/*
 * Copyright (C) 1993-2001 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 *
 * Added redirect stuff and a variety of bug fixes. (mcn@EnGarde.com)
 *
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2014, Joyent, Inc.  All rights reserved.
 */

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/types.h>
#if !defined(__SVR4) && !defined(__svr4__)
#include <strings.h>
#else
#include <sys/byteorder.h>
#endif
#include <sys/time.h>
#include <sys/param.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/file.h>
#define _KERNEL
#include <sys/uio.h>
#undef _KERNEL
#include <sys/socket.h>
#include <sys/ioctl.h>
#if defined(sun) && (defined(__svr4__) || defined(__SVR4))
#include <sys/ioccom.h>
#include <sys/sysmacros.h>
#endif
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <net/if.h>
#if __FreeBSD_version >= 300000
#include <net/if_var.h>
#endif
#include <netdb.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <resolv.h>
#include <ctype.h>
#if defined(linux)
#include <linux/a.out.h>
#else
#include <nlist.h>
#endif
#include "ipf.h"
#include "netinet/ipl.h"
#include "kmem.h"
#include "ipfzone.h"

#ifdef  __hpux
#define nlist   nlist64
#endif

#if     defined(sun) && !SOLARIS2
#define STRERROR(x)     sys_errlist[x]
extern  char    *sys_errlist[];
#else
#define STRERROR(x)     strerror(x)
#endif

int     use_inet6 = 0;
extern char     thishost[MAXHOSTNAMELEN];

extern  char    *optarg;

void    dostats __P((int, natstat_t *, int, int));
void    flushtable __P((int, int));
void    usage __P((char *));
int     main __P((int, char *[]));
void    showhostmap __P((natstat_t *nsp));
void    natstat_dead __P((natstat_t *, char *));
void    dostats_live __P((int, natstat_t *, int));
void    showhostmap_live __P((int, natstat_t *));

int     opts;

void
usage(char *name)
{
        fprintf(stderr, "Usage: %s [-CdFhlnrRsv] [-f filename]", name);
        fprintf(stderr, " [-G|-z zonename]\n");
        exit(1);
}


int
main(int argc, char *argv[])
{
        char *file, *core, *kernel;
        natstat_t ns, *nsp;
        int fd, c, mode;
        ipfobj_t obj;

        fd = -1;
        opts = 0;
        nsp = &ns;
        file = NULL;
        core = NULL;
        kernel = NULL;
        mode = O_RDWR;

        while ((c = getopt(argc, argv, "CdFf:G:hlM:N:nrRsvz:")) != -1)
                switch (c) {
                case 'C' :
                        opts |= OPT_CLEAR;
                        break;
                case 'd' :
                        opts |= OPT_DEBUG;
                        break;
                case 'f' :
                        file = optarg;
                        break;
                case 'F' :
                        opts |= OPT_FLUSH;
                        break;
                case 'G' :
                        setzonename_global(optarg);
                        break;
                case 'h' :
                        opts |= OPT_HITS;
                        break;
                case 'l' :
                        opts |= OPT_LIST;
                        mode = O_RDONLY;
                        break;
                case 'M' :
                        core = optarg;
                        break;
                case 'N' :
                        kernel = optarg;
                        break;
                case 'n' :
                        opts |= OPT_DONOTHING;
                        mode = O_RDONLY;
                        break;
                case 'R' :
                        opts |= OPT_NORESOLVE;
                        break;
                case 'r' :
                        opts |= OPT_REMOVE;
                        break;
                case 's' :
                        opts |= OPT_STAT;
                        mode = O_RDONLY;
                        break;
                case 'v' :
                        opts |= OPT_VERBOSE;
                        break;
                case 'z' :
                        setzonename(optarg);
                        break;
                default :
                        usage(argv[0]);
                }

        initparse();

        if ((kernel != NULL) || (core != NULL)) {
                (void) setgid(getgid());
                (void) setreuid(getuid(), getuid());
        }

        bzero((char *)&ns, sizeof (ns));

        if ((opts & OPT_DONOTHING) == 0) {
                if (checkrev(IPL_NAME) == -1) {
                        fprintf(stderr, "User/kernel version check failed\n");
                        exit(1);
                }
        }


        if (!(opts & OPT_DONOTHING) && (kernel == NULL) && (core == NULL)) {
#ifdef notdef
                if (openkmem(kernel, core) == -1)
                        exit(1);
#endif
                if (((fd = open(IPNAT_NAME, mode)) == -1) &&
                    ((fd = open(IPNAT_NAME, O_RDONLY)) == -1)) {
                        (void) fprintf(stderr, "%s: open: %s\n", IPNAT_NAME,
                            STRERROR(errno));
                        exit(1);
                }

                if (setzone(fd) != 0) {
                        close(fd);
                        exit(1);
                }

