | |
357 | } | |
358 | ||
359 | if (sk->sk_write_pending || icsk->icsk_ack.pingpong || | |
360 | icsk->icsk_accept_queue.rskq_defer_accept) { | |
361 | /* Save one ACK. Data will be ready after | |
362 | * several ticks, if write_pending is set. | |
363 | * | |
364 | * It may be deleted, but with this feature tcpdumps | |
365 | * look so _wonderfully_ clever, that I was not able | |
366 | * to stand against the temptation 8) --ANK | |
367 | */ | |
368 | /* | |
369 | * OK, in DCCP we can as well do a similar trick, its | |
370 | * even in the draft, but there is no need for us to | |
371 | * schedule an ack here, as dccp_sendmsg does this for | |
372 | * us, also stated in the draft. -acme | |
373 | */ | |
374 | __kfree_skb(skb); | |
375 | return 0; | |
8109b02b | 376 | } |
7c657876 ACM |
377 | dccp_send_ack(sk); |
378 | return -1; | |
379 | } | |
380 | ||
381 | out_invalid_packet: | |
0c10c5d9 ACM |
382 | /* dccp_v4_do_rcv will send a reset */ |
383 | DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; | |
8109b02b | 384 | return 1; |
7c657876 ACM |
385 | } |
386 | ||
387 | static int dccp_rcv_respond_partopen_state_process(struct sock *sk, | |
388 | struct sk_buff *skb, | |
389 | const struct dccp_hdr *dh, | |
390 | const unsigned len) | |
391 | { | |
392 | int queued = 0; | |
393 | ||
394 | switch (dh->dccph_type) { | |
395 | case DCCP_PKT_RESET: | |
396 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); | |
397 | break; | |
2a9bc9bb ACM |
398 | case DCCP_PKT_DATA: |
399 | if (sk->sk_state == DCCP_RESPOND) | |
400 | break; | |
7c657876 ACM |
401 | case DCCP_PKT_DATAACK: |
402 | case DCCP_PKT_ACK: | |
403 | /* | |
7690af3f ACM |
404 | * FIXME: we should be reseting the PARTOPEN (DELACK) timer |
405 | * here but only if we haven't used the DELACK timer for | |
406 | * something else, like sending a delayed ack for a TIMESTAMP | |
407 | * echo, etc, for now were not clearing it, sending an extra | |
408 | * ACK when there is nothing else to do in DELACK is not a big | |
409 | * deal after all. | |
7c657876 ACM |
410 | */ |
411 | ||
412 | /* Stop the PARTOPEN timer */ | |
413 | if (sk->sk_state == DCCP_PARTOPEN) | |
414 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); | |
415 | ||
416 | dccp_sk(sk)->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq; | |
417 | dccp_set_state(sk, DCCP_OPEN); | |
418 | ||
2a9bc9bb ACM |
419 | if (dh->dccph_type == DCCP_PKT_DATAACK || |
420 | dh->dccph_type == DCCP_PKT_DATA) { | |
709dd3aa | 421 | __dccp_rcv_established(sk, skb, dh, len); |
7690af3f | 422 | queued = 1; /* packet was queued |
709dd3aa | 423 | (by __dccp_rcv_established) */ |
7c657876 ACM |
424 | } |
425 | break; | |
426 | } | |
427 | ||
428 | return queued; | |
429 | } | |
430 | ||
431 | int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, | |
432 | struct dccp_hdr *dh, unsigned len) | |
433 | { | |
434 | struct dccp_sock *dp = dccp_sk(sk); | |
0c10c5d9 | 435 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
7c657876 ACM |
436 | const int old_state = sk->sk_state; |
437 | int queued = 0; | |
438 | ||
8649b0d4 ACM |
439 | /* |
440 | * Step 3: Process LISTEN state | |
8649b0d4 ACM |
441 | * |
442 | * If S.state == LISTEN, | |
d83ca5ac GR |
443 | * If P.type == Request or P contains a valid Init Cookie option, |
