tftpd.c revision 94443
11592Srgrimes/* 21592Srgrimes * Copyright (c) 1983, 1993 31592Srgrimes * The Regents of the University of California. All rights reserved. 41592Srgrimes * 51592Srgrimes * Redistribution and use in source and binary forms, with or without 61592Srgrimes * modification, are permitted provided that the following conditions 71592Srgrimes * are met: 81592Srgrimes * 1. Redistributions of source code must retain the above copyright 91592Srgrimes * notice, this list of conditions and the following disclaimer. 101592Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111592Srgrimes * notice, this list of conditions and the following disclaimer in the 121592Srgrimes * documentation and/or other materials provided with the distribution. 131592Srgrimes * 3. All advertising materials mentioning features or use of this software 141592Srgrimes * must display the following acknowledgement: 151592Srgrimes * This product includes software developed by the University of 161592Srgrimes * California, Berkeley and its contributors. 171592Srgrimes * 4. Neither the name of the University nor the names of its contributors 181592Srgrimes * may be used to endorse or promote products derived from this software 191592Srgrimes * without specific prior written permission. 201592Srgrimes * 211592Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221592Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231592Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241592Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251592Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261592Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271592Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281592Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291592Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301592Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311592Srgrimes * SUCH DAMAGE. 321592Srgrimes */ 331592Srgrimes 341592Srgrimes#ifndef lint 3531512Scharnierstatic const char copyright[] = 361592Srgrimes"@(#) Copyright (c) 1983, 1993\n\ 371592Srgrimes The Regents of the University of California. All rights reserved.\n"; 381592Srgrimes#endif /* not lint */ 391592Srgrimes 401592Srgrimes#ifndef lint 4131512Scharnier#if 0 421592Srgrimesstatic char sccsid[] = "@(#)tftpd.c 8.1 (Berkeley) 6/4/93"; 4331512Scharnier#endif 4431512Scharnierstatic const char rcsid[] = 4550476Speter "$FreeBSD: head/libexec/tftpd/tftpd.c 94443 2002-04-11 17:14:22Z ume $"; 461592Srgrimes#endif /* not lint */ 471592Srgrimes 481592Srgrimes/* 491592Srgrimes * Trivial file transfer protocol server. 501592Srgrimes * 511592Srgrimes * This version includes many modifications by Jim Guyton 521592Srgrimes * <guyton@rand-unix>. 531592Srgrimes */ 541592Srgrimes 551592Srgrimes#include <sys/param.h> 561592Srgrimes#include <sys/ioctl.h> 571592Srgrimes#include <sys/stat.h> 581592Srgrimes#include <sys/socket.h> 5918458Simp#include <sys/types.h> 601592Srgrimes 611592Srgrimes#include <netinet/in.h> 621592Srgrimes#include <arpa/tftp.h> 631592Srgrimes#include <arpa/inet.h> 641592Srgrimes 651592Srgrimes#include <ctype.h> 661592Srgrimes#include <errno.h> 671592Srgrimes#include <fcntl.h> 6845393Sbrian#include <libutil.h> 691592Srgrimes#include <netdb.h> 7031512Scharnier#include <pwd.h> 711592Srgrimes#include <setjmp.h> 721592Srgrimes#include <signal.h> 731592Srgrimes#include <stdio.h> 741592Srgrimes#include <stdlib.h> 751592Srgrimes#include <string.h> 761592Srgrimes#include <syslog.h> 771592Srgrimes#include <unistd.h> 781592Srgrimes 791592Srgrimes#include "tftpsubs.h" 801592Srgrimes 811592Srgrimes#define TIMEOUT 5 8284047Sobrien#define MAX_TIMEOUTS 5 831592Srgrimes 841592Srgrimesint peer; 851592Srgrimesint rexmtval = TIMEOUT; 8684047Sobrienint max_rexmtval = 2*TIMEOUT; 871592Srgrimes 881592Srgrimes#define PKTSIZE SEGSIZE+4 891592Srgrimeschar buf[PKTSIZE]; 901592Srgrimeschar ackbuf[PKTSIZE]; 9194443Sumestruct sockaddr_storage from; 921592Srgrimesint fromlen; 931592Srgrimes 9490333Simpvoid tftp(struct tftphdr *, int); 9594443Sumestatic void unmappedaddr(struct sockaddr_in6 *); 961592Srgrimes 971592Srgrimes/* 981592Srgrimes * Null-terminated directory prefix list for absolute pathname requests and 991592Srgrimes * search list for relative pathname requests. 