source: mainline/uspace/srv/net/tcp/tqueue.c@ 975d528

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 975d528 was 975d528, checked in by Jiri Svoboda <jiri@…>, 8 years ago

Add unit tests for TCP tqueue. Fix tqueue possibly being finalized without freeing pending segments.
  • Property mode set to 100644
File size: 10.2 KB
Line 
1/*
2 * Copyright (c) 2015 Jiri Svoboda
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup tcp
30 * @{
31 */
32
33/**
34 * @file TCP transmission queue
35 */
36
37#include <adt/list.h>
38#include <errno.h>
39#include <fibril_synch.h>
40#include <byteorder.h>
41#include <io/log.h>
42#include <macros.h>
43#include <mem.h>
44#include <stdlib.h>
45
46#include "conn.h"
47#include "inet.h"
48#include "ncsim.h"
49#include "rqueue.h"
50#include "segment.h"
51#include "seq_no.h"
52#include "tqueue.h"
53#include "tcp_type.h"
54
55#define RETRANSMIT_TIMEOUT (2*1000*1000)
56
57static void retransmit_timeout_func(void *);
58static void tcp_tqueue_timer_set(tcp_conn_t *);
59static void tcp_tqueue_timer_clear(tcp_conn_t *);
60static void tcp_tqueue_seg(tcp_conn_t *, tcp_segment_t *);
61static void tcp_conn_transmit_segment(tcp_conn_t *, tcp_segment_t *);
62static void tcp_prepare_transmit_segment(tcp_conn_t *, tcp_segment_t *);
63static void tcp_tqueue_send_immed(tcp_conn_t *, tcp_segment_t *);
64
65int tcp_tqueue_init(tcp_tqueue_t *tqueue, tcp_conn_t *conn,
66 tcp_tqueue_cb_t *cb)
67{
68 tqueue->conn = conn;
69 tqueue->timer = fibril_timer_create(&conn->lock);
70 tqueue->cb = cb;
71 if (tqueue->timer == NULL)
72 return ENOMEM;
73
74 list_initialize(&tqueue->list);
75
76 return EOK;
77}
78
79void tcp_tqueue_clear(tcp_tqueue_t *tqueue)
80{
81 tcp_tqueue_timer_clear(tqueue->conn);
82}
83
84void tcp_tqueue_fini(tcp_tqueue_t *tqueue)
85{
86 link_t *link;
87 tcp_tqueue_entry_t *tqe;
88
89 if (tqueue->timer != NULL) {
90 fibril_timer_destroy(tqueue->timer);
91 tqueue->timer = NULL;
92 }
93
94 while (!list_empty(&tqueue->list)) {
95 link = list_first(&tqueue->list);
96 tqe = list_get_instance(link, tcp_tqueue_entry_t, link);
97 list_remove(link);
98
99 tcp_segment_delete(tqe->seg);
100 free(tqe);
101 }
102}
103
104void tcp_tqueue_ctrl_seg(tcp_conn_t *conn, tcp_control_t ctrl)
105{
106 tcp_segment_t *seg;
107
108 log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_tqueue_ctrl_seg(%p, %u)", conn, ctrl);
109
110 seg = tcp_segment_make_ctrl(ctrl);
111 tcp_tqueue_seg(conn, seg);
112 tcp_segment_delete(seg);
113}
114
115static void tcp_tqueue_seg(tcp_conn_t *conn, tcp_segment_t *seg)
116{
117 tcp_segment_t *rt_seg;
118 tcp_tqueue_entry_t *tqe;
119
120 log_msg(LOG_DEFAULT, LVL_DEBUG, "%s: tcp_tqueue_seg(%p, %p)", conn->name, conn,
121 seg);
122
123 /*
124 * Add segment to retransmission queue
125 */
126
127 if (seg->len > 0) {
128 rt_seg = tcp_segment_dup(seg);
129 if (rt_seg == NULL) {
130 log_msg(LOG_DEFAULT, LVL_ERROR, "Memory allocation failed.");
131 /* XXX Handle properly */
132 return;
133 }
134
135 tqe = calloc(1, sizeof(tcp_tqueue_entry_t));
136 if (tqe == NULL) {
137 log_msg(LOG_DEFAULT, LVL_ERROR, "Memory allocation failed.");
138 /* XXX Handle properly */
139 return;
140 }
141
142 tqe->conn = conn;
143 tqe->seg = rt_seg;
144 rt_seg->seq = conn->snd_nxt;
145
146 list_append(&tqe->link, &conn->retransmit.list);
147
148 /* Set retransmission timer */
149 tcp_tqueue_timer_set(conn);
150 }
151
152 tcp_prepare_transmit_segment(conn, seg);
153}
154
155static void tcp_prepare_transmit_segment(tcp_conn_t *conn, tcp_segment_t *seg)
156{
157 /*
158 * Always send ACK once we have received SYN, except for RST segments.
