added for loop to loop through the linked list from getaddrinfo not sure why exactly i need to do it if i listen on my own port but the book did it so i did it. I also learned how to see what IP and what port the client connects from

1 files changed, 33 insertions, 18 deletions

diff --git a/listen.c b/listen.c
index e8bb789..076d080 100644
--- a/listen.c
+++ b/listen.c
@@ -12,15 +12,16 @@
 #include <netinet/in.h>
 
 // int listen(int sockfd, int backlog); 
-
+#define __FAIL EXIT_FAILURE
 #define BACKLOG 2
 
 int main () {
 
-	int sockfd; // socket fd
+	int sockfd = -1; // socket fd
 	int gai_result; // result from getaddrinfo
-	int bind_result; // result from bind
+	int bind_result = -1; // result from bind
 	struct addrinfo *res; // Pointer to linked list sent back by gai
+	struct addrinfo *p; // for linked list stuff
 	struct addrinfo hints; // Options we pass to gai
 	memset(&hints, 0, sizeof(hints)); // We set this struct to 0 and then give it all the options we want below
 	hints.ai_family = AF_INET;
@@ -29,22 +30,29 @@ int main () {
 
 	gai_result = getaddrinfo(NULL, "62000", &hints, &res); // NULL because we are going to listen
 	if (gai_result != 0) {
-		fprintf(stderr, "gai_result: %d\n", gai_result);
-		exit(1);
+   		fprintf(stderr, "gai_result: %d\n", gai_result);
+   		exit(__FAIL);
 	}
+	
+	for (p = res ; p != NULL ; p = p->ai_next) { // Loop 
 
-	sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol); // Socket, get the family, socktype and protocol.
-	if (sockfd == -1) {
-		fprintf(stderr, "sockfd: %d\n", sockfd);
-		exit(1);
-	}
+		sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol); // Socket, get the family, socktype and protocol.
+		if (sockfd == -1) {
+			fprintf(stderr, "sockfd: %d\n", sockfd);
+			continue;
+		}
 
-	bind_result = bind(sockfd, res->ai_addr, res->ai_addrlen); // Bind to socket fd. pass our own address (ai_addr) and the length
-	if (bind_result != 0) {
-		fprintf(stderr, "bind_result: %d\n", bind_result);
-		exit(1);
+		bind_result = bind(sockfd, p->ai_addr, p->ai_addrlen); // Bind to socket fd. pass our own address (ai_addr) and the length
+		if (bind_result != 0) {
+			fprintf(stderr, "bind_result: %d\n", bind_result);
+			close(sockfd);
+			continue;
+		}
 	}
-
+	if (sockfd == -1 || bind_result == -1) {
+		exit(__FAIL);
+	}
+	
 	freeaddrinfo(res); // free the info because we dont need it anymore
 
 	fprintf(stdout, "Waiting for a connection...\n");
@@ -58,11 +66,18 @@ int main () {
 	fprintf(stdout, "Connection is being established...\n");
 	if (newfd == -1) {
 		fprintf(stderr, "newfd: %d\n", newfd);
-		exit(1);
+		exit(__FAIL);
 	}
 
-	fprintf(stdout, "Connection established!\n");
-	char *msg = "Server says hi!\n";
+	char host_ip[NI_MAXHOST];
+	char port_port[NI_MAXSERV];
+	int gni;
+    gni = getnameinfo((struct sockaddr *)&their_addr, addr_size, host_ip, sizeof(host_ip), port_port, sizeof(port_port), NI_NUMERICSERV | NI_NUMERICHOST);
+	
+	if (gni == 0) {
+		fprintf(stdout, "Client %s %s just connected!\n", host_ip, port_port);
+	}
+	char *msg = "Connection established!\n";
 	int len;
 	int bytes_sent;
 	len = strlen(msg);