ip.h

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#ifndef _IPXE_IP_H
#define _IPXE_IP_H

/** @file
 *
 * IP protocol
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stdint.h>
#include <ipxe/in.h>
#include <ipxe/list.h>
#include <ipxe/retry.h>
#include <ipxe/netdevice.h>

struct io_buffer;

/* IP constants */

#define IP_VER                  0x40U
#define IP_MASK_VER             0xf0U
#define IP_MASK_HLEN            0x0fU
#define IP_MASK_OFFSET          0x1fffU
#define IP_MASK_DONOTFRAG       0x4000U
#define IP_MASK_MOREFRAGS       0x2000U
#define IP_PSHLEN       12

/* IP header defaults */
#define IP_TOS          0
#define IP_TTL          64

/** An IPv4 packet header */
struct iphdr {
        uint8_t  verhdrlen;
        uint8_t  service;
        uint16_t len;
        uint16_t ident;
        uint16_t frags;
        uint8_t  ttl;
        uint8_t  protocol;
        uint16_t chksum;
        struct in_addr src;
        struct in_addr dest;
} __attribute__ (( packed ));

/** An IPv4 pseudo header */
struct ipv4_pseudo_header {
        struct in_addr src;
        struct in_addr dest;
        uint8_t zero_padding;
        uint8_t protocol;
        uint16_t len;
};

/** An IPv4 address/routing table entry
 *
 * Routing table entries are maintained in order of specificity.  For
 * a given destination address, the first matching table entry will be
 * used as the egress route.
 */
struct ipv4_miniroute {
        /** List of miniroutes */
        struct list_head list;

        /** Network device
         *
         * When this routing table entry is matched, this is the
         * egress network device to be used.
         */
        struct net_device *netdev;

        /** IPv4 address
         *
         * When this routing table entry is matched, this is the
         * source address to be used.
         *
         * The presence of this routing table entry also indicates
         * that this address is a valid local destination address for
         * the matching network device.
         */
        struct in_addr address;
        /** Subnet network address
         *
         * A subnet is a range of addresses defined by a network
         * address and subnet mask.  A destination address with all of
         * the subnet mask bits in common with the network address is
         * within the subnet and therefore matches this routing table
         * entry.
         */
        struct in_addr network;
        /** Subnet mask
         *
         * An address with all of these bits in common with the
         * network address matches this routing table entry.
         */
        struct in_addr netmask;
        /** Gateway address, or zero
         *
         * When this routing table entry is matched and this address
         * is non-zero, it will be used as the next-hop address.
         *
         * When this routing table entry is matched and this address
         * is zero, the subnet is local (on-link) and the next-hop
         * address will be the original destination address.
         */
        struct in_addr gateway;
        /** Host mask
         *
         * An address in a local subnet with all of these bits set to
         * zero represents the network address, and an address in a
         * local subnet with all of these bits set to one represents
         * the local directed broadcast address.  All other addresses
         * in a local subnet are valid host addresses.
         *
         * For most local subnets, this is the inverse of the subnet
         * mask.  In a small subnet (/31 or /32) there is no network
         * address or directed broadcast address, and all addresses in
         * the subnet are valid host addresses.
         *
         * When this routing table entry is matched and the subnet is
         * local, a next-hop address with all of these bits set to one
         * will be treated as a local broadcast address.  All other
         * next-hop addresses will be treated as unicast addresses.
         *
         * When this routing table entry is matched and the subnet is
         * non-local, the next-hop address is always a unicast
         * address.  The host mask for non-local subnets is therefore
         * set to @c INADDR_NONE to allow the same logic to be used as
         * for local subnets.
         */
        struct in_addr hostmask;
};

extern struct list_head ipv4_miniroutes;

extern struct net_protocol ipv4_protocol __net_protocol;

extern struct ipv4_miniroute * ipv4_route ( unsigned int scope_id,
                                            struct in_addr *dest );
extern int ipv4_has_any_addr ( struct net_device *netdev );
extern int parse_ipv4_setting ( const struct setting_type *type,
                                const char *value, void *buf, size_t len );
extern int format_ipv4_setting ( const struct setting_type *type,
                                 const void *raw, size_t raw_len, char *buf,
                                 size_t len );

#endif /* _IPXE_IP_H */