Commit | Line | Data |
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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); | |
e92ae93a | 71 | u64 lswl, lawl; |
7c657876 ACM |
72 | |
73 | /* | |
74 | * Step 5: Prepare sequence numbers for Sync | |
75 | * If P.type == Sync or P.type == SyncAck, | |
76 | * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL, | |
77 | * / * P is valid, so update sequence number variables | |
78 | * accordingly. After this update, P will pass the tests | |
79 | * in Step 6. A SyncAck is generated if necessary in | |
80 | * Step 15 * / | |
81 | * Update S.GSR, S.SWL, S.SWH | |
82 | * Otherwise, | |
83 | * Drop packet and return | |
84 | */ | |
8109b02b | 85 | if (dh->dccph_type == DCCP_PKT_SYNC || |
7c657876 | 86 | dh->dccph_type == DCCP_PKT_SYNCACK) { |
7690af3f ACM |
87 | if (between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, |
88 | dp->dccps_awl, dp->dccps_awh) && | |
8d13bf9a GR |
89 | dccp_delta_seqno(dp->dccps_swl, |
90 | DCCP_SKB_CB(skb)->dccpd_seq) >= 0) | |
7c657876 ACM |
91 | dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq); |
92 | else | |
93 | return -1; | |
e92ae93a | 94 | } |
c9eaf173 | 95 | |
7c657876 ACM |
96 | /* |
97 | * Step 6: Check sequence numbers | |
98 | * Let LSWL = S.SWL and LAWL = S.AWL | |
99 | * If P.type == CloseReq or P.type == Close or P.type == Reset, | |
100 | * LSWL := S.GSR + 1, LAWL := S.GAR | |
101 | * If LSWL <= P.seqno <= S.SWH | |
102 | * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH), | |
103 | * Update S.GSR, S.SWL, S.SWH | |
104 | * If P.type != Sync, | |
105 | * Update S.GAR | |
106 | * Otherwise, | |
107 | * Send Sync packet acknowledging P.seqno | |
108 | * Drop packet and return | |
109 | */ | |
e92ae93a ACM |
110 | lswl = dp->dccps_swl; |
111 | lawl = dp->dccps_awl; | |
112 | ||
113 | if (dh->dccph_type == DCCP_PKT_CLOSEREQ || | |
c59eab46 ACM |
114 | dh->dccph_type == DCCP_PKT_CLOSE || |
115 | dh->dccph_type == DCCP_PKT_RESET) { | |
7c657876 ACM |
116 | lswl = dp->dccps_gsr; |
117 | dccp_inc_seqno(&lswl); | |
118 | lawl = dp->dccps_gar; | |
119 | } | |
120 | ||
121 | if (between48(DCCP_SKB_CB(skb)->dccpd_seq, lswl, dp->dccps_swh) && | |
122 | (DCCP_SKB_CB(skb)->dccpd_ack_seq == DCCP_PKT_WITHOUT_ACK_SEQ || | |
7690af3f ACM |
123 | between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, |
124 | lawl, dp->dccps_awh))) { | |
7c657876 ACM |
125 | dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq); |
126 | ||
127 | if (dh->dccph_type != DCCP_PKT_SYNC && | |
7690af3f ACM |
128 | (DCCP_SKB_CB(skb)->dccpd_ack_seq != |
129 | DCCP_PKT_WITHOUT_ACK_SEQ)) | |
7c657876 ACM |
130 | dp->dccps_gar = DCCP_SKB_CB(skb)->dccpd_ack_seq; |
131 | } else { | |
59348b19 GR |
132 | DCCP_WARN("DCCP: Step 6 failed for %s packet, " |
133 | "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and " | |
134 | "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), " | |
135 | "sending SYNC...\n", dccp_packet_name(dh->dccph_type), | |
136 | (unsigned long long) lswl, | |
137 | (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq, | |
138 | (unsigned long long) dp->dccps_swh, | |
139 | (DCCP_SKB_CB(skb)->dccpd_ack_seq == | |
c9eaf173 | 140 | DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist" : "exists", |
59348b19 GR |
141 | (unsigned long long) lawl, |
142 | (unsigned long long) DCCP_SKB_CB(skb)->dccpd_ack_seq, | |
143 | (unsigned long long) dp->dccps_awh); | |
e92ae93a | 144 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); |
7c657876 ACM |
145 | return -1; |
146 | } | |
147 | ||
148 | return 0; | |
149 | } | |
150 | ||
c25a18ba ACM |
151 | static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, |
152 | const struct dccp_hdr *dh, const unsigned len) | |
7c657876 ACM |
153 | { |
154 | struct dccp_sock *dp = dccp_sk(sk); | |
155 | ||
7c657876 ACM |
156 | switch (dccp_hdr(skb)->dccph_type) { |
157 | case DCCP_PKT_DATAACK: | |
158 | case DCCP_PKT_DATA: | |
159 | /* | |
7690af3f ACM |
160 | * FIXME: check if sk_receive_queue is full, schedule DATA_DROPPED |
161 | * option if it is. | |
7c657876 ACM |
162 | */ |
163 | __skb_pull(skb, dh->dccph_doff * 4); | |
164 | __skb_queue_tail(&sk->sk_receive_queue, skb); | |
165 | skb_set_owner_r(skb, sk); | |
166 | sk->sk_data_ready(sk, 0); | |
167 | return 0; | |
168 | case DCCP_PKT_ACK: | |
169 | goto discard; | |
170 | case DCCP_PKT_RESET: | |
171 | /* | |
172 | * Step 9: Process Reset | |
173 | * If P.type == Reset, | |
174 | * Tear down connection | |
175 | * S.state := TIMEWAIT | |
176 | * Set TIMEWAIT timer | |
177 | * Drop packet and return | |
178 | */ | |
179 | dccp_fin(sk, skb); | |
180 | dccp_time_wait(sk, DCCP_TIME_WAIT, 0); | |
181 | return 0; | |
182 | case DCCP_PKT_CLOSEREQ: | |
183 | dccp_rcv_closereq(sk, skb); | |
184 | goto discard; | |
185 | case DCCP_PKT_CLOSE: | |
186 | dccp_rcv_close(sk, skb); | |
187 | return 0; | |
188 | case DCCP_PKT_REQUEST: | |
8109b02b ACM |
189 | /* Step 7 |
190 | * or (S.is_server and P.type == Response) | |
7c657876 ACM |
191 | * or (S.is_client and P.type == Request) |
192 | * or (S.state >= OPEN and P.type == Request | |
193 | * and P.seqno >= S.OSR) | |
194 | * or (S.state >= OPEN and P.type == Response | |
195 | * and P.seqno >= S.OSR) | |
196 | * or (S.state == RESPOND and P.type == Data), | |
197 | * Send Sync packet acknowledging P.seqno | |
198 | * Drop packet and return | |
199 | */ | |
200 | if (dp->dccps_role != DCCP_ROLE_LISTEN) | |
201 | goto send_sync; | |
202 | goto check_seq; | |
203 | case DCCP_PKT_RESPONSE: | |
204 | if (dp->dccps_role != DCCP_ROLE_CLIENT) | |
205 | goto send_sync; | |
206 | check_seq: | |
8d13bf9a GR |
207 | if (dccp_delta_seqno(dp->dccps_osr, |
208 | DCCP_SKB_CB(skb)->dccpd_seq) >= 0) { | |
7c657876 | 209 | send_sync: |
e92ae93a ACM |
210 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, |
211 | DCCP_PKT_SYNC); | |
7c657876 ACM |
212 | } |
213 | break; | |
e92ae93a ACM |
214 | case DCCP_PKT_SYNC: |
215 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, | |
216 | DCCP_PKT_SYNCACK); | |
217 | /* | |
0e64e94e | 218 | * From RFC 4340, sec. 5.7 |
e92ae93a ACM |
219 | * |
220 | * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets | |
221 | * MAY have non-zero-length application data areas, whose | |
0e64e94e | 222 | * contents receivers MUST ignore. |
e92ae93a ACM |
223 | */ |
224 | goto discard; | |
7c657876 ACM |
225 | } |
226 | ||
227 | DCCP_INC_STATS_BH(DCCP_MIB_INERRS); | |
228 | discard: | |
229 | __kfree_skb(skb); | |
230 | return 0; | |
231 | } | |
232 | ||
709dd3aa AB |
233 | int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, |
234 | const struct dccp_hdr *dh, const unsigned len) | |
235 | { | |
236 | struct dccp_sock *dp = dccp_sk(sk); | |
237 | ||
238 | if (dccp_check_seqno(sk, skb)) | |
239 | goto discard; | |
240 | ||
241 | if (dccp_parse_options(sk, skb)) | |
242 | goto discard; | |
243 | ||
244 | if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) | |
245 | dccp_event_ack_recv(sk, skb); | |
246 | ||
a4bf3902 | 247 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
709dd3aa AB |
248 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, |
249 | DCCP_SKB_CB(skb)->dccpd_seq, | |
250 | DCCP_ACKVEC_STATE_RECEIVED)) | |
251 | goto discard; | |
