ipf/netinet/ip_ftp_pxy.c

	ip_ftp_pxy.c revision ab25eeb551a4be927a4b6ae2cf8aff7ed17decb4
/*
 * Copyright (C) 1997-2003 by Darren Reed
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 *
 * $Id: ip_ftp_pxy.c,v 2.88.2.15 2005/03/19 19:38:10 darrenr Exp $
 *
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Simple FTP transparent proxy for in-kernel use.  For use with the NAT
 * code.
*/

#pragma ident   "%Z%%M% %I% %E% SMI"


#define IPF_FTP_PROXY

#define IPF_MINPORTLEN  18
#define IPF_MAXPORTLEN  30
#define IPF_MIN227LEN   39
#define IPF_MAX227LEN   51
#define IPF_MIN229LEN   47
#define IPF_MAX229LEN   51

#define FTPXY_GO    0
#define FTPXY_INIT  1
#define FTPXY_USER_1    2
#define FTPXY_USOK_1    3
#define FTPXY_PASS_1    4
#define FTPXY_PAOK_1    5
#define FTPXY_AUTH_1    6
#define FTPXY_AUOK_1    7
#define FTPXY_ADAT_1    8
#define FTPXY_ADOK_1    9
#define FTPXY_ACCT_1    10
#define FTPXY_ACOK_1    11
#define FTPXY_USER_2    12
#define FTPXY_USOK_2    13
#define FTPXY_PASS_2    14
#define FTPXY_PAOK_2    15

/*
 * Values for FTP commands.  Numerics cover 0-999
 */
#define FTPXY_C_PASV    1000

int ippr_ftp_client __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int));
int ippr_ftp_complete __P((char *, size_t));
int ippr_ftp_in __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_ftp_init __P((void));
void ippr_ftp_fini __P((void));
int ippr_ftp_new __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_ftp_out __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_ftp_pasv __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int));
int ippr_ftp_epsv __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *, int));
int ippr_ftp_port __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *, int));
int ippr_ftp_process __P((fr_info_t *, nat_t *, ftpinfo_t *, int));
int ippr_ftp_server __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int));
int ippr_ftp_valid __P((ftpinfo_t *, int, char *, size_t));
int ippr_ftp_server_valid __P((ftpside_t *, char *, size_t));
int ippr_ftp_client_valid __P((ftpside_t *, char *, size_t));
u_short ippr_ftp_atoi __P((char **));
int ippr_ftp_pasvreply __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *,
                u_int, char *, char *, u_int));


int ftp_proxy_init = 0;
int ippr_ftp_pasvonly = 0;
int ippr_ftp_insecure = 0;  /* Do not require logins before transfers */
int ippr_ftp_pasvrdr = 0;
int ippr_ftp_forcepasv = 0; /* PASV must be last command prior to 227 */
#if defined(_KERNEL)
int ippr_ftp_debug = 0;
#else
int ippr_ftp_debug = 2;
#endif
/*
 * 1 - security
 * 2 - errors
 * 3 - error debugging
 * 4 - parsing errors
 * 5 - parsing info
 * 6 - parsing debug
 */

static  frentry_t   ftppxyfr;
static  ipftuneable_t   ftptune = {
    { &ippr_ftp_debug },
    "ippr_ftp_debug",
    0,
    10,
    sizeof(ippr_ftp_debug),
    0,
    NULL
};


/*
 * Initialize local structures.
 */
int ippr_ftp_init()
{
    bzero((char *)&ftppxyfr, sizeof(ftppxyfr));
    ftppxyfr.fr_ref = 1;
    ftppxyfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
    MUTEX_INIT(&ftppxyfr.fr_lock, "FTP Proxy Mutex");
    ftp_proxy_init = 1;
    (void) fr_addipftune(&ftptune);

    return 0;
}


void ippr_ftp_fini()
{
    (void) fr_delipftune(&ftptune);

    if (ftp_proxy_init == 1) {
        MUTEX_DESTROY(&ftppxyfr.fr_lock);
        ftp_proxy_init = 0;
    }
}


int ippr_ftp_new(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
    ftpinfo_t *ftp;
    ftpside_t *f;

    KMALLOC(ftp, ftpinfo_t *);
    if (ftp == NULL)
        return -1;

    fin = fin;  /* LINT */
    nat = nat;  /* LINT */

    aps->aps_data = ftp;
    aps->aps_psiz = sizeof(ftpinfo_t);

    bzero((char *)ftp, sizeof(*ftp));
    f = &ftp->ftp_side[0];
    f->ftps_rptr = f->ftps_buf;
    f->ftps_wptr = f->ftps_buf;
    f = &ftp->ftp_side[1];
    f->ftps_rptr = f->ftps_buf;
    f->ftps_wptr = f->ftps_buf;
    ftp->ftp_passok = FTPXY_INIT;
    ftp->ftp_incok = 0;
    return 0;
}


int ippr_ftp_port(fin, ip, nat, f, dlen)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpside_t *f;
int dlen;
{
    tcphdr_t *tcp, tcph, *tcp2 = &tcph;
    char newbuf[IPF_FTPBUFSZ], *s;
    struct in_addr swip, swip2;
    u_int a1, a2, a3, a4;
    int inc, off, flags;
    u_short a5, a6, sp;
    size_t nlen, olen;
    fr_info_t fi;
    nat_t *nat2;
    mb_t *m;

    m = fin->fin_m;
    tcp = (tcphdr_t *)fin->fin_dp;
    off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;

    /*
     * Check for client sending out PORT message.
     */
    if (dlen < IPF_MINPORTLEN) {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_port:dlen(%d) < IPF_MINPORTLEN\n",
                   dlen);
        return 0;
    }
    /*
     * Skip the PORT command + space
     */
    s = f->ftps_rptr + 5;
    /*
     * Pick out the address components, two at a time.
     */
    a1 = ippr_ftp_atoi(&s);
    if (s == NULL) {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 1);
        return 0;
    }
    a2 = ippr_ftp_atoi(&s);
    if (s == NULL) {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 2);
        return 0;
    }

