tests: virtio-9p: add version operation test
[qemu.git] / slirp / tftp.c
1 /*
2 * tftp.c - a simple, read-only tftp server for qemu
3 *
4 * Copyright (c) 2004 Magnus Damm <damm@opensource.se>
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 "qemu/osdep.h"
26 #include "slirp.h"
27 #include "qemu-common.h"
28 #include "qemu/cutils.h"
29
30 static inline int tftp_session_in_use(struct tftp_session *spt)
31 {
32 return (spt->slirp != NULL);
33 }
34
35 static inline void tftp_session_update(struct tftp_session *spt)
36 {
37 spt->timestamp = curtime;
38 }
39
40 static void tftp_session_terminate(struct tftp_session *spt)
41 {
42 if (spt->fd >= 0) {
43 close(spt->fd);
44 spt->fd = -1;
45 }
46 g_free(spt->filename);
47 spt->slirp = NULL;
48 }
49
50 static int tftp_session_allocate(Slirp *slirp, struct sockaddr_storage *srcsas,
51 struct tftp_t *tp)
52 {
53 struct tftp_session *spt;
54 int k;
55
56 for (k = 0; k < TFTP_SESSIONS_MAX; k++) {
57 spt = &slirp->tftp_sessions[k];
58
59 if (!tftp_session_in_use(spt))
60 goto found;
61
62 /* sessions time out after 5 inactive seconds */
63 if ((int)(curtime - spt->timestamp) > 5000) {
64 tftp_session_terminate(spt);
65 goto found;
66 }
67 }
68
69 return -1;
70
71 found:
72 memset(spt, 0, sizeof(*spt));
73 spt->client_addr = *srcsas;
74 spt->fd = -1;
75 spt->block_size = 512;
76 spt->client_port = tp->udp.uh_sport;
77 spt->slirp = slirp;
78
79 tftp_session_update(spt);
80
81 return k;
82 }
83
84 static int tftp_session_find(Slirp *slirp, struct sockaddr_storage *srcsas,
85 struct tftp_t *tp)
86 {
87 struct tftp_session *spt;
88 int k;
89
90 for (k = 0; k < TFTP_SESSIONS_MAX; k++) {
91 spt = &slirp->tftp_sessions[k];
92
93 if (tftp_session_in_use(spt)) {
94 if (sockaddr_equal(&spt->client_addr, srcsas)) {
95 if (spt->client_port == tp->udp.uh_sport) {
96 return k;
97 }
98 }
99 }
100 }
101
102 return -1;
103 }
104
105 static int tftp_read_data(struct tftp_session *spt, uint32_t block_nr,
106 uint8_t *buf, int len)
107 {
108 int bytes_read = 0;
109
110 if (spt->fd < 0) {
111 spt->fd = open(spt->filename, O_RDONLY | O_BINARY);
112 }
113
114 if (spt->fd < 0) {
115 return -1;
116 }
117
118 if (len) {
119 lseek(spt->fd, block_nr * spt->block_size, SEEK_SET);
120
121 bytes_read = read(spt->fd, buf, len);
122 }
123
124 return bytes_read;
125 }
126
127 static struct tftp_t *tftp_prep_mbuf_data(struct tftp_session *spt,
128 struct mbuf *m)
129 {
130 struct tftp_t *tp;
131
132 memset(m->m_data, 0, m->m_size);
133
134 m->m_data += IF_MAXLINKHDR;
135 if (spt->client_addr.ss_family == AF_INET6) {
136 m->m_data += sizeof(struct ip6);
137 } else {
138 m->m_data += sizeof(struct ip);
139 }
140 tp = (void *)m->m_data;
141 m->m_data += sizeof(struct udphdr);
142
143 return tp;
144 }
145
146 static void tftp_udp_output(struct tftp_session *spt, struct mbuf *m,
147 struct tftp_t *recv_tp)
148 {
149 if (spt->client_addr.ss_family == AF_INET6) {
150 struct sockaddr_in6 sa6, da6;
151
152 sa6.sin6_addr = spt->slirp->vhost_addr6;
153 sa6.sin6_port = recv_tp->udp.uh_dport;
154 da6.sin6_addr = ((struct sockaddr_in6 *)&spt->client_addr)->sin6_addr;
155 da6.sin6_port = spt->client_port;
156
157 udp6_output(NULL, m, &sa6, &da6);
158 } else {
159 struct sockaddr_in sa4, da4;
160
161 sa4.sin_addr = spt->slirp->vhost_addr;
162 sa4.sin_port = recv_tp->udp.uh_dport;
163 da4.sin_addr = ((struct sockaddr_in *)&spt->client_addr)->sin_addr;
164 da4.sin_port = spt->client_port;
165
