| 1 |
pcg |
1.1 |
/* |
| 2 |
|
|
ether_emu.C -- ethernet "emulator" library |
| 3 |
pcg |
1.2 |
Copyright (C) 2003 Marc Lehmann <pcg@goof.com> |
| 4 |
pcg |
1.1 |
|
| 5 |
|
|
This program is free software; you can redistribute it and/or modify |
| 6 |
|
|
it under the terms of the GNU General Public License as published by |
| 7 |
|
|
the Free Software Foundation; either version 2 of the License, or |
| 8 |
|
|
(at your option) any later version. |
| 9 |
|
|
|
| 10 |
|
|
This program is distributed in the hope that it will be useful, |
| 11 |
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 |
|
|
GNU General Public License for more details. |
| 14 |
|
|
|
| 15 |
|
|
You should have received a copy of the GNU General Public License |
| 16 |
|
|
along with this program; if not, write to the Free Software |
| 17 |
|
|
Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 |
|
|
*/ |
| 19 |
|
|
|
| 20 |
|
|
#include "config.h" |
| 21 |
|
|
|
| 22 |
|
|
#include <map> |
| 23 |
|
|
|
| 24 |
|
|
#include "vpn.h" |
| 25 |
|
|
|
| 26 |
|
|
struct ether_emu : map<u32, int> { |
| 27 |
|
|
typedef map<u32, int> ipv4map; |
| 28 |
|
|
ipv4map ipv4; |
| 29 |
|
|
|
| 30 |
|
|
bool tun_to_tap (tap_packet *pkt); |
| 31 |
|
|
bool tap_to_tun (tap_packet *pkt); |
| 32 |
|
|
|
| 33 |
|
|
void set_ipv4 (u32 ip, int dst) |
| 34 |
|
|
{ |
| 35 |
|
|
(ipv4.insert (pair<u32, int>(ip, dst)).first)->second = dst; |
| 36 |
|
|
} |
| 37 |
|
|
}; |
| 38 |
|
|
|
| 39 |
|
|
static struct ether_emu ether_emu; |
| 40 |
|
|
|
| 41 |
|
|
bool |
| 42 |
|
|
ether_emu::tun_to_tap (tap_packet *pkt) |
| 43 |
|
|
{ |
| 44 |
|
|
int dst; |
| 45 |
|
|
|
| 46 |
|
|
if (pkt->is_ipv4 ()) |
| 47 |
|
|
{ |
| 48 |
|
|
// update arp cache for _local_ hosts |
| 49 |
|
|
set_ipv4 (pkt->ipv4_src (), THISNODE->id); |
| 50 |
|
|
|
| 51 |
|
|
ipv4map::iterator i = ipv4.find (pkt->ipv4_dst ()); |
| 52 |
|
|
|
| 53 |
|
|
if (i == ipv4.end ()) |
| 54 |
|
|
{ |
| 55 |
|
|
u32 ip_src = pkt->ipv4_src (); |
| 56 |
|
|
u32 ip_dst = pkt->ipv4_dst (); |
| 57 |
|
|
|
| 58 |
|
|
// throw away current packet and make it an arp request |
| 59 |
|
|
(*pkt)[12] = 0x08; (*pkt)[13] = 0x06; |
| 60 |
|
|
(*pkt)[14] = 0x00; (*pkt)[15] = 0x01; // hw |
| 61 |
|
|
(*pkt)[16] = 0x08; (*pkt)[17] = 0x00; // prot |
| 62 |
|
|
(*pkt)[18] = 0x06; // hw_len |
| 63 |
|
|
(*pkt)[19] = 0x04; // prot_len |
| 64 |
|
|
(*pkt)[20] = 0x00; (*pkt)[21] = 0x01; // op |
| 65 |
|
|
|
| 66 |
|
|
id2mac (THISNODE->id, &(*pkt)[22]); |
| 67 |
|
|
*(u32 *)&(*pkt)[28] = ip_src; |
| 68 |
|
|
id2mac (0, &(*pkt)[32]); |
| 69 |
|
|
*(u32 *)&(*pkt)[38] = ip_dst; |
| 70 |
|
|
|
| 71 |
|
|
pkt->len = 42; |
| 72 |
|
|
|
| 73 |
|
|
dst = 0; |
