899 lines
21 KiB
C
899 lines
21 KiB
C
/*
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* Copyright (c) 1983, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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static const char copyright[] =
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"@(#) Copyright (c) 1983, 1993\n\
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The Regents of the University of California. All rights reserved.\n";
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#endif /* not lint */
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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)tftpd.c 8.1 (Berkeley) 6/4/93";
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#endif
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static const char rcsid[] =
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"$FreeBSD$";
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#endif /* not lint */
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/*
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* Trivial file transfer protocol server.
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*
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* This version includes many modifications by Jim Guyton
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* <guyton@rand-unix>.
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*/
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#include <sys/param.h>
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#include <sys/ioctl.h>
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#include <sys/stat.h>
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#include <sys/socket.h>
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#include <sys/types.h>
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#include <netinet/in.h>
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#include <arpa/tftp.h>
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#include <arpa/inet.h>
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#include <ctype.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <libutil.h>
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#include <netdb.h>
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#include <pwd.h>
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#include <setjmp.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <syslog.h>
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#include <unistd.h>
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#include "tftpsubs.h"
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#define TIMEOUT 5
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#define MAX_TIMEOUTS 5
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int peer;
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int rexmtval = TIMEOUT;
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int max_rexmtval = 2*TIMEOUT;
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#define PKTSIZE SEGSIZE+4
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char buf[PKTSIZE];
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char ackbuf[PKTSIZE];
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struct sockaddr_storage from;
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int fromlen;
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void tftp(struct tftphdr *, int);
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static void unmappedaddr(struct sockaddr_in6 *);
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/*
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* Null-terminated directory prefix list for absolute pathname requests and
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* search list for relative pathname requests.
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*
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* MAXDIRS should be at least as large as the number of arguments that
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* inetd allows (currently 20).
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*/
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#define MAXDIRS 20
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static struct dirlist {
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const char *name;
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int len;
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} dirs[MAXDIRS+1];
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static int suppress_naks;
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static int logging;
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static int ipchroot;
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static int create_new = 0;
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static mode_t mask = S_IWGRP|S_IWOTH;
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static const char *errtomsg(int);
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static void nak(int);
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static void oack(void);
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static void timer(int);
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static void justquit(int);
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int
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main(int argc, char *argv[])
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{
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struct tftphdr *tp;
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int n;
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int ch, on;
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struct sockaddr_storage me;
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int len;
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char *chroot_dir = NULL;
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struct passwd *nobody;
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const char *chuser = "nobody";
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openlog("tftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
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while ((ch = getopt(argc, argv, "cClns:u:Uw")) != -1) {
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switch (ch) {
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case 'c':
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ipchroot = 1;
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break;
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case 'C':
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ipchroot = 2;
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break;
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case 'l':
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logging = 1;
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break;
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case 'n':
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suppress_naks = 1;
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break;
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case 's':
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chroot_dir = optarg;
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break;
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case 'u':
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chuser = optarg;
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break;
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case 'U':
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mask = strtol(optarg, NULL, 0);
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break;
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case 'w':
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create_new = 1;
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break;
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default:
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syslog(LOG_WARNING, "ignoring unknown option -%c", ch);
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}
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}
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if (optind < argc) {
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struct dirlist *dirp;
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/* Get list of directory prefixes. Skip relative pathnames. */
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for (dirp = dirs; optind < argc && dirp < &dirs[MAXDIRS];
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optind++) {
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if (argv[optind][0] == '/') {
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dirp->name = argv[optind];
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dirp->len = strlen(dirp->name);
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dirp++;
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}
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}
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}
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else if (chroot_dir) {
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dirs->name = "/";
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dirs->len = 1;
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}
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if (ipchroot > 0 && chroot_dir == NULL) {
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syslog(LOG_ERR, "-c requires -s");
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exit(1);
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}
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umask(mask);
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on = 1;
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if (ioctl(0, FIONBIO, &on) < 0) {
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syslog(LOG_ERR, "ioctl(FIONBIO): %m");
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exit(1);
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}
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fromlen = sizeof (from);
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n = recvfrom(0, buf, sizeof (buf), 0,
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(struct sockaddr *)&from, &fromlen);
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if (n < 0) {
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syslog(LOG_ERR, "recvfrom: %m");
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exit(1);
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}
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/*
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* Now that we have read the message out of the UDP
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* socket, we fork and exit. Thus, inetd will go back
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* to listening to the tftp port, and the next request
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* to come in will start up a new instance of tftpd.
