From 1a13289da96489aeded385366389ab30efb34525 Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cdo@wip.sh>
Date: Thu, 13 Oct 2022 13:45:01 +0100
Subject: [PATCH] Improve error handling

---
 main.c | 31 ++++++++++++++++++-------------
 1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/main.c b/main.c
index 74ce543..5a00135 100644
--- a/main.c
+++ b/main.c
@@ -20,6 +20,7 @@
 #include <netinet/in.h>
 #include <signal.h>
 #include <stdbool.h>
+#include <stdlib.h>
 #include <stdio.h>
 #include <sys/socket.h>
 #include <unistd.h>
@@ -39,6 +40,8 @@ int main(int argc, char *argv[])
 	(void)argc;
 	(void)argv;
 
+	int res = EXIT_SUCCESS;
+
 	/*
 	 * Register signal handler for SIGTERM and SIGINT.
 	 *
@@ -48,11 +51,11 @@ int main(int argc, char *argv[])
 	 */
 	if (signal(SIGTERM, handle_exit_signal) == SIG_ERR) {
 		fprintf(stderr, "Failed to register SIGTERM signal handler\n");
-		return 1;
+		return EXIT_FAILURE;
 	}
 	if (signal(SIGINT, handle_exit_signal) == SIG_ERR) {
 		fprintf(stderr, "Failed to register SIGINT signal handler\n");
-		return 1;
+		return EXIT_FAILURE;
 	}
 
 	/*
@@ -65,7 +68,7 @@ int main(int argc, char *argv[])
 	int sfd = socket(AF_INET6, SOCK_STREAM, 0);
 	if (sfd == -1) {
 		fprintf(stderr, "Failed to open socket\n");
-		return 1;
+		return EXIT_FAILURE;
 	}
 	const struct sockaddr_in6 haddr = {
 		.sin6_family = AF_INET6,
@@ -74,11 +77,13 @@ int main(int argc, char *argv[])
 	};
 	if (bind(sfd, (const struct sockaddr *)&haddr, sizeof(haddr)) == -1) {
 		fprintf(stderr, "Error binding socket to address\n");
-		return 1;
+		res = EXIT_FAILURE;
+		goto close_server_socket;
 	}
 	if (listen(sfd, 8) == -1) {
 		fprintf(stderr, "Error attempting to listen on socket\n");
-		return 1;
+		res = EXIT_FAILURE;
+		goto close_server_socket;
 	}
 
 	struct sockaddr_in6 paddr;
@@ -100,10 +105,9 @@ int main(int argc, char *argv[])
 		 */
 		cfd = accept(sfd, (struct sockaddr *)&paddr, &paddr_size);
 		if (cfd == -1) {
-			if (errno == EINTR)
-				continue;
-			fprintf(stderr, "Error accepting connection\n");
-			return 1;
+			if (errno != EINTR)
+				fprintf(stderr, "Error accepting connection\n");
+			continue;
 		}
 
 		/*
@@ -118,7 +122,7 @@ int main(int argc, char *argv[])
 		} while (errno == EINTR);
 		if (n == -1) {
 			fprintf(stderr, "Error reading selector from client\n");
-			return 1;
+			goto close_client_socket;
 		}
 
 		/*
@@ -135,16 +139,17 @@ int main(int argc, char *argv[])
 		}
 		if (slen == n) {
 			fprintf(stderr, "Received invalid selector (no CRLF)\n");
-			return 1;
+			goto close_client_socket;
 		}
 
 		sbuf[slen] = '\0';
 		printf("Received selector: \"%s\"\n", sbuf);
 
+	close_client_socket:
 		close(cfd);
 	}
 
+close_server_socket:
 	close(sfd);
-
-	return 0;
+	return res;
 }