    /*
     * Check that IP address in the PORT/PASV reply is the same as the
     * sender of the command - prevents using PORT for port scanning.
     */
    a1 <<= 16;
    a1 |= a2;
    if (((nat->nat_dir == NAT_OUTBOUND) &&
         (a1 != ntohl(nat->nat_inip.s_addr))) ||
        ((nat->nat_dir == NAT_INBOUND) &&
         (a1 != ntohl(nat->nat_oip.s_addr)))) {
        if (ippr_ftp_debug > 0)
            printf("ippr_ftp_port:%s != nat->nat_inip\n", "a1");
        return APR_ERR(1);
    }

    a5 = ippr_ftp_atoi(&s);
    if (s == NULL) {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 3);
        return 0;
    }
    if (*s == ')')
        s++;

    /*
     * check for CR-LF at the end.
     */
    if (*s == '\n')
        s--;
    if ((*s == '\r') && (*(s + 1) == '\n')) {
        s += 2;
        a6 = a5 & 0xff;
    } else {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_port:missing %s\n", "cr-lf");
        return 0;
    }

    a5 >>= 8;
    a5 &= 0xff;
    sp = a5 << 8 | a6;
    /*
     * Don't allow the PORT command to specify a port < 1024 due to
     * security crap.
     */
    if (sp < 1024) {
        if (ippr_ftp_debug > 0)
            printf("ippr_ftp_port:sp(%d) < 1024\n", sp);
        return 0;
    }
    /*
     * Calculate new address parts for PORT command
     */
    if (nat->nat_dir == NAT_INBOUND)
        a1 = ntohl(nat->nat_oip.s_addr);
    else
        a1 = ntohl(ip->ip_src.s_addr);
    a2 = (a1 >> 16) & 0xff;
    a3 = (a1 >> 8) & 0xff;
    a4 = a1 & 0xff;
    a1 >>= 24;
    olen = s - f->ftps_rptr;
    /* DO NOT change this to snprintf! */
#if defined(SNPRINTF) && defined(_KERNEL)
    (void) SNPRINTF(newbuf, sizeof(newbuf), "%s %u,%u,%u,%u,%u,%u\r\n",
         "PORT", a1, a2, a3, a4, a5, a6);
#else
    (void) sprintf(newbuf, "%s %u,%u,%u,%u,%u,%u\r\n",
               "PORT", a1, a2, a3, a4, a5, a6);
#endif

    nlen = strlen(newbuf);
    inc = nlen - olen;
    if ((inc + ip->ip_len) > 65535) {
        if (ippr_ftp_debug > 0)
            printf("ippr_ftp_port:inc(%d) + ip->ip_len > 65535\n",
                   inc);
        return 0;
    }

#if !defined(_KERNEL)
    bcopy(newbuf, MTOD(m, char *) + off, nlen);
#else
# if defined(MENTAT)
    if (inc < 0)
        (void)adjmsg(m, inc);
# else /* defined(MENTAT) */
    /*
     * m_adj takes care of pkthdr.len, if required and treats inc<0 to
     * mean remove -len bytes from the end of the packet.
     * The mbuf chain will be extended if necessary by m_copyback().
     */
    if (inc < 0)
        m_adj(m, inc);
# endif /* defined(MENTAT) */
#endif /* !defined(_KERNEL) */
    COPYBACK(m, off, nlen, newbuf);

    if (inc != 0) {
        ip->ip_len += inc;
        fin->fin_dlen += inc;
        fin->fin_plen += inc;
    }

    /*
     * The server may not make the connection back from port 20, but
     * it is the most likely so use it here to check for a conflicting
     * mapping.
     */
    bcopy((char *)fin, (char *)&fi, sizeof(fi));
    fi.fin_state = NULL;
    fi.fin_nat = NULL;
    fi.fin_flx |= FI_IGNORE;
    fi.fin_data[0] = sp;
    fi.fin_data[1] = fin->fin_data[1] - 1;
    /*
     * Add skeleton NAT entry for connection which will come back the
     * other way.
     */
    if (nat->nat_dir == NAT_OUTBOUND)
        nat2 = nat_outlookup(&fi, NAT_SEARCH|IPN_TCP, nat->nat_p,
                     nat->nat_inip, nat->nat_oip);
    else
        nat2 = nat_inlookup(&fi, NAT_SEARCH|IPN_TCP, nat->nat_p,
                    nat->nat_inip, nat->nat_oip);
    if (nat2 == NULL) {
        int slen;

        slen = ip->ip_len;
        ip->ip_len = fin->fin_hlen + sizeof(*tcp2);
        bzero((char *)tcp2, sizeof(*tcp2));
        tcp2->th_win = htons(8192);
        tcp2->th_sport = htons(sp);
        TCP_OFF_A(tcp2, 5);
        tcp2->th_flags = TH_SYN;
        tcp2->th_dport = 0; /* XXX - don't specify remote port */
        fi.fin_data[1] = 0;
        fi.fin_dlen = sizeof(*tcp2);
        fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
        fi.fin_dp = (char *)tcp2;
        fi.fin_fr = &ftppxyfr;
        fi.fin_out = nat->nat_dir;
        fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
        swip = ip->ip_src;
        swip2 = ip->ip_dst;
        if (nat->nat_dir == NAT_OUTBOUND) {
            fi.fin_fi.fi_saddr = nat->nat_inip.s_addr;
            ip->ip_src = nat->nat_inip;
        } else if (nat->nat_dir == NAT_INBOUND) {
            fi.fin_fi.fi_saddr = nat->nat_oip.s_addr;
            ip->ip_src = nat->nat_oip;
        }

        flags = NAT_SLAVE|IPN_TCP|SI_W_DPORT;
        if (nat->nat_dir == NAT_INBOUND)
            flags |= NAT_NOTRULEPORT;
        nat2 = nat_new(&fi, nat->nat_ptr, NULL, flags, nat->nat_dir);

