/*      $OpenBSD: if_pflog.c,v 1.27 2007/12/20 02:53:02 brad Exp $      */
/*
 * The authors of this code are John Ioannidis (ji@tla.org),
 * Angelos D. Keromytis (kermit@csd.uch.gr) and 
 * Niels Provos (provos@physnet.uni-hamburg.de).
 *
 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 
 * in November 1995.
 *
 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
 * by Angelos D. Keromytis.
 *
 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
 * and Niels Provos.
 *
 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
 * and Niels Provos.
 * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
 *
 * Copyright (c) 2010 The DragonFly Project.  All rights reserved.
 *
 * Permission to use, copy, and modify this software with or without fee
 * is hereby granted, provided that this entire notice is included in
 * all copies of any software which is or includes a copy or
 * modification of this software. 
 * You may use this code under the GNU public license if you so wish. Please
 * contribute changes back to the authors under this freer than GPL license
 * so that we may further the use of strong encryption without limitations to
 * all.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
 * PURPOSE.
 */

#include "opt_inet.h"
#include "opt_inet6.h"
#include "use_bpf.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/in_cksum.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sockio.h>
#include <sys/thread2.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/ifq_var.h>
#include <net/route.h>
#include <net/bpf.h>

#ifdef  INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#endif

#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/nd6.h>
#endif /* INET6 */

#include <net/pf/pfvar.h>
#include <net/pf/if_pflog.h>

#define PFLOGNAME       "pflog"

#define PFLOGMTU        (32768 + MHLEN + MLEN)

#ifdef PFLOGDEBUG
#define DPRINTF(x)      do { if (pflogdebug) kprintf x ; } while (0)
#else
#define DPRINTF(x)
#endif

static void     pflogattach(void);
static int      pflogoutput(struct ifnet *, struct mbuf *,
                    struct sockaddr *, struct rtentry *);
static int      pflogioctl(struct ifnet *, u_long, caddr_t __unused,
                    struct ucred * __unused);
static void     pflogstart(struct ifnet *, struct ifaltq_subque *);
static int      pflog_clone_create(struct if_clone *, int, caddr_t, caddr_t);
static int      pflog_clone_destroy(struct ifnet *);

static struct if_clone pflog_cloner = IF_CLONE_INITIALIZER(
    PFLOGNAME, pflog_clone_create, pflog_clone_destroy, 1, 1);

static LIST_HEAD(, pflog_softc) pflogif_list;
static struct ifnet *pflogifs[PFLOGIFS_MAX]; /* for fast access */

static void
pflogattach(void)
{
        int     i;
        LIST_INIT(&pflogif_list);
        for (i = 0; i < PFLOGIFS_MAX; i++)
                pflogifs[i] = NULL;
        if_clone_attach(&pflog_cloner);
}

static int
pflog_clone_create(struct if_clone *ifc, int unit,
                   caddr_t params __unused, caddr_t data __unused)
{
        struct ifnet *ifp;
        struct pflog_softc *pflogif;

        lwkt_gettoken(&pf_token);

        if (unit >= PFLOGIFS_MAX) {
                lwkt_reltoken(&pf_token);
                return (EINVAL);
        }

        pflogif = kmalloc(sizeof(*pflogif), M_DEVBUF, M_WAITOK | M_ZERO);
        pflogif->sc_unit = unit;
        lwkt_reltoken(&pf_token);

        ifp = &pflogif->sc_if;
        if_initname(ifp, ifc->ifc_name, unit);
        ifp->if_softc = pflogif;
        ifp->if_mtu = PFLOGMTU;
        ifp->if_ioctl = pflogioctl;
        ifp->if_output = pflogoutput;
        ifp->if_start = pflogstart;
        ifp->if_type = IFT_PFLOG;
        ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
        ifp->if_hdrlen = PFLOG_HDRLEN;

        if_attach(ifp, NULL);
#if NBPF > 0
        bpfattach(&pflogif->sc_if, DLT_PFLOG, PFLOG_HDRLEN);
#endif

        lwkt_gettoken(&pf_token);
        crit_enter();
        LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
        pflogifs[unit] = ifp;
        crit_exit();
        lwkt_reltoken(&pf_token);

        return (0);
}

static int
pflog_clone_destroy(struct ifnet *ifp)
{
        struct pflog_softc      *pflogif = ifp->if_softc;

        lwkt_gettoken(&pf_token);

        crit_enter();
        pflogifs[pflogif->sc_unit] = NULL;
        LIST_REMOVE(pflogif, sc_list);
        crit_exit();

        lwkt_reltoken(&pf_token);
#if NBPF > 0
        bpfdetach(ifp);
#endif
        if_detach(ifp);
        lwkt_gettoken(&pf_token);
        kfree(pflogif, M_DEVBUF);
        lwkt_reltoken(&pf_token);

        return 0;
}

/*
 * Start output on the pflog interface.
 */
static void
pflogstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
{
        struct mbuf *m;

        ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
        ASSERT_LWKT_TOKEN_HELD(&pf_token);

        for (;;) {
                m = ifsq_dequeue(ifsq);
                if (m == NULL)
                        return;
                else
                        m_freem(m);
        }
}

static int
pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
            struct rtentry *rt)
{
        m_freem(m);
        return (0);
}

static int
pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data __unused,
           struct ucred *cr __unused)
{

        lwkt_gettoken(&pf_token);

        switch (cmd) {
        case SIOCSIFFLAGS:
                lwkt_reltoken(&pf_token);
                if (ifp->if_flags & IFF_UP)
                        ifp->if_flags |= IFF_RUNNING;
                else
                        ifp->if_flags &= ~IFF_RUNNING;
                lwkt_gettoken(&pf_token);
                break;
        default:
                lwkt_reltoken(&pf_token);
                return (EINVAL);
        }

        lwkt_reltoken(&pf_token);
        return (0);
}

int
pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
             u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
             struct pf_ruleset *ruleset, struct pf_pdesc *pd)
{
        struct ifnet *ifn = NULL;
        struct pfloghdr hdr;

        ASSERT_LWKT_TOKEN_HELD(&pf_token);

        if (kif == NULL || m == NULL || rm == NULL)
                return (-1);

        if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
                return (0);

        bzero(&hdr, sizeof(hdr));
        hdr.length = PFLOG_REAL_HDRLEN;
        hdr.af = af;
        hdr.action = rm->action;
        hdr.reason = reason;
        memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));

        if (am == NULL) {
                hdr.rulenr = htonl(rm->nr);
                hdr.subrulenr = -1;
        } else {
                hdr.rulenr = htonl(am->nr);
                hdr.subrulenr = htonl(rm->nr);
                if (ruleset != NULL && ruleset->anchor != NULL)
                        strlcpy(hdr.ruleset, ruleset->anchor->name,
                            sizeof(hdr.ruleset));
        }
        if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
                pd->lookup.done = pf_socket_lookup(dir, pd);
        if (pd->lookup.done > 0) {
                hdr.uid = pd->lookup.uid;
                hdr.pid = pd->lookup.pid;
        } else {
                hdr.uid = UID_MAX;
                hdr.pid = NO_PID;
        }
        hdr.rule_uid = rm->cuid;
        hdr.rule_pid = rm->cpid;
        hdr.dir = dir;

#ifdef INET
        if (af == AF_INET) {
                struct ip *ip;
                ip = mtod(m, struct ip *);      

                if (dir == PF_OUT) {
                        ip->ip_sum = 0;
                        ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
                }                               
        }
#endif /* INET */

        IFNET_STAT_INC(ifn, opackets, 1);
        IFNET_STAT_INC(ifn, obytes, m->m_pkthdr.len);
        if (ifn->if_bpf) {
                bpf_gettoken();
                if (ifn->if_bpf) {
                        bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
                            BPF_DIRECTION_OUT);
                }
                bpf_reltoken();
        }

        return (0);
}

static int
pflog_modevent(module_t mod, int type, void *data)
{
        int error = 0;

        struct pflog_softc *pflogif, *tmp;

        lwkt_gettoken(&pf_token);

        switch (type) {
        case MOD_LOAD:
                lwkt_reltoken(&pf_token);
                pflogattach();
                lwkt_gettoken(&pf_token);
                break;

        case MOD_UNLOAD:
                lwkt_reltoken(&pf_token);
                if_clone_detach(&pflog_cloner);
                LIST_FOREACH_MUTABLE(pflogif, &pflogif_list, sc_list, tmp)
                        pflog_clone_destroy(&pflogif->sc_if);
                lwkt_gettoken(&pf_token);
                break;

        default:
                error = EINVAL;
                break;
        }
        lwkt_reltoken(&pf_token);
        return error;
}

static moduledata_t pflog_mod = {
        "pflog",
        pflog_modevent,
        0
};

DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(pflog, PFLOG_MODVER);
/* Do not run before pf is initialized. */
MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER);