Fixed segfault issue by using MAX_CONNECTIONS instead of 'sizeof'

easysock.c

@@ -1,169 +0,0 @@
-#include "easysock.h"
-
-int create_socket(int network, char transport) {  
-	int domain;
-	int type;
-
-	if (network == 4) {
-		domain = AF_INET;
-	} else if (network == 6) {
-		domain = AF_INET6;
-	} else {
-		return -1;
-	}
-
-	if (transport == 'T') {
-		type = SOCK_STREAM;
-	} else if (transport == 'U') {
-		type = SOCK_DGRAM;
-	} else {
-		return -1;
-	}
-
-	int newSock = socket(domain,type,0);
-	return newSock;
-}
-
-
-void create_addr(int network, char* address, int port,struct sockaddr* dest) {
-	if (network == 4) {
-		struct sockaddr_in listen_address;
-		
-		listen_address.sin_family = AF_INET;
-		listen_address.sin_port = htons(port);
-		inet_pton(AF_INET,address,&listen_address.sin_addr);
-		memcpy(dest,&listen_address,sizeof(listen_address));
-		return;	
-
-	} else if (network == 6) {
-		struct sockaddr_in6 listen_ipv6;
-		listen_ipv6.sin6_family = AF_INET6;
-		listen_ipv6.sin6_port = htons(port);
-		inet_pton(AF_INET6,address,&listen_ipv6.sin6_addr);
-		memcpy(dest,&listen_ipv6,sizeof(listen_ipv6));
-		return;
-
-	} else {
-		exit(202);
-	}
-		
-}
-
-int create_local (int network, char transport, char* address, int port,struct sockaddr* addr_struct) {
-	int socket = create_socket(network,transport);
-	if (socket < 0) {
-		exit(errno);
-	}
-	create_addr(network,address,port,addr_struct);
-	int addrlen;
-	if (network == 4) {
-		addrlen = sizeof(struct sockaddr_in);
-	} else if (network == 6) {
-		addrlen = sizeof(struct sockaddr_in6);
-	} else {
-		exit(207);
-	}
-
-	/* The value of addrlen should be the size of the 'sockaddr'. 
-	This should be set to the size of 'sockaddr_in' for IPv4, and 'sockaddr_in6' for IPv6.
-	See https://stackoverflow.com/questions/73707162/socket-bind-failed-with-invalid-argument-error-for-program-running-on-macos */
-
-	int i = bind (socket,addr_struct,(socklen_t)addrlen);
-	if (i < 0) {
-		exit(errno);
-	}
-	return socket;
-}
-
-int create_remote (int network,char transport,char* address,int port,struct sockaddr* remote_addr_struct) {
-
-	struct addrinfo hints;  /* Used to tell getaddrinfo what kind of address we want */
-	struct addrinfo* results; /* Used by getaddrinfo to store the addresses */
-
-
-	if (check_ip_ver(address) < 0) { /* If the address is a domain name */
-		int err_code;
-		char* port_str = malloc(10 * sizeof(char));
-
-		sprintf(port_str,"%d",port); /* getaddrinfo expects a string for its port */
-
-
-		memset(&hints,'\0',sizeof(hints));
-		hints.ai_socktype = char_to_socktype(transport);
-
-		err_code = getaddrinfo(address,port_str,&hints,&results);
-		if (err_code != 0) {
-			exit(err_code);
-		}
-		remote_addr_struct = results->ai_addr;
-		network = inet_to_int(results->ai_family);
-	} else {
-	        create_addr(network,address,port,remote_addr_struct);
-	}
-
-	int socket = create_socket(network,transport);
-	if (socket < 0) {
-                exit(errno);
-        }
-
-       	int addrlen;
-	if (network == 4) {
-		addrlen = sizeof(struct sockaddr_in);
-	} else if (network == 6) {
-		addrlen = sizeof(struct sockaddr_in6);
-	} else {
-		exit(207);
-	}
-
-	/* The value of addrlen should be the size of the 'sockaddr'. 
-	This should be set to the size of 'sockaddr_in' for IPv4, and 'sockaddr_in6' for IPv6.
-	See https://stackoverflow.com/questions/73707162/socket-bind-failed-with-invalid-argument-error-for-program-running-on-macos */
-
-        int i = connect(socket,remote_addr_struct,(socklen_t)addrlen);
-	if (i < 0) {
-		exit(errno);
-	}
-        return socket;
-}
-
-
-int check_ip_ver(char* address) {
-	char buffer[16]; /* 16 chars - 128 bits - is enough to hold an ipv6 address */
-	if (inet_pton(AF_INET,address,buffer) == 1) {
-		return 4;
-	} else if (inet_pton(AF_INET6,address,buffer) == 1) {
-		return 6;
-	} else {
-		return -1;
-	}
-}
-
-int int_to_inet(int network) {
-	if (network == 4) {
-		return AF_INET;
-	} else if (network == 6) {
-		return AF_INET6;
-	} else {
-		exit(207);
-	}
-}
-
-int inet_to_int(int af_type) {
-	if (af_type == AF_INET) {
-		return 4;
-	} else if (af_type == AF_INET6) {
-		return 6;
-	} else {
-		exit(207);
-	}
-}
-
-int char_to_socktype(char transport) {
-	if (transport == 'T') {
-		return SOCK_STREAM;
-	} else if (transport == 'U') {
-		return SOCK_DGRAM;
-	} else {
-		exit(250);
-	}
-}

