xref: /freebsd/usr.bin/tftp/tftp.c (revision 397e83df75e0fcd0d3fcb95ae4d794cb7600fc89)
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 #include <sys/cdefs.h>
33 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
34 
35 /*
36  * TFTP User Program -- Protocol Machines
37  */
38 #include <sys/socket.h>
39 #include <sys/stat.h>
40 
41 #include <netinet/in.h>
42 
43 #include <arpa/tftp.h>
44 
45 #include <assert.h>
46 #include <err.h>
47 #include <netdb.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <syslog.h>
52 
53 #include "tftp.h"
54 #include "tftp-file.h"
55 #include "tftp-utils.h"
56 #include "tftp-io.h"
57 #include "tftp-transfer.h"
58 #include "tftp-options.h"
59 
60 /*
61  * Send the requested file.
62  */
63 int
64 xmitfile(int peer, char *port, int fd, char *name, char *mode)
65 {
66 	struct tftphdr *rp;
67 	int n, i, ret = 0;
68 	uint16_t block;
69 	struct sockaddr_storage serv;	/* valid server port number */
70 	char recvbuffer[MAXPKTSIZE];
71 	struct tftp_stats tftp_stats;
72 
73 	stats_init(&tftp_stats);
74 
75 	memset(&serv, 0, sizeof(serv));
76 	rp = (struct tftphdr *)recvbuffer;
77 
78 	if (port == NULL) {
79 		struct servent *se;
80 		se = getservbyname("tftp", "udp");
81 		assert(se != NULL);
82 		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
83 	} else
84 		((struct sockaddr_in *)&peer_sock)->sin_port =
85 		    htons(atoi(port));
86 
87 	for (i = 0; i < 12; i++) {
88 		struct sockaddr_storage from;
89 
90 		/* Tell the other side what we want to do */
91 		if (debug & DEBUG_SIMPLE)
92 			printf("Sending %s\n", name);
93 
94 		n = send_wrq(peer, name, mode);
95 		if (n > 0) {
96 			printf("Cannot send WRQ packet\n");
97 			return -1;
98 		}
99 
100 		/*
101 		 * The first packet we receive has the new destination port
102 		 * we have to send the next packets to.
103 		 */
104 		n = receive_packet(peer, recvbuffer,
105 		    MAXPKTSIZE, &from, timeoutpacket);
106 
107 		/* We got some data! */
108 		if (n >= 0) {
109 			((struct sockaddr_in *)&peer_sock)->sin_port =
110 			    ((struct sockaddr_in *)&from)->sin_port;
111 			break;
112 		}
113 
114 		/* This should be retried */
115 		if (n == RP_TIMEOUT) {
116 			printf("Try %d, didn't receive answer from remote.\n",
117 			    i + 1);
118 			continue;
119 		}
120 
121 		/* Everything else is fatal */
122 		break;
123 	}
124 	if (i == 12) {
125 		printf("Transfer timed out.\n");
126 		return -1;
127 	}
128 	if (rp->th_opcode == ERROR) {
129 		printf("Got ERROR, aborted\n");
130 		return -1;
131 	}
132 
133 	/*
134 	 * If the first packet is an OACK instead of an ACK packet,
135 	 * handle it different.
136 	 */
137 	if (rp->th_opcode == OACK) {
138 		if (!options_rfc_enabled) {
139 			printf("Got OACK while options are not enabled!\n");
140 			send_error(peer, EBADOP);
141 			return -1;
142 		}
143 
144 		parse_options(peer, rp->th_stuff, n + 2);
145 	}
146 
147 	if (read_init(fd, NULL, mode) < 0) {
148 		warn("read_init()");
149 		return -1;
150 	}
151 
152 	block = 1;
153 	if (tftp_send(peer, &block, &tftp_stats) != 0)
154 		ret = -1;
155 
156 	read_close();
157 	if (tftp_stats.amount > 0)
158 		printstats("Sent", verbose, &tftp_stats);
159 	return ret;
160 }
161 
162 /*
163  * Receive a file.
164  */
165 int
166 recvfile(int peer, char *port, int fd, char *name, char *mode)
167 {
168 	struct tftphdr *rp;
169 	uint16_t block;
170 	char recvbuffer[MAXPKTSIZE];
171 	int n, i, ret = 0;
172 	struct tftp_stats tftp_stats;
173 
174 	stats_init(&tftp_stats);
175 
176 	rp = (struct tftphdr *)recvbuffer;
177 
178 	if (port == NULL) {
179 		struct servent *se;
180 		se = getservbyname("tftp", "udp");
181 		assert(se != NULL);
182 		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
183 	} else
184 		((struct sockaddr_in *)&peer_sock)->sin_port =
185 		    htons(atoi(port));
186 
187 	for (i = 0; i < 12; i++) {
188 		struct sockaddr_storage from;
189 
190 		/* Tell the other side what we want to do */
191 		if (debug & DEBUG_SIMPLE)
192 			printf("Requesting %s\n", name);
193 
194 		n = send_rrq(peer, name, mode);
195 		if (n > 0) {
196 			printf("Cannot send RRQ packet\n");
197 			return -1;
198 		}
199 
200 		/*
201 		 * The first packet we receive has the new destination port
202 		 * we have to send the next packets to.
203 		 */
204 		n = receive_packet(peer, recvbuffer,
205 		    MAXPKTSIZE, &from, timeoutpacket);
206 
207 		/* We got something useful! */
208 		if (n >= 0) {
209 			((struct sockaddr_in *)&peer_sock)->sin_port =
210 			    ((struct sockaddr_in *)&from)->sin_port;
211 			break;
212 		}
213 
214 		/* We should retry if this happens */
215 		if (n == RP_TIMEOUT) {
216 			printf("Try %d, didn't receive answer from remote.\n",
217 			    i + 1);
218 			continue;
219 		}
220 
221 		/* Otherwise it is a fatal error */
222 		break;
223 	}
224 	if (i == 12) {
225 		printf("Transfer timed out.\n");
226 		return -1;
227 	}
228 	if (rp->th_opcode == ERROR) {
229 		tftp_log(LOG_ERR, "Error code %d: %s", rp->th_code, rp->th_msg);
230 		return -1;
231 	}
232 
233 	if (write_init(fd, NULL, mode) < 0) {
234 		warn("write_init");
235 		return -1;
236 	}
237 
238 	/*
239 	 * If the first packet is an OACK packet instead of an DATA packet,
240 	 * handle it different.
241 	 */
242 	if (rp->th_opcode == OACK) {
243 		if (!options_rfc_enabled) {
244 			printf("Got OACK while options are not enabled!\n");
245 			send_error(peer, EBADOP);
246 			return -1;
247 		}
248 
249 		parse_options(peer, rp->th_stuff, n + 2);
250 
251 		n = send_ack(peer, 0);
252 		if (n > 0) {
253 			printf("Cannot send ACK on OACK.\n");
254 			return -1;
255 		}
256 		block = 0;
257 		if (tftp_receive(peer, &block, &tftp_stats, NULL, 0) != 0)
258 			ret = -1;
259 	} else {
260 		block = 1;
261 		if (tftp_receive(peer, &block, &tftp_stats, rp, n) != 0)
262 			ret = -1;
263 	}
264 
265 	if (tftp_stats.amount > 0)
266 		printstats("Received", verbose, &tftp_stats);
267 	return ret;
268 }
269