159 * (Spec says we should always send ACK once connection has been
160 * established.)
161 */
162 if (tcp_conn_got_syn(conn) && (seg->ctrl & CTL_RST) == 0)
163 seg->ctrl |= CTL_ACK;
164
165 seg->seq = conn->snd_nxt;
166 conn->snd_nxt += seg->len;
167
168 tcp_conn_transmit_segment(conn, seg);
169}
170
171/** Transmit data from the send buffer.
172 *
173 * @param conn Connection
174 */
175void tcp_tqueue_new_data(tcp_conn_t *conn)
176{
177 size_t avail_wnd;
178 size_t xfer_seqlen;
179 size_t snd_buf_seqlen;
180 size_t data_size;
181 tcp_control_t ctrl;
182 bool send_fin;
183
184 tcp_segment_t *seg;
185
186 log_msg(LOG_DEFAULT, LVL_DEBUG, "%s: tcp_tqueue_new_data()", conn->name);
187
188 /* Number of free sequence numbers in send window */
189 avail_wnd = (conn->snd_una + conn->snd_wnd) - conn->snd_nxt;
190 snd_buf_seqlen = conn->snd_buf_used + (conn->snd_buf_fin ? 1 : 0);
191
192 xfer_seqlen = min(snd_buf_seqlen, avail_wnd);
193 log_msg(LOG_DEFAULT, LVL_DEBUG, "%s: snd_buf_seqlen = %zu, SND.WND = %" PRIu32 ", "
194 "xfer_seqlen = %zu", conn->name, snd_buf_seqlen, conn->snd_wnd,
195 xfer_seqlen);
196
197 if (xfer_seqlen == 0)
198 return;
199
200 /* XXX Do not always send immediately */
201
202 send_fin = conn->snd_buf_fin && xfer_seqlen == snd_buf_seqlen;
203 data_size = xfer_seqlen - (send_fin ? 1 : 0);
204
205 if (send_fin) {
206 log_msg(LOG_DEFAULT, LVL_DEBUG, "%s: Sending out FIN.", conn->name);
207 /* We are sending out FIN */
208 ctrl = CTL_FIN;
209 } else {
210 ctrl = 0;
211 }
212
213 seg = tcp_segment_make_data(ctrl, conn->snd_buf, data_size);
214 if (seg == NULL) {
215 log_msg(LOG_DEFAULT, LVL_ERROR, "Memory allocation failure.");
216 return;
217 }
218
219 /* Remove data from send buffer */
220 memmove(conn->snd_buf, conn->snd_buf + data_size,
221 conn->snd_buf_used - data_size);
222 conn->snd_buf_used -= data_size;
223
224 if (send_fin)
225 conn->snd_buf_fin = false;
226
227 fibril_condvar_broadcast(&conn->snd_buf_cv);
228
229 if (send_fin)
230 tcp_conn_fin_sent(conn);
231
232 tcp_tqueue_seg(conn, seg);
233 tcp_segment_delete(seg);
234}
235
236/** Remove ACKed segments from retransmission queue and possibly transmit
237 * more data.
238 *
239 * This should be called when SND.UNA is updated due to incoming ACK.
240 */
241void tcp_tqueue_ack_received(tcp_conn_t *conn)
242{
243 link_t *cur, *next;
244
245 log_msg(LOG_DEFAULT, LVL_DEBUG, "%s: tcp_tqueue_ack_received(%p)", conn->name,
246 conn);
247
248 cur = conn->retransmit.list.head.next;
249
250 while (cur != &conn->retransmit.list.head) {
251 next = cur->next;
252
253 tcp_tqueue_entry_t *tqe = list_get_instance(cur,
254 tcp_tqueue_entry_t, link);
255
256 if (seq_no_segment_acked(conn, tqe->seg, conn->snd_una)) {
257 /* Remove acknowledged segment */
258 list_remove(cur);
259
260 if ((tqe->seg->ctrl & CTL_FIN) != 0) {
261 log_msg(LOG_DEFAULT, LVL_DEBUG, "Fin has been acked");
262 log_msg(LOG_DEFAULT, LVL_DEBUG, "SND.UNA=%" PRIu32
263 " SEG.SEQ=%" PRIu32 " SEG.LEN=%" PRIu32,
264 conn->snd_una, tqe->seg->seq, tqe->seg->len);
265 /* Our FIN has been acked */
266 conn->fin_is_acked = true;
267 }
268
269 tcp_segment_delete(tqe->seg);
270 free(tqe);
271
272 /* Reset retransmission timer */
273 tcp_tqueue_timer_set(conn);
274 }
275
276 cur = next;
277 }
278
279 /* Clear retransmission timer if the queue is empty. */
280 if (list_empty(&conn->retransmit.list))
