conf, log: Instead of abusing log levels, add log_conf_parsed flag

We currently use a LOG_EMERG log mask to represent the fact that we
don't know yet what the mask resulting from configuration should be,
before the command line is parsed.

However, we have the necessity of representing another phase as well,
that is, configuration is parsed but we didn't daemonise yet, or
we're not ready for operation yet. The next patch will add that
notion explicitly.

Mapping these cases to further log levels isn't really practical.
Introduce boolean log flags to represent them, instead of abusing
log priorities.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

conf.c

@@ -1626,9 +1626,6 @@ void conf(struct ctx *c, int argc, char **argv)
 			     logfile, logsize);
 	}
 
-	/* Once the log mask is not LOG_EARLY, we will no longer log to stderr
-	 * if there was a log file specified.
-	 */
 	if (c->debug)
 		__setlogmask(LOG_UPTO(LOG_DEBUG));
 	else if (c->quiet)
@@ -1636,6 +1633,8 @@ void conf(struct ctx *c, int argc, char **argv)
 	else
 		__setlogmask(LOG_UPTO(LOG_INFO));
 
+	log_conf_parsed = true;		/* Stop printing everything */
+
 	nl_sock_init(c, false);
 	if (!v6_only)
 		c->ifi4 = conf_ip4(ifi4, &c->ip4, c->mac);

log.c

@@ -30,12 +30,9 @@
 #include "util.h"
 #include "passt.h"
 
-/* LOG_EARLY means we don't know yet: log everything. LOG_EMERG is unused */
-#define LOG_EARLY		LOG_MASK(LOG_EMERG)
-
 static int	log_sock = -1;		/* Optional socket to system logger */
 static char	log_ident[BUFSIZ];	/* Identifier string for openlog() */
-static int	log_mask = LOG_EARLY;	/* Current log priority mask */
+static int	log_mask;		/* Current log priority mask */
 static int	log_opt;		/* Options for openlog() */
 
 static int	log_file = -1;		/* Optional log file descriptor */
@@ -45,12 +42,13 @@ static size_t	log_cut_size;		/* Bytes to cut at start on rotation */
 static char	log_header[BUFSIZ];	/* File header, written back on cuts */
 
 static time_t	log_start;		/* Start timestamp */
+
 int		log_trace;		/* --trace mode enabled */
+bool		log_conf_parsed;	/* Logging options already parsed */
 
 void vlogmsg(int pri, const char *format, va_list ap)
 {
 	bool debug_print = (log_mask & LOG_MASK(LOG_DEBUG)) && log_file == -1;
-	bool early_print = LOG_PRI(log_mask) == LOG_EARLY;
 	struct timespec tp;
 
 	if (debug_print) {
@@ -60,7 +58,7 @@ void vlogmsg(int pri, const char *format, va_list ap)
 			(long long int)tp.tv_nsec / (100L * 1000));
 	}
 
-	if ((log_mask & LOG_MASK(LOG_PRI(pri))) || early_print) {
+	if ((log_mask & LOG_MASK(LOG_PRI(pri))) || !log_conf_parsed) {
 		va_list ap2;
 
 		va_copy(ap2, ap); /* Don't clobber ap, we need it again */
@@ -72,7 +70,7 @@ void vlogmsg(int pri, const char *format, va_list ap)
 		va_end(ap2);
 	}
 
-	if (debug_print || (early_print && !(log_opt & LOG_PERROR))) {
+	if (debug_print || (!log_conf_parsed && !(log_opt & LOG_PERROR))) {
 		(void)vfprintf(stderr, format, ap);
 		if (format[strlen(format)] != '\n')
 			fprintf(stderr, "\n");

log.h

@@ -6,6 +6,7 @@
 #ifndef LOG_H
 #define LOG_H
 
+#include <stdbool.h>
 #include <syslog.h>
 
 #define LOGFILE_SIZE_DEFAULT		(1024 * 1024UL)
@@ -28,6 +29,8 @@ void logmsg(int pri, const char *format, ...)
 	} while (0)
 
 extern int log_trace;
+extern bool log_conf_parsed;
+
 void trace_init(int enable);
 #define trace(...)							\
 	do {								\