VirtualBox

source: vbox/trunk/src/VBox/Devices/Network/slirp/tftp.c@ 1023

Last change on this file since 1023 was 1023, checked in by vboxsync, 18 years ago

make slirp compile on win boxes again

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File size: 9.1 KB
Line 
1/*
2 * tftp.c - a simple, read-only tftp server for qemu
3 *
4 * Copyright (c) 2004 Magnus Damm <[email protected]>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25#include <slirp.h>
26
27struct tftp_session {
28 int in_use;
29 unsigned char filename[TFTP_FILENAME_MAX];
30
31 struct in_addr client_ip;
32 u_int16_t client_port;
33
34 int timestamp;
35};
36
37struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
38
39const char *tftp_prefix;
40
41static void tftp_session_update(struct tftp_session *spt)
42{
43 spt->timestamp = curtime;
44 spt->in_use = 1;
45}
46
47static void tftp_session_terminate(struct tftp_session *spt)
48{
49 spt->in_use = 0;
50}
51
52static int tftp_session_allocate(struct tftp_t *tp)
53{
54 struct tftp_session *spt;
55 int k;
56
57 for (k = 0; k < TFTP_SESSIONS_MAX; k++) {
58 spt = &tftp_sessions[k];
59
60 if (!spt->in_use)
61 goto found;
62
63 /* sessions time out after 5 inactive seconds */
64 if ((int)(curtime - spt->timestamp) > 5000)
65 goto found;
66 }
67
68 return -1;
69
70 found:
71 memset(spt, 0, sizeof(*spt));
72 memcpy(&spt->client_ip, &tp->ip.ip_src, sizeof(spt->client_ip));
73 spt->client_port = tp->udp.uh_sport;
74
75 tftp_session_update(spt);
76
77 return k;
78}
79
80static int tftp_session_find(struct tftp_t *tp)
81{
82 struct tftp_session *spt;
83 int k;
84
85 for (k = 0; k < TFTP_SESSIONS_MAX; k++) {
86 spt = &tftp_sessions[k];
87
88 if (spt->in_use) {
89 if (!memcmp(&spt->client_ip, &tp->ip.ip_src, sizeof(spt->client_ip))) {
90 if (spt->client_port == tp->udp.uh_sport) {
91 return k;
92 }
93 }
94 }
95 }
96
97 return -1;
98}
99
100static int tftp_read_data(struct tftp_session *spt, u_int16_t block_nr,
101 u_int8_t *buf, int len)
102{
103 int fd;
104 int bytes_read = 0;
105 char buffer[1024];
106 int n;
107
108#ifndef VBOX
109 n = snprintf(buffer, sizeof(buffer), "%s/%s",
110 tftp_prefix, spt->filename);
111#else
112 n = RTStrPrintf(buffer, sizeof(buffer), "%s/%s",
113 tftp_prefix, spt->filename);
114#endif
115 if (n >= sizeof(buffer))
116 return -1;
117
118 fd = open(buffer, O_RDONLY | O_BINARY);
119
120 if (fd < 0) {
121 return -1;
122 }
123
124 if (len) {
125 lseek(fd, block_nr * 512, SEEK_SET);
126
127 bytes_read = read(fd, buf, len);
128 }
129
130 close(fd);
131
132 return bytes_read;
133}
134
135static int tftp_send_oack(struct tftp_session *spt,
136 const char *key, uint32_t value,
137 struct tftp_t *recv_tp)
138{
139 struct sockaddr_in saddr, daddr;
140 struct mbuf *m;
141 struct tftp_t *tp;
142 int n = 0;
143
144 m = m_get();
145
146 if (!m)
147 return -1;
148
149 memset(m->m_data, 0, m->m_size);
150
151 m->m_data += if_maxlinkhdr;
152 tp = (void *)m->m_data;
153 m->m_data += sizeof(struct udpiphdr);
154
155 tp->tp_op = htons(TFTP_OACK);
