text: /****************************************************************************
   * net/route/net_del_fileroute.c
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.  The
   * ASF licenses this file to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance with the
   * License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations
   * under the License.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdint.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <string.h>
  #include <errno.h>
  #include <debug.h>
  
  #include <arpa/inet.h>
  
  #include <nuttx/fs/fs.h>
  #include <nuttx/net/ip.h>
  
  #include "route/fileroute.h"
  #include "route/cacheroute.h"
  #include "route/route.h"
  
  #if defined(CONFIG_ROUTE_IPv4_FILEROUTE) || defined(CONFIG_ROUTE_IPv6_FILEROUTE)
  
  /****************************************************************************
   * Private Types
   ****************************************************************************/
  
  #ifdef CONFIG_ROUTE_IPv4_FILEROUTE
  struct route_match_ipv4_s
  {
    in_addr_t                    target;   /* The target IP address to match */
    in_addr_t                    netmask;  /* The network mask to match */
    unsigned int                 index;    /* Index of match */
  };
  #endif
  
  #ifdef CONFIG_ROUTE_IPv6_FILEROUTE
  struct route_match_ipv6_s
  {
    net_ipv6addr_t               target;   /* The target IP address to match */
    net_ipv6addr_t               netmask;  /* The network mask to match */
    unsigned int                 index;    /* Index of match */
  };
  #endif
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: net_match_ipv4
   *
   * Description:
   *   Return 1 if the route is available
   *
   * Input Parameters:
   *   route - The next route to examine
   *   arg   - The match values (cast to void*)
   *
   * Returned Value:
   *   0 if the entry is not a match; 1 if the entry matched and was cleared.
   *
   ****************************************************************************/
  
  #ifdef CONFIG_ROUTE_IPv4_FILEROUTE
  static int net_match_ipv4(FAR struct net_route_ipv4_s *route, FAR void *arg)
  {
    FAR struct route_match_ipv4_s *match =
                      (FAR struct route_match_ipv4_s *)arg;
  
    /* To match, the masked target address must be the same, and the masks
     * must be the same.
     */
  
    net_ipv4_dumproute("Comparing", route);
    ninfo("With:\n");
    ninfo("  target=%08lx netmask=%08lx\n",
          htonl(match->target), htonl(match->netmask));
  
    if (net_ipv4addr_maskcmp(route->target, match->target, match->netmask) &&
        net_ipv4addr_cmp(route->netmask, match->netmask))
      {
        /* They match.. a non-zero value to terminate the traversal.  The last
         * value of index is the index to the matching entry.
         */
  
        return 1;
      }
  
    /* Next time we are here, this will be the routing table index */
  
    match->index++;
    return 0;
  }
  #endif
  
  #ifdef CONFIG_ROUTE_IPv6_FILEROUTE
  static int net_match_ipv6(FAR struct net_route_ipv6_s *route, FAR void *arg)
  {
    FAR struct route_match_ipv6_s *match =
                      (FAR struct route_match_ipv6_s *)arg;
  
    /* To match, the masked target address must be the same, and the masks
     * must be the same.
     */
  
    net_ipv6_dumproute("Comparing", route);
    ninfo("With:\n");
    ninfo("  target:  %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
          htons(match->target[0]),  htons(match->target[1]),
          htons(match->target[2]),  htons(match->target[3]),
          htons(match->target[4]),  htons(match->target[5]),
          htons(match->target[6]),  htons(match->target[7]));
    ninfo("  netmask: %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
          htons(match->netmask[0]), htons(match->netmask[1]),
          htons(match->netmask[2]), htons(match->netmask[3]),
          htons(match->netmask[4]), htons(match->netmask[5]),
          htons(match->netmask[6]), htons(match->netmask[7]));
  
    if (net_ipv6addr_maskcmp(route->target, match->target, match->netmask) &&
        net_ipv6addr_cmp(route->netmask, match->netmask))
      {
        /* They match.. a non-zero value to terminate the traversal.  The last
         * value of index is the index to the matching entry.
         */
  
        return 1;
      }
  
    /* Next time we are here, this will be the routing table index */
  
    match->index++;
    return 0;
  }
  #endif
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: net_delroute_ipv4 and net_delroute_ipv6
   *
   * Description:
   *   Remove an existing route from the routing table
   *
   * Input Parameters:
   *
   * Returned Value:
   *   OK on success; Negated errno on failure.
   *
   ****************************************************************************/
  
