Reviewed by: rpaulo Approved by: rpaulo Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D6593
584 lines
13 KiB
C
584 lines
13 KiB
C
/*-
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* Copyright (c) 1983, 1988, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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* Copyright (c) 2002 Networks Associates Technology, Inc.
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* All rights reserved.
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*
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* Portions of this software were developed for the FreeBSD Project by
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* ThinkSec AS and NAI Labs, the Security Research Division of Network
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* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
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* ("CBOSS"), as part of the DARPA CHATS research program.
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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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#if 0
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#ifndef lint
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static const char copyright[] =
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"@(#) Copyright (c) 1983, 1988, 1989, 1993\n\
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The Regents of the University of California. All rights reserved.\n";
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#endif /* not lint */
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#ifndef lint
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static const char sccsid[] = "@(#)rlogind.c 8.1 (Berkeley) 6/4/93";
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#endif /* not lint */
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#endif
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* remote login server:
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* \0
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* remuser\0
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* locuser\0
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* terminal_type/speed\0
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* data
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*/
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#define FD_SETSIZE 16 /* don't need many bits for select */
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <sys/ioctl.h>
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#include <signal.h>
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#include <termios.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/tcp.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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#include <errno.h>
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#include <libutil.h>
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#include <paths.h>
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#include <poll.h>
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#include <pwd.h>
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#include <syslog.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 <unistd.h>
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#ifdef USE_BLACKLIST
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#include <blacklist.h>
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#endif
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#ifndef TIOCPKT_WINDOW
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#define TIOCPKT_WINDOW 0x80
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#endif
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#define ARGSTR "Daln"
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char *env[2];
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#define NMAX 30
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char lusername[NMAX+1], rusername[NMAX+1];
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static char term[64] = "TERM=";
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#define ENVSIZE (sizeof("TERM=")-1) /* skip null for concatenation */
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int keepalive = 1;
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int check_all = 0;
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int no_delay;
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struct passwd *pwd;
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union sockunion {
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struct sockinet {
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u_char si_len;
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u_char si_family;
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u_short si_port;
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} su_si;
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struct sockaddr_in su_sin;
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struct sockaddr_in6 su_sin6;
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};
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#define su_len su_si.si_len
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#define su_family su_si.si_family
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#define su_port su_si.si_port
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void doit(int, union sockunion *);
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int control(int, char *, int);
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void protocol(int, int);
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void cleanup(int);
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void fatal(int, char *, int);
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int do_rlogin(union sockunion *);
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void getstr(char *, int, char *);
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void setup_term(int);
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int do_krb_login(struct sockaddr_in *);
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void usage(void);
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int
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main(int argc, char *argv[])
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{
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extern int __check_rhosts_file;
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union sockunion from;
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socklen_t fromlen;
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int ch, on;
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openlog("rlogind", LOG_PID | LOG_CONS, LOG_AUTH);
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opterr = 0;
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while ((ch = getopt(argc, argv, ARGSTR)) != -1)
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switch (ch) {
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case 'D':
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no_delay = 1;
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break;
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case 'a':
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check_all = 1;
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break;
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case 'l':
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__check_rhosts_file = 0;
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break;
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case 'n':
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keepalive = 0;
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break;
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case '?':
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default:
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usage();
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break;
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}
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argc -= optind;
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argv += optind;
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fromlen = sizeof (from);
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if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
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syslog(LOG_ERR,"Can't get peer name of remote host: %m");
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fatal(STDERR_FILENO, "Can't get peer name of remote host", 1);
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}
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on = 1;
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if (keepalive &&
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setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0)
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syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
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if (no_delay &&
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setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
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syslog(LOG_WARNING, "setsockopt (TCP_NODELAY): %m");
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if (from.su_family == AF_INET)
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{
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on = IPTOS_LOWDELAY;
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if (setsockopt(0, IPPROTO_IP, IP_TOS, (char *)&on, sizeof(int)) < 0)
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syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
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}
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doit(0, &from);
