picotcp/lwip ipv4/ipv6 fully functional, needs stress testing

tests/api_test/udpclient.c

@@ -0,0 +1,92 @@
+/* 
+ * udpclient.c - A simple UDP client
+ * usage: udpclient <host> <port>
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h> 
+#include <fcntl.h>
+
+#define BUFSIZE 1024
+
+/* 
+ * error - wrapper for perror
+ */
+void error(char *msg) {
+    perror(msg);
+    exit(0);
+}
+
+int main(int argc, char **argv) {
+    int sockfd, portno, n;
+    int serverlen;
+    struct sockaddr_in serveraddr;
+    struct hostent *server;
+    char *hostname;
+    char buf[BUFSIZE];
+
+    /* check command line arguments */
+    if (argc != 3) {
+       fprintf(stderr,"usage: %s <hostname> <port>\n", argv[0]);
+       exit(0);
+    }
+    hostname = argv[1];
+    portno = atoi(argv[2]);
+
+    /* socket: create the socket */
+    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+    if (sockfd < 0) 
+        error("ERROR opening socket");
+
+    /* gethostbyname: get the server's DNS entry */
+    server = gethostbyname(hostname);
+    if (server == NULL) {
+        fprintf(stderr,"ERROR, no such host as %s\n", hostname);
+        exit(0);
+    }
+
+    /* build the server's Internet address */
+    bzero((char *) &serveraddr, sizeof(serveraddr));
+    serveraddr.sin_family = AF_INET;
+    bcopy((char *)server->h_addr, 
+      (char *)&serveraddr.sin_addr.s_addr, server->h_length);
+    serveraddr.sin_port = htons(portno);
+
+    /* get a message from the user */
+    char *msg = "A message to the server!\0";
+    fcntl(sockfd, F_SETFL, O_NONBLOCK); 
+    long count = 0;
+    while(1)
+    {
+        count++;
+        printf("\nTX(%lu)...\n", count);
+        usleep(10000);
+        //bzero(buf, BUFSIZE);
+        //printf("\nPlease enter msg: ");
+        //fgets(buf, BUFSIZE, stdin);
+
+        /* send the message to the server */
+        serverlen = sizeof(serveraddr);
+        printf("A\n");
+        n = sendto(sockfd, msg, strlen(msg), 0, (struct sockaddr *)&serveraddr, serverlen);
+        printf("B\n");
+        //if (n < 0) 
+        //    error("ERROR in sendto");
+        
+        /* print the server's reply */
+        printf("C\n");
+        memset(buf, 0, sizeof(buf));
+        printf("D\n");
+        n = recvfrom(sockfd, buf, BUFSIZE, 0, (struct sockaddr *)&serveraddr, (socklen_t *)&serverlen);
+        printf("E\n");
+        //if (n < 0) 
+        //    printf("ERROR in recvfrom: %d", n);
+        printf("Echo from server: %s", buf);
+    }
+    return 0;
+}