xref: /freebsd/libexec/tftpd/tftp-utils.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (C) 2008 Edwin Groothuis. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/socket.h>
32 #include <sys/stat.h>
33 #include <sys/time.h>
34 
35 #include <netinet/in.h>
36 #include <arpa/tftp.h>
37 
38 #include <errno.h>
39 #include <stdarg.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <syslog.h>
44 
45 #include "tftp-utils.h"
46 #include "tftp-io.h"
47 
48 /*
49  * Default values, can be changed later via the TFTP Options
50  */
51 int		timeoutpacket = TIMEOUT;
52 int		timeoutnetwork = MAX_TIMEOUTS * TIMEOUT;
53 int		maxtimeouts = MAX_TIMEOUTS;
54 uint16_t	segsize = SEGSIZE;
55 uint16_t	pktsize = SEGSIZE + 4;
56 uint16_t	windowsize = WINDOWSIZE;
57 
58 int	acting_as_client;
59 
60 
61 /*
62  * Set timeout values for packet reception. The idea is that you
63  * get 'maxtimeouts' of 5 seconds between 'timeoutpacket' (i.e. the
64  * first timeout) to 'timeoutnetwork' (i.e. the last timeout)
65  */
66 int
67 settimeouts(int _timeoutpacket, int _timeoutnetwork, int _maxtimeouts __unused)
68 {
69 	int i;
70 
71 	/* We cannot do impossible things */
72 	if (_timeoutpacket >= _timeoutnetwork)
73 		return (0);
74 
75 	maxtimeouts = 0;
76 	i = _timeoutpacket;
77 	while (i < _timeoutnetwork || maxtimeouts < MIN_TIMEOUTS) {
78 		maxtimeouts++;
79 		i += 5;
80 	}
81 
82 	timeoutpacket = _timeoutpacket;
83 	timeoutnetwork = i;
84 	return (1);
85 }
86 
87 /* translate IPv4 mapped IPv6 address to IPv4 address */
88 void
89 unmappedaddr(struct sockaddr_in6 *sin6)
90 {
91 	struct sockaddr_in *sin4;
92 	u_int32_t addr;
93 	int port;
94 
95 	if (sin6->sin6_family != AF_INET6 ||
96 	    !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
97 		return;
98 	sin4 = (struct sockaddr_in *)sin6;
99 	memcpy(&addr, &sin6->sin6_addr.s6_addr[12], sizeof(addr));
100 	port = sin6->sin6_port;
101 	memset(sin4, 0, sizeof(struct sockaddr_in));
102 	sin4->sin_addr.s_addr = addr;
103 	sin4->sin_port = port;
104 	sin4->sin_family = AF_INET;
105 	sin4->sin_len = sizeof(struct sockaddr_in);
106 }
107 
108 /* Get a field from a \0 separated string */
109 ssize_t
110 get_field(int peer, char *buffer, ssize_t size)
111 {
112 	char *cp = buffer;
113 
114 	while (cp < buffer + size) {
115 		if (*cp == '\0') break;
116 		cp++;
117 	}
118 	if (*cp != '\0') {
119 		tftp_log(LOG_ERR, "Bad option - no trailing \\0 found");
120 		send_error(peer, EBADOP);
121 		exit(1);
122 	}
123 	return (cp - buffer + 1);
124 }
125 
126 /*
127  * Logging functions
128  */
129 static int _tftp_logtostdout = 1;
130 
131 void
132 tftp_openlog(const char *ident, int logopt, int facility)
133 {
134 
135 	_tftp_logtostdout = (ident == NULL);
136 	if (_tftp_logtostdout == 0)
137 		openlog(ident, logopt, facility);
138 }
139 
140 void
141 tftp_closelog(void)
142 {
143 
144 	if (_tftp_logtostdout == 0)
145 		closelog();
146 }
147 
148 void
149 tftp_log(int priority, const char *message, ...)
