ndp.h

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#ifndef _IPXE_NDP_H
#define _IPXE_NDP_H

/** @file
 *
 * Neighbour discovery protocol
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stdint.h>
#include <ipxe/in.h>
#include <ipxe/ipv6.h>
#include <ipxe/icmpv6.h>
#include <ipxe/neighbour.h>

/** An NDP option header */
struct ndp_option_header {
        /** Type */
        uint8_t type;
        /** Length (in blocks of 8 bytes) */
        uint8_t blocks;
} __attribute__ (( packed ));

/** NDP option block size */
#define NDP_OPTION_BLKSZ 8U

/** NDP source link-layer address option */
#define NDP_OPT_LL_SOURCE 1

/** NDP target link-layer address option */
#define NDP_OPT_LL_TARGET 2

/** NDP source or target link-layer address option */
struct ndp_ll_addr_option {
        /** NDP option header */
        struct ndp_option_header header;
        /** Link-layer address */
        uint8_t ll_addr[0];
} __attribute__ (( packed ));

/** NDP prefix information option */
#define NDP_OPT_PREFIX 3

/** NDP prefix information */
struct ndp_prefix_information_option {
        /** NDP option header */
        struct ndp_option_header header;
        /** Prefix length */
        uint8_t prefix_len;
        /** Flags */
        uint8_t flags;
        /** Valid lifetime */
        uint32_t valid;
        /** Preferred lifetime */
        uint32_t preferred;
        /** Reserved */
        uint32_t reserved;
        /** Prefix */
        struct in6_addr prefix;
} __attribute__ (( packed ));

/** NDP on-link flag */
#define NDP_PREFIX_ON_LINK 0x80

/** NDP autonomous address configuration flag */
#define NDP_PREFIX_AUTONOMOUS 0x40

/** NDP recursive DNS server option */
#define NDP_OPT_RDNSS 25

/** NDP recursive DNS server */
struct ndp_rdnss_option {
        /** NDP option header */
        struct ndp_option_header header;
        /** Reserved */
        uint16_t reserved;
        /** Lifetime */
        uint32_t lifetime;
        /** Addresses */
        struct in6_addr addresses[0];
} __attribute__ (( packed ));

/** NDP DNS search list option */
#define NDP_OPT_DNSSL 31

/** NDP DNS search list */
struct ndp_dnssl_option {
        /** NDP option header */
        struct ndp_option_header header;
        /** Reserved */
        uint16_t reserved;
        /** Lifetime */
        uint32_t lifetime;
        /** Domain names */
        uint8_t names[0];
} __attribute__ (( packed ));

/** An NDP option */
union ndp_option {
        /** Option header */
        struct ndp_option_header header;
        /** Source or target link-layer address option */
        struct ndp_ll_addr_option ll_addr;
        /** Prefix information option */
        struct ndp_prefix_information_option prefix;
        /** Recursive DNS server option */
        struct ndp_rdnss_option rdnss;
        /** DNS search list option */
        struct ndp_dnssl_option dnssl;
} __attribute__ (( packed ));

/** An NDP neighbour solicitation or advertisement header */
struct ndp_neighbour_header {
        /** ICMPv6 header */
        struct icmp_header icmp;
        /** Flags */
        uint8_t flags;
        /** Reserved */
        uint8_t reserved[3];
        /** Target address */
        struct in6_addr target;
        /** Options */
        union ndp_option option[0];
} __attribute__ (( packed ));

/** NDP router flag */
#define NDP_NEIGHBOUR_ROUTER 0x80

/** NDP solicited flag */
#define NDP_NEIGHBOUR_SOLICITED 0x40

/** NDP override flag */
#define NDP_NEIGHBOUR_OVERRIDE 0x20

/** An NDP router advertisement header */
struct ndp_router_advertisement_header {
        /** ICMPv6 header */
        struct icmp_header icmp;
        /** Current hop limit */
        uint8_t hop_limit;
        /** Flags */
        uint8_t flags;
        /** Router lifetime */
        uint16_t lifetime;
        /** Reachable time */
        uint32_t reachable;
        /** Retransmission timer */
        uint32_t retransmit;
        /** Options */
        union ndp_option option[0];
} __attribute__ (( packed ));

/** NDP managed address configuration */
#define NDP_ROUTER_MANAGED 0x80

/** NDP other configuration */
#define NDP_ROUTER_OTHER 0x40

/** An NDP router solicitation header */
struct ndp_router_solicitation_header {
        /** ICMPv6 header */
        struct icmp_header icmp;
        /** Reserved */
        uint32_t reserved;
        /** Options */
        union ndp_option option[0];
} __attribute__ (( packed ));

/** An NDP header */
union ndp_header {
        /** ICMPv6 header */
        struct icmp_header icmp;
        /** Neighbour solicitation or advertisement header */
        struct ndp_neighbour_header neigh;
        /** Router solicitation header */
        struct ndp_router_solicitation_header rsol;
        /** Router advertisement header */
        struct ndp_router_advertisement_header radv;
} __attribute__ (( packed ));

extern struct neighbour_discovery ndp_discovery;

/**
 * Transmit packet, determining link-layer address via NDP
 *
 * @v iobuf             I/O buffer
 * @v netdev            Network device
 * @v net_dest          Destination network-layer address
 * @v net_source        Source network-layer address
 * @v ll_source         Source link-layer address
 * @ret rc              Return status code
 */
static inline int ndp_tx ( struct io_buffer *iobuf, struct net_device *netdev,
                           const void *net_dest, const void *net_source,
                           const void *ll_source ) {

        return neighbour_tx ( iobuf, netdev, &ipv6_protocol, net_dest,
                              &ndp_discovery, net_source, ll_source );
}

/** NDP settings block name */
#define NDP_SETTINGS_NAME "ndp"

#endif /* _IPXE_NDP_H */