fingerd.c revision 206040
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 34#ifndef lint 35static const char copyright[] = 36"@(#) Copyright (c) 1983, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38#endif /* not lint */ 39 40#ifndef lint 41#if 0 42static char sccsid[] = "@(#)fingerd.c 8.1 (Berkeley) 6/4/93"; 43#endif 44static const char rcsid[] = 45 "$FreeBSD: head/libexec/fingerd/fingerd.c 206040 2010-04-01 13:16:32Z des $"; 46#endif /* not lint */ 47 48#include <sys/types.h> 49#include <sys/param.h> 50#include <sys/socket.h> 51#include <netinet/in.h> 52#include <netinet/tcp.h> 53#include <arpa/inet.h> 54#include <errno.h> 55 56#include <unistd.h> 57#include <syslog.h> 58#include <libutil.h> 59#include <netdb.h> 60#include <stdio.h> 61#include <stdlib.h> 62#include <string.h> 63#include "pathnames.h" 64 65void logerr(const char *, ...) __printflike(1, 2) __dead2; 66 67int 68main(int argc, char *argv[]) 69{ 70 FILE *fp; 71 int ch; 72 char *lp; 73 struct sockaddr_storage ss; 74 socklen_t sval; 75 int p[2], debug, kflag, logging, pflag, secure; 76#define ENTRIES 50 77 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog; 78 char rhost[MAXHOSTNAMELEN]; 79 80 prog = _PATH_FINGER; 81 debug = logging = kflag = pflag = secure = 0; 82 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON); 83 opterr = 0; 84 while ((ch = getopt(argc, argv, "dklp:s")) != -1) 85 switch (ch) { 86 case 'd': 87 debug = 1; 88 break; 89 case 'k': 90 kflag = 1; 91 break; 92 case 'l': 93 logging = 1; 94 break; 95 case 'p': 96 prog = optarg; 97 pflag = 1; 98 break; 99 case 's': 100 secure = 1; 101 break; 102 case '?': 103 default: 104 logerr("illegal option -- %c", optopt); 105 } 106 107 /* 108 * Enable server-side Transaction TCP. 109 */ 110 if (!debug) { 111 int one = 1; 112 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one, 113 sizeof one) < 0) { 114 logerr("setsockopt(TCP_NOPUSH) failed: %m"); 115 } 116 } 117 118 if (!fgets(line, sizeof(line), stdin)) 119 exit(1); 120 121 if (!debug && (logging || pflag)) { 122 sval = sizeof(ss); 123 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) 124 logerr("getpeername: %s", strerror(errno)); 125 realhostname_sa(rhost, sizeof rhost - 1, 126 (struct sockaddr *)&ss, sval); 127 rhost[sizeof(rhost) - 1] = '\0'; 128 if (pflag) 129 setenv("FINGERD_REMOTE_HOST", rhost, 1); 130 } 131 132 if (logging) { 133 char *t; 134 char *end; 135 136 end = memchr(line, 0, sizeof(line)); 137 if (end == NULL) { 138 if ((t = malloc(sizeof(line) + 1)) == NULL) 139 logerr("malloc: %s", strerror(errno)); 140 memcpy(t, line, sizeof(line)); 141 t[sizeof(line)] = 0; 142 } else { 143 if ((t = strdup(line)) == NULL) 144 logerr("strdup: %s", strerror(errno)); 145 } 146 for (end = t; *end; end++) 147 if (*end == '\n' || *end == '\r') 148 *end = ' '; 149 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t); 150 } 151 152 comp = &av[2]; 153 av[3] = "--"; 154 if (kflag) 155 *comp-- = "-k"; 156 for (lp = line, ap = &av[4];;) { 157 *ap = strtok(lp, " \t\r\n"); 158 if (!*ap) { 159 if (secure && ap == &av[4]) { 160 puts("must provide username\r\n"); 161 exit(1); 162 } 163 break; 164 } 165 if (secure && strchr(*ap, '@')) { 166 puts("forwarding service denied\r\n"); 167 exit(1); 168 } 169 170 /* RFC742: "/[Ww]" == "-l" */ 171 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { 172 *comp-- = "-l"; 173 } 174 else if (++ap == av + ENTRIES) { 175 *ap = NULL; 176 break; 177 } 178 lp = NULL; 179 } 180 181 if ((lp = strrchr(prog, '/')) != NULL) 182 *comp = ++lp; 183 else 184 *comp = prog; 185 if (pipe(p) < 0) 186 logerr("pipe: %s", strerror(errno)); 187 188 if (debug) { 189 fprintf(stderr, "%s", prog); 190 for (ap = comp; *ap != NULL; ++ap) 191 fprintf(stderr, " %s", *ap); 192 fprintf(stderr, "\n"); 193 } 194 195 switch(vfork()) { 196 case 0: 197 (void)close(p[0]); 198 if (p[1] != STDOUT_FILENO) { 199 (void)dup2(p[1], STDOUT_FILENO); 200 (void)close(p[1]); 201 } 202 dup2(STDOUT_FILENO, STDERR_FILENO); 203 204 execv(prog, comp); 205 write(STDERR_FILENO, prog, strlen(prog)); 206#define MSG ": cannot execute\n" 207 write(STDERR_FILENO, MSG, strlen(MSG)); 208#undef MSG 209 _exit(1); 210 case -1: 211 logerr("fork: %s", strerror(errno)); 212 } 213 (void)close(p[1]); 214 if (!(fp = fdopen(p[0], "r"))) 215 logerr("fdopen: %s", strerror(errno)); 216 while ((ch = getc(fp)) != EOF) { 217 if (ch == '\n') 218 putchar('\r'); 219 putchar(ch); 220 } 221 exit(0); 222} 223 224#include <stdarg.h> 225 226void 227logerr(const char *fmt, ...) 228{ 229 va_list ap; 230 va_start(ap, fmt); 231 (void)vsyslog(LOG_ERR, fmt, ap); 232 va_end(ap); 233 exit(1); 234 /* NOTREACHED */ 235} 236