/*      $NetBSD: dumprmt.c,v 1.37 2013/06/15 01:27:19 christos Exp $    */

/*-
 * 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.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)dumprmt.c   8.3 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: dumprmt.c,v 1.37 2013/06/15 01:27:19 christos Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/mtio.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.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 *, int);
__dead static   void    rmtconnaborted(int);
static  int     rmtgetb(void);
static  void    rmtgetconn(void);
static  void    rmtgets(char *, int);
        int     rmtread(char *, int);
static  int     rmtreply(const char *, int);
        int     rmtseek(int, int);

extern  int ntrec;              /* blocking factor on tape */

int
rmthost(const char *host)
{

        if ((rmtpeer = strdup(host)) == NULL)
                err(X_STARTUP, "strdup");
        signal(SIGPIPE, rmtconnaborted);
        rmtgetconn();
        if (rmtape < 0)
                return (0);
        return (1);
}

static void
rmtconnaborted(int dummy __unused)
{

        errx(X_ABORT, "Lost connection to remote host.");
}

void
rmtgetconn(void)
{
        char *cp;
        static struct servent *sp = NULL;
        static struct passwd *pwd = NULL;
        char *tuser, *name;
        int size, opt;

        if (sp == NULL) {
                sp = getservbyname("shell", "tcp");
                if (sp == NULL)
                        errx(X_STARTUP, "shell/tcp: unknown service");
                pwd = getpwuid(getuid());
                if (pwd == NULL)
                        errx(X_STARTUP, "who are you?");
        }
        if ((name = strdup(pwd->pw_name)) == NULL)
                err(X_STARTUP, "strdup");
        if ((cp = strchr(rmtpeer, '@')) != NULL) {
                tuser = rmtpeer;
                *cp = '\0';
                if (!okname(tuser))
                        exit(X_STARTUP);
                rmtpeer = ++cp;
        } else
                tuser = name;

        rmtape = rcmd(&rmtpeer, (u_short)sp->s_port, name, tuser, _PATH_RMT,
            (int *)0);
        (void)free(name);
        if (rmtape < 0)
                return;

        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));

        opt = IPTOS_THROUGHPUT;
        (void)setsockopt(rmtape, IPPROTO_IP, IP_TOS, &opt, sizeof (opt));

        opt = 1;
        (void)setsockopt(rmtape, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof (opt));
}

static int
okname(const char *cp0)
{
        const char *cp;
        unsigned char c;

        for (cp = cp0; *cp; cp++) {
                c = *cp;
                if (!isascii(c) || !(isalnum(c) || c == '_' || c == '-')) {
                        warnx("invalid user name: %s", cp0);
                        return (0);
                }
        }
        return (1);
}

int
rmtopen(const char *tapedevice, int mode, int verbose)
{
        char buf[256];

        (void)snprintf(buf, sizeof buf, "O%s\n%d\n", tapedevice, mode);
        rmtstate = TS_OPEN;
        return (rmtcall(tapedevice, buf, verbose));
}

void
rmtclose(void)
{

        if (rmtstate != TS_OPEN)
                return;
        rmtcall("close", "C\n", 1);
        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, 1);
        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", 1));
}

#if 0           /* XXX unused? */
void
rmtwrite0(int count)
{
        char line[30];

        (void)snprintf(line, sizeof line, "W%d\n", count);
        write(rmtape, line, strlen(line));
}

void
rmtwrite1(char *buf, int count)
{

        write(rmtape, buf, count);
}

int
rmtwrite2(void)
{

        return (rmtreply("write", 1));
}
#endif

int
rmtseek(int offset, int pos)
{
        char line[80];

        (void)snprintf(line, sizeof line, "L%d\n%d\n", offset, pos);
        return (rmtcall("seek", line, 1));
}


#if 0           /* XXX unused? */
struct mtget *
rmtstatus(void)
{
        struct  mtget mts;
        int i;
        char *cp;

        if (rmtstate != TS_OPEN)
                return (NULL);
        rmtcall("status", "S\n", 1);
        for (i = 0, cp = (char *)&mts; i < sizeof(mts); i++)
                *cp++ = rmtgetb();
        return (&mts);
}
#endif

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, 1));
}

static int
rmtcall(const char *cmd, const char *buf, int verbose)
{

        if ((size_t)write(rmtape, buf, strlen(buf)) != strlen(buf))
                rmtconnaborted(0);
        return (rmtreply(cmd, verbose));
}

static int
rmtreply(const char *cmd, int verbose)
{
        char *cp;
        char code[30], emsg[BUFSIZ];

        rmtgets(code, sizeof (code));
        if (*code == 'E' || *code == 'F') {
                rmtgets(emsg, sizeof (emsg));
                if (verbose)
                        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);
}