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*
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* We do this so that inetd can run tftpd in "wait" mode.
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* The problem with tftpd running in "nowait" mode is that
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* inetd may get one or more successful "selects" on the
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* tftp port before we do our receive, so more than one
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* instance of tftpd may be started up. Worse, if tftpd
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* break before doing the above "recvfrom", inetd would
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* spawn endless instances, clogging the system.
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*/
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{
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int pid;
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int i, j;
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for (i = 1; i < 20; i++) {
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pid = fork();
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if (pid < 0) {
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sleep(i);
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/*
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* flush out to most recently sent request.
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*
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* This may drop some request, but those
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* will be resent by the clients when
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* they timeout. The positive effect of
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* this flush is to (try to) prevent more
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* than one tftpd being started up to service
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* a single request from a single client.
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*/
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j = sizeof from;
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i = recvfrom(0, buf, sizeof (buf), 0,
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(struct sockaddr *)&from, &j);
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if (i > 0) {
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n = i;
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fromlen = j;
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}
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} else {
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break;
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}
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}
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if (pid < 0) {
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syslog(LOG_ERR, "fork: %m");
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exit(1);
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} else if (pid != 0) {
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exit(0);
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}
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}
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/*
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* Since we exit here, we should do that only after the above
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* recvfrom to keep inetd from constantly forking should there
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* be a problem. See the above comment about system clogging.
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*/
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if (chroot_dir) {
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if (ipchroot > 0) {
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char *tempchroot;
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struct stat sb;
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int statret;
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struct sockaddr_storage ss;
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char hbuf[NI_MAXHOST];
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memcpy(&ss, &from, from.ss_len);
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unmappedaddr((struct sockaddr_in6 *)&ss);
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getnameinfo((struct sockaddr *)&ss, ss.ss_len,
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hbuf, sizeof(hbuf), NULL, 0,
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NI_NUMERICHOST | NI_WITHSCOPEID);
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asprintf(&tempchroot, "%s/%s", chroot_dir, hbuf);
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if (ipchroot == 2)
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statret = stat(tempchroot, &sb);
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if (ipchroot == 1 ||
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(statret == 0 && (sb.st_mode & S_IFDIR)))
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chroot_dir = tempchroot;
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}
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/* Must get this before chroot because /etc might go away */
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if ((nobody = getpwnam(chuser)) == NULL) {
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syslog(LOG_ERR, "%s: no such user", chuser);
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exit(1);
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}
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if (chroot(chroot_dir)) {
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syslog(LOG_ERR, "chroot: %s: %m", chroot_dir);
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exit(1);
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}
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chdir( "/" );
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setuid(nobody->pw_uid);
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setgroups(1, &nobody->pw_gid);
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}
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len = sizeof(me);
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if (getsockname(0, (struct sockaddr *)&me, &len) == 0) {
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switch (me.ss_family) {
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case AF_INET:
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((struct sockaddr_in *)&me)->sin_port = 0;
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break;
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case AF_INET6:
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((struct sockaddr_in6 *)&me)->sin6_port = 0;
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break;
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default:
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/* unsupported */
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break;
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}
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} else {
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memset(&me, 0, sizeof(me));
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me.ss_family = from.ss_family;
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me.ss_len = from.ss_len;
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}
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alarm(0);
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close(0);
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close(1);
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peer = socket(from.ss_family, SOCK_DGRAM, 0);
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if (peer < 0) {
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syslog(LOG_ERR, "socket: %m");
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exit(1);
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}
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if (bind(peer, (struct sockaddr *)&me, me.ss_len) < 0) {
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syslog(LOG_ERR, "bind: %m");
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exit(1);
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}
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if (connect(peer, (struct sockaddr *)&from, from.ss_len) < 0) {
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syslog(LOG_ERR, "connect: %m");
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exit(1);
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}
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tp = (struct tftphdr *)buf;
