- basic port listening functionality (prototyping)

fsipd.c

@@ -30,10 +30,8 @@
 #include <sys/time.h>
 #include <sys/file.h>
 #include <sys/socket.h>
-#include <net/if.h>
+#include <netdb.h>
-#include <net/if_var.h>
+#include <netinet/in.h>
-#include <net/if_types.h>
-#include <ifaddrs.h>
 
 #include <err.h>
 #include <errno.h>
@@ -46,15 +44,21 @@
 #include <string.h>
 #include <sysexits.h>
 #include <unistd.h>
+#include <syslog.h>
 #include <libutil.h>
 
+#define	PORT 5060
+#define BACKLOG 1024
+
 /* Globals */
 struct pidfh *pfh;
+struct sockaddr_in sa;
+struct protoent *proto_tcp, *proto_udp;
 
 /*
  * Prepare for a clean shutdown
  */
-void 
+void
 daemon_shutdown()
 {
 	pidfile_remove(pfh);
@@ -63,12 +67,13 @@ daemon_shutdown()
 /*
  * Act upon receiving signals
  */
-void 
+void
 signal_handler(int sig)
 {
 	switch (sig) {
 
 	case SIGHUP:
+		break;
 	case SIGINT:
 	case SIGTERM:
 		daemon_shutdown();
@@ -79,92 +84,130 @@ signal_handler(int sig)
 	}
 }
 
+void
+process_request(char *str)
+{
+	/* check input str for SIP requests */
+	syslog(LOG_ALERT, "incoming packet: %s\n", str);
+}
+
 /*
  * Daemonize and persist pid
  */
-int 
+int
 daemon_start()
 {
 	struct sigaction sig_action;
 	sigset_t sig_set;
 	pid_t otherpid;
+	int curPID;
+	register int s, c;
+	unsigned int b;
+	FILE *client;
+	char inputstr[8192];
 
-	char *no_fork = getenv("no_fork");
+	/* Check if we can acquire the pid file */
+	pfh = pidfile_open(NULL, 0600, &otherpid);
 
-	if (!no_fork || strcmp("1", no_fork)) {
+	if (pfh == NULL) {
-
+		if (errno == EEXIST) {
-		/* Check if parent process id is set */
+			errx(EXIT_FAILURE, "Daemon already running, pid: %jd.", (intmax_t)otherpid);
-		if (getppid() == 1) {
-			/* PPID exists, therefore we are already a daemon */
-			return (EXIT_FAILURE);
 		}
-		/* Check if we can acquire the pid file */
+		warn("Cannot open or create pidfile.");
-		pfh = pidfile_open(NULL, 0600, &otherpid);
-
-		if (pfh == NULL) {
-			if (errno == EEXIST) {
-				errx(EXIT_FAILURE, "Daemon already running, pid: %jd.", (intmax_t)otherpid);
-			}
-			warn("Cannot open or create pidfile.");
-		}
-		/* fork ourselves if not asked otherwise */
-		if (fork()) {
-			return (EXIT_SUCCESS);
-		}
-		/* we are the child, complete the daemonization */
-
-		/* Close standard IO */
-		fclose(stdin);
-		fclose(stdout);
-		fclose(stderr);
-
-		/* Block unnecessary signals */
-		sigemptyset(&sig_set);
-		sigaddset(&sig_set, SIGCHLD);	/* ignore child - i.e. we
-						 * don't need to wait for it */
-		sigaddset(&sig_set, SIGTSTP);	/* ignore Tty stop signals */
-		sigaddset(&sig_set, SIGTTOU);	/* ignore Tty background
-						 * writes */
-		sigaddset(&sig_set, SIGTTIN);	/* ignore Tty background reads */
-		sigprocmask(SIG_BLOCK, &sig_set, NULL);	/* Block the above
-							 * specified signals */
-
-		/* Catch necessary signals */
-		sig_action.sa_handler = signal_handler;
-		sigemptyset(&sig_action.sa_mask);
-		sig_action.sa_flags = 0;
-
-		sigaction(SIGTERM, &sig_action, NULL);
-		sigaction(SIGHUP, &sig_action, NULL);
-		sigaction(SIGINT, &sig_action, NULL);
-
-		/* create new session and process group */
-		setsid();
-
-		/* persist pid */
-		pidfile_write(pfh);
-
 	}
 
+	/* setup socket */
+	if ((proto_tcp = getprotobyname("tcp")) == NULL)
+		return -1;
+
+	bzero(&sa, sizeof(sa));
+	sa.sin_port = htons(PORT);
+	sa.sin_family = AF_INET;
+	sa.sin_addr.s_addr = htonl(INADDR_ANY);
+
+	if ((s = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
+	    perror("socket");
+	    return EXIT_FAILURE;
+	}
+
+	if (bind(s, (struct sockaddr *)&sa, sizeof sa) < 0) {
+        	perror("bind");
+        	return EXIT_FAILURE;
+    	}
+
+	/* start daemonizing */
+	curPID = fork();
+
+	switch (curPID) {
+	case 0:			/* This process is the child */
+		break;
+	case -1:			/* fork() failed, should exit */
+		perror("fork");
+		return (EXIT_FAILURE);
+	default:			/* fork() successful, should exit */
+		return (EXIT_SUCCESS);
+	}
+
+	/* we are the child, complete the daemonization */
+	/* Close standard IO */
+	fclose(stdin);
+	fclose(stdout);
+	fclose(stderr);
+
+	/* Block unnecessary signals */
+	sigemptyset(&sig_set);
+	sigaddset(&sig_set, SIGCHLD);	/* ignore child - i.e. we don't need
+					 * to wait for it */
+	sigaddset(&sig_set, SIGTSTP);	/* ignore Tty stop signals */
+	sigaddset(&sig_set, SIGTTOU);	/* ignore Tty background writes */
+	sigaddset(&sig_set, SIGTTIN);	/* ignore Tty background reads */
+	sigprocmask(SIG_BLOCK, &sig_set, NULL);	/* Block the above specified
+						 * signals */
+
+	/* Catch necessary signals */
+	sig_action.sa_handler = signal_handler;
+	sigemptyset(&sig_action.sa_mask);
+	sig_action.sa_flags = 0;
+
+	sigaction(SIGTERM, &sig_action, NULL);
+	sigaction(SIGHUP, &sig_action, NULL);
+	sigaction(SIGINT, &sig_action, NULL);
+
+	/* create new session and process group */
+	setsid();
+
+	/* persist pid */
+	pidfile_write(pfh);
+
 	/* TODO: Network Logic Here */
+
+	listen(s, BACKLOG);
+
 	while (1) {
 
-		sleep(5);
+		b = sizeof(sa);
-
+		if ((c = accept(s, (struct sockaddr *)&sa, &b)) < 0) {
-	}
+			perror("accept");
-
+			return (EXIT_FAILURE);
-	return (0);
-}
-
-int 
-main(int argc, char *argv[])
-{
-	if (argc > 1) {
-		char *first_arg = argv[1];
-
-		if (!strcmp(first_arg, "start")) {
-			return daemon_start();
 		}
+
+		if ((client = fdopen(c, "w")) == NULL) {
+			perror("fdopen");
+			return (EXIT_FAILURE);
+		}
+
+		fgets(inputstr, sizeof(inputstr), client);
+
+		process_request(inputstr);
+
+		fclose(client);
 	}
+
 	return (EXIT_SUCCESS);
 }
+
+int
+main(int argc, char *argv[])
+{
+	return (daemon_start());
+}