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 | ||
bd5435e7 IM |
22 | /* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */ |
23 | int sysctl_dccp_sync_ratelimit __read_mostly = HZ / 8; | |
24 | ||
7c657876 ACM |
25 | static void dccp_fin(struct sock *sk, struct sk_buff *skb) |
26 | { | |
27 | sk->sk_shutdown |= RCV_SHUTDOWN; | |
28 | sock_set_flag(sk, SOCK_DONE); | |
29 | __skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4); | |
30 | __skb_queue_tail(&sk->sk_receive_queue, skb); | |
31 | skb_set_owner_r(skb, sk); | |
32 | sk->sk_data_ready(sk, 0); | |
33 | } | |
34 | ||
35 | static void dccp_rcv_close(struct sock *sk, struct sk_buff *skb) | |
36 | { | |
017487d7 | 37 | dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); |
7ad07e7c ACM |
38 | dccp_fin(sk, skb); |
39 | dccp_set_state(sk, DCCP_CLOSED); | |
331968bd | 40 | sk_wake_async(sk, 1, POLL_HUP); |
7c657876 ACM |
41 | } |
42 | ||
43 | static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) | |
44 | { | |
45 | /* | |
46 | * Step 7: Check for unexpected packet types | |
47 | * If (S.is_server and P.type == CloseReq) | |
48 | * Send Sync packet acknowledging P.seqno | |
49 | * Drop packet and return | |
50 | */ | |
51 | if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) { | |
e92ae93a | 52 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); |
7c657876 ACM |
53 | return; |
54 | } | |
55 | ||
811265b8 ACM |
56 | if (sk->sk_state != DCCP_CLOSING) |
57 | dccp_set_state(sk, DCCP_CLOSING); | |
7ad07e7c | 58 | dccp_send_close(sk, 0); |
7c657876 ACM |
59 | } |
60 | ||
d8ef2c29 GR |
61 | static u8 dccp_reset_code_convert(const u8 code) |
62 | { | |
63 | const u8 error_code[] = { | |
64 | [DCCP_RESET_CODE_CLOSED] = 0, /* normal termination */ | |
65 | [DCCP_RESET_CODE_UNSPECIFIED] = 0, /* nothing known */ | |
66 | [DCCP_RESET_CODE_ABORTED] = ECONNRESET, | |
67 | ||
68 | [DCCP_RESET_CODE_NO_CONNECTION] = ECONNREFUSED, | |
69 | [DCCP_RESET_CODE_CONNECTION_REFUSED] = ECONNREFUSED, | |
70 | [DCCP_RESET_CODE_TOO_BUSY] = EUSERS, | |
71 | [DCCP_RESET_CODE_AGGRESSION_PENALTY] = EDQUOT, | |
72 | ||
73 | [DCCP_RESET_CODE_PACKET_ERROR] = ENOMSG, | |
74 | [DCCP_RESET_CODE_BAD_INIT_COOKIE] = EBADR, | |
75 | [DCCP_RESET_CODE_BAD_SERVICE_CODE] = EBADRQC, | |
76 | [DCCP_RESET_CODE_OPTION_ERROR] = EILSEQ, | |
77 | [DCCP_RESET_CODE_MANDATORY_ERROR] = EOPNOTSUPP, | |
78 | }; | |
79 | ||
80 | return code >= DCCP_MAX_RESET_CODES ? 0 : error_code[code]; | |
81 | } | |
82 | ||
83 | static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb) | |
84 | { | |
85 | u8 err = dccp_reset_code_convert(dccp_hdr_reset(skb)->dccph_reset_code); | |
86 | ||
87 | sk->sk_err = err; | |
88 | ||
89 | /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */ | |
90 | dccp_fin(sk, skb); | |
91 | ||
92 | if (err && !sock_flag(sk, SOCK_DEAD)) | |
93 | sk_wake_async(sk, 0, POLL_ERR); | |
94 | dccp_time_wait(sk, DCCP_TIME_WAIT, 0); | |
95 | } | |
96 | ||
c25a18ba | 97 | static void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
98 | { |
99 | struct dccp_sock *dp = dccp_sk(sk); | |
100 | ||
a4bf3902 | 101 | if (dccp_msk(sk)->dccpms_send_ack_vector) |