1001592Srgrimes * 1011592Srgrimes * MAXDIRS should be at least as large as the number of arguments that 1021592Srgrimes * inetd allows (currently 20). 1031592Srgrimes */ 1041592Srgrimes#define MAXDIRS 20 1051592Srgrimesstatic struct dirlist { 1061592Srgrimes char *name; 1071592Srgrimes int len; 1081592Srgrimes} dirs[MAXDIRS+1]; 1091592Srgrimesstatic int suppress_naks; 1101592Srgrimesstatic int logging; 11171616Sbillfstatic int ipchroot; 1121592Srgrimes 11390333Simpstatic char *errtomsg(int); 11490333Simpstatic void nak(int); 11590333Simpstatic void oack(); 1161592Srgrimes 1171592Srgrimesint 11890333Simpmain(int argc, char *argv[]) 1191592Srgrimes{ 12090333Simp struct tftphdr *tp; 12190333Simp int n; 1221592Srgrimes int ch, on; 12394443Sume struct sockaddr_storage me; 12494443Sume int len; 12518458Simp char *chroot_dir = NULL; 12618458Simp struct passwd *nobody; 12765850Swollman char *chuser = "nobody"; 1281592Srgrimes 12935152Sphk openlog("tftpd", LOG_PID | LOG_NDELAY, LOG_FTP); 13071616Sbillf while ((ch = getopt(argc, argv, "cClns:u:")) != -1) { 1311592Srgrimes switch (ch) { 13271616Sbillf case 'c': 13371616Sbillf ipchroot = 1; 13471616Sbillf break; 13571616Sbillf case 'C': 13671616Sbillf ipchroot = 2; 13771616Sbillf break; 1381592Srgrimes case 'l': 1391592Srgrimes logging = 1; 1401592Srgrimes break; 1411592Srgrimes case 'n': 1421592Srgrimes suppress_naks = 1; 1431592Srgrimes break; 14418458Simp case 's': 14518458Simp chroot_dir = optarg; 14618458Simp break; 14765850Swollman case 'u': 14865850Swollman chuser = optarg; 14965850Swollman break; 1501592Srgrimes default: 1511592Srgrimes syslog(LOG_WARNING, "ignoring unknown option -%c", ch); 1521592Srgrimes } 1531592Srgrimes } 1541592Srgrimes if (optind < argc) { 1551592Srgrimes struct dirlist *dirp; 1561592Srgrimes 1571592Srgrimes /* Get list of directory prefixes. Skip relative pathnames. */ 1581592Srgrimes for (dirp = dirs; optind < argc && dirp < &dirs[MAXDIRS]; 1591592Srgrimes optind++) { 1601592Srgrimes if (argv[optind][0] == '/') { 1611592Srgrimes dirp->name = argv[optind]; 1621592Srgrimes dirp->len = strlen(dirp->name); 1631592Srgrimes dirp++; 1641592Srgrimes } 1651592Srgrimes } 1661592Srgrimes } 16718458Simp else if (chroot_dir) { 16818458Simp dirs->name = "/"; 16918458Simp dirs->len = 1; 17018458Simp } 17171616Sbillf if (ipchroot && chroot_dir == NULL) { 17271616Sbillf syslog(LOG_ERR, "-c requires -s"); 17371616Sbillf exit(1); 17471616Sbillf } 1751592Srgrimes 1761592Srgrimes on = 1; 1771592Srgrimes if (ioctl(0, FIONBIO, &on) < 0) { 17831512Scharnier syslog(LOG_ERR, "ioctl(FIONBIO): %m"); 1791592Srgrimes exit(1); 1801592Srgrimes } 1811592Srgrimes fromlen = sizeof (from); 1821592Srgrimes n = recvfrom(0, buf, sizeof (buf), 0, 1831592Srgrimes (struct sockaddr *)&from, &fromlen); 1841592Srgrimes if (n < 0) { 18531512Scharnier syslog(LOG_ERR, "recvfrom: %m"); 1861592Srgrimes exit(1); 1871592Srgrimes } 1881592Srgrimes /* 1891592Srgrimes * Now that we have read the message out of the UDP 1901592Srgrimes * socket, we fork and exit. Thus, inetd will go back 1911592Srgrimes * to listening to the tftp port, and the next request 1921592Srgrimes * to come in will start up a new instance of tftpd. 1931592Srgrimes * 1941592Srgrimes * We do this so that inetd can run tftpd in "wait" mode. 1951592Srgrimes * The problem with tftpd running in "nowait" mode is that 1961592Srgrimes * inetd may get one or more successful "selects" on the 1971592Srgrimes * tftp port before we do our receive, so more than one 1981592Srgrimes * instance of tftpd may be started up. Worse, if tftpd 1991592Srgrimes * break before doing the above "recvfrom", inetd would 2001592Srgrimes * spawn endless instances, clogging the system. 