Commit | Line | Data |
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8c5eec2f DF |
1 | /* |
2 | * Copyright (c) 1983 Regents of the University of California. | |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
5 | */ | |
6 | ||
7 | #ifndef lint | |
8 | char copyright[] = | |
9 | "@(#) Copyright (c) 1983 Regents of the University of California.\n\ | |
10 | All rights reserved.\n"; | |
11 | #endif not lint | |
12 | ||
ce4fd43b | 13 | #ifndef lint |
076ae92c | 14 | static char sccsid[] = "@(#)tftpd.c 5.2 (Berkeley) %G%"; |
8c5eec2f | 15 | #endif not lint |
f8675e8e SL |
16 | |
17 | /* | |
18 | * Trivial file transfer protocol server. | |
19 | */ | |
20 | #include <sys/types.h> | |
f8675e8e | 21 | #include <sys/socket.h> |
f8675e8e | 22 | #include <sys/ioctl.h> |
ce4fd43b SL |
23 | #include <sys/wait.h> |
24 | #include <sys/stat.h> | |
de3b21e8 SL |
25 | |
26 | #include <netinet/in.h> | |
27 | ||
533343f1 SL |
28 | #include <arpa/tftp.h> |
29 | ||
de3b21e8 | 30 | #include <signal.h> |
f8675e8e | 31 | #include <stdio.h> |
f8675e8e SL |
32 | #include <errno.h> |
33 | #include <ctype.h> | |
4d5e33bd | 34 | #include <netdb.h> |
103499bc | 35 | #include <setjmp.h> |
3f99c0f7 | 36 | #include <syslog.h> |
103499bc | 37 | |
103499bc | 38 | #define TIMEOUT 5 |
de3b21e8 | 39 | |
f8675e8e | 40 | extern int errno; |
4d5e33bd | 41 | struct sockaddr_in sin = { AF_INET }; |
bb933cc2 | 42 | int peer; |
103499bc SL |
43 | int rexmtval = TIMEOUT; |
44 | int maxtimeout = 5*TIMEOUT; | |
f8675e8e | 45 | char buf[BUFSIZ]; |
bb933cc2 MK |
46 | struct sockaddr_in from; |
47 | int fromlen; | |
f8675e8e | 48 | |
bb933cc2 | 49 | main() |
f8675e8e | 50 | { |
f8675e8e SL |
51 | register struct tftphdr *tp; |
52 | register int n; | |
53 | ||
076ae92c | 54 | openlog("tftpd", LOG_PID, LOG_DAEMON); |
bb933cc2 MK |
55 | alarm(10); |
56 | fromlen = sizeof (from); | |
57 | n = recvfrom(0, buf, sizeof (buf), 0, | |
58 | (caddr_t)&from, &fromlen); | |
59 | if (n < 0) { | |
60 | perror("tftpd: recvfrom"); | |
4d5e33bd SL |
61 | exit(1); |
62 | } | |
bb933cc2 MK |
63 | from.sin_family = AF_INET; |
64 | alarm(0); | |
bb933cc2 MK |
65 | close(0); |
66 | close(1); | |
67 | peer = socket(AF_INET, SOCK_DGRAM, 0); | |
68 | if (peer < 0) { | |
3f99c0f7 | 69 | syslog(LOG_ERR, "socket: %m"); |
bb933cc2 MK |
70 | exit(1); |
71 | } | |
72 | if (bind(peer, (caddr_t)&sin, sizeof (sin)) < 0) { | |
3f99c0f7 | 73 | syslog(LOG_ERR, "bind: %m"); |
bb933cc2 | 74 | exit(1); |
f8675e8e | 75 | } |
bb933cc2 | 76 | if (connect(peer, (caddr_t)&from, sizeof(from)) < 0) { |
3f99c0f7 | 77 | syslog(LOG_ERR, "connect: %m"); |
bb933cc2 | 78 | exit(1); |
f8675e8e | 79 | } |
bb933cc2 MK |
80 | tp = (struct tftphdr *)buf; |
81 | tp->th_opcode = ntohs(tp->th_opcode); | |
82 | if (tp->th_opcode == RRQ || tp->th_opcode == WRQ) | |
83 | tftp(tp, n); | |
84 | exit(1); | |
103499bc SL |
85 | } |
86 | ||
f8675e8e SL |
87 | int validate_access(); |
88 | int sendfile(), recvfile(); | |
89 | ||
90 | struct formats { | |
91 | char *f_mode; | |
92 | int (*f_validate)(); | |
93 | int (*f_send)(); | |
94 | int (*f_recv)(); | |
95 | } formats[] = { | |
96 | { "netascii", validate_access, sendfile, recvfile }, | |
97 | { "octet", validate_access, sendfile, recvfile }, | |
98 | #ifdef notdef | |
99 | { "mail", validate_user, sendmail, recvmail }, | |
100 | #endif | |
101 | { 0 } | |
102 | }; | |
103 | ||
f8675e8e SL |
104 | /* |
105 | * Handle initial connection protocol. | |
106 | */ | |
bb933cc2 | 107 | tftp(tp, size) |
