1 /*
2 * Copyright (C) 2008 Edwin Groothuis. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/ioctl.h>
32 #include <sys/stat.h>
33 #include <sys/socket.h>
34
35 #include <netinet/in.h>
36 #include <arpa/tftp.h>
37
38 #include <errno.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <syslog.h>
42
43 #include "tftp-file.h"
44 #include "tftp-io.h"
45 #include "tftp-utils.h"
46 #include "tftp-options.h"
47 #include "tftp-transfer.h"
48
49 /*
50 * Send a file via the TFTP data session.
51 */
52 void
tftp_send(int peer,uint16_t * block,struct tftp_stats * ts)53 tftp_send(int peer, uint16_t *block, struct tftp_stats *ts)
54 {
55 struct tftphdr *rp;
56 int size, n_data, n_ack, try;
57 uint16_t oldblock;
58 char sendbuffer[MAXPKTSIZE];
59 char recvbuffer[MAXPKTSIZE];
60
61 rp = (struct tftphdr *)recvbuffer;
62 *block = 1;
63 ts->amount = 0;
64 do {
65 if (debug&DEBUG_SIMPLE)
66 tftp_log(LOG_DEBUG, "Sending block %d", *block);
67
68 size = read_file(sendbuffer, segsize);
69 if (size < 0) {
70 tftp_log(LOG_ERR, "read_file returned %d", size);
71 send_error(peer, errno + 100);
72 goto abort;
73 }
74
75 for (try = 0; ; try++) {
76 n_data = send_data(peer, *block, sendbuffer, size);
77 if (n_data > 0) {
78 if (try == maxtimeouts) {
79 tftp_log(LOG_ERR,
80 "Cannot send DATA packet #%d, "
81 "giving up", *block);
82 return;
83 }
84 tftp_log(LOG_ERR,
85 "Cannot send DATA packet #%d, trying again",
86 *block);
87 continue;
88 }
89
90 n_ack = receive_packet(peer, recvbuffer,
91 MAXPKTSIZE, NULL, timeoutpacket);
92 if (n_ack < 0) {
93 if (n_ack == RP_TIMEOUT) {
94 if (try == maxtimeouts) {
95 tftp_log(LOG_ERR,
96 "Timeout #%d send ACK %d "
97 "giving up", try, *block);
98 return;
99 }
100 tftp_log(LOG_WARNING,
101 "Timeout #%d on ACK %d",
102 try, *block);
103 continue;
104 }
105
106 /* Either read failure or ERROR packet */
107 if (debug&DEBUG_SIMPLE)
108 tftp_log(LOG_ERR, "Aborting: %s",
109 rp_strerror(n_ack));
110 goto abort;
111 }
112 if (rp->th_opcode == ACK) {
113 ts->blocks++;
114 if (rp->th_block == *block) {
115 ts->amount += size;
116 break;
117 }
118
119 /* Re-synchronize with the other side */
120 (void) synchnet(peer);
121 if (rp->th_block == (*block - 1)) {
122 ts->retries++;
123 continue;
124 }
125 }
126
127 }
128 oldblock = *block;
129 (*block)++;
130 if (oldblock > *block) {
131 if (options[OPT_ROLLOVER].o_request == NULL) {
132 /*
133 * "rollover" option not specified in
134 * tftp client. Default to rolling block
135 * counter to 0.
136 */
137 *block = 0;
138 } else {
139 *block = atoi(options[OPT_ROLLOVER].o_request);
140 }
141
142 ts->rollovers++;
143 }
144 gettimeofday(&(ts->tstop), NULL);
145 } while (size == segsize);
146 abort:
147 return;
148 }
149
150 /*
151 * Receive a file via the TFTP data session.
152 *
153 * - It could be that the first block has already arrived while
154 * trying to figure out if we were receiving options or not. In
155 * that case it is passed to this function.
