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POSIX PCAP: Speed improvements

pcap
Paul Hollinsky 2019-05-06 16:54:18 -04:00
parent eb43465c2a
commit d017d26795
1 changed files with 12 additions and 6 deletions
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18
platform/posix/pcap.cpp
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@ -24,7 +24,7 @@ std::vector<PCAP::PCAPFoundDevice> PCAP::FindAll() {
char errbuf[PCAP_ERRBUF_SIZE] = { 0 }; char errbuf[PCAP_ERRBUF_SIZE] = { 0 };
bool success = false; bool success = false;
// Calling pcap_findalldevs too quickly can cause various errors. Retry a few times in this case. // Calling pcap_findalldevs too quickly can cause various errors. Retry a few times in this case.
for(auto retry = 0; retry < 10; retry++) { for(auto retry = 0; retry < 3; retry++) {
auto ret = pcap_findalldevs(&alldevs, errbuf); auto ret = pcap_findalldevs(&alldevs, errbuf);
if(ret == 0) { if(ret == 0) {
success = true; success = true;
@ -81,20 +81,27 @@ std::vector<PCAP::PCAPFoundDevice> PCAP::FindAll() {
auto& interface = knownInterfaces[i]; auto& interface = knownInterfaces[i];
errbuf[0] = '\0'; errbuf[0] = '\0';
interface.fp = pcap_open_live(interface.nameFromPCAP.c_str(), UINT16_MAX, 1, 0, errbuf); interface.fp = pcap_create(interface.nameFromPCAP.c_str(), errbuf);
if(interface.fp == nullptr) { if(interface.fp == nullptr) {
// TODO Flag error that interface could not be opened? // TODO Flag error that interface could not be opened?
// This can happen if, on Linux, you are not running as root // This can happen if, on Linux, you are not running as root
continue; continue;
} }
pcap_set_snaplen(interface.fp, UINT16_MAX);
pcap_set_timeout(interface.fp, 1);
pcap_set_immediate_mode(interface.fp, 1);
pcap_setnonblock(interface.fp, 1, errbuf);
if(pcap_activate(interface.fp)) {
// TODO Flag error that interface could not be opened?
// This can happen if, on Linux, you are not running as root
continue;
}
// TODO Propagate this up // TODO Propagate this up
// if(strlen(errbuf) != 0) { // The open succeeded but we got a warning // if(strlen(errbuf) != 0) { // The open succeeded but we got a warning
// std::cout << "Warning for " << interface.nameFromPCAP << " " << errbuf << std::endl; // std::cout << "Warning for " << interface.nameFromPCAP << " " << errbuf << std::endl;
// } // }
pcap_setnonblock(interface.fp, 1, errbuf);
EthernetPacket requestPacket; EthernetPacket requestPacket;
requestPacket.payload.reserve(4); requestPacket.payload.reserve(4);
requestPacket.payload = { requestPacket.payload = {
@ -107,7 +114,7 @@ std::vector<PCAP::PCAPFoundDevice> PCAP::FindAll() {
auto bs = requestPacket.getBytestream(); auto bs = requestPacket.getBytestream();
pcap_sendpacket(interface.fp, bs.data(), (int)bs.size()); pcap_sendpacket(interface.fp, bs.data(), (int)bs.size());
auto timeout = std::chrono::high_resolution_clock::now() + std::chrono::milliseconds(50); auto timeout = std::chrono::high_resolution_clock::now() + std::chrono::milliseconds(5);
while(std::chrono::high_resolution_clock::now() <= timeout) { // Wait up to 5ms for the response while(std::chrono::high_resolution_clock::now() <= timeout) { // Wait up to 5ms for the response
struct pcap_pkthdr* header; struct pcap_pkthdr* header;
const uint8_t* data; const uint8_t* data;
@ -157,7 +164,6 @@ std::vector<PCAP::PCAPFoundDevice> PCAP::FindAll() {
pcap_close(interface.fp); pcap_close(interface.fp);
interface.fp = nullptr; interface.fp = nullptr;
} }
return foundDevices; return foundDevices;
} }