filter packet on ether type

trx_ecpri.c

@@ -7,6 +7,8 @@
 #include <immintrin.h>
 #include <inttypes.h>
 #include <limits.h>
+#include <linux/filter.h>
+#include <linux/if_ether.h>
 #include <linux/if_packet.h>
 #include <math.h>
 #include <netdb.h>
@@ -709,6 +711,19 @@ int start(TRXEcpriState * s) {
 
   log_debug("TRX_ECPRI", "raw socket setup");
 
+  /* From the example above: tcpdump -i em1 port 22 -dd */
+  struct sock_filter code[] = {
+    { 0x28, 0, 0, 0x0000000c },
+    { 0x15, 0, 1, 0x0000aefe },
+    { 0x06, 0, 0, 0x00040000 },
+    { 0x06, 0, 0, 0x00000000 },
+  };
+
+  struct sock_fprog bpf = {
+          .len = 4,
+          .filter = code,
+  };
+
   //set_latency_target();
 
   tx_seq_id = 0;
@@ -779,7 +794,16 @@ int start(TRXEcpriState * s) {
     return 1;
   }
   // Only receive incoming packets, don't capture packets we are sending
-  setsockopt(recv_sockfd, SOL_PACKET, PACKET_IGNORE_OUTGOING, &(int){1}, sizeof(int));
+  if(setsockopt(recv_sockfd, SOL_PACKET, PACKET_IGNORE_OUTGOING, &(int){1}, sizeof(int))) {
+    perror("setsockopt PACKET_IGNORE_OUTGOING: ");
+    return 1;
+  }
+  // Filter on MAC ADDRESS
+  if (setsockopt(recv_sockfd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf))) {
+    perror("setsockopt SO_ATTACH_FILTER: ");
+    return 1;
+  }
+
 
   connect_sk_addr.sll_ifindex = if_index;
   connect_sk_addr.sll_halen = ETH_ALEN;