fingerd.c revision 262435
1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#ifndef lint 31static const char copyright[] = 32"@(#) Copyright (c) 1983, 1993\n\ 33 The Regents of the University of California. All rights reserved.\n"; 34#endif /* not lint */ 35 36#ifndef lint 37#if 0 38static char sccsid[] = "@(#)fingerd.c 8.1 (Berkeley) 6/4/93"; 39#endif 40static const char rcsid[] = 41 "$FreeBSD: stable/10/libexec/fingerd/fingerd.c 262435 2014-02-24 08:21:49Z brueffer $"; 42#endif /* not lint */ 43 44#include <sys/types.h> 45#include <sys/param.h> 46#include <sys/socket.h> 47#include <netinet/in.h> 48#include <netinet/tcp.h> 49#include <arpa/inet.h> 50#include <errno.h> 51 52#include <unistd.h> 53#include <syslog.h> 54#include <libutil.h> 55#include <netdb.h> 56#include <stdio.h> 57#include <stdlib.h> 58#include <string.h> 59#include "pathnames.h" 60 61void logerr(const char *, ...) __printflike(1, 2) __dead2; 62 63int 64main(int argc, char *argv[]) 65{ 66 FILE *fp; 67 int ch; 68 char *lp; 69 struct sockaddr_storage ss; 70 socklen_t sval; 71 int p[2], debug, kflag, logging, pflag, secure; 72#define ENTRIES 50 73 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog; 74 char rhost[MAXHOSTNAMELEN]; 75 76 prog = _PATH_FINGER; 77 debug = logging = kflag = pflag = secure = 0; 78 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON); 79 opterr = 0; 80 while ((ch = getopt(argc, argv, "dklp:s")) != -1) 81 switch (ch) { 82 case 'd': 83 debug = 1; 84 break; 85 case 'k': 86 kflag = 1; 87 break; 88 case 'l': 89 logging = 1; 90 break; 91 case 'p': 92 prog = optarg; 93 pflag = 1; 94 break; 95 case 's': 96 secure = 1; 97 break; 98 case '?': 99 default: 100 logerr("illegal option -- %c", optopt); 101 } 102 103 /* 104 * Enable server-side Transaction TCP. 105 */ 106 if (!debug) { 107 int one = 1; 108 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one, 109 sizeof one) < 0) { 110 logerr("setsockopt(TCP_NOPUSH) failed: %m"); 111 } 112 } 113 114 if (!fgets(line, sizeof(line), stdin)) 115 exit(1); 116 117 if (!debug && (logging || pflag)) { 118 sval = sizeof(ss); 119 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) 120 logerr("getpeername: %s", strerror(errno)); 121 realhostname_sa(rhost, sizeof rhost - 1, 122 (struct sockaddr *)&ss, sval); 123 rhost[sizeof(rhost) - 1] = '\0'; 124 if (pflag) 125 setenv("FINGERD_REMOTE_HOST", rhost, 1); 126 } 127 128 if (logging) { 129 char *t; 130 char *end; 131 132 end = memchr(line, 0, sizeof(line)); 133 if (end == NULL) { 134 if ((t = malloc(sizeof(line) + 1)) == NULL) 135 logerr("malloc: %s", strerror(errno)); 136 memcpy(t, line, sizeof(line)); 137 t[sizeof(line)] = 0; 138 } else { 139 if ((t = strdup(line)) == NULL) 140 logerr("strdup: %s", strerror(errno)); 141 } 142 for (end = t; *end; end++) 143 if (*end == '\n' || *end == '\r') 144 *end = ' '; 145 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t); 146 } 147 148 comp = &av[2]; 149 av[3] = "--"; 150 if (kflag) 151 *comp-- = "-k"; 152 for (lp = line, ap = &av[4];;) { 153 *ap = strtok(lp, " \t\r\n"); 154 if (!*ap) { 155 if (secure && ap == &av[4]) { 156 puts("must provide username\r\n"); 157 exit(1); 158 } 159 break; 160 } 161 if (secure && strchr(*ap, '@')) { 162 puts("forwarding service denied\r\n"); 163 exit(1); 164 } 165 166 /* RFC742: "/[Ww]" == "-l" */ 167 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { 168 *comp-- = "-l"; 169 } 170 else if (++ap == av + ENTRIES) { 171 *ap = NULL; 172 break; 173 } 174 lp = NULL; 175 } 176 177 if ((lp = strrchr(prog, '/')) != NULL) 178 *comp = ++lp; 179 else 180 *comp = prog; 181 if (pipe(p) < 0) 182 logerr("pipe: %s", strerror(errno)); 183 184 if (debug) { 185 fprintf(stderr, "%s", prog); 186 for (ap = comp; *ap != NULL; ++ap) 187 fprintf(stderr, " %s", *ap); 188 fprintf(stderr, "\n"); 189 } 190 191 switch(vfork()) { 192 case 0: 193 (void)close(p[0]); 194 if (p[1] != STDOUT_FILENO) { 195 (void)dup2(p[1], STDOUT_FILENO); 196 (void)close(p[1]); 197 } 198 dup2(STDOUT_FILENO, STDERR_FILENO); 199 200 execv(prog, comp); 201 write(STDERR_FILENO, prog, strlen(prog)); 202#define MSG ": cannot execute\n" 203 write(STDERR_FILENO, MSG, strlen(MSG)); 204#undef MSG 205 _exit(1); 206 case -1: 207 logerr("fork: %s", strerror(errno)); 208 } 209 (void)close(p[1]); 210 if (!(fp = fdopen(p[0], "r"))) 211 logerr("fdopen: %s", strerror(errno)); 212 while ((ch = getc(fp)) != EOF) { 213 if (ch == '\n') 214 putchar('\r'); 215 putchar(ch); 216 } 217 exit(0); 218} 219 220#include <stdarg.h> 221 222void 223logerr(const char *fmt, ...) 224{ 225 va_list ap; 226 va_start(ap, fmt); 227 (void)vsyslog(LOG_ERR, fmt, ap); 228 va_end(ap); 229 exit(1); 230 /* NOTREACHED */ 231} 232