1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2010,2011 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/net/arp.h>
#include <grub/net/netbuff.h>
#include <grub/mm.h>
#include <grub/net.h>
#include <grub/net/ethernet.h>
#include <grub/net/ip.h>
#include <grub/time.h>
/* ARP header operation codes */
enum
{
ARP_REQUEST = 1,
ARP_REPLY = 2
};
enum
{
/* IANA ARP constant to define hardware type as ethernet. */
GRUB_NET_ARPHRD_ETHERNET = 1
};
struct arppkt {
grub_uint16_t hrd;
grub_uint16_t pro;
grub_uint8_t hln;
grub_uint8_t pln;
grub_uint16_t op;
grub_uint8_t sender_mac[6];
grub_uint32_t sender_ip;
grub_uint8_t recv_mac[6];
grub_uint32_t recv_ip;
} GRUB_PACKED;
static int have_pending;
static grub_uint32_t pending_req;
grub_err_t
grub_net_arp_send_request (struct grub_net_network_level_interface *inf,
const grub_net_network_level_address_t *proto_addr)
{
struct grub_net_buff nb;
struct arppkt *arp_packet;
grub_net_link_level_address_t target_mac_addr;
grub_err_t err;
int i;
grub_uint8_t *nbd;
grub_uint8_t arp_data[128];
if (proto_addr->type != GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4)
return grub_error (GRUB_ERR_BUG, "unsupported address family");
/* Build a request packet. */
nb.head = arp_data;
nb.end = arp_data + sizeof (arp_data);
grub_netbuff_clear (&nb);
grub_netbuff_reserve (&nb, 128);
err = grub_netbuff_push (&nb, sizeof (*arp_packet));
if (err)
return err;
arp_packet = (struct arppkt *) nb.data;
arp_packet->hrd = grub_cpu_to_be16_compile_time (GRUB_NET_ARPHRD_ETHERNET);
arp_packet->hln = 6;
arp_packet->pro = grub_cpu_to_be16_compile_time (GRUB_NET_ETHERTYPE_IP);
arp_packet->pln = 4;
arp_packet->op = grub_cpu_to_be16_compile_time (ARP_REQUEST);
/* Sender hardware address. */
grub_memcpy (arp_packet->sender_mac, &inf->hwaddress.mac, 6);
arp_packet->sender_ip = inf->address.ipv4;
grub_memset (arp_packet->recv_mac, 0, 6);
arp_packet->recv_ip = proto_addr->ipv4;
/* Target protocol address */
grub_memset (&target_mac_addr.mac, 0xff, 6);
nbd = nb.data;
send_ethernet_packet (inf, &nb, target_mac_addr, GRUB_NET_ETHERTYPE_ARP);
for (i = 0; i < GRUB_NET_TRIES; i++)
{
if (grub_net_link_layer_resolve_check (inf, proto_addr))
return GRUB_ERR_NONE;
pending_req = proto_addr->ipv4;
have_pending = 0;
grub_net_poll_cards (GRUB_NET_INTERVAL + (i * GRUB_NET_INTERVAL_ADDITION),
&have_pending);
if (grub_net_link_layer_resolve_check (inf, proto_addr))
return GRUB_ERR_NONE;
nb.data = nbd;
send_ethernet_packet (inf, &nb, target_mac_addr, GRUB_NET_ETHERTYPE_ARP);
}
return GRUB_ERR_NONE;
}
grub_err_t
grub_net_arp_receive (struct grub_net_buff *nb, struct grub_net_card *card,
grub_uint16_t *vlantag)
{
struct arppkt *arp_packet = (struct arppkt *) nb->data;
grub_net_network_level_address_t sender_addr, target_addr;
grub_net_link_level_address_t sender_mac_addr;
struct grub_net_network_level_interface *inf;
if (arp_packet->pro != grub_cpu_to_be16_compile_time (GRUB_NET_ETHERTYPE_IP)
|| arp_packet->pln != 4 || arp_packet->hln != 6
|| nb->tail - nb->data < (int) sizeof (*arp_packet))
return GRUB_ERR_NONE;
sender_addr.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
target_addr.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
sender_addr.ipv4 = arp_packet->sender_ip;
target_addr.ipv4 = arp_packet->recv_ip;
if (arp_packet->sender_ip == pending_req)
have_pending = 1;
sender_mac_addr.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET;
grub_memcpy (sender_mac_addr.mac, arp_packet->sender_mac,
sizeof (sender_mac_addr.mac));
grub_net_link_layer_add_address (card, &sender_addr, &sender_mac_addr, 1);
FOR_NET_NETWORK_LEVEL_INTERFACES (inf)
{
/* Verify vlantag id */
if (inf->card == card && inf->vlantag != *vlantag)
{
grub_dprintf ("net", "invalid vlantag! %x != %x\n",
inf->vlantag, *vlantag);
break;
}
/* Am I the protocol address target? */
if (grub_net_addr_cmp (&inf->address, &target_addr) == 0
&& arp_packet->op == grub_cpu_to_be16_compile_time (ARP_REQUEST))
{
grub_net_link_level_address_t target;
struct grub_net_buff nb_reply;
struct arppkt *arp_reply;
grub_uint8_t arp_data[128];
grub_err_t err;
nb_reply.head = arp_data;
nb_reply.end = arp_data + sizeof (arp_data);
grub_netbuff_clear (&nb_reply);
grub_netbuff_reserve (&nb_reply, 128);
err = grub_netbuff_push (&nb_reply, sizeof (*arp_packet));
if (err)
return err;
arp_reply = (struct arppkt *) nb_reply.data;
arp_reply->hrd = grub_cpu_to_be16_compile_time (GRUB_NET_ARPHRD_ETHERNET);
arp_reply->pro = grub_cpu_to_be16_compile_time (GRUB_NET_ETHERTYPE_IP);
arp_reply->pln = 4;
arp_reply->hln = 6;
arp_reply->op = grub_cpu_to_be16_compile_time (ARP_REPLY);
arp_reply->sender_ip = arp_packet->recv_ip;
arp_reply->recv_ip = arp_packet->sender_ip;
arp_reply->hln = 6;
target.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET;
grub_memcpy (target.mac, arp_packet->sender_mac, 6);
grub_memcpy (arp_reply->sender_mac, inf->hwaddress.mac, 6);
grub_memcpy (arp_reply->recv_mac, arp_packet->sender_mac, 6);
/* Change operation to REPLY and send packet */
send_ethernet_packet (inf, &nb_reply, target, GRUB_NET_ETHERTYPE_ARP);
}
}
return GRUB_ERR_NONE;
}
|