252 | ||
151a9931 GR |
253 | ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); |
254 | ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); | |
709dd3aa AB |
255 | |
256 | return __dccp_rcv_established(sk, skb, dh, len); | |
257 | discard: | |
258 | __kfree_skb(skb); | |
259 | return 0; | |
260 | } | |
261 | ||
f21e68ca ACM |
262 | EXPORT_SYMBOL_GPL(dccp_rcv_established); |
263 | ||
7c657876 ACM |
264 | static int dccp_rcv_request_sent_state_process(struct sock *sk, |
265 | struct sk_buff *skb, | |
266 | const struct dccp_hdr *dh, | |
267 | const unsigned len) | |
268 | { | |
8109b02b | 269 | /* |
7c657876 ACM |
270 | * Step 4: Prepare sequence numbers in REQUEST |
271 | * If S.state == REQUEST, | |
272 | * If (P.type == Response or P.type == Reset) | |
273 | * and S.AWL <= P.ackno <= S.AWH, | |
274 | * / * Set sequence number variables corresponding to the | |
275 | * other endpoint, so P will pass the tests in Step 6 * / | |
276 | * Set S.GSR, S.ISR, S.SWL, S.SWH | |
277 | * / * Response processing continues in Step 10; Reset | |
278 | * processing continues in Step 9 * / | |
279 | */ | |
280 | if (dh->dccph_type == DCCP_PKT_RESPONSE) { | |
281 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
282 | struct dccp_sock *dp = dccp_sk(sk); | |
283 | ||
284 | /* Stop the REQUEST timer */ | |
285 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); | |
286 | BUG_TRAP(sk->sk_send_head != NULL); | |
287 | __kfree_skb(sk->sk_send_head); | |
288 | sk->sk_send_head = NULL; | |
289 | ||
7690af3f ACM |
290 | if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, |
291 | dp->dccps_awl, dp->dccps_awh)) { | |
292 | dccp_pr_debug("invalid ackno: S.AWL=%llu, " | |
293 | "P.ackno=%llu, S.AWH=%llu \n", | |
294 | (unsigned long long)dp->dccps_awl, | |
295 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, | |
296 | (unsigned long long)dp->dccps_awh); | |
7c657876 ACM |
297 | goto out_invalid_packet; |
298 | } | |
9e377202 | 299 | |
afe00251 AB |
300 | if (dccp_parse_options(sk, skb)) |
301 | goto out_invalid_packet; | |
302 | ||
89560b53 | 303 | /* Obtain RTT sample from SYN exchange (used by CCID 3) */ |
9823b7b5 ACM |
304 | if (dp->dccps_options_received.dccpor_timestamp_echo) |
305 | dp->dccps_syn_rtt = dccp_sample_rtt(sk, | |
306 | ktime_get_real(), | |
307 | NULL); | |
89560b53 | 308 | |
c9eaf173 YH |
309 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
310 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, | |
311 | DCCP_SKB_CB(skb)->dccpd_seq, | |
312 | DCCP_ACKVEC_STATE_RECEIVED)) | |
313 | goto out_invalid_packet; /* FIXME: change error code */ | |
7c657876 ACM |
314 | |
315 | dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; | |
03ace394 ACM |
316 | dccp_update_gsr(sk, dp->dccps_isr); |
317 | /* | |
318 | * SWL and AWL are initially adjusted so that they are not less than | |
319 | * the initial Sequence Numbers received and sent, respectively: | |
320 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
321 | * AWL := max(GSS - W' + 1, ISS). | |
322 | * These adjustments MUST be applied only at the beginning of the | |
323 | * connection. | |
324 | * | |
325 | * AWL was adjusted in dccp_v4_connect -acme | |
326 | */ | |
327 | dccp_set_seqno(&dp->dccps_swl, | |
328 | max48(dp->dccps_swl, dp->dccps_isr)); | |
7c657876 | 329 | |
d83d8461 | 330 | dccp_sync_mss(sk, icsk->icsk_pmtu_cookie); |
7c657876 ACM |
331 | |
332 | /* | |
333 | * Step 10: Process REQUEST state (second part) | |
334 | * If S.state == REQUEST, | |
7690af3f ACM |
335 | * / * If we get here, P is a valid Response from the |
336 | * server (see Step 4), and we should move to | |
337 | * PARTOPEN state. PARTOPEN means send an Ack, | |
338 | * don't send Data packets, retransmit Acks | |
339 | * periodically, and always include any Init Cookie | |
340 | * from the Response * / | |
7c657876 ACM |
341 | * S.state := PARTOPEN |
342 | * Set PARTOPEN timer | |
8109b02b | 343 | * Continue with S.state == PARTOPEN |
7690af3f ACM |
344 | * / * Step 12 will send the Ack completing the |
345 | * three-way handshake * / | |
7c657876 ACM |
346 | */ |
347 | dccp_set_state(sk, DCCP_PARTOPEN); | |
348 | ||
349 | /* Make sure socket is routed, for correct metrics. */ | |
57cca05a | 350 | icsk->icsk_af_ops->rebuild_header(sk); |
7c657876 ACM |
351 | |
352 | if (!sock_flag(sk, SOCK_DEAD)) { | |
353 | sk->sk_state_change(sk); | |
354 | sk_wake_async(sk, 0, POLL_OUT); | |
355 | } | |
356 | ||
357 | if (sk->sk_write_pending || icsk->icsk_ack.pingpong || | |
358 | icsk->icsk_accept_queue.rskq_defer_accept) { | |
359 | /* Save one ACK. Data will be ready after | |
360 | * several ticks, if write_pending is set. | |
361 | * | |
362 | * It may be deleted, but with this feature tcpdumps | |
363 | * look so _wonderfully_ clever, that I was not able | |
364 | * to stand against the temptation 8) --ANK | |
365 | */ | |
366 | /* | |
367 | * OK, in DCCP we can as well do a similar trick, its | |
368 | * even in the draft, but there is no need for us to | |
369 | * schedule an ack here, as dccp_sendmsg does this for | |
370 | * us, also stated in the draft. -acme | |
371 | */ | |
372 | __kfree_skb(skb); | |
373 | return 0; | |
8109b02b | 374 | } |
7c657876 ACM |
375 | dccp_send_ack(sk); |
376 | return -1; | |
377 | } | |
378 | ||
379 | out_invalid_packet: | |
0c10c5d9 ACM |
380 | /* dccp_v4_do_rcv will send a reset */ |
381 | DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; | |
8109b02b | 382 | return 1; |
7c657876 ACM |
383 | } |
384 | ||
385 | static int dccp_rcv_respond_partopen_state_process(struct sock *sk, | |
386 | struct sk_buff *skb, | |
387 | const struct dccp_hdr *dh, | |
388 | const unsigned len) | |
389 | { | |
390 | int queued = 0; | |
391 | ||
392 | switch (dh->dccph_type) { | |
393 | case DCCP_PKT_RESET: | |
394 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); | |
395 | break; | |
2a9bc9bb ACM |
396 | case DCCP_PKT_DATA: |
397 | if (sk->sk_state == DCCP_RESPOND) | |
398 | break; | |
7c657876 ACM |
399 | case DCCP_PKT_DATAACK: |
400 | case DCCP_PKT_ACK: | |
401 | /* | |
7690af3f ACM |
402 | * FIXME: we should be reseting the PARTOPEN (DELACK) timer |
403 | * here but only if we haven't used the DELACK timer for | |
404 | * something else, like sending a delayed ack for a TIMESTAMP | |
405 | * echo, etc, for now were not clearing it, sending an extra | |
406 | * ACK when there is nothing else to do in DELACK is not a big | |
407 | * deal after all. | |
7c657876 ACM |
408 | */ |
409 | ||
410 | /* Stop the PARTOPEN timer */ | |
411 | if (sk->sk_state == DCCP_PARTOPEN) | |
412 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); | |
413 | ||
414 | dccp_sk(sk)->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq; | |
415 | dccp_set_state(sk, DCCP_OPEN); | |
416 | ||
2a9bc9bb ACM |
417 | if (dh->dccph_type == DCCP_PKT_DATAACK || |
418 | dh->dccph_type == DCCP_PKT_DATA) { | |
709dd3aa | 419 | __dccp_rcv_established(sk, skb, dh, len); |
7690af3f | 420 | queued = 1; /* packet was queued |
709dd3aa | 421 | (by __dccp_rcv_established) */ |
7c657876 ACM |
422 | } |
423 | break; | |
424 | } | |
425 | ||
426 | return queued; | |
427 | } | |
428 | ||
429 | int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, | |
430 | struct dccp_hdr *dh, unsigned len) | |
431 | { | |
432 | struct dccp_sock *dp = dccp_sk(sk); | |
0c10c5d9 | 433 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
7c657876 ACM |
434 | const int old_state = sk->sk_state; |
435 | int queued = 0; | |
436 | ||
8649b0d4 ACM |
437 | /* |
438 | * Step 3: Process LISTEN state | |
8649b0d4 ACM |
439 | * |
440 | * If S.state == LISTEN, | |
d83ca5ac GR |
441 | * If P.type == Request or P contains a valid Init Cookie option, |
442 | * (* Must scan the packet's options to check for Init | |
443 | * Cookies. Only Init Cookies are processed here, | |
444 | * however; other options are processed in Step 8. This | |
445 | * scan need only be performed if the endpoint uses Init | |
446 | * Cookies *) | |
447 | * (* Generate a new socket and switch to that socket *) | |
448 | * Set S := new socket for this port pair | |
449 | * S.state = RESPOND | |
450 | * Choose S.ISS (initial seqno) or set from Init Cookies | |
451 | * Initialize S.GAR := S.ISS | |
452 | * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init | |
453 | * Cookies Continue with S.state == RESPOND | |
454 | * (* A Response packet will be generated in Step 11 *) | |
455 | * Otherwise, | |
456 | * Generate Reset(No Connection) unless P.type == Reset | |
457 | * Drop packet and return | |
8649b0d4 ACM |
458 | */ |
459 | if (sk->sk_state == DCCP_LISTEN) { | |
460 | if (dh->dccph_type == DCCP_PKT_REQUEST) { | |
57cca05a ACM |
461 | if (inet_csk(sk)->icsk_af_ops->conn_request(sk, |
462 | skb) < 0) | |
8649b0d4 ACM |
463 | return 1; |
464 | ||
465 | /* FIXME: do congestion control initialization */ | |
466 | goto discard; | |
467 | } | |
468 | if (dh->dccph_type == DCCP_PKT_RESET) | |
469 | goto discard; | |
470 | ||
0c10c5d9 ACM |
471 | /* Caller (dccp_v4_do_rcv) will send Reset */ |
472 | dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; | |
8649b0d4 ACM |
473 | return 1; |
474 | } | |
475 | ||
476 | if (sk->sk_state != DCCP_REQUESTING) { | |
7c657876 ACM |
477 | if (dccp_check_seqno(sk, skb)) |
478 | goto discard; | |
479 | ||
480 | /* | |
481 | * Step 8: Process options and mark acknowledgeable | |
482 | */ | |
483 | if (dccp_parse_options(sk, skb)) | |
484 | goto discard; | |
485 | ||
0c10c5d9 | 486 | if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) |
7c657876 ACM |
487 | dccp_event_ack_recv(sk, skb); |
488 | ||
8109b02b | 489 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
ae31c339 | 490 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, |
8109b02b ACM |
491 | DCCP_SKB_CB(skb)->dccpd_seq, |
492 | DCCP_ACKVEC_STATE_RECEIVED)) | |
493 | goto discard; | |
e84a9f5e | 494 | |
151a9931 GR |
495 | ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); |
496 | ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); | |
7c657876 ACM |
497 | } |
498 | ||
499 | /* | |
500 | * Step 9: Process Reset | |
501 | * If P.type == Reset, | |
502 | * Tear down connection | |
503 | * S.state := TIMEWAIT | |
504 | * Set TIMEWAIT timer | |
505 | * Drop packet and return | |
506 | */ | |
507 | if (dh->dccph_type == DCCP_PKT_RESET) { | |
7690af3f ACM |
508 | /* |
509 | * Queue the equivalent of TCP fin so that dccp_recvmsg | |
510 | * exits the loop | |
511 | */ | |
7c657876 ACM |
512 | dccp_fin(sk, skb); |
513 | dccp_time_wait(sk, DCCP_TIME_WAIT, 0); | |
514 | return 0; | |
515 | /* | |
516 | * Step 7: Check for unexpected packet types | |
517 | * If (S.is_server and P.type == CloseReq) | |
518 | * or (S.is_server and P.type == Response) | |
519 | * or (S.is_client and P.type == Request) | |
520 | * or (S.state == RESPOND and P.type == Data), | |
