Create separate file for receiving UDP packets and clean the code

packet-exchange/build/Makefile

@@ -6,6 +6,8 @@ CLIENT_PROG = client
 SRCDIR = ../src
 
 SERVER_SRCS  = server.c
+SERVER_SRCS  += recv_packet.c
+
 CLIENT_SRCS  = client.c
 CLIENT_SRCS += send_packet.c
 

packet-exchange/src/client.c

@@ -129,7 +129,7 @@ int main(int argc, char *argv[]) {
   // Process bash options
   process_options(argc, argv, &param, &main_param);
 
-  init_udp_etf(param.enable_etf, param.enable_timestamps, main_param.packet_priority, param.network_if, main_param.tx_buffer_len);
+  init_udp_send(param.enable_etf, param.enable_timestamps, main_param.packet_priority, param.network_if, main_param.tx_buffer_len);
 
   usleep(10000);
 

packet-exchange/src/recv_packet.c

+#define _GNU_SOURCE
+#include <arpa/inet.h>
+#include <errno.h>
+#include <error.h>
+#include <inttypes.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <pthread.h>
+#include <sched.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#define SERVER_PORT "50000"
+#define BUFFER_SIZE 1024
+
+static char rx_buffer[BUFFER_SIZE];
+
+int init_udp_recv() {
+  int status;
+  int fd = -1;
+  struct addrinfo hints, *servinfo, *servinfo_it;
+
+  memset(&hints, 0, sizeof hints);
+  hints.ai_family = AF_UNSPEC;
+  hints.ai_socktype = SOCK_DGRAM;
+  hints.ai_flags = AI_PASSIVE;
+
+  status = getaddrinfo(NULL, SERVER_PORT, &hints, &servinfo);
+  if (status != 0) {
+    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
+    exit(EXIT_FAILURE);
+  }
+
+  for (servinfo_it = servinfo; servinfo_it;
+       servinfo_it = servinfo_it->ai_next) {
+    fd = socket(servinfo->ai_family, servinfo->ai_socktype,
+                servinfo->ai_protocol);
+
+    if (bind(fd, servinfo_it->ai_addr, servinfo_it->ai_addrlen) == -1) {
+      close(fd);
+      continue;
+    }
+    break;
+  }
+
+  freeaddrinfo(servinfo);
+
+  if(fd == -1)
+    error(EXIT_FAILURE, errno, "Couldn't create receive socket");
+
+  printf("waiting to receive...\n");
+
+  return fd;
+}
+
+void recv_udp_packet(int fd) {
+#ifdef DEBUG
+  int bytes_received = 0;
+
+  bytes_received = recvfrom(fd, rx_buffer, BUFFER_SIZE - 1, 0, NULL, NULL);
+
+  if (bytes_received == -1)
+    error(EXIT_FAILURE, errno, "Error while attempting to receive packets");
+#else
+  recvfrom(fd, rx_buffer, BUFFER_SIZE - 1, 0, NULL, NULL);
+#endif
+}

packet-exchange/src/recv_packet.h

+#ifndef RECV_PACKET
+#define RECV_PACKET
+
+int init_udp_recv();
+void recv_udp_packet(int fd);
+
+#endif

packet-exchange/src/send_packet.c

@@ -90,7 +90,7 @@ static void init_tx_buffer(size_t _tx_buffer_len) {
 /*
  * Init UDP socket
  */
-void init_udp_etf(int use_etf, int use_timestamps, int packet_priority,
+void init_udp_send(int use_etf, int use_timestamps, int packet_priority,
                   char *network_if, size_t _tx_buffer_len) {
   int index;
 

packet-exchange/src/send_packet.h

@@ -4,7 +4,7 @@
 #include <stdint.h>
 #include <stdio.h>
 
-void init_udp_etf(int use_etf, int use_timestamps, int so_priority, char * network_if, size_t tx_buffer_len);
+void init_udp_send(int use_etf, int use_timestamps, int so_priority, char * network_if, size_t tx_buffer_len);
 void send_udp_packet(int use_etf, int use_timestamps, uint64_t txtime, const char *server_ip);
 
 #endif

packet-exchange/src/server.c

@@ -29,6 +29,8 @@
 #include <time.h>
 #include <unistd.h>
 
+#include "recv_packet.h"
+
 #define NSEC_PER_SEC UINT64_C(1000000000)
 
 #define SERVER_PORT "50000"
@@ -71,13 +73,6 @@ static void *packet_receiving_thread(void *p) {
   uint64_t diff = 0;
   cpu_set_t mask;
 
-  char buf[BUFFER_SIZE];
-  int bytes_received = 0;
-  struct sockaddr_storage client_addr;
-  socklen_t addr_len;
-
-  addr_len = sizeof client_addr;
-
   stats->min_interval = UINT64_MAX;
   stats->max_interval = 0;
 
@@ -96,12 +91,10 @@ static void *packet_receiving_thread(void *p) {
 
   // Packet receiving loop
   for (stats->packets_received = 0;; stats->packets_received++) {
-    bytes_received = recvfrom(param->sockfd, buf, BUFFER_SIZE - 1, 0,
-                              (struct sockaddr *)&client_addr, &addr_len);
-    clock_gettime(CLOCK_MONOTONIC, &current);
 
-    if (bytes_received == -1)
-      error(EXIT_FAILURE, errno, "Error while attempting to receive packets");
+    recv_udp_packet(param->sockfd);
+
+    clock_gettime(CLOCK_MONOTONIC, &current);
 
     if (stats->packets_received) {
       diff = calcdiff_ns(current, previous);
@@ -129,7 +122,7 @@ int main(int argc, char *argv[]) {
   // Process bash options
   process_options(argc, argv, &param, &main_param);
 
-  init_server(&param);
+  param.sockfd = init_udp_recv();
 
   usleep(10000);
 
@@ -172,39 +165,6 @@ static void process_options(int argc, char *argv[], thread_param_t *param,
   }
 }
 
-void init_server(thread_param_t *param) {
-  int status;
-  struct addrinfo hints, *servinfo, *servinfo_it;
-
-  memset(&hints, 0, sizeof hints);
-  hints.ai_family = AF_UNSPEC;
-  hints.ai_socktype = SOCK_DGRAM;
-  hints.ai_flags = AI_PASSIVE;
-
-  status = getaddrinfo(NULL, SERVER_PORT, &hints, &servinfo);
-  if (status != 0) {
-    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
-    exit(EXIT_FAILURE);
-  }
-
-  for (servinfo_it = servinfo; servinfo_it;
-       servinfo_it = servinfo_it->ai_next) {
-    param->sockfd = socket(servinfo->ai_family, servinfo->ai_socktype,
-                           servinfo->ai_protocol);
-
-    if (bind(param->sockfd, servinfo_it->ai_addr, servinfo_it->ai_addrlen) ==
-        -1) {
-      close(param->sockfd);
-      continue;
-    }
-    break;
-  }
-
-  freeaddrinfo(servinfo);
-
-  printf("waiting to receive...\n");
-}
-
 static inline uint64_t calcdiff_ns(struct timespec t1, struct timespec t2) {
   uint64_t diff;
   diff = NSEC_PER_SEC * (uint64_t)((int)t1.tv_sec - (int)t2.tv_sec);