| 74 |
|
|
} |
| 75 |
|
|
else |
| 76 |
|
|
dst = i->second; |
| 77 |
|
|
} |
| 78 |
|
|
else |
| 79 |
|
|
dst = 0; // broadcast non-ip |
| 80 |
|
|
|
| 81 |
|
|
id2mac (THISNODE->id, pkt->src); |
| 82 |
|
|
id2mac (dst, pkt->dst); |
| 83 |
|
|
|
| 84 |
|
|
return true; |
| 85 |
|
|
} |
| 86 |
|
|
|
| 87 |
|
|
bool |
| 88 |
|
|
ether_emu::tap_to_tun (tap_packet *pkt) |
| 89 |
|
|
{ |
| 90 |
|
|
if (pkt->is_arp ()) |
| 91 |
|
|
{ |
| 92 |
|
|
u32 ip_src = *(u32 *)&(*pkt)[28]; |
| 93 |
|
|
|
| 94 |
|
|
// always update with all info we can get. in this case, the arp sender. |
| 95 |
|
|
set_ipv4 (ip_src, mac2id (&(*pkt)[22])); |
| 96 |
|
|
|
| 97 |
|
|
//TODO: remove cache dumper |
| 98 |
|
|
//for (ipv4map::iterator i = ipv4.begin (); i != ipv4.end (); ++i) printf ("%08lx => %d\n", i->first, i->second); |
| 99 |
|
|
|
| 100 |
|
|
if ((*pkt)[20] == 0x00 && (*pkt)[21] == 0x01) // arp request |
| 101 |
|
|
{ |
| 102 |
|
|
// send a reply, if applicable |
| 103 |
|
|
u32 ip_dst = *(u32 *)&(*pkt)[38]; |
| 104 |
|
|
ipv4map::iterator i = ipv4.find (ip_dst); |
| 105 |
|
|
|
| 106 |
|
|
// TODO: look up list of local networks and answer for them |
| 107 |
|
|
if (i != ipv4.end () && i->second == THISNODE->id) |
| 108 |
|
|
{ |
| 109 |
|
|
// create an arp reply |
| 110 |
|
|
tap_packet *rep = new tap_packet; |
| 111 |
|
|
|
| 112 |
|
|
id2mac (THISNODE->id, rep->src); |
| 113 |
|
|
memcpy (rep->dst, pkt->src, sizeof (mac)); |
| 114 |
|
|
|
| 115 |
|
|
(*rep)[12] = 0x08; (*rep)[13] = 0x06; |
| 116 |
|
|
(*rep)[14] = 0x00; (*rep)[15] = 0x01; // hw |
| 117 |
|
|
(*rep)[16] = 0x08; (*rep)[17] = 0x00; // prot |
| 118 |
|
|
(*rep)[18] = 0x06; // hw_len |
| 119 |
|
|
(*rep)[19] = 0x04; // prot_len |
| 120 |
|
|
(*rep)[20] = 0x00; (*rep)[21] = 0x02; // op |
| 121 |
|
|
|
| 122 |
|
|
id2mac (THISNODE->id, &(*rep)[22]); |
| 123 |
|
|
*(u32 *)&(*rep)[28] = ip_dst; |
| 124 |
|
|
memcpy (&(*rep)[32], &(*pkt)[22], sizeof (mac)); |
| 125 |
|
|
*(u32 *)&(*rep)[38] = ip_src; |
| 126 |
|
|
|
| 127 |
|
|
rep->len = 42; |
| 128 |
|
|
|
| 129 |
|
|
network.inject_data_packet (rep, mac2id (rep->dst)); |
| 130 |
|
|
|
| 131 |
|
|
delete rep; |
| 132 |
|
|
} |
| 133 |
|
|
} |
| 134 |
|
|
else if ((*pkt)[20] == 0x00 && (*pkt)[21] == 0x02) // arp reply |
| 135 |
|
|
set_ipv4 (*(u32 *)&(*pkt)[28], mac2id (&(*pkt)[22])); |
| 136 |
|
|
|
| 137 |
|
|
return false; |
| 138 |
|
|
} |
| 139 |
|
|
else if (pkt->is_ipv4 ()) |
| 140 |
|
|
{ |
| 141 |
|
|
// update arp cache |
| 142 |
|
|
set_ipv4 (pkt->ipv4_src (), mac2id (pkt->src)); |
| 143 |
|
|
set_ipv4 (pkt->ipv4_dst (), mac2id (pkt->dst)); |
| 144 |
|
|
} |
| 145 |
|
|
|
| 146 |
|
|
return true; |
| 147 |
|
|
} |
| 148 |
|
|
|
