syslogd/sysklogd-1.4.1-ksyslogsize.diff

---
 klogd.c |   52 +++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 5 deletions(-)

--- klogd.c
+++ klogd.c	2022-10-14 13:17:38.386601331 +0000
@@ -309,8 +309,10 @@ static int	use_syscall = 0,
 		no_fork = 0;	/* don't fork - don't run in daemon mode */
 
 static char	*symfile = (char *) 0,
-		log_buffer[LOG_BUFFER_SIZE];
+		*log_buffer = (char *) 0;
 
+static int	log_buf_size = 0;
+ 
 static FILE *output_file = (FILE *) 0;
 
 static enum LOGSRC {none, proc, kernel} logsrc;
@@ -932,8 +934,8 @@ static void LogKernelLine(void)
 	 * which will contain old messages.  Then read the kernel log
 	 * messages into this fresh buffer.
 	 */
-	memset(log_buffer, '\0', sizeof(log_buffer));
-	if ( (rdcnt = ksyslog(2, log_buffer, sizeof(log_buffer)-1)) < 0 )
+	memset(log_buffer, '\0', log_buf_size);
+	if ( (rdcnt = ksyslog(2, log_buffer, log_buf_size-1)) < 0 )
 	{
 		if ( errno == EINTR )
 			return;
@@ -957,8 +959,8 @@ static void LogProcLine(void)
 	 * which will contain old messages.  Then read the kernel messages
 	 * from the message pseudo-file into this fresh buffer.
 	 */
-	memset(log_buffer, '\0', sizeof(log_buffer));
-	if ( (rdcnt = read(kmsg, log_buffer, sizeof(log_buffer)-1)) < 0 )
+	memset(log_buffer, '\0', log_buf_size);
+	if ( (rdcnt = read(kmsg, log_buffer, log_buf_size-1)) < 0 )
 	{
 		if ( errno == EINTR )
 			return;
@@ -971,6 +973,44 @@ static void LogProcLine(void)
 	return;
 }
 
+static void SetBufSize(void)
+
+{
+	auto int n, sz;
+
+	n = ksyslog(10, NULL, 0);       /* read ringbuffer size */
+	if (n > 0) {
+		log_buf_size = n;
+		log_buffer = (char *) malloc(log_buf_size);
+		if (!log_buffer) {
+			perror("ksyslog");
+			exit(1);
+		}
+	}
+
+	if (!log_buf_size) {
+		sz = LOG_BUFFER_SIZE;
+		while (1) {
+			log_buffer = (char *) malloc(sz+8);
+			if (!log_buffer) {
+				perror("ksyslog");
+				exit(1);
+			}
+			n = ksyslog(3, log_buffer, sz+8);
+			if (n < sz+8 || sz >= (1<<22))
+				break;
+			free(log_buffer);
+			sz <<= 1;
+		}
+		log_buf_size = sz;
+	}
+
+ 	if (n < 0) {
+ 		perror("ksyslog");
+ 		exit(1);
+	}
+}
+
 
 int main(argc, argv)
 
@@ -1049,6 +1089,8 @@ int main(argc, argv)
 		console_log_level = *log_level - '0';
 	}		
 
+	/* get/probe for the kernel ring buffer size */
+	SetBufSize();
 
 #ifndef TESTING
 	/*