1 /* $NetBSD: tftp.c,v 1.4 1997/09/17 16:57:07 drochner Exp $ */
2
3 /*
4 * Copyright (c) 1996
5 * Matthias Drochner. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed for the NetBSD Project
18 * by Matthias Drochner.
19 * 4. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 *
33 * $FreeBSD: src/lib/libstand/tftp.c,v 1.2.6.4 2001/07/14 14:00:03 mikeh Exp $
34 */
35
36 /*
37 * Simple TFTP implementation for libsa.
38 * Assumes:
39 * - socket descriptor (int) at open_file->f_devdata
40 * - server host IP in global servip
41 * Restrictions:
42 * - read only
43 * - lseek only with SEEK_SET or SEEK_CUR
44 * - no big time differences between transfers (<tftp timeout)
45 */
46
47 #include <sys/param.h>
48 #include <sys/stat.h>
49 #include <netinet/in.h>
50 #include <netinet/udp.h>
51 #include <netinet/ip.h>
52 #include <netinet/in_systm.h>
53 #include <arpa/tftp.h>
54
55 #include <string.h>
56
57 #include "stand.h"
58 #include "net.h"
59 #include "netif.h"
60
61 #include "tftp.h"
62
63 static int tftp_open(const char *path, struct open_file *f);
64 static int tftp_close(struct open_file *f);
65 static int tftp_read(struct open_file *f, void *buf, size_t size, size_t *resid);
66 static int tftp_write(struct open_file *f, void *buf, size_t size, size_t *resid);
67 static off_t tftp_seek(struct open_file *f, off_t offset, int where);
68 static int tftp_stat(struct open_file *f, struct stat *sb);
69
70 struct fs_ops tftp_fsops = {
71 "tftp",
72 tftp_open,
73 tftp_close,
74 tftp_read,
75 tftp_write,
76 tftp_seek,
77 tftp_stat,
78 null_readdir
79 };
80
81 extern struct in_addr servip;
82
83 static int tftpport = 2000;
84
85 #define RSPACE 520 /* max data packet, rounded up */
86
87 struct tftp_handle {
88 struct iodesc *iodesc;
89 int currblock; /* contents of lastdata */
90 int islastblock; /* flag */
91 int validsize;
92 int off;
93 char *path; /* saved for re-requests */
94 struct {
95 u_char header[HEADER_SIZE];
96 struct tftphdr t;
97 u_char space[RSPACE];
98 } __packed __aligned(4) lastdata;
99 };
100
101 static int tftperrors[8] = {
102 0, /* ??? */
103 ENOENT,
104 EPERM,
105 ENOSPC,
106 EINVAL, /* ??? */
107 EINVAL, /* ??? */
108 EEXIST,
109 EINVAL /* ??? */
110 };
111
112 static ssize_t
recvtftp(struct iodesc * d,void * pkt,size_t max_len,time_t tleft)113 recvtftp(struct iodesc *d, void *pkt, size_t max_len, time_t tleft)
114 {
115 struct tftphdr *t;
116 ssize_t len;
117 ssize_t tmp_len;
118
119 /*
120 * Note: errno of 0 with -1 return means udp poll failed or
121 * packet was not for us.
122 *
123 * We may end up broadcasting the initial TFTP request. Take the
124 * first DATA result and save any ERROR result in case we do not
125 * get a DATA.
126 */
127 errno = 0;
128 bzero(pkt, max_len);
129 if (d->xid == 1) {
130 len = -1;
131 while ((tmp_len = readudp(d, pkt, max_len, tleft)) > 0) {
132 len = tmp_len;
133 t = (struct tftphdr *)pkt;
134 if (ntohs(t->th_opcode) == DATA)
135 break;
136 }
137 } else {
138 len = readudp(d, pkt, max_len, tleft);
139 }
140 if ((int)len < (int)sizeof(*t))
141 return (-1);
142 t = (struct tftphdr *)pkt;
143 errno = 0;
144
145 switch (ntohs(t->th_opcode)) {
146 case DATA: {
147 int got;
148
149 if (htons(t->th_block) != (uint16_t)d->xid) {
150 /*
151 * Expected block?
152 */
153 return (-1);
154 }
155 if (d->xid == 1) {
156 /*
157 * First data packet from new port. Set destip in
158 * case we got replies from multiple hosts, so only
159 * one host is selected.
