Added basic syslog support (everything is LOG_INFO) and console detaching.

base.c

@@ -7,6 +7,7 @@
 #include <string.h>
 #include <pwd.h>
 #include <grp.h>
+#include <stdlib.h>
 #include "config.h"
 #if defined USE_IPTABLES
 # include <limits.h>
@@ -33,6 +34,8 @@ typedef struct base_instance_t {
 	char *group;
 	char *redirector_name;
 	redirector_subsys *redirector;
+	char *log_name;
+	bool daemon;
 } base_instance;
 
 static base_instance instance = {
@@ -212,6 +215,8 @@ static parser_entry base_entries[] =
 	{ .key = "user",       .type = pt_pchar,   .addr = &instance.user },
 	{ .key = "group",      .type = pt_pchar,   .addr = &instance.group },
 	{ .key = "redirector", .type = pt_pchar,   .addr = &instance.redirector_name },
+	{ .key = "log",        .type = pt_pchar,   .addr = &instance.log_name },
+	{ .key = "daemon",     .type = pt_bool,    .addr = &instance.daemon },
 	{ }
 };
 
@@ -269,6 +274,7 @@ static int base_init()
 {
 	uid_t uid;
 	gid_t gid;
+	int devnull = -1;
 
 	if (!instance.configured) {
 		log_error("there is no configured instance of `base`, check config file");
@@ -296,6 +302,20 @@ static int base_init()
 		gid = gr->gr_gid;
 	}
 
+	if (log_preopen(
+			instance.log_name ? instance.log_name : instance.daemon ? "syslog:daemon" : "stderr"
+	) < 0 ) {
+		goto fail;
+	}
+
+	if (instance.daemon) {
+		devnull = open("/dev/null", O_RDWR);
+		if (devnull == -1) {
+			log_errno("open(\"/dev/null\", O_RDWR");
+			goto fail;
+		}
+	}
+
 	if (instance.chroot) {
 		if (chroot(instance.chroot) < 0) {
 			log_errno("chroot(%s)", instance.chroot);
@@ -303,6 +323,13 @@ static int base_init()
 		}
 	}
 
+	if (instance.daemon || instance.chroot) {
+		if (chdir("/") < 0) {
+			log_errno("chdir(\"/\")");
+			goto fail;
+		}
+	}
+
 	if (instance.group) {
 		if (setgid(gid) < 0) {
 			log_errno("setgid(%i)", gid);
@@ -317,14 +344,41 @@ static int base_init()
 		}
 	}
 
-#if 0
-	if (daemon(0, 0) < 0) {
-		log_errno("daemon()");
+	if (instance.daemon) {
+		switch (fork()) {
+		case -1: // error
+			log_errno("fork()");
+			goto fail;
+		case 0:  // child
+			break;
+		default: // parent, pid is returned
+			exit(EXIT_SUCCESS);
+		}
+	}
+
+	log_open(); // child has nothing to do with TTY
+
+	if (instance.daemon) {
+		if (setsid() < 0) {
+			log_errno("setsid()");
 			goto fail;
 		}
-#endif
+
+		int fds[] = { STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO };
+		int *pfd;
+		FOREACH(pfd, fds)
+			if (dup2(devnull, *pfd) < 0) {
+				log_errno("dup2(devnull, %i)", *pfd);
+				goto fail;
+			}
+
+		close(devnull);
+		devnull = -1;
+	}
 	return 0;
 fail:
+	if (devnull != -1)
+		close(devnull);
 	if (instance.redirector->fini)
 		instance.redirector->fini();
 	return -1;

log.c

@@ -6,10 +6,83 @@
 #include <sys/time.h>
 #include <sys/types.h>
 #include <event.h>
+#include "utils.h"
 #include "log.h"
 
 static const char *lowmem = "<Can't print error, not enough memory>";
 