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return 0;
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}
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int child;
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int netf;
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char line[MAXPATHLEN];
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int confirmed;
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struct winsize win = { 0, 0, 0, 0 };
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void
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doit(int f, union sockunion *fromp)
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{
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int master, pid, on = 1;
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int authenticated = 0;
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char hostname[2 * MAXHOSTNAMELEN + 1];
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char nameinfo[2 * INET6_ADDRSTRLEN + 1];
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char c;
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alarm(60);
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read(f, &c, 1);
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if (c != 0)
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exit(1);
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alarm(0);
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realhostname_sa(hostname, sizeof(hostname) - 1,
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(struct sockaddr *)fromp, fromp->su_len);
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/* error check ? */
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fromp->su_port = ntohs((u_short)fromp->su_port);
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hostname[sizeof(hostname) - 1] = '\0';
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{
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if ((fromp->su_family != AF_INET
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#ifdef INET6
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&& fromp->su_family != AF_INET6
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#endif
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) ||
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fromp->su_port >= IPPORT_RESERVED ||
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fromp->su_port < IPPORT_RESERVED/2) {
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getnameinfo((struct sockaddr *)fromp,
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fromp->su_len,
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nameinfo, sizeof(nameinfo), NULL, 0,
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NI_NUMERICHOST);
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/* error check ? */
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syslog(LOG_NOTICE, "Connection from %s on illegal port",
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nameinfo);
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#ifdef USE_BLACKLIST
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blacklist(1, STDIN_FILENO, "illegal port");
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#endif
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fatal(f, "Permission denied", 0);
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}
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#ifdef IP_OPTIONS
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if (fromp->su_family == AF_INET)
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{
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u_char optbuf[BUFSIZ/3];
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socklen_t optsize = sizeof(optbuf);
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int ipproto, i;
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struct protoent *ip;
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if ((ip = getprotobyname("ip")) != NULL)
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ipproto = ip->p_proto;
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else
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ipproto = IPPROTO_IP;
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if (getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf,
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&optsize) == 0 && optsize != 0) {
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for (i = 0; i < optsize; ) {
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u_char c = optbuf[i];
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if (c == IPOPT_LSRR || c == IPOPT_SSRR) {
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syslog(LOG_NOTICE,
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"Connection refused from %s with IP option %s",
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inet_ntoa(fromp->su_sin.sin_addr),
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c == IPOPT_LSRR ? "LSRR" : "SSRR");
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#ifdef USE_BLACKLIST
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blacklist(1, STDIN_FILENO, "source routing present");
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#endif
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exit(1);
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}
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if (c == IPOPT_EOL)
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break;
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i += (c == IPOPT_NOP) ? 1 : optbuf[i+1];
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}
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}
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}
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#endif
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if (do_rlogin(fromp) == 0)
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authenticated++;
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}
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if (confirmed == 0) {
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write(f, "", 1);
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confirmed = 1; /* we sent the null! */
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}
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netf = f;
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pid = forkpty(&master, line, NULL, &win);
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if (pid < 0) {
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if (errno == ENOENT)
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fatal(f, "Out of ptys", 0);
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else
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fatal(f, "Forkpty", 1);
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}
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if (pid == 0) {
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if (f > 2) /* f should always be 0, but... */
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(void) close(f);
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setup_term(0);
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if (*lusername=='-') {
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syslog(LOG_ERR, "tried to pass user \"%s\" to login",
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lusername);
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#ifdef USE_BLACKLIST
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blacklist(1, STDIN_FILENO, "invalid user");
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#endif
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fatal(STDERR_FILENO, "invalid user", 0);
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}
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#ifdef USE_BLACKLIST
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blacklist(0, STDIN_FILENO, "success");
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#endif
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if (authenticated) {
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execl(_PATH_LOGIN, "login", "-p",
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"-h", hostname, "-f", lusername, (char *)NULL);
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} else
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execl(_PATH_LOGIN, "login", "-p",
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"-h", hostname, lusername, (char *)NULL);
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fatal(STDERR_FILENO, _PATH_LOGIN, 1);
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/*NOTREACHED*/
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}
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ioctl(f, FIONBIO, &on);
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ioctl(master, FIONBIO, &on);
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ioctl(master, TIOCPKT, &on);
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signal(SIGCHLD, cleanup);
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protocol(f, master);
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signal(SIGCHLD, SIG_IGN);
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cleanup(0);
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}
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char magic[2] = { 0377, 0377 };
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char oobdata[] = {TIOCPKT_WINDOW};
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/*
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* Handle a "control" request (signaled by magic being present)
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* in the data stream. For now, we are only willing to handle
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* window size changes.
