package/busybox/patches/244-udhcpc_add_6rd_option.patch

   1 --- a/networking/udhcp/common.c
   2 +++ b/networking/udhcp/common.c
   3 @@ -54,6 +54,8 @@ 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 (RFC)     */
   8 +       { OPTION_6RD                              , 0x96 }, /* DHCP_6RD (Comcast) */
   9         { OPTION_STRING                           , 0xfc }, /* DHCP_WPAD          */
  10
  11         /* Options below have no match in dhcp_option_strings[],
  12 @@ -114,6 +116,8 @@ const char dhcp_option_strings[] ALIGN1
  13  // doesn't work in udhcpd.conf since OPTION_STATIC_ROUTES
  14  // is not handled yet by "string->option" conversion code:
  15         "staticroutes" "\0"/* DHCP_STATIC_ROUTES  */
  16 +       "ip6rd" "\0"       /* DHCP_6RD (RFC)      */
  17 +       "ip6rd" "\0"       /* DHCP_6RD (Comcast)  */
  18         "wpad" "\0"        /* DHCP_WPAD           */
  19         ;
  20
  21 @@ -141,6 +145,7 @@ const uint8_t dhcp_option_lengths[] ALIG
  22         [OPTION_S32] =     4,
  23         /* Just like OPTION_STRING, we use minimum length here */
  24         [OPTION_STATIC_ROUTES] = 5,
  25 +       [OPTION_6RD]           = 22,
  26  };
  27
  28
  29 --- a/networking/udhcp/dhcpc.c
  30 +++ b/networking/udhcp/dhcpc.c
  31 @@ -45,6 +45,7 @@ static const uint8_t len_of_option_as_st
  32         [OPTION_IP              ] = sizeof("255.255.255.255 "),
  33         [OPTION_IP_PAIR         ] = sizeof("255.255.255.255 ") * 2,
  34         [OPTION_STATIC_ROUTES   ] = sizeof("255.255.255.255/32 255.255.255.255 "),
  35 +       [OPTION_6RD             ] = sizeof("32 128 FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF 255.255.255.255 "),
  36         [OPTION_STRING          ] = 1,
  37  #if ENABLE_FEATURE_UDHCP_RFC3397
  38         [OPTION_DNS_STRING      ] = 1, /* unused */
  39 @@ -68,6 +69,23 @@ static int sprint_nip(char *dest, const
  40         return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
  41  }
  42
  43 +static int sprint_nip6(char *dest, const char *pre, const uint8_t *ip)
  44 +{
  45 +       int len = 0;
  46 +       int off;
  47 +       uint16_t word;
  48 +
  49 +       len += sprintf(dest, "%s", pre);
  50 +
  51 +       for (off = 0; off < 16; off += 2)
  52 +       {
  53 +               move_from_unaligned16(word, &ip[off]);
  54 +               len += sprintf(dest+len, "%s%04X", off ? ":" : "", htons(word));
  55 +       }
  56 +
  57 +       return len;
  58 +}
  59 +
  60  /* really simple implementation, just count the bits */
  61  static int mton(uint32_t mask)
  62  {
  63 @@ -177,6 +195,70 @@ static NOINLINE char *xmalloc_optname_op
  64
  65                         return ret;
  66                 }
  67 +               case OPTION_6RD: {
  68 +                       /* Option binary format:
  69 +                        *  0                   1                   2                   3
  70 +                        *  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
  71 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  72 +                        *  |  OPTION_6RD   | option-length |  IPv4MaskLen  |  6rdPrefixLen |
  73 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  74 +                        *  |                                                               |
  75 +                        *  |                           6rdPrefix                           |
  76 +                        *  |                          (16 octets)                          |
  77 +                        *  |                                                               |
  78 +                        *  |                                                               |
  79 +                        *  |                                                               |
  80 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  81 +                        *  |                     6rdBRIPv4Address(es)                      |
  82 +                        *  .                                                               .
  83 +                        *  .                                                               .
  84 +                        *  .                                                               .
  85 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  86 +                        *
  87 +                        * We convert it to a string "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address"
  88 +                        */
  89 +
  90 +                       /* Sanity check: ensure that our length is at least 22 bytes, that
  91 +                        * IPv4MaskLen is <= 32, 6rdPrefixLen <= 128 and that the sum of
  92 +                        * (32 - IPv4MaskLen) + 6rdPrefixLen is less than or equal to 128.
  93 +                        * If any of these requirements is not fulfilled, return with empty
  94 +                        * value.
  95 +                        */
  96 +                       if ((len >= 22) && (*option <= 32) && (*(option+1) <= 128) &&
  97 +                           (((32 - *option) + *(option+1)) <= 128))
  98 +                       {
  99 +                               /* IPv4MaskLen */
 100 +                               dest += sprintf(dest, "%u ", *option++);
 101 +                               len--;
 102 +
 103 +                               /* 6rdPrefixLen */
 104 +                               dest += sprintf(dest, "%u ", *option++);
 105 +                               len--;
 106 +
 107 +                               /* 6rdPrefix */
 108 +                               dest += sprint_nip6(dest, "", option);
 109 +                               option += 16;
 110 +                               len -= 16;
 111 +
 112 +                               /* 6rdBRIPv4Addresses */
 113 +                               while (len >= 4)
 114 +                               {
 115 +                                       dest += sprint_nip(dest, " ", option);
 116 +                                       option += 4;
 117 +                                       len -= 4;
 118 +
 119 +                                       /* the code to determine the option size fails to work with
 120 +                                        * lengths that are not a multiple of the minimum length,
 121 +                                        * adding all advertised 6rdBRIPv4Addresses here would
 122 +                                        * overflow the destination buffer, therefore skip the rest
 123 +                                        * for now
 124 +                                        */
 125 +                                       break;
 126 +                               }
 127 +                       }
 128 +
 129 +                       return ret;
 130 +               }
 131  #if ENABLE_FEATURE_UDHCP_RFC3397
 132                 case OPTION_DNS_STRING:
 133                         /* unpack option into dest; use ret for prefix (i.e., "optname=") */
 134 --- a/networking/udhcp/common.h
 135 +++ b/networking/udhcp/common.h
 136 @@ -88,6 +88,7 @@ enum {
 137         OPTION_S32,
 138         OPTION_BIN,
 139         OPTION_STATIC_ROUTES,
 140 +       OPTION_6RD,
 141  #if ENABLE_FEATURE_UDHCP_RFC3397
 142         OPTION_DNS_STRING,  /* RFC1035 compressed domain name list */
 143         OPTION_SIP_SERVERS,