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    /*	$OpenBSD: pf.c,v 1.17 2017/04/19 05:36:13 natano Exp $ */  | 
    
    
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    /*  | 
    
    
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     * Copyright (c) 1993-95 Mats O Jansson.  All rights reserved.  | 
    
    
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     * Copyright (c) 1990 The Regents of the University of California.  | 
    
    
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     * All rights reserved.  | 
    
    
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     *  | 
    
    
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     * This code is partly derived from rarpd.  | 
    
    
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     *  | 
    
    
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     * Redistribution and use in source and binary forms, with or without  | 
    
    
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     * modification, are permitted provided that the following conditions  | 
    
    
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     * are met:  | 
    
    
    13  | 
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     * 1. Redistributions of source code must retain the above copyright  | 
    
    
    14  | 
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     *    notice, this list of conditions and the following disclaimer.  | 
    
    
    15  | 
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     * 2. Redistributions in binary form must reproduce the above copyright  | 
    
    
    16  | 
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     *    notice, this list of conditions and the following disclaimer in the  | 
    
    
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     *    documentation and/or other materials provided with the distribution.  | 
    
    
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     *  | 
    
    
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     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR  | 
    
    
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     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES  | 
    
    
    21  | 
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     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  | 
    
    
    22  | 
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     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,  | 
    
    
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     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT  | 
    
    
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     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,  | 
    
    
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     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY  | 
    
    
    26  | 
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     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT  | 
    
    
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     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF  | 
    
    
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     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  | 
    
    
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     */  | 
    
    
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    #include <stdio.h>  | 
    
    
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    #include <unistd.h>  | 
    
    
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    #include <sys/types.h>  | 
    
    
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    #include <sys/time.h>  | 
    
    
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    #include <sys/ioctl.h>  | 
    
    
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    #include <sys/file.h>  | 
    
    
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    #include <sys/socket.h>  | 
    
    
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    #include <sys/uio.h>  | 
    
    
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    #include <net/if.h>  | 
    
    
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    #include <net/bpf.h>  | 
    
    
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    #include <netinet/in.h>  | 
    
    
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    #include <netinet/if_ether.h>  | 
    
    
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    #include <netdb.h>  | 
    
    
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    #include <ctype.h>  | 
    
    
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    #include <string.h>  | 
    
    
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    #include <err.h>  | 
    
    
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    #include <errno.h>  | 
    
    
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    #include <syslog.h>  | 
    
    
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    #include "common/mopdef.h"  | 
    
    
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    /*  | 
    
    
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     * Variables  | 
    
    
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     */  | 
    
    
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    extern int promisc;  | 
    
    
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    /*  | 
    
    
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     * Return information to device.c how to open device.  | 
    
    
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     * In this case the driver can handle both Ethernet type II and  | 
    
    
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     * IEEE 802.3 frames (SNAP) in a single pfOpen.  | 
    
    
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     */  | 
    
    
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    /* ARGSUSED */  | 
    
    
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    int  | 
    
    
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    pfTrans(char *interface)  | 
    
    
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    { | 
    
    
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    	return (TRANS_ETHER + TRANS_8023 + TRANS_AND);  | 
    
    
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    }  | 
    
    
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    /*  | 
    
    
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     * Open and initialize packet filter.  | 
    
    
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     */  | 
    
    
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    /* ARGSUSED */  | 
    
    
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    int  | 
    
    
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    pfInit(char *interface, int mode, u_short protocol, int typ)  | 
    
    
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    { | 
    
    
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    	int		fd;  | 
    
    
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    	struct ifreq	ifr;  | 
    
    
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    	u_int		dlt;  | 
    
    
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    	int		immediate;  | 
    
    
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    	static struct bpf_insn insns[] = { | 
    
    
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    		BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 12),  | 
    
    
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    		BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 4, 0),  | 
    
    
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    		BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 20),  | 
    
    
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    		BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 0, 3),  | 
    
    
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    		BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 14),  | 
    
    
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    		BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xaaaa, 0, 1),  | 
    
    
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    		BPF_STMT(BPF_RET | BPF_K, 1520),  | 
    
    
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    		BPF_STMT(BPF_RET | BPF_K, 0),  | 
    
    
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    	};  | 
    
    
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    	static struct bpf_program filter = { | 
    
    
    97  | 
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    		sizeof insns / sizeof(insns[0]),  | 
    
    
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    		insns  | 
    
    
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    	};  | 
    
    
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    	if ((fd = open("/dev/bpf", mode)) == -1) { | 
    
    
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    		syslog(LOG_ERR,"pfInit: open bpf %m");  | 
    
    
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    		return (-1);  | 
    
    
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    	}  | 
    
    
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    	/* Set immediate mode so packets are processed as they arrive. */  | 
    
