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 31 static 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 38 static char sccsid[] = "@(#)fingerd.c 8.1 (Berkeley) 6/4/93"; 39 #endif 40 static const char rcsid[] = 41 "$FreeBSD$"; 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 #ifdef USE_BLACKLIST 61 #include <blacklist.h> 62 #endif 63 64 void logerr(const char *, ...) __printflike(1, 2) __dead2; 65 66 int 67 main(int argc, char *argv[]) 68 { 69 FILE *fp; 70 int ch; 71 char *lp; 72 struct sockaddr_storage ss; 73 socklen_t sval; 74 int p[2], debug, kflag, logging, pflag, secure; 75 #define ENTRIES 50 76 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog; 77 char rhost[MAXHOSTNAMELEN]; 78 79 prog = _PATH_FINGER; 80 debug = logging = kflag = pflag = secure = 0; 81 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON); 82 opterr = 0; 83 while ((ch = getopt(argc, argv, "dklp:s")) != -1) 84 switch (ch) { 85 case 'd': 86 debug = 1; 87 break; 88 case 'k': 89 kflag = 1; 90 break; 91 case 'l': 92 logging = 1; 93 break; 94 case 'p': 95 prog = optarg; 96 pflag = 1; 97 break; 98 case 's': 99 secure = 1; 100 break; 101 case '?': 102 default: 103 logerr("illegal option -- %c", optopt); 104 } 105 106 /* 107 * Enable server-side Transaction TCP. 108 */ 109 if (!debug) { 110 int one = 1; 111 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one, 112 sizeof one) < 0) { 113 logerr("setsockopt(TCP_NOPUSH) failed: %m"); 114 } 115 } 116 117 if (!fgets(line, sizeof(line), stdin)) 118 exit(1); 119 120 if (!debug && (logging || pflag)) { 121 sval = sizeof(ss); 122 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) 123 logerr("getpeername: %s", strerror(errno)); 124 realhostname_sa(rhost, sizeof rhost - 1, 125 (struct sockaddr *)&ss, sval); 126 rhost[sizeof(rhost) - 1] = '\0'; 127 if (pflag) 128 setenv("FINGERD_REMOTE_HOST", rhost, 1); 129 } 130 131 if (logging) { 132 char *t; 133 char *end; 134 135 end = memchr(line, 0, sizeof(line)); 136 if (end == NULL) { 137 if ((t = malloc(sizeof(line) + 1)) == NULL) 138 logerr("malloc: %s", strerror(errno)); 139 memcpy(t, line, sizeof(line)); 140 t[sizeof(line)] = 0; 141 } else { 142 if ((t = strdup(line)) == NULL) 143 logerr("strdup: %s", strerror(errno)); 144 } 145 for (end = t; *end; end++) 146 if (*end == '\n' || *end == '\r') 147 *end = ' '; 148 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t); 149 } 150 151 comp = &av[2]; 152 av[3] = "--"; 153 if (kflag) 154 *comp-- = "-k"; 155 for (lp = line, ap = &av[4];;) { 156 *ap = strtok(lp, " \t\r\n"); 157 if (!*ap) { 158 if (secure && ap == &av[4]) { 159 #ifdef USE_BLACKLIST 160 blacklist(1, STDIN_FILENO, "nousername"); 161 #endif 162 puts("must provide username\r\n"); 163 exit(1); 164 } 165 break; 166 } 167 if (secure && strchr(*ap, '@')) { 168 #ifdef USE_BLACKLIST 169 blacklist(1, STDIN_FILENO, "noforwarding"); 170 #endif 171 puts("forwarding service denied\r\n"); 172 exit(1); 173 } 174 175 /* RFC742: "/[Ww]" == "-l" */ 176 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { 177 *comp-- = "-l"; 178 } 179 else if (++ap == av + ENTRIES) { 180 *ap = NULL; 181 break; 182 } 183 lp = NULL; 184 } 185 186 if ((lp = strrchr(prog, '/')) != NULL) 187 *comp = ++lp; 188 else 189 *comp = prog; 190 if (pipe(p) < 0) 191 logerr("pipe: %s", strerror(errno)); 192 193 if (debug) { 194 fprintf(stderr, "%s", prog); 195 for (ap = comp; *ap != NULL; ++ap) 196 fprintf(stderr, " %s", *ap); 197 fprintf(stderr, "\n"); 198 } 199 200 switch(vfork()) { 201 case 0: 202 (void)close(p[0]); 203 if (p[1] != STDOUT_FILENO) { 204 (void)dup2(p[1], STDOUT_FILENO); 205 (void)close(p[1]); 206 } 207 dup2(STDOUT_FILENO, STDERR_FILENO); 208 209 #ifdef USE_BLACKLIST 210 blacklist(0, STDIN_FILENO, "success"); 211 #endif 212 execv(prog, comp); 213 write(STDERR_FILENO, prog, strlen(prog)); 214 #define MSG ": cannot execute\n" 215 write(STDERR_FILENO, MSG, strlen(MSG)); 216 #undef MSG 217 _exit(1); 218 case -1: 219 logerr("fork: %s", strerror(errno)); 220 } 221 (void)close(p[1]); 222 if (!(fp = fdopen(p[0], "r"))) 223 logerr("fdopen: %s", strerror(errno)); 224 while ((ch = getc(fp)) != EOF) { 225 if (ch == '\n') 226 putchar('\r'); 227 putchar(ch); 228 } 229 exit(0); 230 } 231 232 #include <stdarg.h> 233 234 void 235 logerr(const char *fmt, ...) 236 { 237 va_list ap; 238 va_start(ap, fmt); 239 (void)vsyslog(LOG_ERR, fmt, ap); 240 va_end(ap); 241 exit(1); 242 /* NOTREACHED */ 243 } 244