diff --git a/libexec/tftpd/tftpd.8 b/libexec/tftpd/tftpd.8 index e4f5ab94a2fe..a984cdc32c94 100644 --- a/libexec/tftpd/tftpd.8 +++ b/libexec/tftpd/tftpd.8 @@ -1,312 +1,326 @@ .\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)tftpd.8 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd March 2, 2020 +.Dd July 20, 2023 .Dt TFTPD 8 .Os .Sh NAME .Nm tftpd .Nd Internet Trivial File Transfer Protocol server .Sh SYNOPSIS .Nm tftpd .Op Fl cdClnow .Op Fl F Ar strftime-format .Op Fl s Ar directory .Op Fl u Ar user .Op Fl U Ar umask .Op Ar directory ... .Sh DESCRIPTION The .Nm utility is a server which supports the Internet Trivial File Transfer Protocol .Pq Tn RFC 1350 . The .Tn TFTP server operates at the port indicated in the .Ql tftp service description; see .Xr services 5 . The server is normally started by .Xr inetd 8 . .Pp The use of .Xr tftp 1 does not require an account or password on the remote system. Due to the lack of authentication information, .Nm will allow only publicly readable files to be accessed. Files containing the string .Dq Li "/../" or starting with .Dq Li "../" are not allowed. -Files may be written only if they already exist and are publicly writable. +Files may be written only if they already exist (unless the +.Fl w +option is used) and are publicly writable (unless chrooted and the +.Fl S +option is used). Note that this extends the concept of .Dq public to include all users on all hosts that can be reached through the network; this may not be appropriate on all systems, and its implications should be considered before enabling tftp service. The server should have the user ID with the lowest possible privilege. .Pp Access to files may be restricted by invoking .Nm with a list of directories by including up to 20 pathnames as server program arguments in .Xr inetd.conf 5 . In this case access is restricted to files whose names are prefixed by the one of the given directories. The given directories are also treated as a search path for relative filename requests. .Pp The .Fl s option provides additional security by changing the root directory of .Nm , thereby prohibiting accesses to outside of the specified .Ar directory . Because .Xr chroot 2 requires super-user privileges, .Nm must be run as .Li root . However, after performing the .Xr chroot 2 call, .Nm will set its user ID to that of the specified .Ar user , or .Dq Li nobody if no .Fl u option is specified. .Pp The options are: .Bl -tag -width Ds .It Fl c Changes the default root directory of a connecting host via .Xr chroot 2 based on the connecting IP address. This prevents multiple clients from writing to the same file at the same time. If the directory does not exist, the client connection is refused. The .Fl s option is required for .Fl c and the specified .Ar directory is used as a base. .It Fl C Operates the same as .Fl c except it falls back to .Ar directory specified via .Fl s if a directory does not exist for the client's IP. .It Fl F Use this .Xr strftime 3 compatible format string for the creation of the suffix if .Fl W is specified. By default the string "%Y%m%d" is used. .It Fl d, d Ar [value] Enables debug output. If .Ar value is not specified, then the debug level is increased by one for each instance of .Fl d which is specified. .Pp If .Ar value is specified, then the debug level is set to .Ar value . The debug level is a bitmask implemented in .Pa src/libexec/tftpd/tftp-utils.h . Valid values are 0 (DEBUG_NONE), 1 (DEBUG_PACKETS), 2, (DEBUG_SIMPLE), 4 (DEBUG_OPTIONS), and 8 (DEBUG_ACCESS). Multiple debug values can be combined in the bitmask by logically OR'ing the values. For example, specifying .Fl d .Ar 15 will enable all the debug values. .It Fl l Log all requests using .Xr syslog 