source: mainline/uspace/srv/net/tl/tcp/tqueue.c@ 5f9ecd3

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 5f9ecd3 was 704586fb, checked in by Jiri Svoboda <jiri@…>, 14 years ago

Fix RST to refuse connection and handle it properly in connect().
  • Property mode set to 100644
File size: 8.7 KB
Line 
1/*
2 * Copyright (c) 2011 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#include "conn.h"
46#include "ncsim.h"
47#include "pdu.h"
48#include "rqueue.h"
49#include "segment.h"
50#include "seq_no.h"
51#include "tqueue.h"
52#include "tcp.h"
53#include "tcp_type.h"
54
55#define RETRANSMIT_TIMEOUT (2*1000*1000)
56
57static void retransmit_timeout_func(void *arg);
58static void tcp_tqueue_timer_set(tcp_conn_t *conn);
59static void tcp_tqueue_timer_clear(tcp_conn_t *conn);
60
61int tcp_tqueue_init(tcp_tqueue_t *tqueue, tcp_conn_t *conn)
62{
63 tqueue->conn = conn;
64 tqueue->timer = fibril_timer_create();
65 if (tqueue->timer == NULL)
66 return ENOMEM;
67
68 list_initialize(&tqueue->list);
69
70 return EOK;
71}
72
73void tcp_tqueue_clear(tcp_tqueue_t *tqueue)
74{
75 tcp_tqueue_timer_clear(tqueue->conn);
76}
77
78void tcp_tqueue_fini(tcp_tqueue_t *tqueue)
79{
80 if (tqueue->timer != NULL) {
81 fibril_timer_destroy(tqueue->timer);
82 tqueue->timer = NULL;
83 }
84}
85
86void tcp_tqueue_ctrl_seg(tcp_conn_t *conn, tcp_control_t ctrl)
87{
88 tcp_segment_t *seg;
89
90 log_msg(LVL_DEBUG, "tcp_tqueue_ctrl_seg(%p, %u)", conn, ctrl);
91
92 seg = tcp_segment_make_ctrl(ctrl);
93 tcp_tqueue_seg(conn, seg);
94}
95
96void tcp_tqueue_seg(tcp_conn_t *conn, tcp_segment_t *seg)
97{
98 tcp_segment_t *rt_seg;
99 tcp_tqueue_entry_t *tqe;
100
101 log_msg(LVL_DEBUG, "%s: tcp_tqueue_seg(%p, %p)", conn->name, conn,
102 seg);
103
104 /*
105 * Add segment to retransmission queue
106 */
107
108 if (seg->len > 0) {
109 rt_seg = tcp_segment_dup(seg);
110 if (rt_seg == NULL) {
111 log_msg(LVL_ERROR, "Memory allocation failed.");
112 /* XXX Handle properly */
113 return;
114 }
115
116 tqe = calloc(1, sizeof(tcp_tqueue_entry_t));
117 if (tqe == NULL) {
118 log_msg(LVL_ERROR, "Memory allocation failed.");
119 /* XXX Handle properly */
120 return;
121 }
122
123 tqe->conn = conn;
124 tqe->seg = rt_seg;
125 list_append(&tqe->link, &conn->retransmit.list);
126
127 /* Set retransmission timer */
128 tcp_tqueue_timer_set(conn);
129 }
130
131 tcp_prepare_transmit_segment(conn, seg);
132}
133
134void tcp_prepare_transmit_segment(tcp_conn_t *conn, tcp_segment_t *seg)
135{
136 /*
137 * Always send ACK once we have received SYN, except for RST segments.
138 * (Spec says we should always send ACK once connection has been
139 * established.)
140 */
141 if (tcp_conn_got_syn(conn) && (seg->ctrl & CTL_RST) == 0)
142 seg->ctrl |= CTL_ACK;
143
144 seg->seq = conn->snd_nxt;
145 conn->snd_nxt += seg->len;
146
147 tcp_conn_transmit_segment(conn, seg);
148}
149
150/** Transmit data from the send buffer.