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tp->th_opcode = ntohs(tp->th_opcode);
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if (tp->th_opcode == RRQ || tp->th_opcode == WRQ)
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tftp(tp, n);
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exit(1);
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}
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struct formats;
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int validate_access(char **, int);
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void xmitfile(struct formats *);
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void recvfile(struct formats *);
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struct formats {
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const char *f_mode;
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int (*f_validate)(char **, int);
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void (*f_send)(struct formats *);
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void (*f_recv)(struct formats *);
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int f_convert;
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} formats[] = {
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{ "netascii", validate_access, xmitfile, recvfile, 1 },
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{ "octet", validate_access, xmitfile, recvfile, 0 },
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#ifdef notdef
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{ "mail", validate_user, sendmail, recvmail, 1 },
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#endif
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{ 0, NULL, NULL, NULL, 0 }
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};
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struct options {
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const char *o_type;
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char *o_request;
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int o_reply; /* turn into union if need be */
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} options[] = {
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{ "tsize", NULL, 0 }, /* OPT_TSIZE */
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{ "timeout", NULL, 0 }, /* OPT_TIMEOUT */
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{ NULL, NULL, 0 }
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};
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enum opt_enum {
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OPT_TSIZE = 0,
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OPT_TIMEOUT,
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};
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/*
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* Handle initial connection protocol.
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*/
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void
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tftp(struct tftphdr *tp, int size)
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{
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char *cp;
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int i, first = 1, has_options = 0, ecode;
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struct formats *pf;
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char *filename, *mode, *option, *ccp;
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char fnbuf[MAXPATHLEN];
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cp = tp->th_stuff;
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again:
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while (cp < buf + size) {
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if (*cp == '\0')
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break;
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cp++;
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}
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if (*cp != '\0') {
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nak(EBADOP);
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exit(1);
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}
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i = cp - tp->th_stuff;
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if (i >= sizeof(fnbuf)) {
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nak(EBADOP);
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exit(1);
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}
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memcpy(fnbuf, tp->th_stuff, i);
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fnbuf[i] = '\0';
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filename = fnbuf;
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if (first) {
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mode = ++cp;
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first = 0;
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goto again;
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}
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for (cp = mode; *cp; cp++)
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if (isupper(*cp))
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*cp = tolower(*cp);
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for (pf = formats; pf->f_mode; pf++)
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if (strcmp(pf->f_mode, mode) == 0)
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break;
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if (pf->f_mode == 0) {
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nak(EBADOP);
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exit(1);
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}
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while (++cp < buf + size) {
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for (i = 2, ccp = cp; i > 0; ccp++) {
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if (ccp >= buf + size) {
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/*
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* Don't reject the request, just stop trying
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* to parse the option and get on with it.
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* Some Apple OpenFirmware versions have
|
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* trailing garbage on the end of otherwise
|
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* valid requests.
|
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*/
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goto option_fail;
|
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} else if (*ccp == '\0')
|
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i--;
|
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}
|
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for (option = cp; *cp; cp++)
|
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if (isupper(*cp))
|
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*cp = tolower(*cp);
|
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for (i = 0; options[i].o_type != NULL; i++)
|
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if (strcmp(option, options[i].o_type) == 0) {
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options[i].o_request = ++cp;
|
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has_options = 1;
|
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}
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cp = ccp-1;
|
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}
|
|
|
|
option_fail:
|
|
if (options[OPT_TIMEOUT].o_request) {
|
|
int to = atoi(options[OPT_TIMEOUT].o_request);
|
|
if (to < 1 || to > 255) {
|
|
nak(EBADOP);
|
|
exit(1);
|
|
}
|
|
else if (to <= max_rexmtval)
|
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options[OPT_TIMEOUT].o_reply = rexmtval = to;
|
|
else
|
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options[OPT_TIMEOUT].o_request = NULL;
|
|
}
|
|
|
|
ecode = (*pf->f_validate)(&filename, tp->th_opcode);
|
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if (has_options)
|
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oack();
|
|
if (logging) {
|
|
char hbuf[NI_MAXHOST];
|
|
|
|
getnameinfo((struct sockaddr *)&from, from.ss_len,
|
|
hbuf, sizeof(hbuf), NULL, 0,
|
|
NI_WITHSCOPEID);
|
|
syslog(LOG_INFO, "%s: %s request for %s: %s", hbuf,
|
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tp->th_opcode == WRQ ? "write" : "read",
|
|
filename, errtomsg(ecode));
|
|
}
|
|
if (ecode) {
|
|
/*
|
|
* Avoid storms of naks to a RRQ broadcast for a relative
|
|
* bootfile pathname from a diskless Sun.
