/*      $NetBSD: in_proto.c,v 1.131 2022/09/03 02:53:18 thorpej 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.
 */

/*
 * Copyright (c) 1982, 1986, 1993
 *      The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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.
 *
 *      @(#)in_proto.c  8.2 (Berkeley) 2/9/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in_proto.c,v 1.131 2022/09/03 02:53:18 thorpej Exp $");

#ifdef _KERNEL_OPT
#include "opt_mrouting.h"
#include "opt_inet.h"
#include "opt_ipsec.h"
#include "opt_pim.h"
#include "opt_gateway.h"
#include "opt_dccp.h"
#include "opt_sctp.h"
#include "opt_compat_netbsd.h"
#include "opt_net_mpsafe.h"
#endif

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/domain.h>
#include <sys/mbuf.h>

#include <net/if.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <netinet/in_ifattach.h>
#include <netinet/in_pcb.h>
#include <netinet/in_proto.h>

#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet/ip6.h>
#endif

#include <netinet/igmp_var.h>
#ifdef PIM
#include <netinet/pim_var.h>
#endif
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_debug.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/ip_encap.h>

#ifdef DCCP
#include <netinet/dccp.h>
#include <netinet/dccp_var.h>
#endif

#ifdef SCTP
#include <netinet/sctp.h>
#include <netinet/sctp_var.h>
#endif

/*
 * TCP/IP protocol family: IP, ICMP, UDP, TCP.
 */

#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/key.h>
#endif  /* IPSEC */

#include "carp.h"
#if NCARP > 0
#include <netinet/ip_carp.h>
#endif

#include "pfsync.h"
#if NPFSYNC > 0
#include <net/pfvar.h>
#include <net/if_pfsync.h>
#endif

DOMAIN_DEFINE(inetdomain);      /* forward declare and add to link set */

/* Wrappers to acquire kernel_lock. */

PR_WRAP_CTLINPUT(rip_ctlinput)
PR_WRAP_CTLINPUT(udp_ctlinput)
PR_WRAP_CTLINPUT(tcp_ctlinput)

#define rip_ctlinput    rip_ctlinput_wrapper
#define udp_ctlinput    udp_ctlinput_wrapper
#define tcp_ctlinput    tcp_ctlinput_wrapper

PR_WRAP_CTLOUTPUT(rip_ctloutput)
PR_WRAP_CTLOUTPUT(udp_ctloutput)
PR_WRAP_CTLOUTPUT(tcp_ctloutput)

#define rip_ctloutput   rip_ctloutput_wrapper
#define udp_ctloutput   udp_ctloutput_wrapper
#define tcp_ctloutput   tcp_ctloutput_wrapper

#ifdef DCCP
PR_WRAP_CTLINPUT(dccp_ctlinput)
PR_WRAP_CTLOUTPUT(dccp_ctloutput)

#define dccp_ctlinput   dccp_ctlinput_wrapper
#define dccp_ctloutput  dccp_ctloutput_wrapper
#endif

#ifdef SCTP
PR_WRAP_CTLINPUT(sctp_ctlinput)
PR_WRAP_CTLOUTPUT(sctp_ctloutput)

#define sctp_ctlinput   sctp_ctlinput_wrapper
#define sctp_ctloutput  sctp_ctloutput_wrapper
#endif

#ifdef NET_MPSAFE
PR_WRAP_INPUT(udp_input)
PR_WRAP_INPUT(tcp_input)
#ifdef DCCP
PR_WRAP_INPUT(dccp_input)
#endif
#ifdef SCTP
PR_WRAP_INPUT(sctp_input)
#endif
PR_WRAP_INPUT(rip_input)
#if NPFSYNC > 0
PR_WRAP_INPUT(pfsync_input)
#endif
PR_WRAP_INPUT(igmp_input)
#ifdef PIM
PR_WRAP_INPUT(pim_input)
#endif

#define udp_input               udp_input_wrapper
#define tcp_input               tcp_input_wrapper
#define dccp_input              dccp_input_wrapper
#define sctp_input              sctp_input_wrapper
#define rip_input               rip_input_wrapper
#define pfsync_input            pfsync_input_wrapper
#define igmp_input              igmp_input_wrapper
#define pim_input               pim_input_wrapper
#endif

#if defined(IPSEC)

#ifdef IPSEC_RUMPKERNEL
/*
 * .pr_input = ipsec4_common_input won't be resolved on loading
 * the ipsec shared library. We need a wrapper anyway.
 */
static void
ipsec4_common_input_wrapper(struct mbuf *m, int off, int proto)
{

        if (ipsec_enabled) {
                ipsec4_common_input(m, off, proto);
        } else {
                m_freem(m);
        }
}
#define ipsec4_common_input     ipsec4_common_input_wrapper

/* The ctlinput functions may not be loaded */
#define IPSEC_WRAP_CTLINPUT(name)                       \
static void *                                           \
name##_wrapper(int a, const struct sockaddr *b, void *c)\
{                                                       \
        void *rv;                                       \
        KERNEL_LOCK(1, NULL);                           \
        if (ipsec_enabled)                              \
                rv = name(a, b, c);                     \
        else                                            \
                rv = NULL;                              \
        KERNEL_UNLOCK_ONE(NULL);                        \
        return rv;                                      \
}
IPSEC_WRAP_CTLINPUT(ah4_ctlinput)
IPSEC_WRAP_CTLINPUT(esp4_ctlinput)