521 | * Send Sync packet acknowledging P.seqno | |
522 | * Drop packet and return | |
523 | */ | |
524 | } else if ((dp->dccps_role != DCCP_ROLE_CLIENT && | |
7690af3f ACM |
525 | (dh->dccph_type == DCCP_PKT_RESPONSE || |
526 | dh->dccph_type == DCCP_PKT_CLOSEREQ)) || | |
7c657876 ACM |
527 | (dp->dccps_role == DCCP_ROLE_CLIENT && |
528 | dh->dccph_type == DCCP_PKT_REQUEST) || | |
7690af3f ACM |
529 | (sk->sk_state == DCCP_RESPOND && |
530 | dh->dccph_type == DCCP_PKT_DATA)) { | |
0c10c5d9 | 531 | dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC); |
7c657876 | 532 | goto discard; |
7ad07e7c ACM |
533 | } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { |
534 | dccp_rcv_closereq(sk, skb); | |
535 | goto discard; | |
536 | } else if (dh->dccph_type == DCCP_PKT_CLOSE) { | |
537 | dccp_rcv_close(sk, skb); | |
538 | return 0; | |
7c657876 ACM |
539 | } |
540 | ||
2b80230a | 541 | if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) { |
0c10c5d9 | 542 | dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK); |
2b80230a ACM |
543 | goto discard; |
544 | } | |
545 | ||
7c657876 ACM |
546 | switch (sk->sk_state) { |
547 | case DCCP_CLOSED: | |
0c10c5d9 | 548 | dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; |
7c657876 ACM |
549 | return 1; |
550 | ||
7c657876 ACM |
551 | case DCCP_REQUESTING: |
552 | /* FIXME: do congestion control initialization */ | |
553 | ||
554 | queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); | |
555 | if (queued >= 0) | |
556 | return queued; | |
557 | ||
558 | __kfree_skb(skb); | |
559 | return 0; | |
560 | ||
561 | case DCCP_RESPOND: | |
562 | case DCCP_PARTOPEN: | |
7690af3f ACM |
563 | queued = dccp_rcv_respond_partopen_state_process(sk, skb, |
564 | dh, len); | |
7c657876 ACM |
565 | break; |
566 | } | |
567 | ||
7690af3f ACM |
568 | if (dh->dccph_type == DCCP_PKT_ACK || |
569 | dh->dccph_type == DCCP_PKT_DATAACK) { | |
7c657876 ACM |
570 | switch (old_state) { |
571 | case DCCP_PARTOPEN: | |
572 | sk->sk_state_change(sk); | |
573 | sk_wake_async(sk, 0, POLL_OUT); | |
574 | break; | |
575 | } | |
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 | /** | |
588 | * dccp_sample_rtt - Sample RTT from packet exchange | |
589 | * | |
590 | * @sk: connected dccp_sock | |
591 | * @t_recv: receive timestamp of packet with timestamp echo | |
592 | * @t_hist: packet history timestamp or NULL | |
593 | */ | |
9823b7b5 | 594 | u32 dccp_sample_rtt(struct sock *sk, ktime_t t_recv, ktime_t *t_hist) |
4712a792 GR |
595 | { |
596 | struct dccp_sock *dp = dccp_sk(sk); | |
597 | struct dccp_options_received *or = &dp->dccps_options_received; | |
9823b7b5 | 598 | s64 delta; |
4712a792 GR |
599 | |
600 | if (t_hist == NULL) { | |
601 | if (!or->dccpor_timestamp_echo) { | |
602 | DCCP_WARN("packet without timestamp echo\n"); | |
603 | return DCCP_SANE_RTT_MAX; | |
604 | } | |
9823b7b5 ACM |
605 | ktime_sub_us(t_recv, or->dccpor_timestamp_echo * 10); |
606 | delta = ktime_to_us(t_recv); | |
4712a792 | 607 | } else |
9823b7b5 | 608 | delta = ktime_us_delta(t_recv, *t_hist); |
4712a792 GR |
609 | |
610 | delta -= or->dccpor_elapsed_time * 10; /* either set or 0 */ | |
611 | ||
612 | if (unlikely(delta <= 0)) { | |
613 | DCCP_WARN("unusable RTT sample %ld, using min\n", (long)delta); | |
614 | return DCCP_SANE_RTT_MIN; | |
615 | } | |
9823b7b5 | 616 | if (unlikely(delta - (s64)DCCP_SANE_RTT_MAX > 0)) { |
4712a792 GR |
617 | DCCP_WARN("RTT sample %ld too large, using max\n", (long)delta); |
618 | return DCCP_SANE_RTT_MAX; | |
619 | } | |
620 | ||
621 | return delta; | |
622 | } | |
623 | ||
624 | EXPORT_SYMBOL_GPL(dccp_sample_rtt); |