fingerd.c revision 1.32
1/* $OpenBSD: fingerd.c,v 1.32 2006/01/17 17:51:21 millert Exp $ */ 2 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 33static 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 40static char sccsid[] = "from: @(#)fingerd.c 8.1 (Berkeley) 6/4/93"; 41#else 42static char rcsid[] = "$OpenBSD: fingerd.c,v 1.32 2006/01/17 17:51:21 millert Exp $"; 43#endif 44#endif /* not lint */ 45 46#include <sys/param.h> 47#include <sys/socket.h> 48#include <netinet/in.h> 49#include <arpa/inet.h> 50#include <errno.h> 51 52#include <unistd.h> 53#include <syslog.h> 54#include <netdb.h> 55#include <stdio.h> 56#include <stdlib.h> 57#include <string.h> 58#include <stdarg.h> 59#include "pathnames.h" 60 61void err(const char *, ...); 62void usage(void); 63 64void 65usage(void) 66{ 67 syslog(LOG_ERR, 68 "usage: fingerd [-lMmpSsu] [-P filename]"); 69 exit(2); 70} 71 72 73int 74main(int argc, char *argv[]) 75{ 76 FILE *fp; 77 int ch, ac = 2; 78 int p[2], logging, secure, user_required, short_list; 79#define ENTRIES 50 80 char **comp, *prog; 81 char **ap, *av[ENTRIES + 1], line[8192], *lp, *hname; 82 char hostbuf[MAXHOSTNAMELEN]; 83 84 prog = _PATH_FINGER; 85 logging = secure = user_required = short_list = 0; 86 openlog("fingerd", LOG_PID, LOG_DAEMON); 87 opterr = 0; 88 while ((ch = getopt(argc, argv, "sluSmMpP:")) != -1) 89 switch (ch) { 90 case 'l': 91 logging = 1; 92 break; 93 case 'P': 94 prog = optarg; 95 break; 96 case 's': 97 secure = 1; 98 break; 99 case 'u': 100 user_required = 1; 101 break; 102 case 'S': 103 if (ac < ENTRIES) { 104 short_list = 1; 105 av[ac++] = "-s"; 106 } 107 break; 108 case 'm': 109 if (ac < ENTRIES) 110 av[ac++] = "-m"; 111 break; 112 case 'M': 113 if (ac < ENTRIES) 114 av[ac++] = "-M"; 115 break; 116 case 'p': 117 if (ac < ENTRIES) 118 av[ac++] = "-p"; 119 break; 120 default: 121 usage(); 122 } 123 124 if (logging) { 125 struct sockaddr_storage ss; 126 struct sockaddr *sa; 127 socklen_t sval; 128 129 sval = sizeof(ss); 130 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) { 131 /* err("getpeername: %s", strerror(errno)); */ 132 exit(1); 133 } 134 sa = (struct sockaddr *)&ss; 135 if (getnameinfo(sa, sa->sa_len, hostbuf, sizeof(hostbuf), 136 NULL, 0, 0) != 0) { 137 strlcpy(hostbuf, "?", sizeof(hostbuf)); 138 } 139 hname = hostbuf; 140 } 141 142 if (fgets(line, sizeof(line), stdin) == NULL) { 143 if (logging) 144 syslog(LOG_NOTICE, "query from %s: %s", hname, 145 feof(stdin) ? "EOF" : strerror(errno)); 146 exit(1); 147 } 148 149 if (logging) 150 syslog(LOG_NOTICE, "query from %s: `%.*s'", hname, 151 (int)strcspn(line, "\r\n"), line); 152 153 /* 154 * Note: we assume that finger(1) will treat "--" as end of 155 * command args (ie: that it uses getopt(3)). 156 */ 157 av[ac++] = "--"; 158 comp = &av[1]; 159 for (lp = line, ap = &av[ac]; ac < ENTRIES;) { 160 if ((*ap = strtok(lp, " \t\r\n")) == NULL) 161 break; 162 lp = NULL; 163 if (secure && strchr(*ap, '@')) { 164 (void) puts("forwarding service denied\r"); 165 exit(1); 166 } 167 168 ch = strlen(*ap); 169 while ((*ap)[ch-1] == '@') 170 (*ap)[--ch] = '\0'; 171 if (**ap == '\0') 172 continue; 173 174 /* RFC1196: "/[Ww]" == "-l" */ 175 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { 176 if (!short_list) { 177 av[1] = "-l"; 178 comp = &av[0]; 179 } 180 } else { 181 ap++; 182 ac++; 183 } 184 } 185 av[ENTRIES - 1] = NULL; 186 187 if ((lp = strrchr(prog, '/'))) 188 *comp = ++lp; 189 else 190 *comp = prog; 191 192 if (user_required) { 193 for (ap = comp + 1; strcmp("--", *(ap++)); ) 194 ; 195 if (*ap == NULL) { 196 (void) puts("must provide username\r"); 197 exit(1); 198 } 199 } 200 201 if (pipe(p) < 0) 202 err("pipe: %s", strerror(errno)); 203 204 switch (vfork()) { 205 case 0: 206 (void) close(p[0]); 207 if (p[1] != 1) { 208 (void) dup2(p[1], 1); 209 (void) close(p[1]); 210 } 211 execv(prog, comp); 212 err("execv: %s: %s", prog, strerror(errno)); 213 _exit(1); 214 case -1: 215 err("fork: %s", strerror(errno)); 216 } 217 (void) close(p[1]); 218 if (!(fp = fdopen(p[0], "r"))) 219 err("fdopen: %s", strerror(errno)); 220 while ((ch = getc(fp)) != EOF) { 221 if (ch == '\n') 222 putchar('\r'); 223 putchar(ch); 224 } 225 exit(0); 226} 227 228void 229err(const char *fmt, ...) 230{ 231 va_list ap; 232 233 va_start(ap, fmt); 234 (void) vsyslog(LOG_ERR, fmt, ap); 235 va_end(ap); 236 exit(1); 237 /* NOTREACHED */ 238} 239