ia64/linux-2.6.18-xen.hg

view net/dccp/output.c @ 673:3161879fdf22

[IA64] xencomm: support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap

support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Tue Sep 16 21:26:15 2008 +0900 (2008-09-16)
parents 831230e53067
children
line source
1 /*
2 * net/dccp/output.c
3 *
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 */
13 #include <linux/dccp.h>
14 #include <linux/kernel.h>
15 #include <linux/skbuff.h>
17 #include <net/inet_sock.h>
18 #include <net/sock.h>
20 #include "ackvec.h"
21 #include "ccid.h"
22 #include "dccp.h"
24 static inline void dccp_event_ack_sent(struct sock *sk)
25 {
26 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
27 }
29 static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
30 {
31 skb_set_owner_w(skb, sk);
32 WARN_ON(sk->sk_send_head);
33 sk->sk_send_head = skb;
34 }
36 /*
37 * All SKB's seen here are completely headerless. It is our
38 * job to build the DCCP header, and pass the packet down to
39 * IP so it can do the same plus pass the packet off to the
40 * device.
41 */
42 static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
43 {
44 if (likely(skb != NULL)) {
45 const struct inet_sock *inet = inet_sk(sk);
46 const struct inet_connection_sock *icsk = inet_csk(sk);
47 struct dccp_sock *dp = dccp_sk(sk);
48 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
49 struct dccp_hdr *dh;
50 /* XXX For now we're using only 48 bits sequence numbers */
51 const u32 dccp_header_size = sizeof(*dh) +
52 sizeof(struct dccp_hdr_ext) +
53 dccp_packet_hdr_len(dcb->dccpd_type);
54 int err, set_ack = 1;
55 u64 ackno = dp->dccps_gsr;
57 dccp_inc_seqno(&dp->dccps_gss);
59 switch (dcb->dccpd_type) {
60 case DCCP_PKT_DATA:
61 set_ack = 0;
62 /* fall through */
63 case DCCP_PKT_DATAACK:
64 break;
66 case DCCP_PKT_REQUEST:
67 set_ack = 0;
68 /* fall through */
70 case DCCP_PKT_SYNC:
71 case DCCP_PKT_SYNCACK:
72 ackno = dcb->dccpd_seq;
73 /* fall through */
74 default:
75 /*
76 * Only data packets should come through with skb->sk
77 * set.
78 */
79 WARN_ON(skb->sk);
80 skb_set_owner_w(skb, sk);
81 break;
82 }
84 dcb->dccpd_seq = dp->dccps_gss;
86 if (dccp_insert_options(sk, skb)) {
87 kfree_skb(skb);
88 return -EPROTO;
89 }
91 skb->h.raw = skb_push(skb, dccp_header_size);
92 dh = dccp_hdr(skb);
94 /* Build DCCP header and checksum it. */
95 memset(dh, 0, dccp_header_size);
96 dh->dccph_type = dcb->dccpd_type;
97 dh->dccph_sport = inet->sport;
98 dh->dccph_dport = inet->dport;
99 dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4;
100 dh->dccph_ccval = dcb->dccpd_ccval;
101 /* XXX For now we're using only 48 bits sequence numbers */
102 dh->dccph_x = 1;
104 dp->dccps_awh = dp->dccps_gss;
105 dccp_hdr_set_seq(dh, dp->dccps_gss);
106 if (set_ack)
107 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);
109 switch (dcb->dccpd_type) {
110 case DCCP_PKT_REQUEST:
111 dccp_hdr_request(skb)->dccph_req_service =
112 dp->dccps_service;
113 break;
114 case DCCP_PKT_RESET:
115 dccp_hdr_reset(skb)->dccph_reset_code =
116 dcb->dccpd_reset_code;
117 break;
118 }
120 icsk->icsk_af_ops->send_check(sk, skb->len, skb);
122 if (set_ack)
123 dccp_event_ack_sent(sk);
125 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
127 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
128 err = icsk->icsk_af_ops->queue_xmit(skb, 0);
129 if (err <= 0)
130 return err;
132 /* NET_XMIT_CN is special. It does not guarantee,
133 * that this packet is lost. It tells that device
134 * is about to start to drop packets or already
135 * drops some packets of the same priority and
136 * invokes us to send less aggressively.
