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
|
// MIT License, Copyright (c) 2020 Marvin Borner
#include <def.h>
#include <mem.h>
#include <net.h>
#include <pci.h>
#include <print.h>
#include <rtl8139.h>
int ethernet_send_packet(u8 *dst_mac_addr, u8 *data, int len, int prot)
{
struct ethernet_packet *packet = malloc(sizeof(*packet) + len);
void *packet_data = (u32 *)packet + sizeof(*packet);
memcpy(packet->src_mac_addr, rtl8139_get_mac(), 6);
memcpy(packet->dst_mac_addr, dst_mac_addr, 6);
memcpy(packet_data, data, len);
packet->type = htons(prot);
rtl8139_send_packet(packet, sizeof(*packet) + len);
free(packet);
return len;
}
u16 ip_calculate_checksum(struct ip_packet *packet)
{
int array_size = sizeof(*packet) / 2;
u16 *array = (u16 *)packet;
u32 sum = 0;
for (int i = 0; i < array_size; i++) {
u32 first_byte = *((u8 *)(&array[i]));
u32 second_byte = *((u8 *)(&array[i]) + 1);
sum += (first_byte << 8) | (second_byte);
}
u32 carry = sum >> 16;
sum = sum & 0x0000ffff;
sum = sum + carry;
u16 ret = ~sum;
return ret;
}
void ip_send_packet(u32 dst, void *data, int len, int prot)
{
struct ip_packet *packet = malloc(sizeof(*packet) + len);
memset(packet, 0, sizeof(*packet));
packet->version = 4;
packet->ihl = 5; // 5 * 4 = 20B
packet->length = sizeof(*packet) + len;
packet->id = 0; // TODO: IP fragmentation
packet->ttl = 64;
packet->protocol = prot;
packet->src = 0;
packet->dst = dst;
void *packet_data = (u32 *)packet + packet->ihl * 4;
memcpy(packet_data, data, len);
packet->length = htons(sizeof(*packet) + len);
packet->checksum = htons(ip_calculate_checksum(packet));
// TODO: arp destination lookup
ethernet_send_packet((u8 *)0x424242424242, (u8 *)packet, htons(packet->length),
ETHERNET_TYPE_IP4);
}
void ip_handle_packet(struct ip_packet *packet, int len)
{
switch (packet->protocol) {
case IP_PROT_ICMP:
print("ICMP Packet!\n");
ip_send_packet(packet->src, packet->data, len, IP_PROT_ICMP);
break;
case IP_PROT_TCP:
print("TCP Packet!\n");
break;
case IP_PROT_UDP:
print("UDP Packet!\n");
break;
default:
printf("Unknown IP protocol %d\n", packet->protocol);
}
}
void ethernet_handle_packet(struct ethernet_packet *packet, int len)
{
void *data = packet->data;
int data_len = len - sizeof(*packet);
if (ntohs(packet->type) == ETHERNET_TYPE_ARP) {
print("ARP PACKET\n");
} else if (ntohs(packet->type) == ETHERNET_TYPE_IP4) {
print("IP4 PACKET\n");
ip_handle_packet(data, data_len);
} else if (ntohs(packet->type) == ETHERNET_TYPE_IP6) {
print("IP6 PACKET\n");
/* ip_handle_packet(data, data_len); */
} else {
printf("UNKNOWN PACKET %x\n", ntohs(packet->type));
}
}
void net_install()
{
rtl8139_install();
}
|