        if (nat2 != NULL) {
            (void) nat_proto(&fi, nat2, IPN_TCP);
            nat_update(&fi, nat2, nat->nat_ptr);
            fi.fin_ifp = NULL;
            if (nat->nat_dir == NAT_INBOUND) {
                fi.fin_fi.fi_daddr = nat->nat_inip.s_addr;
                ip->ip_dst = nat->nat_inip;
            }
            (void) fr_addstate(&fi, &nat2->nat_state, SI_W_DPORT);
            if (fi.fin_state != NULL)
                fr_statederef(&fi, (ipstate_t **)&fi.fin_state);
        }
        ip->ip_len = slen;
        ip->ip_src = swip;
        ip->ip_dst = swip2;
    } else {
        ipstate_t *is;

        nat_update(&fi, nat2, nat->nat_ptr);
        READ_ENTER(&ipf_state);
        is = nat2->nat_state;
        if (is != NULL) {
            MUTEX_ENTER(&is->is_lock);
            (void)fr_tcp_age(&is->is_sti, &fi, ips_tqtqb,
                     is->is_flags);
            MUTEX_EXIT(&is->is_lock);
        }
        RWLOCK_EXIT(&ipf_state);
    }
    return APR_INC(inc);
}


int ippr_ftp_client(fin, ip, nat, ftp, dlen)
fr_info_t *fin;
nat_t *nat;
ftpinfo_t *ftp;
ip_t *ip;
int dlen;
{
    char *rptr, *wptr, cmd[6], c;
    ftpside_t *f;
    int inc, i;

    inc = 0;
    f = &ftp->ftp_side[0];
    rptr = f->ftps_rptr;
    wptr = f->ftps_wptr;

    for (i = 0; (i < 5) && (i < dlen); i++) {
        c = rptr[i];
        if (ISALPHA(c)) {
            cmd[i] = TOUPPER(c);
        } else {
            cmd[i] = c;
        }
    }
    cmd[i] = '\0';

    ftp->ftp_incok = 0;
    if (!strncmp(cmd, "USER ", 5) || !strncmp(cmd, "XAUT ", 5)) {
        if (ftp->ftp_passok == FTPXY_ADOK_1 ||
            ftp->ftp_passok == FTPXY_AUOK_1) {
            ftp->ftp_passok = FTPXY_USER_2;
            ftp->ftp_incok = 1;
        } else {
            ftp->ftp_passok = FTPXY_USER_1;
            ftp->ftp_incok = 1;
        }
    } else if (!strncmp(cmd, "AUTH ", 5)) {
        ftp->ftp_passok = FTPXY_AUTH_1;
        ftp->ftp_incok = 1;
    } else if (!strncmp(cmd, "PASS ", 5)) {
        if (ftp->ftp_passok == FTPXY_USOK_1) {
            ftp->ftp_passok = FTPXY_PASS_1;
            ftp->ftp_incok = 1;
        } else if (ftp->ftp_passok == FTPXY_USOK_2) {
            ftp->ftp_passok = FTPXY_PASS_2;
            ftp->ftp_incok = 1;
        }
    } else if ((ftp->ftp_passok == FTPXY_AUOK_1) &&
           !strncmp(cmd, "ADAT ", 5)) {
        ftp->ftp_passok = FTPXY_ADAT_1;
        ftp->ftp_incok = 1;
    } else if ((ftp->ftp_passok == FTPXY_PAOK_1 ||
            ftp->ftp_passok == FTPXY_PAOK_2) &&
         !strncmp(cmd, "ACCT ", 5)) {
        ftp->ftp_passok = FTPXY_ACCT_1;
        ftp->ftp_incok = 1;
    } else if ((ftp->ftp_passok == FTPXY_GO) && !ippr_ftp_pasvonly &&
         !strncmp(cmd, "PORT ", 5)) {
        inc = ippr_ftp_port(fin, ip, nat, f, dlen);
    } else if (ippr_ftp_insecure && !ippr_ftp_pasvonly &&
           !strncmp(cmd, "PORT ", 5)) {
        inc = ippr_ftp_port(fin, ip, nat, f, dlen);
    }

    while ((*rptr++ != '\n') && (rptr < wptr))
        ;
    f->ftps_rptr = rptr;
    return inc;
}


int ippr_ftp_pasv(fin, ip, nat, ftp, dlen)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpinfo_t *ftp;
int dlen;
{
    u_int a1, a2, a3, a4, data_ip;
    char newbuf[IPF_FTPBUFSZ];
    char *s, *brackets[2];
    u_short a5, a6;
    ftpside_t *f;

    if (ippr_ftp_forcepasv != 0 &&
        ftp->ftp_side[0].ftps_cmds != FTPXY_C_PASV) {
        if (ippr_ftp_debug > 0)
            printf("ippr_ftp_pasv:ftps_cmds(%d) != FTPXY_C_PASV\n",
                   ftp->ftp_side[0].ftps_cmds);
        return 0;
    }

    f = &ftp->ftp_side[1];

#define PASV_REPLEN 24
    /*
     * Check for PASV reply message.
     */
    if (dlen < IPF_MIN227LEN) {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_pasv:dlen(%d) < IPF_MIN227LEN\n",
                   dlen);
        return 0;
    } else if (strncmp(f->ftps_rptr,
               "227 Entering Passive Mod", PASV_REPLEN)) {
        if (ippr_ftp_debug > 0)
            printf("ippr_ftp_pasv:%d reply wrong\n", 227);
        return 0;
    }

    brackets[0] = "";
    brackets[1] = "";
    /*
     * Skip the PASV reply + space
     */
    s = f->ftps_rptr + PASV_REPLEN;
    while (*s && !ISDIGIT(*s)) {
        if (*s == '(') {
            brackets[0] = "(";
            brackets[1] = ")";
        }
        s++;
    }