137 */
138 return err == NET_XMIT_CN ? 0 : err;
139 }
140 return -ENOBUFS;
141 }
143 unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
144 {
145 struct inet_connection_sock *icsk = inet_csk(sk);
146 struct dccp_sock *dp = dccp_sk(sk);
147 int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len -
148 sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext));
150 /* Now subtract optional transport overhead */
151 mss_now -= icsk->icsk_ext_hdr_len;
153 /*
154 * FIXME: this should come from the CCID infrastructure, where, say,
155 * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets
156 * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED
157 * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to
158 * make it a multiple of 4
159 */
161 mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4;
163 /* And store cached results */
164 icsk->icsk_pmtu_cookie = pmtu;
165 dp->dccps_mss_cache = mss_now;
167 return mss_now;
168 }
170 EXPORT_SYMBOL_GPL(dccp_sync_mss);
172 void dccp_write_space(struct sock *sk)
173 {
174 read_lock(&sk->sk_callback_lock);
176 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
177 wake_up_interruptible(sk->sk_sleep);
178 /* Should agree with poll, otherwise some programs break */
179 if (sock_writeable(sk))
180 sk_wake_async(sk, 2, POLL_OUT);
182 read_unlock(&sk->sk_callback_lock);
183 }
185 /**
186 * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet
187 * @sk: socket to wait for
188 * @timeo: for how long
189 */
190 static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb,
191 long *timeo)
192 {
193 struct dccp_sock *dp = dccp_sk(sk);
194 DEFINE_WAIT(wait);
195 long delay;
196 int rc;
198 while (1) {
199 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
201 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
202 goto do_error;
203 if (!*timeo)
204 goto do_nonblock;
205 if (signal_pending(current))
206 goto do_interrupted;
208 rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb,
209 skb->len);
210 if (rc <= 0)
211 break;
212 delay = msecs_to_jiffies(rc);
213 if (delay > *timeo || delay < 0)
214 goto do_nonblock;
216 sk->sk_write_pending++;
217 release_sock(sk);
218 *timeo -= schedule_timeout(delay);
219 lock_sock(sk);
220 sk->sk_write_pending--;
221 }
222 out:
223 finish_wait(sk->sk_sleep, &wait);
224 return rc;
226 do_error:
227 rc = -EPIPE;
228 goto out;
229 do_nonblock:
230 rc = -EAGAIN;
231 goto out;
232 do_interrupted:
233 rc = sock_intr_errno(*timeo);
234 goto out;
235 }
237 int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo)
238 {
239 const struct dccp_sock *dp = dccp_sk(sk);
240 int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb,
241 skb->len);
243 if (err > 0)
244 err = dccp_wait_for_ccid(sk, skb, timeo);
246 if (err == 0) {
247 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
248 const int len = skb->len;
250 if (sk->sk_state == DCCP_PARTOPEN) {
251 /* See 8.1.5. Handshake Completion */
252 inet_csk_schedule_ack(sk);
253 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
254 inet_csk(sk)->icsk_rto,
255 DCCP_RTO_MAX);
256 dcb->dccpd_type = DCCP_PKT_DATAACK;
257 } else if (dccp_ack_pending(sk))
258 dcb->dccpd_type = DCCP_PKT_DATAACK;
259 else
260 dcb->dccpd_type = DCCP_PKT_DATA;
262 err = dccp_transmit_skb(sk, skb);
263 ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len);
264 } else
265 kfree_skb(skb);
267 return err;
268 }
270 int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
271 {
272 if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0)
273 return -EHOSTUNREACH; /* Routing failure or similar. */
275 return dccp_transmit_skb(sk, (skb_cloned(skb) ?