|
|
*/
|
|
if (suppress_naks && *filename != '/' && ecode == ENOTFOUND)
|
|
exit(0);
|
|
nak(ecode);
|
|
exit(1);
|
|
}
|
|
if (tp->th_opcode == WRQ)
|
|
(*pf->f_recv)(pf);
|
|
else
|
|
(*pf->f_send)(pf);
|
|
exit(0);
|
|
}
|
|
|
|
|
|
FILE *file;
|
|
|
|
/*
|
|
* Validate file access. Since we
|
|
* have no uid or gid, for now require
|
|
* file to exist and be publicly
|
|
* readable/writable.
|
|
* If we were invoked with arguments
|
|
* from inetd then the file must also be
|
|
* in one of the given directory prefixes.
|
|
* Note also, full path name must be
|
|
* given as we have no login directory.
|
|
*/
|
|
int
|
|
validate_access(char **filep, int mode)
|
|
{
|
|
struct stat stbuf;
|
|
int fd;
|
|
struct dirlist *dirp;
|
|
static char pathname[MAXPATHLEN];
|
|
char *filename = *filep;
|
|
|
|
/*
|
|
* Prevent tricksters from getting around the directory restrictions
|
|
*/
|
|
if (strstr(filename, "/../"))
|
|
return (EACCESS);
|
|
|
|
if (*filename == '/') {
|
|
/*
|
|
* Allow the request if it's in one of the approved locations.
|
|
* Special case: check the null prefix ("/") by looking
|
|
* for length = 1 and relying on the arg. processing that
|
|
* it's a /.
|
|
*/
|
|
for (dirp = dirs; dirp->name != NULL; dirp++) {
|
|
if (dirp->len == 1 ||
|
|
(!strncmp(filename, dirp->name, dirp->len) &&
|
|
filename[dirp->len] == '/'))
|
|
break;
|
|
}
|
|
/* If directory list is empty, allow access to any file */
|
|
if (dirp->name == NULL && dirp != dirs)
|
|
return (EACCESS);
|
|
if (stat(filename, &stbuf) < 0)
|
|
return (errno == ENOENT ? ENOTFOUND : EACCESS);
|
|
if ((stbuf.st_mode & S_IFMT) != S_IFREG)
|
|
return (ENOTFOUND);
|
|
if (mode == RRQ) {
|
|
if ((stbuf.st_mode & S_IROTH) == 0)
|
|
return (EACCESS);
|
|
} else {
|
|
if ((stbuf.st_mode & S_IWOTH) == 0)
|
|
return (EACCESS);
|
|
}
|
|
} else {
|
|
int err;
|
|
|
|
/*
|
|
* Relative file name: search the approved locations for it.
|
|
* Don't allow write requests that avoid directory
|
|
* restrictions.
|
|
*/
|
|
|
|
if (!strncmp(filename, "../", 3))
|
|
return (EACCESS);
|
|
|
|
/*
|
|
* If the file exists in one of the directories and isn't
|
|
* readable, continue looking. However, change the error code
|
|
* to give an indication that the file exists.
