text: /****************************************************************************
   * netutils/netlib/netlib_ipv6route.c
   *
   *   Copyright (C) 2017 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * 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. The name of the author may not be used to endorse or promote
   *    products derived from this software without specific prior
   *    written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdio.h>
  #include <string.h>
  #include <assert.h>
  #include <errno.h>
  
  #include <arpa/inet.h>
  
  #include "netutils/netlib.h"
  
  #if defined(CONFIG_NET_IPv6) && defined(HAVE_ROUTE_PROCFS)
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /* Determines the size of an intermediate buffer that must be large enough
   * to handle the longest line generated by this logic.
   */
  
  #define PROCFS_LINELEN 58
  
  /* The form of the entry from the routing table file:
   *
   *            11111111112222222222333333333344444444445555
   *   12345678901234567890123456789012345678901234567890123
   *   nnnn. target:  xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
   *         netmask: xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
   *         router:  xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
   */
  
  #define ADDR_OFFSET  15
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: set_nul_terminator
   *
   * Description:
   *   Make sure that the string is NUL terminated.
   *
   ****************************************************************************/
  
  static void set_nul_terminator(FAR char *str)
  {
     /* The first non-hex character that is not ':' terminates the address */
  
     while ((*str >= '0' && *str <= '9') ||
            (*str >= 'a' && *str <= 'f') ||
            (*str >= 'A' && *str <= 'F') ||
             *str == ':')
       {
         str++;
       }
  
     *str = '\0';
  }
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: netlib_read_ipv6route
   *
   * Description:
   *   Read the next entry from the IPv6 routing table.
   *
   * Input Parameters:
   *   fd     - The open file descriptor to the procfs' IPv6 routing table.
   *   route  - The location to return that the next routing table entry.
   *
   * Returned Value:
   *   sizeof(struct netlib_ipv6_route_s) is returned on success.  Zero is
   *   returned if the end of file is encountered.  A negated errno value is
   *   returned on any failure.
   *
   ****************************************************************************/
  
  ssize_t netlib_read_ipv6route(FILE *stream,
                                FAR struct netlib_ipv6_route_s *route)
  {
    char line[PROCFS_LINELEN];
    FAR char *addr;
    int ret;
  
    DEBUGASSERT(stream != NULL && route != NULL);
  
    /* The form of the entries read from the routing table:
     *
     *            1111111111222222222233333333334444444444555
     *   1234567890123456789012345678901234567890123456789012
     *   nnnn. target:  xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
     *         netmask: xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
     *         router:  xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
     */
  
    /* Read the first line from the file */
  
    if (fgets(line, PROCFS_LINELEN, stream) == NULL)
      {
        /* End of file (or possibly a read error?) */
  
        return 0;
      }
  
    /* The first line of the group should consist of a number index */
  
    if (line[0] < '0' || line[0] > 9)
      {
        return -EINVAL;
      }
  
    /* Make certain that there is a NUL terminator */
  
    line[PROCFS_LINELEN - 1] = '\0';
  
    /* Convert the prefix address to binary */
  
    addr = &line[ADDR_OFFSET];
    set_nul_terminator(addr);
  
    ret = inet_pton(AF_INET6, addr, &route->prefix);
    if (ret < 0)
      {
        return ret;
      }
    else if (ret == 0)
      {
        return -EINVAL;
      }
  
    /* Read the second line from the file */
  
    if (fgets(line, PROCFS_LINELEN, stream) == NULL)
      {
        /* End of file (or possibly a read error?) */
  
        return 0;
      }
  
    /* The second line of the group should not include an index */
  
    if (line[0] != ' ')
      {
        return -EINVAL;
      }
  
    /* Make certain that there is a NUL terminator */
  
    line[PROCFS_LINELEN - 1] = '\0';
  
    /* Convert the prefix address to binary */
  
    addr = &line[ADDR_OFFSET];
    set_nul_terminator(addr);
  
    ret = inet_pton(AF_INET6, addr, &route->netmask);
    if (ret < 0)
      {
        return ret;
      }
    else if (ret == 0)
      {
        return -EINVAL;
      }
  
    /* Read the third line from the file */
  
    if (fgets(line, PROCFS_LINELEN, stream) == NULL)
      {
        /* End of file (or possibly a read error?) */
  
        return 0;
      }
  
    /* The third line of the group should not include an index */
  
    if (line[0] != ' ')
      {
        return -EINVAL;
      }
  
    /* Make certain that there is a NUL terminator */
  
    line[PROCFS_LINELEN - 1] = '\0';
  
    /* Convert the prefix address to binary */
  
    addr = &line[ADDR_OFFSET];
    set_nul_terminator(addr);
  
    ret = inet_pton(AF_INET6, addr, &route->router);
    if (ret < 0)
      {
        return ret;
      }
    else if (ret == 0)
      {
        return -EINVAL;
      }
  
    return sizeof(struct netlib_ipv6_route_s);
  }
  
  #endif /* CONFIG_NET_IPv6 && HAVE_ROUTE_PROCFS */
  