#ident "$Id$"
/*
 * parse_hesiod.c
 *
 * Module for Linux automountd to parse a hesiod filesystem entry.
 */

#include <sys/types.h>
#include <ctype.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>

#define MODULE_PARSE
#include "automount.h"

#define MODPREFIX "parse(hesiod): "
int parse_version = AUTOFS_PARSE_VERSION; /* Required by protocol */

#define HESIOD_LEN 512

/* Break out the fields in an AFS record of the form:
   "AFS /afs/athena/mit/tytso w /mit/tytso-afs" */
static int parse_afs(const char *filsysline, const char *name, int name_len,
                     char *source, int source_len,
                     char *options, int options_len)
{
  const char *p;
  int i;

  p = filsysline;

  while(isspace(*p)) p++;    /* Skip whitespace. */
  while(!isspace(*p)) p++;   /* Skip the filesystem type. */
  while(isspace(*p)) p++;    /* Skip whitespace. */

  /* Isolate the source for this AFS fs. */
  for(i = 0; (!isspace(p[i]) && i < source_len); i++) {
    source[i] = p[i];
  }
  source[i] = 0;
  p += i;

  while((*p) && (isspace(*p))) p++;    /* Skip whitespace. */

  /* Isolate the source for this AFS fs. */
  for(i = 0; (!isspace(p[i]) && i < options_len); i++) {
    options[i] = p[i];
  }
  options[i] = 0;

  if(!strcmp(options, "r"))             /* Hack for "r" or "w" options. */
    strcpy(options, "ro");
  if(!strcmp(options, "w"))
    strcpy(options, "rw");

  syslog(LOG_DEBUG, MODPREFIX "parsing AFS record gives '%s'->'%s' with options"         " '%s'", name, source, options);

  return 0;
}

/* Break out the fields in an NFS record of the form:
   "NFS /export/src nelson.tx.ncsu.edu w /ncsu/tx-src" */
static int parse_nfs(const char *filsysline, const char *name, int name_len,
                     char *source, int source_len,
                     char *options, int options_len)
{
  const char *p;
  char mount[HESIOD_LEN + 1];
  int i;

  p = filsysline;

  while(isspace(*p)) p++;    /* Skip whitespace. */
  while(!isspace(*p)) p++;   /* Skip the filesystem type. */
  while(isspace(*p)) p++;    /* Skip whitespace. */

  /* Isolate the remote mountpoint for this NFS fs. */
  for(i = 0; (!isspace(p[i]) && i < sizeof(mount)); i++) {
    mount[i] = p[i];
  }
  mount[i] = 0;
  p += i;

  while((*p) && (isspace(*p))) p++;    /* Skip whitespace. */

  /* Isolate the remote host. */
  for(i = 0; (!isspace(p[i]) && i < source_len); i++) {
    source[i] = p[i];
  }
  source[i] = 0;
  p += i;

  /* Append ":mountpoint" to the source to get "host:mountpoint". */
  strncat(source, ":", source_len);
  strncat(source, mount, source_len);

  while((*p) && (isspace(*p))) p++;    /* Skip whitespace. */

  /* Isolate the mount options. */
  for(i = 0; (!isspace(p[i]) && i < options_len); i++) {
    options[i] = p[i];
  }
  options[i] = 0;

  if(!strcmp(options, "r"))             /* Hack for "r" or "w" options. */
    strcpy(options, "ro");
  if(!strcmp(options, "w"))
    strcpy(options, "rw");

  syslog(LOG_DEBUG, MODPREFIX "parsing NFS record gives '%s'->'%s' with options"         "'%s'", name, source, options);

  return 0;
}

/* Break out the fields in a generic record of the form:
   "UFS /dev/ra0g w /site" */
static int parse_generic(const char *filsysline, const char *name, int name_len,
                         char *source, int source_len,
                         char *options, int options_len)
{
  const char *p;
  int i;

  p = filsysline;

  while(isspace(*p)) p++;    /* Skip whitespace. */
  while(!isspace(*p)) p++;   /* Skip the filesystem type. */
  while(isspace(*p)) p++;    /* Skip whitespace. */

  /* Isolate the source for this fs. */
  for(i = 0; (!isspace(p[i]) && i < source_len); i++) {
    source[i] = p[i];
  }
  source[i] = 0;
  p += i;

  while((*p) && (isspace(*p))) p++;    /* Skip whitespace. */

  /* Isolate the mount options. */
  for(i = 0; (!isspace(p[i]) && i < options_len); i++) {
    options[i] = p[i];
  }
  options[i] = 0;

  if(!strcmp(options, "r"))             /* Hack for "r" or "w" options. */
    strcpy(options, "ro");
  if(!strcmp(options, "w"))
    strcpy(options, "rw");

  syslog(LOG_DEBUG, MODPREFIX "parsing generic record gives '%s'->'%s' "
         "with options '%s'", name, source, options);
  return 0;
}

int parse_init(int argc, const char * const *argv, void **context)
{
  return 0;
}

int parse_done(void *context)
{
  return 0;
}

int parse_mount(const char *root, const char *name,
                int name_len, const char *mapent, void *context)
{
  char source[HESIOD_LEN+1],
       fstype[HESIOD_LEN+1],
       options[HESIOD_LEN+1],
       *q;
  const char *p;

  p = mapent;
  q = fstype;

  while(isspace(*p)) p++;    /* Skip any initial whitespace... */

  while(!isspace(*p)) {      /* Isolate the filesystem type... */
    *q++ = tolower(*p++);
  }
  *q = 0;

  if(!strcasecmp(fstype, "err")) {    /* If it's an error message... */
    syslog(LOG_DEBUG, MODPREFIX "%s", mapent);
    return 1;
  }
  else                                /* If it's an AFS fs... */
  if(!strcasecmp(fstype, "afs")) parse_afs(mapent, name, name_len,
                                           source, sizeof(source),
                                           options, sizeof(options));
  else                                /* If it's NFS... */
  if(!strcasecmp(fstype, "nfs")) parse_nfs(mapent, name, name_len,
                                           source, sizeof(source),
                                           options, sizeof(options));
  else                                /* Punt. */
  parse_generic(mapent, name, name_len, source, sizeof(source),
                        options, sizeof(options));

  syslog(LOG_DEBUG, MODPREFIX "mount %s is type %s from %s",
         name, fstype, source);

  return do_mount(root, name, name_len, source, fstype, options);
}