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    /*	$OpenBSD: filter.c,v 1.21 2015/01/21 21:50:33 deraadt Exp $ */  | 
    
    
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    /*  | 
    
    
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     * Copyright (c) 2004, 2005 Camiel Dobbelaar, <cd@sentia.nl>  | 
    
    
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     *  | 
    
    
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     * Permission to use, copy, modify, and distribute this software for any  | 
    
    
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     * purpose with or without fee is hereby granted, provided that the above  | 
    
    
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     * copyright notice and this permission notice appear in all copies.  | 
    
    
    9  | 
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     *  | 
    
    
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     * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES  | 
    
    
    11  | 
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     * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF  | 
    
    
    12  | 
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     * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  | 
    
    
    13  | 
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     * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES  | 
    
    
    14  | 
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     * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN  | 
    
    
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     * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  | 
    
    
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     * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  | 
    
    
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     */  | 
    
    
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    #include <sys/ioctl.h>  | 
    
    
    20  | 
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    #include <sys/types.h>  | 
    
    
    21  | 
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    #include <sys/socket.h>  | 
    
    
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    23  | 
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    #include <netinet/in.h>  | 
    
    
    24  | 
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    #include <netinet/tcp.h>  | 
    
    
    25  | 
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    #include <arpa/inet.h>  | 
    
    
    26  | 
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    #include <net/if.h>  | 
    
    
    27  | 
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    #include <net/pfvar.h>  | 
    
    
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    29  | 
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    #include <err.h>  | 
    
    
    30  | 
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    #include <errno.h>  | 
    
    
    31  | 
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    #include <fcntl.h>  | 
    
    
    32  | 
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    #include <stdio.h>  | 
    
    
    33  | 
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    #include <string.h>  | 
    
    
    34  | 
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    #include <unistd.h>  | 
    
    
    35  | 
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    36  | 
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    #include "filter.h"  | 
    
    
    37  | 
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    38  | 
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    /* From netinet/in.h, but only _KERNEL_ gets them. */  | 
    
    
    39  | 
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    #define satosin(sa)	((struct sockaddr_in *)(sa))  | 
    
    
    40  | 
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    #define satosin6(sa)	((struct sockaddr_in6 *)(sa))  | 
    
    
    41  | 
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    42  | 
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    int add_addr(struct sockaddr *, struct pf_pool *);  | 
    
    
    43  | 
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    int prepare_rule(u_int32_t, struct sockaddr *, struct sockaddr *,  | 
    
    
    44  | 
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        u_int16_t);  | 
    
    
    45  | 
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    46  | 
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    static struct pfioc_rule	pfr;  | 
    
    
    47  | 
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    static struct pfioc_trans	pft;  | 
    
    
    48  | 
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    static struct pfioc_trans_e	pfte;  | 
    
    
    49  | 
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    static int dev, rule_log;  | 
    
    
    50  | 
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    static char *qname, *tagname;  | 
    
    
    51  | 
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    52  | 
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    int  | 
    
    
    53  | 
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    add_addr(struct sockaddr *addr, struct pf_pool *pfp)  | 
    
    
    54  | 
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    { | 
    
    
    55  | 
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    	if (addr->sa_family == AF_INET) { | 
    
    
    56  | 
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    		memcpy(&pfp->addr.v.a.addr.v4,  | 
    
    
    57  | 
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    		    &satosin(addr)->sin_addr.s_addr, 4);  | 
    
    
    58  | 
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    		memset(&pfp->addr.v.a.mask.addr8, 255, 4);  | 
    
    
    59  | 
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    	} else { | 
    
    
    60  | 
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    		memcpy(&pfp->addr.v.a.addr.v6,  | 
    
    
    61  | 
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    		    &satosin6(addr)->sin6_addr.s6_addr, 16);  | 
    
    
    62  | 
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    		memset(&pfp->addr.v.a.mask.addr8, 255, 16);  | 
    
    
    63  | 
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    	}  | 
    
    
    64  | 
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    	pfp->addr.type = PF_ADDR_ADDRMASK;  | 
    
    
    65  | 
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    	return (0);  | 
    
    
    66  | 
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    }  | 
    
    
    67  | 
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    68  | 
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    int  | 
    
    
    69  | 
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    add_nat(u_int32_t id, struct sockaddr *src, int s_rd, struct sockaddr *dst,  | 
    