    /*
     * Pick out the address components, two at a time.
     */
    a1 = ippr_ftp_atoi(&s);
    if (s == NULL) {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 1);
        return 0;
    }
    a2 = ippr_ftp_atoi(&s);
    if (s == NULL) {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 2);
        return 0;
    }

    /*
     * check that IP address in the PASV reply is the same as the
     * sender of the command - prevents using PASV for port scanning.
     */
    a1 <<= 16;
    a1 |= a2;

    if (((nat->nat_dir == NAT_INBOUND) &&
         (a1 != ntohl(nat->nat_inip.s_addr))) ||
        ((nat->nat_dir == NAT_OUTBOUND) &&
         (a1 != ntohl(nat->nat_oip.s_addr)))) {
        if (ippr_ftp_debug > 0)
            printf("ippr_ftp_pasv:%s != nat->nat_oip\n", "a1");
        return 0;
    }

    a5 = ippr_ftp_atoi(&s);
    if (s == NULL) {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 3);
        return 0;
    }

    if (*s == ')')
        s++;
    if (*s == '.')
        s++;
    if (*s == '\n')
        s--;
    /*
     * check for CR-LF at the end.
     */
    if ((*s == '\r') && (*(s + 1) == '\n')) {
        s += 2;
    } else {
        if (ippr_ftp_debug > 1)
            printf("ippr_ftp_pasv:missing %s", "cr-lf\n");
        return 0;
    }

    a6 = a5 & 0xff;
    a5 >>= 8;
    /*
     * Calculate new address parts for 227 reply
     */
    if (nat->nat_dir == NAT_INBOUND) {
        data_ip = nat->nat_outip.s_addr;
        a1 = ntohl(data_ip);
    } else
        data_ip = htonl(a1);

    a2 = (a1 >> 16) & 0xff;
    a3 = (a1 >> 8) & 0xff;
    a4 = a1 & 0xff;
    a1 >>= 24;

#if defined(SNPRINTF) && defined(_KERNEL)
    (void) SNPRINTF(newbuf, sizeof(newbuf), "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
        "227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
        a5, a6, brackets[1]);
#else
    (void) sprintf(newbuf, "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
        "227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
        a5, a6, brackets[1]);
#endif
    return ippr_ftp_pasvreply(fin, ip, nat, f, (a5 << 8 | a6),
                  newbuf, s, data_ip);
}

int ippr_ftp_pasvreply(fin, ip, nat, f, port, newmsg, s, data_ip)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpside_t *f;
u_int port;
char *newmsg;
char *s;
u_int data_ip;
{
    int inc, off, nflags, sflags;
    tcphdr_t *tcp, tcph, *tcp2;
    struct in_addr swip, swip2;
    struct in_addr data_addr;
    size_t nlen, olen;
    fr_info_t fi;
    nat_t *nat2;
    mb_t *m;

    m = fin->fin_m;
    tcp = (tcphdr_t *)fin->fin_dp;
    off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;

    data_addr.s_addr = data_ip;
    tcp2 = &tcph;
    inc = 0;


    olen = s - f->ftps_rptr;
    nlen = strlen(newmsg);
    inc = nlen - olen;
    if ((inc + ip->ip_len) > 65535) {
        if (ippr_ftp_debug > 0)
            printf("ippr_ftp_pasv:inc(%d) + ip->ip_len > 65535\n",
                   inc);
        return 0;
    }

#if !defined(_KERNEL)
    bcopy(newmsg, MTOD(m, char *) + off, nlen);
#else
# if defined(MENTAT)
    if (inc < 0)
        (void)adjmsg(m, inc);
# else /* defined(MENTAT) */
    /*
     * m_adj takes care of pkthdr.len, if required and treats inc<0 to
     * mean remove -len bytes from the end of the packet.
     * The mbuf chain will be extended if necessary by m_copyback().
     */
    if (inc < 0)
        m_adj(m, inc);
# endif /* defined(MENTAT) */
#endif /* !defined(_KERNEL) */
    COPYBACK(m, off, nlen, newmsg);

    if (inc != 0) {
        ip->ip_len += inc;
        fin->fin_dlen += inc;
        fin->fin_plen += inc;
    }

    /*
     * Add skeleton NAT entry for connection which will come back the
     * other way.
     */
    bcopy((char *)fin, (char *)&fi, sizeof(fi));
    fi.fin_state = NULL;
    fi.fin_nat = NULL;
    fi.fin_flx |= FI_IGNORE;
    fi.fin_data[0] = 0;
    fi.fin_data[1] = port;
    nflags = IPN_TCP|SI_W_SPORT;
    if (ippr_ftp_pasvrdr && f->ftps_ifp)
        nflags |= SI_W_DPORT;
    if (nat->nat_dir == NAT_OUTBOUND)
        nat2 = nat_outlookup(&fi, nflags|NAT_SEARCH,
                     nat->nat_p, nat->nat_inip, nat->nat_oip);
    else
        nat2 = nat_inlookup(&fi, nflags|NAT_SEARCH,
                    nat->nat_p, nat->nat_inip, nat->nat_oip);
    if (nat2 == NULL) {
        int slen;

        slen = ip->ip_len;
        ip->ip_len = fin->fin_hlen + sizeof(*tcp2);
        bzero((char *)tcp2, sizeof(*tcp2));
        tcp2->th_win = htons(8192);
        tcp2->th_sport = 0;     /* XXX - fake it for nat_new */
        TCP_OFF_A(tcp2, 5);
        tcp2->th_flags = TH_SYN;
        fi.fin_data[1] = port;
        fi.fin_dlen = sizeof(*tcp2);
        tcp2->th_dport = htons(port);
        fi.fin_data[0] = 0;
        fi.fin_dp = (char *)tcp2;
        fi.fin_plen = fi.fin_hlen + sizeof(*tcp);
        fi.fin_fr = &ftppxyfr;
        fi.fin_out = nat->nat_dir;
        fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
        swip = ip->ip_src;
        swip2 = ip->ip_dst;
        if (nat->nat_dir == NAT_OUTBOUND) {
            fi.fin_fi.fi_daddr = data_addr.s_addr;
            fi.fin_fi.fi_saddr = nat->nat_inip.s_addr;
            ip->ip_dst = data_addr;
            ip->ip_src = nat->nat_inip;
        } else if (nat->nat_dir == NAT_INBOUND) {
            fi.fin_fi.fi_saddr = nat->nat_oip.s_addr;
            fi.fin_fi.fi_daddr = nat->nat_outip.s_addr;
            ip->ip_src = nat->nat_oip;
            ip->ip_dst = nat->nat_outip;
        }

