/* $OpenBSD: fingerd.c,v 1.35 2009/10/27 23:59:31 deraadt Exp $ */ /* * Copyright (c) 1983, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/param.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <errno.h> #include <err.h> #include <unistd.h> #include <syslog.h> #include <netdb.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdarg.h> #include "pathnames.h" __dead void logerr(const char *, ...); __dead void usage(void); void usage(void) { syslog(LOG_ERR, "usage: fingerd [-lMmpSsu] [-P filename]"); exit(2); } int main(int argc, char *argv[]) { FILE *fp; int ch, ac = 2; int p[2], logging, secure, user_required, short_list; #define ENTRIES 50 char **comp, *prog; char **ap, *av[ENTRIES + 1], line[8192], *lp, *hname; char hostbuf[MAXHOSTNAMELEN]; prog = _PATH_FINGER; logging = secure = user_required = short_list = 0; openlog("fingerd", LOG_PID, LOG_DAEMON); opterr = 0; while ((ch = getopt(argc, argv, "sluSmMpP:")) != -1) switch (ch) { case 'l': logging = 1; break; case 'P': prog = optarg; break; case 's': secure = 1; break; case 'u': user_required = 1; break; case 'S': if (ac < ENTRIES) { short_list = 1; av[ac++] = "-s"; } break; case 'm': if (ac < ENTRIES) av[ac++] = "-m"; break; case 'M': if (ac < ENTRIES) av[ac++] = "-M"; break; case 'p': if (ac < ENTRIES) av[ac++] = "-p"; break; default: usage(); } if (logging) { struct sockaddr_storage ss; struct sockaddr *sa; socklen_t sval; sval = sizeof(ss); if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0) err(1, "getpeername"); sa = (struct sockaddr *)&ss; if (getnameinfo(sa, sa->sa_len, hostbuf, sizeof(hostbuf), NULL, 0, 0) != 0) { strlcpy(hostbuf, "?", sizeof(hostbuf)); } hname = hostbuf; } if (fgets(line, sizeof(line), stdin) == NULL) { if (logging) syslog(LOG_NOTICE, "query from %s: %s", hname, feof(stdin) ? "EOF" : strerror(errno)); exit(1); } if (logging) syslog(LOG_NOTICE, "query from %s: `%.*s'", hname, (int)strcspn(line, "\r\n"), line); /* * Note: we assume that finger(1) will treat "--" as end of * command args (ie: that it uses getopt(3)). */ av[ac++] = "--"; comp = &av[1]; for (lp = line, ap = &av[ac]; ac < ENTRIES;) { size_t len; if ((*ap = strtok(lp, " \t\r\n")) == NULL) break; lp = NULL; if (secure && strchr(*ap, '@')) { (void) puts("forwarding service denied\r"); exit(1); } len = strlen(*ap); while (len > 0 && (*ap)[len - 1] == '@') (*ap)[--len] = '\0'; if (**ap == '\0') continue; /* RFC1196: "/[Ww]" == "-l" */ if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) { if (!short_list) { av[1] = "-l"; comp = &av[0]; } } else { ap++; ac++; } } av[ENTRIES - 1] = NULL; if ((lp = strrchr(prog, '/'))) *comp = ++lp; else *comp = prog; if (user_required) { for (ap = comp + 1; strcmp("--", *(ap++)); ) ; if (*ap == NULL) { (void) puts("must provide username\r"); exit(1); } } if (pipe(p) < 0) logerr("pipe: %s", strerror(errno)); switch (vfork()) { case 0: (void) close(p[0]); if (p[1] != 1) { (void) dup2(p[1], 1); (void) close(p[1]); } execv(prog, comp); logerr("execv: %s: %s", prog, strerror(errno)); case -1: logerr("fork: %s", strerror(errno)); } (void) close(p[1]); if (!(fp = fdopen(p[0], "r"))) logerr("fdopen: %s", strerror(errno)); while ((ch = getc(fp)) != EOF) { if (ch == '\n') putchar('\r'); putchar(ch); } exit(0); } void logerr(const char *fmt, ...) { va_list ap; va_start(ap, fmt); (void) vsyslog(LOG_ERR, fmt, ap); va_end(ap); exit(1); }