ae31c339 ACM |
102 | dccp_ackvec_check_rcv_ackno(dp->dccps_hc_rx_ackvec, sk, |
103 | DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
7c657876 ACM |
104 | } |
105 | ||
106 | static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb) | |
107 | { | |
108 | const struct dccp_hdr *dh = dccp_hdr(skb); | |
109 | struct dccp_sock *dp = dccp_sk(sk); | |
cbe1f5f8 GR |
110 | u64 lswl, lawl, seqno = DCCP_SKB_CB(skb)->dccpd_seq, |
111 | ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; | |
7c657876 ACM |
112 | |
113 | /* | |
114 | * Step 5: Prepare sequence numbers for Sync | |
115 | * If P.type == Sync or P.type == SyncAck, | |
116 | * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL, | |
117 | * / * P is valid, so update sequence number variables | |
118 | * accordingly. After this update, P will pass the tests | |
119 | * in Step 6. A SyncAck is generated if necessary in | |
120 | * Step 15 * / | |
121 | * Update S.GSR, S.SWL, S.SWH | |
122 | * Otherwise, | |
123 | * Drop packet and return | |
124 | */ | |
8109b02b | 125 | if (dh->dccph_type == DCCP_PKT_SYNC || |
7c657876 | 126 | dh->dccph_type == DCCP_PKT_SYNCACK) { |
cbe1f5f8 GR |
127 | if (between48(ackno, dp->dccps_awl, dp->dccps_awh) && |
128 | dccp_delta_seqno(dp->dccps_swl, seqno) >= 0) | |
129 | dccp_update_gsr(sk, seqno); | |
7c657876 ACM |
130 | else |
131 | return -1; | |
e92ae93a | 132 | } |
c9eaf173 | 133 | |
7c657876 ACM |
134 | /* |
135 | * Step 6: Check sequence numbers | |
136 | * Let LSWL = S.SWL and LAWL = S.AWL | |
137 | * If P.type == CloseReq or P.type == Close or P.type == Reset, | |
138 | * LSWL := S.GSR + 1, LAWL := S.GAR | |
139 | * If LSWL <= P.seqno <= S.SWH | |
140 | * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH), | |
141 | * Update S.GSR, S.SWL, S.SWH | |
142 | * If P.type != Sync, | |
143 | * Update S.GAR | |
7c657876 | 144 | */ |
e92ae93a ACM |
145 | lswl = dp->dccps_swl; |
146 | lawl = dp->dccps_awl; | |
147 | ||
148 | if (dh->dccph_type == DCCP_PKT_CLOSEREQ || | |
c59eab46 ACM |
149 | dh->dccph_type == DCCP_PKT_CLOSE || |
150 | dh->dccph_type == DCCP_PKT_RESET) { | |
cbe1f5f8 | 151 | lswl = ADD48(dp->dccps_gsr, 1); |
7c657876 ACM |
152 | lawl = dp->dccps_gar; |
153 | } | |
154 | ||
cbe1f5f8 GR |
155 | if (between48(seqno, lswl, dp->dccps_swh) && |
156 | (ackno == DCCP_PKT_WITHOUT_ACK_SEQ || | |
157 | between48(ackno, lawl, dp->dccps_awh))) { | |
158 | dccp_update_gsr(sk, seqno); | |
7c657876 ACM |
159 | |
160 | if (dh->dccph_type != DCCP_PKT_SYNC && | |
cbe1f5f8 GR |
161 | (ackno != DCCP_PKT_WITHOUT_ACK_SEQ)) |
162 | dp->dccps_gar = ackno; | |
7c657876 | 163 | } else { |
a94f0f97 GR |
164 | unsigned long now = jiffies; |
165 | /* | |
166 | * Step 6: Check sequence numbers | |
167 | * Otherwise, | |
168 | * If P.type == Reset, | |
169 | * Send Sync packet acknowledging S.GSR | |
170 | * Otherwise, | |
171 | * Send Sync packet acknowledging P.seqno | |
172 | * Drop packet and return | |
173 | * | |
174 | * These Syncs are rate-limited as per RFC 4340, 7.5.4: | |
175 | * at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second. | |
176 | */ | |
177 | if (time_before(now, (dp->dccps_rate_last + | |
