xref: /illumos-gate/usr/src/cmd/backup/lib/rmtlib.c (revision 2a8bcb4efb45d99ac41c94a75c396b362c414f7f)

/*LINTLIBRARY*/
/*PROTOLIB1*/
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#include <myrcmd.h>
#include <stdio.h>
#include <locale.h>
#include <ctype.h>
#include <pwd.h>
#include <string.h>
#include <signal.h>
#include <sys/mtio.h>
#include <sys/socket.h>
#include <unistd.h>
#include <netdb.h>
#include <locale.h>
#include <stdlib.h>
#include <errno.h>
#include <rmt.h>
#include <libintl.h>

#define	sigvec		sigaction
#define	sv_handler	sa_handler

#include <netinet/in.h>

extern	int32_t	tp_bsize;

#define	TS_CLOSED	0
#define	TS_OPEN		1

static int	rmtstate = TS_CLOSED;
static int	rmtape = -1;
static int	rmtversion = 0;
static char	*rmtpeer, *rmtpeer_malloc;
static uint_t	ntrec;			/* blocking factor on tape */

static char *domainname = "hsm_libdump";	/* for dgettext() */

#ifdef __STDC__
static void rmtmsg(const char *, ...);	/* package print routine */
static void rmtconnaborted(int);
static void rmtgetconn(void);
static int rmtstatus_extended(struct mtget *);
static int rmtioctl_extended(int, long);
static int map_extended_ioctl(int);
static int okname(char *);
static int rmtcall(char *, char *);
static int rmtreply(char *);
static int rmtpush(char *, uint_t);
static void rmtgets(char *, int);

static void (*print)(const char *, ...);	/* print routine */
static void (*Exit)(int);			/* exit routine */
#else
static void rmtmsg();
static void rmtconnaborted();
static void rmtgetconn();
static int okname();
static int rmtstatus_extended();
static int rmtioctl_extended();
static int map_extended_ioctl();
static int rmtcall();
static int rmtreply();
static int rmtpush();
static void rmtgets();

static void (*print)();
static void (*Exit)();
#endif

/*
 * Get a program-specific print and exit routine into
 * the package.  This is primarily for dump's benefit.
 * This routine is optional -- if not called the two
 * default to fprintf(stderr) and exit.
 */
#ifdef __STDC__
void
rmtinit(
	void (*errmsg)(const char *, ...),	/* print routine */
	void (*errexit)(int))			/* exit routine */
#else
void
rmtinit(void (*errmsg)(), void (*errexit)())
#endif
{
	print = errmsg;
	Exit = errexit;
}

int
rmthost(char *host, uint_t blocksize)
{
	struct sigvec sv;

#ifdef __STDC__
	if (print == (void (*)(const char *, ...))0)
#else
	if (print == (void (*)())0)
#endif
		print = rmtmsg;
#ifdef __STDC__
	if (Exit == (void (*)(int))0)
#else
	if (Exit == (void (*)())0)
#endif
		Exit = exit;
	if (rmtape >= 0 && rmtstate != TS_OPEN) {
		(void) close(rmtape);
		rmtape = -1;
	}
	if (rmtpeer_malloc)
		(void) free(rmtpeer_malloc);
	rmtpeer = rmtpeer_malloc = strdup(host);
	if (rmtpeer == (char *)0)
		return (0);
	ntrec = blocksize;
	sv.sa_flags = SA_RESTART;
	(void) sigemptyset(&sv.sa_mask);
	sv.sv_handler = rmtconnaborted;
	(void) sigvec(SIGPIPE, &sv, (struct sigvec *)0);
	rmtgetconn();
	if (rmtape < 0)
		return (0);
	return (1);
}

/*ARGSUSED*/
static void
rmtconnaborted(int sig)
{
	print(dgettext(domainname, "Lost connection to remote host.\n"));
	Exit(1);
}

static void
#ifdef __STDC__
rmtgetconn(void)
#else
rmtgetconn()
#endif
{
	static struct servent *sp = 0;
	static struct passwd *pwd = 0;
	char *tuser, *host, *device;
	uint_t size;