156 */
157 void
tftp_receive(int peer,uint16_t * block,struct tftp_stats * ts,struct tftphdr * firstblock,size_t fb_size)158 tftp_receive(int peer, uint16_t *block, struct tftp_stats *ts,
159 struct tftphdr *firstblock, size_t fb_size)
160 {
161 struct tftphdr *rp;
162 uint16_t oldblock;
163 int n_data, n_ack, writesize, i, retry;
164 char recvbuffer[MAXPKTSIZE];
165
166 ts->amount = 0;
167
168 if (firstblock != NULL) {
169 writesize = write_file(firstblock->th_data, fb_size);
170 ts->amount += writesize;
171 for (i = 0; ; i++) {
172 n_ack = send_ack(peer, *block);
173 if (n_ack > 0) {
174 if (i == maxtimeouts) {
175 tftp_log(LOG_ERR,
176 "Cannot send ACK packet #%d, "
177 "giving up", *block);
178 return;
179 }
180 tftp_log(LOG_ERR,
181 "Cannot send ACK packet #%d, trying again",
182 *block);
183 continue;
184 }
185
186 break;
187 }
188
189 if (fb_size != segsize) {
190 gettimeofday(&(ts->tstop), NULL);
191 return;
192 }
193 }
194
195 rp = (struct tftphdr *)recvbuffer;
196 do {
197 oldblock = *block;
198 (*block)++;
199 if (oldblock > *block) {
200 if (options[OPT_ROLLOVER].o_request == NULL) {
201 /*
202 * "rollover" option not specified in
203 * tftp client. Default to rolling block
204 * counter to 0.
205 */
206 *block = 0;
207 } else {
208 *block = atoi(options[OPT_ROLLOVER].o_request);
209 }
210
211 ts->rollovers++;
212 }
213
214 for (retry = 0; ; retry++) {
215 if (debug&DEBUG_SIMPLE)
216 tftp_log(LOG_DEBUG,
217 "Receiving DATA block %d", *block);
218
219 n_data = receive_packet(peer, recvbuffer,
220 MAXPKTSIZE, NULL, timeoutpacket);
221 if (n_data < 0) {
222 if (retry == maxtimeouts) {
223 tftp_log(LOG_ERR,
224 "Timeout #%d on DATA block %d, "
225 "giving up", retry, *block);
226 return;
227 }
228 if (n_data == RP_TIMEOUT) {
229 tftp_log(LOG_WARNING,
230 "Timeout #%d on DATA block %d",
231 retry, *block);
232 send_ack(peer, oldblock);
233 continue;
234 }
235
236 /* Either read failure or ERROR packet */
237 if (debug&DEBUG_SIMPLE)
238 tftp_log(LOG_DEBUG, "Aborting: %s",
239 rp_strerror(n_data));
240 goto abort;
241 }
242 if (rp->th_opcode == DATA) {
243 ts->blocks++;
244
245 if (rp->th_block == *block)
246 break;
247
248 tftp_log(LOG_WARNING,
249 "Expected DATA block %d, got block %d",
250 *block, rp->th_block);
251
252 /* Re-synchronize with the other side */
253 (void) synchnet(peer);
254 if (rp->th_block == (*block-1)) {
255 tftp_log(LOG_INFO, "Trying to sync");
256 *block = oldblock;
257 ts->retries++;
258 goto send_ack; /* rexmit */
259 }
260
261 } else {
262 tftp_log(LOG_WARNING,
263 "Expected DATA block, got %s block",
264 packettype(rp->th_opcode));
265 }
266 }
267
268 if (n_data > 0) {
269 writesize = write_file(rp->th_data, n_data);
270 ts->amount += writesize;
271 if (writesize <= 0) {
272 tftp_log(LOG_ERR,
273 "write_file returned %d", writesize);
274 if (writesize < 0)
275 send_error(peer, errno + 100);
276 else
277 send_error(peer, ENOSPACE);
278 goto abort;
279 }
280 }
281
282 send_ack:
283 for (i = 0; ; i++) {
284 n_ack = send_ack(peer, *block);
285 if (n_ack > 0) {
286
287 if (i == maxtimeouts) {
288 tftp_log(LOG_ERR,
289 "Cannot send ACK packet #%d, "
290 "giving up", *block);
291 return;
292 }
293
294 tftp_log(LOG_ERR,
295 "Cannot send ACK packet #%d, trying again",
296 *block);
297 continue;
298 }
299
300 break;
301 }
302 gettimeofday(&(ts->tstop), NULL);
303 } while (n_data == segsize);
304
305 /* Don't do late packet management for the client implementation */
306 if (acting_as_client)
307 return;
308
309 for (i = 0; ; i++) {
310 n_data = receive_packet(peer, (char *)rp, pktsize,
311 NULL, timeoutpacket);
312 if (n_data <= 0)
313 break;
314 if (n_data > 0 &&
315 rp->th_opcode == DATA && /* and got a data block */
316 *block == rp->th_block) /* then my last ack was lost */
317 send_ack(peer, *block); /* resend final ack */
318 }
319
320 abort:
321 return;
322 }
323