/*      $NetBSD: ipsec.h,v 1.94 2026/04/05 10:19:57 andvar Exp $        */
/*      $FreeBSD: ipsec.h,v 1.2.4.2 2004/02/14 22:23:23 bms Exp $       */
/*      $KAME: ipsec.h,v 1.53 2001/11/20 08:32:38 itojun Exp $  */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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 project 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 PROJECT 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 PROJECT 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.
 */

#ifndef _NETIPSEC_IPSEC_H_
#define _NETIPSEC_IPSEC_H_

#if defined(_KERNEL_OPT)
#include "opt_inet.h"
#include "opt_ipsec.h"
#endif

#include <net/pfkeyv2.h>

#ifdef _KERNEL
#include <sys/socketvar.h>
#include <sys/localcount.h>

#include <netinet/in_pcb.h>
#include <netipsec/keydb.h>

/*
 * Security Policy Index
 * Ensure that both address families in the "src" and "dst" are same.
 * When the value of the ul_proto is ICMPv6, the port field in "src"
 * specifies ICMPv6 type, and the port field in "dst" specifies ICMPv6 code.
 */
struct secpolicyindex {
        u_int8_t dir;                   /* direction of packet flow, see blow */
        union sockaddr_union src;       /* IP src address for SP */
        union sockaddr_union dst;       /* IP dst address for SP */
        u_int8_t prefs;                 /* prefix length in bits for src */
        u_int8_t prefd;                 /* prefix length in bits for dst */
        u_int16_t ul_proto;             /* upper layer Protocol */
};

/* Security Policy Data Base */
struct secpolicy {
        struct pslist_entry pslist_entry;

        struct localcount localcount;   /* reference count */
        struct secpolicyindex spidx;    /* selector */
        u_int32_t id;                   /* It's unique number on the system. */
        u_int state;                    /* 0: dead, others: alive */
#define IPSEC_SPSTATE_DEAD      0
#define IPSEC_SPSTATE_ALIVE     1

        u_int origin;                   /* who generate this SP. */
#define IPSEC_SPORIGIN_USER     0
#define IPSEC_SPORIGIN_KERNEL   1

        u_int policy;           /* DISCARD, NONE or IPSEC, see keyv2.h */
        struct ipsecrequest *req;
                                /* pointer to the ipsec request tree, */
                                /* if policy == IPSEC else this value == NULL.*/

        /*
         * lifetime handler.
         * the policy can be used without limitation if both lifetime and
         * validtime are zero.
         * "lifetime" is passed by sadb_lifetime.sadb_lifetime_addtime.
         * "validtime" is passed by sadb_lifetime.sadb_lifetime_usetime.
         */
        time_t created;         /* time created the policy */
        time_t lastused;        /* updated every when kernel sends a packet */
        time_t lifetime;        /* duration of the lifetime of this policy */
        time_t validtime;       /* duration this policy is valid without use */
};

/* Request for IPsec */
struct ipsecrequest {
        struct ipsecrequest *next;
                                /* pointer to next structure */
                                /* If NULL, it means the end of chain. */
        struct secasindex saidx;/* hint for search proper SA */
                                /* if __ss_len == 0 then no address specified.*/
        u_int level;            /* IPsec level defined below. */

        struct secpolicy *sp;   /* back pointer to SP */
};

/* security policy in PCB */
struct inpcbpolicy {
        struct secpolicy *sp_in;
        struct secpolicy *sp_out;
        int priv;                       /* privileged socket ? */

        /* cached policy */
        struct {
                struct secpolicy *cachesp;
                struct secpolicyindex cacheidx;
                int cachehint;          /* processing requirement hint: */
#define IPSEC_PCBHINT_UNKNOWN   0       /* Unknown */
#define IPSEC_PCBHINT_YES       1       /* IPsec processing is required */
#define IPSEC_PCBHINT_NO        2       /* IPsec processing not required */
                u_int cachegen;         /* spdgen when cache filled */
        } sp_cache[3];                  /* XXX 3 == IPSEC_DIR_MAX */
        int sp_cacheflags;
#define IPSEC_PCBSP_CONNECTED   1
        struct inpcb *sp_inp;           /* back pointer */
};

extern u_int ipsec_spdgen;

static __inline bool
ipsec_pcb_skip_ipsec(struct inpcbpolicy *pcbsp, int dir)
{

        KASSERT(inp_locked(pcbsp->sp_inp));

        return pcbsp->sp_cache[(dir)].cachehint == IPSEC_PCBHINT_NO &&
            pcbsp->sp_cache[(dir)].cachegen == ipsec_spdgen;
}