        sflags = nflags;
        nflags |= NAT_SLAVE;
        if (nat->nat_dir == NAT_INBOUND)
            nflags |= NAT_NOTRULEPORT;
        nat2 = nat_new(&fi, nat->nat_ptr, NULL, nflags, nat->nat_dir);
        if (nat2 != NULL) {
            (void) nat_proto(&fi, nat2, IPN_TCP);
            nat_update(&fi, nat2, nat->nat_ptr);
            fi.fin_ifp = NULL;
            if (nat->nat_dir == NAT_INBOUND) {
                fi.fin_fi.fi_daddr = nat->nat_inip.s_addr;
                ip->ip_dst = nat->nat_inip;
            }
            (void) fr_addstate(&fi, &nat2->nat_state, sflags);
            if (fi.fin_state != NULL)
                fr_statederef(&fi, (ipstate_t **)&fi.fin_state);
        }

        ip->ip_len = slen;
        ip->ip_src = swip;
        ip->ip_dst = swip2;
    } else {
        ipstate_t *is;

        nat_update(&fi, nat2, nat->nat_ptr);
        READ_ENTER(&ipf_state);
        is = nat2->nat_state;
        if (is != NULL) {
            MUTEX_ENTER(&is->is_lock);
            (void)fr_tcp_age(&is->is_sti, &fi, ips_tqtqb,
                     is->is_flags);
            MUTEX_EXIT(&is->is_lock);
        }
        RWLOCK_EXIT(&ipf_state);
    }
    return inc;
}


int ippr_ftp_server(fin, ip, nat, ftp, dlen)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpinfo_t *ftp;
int dlen;
{
    char *rptr, *wptr;
    ftpside_t *f;
    int inc;

    inc = 0;
    f = &ftp->ftp_side[1];
    rptr = f->ftps_rptr;
    wptr = f->ftps_wptr;

    if (*rptr == ' ')
        goto server_cmd_ok;
    if (!ISDIGIT(*rptr) || !ISDIGIT(*(rptr + 1)) || !ISDIGIT(*(rptr + 2)))
        return 0;
    if (ftp->ftp_passok == FTPXY_GO) {
        if (!strncmp(rptr, "227 ", 4))
            inc = ippr_ftp_pasv(fin, ip, nat, ftp, dlen);
        else if (!strncmp(rptr, "229 ", 4))
            inc = ippr_ftp_epsv(fin, ip, nat, f, dlen);
    } else if (ippr_ftp_insecure && !strncmp(rptr, "227 ", 4)) {
        inc = ippr_ftp_pasv(fin, ip, nat, ftp, dlen);
    } else if (ippr_ftp_insecure && !strncmp(rptr, "229 ", 4)) {
        inc = ippr_ftp_epsv(fin, ip, nat, f, dlen);
    } else if (*rptr == '5' || *rptr == '4')
        ftp->ftp_passok = FTPXY_INIT;
    else if (ftp->ftp_incok) {
        if (*rptr == '3') {
            if (ftp->ftp_passok == FTPXY_ACCT_1)
                ftp->ftp_passok = FTPXY_GO;
            else
                ftp->ftp_passok++;
        } else if (*rptr == '2') {
            switch (ftp->ftp_passok)
            {
            case FTPXY_USER_1 :
            case FTPXY_USER_2 :
            case FTPXY_PASS_1 :
            case FTPXY_PASS_2 :
            case FTPXY_ACCT_1 :
                ftp->ftp_passok = FTPXY_GO;
                break;
            default :
                ftp->ftp_passok += 3;
                break;
            }
        }
    }
server_cmd_ok:
    ftp->ftp_incok = 0;

    while ((*rptr++ != '\n') && (rptr < wptr))
        ;
    f->ftps_rptr = rptr;
    return inc;
}


/*
 * Look to see if the buffer starts with something which we recognise as
 * being the correct syntax for the FTP protocol.
 */
int ippr_ftp_client_valid(ftps, buf, len)
ftpside_t *ftps;
char *buf;
size_t len;
{
    register char *s, c, pc;
    register size_t i = len;
    char cmd[5];

    s = buf;

    if (ftps->ftps_junk == 1)
        return 1;

    if (i < 5) {
        if (ippr_ftp_debug > 3)
            printf("ippr_ftp_client_valid:i(%d) < 5\n", (int)i);
        return 2;
    }

    i--;
    c = *s++;

    if (ISALPHA(c)) {
        cmd[0] = TOUPPER(c);
        c = *s++;
        i--;
        if (ISALPHA(c)) {
            cmd[1] = TOUPPER(c);
            c = *s++;
            i--;
            if (ISALPHA(c)) {
                cmd[2] = TOUPPER(c);
                c = *s++;
                i--;
                if (ISALPHA(c)) {
                    cmd[3] = TOUPPER(c);
                    c = *s++;
                    i--;
                    if ((c != ' ') && (c != '\r'))
                        goto bad_client_command;
                } else if ((c != ' ') && (c != '\r'))
                    goto bad_client_command;
            } else
                goto bad_client_command;
        } else
            goto bad_client_command;
    } else {
bad_client_command:
        if (ippr_ftp_debug > 3)
            printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*s]\n",
                   "ippr_ftp_client_valid",
                   ftps->ftps_junk, (int)len, (int)i, c,
                   (int)len, buf);
        return 1;
    }

