nhrpd: implement next hop resolution protocol
This provides DMVPN support and integrates to strongSwan. Please read
README.nhrpd and README.kernel for more details.
diff --git a/nhrpd/nhrp_protocol.h b/nhrpd/nhrp_protocol.h
new file mode 100644
index 0000000..a4bc9fa
--- /dev/null
+++ b/nhrpd/nhrp_protocol.h
@@ -0,0 +1,128 @@
+/* nhrp_protocol.h - NHRP protocol definitions
+ *
+ * Copyright (c) 2007-2012 Timo Teräs <timo.teras@iki.fi>
+ *
+ * This software is licensed under the MIT License.
+ * See MIT-LICENSE.txt for additional details.
+ */
+
+#ifndef NHRP_PROTOCOL_H
+#define NHRP_PROTOCOL_H
+
+#include <stdint.h>
+
+/* NHRP Ethernet protocol number */
+#define ETH_P_NHRP 0x2001
+
+/* NHRP Version */
+#define NHRP_VERSION_RFC2332 1
+
+/* NHRP Packet Types */
+#define NHRP_PACKET_RESOLUTION_REQUEST 1
+#define NHRP_PACKET_RESOLUTION_REPLY 2
+#define NHRP_PACKET_REGISTRATION_REQUEST 3
+#define NHRP_PACKET_REGISTRATION_REPLY 4
+#define NHRP_PACKET_PURGE_REQUEST 5
+#define NHRP_PACKET_PURGE_REPLY 6
+#define NHRP_PACKET_ERROR_INDICATION 7
+#define NHRP_PACKET_TRAFFIC_INDICATION 8
+
+/* NHRP Extension Types */
+#define NHRP_EXTENSION_FLAG_COMPULSORY 0x8000
+#define NHRP_EXTENSION_END 0
+#define NHRP_EXTENSION_PAYLOAD 0
+#define NHRP_EXTENSION_RESPONDER_ADDRESS 3
+#define NHRP_EXTENSION_FORWARD_TRANSIT_NHS 4
+#define NHRP_EXTENSION_REVERSE_TRANSIT_NHS 5
+#define NHRP_EXTENSION_AUTHENTICATION 7
+#define NHRP_EXTENSION_VENDOR 8
+#define NHRP_EXTENSION_NAT_ADDRESS 9
+
+/* NHRP Error Indication Codes */
+#define NHRP_ERROR_UNRECOGNIZED_EXTENSION 1
+#define NHRP_ERROR_LOOP_DETECTED 2
+#define NHRP_ERROR_PROTOCOL_ADDRESS_UNREACHABLE 6
+#define NHRP_ERROR_PROTOCOL_ERROR 7
+#define NHRP_ERROR_SDU_SIZE_EXCEEDED 8
+#define NHRP_ERROR_INVALID_EXTENSION 9
+#define NHRP_ERROR_INVALID_RESOLUTION_REPLY 10
+#define NHRP_ERROR_AUTHENTICATION_FAILURE 11
+#define NHRP_ERROR_HOP_COUNT_EXCEEDED 15
+
+/* NHRP CIE Codes */
+#define NHRP_CODE_SUCCESS 0
+#define NHRP_CODE_ADMINISTRATIVELY_PROHIBITED 4
+#define NHRP_CODE_INSUFFICIENT_RESOURCES 5
+#define NHRP_CODE_NO_BINDING_EXISTS 11
+#define NHRP_CODE_BINDING_NON_UNIQUE 13
+#define NHRP_CODE_UNIQUE_ADDRESS_REGISTERED 14
+
+/* NHRP Flags for Resolution request/reply */
+#define NHRP_FLAG_RESOLUTION_SOURCE_IS_ROUTER 0x8000
+#define NHRP_FLAG_RESOLUTION_AUTHORATIVE 0x4000
+#define NHRP_FLAG_RESOLUTION_DESTINATION_STABLE 0x2000
+#define NHRP_FLAG_RESOLUTION_UNIQUE 0x1000
+#define NHRP_FLAG_RESOLUTION_SOURCE_STABLE 0x0800
+#define NHRP_FLAG_RESOLUTION_NAT 0x0002
+
+/* NHRP Flags for Registration request/reply */
+#define NHRP_FLAG_REGISTRATION_UNIQUE 0x8000
+#define NHRP_FLAG_REGISTRATION_NAT 0x0002
+
+/* NHRP Flags for Purge request/reply */
+#define NHRP_FLAG_PURGE_NO_REPLY 0x8000
+
+/* NHRP Authentication extension types (ala Cisco) */
+#define NHRP_AUTHENTICATION_PLAINTEXT 0x00000001
+
+/* NHRP Packet Structures */
+struct nhrp_packet_header {
+ /* Fixed header */
+ uint16_t afnum;
+ uint16_t protocol_type;
+ uint8_t snap[5];
+ uint8_t hop_count;
+ uint16_t packet_size;
+ uint16_t checksum;
+ uint16_t extension_offset;
+ uint8_t version;
+ uint8_t type;
+ uint8_t src_nbma_address_len;
+ uint8_t src_nbma_subaddress_len;
+
+ /* Mandatory header */
+ uint8_t src_protocol_address_len;
+ uint8_t dst_protocol_address_len;
+ uint16_t flags;
+ union {
+ uint32_t request_id;
+ struct {
+ uint16_t code;
+ uint16_t offset;
+ } error;
+ } u;
+} __attribute__((packed));
+
+struct nhrp_cie_header {
+ uint8_t code;
+ uint8_t prefix_length;
+ uint16_t unused;
+ uint16_t mtu;
+ uint16_t holding_time;
+ uint8_t nbma_address_len;
+ uint8_t nbma_subaddress_len;
+ uint8_t protocol_address_len;
+ uint8_t preference;
+} __attribute__((packed));
+
+struct nhrp_extension_header {
+ uint16_t type;
+ uint16_t length;
+} __attribute__((packed));
+
+struct nhrp_cisco_authentication_extension {
+ uint32_t type;
+ uint8_t secret[8];
+} __attribute__((packed));
+
+#endif