net_flood: fix CRC error, make more precise

Issue #2953
This commit is contained in:
Martin Stein 2018-07-12 15:26:30 +02:00 committed by Christian Helmuth
parent 304cb290d9
commit 7b47c8f0c6
2 changed files with 108 additions and 95 deletions

View File

@ -39,8 +39,9 @@ class Main : public Nic_handler,
using Periodic_timeout = Timer::Periodic_timeout<Main>;
struct Bad_protocol : Exception { };
enum { IPV4_TIME_TO_LIVE = 64 };
enum { ICMP_DATA_SIZE = 56 };
enum { ICMP_SEQ = 1 };
enum { SRC_PORT = 50000 };
enum { FIRST_DST_PORT = 49152 };
@ -50,7 +51,7 @@ class Main : public Nic_handler,
Attached_rom_dataspace _config_rom { _env, "config" };
Xml_node _config { _config_rom.xml() };
Timer::Connection _timer { _env };
Microseconds _period_us { 100 };
Microseconds _period_us { 1 };
Constructible<Periodic_timeout> _period { };
Heap _heap { &_env.ram(), &_env.rm() };
bool const _verbose { _config.attribute_value("verbose", false) };
@ -63,6 +64,9 @@ class Main : public Nic_handler,
Ipv4_address() };
Protocol const _protocol { _config.attribute_value("protocol", Protocol::ICMP) };
Port _dst_port { FIRST_DST_PORT };
size_t _ping_sz { _init_ping_sz() };
size_t _init_ping_sz() const;
void _handle_arp(Ethernet_frame &eth,
Size_guard &size_guard);
@ -195,6 +199,18 @@ void Main::_handle_arp(Ethernet_frame &eth,
}
size_t Main::_init_ping_sz() const
{
enum { IP_SZ = sizeof(Ethernet_frame) + sizeof(Ipv4_packet) };
switch (_protocol) {
case Protocol::ICMP: return IP_SZ + sizeof(Icmp_packet);
case Protocol::UDP: return IP_SZ + sizeof(Udp_packet);
case Protocol::TCP: return IP_SZ + sizeof(Tcp_packet);
default: throw Bad_protocol();
}
}
void Main::_send_arp_reply(Ethernet_frame &req_eth,
Arp_packet &req_arp)
{
@ -258,97 +274,98 @@ void Main::_send_ping(Duration)
_broadcast_arp_request(ip_config().gateway); }
return;
}
_nic.send(sizeof(Ethernet_frame) + sizeof(Ipv4_packet) +
sizeof(Icmp_packet) + ICMP_DATA_SIZE,
[&] (void *pkt_base, Size_guard &size_guard)
{
/* create ETH header */
Ethernet_frame &eth = Ethernet_frame::construct_at(pkt_base, size_guard);
eth.dst(_dst_mac);
eth.src(_nic.mac());
eth.type(Ethernet_frame::Type::IPV4);
/* create IP header */
size_t const ip_off = size_guard.head_size();
Ipv4_packet &ip = eth.construct_at_data<Ipv4_packet>(size_guard);
ip.header_length(sizeof(Ipv4_packet) / 4);
ip.version(4);
ip.time_to_live(IPV4_TIME_TO_LIVE);
ip.src(ip_config().interface.address);
ip.dst(_dst_ip);
/* select IP-encapsulated protocol */
switch (_protocol) {
case Protocol::ICMP:
try {
while (true) {
_nic.send(_ping_sz, [&] (void *pkt_base, Size_guard &size_guard)
{
/* adapt IP header to ICMP */
ip.protocol(Ipv4_packet::Protocol::ICMP);
/* create ETH header */
Ethernet_frame &eth = Ethernet_frame::construct_at(pkt_base, size_guard);
eth.dst(_dst_mac);
eth.src(_nic.mac());
eth.type(Ethernet_frame::Type::IPV4);
/* create ICMP header */
Icmp_packet &icmp = ip.construct_at_data<Icmp_packet>(size_guard);
icmp.type(Icmp_packet::Type::ECHO_REQUEST);
icmp.code(Icmp_packet::Code::ECHO_REQUEST);
icmp.query_id(_dst_port.value);
icmp.query_seq(ICMP_SEQ);
/* create IP header */
size_t const ip_off = size_guard.head_size();
Ipv4_packet &ip = eth.construct_at_data<Ipv4_packet>(size_guard);
ip.header_length(sizeof(Ipv4_packet) / 4);
ip.version(4);
ip.time_to_live(IPV4_TIME_TO_LIVE);
ip.src(ip_config().interface.address);
ip.dst(_dst_ip);
/* finish ICMP header */
icmp.update_checksum(ICMP_DATA_SIZE);
/* select IP-encapsulated protocol */
switch (_protocol) {
case Protocol::ICMP:
{
/* adapt IP header to ICMP */
ip.protocol(Ipv4_packet::Protocol::ICMP);
/* prepare next ICMP ping */
if (_dst_port.value == LAST_DST_PORT) {
_dst_port.value = FIRST_DST_PORT; }
else {
_dst_port.value++; }
break;
}
case Protocol::UDP:
{
/* adapt IP header to UDP */
ip.protocol(Ipv4_packet::Protocol::UDP);
/* create ICMP header */
Icmp_packet &icmp = ip.construct_at_data<Icmp_packet>(size_guard);
icmp.type(Icmp_packet::Type::ECHO_REQUEST);
icmp.code(Icmp_packet::Code::ECHO_REQUEST);
icmp.query_id(_dst_port.value);
icmp.query_seq(ICMP_SEQ);
icmp.update_checksum(0);
/* create UDP header */
size_t const udp_off = size_guard.head_size();
Udp_packet &udp = ip.construct_at_data<Udp_packet>(size_guard);
udp.src_port(Port(SRC_PORT));
udp.dst_port(_dst_port);
/* prepare next ICMP ping */
if (_dst_port.value == LAST_DST_PORT) {
_dst_port.value = FIRST_DST_PORT; }
else {
_dst_port.value++; }
break;
}
case Protocol::UDP:
{
/* adapt IP header to UDP */
ip.protocol(Ipv4_packet::Protocol::UDP);
/* finish UDP header */
udp.length(size_guard.head_size() - udp_off);
udp.update_checksum(ip.src(), ip.dst());
/* create UDP header */
size_t const udp_off = size_guard.head_size();
Udp_packet &udp = ip.construct_at_data<Udp_packet>(size_guard);
udp.src_port(Port(SRC_PORT));
udp.dst_port(_dst_port);
/* prepare next ping */
if (_dst_port.value == LAST_DST_PORT) {
_dst_port.value = FIRST_DST_PORT; }
else {
_dst_port.value++; }
break;
}
case Protocol::TCP:
{
/* adapt IP header to TCP */
ip.protocol(Ipv4_packet::Protocol::TCP);
/* finish UDP header */
udp.length(size_guard.head_size() - udp_off);
udp.update_checksum(ip.src(), ip.dst());
/* create TCP header */
size_t const tcp_off = size_guard.head_size();
Tcp_packet &tcp = ip.construct_at_data<Tcp_packet>(size_guard);
tcp.src_port(Port(SRC_PORT));
tcp.dst_port(_dst_port);
/* prepare next ping */
if (_dst_port.value == LAST_DST_PORT) {
_dst_port.value = FIRST_DST_PORT; }
else {
_dst_port.value++; }
break;
}
case Protocol::TCP:
{
/* adapt IP header to TCP */
ip.protocol(Ipv4_packet::Protocol::TCP);
/* finish TCP header */
tcp.update_checksum(ip.src(), ip.dst(), size_guard.head_size() - tcp_off);
/* create TCP header */
size_t const tcp_off = size_guard.head_size();
Tcp_packet &tcp = ip.construct_at_data<Tcp_packet>(size_guard);
tcp.src_port(Port(SRC_PORT));
tcp.dst_port(_dst_port);
/* prepare next ping */
if (_dst_port.value == LAST_DST_PORT) {
_dst_port.value = FIRST_DST_PORT; }
else {
_dst_port.value++; }
break;
}
/* finish TCP header */
tcp.update_checksum(ip.src(), ip.dst(), size_guard.head_size() - tcp_off);
/* prepare next ping */
if (_dst_port.value == LAST_DST_PORT) {
_dst_port.value = FIRST_DST_PORT; }
else {
_dst_port.value++; }
break;
}
}
/* finish IP header */
ip.total_length(size_guard.head_size() - ip_off);
ip.update_checksum();
});
}
/* finish IP header */
ip.total_length(size_guard.head_size() - ip_off);
ip.update_checksum();
});
}
catch (Net::Packet_stream_source::Packet_alloc_failed) { }
}

