137 lines
4.0 KiB
C
137 lines
4.0 KiB
C
/* $OpenBSD: talkd.c,v 1.26 2019/06/28 13:32:53 deraadt Exp $ */
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/*
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* Copyright (c) 1983 Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* The top level of the daemon, the format is heavily borrowed
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* from rwhod.c. Basically: find out who and where you are;
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* disconnect all descriptors and ttys, and then endless
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* loop on waiting for and processing requests
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*/
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#include <sys/socket.h>
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#include <protocols/talkd.h>
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#include <errno.h>
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#include <limits.h>
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#include <paths.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <syslog.h>
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#include <unistd.h>
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#include "talkd.h"
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int debug = 0;
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void timeout(int);
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long lastmsgtime;
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char hostname[HOST_NAME_MAX+1];
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#define TIMEOUT 30
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#define MAXIDLE 120
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int
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main(int argc, char *argv[])
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{
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if (getuid() != 0) {
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fprintf(stderr, "%s: getuid: not super-user\n", argv[0]);
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exit(1);
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}
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openlog("talkd", LOG_PID, LOG_DAEMON);
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if (gethostname(hostname, sizeof(hostname)) == -1) {
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syslog(LOG_ERR, "gethostname: %m");
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_exit(1);
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}
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if (chdir(_PATH_DEV) == -1) {
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syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
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_exit(1);
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}
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if (argc > 1 && strcmp(argv[1], "-d") == 0)
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debug = 1;
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init_table();
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signal(SIGALRM, timeout);
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alarm(TIMEOUT);
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if (pledge("stdio rpath wpath cpath inet dns", NULL) == -1) {
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syslog(LOG_ERR, "pledge: %m");
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_exit(1);
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}
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for (;;) {
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CTL_RESPONSE response;
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socklen_t len = sizeof(response.addr);
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CTL_MSG request;
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int cc;
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struct sockaddr ctl_addr;
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memset(&response, 0, sizeof(response));
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cc = recvfrom(STDIN_FILENO, (char *)&request,
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sizeof(request), 0, (struct sockaddr *)&response.addr,
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&len);
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if (cc != sizeof(request)) {
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if (cc == -1 && errno != EINTR)
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syslog(LOG_WARNING, "recvfrom: %m");
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continue;
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}
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/* Force NUL termination */
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request.l_name[sizeof(request.l_name) - 1] = '\0';
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request.r_name[sizeof(request.r_name) - 1] = '\0';
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request.r_tty[sizeof(request.r_tty) - 1] = '\0';
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memcpy(&ctl_addr, &request.ctl_addr, sizeof(ctl_addr));
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ctl_addr.sa_family = ntohs(request.ctl_addr.sa_family);
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ctl_addr.sa_len = sizeof(ctl_addr);
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if (ctl_addr.sa_family != AF_INET)
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continue;
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lastmsgtime = time(0);
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process_request(&request, &response);
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/* can block here, is this what I want? */
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cc = sendto(STDOUT_FILENO, (char *)&response,
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sizeof(response), 0, &ctl_addr, sizeof(ctl_addr));
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if (cc != sizeof(response))
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syslog(LOG_WARNING, "sendto: %m");
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}
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}
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void
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timeout(int signo)
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{
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int save_errno = errno;
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if (time(0) - lastmsgtime >= MAXIDLE)
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_exit(0);
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alarm(TIMEOUT);
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errno = save_errno;
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}
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