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Version 1.2p1

    1: /*
    2:  *  $Id: libnet_link_pf.c,v 1.1.1.3 2023/09/27 11:11:38 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: #include "common.h"
   34: 
   35: #include "../include/gnuc.h"
   36: #ifdef HAVE_OS_PROTO_H
   37: #include "../include/os-proto.h"
   38: #endif
   39: 
   40: struct libnet_link_int *
   41: libnet_open_link_interface(int8_t *device, int8_t *ebuf)
   42: {
   43:     register struct libnet_link_int *l;
   44:     int16_t enmode;
   45:     int backlog = -1;   /* request the most */
   46:     struct enfilter Filter;
   47:     struct endevp devparams;
   48: 
   49:     l = (struct libnet_link_int *)malloc(sizeof(*l));
   50:     if (l == NULL)
   51:     {
   52:         snprintf(ebuf, LIBNET_ERRBUF_SIZE,
   53:                  "libnet_open_link_int: %s", strerror(errno));
   54:         return (0);
   55:     }
   56:     memset(l, 0, sizeof(*l));
   57:     l->fd = pfopen(device, O_RDWR);
   58:     if (l->fd < 0)
   59:     {
   60:         snprintf(ebuf, LIBNET_ERRBUF_SIZE,
   61:                  "pf open: %s: %s\nyour system may not be properly configured; see \"man packetfilter(4)\"",
   62:             device, strerror(errno));
   63:         goto bad;
   64:     }
   65: 
   66:     enmode = ENTSTAMP|ENBATCH|ENNONEXCL;
   67:     if (ioctl(l->fd, EIOCMBIS, (caddr_t)&enmode) < 0)
   68:     {
   69:         snprintf(ebuf, LIBNET_ERRBUF_SIZE,
   70:                  "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:         snprintf(ebuf, LIBNET_ERRBUF_SIZE,
   82:                  "EIOCSETW: %s", strerror(errno));
   83:         goto bad;
   84:     }
   85:     /*
   86:      *  discover interface type
   87:      */
   88:     if (ioctl(l->fd, EIOCDEVP, (caddr_t)&devparams) < 0)
   89:     {
   90:         snprintf(ebuf, LIBNET_ERRBUF_SIZE,
   91:                  "EIOCDEVP: %s", strerror(errno));
   92:         goto bad;
   93:     }
   94: 
   95:     /* HACK: to compile prior to Ultrix 4.2 */
   96: #ifndef	ENDT_FDDI
   97: #define	ENDT_FDDI   4
   98: #endif
   99:     switch (devparams.end_dev_type)
  100:     {
  101:         case ENDT_10MB:
  102:             l->linktype = DLT_EN10MB;
  103:             break;
  104:         case ENDT_FDDI:
  105:             l->linktype = DLT_FDDI;
  106:             break;
  107:         default:
  108:             /*
  109:              * XXX
  110:              * Currently, the Ultrix packet filter supports only
  111:              * Ethernet and FDDI.  Eventually, support for SLIP and PPP
  112:              * (and possibly others: T1?) should be added.
  113:              */
  114:             l->linktype = DLT_EN10MB;
  115:             break;
  116: 	}
  117:     /*
  118:      *  acceptag all packets
  119:      */
  120:     bzero((int8_t *)&Filter, sizeof(Filter));
  121:     Filter.enf_Priority = 37;	/* anything > 2 */
  122:     Filter.enf_FilterLen = 0;	/* means "always true" */
  123:     if (ioctl(l->fd, EIOCSETF, (caddr_t)&Filter) < 0)
  124:     {
  125:         snprintf(ebuf, LIBNET_ERRBUF_SIZE,
  126:                  "EIOCSETF: %s", strerror(errno));
  127:         goto bad;
  128:     }
  129: 
  130:     return (l);
  131: bad:
  132:     free(l);
  133:     return (NULL);
  134: }
  135: 
  136: 
  137: int
  138: libnet_close_link_interface(struct libnet_link_int *l)
  139: {
  140:     if (close(l->fd) == 0)
  141:     {
  142:         free(l);
  143:         return (1);
  144:     }
  145:     else
  146:     {
  147:         free(l);
  148:         return (-1);
  149:     }
  150: }
  151: 
  152: 
  153: int
  154: libnet_write_link_layer(struct libnet_link_int *l, const int8_t *device,
  155:             const uint8_t *buf, int len)
  156: {
  157:     int c;
  158: 
  159:     c = write(l->fd, buf, len);
  160:     if (c != len)
  161:     {
  162:         snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
  163:             "libnet_write_link: %d bytes written (%s)", c,
  164:             strerror(errno));
  165:     }
  166:     return (c);
  167: }
  168: 
  169: /**
  170:  * Local Variables:
  171:  *  indent-tabs-mode: nil
  172:  *  c-file-style: "stroustrup"
  173:  * End:
  174:  */