udhcpc: add support for DHCP option 212 (RFC 5969)
The patch is from OpenWRT people.
function old new delta
xmalloc_optname_optval 637 874 +237
dhcp_option_strings 237 243 +6
dhcp_optflags 68 70 +2
len_of_option_as_string 12 13 +1
dhcp_option_lengths 12 13 +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/0 up/down: 247/0) Total: 247 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index ddfe3cc..311d486 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -100,6 +100,7 @@
[OPTION_IP ] = sizeof("255.255.255.255 "),
[OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2,
[OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "),
+ [OPTION_6RD ] = sizeof("32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 "),
[OPTION_STRING ] = 1,
#if ENABLE_FEATURE_UDHCP_RFC3397
[OPTION_DNS_STRING ] = 1, /* unused */
@@ -123,6 +124,24 @@
return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
}
+static int sprint_nip6(char *dest, const char *pre, const uint8_t *ip)
+{
+ char hexstrbuf[16 * 2];
+ bin2hex(hexstrbuf, (void*)ip, 16);
+ return sprintf(dest, "%s"
+ "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",
+ pre,
+ hexstrbuf + 0 * 4,
+ hexstrbuf + 1 * 4,
+ hexstrbuf + 2 * 4,
+ hexstrbuf + 3 * 4,
+ hexstrbuf + 4 * 4,
+ hexstrbuf + 5 * 4,
+ hexstrbuf + 6 * 4,
+ hexstrbuf + 7 * 4
+ );
+}
+
/* really simple implementation, just count the bits */
static int mton(uint32_t mask)
{
@@ -147,7 +166,8 @@
type = optflag->flags & OPTION_TYPE_MASK;
optlen = dhcp_option_lengths[type];
- upper_length = len_of_option_as_string[type] * ((unsigned)len / (unsigned)optlen);
+ upper_length = len_of_option_as_string[type]
+ * ((unsigned)(len + optlen - 1) / (unsigned)optlen);
dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
dest += sprintf(ret, "%s=", opt_name);
@@ -232,6 +252,62 @@
return ret;
}
+ case OPTION_6RD: {
+ /* Option binary format (see RFC 5969):
+ * 0 1 2 3
+ * 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
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | OPTION_6RD | option-length | IPv4MaskLen | 6rdPrefixLen |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * | 6rdPrefix |
+ * | (16 octets) |
+ * | |
+ * | |
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | 6rdBRIPv4Address(es) |
+ * . .
+ * . .
+ * . .
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * We convert it to a string
+ * "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address..."
+ */
+
+ /* Sanity check: ensure that our length is at least 22 bytes, that
+ * IPv4MaskLen <= 32,
+ * 6rdPrefixLen <= 128,
+ * 6rdPrefixLen + (32 - IPv4MaskLen) <= 128
+ * (2nd condition need no check - it follows from 1st and 3rd).
+ * If any of these requirements is not fulfilled, return with empty
+ * value.
+ */
+ if (len >= 22
+ && option[0] <= 32
+ && (option[1] + 32 - option[0]) <= 128
+ ) {
+ /* IPv4MaskLen */
+ dest += sprintf(dest, "%u ", *option++);
+ /* 6rdPrefixLen */
+ dest += sprintf(dest, "%u ", *option++);
+ /* 6rdPrefix */
+ dest += sprint_nip6(dest, "", option);
+ option += 16;
+ len -= 1 + 1 + 16;
+ /* 6rdBRIPv4Address(es) */
+ while (1) {
+ dest += sprint_nip(dest, " ", option);
+ option += 4;
+ len -= 4;
+ if (len < 0)
+ break;
+ }
+ }
+
+ return ret;
+ }
#if ENABLE_FEATURE_UDHCP_RFC3397
case OPTION_DNS_STRING:
/* unpack option into dest; use ret for prefix (i.e., "optname=") */
@@ -394,7 +470,7 @@
len = temp[-OPT_DATA + OPT_LEN];
*curr = xmalloc(sizeof("optNNN=") + 1 + len*2);
ofs = sprintf(*curr, "opt%u=", i);
- bin2hex(*curr + ofs, (void*) temp, len)[0] = '\0';
+ *bin2hex(*curr + ofs, (void*) temp, len) = '\0';
putenv(*curr++);
}
i++;