    
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    	immediate = 1;  | 
    
    
    108  | 
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    	if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) { | 
    
    
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    		syslog(LOG_ERR,"pfInit: BIOCIMMEDIATE: %m");  | 
    
    
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    		return (-1);  | 
    
    
    111  | 
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    	}  | 
    
    
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    	strncpy(ifr.ifr_name, interface, sizeof ifr.ifr_name);  | 
    
    
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    	if (ioctl(fd, BIOCSETIF, &ifr) < 0) { | 
    
    
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    		syslog(LOG_ERR,"pfInit: BIOCSETIF: %m");  | 
    
    
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    		return (-1);  | 
    
    
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    	}  | 
    
    
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    	/* Check that the data link layer is an Ethernet; this code won't work  | 
    
    
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    	 * with anything else. */  | 
    
    
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    	if (ioctl(fd, BIOCGDLT, &dlt) < 0) { | 
    
    
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    		syslog(LOG_ERR,"pfInit: BIOCGDLT: %m");  | 
    
    
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    		return (-1);  | 
    
    
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    	}  | 
    
    
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    	if (dlt != DLT_EN10MB) { | 
    
    
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    		syslog(LOG_ERR,"pfInit: %s is not ethernet", interface);  | 
    
    
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    		return (-1);  | 
    
    
    126  | 
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    	}  | 
    
    
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    	if (promisc)  | 
    
    
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    		/* Set promiscuous mode. */  | 
    
    
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    		if (ioctl(fd, BIOCPROMISC, 0) < 0) { | 
    
    
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    			syslog(LOG_ERR,"pfInit: BIOCPROMISC: %m");  | 
    
    
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    			return (-1);  | 
    
    
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    		}  | 
    
    
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    	/* Set filter program. */  | 
    
    
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    	insns[1].k = protocol;  | 
    
    
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    	insns[3].k = protocol;  | 
    
    
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    	if (ioctl(fd, BIOCSETF, &filter) < 0) { | 
    
    
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    		syslog(LOG_ERR,"pfInit: BIOCSETF: %m");  | 
    
    
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    		return (-1);  | 
    
    
    141  | 
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    	}  | 
    
    
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    143  | 
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    	/* XXX set the same write filter (for protocol only) */  | 
    
    
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    	if (ioctl(fd, BIOCSETWF, &filter) < 0) { | 
    
    
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    		syslog(LOG_ERR,"pfInit: BIOCSETWF: %m");  | 
    
    
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    		return (-1);  | 
    
    
    147  | 
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    	}  | 
    
    
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    	/* Lock the interface to prevent further changes */  | 
    
    
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    	if (ioctl(fd, BIOCLOCK) < 0) { | 
    
    
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    		syslog(LOG_ERR,"pfInit: BIOCLOCK: %m");  | 
    
    
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    		return (-1);  | 
    
    
    153  | 
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    	}  | 
    
    
    154  | 
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    	return (fd);  | 
    
    
    156  | 
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    }  | 
    
    
    157  | 
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    158  | 
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    /*  | 
    
    
    159  | 
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     * Add a Multicast address to the interface  | 
    
    
    160  | 
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     */  | 
    
    
    161  | 
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    /* ARGSUSED */  | 
    
    
    162  | 
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    int  | 
    
    
    163  | 
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    pfAddMulti(int s, char *interface, char *addr)  | 
    
    
    164  | 
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    { | 
    
    
    165  | 
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    	struct ifreq	ifr;  | 
    
    
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    	int		fd;  | 
    
    
    167  | 
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    	strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name) - 1);  | 
    
    
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    	ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = 0;  | 
    
    
    170  | 
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    	ifr.ifr_addr.sa_family = AF_UNSPEC;  | 
    
    
    172  | 
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    	bcopy(addr, ifr.ifr_addr.sa_data, 6);  | 
    
    
    173  | 
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    174  | 
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    	/*  | 
    
    
    175  | 
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    	 * open a socket, temporarily, to use for SIOC* ioctls  | 
    
    
    176  | 
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    	 */  | 
    
    
    177  | 
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    	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { | 
    
    
    178  | 
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    		syslog(LOG_ERR, "pfAddMulti: socket: %m");  | 
    
    
    179  | 
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    		return (-1);  | 
    
    
    180  | 
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    	}  | 
    
    
    181  | 
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    	if (ioctl(fd, SIOCADDMULTI, &ifr) < 0) { | 
    
    
    182  | 
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    		syslog(LOG_ERR, "pfAddMulti: SIOCADDMULTI: %m");  | 
    
    
    183  | 
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    		close(fd);  | 
    
    
    184  | 
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    		return (-1);  | 
    
