good progress. basic num_station data going & listener udp port works

1 files changed, 31 insertions, 19 deletions

diff --git a/listener.c b/listener.c
index 723cb1b..2d46307 100644
--- a/listener.c
+++ b/listener.c
@@ -13,9 +13,9 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 
-#define MYPORT "4950"    // the port users will be connecting to
+// #define MYPORT "4950"    // the port users will be connecting to
 
-#define MAXBUFLEN 100
+#define MAXBUFLEN 16384
 
 // get sockaddr, IPv4 or IPv6:
 void *get_in_addr(struct sockaddr *sa)
@@ -27,7 +27,7 @@ void *get_in_addr(struct sockaddr *sa)
     return &(((struct sockaddr_in6*)sa)->sin6_addr);
 }
 
-int main(void)
+int main(int argc, char *argv[])
 {
     int sockfd;
     struct addrinfo hints, *servinfo, *p;
@@ -38,12 +38,20 @@ int main(void)
     socklen_t addr_len;
     char s[INET6_ADDRSTRLEN];
 
+    if (argc != 2) {
+        fprintf(stderr,"<udp port>\n");
+        exit(1);
+    }
+
+    const char* udp_port = argv[1];
+
+
     memset(&hints, 0, sizeof hints);
-    hints.ai_family = AF_INET6; // set to AF_INET to use IPv4
+    hints.ai_family = AF_INET; // set to AF_INET to use IPv4
     hints.ai_socktype = SOCK_DGRAM;
     hints.ai_flags = AI_PASSIVE; // use my IP
 
-    if ((rv = getaddrinfo(NULL, MYPORT, &hints, &servinfo)) != 0) {
+    if ((rv = getaddrinfo(NULL, udp_port, &hints, &servinfo)) != 0) {
         fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
         return 1;
     }
@@ -72,22 +80,26 @@ int main(void)
 
     freeaddrinfo(servinfo);
 
-    printf("listener: waiting to recvfrom...\n");
+    int count = 0;
 
-    addr_len = sizeof their_addr;
-    if ((numbytes = recvfrom(sockfd, buf, MAXBUFLEN-1 , 0,
-        (struct sockaddr *)&their_addr, &addr_len)) == -1) {
-        perror("recvfrom");
-        exit(1);
-    }
+    while(1) {
+        printf("\nlistener: waiting to recvfrom... %d times\n", count++);
 
-    printf("listener: got packet from %s\n",
-        inet_ntop(their_addr.ss_family,
-            get_in_addr((struct sockaddr *)&their_addr),
-            s, sizeof s));
-    printf("listener: packet is %d bytes long\n", numbytes);
-    buf[numbytes] = '\0';
-    printf("listener: packet contains \"%s\"\n", buf);
+        addr_len = sizeof their_addr;
+        if ((numbytes = recvfrom(sockfd, buf, MAXBUFLEN , 0,
+            (struct sockaddr *)&their_addr, &addr_len)) == -1) {
+            perror("recvfrom");
+            exit(1);
+        }
+
+        printf("listener: got packet from %s\n",
+            inet_ntop(their_addr.ss_family,
+                get_in_addr((struct sockaddr *)&their_addr),
+                s, sizeof s));
+        printf("listener: packet is %d bytes long\n", numbytes);
+        buf[numbytes] = '\0';
+        printf("listener: packet contains \"%s\"\n", buf);
+    }
 
     close(sockfd);