[tcpdump-workers] libpcap: hw timestamps via adapter_unsynced do not work

[belinea123--- via tcpdump-workers]

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Hello list,
 
I use libpcap on linux to start a measurement on the PCIe NIC that my company 
developed. I set the tstamp type to adapter_unsynced. pcap_set_tstamp_type 
returns with PCAP_WARNING_TSTAMP_TYPE_NOTSUP. The packets I receive in the 
packet_handler function I registered contain a software timestamp (number of 
seconds sind 1970-01-01).
 
When I capture via tcpdump I get the correct hardware timestamps (number of 
seconds since the NIC was powered). I use following command:
sudo tcpdump -U -i eth0 -j adapter_unsynced -w log.pcap
 
Do you have an idea why libpcap does not read the hw timestamp but tcpdump does?
 
NIC tstamp capabilities:
 
Time stamping parameters for enp5s0f1:
Capabilities:
    hardware-transmit     (SOF_TIMESTAMPING_TX_HARDWARE)
    software-transmit     (SOF_TIMESTAMPING_TX_SOFTWARE)
    hardware-receive      (SOF_TIMESTAMPING_RX_HARDWARE)
    software-receive      (SOF_TIMESTAMPING_RX_SOFTWARE)
    software-system-clock (SOF_TIMESTAMPING_SOFTWARE)
    hardware-raw-clock    (SOF_TIMESTAMPING_RAW_HARDWARE)
PTP Hardware Clock: none
Hardware Transmit Timestamp Modes:
    off                   (HWTSTAMP_TX_OFF)
    on                    (HWTSTAMP_TX_ON)
Hardware Receive Filter Modes:
    none                  (HWTSTAMP_FILTER_NONE)
    all                   (HWTSTAMP_FILTER_ALL)
 
 
 
pcap version:
libpcap version 1.9.1 (with TPACKET_V3)
 
tcpdump version 4.9.3 (with libpcap 1.9.1 with TPACKET_V3)
 
Here is the code of my application:
 

        printf("pcap_create device: %s\n", deviceName.c_str());
        handle = pcap_create(deviceName.c_str(), errbuf);
        int returnVal = pcap_set_snaplen(handle, 65536);
        if (returnVal != 0) printf("pcap_set_snaplen failed %s\n", 
pcap_geterr(handle));
        returnVal = pcap_set_timeout(handle, 1000);
        if (returnVal != 0) printf("pcap_set_timeout failed %s\n", 
pcap_geterr(handle));
        returnVal = pcap_set_buffer_size(handle, 1000000);
        if (returnVal != 0)
            printf("pcap_set_buffer_size failed %s\n", pcap_geterr(handle));
        returnVal = pcap_set_promisc(handle, 1);
        if (returnVal != 0) printf("pcap_set_promisc failed %s\n", 
pcap_geterr(handle));
        int* tstypes;
        int ntstypes = pcap_list_tstamp_types(handle, &tstypes);
        printf("pcap_list_tstamp_types: number: %d\n", ntstypes);
        int requiredTimestampType = 0;
        if(ntstypes > 0)
        {
            for(int i = 0; i < ntstypes; i++)
            {
                const char* tsName = pcap_tstamp_type_val_to_name(tstypes[i]);
                printf("index: %d. name: %s\n", i, tsName);
                
                if(strcmp(tsName, "adapter_unsynced") == 0)
                {
                     requiredTimestampType = i;
                }
            }
        }
        
        printf("requiredTimestampType: %d\n", requiredTimestampType);
        returnVal = pcap_set_tstamp_type(handle, requiredTimestampType);
        if (returnVal != 0)
        {
            printf("pcap_set_tstamp_type failed %s\n", pcap_geterr(handle));
            
            if(returnVal == PCAP_ERROR_ACTIVATED)
                printf("pcap_set_tstamp_type PCAP_ERROR_ACTIVATED\n");
            else if(returnVal == PCAP_ERROR_CANTSET_TSTAMP_TYPE)
                printf("pcap_set_tstamp_type PCAP_ERROR_CANTSET_TSTAMP_TYPE\n");
            else if(returnVal == PCAP_WARNING_TSTAMP_TYPE_NOTSUP)
                printf("pcap_set_tstamp_type 
PCAP_WARNING_TSTAMP_TYPE_NOTSUP\n");
                
        }
        else
        {
            printf("pcap_set_tstamp_type ok\n");
        }
        
        pcap_free_tstamp_types(tstypes);
        returnVal = pcap_activate(handle);
 

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