160 */
161 struct udphdr *uh;
162 struct ip *ip;
163
164 uh = (struct udphdr *) pkt - 1;
165 ip = (struct ip *)uh - 1;
166 d->destport = uh->uh_sport;
167 d->destip = ip->ip_src;
168 } /* else check uh_sport has not changed??? */
169 got = len - (t->th_data - (char *)t);
170 return got;
171 }
172 case ERROR:
173 if ((unsigned) ntohs(t->th_code) >= 8) {
174 printf("illegal tftp error %d\n", ntohs(t->th_code));
175 errno = EIO;
176 } else {
177 #ifdef DEBUG
178 printf("tftp-error %d\n", ntohs(t->th_code));
179 #endif
180 errno = tftperrors[ntohs(t->th_code)];
181 }
182 return (-1);
183 default:
184 #ifdef DEBUG
185 printf("tftp type %d not handled\n", ntohs(t->th_opcode));
186 #endif
187 return (-1);
188 }
189 }
190
191 /* send request, expect first block (or error) */
192 static int
tftp_makereq(struct tftp_handle * h)193 tftp_makereq(struct tftp_handle *h)
194 {
195 struct {
196 u_char header[HEADER_SIZE];
197 struct tftphdr t;
198 u_char space[FNAME_SIZE + 6];
199 } __packed __aligned(4) wbuf;
200 char *wtail;
201 int l;
202 ssize_t res;
203 struct tftphdr *t;
204
205 wbuf.t.th_opcode = htons((u_short) RRQ);
206 wtail = wbuf.t.th_stuff;
207 l = strlen(h->path);
208 bcopy(h->path, wtail, l + 1);
209 wtail += l + 1;
210 bcopy("octet", wtail, 6);
211 wtail += 6;
212
213 t = &h->lastdata.t;
214
215 /* h->iodesc->myport = htons(--tftpport); */
216 h->iodesc->myport = htons(tftpport + (getsecs() & 0x3ff));
217 h->iodesc->destport = htons(IPPORT_TFTP);
218 h->iodesc->xid = 1; /* expected block */
219
220 res = sendrecv(h->iodesc, sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
221 recvtftp, t, sizeof(*t) + RSPACE);
222
223 if (res == -1)
224 return (errno);
225
226 h->currblock = 1;
227 h->validsize = res;
228 h->islastblock = 0;
229 if (res < SEGSIZE)
230 h->islastblock = 1; /* very short file */
231 return (0);
232 }
233
234 /* ack block, expect next */
235 static int
tftp_getnextblock(struct tftp_handle * h)236 tftp_getnextblock(struct tftp_handle *h)
237 {
238 struct {
239 u_char header[HEADER_SIZE];
240 struct tftphdr t;
241 } __packed __aligned(4) wbuf;
242 char *wtail;
243 int res;
244 struct tftphdr *t;
245
246 /*
247 * Ack previous block
248 */
249 wbuf.t.th_opcode = htons((u_short) ACK);
250 wtail = (char *) &wbuf.t.th_block;
251 wbuf.t.th_block = htons((u_short) h->currblock);
252 wtail += 2;
253
254 t = &h->lastdata.t;
255
256 h->iodesc->xid = h->currblock + 1; /* expected block */
257
258 res = sendrecv(h->iodesc, sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
259 recvtftp, t, sizeof(*t) + RSPACE);
260
261 if (res == -1) /* 0 is OK! */
262 return (errno);
263
264 h->currblock++;
265 h->validsize = res;
266 if (res < SEGSIZE)
267 h->islastblock = 1; /* EOF */
268 return (0);
269 }
270
271 static int
tftp_open(const char * path,struct open_file * f)272 tftp_open(const char *path, struct open_file *f)
273 {
274 struct tftp_handle *tftpfile;
275 struct iodesc *io;
276 int res;
277
278 /* Avoid trying out tftp_open for disk devices in the EFI loader */
279 #ifndef __i386__
280 if (strcmp(f->f_dev->dv_name, "net") != 0)
281 return (EINVAL);
282 #endif
283
284 tftpfile = (struct tftp_handle *) malloc(sizeof(*tftpfile));
285 if (!tftpfile)
286 return (ENOMEM);
287
288 tftpfile->iodesc = io = socktodesc(*(int *) (f->f_devdata));
289 if (io == NULL) {
290 free(tftpfile);
291 return (EINVAL);