178 | sysctl_dccp_sync_ratelimit))) | |
179 | return 0; | |
180 | ||
59348b19 GR |
181 | DCCP_WARN("DCCP: Step 6 failed for %s packet, " |
182 | "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and " | |
183 | "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), " | |
184 | "sending SYNC...\n", dccp_packet_name(dh->dccph_type), | |
cbe1f5f8 | 185 | (unsigned long long) lswl, (unsigned long long) seqno, |
59348b19 | 186 | (unsigned long long) dp->dccps_swh, |
cbe1f5f8 GR |
187 | (ackno == DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist" |
188 | : "exists", | |
189 | (unsigned long long) lawl, (unsigned long long) ackno, | |
59348b19 | 190 | (unsigned long long) dp->dccps_awh); |
a94f0f97 GR |
191 | |
192 | dp->dccps_rate_last = now; | |
193 | ||
e155d769 GR |
194 | if (dh->dccph_type == DCCP_PKT_RESET) |
195 | seqno = dp->dccps_gsr; | |
cbe1f5f8 | 196 | dccp_send_sync(sk, seqno, DCCP_PKT_SYNC); |
7c657876 ACM |
197 | return -1; |
198 | } | |
199 | ||
200 | return 0; | |
201 | } | |
202 | ||
c25a18ba ACM |
203 | static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, |
204 | const struct dccp_hdr *dh, const unsigned len) | |
7c657876 ACM |
205 | { |
206 | struct dccp_sock *dp = dccp_sk(sk); | |
207 | ||
7c657876 ACM |
208 | switch (dccp_hdr(skb)->dccph_type) { |
209 | case DCCP_PKT_DATAACK: | |
210 | case DCCP_PKT_DATA: | |
211 | /* | |
7690af3f ACM |
212 | * FIXME: check if sk_receive_queue is full, schedule DATA_DROPPED |
213 | * option if it is. | |
7c657876 ACM |
214 | */ |
215 | __skb_pull(skb, dh->dccph_doff * 4); | |
216 | __skb_queue_tail(&sk->sk_receive_queue, skb); | |
217 | skb_set_owner_r(skb, sk); | |
218 | sk->sk_data_ready(sk, 0); | |
219 | return 0; | |
220 | case DCCP_PKT_ACK: | |
221 | goto discard; | |
222 | case DCCP_PKT_RESET: | |
223 | /* | |
224 | * Step 9: Process Reset | |
225 | * If P.type == Reset, | |
226 | * Tear down connection | |
227 | * S.state := TIMEWAIT | |
228 | * Set TIMEWAIT timer | |
229 | * Drop packet and return | |
d8ef2c29 GR |
230 | */ |
231 | dccp_rcv_reset(sk, skb); | |
7c657876 ACM |
232 | return 0; |
233 | case DCCP_PKT_CLOSEREQ: | |
234 | dccp_rcv_closereq(sk, skb); | |
235 | goto discard; | |
236 | case DCCP_PKT_CLOSE: | |
237 | dccp_rcv_close(sk, skb); | |
238 | return 0; | |
239 | case DCCP_PKT_REQUEST: | |
8109b02b ACM |
240 | /* Step 7 |
241 | * or (S.is_server and P.type == Response) | |
7c657876 ACM |
242 | * or (S.is_client and P.type == Request) |
243 | * or (S.state >= OPEN and P.type == Request | |
244 | * and P.seqno >= S.OSR) | |
245 | * or (S.state >= OPEN and P.type == Response | |
246 | * and P.seqno >= S.OSR) | |
247 | * or (S.state == RESPOND and P.type == Data), | |
248 | * Send Sync packet acknowledging P.seqno | |
249 | * Drop packet and return | |
250 | */ | |
251 | if (dp->dccps_role != DCCP_ROLE_LISTEN) | |
252 | goto send_sync; | |
253 | goto check_seq; | |
254 | case DCCP_PKT_RESPONSE: | |
255 | if (dp->dccps_role != DCCP_ROLE_CLIENT) | |
256 | goto send_sync; | |
257 | check_seq: | |
8d13bf9a GR |
258 | if (dccp_delta_seqno(dp->dccps_osr, |
259 | DCCP_SKB_CB(skb)->dccpd_seq) >= 0) { | |