166 udp_output(NULL, m, &sa4, &da4, IPTOS_LOWDELAY);
167 }
168 }
169
170 static int tftp_send_oack(struct tftp_session *spt,
171 const char *keys[], uint32_t values[], int nb,
172 struct tftp_t *recv_tp)
173 {
174 struct mbuf *m;
175 struct tftp_t *tp;
176 int i, n = 0;
177
178 m = m_get(spt->slirp);
179
180 if (!m)
181 return -1;
182
183 tp = tftp_prep_mbuf_data(spt, m);
184
185 tp->tp_op = htons(TFTP_OACK);
186 for (i = 0; i < nb; i++) {
187 n += snprintf(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%s",
188 keys[i]) + 1;
189 n += snprintf(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%u",
190 values[i]) + 1;
191 }
192
193 m->m_len = sizeof(struct tftp_t) - (TFTP_BLOCKSIZE_MAX + 2) + n
194 - sizeof(struct udphdr);
195 tftp_udp_output(spt, m, recv_tp);
196
197 return 0;
198 }
199
200 static void tftp_send_error(struct tftp_session *spt,
201 uint16_t errorcode, const char *msg,
202 struct tftp_t *recv_tp)
203 {
204 struct mbuf *m;
205 struct tftp_t *tp;
206
207 m = m_get(spt->slirp);
208
209 if (!m) {
210 goto out;
211 }
212
213 tp = tftp_prep_mbuf_data(spt, m);
214
215 tp->tp_op = htons(TFTP_ERROR);
216 tp->x.tp_error.tp_error_code = htons(errorcode);
217 pstrcpy((char *)tp->x.tp_error.tp_msg, sizeof(tp->x.tp_error.tp_msg), msg);
218
219 m->m_len = sizeof(struct tftp_t) - (TFTP_BLOCKSIZE_MAX + 2) + 3 + strlen(msg)
220 - sizeof(struct udphdr);
221 tftp_udp_output(spt, m, recv_tp);
222
223 out:
224 tftp_session_terminate(spt);
225 }
226
227 static void tftp_send_next_block(struct tftp_session *spt,
228 struct tftp_t *recv_tp)
229 {
230 struct mbuf *m;
231 struct tftp_t *tp;
232 int nobytes;
233
234 m = m_get(spt->slirp);
235
236 if (!m) {
237 return;
238 }
239
240 tp = tftp_prep_mbuf_data(spt, m);
241
242 tp->tp_op = htons(TFTP_DATA);
243 tp->x.tp_data.tp_block_nr = htons((spt->block_nr + 1) & 0xffff);
244
245 nobytes = tftp_read_data(spt, spt->block_nr, tp->x.tp_data.tp_buf,
246 spt->block_size);
247
248 if (nobytes < 0) {
249 m_free(m);
250
251 /* send "file not found" error back */
252
253 tftp_send_error(spt, 1, "File not found", tp);
254
255 return;
256 }
257
258 m->m_len = sizeof(struct tftp_t) - (TFTP_BLOCKSIZE_MAX - nobytes)
259 - sizeof(struct udphdr);
260 tftp_udp_output(spt, m, recv_tp);
261
262 if (nobytes == spt->block_size) {
263 tftp_session_update(spt);
264 }
265 else {
266 tftp_session_terminate(spt);
267 }
268
269 spt->block_nr++;
270 }
271
272 static void tftp_handle_rrq(Slirp *slirp, struct sockaddr_storage *srcsas,
273 struct tftp_t *tp, int pktlen)
274 {
275 struct tftp_session *spt;
276 int s, k;
277 size_t prefix_len;
278 char *req_fname;
279 const char *option_name[2];
280 uint32_t option_value[2];
281 int nb_options = 0;
282
283 /* check if a session already exists and if so terminate it */
284 s = tftp_session_find(slirp, srcsas, tp);
285 if (s >= 0) {
286 tftp_session_terminate(&slirp->tftp_sessions[s]);
287 }
288
289 s = tftp_session_allocate(slirp, srcsas, tp);
290
291 if (s < 0) {
292 return;
293 }
294
295 spt = &slirp->tftp_sessions[s];
296
297 /* unspecified prefix means service disabled */
298 if (!slirp->tftp_prefix) {
299 tftp_send_error(spt, 2, "Access violation", tp);
300 return;
301 }
302
303 /* skip header fields */
304 k = 0;
305 pktlen -= offsetof(struct tftp_t, x.tp_buf);
306
307 /* prepend tftp_prefix */
308 prefix_len = strlen(slirp->tftp_prefix);
309 spt->filename = g_malloc(prefix_len + TFTP_FILENAME_MAX + 2);
310 memcpy(spt->filename, slirp->tftp_prefix, prefix_len);