3 with the facility of .Dv LOG_FTP . .Sy Note : Logging of .Dv LOG_FTP messages must also be enabled in the syslog configuration file, .Xr syslog.conf 5 . .It Fl n Suppress negative acknowledgement of requests for nonexistent relative filenames. .It Fl o Disable support for RFC2347 style TFTP Options. .It Fl s Ar directory Cause .Nm to change its root directory to .Ar directory . After doing that but before accepting commands, .Nm will switch credentials to an unprivileged user. +.It Fl S +If +.Nm +runs chrooted, the option allows write requests according to generic +file permissions, skipping requirement for files to be publicly writable. +The option is ignored for non-chrooted run. .It Fl u Ar user Switch credentials to .Ar user (default .Dq Li nobody ) when the .Fl s option is used. The user must be specified by name, not a numeric UID. .It Fl U Ar umask Set the .Ar umask for newly created files. The default is 022 .Pq Dv S_IWGRP | S_IWOTH . .It Fl w Allow write requests to create new files. By default .Nm requires that the file specified in a write request exist. Note that this only works in directories writable by the user specified with .Fl u option .It Fl W As .Fl w but append a YYYYMMDD.nn sequence number to the end of the filename. Note that the string YYYYMMDD can be changed with the .Fl F option. .El .Sh SEE ALSO .Xr tftp 1 , .Xr chroot 2 , .Xr syslog 3 , .Xr inetd.conf 5 , .Xr services 5 , .Xr syslog.conf 5 , .Xr inetd 8 .Pp The following RFC's are supported: .Rs .%T RFC 1350: The TFTP Protocol (Revision 2) .Re .Rs .%T RFC 2347: TFTP Option Extension .Re .Rs .%T RFC 2348: TFTP Blocksize Option .Re .Rs .%T RFC 2349: TFTP Timeout Interval and Transfer Size Options .Re .Rs .%T RFC 7440: TFTP Windowsize Option .Re .Pp The non-standard .Cm rollover and .Cm blksize2 TFTP options are mentioned here: .Rs .%T Extending TFTP .%U http://www.compuphase.com/tftp.htm .Re .Sh HISTORY The .Nm utility appeared in .Bx 4.2 ; the .Fl s option was introduced in .Fx 2.2 , the .Fl u option was introduced in .Fx 4.2 , the .Fl c option was introduced in .Fx 4.3 , -and the +the .Fl F and .Fl W options were introduced in -.Fx 7.4 . +.Fx 7.4 , +and the +.Fl S +option was introduced in +.Fx 13.3 . .Pp Support for Timeout Interval and Transfer Size Options (RFC2349) was introduced in .Fx 5.0 , support for the TFTP Blocksize Option (RFC2348) and the blksize2 option was introduced in .Fx 7.4 . .Pp Edwin Groothuis performed a major rewrite of the .Nm and .Xr tftp 1 code to support RFC2348. .Pp Support for the windowsize option (RFC7440) was introduced in .Fx 13.0 . .Sh NOTES Files larger than 33,553,919 octets (65535 blocks, last one <512 octets) cannot be correctly transferred without client and server supporting blocksize negotiation (RFCs 2347 and 2348), or the non-standard TFTP rollover option. As a kludge, .Nm accepts a sequence of block number which wrap to zero after 65535, even if the rollover option is not specified. .Pp Many tftp clients will not transfer files over 16,776,703 octets (32767 blocks), as they incorrectly count the block number using a signed rather than unsigned 16-bit integer. diff --git a/libexec/tftpd/tftpd.c b/libexec/tftpd/tftpd.c index 02fbaaf0d371..56b97d4791bc 100644 --- a/libexec/tftpd/tftpd.c +++ b/libexec/tftpd/tftpd.c @@ -1,860 +1,869 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1983, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint static const char copyright[] = "@(#) Copyright (c) 1983, 1993\n\ The Regents of the University of California. All rights reserved.\n"; #endif /* not lint */ #ifndef lint #if 0 static char sccsid[] = "@(#)tftpd.c 8.1 (Berkeley) 6/4/93"; #endif #endif /* not lint */ #include __FBSDID("$FreeBSD$"); /* * Trivial file transfer protocol server. * * This version includes many modifications by Jim Guyton * . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "tftp-file.h" #include "tftp-io.h" #include "tftp-utils.h" #include "tftp-transfer.h" #include "tftp-options.h" #ifdef LIBWRAP #include #endif static void tftp_wrq(int peer, char *, ssize_t); static void tftp_rrq(int peer, char *, ssize_t); /* * Null-terminated directory prefix list for absolute pathname requests and * search list for relative pathname requests. * * MAXDIRS should be at least as large as the number of arguments that * inetd allows (currently 20). */ #define MAXDIRS 20 static struct dirlist { const char *name; int len; } dirs[MAXDIRS+1]; static int suppress_naks; static int logging; static int ipchroot; +static int check_woth = 1; static int create_new = 0; static const char *newfile_format = "%Y%m%d"; static int increase_name = 0; static mode_t mask = S_IWGRP | S_IWOTH; struct formats; static void tftp_recvfile(int peer, const char *mode); static void tftp_xmitfile(int peer, const char *mode); static int validate_access(int peer, char **, int); static char peername[NI_MAXHOST]; static FILE *file; static struct formats { const char *f_mode; int f_convert; } formats[] = { { "netascii", 1 }, { "octet", 0 }, { NULL, 0 } }; int main(int argc, char *argv[]) { struct tftphdr *tp; int peer; socklen_t peerlen, len; ssize_t n; int ch; char *chroot_dir = NULL; struct passwd *nobody; const char *chuser = "nobody"; char recvbuffer[MAXPKTSIZE]; int allow_ro = 1, allow_wo = 1; tzset(); /* syslog in localtime */ acting_as_client = 0; tftp_openlog("tftpd", LOG_PID | LOG_NDELAY, LOG_FTP); - while ((ch = getopt(argc, argv, "cCd:F:lnoOp:s:u:U:wW")) != -1) { + while ((ch = getopt(argc, argv, "cCd:F:lnoOp:s:Su:U:wW")) != -1) { +>>>>>>> 273a307d0b80 (tftpd: introduce new option -S) switch (ch) { case 'c': ipchroot = 1; break; case 'C': ipchroot = 2; break; case 'd': if (atoi(optarg) != 0) debug += atoi(optarg); else debug |= debug_finds(optarg); break; case 'F': newfile_format = optarg; break; case 'l': logging = 1; break; case 'n': suppress_naks = 1; break; case 'o': options_rfc_enabled = 0; break; case 'O': options_extra_enabled = 0; break; case 'p': packetdroppercentage = atoi(optarg); tftp_log(LOG_INFO, "Randomly dropping %d out of 100 packets", packetdroppercentage); break; case 's': chroot_dir = optarg; break; + case 'S': + check_woth = -1; + break; case 'u': chuser = optarg; break; case 'U': mask = strtol(optarg, NULL, 0); break; case 'w': create_new = 1; break; case 'W': create_new = 1; increase_name = 1; break; default: tftp_log(LOG_WARNING, "ignoring unknown option -%c", ch); } } if (optind < argc) { struct dirlist *dirp; /* Get list of directory prefixes. Skip relative pathnames. */ for (dirp = dirs; optind < argc && dirp < &dirs[MAXDIRS]; optind++) { if (argv[optind][0] == '/') { dirp->name = argv[optind]; dirp->len = strlen(dirp->name); dirp++; } } } else if (chroot_dir) { dirs->name = "/"; dirs->len = 1; } if (ipchroot > 0 && chroot_dir == NULL) { tftp_log(LOG_ERR, "-c requires -s"); exit(1); } umask(mask); { int on = 1; if (ioctl(0, FIONBIO, &on) < 0) { tftp_log(LOG_ERR, "ioctl(FIONBIO): %s", strerror(errno)); exit(1); } } /* Find out who we are talking to and what we are going to do */ peerlen = sizeof(peer_sock); n = recvfrom(0, recvbuffer, MAXPKTSIZE, 0, (struct sockaddr *)&peer_sock, &peerlen); if (n < 0) { tftp_log(LOG_ERR, "recvfrom: %s", strerror(errno)); exit(1); } getnameinfo((struct sockaddr *)&peer_sock, peer_sock.ss_len, peername, sizeof(peername), NULL, 0, NI_NUMERICHOST); /* * Now that we have read the message out of the UDP * socket, we fork and exit. Thus, inetd will go back * to listening to the tftp port, and the next