    
    70  | 
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        u_int16_t d_port, struct sockaddr *nat, u_int16_t nat_range_low,  | 
    
    
    71  | 
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        u_int16_t nat_range_high)  | 
    
    
    72  | 
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    { | 
    
    
    73  | 
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    	if (!src || !dst || !d_port || !nat || !nat_range_low ||  | 
    
    
    74  | 
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    	    !nat_range_high || (src->sa_family != nat->sa_family)) { | 
    
    
    75  | 
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    		errno = EINVAL;  | 
    
    
    76  | 
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    		return (-1);  | 
    
    
    77  | 
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    	}  | 
    
    
    78  | 
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    79  | 
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    	if (prepare_rule(id, src, dst, d_port) == -1)  | 
    
    
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    		return (-1);  | 
    
    
    81  | 
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    82  | 
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    	if (add_addr(nat, &pfr.rule.nat) == -1)  | 
    
    
    83  | 
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    		return (-1);  | 
    
    
    84  | 
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    85  | 
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    	pfr.rule.direction = PF_OUT;  | 
    
    
    86  | 
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    	pfr.rule.onrdomain = s_rd;  | 
    
    
    87  | 
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    	pfr.rule.rtableid = -1;  | 
    
    
    88  | 
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    	pfr.rule.nat.proxy_port[0] = nat_range_low;  | 
    
    
    89  | 
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    	pfr.rule.nat.proxy_port[1] = nat_range_high;  | 
    
    
    90  | 
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    	if (ioctl(dev, DIOCADDRULE, &pfr) == -1)  | 
    
    
    91  | 
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    		return (-1);  | 
    
    
    92  | 
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    93  | 
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    	return (0);  | 
    
    
    94  | 
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    }  | 
    
    
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    96  | 
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    int  | 
    
    
    97  | 
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    add_rdr(u_int32_t id, struct sockaddr *src, int s_rd, struct sockaddr *dst,  | 
    
    
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        u_int16_t d_port, struct sockaddr *rdr, u_int16_t rdr_port, int d_rd)  | 
    
    
    99  | 
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    { | 
    
    
    100  | 
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    	if (!src || !dst || !d_port || !rdr || !rdr_port ||  | 
    
    
    101  | 
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    	    (src->sa_family != rdr->sa_family)) { | 
    
    
    102  | 
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    		errno = EINVAL;  | 
    
    
    103  | 
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    		return (-1);  | 
    
    
    104  | 
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    	}  | 
    
    
    105  | 
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    106  | 
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    	if (prepare_rule(id, src, dst, d_port) == -1)  | 
    
    
    107  | 
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    		return (-1);  | 
    
    
    108  | 
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    109  | 
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    	if (add_addr(rdr, &pfr.rule.rdr) == -1)  | 
    
    
    110  | 
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    		return (-1);  | 
    
    
    111  | 
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    112  | 
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    	pfr.rule.direction = PF_IN;  | 
    
    
    113  | 
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    	pfr.rule.onrdomain = s_rd;  | 
    
    
    114  | 
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    	pfr.rule.rtableid = d_rd;  | 
    
    
    115  | 
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    	pfr.rule.rdr.proxy_port[0] = rdr_port;  | 
    
    
    116  | 
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    	if (ioctl(dev, DIOCADDRULE, &pfr) == -1)  | 
    
    
    117  | 
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    		return (-1);  | 
    
    
    118  | 
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    	return (0);  | 
    
    
    120  | 
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    }  | 
    
    
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    int  | 
    
    
    123  | 
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    do_commit(void)  | 
    
    
    124  | 
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    { | 
    
    
    125  | 
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    	if (ioctl(dev, DIOCXCOMMIT, &pft) == -1)  | 
    
    
    126  | 
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    		return (-1);  | 
    
    
    127  | 
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    128  | 
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    	return (0);  | 
    
    
    129  | 
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    }  | 
    
    
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    int  | 
    
    
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    do_rollback(void)  | 
    
    
    133  | 
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    { | 
    
    
    134  | 
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    	if (ioctl(dev, DIOCXROLLBACK, &pft) == -1)  | 
    
    
    135  | 
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    		return (-1);  | 
    
    
    136  | 
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    137  | 
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    	return (0);  | 
    