    for (; i; i--) {
        pc = c;
        c = *s++;
        if ((pc == '\r') && (c == '\n')) {
            cmd[4] = '\0';
            if (!strcmp(cmd, "PASV"))
                ftps->ftps_cmds = FTPXY_C_PASV;
            else
                ftps->ftps_cmds = 0;
            return 0;
        }
    }
#if !defined(_KERNEL)
    printf("ippr_ftp_client_valid:junk after cmd[%*.*s]\n",
           (int)len, (int)len, buf);
#endif
    return 2;
}


int ippr_ftp_server_valid(ftps, buf, len)
ftpside_t *ftps;
char *buf;
size_t len;
{
    register char *s, c, pc;
    register size_t i = len;
    int cmd;

    s = buf;
    cmd = 0;

    if (ftps->ftps_junk == 1)
        return 1;

    if (i < 5) {
        if (ippr_ftp_debug > 3)
            printf("ippr_ftp_servert_valid:i(%d) < 5\n", (int)i);
        return 2;
    }

    c = *s++;
    i--;
    if (c == ' ')
        goto search_eol;

    if (ISDIGIT(c)) {
        cmd = (c - '0') * 100;
        c = *s++;
        i--;
        if (ISDIGIT(c)) {
            cmd += (c - '0') * 10;
            c = *s++;
            i--;
            if (ISDIGIT(c)) {
                cmd += (c - '0');
                c = *s++;
                i--;
                if ((c != '-') && (c != ' '))
                    goto bad_server_command;
            } else
                goto bad_server_command;
        } else
            goto bad_server_command;
    } else {
bad_server_command:
        if (ippr_ftp_debug > 3)
            printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*s]\n",
                   "ippr_ftp_server_valid",
                   ftps->ftps_junk, (int)len, (int)i,
                   c, (int)len, buf);
        return 1;
    }
search_eol:
    for (; i; i--) {
        pc = c;
        c = *s++;
        if ((pc == '\r') && (c == '\n')) {
            ftps->ftps_cmds = cmd;
            return 0;
        }
    }
    if (ippr_ftp_debug > 3)
        printf("ippr_ftp_server_valid:junk after cmd[%*s]\n",
               (int)len, buf);
    return 2;
}


int ippr_ftp_valid(ftp, side, buf, len)
ftpinfo_t *ftp;
int side;
char *buf;
size_t len;
{
    ftpside_t *ftps;
    int ret;

    ftps = &ftp->ftp_side[side];

    if (side == 0)
        ret = ippr_ftp_client_valid(ftps, buf, len);
    else
        ret = ippr_ftp_server_valid(ftps, buf, len);
    return ret;
}


/*
 * For map rules, the following applies:
 * rv == 0 for outbound processing,
 * rv == 1 for inbound processing.
 * For rdr rules, the following applies:
 * rv == 0 for inbound processing,
 * rv == 1 for outbound processing.
 */
int ippr_ftp_process(fin, nat, ftp, rv)
fr_info_t *fin;
nat_t *nat;
ftpinfo_t *ftp;
int rv;
{
    int mlen, len, off, inc, i, sel, sel2, ok, ackoff, seqoff;
    char *rptr, *wptr, *s;
    u_32_t thseq, thack;
    ap_session_t *aps;
    ftpside_t *f, *t;
    tcphdr_t *tcp;
    ip_t *ip;
    mb_t *m;

    m = fin->fin_m;
    ip = fin->fin_ip;
    tcp = (tcphdr_t *)fin->fin_dp;
    off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;

    f = &ftp->ftp_side[rv];
    t = &ftp->ftp_side[1 - rv];
    thseq = ntohl(tcp->th_seq);
    thack = ntohl(tcp->th_ack);

#ifdef __sgi
    mlen = fin->fin_plen - off;
#else
    mlen = MSGDSIZE(m) - off;
#endif
    if (ippr_ftp_debug > 4)
        printf("ippr_ftp_process: mlen %d\n", mlen);

    if (mlen <= 0) {
        if ((tcp->th_flags & TH_OPENING) == TH_OPENING) {
            f->ftps_seq[0] = thseq + 1;
            t->ftps_seq[0] = thack;
        }
        return 0;
    }
    aps = nat->nat_aps;

    sel = aps->aps_sel[1 - rv];
    sel2 = aps->aps_sel[rv];
    if (rv == 0) {
        seqoff = aps->aps_seqoff[sel];
        if (aps->aps_seqmin[sel] > seqoff + thseq)
            seqoff = aps->aps_seqoff[!sel];
        ackoff = aps->aps_ackoff[sel2];
        if (aps->aps_ackmin[sel2] > ackoff + thack)
            ackoff = aps->aps_ackoff[!sel2];
    } else {
        seqoff = aps->aps_ackoff[sel];
        if (ippr_ftp_debug > 2)
            printf("seqoff %d thseq %x ackmin %x\n", seqoff, thseq,
                   aps->aps_ackmin[sel]);
        if (aps->aps_ackmin[sel] > seqoff + thseq)
            seqoff = aps->aps_ackoff[!sel];

        ackoff = aps->aps_seqoff[sel2];
        if (ippr_ftp_debug > 2)
            printf("ackoff %d thack %x seqmin %x\n", ackoff, thack,
                   aps->aps_seqmin[sel2]);
        if (ackoff > 0) {
            if (aps->aps_seqmin[sel2] > ackoff + thack)
                ackoff = aps->aps_seqoff[!sel2];
        } else {
            if (aps->aps_seqmin[sel2] > thack)
                ackoff = aps->aps_seqoff[!sel2];
        }
    }
    if (ippr_ftp_debug > 2) {
        printf("%s: %x seq %x/%d ack %x/%d len %d/%d off %d\n",
               rv ? "IN" : "OUT", tcp->th_flags, thseq, seqoff,
               thack, ackoff, mlen, fin->fin_plen, off);
        printf("sel %d seqmin %x/%x offset %d/%d\n", sel,
               aps->aps_seqmin[sel], aps->aps_seqmin[sel2],
               aps->aps_seqoff[sel], aps->aps_seqoff[sel2]);
        printf("sel %d ackmin %x/%x offset %d/%d\n", sel2,
               aps->aps_ackmin[sel], aps->aps_ackmin[sel2],
               aps->aps_ackoff[sel], aps->aps_ackoff[sel2]);
    }

