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Add Untagged Profinet frame #11

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Add Untagged Profinet frame #11

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18 changes: 14 additions & 4 deletions src/pcapInterface.c
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Original file line number Diff line number Diff line change
Expand Up @@ -87,14 +87,24 @@ void profinet_pcap_callback(unsigned char *args, const struct pcap_pkthdr *packe
struct ether_header header;
memcpy(&header, packet, sizeof(header));

if (header.ether_type != htons(ETH_P_8021Q)) return;

const int packetLength = packetInfo->len;
int payloadOffset;

if (header.ether_type == htons(ETH_P_8021Q)) {
/* 802.1Q tagged frame: 4-byte VLAN tag after Ethernet header */
payloadOffset = (int) sizeof(struct ether_header) + 4;
} else if (header.ether_type == htons(0x8892)) {
/* Untagged Profinet frame */
payloadOffset = (int) sizeof(struct ether_header);
} else {
return;
}

const int profinetPacketSize = packetLength - (int) sizeof(struct ether_header) - 4;
const int profinetPacketSize = packetLength - payloadOffset;
if (profinetPacketSize <= 0) return;

unsigned char profinetPacketRaw[profinetPacketSize];
memcpy(profinetPacketRaw, packet + sizeof(struct ether_header) + 4, profinetPacketSize);
memcpy(profinetPacketRaw, packet + payloadOffset, profinetPacketSize);

struct profinet_dcp_header dcpHeader;
memcpy(&dcpHeader, profinetPacketRaw, sizeof(dcpHeader));
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