xref: /freebsd/usr.bin/tftp/tftp.c (revision a3cf0ef5a295c885c895fabfd56470c0d1db322d)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if 0
35 #ifndef lint
36 static char sccsid[] = "@(#)tftp.c	8.1 (Berkeley) 6/6/93";
37 #endif /* not lint */
38 #endif
39 
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
44 
45 /*
46  * TFTP User Program -- Protocol Machines
47  */
48 #include <sys/socket.h>
49 #include <sys/stat.h>
50 
51 #include <netinet/in.h>
52 
53 #include <arpa/tftp.h>
54 
55 #include <err.h>
56 #include <netdb.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <syslog.h>
61 
62 #include "tftp.h"
63 #include "tftp-file.h"
64 #include "tftp-utils.h"
65 #include "tftp-io.h"
66 #include "tftp-transfer.h"
67 #include "tftp-options.h"
68 
69 /*
70  * Send the requested file.
71  */
72 void
73 xmitfile(int peer, char *port, int fd, char *name, char *mode)
74 {
75 	struct tftphdr *rp;
76 	int n, i;
77 	uint16_t block;
78 	struct sockaddr_storage serv;	/* valid server port number */
79 	char recvbuffer[MAXPKTSIZE];
80 	struct tftp_stats tftp_stats;
81 
82 	stats_init(&tftp_stats);
83 
84 	memset(&serv, 0, sizeof(serv));
85 	rp = (struct tftphdr *)recvbuffer;
86 
87 	if (port == NULL) {
88 		struct servent *se;
89 		se = getservbyname("tftp", "udp");
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;
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;
135 	}
136 	if (rp->th_opcode == ERROR) {
137 		printf("Got ERROR, aborted\n");
138 		return;
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;
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;
158 	}
159 
160 	block = 1;
161 	tftp_send(peer, &block, &tftp_stats);
162 
163 	read_close();
164 	if (tftp_stats.amount > 0)
165 		printstats("Sent", verbose, &tftp_stats);
166 
167 	txrx_error = 1;
168 }
169 
170 /*
171  * Receive a file.
172  */
173 void
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;
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 		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
190 	} else
191 		((struct sockaddr_in *)&peer_sock)->sin_port =
192 		    htons(atoi(port));
193 
194 	for (i = 0; i < 12; i++) {
195 		struct sockaddr_storage from;
196 
197 		/* Tell the other side what we want to do */
198 		if (debug&DEBUG_SIMPLE)
199 			printf("Requesting %s\n", name);
200 
201 		n = send_rrq(peer, name, mode);
202 		if (n > 0) {
203 			printf("Cannot send RRQ packet\n");
204 			return;
205 		}
206 
207 		/*
208 		 * The first packet we receive has the new destination port
209 		 * we have to send the next packets to.
210 		 */
211 		n = receive_packet(peer, recvbuffer,
212 		    MAXPKTSIZE, &from, timeoutpacket);
213 
214 		/* We got something useful! */
215 		if (n >= 0) {
216 			((struct sockaddr_in *)&peer_sock)->sin_port =
217 			    ((struct sockaddr_in *)&from)->sin_port;
218 			break;
219 		}
220 
221 		/* We should retry if this happens */
222 		if (n == RP_TIMEOUT) {
223 			printf("Try %d, didn't receive answer from remote.\n",
224 			    i + 1);
225 			continue;
226 		}
227 
228 		/* Otherwise it is a fatal error */
229 		break;
230 	}
231 	if (i == 12) {
232 		printf("Transfer timed out.\n");
233 		return;
234 	}
235 	if (rp->th_opcode == ERROR) {
236 		tftp_log(LOG_ERR, "Error code %d: %s", rp->th_code, rp->th_msg);
237 		return;
238 	}
239 
240 	if (write_init(fd, NULL, mode) < 0) {
241 		warn("write_init");
242 		return;
243 	}
244 
245 	/*
246 	 * If the first packet is an OACK packet instead of an DATA packet,
247 	 * handle it different.
248 	 */
249 	if (rp->th_opcode == OACK) {
250 		if (!options_rfc_enabled) {
251 			printf("Got OACK while options are not enabled!\n");
252 			send_error(peer, EBADOP);
253 			return;
254 		}
255 
256 		parse_options(peer, rp->th_stuff, n + 2);
257 
258 		n = send_ack(peer, 0);
259 		if (n > 0) {
260 			printf("Cannot send ACK on OACK.\n");
261 			return;
262 		}
263 		block = 0;
264 		tftp_receive(peer, &block, &tftp_stats, NULL, 0);
265 	} else {
266 		block = 1;
267 		tftp_receive(peer, &block, &tftp_stats, rp, n);
268 	}
269 
270 	write_close();
271 	if (tftp_stats.amount > 0)
272 		printstats("Received", verbose, &tftp_stats);
273 	return;
274 }
275