2011592Srgrimes */ 2021592Srgrimes { 2031592Srgrimes int pid; 2041592Srgrimes int i, j; 2051592Srgrimes 2061592Srgrimes for (i = 1; i < 20; i++) { 2071592Srgrimes pid = fork(); 2081592Srgrimes if (pid < 0) { 2091592Srgrimes sleep(i); 2101592Srgrimes /* 2111592Srgrimes * flush out to most recently sent request. 2121592Srgrimes * 2131592Srgrimes * This may drop some request, but those 2141592Srgrimes * will be resent by the clients when 2151592Srgrimes * they timeout. The positive effect of 2161592Srgrimes * this flush is to (try to) prevent more 2171592Srgrimes * than one tftpd being started up to service 2181592Srgrimes * a single request from a single client. 2191592Srgrimes */ 2201592Srgrimes j = sizeof from; 2211592Srgrimes i = recvfrom(0, buf, sizeof (buf), 0, 2221592Srgrimes (struct sockaddr *)&from, &j); 2231592Srgrimes if (i > 0) { 2241592Srgrimes n = i; 2251592Srgrimes fromlen = j; 2261592Srgrimes } 2271592Srgrimes } else { 2281592Srgrimes break; 2291592Srgrimes } 2301592Srgrimes } 2311592Srgrimes if (pid < 0) { 23231512Scharnier syslog(LOG_ERR, "fork: %m"); 2331592Srgrimes exit(1); 2341592Srgrimes } else if (pid != 0) { 2351592Srgrimes exit(0); 2361592Srgrimes } 2371592Srgrimes } 23818458Simp 23918458Simp /* 24018458Simp * Since we exit here, we should do that only after the above 24118458Simp * recvfrom to keep inetd from constantly forking should there 24218458Simp * be a problem. See the above comment about system clogging. 24318458Simp */ 24418458Simp if (chroot_dir) { 24571616Sbillf if (ipchroot) { 24671616Sbillf char *tempchroot; 24771616Sbillf struct stat sb; 24871616Sbillf int statret; 24994443Sume struct sockaddr_storage ss; 25094443Sume char hbuf[NI_MAXHOST]; 25171616Sbillf 25294443Sume memcpy(&ss, &from, from.ss_len); 25394443Sume unmappedaddr((struct sockaddr_in6 *)&ss); 25494443Sume getnameinfo((struct sockaddr *)&ss, ss.ss_len, 25594443Sume hbuf, sizeof(hbuf), NULL, 0, 25694443Sume NI_NUMERICHOST | NI_WITHSCOPEID); 25794443Sume asprintf(&tempchroot, "%s/%s", chroot_dir, hbuf); 25871616Sbillf statret = stat(tempchroot, &sb); 25971616Sbillf if ((sb.st_mode & S_IFDIR) && 26071616Sbillf (statret == 0 || (statret == -1 && ipchroot == 1))) 26171616Sbillf chroot_dir = tempchroot; 26271616Sbillf } 26318458Simp /* Must get this before chroot because /etc might go away */ 26465850Swollman if ((nobody = getpwnam(chuser)) == NULL) { 26565850Swollman syslog(LOG_ERR, "%s: no such user", chuser); 26618458Simp exit(1); 26718458Simp } 26818458Simp if (chroot(chroot_dir)) { 26918458Simp syslog(LOG_ERR, "chroot: %s: %m", chroot_dir); 27018458Simp exit(1); 27118458Simp } 27218458Simp chdir( "/" ); 27318458Simp setuid(nobody->pw_uid); 27485299Sobrien setgroups(1, &nobody->pw_gid); 27518458Simp } 27618458Simp 27794443Sume len = sizeof(me); 27894443Sume if (getsockname(0, (struct sockaddr *)&me, &len) == 0) { 27994443Sume switch (me.ss_family) { 28094443Sume case AF_INET: 28194443Sume ((struct sockaddr_in *)&me)->sin_port = 0; 28294443Sume break; 28394443Sume case AF_INET6: 28494443Sume ((struct sockaddr_in6 *)&me)->sin6_port = 0; 28594443Sume break; 28694443Sume default: 28794443Sume /* unsupported */ 28894443Sume break; 28994443Sume } 29094443Sume } else { 29194443Sume memset(&me, 0, sizeof(me)); 29294443Sume me.ss_family = from.ss_family; 29394443Sume me.ss_len = from.ss_len; 29494443Sume } 2951592Srgrimes alarm(0); 2961592Srgrimes close(0); 2971592Srgrimes close(1); 29894443Sume peer = socket(from.ss_family, SOCK_DGRAM, 0); 2991592Srgrimes if (peer < 0) { 30031512Scharnier syslog(LOG_ERR, "socket: %m"); 3011592Srgrimes exit(1); 3021592Srgrimes } 30394443Sume if (bind(peer, (struct sockaddr *)&me, me.ss_len) < 0) { 30431512Scharnier syslog(LOG_ERR, "bind: %m"); 3051592Srgrimes exit(1); 3061592Srgrimes } 30794443Sume if (connect(peer, (struct sockaddr *)&from, from.ss_len) < 0) { 30831512Scharnier syslog(LOG_ERR, "connect: %m"); 3091592Srgrimes exit(1); 3101592Srgrimes } 3111592Srgrimes tp = (struct tftphdr *)buf; 3121592Srgrimes tp->th_opcode = ntohs(tp->th_opcode); 3131592Srgrimes if (tp->th_opcode == RRQ || tp->th_opcode == WRQ) 3141592Srgrimes tftp(tp, n); 3151592Srgrimes exit(1); 3161592Srgrimes} 3171592Srgrimes 3181592Srgrimesstruct formats; 31990333Simpint validate_access(char **, int); 32090333Simpvoid xmitfile(struct formats *); 32190333Simpvoid recvfile(struct formats *); 3221592Srgrimes 3231592Srgrimesstruct formats { 3241592Srgrimes char *f_mode; 32590333Simp int (*f_validate)(char **, int); 32690333Simp void (*f_send)(struct formats *); 32790333Simp void (*f_recv)(struct formats *); 3281592Srgrimes int f_convert; 3291592Srgrimes} formats[] = { 33040765Sdg { "netascii", validate_access, xmitfile, recvfile, 1 }, 33140765Sdg { "octet", validate_access, xmitfile, recvfile, 0 }, 3321592Srgrimes#ifdef notdef 3331592Srgrimes { "mail", validate_user, sendmail, recvmail, 1 }, 3341592Srgrimes#endif 3351592Srgrimes { 0 } 3361592Srgrimes}; 3371592Srgrimes 33884047Sobrienstruct options { 33984047Sobrien char *o_type; 34084047Sobrien char *o_request; 34184047Sobrien int o_reply; /* turn into union if need be */ 34284047Sobrien} options[] = { 34384047Sobrien { "tsize" }, /* OPT_TSIZE */ 34484047Sobrien { "timeout" }, /* OPT_TIMEOUT */ 34584047Sobrien { NULL } 34684047Sobrien}; 34784047Sobrien 34884047Sobrienenum opt_enum { 34984047Sobrien OPT_TSIZE = 0, 35084047Sobrien OPT_TIMEOUT, 35184047Sobrien}; 35284047Sobrien 3531592Srgrimes/* 3541592Srgrimes * Handle initial connection protocol. 3551592Srgrimes */ 3561592Srgrimesvoid 35790333Simptftp(struct tftphdr *tp, int size) 3581592Srgrimes{ 35990333Simp char *cp; 36084047Sobrien int i, first = 1, has_options = 0, ecode; 36190333Simp struct formats *pf; 36284047Sobrien char *filename, *mode, *option, *ccp; 3631592Srgrimes 3641592Srgrimes filename = cp = tp->th_stuff; 3651592Srgrimesagain: 3661592Srgrimes while (cp < buf + size) { 3671592Srgrimes if (*cp == '\0') 3681592Srgrimes break; 3691592Srgrimes cp++; 3701592Srgrimes } 3711592Srgrimes if (*cp != '\0') { 3721592Srgrimes nak(EBADOP); 3731592Srgrimes exit(1); 3741592Srgrimes } 3751592Srgrimes if (first) { 3761592Srgrimes mode = ++cp; 3771592Srgrimes first = 0; 3781592Srgrimes goto again; 3791592Srgrimes } 3801592Srgrimes for (cp = mode; *cp; cp++) 3811592Srgrimes if (isupper(*cp)) 3821592Srgrimes *cp = tolower(*cp); 3831592Srgrimes for (pf = formats; pf->f_mode; pf++) 3841592Srgrimes if (strcmp(pf->f_mode, mode) == 0) 3851592Srgrimes break; 3861592Srgrimes if (pf->f_mode == 0) { 3871592Srgrimes nak(EBADOP); 3881592Srgrimes exit(1); 3891592Srgrimes } 39084047Sobrien while (++cp < buf + size) { 39184047Sobrien for (i = 2, ccp = cp; i > 0; ccp++) { 39284047Sobrien if (ccp >= buf + size) { 39386765Sbenno /* 39486765Sbenno * Don't reject the request, just stop trying 39586765Sbenno * to parse the option and get on with it. 39686765Sbenno * Some Apple OpenFirmware versions have 39786765Sbenno * trailing garbage on the end of otherwise 39886765Sbenno * valid requests. 39986765Sbenno */ 40086765Sbenno goto option_fail; 40184047Sobrien } else if (*ccp == '\0') 40284047Sobrien i--; 40384047Sobrien } 40484047Sobrien for (option = cp; *cp; cp++) 40584047Sobrien if (isupper(*cp)) 40684047Sobrien *cp = tolower(*cp); 40784047Sobrien for (i = 0; options[i].o_type != NULL; i++) 40884047Sobrien if (strcmp(option, options[i].o_type) == 0) { 40984047Sobrien options[i].o_request = ++cp; 41084047Sobrien has_options = 1; 41184047Sobrien } 41284047Sobrien cp = ccp-1; 41384047Sobrien } 41484047Sobrien 41586765Sbennooption_fail: 41684047Sobrien if (options[OPT_TIMEOUT].o_request) { 41784047Sobrien int to = atoi(options[OPT_TIMEOUT].o_request); 41884047Sobrien if (to < 1 || to > 255) { 41984047Sobrien nak(EBADOP); 42084047Sobrien exit(1); 42184047Sobrien } 42284047Sobrien else if (to <= max_rexmtval) 42384047Sobrien options[OPT_TIMEOUT].o_reply = rexmtval = to; 42484047Sobrien else 42584047Sobrien options[OPT_TIMEOUT].o_request = NULL; 42684047Sobrien } 42784047Sobrien 4281592Srgrimes ecode = (*pf->f_validate)(&filename, tp->th_opcode); 42984047Sobrien if (has_options) 43084047Sobrien oack(); 4311592Srgrimes if (logging) { 43294443Sume char hbuf[NI_MAXHOST]; 43345393Sbrian 43494443Sume getnameinfo((struct sockaddr *)&from, from.ss_len, 43594443Sume hbuf, sizeof(hbuf), NULL, 0, 43694443Sume NI_WITHSCOPEID); 43794443Sume syslog(LOG_INFO, "%s: %s request for %s: %s", hbuf, 4381592Srgrimes tp->th_opcode == WRQ ? "write" : "read", 4391592Srgrimes filename, errtomsg(ecode)); 4401592Srgrimes } 4411592Srgrimes if (ecode) { 4421592Srgrimes /* 4431592Srgrimes * Avoid storms of naks to a RRQ broadcast for a relative 4441592Srgrimes * bootfile pathname from a diskless Sun. 4451592Srgrimes */ 4461592Srgrimes if (suppress_naks && *filename != '/' && ecode == ENOTFOUND) 4471592Srgrimes exit(0); 4481592Srgrimes nak(ecode); 4491592Srgrimes exit(1); 4501592Srgrimes } 4511592Srgrimes if (tp->th_opcode == WRQ) 4521592Srgrimes (*pf->f_recv)(pf); 4531592Srgrimes else 4541592Srgrimes (*pf->f_send)(pf); 4551592Srgrimes exit(0); 4561592Srgrimes} 4571592Srgrimes 4581592Srgrimes 4591592SrgrimesFILE *file; 4601592Srgrimes 4611592Srgrimes/* 4621592Srgrimes * Validate file access. Since we 4631592Srgrimes * have no uid or gid, for now require 4641592Srgrimes * file to exist and be publicly 4651592Srgrimes * readable/writable. 4661592Srgrimes * If we were invoked with arguments 4671592Srgrimes * from inetd then the file must also be 4681592Srgrimes * in one of the given directory prefixes. 4691592Srgrimes * Note also, full path name must be 4701592Srgrimes * given as we have no login directory. 4711592Srgrimes */ 4721592Srgrimesint 47390333Simpvalidate_access(char **filep, int mode) 4741592Srgrimes{ 4751592Srgrimes struct stat stbuf; 4761592Srgrimes int fd; 4771592Srgrimes struct dirlist *dirp; 4781592Srgrimes static char pathname[MAXPATHLEN]; 4791592Srgrimes char *filename = *filep; 4801592Srgrimes 4811592Srgrimes /* 4821592Srgrimes * Prevent tricksters from getting around the directory restrictions 4831592Srgrimes */ 4841592Srgrimes if (strstr(filename, "/../")) 4851592Srgrimes return (EACCESS); 4861592Srgrimes 4871592Srgrimes if (*filename == '/') { 4881592Srgrimes /* 4891592Srgrimes * Allow the request if it's in one of the approved locations. 4901592Srgrimes * Special case: check the null prefix ("/") by looking 4911592Srgrimes * for length = 1 and relying on the arg. processing that 4921592Srgrimes * it's a /. 4931592Srgrimes */ 4941592Srgrimes for (dirp = dirs; dirp->name != NULL; dirp++) { 4951592Srgrimes if (dirp->len == 1 || 4961592Srgrimes (!strncmp(filename, dirp->name, dirp->len) && 4971592Srgrimes filename[dirp->len] == '/')) 4981592Srgrimes break; 4991592Srgrimes } 5001592Srgrimes /* If directory list is empty, allow access to any file */ 5011592Srgrimes if (dirp->name == NULL && dirp != dirs) 5021592Srgrimes return (EACCESS); 5031592Srgrimes if (stat(filename, &stbuf) < 0) 5041592Srgrimes return (errno == ENOENT ? ENOTFOUND : EACCESS); 5051592Srgrimes if ((stbuf.st_mode & S_IFMT) != S_IFREG) 5061592Srgrimes return (ENOTFOUND); 5071592Srgrimes if (mode == RRQ) { 5081592Srgrimes if ((stbuf.st_mode & S_IROTH) == 0) 5091592Srgrimes return (EACCESS); 5101592Srgrimes } else { 5111592Srgrimes if ((stbuf.st_mode & S_IWOTH) == 0) 5121592Srgrimes return (EACCESS); 5131592Srgrimes } 5141592Srgrimes } else { 5151592Srgrimes int err; 5161592Srgrimes 5171592Srgrimes /* 5181592Srgrimes * Relative file name: search the approved locations for it. 5196750Sjkh * Don't allow write requests that avoid directory 5201592Srgrimes * restrictions. 5211592Srgrimes */ 5221592Srgrimes 5236750Sjkh if (!strncmp(filename, "../", 3)) 5241592Srgrimes return (EACCESS); 5251592Srgrimes 5261592Srgrimes /* 5271592Srgrimes * If the file exists in one of the directories and isn't 5281592Srgrimes * readable, continue looking. However, change the error code 5291592Srgrimes * to give an indication that the file exists. 