7c657876 | 260 | send_sync: |
e92ae93a ACM |
261 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, |
262 | DCCP_PKT_SYNC); | |
7c657876 ACM |
263 | } |
264 | break; | |
e92ae93a ACM |
265 | case DCCP_PKT_SYNC: |
266 | dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, | |
267 | DCCP_PKT_SYNCACK); | |
268 | /* | |
0e64e94e | 269 | * From RFC 4340, sec. 5.7 |
e92ae93a ACM |
270 | * |
271 | * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets | |
272 | * MAY have non-zero-length application data areas, whose | |
0e64e94e | 273 | * contents receivers MUST ignore. |
e92ae93a ACM |
274 | */ |
275 | goto discard; | |
7c657876 ACM |
276 | } |
277 | ||
278 | DCCP_INC_STATS_BH(DCCP_MIB_INERRS); | |
279 | discard: | |
280 | __kfree_skb(skb); | |
281 | return 0; | |
282 | } | |
283 | ||
709dd3aa AB |
284 | int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, |
285 | const struct dccp_hdr *dh, const unsigned len) | |
286 | { | |
287 | struct dccp_sock *dp = dccp_sk(sk); | |
288 | ||
289 | if (dccp_check_seqno(sk, skb)) | |
290 | goto discard; | |
291 | ||
292 | if (dccp_parse_options(sk, skb)) | |
293 | goto discard; | |
294 | ||
295 | if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) | |
296 | dccp_event_ack_recv(sk, skb); | |
297 | ||
a4bf3902 | 298 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
709dd3aa AB |
299 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, |
300 | DCCP_SKB_CB(skb)->dccpd_seq, | |
301 | DCCP_ACKVEC_STATE_RECEIVED)) | |
302 | goto discard; | |
303 | ||
151a9931 GR |
304 | ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); |
305 | ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); | |
709dd3aa AB |
306 | |
307 | return __dccp_rcv_established(sk, skb, dh, len); | |
308 | discard: | |
309 | __kfree_skb(skb); | |
310 | return 0; | |
311 | } | |
312 | ||
f21e68ca ACM |
313 | EXPORT_SYMBOL_GPL(dccp_rcv_established); |
314 | ||
7c657876 ACM |
315 | static int dccp_rcv_request_sent_state_process(struct sock *sk, |
316 | struct sk_buff *skb, | |
317 | const struct dccp_hdr *dh, | |
318 | const unsigned len) | |
319 | { | |
8109b02b | 320 | /* |
7c657876 ACM |
321 | * Step 4: Prepare sequence numbers in REQUEST |
322 | * If S.state == REQUEST, | |
323 | * If (P.type == Response or P.type == Reset) | |
324 | * and S.AWL <= P.ackno <= S.AWH, | |
325 | * / * Set sequence number variables corresponding to the | |
326 | * other endpoint, so P will pass the tests in Step 6 * / | |
327 | * Set S.GSR, S.ISR, S.SWL, S.SWH | |
328 | * / * Response processing continues in Step 10; Reset | |
329 | * processing continues in Step 9 * / | |
330 | */ | |
331 | if (dh->dccph_type == DCCP_PKT_RESPONSE) { | |
332 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
333 | struct dccp_sock *dp = dccp_sk(sk); | |
3393da82 | 334 | long tstamp = dccp_timestamp(); |
7c657876 ACM |
335 | |
336 | /* Stop the REQUEST timer */ | |
337 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); | |
338 | BUG_TRAP(sk->sk_send_head != NULL); | |
339 | __kfree_skb(sk->sk_send_head); | |
340 | sk->sk_send_head = NULL; | |
341 | ||
7690af3f ACM |