|
|
*/
|
|
err = ENOTFOUND;
|
|
for (dirp = dirs; dirp->name != NULL; dirp++) {
|
|
snprintf(pathname, sizeof(pathname), "%s/%s",
|
|
dirp->name, filename);
|
|
if (stat(pathname, &stbuf) == 0 &&
|
|
(stbuf.st_mode & S_IFMT) == S_IFREG) {
|
|
if ((stbuf.st_mode & S_IROTH) != 0) {
|
|
break;
|
|
}
|
|
err = EACCESS;
|
|
}
|
|
}
|
|
if (dirp->name != NULL)
|
|
*filep = filename = pathname;
|
|
else if (mode == RRQ)
|
|
return (err);
|
|
}
|
|
if (options[OPT_TSIZE].o_request) {
|
|
if (mode == RRQ)
|
|
options[OPT_TSIZE].o_reply = stbuf.st_size;
|
|
else
|
|
/* XXX Allows writes of all sizes. */
|
|
options[OPT_TSIZE].o_reply =
|
|
atoi(options[OPT_TSIZE].o_request);
|
|
}
|
|
if (mode == RRQ)
|
|
fd = open(filename, O_RDONLY);
|
|
else {
|
|
if (create_new)
|
|
fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0666);
|
|
else
|
|
fd = open(filename, O_WRONLY|O_TRUNC);
|
|
}
|
|
if (fd < 0)
|
|
return (errno + 100);
|
|
file = fdopen(fd, (mode == RRQ)? "r":"w");
|
|
if (file == NULL) {
|
|
close(fd);
|
|
return (errno + 100);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
int timeouts;
|
|
jmp_buf timeoutbuf;
|
|
|
|
void
|
|
timer(int sig __unused)
|
|
{
|
|
if (++timeouts > MAX_TIMEOUTS)
|
|
exit(1);
|
|
longjmp(timeoutbuf, 1);
|
|
}
|
|
|
|
/*
|
|
* Send the requested file.
|
|
*/
|
|
void
|
|
xmitfile(struct formats *pf)
|
|
{
|
|
struct tftphdr *dp;
|
|
struct tftphdr *ap; /* ack packet */
|
|
int size, n;
|
|
volatile unsigned short block;
|
|
|
|
signal(SIGALRM, timer);
|
|
dp = r_init();
|
|
ap = (struct tftphdr *)ackbuf;
|
|
block = 1;
|
|
do {
|
|
size = readit(file, &dp, pf->f_convert);
|
|
if (size < 0) {
|
|
nak(errno + 100);
|
|
goto abort;
|
|
}
|
|
dp->th_opcode = htons((u_short)DATA);
|
|
dp->th_block = htons((u_short)block);
|
|
timeouts = 0;
|
|
(void)setjmp(timeoutbuf);
|
|
|
|
send_data:
|
|
{
|
|
int i, t = 1;
|
|
for (i = 0; ; i++){
|
|
if (send(peer, dp, size + 4, 0) != size + 4) {
|
|
sleep(t);
|
|
t = (t < 32) ? t<< 1 : t;
|
|
if (i >= 12) {
|
|
syslog(LOG_ERR, "write: %m");
|
|
goto abort;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
read_ahead(file, pf->f_convert);
|
|
for ( ; ; ) {
|
|
alarm(rexmtval); /* read the ack */
|
|
n = recv(peer, ackbuf, sizeof (ackbuf), 0);
|
|
alarm(0);
|
|
if (n < 0) {
|
|
syslog(LOG_ERR, "read: %m");
|
|
goto abort;
|
|
}
|
|
ap->th_opcode = ntohs((u_short)ap->th_opcode);
|
|
ap->th_block = ntohs((u_short)ap->th_block);
|
|
|
|
if (ap->th_opcode == ERROR)
|
|
goto abort;
|
|
|
|
if (ap->th_opcode == ACK) {
|
|
if (ap->th_block == block)
|
|
break;
|
|
/* Re-synchronize with the other side */
|
|
(void) synchnet(peer);
|
|
if (ap->th_block == (block -1))
|
|
goto send_data;
|
|
}
|
|
|
|
}
|
|
block++;
|
|
} while (size == SEGSIZE);
|
|
abort:
|
|
(void) fclose(file);
|
|
}
|
|
|
|
void
|
|
justquit(int sig __unused)
|
|
{
|
|
exit(0);
|
|
}
|
|
|
|
|
|
/*
|
|
* Receive a file.