f8675e8e SL |
108 | struct tftphdr *tp; |
109 | int size; | |
110 | { | |
111 | register char *cp; | |
112 | int first = 1, ecode; | |
113 | register struct formats *pf; | |
114 | char *filename, *mode; | |
115 | ||
f8675e8e SL |
116 | filename = cp = tp->th_stuff; |
117 | again: | |
118 | while (cp < buf + size) { | |
119 | if (*cp == '\0') | |
120 | break; | |
121 | cp++; | |
122 | } | |
123 | if (*cp != '\0') { | |
124 | nak(EBADOP); | |
125 | exit(1); | |
126 | } | |
127 | if (first) { | |
128 | mode = ++cp; | |
129 | first = 0; | |
130 | goto again; | |
131 | } | |
132 | for (cp = mode; *cp; cp++) | |
133 | if (isupper(*cp)) | |
134 | *cp = tolower(*cp); | |
135 | for (pf = formats; pf->f_mode; pf++) | |
136 | if (strcmp(pf->f_mode, mode) == 0) | |
137 | break; | |
138 | if (pf->f_mode == 0) { | |
139 | nak(EBADOP); | |
140 | exit(1); | |
141 | } | |
bb933cc2 | 142 | ecode = (*pf->f_validate)(filename, tp->th_opcode); |
f8675e8e SL |
143 | if (ecode) { |
144 | nak(ecode); | |
145 | exit(1); | |
146 | } | |
147 | if (tp->th_opcode == WRQ) | |
148 | (*pf->f_recv)(pf); | |
149 | else | |
150 | (*pf->f_send)(pf); | |
151 | exit(0); | |
152 | } | |
153 | ||
bb933cc2 MK |
154 | int fd; |
155 | ||
f8675e8e SL |
156 | /* |
157 | * Validate file access. Since we | |
158 | * have no uid or gid, for now require | |
159 | * file to exist and be publicly | |
160 | * readable/writable. | |
161 | * Note also, full path name must be | |
162 | * given as we have no login directory. | |
163 | */ | |
bb933cc2 | 164 | validate_access(file, mode) |
f8675e8e | 165 | char *file; |
f8675e8e SL |
166 | int mode; |
167 | { | |
168 | struct stat stbuf; | |
169 | ||
170 | if (*file != '/') | |
171 | return (EACCESS); | |
172 | if (stat(file, &stbuf) < 0) | |
173 | return (errno == ENOENT ? ENOTFOUND : EACCESS); | |
174 | if (mode == RRQ) { | |
175 | if ((stbuf.st_mode&(S_IREAD >> 6)) == 0) | |
176 | return (EACCESS); | |
177 | } else { | |
178 | if ((stbuf.st_mode&(S_IWRITE >> 6)) == 0) | |
179 | return (EACCESS); | |
180 | } | |
181 | fd = open(file, mode == RRQ ? 0 : 1); | |
182 | if (fd < 0) | |
183 | return (errno + 100); | |
184 | return (0); | |
185 | } | |
186 | ||
103499bc SL |
187 | int timeout; |
188 | jmp_buf timeoutbuf; | |
f8675e8e SL |
189 | |
190 | timer() | |
191 | { | |
103499bc SL |
192 | |
193 | timeout += rexmtval; | |
194 | if (timeout >= maxtimeout) | |
f8675e8e | 195 | exit(1); |
103499bc | 196 | longjmp(timeoutbuf, 1); |
f8675e8e SL |
197 | } |
198 | ||
199 | /* | |
200 | * Send the requested file. | |
201 | */ | |
202 | sendfile(pf) | |
203 | struct format *pf; | |
204 | { | |
205 | register struct tftphdr *tp; | |
206 | register int block = 1, size, n; | |
207 | ||
103499bc | 208 | signal(SIGALRM, timer); |
f8675e8e SL |
209 | tp = (struct tftphdr *)buf; |
210 | do { | |
211 | size = read(fd, tp->th_data, SEGSIZE); | |
212 | if (size < 0) { | |
213 | nak(errno + 100); | |
bb933cc2 | 214 | return; |
f8675e8e SL |
215 | } |
216 | tp->th_opcode = htons((u_short)DATA); | |
217 | tp->th_block = htons((u_short)block); | |
218 | timeout = 0; | |
103499bc | 219 | (void) setjmp(timeoutbuf); |
bb933cc2 MK |
220 | if (send(peer, buf, size + 4, 0) != size + 4) { |
221 | perror("tftpd: send"); | |
222 | return; | |
f8675e8e | 223 | } |
103499bc SL |
224 | do { |
225 | alarm(rexmtval); | |
bb933cc2 | 226 | n = recv(peer, buf, sizeof (buf), 0); |
f8675e8e | 227 | alarm(0); |
103499bc | 228 | if (n < 0) { |
bb933cc2 MK |