156 n += sprintf(tp->x.tp_buf + n, "%s", key) + 1;
157 n += sprintf(tp->x.tp_buf + n, "%u", value) + 1;
158
159 saddr.sin_addr = recv_tp->ip.ip_dst;
160 saddr.sin_port = recv_tp->udp.uh_dport;
161
162 daddr.sin_addr = spt->client_ip;
163 daddr.sin_port = spt->client_port;
164
165 m->m_len = sizeof(struct tftp_t) - 514 + n -
166 sizeof(struct ip) - sizeof(struct udphdr);
167 udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
168
169 return 0;
170}
171
172
173
174static int tftp_send_error(struct tftp_session *spt,
175 u_int16_t errorcode, const char *msg,
176 struct tftp_t *recv_tp)
177{
178 struct sockaddr_in saddr, daddr;
179 struct mbuf *m;
180 struct tftp_t *tp;
181 int nobytes;
182
183 m = m_get();
184
185 if (!m) {
186 return -1;
187 }
188
189 memset(m->m_data, 0, m->m_size);
190
191 m->m_data += if_maxlinkhdr;
192 tp = (void *)m->m_data;
193 m->m_data += sizeof(struct udpiphdr);
194
195 tp->tp_op = htons(TFTP_ERROR);
196 tp->x.tp_error.tp_error_code = htons(errorcode);
197#ifndef VBOX
198 strcpy(tp->x.tp_error.tp_msg, msg);
199#else /* VBOX */
200 strcpy((char *)tp->x.tp_error.tp_msg, msg);
201#endif /* VBOX */
202
203 saddr.sin_addr = recv_tp->ip.ip_dst;
204 saddr.sin_port = recv_tp->udp.uh_dport;
205
206 daddr.sin_addr = spt->client_ip;
207 daddr.sin_port = spt->client_port;
208
209 nobytes = 2;
210
211 m->m_len = sizeof(struct tftp_t) - 514 + 3 + strlen(msg) -
212 sizeof(struct ip) - sizeof(struct udphdr);
213
214 udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
215
216 tftp_session_terminate(spt);
217
218 return 0;
219}
220
221static int tftp_send_data(struct tftp_session *spt,
222 u_int16_t block_nr,
223 struct tftp_t *recv_tp)
224{
225 struct sockaddr_in saddr, daddr;
226 struct mbuf *m;
227 struct tftp_t *tp;
228 int nobytes;
229
230 if (block_nr < 1) {
231 return -1;
232 }
233
234 m = m_get();
235
236 if (!m) {
237 return -1;
238 }
239
240 memset(m->m_data, 0, m->m_size);
241
242 m->m_data += if_maxlinkhdr;
243 tp = (void *)m->m_data;
244 m->m_data += sizeof(struct udpiphdr);
245
246 tp->tp_op = htons(TFTP_DATA);
247 tp->x.tp_data.tp_block_nr = htons(block_nr);
248
249 saddr.sin_addr = recv_tp->ip.ip_dst;
250 saddr.sin_port = recv_tp->udp.uh_dport;
251
252 daddr.sin_addr = spt->client_ip;
253 daddr.sin_port = spt->client_port;
254
255 nobytes = tftp_read_data(spt, block_nr - 1, tp->x.tp_data.tp_buf, 512);
256
257 if (nobytes < 0) {
258 m_free(m);
259
260 /* send "file not found" error back */
261
262 tftp_send_error(spt, 1, "File not found", tp);
263
264 return -1;
265 }
266
267 m->m_len = sizeof(struct tftp_t) - (512 - nobytes) -
268 sizeof(struct ip) - sizeof(struct udphdr);
269
270 udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
271
272 if (nobytes == 512) {
273 tftp_session_update(spt);
274 }
275 else {
276 tftp_session_terminate(spt);
277 }
278
279 return 0;
280}
281
282static void tftp_handle_rrq(struct tftp_t *tp, int pktlen)
283{
284 struct tftp_session *spt;
285 int s, k, n;
286 u_int8_t *src, *dst;
287
288 s = tftp_session_allocate(tp);
289
290 if (s < 0) {