|
|
*/
|
|
void
|
|
recvfile(struct formats *pf)
|
|
{
|
|
struct tftphdr *dp;
|
|
struct tftphdr *ap; /* ack buffer */
|
|
int n, size;
|
|
volatile unsigned short block;
|
|
|
|
signal(SIGALRM, timer);
|
|
dp = w_init();
|
|
ap = (struct tftphdr *)ackbuf;
|
|
block = 0;
|
|
do {
|
|
timeouts = 0;
|
|
ap->th_opcode = htons((u_short)ACK);
|
|
ap->th_block = htons((u_short)block);
|
|
block++;
|
|
(void) setjmp(timeoutbuf);
|
|
send_ack:
|
|
if (send(peer, ackbuf, 4, 0) != 4) {
|
|
syslog(LOG_ERR, "write: %m");
|
|
goto abort;
|
|
}
|
|
write_behind(file, pf->f_convert);
|
|
for ( ; ; ) {
|
|
alarm(rexmtval);
|
|
n = recv(peer, dp, PKTSIZE, 0);
|
|
alarm(0);
|
|
if (n < 0) { /* really? */
|
|
syslog(LOG_ERR, "read: %m");
|
|
goto abort;
|
|
}
|
|
dp->th_opcode = ntohs((u_short)dp->th_opcode);
|
|
dp->th_block = ntohs((u_short)dp->th_block);
|
|
if (dp->th_opcode == ERROR)
|
|
goto abort;
|
|
if (dp->th_opcode == DATA) {
|
|
if (dp->th_block == block) {
|
|
break; /* normal */
|
|
}
|
|
/* Re-synchronize with the other side */
|
|
(void) synchnet(peer);
|
|
if (dp->th_block == (block-1))
|
|
goto send_ack; /* rexmit */
|
|
}
|
|
}
|
|
/* size = write(file, dp->th_data, n - 4); */
|
|
size = writeit(file, &dp, n - 4, pf->f_convert);
|
|
if (size != (n-4)) { /* ahem */
|
|
if (size < 0) nak(errno + 100);
|
|
else nak(ENOSPACE);
|
|
goto abort;
|
|
}
|
|
} while (size == SEGSIZE);
|
|
write_behind(file, pf->f_convert);
|
|
(void) fclose(file); /* close data file */
|
|
|
|
ap->th_opcode = htons((u_short)ACK); /* send the "final" ack */
|
|
ap->th_block = htons((u_short)(block));
|
|
(void) send(peer, ackbuf, 4, 0);
|
|
|
|
signal(SIGALRM, justquit); /* just quit on timeout */
|
|
alarm(rexmtval);
|
|
n = recv(peer, buf, sizeof (buf), 0); /* normally times out and quits */
|
|
alarm(0);
|
|
if (n >= 4 && /* if read some data */
|
|
dp->th_opcode == DATA && /* and got a data block */
|
|
block == dp->th_block) { /* then my last ack was lost */
|
|
(void) send(peer, ackbuf, 4, 0); /* resend final ack */
|
|
}
|
|
abort:
|
|
return;
|
|
}
|
|
|
|
struct errmsg {
|
|
int e_code;
|
|
const char *e_msg;
|
|
} errmsgs[] = {
|
|
{ EUNDEF, "Undefined error code" },
|
|
{ ENOTFOUND, "File not found" },
|
|
{ EACCESS, "Access violation" },
|
|
{ ENOSPACE, "Disk full or allocation exceeded" },
|
|
{ EBADOP, "Illegal TFTP operation" },
|
|
{ EBADID, "Unknown transfer ID" },
|
|
{ EEXISTS, "File already exists" },
|
|
{ ENOUSER, "No such user" },
|
|
{ EOPTNEG, "Option negotiation" },
|
|
{ -1, 0 }
|
|
};
|
|
|
|
static const char *
|
|
errtomsg(int error)
|
|
{
|
|
static char ebuf[20];
|
|
struct errmsg *pe;
|
|
if (error == 0)
|
|
return "success";
|
|
for (pe = errmsgs; pe->e_code >= 0; pe++)
|
|
if (pe->e_code == error)
|
|
return pe->e_msg;
|
|
snprintf(ebuf, sizeof(buf), "error %d", error);
|
|
return ebuf;
|
|
}
|
|
|
|
/*
|
|
* Send a nak packet (error message).