    
    138  | 
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    }  | 
    
    
    139  | 
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    void  | 
    
    
    141  | 
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    init_filter(char *opt_qname, char *opt_tagname, int opt_verbose)  | 
    
    
    142  | 
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    { | 
    
    
    143  | 
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    	struct pf_status status;  | 
    
    
    144  | 
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    145  | 
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    	qname = opt_qname;  | 
    
    
    146  | 
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    	tagname = opt_tagname;  | 
    
    
    147  | 
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    148  | 
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    	if (opt_verbose == 1)  | 
    
    
    149  | 
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    		rule_log = PF_LOG;  | 
    
    
    150  | 
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    	else if (opt_verbose == 2)  | 
    
    
    151  | 
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    		rule_log = PF_LOG_ALL;  | 
    
    
    152  | 
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    153  | 
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    	dev = open("/dev/pf", O_RDWR); | 
    
    
    154  | 
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    	if (dev == -1)  | 
    
    
    155  | 
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    		err(1, "open /dev/pf");  | 
    
    
    156  | 
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    	if (ioctl(dev, DIOCGETSTATUS, &status) == -1)  | 
    
    
    157  | 
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    		err(1, "DIOCGETSTATUS");  | 
    
    
    158  | 
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    	if (!status.running)  | 
    
    
    159  | 
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    		errx(1, "pf is disabled");  | 
    
    
    160  | 
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    }  | 
    
    
    161  | 
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    162  | 
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    int  | 
    
    
    163  | 
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    prepare_commit(u_int32_t id)  | 
    
    
    164  | 
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    { | 
    
    
    165  | 
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    	char an[PF_ANCHOR_NAME_SIZE];  | 
    
    
    166  | 
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    167  | 
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    	memset(&pft, 0, sizeof pft);  | 
    
    
    168  | 
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    	pft.size = 1;  | 
    
    
    169  | 
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    	pft.esize = sizeof pfte;  | 
    
    
    170  | 
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    	pft.array = &pfte;  | 
    
    
    171  | 
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    172  | 
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    	snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR,  | 
    
    
    173  | 
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    	    getpid(), id);  | 
    
    
    174  | 
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    	memset(&pfte, 0, sizeof pfte);  | 
    
    
    175  | 
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    	strlcpy(pfte.anchor, an, PF_ANCHOR_NAME_SIZE);  | 
    
    
    176  | 
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    	pfte.type = PF_TRANS_RULESET;  | 
    
    
    177  | 
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    178  | 
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    	if (ioctl(dev, DIOCXBEGIN, &pft) == -1)  | 
    
    
    179  | 
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    		return (-1);  | 
    
    
    180  | 
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    181  | 
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    	return (0);  | 
    
    
    182  | 
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    }  | 
    
    
    183  | 
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    184  | 
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    int  | 
    
    
    185  | 
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    prepare_rule(u_int32_t id, struct sockaddr *src,  | 
    
    
    186  | 
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        struct sockaddr *dst, u_int16_t d_port)  | 
    
    
    187  | 
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    { | 
    
    
    188  | 
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    	char an[PF_ANCHOR_NAME_SIZE];  | 
    
    
    189  | 
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    190  | 
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    	if ((src->sa_family != AF_INET && src->sa_family != AF_INET6) ||  | 
    
    
    191  | 
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    	    (src->sa_family != dst->sa_family)) { | 
    
    
    192  | 
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    		errno = EPROTONOSUPPORT;  | 
    
    
    193  | 
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    		return (-1);  | 
    
    
    194  | 
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    	}  | 
    
    
    195  | 
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    196  | 
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    	memset(&pfr, 0, sizeof pfr);  | 
    
    
    197  | 
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    	snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR,  | 
    
    
    198  | 
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    	    getpid(), id);  | 
    
    
    199  | 
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    	strlcpy(pfr.anchor, an, PF_ANCHOR_NAME_SIZE);  | 
    
    
    200  | 
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    201  | 
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    	pfr.ticket = pfte.ticket;  | 
    
    
    202  | 
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    203  | 
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    	/* Generic for all rule types. */  | 
    
    
    204  | 
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    	pfr.rule.af = src->sa_family;  | 
    
    
    205  | 
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    	pfr.rule.proto = IPPROTO_TCP;  | 
    