	if (sp == 0) {
		sp = getservbyname("shell", "tcp");
		if (sp == 0) {
			print(dgettext(domainname,
				"shell/tcp: unknown service\n"));
			Exit(1);
		}
		pwd = getpwuid(getuid());
		if (pwd == 0) {
			print(dgettext(domainname,
				"Cannot find password entry for uid %d\n"),
				getuid());
			Exit(1);
		}
	}
	/* Was strrchr(), be consistent with dump */
	host = strchr(rmtpeer, '@');
	if (host) {
		tuser = rmtpeer;
		*host++ = 0;
		rmtpeer = host;
		if (!okname(tuser))
			Exit(1);
	} else {
		host = rmtpeer;
		tuser = pwd->pw_name;
	}
	/* Was strrchr() - be consistent with dump and restore */
	device = strchr(host, ':');
	if (device)
		*device = 0;	/* throw away device name */
	/*
	 * myrcmd() replaces the contents of rmtpeer with a pointer
	 * to a static copy of the canonical host name.  However,
	 * since we never refer to rmtpeer again (other than to
	 * overwrite it in the next rmthost() invocation), we don't
	 * really care.
	 */
	/* LINTED sp->s_port is an int, even though port numbers are 1..65535 */
	rmtape = myrcmd(&rmtpeer, (ushort_t)sp->s_port, pwd->pw_name,
			tuser, "/etc/rmt");
	if (rmtape < 0) {
		if (*myrcmd_stderr)
			print("%s", myrcmd_stderr);
	} else {
		size = ntrec * tp_bsize;
		while (size > tp_bsize &&
		    setsockopt(rmtape, SOL_SOCKET, SO_SNDBUF, (char *)&size,
		    sizeof (size)) < 0)
			size -= tp_bsize;
	}
}

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

	for (cp = cp0; *cp; cp++) {
		c = (uchar_t)*cp;
		if (!isascii(c) || !(isalnum(c) || c == '_' || c == '-')) {
			print(dgettext(domainname,
				"invalid user name %s\n"), cp0);
			return (0);
		}
	}
	return (1);
}

int
rmtopen(char *tape, int mode)
{
	struct mtget mt;
	char buf[256];
	int fd;

	(void) snprintf(buf, sizeof (buf), "O%s\n%d\n", tape, mode);
	rmtstate = TS_OPEN;
	fd = rmtcall(tape, buf);
	if (fd != -1) {
		/* see if the rmt server supports the extended protocol */
		rmtversion = rmtioctl(-1, 0);

		/*
		 * Some rmt daemons apparently close the connection
		 * when they get a bogus ioctl.  See 1210852 (ignore
		 * the evaluation).  Make sure we can still talk to
		 * the device, re-opening it if necessary.
		 */
		if (rmtversion < 1) {
			if (rmtstatus(&mt) < 0) {
				rmtclose();
				rmtgetconn();
				rmtversion = 0;
			}
		}
	}
	return (fd);
}

void
#ifdef __STDC__
rmtclose(void)
#else
rmtclose()
#endif
{
	if (rmtstate != TS_OPEN)
		return;
	(void) rmtcall("close", "C\n");
	rmtstate = TS_CLOSED;
}

int
rmtstatus(struct mtget *mt)
{
	char *buf = (char *)mt;
	int n, i, cc;

	if (rmtversion > 0)
		return (rmtstatus_extended(mt));

	n = rmtcall("status", "S");
	if (n < 0) {
		return (-1);
	}
	if ((unsigned)n > sizeof (*mt)) {
		print(dgettext(domainname,
		    "rmtstatus: expected response size %d, got %d\n"),
		    sizeof (struct mtget), n);
		print(dgettext(domainname,
		    "This means the remote rmt daemon is not compatible.\n"));
		rmtconnaborted(0);
	}
	i = 0;
	while (i < n) {
		cc = read(rmtape, buf+i, n - i);
		if (cc <= 0)
			rmtconnaborted(0);
		i += cc;
	}
	return (n);
}

static int
rmtstatus_extended(struct mtget *mt)
{
	if ((mt->mt_type = rmtcall("status", "sT")) == -1)
		return (-1);
	mt->mt_dsreg = rmtcall("status", "sD");
	mt->mt_erreg = rmtcall("status", "sE");
	mt->mt_resid = rmtcall("status", "sR");
	mt->mt_fileno = rmtcall("status", "sF");
	mt->mt_blkno = rmtcall("status", "sB");
	mt->mt_flags = rmtcall("status", "sf");
	mt->mt_bf = rmtcall("status", "sb");
	return (0);
}

int
rmtread(char *buf, uint_t count)
{
	char line[30];
	int n, i, cc;