342 | if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, |
343 | dp->dccps_awl, dp->dccps_awh)) { | |
344 | dccp_pr_debug("invalid ackno: S.AWL=%llu, " | |
345 | "P.ackno=%llu, S.AWH=%llu \n", | |
346 | (unsigned long long)dp->dccps_awl, | |
347 | (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, | |
348 | (unsigned long long)dp->dccps_awh); | |
7c657876 ACM |
349 | goto out_invalid_packet; |
350 | } | |
9e377202 | 351 | |
afe00251 AB |
352 | if (dccp_parse_options(sk, skb)) |
353 | goto out_invalid_packet; | |
354 | ||
3393da82 GR |
355 | /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */ |
356 | if (likely(dp->dccps_options_received.dccpor_timestamp_echo)) | |
357 | dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp - | |
358 | dp->dccps_options_received.dccpor_timestamp_echo)); | |
89560b53 | 359 | |
c9eaf173 YH |
360 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
361 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, | |
362 | DCCP_SKB_CB(skb)->dccpd_seq, | |
363 | DCCP_ACKVEC_STATE_RECEIVED)) | |
364 | goto out_invalid_packet; /* FIXME: change error code */ | |
7c657876 ACM |
365 | |
366 | dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; | |
03ace394 ACM |
367 | dccp_update_gsr(sk, dp->dccps_isr); |
368 | /* | |
369 | * SWL and AWL are initially adjusted so that they are not less than | |
370 | * the initial Sequence Numbers received and sent, respectively: | |
371 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
372 | * AWL := max(GSS - W' + 1, ISS). | |
373 | * These adjustments MUST be applied only at the beginning of the | |
374 | * connection. | |
375 | * | |
376 | * AWL was adjusted in dccp_v4_connect -acme | |
377 | */ | |
378 | dccp_set_seqno(&dp->dccps_swl, | |
379 | max48(dp->dccps_swl, dp->dccps_isr)); | |
7c657876 | 380 | |
d83d8461 | 381 | dccp_sync_mss(sk, icsk->icsk_pmtu_cookie); |
7c657876 ACM |
382 | |
383 | /* | |
384 | * Step 10: Process REQUEST state (second part) | |
385 | * If S.state == REQUEST, | |
7690af3f ACM |
386 | * / * If we get here, P is a valid Response from the |
387 | * server (see Step 4), and we should move to | |
388 | * PARTOPEN state. PARTOPEN means send an Ack, | |
389 | * don't send Data packets, retransmit Acks | |
390 | * periodically, and always include any Init Cookie | |
391 | * from the Response * / | |
7c657876 ACM |
392 | * S.state := PARTOPEN |
393 | * Set PARTOPEN timer | |
8109b02b | 394 | * Continue with S.state == PARTOPEN |
7690af3f ACM |
395 | * / * Step 12 will send the Ack completing the |
396 | * three-way handshake * / | |
7c657876 ACM |
397 | */ |
398 | dccp_set_state(sk, DCCP_PARTOPEN); | |
399 | ||
400 | /* Make sure socket is routed, for correct metrics. */ | |
57cca05a | 401 | icsk->icsk_af_ops->rebuild_header(sk); |
7c657876 ACM |
402 | |
403 | if (!sock_flag(sk, SOCK_DEAD)) { | |
404 | sk->sk_state_change(sk); | |
405 | sk_wake_async(sk, 0, POLL_OUT); | |
406 | } | |
407 | ||
408 | if (sk->sk_write_pending || icsk->icsk_ack.pingpong || | |
409 | icsk->icsk_accept_queue.rskq_defer_accept) { | |
410 | /* Save one ACK. Data will be ready after | |
411 | * several ticks, if write_pending is set. | |