5301592Srgrimes */ 5311592Srgrimes err = ENOTFOUND; 5321592Srgrimes for (dirp = dirs; dirp->name != NULL; dirp++) { 53324193Simp snprintf(pathname, sizeof(pathname), "%s/%s", 53424193Simp dirp->name, filename); 5351592Srgrimes if (stat(pathname, &stbuf) == 0 && 5361592Srgrimes (stbuf.st_mode & S_IFMT) == S_IFREG) { 5371592Srgrimes if ((stbuf.st_mode & S_IROTH) != 0) { 5381592Srgrimes break; 5391592Srgrimes } 5401592Srgrimes err = EACCESS; 5411592Srgrimes } 5421592Srgrimes } 5431592Srgrimes if (dirp->name == NULL) 5441592Srgrimes return (err); 5451592Srgrimes *filep = filename = pathname; 5461592Srgrimes } 54784047Sobrien if (options[OPT_TSIZE].o_request) { 54884047Sobrien if (mode == RRQ) 54984047Sobrien options[OPT_TSIZE].o_reply = stbuf.st_size; 55084047Sobrien else 55184047Sobrien /* XXX Allows writes of all sizes. */ 55284047Sobrien options[OPT_TSIZE].o_reply = 55384047Sobrien atoi(options[OPT_TSIZE].o_request); 55484047Sobrien } 55520052Sjoerg fd = open(filename, mode == RRQ ? O_RDONLY : O_WRONLY|O_TRUNC); 5561592Srgrimes if (fd < 0) 5571592Srgrimes return (errno + 100); 5581592Srgrimes file = fdopen(fd, (mode == RRQ)? "r":"w"); 5591592Srgrimes if (file == NULL) { 5601592Srgrimes return errno+100; 5611592Srgrimes } 5621592Srgrimes return (0); 5631592Srgrimes} 5641592Srgrimes 56584047Sobrienint timeouts; 5661592Srgrimesjmp_buf timeoutbuf; 5671592Srgrimes 5681592Srgrimesvoid 56990333Simptimer(int sig __unused) 5701592Srgrimes{ 57184047Sobrien if (++timeouts > MAX_TIMEOUTS) 5721592Srgrimes exit(1); 5731592Srgrimes longjmp(timeoutbuf, 1); 5741592Srgrimes} 5751592Srgrimes 5761592Srgrimes/* 5771592Srgrimes * Send the requested file. 5781592Srgrimes */ 5791592Srgrimesvoid 58090333Simpxmitfile(struct formats *pf) 5811592Srgrimes{ 5821592Srgrimes struct tftphdr *dp, *r_init(); 58390333Simp struct tftphdr *ap; /* ack packet */ 58490333Simp int size, n; 58571926Sasmodai volatile unsigned short block; 5861592Srgrimes 5871592Srgrimes signal(SIGALRM, timer); 5881592Srgrimes dp = r_init(); 5891592Srgrimes ap = (struct tftphdr *)ackbuf; 5901592Srgrimes block = 1; 5911592Srgrimes do { 5921592Srgrimes size = readit(file, &dp, pf->f_convert); 5931592Srgrimes if (size < 0) { 5941592Srgrimes nak(errno + 100); 5951592Srgrimes goto abort; 5961592Srgrimes } 5971592Srgrimes dp->th_opcode = htons((u_short)DATA); 5981592Srgrimes dp->th_block = htons((u_short)block); 59984047Sobrien timeouts = 0; 6001592Srgrimes (void)setjmp(timeoutbuf); 6011592Srgrimes 6021592Srgrimessend_data: 60394299Sambrisko { 60494299Sambrisko int i, t = 1; 60594299Sambrisko for (i = 0; ; i++){ 60694299Sambrisko if (send(peer, dp, size + 4, 0) != size + 4) { 60794299Sambrisko sleep(t); 60894299Sambrisko t = (t < 32) ? t<< 1 : t; 60994299Sambrisko if (i >= 12) { 61094299Sambrisko syslog(LOG_ERR, "write: %m"); 61194299Sambrisko goto abort; 61294299Sambrisko } 61394299Sambrisko } 61494299Sambrisko break; 61594299Sambrisko } 6161592Srgrimes } 6171592Srgrimes read_ahead(file, pf->f_convert); 6181592Srgrimes for ( ; ; ) { 6191592Srgrimes alarm(rexmtval); /* read the ack */ 6201592Srgrimes n = recv(peer, ackbuf, sizeof (ackbuf), 0); 6211592Srgrimes alarm(0); 6221592Srgrimes if (n < 0) { 62331512Scharnier syslog(LOG_ERR, "read: %m"); 6241592Srgrimes goto abort; 6251592Srgrimes } 6261592Srgrimes ap->th_opcode = ntohs((u_short)ap->th_opcode); 6271592Srgrimes ap->th_block = ntohs((u_short)ap->th_block); 6281592Srgrimes 6291592Srgrimes if (ap->th_opcode == ERROR) 6301592Srgrimes goto abort; 6311592Srgrimes 6321592Srgrimes if (ap->th_opcode == ACK) { 6331592Srgrimes if (ap->th_block == block) 6341592Srgrimes break; 6351592Srgrimes /* Re-synchronize with the other side */ 6361592Srgrimes (void) synchnet(peer); 6371592Srgrimes if (ap->th_block == (block -1)) 6381592Srgrimes goto send_data; 6391592Srgrimes } 6401592Srgrimes 6411592Srgrimes } 6421592Srgrimes block++; 6431592Srgrimes } while (size == SEGSIZE); 6441592Srgrimesabort: 6451592Srgrimes (void) fclose(file); 6461592Srgrimes} 6471592Srgrimes 6481592Srgrimesvoid 64990333Simpjustquit(int sig __unused) 6501592Srgrimes{ 