  #ifdef CONFIG_ROUTE_IPv4_FILEROUTE
  int net_delroute_ipv4(in_addr_t target, in_addr_t netmask)
  {
    struct route_match_ipv4_s match;
    struct net_route_ipv4_s route;
    struct file fshandle;
    off_t filesize;
    ssize_t nwritten;
    ssize_t nread;
    off_t pos;
    int nentries;
    int index;
    int ret;
  
    /* We must lock out other accesses to the routing table while we remove
     * entry
     */
  
    ret = net_lockroute_ipv4();
    if (ret < 0)
      {
        nerr("ERROR: net_lockroute_ipv4 faled: %d\n", ret);
        return ret;
      }
  
    /* Get the size of the routing table (in entries) */
  
    nentries = net_routesize_ipv4();
    if (nentries < 0)
      {
        ret = nentries;
        goto errout_with_lock;
      }
    else if (nentries == 0)
      {
        ret = -ENOENT;
        goto errout_with_lock;
      }
  
    /* Set up the comparison structure */
  
    net_ipv4addr_copy(match.target, target);
    net_ipv4addr_copy(match.netmask, netmask);
    match.index = 0;
  
    /* Then find the index into the routing table where the match can be
     * found
     */
  
    ret = net_foreachroute_ipv4(net_match_ipv4, &match);
    if (ret < 0)
      {
        /* And error occurred */
  
        goto errout_with_lock;
      }
    else if (ret == 0)
      {
        /* No match found */
  
        ret = -ENOENT;
        goto errout_with_lock;
      }
  
    /* Open the routing table for read/write access */
  
    ret = net_openroute_ipv4(O_RDWR, &fshandle);
    if (ret < 0)
      {
        nerr("ERROR: Could not open IPv4 routing table: %d\n", ret);
        goto errout_with_lock;
      }
  
  #ifdef CONFIG_ROUTE_IPv4_CACHEROUTE
    /* We are committed to modifying the routing table.  Flush the in-memory
     * routing table cache.
     */
  
    net_flushcache_ipv4();
  #endif
  
    /* Loop, copying each entry, to the previous entry thus removing the entry
     * to be deleted.
     */
  
    for (index = match.index + 1; index < nentries; index++)
      {
        /* Seek to the current entry to be moved */
  
        pos = net_seekroute_ipv4(&fshandle, index);
        if (pos < 0)
          {
            nerr("ERROR: net_readroute_ipv4 failed: %ld\n", (long)pos);
            ret = (int)pos;
            goto errout_with_fshandle;
          }
  
        /* Read the routing table entry at this position */
  
        nread = net_readroute_ipv4(&fshandle, &route);
        if (nread < 0)
          {
            nerr("ERROR: net_readroute_ipv4 failed: %ld\n", (long)nread);
            ret = (int)nread;
            goto errout_with_fshandle;
          }
        else if (nread == 0)
          {
            nerr("ERROR: Unexpected end of file\n");
            ret = -EINVAL;
            goto errout_with_fshandle;
          }
  
        /* Seek to the previous entry to be replaced */
  
        pos = net_seekroute_ipv4(&fshandle, index - 1);
        if (pos < 0)
          {
            nerr("ERROR: net_readroute_ipv4 failed: %ld\n", (long)pos);
            ret = (int)pos;
            goto errout_with_fshandle;
          }
  
        /* Now write the record to its new location */
  
        nwritten = net_writeroute_ipv4(&fshandle, &route);
        if (nwritten < 0)
          {
            nerr("ERROR: net_readroute_ipv4 failed: %ld\n", (long)nwritten);
            ret = (int)nwritten;
            goto errout_with_fshandle;
          }
      }
  
    /* Now truncate the one duplicate entry at the end of the file.  This may
     * result in a zero length file.
     */
  
    filesize = (nentries - 1) * sizeof(struct net_route_ipv4_s);
    ret = file_truncate(&fshandle, filesize);
  
  errout_with_fshandle:
    net_closeroute_ipv4(&fshandle);
  
  errout_with_lock:
    net_unlockroute_ipv4();
    return ret;
  }
  #endif
  
  #ifdef CONFIG_ROUTE_IPv6_FILEROUTE
  int net_delroute_ipv6(net_ipv6addr_t target, net_ipv6addr_t netmask)
  {
    struct route_match_ipv6_s match;
    struct net_route_ipv6_s route;
    struct file fshandle;
    off_t filesize;
    ssize_t nwritten;
    ssize_t nread;
    off_t pos;
    int nentries;
    int index;
    int ret;
  
    /* We must lock out other accesses to the routing table while we remove
     * entry
     */
  
    ret = net_lockroute_ipv6();
    if (ret < 0)
      {
        nerr("ERROR: net_lockroute_ipv6 failed: %d\n", ret);
        return ret;
      }
  
    /* Get the size of the routing table (in entries) */
  
    nentries = net_routesize_ipv6();
    if (nentries < 0)
      {
        ret = nentries;
        goto errout_with_lock;
      }
    else if (nentries == 0)
      {
        ret = -ENOENT;
        goto errout_with_lock;
      }
  
    /* Set up the comparison structure */
  
    net_ipv6addr_copy(match.target, target);
    net_ipv6addr_copy(match.netmask, netmask);
    match.index = 0;
  
    /* Then find the index into the routing table where the match can be
     * found
     */
  
    ret = net_foreachroute_ipv6(net_match_ipv6, &match);
    if (ret < 0)
      {
        /* And error occurred */
  
        ret = ret;
        goto errout_with_lock;
      }
    else if (ret == 0)
      {
        /* No match found */
  
        ret = -ENOENT;
        goto errout_with_lock;
      }
  
    /* Open the routing table for read/write access */
  
    ret = net_openroute_ipv6(O_RDWR, &fshandle);
    if (ret < 0)
      {
        nerr("ERROR: Could not open IPv6 routing table: %d\n", ret);
        goto errout_with_lock;
      }
  
  #ifdef CONFIG_ROUTE_IPv6_CACHEROUTE
    /* We are committed to modifying the routing table.  Flush the in-memory
     * routing table cache.
     */
  
    net_flushcache_ipv6();
  #endif
  
    /* Loop, copying each entry, to the previous entry thus removing the entry
     * to be deleted.
     */
  
    for (index = match.index + 1; index < nentries; index++)
      {
        /* Seek to the current entry to be moved */
  
        pos = net_seekroute_ipv6(&fshandle, index);
        if (pos < 0)
          {
            nerr("ERROR: net_readroute_ipv6 failed: %ld\n", (long)pos);
            ret = (int)pos;
            goto errout_with_fshandle;
          }
  
        /* Read the routing table entry at this position */
  
        nread = net_readroute_ipv6(&fshandle, &route);
        if (nread < 0)
          {
            nerr("ERROR: net_readroute_ipv6 failed: %ld\n", (long)nread);
            ret = (int)nread;
            goto errout_with_fshandle;
          }
        else if (nread == 0)
          {
            nerr("ERROR: Unexpected end of file\n");
            ret = -EINVAL;
            goto errout_with_fshandle;
          }
  
        /* Seek to the previous entry to be replaced */
  
        pos = net_seekroute_ipv6(&fshandle, index - 1);
        if (pos < 0)
          {
            nerr("ERROR: net_readroute_ipv6 failed: %ld\n", (long)pos);
            ret = (int)pos;
            goto errout_with_fshandle;
          }
  
        /* Now write the record to its new location */
  
        nwritten = net_writeroute_ipv6(&fshandle, &route);
        if (nwritten < 0)
          {
            nerr("ERROR: net_readroute_ipv6 failed: %ld\n", (long)nwritten);
            ret = (int)nwritten;
            goto errout_with_fshandle;
          }
      }
  
    /* Now truncate the one duplicate entry at the end of the file.  This may
     * result in a zero length file.
     */
  
    filesize = (nentries - 1) * sizeof(struct net_route_ipv6_s);
    ret = file_truncate(&fshandle, filesize);
  
  errout_with_fshandle:
    net_closeroute_ipv6(&fshandle);
  
  errout_with_lock:
    net_unlockroute_ipv6();
    return ret;
  }
  #endif
  
  #endif /* CONFIG_ROUTE_IPv4_FILEROUTE || CONFIG_ROUTE_IPv6_FILEROUTE  */
  