package/busybox/patches/244-udhcpc_add_6rd_option.patch

   1 diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
   2 index 0a60261..eaf2b4b 100644
   3 --- a/networking/udhcp/common.c
   4 +++ b/networking/udhcp/common.c
   5 @@ -56,6 +56,8 @@ const struct dhcp_optflag dhcp_optflags[] = {
   6  #endif
   7         { OPTION_STATIC_ROUTES                    , 0x79 }, /* DHCP_STATIC_ROUTES */
   8         { OPTION_STATIC_ROUTES                    , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
   9 +       { OPTION_6RD                              , 0xd4 }, /* DHCP_6RD (RFC)     */
  10 +       { OPTION_6RD                              , 0x96 }, /* DHCP_6RD (Comcast) */
  11         { OPTION_STRING                           , 0xfc }, /* DHCP_WPAD          */
  12
  13         /* Options below have no match in dhcp_option_strings[],
  14 @@ -118,6 +120,8 @@ const char dhcp_option_strings[] ALIGN1 =
  15  // doesn't work in udhcpd.conf since OPTION_STATIC_ROUTES
  16  // is not handled yet by "string->option" conversion code:
  17         "staticroutes" "\0"/* DHCP_STATIC_ROUTES  */
  18 +       "ip6rd" "\0"       /* DHCP_6RD (RFC)      */
  19 +       "ip6rd" "\0"       /* DHCP_6RD (Comcast)  */
  20         "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
  21         "wpad" "\0"        /* DHCP_WPAD           */
  22         ;
  23 @@ -146,6 +150,7 @@ const uint8_t dhcp_option_lengths[] ALIGN1 = {
  24         [OPTION_S32] =     4,
  25         /* Just like OPTION_STRING, we use minimum length here */
  26         [OPTION_STATIC_ROUTES] = 5,
  27 +       [OPTION_6RD]           = 22,
  28  };
  29
  30
  31 diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
  32 index f8f18ff..56cd8b0 100644
  33 --- a/networking/udhcp/common.h
  34 +++ b/networking/udhcp/common.h
  35 @@ -88,6 +88,7 @@ enum {
  36         OPTION_S32,
  37         OPTION_BIN,
  38         OPTION_STATIC_ROUTES,
  39 +       OPTION_6RD,
  40  #if ENABLE_FEATURE_UDHCP_RFC3397
  41         OPTION_DNS_STRING,  /* RFC1035 compressed domain name list */
  42         OPTION_SIP_SERVERS,
  43 diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
  44 index 78aabed..993326f 100644
  45 --- a/networking/udhcp/dhcpc.c
  46 +++ b/networking/udhcp/dhcpc.c
  47 @@ -45,6 +45,7 @@ static const uint8_t len_of_option_as_string[] = {
  48         [OPTION_IP              ] = sizeof("255.255.255.255 "),
  49         [OPTION_IP_PAIR         ] = sizeof("255.255.255.255 ") * 2,
  50         [OPTION_STATIC_ROUTES   ] = sizeof("255.255.255.255/32 255.255.255.255 "),
  51 +       [OPTION_6RD             ] = sizeof("32 128 FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF 255.255.255.255 "),
  52         [OPTION_STRING          ] = 1,
  53  #if ENABLE_FEATURE_UDHCP_RFC3397
  54         [OPTION_DNS_STRING      ] = 1, /* unused */
  55 @@ -68,6 +69,23 @@ static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
  56         return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
  57  }
  58
  59 +static int sprint_nip6(char *dest, const char *pre, const uint8_t *ip)
  60 +{
  61 +       int len = 0;
  62 +       int off;
  63 +       uint16_t word;
  64 +
  65 +       len += sprintf(dest, "%s", pre);
  66 +
  67 +       for (off = 0; off < 16; off += 2)
  68 +       {
  69 +               move_from_unaligned16(word, &ip[off]);
  70 +               len += sprintf(dest+len, "%s%04X", off ? ":" : "", htons(word));
  71 +       }
  72 +
  73 +       return len;
  74 +}
  75 +
  76  /* really simple implementation, just count the bits */
  77  static int mton(uint32_t mask)
  78  {
  79 @@ -177,6 +195,70 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_
  80
  81                         return ret;
  82                 }
  83 +               case OPTION_6RD: {
  84 +                       /* Option binary format:
  85 +                        *  0                   1                   2                   3
  86 +                        *  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
  87 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  88 +                        *  |  OPTION_6RD   | option-length |  IPv4MaskLen  |  6rdPrefixLen |
  89 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  90 +                        *  |                                                               |
  91 +                        *  |                           6rdPrefix                           |
  92 +                        *  |                          (16 octets)                          |
  93 +                        *  |                                                               |
  94 +                        *  |                                                               |
  95 +                        *  |                                                               |
  96 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  97 +                        *  |                     6rdBRIPv4Address(es)                      |
  98 +                        *  .                                                               .
  99 +                        *  .                                                               .
 100 +                        *  .                                                               .
 101 +                        *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 102 +                        *
 103 +                        * We convert it to a string "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address"
 104 +                        */
 105 +
 106 +                       /* Sanity check: ensure that our length is at least 22 bytes, that
 107 +                        * IPv4MaskLen is <= 32, 6rdPrefixLen <= 128 and that the sum of
 108 +                        * (32 - IPv4MaskLen) + 6rdPrefixLen is less than or equal to 128.
 109 +                        * If any of these requirements is not fulfilled, return with empty
 110 +                        * value.
 111 +                        */
 112 +                       if ((len >= 22) && (*option <= 32) && (*(option+1) <= 128) &&
 113 +                           (((32 - *option) + *(option+1)) <= 128))
 114 +                       {
 115 +                               /* IPv4MaskLen */
 116 +                               dest += sprintf(dest, "%u ", *option++);
 117 +                               len--;
 118 +
 119 +                               /* 6rdPrefixLen */
 120 +                               dest += sprintf(dest, "%u ", *option++);
 121 +                               len--;
 122 +
 123 +                               /* 6rdPrefix */
 124 +                               dest += sprint_nip6(dest, "", option);
 125 +                               option += 16;
 126 +                               len -= 16;
 127 +
 128 +                               /* 6rdBRIPv4Addresses */
 129 +                               while (len >= 4)
 130 +                               {
 131 +                                       dest += sprint_nip(dest, " ", option);
 132 +                                       option += 4;
 133 +                                       len -= 4;
 134 +
 135 +                                       /* the code to determine the option size fails to work with
 136 +                                        * lengths that are not a multiple of the minimum length,
 137 +                                        * adding all advertised 6rdBRIPv4Addresses here would
 138 +                                        * overflow the destination buffer, therefore skip the rest
 139 +                                        * for now
 140 +                                        */
 141 +                                       break;
 142 +                               }
 143 +                       }
 144 +
 145 +                       return ret;
 146 +               }
 147  #if ENABLE_FEATURE_UDHCP_RFC3397
 148                 case OPTION_DNS_STRING:
 149                         /* unpack option into dest; use ret for prefix (i.e., "optname=") */