444 | * (* Must scan the packet's options to check for Init | |
445 | * Cookies. Only Init Cookies are processed here, | |
446 | * however; other options are processed in Step 8. This | |
447 | * scan need only be performed if the endpoint uses Init | |
448 | * Cookies *) | |
449 | * (* Generate a new socket and switch to that socket *) | |
450 | * Set S := new socket for this port pair | |
451 | * S.state = RESPOND | |
452 | * Choose S.ISS (initial seqno) or set from Init Cookies | |
453 | * Initialize S.GAR := S.ISS | |
454 | * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init | |
455 | * Cookies Continue with S.state == RESPOND | |
456 | * (* A Response packet will be generated in Step 11 *) | |
457 | * Otherwise, | |
458 | * Generate Reset(No Connection) unless P.type == Reset | |
459 | * Drop packet and return | |
8649b0d4 ACM |
460 | */ |
461 | if (sk->sk_state == DCCP_LISTEN) { | |
462 | if (dh->dccph_type == DCCP_PKT_REQUEST) { | |
57cca05a ACM |
463 | if (inet_csk(sk)->icsk_af_ops->conn_request(sk, |
464 | skb) < 0) | |
8649b0d4 ACM |
465 | return 1; |
466 | ||
467 | /* FIXME: do congestion control initialization */ | |
468 | goto discard; | |
469 | } | |
470 | if (dh->dccph_type == DCCP_PKT_RESET) | |
471 | goto discard; | |
472 | ||
0c10c5d9 ACM |
473 | /* Caller (dccp_v4_do_rcv) will send Reset */ |
474 | dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; | |
8649b0d4 ACM |
475 | return 1; |
476 | } | |
477 | ||
478 | if (sk->sk_state != DCCP_REQUESTING) { | |
7c657876 ACM |
479 | if (dccp_check_seqno(sk, skb)) |
480 | goto discard; | |
481 | ||
482 | /* | |
483 | * Step 8: Process options and mark acknowledgeable | |
484 | */ | |
485 | if (dccp_parse_options(sk, skb)) | |
486 | goto discard; | |
487 | ||
0c10c5d9 | 488 | if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) |
7c657876 ACM |
489 | dccp_event_ack_recv(sk, skb); |
490 | ||
8109b02b | 491 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
ae31c339 | 492 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, |
8109b02b ACM |
493 | DCCP_SKB_CB(skb)->dccpd_seq, |
494 | DCCP_ACKVEC_STATE_RECEIVED)) | |
495 | goto discard; | |
e84a9f5e | 496 | |
151a9931 GR |
497 | ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); |
498 | ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); | |
7c657876 ACM |
499 | } |
500 | ||
501 | /* | |
502 | * Step 9: Process Reset | |
503 | * If P.type == Reset, | |
504 | * Tear down connection | |
505 | * S.state := TIMEWAIT | |
506 | * Set TIMEWAIT timer | |
507 | * Drop packet and return | |
508 | */ | |
509 | if (dh->dccph_type == DCCP_PKT_RESET) { | |
7690af3f ACM |
510 | /* |
511 | * Queue the equivalent of TCP fin so that dccp_recvmsg | |
512 | * exits the loop | |
513 | */ | |
7c657876 ACM |
514 | dccp_fin(sk, skb); |
515 | dccp_time_wait(sk, DCCP_TIME_WAIT, 0); | |
516 | return 0; | |
517 | /* | |
518 | * Step 7: Check for unexpected packet types | |
519 | * If (S.is_server and P.type == CloseReq) | |
520 | * or (S.is_server and P.type == Response) | |
521 | * or (S.is_client and P.type == Request) | |
522 | * or (S.state == RESPOND and P.type == Data), | |
523 | * Send Sync packet acknowledging P.seqno | |
524 | * Drop packet and return | |
525 | */ | |
