tftp.c revision 337247 
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 337247 2018-08-03 14:17:11Z 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 <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 */
68void
69xmitfile(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 */
169void
170recvfile(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	if (tftp_stats.amount > 0)
267		printstats("Received", verbose, &tftp_stats);
268	return;
269}
270