text: /*-
   * SPDX-License-Identifier: BSD-3-Clause
   *
   * Copyright (c) 1980, 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.
   */
  
  #ifndef lint
  #if 0
  static char sccsid[] = "@(#)dumprmt.c	8.3 (Berkeley) 4/28/95";
  #endif
  static const char rcsid[] =
    "$FreeBSD$";
  #endif /* not lint */
  
  #include <sys/param.h>
  #include <sys/mtio.h>
  #include <sys/socket.h>
  #include <sys/time.h>
  
  #include <ufs/ufs/dinode.h>
  
  #include <netinet/in.h>
  #include <netinet/in_systm.h>
  #include <netinet/ip.h>
  #include <netinet/tcp.h>
  
  #include <protocols/dumprestore.h>
  
  #include <ctype.h>
  #include <netdb.h>
  #include <pwd.h>
  #include <stdio.h>
  #include <limits.h>
  #include <errno.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #include "pathnames.h"
  #include "dump.h"
  
  #define	TS_CLOSED	0
  #define	TS_OPEN		1
  
  static	int rmtstate = TS_CLOSED;
  static	int rmtape;
  static	char *rmtpeer;
  
  static	int okname(const char *);
  static	int rmtcall(const char *, const char *);
  static	void rmtconnaborted(int);
  static	int rmtgetb(void);
  static	void rmtgetconn(void);
  static	void rmtgets(char *, int);
  static	int rmtreply(const char *);
  
  static	int errfd = -1;
  extern	int ntrec;		/* blocking factor on tape */
  
  int
  rmthost(const char *host)
  {
  
  	rmtpeer = strdup(host);
  	if (rmtpeer == NULL)
  		return (0);
  	signal(SIGPIPE, rmtconnaborted);
  	rmtgetconn();
  	if (rmtape < 0)
  		return (0);
  	return (1);
  }
  
  static void
  rmtconnaborted(int sig __unused)
  {
  	msg("Lost connection to remote host.\n");
  	if (errfd != -1) {
  		fd_set r;
  		struct timeval t;
  
  		FD_ZERO(&r);
  		FD_SET(errfd, &r);
  		t.tv_sec = 0;
  		t.tv_usec = 0;
  		if (select(errfd + 1, &r, NULL, NULL, &t)) {
  			int i;
  			char buf[2048];
  
  			if ((i = read(errfd, buf, sizeof(buf) - 1)) > 0) {
  				buf[i] = '\0';
  				msg("on %s: %s%s", rmtpeer, buf,
  					buf[i - 1] == '\n' ? "" : "\n");
  			}
  		}
  	}
  
  	exit(X_ABORT);
  }
  
  void
  rmtgetconn(void)
  {
  	char *cp;
  	const char *rmt;
  	static struct servent *sp = NULL;
  	static struct passwd *pwd = NULL;
  	char *tuser;
  	int size;
  	int throughput;
  	int on;
  
  	if (sp == NULL) {
  		sp = getservbyname("shell", "tcp");
  		if (sp == NULL) {
  			msg("shell/tcp: unknown service\n");
  			exit(X_STARTUP);
  		}
  		pwd = getpwuid(getuid());
  		if (pwd == NULL) {
  			msg("who are you?\n");
  			exit(X_STARTUP);
  		}
  	}
  	if ((cp = strchr(rmtpeer, '@')) != NULL) {
  		tuser = rmtpeer;
  		*cp = '\0';
  		if (!okname(tuser))
  			exit(X_STARTUP);
  		rmtpeer = ++cp;
  	} else
  		tuser = pwd->pw_name;
  	if ((rmt = getenv("RMT")) == NULL)
  		rmt = _PATH_RMT;
  	msg("%s", "");
  	rmtape = rcmd(&rmtpeer, (u_short)sp->s_port, pwd->pw_name,
  		      tuser, rmt, &errfd);
  	if (rmtape < 0) {
  		msg("login to %s as %s failed.\n", rmtpeer, tuser);
  		return;
  	}
  	(void)fprintf(stderr, "Connection to %s established.\n", rmtpeer);
  	size = ntrec * TP_BSIZE;
  	if (size > 60 * 1024)		/* XXX */
  		size = 60 * 1024;
  	/* Leave some space for rmt request/response protocol */
  	size += 2 * 1024;
  	while (size > TP_BSIZE &&
  	    setsockopt(rmtape, SOL_SOCKET, SO_SNDBUF, &size, sizeof (size)) < 0)
  		    size -= TP_BSIZE;
  	(void)setsockopt(rmtape, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size));
  	throughput = IPTOS_THROUGHPUT;
  	if (setsockopt(rmtape, IPPROTO_IP, IP_TOS,
  	    &throughput, sizeof(throughput)) < 0)
  		perror("IP_TOS:IPTOS_THROUGHPUT setsockopt");
  	on = 1;
  	if (setsockopt(rmtape, IPPROTO_TCP, TCP_NODELAY, &on, sizeof (on)) < 0)
  		perror("TCP_NODELAY setsockopt");
  }
  
  static int
  okname(const char *cp0)
  {
  	const char *cp;
  	int c;
  
  	for (cp = cp0; *cp; cp++) {
  		c = *cp;
  		if (!isascii(c) || !(isalnum(c) || c == '_' || c == '-')) {
  			msg("invalid user name %s\n", cp0);
  			return (0);
  		}
  	}
  	return (1);
  }
  
  int
  rmtopen(const char *tape, int mode)
  {
  	char buf[256];
  