151 *
152 * @param conn Connection
153 */
154void tcp_tqueue_new_data(tcp_conn_t *conn)
155{
156 size_t avail_wnd;
157 size_t xfer_seqlen;
158 size_t snd_buf_seqlen;
159 size_t data_size;
160 tcp_control_t ctrl;
161 bool send_fin;
162
163 tcp_segment_t *seg;
164
165 log_msg(LVL_DEBUG, "%s: tcp_tqueue_new_data()", conn->name);
166
167 /* Number of free sequence numbers in send window */
168 avail_wnd = (conn->snd_una + conn->snd_wnd) - conn->snd_nxt;
169 snd_buf_seqlen = conn->snd_buf_used + (conn->snd_buf_fin ? 1 : 0);
170
171 xfer_seqlen = min(snd_buf_seqlen, avail_wnd);
172 log_msg(LVL_DEBUG, "%s: snd_buf_seqlen = %zu, SND.WND = %zu, "
173 "xfer_seqlen = %zu", conn->name, snd_buf_seqlen, conn->snd_wnd,
174 xfer_seqlen);
175
176 if (xfer_seqlen == 0)
177 return;
178
179 /* XXX Do not always send immediately */
180
181 send_fin = conn->snd_buf_fin && xfer_seqlen == snd_buf_seqlen;
182 data_size = xfer_seqlen - (send_fin ? 1 : 0);
183
184 if (send_fin) {
185 log_msg(LVL_DEBUG, "%s: Sending out FIN.", conn->name);
186 /* We are sending out FIN */
187 ctrl = CTL_FIN;
188 tcp_conn_fin_sent(conn);
189 } else {
190 ctrl = 0;
191 }
192
193 seg = tcp_segment_make_data(ctrl, conn->snd_buf, data_size);
194 if (seg == NULL) {
195 log_msg(LVL_ERROR, "Memory allocation failure.");
196 return;
197 }
198
199 /* Remove data from send buffer */
200 memmove(conn->snd_buf, conn->snd_buf + data_size,
201 conn->snd_buf_used - data_size);
202 conn->snd_buf_used -= data_size;
203
204 if (send_fin)
205 conn->snd_buf_fin = false;
206
207 tcp_tqueue_seg(conn, seg);
208}
209
210/** Remove ACKed segments from retransmission queue and possibly transmit
211 * more data.
212 *
213 * This should be called when SND.UNA is updated due to incoming ACK.
214 */
215void tcp_tqueue_ack_received(tcp_conn_t *conn)
216{
217 link_t *cur, *next;
218
219 log_msg(LVL_DEBUG, "%s: tcp_tqueue_ack_received(%p)", conn->name,
220 conn);
221
222 cur = conn->retransmit.list.head.next;
223
224 while (cur != &conn->retransmit.list.head) {
225 next = cur->next;
226
227 tcp_tqueue_entry_t *tqe = list_get_instance(cur,
228 tcp_tqueue_entry_t, link);
229
230 if (seq_no_segment_acked(conn, tqe->seg, conn->snd_una)) {
231 /* Remove acknowledged segment */
232 list_remove(cur);
233
234 if ((tqe->seg->ctrl & CTL_FIN) != 0) {
235 /* Our FIN has been acked */
236 conn->fin_is_acked = true;
237 }
238
239 tcp_segment_delete(tqe->seg);
240 free(tqe);
241
242 /* Reset retransmission timer */
243 tcp_tqueue_timer_set(conn);
244 }
245
246 cur = next;
247 }
248
249 /* Clear retransmission timer if the queue is empty. */
250 if (list_empty(&conn->retransmit.list))
251 tcp_tqueue_timer_clear(conn);
252
253 /* Possibly transmit more data */