    /*
     * XXX - Ideally, this packet should get dropped because we now know
     * that it is out of order (and there is no real danger in doing so
     * apart from causing packets to go through here ordered).
     */
    if (ippr_ftp_debug > 2) {
        printf("rv %d t:seq[0] %x seq[1] %x %d/%d\n",
               rv, t->ftps_seq[0], t->ftps_seq[1], seqoff, ackoff);
    }

    ok = 0;
    if (t->ftps_seq[0] == 0) {
        t->ftps_seq[0] = thack;
        ok = 1;
    } else {
        if (ackoff == 0) {
            if (t->ftps_seq[0] == thack)
                ok = 1;
            else if (t->ftps_seq[1] == thack) {
                t->ftps_seq[0] = thack;
                ok = 1;
            }
        } else {
            if (t->ftps_seq[0] + ackoff == thack)
                ok = 1;
            else if (t->ftps_seq[0] == thack + ackoff)
                ok = 1;
            else if (t->ftps_seq[1] + ackoff == thack) {
                t->ftps_seq[0] = thack - ackoff;
                ok = 1;
            } else if (t->ftps_seq[1] == thack + ackoff) {
                t->ftps_seq[0] = thack - ackoff;
                ok = 1;
            }
        }
    }

    if (ippr_ftp_debug > 2) {
        if (!ok)
            printf("%s ok\n", "not");
    }

    if (!mlen) {
        if (t->ftps_seq[0] + ackoff != thack) {
            if (ippr_ftp_debug > 1) {
                printf("%s:seq[0](%x) + (%x) != (%x)\n",
                       "ippr_ftp_process", t->ftps_seq[0],
                       ackoff, thack);
            }
            return APR_ERR(1);
        }

        if (ippr_ftp_debug > 2) {
            printf("ippr_ftp_process:f:seq[0] %x seq[1] %x\n",
                f->ftps_seq[0], f->ftps_seq[1]);
        }

        if (tcp->th_flags & TH_FIN) {
            if (thseq == f->ftps_seq[1]) {
                f->ftps_seq[0] = f->ftps_seq[1] - seqoff;
                f->ftps_seq[1] = thseq + 1 - seqoff;
            } else {
                if (ippr_ftp_debug > 1) {
                    printf("FIN: thseq %x seqoff %d ftps_seq %x\n",
                           thseq, seqoff, f->ftps_seq[0]);
                }
                return APR_ERR(1);
            }
        }
        f->ftps_len = 0;
        return 0;
    }

    ok = 0;
    if ((thseq == f->ftps_seq[0]) || (thseq == f->ftps_seq[1])) {
        ok = 1;
    /*
     * Retransmitted data packet.
     */
    } else if ((thseq + mlen == f->ftps_seq[0]) ||
           (thseq + mlen == f->ftps_seq[1])) {
        ok = 1;
    }

    if (ok == 0) {
        inc = thseq - f->ftps_seq[0];
        if (ippr_ftp_debug > 1) {
            printf("inc %d sel %d rv %d\n", inc, sel, rv);
            printf("th_seq %x ftps_seq %x/%x\n",
                   thseq, f->ftps_seq[0], f->ftps_seq[1]);
            printf("ackmin %x ackoff %d\n", aps->aps_ackmin[sel],
                   aps->aps_ackoff[sel]);
            printf("seqmin %x seqoff %d\n", aps->aps_seqmin[sel],
                   aps->aps_seqoff[sel]);
        }

        return APR_ERR(1);
    }

    inc = 0;
    rptr = f->ftps_rptr;
    wptr = f->ftps_wptr;
    f->ftps_seq[0] = thseq;
    f->ftps_seq[1] = f->ftps_seq[0] + mlen;
    f->ftps_len = mlen;

    while (mlen > 0) {
        len = MIN(mlen, sizeof(f->ftps_buf) - (wptr - rptr));
        COPYDATA(m, off, len, wptr);
        mlen -= len;
        off += len;
        wptr += len;

        if (ippr_ftp_debug > 3)
            printf("%s:len %d/%d off %d wptr %lx junk %d [%*s]\n",
                   "ippr_ftp_process",
                   len, mlen, off, (u_long)wptr, f->ftps_junk,
                   len, rptr);

        f->ftps_wptr = wptr;
        if (f->ftps_junk != 0) {
            i = f->ftps_junk;
            f->ftps_junk = ippr_ftp_valid(ftp, rv, rptr,
                              wptr - rptr);

            if (ippr_ftp_debug > 5)
                printf("%s:junk %d -> %d\n",
                       "ippr_ftp_process", i, f->ftps_junk);

            if (f->ftps_junk != 0) {
                if (wptr - rptr == sizeof(f->ftps_buf)) {
                    if (ippr_ftp_debug > 4)
                        printf("%s:full buffer\n",
                               "ippr_ftp_process");
                    f->ftps_rptr = f->ftps_buf;
                    f->ftps_wptr = f->ftps_buf;
                    rptr = f->ftps_rptr;
                    wptr = f->ftps_wptr;
                    /*
                     * Because we throw away data here that
                     * we would otherwise parse, set the
                     * junk flag to indicate just ignore
                     * any data upto the next CRLF.
                     */
                    f->ftps_junk = 1;
                    continue;
                }
            }
        }

        while ((f->ftps_junk == 0) && (wptr > rptr)) {
            len = wptr - rptr;
            f->ftps_junk = ippr_ftp_valid(ftp, rv, rptr, len);

            if (ippr_ftp_debug > 3) {
                printf("%s=%d len %d rv %d ptr %lx/%lx ",
                       "ippr_ftp_valid",
                       f->ftps_junk, len, rv, (u_long)rptr,
                       (u_long)wptr);
                printf("buf [%*s]\n", len, rptr);
            }

            if (f->ftps_junk == 0) {
                f->ftps_rptr = rptr;
                if (rv)
                    inc += ippr_ftp_server(fin, ip, nat,
                                   ftp, len);
                else
                    inc += ippr_ftp_client(fin, ip, nat,
                                   ftp, len);
                rptr = f->ftps_rptr;
                wptr = f->ftps_wptr;
            }
        }

