Improvement: Avoid "exit" in the libraries.

Using "exit" in a library isn't too great, depending on the application.
In an embedded environment, where the application may have other functions,
it's better to just return an error.

Removes the use of "exit". Adds a return status to HTTPServerInit. Also
adds protective checks in HTTPServerRun and HTTPServerClose, if these
were called, despite HTTPServerInit failing (so socket was invalid).

See: #9

Author: TangoBravo64

FreeRTOS/lib/server.c

@@ -36,13 +36,14 @@ HTTPReq http_req[MAX_HTTP_CLIENT];
 uint8_t req_buf[MAX_HTTP_CLIENT][MAX_HEADER_SIZE + MAX_BODY_SIZE];
 uint8_t res_buf[MAX_HTTP_CLIENT][MAX_HEADER_SIZE + MAX_BODY_SIZE];
 
-void HTTPServerInit(HTTPServer *srv, uint16_t port) {
+int HTTPServerInit(HTTPServer *srv, uint16_t port) {
 	struct sockaddr_in srv_addr;
 	unsigned int i;
 
 	/* Have a server socket. */
 	srv->sock = socket(AF_INET, SOCK_STREAM, 0);
-	if(srv->sock < 0) exit(1);
+	if(srv->sock < 0)
+		return -1;
 	/* Set server address. */
 	memset(&srv_addr, 0, sizeof(srv_addr));
 	srv_addr.sin_family = AF_INET;
@@ -52,7 +53,8 @@ void HTTPServerInit(HTTPServer *srv, uint16_t port) {
 	setsockopt(srv->sock, SOL_SOCKET, SO_REUSEADDR, &(int){1}, sizeof(int));
 	/* Bind the server socket with the server address. */
 	if(bind(srv->sock, (struct sockaddr*) &srv_addr, sizeof(srv_addr)) == -1) {
-		exit(1);
+		HTTPServerClose(srv);
+		return -1;
 	}
 	/* Set the server socket non-blocking. */
 	fcntl(srv->sock, F_SETFL, O_NONBLOCK);
@@ -75,6 +77,7 @@ void HTTPServerInit(HTTPServer *srv, uint16_t port) {
 		http_req[i].clisock = -1;
 		http_req[i].work_state = NOTWORK_SOCKET;
 	}
+	return 0;
 }
 
 void _HTTPServerAccept(HTTPServer *srv) {
@@ -385,6 +388,9 @@ void HTTPServerRun(HTTPServer *srv, HTTPREQ_CALLBACK callback) {
 	struct timeval timeout = {0, 0};
 	uint16_t i;
 
+	if (srv->sock < 0)
+		return;
+
 	/* Copy master socket queue to readable, writeable socket queue. */
 	readable = srv->_read_sock_pool;
 	writeable = srv->_write_sock_pool;
@@ -426,8 +432,11 @@ void HTTPServerRun(HTTPServer *srv, HTTPREQ_CALLBACK callback) {
 }
 
 void HTTPServerClose(HTTPServer *srv) {
+	if (srv->sock < 0)
+		return;
 	shutdown(srv->sock, SHUT_RDWR);
 	close((srv)->sock);
+	srv->sock = -1;
 }
 
 #ifdef MICRO_HTTP_SERVER_EXAMPLE

FreeRTOS/lib/server.h

@@ -78,7 +78,7 @@ typedef struct _HTTPResMessage {
 
 typedef void (*HTTPREQ_CALLBACK)(HTTPReqMessage *, HTTPResMessage *);
 
-void HTTPServerInit(HTTPServer *, uint16_t);
+int  HTTPServerInit(HTTPServer *, uint16_t);
 void HTTPServerRun(HTTPServer *, HTTPREQ_CALLBACK);
 #define HTTPServerRunLoop(srv, callback) { \
 	while(1) { \

FreeRTOS/src/main.c

@@ -47,14 +47,19 @@ void MicroHTTPServer_task() {
 	AddRoute(HTTP_POST, "/fib", Fib);
 	AddRoute(HTTP_POST, "/led", LED);
 	USART_Printf(USART2, "Going to start Micro HTTP Server.\r\n");
-	HTTPServerInit(&srv, MHS_PORT);
-	USART_Printf(USART2, "Micro HTTP Server started and listening.\r\n");
-	while(1) {
-		HTTPServerRun(&srv, Dispatch);
-		/* Reschedule after each HTTP server run turn. */
-		vTaskDelay(10);
+	if (HTTPServerInit(&srv, MHS_PORT) < 0) {
+		USART_Printf(USART2, "Micro HTTP Server initialzation failed.\r\n");
+	}
+	else
+	{
+		USART_Printf(USART2, "Micro HTTP Server started and listening.\r\n");
+		while(1) {
+			HTTPServerRun(&srv, Dispatch);
+			/* Reschedule after each HTTP server run turn. */
+			vTaskDelay(10);
+		}
+		HTTPServerClose(&srv);
 	}
-	HTTPServerClose(&srv);
 