#else /* !IPSEC_RUMPKERNEL */

PR_WRAP_CTLINPUT(ah4_ctlinput)
PR_WRAP_CTLINPUT(esp4_ctlinput)

#endif /* !IPSEC_RUMPKERNEL */

#define ah4_ctlinput    ah4_ctlinput_wrapper
#define esp4_ctlinput   esp4_ctlinput_wrapper

#endif /* IPSEC */

const struct protosw inetsw[] = {
{       .pr_domain = &inetdomain,
        .pr_init = ip_init,
        .pr_fasttimo = ip_fasttimo,
        .pr_slowtimo = ip_slowtimo,
        .pr_drain = ip_drainstub,
},
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_ICMP,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input = icmp_input,
        .pr_ctlinput = rip_ctlinput,
        .pr_ctloutput = rip_ctloutput,
        .pr_usrreqs = &rip_usrreqs,
        .pr_init = icmp_init,
},
{       .pr_type = SOCK_DGRAM,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_UDP,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
        .pr_input = udp_input,
        .pr_ctlinput = udp_ctlinput,
        .pr_ctloutput = udp_ctloutput,
        .pr_usrreqs = &udp_usrreqs,
        .pr_init = udp_init,
},
{       .pr_type = SOCK_STREAM,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_TCP,
        .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_LISTEN|PR_ABRTACPTDIS|PR_PURGEIF,
        .pr_input = tcp_input,
        .pr_ctlinput = tcp_ctlinput,
        .pr_ctloutput = tcp_ctloutput,
        .pr_usrreqs = &tcp_usrreqs,
        .pr_init = tcp_init,
        .pr_fasttimo = tcp_fasttimo,
        .pr_drain = tcp_drainstub,
},
#ifdef DCCP
{       .pr_type = SOCK_CONN_DGRAM,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_DCCP,
        .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_ATOMIC|PR_LISTEN|PR_ABRTACPTDIS,
        .pr_input = dccp_input,
        .pr_ctlinput = dccp_ctlinput,
        .pr_ctloutput = dccp_ctloutput,
        .pr_usrreqs = &dccp_usrreqs,
        .pr_init = dccp_init,
},
#endif
#ifdef SCTP
{       .pr_type = SOCK_DGRAM,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_SCTP,
        .pr_flags = PR_ADDR_OPT|PR_WANTRCVD,
        .pr_input = sctp_input,
        .pr_ctlinput = sctp_ctlinput,
        .pr_ctloutput = sctp_ctloutput,
        .pr_usrreqs = &sctp_usrreqs,
        .pr_init = sctp_init,
        .pr_drain = sctp_drain
},
{       .pr_type = SOCK_SEQPACKET,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_SCTP,
        .pr_flags = PR_ADDR_OPT|PR_WANTRCVD,
        .pr_input = sctp_input,
        .pr_ctlinput = sctp_ctlinput,
        .pr_ctloutput = sctp_ctloutput,
        .pr_usrreqs = &sctp_usrreqs,
        .pr_drain = sctp_drain
},
{       .pr_type = SOCK_STREAM,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_SCTP,
        .pr_flags = PR_CONNREQUIRED|PR_ADDR_OPT|PR_WANTRCVD|PR_LISTEN,
        .pr_input = sctp_input,
        .pr_ctlinput = sctp_ctlinput,
        .pr_ctloutput = sctp_ctloutput,
        .pr_usrreqs = &sctp_usrreqs,
        .pr_drain = sctp_drain
},
#endif /* SCTP */
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_RAW,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
        .pr_input = rip_input,
        .pr_ctlinput = rip_ctlinput,
        .pr_ctloutput = rip_ctloutput,
        .pr_usrreqs = &rip_usrreqs,
},
#ifdef GATEWAY
{       .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_IP,
        .pr_slowtimo = ipflow_slowtimo,
        .pr_init = ipflow_poolinit,
},
#endif /* GATEWAY */
#ifdef IPSEC
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_AH,
        .pr_flags = PR_ATOMIC|PR_ADDR,
        .pr_input = ipsec4_common_input,
        .pr_ctlinput = ah4_ctlinput,
},
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_ESP,
        .pr_flags = PR_ATOMIC|PR_ADDR,
        .pr_input = ipsec4_common_input,
        .pr_ctlinput = esp4_ctlinput,
},
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_IPCOMP,
        .pr_flags = PR_ATOMIC|PR_ADDR,
        .pr_input = ipsec4_common_input,
},
#endif /* IPSEC */
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_IPV4,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input = encap4_input,
        .pr_ctlinput = rip_ctlinput,
        .pr_ctloutput = rip_ctloutput,
        .pr_usrreqs = &rip_usrreqs,
        .pr_init = encap_init,
},
#ifdef INET6
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_IPV6,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input = encap4_input,
        .pr_ctlinput = rip_ctlinput,
        .pr_ctloutput = rip_ctloutput,
        .pr_usrreqs = &rip_usrreqs,
        .pr_init = encap_init,
},
#endif /* INET6 */
#if NCARP > 0
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_CARP,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input = carp_proto_input,
        .pr_ctloutput = rip_ctloutput,
        .pr_usrreqs = &rip_usrreqs,
        .pr_init = carp_init,
},
#endif /* NCARP > 0 */
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_L2TP,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input = encap4_input,
        .pr_ctlinput = rip_ctlinput,
        .pr_ctloutput = rip_ctloutput,
        .pr_usrreqs = &rip_usrreqs,     /*XXX*/
        .pr_init = encap_init,
},
#if NPFSYNC > 0
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_PFSYNC,
        .pr_flags        = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input        = pfsync_input,
        .pr_ctloutput = rip_ctloutput,
        .pr_usrreqs      = &rip_usrreqs,
},
#endif /* NPFSYNC > 0 */
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_IGMP,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input = igmp_input, 
        .pr_ctloutput = rip_ctloutput,
        .pr_ctlinput = rip_ctlinput,
        .pr_usrreqs = &rip_usrreqs,
        .pr_fasttimo = igmp_fasttimo,
        .pr_slowtimo = igmp_slowtimo,
        .pr_init = igmp_init,
},
#ifdef PIM
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_protocol = IPPROTO_PIM,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input = pim_input, 
        .pr_ctloutput = rip_ctloutput,
        .pr_ctlinput = rip_ctlinput,
        .pr_usrreqs = &rip_usrreqs,
},
#endif /* PIM */
/* raw wildcard */
{       .pr_type = SOCK_RAW,
        .pr_domain = &inetdomain,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
        .pr_input = rip_input, 
        .pr_ctloutput = rip_ctloutput,
        .pr_ctlinput = rip_ctlinput,
        .pr_usrreqs = &rip_usrreqs,
        .pr_init = rip_init,
},
};