        /*
         * Off to a bad start so lets just forget about using the
         * ftp proxy for this connection.
         */
        if ((f->ftps_cmds == 0) && (f->ftps_junk == 1)) {
            /* f->ftps_seq[1] += inc; */

            if (ippr_ftp_debug > 1)
                printf("%s:cmds == 0 junk == 1\n",
                       "ippr_ftp_process");
            return APR_ERR(2);
        }

        if ((f->ftps_junk != 0) && (rptr < wptr)) {
            for (s = rptr; s < wptr; s++) {
                if ((*s == '\r') && (s + 1 < wptr) &&
                    (*(s + 1) == '\n')) {
                    rptr = s + 2;
                    f->ftps_junk = 0;
                    break;
                }
            }
        }

        if (rptr == wptr) {
            rptr = wptr = f->ftps_buf;
        } else {
            /*
             * Compact the buffer back to the start.  The junk
             * flag should already be set and because we're not
             * throwing away any data, it is preserved from its
             * current state.
             */
            if (rptr > f->ftps_buf) {
                bcopy(rptr, f->ftps_buf, len);
                wptr -= rptr - f->ftps_buf;
                rptr = f->ftps_buf;
            }
        }
        f->ftps_rptr = rptr;
        f->ftps_wptr = wptr;
    }

    /* f->ftps_seq[1] += inc; */
    if (tcp->th_flags & TH_FIN)
        f->ftps_seq[1]++;
    if (ippr_ftp_debug > 3) {
#ifdef __sgi
        mlen = fin->fin_plen;
#else
        mlen = MSGDSIZE(m);
#endif
        mlen -= off;
        printf("ftps_seq[1] = %x inc %d len %d\n",
               f->ftps_seq[1], inc, mlen);
    }

    f->ftps_rptr = rptr;
    f->ftps_wptr = wptr;
    return APR_INC(inc);
}


int ippr_ftp_out(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
    ftpinfo_t *ftp;
    int rev;

    ftp = aps->aps_data;
    if (ftp == NULL)
        return 0;

    rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
    if (ftp->ftp_side[1 - rev].ftps_ifp == NULL)
        ftp->ftp_side[1 - rev].ftps_ifp = fin->fin_ifp;

    return ippr_ftp_process(fin, nat, ftp, rev);
}


int ippr_ftp_in(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
    ftpinfo_t *ftp;
    int rev;

    ftp = aps->aps_data;
    if (ftp == NULL)
        return 0;

    rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
    if (ftp->ftp_side[rev].ftps_ifp == NULL)
        ftp->ftp_side[rev].ftps_ifp = fin->fin_ifp;

    return ippr_ftp_process(fin, nat, ftp, 1 - rev);
}


/*
 * ippr_ftp_atoi - implement a version of atoi which processes numbers in
 * pairs separated by commas (which are expected to be in the range 0 - 255),
 * returning a 16 bit number combining either side of the , as the MSB and
 * LSB.
 */
u_short ippr_ftp_atoi(ptr)
char **ptr;
{
    register char *s = *ptr, c;
    register u_char i = 0, j = 0;

    while (((c = *s++) != '\0') && ISDIGIT(c)) {
        i *= 10;
        i += c - '0';
    }
    if (c != ',') {
        *ptr = NULL;
        return 0;
    }
    while (((c = *s++) != '\0') && ISDIGIT(c)) {
        j *= 10;
        j += c - '0';
    }
    *ptr = s;
    i &= 0xff;
    j &= 0xff;
    return (i << 8) | j;
}


int ippr_ftp_epsv(fin, ip, nat, f, dlen)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpside_t *f;
int dlen;
{
    char newbuf[IPF_FTPBUFSZ];
    char *s;
    u_short ap = 0;

#define EPSV_REPLEN 33
    /*
     * Check for EPSV reply message.
     */
    if (dlen < IPF_MIN229LEN)
        return (0);
    else if (strncmp(f->ftps_rptr,
             "229 Entering Extended Passive Mode", EPSV_REPLEN))
        return (0);

    /*
     * Skip the EPSV command + space
     */
    s = f->ftps_rptr + 33;
    while (*s && !ISDIGIT(*s))
        s++;

    /*
     * As per RFC 2428, there are no addres components in the EPSV
     * response.  So we'll go straight to getting the port.
     */
    while (*s && ISDIGIT(*s)) {
        ap *= 10;
        ap += *s++ - '0';
    }

    if (!s)
        return 0;

    if (*s == '|')
        s++;
    if (*s == ')')
        s++;
    if (*s == '\n')
        s--;
    /*
     * check for CR-LF at the end.
     */
    if ((*s == '\r') && (*(s + 1) == '\n')) {
        s += 2;
    } else
        return 0;

#if defined(SNPRINTF) && defined(_KERNEL)
    (void) SNPRINTF(newbuf, sizeof(newbuf), "%s (|||%u|)\r\n",
         "229 Entering Extended Passive Mode", ap);
#else
    (void) sprintf(newbuf, "%s (|||%u|)\r\n",
               "229 Entering Extended Passive Mode", ap);
#endif

    return ippr_ftp_pasvreply(fin, ip, nat, f, (u_int)ap, newbuf, s,
                  ip->ip_src.s_addr);
}