/*      $NetBSD: if_pflog.c,v 1.22 2020/01/29 05:52:27 thorpej Exp $    */
/*      $OpenBSD: if_pflog.c,v 1.24 2007/05/26 17:13:30 jason 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.
 *
 * 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_pflog.c,v 1.22 2020/01/29 05:52:27 thorpej Exp $");

#ifdef _KERNEL_OPT
#include "opt_inet.h"
#endif

#include "pflog.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/ioctl.h>

#include <net/if.h>
#include <net/if_types.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/pfvar.h>
#include <net/if_pflog.h>

#include "ioconf.h"

#define PFLOGMTU        (32768 + MHLEN + MLEN)

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

#ifdef _MODULE
void    pflogdetach(void);
#endif /* _MODULE */
int     pflogoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
            const struct rtentry *);
int     pflogioctl(struct ifnet *, u_long, void *);
void    pflogstart(struct ifnet *);
int     pflog_clone_create(struct if_clone *, int);
int     pflog_clone_destroy(struct ifnet *);

LIST_HEAD(, pflog_softc)        pflogif_list;
struct if_clone pflog_cloner =
    IF_CLONE_INITIALIZER("pflog", pflog_clone_create, pflog_clone_destroy);

struct ifnet    *pflogifs[PFLOGIFS_MAX];        /* for fast access */

void
pflogattach(int npflog)
{
        int i;

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

#ifdef _MODULE
void
pflogdetach(void)
{
        int i;

        for (i = 0; i < PFLOGIFS_MAX; i++) {
                if (pflogifs[i] != NULL)
                        pflog_clone_destroy(pflogifs[i]);
        }
        if_clone_detach(&pflog_cloner);
}
#endif /* _MODULE */

int
pflog_clone_create(struct if_clone *ifc, int unit)
{
        struct ifnet *ifp;
        struct pflog_softc *pflogif;
        int s;

        if (unit >= PFLOGIFS_MAX)
                return (EINVAL);

        if ((pflogif = malloc(sizeof(*pflogif), M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
                return (ENOMEM);

        pflogif->sc_unit = unit;
        ifp = &pflogif->sc_if;
        snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", 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;
#ifndef __NetBSD__
        ifp->if_snd.ifq_maxlen = ifqmaxlen;
#endif /* !__NetBSD__ */
        ifp->if_hdrlen = PFLOG_HDRLEN;
        if_attach(ifp);
        if_alloc_sadl(ifp);

#ifdef __NetBSD__
        bpf_attach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
#else
        bpfattach(&pflogif->sc_if.if_bpf, ifp, DLT_PFLOG, PFLOG_HDRLEN);
#endif /* !__NetBSD__ */

        s = splnet();
        LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
        pflogifs[unit] = ifp;
        splx(s);

        return (0);
}

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

        s = splnet();
        pflogifs[pflogif->sc_unit] = NULL;
        LIST_REMOVE(pflogif, sc_list);
        splx(s);

        bpf_detach(ifp);
        if_detach(ifp);
        free(pflogif, M_DEVBUF);
        return (0);
}

/*
 * Start output on the pflog interface.
 */
void
pflogstart(struct ifnet *ifp)
{
        struct mbuf *m;
        int s;

        for (;;) {
                s = splnet();
                IF_DROP(&ifp->if_snd);
                IF_DEQUEUE(&ifp->if_snd, m);
                splx(s);

                if (m == NULL)
                        return;
                else
                        m_freem(m);
        }
}

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

/* ARGSUSED */
int
pflogioctl(struct ifnet *ifp, u_long cmd, void *data)
{
        int error = 0;

        switch (cmd) {
        case SIOCSIFFLAGS:
                if ((error = ifioctl_common(ifp, cmd, data)) != 0)
                        break;
                /*FALLTHROUGH*/
        case SIOCINITIFADDR:
        case SIOCAIFADDR:
        case SIOCSIFDSTADDR:
                if (ifp->if_flags & IFF_UP)
                        ifp->if_flags |= IFF_RUNNING;
                else
                        ifp->if_flags &= ~IFF_RUNNING;
                break;
        default:
                error = ifioctl_common(ifp, cmd, data);
        }

        return error;
}

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;
        struct pfloghdr hdr;

        if (kif == NULL || m == NULL || rm == NULL || pd == 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 && dir == PF_OUT) {
                struct ip *ip;

                ip = mtod(m, struct ip *);
                ip->ip_sum = 0;
                ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
        }
#endif /* INET */

#ifdef __NetBSD__
        if_statadd2(ifn, if_opackets, 1, if_obytes, m->m_pkthdr.len);
#else
        ifn->if_opackets++;
        ifn->if_obytes += m->m_pkthdr.len;
#endif /* __NetBSD__ */

#ifdef __NetBSD__
        bpf_mtap2(ifn->if_bpf, &hdr, PFLOG_HDRLEN, m, BPF_D_OUT);
#else
        bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
            BPF_DIRECTION_OUT);
#endif /* !__NetBSD__ */


        return (0);
}