254 tcp_tqueue_new_data(conn);
255}
256
257void tcp_conn_transmit_segment(tcp_conn_t *conn, tcp_segment_t *seg)
258{
259 log_msg(LVL_DEBUG, "%s: tcp_conn_transmit_segment(%p, %p)",
260 conn->name, conn, seg);
261
262 seg->wnd = conn->rcv_wnd;
263
264 if ((seg->ctrl & CTL_ACK) != 0)
265 seg->ack = conn->rcv_nxt;
266 else
267 seg->ack = 0;
268
269 tcp_transmit_segment(&conn->ident, seg);
270}
271
272void tcp_transmit_segment(tcp_sockpair_t *sp, tcp_segment_t *seg)
273{
274 log_msg(LVL_DEBUG, "tcp_transmit_segment(f:(%x,%u),l:(%x,%u), %p)",
275 sp->foreign.addr.ipv4, sp->foreign.port,
276 sp->local.addr.ipv4, sp->local.port, seg);
277
278 log_msg(LVL_DEBUG, "SEG.SEQ=%" PRIu32 ", SEG.WND=%" PRIu32,
279 seg->seq, seg->wnd);
280
281 tcp_segment_dump(seg);
282/*
283 tcp_pdu_prepare(conn, seg, &data, &len);
284 tcp_pdu_transmit(data, len);
285*/
286// tcp_rqueue_bounce_seg(sp, seg);
287// tcp_ncsim_bounce_seg(sp, seg);
288
289 tcp_pdu_t *pdu;
290
291 if (tcp_pdu_encode(sp, seg, &pdu) != EOK) {
292 log_msg(LVL_WARN, "Not enough memory. Segment dropped.");
293 return;
294 }
295
296 tcp_transmit_pdu(pdu);
297 tcp_pdu_delete(pdu);
298}
299
300static void retransmit_timeout_func(void *arg)
301{
302 tcp_conn_t *conn = (tcp_conn_t *) arg;
303 tcp_tqueue_entry_t *tqe;
304 tcp_segment_t *rt_seg;
305 link_t *link;
306
307 log_msg(LVL_DEBUG, "### %s: retransmit_timeout_func(%p)", conn->name, conn);
308
309 if (conn->cstate == st_closed) {
310 log_msg(LVL_DEBUG, "Connection already closed.");
311 return;
312 }
313
314 link = list_first(&conn->retransmit.list);
315 if (link == NULL) {
316 log_msg(LVL_DEBUG, "Nothing to retransmit");
317 return;
318 }
319
320 tqe = list_get_instance(link, tcp_tqueue_entry_t, link);
321
322 rt_seg = tcp_segment_dup(tqe->seg);
323 if (rt_seg == NULL) {
324 log_msg(LVL_ERROR, "Memory allocation failed.");
325 /* XXX Handle properly */
326 return;
327 }
328
329 log_msg(LVL_DEBUG, "### %s: retransmitting segment", conn->name);
330 tcp_conn_transmit_segment(tqe->conn, rt_seg);
331
332 /* Reset retransmission timer */
333 tcp_tqueue_timer_set(tqe->conn);
334}
335
336/** Set or re-set retransmission timer */
337static void tcp_tqueue_timer_set(tcp_conn_t *conn)
338{
339 log_msg(LVL_DEBUG, "### %s: tcp_tqueue_timer_set()", conn->name);
340
341 (void) retransmit_timeout_func;
342 fibril_timer_set(conn->retransmit.timer, RETRANSMIT_TIMEOUT,
343 retransmit_timeout_func, (void *) conn);
344}
345
346/** Clear retransmission timer */
347static void tcp_tqueue_timer_clear(tcp_conn_t *conn)
348{
349 log_msg(LVL_DEBUG, "### %s: tcp_tqueue_timer_clear()", conn->name);
350
351 fibril_timer_clear(conn->retransmit.timer);
352}
353
354/**
355 * @}
356 */
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