tftp.c revision 339060 
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 * 4. 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
32static 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: stable/10/usr.bin/tftp/tftp.c 339060 2018-10-01 16:09:20Z asomers $");
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 <assert.h>
52#include <err.h>
53#include <netdb.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <syslog.h>
58
59#include "tftp.h"
60#include "tftp-file.h"
61#include "tftp-utils.h"
62#include "tftp-io.h"
63#include "tftp-transfer.h"
64#include "tftp-options.h"
65
66/*
67 * Send the requested file.
68 */
69void
70xmitfile(int peer, char *port, int fd, char *name, char *mode)
71{
72	struct tftphdr *rp;
73	int n, i;
74	uint16_t block;
75	struct sockaddr_storage serv;	/* valid server port number */
76	char recvbuffer[MAXPKTSIZE];
77	struct tftp_stats tftp_stats;
78
79	stats_init(&tftp_stats);
80
81	memset(&serv, 0, sizeof(serv));
82	rp = (struct tftphdr *)recvbuffer;
83
84	if (port == NULL) {
85		struct servent *se;
86		se = getservbyname("tftp", "udp");
87		assert(se != NULL);
88		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
89	} else
90		((struct sockaddr_in *)&peer_sock)->sin_port =
91		    htons(atoi(port));
92
93	for (i = 0; i < 12; i++) {
94		struct sockaddr_storage from;
95
96		/* Tell the other side what we want to do */
97		if (debug&DEBUG_SIMPLE)
98			printf("Sending %s\n", name);
99
100		n = send_wrq(peer, name, mode);
101		if (n > 0) {
102			printf("Cannot send WRQ packet\n");
103			return;
104		}
105
106		/*
107		 * The first packet we receive has the new destination port
108		 * we have to send the next packets to.
109		 */
110		n = receive_packet(peer, recvbuffer,
111		    MAXPKTSIZE, &from, timeoutpacket);
112
113		/* We got some data! */
114		if (n >= 0) {
115			((struct sockaddr_in *)&peer_sock)->sin_port =
116			    ((struct sockaddr_in *)&from)->sin_port;
117			break;
118		}
119
120		/* This should be retried */
121		if (n == RP_TIMEOUT) {
122			printf("Try %d, didn't receive answer from remote.\n",
123			    i + 1);
124			continue;
125		}
126
127		/* Everything else is fatal */
128		break;
129	}
130	if (i == 12) {
131		printf("Transfer timed out.\n");
132		return;
133	}
134	if (rp->th_opcode == ERROR) {
135		printf("Got ERROR, aborted\n");
136		return;
137	}
138
139	/*
140	 * If the first packet is an OACK instead of an ACK packet,
141	 * handle it different.
142	 */
143	if (rp->th_opcode == OACK) {
144		if (!options_rfc_enabled) {
145			printf("Got OACK while options are not enabled!\n");
146			send_error(peer, EBADOP);
147			return;
148		}
149
150		parse_options(peer, rp->th_stuff, n + 2);
151	}
152
153	if (read_init(fd, NULL, mode) < 0) {
154		warn("read_init()");
155		return;
156	}
157
158	block = 1;
159	tftp_send(peer, &block, &tftp_stats);
160
161	read_close();
162	if (tftp_stats.amount > 0)
163		printstats("Sent", verbose, &tftp_stats);
164
165	txrx_error = 1;
166}
167
168/*
169 * Receive a file.
170 */
171void
172recvfile(int peer, char *port, int fd, char *name, char *mode)
173{
174	struct tftphdr *rp;
175	uint16_t block;
176	char recvbuffer[MAXPKTSIZE];
177	int n, i;
178	struct tftp_stats tftp_stats;
179
180	stats_init(&tftp_stats);
181
182	rp = (struct tftphdr *)recvbuffer;
183
184	if (port == NULL) {
185		struct servent *se;
186		se = getservbyname("tftp", "udp");
187		assert(se != NULL);
188		((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
189	} else
190		((struct sockaddr_in *)&peer_sock)->sin_port =
191		    htons(atoi(port));
192
193	for (i = 0; i < 12; i++) {
194		struct sockaddr_storage from;
195
196		/* Tell the other side what we want to do */
197		if (debug&DEBUG_SIMPLE)
198			printf("Requesting %s\n", name);
199
200		n = send_rrq(peer, name, mode);
201		if (n > 0) {
202			printf("Cannot send RRQ packet\n");
203			return;
204		}
205
206		/*
207		 * The first packet we receive has the new destination port
208		 * we have to send the next packets to.
209		 */
210		n = receive_packet(peer, recvbuffer,
211		    MAXPKTSIZE, &from, timeoutpacket);
212
213		/* We got something useful! */
214		if (n >= 0) {
215			((struct sockaddr_in *)&peer_sock)->sin_port =
216			    ((struct sockaddr_in *)&from)->sin_port;
217			break;
218		}
219
220		/* We should retry if this happens */
221		if (n == RP_TIMEOUT) {
222			printf("Try %d, didn't receive answer from remote.\n",
223			    i + 1);
224			continue;
225		}
226
227		/* Otherwise it is a fatal error */
228		break;
229	}
230	if (i == 12) {
231		printf("Transfer timed out.\n");
232		return;
233	}
234	if (rp->th_opcode == ERROR) {
235		tftp_log(LOG_ERR, "Error code %d: %s", rp->th_code, rp->th_msg);
236		return;
237	}
238
239	if (write_init(fd, NULL, mode) < 0) {
240		warn("write_init");
241		return;
242	}
243
244	/*
245	 * If the first packet is an OACK packet instead of an DATA packet,
246	 * handle it different.
247	 */
248	if (rp->th_opcode == OACK) {
249		if (!options_rfc_enabled) {
250			printf("Got OACK while options are not enabled!\n");
251			send_error(peer, EBADOP);
252			return;
253		}
254
255		parse_options(peer, rp->th_stuff, n + 2);
256
257		n = send_ack(peer, 0);
258		if (n > 0) {
259			printf("Cannot send ACK on OACK.\n");
260			return;
261		}
262		block = 0;
263		tftp_receive(peer, &block, &tftp_stats, NULL, 0);
264	} else {
265		block = 1;
266		tftp_receive(peer, &block, &tftp_stats, rp, n);
267	}
268
269	if (tftp_stats.amount > 0)
270		printstats("Received", verbose, &tftp_stats);
271	return;
272}
273