412 | * | |
413 | * It may be deleted, but with this feature tcpdumps | |
414 | * look so _wonderfully_ clever, that I was not able | |
415 | * to stand against the temptation 8) --ANK | |
416 | */ | |
417 | /* | |
418 | * OK, in DCCP we can as well do a similar trick, its | |
419 | * even in the draft, but there is no need for us to | |
420 | * schedule an ack here, as dccp_sendmsg does this for | |
421 | * us, also stated in the draft. -acme | |
422 | */ | |
423 | __kfree_skb(skb); | |
424 | return 0; | |
8109b02b | 425 | } |
7c657876 ACM |
426 | dccp_send_ack(sk); |
427 | return -1; | |
428 | } | |
429 | ||
430 | out_invalid_packet: | |
0c10c5d9 ACM |
431 | /* dccp_v4_do_rcv will send a reset */ |
432 | DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; | |
8109b02b | 433 | return 1; |
7c657876 ACM |
434 | } |
435 | ||
436 | static int dccp_rcv_respond_partopen_state_process(struct sock *sk, | |
437 | struct sk_buff *skb, | |
438 | const struct dccp_hdr *dh, | |
439 | const unsigned len) | |
440 | { | |
441 | int queued = 0; | |
442 | ||
443 | switch (dh->dccph_type) { | |
444 | case DCCP_PKT_RESET: | |
445 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); | |
446 | break; | |
2a9bc9bb ACM |
447 | case DCCP_PKT_DATA: |
448 | if (sk->sk_state == DCCP_RESPOND) | |
449 | break; | |
7c657876 ACM |
450 | case DCCP_PKT_DATAACK: |
451 | case DCCP_PKT_ACK: | |
452 | /* | |
7690af3f ACM |
453 | * FIXME: we should be reseting the PARTOPEN (DELACK) timer |
454 | * here but only if we haven't used the DELACK timer for | |
455 | * something else, like sending a delayed ack for a TIMESTAMP | |
456 | * echo, etc, for now were not clearing it, sending an extra | |
457 | * ACK when there is nothing else to do in DELACK is not a big | |
458 | * deal after all. | |
7c657876 ACM |
459 | */ |
460 | ||
461 | /* Stop the PARTOPEN timer */ | |
462 | if (sk->sk_state == DCCP_PARTOPEN) | |
463 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); | |
464 | ||
465 | dccp_sk(sk)->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq; | |
466 | dccp_set_state(sk, DCCP_OPEN); | |
467 | ||
2a9bc9bb ACM |
468 | if (dh->dccph_type == DCCP_PKT_DATAACK || |
469 | dh->dccph_type == DCCP_PKT_DATA) { | |
709dd3aa | 470 | __dccp_rcv_established(sk, skb, dh, len); |
7690af3f | 471 | queued = 1; /* packet was queued |
709dd3aa | 472 | (by __dccp_rcv_established) */ |
7c657876 ACM |
473 | } |
474 | break; | |
475 | } | |
476 | ||
477 | return queued; | |
478 | } | |
479 | ||
480 | int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, | |
481 | struct dccp_hdr *dh, unsigned len) | |
482 | { | |
483 | struct dccp_sock *dp = dccp_sk(sk); | |
0c10c5d9 | 484 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
7c657876 ACM |
485 | const int old_state = sk->sk_state; |
486 | int queued = 0; | |
487 | ||
8649b0d4 ACM |
488 | /* |
489 | * Step 3: Process LISTEN state | |
8649b0d4 ACM |
490 | * |
491 | * If S.state == LISTEN, | |
d83ca5ac GR |
492 | * If P.type == Request or P contains a valid Init Cookie option, |
493 | * (* Must scan the packet's options to check for Init | |