View File

@ -51,7 +51,7 @@ class Net::Nic
using Signal_handler = Genode::Signal_handler<Nic>;
enum { PKT_SIZE = ::Nic::Packet_allocator::DEFAULT_PACKET_SIZE };
enum { BUF_SIZE = 90 * PKT_SIZE };
enum { BUF_SIZE = 1000 * PKT_SIZE };
Genode::Env &_env;
Genode::Allocator &_alloc;
@ -101,20 +101,16 @@ class Net::Nic
void send(Genode::size_t pkt_size,
FUNC && write_to_pkt)
{
try {
Packet_descriptor pkt = _source().alloc_packet(pkt_size);
void *pkt_base = _source().packet_content(pkt);
Packet_descriptor pkt = _source().alloc_packet(pkt_size);
void *pkt_base = _source().packet_content(pkt);
Size_guard size_guard(pkt_size);
write_to_pkt(pkt_base, size_guard);
_source().submit_packet(pkt);
if (_verbose) {
Size_guard size_guard(pkt_size);
write_to_pkt(pkt_base, size_guard);
_source().submit_packet(pkt);
if (_verbose) {
Size_guard size_guard(pkt_size);
try { Genode::log("snd ", Ethernet_frame::cast_from(pkt_base, size_guard)); }
catch (Size_guard::Exceeded) { Genode::log("snd ?"); }
}
try { Genode::log("snd ", Ethernet_frame::cast_from(pkt_base, size_guard)); }
catch (Size_guard::Exceeded) { Genode::log("snd ?"); }
}
catch (Net::Packet_stream_source::Packet_alloc_failed) {
Genode::warning("failed to allocate packet"); }
}