    
    206  | 
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    	pfr.rule.src.addr.type = PF_ADDR_ADDRMASK;  | 
    
    
    207  | 
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    	pfr.rule.dst.addr.type = PF_ADDR_ADDRMASK;  | 
    
    
    208  | 
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    	pfr.rule.nat.addr.type = PF_ADDR_NONE;  | 
    
    
    209  | 
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    	pfr.rule.rdr.addr.type = PF_ADDR_NONE;  | 
    
    
    210  | 
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    211  | 
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    	if (src->sa_family == AF_INET) { | 
    
    
    212  | 
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    		memcpy(&pfr.rule.src.addr.v.a.addr.v4,  | 
    
    
    213  | 
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    		    &satosin(src)->sin_addr.s_addr, 4);  | 
    
    
    214  | 
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    		memset(&pfr.rule.src.addr.v.a.mask.addr8, 255, 4);  | 
    
    
    215  | 
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    		memcpy(&pfr.rule.dst.addr.v.a.addr.v4,  | 
    
    
    216  | 
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    		    &satosin(dst)->sin_addr.s_addr, 4);  | 
    
    
    217  | 
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    		memset(&pfr.rule.dst.addr.v.a.mask.addr8, 255, 4);  | 
    
    
    218  | 
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    	} else { | 
    
    
    219  | 
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    		memcpy(&pfr.rule.src.addr.v.a.addr.v6,  | 
    
    
    220  | 
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    		    &satosin6(src)->sin6_addr.s6_addr, 16);  | 
    
    
    221  | 
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    		memset(&pfr.rule.src.addr.v.a.mask.addr8, 255, 16);  | 
    
    
    222  | 
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    		memcpy(&pfr.rule.dst.addr.v.a.addr.v6,  | 
    
    
    223  | 
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    		    &satosin6(dst)->sin6_addr.s6_addr, 16);  | 
    
    
    224  | 
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    		memset(&pfr.rule.dst.addr.v.a.mask.addr8, 255, 16);  | 
    
    
    225  | 
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    	}  | 
    
    
    226  | 
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    	pfr.rule.dst.port_op = PF_OP_EQ;  | 
    
    
    227  | 
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    	pfr.rule.dst.port[0] = htons(d_port);  | 
    
    
    228  | 
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    229  | 
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    	/*  | 
    
    
    230  | 
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    	 * pass [quick] [log] inet[6] proto tcp \  | 
    
    
    231  | 
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    	 *     from $src to $dst port = $d_port flags S/SA keep state  | 
    
    
    232  | 
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    	 *     (max 1) [queue qname] [tag tagname]  | 
    
    
    233  | 
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    	 */  | 
    
    
    234  | 
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    	if (tagname != NULL)  | 
    
    
    235  | 
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    		pfr.rule.action = PF_MATCH;  | 
    
    
    236  | 
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    	else  | 
    
    
    237  | 
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    		pfr.rule.action = PF_PASS;  | 
    
    
    238  | 
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    	pfr.rule.quick = 1;  | 
    
    
    239  | 
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    	pfr.rule.log = rule_log;  | 
    
    
    240  | 
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    	pfr.rule.keep_state = 1;  | 
    
    
    241  | 
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    	pfr.rule.flags = TH_SYN;  | 
    
    
    242  | 
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    	pfr.rule.flagset = (TH_SYN|TH_ACK);  | 
    
    
    243  | 
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    	pfr.rule.max_states = 1;  | 
    
    
    244  | 
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    	if (qname != NULL)  | 
    
    
    245  | 
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    		strlcpy(pfr.rule.qname, qname, sizeof pfr.rule.qname);  | 
    
    
    246  | 
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    	if (tagname != NULL) { | 
    
    
    247  | 
     | 
     | 
    		pfr.rule.quick = 0;  | 
    
    
    248  | 
     | 
     | 
    		strlcpy(pfr.rule.tagname, tagname,  | 
    
    
    249  | 
     | 
     | 
                                   sizeof pfr.rule.tagname);  | 
    
    
    250  | 
     | 
     | 
    	}  | 
    
    
    251  | 
     | 
     | 
     | 
    
    
    252  | 
     | 
     | 
    	return (0);  | 
    
    
    253  | 
     | 
     | 
    }  |