easysock.h

@@ -1,75 +0,0 @@
-#ifndef EASYSOCK_H_
-#define EASYSOCK_H_
-
-#include <string.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netdb.h>
-#include <arpa/inet.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <errno.h>
-
-
-/* This function takes:
-a layer 3 - network layer - integer, which must be '4' for IPv4
-and 6 for IPv6; and
-a layer 4 - transport layer - character, which must be 'T' for
-TCP or 'U' for UDP. 
-
-It returns the created socket, or -1 if the socket creation failed.*/
-
-int create_socket(int network, char transport);
-
-
-/* This function fills in the sockaddr struct 'dest' based on the given information.
-'network' is an integer that contains '4' for IPv4 or '6' for IPv6;
-'address' is the address that is filled into the struct;
-port is self-explanatory;
-and dest is a pointer to the sockaddr struct that will be filled in. 
-
-The function exits with error code 202 if the network parameter contained neither '4'
-nor '6'. */
-
-void create_addr(int network, char* address, int port,struct sockaddr* dest);
-
-
-
-/* This function utilizes the above two functions; it creates the socket and
-_binds_ the addresses. It is used for local sockets (server sockets). Parameters are
-same as above. 
-
-It prints the error returned by 'bind' if something went wrong, and exits with errno.*/
-
-int create_local (int network, char transport, char* address, int port,struct sockaddr* addr_struct);
-
-
-/* This function utilizes the same functions as 'create_local' but _connects_ to the
-requested address. It is used for remote sockets (client sockets). The paramters are same
-as above. This function needs an empty 'sockaddr *' structure passed to it, which it will fill.
-
-It prints the error returned by 'connect' if something went wrong, and exits with errno.*/
-
-int create_remote (int network,char transport,char* address,int port,struct sockaddr* remote_addr_struct);
-
-/* check_ip_ver - This function checks if the given string is an IPv4 address (returns 4), 
-IPv6 address (returns 6) or neither (returns -1). */
-
-int check_ip_ver(char* address);
-
-/* int_to_inet - Takes an int value (4 for IPv4, 6 for IPv6) and returns AF_INET or
-AF_INET6 respectively. */
-
-int int_to_inet(int network);
-
-/* char_to_socktype - Takes a character that represents a transport-layer protocol
-(currently only supports 'T' for TCP or 'U' for UDP - exits with error code 250 if 
-the given characters is neither of these) and return the appropriate SOCKTYPE value. */
-
-int char_to_socktype(char transport);
-
-/* inet_to_int - Takes an int value that corresponds to AF_INET or AF_INET6,
-and returns the appropriate int value. */
-int inet_to_int(int af_type);
-
-#endif

main.c

@@ -20,7 +20,7 @@ int main() {
 	socklen_t temp_addrlen;
 
 	fd_set read_fd_set;
-	int conn_sockets[MAX_CONNECTIONS] = {0};
+	int conn_sockets[MAX_CONNECTIONS] = {-1};
 	FD_ZERO(&read_fd_set);
 	char buffer[BUFFER_SIZE];
 	User* users = create_user_list("user_file.txt");
@@ -33,7 +33,7 @@ int main() {
 
 	while (true) {
 		FD_ZERO(&read_fd_set);
-		for (int i=0; i < sizeof(conn_sockets); i++) {
+		for (int i=0; i < MAX_CONNECTIONS; i++) {
 			if (conn_sockets[i] > 0) {
 				FD_SET(conn_sockets[i],&read_fd_set);
 			}
@@ -44,7 +44,7 @@ int main() {
 		if (num_conns > 0) {
 			if (FD_ISSET(conn_sockets[0],&read_fd_set)) {
 				int client_sock = accept(conn_sockets[0],&temp_addr,&temp_addrlen);
-				for (int i=0;i < sizeof(conn_sockets); i++) {
+				for (int i=0;i < MAX_CONNECTIONS; i++) {
 					if (conn_sockets[i] <= 0) {
 						conn_sockets[i] = client_sock;
 						break;
@@ -52,13 +52,12 @@ int main() {
 				}
 			}
 
-			for (int i=1; i < sizeof(conn_sockets); i++) {
+			for (int i=1; i < MAX_CONNECTIONS; i++) {
-				printf("Checking FD: %d\n",i);
 				if (FD_ISSET(conn_sockets[i],&read_fd_set)) {
 					int num_bytes_read = recv(conn_sockets[i],buffer,sizeof(buffer),0);
 					if (num_bytes_read <= 0) {
 						close(conn_sockets[i]);
-						conn_sockets[i] = -1;
+						conn_sockets[i] = 0;
 					} else {
 						for (int i=0;i<num_bytes_read;i++) {
 							printf("%c",buffer[i]);