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Handle the LINUX_SLL link-layer type. #37

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Handle the LINUX_SLL link-layer type. #37

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67 changes: 50 additions & 17 deletions src/udpreplay.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <pcap/pcap.h>
#include <pcap/sll.h>
#include <unistd.h>

#define NANOSECONDS_PER_SECOND 1000000000L
Expand Down Expand Up @@ -146,6 +147,16 @@ int main(int argc, char *argv[]) {
return 1;
}

int link_hdr_type = pcap_datalink(handle);
if ( DLT_NULL != link_hdr_type && // loopback
DLT_EN10MB != link_hdr_type && // Ethernet
DLT_LINUX_SLL != link_hdr_type ) { // Linux cooked sockets
const char *dltname = pcap_datalink_val_to_name(link_hdr_type);
std::cerr << "unsupport link-layer type: " << link_hdr_type << "("
<< (dltname ? dltname : "") << ")" << std::endl;
return 1;
}

timespec start = {-1, -1};
timespec pcap_start = {-1, -1};

Expand All @@ -164,25 +175,48 @@ int main(int argc, char *argv[]) {
if (header.len != header.caplen) {
continue;
}
auto eth = reinterpret_cast<const ether_header *>(p);

// jump over and ignore vlan tags
while (ntohs(eth->ether_type) == ETHERTYPE_VLAN) {
p += 4;
eth = reinterpret_cast<const ether_header *>(p);
}
if (ntohs(eth->ether_type) != ETHERTYPE_IP) {
continue;
const struct ip *ip;
if ( DLT_NULL == link_hdr_type ) {
int falimy = *reinterpret_cast<const uint32_t *>(p);
if ( PF_INET != falimy ) { // IP
continue;
}
p += 4;
ip = reinterpret_cast<const struct ip *>(p);
} else if ( DLT_EN10MB == link_hdr_type ) {
const ether_header *eth;
eth = reinterpret_cast<const ether_header *>(p);
// jump over and ignore vlan tags
while ( ETHERTYPE_VLAN == ntohs(eth->ether_type) ) {
p += 4;
eth = reinterpret_cast<const ether_header *>(p);
}
if ( ETHERTYPE_IP != ntohs(eth->ether_type) ) {
continue;
}
p += sizeof(ether_header);
ip = reinterpret_cast<const struct ip *>(p);
} else if ( DLT_LINUX_SLL == link_hdr_type ) {
// ref: http://www.tcpdump.org/linktypes/LINKTYPE_LINUX_SLL.html
const struct sll_header *sll = reinterpret_cast<const sll_header *>(p);
if ( ETHERTYPE_IP != ntohs(sll->sll_protocol) ) {
continue;
}
p += sizeof(struct sll_header);
ip = reinterpret_cast<const struct ip *>(p);
} else {
std::cerr << "unsupport link-layer type: " << link_hdr_type << std::endl;
return 1;
}
auto ip = reinterpret_cast<const struct ip *>(p + sizeof(ether_header));
if (ip->ip_v != 4) {
continue;
if ( 4 != ip->ip_v ) {
continue;
}
if (ip->ip_p != IPPROTO_UDP) {
continue;
if ( IPPROTO_UDP != ip->ip_p ) {
continue;
}
auto udp = reinterpret_cast<const udphdr *>(p + sizeof(ether_header) +
ip->ip_hl * 4);
p += ip->ip_hl * 4;
auto udp = reinterpret_cast<const udphdr *>(p);
if (interval != -1) {
// Use constant packet rate
deadline.tv_sec += interval / 1000L;
Expand Down Expand Up @@ -241,8 +275,7 @@ int main(int argc, char *argv[]) {
#else
ssize_t len = ntohs(udp->uh_ulen) - 8;
#endif
const u_char *d =
&p[sizeof(ether_header) + ip->ip_hl * 4 + sizeof(udphdr)];
const u_char *d = p + sizeof(udphdr);

sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
Expand Down