Add option to pass the tx buffer length

packet-exchange/src/client.c

@@ -3,14 +3,15 @@
  *
  * Bash options:
  *
- *  -a          Run the real time thread on CPU1
- *  -e          Set a txtime (to be used in an ETF qdisc)
- *  -f          Set the network interface to be used
- *  -i USEC     Wake up the real time thread every USEC microseconds (Default: 10ms)
- *  -l N        Wake up the real time thread N times (Default: 0)
- *  -p PRIO     Run the real time thread at priority PRIO
- *  -r USEC     Refresh the non real time main thread every USEC microseconds (Default: 50ms)
- *  -t          Enable timestamps
+ *  -a                    Run the real time thread on CPU1
+ *  -d TX_BUFFER_LEN      Set the length of tx buffer
+ *  -e                    Set a txtime (to be used in an ETF qdisc)
+ *  -f                    Set the network interface to be used
+ *  -i USEC               Wake up the real time thread every USEC microseconds (Default: 10ms)
+ *  -l N                  Wake up the real time thread N times (Default: 0)
+ *  -p PRIO               Run the real time thread at priority PRIO
+ *  -r USEC               Refresh the non real time main thread every USEC microseconds (Default: 50ms)
+ *  -t                    Enable timestamps
  *
  * Large portions taken from cyclictest
  *
@@ -54,6 +55,7 @@ typedef struct thread_param {
 typedef struct main_param {
   int refresh_rate;
   int packet_priority;
+  size_t tx_buffer_len;
 } main_param_t;
 
 static inline void add_ns(struct timespec *t, uint64_t ns);
@@ -126,7 +128,7 @@ 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);
+  init_udp_etf(param.enable_etf, param.enable_timestamps, main_param.packet_priority, param.network_if, main_param.tx_buffer_len);
 
   usleep(10000);
 
@@ -150,7 +152,7 @@ int main(int argc, char *argv[]) {
 static void process_options(int argc, char *argv[], thread_param_t *param,
                             main_param_t *main_param) {
   for (;;) {
-    int c = getopt(argc, argv, "aef:i:l:p:q:r:t");
+    int c = getopt(argc, argv, "ad:ef:i:l:p:q:r:t");
 
     if (c == -1) break;
 
@@ -158,6 +160,13 @@ static void process_options(int argc, char *argv[], thread_param_t *param,
       case 'a':
         param->enable_affinity = 1;
         break;
+      case 'd':
+        main_param->tx_buffer_len = atoi(optarg);
+        if( main_param->tx_buffer_len < 1 ) {
+          fprintf(stderr, "TX_BUFFER_LEN should be greater than 1\n");
+          exit(EXIT_FAILURE);
+        }
+        break;
       case 'e':
         param->enable_etf = 1;
         break;

packet-exchange/src/send_packet.c

@@ -44,11 +44,12 @@
 
 static void print_timestamps(struct msghdr *msg, uint64_t txtime);
 static void process_timestamps(uint64_t txtime);
+static void init_tx_buffer(size_t _tx_buffer_len);
 
 static int so_priority = 3;
 static struct sock_txtime sk_txtime;
-static unsigned char tx_buffer[1024] = "Hi";
-static size_t tx_buffer_len = sizeof(tx_buffer);
+static unsigned char * tx_buffer;
+static size_t tx_buffer_len;
 static int fd;
 
 static int64_t tai_offset;
@@ -69,15 +70,35 @@ static int set_if(char *network_if) {
   return ifreq.ifr_ifindex;
 }
 
+static void init_tx_buffer(size_t _tx_buffer_len) {
+
+  if( _tx_buffer_len < 1) {
+    fprintf(stderr, "tx buffer length should be greater than 1\n");
+    exit(EXIT_FAILURE);
+  }
+
+  tx_buffer_len = _tx_buffer_len;
+  tx_buffer = malloc(tx_buffer_len);
+
+  for(int i = 0; i < ( ((int)tx_buffer_len) - 1); i++) {
+    tx_buffer[i] = (unsigned char) i;
+  }
+
+  tx_buffer[tx_buffer_len - 1] = '\0';
+}
+
 /*
  * Init UDP socket
  */
 void init_udp_etf(int use_etf, int use_timestamps, int packet_priority,
-                  char *network_if) {
+                  char *network_if, size_t _tx_buffer_len) {
   int index;
 
   struct timespec ts_mon;
   struct timespec ts_tai;
+
+  init_tx_buffer(_tx_buffer_len);
+
   clock_gettime(CLOCK_MONOTONIC, &ts_mon);
   clock_gettime(CLOCK_TAI, &ts_tai);
   tai_offset = (ts_mon.tv_sec - ts_tai.tv_sec) * NSEC_PER_SEC + (ts_mon.tv_nsec - ts_tai.tv_nsec);
@@ -240,12 +261,13 @@ static void print_timestamps(struct msghdr *msg, uint64_t txtime) {
 }
 
 #ifdef DEBUG
+
 /*
  * Code from scheduled_tx_tools
  */
 static int process_socket_error_queue() {
   uint8_t msg_control[CMSG_SPACE(sizeof(struct sock_extended_err))];
-  unsigned char err_buffer[sizeof(tx_buffer)];
+  unsigned char err_buffer[256];
   struct sock_extended_err *serr;
   struct cmsghdr *cmsg;
   __u64 tstamp = 0;

packet-exchange/src/send_packet.h

@@ -2,8 +2,9 @@
 #define SEND_PACKET_H
 
 #include <stdint.h>
+#include <stdio.h>
 
-void init_udp_etf(int use_etf, int use_timestamps, int so_priority, char * network_if);
+void init_udp_etf(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