xref: /freebsd/usr.bin/tftp/tftp.c (revision ea825d02749f382c3f7e17f28247f20a48733eab)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if 0
31 #ifndef lint
32 static char sccsid[] = "@(#)tftp.c	8.1 (Berkeley) 6/6/93";
33 #endif /* not lint */
34 #endif
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 /* Many bug fixes are from Jim Guyton <guyton@rand-unix> */
40 
41 /*
42  * TFTP User Program -- Protocol Machines
43  */
44 #include <sys/socket.h>
45 #include <sys/stat.h>
46 
47 #include <netinet/in.h>
48 
49 #include <arpa/tftp.h>
50 
51 #include <err.h>
52 #include <netdb.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <syslog.h>
57 
58 #include "tftp.h"
59 #include "tftp-file.h"
60 #include "tftp-utils.h"
61 #include "tftp-io.h"
62 #include "tftp-transfer.h"
63 #include "tftp-options.h"
64 
65 /*
66  * Send the requested file.
67  */
68 void
69 xmitfile(int peer, char *port, int fd, char *name, char *mode)
70 {
71 	struct tftphdr *rp;
72 	int n, i;
73 	uint16_t block;
74 	struct sockaddr_storage serv;	/* valid server port number */
75 	char recvbuffer[MAXPKTSIZE];
76 	struct tftp_stats tftp_stats;
77 
78 	stats_init(&tftp_stats);
79 
80 	memset(&serv, 0, sizeof(serv));
81 	rp = (struct tftphdr *)recvbuffer;
82 
83 	if (port == NULL) {
84 		struct servent *se;
85 		se = getservbyname("tftp", "udp");
86 		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
87 	} else
88 		((struct sockaddr_in *)&peer_sock)->sin_port =
89 		    htons(atoi(port));
90 
91 	for (i = 0; i < 12; i++) {
92 		struct sockaddr_storage from;
93 
94 		/* Tell the other side what we want to do */
95 		if (debug&DEBUG_SIMPLE)
96 			printf("Sending %s\n", name);
97 
98 		n = send_wrq(peer, name, mode);
99 		if (n > 0) {
100 			printf("Cannot send WRQ packet\n");
101 			return;
102 		}
103 
104 		/*
105 		 * The first packet we receive has the new destination port
106 		 * we have to send the next packets to.
107 		 */
108 		n = receive_packet(peer, recvbuffer,
109 		    MAXPKTSIZE, &from, timeoutpacket);
110 
111 		/* We got some data! */
112 		if (n >= 0) {
113 			((struct sockaddr_in *)&peer_sock)->sin_port =
114 			    ((struct sockaddr_in *)&from)->sin_port;
115 			break;
116 		}
117 
118 		/* This should be retried */
119 		if (n == RP_TIMEOUT) {
120 			printf("Try %d, didn't receive answer from remote.\n",
121 			    i + 1);
122 			continue;
123 		}
124 
125 		/* Everything else is fatal */
126 		break;
127 	}
128 	if (i == 12) {
129 		printf("Transfer timed out.\n");
130 		return;
131 	}
132 	if (rp->th_opcode == ERROR) {
133 		printf("Got ERROR, aborted\n");
134 		return;
135 	}
136 
137 	/*
138 	 * If the first packet is an OACK instead of an ACK packet,
139 	 * handle it different.
140 	 */
141 	if (rp->th_opcode == OACK) {
142 		if (!options_rfc_enabled) {
143 			printf("Got OACK while options are not enabled!\n");
144 			send_error(peer, EBADOP);
145 			return;
146 		}
147 
148 		parse_options(peer, rp->th_stuff, n + 2);
149 	}
150 
151 	if (read_init(fd, NULL, mode) < 0) {
152 		warn("read_init()");
153 		return;
154 	}
155 
156 	block = 1;
157 	tftp_send(peer, &block, &tftp_stats);
158 
159 	read_close();
160 	if (tftp_stats.amount > 0)
161 		printstats("Sent", verbose, &tftp_stats);
162 
163 	txrx_error = 1;
164 }
165 
166 /*
167  * Receive a file.
168  */
169 void
170 recvfile(int peer, char *port, int fd, char *name, char *mode)
171 {
172 	struct tftphdr *rp;
173 	uint16_t block;
174 	char recvbuffer[MAXPKTSIZE];
175 	int n, i;
176 	struct tftp_stats tftp_stats;
177 
178 	stats_init(&tftp_stats);
179 
180 	rp = (struct tftphdr *)recvbuffer;
181 
182 	if (port == NULL) {
183 		struct servent *se;
184 		se = getservbyname("tftp", "udp");
185 		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
186 	} else
187 		((struct sockaddr_in *)&peer_sock)->sin_port =
188 		    htons(atoi(port));
189 
190 	for (i = 0; i < 12; i++) {
191 		struct sockaddr_storage from;
192 
193 		/* Tell the other side what we want to do */
194 		if (debug&DEBUG_SIMPLE)
195 			printf("Requesting %s\n", name);
196 
197 		n = send_rrq(peer, name, mode);
198 		if (n > 0) {
199 			printf("Cannot send RRQ packet\n");
200 			return;
201 		}
202 
203 		/*
204 		 * The first packet we receive has the new destination port
205 		 * we have to send the next packets to.
206 		 */
207 		n = receive_packet(peer, recvbuffer,
208 		    MAXPKTSIZE, &from, timeoutpacket);
209 
210 		/* We got something useful! */
211 		if (n >= 0) {
212 			((struct sockaddr_in *)&peer_sock)->sin_port =
213 			    ((struct sockaddr_in *)&from)->sin_port;
214 			break;
215 		}
216 
217 		/* We should retry if this happens */
218 		if (n == RP_TIMEOUT) {
219 			printf("Try %d, didn't receive answer from remote.\n",
220 			    i + 1);
221 			continue;
222 		}
223 
224 		/* Otherwise it is a fatal error */
225 		break;
226 	}
227 	if (i == 12) {
228 		printf("Transfer timed out.\n");
229 		return;
230 	}
231 	if (rp->th_opcode == ERROR) {
232 		tftp_log(LOG_ERR, "Error code %d: %s", rp->th_code, rp->th_msg);
233 		return;
234 	}
235 
236 	if (write_init(fd, NULL, mode) < 0) {
237 		warn("write_init");
238 		return;
239 	}
240 
241 	/*
242 	 * If the first packet is an OACK packet instead of an DATA packet,
243 	 * handle it different.
244 	 */
245 	if (rp->th_opcode == OACK) {
246 		if (!options_rfc_enabled) {
247 			printf("Got OACK while options are not enabled!\n");
248 			send_error(peer, EBADOP);
249 			return;
250 		}
251 
252 		parse_options(peer, rp->th_stuff, n + 2);
253 
254 		n = send_ack(peer, 0);
255 		if (n > 0) {
256 			printf("Cannot send ACK on OACK.\n");
257 			return;
258 		}
259 		block = 0;
260 		tftp_receive(peer, &block, &tftp_stats, NULL, 0);
261 	} else {
262 		block = 1;
263 		tftp_receive(peer, &block, &tftp_stats, rp, n);
264 	}
265 
266 	write_close();
267 	if (tftp_stats.amount > 0)
268 		printstats("Received", verbose, &tftp_stats);
269 	return;
270 }
271