Fix rx_timestamps on reception

packet-exchange/src/recv_packet.c

@@ -32,7 +32,7 @@
 
 #define BUFFER_SIZE 1024
 
-static void process_timestamps(packet_timestamps_t *packet_ts, int64_t histograms[NB_HISTOGRAMS][MAX_HIST_VAL]);
+static void fill_histograms(packet_timestamps_t *packet_ts, int64_t histograms[NB_HISTOGRAMS][MAX_HIST_VAL]);
 
 static char rx_buffer[BUFFER_SIZE];
 static int sock_fd;
@@ -108,17 +108,17 @@ int init_udp_recv(int use_timestamps, char *network_if) {
  */
 packet_timestamps_t recv_udp_packet(int use_timestamps, int64_t histograms[NB_HISTOGRAMS][MAX_HIST_VAL]) {
 
+  struct cmsghdr *cmsg;
   struct msghdr msg; // Message hardware, sent to the socket
   struct iovec iov; // The iovec structures stores the RX buffer
   struct sockaddr_in sin;
 
-  // Poll file descriptor, used to poll for timestamp messages
-  struct pollfd poll_fd = {sock_fd, POLLPRI, 0};
-  int recvmsgerr, pollerr;
+  int recvmsgerr;
 
   packet_timestamps_t packet_ts;
   struct timespec ts;
 
+
   if (use_timestamps) {
     clock_gettime(CLOCK_REALTIME, &ts);
     packet_ts.enter_user_space = ts_to_uint(ts);
@@ -142,14 +142,17 @@ packet_timestamps_t recv_udp_packet(int use_timestamps, int64_t histograms[NB_HI
   if (recvmsgerr < 0)
     error(EXIT_FAILURE, errno, "recvmsg failed, ret value: %d\n", recvmsgerr);
 
-  if (use_timestamps) {
-    pollerr = poll(&poll_fd, 1, 0);
-    if (pollerr > 0)
-      process_timestamps(&packet_ts, histograms);
-    else
-      fprintf(stderr, "select failed\n");
-  }
+  if(use_timestamps) {
+    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+      if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SO_TIMESTAMPING) {
 
+        struct timespec *stamp = (struct timespec *)CMSG_DATA(cmsg);
+        packet_ts.leave_kernel = ts_to_uint(*stamp);
+        fill_histograms(&packet_ts, histograms);
+
+      }
+    }
+  }
   return packet_ts;
 }
 
@@ -174,51 +177,6 @@ static void fill_histograms(packet_timestamps_t *packet_ts, int64_t histograms[N
   histograms[1][kernel_space_time]++;
 }
 
-static void process_timestamps(packet_timestamps_t *packet_ts, int64_t histograms[NB_HISTOGRAMS][MAX_HIST_VAL]) {
-  char data[256];
-  struct msghdr msg;
-  struct iovec entry;
-  struct sockaddr_in from_addr;
-  struct {
-    struct cmsghdr cm;
-    char control[512];
-  } control;
-  struct cmsghdr *cmsg;
-
-  memset(&msg, 0, sizeof(msg));
-  msg.msg_iov = &entry;
-  msg.msg_iovlen = 1;
-  entry.iov_base = data;
-  entry.iov_len = sizeof(data);
-  msg.msg_name = (caddr_t)&from_addr;
-  msg.msg_namelen = sizeof(from_addr);
-  msg.msg_control = &control;
-  msg.msg_controllen = sizeof(control);
-
-  if (recvmsg(sock_fd, &msg, MSG_ERRQUEUE | MSG_DONTWAIT) == -1) {
-    fprintf(stderr, "recvmsg failed\n");
-    return;
-  }
-
-  for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-    if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SO_TIMESTAMPING) {
-
-      struct timespec *stamp = (struct timespec *)CMSG_DATA(cmsg);
-      packet_ts->leave_kernel = ts_to_uint(*stamp);
-      fill_histograms(packet_ts, histograms);
-
-    } else {
-
-#ifdef DEBUG
-
-      fprintf(stderr, "process_timestamps: level %d type %d", cmsg->cmsg_level,
-              cmsg->cmsg_type);
-#endif
-
-    }
-  }
-}
-
 #ifdef DEBUG
 
 /*