281 tcp_tqueue_timer_clear(conn);
282
283 /* Possibly transmit more data */
284 tcp_tqueue_new_data(conn);
285}
286
287static void tcp_conn_transmit_segment(tcp_conn_t *conn, tcp_segment_t *seg)
288{
289 log_msg(LOG_DEFAULT, LVL_DEBUG, "%s: tcp_conn_transmit_segment(%p, %p)",
290 conn->name, conn, seg);
291
292 seg->wnd = conn->rcv_wnd;
293
294 if ((seg->ctrl & CTL_ACK) != 0)
295 seg->ack = conn->rcv_nxt;
296 else
297 seg->ack = 0;
298
299 tcp_tqueue_send_immed(conn, seg);
300}
301
302void tcp_tqueue_send_immed(tcp_conn_t *conn, tcp_segment_t *seg)
303{
304 log_msg(LOG_DEFAULT, LVL_DEBUG,
305 "tcp_tqueue_send_immed(l:(%u),f:(%u), %p)",
306 conn->ident.local.port, conn->ident.remote.port, seg);
307
308 log_msg(LOG_DEFAULT, LVL_DEBUG, "SEG.SEQ=%" PRIu32 ", SEG.WND=%" PRIu32,
309 seg->seq, seg->wnd);
310
311 tcp_segment_dump(seg);
312
313 conn->retransmit.cb->transmit_seg(&conn->ident, seg);
314}
315
316static void retransmit_timeout_func(void *arg)
317{
318 tcp_conn_t *conn = (tcp_conn_t *) arg;
319 tcp_tqueue_entry_t *tqe;
320 tcp_segment_t *rt_seg;
321 link_t *link;
322
323 log_msg(LOG_DEFAULT, LVL_DEBUG, "### %s: retransmit_timeout_func(%p)", conn->name, conn);
324
325 tcp_conn_lock(conn);
326
327 if (conn->cstate == st_closed) {
328 log_msg(LOG_DEFAULT, LVL_DEBUG, "Connection already closed.");
329 tcp_conn_unlock(conn);
330 tcp_conn_delref(conn);
331 return;
332 }
333
334 link = list_first(&conn->retransmit.list);
335 if (link == NULL) {
336 log_msg(LOG_DEFAULT, LVL_DEBUG, "Nothing to retransmit");
337 tcp_conn_unlock(conn);
338 tcp_conn_delref(conn);
339 return;
340 }
341
342 tqe = list_get_instance(link, tcp_tqueue_entry_t, link);
343
344 rt_seg = tcp_segment_dup(tqe->seg);
345 if (rt_seg == NULL) {
346 log_msg(LOG_DEFAULT, LVL_ERROR, "Memory allocation failed.");
347 tcp_conn_unlock(conn);
348 tcp_conn_delref(conn);
349 /* XXX Handle properly */
350 return;
351 }
352
353 log_msg(LOG_DEFAULT, LVL_DEBUG, "### %s: retransmitting segment", conn->name);
354 tcp_conn_transmit_segment(tqe->conn, rt_seg);
355
356 /* Reset retransmission timer */
357 fibril_timer_set_locked(conn->retransmit.timer, RETRANSMIT_TIMEOUT,
358 retransmit_timeout_func, (void *) conn);
359
360 tcp_conn_unlock(conn);
361
362 log_msg(LOG_DEFAULT, LVL_DEBUG, "### %s: retransmit_timeout_func(%p) end", conn->name, conn);
363}
364
365/** Set or re-set retransmission timer */
366static void tcp_tqueue_timer_set(tcp_conn_t *conn)
367{
368 log_msg(LOG_DEFAULT, LVL_DEBUG, "### %s: tcp_tqueue_timer_set() begin", conn->name);
369
370 /* Clear first to make sure we update refcnt correctly */
371 tcp_tqueue_timer_clear(conn);
372
373 tcp_conn_addref(conn);
374 fibril_timer_set_locked(conn->retransmit.timer, RETRANSMIT_TIMEOUT,
375 retransmit_timeout_func, (void *) conn);
376
377 log_msg(LOG_DEFAULT, LVL_DEBUG, "### %s: tcp_tqueue_timer_set() end", conn->name);
378}
379
380/** Clear retransmission timer */
381static void tcp_tqueue_timer_clear(tcp_conn_t *conn)
382{
383 log_msg(LOG_DEFAULT, LVL_DEBUG, "### %s: tcp_tqueue_timer_clear() begin", conn->name);
384
385 if (fibril_timer_clear_locked(conn->retransmit.timer) == fts_active)
386 tcp_conn_delref(conn);
387
388 log_msg(LOG_DEFAULT, LVL_DEBUG, "### %s: tcp_tqueue_timer_clear() end", conn->name);
389}
390
391/**
392 * @}
393 */
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