+typedef void (*log_func)(const char *file, int line, const char *func, const char *message, const char *appendix);
+
+static void stderr_msg(const char *file, int line, const char *func, const char *message, const char *appendix)
+{
+	struct timeval tv = { };
+	gettimeofday(&tv, 0);
+
+	if (appendix)
+		fprintf(stderr, "%lu.%6.6lu %s:%u %s(...) %s: %s\n", tv.tv_sec, tv.tv_usec, file, line, func, message, appendix);
+	else
+		fprintf(stderr, "%lu.%6.6lu %s:%u %s(...) %s\n", tv.tv_sec, tv.tv_usec, file, line, func, message);
+}
+
+static void syslog_msg(const char *file, int line, const char *func, const char *message, const char *appendix)
+{
+	if (appendix)
+		syslog(LOG_INFO, "%s: %s\n", message, appendix);
+	else
+		syslog(LOG_INFO, "%s\n", message);
+}
+
+static log_func log_msg = stderr_msg;
+static log_func log_msg_next = NULL;
+
+int log_preopen(const char *dst)
+{
+	const char *syslog_prefix = "syslog:";
+	if (strcmp(dst, "stderr") == 0) {
+		log_msg_next = stderr_msg;
+	}
+	else if (strncmp(dst, syslog_prefix, strlen(syslog_prefix)) == 0) {
+		const char *facility_name = dst + strlen(syslog_prefix);
+		int facility = -1;
+		struct {
+			char *name; int value;
+		} *ptpl, tpl[] = {
+			{ "daemon", LOG_DAEMON },
+			{ "local0", LOG_LOCAL0 },
+			{ "local1", LOG_LOCAL1 },
+			{ "local2", LOG_LOCAL2 },
+			{ "local3", LOG_LOCAL3 },
+			{ "local4", LOG_LOCAL4 },
+			{ "local5", LOG_LOCAL5 },
+			{ "local6", LOG_LOCAL6 },
+			{ "local7", LOG_LOCAL7 },
+		};
+		FOREACH(ptpl, tpl) 
+			if (strcmp(facility_name, ptpl->name) == 0) {
+				facility = ptpl->value;
+				break;
+			}
+		if (facility == -1) {
+			log_error("log_preopen(%s, ...): unknown syslog facility");
+			return -1;
+		}
+
+		openlog("redsocks", LOG_NDELAY | LOG_PID, facility);
+		log_msg_next = syslog_msg;
+	}
+	else {
+		log_error("log_preopen(%s, ...): unknown destination", dst);
+		return -1;
+	}
+	return 0;
+}
+
+void log_open()
+{
+	log_msg = log_msg_next;
+	log_msg_next = NULL;
+}
+
 void _log_vwrite(const char *file, int line, const char *func, int do_errno, const char *fmt, va_list ap)
 {
 	int saved_errno = errno;
@@ -23,13 +96,7 @@ void _log_vwrite(const char *file, int line, const char *func, int do_errno, con
 	else 
 		message = lowmem;
 
-	struct timeval tv = { };
-	gettimeofday(&tv, 0);
-
-	if (do_errno)
-		fprintf(stderr, "%lu.%6.6lu %s:%u %s(...) %s: %s\n", tv.tv_sec, tv.tv_usec, file, line, func, message, strerror(saved_errno));
-	else
-		fprintf(stderr, "%lu.%6.6lu %s:%u %s(...) %s\n", tv.tv_sec, tv.tv_usec, file, line, func, message);
+	log_msg(file, line, func, message, do_errno ? strerror(saved_errno) : NULL);
 
 	if (buff)
 		evbuffer_free(buff);

log.h

@@ -2,10 +2,15 @@
 #define LOG_H_WED_JAN_24_18_21_27_2007
 /* $Id$ */
 #include <stdarg.h>
+#include <stdbool.h>
+#include <syslog.h>
 
 #define log_errno(msg...) _log_write(__FILE__, __LINE__, __func__, 1, ## msg)
 #define log_error(msg...) _log_write(__FILE__, __LINE__, __func__, 0, ## msg)
 
+int log_preopen(const char *dst);
+void log_open();
+
 void _log_vwrite(const char *file, int line, const char *func, int do_errno, const char *fmt, va_list ap);
 void _log_write(const char *file, int line, const char *func, int do_errno, const char *fmt, ...);