                bzero((char *)&obj, sizeof (obj));
                obj.ipfo_rev = IPFILTER_VERSION;
                obj.ipfo_size = sizeof (*nsp);
                obj.ipfo_type = IPFOBJ_NATSTAT;
                obj.ipfo_ptr = (void *)nsp;
                if (ioctl(fd, SIOCGNATS, &obj) == -1) {
                        perror("ioctl(SIOCGNATS)");
                        exit(1);
                }
                (void) setgid(getgid());
                (void) setreuid(getuid(), getuid());
        } else if ((kernel != NULL) || (core != NULL)) {
                if (openkmem(kernel, core) == -1)
                        exit(1);

                natstat_dead(nsp, kernel);
                if (opts & (OPT_LIST|OPT_STAT))
                        dostats(fd, nsp, opts, 0);
                exit(0);
        }

        if (opts & (OPT_FLUSH|OPT_CLEAR))
                flushtable(fd, opts);
        if (file) {
                ipnat_parsefile(fd, ipnat_addrule, ioctl, file);
        }
        if (opts & (OPT_LIST|OPT_STAT))
                dostats(fd, nsp, opts, 1);
        return (0);
}


/*
 * Read NAT statistic information in using a symbol table and memory file
 * rather than doing ioctl's.
 */
void
natstat_dead(natstat_t *nsp, char *kernel)
{
        struct nlist nat_nlist[10] = {
                { "nat_table" },                /* 0 */
                { "nat_list" },
                { "maptable" },
                { "ipf_nattable_sz" },
                { "ipf_natrules_sz" },
                { "ipf_rdrrules_sz" },          /* 5 */
                { "ipf_hostmap_sz" },
                { "nat_instances" },
                { "ap_sess_list" },
                { NULL }
        };
        void *tables[2];

        if (nlist(kernel, nat_nlist) == -1) {
                fprintf(stderr, "nlist error\n");
                return;
        }

        /*
         * Normally the ioctl copies all of these values into the structure
         * for us, before returning it to userland, so here we must copy each
         * one in individually.
         */
        kmemcpy((char *)&tables, nat_nlist[0].n_value, sizeof (tables));
        nsp->ns_table[0] = tables[0];
        nsp->ns_table[1] = tables[1];

        kmemcpy((char *)&nsp->ns_list, nat_nlist[1].n_value,
            sizeof (nsp->ns_list));
        kmemcpy((char *)&nsp->ns_maptable, nat_nlist[2].n_value,
            sizeof (nsp->ns_maptable));
        kmemcpy((char *)&nsp->ns_nattab_sz, nat_nlist[3].n_value,
            sizeof (nsp->ns_nattab_sz));
        kmemcpy((char *)&nsp->ns_rultab_sz, nat_nlist[4].n_value,
            sizeof (nsp->ns_rultab_sz));
        kmemcpy((char *)&nsp->ns_rdrtab_sz, nat_nlist[5].n_value,
            sizeof (nsp->ns_rdrtab_sz));
        kmemcpy((char *)&nsp->ns_hostmap_sz, nat_nlist[6].n_value,
            sizeof (nsp->ns_hostmap_sz));
        kmemcpy((char *)&nsp->ns_instances, nat_nlist[7].n_value,
            sizeof (nsp->ns_instances));
        kmemcpy((char *)&nsp->ns_apslist, nat_nlist[8].n_value,
            sizeof (nsp->ns_apslist));
}


/*
 * Display NAT statistics.
 */
void
dostats(int fd, natstat_t *nsp, int opts, int alive)
{
        nat_t *np, nat;
        ipnat_t ipn;

        /*
         * Show statistics ?
         */
        if (opts & OPT_STAT) {
                printf("mapped\tin\t%lu\tout\t%lu\n",
                    nsp->ns_mapped[0], nsp->ns_mapped[1]);
                printf("added\t%lu\texpired\t%lu\n",
                    nsp->ns_added, nsp->ns_expire);
                printf("no memory\t%lu\tbad nat\t%lu\n",
                    nsp->ns_memfail, nsp->ns_badnat);
                printf("inuse\t%lu\norphans\t%u\nrules\t%lu\n",
                    nsp->ns_inuse, nsp->ns_orphans, nsp->ns_rules);
                printf("wilds\t%u\n", nsp->ns_wilds);
                if (opts & OPT_VERBOSE)
                        printf("table %p list %p\n",
                            nsp->ns_table, nsp->ns_list);
        }

