package/busybox/patches/244-udhcpc_add_6rd_option.patch

   1 --- a/networking/udhcp/common.c
   2 +++ b/networking/udhcp/common.c
   3 @@ -54,6 +54,7 @@ const struct dhcp_optflag dhcp_optflags[
   4         { OPTION_SIP_SERVERS                      , 0x78 }, /* DHCP_SIP_SERVERS   */
   5  #endif
   6         { OPTION_STATIC_ROUTES                    , 0x79 }, /* DHCP_STATIC_ROUTES */
   7 +       { OPTION_6RD                              , 0xd4 }, /* DHCP_6RD           */
   8         { OPTION_STRING                           , 0xfc }, /* DHCP_WPAD          */
   9
  10         /* Options below have no match in dhcp_option_strings[],
  11 @@ -114,6 +115,7 @@ const char dhcp_option_strings[] ALIGN1
  12  // doesn't work in udhcpd.conf since OPTION_STATIC_ROUTES
  13  // is not handled yet by "string->option" conversion code:
  14         "staticroutes" "\0"/* DHCP_STATIC_ROUTES  */
  15 +       "ip6rd" "\0"       /* DHCP_6RD            */
  16         "wpad" "\0"        /* DHCP_WPAD           */
  17         ;
  18
  19 @@ -141,6 +143,7 @@ const uint8_t dhcp_option_lengths[] ALIG
  20         [OPTION_S32] =     4,
  21         /* Just like OPTION_STRING, we use minimum length here */
  22         [OPTION_STATIC_ROUTES] = 5,
  23 +       [OPTION_6RD]           = 22,
  24  };
  25
  26
  27 --- a/networking/udhcp/dhcpc.c
  28 +++ b/networking/udhcp/dhcpc.c
  29 @@ -45,6 +45,7 @@ static const uint8_t len_of_option_as_st
  30         [OPTION_IP              ] = sizeof("255.255.255.255 "),
  31         [OPTION_IP_PAIR         ] = sizeof("255.255.255.255 ") * 2,
  32         [OPTION_STATIC_ROUTES   ] = sizeof("255.255.255.255/32 255.255.255.255 "),
  33 +       [OPTION_6RD             ] = sizeof("32 128 FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF 255.255.255.255 "),
  34         [OPTION_STRING          ] = 1,
  35  #if ENABLE_FEATURE_UDHCP_RFC3397
  36         [OPTION_DNS_STRING      ] = 1, /* unused */
  37 @@ -68,6 +69,23 @@ static int sprint_nip(char *dest, const
  38         return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
  39  }
  40
  41 +static int sprint_nip6(char *dest, const char *pre, const uint8_t *ip)
  42 +{
  43 +       int len = 0;
  44 +       int off;
  45 +       uint16_t word;
  46 +
  47 +       len += sprintf(dest, "%s", pre);
  48 +
  49 +       for (off = 0; off < 16; off += 2)
  50 +       {
  51 +               move_from_unaligned16(word, &ip[off]);
  52 +               len += sprintf(dest+len, "%s%04X", off ? ":" : "", htons(word));
  53 +       }
  54 +
  55 +       return len;
  56 +}
  57 +
  58  /* really simple implementation, just count the bits */
  59  static int mton(uint32_t mask)
  60  {
  61 @@ -177,6 +195,70 @@ static NOINLINE char *xmalloc_optname_op
  62
  63                         return ret;
  64                 }
  65 +               case OPTION_6RD: {
  66 +                       /* Option binary format:
  67 +                        *  0                   1                   2                   3
  68 +                        *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  69 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  70 +                        *  |  OPTION_6RD   | option-length |  IPv4MaskLen  |  6rdPrefixLen |
  71 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  72 +                        *  |                                                               |
  73 +                        *  |                           6rdPrefix                           |
  74 +                        *  |                          (16 octets)                          |
  75 +                        *  |                                                               |
  76 +                        *  |                                                               |
  77 +                        *  |                                                               |
  78 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  79 +                        *  |                     6rdBRIPv4Address(es)                      |
  80 +                        *  .                                                               .
  81 +                        *  .                                                               .
  82 +                        *  .                                                               .
  83 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  84 +                        *
  85 +                        * We convert it to a string "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address"
  86 +                        */
  87 +
  88 +                       /* Sanity check: ensure that our length is at least 22 bytes, that
  89 +                        * IPv4MaskLen is <= 32, 6rdPrefixLen <= 128 and that the sum of
  90 +                        * (32 - IPv4MaskLen) + 6rdPrefixLen is less than or equal to 128.
  91 +                        * If any of these requirements is not fulfilled, return with empty
  92 +                        * value.
  93 +                        */
  94 +                       if ((len >= 22) && (*option <= 32) && (*(option+1) <= 128) &&
  95 +                           (((32 - *option) + *(option+1)) <= 128))
  96 +                       {
  97 +                               /* IPv4MaskLen */
  98 +                               dest += sprintf(dest, "%u ", *option++);
  99 +                               len--;
 100 +
 101 +                               /* 6rdPrefixLen */
 102 +                               dest += sprintf(dest, "%u ", *option++);
 103 +                               len--;
 104 +
 105 +                               /* 6rdPrefix */
 106 +                               dest += sprint_nip6(dest, "", option);
 107 +                               option += 16;
 108 +                               len -= 16;
 109 +
 110 +                               /* 6rdBRIPv4Addresses */
 111 +                               while (len >= 4)
 112 +                               {
 113 +                                       dest += sprint_nip(dest, " ", option);
 114 +                                       option += 4;
 115 +                                       len -= 4;
 116 +
 117 +                                       /* the code to determine the option size fails to work with
 118 +                                        * lengths that are not a multiple of the minimum length,
 119 +                                        * adding all advertised 6rdBRIPv4Addresses here would
 120 +                                        * overflow the destination buffer, therefore skip the rest
 121 +                                        * for now
 122 +                                        */
 123 +                                       break;
 124 +                               }
 125 +                       }
 126 +
 127 +                       return ret;
 128 +               }
 129  #if ENABLE_FEATURE_UDHCP_RFC3397
 130                 case OPTION_DNS_STRING:
 131                         /* unpack option into dest; use ret for prefix (i.e., "optname=") */
 132 --- a/networking/udhcp/common.h
 133 +++ b/networking/udhcp/common.h
 134 @@ -88,6 +88,7 @@ enum {
 135         OPTION_S32,
 136         OPTION_BIN,
 137         OPTION_STATIC_ROUTES,
 138 +       OPTION_6RD,
 139  #if ENABLE_FEATURE_UDHCP_RFC3397
 140         OPTION_DNS_STRING,  /* RFC1035 compressed domain name list */
 141         OPTION_SIP_SERVERS,