add support Vendor Class option

This patch adds cli option "-V <hex-string>" which will enable sending
of DHCPv6 option 16 ("vendor class").

Based on Patch by Christian Carstensen

Contributed by T-Labs, Deutsche Telekom Innovation Laboratories

3 files changed, 30 insertions, 8 deletions

diff --git a/src/dhcpv6.c b/src/dhcpv6.c
index eab9cbf..9edf055 100644
--- a/src/dhcpv6.c
+++ b/src/dhcpv6.c
@@ -368,6 +368,15 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 	// Request Information Refresh
 	uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
 
+	// Build vendor-class option
+	size_t vendor_class_len;
+	struct dhcpv6_vendorclass *vendor_class = odhcp6c_get_state(STATE_VENDORCLASS, &vendor_class_len);
+
+	struct {
+		uint16_t type;
+		uint16_t length;
+	} vendor_class_hdr = {htons(DHCPV6_OPT_VENDOR_CLASS), htons(vendor_class_len)};
+
 	// Prepare Header
 	size_t oro_len;
 	void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
@@ -392,6 +401,8 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 		{&oro_refresh, 0},
 		{cl_id, cl_id_len},
 		{srv_id, srv_id_len},
+		{&vendor_class_hdr, vendor_class_len ? sizeof(vendor_class_hdr) : 0},
+		{vendor_class, vendor_class_len},
 		{&reconf_accept, sizeof(reconf_accept)},
 		{&fqdn, fqdn_len},
 		{&hdr_ia_na, sizeof(hdr_ia_na)},
@@ -401,28 +412,28 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 
 	size_t cnt = ARRAY_SIZE(iov);
 	if (type == DHCPV6_MSG_INFO_REQ) {
-		cnt = 5;
+		cnt = 7;
 		iov[2].iov_len = sizeof(oro_refresh);
 		hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
 	} else if (!request_prefix) {
-		cnt = 9;
+		cnt = 11;
 	}
 
 	// Disable IAs if not used
 	if (type != DHCPV6_MSG_SOLICIT) {
-		iov[5].iov_len = 0;
+		iov[7].iov_len = 0;
 		if (ia_na_len == 0)
-			iov[7].iov_len = 0;
+			iov[9].iov_len = 0;
 	}
 
 	if (na_mode == IA_MODE_NONE)
-		iov[7].iov_len = 0;
+		iov[9].iov_len = 0;
 
 	if (!(client_options & DHCPV6_ACCEPT_RECONFIGURE))
-		iov[5].iov_len = 0;
+		iov[7].iov_len = 0;
 
 	if (!(client_options & DHCPV6_CLIENT_FQDN))
-		iov[6].iov_len = 0;
+		iov[8].iov_len = 0;
 
 	struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
 		0, ALL_DHCPV6_RELAYS, ifindex};
diff --git a/src/odhcp6c.c b/src/odhcp6c.c
index 9334c7a..1e8e2bc 100644
--- a/src/odhcp6c.c
+++ b/src/odhcp6c.c
@@ -76,7 +76,7 @@ int main(_unused int argc, char* const argv[])
 	int c;
 	unsigned int client_options = DHCPV6_CLIENT_FQDN | DHCPV6_ACCEPT_RECONFIGURE;
 
-	while ((c = getopt(argc, argv, "S::N:P:FB:c:i:r:Rs:kt:hedp:fa")) != -1) {
+	while ((c = getopt(argc, argv, "S::N:V:P:FB:c:i:r:Rs:kt:hedp:fa")) != -1) {
 		switch (c) {
 		case 'S':
 			allow_slaac_only = (optarg) ? atoi(optarg) : -1;
@@ -95,6 +95,14 @@ int main(_unused int argc, char* const argv[])
 			}
 			break;
 
+		case 'V':
+			l = script_unhexlify(buf, sizeof(buf), optarg);
+			if (!l)
+				help=true;
+
+			odhcp6c_add_state(STATE_VENDORCLASS, buf, l);
+
+			break;
 		case 'P':
 			if (allow_slaac_only >= 0 && allow_slaac_only < 10)
 				allow_slaac_only = 10;
@@ -414,6 +422,7 @@ static int usage(void)
 	"	-N <mode>	Mode for requesting addresses [try|force|none]\n"
 	"	-P <length>	Request IPv6-Prefix (0 = auto)\n"
 	"	-F		Force IPv6-Prefix\n"
+	"	-V <hex-string>	Set vendor-class option. string length must be a multiple of 2\n"
 #ifdef EXT_BFD_PING
 	"	-B <interval>	Enable BFD ping check\n"
 #endif
diff --git a/src/odhcp6c.h b/src/odhcp6c.h
index 024ebea..4ccbcdd 100644
--- a/src/odhcp6c.h
+++ b/src/odhcp6c.h
@@ -43,6 +43,7 @@ enum dhcvp6_opt {
 	DHCPV6_OPT_AUTH = 11,
 	DHCPV6_OPT_STATUS = 13,
 	DHCPV6_OPT_RAPID_COMMIT = 14,
+	DHCPV6_OPT_VENDOR_CLASS = 16,
 	DHCPV6_OPT_RECONF_MESSAGE = 19,
 	DHCPV6_OPT_RECONF_ACCEPT = 20,
 	DHCPV6_OPT_DNS_SERVERS = 23,
@@ -209,6 +210,7 @@ enum odhcp6c_state {
 	STATE_RA_PREFIX,
 	STATE_RA_DNS,
 	STATE_AFTR_NAME,
+	STATE_VENDORCLASS,
 	_STATE_MAX
 };