xref: /freebsd/usr.bin/tftp/tftp.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if 0
33 #ifndef lint
34 static char sccsid[] = "@(#)tftp.c	8.1 (Berkeley) 6/6/93";
35 #endif /* not lint */
36 #endif
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
42 
43 /*
44  * TFTP User Program -- Protocol Machines
45  */
46 #include <sys/socket.h>
47 #include <sys/stat.h>
48 
49 #include <netinet/in.h>
50 
51 #include <arpa/tftp.h>
52 
53 #include <assert.h>
54 #include <err.h>
55 #include <netdb.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <syslog.h>
60 
61 #include "tftp.h"
62 #include "tftp-file.h"
63 #include "tftp-utils.h"
64 #include "tftp-io.h"
65 #include "tftp-transfer.h"
66 #include "tftp-options.h"
67 
68 /*
69  * Send the requested file.
70  */
71 int
72 xmitfile(int peer, char *port, int fd, char *name, char *mode)
73 {
74 	struct tftphdr *rp;
75 	int n, i, ret = 0;
76 	uint16_t block;
77 	struct sockaddr_storage serv;	/* valid server port number */
78 	char recvbuffer[MAXPKTSIZE];
79 	struct tftp_stats tftp_stats;
80 
81 	stats_init(&tftp_stats);
82 
83 	memset(&serv, 0, sizeof(serv));
84 	rp = (struct tftphdr *)recvbuffer;
85 
86 	if (port == NULL) {
87 		struct servent *se;
88 		se = getservbyname("tftp", "udp");
89 		assert(se != NULL);
90 		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
91 	} else
92 		((struct sockaddr_in *)&peer_sock)->sin_port =
93 		    htons(atoi(port));
94 
95 	for (i = 0; i < 12; i++) {
96 		struct sockaddr_storage from;
97 
98 		/* Tell the other side what we want to do */
99 		if (debug & DEBUG_SIMPLE)
100 			printf("Sending %s\n", name);
101 
102 		n = send_wrq(peer, name, mode);
103 		if (n > 0) {
104 			printf("Cannot send WRQ packet\n");
105 			return -1;
106 		}
107 
108 		/*
109 		 * The first packet we receive has the new destination port
110 		 * we have to send the next packets to.
111 		 */
112 		n = receive_packet(peer, recvbuffer,
113 		    MAXPKTSIZE, &from, timeoutpacket);
114 
115 		/* We got some data! */
116 		if (n >= 0) {
117 			((struct sockaddr_in *)&peer_sock)->sin_port =
118 			    ((struct sockaddr_in *)&from)->sin_port;
119 			break;
120 		}
121 
122 		/* This should be retried */
123 		if (n == RP_TIMEOUT) {
124 			printf("Try %d, didn't receive answer from remote.\n",
125 			    i + 1);
126 			continue;
127 		}
128 
129 		/* Everything else is fatal */
130 		break;
131 	}
132 	if (i == 12) {
133 		printf("Transfer timed out.\n");
134 		return -1;
135 	}
136 	if (rp->th_opcode == ERROR) {
137 		printf("Got ERROR, aborted\n");
138 		return -1;
139 	}
140 
141 	/*
142 	 * If the first packet is an OACK instead of an ACK packet,
143 	 * handle it different.
144 	 */
145 	if (rp->th_opcode == OACK) {
146 		if (!options_rfc_enabled) {
147 			printf("Got OACK while options are not enabled!\n");
148 			send_error(peer, EBADOP);
149 			return -1;
150 		}
151 
152 		parse_options(peer, rp->th_stuff, n + 2);
153 	}
154 
155 	if (read_init(fd, NULL, mode) < 0) {
156 		warn("read_init()");
157 		return -1;
158 	}
159 
160 	block = 1;
161 	if (tftp_send(peer, &block, &tftp_stats) != 0)
162 		ret = -1;
163 
164 	read_close();
165 	if (tftp_stats.amount > 0)
166 		printstats("Sent", verbose, &tftp_stats);
167 	return ret;
168 }
169 
170 /*
171  * Receive a file.
172  */
173 int
174 recvfile(int peer, char *port, int fd, char *name, char *mode)
175 {
176 	struct tftphdr *rp;
177 	uint16_t block;
178 	char recvbuffer[MAXPKTSIZE];
179 	int n, i, ret = 0;
180 	struct tftp_stats tftp_stats;
181 
182 	stats_init(&tftp_stats);
183 
184 	rp = (struct tftphdr *)recvbuffer;
185 
186 	if (port == NULL) {
187 		struct servent *se;
188 		se = getservbyname("tftp", "udp");
189 		assert(se != NULL);
190 		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
191 	} else
192 		((struct sockaddr_in *)&peer_sock)->sin_port =
193 		    htons(atoi(port));
194 
195 	for (i = 0; i < 12; i++) {
196 		struct sockaddr_storage from;
197 
198 		/* Tell the other side what we want to do */
199 		if (debug & DEBUG_SIMPLE)
200 			printf("Requesting %s\n", name);
201 
202 		n = send_rrq(peer, name, mode);
203 		if (n > 0) {
204 			printf("Cannot send RRQ packet\n");
205 			return -1;
206 		}
207 
208 		/*
209 		 * The first packet we receive has the new destination port
210 		 * we have to send the next packets to.
211 		 */
212 		n = receive_packet(peer, recvbuffer,
213 		    MAXPKTSIZE, &from, timeoutpacket);
214 
215 		/* We got something useful! */
216 		if (n >= 0) {
217 			((struct sockaddr_in *)&peer_sock)->sin_port =
218 			    ((struct sockaddr_in *)&from)->sin_port;
219 			break;
220 		}
221 
222 		/* We should retry if this happens */
223 		if (n == RP_TIMEOUT) {
224 			printf("Try %d, didn't receive answer from remote.\n",
225 			    i + 1);
226 			continue;
227 		}
228 
229 		/* Otherwise it is a fatal error */
230 		break;
231 	}
232 	if (i == 12) {
233 		printf("Transfer timed out.\n");
234 		return -1;
235 	}
236 	if (rp->th_opcode == ERROR) {
237 		tftp_log(LOG_ERR, "Error code %d: %s", rp->th_code, rp->th_msg);
238 		return -1;
239 	}
240 
241 	if (write_init(fd, NULL, mode) < 0) {
242 		warn("write_init");
243 		return -1;
244 	}
245 
246 	/*
247 	 * If the first packet is an OACK packet instead of an DATA packet,
248 	 * handle it different.
249 	 */
250 	if (rp->th_opcode == OACK) {
251 		if (!options_rfc_enabled) {
252 			printf("Got OACK while options are not enabled!\n");
253 			send_error(peer, EBADOP);
254 			return -1;
255 		}
256 
257 		parse_options(peer, rp->th_stuff, n + 2);
258 
259 		n = send_ack(peer, 0);
260 		if (n > 0) {
261 			printf("Cannot send ACK on OACK.\n");
262 			return -1;
263 		}
264 		block = 0;
265 		if (tftp_receive(peer, &block, &tftp_stats, NULL, 0) != 0)
266 			ret = -1;
267 	} else {
268 		block = 1;
269 		if (tftp_receive(peer, &block, &tftp_stats, rp, n) != 0)
270 			ret = -1;
271 	}
272 
273 	if (tftp_stats.amount > 0)
274 		printstats("Received", verbose, &tftp_stats);
275 	return ret;
276 }
277