|
|
* Error code passed in is one of the
|
|
* standard TFTP codes, or a UNIX errno
|
|
* offset by 100.
|
|
*/
|
|
static void
|
|
nak(int error)
|
|
{
|
|
struct tftphdr *tp;
|
|
int length;
|
|
struct errmsg *pe;
|
|
|
|
tp = (struct tftphdr *)buf;
|
|
tp->th_opcode = htons((u_short)ERROR);
|
|
tp->th_code = htons((u_short)error);
|
|
for (pe = errmsgs; pe->e_code >= 0; pe++)
|
|
if (pe->e_code == error)
|
|
break;
|
|
if (pe->e_code < 0) {
|
|
pe->e_msg = strerror(error - 100);
|
|
tp->th_code = EUNDEF; /* set 'undef' errorcode */
|
|
}
|
|
strcpy(tp->th_msg, pe->e_msg);
|
|
length = strlen(pe->e_msg);
|
|
tp->th_msg[length] = '\0';
|
|
length += 5;
|
|
if (send(peer, buf, length, 0) != length)
|
|
syslog(LOG_ERR, "nak: %m");
|
|
}
|
|
|
|
/* translate IPv4 mapped IPv6 address to IPv4 address */
|
|
static void
|
|
unmappedaddr(struct sockaddr_in6 *sin6)
|
|
{
|
|
struct sockaddr_in *sin4;
|
|
u_int32_t addr;
|
|
int port;
|
|
|
|
if (sin6->sin6_family != AF_INET6 ||
|
|
!IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
|
|
return;
|
|
sin4 = (struct sockaddr_in *)sin6;
|
|
addr = *(u_int32_t *)&sin6->sin6_addr.s6_addr[12];
|
|
port = sin6->sin6_port;
|
|
memset(sin4, 0, sizeof(struct sockaddr_in));
|
|
sin4->sin_addr.s_addr = addr;
|
|
sin4->sin_port = port;
|
|
sin4->sin_family = AF_INET;
|
|
sin4->sin_len = sizeof(struct sockaddr_in);
|
|
}
|
|
|
|
/*
|
|
* Send an oack packet (option acknowledgement).
|
|
*/
|
|
static void
|
|
oack(void)
|
|
{
|
|
struct tftphdr *tp, *ap;
|
|
int size, i, n;
|
|
char *bp;
|
|
|
|
tp = (struct tftphdr *)buf;
|
|
bp = buf + 2;
|
|
size = sizeof(buf) - 2;
|
|
tp->th_opcode = htons((u_short)OACK);
|
|
for (i = 0; options[i].o_type != NULL; i++) {
|
|
if (options[i].o_request) {
|
|
n = snprintf(bp, size, "%s%c%d", options[i].o_type,
|
|
0, options[i].o_reply);
|
|
bp += n+1;
|
|
size -= n+1;
|
|
if (size < 0) {
|
|
syslog(LOG_ERR, "oack: buffer overflow");
|
|
exit(1);
|
|
}
|
|
}
|
|
}
|
|
size = bp - buf;
|
|
ap = (struct tftphdr *)ackbuf;
|
|
signal(SIGALRM, timer);
|
|
timeouts = 0;
|
|
|
|
(void)setjmp(timeoutbuf);
|
|
if (send(peer, buf, size, 0) != size) {
|
|
syslog(LOG_INFO, "oack: %m");
|
|
exit(1);
|
|
}
|
|
|
|
for (;;) {
|
|
alarm(rexmtval);
|
|
n = recv(peer, ackbuf, sizeof (ackbuf), 0);
|
|
alarm(0);
|
|
if (n < 0) {
|
|
syslog(LOG_ERR, "recv: %m");
|
|
exit(1);
|
|
}
|
|
ap->th_opcode = ntohs((u_short)ap->th_opcode);
|
|
ap->th_block = ntohs((u_short)ap->th_block);
|
|
if (ap->th_opcode == ERROR)
|
|
exit(1);
|
|
if (ap->th_opcode == ACK && ap->th_block == 0)
|
|
break;
|
|
}
|
|
}
|