229 | perror("tftpd: recv"); |
230 | return; | |
103499bc SL |
231 | } |
232 | tp->th_opcode = ntohs((u_short)tp->th_opcode); | |
233 | tp->th_block = ntohs((u_short)tp->th_block); | |
234 | if (tp->th_opcode == ERROR) | |
bb933cc2 | 235 | return; |
103499bc | 236 | } while (tp->th_opcode != ACK || tp->th_block != block); |
f8675e8e SL |
237 | block++; |
238 | } while (size == SEGSIZE); | |
f8675e8e SL |
239 | } |
240 | ||
241 | /* | |
242 | * Receive a file. | |
243 | */ | |
244 | recvfile(pf) | |
245 | struct format *pf; | |
246 | { | |
247 | register struct tftphdr *tp; | |
248 | register int block = 0, n, size; | |
249 | ||
103499bc | 250 | signal(SIGALRM, timer); |
f8675e8e SL |
251 | tp = (struct tftphdr *)buf; |
252 | do { | |
253 | timeout = 0; | |
f8675e8e SL |
254 | tp->th_opcode = htons((u_short)ACK); |
255 | tp->th_block = htons((u_short)block); | |
256 | block++; | |
103499bc | 257 | (void) setjmp(timeoutbuf); |
bb933cc2 MK |
258 | if (send(peer, buf, 4, 0) != 4) { |
259 | perror("tftpd: send"); | |
103499bc | 260 | goto abort; |
f8675e8e | 261 | } |
103499bc SL |
262 | do { |
263 | alarm(rexmtval); | |
bb933cc2 | 264 | n = recv(peer, buf, sizeof (buf), 0); |
f8675e8e | 265 | alarm(0); |
103499bc | 266 | if (n < 0) { |
bb933cc2 | 267 | perror("tftpd: recv"); |
103499bc SL |
268 | goto abort; |
269 | } | |
270 | tp->th_opcode = ntohs((u_short)tp->th_opcode); | |
271 | tp->th_block = ntohs((u_short)tp->th_block); | |
272 | if (tp->th_opcode == ERROR) | |
273 | goto abort; | |
274 | } while (tp->th_opcode != DATA || block != tp->th_block); | |
f8675e8e SL |
275 | size = write(fd, tp->th_data, n - 4); |
276 | if (size < 0) { | |
277 | nak(errno + 100); | |
103499bc | 278 | goto abort; |
f8675e8e SL |
279 | } |
280 | } while (size == SEGSIZE); | |
103499bc | 281 | abort: |
f8675e8e SL |
282 | tp->th_opcode = htons((u_short)ACK); |
283 | tp->th_block = htons((u_short)(block)); | |
bb933cc2 | 284 | (void) send(peer, buf, 4, 0); |
f8675e8e SL |
285 | } |
286 | ||
287 | struct errmsg { | |
288 | int e_code; | |
289 | char *e_msg; | |
290 | } errmsgs[] = { | |
291 | { EUNDEF, "Undefined error code" }, | |
292 | { ENOTFOUND, "File not found" }, | |
293 | { EACCESS, "Access violation" }, | |
294 | { ENOSPACE, "Disk full or allocation exceeded" }, | |
295 | { EBADOP, "Illegal TFTP operation" }, | |
296 | { EBADID, "Unknown transfer ID" }, | |
297 | { EEXISTS, "File already exists" }, | |
298 | { ENOUSER, "No such user" }, | |
299 | { -1, 0 } | |
300 | }; | |
301 | ||
302 | /* | |
303 | * Send a nak packet (error message). | |
304 | * Error code passed in is one of the | |
305 | * standard TFTP codes, or a UNIX errno | |
306 | * offset by 100. | |
307 | */ | |
308 | nak(error) | |
309 | int error; | |
310 | { | |
311 | register struct tftphdr *tp; | |
312 | int length; | |
313 | register struct errmsg *pe; | |
314 | extern char *sys_errlist[]; | |
315 | ||
316 | tp = (struct tftphdr *)buf; | |
317 | tp->th_opcode = htons((u_short)ERROR); | |
318 | tp->th_code = htons((u_short)error); | |
319 | for (pe = errmsgs; pe->e_code >= 0; pe++) | |
320 | if (pe->e_code == error) | |
321 | break; | |
322 | if (pe->e_code < 0) | |
323 | pe->e_msg = sys_errlist[error - 100]; | |
324 | strcpy(tp->th_msg, pe->e_msg); | |
325 | length = strlen(pe->e_msg); | |
326 | tp->th_msg[length] = '\0'; | |
327 | length += 5; | |
bb933cc2 | 328 | if (send(peer, buf, length, 0) != length) |
f8675e8e | 329 | perror("nak"); |
bb933cc2 | 330 | exit(1); |
f8675e8e | 331 | } |