jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <Kernel/Heap/kmalloc.h>
8#include <Kernel/InterruptDisabler.h>
9#include <Kernel/Net/EtherType.h>
10#include <Kernel/Net/NetworkAdapter.h>
11#include <Kernel/Net/NetworkingManagement.h>
12#include <Kernel/Process.h>
13#include <Kernel/StdLib.h>
14
15namespace Kernel {
16
17NetworkAdapter::NetworkAdapter(NonnullOwnPtr<KString> interface_name)
18 : m_name(move(interface_name))
19{
20}
21
22NetworkAdapter::~NetworkAdapter() = default;
23
24void NetworkAdapter::send_packet(ReadonlyBytes packet)
25{
26 m_packets_out++;
27 m_bytes_out += packet.size();
28 send_raw(packet);
29}
30
31void NetworkAdapter::send(MACAddress const& destination, ARPPacket const& packet)
32{
33 size_t size_in_bytes = sizeof(EthernetFrameHeader) + sizeof(ARPPacket);
34 auto buffer_result = NetworkByteBuffer::create_zeroed(size_in_bytes);
35 if (buffer_result.is_error()) {
36 dbgln("Dropping ARP packet targeted at {} as there is not enough memory to buffer it", packet.target_hardware_address().to_string());
37 return;
38 }
39 auto* eth = (EthernetFrameHeader*)buffer_result.value().data();
40 eth->set_source(mac_address());
41 eth->set_destination(destination);
42 eth->set_ether_type(EtherType::ARP);
43 memcpy(eth->payload(), &packet, sizeof(ARPPacket));
44 send_packet({ (u8 const*)eth, size_in_bytes });
45}
46
47void NetworkAdapter::fill_in_ipv4_header(PacketWithTimestamp& packet, IPv4Address const& source_ipv4, MACAddress const& destination_mac, IPv4Address const& destination_ipv4, IPv4Protocol protocol, size_t payload_size, u8 type_of_service, u8 ttl)
48{
49 size_t ipv4_packet_size = sizeof(IPv4Packet) + payload_size;
50 VERIFY(ipv4_packet_size <= mtu());
51
52 size_t ethernet_frame_size = ipv4_payload_offset() + payload_size;
53 VERIFY(packet.buffer->size() == ethernet_frame_size);
54 memset(packet.buffer->data(), 0, ipv4_payload_offset());
55 auto& eth = *(EthernetFrameHeader*)packet.buffer->data();
56 eth.set_source(mac_address());
57 eth.set_destination(destination_mac);
58 eth.set_ether_type(EtherType::IPv4);
59 auto& ipv4 = *(IPv4Packet*)eth.payload();
60 ipv4.set_version(4);
61 ipv4.set_internet_header_length(5);
62 ipv4.set_dscp_and_ecn(type_of_service);
63 ipv4.set_source(source_ipv4);
64 ipv4.set_destination(destination_ipv4);
65 ipv4.set_protocol((u8)protocol);
66 ipv4.set_length(ipv4_packet_size);
67 ipv4.set_ident(1);
68 ipv4.set_ttl(ttl);
69 ipv4.set_checksum(ipv4.compute_checksum());
70}
71
72void NetworkAdapter::did_receive(ReadonlyBytes payload)
73{
74 InterruptDisabler disabler;
75 m_packets_in++;
76 m_bytes_in += payload.size();
77
78 if (m_packet_queue_size == max_packet_buffers) {
79 // FIXME: Keep track of the number of dropped packets
80 return;
81 }
82
83 auto packet = acquire_packet_buffer(payload.size());
84 if (!packet) {
85 dbgln("Discarding packet because we're out of memory");
86 return;
87 }
88
89 memcpy(packet->buffer->data(), payload.data(), payload.size());
90
91 m_packet_queue.append(*packet);
92 m_packet_queue_size++;
93
94 if (on_receive)
95 on_receive();
96}
97
98size_t NetworkAdapter::dequeue_packet(u8* buffer, size_t buffer_size, Time& packet_timestamp)
99{
100 InterruptDisabler disabler;
101 if (m_packet_queue.is_empty())
102 return 0;
103 auto packet_with_timestamp = m_packet_queue.take_first();
104 m_packet_queue_size--;
105 packet_timestamp = packet_with_timestamp->timestamp;
106 auto& packet_buffer = packet_with_timestamp->buffer;
107 size_t packet_size = packet_buffer->size();
108 VERIFY(packet_size <= buffer_size);
109 memcpy(buffer, packet_buffer->data(), packet_size);
110 release_packet_buffer(*packet_with_timestamp);
111 return packet_size;
112}
113
114LockRefPtr<PacketWithTimestamp> NetworkAdapter::acquire_packet_buffer(size_t size)
115{
116 auto packet = m_unused_packets.with([size](auto& unused_packets) -> LockRefPtr<PacketWithTimestamp> {
117 if (unused_packets.is_empty())
118 return nullptr;
119
120 auto unused_packet = unused_packets.take_first();
121
122 if (unused_packet->buffer->capacity() >= size)
123 return unused_packet;
124
125 unused_packets.append(*unused_packet);
126 return nullptr;
127 });
128
129 if (packet) {
130 packet->timestamp = kgettimeofday();
131 packet->buffer->set_size(size);
132 return packet;
133 }
134
135 auto buffer_or_error = KBuffer::try_create_with_size("NetworkAdapter: Packet buffer"sv, size, Memory::Region::Access::ReadWrite, AllocationStrategy::AllocateNow);
136 if (buffer_or_error.is_error())
137 return {};
138 packet = adopt_lock_ref_if_nonnull(new (nothrow) PacketWithTimestamp { buffer_or_error.release_value(), kgettimeofday() });
139 if (!packet)
140 return {};
141 packet->buffer->set_size(size);
142 return packet;
143}
144
145void NetworkAdapter::release_packet_buffer(PacketWithTimestamp& packet)
146{
147 m_unused_packets.with([&packet](auto& unused_packets) {
148 unused_packets.append(packet);
149 });
150}
151
152void NetworkAdapter::set_ipv4_address(IPv4Address const& address)
153{
154 m_ipv4_address = address;
155}
156
157void NetworkAdapter::set_ipv4_netmask(IPv4Address const& netmask)
158{
159 m_ipv4_netmask = netmask;
160}
161
162}