	(void) snprintf(line, sizeof (line), "R%d\n", count);
	n = rmtcall("read", line);
	if (n < 0) {
		return (-1);
	}
	if (n > count) {
		print(dgettext(domainname,
		    "rmtread: expected response size %d, got %d\n"),
		    count, n);
		print(dgettext(domainname,
		    "This means the remote rmt daemon is not compatible.\n"));
		rmtconnaborted(0);
	}
	i = 0;
	while (i < n) {
		cc = read(rmtape, buf+i, n - i);
		if (cc <= 0)
			rmtconnaborted(0);
		i += cc;
	}
	return (n);
}

int
rmtwrite(char *buf, uint_t count)
{
	int retval;
	char line[64];		/* numbers can get big */

	(void) snprintf(line, sizeof (line), "W%d\n", count);
	retval = rmtpush(line, strlen(line));
	if (retval <= 0)
		return (-1);

	retval = rmtpush(buf, count);
	if (retval <= 0)
		return (-1);

	return (rmtreply("write"));
}

int
rmtpush(char *buf, uint_t count)
{
	int retval;

	do {
		retval = write(rmtape, buf, count);
		buf += retval;
		count -= retval;
	} while (count && retval > 0);

	return (retval);
}

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));
}

int
rmtioctl(int cmd, long count)
{
	char buf[256];
	int xcmd;

	if (count < 0)
		return (-1);

	if ((xcmd = map_extended_ioctl(cmd)) != -1)
		return (rmtioctl_extended(xcmd, count));

	(void) snprintf(buf, sizeof (buf), "I%d\n%ld\n", cmd, count);
	return (rmtcall("ioctl", buf));
}

/*
 * Map from the standard Sun ioctl commands into the extended version,
 * if possible.
 */
static int
map_extended_ioctl(int cmd)
{
	int xcmd;

	if (rmtversion <= 0)
		return (-1);		/* extended protocol not supported */

	switch (cmd) {
	case MTRETEN:
		xcmd = 2;
		break;
	case MTERASE:
		xcmd = 3;
		break;
	case MTEOM:
		xcmd = 4;
		break;
	case MTNBSF:
		xcmd = 5;
		break;
	default:
		xcmd = -1;		/* not supported */
		break;
	}
	return (xcmd);
}

static int
rmtioctl_extended(int cmd, long count)
{
	char buf[256];

	(void) snprintf(buf, sizeof (buf), "i%d\n%ld\n", cmd, count);
	return (rmtcall("ioctl", buf));
}

static int
rmtcall(char *cmd, char *buf)
{
	if (rmtpush(buf, strlen(buf)) != strlen(buf))
		rmtconnaborted(0);
	return (rmtreply(cmd));
}

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

	rmtgets(code, sizeof (code));
	if (*code == 'E' || *code == 'F') {
		rmtgets(emsg, sizeof (emsg));
		/*
		 * don't print error message for ioctl or status;
		 * or if we are opening up a full path (i.e. device)
		 * and the tape is not loaded (EIO error)
		 */
		if (strcmp(cmd, "ioctl") != 0 &&
		    strcmp(cmd, "status") != 0 &&
		    !(cmd[0] == '/' && atoi(code + 1) == EIO))
			print("%s: %s\n", cmd, emsg);
		errno = atoi(code + 1);
		if (*code == 'F') {
			rmtstate = TS_CLOSED;
			return (-1);
		}
		return (-1);
	}
	if (*code != 'A') {
		print(dgettext(domainname,
			"Protocol to remote tape server botched (code %s?).\n"),
			code);
		rmtconnaborted(0);
	}
	return (atoi(code + 1));
}

static void
rmtgets(char *cp, int len)
{
	int i, n;

	n = recv(rmtape, cp, len-1, MSG_PEEK);
	for (i = 0; i < n; i++)
		if (cp[i] == '\n')
			break;
	n = i + 1;			/* characters to read at once */
	for (i = 0; i < len; i += n, n = 1) {
		n = read(rmtape, cp, n);
		if (n <= 0)
			rmtconnaborted(0);
		cp += n;
		if (cp[-1] == '\n') {
			cp[-1] = '\0';
			return;
		}
	}
	print(dgettext(domainname,
		"Protocol to remote tape server botched (in rmtgets).\n"));
	rmtconnaborted(0);
}

#ifdef __STDC__
#include <stdarg.h>

/* VARARGS1 */
static void
rmtmsg(const char *fmt, ...)
{
	va_list	args;

	va_start(args, fmt);
	(void) vfprintf(stderr, fmt, args);
	(void) fflush(stderr);
}
#else
#include <varargs.h>

/* VARARGS */
static void
rmtmsg(va_dcl)
{
	va_list	args;
	char	*fmt;

	va_start(args);
	fmt = va_arg(args, char *);
	(void) vfprintf(stderr, fmt, args);
	(void) fflush(stderr);
}
#endif