6511592Srgrimes exit(0); 6521592Srgrimes} 6531592Srgrimes 6541592Srgrimes 6551592Srgrimes/* 6561592Srgrimes * Receive a file. 6571592Srgrimes */ 6581592Srgrimesvoid 65990333Simprecvfile(struct formats *pf) 6601592Srgrimes{ 6611592Srgrimes struct tftphdr *dp, *w_init(); 66290333Simp struct tftphdr *ap; /* ack buffer */ 66390333Simp int n, size; 66471926Sasmodai volatile unsigned short block; 6651592Srgrimes 6661592Srgrimes signal(SIGALRM, timer); 6671592Srgrimes dp = w_init(); 6681592Srgrimes ap = (struct tftphdr *)ackbuf; 6691592Srgrimes block = 0; 6701592Srgrimes do { 67184047Sobrien timeouts = 0; 6721592Srgrimes ap->th_opcode = htons((u_short)ACK); 6731592Srgrimes ap->th_block = htons((u_short)block); 6741592Srgrimes block++; 6751592Srgrimes (void) setjmp(timeoutbuf); 6761592Srgrimessend_ack: 6771592Srgrimes if (send(peer, ackbuf, 4, 0) != 4) { 67831512Scharnier syslog(LOG_ERR, "write: %m"); 6791592Srgrimes goto abort; 6801592Srgrimes } 6811592Srgrimes write_behind(file, pf->f_convert); 6821592Srgrimes for ( ; ; ) { 6831592Srgrimes alarm(rexmtval); 6841592Srgrimes n = recv(peer, dp, PKTSIZE, 0); 6851592Srgrimes alarm(0); 6861592Srgrimes if (n < 0) { /* really? */ 68731512Scharnier syslog(LOG_ERR, "read: %m"); 6881592Srgrimes goto abort; 6891592Srgrimes } 6901592Srgrimes dp->th_opcode = ntohs((u_short)dp->th_opcode); 6911592Srgrimes dp->th_block = ntohs((u_short)dp->th_block); 6921592Srgrimes if (dp->th_opcode == ERROR) 6931592Srgrimes goto abort; 6941592Srgrimes if (dp->th_opcode == DATA) { 6951592Srgrimes if (dp->th_block == block) { 6961592Srgrimes break; /* normal */ 6971592Srgrimes } 6981592Srgrimes /* Re-synchronize with the other side */ 6991592Srgrimes (void) synchnet(peer); 7001592Srgrimes if (dp->th_block == (block-1)) 7011592Srgrimes goto send_ack; /* rexmit */ 7021592Srgrimes } 7031592Srgrimes } 7041592Srgrimes /* size = write(file, dp->th_data, n - 4); */ 7051592Srgrimes size = writeit(file, &dp, n - 4, pf->f_convert); 7061592Srgrimes if (size != (n-4)) { /* ahem */ 7071592Srgrimes if (size < 0) nak(errno + 100); 7081592Srgrimes else nak(ENOSPACE); 7091592Srgrimes goto abort; 7101592Srgrimes } 7111592Srgrimes } while (size == SEGSIZE); 7121592Srgrimes write_behind(file, pf->f_convert); 7131592Srgrimes (void) fclose(file); /* close data file */ 7141592Srgrimes 7151592Srgrimes ap->th_opcode = htons((u_short)ACK); /* send the "final" ack */ 7161592Srgrimes ap->th_block = htons((u_short)(block)); 7171592Srgrimes (void) send(peer, ackbuf, 4, 0); 7181592Srgrimes 7191592Srgrimes signal(SIGALRM, justquit); /* just quit on timeout */ 7201592Srgrimes alarm(rexmtval); 7211592Srgrimes n = recv(peer, buf, sizeof (buf), 0); /* normally times out and quits */ 7221592Srgrimes alarm(0); 7231592Srgrimes if (n >= 4 && /* if read some data */ 7241592Srgrimes dp->th_opcode == DATA && /* and got a data block */ 7251592Srgrimes block == dp->th_block) { /* then my last ack was lost */ 7261592Srgrimes (void) send(peer, ackbuf, 4, 0); /* resend final ack */ 7271592Srgrimes } 7281592Srgrimesabort: 7291592Srgrimes return; 7301592Srgrimes} 7311592Srgrimes 7321592Srgrimesstruct errmsg { 7331592Srgrimes int e_code; 7341592Srgrimes char *e_msg; 7351592Srgrimes} errmsgs[] = { 7361592Srgrimes { EUNDEF, "Undefined error code" }, 7371592Srgrimes { ENOTFOUND, "File not found" }, 7381592Srgrimes { EACCESS, "Access violation" }, 7391592Srgrimes { ENOSPACE, "Disk full or allocation exceeded" }, 7401592Srgrimes { EBADOP, "Illegal TFTP operation" }, 7411592Srgrimes { EBADID, "Unknown transfer ID" }, 7421592Srgrimes { EEXISTS, "File already exists" }, 7431592Srgrimes { ENOUSER, "No such user" }, 74484047Sobrien { EOPTNEG, "Option negotiation" }, 7451592Srgrimes { -1, 0 } 7461592Srgrimes}; 7471592Srgrimes 7481592Srgrimesstatic char * 74990333Simperrtomsg(int error) 7501592Srgrimes{ 7511592Srgrimes static char buf[20]; 75290333Simp struct errmsg *pe; 7531592Srgrimes if (error == 0) 7541592Srgrimes return "success"; 7551592Srgrimes for (pe = errmsgs; pe->e_code >= 0; pe++) 7561592Srgrimes if (pe->e_code == error) 7571592Srgrimes return pe->e_msg; 75824193Simp snprintf(buf, sizeof(buf), "error %d", error); 7591592Srgrimes return buf; 7601592Srgrimes} 7611592Srgrimes 7621592Srgrimes/* 7631592Srgrimes * Send a nak packet (error message). 