 	vTaskDelete(NULL);
 }

c-version/lib/server.c

@@ -36,13 +36,14 @@ HTTPReq http_req[MAX_HTTP_CLIENT];
 uint8_t req_buf[MAX_HTTP_CLIENT][MAX_HEADER_SIZE + MAX_BODY_SIZE];
 uint8_t res_buf[MAX_HTTP_CLIENT][MAX_HEADER_SIZE + MAX_BODY_SIZE];
 
-void HTTPServerInit(HTTPServer *srv, uint16_t port) {
+int HTTPServerInit(HTTPServer *srv, uint16_t port) {
 	struct sockaddr_in srv_addr;
 	unsigned int i;
 
 	/* Have a server socket. */
 	srv->sock = socket(AF_INET, SOCK_STREAM, 0);
-	if(srv->sock < 0) exit(1);
+	if(srv->sock < 0)
+		return -1;
 	/* Set server address. */
 	memset(&srv_addr, 0, sizeof(srv_addr));
 	srv_addr.sin_family = AF_INET;
@@ -52,7 +53,8 @@ void HTTPServerInit(HTTPServer *srv, uint16_t port) {
 	setsockopt(srv->sock, SOL_SOCKET, SO_REUSEADDR, &(int){1}, sizeof(int));
 	/* Bind the server socket with the server address. */
 	if(bind(srv->sock, (struct sockaddr*) &srv_addr, sizeof(srv_addr)) == -1) {
-		exit(1);
+		HTTPServerClose(srv);
+		return -1;
 	}
 	/* Set the server socket non-blocking. */
 	fcntl(srv->sock, F_SETFL, O_NONBLOCK);
@@ -75,6 +77,7 @@ void HTTPServerInit(HTTPServer *srv, uint16_t port) {
 		http_req[i].clisock = -1;
 		http_req[i].work_state = NOTWORK_SOCKET;
 	}
+	return 0;
 }
 
 void _HTTPServerAccept(HTTPServer *srv) {
@@ -385,6 +388,9 @@ void HTTPServerRun(HTTPServer *srv, HTTPREQ_CALLBACK callback) {
 	struct timeval timeout = {0, 0};
 	uint16_t i;
 
+	if (srv->sock < 0)
+		return;
+
 	/* Copy master socket queue to readable, writeable socket queue. */
 	readable = srv->_read_sock_pool;
 	writeable = srv->_write_sock_pool;
@@ -426,8 +432,11 @@ void HTTPServerRun(HTTPServer *srv, HTTPREQ_CALLBACK callback) {
 }
 
 void HTTPServerClose(HTTPServer *srv) {
+	if (srv->sock < 0)
+		return;
 	shutdown(srv->sock, SHUT_RDWR);
 	close((srv)->sock);
+	srv->sock = -1;
 }
 
 #ifdef MICRO_HTTP_SERVER_EXAMPLE

c-version/lib/server.h

@@ -78,7 +78,7 @@ typedef struct _HTTPResMessage {
 
 typedef void (*HTTPREQ_CALLBACK)(HTTPReqMessage *, HTTPResMessage *);
 
-void HTTPServerInit(HTTPServer *, uint16_t);
+int  HTTPServerInit(HTTPServer *, uint16_t);
 void HTTPServerRun(HTTPServer *, HTTPREQ_CALLBACK);
 #define HTTPServerRunLoop(srv, callback) { \
 	while(1) { \

c-version/main.c

@@ -21,7 +21,8 @@ int main(void) {
 	AddRoute(HTTP_GET, "/", HelloPage);
 	AddRoute(HTTP_POST, "/fib", Fib);
 	/* Initial the HTTP server and make it listening on MHS_PORT. */
-	HTTPServerInit(&srv, MHS_PORT);
+	if (HTTPServerInit(&srv, MHS_PORT) < 0)
+		return -1;
 	/* Run the HTTP server forever. */
 	/* Run the dispatch callback if there is a new request */
 	HTTPServerRunLoop(&srv, Dispatch);