Option 77 Additions to dhclient

These changes were present in the dhclient used in pfSense 2.3, they
seem not to have made it into FreeBSD 11 as used in pfSense 2.4.

I have merely taken the changes and applied them to the FreeBSD 11
dhclient. Users who require this have tested it and confirm it is
working fine.

Reworked-by: Franco Fichtner <franco@opnsense.org>

sbin/dhclient/bpf.c

@@ -94,19 +94,30 @@ if_register_bpf(struct interface_info *info, int flags)
  * 'ip and udp and src port bootps and dst port (bootps or bootpc)'
  */
 struct bpf_insn dhcp_bpf_wfilter[] = {
+	/* Set packet index for IP packet... */
+	BPF_STMT(BPF_LDX + BPF_W + BPF_IMM, 0),
+
+	/* Test whether this is a VLAN packet... */
+	BPF_STMT(BPF_LD + BPF_B + BPF_IND, 12),
+	BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_VLAN, 0, 1),
+
+	/* Correct the packet index for VLAN... */
+	BPF_STMT(BPF_LDX + BPF_W + BPF_IMM, 4),
+
+	/* Make sure it is an IPv4 packet... */
 	BPF_STMT(BPF_LD + BPF_B + BPF_IND, 14),
 	BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, (IPVERSION << 4) + 5, 0, 12),
 
 	/* Make sure this is an IP packet... */
-	BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 12),
+	BPF_STMT(BPF_LD + BPF_H + BPF_IND, 12),
 	BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_IP, 0, 10),
 
 	/* Make sure it's a UDP packet... */
-	BPF_STMT(BPF_LD + BPF_B + BPF_ABS, 23),
+	BPF_STMT(BPF_LD + BPF_B + BPF_IND, 23),
 	BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 0, 8),
 
 	/* Make sure this isn't a fragment... */
-	BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 20),
+	BPF_STMT(BPF_LD + BPF_H + BPF_IND, 20),
 	BPF_JUMP(BPF_JMP + BPF_JSET + BPF_K, 0x1fff, 6, 0),	/* patched */
 
 	/* Get the IP header length... */

sbin/dhclient/conflex.c

@@ -471,6 +471,8 @@ intern(char *atom, int dfv)
 	case 's':
 		if (!strcasecmp(atom + 1, "earch"))
 			return (SEARCH);
+		if (!strcasecmp(atom + 1, "end-interface"))
+			return (SEND_INTERFACE);
 		if (!strcasecmp(atom + 1, "tarts"))
 			return (STARTS);
 		if (!strcasecmp(atom + 1, "iaddr"))
@@ -519,6 +521,10 @@ intern(char *atom, int dfv)
 	case 'v':
 		if (!strcasecmp(atom + 1, "endor-class"))
 			return (VENDOR_CLASS);
+		if (!strcasecmp(atom + 1, "lan-id"))
+			return (VLAN_ID);
+		if (!strcasecmp(atom + 1, "lan-pcp"))
+			return (VLAN_PCP);
 		break;
 	case 'y':
 		if (!strcasecmp(atom + 1, "iaddr"))

sbin/dhclient/dhcpd.h

@@ -154,6 +154,9 @@ struct client_config {
 	u_int8_t		 required_options[256];
 	u_int8_t		 requested_options[256];
 	int			 requested_option_count;
+	int			 vlan_id;
+	int			 vlan_pcp;
+	char			*send_interface;
 	time_t			 timeout;
 	time_t			 initial_interval;
 	time_t			 retry_interval;

sbin/dhclient/dhctoken.h

@@ -129,6 +129,9 @@
 #define AUTHORITATIVE	333
 #define TOKEN_NOT	334
 #define ALWAYS_REPLY_RFC1048 335
+#define VLAN_ID		336
+#define VLAN_PCP	337
+#define SEND_INTERFACE	338
 
 #define is_identifier(x)	((x) >= FIRST_TOKEN &&	\
 				 (x) != STRING &&	\

sbin/dhclient/dispatch.c

@@ -69,6 +69,7 @@ static int interface_status(struct interface_info *ifinfo);
 void
 discover_interfaces(struct interface_info *iface)
 {
+	char *sname = iface->client->config->send_interface;
 	struct ifaddrs *ifap, *ifa;
 	struct sockaddr_in foo;
 	struct ifreq *tif;
@@ -124,7 +125,20 @@ discover_interfaces(struct interface_info *iface)
 
 	/* Register the interface... */
 	if_register_receive(iface);
-	if_register_send(iface);
+	if (sname != NULL) {
+		char rname[IFNAMSIZ];
+
+		/* Change interface name for bpf registration */
+		strlcpy(rname, iface->name, IFNAMSIZ);
+		strlcpy(iface->ifp->ifr_name, sname, IFNAMSIZ);
+
+		if_register_send(iface);
+
+		/* Change name back to original */
+		strlcpy(iface->ifp->ifr_name, rname, IFNAMSIZ);
+	} else {
+		if_register_send(iface);
+	}
 	add_protocol(iface->name, iface->rfdesc, got_one, iface);
 	freeifaddrs(ifap);
 }

sbin/dhclient/packet.c

@@ -92,19 +92,29 @@ void
 assemble_hw_header(struct interface_info *interface, unsigned char *buf,
     int *bufix)
 {
-	struct ether_header eh;
-
-	memset(eh.ether_dhost, 0xff, sizeof(eh.ether_dhost));
-	if (interface->hw_address.hlen == sizeof(eh.ether_shost))
-		memcpy(eh.ether_shost, interface->hw_address.haddr,
-		    sizeof(eh.ether_shost));
+	int vlpcp = interface->client->config->vlan_pcp;
+	int vlid = interface->client->config->vlan_id;
+	int plen = ETHER_HEADER_SIZE;
+	struct ether_vlan_header eh;
+
+	memset(eh.evl_dhost, 0xff, sizeof(eh.evl_dhost));
+	if (interface->hw_address.hlen == sizeof(eh.evl_shost))
+		memcpy(eh.evl_shost, interface->hw_address.haddr,
+		    sizeof(eh.evl_shost));
 	else
-		memset(eh.ether_shost, 0x00, sizeof(eh.ether_shost));
+		memset(eh.evl_shost, 0x00, sizeof(eh.evl_shost));
 
-	eh.ether_type = htons(ETHERTYPE_IP);
+	eh.evl_encap_proto = htons(ETHERTYPE_IP);
+
+	if (vlid != 0) {
+		eh.evl_tag = htons(EVL_MAKETAG(vlid, vlpcp, 0));
+		eh.evl_encap_proto = htons(ETHERTYPE_VLAN);
+		eh.evl_proto = htons(ETHERTYPE_IP);
+		plen += ETHER_VLAN_ENCAP_LEN;
+	}
 
-	memcpy(&buf[*bufix], &eh, ETHER_HEADER_SIZE);
-	*bufix += ETHER_HEADER_SIZE;
+	memcpy(&buf[*bufix], &eh, plen);
+	*bufix += plen;
 }
 
 void