291 return;
292 }
293
294 spt = &tftp_sessions[s];
295
296 src = tp->x.tp_buf;
297 dst = spt->filename;
298 n = pktlen - ((uint8_t *)&tp->x.tp_buf[0] - (uint8_t *)tp);
299
300 /* get name */
301
302 for (k = 0; k < n; k++) {
303 if (k < TFTP_FILENAME_MAX) {
304 dst[k] = src[k];
305 }
306 else {
307 return;
308 }
309
310 if (src[k] == '\0') {
311 break;
312 }
313 }
314
315 if (k >= n) {
316 return;
317 }
318
319 k++;
320
321 /* check mode */
322 if ((n - k) < 6) {
323 return;
324 }
325
326 if (memcmp(&src[k], "octet\0", 6) != 0) {
327 tftp_send_error(spt, 4, "Unsupported transfer mode", tp);
328 return;
329 }
330
331 k += 6; /* skipping octet */
332
333 /* do sanity checks on the filename */
334
335#ifndef VBOX
336 if ((spt->filename[0] != '/')
337 || (spt->filename[strlen(spt->filename) - 1] == '/')
338 || strstr(spt->filename, "/../")) {
339#else /* VBOX */
340 if ((spt->filename[0] != '/')
341 || (spt->filename[strlen((const char *)spt->filename) - 1] == '/')
342 || strstr((char *)spt->filename, "/../")) {
343#endif /* VBOX */
344 tftp_send_error(spt, 2, "Access violation", tp);
345 return;
346 }
347
348 /* only allow exported prefixes */
349
350 if (!tftp_prefix) {
351 tftp_send_error(spt, 2, "Access violation", tp);
352 return;
353 }
354
355 /* check if the file exists */
356
357 if (tftp_read_data(spt, 0, spt->filename, 0) < 0) {
358 tftp_send_error(spt, 1, "File not found", tp);
359 return;
360 }
361
362 if (src[n - 1] != 0) {
363 tftp_send_error(spt, 2, "Access violation", tp);
364 return;
365 }
366
367 while (k < n) {
368 const char *key, *value;
369
370 key = src + k;
371 k += strlen(key) + 1;
372
373 if (k >= n) {
374 tftp_send_error(spt, 2, "Access violation", tp);
375 return;
376 }
377
378 value = src + k;
379 k += strlen(value) + 1;
380
381 if (strcmp(key, "tsize") == 0) {
382 int tsize = atoi(value);
383 struct stat stat_p;
384
385 if (tsize == 0 && tftp_prefix) {
386 char buffer[1024];
387 int len;
388
389#ifndef VBOX
390 len = snprintf(buffer, sizeof(buffer), "%s/%s",
391 tftp_prefix, spt->filename);
392#else
393 len = RTStrPrintf(buffer, sizeof(buffer), "%s/%s",
394 tftp_prefix, spt->filename);
395#endif
396
397 if (stat(buffer, &stat_p) == 0)
398 tsize = stat_p.st_size;
399 else {
400 tftp_send_error(spt, 1, "File not found", tp);
401 return;
402 }
403 }
404
405 tftp_send_oack(spt, "tsize", tsize, tp);
406 }
407 }
408
409 tftp_send_data(spt, 1, tp);
410}
411
412static void tftp_handle_ack(struct tftp_t *tp, int pktlen)
413{
414 int s;
415
416 s = tftp_session_find(tp);
417
418 if (s < 0) {
419 return;
420 }
421
422 if (tftp_send_data(&tftp_sessions[s],
423 ntohs(tp->x.tp_data.tp_block_nr) + 1,
424 tp) < 0) {
425 return;
426 }
427}
428
429void tftp_input(struct mbuf *m)
430{
431 struct tftp_t *tp = (struct tftp_t *)m->m_data;
432
433 switch(ntohs(tp->tp_op)) {
434 case TFTP_RRQ:
435 tftp_handle_rrq(tp, m->m_len);
436 break;
437
438 case TFTP_ACK:
439 tftp_handle_ack(tp, m->m_len);
440 break;
441 }
442}
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