7641592Srgrimes * Error code passed in is one of the 7651592Srgrimes * standard TFTP codes, or a UNIX errno 7661592Srgrimes * offset by 100. 7671592Srgrimes */ 7681592Srgrimesstatic void 76990333Simpnak(int error) 7701592Srgrimes{ 77190333Simp struct tftphdr *tp; 7721592Srgrimes int length; 77390333Simp struct errmsg *pe; 7741592Srgrimes 7751592Srgrimes tp = (struct tftphdr *)buf; 7761592Srgrimes tp->th_opcode = htons((u_short)ERROR); 7771592Srgrimes tp->th_code = htons((u_short)error); 7781592Srgrimes for (pe = errmsgs; pe->e_code >= 0; pe++) 7791592Srgrimes if (pe->e_code == error) 7801592Srgrimes break; 7811592Srgrimes if (pe->e_code < 0) { 7821592Srgrimes pe->e_msg = strerror(error - 100); 7831592Srgrimes tp->th_code = EUNDEF; /* set 'undef' errorcode */ 7841592Srgrimes } 7851592Srgrimes strcpy(tp->th_msg, pe->e_msg); 7861592Srgrimes length = strlen(pe->e_msg); 7871592Srgrimes tp->th_msg[length] = '\0'; 7881592Srgrimes length += 5; 7891592Srgrimes if (send(peer, buf, length, 0) != length) 79031512Scharnier syslog(LOG_ERR, "nak: %m"); 7911592Srgrimes} 79284047Sobrien 79394443Sume/* translate IPv4 mapped IPv6 address to IPv4 address */ 79494443Sumestatic void 79594443Sumeunmappedaddr(struct sockaddr_in6 *sin6) 79694443Sume{ 79794443Sume struct sockaddr_in *sin4; 79894443Sume u_int32_t addr; 79994443Sume int port; 80094443Sume 80194443Sume if (sin6->sin6_family != AF_INET6 || 80294443Sume !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 80394443Sume return; 80494443Sume sin4 = (struct sockaddr_in *)sin6; 80594443Sume addr = *(u_int32_t *)&sin6->sin6_addr.s6_addr[12]; 80694443Sume port = sin6->sin6_port; 80794443Sume memset(sin4, 0, sizeof(struct sockaddr_in)); 80894443Sume sin4->sin_addr.s_addr = addr; 80994443Sume sin4->sin_port = port; 81094443Sume sin4->sin_family = AF_INET; 81194443Sume sin4->sin_len = sizeof(struct sockaddr_in); 81294443Sume} 81394443Sume 81484047Sobrien/* 81584047Sobrien * Send an oack packet (option acknowledgement). 81684047Sobrien */ 81784047Sobrienstatic void 81890333Simpoack(void) 81984047Sobrien{ 82084047Sobrien struct tftphdr *tp, *ap; 82184047Sobrien int size, i, n; 82284047Sobrien char *bp; 82384047Sobrien 82484047Sobrien tp = (struct tftphdr *)buf; 82584047Sobrien bp = buf + 2; 82684047Sobrien size = sizeof(buf) - 2; 82784047Sobrien tp->th_opcode = htons((u_short)OACK); 82884047Sobrien for (i = 0; options[i].o_type != NULL; i++) { 82984047Sobrien if (options[i].o_request) { 83084047Sobrien n = snprintf(bp, size, "%s%c%d", options[i].o_type, 83184047Sobrien 0, options[i].o_reply); 83284047Sobrien bp += n+1; 83384047Sobrien size -= n+1; 83484047Sobrien if (size < 0) { 83584047Sobrien syslog(LOG_ERR, "oack: buffer overflow"); 83684047Sobrien exit(1); 83784047Sobrien } 83884047Sobrien } 83984047Sobrien } 84084047Sobrien size = bp - buf; 84184047Sobrien ap = (struct tftphdr *)ackbuf; 84284047Sobrien signal(SIGALRM, timer); 84384047Sobrien timeouts = 0; 84484047Sobrien 84584047Sobrien (void)setjmp(timeoutbuf); 84684047Sobrien if (send(peer, buf, size, 0) != size) { 84784047Sobrien syslog(LOG_INFO, "oack: %m"); 84884047Sobrien exit(1); 84984047Sobrien } 85084047Sobrien 85184047Sobrien for (;;) { 85284047Sobrien alarm(rexmtval); 85384047Sobrien n = recv(peer, ackbuf, sizeof (ackbuf), 0); 85484047Sobrien alarm(0); 85584047Sobrien if (n < 0) { 85684047Sobrien syslog(LOG_ERR, "recv: %m"); 85784047Sobrien exit(1); 85884047Sobrien } 85984047Sobrien ap->th_opcode = ntohs((u_short)ap->th_opcode); 86084047Sobrien ap->th_block = ntohs((u_short)ap->th_block); 86184047Sobrien if (ap->th_opcode == ERROR) 86284047Sobrien exit(1); 86384047Sobrien if (ap->th_opcode == ACK && ap->th_block == 0) 86484047Sobrien break; 86584047Sobrien } 86684047Sobrien} 867