1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 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#include <sys/types.h> 33#include <sys/param.h> 34#include <sys/socket.h> 35#include <netinet/in.h> 36#include <netinet/tcp.h> 37#include <arpa/inet.h> 38#include <errno.h> 39 40#include <unistd.h> 41#include <syslog.h> 42#include <libutil.h> 43#include <netdb.h> 44#include <stdio.h> 45#include <stdlib.h> 46#include <string.h> 47#include "pathnames.h" 48#ifdef USE_BLACKLIST 49#include <blacklist.h> 50#endif 51 52void logerr(const char *, ...) __printflike(1, 2) __dead2; 53 54int 55main(int argc, char *argv[]) 56{ 57 FILE *fp; 58 int ch; 59 char *lp; 60 struct sockaddr_storage ss; 61 socklen_t sval; 62 int p[2], debug, kflag, logging, pflag, secure; 63#define ENTRIES 50 64 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog; 65 char rhost[MAXHOSTNAMELEN]; 66 67 prog = _PATH_FINGER; 68 debug = logging = kflag = pflag = secure = 0; 69 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON); 70 opterr = 0; 71 while ((ch = getopt(argc, argv, "dklp:s")) != -1) 72 switch (ch) { 73 case 'd': 74 debug = 1; 75 break; 76 case 'k': 77 kflag = 1; 78 break; 79 case 'l': 80 logging = 1; 81 break; 82 case 'p': 83 prog = optarg; 84 pflag = 1; 85 break; 86 case 's': 87 secure = 1; 88 break; 89 case '?': 90 default: 91 logerr("illegal option -- %c", optopt); 92 } 93 94 /* 95 * Enable server-side Transaction TCP. 96 */ 97 if (!debug) { 98 int one = 1; 99 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one, 100 sizeof one) < 0) { 101 logerr("setsockopt(TCP_NOPUSH) failed: %m"); 102 } 103 } 104 105 if (!fgets(line, sizeof(line), stdin)) 106 exit(1); 107 108 if (!debug && (logging || pflag)) { 109 sval = sizeof(ss); 110 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) 111 logerr("getpeername: %s", strerror(errno)); 112 realhostname_sa(rhost, sizeof rhost - 1, 113 (struct sockaddr *)&ss, sval); 114 rhost[sizeof(rhost) - 1] = '\0'; 115 if (pflag) 116 setenv("FINGERD_REMOTE_HOST", rhost, 1); 117 } 118 119 if (logging) { 120 char *t; 121 char *end; 122 123 end = memchr(line, 0, sizeof(line)); 124 if (end == NULL) { 125 if ((t = malloc(sizeof(line) + 1)) == NULL) 126 logerr("malloc: %s", strerror(errno)); 127 memcpy(t, line, sizeof(line)); 128 t[sizeof(line)] = 0; 129 } else { 130 if ((t = strdup(line)) == NULL) 131 logerr("strdup: %s", strerror(errno)); 132 } 133 for (end = t; *end; end++) 134 if (*end == '\n' || *end == '\r') 135 *end = ' '; 136 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t); 137 } 138 139 comp = &av[2]; 140 av[3] = "--"; 141 if (kflag) 142 *comp-- = "-k"; 143 for (lp = line, ap = &av[4];;) { 144 *ap = strtok(lp, " \t\r\n"); 145 if (!*ap) { 146 if (secure && ap == &av[4]) { 147#ifdef USE_BLACKLIST 148 blacklist(1, STDIN_FILENO, "nousername"); 149#endif 150 puts("must provide username\r\n"); 151 exit(1); 152 } 153 break; 154 } 155 if (secure && strchr(*ap, '@')) { 156#ifdef USE_BLACKLIST 157 blacklist(1, STDIN_FILENO, "noforwarding"); 158#endif 159 puts("forwarding service denied\r\n"); 160 exit(1); 161 } 162 163 /* RFC742: "/[Ww]" == "-l" */ 164 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { 165 *comp-- = "-l"; 166 } 167 else if (++ap == av + ENTRIES) { 168 *ap = NULL; 169 break; 170 } 171 lp = NULL; 172 } 173 174 if ((lp = strrchr(prog, '/')) != NULL) 175 *comp = ++lp; 176 else 177 *comp = prog; 178 if (pipe(p) < 0) 179 logerr("pipe: %s", strerror(errno)); 180 181 if (debug) { 182 fprintf(stderr, "%s", prog); 183 for (ap = comp; *ap != NULL; ++ap) 184 fprintf(stderr, " %s", *ap); 185 fprintf(stderr, "\n"); 186 } 187 188 switch(vfork()) { 189 case 0: 190 (void)close(p[0]); 191 if (p[1] != STDOUT_FILENO) { 192 (void)dup2(p[1], STDOUT_FILENO); 193 (void)close(p[1]); 194 } 195 dup2(STDOUT_FILENO, STDERR_FILENO); 196 197#ifdef USE_BLACKLIST 198 blacklist(0, STDIN_FILENO, "success"); 199#endif 200 execv(prog, comp); 201 write(STDERR_FILENO, prog, strlen(prog)); 202#define MSG ": cannot execute\n" 203 write(STDERR_FILENO, MSG, strlen(MSG)); 204#undef MSG 205 _exit(1); 206 case -1: 207 logerr("fork: %s", strerror(errno)); 208 } 209 (void)close(p[1]); 210 if (!(fp = fdopen(p[0], "r"))) 211 logerr("fdopen: %s", strerror(errno)); 212 while ((ch = getc(fp)) != EOF) { 213 if (ch == '\n') 214 putchar('\r'); 215 putchar(ch); 216 } 217 exit(0); 218} 219 220#include <stdarg.h> 221 222void 223logerr(const char *fmt, ...) 224{ 225 va_list ap; 226 va_start(ap, fmt); 227 (void)vsyslog(LOG_ERR, fmt, ap); 228 va_end(ap); 229 exit(1); 230 /* NOTREACHED */ 231} 232