526 | } else if ((dp->dccps_role != DCCP_ROLE_CLIENT && | |
7690af3f ACM |
527 | (dh->dccph_type == DCCP_PKT_RESPONSE || |
528 | dh->dccph_type == DCCP_PKT_CLOSEREQ)) || | |
7c657876 ACM |
529 | (dp->dccps_role == DCCP_ROLE_CLIENT && |
530 | dh->dccph_type == DCCP_PKT_REQUEST) || | |
7690af3f ACM |
531 | (sk->sk_state == DCCP_RESPOND && |
532 | dh->dccph_type == DCCP_PKT_DATA)) { | |
0c10c5d9 | 533 | dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC); |
7c657876 | 534 | goto discard; |
7ad07e7c ACM |
535 | } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { |
536 | dccp_rcv_closereq(sk, skb); | |
537 | goto discard; | |
538 | } else if (dh->dccph_type == DCCP_PKT_CLOSE) { | |
539 | dccp_rcv_close(sk, skb); | |
540 | return 0; | |
7c657876 ACM |
541 | } |
542 | ||
543 | switch (sk->sk_state) { | |
544 | case DCCP_CLOSED: | |
0c10c5d9 | 545 | dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; |
7c657876 ACM |
546 | return 1; |
547 | ||
7c657876 ACM |
548 | case DCCP_REQUESTING: |
549 | /* FIXME: do congestion control initialization */ | |
550 | ||
551 | queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); | |
552 | if (queued >= 0) | |
553 | return queued; | |
554 | ||
555 | __kfree_skb(skb); | |
556 | return 0; | |
557 | ||
558 | case DCCP_RESPOND: | |
559 | case DCCP_PARTOPEN: | |
7690af3f ACM |
560 | queued = dccp_rcv_respond_partopen_state_process(sk, skb, |
561 | dh, len); | |
7c657876 ACM |
562 | break; |
563 | } | |
564 | ||
7690af3f ACM |
565 | if (dh->dccph_type == DCCP_PKT_ACK || |
566 | dh->dccph_type == DCCP_PKT_DATAACK) { | |
7c657876 ACM |
567 | switch (old_state) { |
568 | case DCCP_PARTOPEN: | |
569 | sk->sk_state_change(sk); | |
570 | sk_wake_async(sk, 0, POLL_OUT); | |
571 | break; | |
572 | } | |
08831700 GR |
573 | } else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) { |
574 | dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK); | |
575 | goto discard; | |
7c657876 ACM |
576 | } |
577 | ||
8109b02b | 578 | if (!queued) { |
7c657876 ACM |
579 | discard: |
580 | __kfree_skb(skb); | |
581 | } | |
582 | return 0; | |
583 | } | |
f21e68ca ACM |
584 | |
585 | EXPORT_SYMBOL_GPL(dccp_rcv_state_process); | |
4712a792 GR |
586 | |
587 | /** | |
3393da82 GR |
588 | * dccp_sample_rtt - Validate and finalise computation of RTT sample |
589 | * @delta: number of microseconds between packet and acknowledgment | |
590 | * The routine is kept generic to work in different contexts. It should be | |
591 | * called immediately when the ACK used for the RTT sample arrives. | |
4712a792 | 592 | */ |
3393da82 | 593 | u32 dccp_sample_rtt(struct sock *sk, long delta) |
4712a792 | 594 | { |
3393da82 GR |
595 | /* dccpor_elapsed_time is either zeroed out or set and > 0 */ |
596 | delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10; | |
4712a792 GR |
597 | |
598 | if (unlikely(delta <= 0)) { | |
3393da82 | 599 | DCCP_WARN("unusable RTT sample %ld, using min\n", delta); |
4712a792 GR |
600 | return DCCP_SANE_RTT_MIN; |
601 | } | |
3393da82 GR |
602 | if (unlikely(delta > DCCP_SANE_RTT_MAX)) { |
603 | DCCP_WARN("RTT sample %ld too large, using max\n", delta); | |
4712a792 GR |
604 | return DCCP_SANE_RTT_MAX; |
605 | } | |
606 | ||
607 | return delta; | |
608 | } | |
609 | ||
610 | EXPORT_SYMBOL_GPL(dccp_sample_rtt); |