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*/
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int
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control(int pty, char *cp, int n)
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{
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struct winsize w;
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if (n < 4 + (int)sizeof(w) || cp[2] != 's' || cp[3] != 's')
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return (0);
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oobdata[0] &= ~TIOCPKT_WINDOW; /* we know he heard */
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bcopy(cp+4, (char *)&w, sizeof(w));
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w.ws_row = ntohs(w.ws_row);
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w.ws_col = ntohs(w.ws_col);
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w.ws_xpixel = ntohs(w.ws_xpixel);
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w.ws_ypixel = ntohs(w.ws_ypixel);
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(void)ioctl(pty, TIOCSWINSZ, &w);
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return (4+sizeof (w));
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}
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/*
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* rlogin "protocol" machine.
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*/
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void
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protocol(int f, int p)
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{
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char pibuf[1024+1], fibuf[1024], *pbp = NULL, *fbp = NULL;
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int pcc = 0, fcc = 0;
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int cc, nfd, n;
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char cntl;
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/*
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* Must ignore SIGTTOU, otherwise we'll stop
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* when we try and set slave pty's window shape
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* (our controlling tty is the master pty).
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*/
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(void) signal(SIGTTOU, SIG_IGN);
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send(f, oobdata, 1, MSG_OOB); /* indicate new rlogin */
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if (f > p)
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nfd = f + 1;
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else
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nfd = p + 1;
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for (;;) {
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struct pollfd set[2];
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set[0].fd = p;
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set[0].events = POLLPRI;
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set[1].fd = f;
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set[1].events = 0;
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if (fcc)
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set[0].events |= POLLOUT;
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else
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set[1].events |= POLLIN;
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if (pcc >= 0) {
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if (pcc)
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set[1].events |= POLLOUT;
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else
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set[0].events |= POLLIN;
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}
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if ((n = poll(set, 2, INFTIM)) < 0) {
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if (errno == EINTR)
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continue;
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fatal(f, "poll", 1);
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}
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if (n == 0) {
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/* shouldn't happen... */
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sleep(5);
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continue;
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}
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#define pkcontrol(c) ((c)&(TIOCPKT_FLUSHWRITE|TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))
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if (set[0].revents & POLLPRI) {
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cc = read(p, &cntl, 1);
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if (cc == 1 && pkcontrol(cntl)) {
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cntl |= oobdata[0];
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send(f, &cntl, 1, MSG_OOB);
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if (cntl & TIOCPKT_FLUSHWRITE)
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pcc = 0;
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}
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}
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if (set[1].revents & POLLIN) {
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fcc = read(f, fibuf, sizeof(fibuf));
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if (fcc < 0 && errno == EWOULDBLOCK)
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fcc = 0;
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else {
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char *cp;
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int left, n;
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if (fcc <= 0)
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break;
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fbp = fibuf;
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top:
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for (cp = fibuf; cp < fibuf+fcc-1; cp++)
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if (cp[0] == magic[0] &&
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cp[1] == magic[1]) {
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left = fcc - (cp-fibuf);
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n = control(p, cp, left);
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if (n) {
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left -= n;
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if (left > 0)
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bcopy(cp+n, cp, left);
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fcc -= n;
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goto top; /* n^2 */
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}
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}
|
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}
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|
}
|
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|
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if (set[0].revents & POLLOUT && fcc > 0) {
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cc = write(p, fbp, fcc);
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if (cc > 0) {
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fcc -= cc;
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fbp += cc;
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}
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}
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|
|
|
if (set[0].revents & POLLIN) {
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pcc = read(p, pibuf, sizeof (pibuf));
|
|
pbp = pibuf;
|
|
if (pcc < 0 && errno == EWOULDBLOCK)
|
|
pcc = 0;
|
|
else if (pcc <= 0)
|
|
break;
|
|
else if (pibuf[0] == 0) {
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pbp++, pcc--;
|
|
} else {
|
|
if (pkcontrol(pibuf[0])) {
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pibuf[0] |= oobdata[0];
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send(f, &pibuf[0], 1, MSG_OOB);
|
|
}
|
|
pcc = 0;
|
|
}
|
|
}
|
|
if (set[1].revents & POLLOUT && pcc > 0) {
|
|
cc = write(f, pbp, pcc);
|
|
if (cc > 0) {
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|
pcc -= cc;
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|
pbp += cc;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void
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|
cleanup(int signo __unused)
|
|
{
|
|
|
|
shutdown(netf, SHUT_RDWR);
|
|
exit(1);
|
|
}
|
|
|
|
void
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|
fatal(int f, char *msg, int syserr)
|
|
{
|
|
int len;
|
|
char buf[BUFSIZ], *bp = buf;
|
|
|
|
/*
|
|
* Prepend binary one to message if we haven't sent
|
|
* the magic null as confirmation.