494 | * Cookies. Only Init Cookies are processed here, | |
495 | * however; other options are processed in Step 8. This | |
496 | * scan need only be performed if the endpoint uses Init | |
497 | * Cookies *) | |
498 | * (* Generate a new socket and switch to that socket *) | |
499 | * Set S := new socket for this port pair | |
500 | * S.state = RESPOND | |
501 | * Choose S.ISS (initial seqno) or set from Init Cookies | |
502 | * Initialize S.GAR := S.ISS | |
503 | * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init | |
504 | * Cookies Continue with S.state == RESPOND | |
505 | * (* A Response packet will be generated in Step 11 *) | |
506 | * Otherwise, | |
507 | * Generate Reset(No Connection) unless P.type == Reset | |
508 | * Drop packet and return | |
8649b0d4 ACM |
509 | */ |
510 | if (sk->sk_state == DCCP_LISTEN) { | |
511 | if (dh->dccph_type == DCCP_PKT_REQUEST) { | |
57cca05a ACM |
512 | if (inet_csk(sk)->icsk_af_ops->conn_request(sk, |
513 | skb) < 0) | |
8649b0d4 ACM |
514 | return 1; |
515 | ||
516 | /* FIXME: do congestion control initialization */ | |
517 | goto discard; | |
518 | } | |
519 | if (dh->dccph_type == DCCP_PKT_RESET) | |
520 | goto discard; | |
521 | ||
0c10c5d9 ACM |
522 | /* Caller (dccp_v4_do_rcv) will send Reset */ |
523 | dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; | |
8649b0d4 ACM |
524 | return 1; |
525 | } | |
526 | ||
527 | if (sk->sk_state != DCCP_REQUESTING) { | |
7c657876 ACM |
528 | if (dccp_check_seqno(sk, skb)) |
529 | goto discard; | |
530 | ||
531 | /* | |
532 | * Step 8: Process options and mark acknowledgeable | |
533 | */ | |
534 | if (dccp_parse_options(sk, skb)) | |
535 | goto discard; | |
536 | ||
0c10c5d9 | 537 | if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) |
7c657876 ACM |
538 | dccp_event_ack_recv(sk, skb); |
539 | ||
8109b02b | 540 | if (dccp_msk(sk)->dccpms_send_ack_vector && |
ae31c339 | 541 | dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, |
8109b02b ACM |
542 | DCCP_SKB_CB(skb)->dccpd_seq, |
543 | DCCP_ACKVEC_STATE_RECEIVED)) | |
544 | goto discard; | |
e84a9f5e | 545 | |
151a9931 GR |
546 | ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); |
547 | ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); | |
7c657876 ACM |
548 | } |
549 | ||
550 | /* | |
551 | * Step 9: Process Reset | |
552 | * If P.type == Reset, | |
553 | * Tear down connection | |
554 | * S.state := TIMEWAIT | |
555 | * Set TIMEWAIT timer | |
556 | * Drop packet and return | |
557 | */ | |
558 | if (dh->dccph_type == DCCP_PKT_RESET) { | |
d8ef2c29 | 559 | dccp_rcv_reset(sk, skb); |
7c657876 ACM |
560 | return 0; |
561 | /* | |
562 | * Step 7: Check for unexpected packet types | |
563 | * If (S.is_server and P.type == CloseReq) | |
564 | * or (S.is_server and P.type == Response) | |
565 | * or (S.is_client and P.type == Request) | |
566 | * or (S.state == RESPOND and P.type == Data), | |
567 | * Send Sync packet acknowledging P.seqno | |
568 | * Drop packet and return | |
569 | */ | |
570 | } else if ((dp->dccps_role != DCCP_ROLE_CLIENT && | |
7690af3f ACM |
571 | (dh->dccph_type == DCCP_PKT_RESPONSE || |
572 | dh->dccph_type == DCCP_PKT_CLOSEREQ)) || | |