    
    185  | 
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    	}  | 
    
    
    186  | 
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    	close(fd);  | 
    
    
    187  | 
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    188  | 
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    	return (0);  | 
    
    
    189  | 
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    }  | 
    
    
    190  | 
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    191  | 
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    /*  | 
    
    
    192  | 
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     * Delete a Multicast address from the interface  | 
    
    
    193  | 
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     */  | 
    
    
    194  | 
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    /* ARGSUSED */  | 
    
    
    195  | 
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    int  | 
    
    
    196  | 
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    pfDelMulti(int s, char *interface, char *addr)  | 
    
    
    197  | 
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    { | 
    
    
    198  | 
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    	struct ifreq	ifr;  | 
    
    
    199  | 
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    	int		fd;  | 
    
    
    200  | 
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    201  | 
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    	strncpy(ifr.ifr_name, interface, sizeof (ifr.ifr_name) - 1);  | 
    
    
    202  | 
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    	ifr.ifr_name[sizeof(ifr.ifr_name)-1] = 0;  | 
    
    
    203  | 
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    204  | 
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    	ifr.ifr_addr.sa_family = AF_UNSPEC;  | 
    
    
    205  | 
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    	bcopy(addr, ifr.ifr_addr.sa_data, 6);  | 
    
    
    206  | 
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    207  | 
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    	/*  | 
    
    
    208  | 
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    	 * open a socket, temporarily, to use for SIOC* ioctls  | 
    
    
    209  | 
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    	 *  | 
    
    
    210  | 
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    	 */  | 
    
    
    211  | 
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    	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { | 
    
    
    212  | 
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    		syslog(LOG_ERR, "pfDelMulti: socket: %m");  | 
    
    
    213  | 
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    		return (-1);  | 
    
    
    214  | 
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    	}  | 
    
    
    215  | 
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    	if (ioctl(fd, SIOCDELMULTI, &ifr) < 0) { | 
    
    
    216  | 
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    		syslog(LOG_ERR, "pfAddMulti: SIOCDELMULTI: %m");  | 
    
    
    217  | 
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    		close(fd);  | 
    
    
    218  | 
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    		return (-1);  | 
    
    
    219  | 
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    	}  | 
    
    
    220  | 
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    	close(fd);  | 
    
    
    221  | 
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    222  | 
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    	return (0);  | 
    
    
    223  | 
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    }  | 
    
    
    224  | 
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    225  | 
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    /*  | 
    
    
    226  | 
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     * read a packet  | 
    
    
    227  | 
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     */  | 
    
    
    228  | 
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    int  | 
    
    
    229  | 
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    pfRead(int fd, u_char *buf, int len)  | 
    
    
    230  | 
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    { | 
    
    
    231  | 
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    	return (read(fd, buf, len));  | 
    
    
    232  | 
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    }  | 
    
    
    233  | 
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    234  | 
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    /*  | 
    
    
    235  | 
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     * write a packet  | 
    
    
    236  | 
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     */  | 
    
    
    237  | 
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    int  | 
    
    
    238  | 
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    pfWrite(int fd, u_char *buf, int len, int trans)  | 
    
    
    239  | 
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    { | 
    
    
    240  | 
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    	struct iovec	iov[2];  | 
    
    
    241  | 
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    242  | 
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    	/* XXX */  | 
    
    
    243  | 
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    	switch (trans) { | 
    
    
    244  | 
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    	case TRANS_8023:  | 
    
    
    245  | 
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    		iov[0].iov_base = buf;  | 
    
    
    246  | 
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    		iov[0].iov_len = 22;  | 
    
    
    247  | 
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    		iov[1].iov_base = buf + 22;  | 
    
    
    248  | 
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    		iov[1].iov_len = len - 22;  | 
    
    
    249  | 
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    		break;  | 
    
    
    250  | 
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    	default:  | 
    
    
    251  | 
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    		iov[0].iov_base = buf;  | 
    
    
    252  | 
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    		iov[0].iov_len = 14;  | 
    
    
    253  | 
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    		iov[1].iov_base = buf + 14;  | 
    
    
    254  | 
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    		iov[1].iov_len = len - 14;  | 
    
    
    255  | 
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    		break;  | 
    
    
    256  | 
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    	}  | 
    
    
    257  | 
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    258  | 
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    	if (writev(fd, iov, 2) == len)  | 
    
    
    259  | 
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    		return (len);  | 
    
    
    260  | 
     | 
     | 
     | 
    
    
    261  | 
     | 
     | 
    	return (-1);  | 
    
    
    262  | 
     | 
     | 
    }  | 
    
    
    263  | 
     | 
     | 
     |