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1.1.6

    1: /*
    2:  *  $Id: libnet_link_pf.c,v 1.1.1.2 2013/07/22 11:54:42 misho Exp $
    3:  *
    4:  *  libnet
    5:  *  libnet_pf.c - pf routines
    6:  *
    7:  *  Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
    8:  *  All rights reserved.
    9:  *
   10:  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
   11:  *	The Regents of the University of California.  All rights reserved.
   12:  *
   13:  * Redistribution and use in source and binary forms, with or without
   14:  * modification, are permitted provided that: (1) source code distributions
   15:  * retain the above copyright notice and this paragraph in its entirety, (2)
   16:  * distributions including binary code include the above copyright notice and
   17:  * this paragraph in its entirety in the documentation or other materials
   18:  * provided with the distribution, and (3) all advertising materials mentioning
   19:  * features or use of this software display the following acknowledgement:
   20:  * ``This product includes software developed by the University of California,
   21:  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
   22:  * the University nor the names of its contributors may be used to endorse
   23:  * or promote products derived from this software without specific prior
   24:  * written permission.
   25:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
   26:  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
   27:  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
   28:  *
   29:  * packet filter subroutines for tcpdump
   30:  *	Extraction/creation by Jeffrey Mogul, DECWRL
   31:  */
   32: 
   33: #if (HAVE_CONFIG_H)
   34: #include "../include/config.h"
   35: #endif
   36: #include "../include/low_libnet.h"
   37: 
   38: #include "../include/gnuc.h"
   39: #ifdef HAVE_OS_PROTO_H
   40: #include "../include/os-proto.h"
   41: #endif
   42: 
   43: struct libnet_link_int *
   44: libnet_open_link_interface(int8_t *device, int8_t *ebuf)
   45: {
   46:     register struct libnet_link_int *l;
   47:     int16_t enmode;
   48:     int backlog = -1;   /* request the most */
   49:     struct enfilter Filter;
   50:     struct endevp devparams;
   51: 
   52:     l = (struct libnet_link_int *)malloc(sizeof(*l));
   53:     if (l == NULL)
   54:     {
   55:         sprintf(ebuf, "libnet_open_link_int: %s", strerror(errno));
   56:         return (0);
   57:     }
   58:     memset(l, 0, sizeof(*l));
   59:     l->fd = pfopen(device, O_RDWR);
   60:     if (l->fd < 0)
   61:     {
   62:         sprintf(ebuf, "pf open: %s: %s\n\your system may not be properly configured; see \"man packetfilter(4)\"\n",
   63:             device, strerror(errno));
   64:         goto bad;
   65:     }
   66: 
   67:     enmode = ENTSTAMP|ENBATCH|ENNONEXCL;
   68:     if (ioctl(l->fd, EIOCMBIS, (caddr_t)&enmode) < 0)
   69:     {
   70:         sprintf(ebuf, "EIOCMBIS: %s", strerror(errno));
   71:         goto bad;
   72:     }
   73: #ifdef	ENCOPYALL
   74:     /* Try to set COPYALL mode so that we see packets to ourself */
   75:     enmode = ENCOPYALL;
   76:     ioctl(l->fd, EIOCMBIS, (caddr_t)&enmode);   /* OK if this fails */
   77: #endif
   78: 	/* set the backlog */
   79:     if (ioctl(l->fd, EIOCSETW, (caddr_t)&backlog) < 0)
   80:     {
   81:         sprintf(ebuf, "EIOCSETW: %s", strerror(errno));
   82:         goto bad;
   83:     }
   84:     /*
   85:      *  discover interface type
   86:      */
   87:     if (ioctl(l->fd, EIOCDEVP, (caddr_t)&devparams) < 0)
   88:     {
   89:         sprintf(ebuf, "EIOCDEVP: %s", strerror(errno));
   90:         goto bad;
   91:     }
   92: 
   93:     /* HACK: to compile prior to Ultrix 4.2 */
   94: #ifndef	ENDT_FDDI
   95: #define	ENDT_FDDI   4
   96: #endif
   97:     switch (devparams.end_dev_type)
   98:     {
   99:         case ENDT_10MB:
  100:             l->linktype = DLT_EN10MB;
  101:             break;
  102:         case ENDT_FDDI:
  103:             l->linktype = DLT_FDDI;
  104:             break;
  105:         default:
  106:             /*
  107:              * XXX
  108:              * Currently, the Ultrix packet filter supports only
  109:              * Ethernet and FDDI.  Eventually, support for SLIP and PPP
  110:              * (and possibly others: T1?) should be added.
  111:              */
  112:             l->linktype = DLT_EN10MB;
  113:             break;
  114: 	}
  115:     /*
  116:      *  acceptag all packets
  117:      */
  118:     bzero((int8_t *)&Filter, sizeof(Filter));
  119:     Filter.enf_Priority = 37;	/* anything > 2 */
  120:     Filter.enf_FilterLen = 0;	/* means "always true" */
  121:     if (ioctl(l->fd, EIOCSETF, (caddr_t)&Filter) < 0)
  122:     {
  123:         sprintf(ebuf, "EIOCSETF: %s", strerror(errno));
  124:         goto bad;
  125:     }
  126: 
  127:     return (l);
  128: bad:
  129:     free(l);
  130:     return (NULL);
  131: }
  132: 
  133: 
  134: int
  135: libnet_close_link_interface(struct libnet_link_int *l)
  136: {
  137:     if (close(l->fd) == 0)
  138:     {
  139:         free(l);
  140:         return (1);
  141:     }
  142:     else
  143:     {
  144:         free(l);
  145:         return (-1);
  146:     }
  147: }
  148: 
  149: 
  150: int
  151: libnet_write_link_layer(struct libnet_link_int *l, const int8_t *device,
  152:             const uint8_t *buf, int len)
  153: {
  154:     int c;
  155: 
  156:     c = write(l->fd, buf, len);
  157:     if (c != len)
  158:     {
  159:         snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
  160:             "libnet_write_link: %d bytes written (%s)\n", c,
  161:             strerror(errno));
  162:     }
  163:     return (c);
  164: }