|
|
*/
|
|
if (!confirmed)
|
|
*bp++ = '\01'; /* error indicator */
|
|
if (syserr)
|
|
len = snprintf(bp, sizeof(buf), "rlogind: %s: %s.\r\n",
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msg, strerror(errno));
|
|
else
|
|
len = snprintf(bp, sizeof(buf), "rlogind: %s.\r\n", msg);
|
|
if (len < 0)
|
|
len = 0;
|
|
(void) write(f, buf, bp + len - buf);
|
|
exit(1);
|
|
}
|
|
|
|
int
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|
do_rlogin(union sockunion *dest)
|
|
{
|
|
|
|
getstr(rusername, sizeof(rusername), "remuser too long");
|
|
getstr(lusername, sizeof(lusername), "locuser too long");
|
|
getstr(term+ENVSIZE, sizeof(term)-ENVSIZE, "Terminal type too long");
|
|
|
|
pwd = getpwnam(lusername);
|
|
if (pwd == NULL)
|
|
return (-1);
|
|
/* XXX why don't we syslog() failure? */
|
|
|
|
return (iruserok_sa(dest, dest->su_len, pwd->pw_uid == 0, rusername,
|
|
lusername));
|
|
}
|
|
|
|
void
|
|
getstr(char *buf, int cnt, char *errmsg)
|
|
{
|
|
char c;
|
|
|
|
do {
|
|
if (read(STDIN_FILENO, &c, 1) != 1)
|
|
exit(1);
|
|
if (--cnt < 0) {
|
|
#ifdef USE_BLACKLIST
|
|
blacklist(1, STDIN_FILENO, "buffer overflow");
|
|
#endif
|
|
fatal(STDOUT_FILENO, errmsg, 0);
|
|
}
|
|
*buf++ = c;
|
|
} while (c != 0);
|
|
}
|
|
|
|
extern char **environ;
|
|
|
|
void
|
|
setup_term(int fd)
|
|
{
|
|
char *cp;
|
|
char *speed;
|
|
struct termios tt, def;
|
|
|
|
cp = strchr(term + ENVSIZE, '/');
|
|
#ifndef notyet
|
|
tcgetattr(fd, &tt);
|
|
if (cp) {
|
|
*cp++ = '\0';
|
|
speed = cp;
|
|
cp = strchr(speed, '/');
|
|
if (cp)
|
|
*cp++ = '\0';
|
|
cfsetspeed(&tt, atoi(speed));
|
|
}
|
|
|
|
cfmakesane(&def);
|
|
tt.c_iflag = def.c_iflag;
|
|
tt.c_oflag = def.c_oflag;
|
|
tt.c_lflag = def.c_lflag;
|
|
tcsetattr(fd, TCSAFLUSH, &tt);
|
|
#else
|
|
if (cp) {
|
|
*cp++ = '\0';
|
|
speed = cp;
|
|
cp = strchr(speed, '/');
|
|
if (cp)
|
|
*cp++ = '\0';
|
|
tcgetattr(fd, &tt);
|
|
cfsetspeed(&tt, atoi(speed));
|
|
tcsetattr(fd, TCSAFLUSH, &tt);
|
|
}
|
|
#endif
|
|
|
|
env[0] = term;
|
|
env[1] = 0;
|
|
environ = env;
|
|
}
|
|
|
|
void
|
|
usage(void)
|
|
{
|
|
syslog(LOG_ERR, "usage: rlogind [-" ARGSTR "]");
|
|
}
|