1 files changed, 85 insertions, 0 deletions
diff --git a/user_client.c b/user_client.c
new file mode 100644
index 0000000..68c79af
--- /dev/null
+++ b/user_client.c
@@ -0,0 +1,85 @@
+// udp client driver program
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "common.h"
+
+static const unsigned char payload_request[] = { PAYLOAD_REQUEST, 0xFF};
+
+struct {
+    unsigned long long int send_start;
+    unsigned long long int received_end;
+} timings[MAX_UDP_PACKETS];
+
+static int set_ts(unsigned long long int * const out) {
+  struct timeval tv = {};
+
+  if (gettimeofday(&tv, NULL) != 0)
+    return 1;
+
+  *out = (tv.tv_sec * 1000 * 1000) + tv.tv_usec;
+  return 0;
+}
+
+int main() {
+  char buffer[BUFSIZ];
+  int sockfd;
+  struct sockaddr_in servaddr = {};
+
+  servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
+  servaddr.sin_port = htons(UDP_PORT);
+  servaddr.sin_family = AF_INET;
+  sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sockfd < 0) {
+    perror("udp socket");
+    return 1;
+  }
+
+  if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0) {
+    perror("udp connect");
+    return 1;
+  }
+
+  size_t i;
+  ssize_t n;
+  for (i = 0; i < MAX_UDP_PACKETS; ++i) {
+    if (set_ts(&timings[i].send_start) != 0) {
+      n = -1;
+      break;
+    }
+
+    n = sendto(sockfd, payload_request, sizeof(payload_request), 0, NULL, 0);
+    if (n < 0) {
+      perror("udp sendto");
+      break;
+    }
+
+    n = recvfrom(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr *)NULL,
+                 NULL);
+    if (n < 0) {
+      perror("udp recvfrom");
+      break;
+    }
+
+    if (set_ts(&timings[i].received_end) != 0) {
+      n = -1;
+      break;
+    }
+  }
+
+  close(sockfd);
+
+  printf("# packet_number rtt\n");
+  for (size_t i = 0; i < MAX_UDP_PACKETS; ++i) {
+    printf("%zu %lld\n", i, timings[i].received_end - timings[i].send_start);
+  }
+
+  return !(i == MAX_UDP_PACKETS);
+}