Add ENET device to i.MX6 SOC.
[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->client_port = tp->udp.uh_sport;
76 spt->slirp = slirp;
77
78 tftp_session_update(spt);
79
80 return k;
81 }
82
83 static int tftp_session_find(Slirp *slirp, struct sockaddr_storage *srcsas,
84 struct tftp_t *tp)
85 {
86 struct tftp_session *spt;
87 int k;
88
89 for (k = 0; k < TFTP_SESSIONS_MAX; k++) {
90 spt = &slirp->tftp_sessions[k];
91
92 if (tftp_session_in_use(spt)) {
93 if (sockaddr_equal(&spt->client_addr, srcsas)) {
94 if (spt->client_port == tp->udp.uh_sport) {
95 return k;
96 }
97 }
98 }
99 }
100
101 return -1;
102 }
103
104 static int tftp_read_data(struct tftp_session *spt, uint32_t block_nr,
105 uint8_t *buf, int len)
106 {
107 int bytes_read = 0;
108
109 if (spt->fd < 0) {
110 spt->fd = open(spt->filename, O_RDONLY | O_BINARY);
111 }
112
113 if (spt->fd < 0) {
114 return -1;
115 }
116
117 if (len) {
118 lseek(spt->fd, block_nr * 512, SEEK_SET);
119
120 bytes_read = read(spt->fd, buf, len);
121 }
122
123 return bytes_read;
124 }
125
126 static struct tftp_t *tftp_prep_mbuf_data(struct tftp_session *spt,
127 struct mbuf *m)
128 {
129 struct tftp_t *tp;
130
131 memset(m->m_data, 0, m->m_size);
132
133 m->m_data += IF_MAXLINKHDR;
134 if (spt->client_addr.ss_family == AF_INET6) {
135 m->m_data += sizeof(struct ip6);
136 } else {
137 m->m_data += sizeof(struct ip);
138 }
139 tp = (void *)m->m_data;
140 m->m_data += sizeof(struct udphdr);
141
142 return tp;
143 }
144
145 static void tftp_udp_output(struct tftp_session *spt, struct mbuf *m,
146 struct tftp_t *recv_tp)
147 {
148 if (spt->client_addr.ss_family == AF_INET6) {
149 struct sockaddr_in6 sa6, da6;
150
151 sa6.sin6_addr = spt->slirp->vhost_addr6;
152 sa6.sin6_port = recv_tp->udp.uh_dport;
153 da6.sin6_addr = ((struct sockaddr_in6 *)&spt->client_addr)->sin6_addr;
154 da6.sin6_port = spt->client_port;
155
156 udp6_output(NULL, m, &sa6, &da6);
157 } else {
158 struct sockaddr_in sa4, da4;
159
160 sa4.sin_addr = spt->slirp->vhost_addr;
161 sa4.sin_port = recv_tp->udp.uh_dport;
162 da4.sin_addr = ((struct sockaddr_in *)&spt->client_addr)->sin_addr;
163 da4.sin_port = spt->client_port;
164
165 udp_output(NULL, m, &sa4, &da4, IPTOS_LOWDELAY);
166 }
167 }
168
169 static int tftp_send_oack(struct tftp_session *spt,
170 const char *keys[], uint32_t values[], int nb,
171 struct tftp_t *recv_tp)
172 {
173 struct mbuf *m;
174 struct tftp_t *tp;
175 int i, n = 0;
176
177 m = m_get(spt->slirp);
178
179 if (!m)
180 return -1;
181
182 tp = tftp_prep_mbuf_data(spt, m);
183
184 tp->tp_op = htons(TFTP_OACK);
185 for (i = 0; i < nb; i++) {
186 n += snprintf(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%s",
187 keys[i]) + 1;
188 n += snprintf(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%u",
189 values[i]) + 1;
190 }
191
192 m->m_len = sizeof(struct tftp_t) - 514 + n - sizeof(struct udphdr);
193 tftp_udp_output(spt, m, recv_tp);
194
195 return 0;
196 }
197
198 static void tftp_send_error(struct tftp_session *spt,
199 uint16_t errorcode, const char *msg,
200 struct tftp_t *recv_tp)
201 {
202 struct mbuf *m;
203 struct tftp_t *tp;
204
205 m = m_get(spt->slirp);
206
207 if (!m) {
208 goto out;
209 }
210
211 memset(m->m_data, 0, m->m_size);
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) - 514 + 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 memset(m->m_data, 0, m->m_size);
241
242 tp = tftp_prep_mbuf_data(spt, m);
243
244 tp->tp_op = htons(TFTP_DATA);
245 tp->x.tp_data.tp_block_nr = htons((spt->block_nr + 1) & 0xffff);
246
247 nobytes = tftp_read_data(spt, spt->block_nr, tp->x.tp_data.tp_buf, 512);
248
249 if (nobytes < 0) {
250 m_free(m);
251
252 /* send "file not found" error back */
253
254 tftp_send_error(spt, 1, "File not found", tp);
255
256 return;
257 }
258
259 m->m_len = sizeof(struct tftp_t) - (512 - nobytes) - sizeof(struct udphdr);
260 tftp_udp_output(spt, m, recv_tp);
261
262 if (nobytes == 512) {
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 /* If blksize option is bigger than what we will
393 * emit, accept the option with our packet size.
394 * Otherwise, simply do as we didn't see the option.
395 */
396 if (blksize >= 512) {
397 option_name[nb_options] = "blksize";
398 option_value[nb_options] = 512;
399 nb_options++;
400 }
401 }
402 }
403
404 if (nb_options > 0) {
405 assert(nb_options <= ARRAY_SIZE(option_name));
406 tftp_send_oack(spt, option_name, option_value, nb_options, tp);
407 return;
408 }
409
410 spt->block_nr = 0;
411 tftp_send_next_block(spt, tp);
412 }
413
414 static void tftp_handle_ack(Slirp *slirp, struct sockaddr_storage *srcsas,
415 struct tftp_t *tp, int pktlen)
416 {
417 int s;
418
419 s = tftp_session_find(slirp, srcsas, tp);
420
421 if (s < 0) {
422 return;
423 }
424
425 tftp_send_next_block(&slirp->tftp_sessions[s], tp);
426 }
427
428 static void tftp_handle_error(Slirp *slirp, struct sockaddr_storage *srcsas,
429 struct tftp_t *tp, int pktlen)
430 {
431 int s;
432
433 s = tftp_session_find(slirp, srcsas, tp);
434
435 if (s < 0) {
436 return;
437 }
438
439 tftp_session_terminate(&slirp->tftp_sessions[s]);
440 }
441
442 void tftp_input(struct sockaddr_storage *srcsas, struct mbuf *m)
443 {
444 struct tftp_t *tp = (struct tftp_t *)m->m_data;
445
446 switch(ntohs(tp->tp_op)) {
447 case TFTP_RRQ:
448 tftp_handle_rrq(m->slirp, srcsas, tp, m->m_len);
449 break;
450
451 case TFTP_ACK:
452 tftp_handle_ack(m->slirp, srcsas, tp, m->m_len);
453 break;
454
455 case TFTP_ERROR:
456 tftp_handle_error(m->slirp, srcsas, tp, m->m_len);
457 break;
458 }
459 }