  	(void)snprintf(buf, sizeof (buf), "O%.226s\n%d\n", tape, mode);
  	rmtstate = TS_OPEN;
  	return (rmtcall(tape, buf));
  }
  
  void
  rmtclose(void)
  {
  
  	if (rmtstate != TS_OPEN)
  		return;
  	rmtcall("close", "C\n");
  	rmtstate = TS_CLOSED;
  }
  
  int
  rmtread(char *buf, int count)
  {
  	char line[30];
  	int n, i, cc;
  
  	(void)snprintf(line, sizeof (line), "R%d\n", count);
  	n = rmtcall("read", line);
  	if (n < 0)
  		/* rmtcall() properly sets errno for us on errors. */
  		return (n);
  	for (i = 0; i < n; i += cc) {
  		cc = read(rmtape, buf+i, n - i);
  		if (cc <= 0)
  			rmtconnaborted(0);
  	}
  	return (n);
  }
  
  int
  rmtwrite(const char *buf, int count)
  {
  	char line[30];
  
  	(void)snprintf(line, sizeof (line), "W%d\n", count);
  	write(rmtape, line, strlen(line));
  	write(rmtape, buf, count);
  	return (rmtreply("write"));
  }
  
  void
  rmtwrite0(int count)
  {
  	char line[30];
  
  	(void)snprintf(line, sizeof (line), "W%d\n", count);
  	write(rmtape, line, strlen(line));
  }
  
  void
  rmtwrite1(const char *buf, int count)
  {
  
  	write(rmtape, buf, count);
  }
  
  int
  rmtwrite2(void)
  {
  
  	return (rmtreply("write"));
  }
  
  int
  rmtseek(int offset, int pos)	/* XXX off_t ? */
  {
  	char line[80];
  
  	(void)snprintf(line, sizeof (line), "L%d\n%d\n", offset, pos);
  	return (rmtcall("seek", line));
  }
  
  struct	mtget mts;
  
  struct mtget *
  rmtstatus(void)
  {
  	int i;
  	char *cp;
  
  	if (rmtstate != TS_OPEN)
  		return (NULL);
  	rmtcall("status", "S\n");
  	for (i = 0, cp = (char *)&mts; i < sizeof(mts); i++)
  		*cp++ = rmtgetb();
  	return (&mts);
  }
  
  int
  rmtioctl(int cmd, int count)
  {
  	char buf[256];
  
  	if (count < 0)
  		return (-1);
  	(void)snprintf(buf, sizeof (buf), "I%d\n%d\n", cmd, count);
  	return (rmtcall("ioctl", buf));
  }
  
  static int
  rmtcall(const char *cmd, const char *buf)
  {
  
  	if (write(rmtape, buf, strlen(buf)) != strlen(buf))
  		rmtconnaborted(0);
  	return (rmtreply(cmd));
  }
  
  static int
  rmtreply(const char *cmd)
  {
  	char *cp;
  	char code[30], emsg[BUFSIZ];
  
  	rmtgets(code, sizeof (code));
  	if (*code == 'E' || *code == 'F') {
  		rmtgets(emsg, sizeof (emsg));
  		msg("%s: %s", cmd, emsg);
  		errno = atoi(code + 1);
  		if (*code == 'F')
  			rmtstate = TS_CLOSED;
  		return (-1);
  	}
  	if (*code != 'A') {
  		/* Kill trailing newline */
  		cp = code + strlen(code);
  		if (cp > code && *--cp == '\n')
  			*cp = '\0';
  
  		msg("Protocol to remote tape server botched (code \"%s\").\n",
  		    code);
  		rmtconnaborted(0);
  	}
  	return (atoi(code + 1));
  }
  
  int
  rmtgetb(void)
  {
  	char c;
  
  	if (read(rmtape, &c, 1) != 1)
  		rmtconnaborted(0);
  	return (c);
  }
  
  /* Get a line (guaranteed to have a trailing newline). */
  void
  rmtgets(char *line, int len)
  {
  	char *cp = line;
  
  	while (len > 1) {
  		*cp = rmtgetb();
  		if (*cp == '\n') {
  			cp[1] = '\0';
  			return;
  		}
  		cp++;
  		len--;
  	}
  	*cp = '\0';
  	msg("Protocol to remote tape server botched.\n");
  	msg("(rmtgets got \"%s\").\n", line);
  	rmtconnaborted(0);
  }
  