request * to come in will start up a new instance of tftpd. * * We do this so that inetd can run tftpd in "wait" mode. * The problem with tftpd running in "nowait" mode is that * inetd may get one or more successful "selects" on the * tftp port before we do our receive, so more than one * instance of tftpd may be started up. Worse, if tftpd * break before doing the above "recvfrom", inetd would * spawn endless instances, clogging the system. */ { int i, pid; for (i = 1; i < 20; i++) { pid = fork(); if (pid < 0) { sleep(i); /* * flush out to most recently sent request. * * This may drop some request, but those * will be resent by the clients when * they timeout. The positive effect of * this flush is to (try to) prevent more * than one tftpd being started up to service * a single request from a single client. */ peerlen = sizeof peer_sock; i = recvfrom(0, recvbuffer, MAXPKTSIZE, 0, (struct sockaddr *)&peer_sock, &peerlen); if (i > 0) { n = i; } } else { break; } } if (pid < 0) { tftp_log(LOG_ERR, "fork: %s", strerror(errno)); exit(1); } else if (pid != 0) { exit(0); } } #ifdef LIBWRAP /* * See if the client is allowed to talk to me. * (This needs to be done before the chroot()) */ { struct request_info req; request_init(&req, RQ_CLIENT_ADDR, peername, 0); request_set(&req, RQ_DAEMON, "tftpd", 0); if (hosts_access(&req) == 0) { if (debug&DEBUG_ACCESS) tftp_log(LOG_WARNING, "Access denied by 'tftpd' entry " "in /etc/hosts.allow"); /* * Full access might be disabled, but maybe the * client is allowed to do read-only access. */ request_set(&req, RQ_DAEMON, "tftpd-ro", 0); allow_ro = hosts_access(&req); request_set(&req, RQ_DAEMON, "tftpd-wo", 0); allow_wo = hosts_access(&req); if (allow_ro == 0 && allow_wo == 0) { tftp_log(LOG_WARNING, "Unauthorized access from %s", peername); exit(1); } if (debug&DEBUG_ACCESS) { if (allow_ro) tftp_log(LOG_WARNING, "But allowed readonly access " "via 'tftpd-ro' entry"); if (allow_wo) tftp_log(LOG_WARNING, "But allowed writeonly access " "via 'tftpd-wo' entry"); } } else if (debug&DEBUG_ACCESS) tftp_log(LOG_WARNING, "Full access allowed" "in /etc/hosts.allow"); } #endif /* * Since we exit here, we should do that only after the above * recvfrom to keep inetd from constantly forking should there * be a problem. See the above comment about system clogging. */ if (chroot_dir) { if (ipchroot > 0) { char *tempchroot; struct stat sb; int statret; struct sockaddr_storage ss; char hbuf[NI_MAXHOST]; statret = -1; memcpy(&ss, &peer_sock, peer_sock.ss_len); unmappedaddr((struct sockaddr_in6 *)&ss); getnameinfo((struct sockaddr *)&ss, ss.ss_len, hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST); asprintf(&tempchroot, "%s/%s", chroot_dir, hbuf); if (ipchroot == 2) statret = stat(tempchroot, &sb); if (ipchroot == 1 || (statret == 0 && (sb.st_mode & S_IFDIR))) chroot_dir = tempchroot; } /* Must get this before chroot because /etc might go away */ if ((nobody = getpwnam(chuser)) == NULL) { tftp_log(LOG_ERR, "%s: no such user", chuser); exit(1); } if (chroot(chroot_dir)) { tftp_log(LOG_ERR, "chroot: %s: %s", chroot_dir, strerror(errno)); exit(1); } if (chdir("/") != 0) { tftp_log(LOG_ERR, "chdir: %s", strerror(errno)); exit(1); } if (setgroups(1, &nobody->pw_gid) != 0) { tftp_log(LOG_ERR, "setgroups failed"); exit(1); } if (setuid(nobody->pw_uid) != 0) { tftp_log(LOG_ERR, "setuid failed"); exit(1); } + if (check_woth == -1) + check_woth = 0; } + if (check_woth == -1) + check_woth = 1; len = sizeof(me_sock); if (getsockname(0, (struct sockaddr *)&me_sock, &len) == 0) { switch (me_sock.ss_family) { case AF_INET: ((struct sockaddr_in *)&me_sock)->sin_port = 0; break; case AF_INET6: ((struct sockaddr_in6 *)&me_sock)->sin6_port = 0; break; default: /* unsupported */ break; } } else { memset(&me_sock, 0, sizeof(me_sock)); me_sock.ss_family = peer_sock.ss_family; me_sock.ss_len = peer_sock.ss_len; } close(0); close(1); peer = socket(peer_sock.ss_family, SOCK_DGRAM, 0); if (peer < 0) { tftp_log(LOG_ERR, "socket: %s", strerror(errno)); exit(1); } if (bind(peer, (struct sockaddr *)&me_sock, me_sock.ss_len) < 0) { tftp_log(LOG_ERR, "bind: %s", strerror(errno)); exit(1); } tp = (struct tftphdr *)recvbuffer; tp->th_opcode = ntohs(tp->th_opcode); if (tp->th_opcode == RRQ) { if (allow_ro) tftp_rrq(peer, tp->th_stuff, n - 1); else { tftp_log(LOG_WARNING, "%s read access denied", peername); exit(1); } } else if (tp->th_opcode == WRQ) { if (allow_wo) tftp_wrq(peer, tp->th_stuff, n - 1); else { tftp_log(LOG_WARNING, "%s write access denied", peername); exit(1); } } else send_error(peer, EBADOP); exit(1); } static void reduce_path(char *fn) { char *slash, *ptr; /* Reduce all "/+./" to "/" (just in case we've got "/./../" later */ while ((slash = strstr(fn, "/./")) != NULL) { for (ptr = slash; ptr > fn && ptr[-1] == '/'; ptr--) ; slash += 2; while (*slash) *++ptr = *++slash; } /* Now reduce all "/something/+../" to "/" */ while ((slash = strstr(fn, "/../")) != NULL) { if (slash == fn) break; for (ptr = slash; ptr > fn && ptr[-1] == '/'; ptr--) ; for (ptr--; ptr >= fn; ptr--) if (*ptr == '/') break; if (ptr < fn) break; slash += 3; while (*slash) *++ptr = *++slash; } } static char * parse_header(int peer, char *recvbuffer, ssize_t size, char **filename, char **mode) { char *cp; int i; struct formats *pf; *mode = NULL; cp = recvbuffer; i = get_field(peer, recvbuffer, size); if (i >= PATH_MAX) { tftp_log(LOG_ERR, "Bad option - filename too long"); send_error(peer, EBADOP); exit(1); } *filename = recvbuffer; tftp_log(LOG_INFO, "Filename: '%s'", *filename); cp += i; i = get_field(peer, cp, size); *mode = cp; cp += i; /* Find the file transfer mode */ for (cp = *mode; *cp; cp++) if (isupper(*cp)) *cp = tolower(*cp); for (pf = formats; pf->f_mode; pf++) if (strcmp(pf->f_mode, *mode) == 0) break; if (pf->f_mode == NULL) { tftp_log(LOG_ERR, "Bad option - Unknown transfer mode (%s)", *mode); send_error(peer, EBADOP); exit(1); } tftp_log(LOG_INFO, "Mode: '%s'", *mode); return (cp + 1); } /* * WRQ - receive a file from the client */ void tftp_wrq(int peer, char *recvbuffer, ssize_t size) { char *cp; int has_options = 0, ecode; char *filename, *mode; char fnbuf[PATH_MAX]; cp = parse_header(peer, recvbuffer, size, &filename, &mode); size -= (cp - recvbuffer) + 1; strlcpy(fnbuf, filename, sizeof(fnbuf)); reduce_path(fnbuf); filename = fnbuf; if (size > 0) { if (options_rfc_enabled) has_options = !parse_options(peer, cp, size); else tftp_log(LOG_INFO, "Options found but not enabled"); } ecode = validate_access(peer, &filename, WRQ); if (ecode == 0) { if (has_options) send_oack(peer); else send_ack(peer, 0); } if (logging) { tftp_log(LOG_INFO, "%s: write request for %s: %s", peername, filename, errtomsg(ecode)); } if (ecode) { send_error(peer, ecode); exit(1); } tftp_recvfile(peer, mode); exit(0); } /* * RRQ - send a file to the client */ void tftp_rrq(int peer, char *recvbuffer, ssize_t size) { char *cp; int has_options = 0, ecode; char *filename, *mode; char fnbuf[PATH_MAX]; cp = parse_header(peer, recvbuffer, size, &filename, &mode); size -= (cp - recvbuffer) + 1; strlcpy(fnbuf, filename, sizeof(fnbuf)); reduce_path(fnbuf); filename = fnbuf; if (size > 0) { if (options_rfc_enabled) has_options = !parse_options(peer, cp, size); else tftp_log(LOG_INFO, "Options found but not enabled"); } ecode = validate_access(peer, &filename, RRQ); if (ecode == 0) { if (has_options) { int n; char lrecvbuffer[MAXPKTSIZE]; struct tftphdr *rp = (struct tftphdr *)lrecvbuffer; send_oack(peer); n = receive_packet(peer, lrecvbuffer, MAXPKTSIZE, NULL, timeoutpacket); if (n < 0) { if (debug&DEBUG_SIMPLE) tftp_log(LOG_DEBUG, "Aborting: %s", rp_strerror(n)); return; } if (rp->th_opcode != ACK) { if (debug&DEBUG_SIMPLE) tftp_log(LOG_DEBUG, "Expected ACK, got %s on OACK", packettype(rp->th_opcode)); return; } } } if (logging) tftp_log(LOG_INFO, "%s: read request for %s: %s", peername, 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); send_error(peer, ecode); exit(1); } tftp_xmitfile(peer, mode); } /* * Find the next value for YYYYMMDD.nn when the file to be written should * be unique. Due to the limitations of nn, we will fail if nn reaches 100. * Besides, that is four updates per hour on a file, which is kind of * execessive anyway. */ static int find_next_name(char *filename, int *fd) { int i; time_t tval; size_t len; struct tm lt; char yyyymmdd[MAXPATHLEN]; char newname[MAXPATHLEN]; /* Create the YYYYMMDD part of the filename */ time(&tval); lt = *localtime(&tval); len = strftime(yyyymmdd, sizeof(yyyymmdd), newfile_format, <); if (len == 0) { syslog(LOG_WARNING, "Filename suffix too long (%d characters maximum)", MAXPATHLEN); return (EACCESS); } /* Make sure the new filename is not too long */ if (strlen(filename) > MAXPATHLEN - len - 5) { syslog(LOG_WARNING, "Filename too long (%zd characters, %zd maximum)", strlen(filename), MAXPATHLEN - len - 5); return (EACCESS); } /* Find the first file which doesn't exist */ for (i = 0; i < 100; i++) { sprintf(newname, "%s.%s.%02d", filename, yyyymmdd, i); *fd = open(newname, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH); if (*fd > 0) return 0; } return (EEXIST); } /* * 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(int peer, char **filep, int mode) { struct stat stbuf; int fd; int error; 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) + if (check_woth && ((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 (mode == RRQ) { if ((stbuf.st_mode & S_IROTH) != 0) break; } else { - if ((stbuf.st_mode & S_IWOTH) != 0) + if (!check_woth || ((stbuf.st_mode & S_IWOTH) != 0)) break; } err = EACCESS; } } if (dirp->name != NULL) *filep = filename = pathname; else if (mode == RRQ) return (err); else if (err != ENOTFOUND || !create_new) return (err); } /* * This option is handled here because it (might) require(s) the * size of the file. */ option_tsize(peer, NULL, mode, &stbuf); if (mode == RRQ) fd = open(filename, O_RDONLY); else { if (create_new) { if (increase_name) { error = find_next_name(filename, &fd); if (error > 0) return (error + 100); } else fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH ); } 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); } static void tftp_xmitfile(int peer, const char *mode) { uint16_t block; time_t now; struct tftp_stats ts; memset(&ts, 0, sizeof(ts)); now = time(NULL); if (debug&DEBUG_SIMPLE) tftp_log(LOG_DEBUG, "Transmitting file"); read_init(0, file, mode); block = 1; tftp_send(peer, &block, &ts); read_close(); if (debug&DEBUG_SIMPLE) tftp_log(LOG_INFO, "Sent %jd bytes in %jd seconds", (intmax_t)ts.amount, (intmax_t)time(NULL) - now); } static void tftp_recvfile(int peer, const char *mode) { uint16_t block; struct timeval now1, now2; struct tftp_stats ts; gettimeofday(&now1, NULL); if (debug&DEBUG_SIMPLE) tftp_log(LOG_DEBUG, "Receiving file"); write_init(0, file, mode); block = 0; tftp_receive(peer, &block, &ts, NULL, 0); gettimeofday(&now2, NULL); if (debug&DEBUG_SIMPLE) { double f; if (now1.tv_usec > now2.tv_usec) { now2.tv_usec += 1000000; now2.tv_sec--; } f = now2.tv_sec - now1.tv_sec + (now2.tv_usec - now1.tv_usec) / 100000.0; tftp_log(LOG_INFO, "Download of %jd bytes in %d blocks completed after %0.1f seconds\n", (intmax_t)ts.amount, block, f); } return; }