const struct sockaddr_in in_any = {
          .sin_len = sizeof(struct sockaddr_in)
        , .sin_family = AF_INET
        , .sin_port = 0
        , .sin_addr = {.s_addr = 0 /* INADDR_ANY */}
};

struct domain inetdomain = {
        .dom_family = PF_INET, .dom_name = "internet", .dom_init = NULL,
        .dom_externalize = NULL, .dom_dispose = NULL,
        .dom_protosw = inetsw,
        .dom_protoswNPROTOSW = &inetsw[__arraycount(inetsw)],
        .dom_rtattach = rt_inithead,
        .dom_rtoffset = 32,
        .dom_maxrtkey = sizeof(struct ip_pack4),
        .dom_if_up = in_if_up,
        .dom_if_down = in_if_down,
        .dom_ifattach = in_domifattach,
        .dom_ifdetach = in_domifdetach,
        .dom_if_link_state_change = in_if_link_state_change,
        .dom_link = { NULL },
        .dom_mowner = MOWNER_INIT("",""),
        .dom_sa_cmpofs = offsetof(struct sockaddr_in, sin_addr),
        .dom_sa_cmplen = sizeof(struct in_addr),
        .dom_sa_any = (const struct sockaddr *)&in_any,
        .dom_sockaddr_const_addr = sockaddr_in_const_addr,
        .dom_sockaddr_addr = sockaddr_in_addr,
};

u_char  ip_protox[IPPROTO_MAX];

static void
sockaddr_in_addrlen(const struct sockaddr *sa, socklen_t *slenp)
{
        socklen_t slen;

        if (slenp == NULL)
                return;

        slen = sockaddr_getlen(sa);
        *slenp = (socklen_t)MIN(sizeof(struct in_addr),
            slen - MIN(slen, offsetof(struct sockaddr_in, sin_addr)));
}

const void *
sockaddr_in_const_addr(const struct sockaddr *sa, socklen_t *slenp)
{
        const struct sockaddr_in *sin;

        sockaddr_in_addrlen(sa, slenp);
        sin = (const struct sockaddr_in *)sa;
        return &sin->sin_addr;
}

void *
sockaddr_in_addr(struct sockaddr *sa, socklen_t *slenp)
{
        struct sockaddr_in *sin;

        sockaddr_in_addrlen(sa, slenp);
        sin = (struct sockaddr_in *)sa;
        return &sin->sin_addr;
}

int
sockaddr_in_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
{
        uint_fast8_t len;
        const uint_fast8_t addrofs = offsetof(struct sockaddr_in, sin_addr),
                           addrend = addrofs + sizeof(struct in_addr);
        int rc;
        const struct sockaddr_in *sin1, *sin2;

        sin1 = satocsin(sa1);
        sin2 = satocsin(sa2);

        len = MIN(addrend, MIN(sin1->sin_len, sin2->sin_len));

        if (len > addrofs &&
             (rc = memcmp(&sin1->sin_addr, &sin2->sin_addr,
                          len - addrofs)) != 0)
                return rc;

        return sin1->sin_len - sin2->sin_len;
}