/* SP acquiring list table. */
struct secspacq {
        LIST_ENTRY(secspacq) chain;

        struct secpolicyindex spidx;

        time_t created;         /* for lifetime */
        int count;              /* for lifetime */
        /* XXX: here is mbuf place holder to be sent ? */
};
#endif /* _KERNEL */

/* buffer size for formatted output of ipsec address (addr + '%' + scope_id?) */
#define IPSEC_ADDRSTRLEN        (INET6_ADDRSTRLEN + 11)
/* buffer size for ipsec_logsastr() */
#define IPSEC_LOGSASTRLEN       192

/* according to IANA assignment, port 0x0000 and proto 0xff are reserved. */
#define IPSEC_PORT_ANY          0
#define IPSEC_ULPROTO_ANY       255
#define IPSEC_PROTO_ANY         255

/* mode of security protocol */
/* NOTE: DON'T use IPSEC_MODE_ANY at SPD.  It's only use in SAD */
#define IPSEC_MODE_ANY          0       /* i.e. wildcard. */
#define IPSEC_MODE_TRANSPORT    1
#define IPSEC_MODE_TUNNEL       2
#define IPSEC_MODE_TCPMD5       3       /* TCP MD5 mode */

/*
 * Direction of security policy.
 * NOTE: Since INVALID is used just as flag.
 * The other are used for loop counter too.
 */
#define IPSEC_DIR_ANY           0
#define IPSEC_DIR_INBOUND       1
#define IPSEC_DIR_OUTBOUND      2
#define IPSEC_DIR_MAX           3
#define IPSEC_DIR_INVALID       4

#define IPSEC_DIR_IS_VALID(dir)         ((dir) >= 0 && (dir) <= IPSEC_DIR_MAX)
#define IPSEC_DIR_IS_INOROUT(dir)       ((dir) == IPSEC_DIR_INBOUND || \
                                         (dir) == IPSEC_DIR_OUTBOUND)

/* Policy level */
/*
 * IPSEC, ENTRUST and BYPASS are allowed for setsockopt() in PCB,
 * DISCARD, IPSEC and NONE are allowed for setkey() in SPD.
 * DISCARD and NONE are allowed for system default.
 */
#define IPSEC_POLICY_DISCARD    0       /* discarding packet */
#define IPSEC_POLICY_NONE       1       /* through IPsec engine */
#define IPSEC_POLICY_IPSEC      2       /* do IPsec */
#define IPSEC_POLICY_ENTRUST    3       /* consulting SPD if present. */
#define IPSEC_POLICY_BYPASS     4       /* only for privileged socket. */

/* Security protocol level */
#define IPSEC_LEVEL_DEFAULT     0       /* reference to system default */
#define IPSEC_LEVEL_USE         1       /* use SA if present. */
#define IPSEC_LEVEL_REQUIRE     2       /* require SA. */
#define IPSEC_LEVEL_UNIQUE      3       /* unique SA. */

#define IPSEC_MANUAL_REQID_MAX  0x3fff
                                /*
                                 * if security policy level == unique, this id
                                 * indicate to a relative SA for use, else is
                                 * zero.
                                 * 1 - 0x3fff are reserved for manual keying.
                                 * 0 are reserved for above reason.  Others is
                                 * for kernel use.
                                 * Note that this id doesn't identify SA
                                 * by only itself.
                                 */
#define IPSEC_REPLAYWSIZE  32

#ifdef _KERNEL

extern int ipsec_debug;
#ifdef IPSEC_DEBUG
extern int ipsec_replay;
extern int ipsec_integrity;
#endif

extern struct secpolicy ip4_def_policy;
extern int ip4_esp_trans_deflev;
extern int ip4_esp_net_deflev;
extern int ip4_ah_trans_deflev;
extern int ip4_ah_net_deflev;
extern int ip4_ah_cleartos;
extern int ip4_ah_offsetmask;
extern int ip4_ipsec_dfbit;
extern int ip4_ipsec_ecn;
extern int crypto_support;

#include <sys/syslog.h>

#define DPRINTF(fmt, args...)                                           \
        do {                                                            \
                if (ipsec_debug)                                        \
                        log(LOG_DEBUG, "%s: " fmt, __func__, ##args);   \
        } while (/*CONSTCOND*/0)