150 {
151 	va_list ap;
152 	int serrno;
153 	char *s;
154 
155 	serrno = errno;
156 	va_start(ap, message);
157 	if (_tftp_logtostdout == 0) {
158 		vasprintf(&s, message, ap);
159 		syslog(priority, "%s", s);
160 	} else {
161 		vprintf(message, ap);
162 		printf("\n");
163 	}
164 	va_end(ap);
165 	errno = serrno;
166 }
167 
168 /*
169  * Packet types
170  */
171 struct packettypes packettypes[] = {
172 	{ RRQ,		"RRQ"	},
173 	{ WRQ,		"WRQ"	},
174 	{ DATA,		"DATA"	},
175 	{ ACK,		"ACK"	},
176 	{ ERROR,	"ERROR"	},
177 	{ OACK,		"OACK"	},
178 	{ 0,		NULL	},
179 };
180 
181 const char *
182 packettype(int type)
183 {
184 	static char failed[100];
185 	int i = 0;
186 
187 	while (packettypes[i].name != NULL) {
188 		if (packettypes[i].value == type)
189 			break;
190 		i++;
191 	}
192 	if (packettypes[i].name != NULL)
193 		return packettypes[i].name;
194 	sprintf(failed, "unknown (type: %d)", type);
195 	return (failed);
196 }
197 
198 /*
199  * Debugs
200  */
201 int	debug = DEBUG_NONE;
202 struct debugs debugs[] = {
203 	{ DEBUG_PACKETS,	"packet",	"Packet debugging"	},
204 	{ DEBUG_SIMPLE,		"simple",	"Simple debugging"	},
205 	{ DEBUG_OPTIONS,	"options",	"Options debugging"	},
206 	{ DEBUG_ACCESS,		"access",	"TCPd access debugging"	},
207 	{ DEBUG_NONE,		NULL,		"No debugging"		},
208 };
209 int	packetdroppercentage = 0;
210 
211 int
212 debug_find(char *s)
213 {
214 	int i = 0;
215 
216 	while (debugs[i].name != NULL) {
217 		if (strcasecmp(debugs[i].name, s) == 0)
218 			break;
219 		i++;
220 	}
221 	return (debugs[i].value);
222 }
223 
224 int
225 debug_finds(char *s)
226 {
227 	int i = 0;
228 	char *ps = s;
229 
230 	while (s != NULL) {
231 		ps = strchr(s, ' ');
232 		if (ps != NULL)
233 			*ps = '\0';
234 		i += debug_find(s);
235 		if (ps != NULL)
236 			*ps = ' ';
237 		s = ps;
238 	}
239 	return (i);
240 }
241 
242 const char *
243 debug_show(int d)
244 {
245 	static char s[100];
246 	size_t space = sizeof(s);
247 	int i = 0;
248 
249 	s[0] = '\0';
250 	while (debugs[i].name != NULL) {
251 		if (d&debugs[i].value) {
252 			if (s[0] != '\0')
253 				strlcat(s, " ", space);
254 			strlcat(s, debugs[i].name, space);
255 		}
256 		i++;
257 	}
258 	if (s[0] != '\0')
259 		return (s);
260 	return ("none");
261 }
262 
263 /*
264  * RP_
265  */
266 struct rp_errors rp_errors[] = {
267 	{ RP_TIMEOUT,		"Network timeout" },
268 	{ RP_TOOSMALL,		"Not enough data bytes" },
269 	{ RP_WRONGSOURCE,	"Invalid IP address of UDP port" },
270 	{ RP_ERROR,		"Error packet" },
271 	{ RP_RECVFROM,		"recvfrom() complained" },
272 	{ RP_TOOBIG,		"Too many data bytes" },
273 	{ RP_NONE,		NULL }
274 };
275 
276 char *
277 rp_strerror(int error)
278 {
279 	static char s[100];
280 	size_t space = sizeof(s);
281 	int i = 0;
282 
283 	while (rp_errors[i].desc != NULL) {
284 		if (rp_errors[i].error == error) {
285 			strlcpy(s, rp_errors[i].desc, space);
286 			space -= strlen(rp_errors[i].desc);
287 		}
288 		i++;
289 	}
290 	if (s[0] == '\0')
291 		sprintf(s, "unknown (error=%d)", error);
292 	return (s);
293 }
294 
295 /*
296  * Performance figures
297  */
298 
299 void
300 stats_init(struct tftp_stats *ts)
301 {
302 
303 	ts->amount = 0;
304 	ts->rollovers = 0;
305 	ts->retries = 0;
306 	ts->blocks = 0;
307 	ts->amount = 0;
308 	gettimeofday(&(ts->tstart), NULL);
309 }
310 
311 void
312 printstats(const char *direction, int verbose, struct tftp_stats *ts)
313 {
314 	double delta;	/* compute delta in 1/10's second units */
315 
316 	delta = ((ts->tstop.tv_sec*10.)+(ts->tstop.tv_usec/100000)) -
317 		((ts->tstart.tv_sec*10.)+(ts->tstart.tv_usec/100000));
318 	delta = delta/10.;      /* back to seconds */
319 
320 	printf("%s %zu bytes during %.1f seconds in %u blocks",
321 	    direction, ts->amount, delta, ts->blocks);
322 
323 	if (ts->rollovers != 0)
324 		printf(" with %d rollover%s",
325 		    ts->rollovers, ts->rollovers != 1 ? "s" : "");
326 
327 	if (verbose)
328 		printf(" [%.0f bits/sec]", (ts->amount*8.)/delta);
329 	putchar('\n');
330 }
331