add back in udhcp support

networking/udhcp/common.c

@@ -0,0 +1,135 @@
+/* vi: set sw=4 ts=4: */
+/* common.c
+ *
+ * Functions for debugging and logging as well as some other
+ * simple helper functions.
+ *
+ * Russ Dill <Russ.Dill@asu.edu> 2001-2003
+ * Rewritten by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <paths.h>
+#include <sys/socket.h>
+#include <stdarg.h>
+
+#include "common.h"
+#include "pidfile.h"
+
+
+static int daemonized;
+
+long uptime(void)
+{
+	struct sysinfo info;
+	sysinfo(&info);
+	return info.uptime;
+}
+
+
+/*
+ * This function makes sure our first socket calls
+ * aren't going to fd 1 (printf badness...) and are
+ * not later closed by daemon()
+ */
+static inline void sanitize_fds(void)
+{
+	int zero;
+	if ((zero = open(_PATH_DEVNULL, O_RDWR, 0)) < 0) return;
+	while (zero < 3) zero = dup(zero);
+	close(zero);
+}
+
+
+void background(const char *pidfile)
+{
+#ifdef __uClinux__
+	LOG(LOG_ERR, "Cannot background in uclinux (yet)");
+#else /* __uClinux__ */
+	int pid_fd;
+
+	/* hold lock during fork. */
+	pid_fd = pidfile_acquire(pidfile);
+	if (daemon(0, 0) == -1) { /* bb_xdaemon? */
+		perror("fork");
+		exit(1);
+	}
+	daemonized++;
+	pidfile_write_release(pid_fd);
+#endif /* __uClinux__ */
+}
+
+
+#ifdef UDHCP_SYSLOG
+
+void udhcp_logging(int level, const char *fmt, ...)
+{
+	va_list p;
+	va_list p2;
+
+	va_start(p, fmt);
+	__va_copy(p2, p);
+	if(!daemonized) {
+		vprintf(fmt, p);
+		putchar('\n');
+	}
+	vsyslog(level, fmt, p2);
+	va_end(p);
+}
+
+#else
+
+
+static char *syslog_level_msg[] = {
+	[LOG_EMERG]   = "EMERGENCY!",
+	[LOG_ALERT]   = "ALERT!",
+	[LOG_CRIT]    = "critical!",
+	[LOG_WARNING] = "warning",
+	[LOG_ERR]     = "error",
+	[LOG_INFO]    = "info",
+	[LOG_DEBUG]   = "debug"
+};
+
+
+void udhcp_logging(int level, const char *fmt, ...)
+{
+	va_list p;
+
+	va_start(p, fmt);
+	if(!daemonized) {
+		printf("%s, ", syslog_level_msg[level]);
+		vprintf(fmt, p);
+		putchar('\n');
+	}
+	va_end(p);
+}
+#endif
+
+
+void start_log_and_pid(const char *client_server, const char *pidfile)
+{
+	int pid_fd;
+
+	/* Make sure our syslog fd isn't overwritten */
+	sanitize_fds();
+
+	/* do some other misc startup stuff while we are here to save bytes */
+	pid_fd = pidfile_acquire(pidfile);
+	pidfile_write_release(pid_fd);
+
+	/* equivelent of doing a fflush after every \n */
+	setlinebuf(stdout);
+
+#ifdef UDHCP_SYSLOG
+	openlog(client_server, LOG_PID | LOG_CONS, LOG_LOCAL0);
+#endif
+
+	udhcp_logging(LOG_INFO, "%s (v%s) started", client_server, VERSION);
+}