292 }
293
294 io->destip = servip;
295 tftpfile->off = 0;
296 tftpfile->path = strdup(path);
297 if (tftpfile->path == NULL) {
298 free(tftpfile);
299 return(ENOMEM);
300 }
301
302 res = tftp_makereq(tftpfile);
303
304 if (res) {
305 free(tftpfile->path);
306 free(tftpfile);
307 return (res);
308 }
309 f->f_fsdata = (void *) tftpfile;
310 return (0);
311 }
312
313 /*
314 * Parameters:
315 * resid: out
316 */
317 static int
tftp_read(struct open_file * f,void * addr,size_t size,size_t * resid)318 tftp_read(struct open_file *f, void *addr, size_t size, size_t *resid)
319 {
320 struct tftp_handle *tftpfile;
321 static int tc = 0;
322 tftpfile = (struct tftp_handle *) f->f_fsdata;
323
324 while (size > 0) {
325 int needblock, count;
326
327 if (!(tc++ % 256))
328 twiddle();
329
330 needblock = tftpfile->off / SEGSIZE + 1;
331
332 if (tftpfile->currblock > needblock) /* seek backwards */
333 tftp_makereq(tftpfile); /* no error check, it worked
334 * for open */
335
336 while (tftpfile->currblock < needblock) {
337 int res;
338
339 res = tftp_getnextblock(tftpfile);
340 if (res) { /* no answer */
341 #ifdef DEBUG
342 printf("tftp: read error\n");
343 #endif
344 return (res);
345 }
346 if (tftpfile->islastblock)
347 break;
348 }
349
350 if (tftpfile->currblock == needblock) {
351 int offinblock, inbuffer;
352
353 offinblock = tftpfile->off % SEGSIZE;
354
355 inbuffer = tftpfile->validsize - offinblock;
356 if (inbuffer < 0) {
357 #ifdef DEBUG
358 printf("tftp: invalid offset %d\n",
359 tftpfile->off);
360 #endif
361 return (EINVAL);
362 }
363 count = (size < inbuffer ? size : inbuffer);
364 bcopy(tftpfile->lastdata.t.th_data + offinblock,
365 addr, count);
366
367 addr = (char *)addr + count;
368 tftpfile->off += count;
369 size -= count;
370
371 if ((tftpfile->islastblock) && (count == inbuffer))
372 break; /* EOF */
373 } else {
374 #ifdef DEBUG
375 printf("tftp: block %d not found\n", needblock);
376 #endif
377 return (EINVAL);
378 }
379
380 }
381
382 if (resid)
383 *resid = size;
384 return (0);
385 }
386
387 static int
tftp_close(struct open_file * f)388 tftp_close(struct open_file *f)
389 {
390 struct tftp_handle *tftpfile;
391 tftpfile = (struct tftp_handle *) f->f_fsdata;
392
393 /* let it time out ... */
394 f->f_fsdata = NULL;
395 if (tftpfile) {
396 free(tftpfile->path);
397 free(tftpfile);
398 f->f_fsdata = NULL;
399 }
400 return (0);
401 }
402
403 /*
404 * Parameters:
405 * resid: out
406 */
407 static int
tftp_write(struct open_file * f,void * start,size_t size,size_t * resid)408 tftp_write(struct open_file *f, void *start, size_t size, size_t *resid)
409 {
410 return (EROFS);
411 }
412
413 static int
tftp_stat(struct open_file * f,struct stat * sb)414 tftp_stat(struct open_file *f, struct stat *sb)
415 {
416 sb->st_mode = 0444 | S_IFREG;
417 sb->st_nlink = 1;
418 sb->st_uid = 0;
419 sb->st_gid = 0;
420 sb->st_size = -1;
421 return (0);
422 }
423
424 static off_t
tftp_seek(struct open_file * f,off_t offset,int where)425 tftp_seek(struct open_file *f, off_t offset, int where)
426 {
427 struct tftp_handle *tftpfile;
428 tftpfile = (struct tftp_handle *) f->f_fsdata;
429
430 switch (where) {
431 case SEEK_SET:
432 tftpfile->off = offset;
433 break;
434 case SEEK_CUR:
435 tftpfile->off += offset;
436 break;
437 default:
438 errno = EOFFSET;
439 return (-1);
440 }
441 return (tftpfile->off);
442 }
443