X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=sidebyside;f=sysklogd%2Fklogd.c;h=c54e80a3525ca9ad2d91259aa2a79ad71feb6897;hb=a3aa3e309506ea96fa8f7546f6b22fa85263a934;hp=cd152a57070c270c39ee5f22f72356c705571268;hpb=c418d482baf414ef3f08a95ab99da7091f358b89;p=oweals%2Fbusybox.git

diff --git a/sysklogd/klogd.c b/sysklogd/klogd.c
index cd152a570..c54e80a35 100644
--- a/sysklogd/klogd.c
+++ b/sysklogd/klogd.c
@@ -17,114 +17,119 @@
  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <signal.h>		/* for our signal() handlers */
-#include <string.h>		/* strncpy() */
-#include <errno.h>		/* errno and friends */
-#include <unistd.h>
-#include <ctype.h>
-#include <sys/syslog.h>
+#include "libbb.h"
+#include <syslog.h>
 #include <sys/klog.h>
 
-#include "busybox.h"
-
 static void klogd_signal(int sig)
 {
-	klogctl(7, NULL, 0);
-	klogctl(0, 0, 0);
-	/* logMessage(0, "Kernel log daemon exiting."); */
-	syslog(LOG_NOTICE, "Kernel log daemon exiting.");
-	exit(EXIT_SUCCESS);
+	/* FYI: cmd 7 is equivalent to setting console_loglevel to 7
+	 * via klogctl(8, NULL, 7). */
+	klogctl(7, NULL, 0); /* "7 -- Enable printk's to console" */
+	klogctl(0, NULL, 0); /* "0 -- Close the log. Currently a NOP" */
+	syslog(LOG_NOTICE, "klogd: exiting");
+	kill_myself_with_sig(sig);
 }
 
-static void doKlogd(const int console_log_level) ATTRIBUTE_NORETURN;
-static void doKlogd(const int console_log_level)
+#define log_buffer bb_common_bufsiz1
+enum {
+	KLOGD_LOGBUF_SIZE = sizeof(log_buffer),
+	OPT_LEVEL      = (1 << 0),
+	OPT_FOREGROUND = (1 << 1),
+};
+
+int klogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int klogd_main(int argc UNUSED_PARAM, char **argv)
 {
-	int priority = LOG_INFO;
-	char log_buffer[4096];
-	int i, n, lastc;
-	char *start;
+	int i = 0;
+	char *opt_c;
+	int opt;
+	int used = 0;
+
+	opt = getopt32(argv, "c:n", &opt_c);
+	if (opt & OPT_LEVEL) {
+		/* Valid levels are between 1 and 8 */
+		i = xatou_range(opt_c, 1, 8);
+	}
+	if (!(opt & OPT_FOREGROUND)) {
+		bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
+	}
 
 	openlog("kernel", 0, LOG_KERN);
 
-	/* Set up sig handlers */
-	signal(SIGINT, klogd_signal);
-	signal(SIGKILL, klogd_signal);
-	signal(SIGTERM, klogd_signal);
+	bb_signals(BB_FATAL_SIGS, klogd_signal);
 	signal(SIGHUP, SIG_IGN);
 
-	/* "Open the log. Currently a NOP." */
+	/* "Open the log. Currently a NOP" */
 	klogctl(1, NULL, 0);
 
-	/* Set level of kernel console messaging.. */
-	if (console_log_level != -1)
-		klogctl(8, NULL, console_log_level);
+	/* "printk() prints a message on the console only if it has a loglevel
+	 * less than console_loglevel". Here we set console_loglevel = i. */
+	if (i)
+		klogctl(8, NULL, i);
 
-	syslog(LOG_NOTICE, "klogd started: %s", BB_BANNER);
+	syslog(LOG_NOTICE, "klogd started: %s", bb_banner);
 
 	while (1) {
-		/* Use kernel syscalls */
-		memset(log_buffer, '\0', sizeof(log_buffer));
-		n = klogctl(2, log_buffer, sizeof(log_buffer));
+		int n;
+		int priority;
+		char *start;
+
+		/* "2 -- Read from the log." */
+		start = log_buffer + used;
+		n = klogctl(2, start, KLOGD_LOGBUF_SIZE-1 - used);
 		if (n < 0) {
 			if (errno == EINTR)
 				continue;
-			syslog(LOG_ERR, "klogd: Error return from sys_sycall: %d - %m.\n", errno);
-			exit(EXIT_FAILURE);
+			syslog(LOG_ERR, "klogd: error %d in klogctl(2): %m",
+					errno);
+			break;
 		}
+		start[n] = '\0';
 
 		/* klogctl buffer parsing modelled after code in dmesg.c */
-		start = &log_buffer[0];
-		lastc = '\0';
-		for (i = 0; i < n; i++) {
-			if (lastc == '\0' && log_buffer[i] == '<') {
-				priority = 0;
-				i++;
-				while (isdigit(log_buffer[i])) {
-					priority = priority * 10 + (log_buffer[i] - '0');
-					i++;
+		/* Process each newline-terminated line in the buffer */
+		start = log_buffer;
+		while (1) {
+			char *newline = strchrnul(start, '\n');
+
+			if (*newline == '\0') {
+				/* This line is incomplete... */
+				if (start != log_buffer) {
+					/* move it to the front of the buffer */
+					overlapping_strcpy(log_buffer, start);
+					used = newline - start;
+					/* don't log it yet */
+					break;
 				}
-				if (log_buffer[i] == '>')
-					i++;
-				start = &log_buffer[i];
-			}
-			if (log_buffer[i] == '\n') {
-				log_buffer[i] = '\0';	/* zero terminate this message */
-				syslog(priority, "%s", start);
-				start = &log_buffer[i + 1];
-				priority = LOG_INFO;
+				/* ...but if buffer is full, log it anyway */
+				used = 0;
+				newline = NULL;
+			} else {
+				*newline++ = '\0';
 			}
-			lastc = log_buffer[i];
-		}
-	}
-}
-
-#define OPT_LEVEL        1
-#define OPT_FOREGROUND   2
-
-int klogd_main(int argc, char **argv)
-{
-	unsigned long opt;
-	char *c_arg;
-	int console_log_level = -1;
 
-	/* do normal option parsing */
-	opt = bb_getopt_ulflags (argc, argv, "c:n", &c_arg);
-
-	if (opt & OPT_LEVEL) {
-		/* Valid levels are between 1 and 8 */
-		console_log_level = bb_xgetlarg(c_arg, 10, 1, 8);
-	}
+			/* Extract the priority */
+			priority = LOG_INFO;
+			if (*start == '<') {
+				start++;
+				if (*start) {
+					/* kernel never generates multi-digit prios */
+					priority = (*start - '0');
+					start++;
+				}
+				if (*start == '>')
+					start++;
+			}
+			/* Log (only non-empty lines) */
+			if (*start)
+				syslog(priority, "%s", start);
 
-	if (!(opt & OPT_FOREGROUND)) {
-#ifdef BB_NOMMU
-		vfork_daemon_rexec(0, 1, argc, argv, "-n");
-#else
-		bb_xdaemon(0, 1);
-#endif
+			if (!newline)
+				break;
+			start = newline;
+		}
 	}
-	doKlogd(console_log_level);
 
-	return EXIT_SUCCESS;
+	return EXIT_FAILURE;
 }