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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)fingerd.c 8.1 (Berkeley) 6/4/93 34 * $FreeBSD: src/libexec/fingerd/fingerd.c,v 1.26 2008/08/04 01:25:48 cperciva Exp $ 35 * $DragonFly: src/libexec/fingerd/fingerd.c,v 1.3 2003/11/14 03:54:29 dillon Exp $ 36 */ 37 38 #include <sys/types.h> 39 #include <sys/param.h> 40 #include <sys/socket.h> 41 #include <netinet/in.h> 42 #include <netinet/tcp.h> 43 #include <arpa/inet.h> 44 #include <errno.h> 45 46 #include <unistd.h> 47 #include <syslog.h> 48 #include <libutil.h> 49 #include <netdb.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include "pathnames.h" 54 55 void logerr(const char *, ...) __printflike(1, 2) __dead2; 56 57 int 58 main(int argc, char *argv[]) 59 { 60 FILE *fp; 61 int ch; 62 char *lp; 63 struct sockaddr_storage ss; 64 socklen_t sval; 65 int p[2], logging, pflag, secure; 66 #define ENTRIES 50 67 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog; 68 char rhost[MAXHOSTNAMELEN]; 69 70 prog = _PATH_FINGER; 71 logging = pflag = secure = 0; 72 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON); 73 opterr = 0; 74 while ((ch = getopt(argc, argv, "lp:s")) != -1) 75 switch (ch) { 76 case 'l': 77 logging = 1; 78 break; 79 case 'p': 80 prog = optarg; 81 pflag = 1; 82 break; 83 case 's': 84 secure = 1; 85 break; 86 case '?': 87 default: 88 logerr("illegal option -- %c", optopt); 89 } 90 91 /* 92 * Enable server-side Transaction TCP. 93 */ 94 { 95 int one = 1; 96 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one, 97 sizeof one) < 0) { 98 logerr("setsockopt(TCP_NOPUSH) failed: %m"); 99 } 100 } 101 102 if (!fgets(line, sizeof(line), stdin)) 103 exit(1); 104 105 if (logging || pflag) { 106 sval = sizeof(ss); 107 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) 108 logerr("getpeername: %s", strerror(errno)); 109 realhostname_sa(rhost, sizeof rhost - 1, 110 (struct sockaddr *)&ss, sval); 111 rhost[sizeof(rhost) - 1] = '\0'; 112 if (pflag) 113 setenv("FINGERD_REMOTE_HOST", rhost, 1); 114 } 115 116 if (logging) { 117 char *t; 118 char *end; 119 120 end = memchr(line, 0, sizeof(line)); 121 if (end == NULL) { 122 if ((t = malloc(sizeof(line) + 1)) == NULL) 123 logerr("malloc: %s", strerror(errno)); 124 memcpy(t, line, sizeof(line)); 125 t[sizeof(line)] = 0; 126 } else { 127 if ((t = strdup(line)) == NULL) 128 logerr("strdup: %s", strerror(errno)); 129 } 130 for (end = t; *end; end++) 131 if (*end == '\n' || *end == '\r') 132 *end = ' '; 133 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t); 134 } 135 136 comp = &av[1]; 137 av[2] = "--"; 138 for (lp = line, ap = &av[3];;) { 139 *ap = strtok(lp, " \t\r\n"); 140 if (!*ap) { 141 if (secure && ap == &av[3]) { 142 puts("must provide username\r\n"); 143 exit(1); 144 } 145 break; 146 } 147 if (secure && strchr(*ap, '@')) { 148 puts("forwarding service denied\r\n"); 149 exit(1); 150 } 151 152 /* RFC742: "/[Ww]" == "-l" */ 153 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { 154 av[1] = "-l"; 155 comp = &av[0]; 156 } 157 else if (++ap == av + ENTRIES) { 158 *ap = NULL; 159 break; 160 } 161 lp = NULL; 162 } 163 164 if ((lp = strrchr(prog, '/')) != NULL) 165 *comp = ++lp; 166 else 167 *comp = prog; 168 if (pipe(p) < 0) 169 logerr("pipe: %s", strerror(errno)); 170 171 switch(vfork()) { 172 case 0: 173 close(p[0]); 174 if (p[1] != STDOUT_FILENO) { 175 dup2(p[1], STDOUT_FILENO); 176 close(p[1]); 177 } 178 dup2(STDOUT_FILENO, STDERR_FILENO); 179 180 execv(prog, comp); 181 write(STDERR_FILENO, prog, strlen(prog)); 182 #define MSG ": cannot execute\n" 183 write(STDERR_FILENO, MSG, strlen(MSG)); 184 #undef MSG 185 _exit(1); 186 case -1: 187 logerr("fork: %s", strerror(errno)); 188 } 189 close(p[1]); 190 if (!(fp = fdopen(p[0], "r"))) 191 logerr("fdopen: %s", strerror(errno)); 192 while ((ch = getc(fp)) != EOF) { 193 if (ch == '\n') 194 putchar('\r'); 195 putchar(ch); 196 } 197 exit(0); 198 } 199 200 #include <stdarg.h> 201 202 void 203 logerr(const char *fmt, ...) 204 { 205 va_list ap; 206 va_start(ap, fmt); 207 vsyslog(LOG_ERR, fmt, ap); 208 va_end(ap); 209 exit(1); 210 /* NOTREACHED */ 211 } 212