#define IPSECLOG(level, fmt, args...)                                   \
        do {                                                            \
                if (ipsec_debug)                                        \
                        log(level, "%s: " fmt, __func__, ##args);       \
        } while (/*CONSTCOND*/0)

#define ipsec_indone(m) \
        ((m->m_flags & M_AUTHIPHDR) || (m->m_flags & M_DECRYPTED))
#define ipsec_outdone(m) \
        (m_tag_find((m), PACKET_TAG_IPSEC_OUT_DONE) != NULL)

static __inline bool
ipsec_skip_pfil(struct mbuf *m)
{
        bool rv;

        if (ipsec_indone(m) &&
            ((m->m_pkthdr.pkthdr_flags & PKTHDR_FLAG_IPSEC_SKIP_PFIL) != 0)) {
                m->m_pkthdr.pkthdr_flags &= ~PKTHDR_FLAG_IPSEC_SKIP_PFIL;
                rv = true;
        } else {
                rv = false;
        }

        return rv;
}

void ipsec_pcbconn(struct inpcbpolicy *);
void ipsec_pcbdisconn(struct inpcbpolicy *);
void ipsec_invalpcbcacheall(void);

struct inpcb;
int ipsec4_output(struct mbuf *, struct inpcb *, int, u_long *, bool *, bool *, bool *);

int ipsec_ip_input_checkpolicy(struct mbuf *, bool);
void ipsec_mtu(struct mbuf *, int *);
#ifdef INET6
void ipsec6_udp_cksum(struct mbuf *);
#endif

struct inpcb;
int ipsec_init_pcbpolicy(struct socket *so, struct inpcbpolicy **);
int ipsec_copy_policy(const struct inpcbpolicy *, struct inpcbpolicy *);
u_int ipsec_get_reqlevel(const struct ipsecrequest *);

int ipsec_set_policy(struct inpcb *, const void *, size_t, kauth_cred_t);
int ipsec_get_policy(struct inpcb *, const void *, size_t, struct mbuf **);
int ipsec_delete_pcbpolicy(struct inpcb *);
int ipsec_in_reject(struct mbuf *, struct inpcb *);

struct secasvar *ipsec_lookup_sa(const struct ipsecrequest *,
    const struct mbuf *);

struct secas;
struct tcpcb;
int ipsec_chkreplay(u_int32_t, const struct secasvar *);
int ipsec_updatereplay(u_int32_t, const struct secasvar *);

size_t ipsec_hdrsiz(struct mbuf *, u_int, struct inpcb *);
size_t ipsec4_hdrsiz_tcp(struct tcpcb *);

union sockaddr_union;
const char *ipsec_address(const union sockaddr_union* sa, char *, size_t);
const char *ipsec_logsastr(const struct secasvar *, char *, size_t);

/* NetBSD protosw ctlin entrypoint */
void *esp4_ctlinput(int, const struct sockaddr *, void *);
void *ah4_ctlinput(int, const struct sockaddr *, void *);

void ipsec_output_init(void);
struct m_tag;
void ipsec4_common_input(struct mbuf *m, int, int);
int ipsec4_common_input_cb(struct mbuf *, struct secasvar *, int, int);
int ipsec4_process_packet(struct mbuf *, const struct ipsecrequest *, u_long *);
int ipsec_process_done(struct mbuf *, const struct ipsecrequest *,
    struct secasvar *, int);

struct mbuf *m_clone(struct mbuf *);
struct mbuf *m_makespace(struct mbuf *, int, int, int *);
void *m_pad(struct mbuf *, int);
int m_striphdr(struct mbuf *, int, int);

extern int ipsec_used __read_mostly;
extern int ipsec_enabled __read_mostly;

#endif /* _KERNEL */

#ifndef _KERNEL
char *ipsec_set_policy(const char *, int);
int ipsec_get_policylen(char *);
char *ipsec_dump_policy(char *, const char *);
const char *ipsec_strerror(void);
#endif /* !_KERNEL */

#ifdef _KERNEL
/* External declarations of per-file init functions */
void ah_attach(void);
void esp_attach(void);
void ipcomp_attach(void);
void ipe4_attach(void);
void tcpsignature_attach(void);

void ipsec_attach(void);

void sysctl_net_inet_ipsec_setup(struct sysctllog **);
#ifdef INET6
void sysctl_net_inet6_ipsec6_setup(struct sysctllog **);
#endif

#endif /* _KERNEL */
#endif /* !_NETIPSEC_IPSEC_H_ */