1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #ifndef lint 33 static const char copyright[] = 34 "@(#) Copyright (c) 1983, 1993\n\ 35 The Regents of the University of California. All rights reserved.\n"; 36 #endif /* not lint */ 37 38 #ifndef lint 39 #if 0 40 static char sccsid[] = "@(#)fingerd.c 8.1 (Berkeley) 6/4/93"; 41 #endif 42 static const char rcsid[] = 43 "$FreeBSD$"; 44 #endif /* not lint */ 45 46 #include <sys/types.h> 47 #include <sys/param.h> 48 #include <sys/socket.h> 49 #include <netinet/in.h> 50 #include <netinet/tcp.h> 51 #include <arpa/inet.h> 52 #include <errno.h> 53 54 #include <unistd.h> 55 #include <syslog.h> 56 #include <libutil.h> 57 #include <netdb.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include "pathnames.h" 62 #ifdef USE_BLACKLIST 63 #include <blacklist.h> 64 #endif 65 66 void logerr(const char *, ...) __printflike(1, 2) __dead2; 67 68 int 69 main(int argc, char *argv[]) 70 { 71 FILE *fp; 72 int ch; 73 char *lp; 74 struct sockaddr_storage ss; 75 socklen_t sval; 76 int p[2], debug, kflag, logging, pflag, secure; 77 #define ENTRIES 50 78 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog; 79 char rhost[MAXHOSTNAMELEN]; 80 81 prog = _PATH_FINGER; 82 debug = logging = kflag = pflag = secure = 0; 83 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON); 84 opterr = 0; 85 while ((ch = getopt(argc, argv, "dklp:s")) != -1) 86 switch (ch) { 87 case 'd': 88 debug = 1; 89 break; 90 case 'k': 91 kflag = 1; 92 break; 93 case 'l': 94 logging = 1; 95 break; 96 case 'p': 97 prog = optarg; 98 pflag = 1; 99 break; 100 case 's': 101 secure = 1; 102 break; 103 case '?': 104 default: 105 logerr("illegal option -- %c", optopt); 106 } 107 108 /* 109 * Enable server-side Transaction TCP. 110 */ 111 if (!debug) { 112 int one = 1; 113 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one, 114 sizeof one) < 0) { 115 logerr("setsockopt(TCP_NOPUSH) failed: %m"); 116 } 117 } 118 119 if (!fgets(line, sizeof(line), stdin)) 120 exit(1); 121 122 if (!debug && (logging || pflag)) { 123 sval = sizeof(ss); 124 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) 125 logerr("getpeername: %s", strerror(errno)); 126 realhostname_sa(rhost, sizeof rhost - 1, 127 (struct sockaddr *)&ss, sval); 128 rhost[sizeof(rhost) - 1] = '\0'; 129 if (pflag) 130 setenv("FINGERD_REMOTE_HOST", rhost, 1); 131 } 132 133 if (logging) { 134 char *t; 135 char *end; 136 137 end = memchr(line, 0, sizeof(line)); 138 if (end == NULL) { 139 if ((t = malloc(sizeof(line) + 1)) == NULL) 140 logerr("malloc: %s", strerror(errno)); 141 memcpy(t, line, sizeof(line)); 142 t[sizeof(line)] = 0; 143 } else { 144 if ((t = strdup(line)) == NULL) 145 logerr("strdup: %s", strerror(errno)); 146 } 147 for (end = t; *end; end++) 148 if (*end == '\n' || *end == '\r') 149 *end = ' '; 150 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t); 151 } 152 153 comp = &av[2]; 154 av[3] = "--"; 155 if (kflag) 156 *comp-- = "-k"; 157 for (lp = line, ap = &av[4];;) { 158 *ap = strtok(lp, " \t\r\n"); 159 if (!*ap) { 160 if (secure && ap == &av[4]) { 161 #ifdef USE_BLACKLIST 162 blacklist(1, STDIN_FILENO, "nousername"); 163 #endif 164 puts("must provide username\r\n"); 165 exit(1); 166 } 167 break; 168 } 169 if (secure && strchr(*ap, '@')) { 170 #ifdef USE_BLACKLIST 171 blacklist(1, STDIN_FILENO, "noforwarding"); 172 #endif 173 puts("forwarding service denied\r\n"); 174 exit(1); 175 } 176 177 /* RFC742: "/[Ww]" == "-l" */ 178 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { 179 *comp-- = "-l"; 180 } 181 else if (++ap == av + ENTRIES) { 182 *ap = NULL; 183 break; 184 } 185 lp = NULL; 186 } 187 188 if ((lp = strrchr(prog, '/')) != NULL) 189 *comp = ++lp; 190 else 191 *comp = prog; 192 if (pipe(p) < 0) 193 logerr("pipe: %s", strerror(errno)); 194 195 if (debug) { 196 fprintf(stderr, "%s", prog); 197 for (ap = comp; *ap != NULL; ++ap) 198 fprintf(stderr, " %s", *ap); 199 fprintf(stderr, "\n"); 200 } 201 202 switch(vfork()) { 203 case 0: 204 (void)close(p[0]); 205 if (p[1] != STDOUT_FILENO) { 206 (void)dup2(p[1], STDOUT_FILENO); 207 (void)close(p[1]); 208 } 209 dup2(STDOUT_FILENO, STDERR_FILENO); 210 211 #ifdef USE_BLACKLIST 212 blacklist(0, STDIN_FILENO, "success"); 213 #endif 214 execv(prog, comp); 215 write(STDERR_FILENO, prog, strlen(prog)); 216 #define MSG ": cannot execute\n" 217 write(STDERR_FILENO, MSG, strlen(MSG)); 218 #undef MSG 219 _exit(1); 220 case -1: 221 logerr("fork: %s", strerror(errno)); 222 } 223 (void)close(p[1]); 224 if (!(fp = fdopen(p[0], "r"))) 225 logerr("fdopen: %s", strerror(errno)); 226 while ((ch = getc(fp)) != EOF) { 227 if (ch == '\n') 228 putchar('\r'); 229 putchar(ch); 230 } 231 exit(0); 232 } 233 234 #include <stdarg.h> 235 236 void 237 logerr(const char *fmt, ...) 238 { 239 va_list ap; 240 va_start(ap, fmt); 241 (void)vsyslog(LOG_ERR, fmt, ap); 242 va_end(ap); 243 exit(1); 244 /* NOTREACHED */ 245 } 246