fingerd.c revision 127560
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 127560 2004-03-29 09:29:51Z pjd $"; 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); 66 67int 68main(int argc, char *argv[]) 69{ 70 FILE *fp; 71 int ch; 72 char *lp; 73 struct sockaddr_storage ss; 74 int p[2], logging, pflag, secure, sval; 75#define ENTRIES 50 76 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog; 77 char rhost[MAXHOSTNAMELEN]; 78 79 prog = _PATH_FINGER; 80 logging = pflag = secure = 0; 81 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON); 82 opterr = 0; 83 while ((ch = getopt(argc, argv, "lp:s")) != -1) 84 switch (ch) { 85 case 'l': 86 logging = 1; 87 break; 88 case 'p': 89 prog = optarg; 90 pflag = 1; 91 break; 92 case 's': 93 secure = 1; 94 break; 95 case '?': 96 default: 97 logerr("illegal option -- %c", optopt); 98 } 99 100 /* 101 * Enable server-side Transaction TCP. 102 */ 103 { 104 int one = 1; 105 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one, 106 sizeof one) < 0) { 107 logerr("setsockopt(TCP_NOPUSH) failed: %m"); 108 } 109 } 110 111 if (!fgets(line, sizeof(line), stdin)) 112 exit(1); 113 114 if (logging || pflag) { 115 sval = sizeof(ss); 116 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) 117 logerr("getpeername: %s", strerror(errno)); 118 realhostname_sa(rhost, sizeof rhost - 1, 119 (struct sockaddr *)&ss, sval); 120 rhost[sizeof(rhost) - 1] = '\0'; 121 if (pflag) 122 setenv("FINGERD_REMOTE_HOST", rhost, 1); 123 } 124 125 if (logging) { 126 char *t; 127 char *end; 128 129 end = memchr(line, 0, sizeof(line)); 130 if (end == NULL) { 131 if ((t = malloc(sizeof(line) + 1)) == NULL) 132 logerr("malloc: %s", strerror(errno)); 133 memcpy(t, line, sizeof(line)); 134 t[sizeof(line)] = 0; 135 } else { 136 if ((t = strdup(line)) == NULL) 137 logerr("strdup: %s", strerror(errno)); 138 } 139 for (end = t; *end; end++) 140 if (*end == '\n' || *end == '\r') 141 *end = ' '; 142 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t); 143 } 144 145 comp = &av[1]; 146 av[2] = "--"; 147 for (lp = line, ap = &av[3];;) { 148 *ap = strtok(lp, " \t\r\n"); 149 if (!*ap) { 150 if (secure && ap == &av[3]) { 151 puts("must provide username\r\n"); 152 exit(1); 153 } 154 break; 155 } 156 if (secure && strchr(*ap, '@')) { 157 puts("forwarding service denied\r\n"); 158 exit(1); 159 } 160 161 /* RFC742: "/[Ww]" == "-l" */ 162 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { 163 av[1] = "-l"; 164 comp = &av[0]; 165 } 166 else if (++ap == av + ENTRIES) { 167 *ap = NULL; 168 break; 169 } 170 lp = NULL; 171 } 172 173 if ((lp = strrchr(prog, '/')) != NULL) 174 *comp = ++lp; 175 else 176 *comp = prog; 177 if (pipe(p) < 0) 178 logerr("pipe: %s", strerror(errno)); 179 180 switch(vfork()) { 181 case 0: 182 (void)close(p[0]); 183 if (p[1] != STDOUT_FILENO) { 184 (void)dup2(p[1], STDOUT_FILENO); 185 (void)close(p[1]); 186 } 187 dup2(STDOUT_FILENO, STDERR_FILENO); 188 189 execv(prog, comp); 190 write(STDERR_FILENO, prog, strlen(prog)); 191#define MSG ": cannot execute\n" 192 write(STDERR_FILENO, MSG, strlen(MSG)); 193#undef MSG 194 _exit(1); 195 case -1: 196 logerr("fork: %s", strerror(errno)); 197 } 198 (void)close(p[1]); 199 if (!(fp = fdopen(p[0], "r"))) 200 logerr("fdopen: %s", strerror(errno)); 201 while ((ch = getc(fp)) != EOF) { 202 if (ch == '\n') 203 putchar('\r'); 204 putchar(ch); 205 } 206 exit(0); 207} 208 209#include <stdarg.h> 210 211void 212logerr(const char *fmt, ...) 213{ 214 va_list ap; 215 va_start(ap, fmt); 216 (void)vsyslog(LOG_ERR, fmt, ap); 217 va_end(ap); 218 exit(1); 219 /* NOTREACHED */ 220} 221