        /*
         * Show list of NAT rules and NAT sessions ?
         */
        if (opts & OPT_LIST) {
                if (alive) {
                        dostats_live(fd, nsp, opts);
                        return;
                }
                printf("List of active MAP/Redirect filters:\n");
                while (nsp->ns_list) {
                        if (kmemcpy((char *)&ipn, (long)nsp->ns_list,
                            sizeof (ipn))) {
                                perror("kmemcpy");
                                break;
                        }
                        if (opts & OPT_HITS)
                                printf("%lu ", ipn.in_hits);
                        printnat(&ipn, opts & (OPT_DEBUG|OPT_VERBOSE));
                        nsp->ns_list = ipn.in_next;
                }

                printf("\nList of active sessions:\n");

                for (np = nsp->ns_instances; np; np = nat.nat_next) {
                        if (kmemcpy((char *)&nat, (long)np, sizeof (nat)))
                                break;
                        printactivenat(&nat, opts, 0);
                        if (nat.nat_aps)
                                printaps(nat.nat_aps, opts);
                }

                if (opts & OPT_VERBOSE)
                        showhostmap(nsp);
        }
}


/*
 * Display the active host mapping table.
 */
void
showhostmap(natstat_t *nsp)
{
        hostmap_t hm, *hmp, **maptable;
        uint_t hv;

        printf("\nList of active host mappings:\n");

        maptable = (hostmap_t **)malloc(sizeof (hostmap_t *) *
            nsp->ns_hostmap_sz);
        if (maptable == NULL) {
                perror("malloc");
                exit(1);
        }
        if (kmemcpy((char *)maptable, (ulong_t)nsp->ns_maptable,
            sizeof (hostmap_t *) * nsp->ns_hostmap_sz)) {
                perror("kmemcpy (maptable)");
                return;
        }

        for (hv = 0; hv < nsp->ns_hostmap_sz; hv++) {
                hmp = maptable[hv];

                while (hmp) {
                        if (kmemcpy((char *)&hm, (ulong_t)hmp, sizeof (hm))) {
                                perror("kmemcpy (hostmap)");
                                return;
                        }

                        printhostmap(&hm, hv);
                        hmp = hm.hm_next;
                }
        }
        free(maptable);
}


/*
 * Issue an ioctl to flush either the NAT rules table or the active mapping
 * table or both.
 */
void
flushtable(int fd, int opts)
{
        int n = 0;

        if (opts & OPT_FLUSH) {
                n = FLUSH_TABLE_ALL;
                if (!(opts & OPT_DONOTHING) && ioctl(fd, SIOCIPFFL, &n) == -1)
                        perror("ioctl(SIOCFLNAT)");
                else
                        printf("%d entries flushed from NAT table\n", n);
        }

        if (opts & OPT_CLEAR) {
                n = FLUSH_LIST;
                if (!(opts & OPT_DONOTHING) && ioctl(fd, SIOCIPFFL, &n) == -1)
                        perror("ioctl(SIOCCNATL)");
                else
                        printf("%d entries flushed from NAT list\n", n);
        }
}

/*
 * Display NAT statistics.
 */
void
dostats_live(int fd, natstat_t *nsp, int opts)
{
        ipfgeniter_t iter;
        ipfobj_t obj;
        ipnat_t ipn;
        nat_t nat;

        bzero((char *)&obj, sizeof (obj));
        obj.ipfo_rev = IPFILTER_VERSION;
        obj.ipfo_type = IPFOBJ_GENITER;
        obj.ipfo_size = sizeof (iter);
        obj.ipfo_ptr = &iter;

        iter.igi_type = IPFGENITER_IPNAT;
        iter.igi_nitems = 1;
        iter.igi_data = &ipn;

        /*
         * Show list of NAT rules and NAT sessions ?
         */
        printf("List of active MAP/Redirect filters:\n");
        while (nsp->ns_list) {
                if (ioctl(fd, SIOCGENITER, &obj) == -1)
                        break;
                if (opts & OPT_HITS)
                        printf("%lu ", ipn.in_hits);
                printnat(&ipn, opts & (OPT_DEBUG|OPT_VERBOSE));
                nsp->ns_list = ipn.in_next;
        }

        printf("\nList of active sessions:\n");

        iter.igi_type = IPFGENITER_NAT;
        iter.igi_nitems = 1;
        iter.igi_data = &nat;

        while (nsp->ns_instances != NULL) {
                if (ioctl(fd, SIOCGENITER, &obj) == -1)
                        break;
                printactivenat(&nat, opts, 1);
                if (nat.nat_aps)
                        printaps(nat.nat_aps, opts);
                nsp->ns_instances = nat.nat_next;
        }

        if (opts & OPT_VERBOSE)
                showhostmap_live(fd, nsp);
}

/*
 * Display the active host mapping table.
 */
void
showhostmap_live(int fd, natstat_t *nsp)
{
        hostmap_t hm, *hmp;
        ipfgeniter_t iter;
        ipfobj_t obj;

        bzero((char *)&obj, sizeof (obj));
        obj.ipfo_rev = IPFILTER_VERSION;
        obj.ipfo_type = IPFOBJ_GENITER;
        obj.ipfo_size = sizeof (iter);
        obj.ipfo_ptr = &iter;

        iter.igi_type = IPFGENITER_HOSTMAP;
        iter.igi_nitems = 1;
        iter.igi_data = &hm;

        printf("\nList of active host mappings:\n");

        while (nsp->ns_maplist != NULL) {
                if (ioctl(fd, SIOCGENITER, &obj) == -1)
                        break;
                printhostmap(&hm, 0);
                nsp->ns_maplist = hm.hm_next;
        }
}