276 pskb_copy(skb, GFP_ATOMIC):
277 skb_clone(skb, GFP_ATOMIC)));
278 }
280 struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
281 struct request_sock *req)
282 {
283 struct dccp_hdr *dh;
284 struct dccp_request_sock *dreq;
285 const u32 dccp_header_size = sizeof(struct dccp_hdr) +
286 sizeof(struct dccp_hdr_ext) +
287 sizeof(struct dccp_hdr_response);
288 struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,
289 GFP_ATOMIC);
290 if (skb == NULL)
291 return NULL;
293 /* Reserve space for headers. */
294 skb_reserve(skb, sk->sk_prot->max_header);
296 skb->dst = dst_clone(dst);
297 skb->csum = 0;
299 dreq = dccp_rsk(req);
300 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
301 DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss;
303 if (dccp_insert_options(sk, skb)) {
304 kfree_skb(skb);
305 return NULL;
306 }
308 skb->h.raw = skb_push(skb, dccp_header_size);
310 dh = dccp_hdr(skb);
311 memset(dh, 0, dccp_header_size);
313 dh->dccph_sport = inet_sk(sk)->sport;
314 dh->dccph_dport = inet_rsk(req)->rmt_port;
315 dh->dccph_doff = (dccp_header_size +
316 DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
317 dh->dccph_type = DCCP_PKT_RESPONSE;
318 dh->dccph_x = 1;
319 dccp_hdr_set_seq(dh, dreq->dreq_iss);
320 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr);
321 dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;
323 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
324 return skb;
325 }
327 EXPORT_SYMBOL_GPL(dccp_make_response);
329 static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,
330 const enum dccp_reset_codes code)
332 {
333 struct dccp_hdr *dh;
334 struct dccp_sock *dp = dccp_sk(sk);
335 const u32 dccp_header_size = sizeof(struct dccp_hdr) +
336 sizeof(struct dccp_hdr_ext) +
337 sizeof(struct dccp_hdr_reset);
338 struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,
339 GFP_ATOMIC);
340 if (skb == NULL)
341 return NULL;
343 /* Reserve space for headers. */
344 skb_reserve(skb, sk->sk_prot->max_header);
346 skb->dst = dst_clone(dst);
347 skb->csum = 0;
349 dccp_inc_seqno(&dp->dccps_gss);
351 DCCP_SKB_CB(skb)->dccpd_reset_code = code;
352 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET;
353 DCCP_SKB_CB(skb)->dccpd_seq = dp->dccps_gss;
355 if (dccp_insert_options(sk, skb)) {
356 kfree_skb(skb);
357 return NULL;
358 }
360 skb->h.raw = skb_push(skb, dccp_header_size);
362 dh = dccp_hdr(skb);
363 memset(dh, 0, dccp_header_size);
365 dh->dccph_sport = inet_sk(sk)->sport;
366 dh->dccph_dport = inet_sk(sk)->dport;
367 dh->dccph_doff = (dccp_header_size +
368 DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
369 dh->dccph_type = DCCP_PKT_RESET;
370 dh->dccph_x = 1;
371 dccp_hdr_set_seq(dh, dp->dccps_gss);
372 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr);
374 dccp_hdr_reset(skb)->dccph_reset_code = code;
375 inet_csk(sk)->icsk_af_ops->send_check(sk, skb->len, skb);
377 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
378 return skb;
379 }
381 int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
382 {
383 /*
384 * FIXME: what if rebuild_header fails?
385 * Should we be doing a rebuild_header here?
386 */
387 int err = inet_sk_rebuild_header(sk);
389 if (err == 0) {
390 struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache,
391 code);
392 if (skb != NULL) {
393 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
394 err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0);
395 if (err == NET_XMIT_CN)
396 err = 0;
397 }
398 }
400 return err;
401 }
403 /*
404 * Do all connect socket setups that can be done AF independent.
405 */
406 static inline void dccp_connect_init(struct sock *sk)
407 {
408 struct dccp_sock *dp = dccp_sk(sk);
409 struct dst_entry *dst = __sk_dst_get(sk);
410 struct inet_connection_sock *icsk = inet_csk(sk);
412 sk->sk_err = 0;
413 sock_reset_flag(sk, SOCK_DONE);
415 dccp_sync_mss(sk, dst_mtu(dst));
417 dccp_update_gss(sk, dp->dccps_iss);
418 /*
419 * SWL and AWL are initially adjusted so that they are not less than
420 * the initial Sequence Numbers received and sent, respectively:
421 * SWL := max(GSR + 1 - floor(W/4), ISR),
422 * AWL := max(GSS - W' + 1, ISS).
423 * These adjustments MUST be applied only at the beginning of the
424 * connection.
425 */
426 dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
428 icsk->icsk_retransmits = 0;
429 }
431 int dccp_connect(struct sock *sk)
432 {
433 struct sk_buff *skb;
434 struct inet_connection_sock *icsk = inet_csk(sk);
436 dccp_connect_init(sk);
438 skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation);
439 if (unlikely(skb == NULL))
440 return -ENOBUFS;
442 /* Reserve space for headers. */
443 skb_reserve(skb, sk->sk_prot->max_header);
445 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST;
446 skb->csum = 0;
448 dccp_skb_entail(sk, skb);
449 dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL));
450 DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS);
452 /* Timer for repeating the REQUEST until an answer. */
453 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
454 icsk->icsk_rto, DCCP_RTO_MAX);
455 return 0;
456 }
458 EXPORT_SYMBOL_GPL(dccp_connect);
460 void dccp_send_ack(struct sock *sk)
461 {
462 /* If we have been reset, we may not send again. */
463 if (sk->sk_state != DCCP_CLOSED) {
464 struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header,
465 GFP_ATOMIC);
467 if (skb == NULL) {
468 inet_csk_schedule_ack(sk);
469 inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
470 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
471 TCP_DELACK_MAX,
472 DCCP_RTO_MAX);
473 return;
474 }
476 /* Reserve space for headers */
477 skb_reserve(skb, sk->sk_prot->max_header);
478 skb->csum = 0;
479 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK;
480 dccp_transmit_skb(sk, skb);
481 }
482 }
484 EXPORT_SYMBOL_GPL(dccp_send_ack);
486 void dccp_send_delayed_ack(struct sock *sk)
487 {
488 struct inet_connection_sock *icsk = inet_csk(sk);
489 /*
490 * FIXME: tune this timer. elapsed time fixes the skew, so no problem
491 * with using 2s, and active senders also piggyback the ACK into a
492 * DATAACK packet, so this is really for quiescent senders.
493 */
494 unsigned long timeout = jiffies + 2 * HZ;
496 /* Use new timeout only if there wasn't a older one earlier. */
497 if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) {
498 /* If delack timer was blocked or is about to expire,
499 * send ACK now.
500 *
501 * FIXME: check the "about to expire" part
502 */
503 if (icsk->icsk_ack.blocked) {
504 dccp_send_ack(sk);
505 return;
506 }
508 if (!time_before(timeout, icsk->icsk_ack.timeout))
509 timeout = icsk->icsk_ack.timeout;
510 }
511 icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
512 icsk->icsk_ack.timeout = timeout;
513 sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
514 }
516 void dccp_send_sync(struct sock *sk, const u64 seq,
517 const enum dccp_pkt_type pkt_type)
518 {
519 /*
520 * We are not putting this on the write queue, so
521 * dccp_transmit_skb() will set the ownership to this
522 * sock.
523 */
524 struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
526 if (skb == NULL)
527 /* FIXME: how to make sure the sync is sent? */
528 return;
530 /* Reserve space for headers and prepare control bits. */
531 skb_reserve(skb, sk->sk_prot->max_header);
532 skb->csum = 0;
533 DCCP_SKB_CB(skb)->dccpd_type = pkt_type;
534 DCCP_SKB_CB(skb)->dccpd_seq = seq;
536 dccp_transmit_skb(sk, skb);
537 }
539 EXPORT_SYMBOL_GPL(dccp_send_sync);
541 /*
542 * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This
543 * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under
544 * any circumstances.
545 */
546 void dccp_send_close(struct sock *sk, const int active)
547 {
548 struct dccp_sock *dp = dccp_sk(sk);
549 struct sk_buff *skb;
550 const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC;
552 skb = alloc_skb(sk->sk_prot->max_header, prio);
553 if (skb == NULL)
554 return;
556 /* Reserve space for headers and prepare control bits. */
557 skb_reserve(skb, sk->sk_prot->max_header);
558 skb->csum = 0;
559 DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ?
560 DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ;
562 if (active) {
563 dccp_skb_entail(sk, skb);
564 dccp_transmit_skb(sk, skb_clone(skb, prio));
565 } else
566 dccp_transmit_skb(sk, skb);
567 }