xref: /freebsd/usr.bin/tftp/tftp.c (revision aa64588d28258aef88cc33b8043112e8856948d0)
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 	uint32_t amount;
79 	struct sockaddr_storage serv;	/* valid server port number */
80 	char recvbuffer[MAXPKTSIZE];
81 	struct tftp_stats tftp_stats;
82 
83 	stats_init(&tftp_stats);
84 
85 	memset(&serv, 0, sizeof(serv));
86 	rp = (struct tftphdr *)recvbuffer;
87 
88 	if (port == NULL) {
89 		struct servent *se;
90 		se = getservbyname("tftp", "udp");
91 		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
92 	} else
93 		((struct sockaddr_in *)&peer_sock)->sin_port =
94 		    htons(atoi(port));
95 
96 	for (i = 0; i < 12; i++) {
97 		struct sockaddr_storage from;
98 
99 		/* Tell the other side what we want to do */
100 		if (debug&DEBUG_SIMPLE)
101 			printf("Sending %s\n", name);
102 
103 		n = send_wrq(peer, name, mode);
104 		if (n > 0) {
105 			printf("Cannot send WRQ packet\n");
106 			return;
107 		}
108 
109 		/*
110 		 * The first packet we receive has the new destination port
111 		 * we have to send the next packets to.
112 		 */
113 		n = receive_packet(peer, recvbuffer,
114 		    MAXPKTSIZE, &from, timeoutpacket);
115 
116 		/* We got some data! */
117 		if (n >= 0) {
118 			((struct sockaddr_in *)&peer_sock)->sin_port =
119 			    ((struct sockaddr_in *)&from)->sin_port;
120 			break;
121 		}
122 
123 		/* This should be retried */
124 		if (n == RP_TIMEOUT) {
125 			printf("Try %d, didn't receive answer from remote.\n",
126 			    i + 1);
127 			continue;
128 		}
129 
130 		/* Everything else is fatal */
131 		break;
132 	}
133 	if (i == 12) {
134 		printf("Transfer timed out.\n");
135 		return;
136 	}
137 	if (rp->th_opcode == ERROR) {
138 		printf("Got ERROR, aborted\n");
139 		return;
140 	}
141 
142 	/*
143 	 * If the first packet is an OACK instead of an ACK packet,
144 	 * handle it different.
145 	 */
146 	if (rp->th_opcode == OACK) {
147 		if (!options_rfc_enabled) {
148 			printf("Got OACK while options are not enabled!\n");
149 			send_error(peer, EBADOP);
150 			return;
151 		}
152 
153 		parse_options(peer, rp->th_stuff, n + 2);
154 	}
155 
156 	if (read_init(fd, NULL, mode) < 0) {
157 		warn("read_init()");
158 		return;
159 	}
160 
161 	block = 1;
162 	tftp_send(peer, &block, &tftp_stats);
163 
164 	read_close();
165 	if (amount > 0)
166 		printstats("Sent", verbose, &tftp_stats);
167 
168 	txrx_error = 1;
169 }
170 
171 /*
172  * Receive a file.
173  */
174 void
175 recvfile(int peer, char *port, int fd, char *name, char *mode)
176 {
177 	struct tftphdr *rp;
178 	uint16_t block;
179 	char recvbuffer[MAXPKTSIZE];
180 	int n, i;
181 	struct tftp_stats tftp_stats;
182 
183 	stats_init(&tftp_stats);
184 
185 	rp = (struct tftphdr *)recvbuffer;
186 
187 	if (port == NULL) {
188 		struct servent *se;
189 		se = getservbyname("tftp", "udp");
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;
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 
233 	if (rp->th_opcode == ERROR) {
234 		tftp_log(LOG_ERR, "Error code %d: %s", rp->th_code, rp->th_msg);
235 		return;
236 	}
237 
238 	if (write_init(fd, NULL, mode) < 0) {
239 		warn("write_init");
240 		return;
241 	}
242 
243 	stats_init(&tftp_stats);
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