/*      $OpenBSD: dhcpd.h,v 1.3 2025/02/07 23:08:48 bluhm Exp $ */

/*
 * Copyright (c) 2017 Rafael Zalamena <rzalamena@openbsd.org>
 * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
 * Copyright (c) 1995, 1996, 1997, 1998, 1999
 * The Internet Software Consortium.    All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
 * Enterprises.  To learn more about the Internet Software Consortium,
 * see ``http://www.vix.com/isc''.  To learn more about Vixie
 * Enterprises, see ``http://www.vix.com''.
 */

#ifndef _DHCPD_H_
#define _DHCPD_H_

#include <sys/queue.h>

#define DHCRELAY6_USER  "_dhcp"

/* Maximum size of client hardware address. */
#define CHADDR_SIZE     16

/* Packet context for assembly/disassembly. */
struct packet_ctx {
        /* Client or server socket descriptor. */
        int                              pc_sd;

        /* Layer 2 address information. */
        uint8_t                          pc_htype;
        uint8_t                          pc_hlen;
        uint8_t                          pc_smac[CHADDR_SIZE];
        uint8_t                          pc_dmac[CHADDR_SIZE];

        /* Layer 3 address information. */
        uint16_t                         pc_ethertype;
        struct sockaddr_storage          pc_srcorig;
        struct sockaddr_storage          pc_src;
        struct sockaddr_storage          pc_dst;

        /* Relay Agent Information data. */
        uint8_t                         *pc_raidata;
        size_t                           pc_raidatalen;
        uint32_t                         pc_enterpriseno;
        uint8_t                         *pc_remote;
        size_t                           pc_remotelen;
};

struct hardware {
        u_int8_t htype;
        u_int8_t hlen;
        u_int8_t haddr[CHADDR_SIZE];
};

/* DHCP relaying modes. */
enum dhcp_relay_mode {
        DRM_UNKNOWN,
        DRM_LAYER2,
        DRM_LAYER3,
};

struct interface_info {
        struct hardware          hw_address;
        struct in_addr           primary_address;
        char                     name[IFNAMSIZ];
        int                      rfdesc;
        int                      wfdesc;
        unsigned char           *rbuf;
        size_t                   rbuf_max;
        size_t                   rbuf_offset;
        size_t                   rbuf_len;
        struct ifreq             ifr;
        int                      noifmedia;
        int                      errors;
        int                      dead;
        uint16_t                 index;

        int                      ipv6; /* Has any IPv6 address. */
        int                      gipv6; /* Has global IPv6 address. */
        struct in6_addr          linklocal; /* IPv6 link-local address. */

        TAILQ_ENTRY(interface_info) entry;
};
TAILQ_HEAD(intfq, interface_info);

struct timeout {
        struct timeout  *next;
        time_t           when;
        void             (*func)(void *);
        void            *what;
};

struct protocol {
        struct protocol *next;
        int fd;
        void (*handler)(struct protocol *);
        void *local;
};

struct server_list {
        struct interface_info *intf;
        struct sockaddr_storage to;
        int fd;
        int siteglobaladdr;
        TAILQ_ENTRY(server_list) entry;
};
TAILQ_HEAD(serverq, server_list);

/* bpf.c */
int if_register_bpf(struct interface_info *);
void if_register_send(struct interface_info *);
void if_register_receive(struct interface_info *);
ssize_t send_packet(struct interface_info *,
    void *, size_t, struct packet_ctx *);
ssize_t receive_packet(struct interface_info *, unsigned char *, size_t,
    struct packet_ctx *);

/* dispatch.c */
extern void (*bootp_packet_handler)(struct interface_info *,
    void *, size_t, struct packet_ctx *);
void setup_iflist(void);
struct interface_info *iflist_getbyname(const char *);
struct interface_info *iflist_getbyindex(unsigned int);
struct interface_info *iflist_getbyaddr6(struct in6_addr *);
struct interface_info *register_interface(const char *,
    void (*)(struct protocol *));
void dispatch(void);
void got_one(struct protocol *);
void add_protocol(char *, int, void (*)(struct protocol *), void *);
void remove_protocol(struct protocol *);

/* packet.c */
void assemble_hw_header(unsigned char *, int *, struct packet_ctx *);
void assemble_udp_ip6_header(unsigned char *, int *, struct packet_ctx *,
    unsigned char *, int);
ssize_t decode_hw_header(unsigned char *, int, struct packet_ctx *);
ssize_t decode_udp_ip6_header(unsigned char *, int, struct packet_ctx *,
    size_t, u_int16_t);

/* dhcrelay6.c */
const char *v6addr2str(struct in6_addr *);

extern struct intfq intflist;
extern struct serverq svlist;
extern time_t cur_time;

static inline struct sockaddr_in6 *
ss2sin6(struct sockaddr_storage *ss)
{
        return ((struct sockaddr_in6 *)ss);
}

#endif /* _DHCPD_H_ */