7c657876 ACM |
573 | (dp->dccps_role == DCCP_ROLE_CLIENT && |
574 | dh->dccph_type == DCCP_PKT_REQUEST) || | |
7690af3f ACM |
575 | (sk->sk_state == DCCP_RESPOND && |
576 | dh->dccph_type == DCCP_PKT_DATA)) { | |
0c10c5d9 | 577 | dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC); |
7c657876 | 578 | goto discard; |
7ad07e7c ACM |
579 | } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { |
580 | dccp_rcv_closereq(sk, skb); | |
581 | goto discard; | |
582 | } else if (dh->dccph_type == DCCP_PKT_CLOSE) { | |
583 | dccp_rcv_close(sk, skb); | |
584 | return 0; | |
7c657876 ACM |
585 | } |
586 | ||
587 | switch (sk->sk_state) { | |
588 | case DCCP_CLOSED: | |
0c10c5d9 | 589 | dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; |
7c657876 ACM |
590 | return 1; |
591 | ||
7c657876 ACM |
592 | case DCCP_REQUESTING: |
593 | /* FIXME: do congestion control initialization */ | |
594 | ||
595 | queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); | |
596 | if (queued >= 0) | |
597 | return queued; | |
598 | ||
599 | __kfree_skb(skb); | |
600 | return 0; | |
601 | ||
602 | case DCCP_RESPOND: | |
603 | case DCCP_PARTOPEN: | |
7690af3f ACM |
604 | queued = dccp_rcv_respond_partopen_state_process(sk, skb, |
605 | dh, len); | |
7c657876 ACM |
606 | break; |
607 | } | |
608 | ||
7690af3f ACM |
609 | if (dh->dccph_type == DCCP_PKT_ACK || |
610 | dh->dccph_type == DCCP_PKT_DATAACK) { | |
7c657876 ACM |
611 | switch (old_state) { |
612 | case DCCP_PARTOPEN: | |
613 | sk->sk_state_change(sk); | |
614 | sk_wake_async(sk, 0, POLL_OUT); | |
615 | break; | |
616 | } | |
08831700 GR |
617 | } else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) { |
618 | dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK); | |
619 | goto discard; | |
7c657876 ACM |
620 | } |
621 | ||
8109b02b | 622 | if (!queued) { |
7c657876 ACM |
623 | discard: |
624 | __kfree_skb(skb); | |
625 | } | |
626 | return 0; | |
627 | } | |
f21e68ca ACM |
628 | |
629 | EXPORT_SYMBOL_GPL(dccp_rcv_state_process); | |
4712a792 GR |
630 | |
631 | /** | |
3393da82 GR |
632 | * dccp_sample_rtt - Validate and finalise computation of RTT sample |
633 | * @delta: number of microseconds between packet and acknowledgment | |
634 | * The routine is kept generic to work in different contexts. It should be | |
635 | * called immediately when the ACK used for the RTT sample arrives. | |
4712a792 | 636 | */ |
3393da82 | 637 | u32 dccp_sample_rtt(struct sock *sk, long delta) |
4712a792 | 638 | { |
3393da82 GR |
639 | /* dccpor_elapsed_time is either zeroed out or set and > 0 */ |
640 | delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10; | |
4712a792 GR |
641 | |
642 | if (unlikely(delta <= 0)) { | |
3393da82 | 643 | DCCP_WARN("unusable RTT sample %ld, using min\n", delta); |
4712a792 GR |
644 | return DCCP_SANE_RTT_MIN; |
645 | } | |
3393da82 GR |
646 | if (unlikely(delta > DCCP_SANE_RTT_MAX)) { |
647 | DCCP_WARN("RTT sample %ld too large, using max\n", delta); | |
4712a792 GR |
648 | return DCCP_SANE_RTT_MAX; |
649 | } | |
650 | ||
651 | return delta; | |
652 | } | |
653 | ||
654 | EXPORT_SYMBOL_GPL(dccp_sample_rtt); |