[git commit] udhcpc: add support for DHCP option 212 (RFC 5969)
Denys Vlasenko
vda.linux at googlemail.com
Wed Oct 19 20:40:35 UTC 2011
commit: http://git.busybox.net/busybox/commit/?id=1f56e51ca1d96b70635eb1b9df1d1ab0edd98a72
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
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 at googlemail.com>
---
include/libbb.h | 4 +-
networking/udhcp/common.c | 3 ++
networking/udhcp/common.h | 1 +
networking/udhcp/dhcpc.c | 80 +++++++++++++++++++++++++++++++++++++++++++-
4 files changed, 84 insertions(+), 4 deletions(-)
diff --git a/include/libbb.h b/include/libbb.h
index f79b693..f0f54ef 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -814,9 +814,9 @@ void smart_ulltoa5(unsigned long long ul, char buf[5], const char *scale) FAST_F
const char *make_human_readable_str(unsigned long long size,
unsigned long block_size, unsigned long display_unit) FAST_FUNC;
/* Put a string of hex bytes ("1b2e66fe"...), return advanced pointer */
-char *bin2hex(char *buf, const char *cp, int count) FAST_FUNC;
+char *bin2hex(char *dst, const char *src, int count) FAST_FUNC;
/* Reverse */
-char* hex2bin(char *dst, const char *str, int count) FAST_FUNC;
+char* hex2bin(char *dst, const char *src, int count) FAST_FUNC;
/* Generate a UUID */
void generate_uuid(uint8_t *buf) FAST_FUNC;
diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index 70e3461..ba41905 100644
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -59,6 +59,7 @@ const struct dhcp_optflag dhcp_optflags[] = {
{ OPTION_U16 , 0x84 }, /* DHCP_VLAN_ID */
{ OPTION_U8 , 0x85 }, /* DHCP_VLAN_PRIORITY */
#endif
+ { OPTION_6RD , 0xd4 }, /* DHCP_6RD */
{ OPTION_STATIC_ROUTES , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
{ OPTION_STRING , 0xfc }, /* DHCP_WPAD */
@@ -126,6 +127,7 @@ const char dhcp_option_strings[] ALIGN1 =
"vlanid" "\0" /* DHCP_VLAN_ID */
"vlanpriority" "\0"/* DHCP_VLAN_PRIORITY */
#endif
+ "ip6rd" "\0" /* DHCP_6RD */
"msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
"wpad" "\0" /* DHCP_WPAD */
;
@@ -154,6 +156,7 @@ const uint8_t dhcp_option_lengths[] ALIGN1 = {
[OPTION_S32] = 4,
/* Just like OPTION_STRING, we use minimum length here */
[OPTION_STATIC_ROUTES] = 5,
+ [OPTION_6RD] = 22, /* ignored by udhcp_str2optset */
};
diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index 7862668..da0bd38 100644
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -88,6 +88,7 @@ enum {
OPTION_S32,
OPTION_BIN,
OPTION_STATIC_ROUTES,
+ OPTION_6RD,
#if ENABLE_FEATURE_UDHCP_RFC3397
OPTION_DNS_STRING, /* RFC1035 compressed domain name list */
OPTION_SIP_SERVERS,
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 @@ static const uint8_t len_of_option_as_string[] = {
[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 @@ static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
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 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_
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 @@ static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_
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 @@ static char **fill_envp(struct dhcp_packet *packet)
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++;
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