text: /*
   * Copyright (c) 1999 Martin Blapp
   * 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.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
   *
   * $FreeBSD: src/usr.sbin/rpc.umntall/mounttab.c,v 1.2.2.1 2001/12/13 01:27:20 iedowse Exp $
   */
  
  #include <sys/syslog.h>
  
  #include <rpc/rpc.h>
  #include <vfs/nfs/rpcv2.h>
  
  #include <err.h>
  #include <errno.h>
  #include <limits.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #include "mounttab.h"
  
  struct mtablist *mtabhead;
  
  static void badline(const char *field, const char *bad);
  
  /*
   * Add an entry to PATH_MOUNTTAB for each mounted NFS filesystem,
   * so the client can notify the NFS server even after reboot.
   */
  int
  add_mtab(char *hostp, char *dirp) {
  	FILE *mtabfile;
  
  	if ((mtabfile = fopen(PATH_MOUNTTAB, "a")) == NULL)
  		return (0);
  	else {
  		fprintf(mtabfile, "%ld\t%s\t%s\n",
  		    (long)time(NULL), hostp, dirp);
  		fclose(mtabfile);
  		return (1);
  	}
  }
  
  /*
   * Read mounttab line for line and return struct mtablist.
   */
  int
  read_mtab(void) {
  	struct mtablist **mtabpp, *mtabp;
  	char *hostp, *dirp, *cp;
  	char str[STRSIZ];
  	char *timep, *endp;
  	time_t mnt_time;
  	u_long ultmp;
  	FILE *mtabfile;
  
  	if ((mtabfile = fopen(PATH_MOUNTTAB, "r")) == NULL) {
  		if (errno == ENOENT)
  			return (0);
  		else {
  			syslog(LOG_ERR, "can't open %s", PATH_MOUNTTAB);
  			return (0);
  		}
  	}
  	mnt_time = 0;
  	mtabpp = &mtabhead;
  	while (fgets(str, STRSIZ, mtabfile) != NULL) {
  		cp = str;
  		errno = 0;
  		if (*cp == '#' || *cp == ' ' || *cp == '\n')
  			continue;
  		timep = strsep(&cp, " \t\n");
  		if (timep == NULL || *timep == '\0') {
  			badline("time", timep);
  			continue;
  		}
  		hostp = strsep(&cp, " \t\n");
  		if (hostp == NULL || *hostp == '\0') {
  			badline("host", hostp);
  			continue;
  		}
  		dirp = strsep(&cp, " \t\n");
  		if (dirp == NULL || *dirp == '\0') {
  			badline("dir", dirp);
  			continue;
  		}
  		ultmp = strtoul(timep, &endp, 10);
  		if (ultmp == ULONG_MAX || *endp != '\0') {
  			badline("time", timep);
  			continue;
  		}
  		mnt_time = ultmp;
  		if ((mtabp = malloc(sizeof (struct mtablist))) == NULL) {
  			syslog(LOG_ERR, "malloc");
  			fclose(mtabfile);
  			return (0);
  		}
  		mtabp->mtab_time = mnt_time;
  		memmove(mtabp->mtab_host, hostp, RPCMNT_NAMELEN);
  		mtabp->mtab_host[RPCMNT_NAMELEN - 1] = '\0';
  		memmove(mtabp->mtab_dirp, dirp, RPCMNT_PATHLEN);
  		mtabp->mtab_dirp[RPCMNT_PATHLEN - 1] = '\0';
  		mtabp->mtab_next = NULL;
  		*mtabpp = mtabp;
  		mtabpp = &mtabp->mtab_next;
  	}
  	fclose(mtabfile);
  	return (1);
  }
  
  /*
   * Rewrite PATH_MOUNTTAB from scratch and skip bad entries.
   * Unlink PATH_MOUNTAB if no entry is left.
   */
  int
  write_mtab(int verbose) {
  	struct mtablist *mtabp, *mp;
  	FILE *mtabfile;
  	int line;
  
  	if ((mtabfile = fopen(PATH_MOUNTTAB, "w")) == NULL) {
  		syslog(LOG_ERR, "can't write to %s", PATH_MOUNTTAB);
  			return (0);
  	}
  	line = 0;
  	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
  		if (mtabp->mtab_host[0] == '\0')
  			continue;
  		/* Skip if a later (hence more recent) entry is identical. */
  		for (mp = mtabp->mtab_next; mp != NULL; mp = mp->mtab_next)
  			if (strcmp(mtabp->mtab_host, mp->mtab_host) == 0 &&
  			    strcmp(mtabp->mtab_dirp, mp->mtab_dirp) == 0)
  				break;
  		if (mp != NULL)
  			continue;
  
  		fprintf(mtabfile, "%ld\t%s\t%s\n",
  		    (long)mtabp->mtab_time, mtabp->mtab_host,
  		    mtabp->mtab_dirp);
  		if (verbose)
  			warnx("write mounttab entry %s:%s",
  			    mtabp->mtab_host, mtabp->mtab_dirp);
  		line++;
  	}
  	fclose(mtabfile);
  	if (line == 0) {
  		if (unlink(PATH_MOUNTTAB) == -1) {
  			syslog(LOG_ERR, "can't remove %s", PATH_MOUNTTAB);
  			return (0);
  		}
  	}
  	return (1);
  }
  
  /*
   * Mark the entries as clean where RPC calls have been done successfully.
   */
  void
  clean_mtab(char *hostp, char *dirp, int verbose) {
  	struct mtablist *mtabp;
  	char *host;
  
  	/* Copy hostp in case it points to an entry that we are zeroing out. */
  	host = strdup(hostp);
  	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
  		if (strcmp(mtabp->mtab_host, host) != 0)
  			continue;
  		if (dirp != NULL && strcmp(mtabp->mtab_dirp, dirp) != 0)
  			continue;
  
  		if (verbose)
  			warnx("delete mounttab entry%s %s:%s",
  			    (dirp == NULL) ? " by host" : "",
  			    mtabp->mtab_host, mtabp->mtab_dirp);
  		bzero(mtabp->mtab_host, RPCMNT_NAMELEN);
  	}
  	free(host);
  }
  
  /*
   * Free struct mtablist mtab.
   */
  void
  free_mtab(void) {
  	struct mtablist *mtabp;
  
  	while ((mtabp = mtabhead) != NULL) {
  		mtabhead = mtabhead->mtab_next;
  		free(mtabp);
  	}
  }
  
  /*
   * Print bad lines to syslog.
   */
  static void
  badline(const char *field, const char *bad) {
  	syslog(LOG_ERR, "bad mounttab %s field '%s'", field,
  	    (bad == NULL) ? "<null>" : bad);
  }
  