311 spt->filename[prefix_len] = '/';
312
313 /* get name */
314 req_fname = spt->filename + prefix_len + 1;
315
316 while (1) {
317 if (k >= TFTP_FILENAME_MAX || k >= pktlen) {
318 tftp_send_error(spt, 2, "Access violation", tp);
319 return;
320 }
321 req_fname[k] = tp->x.tp_buf[k];
322 if (req_fname[k++] == '\0') {
323 break;
324 }
325 }
326
327 /* check mode */
328 if ((pktlen - k) < 6) {
329 tftp_send_error(spt, 2, "Access violation", tp);
330 return;
331 }
332
333 if (strcasecmp(&tp->x.tp_buf[k], "octet") != 0) {
334 tftp_send_error(spt, 4, "Unsupported transfer mode", tp);
335 return;
336 }
337
338 k += 6; /* skipping octet */
339
340 /* do sanity checks on the filename */
341 if (!strncmp(req_fname, "../", 3) ||
342 req_fname[strlen(req_fname) - 1] == '/' ||
343 strstr(req_fname, "/../")) {
344 tftp_send_error(spt, 2, "Access violation", tp);
345 return;
346 }
347
348 /* check if the file exists */
349 if (tftp_read_data(spt, 0, NULL, 0) < 0) {
350 tftp_send_error(spt, 1, "File not found", tp);
351 return;
352 }
353
354 if (tp->x.tp_buf[pktlen - 1] != 0) {
355 tftp_send_error(spt, 2, "Access violation", tp);
356 return;
357 }
358
359 while (k < pktlen && nb_options < ARRAY_SIZE(option_name)) {
360 const char *key, *value;
361
362 key = &tp->x.tp_buf[k];
363 k += strlen(key) + 1;
364
365 if (k >= pktlen) {
366 tftp_send_error(spt, 2, "Access violation", tp);
367 return;
368 }
369
370 value = &tp->x.tp_buf[k];
371 k += strlen(value) + 1;
372
373 if (strcasecmp(key, "tsize") == 0) {
374 int tsize = atoi(value);
375 struct stat stat_p;
376
377 if (tsize == 0) {
378 if (stat(spt->filename, &stat_p) == 0)
379 tsize = stat_p.st_size;
380 else {
381 tftp_send_error(spt, 1, "File not found", tp);
382 return;
383 }
384 }
385
386 option_name[nb_options] = "tsize";
387 option_value[nb_options] = tsize;
388 nb_options++;
389 } else if (strcasecmp(key, "blksize") == 0) {
390 int blksize = atoi(value);
391
392 /* Accept blksize up to our maximum size */
393 if (blksize > 0) {
394 spt->block_size = MIN(blksize, TFTP_BLOCKSIZE_MAX);
395 option_name[nb_options] = "blksize";
396 option_value[nb_options] = spt->block_size;
397 nb_options++;
398 }
399 }
400 }
401
402 if (nb_options > 0) {
403 assert(nb_options <= ARRAY_SIZE(option_name));
404 tftp_send_oack(spt, option_name, option_value, nb_options, tp);
405 return;
406 }
407
408 spt->block_nr = 0;
409 tftp_send_next_block(spt, tp);
410 }
411
412 static void tftp_handle_ack(Slirp *slirp, struct sockaddr_storage *srcsas,
413 struct tftp_t *tp, int pktlen)
414 {
415 int s;
416
417 s = tftp_session_find(slirp, srcsas, tp);
418
419 if (s < 0) {
420 return;
421 }
422
423 tftp_send_next_block(&slirp->tftp_sessions[s], tp);
424 }
425
426 static void tftp_handle_error(Slirp *slirp, struct sockaddr_storage *srcsas,
427 struct tftp_t *tp, int pktlen)
428 {
429 int s;
430
431 s = tftp_session_find(slirp, srcsas, tp);
432
433 if (s < 0) {
434 return;
435 }
436
437 tftp_session_terminate(&slirp->tftp_sessions[s]);
438 }
439
440 void tftp_input(struct sockaddr_storage *srcsas, struct mbuf *m)
441 {
442 struct tftp_t *tp = (struct tftp_t *)m->m_data;
443
444 switch(ntohs(tp->tp_op)) {
445 case TFTP_RRQ:
446 tftp_handle_rrq(m->slirp, srcsas, tp, m->m_len);
447 break;
448
449 case TFTP_ACK:
450 tftp_handle_ack(m->slirp, srcsas, tp, m->m_len);
451 break;
452
453 case TFTP_ERROR:
454 tftp_handle_error(m->slirp, srcsas, tp, m->m_len);
455 break;
456 }
457 }