Finer grained logging levels:

#define L_DEBUG "\001"   /* Debugging messages */
#define L_INFO "\002"    /* Informational messages */
#define L_WARN "\003"    /* Warnings */
#define L_ERR "\004"     /* Errors */
#define L_AUTH "\005"    /* Authorization failed etc. */
#define L_FATAL "\006"   /* Fatal errors */
#define L_TRACE "\002"   /* Protocol tracing */
#define L_INFO "\003"    /* Informational messages */
#define L_REMOTE "\004"  /* Remote protocol errors */
#define L_WARN "\004"    /* Local warnings */
#define L_ERR "\005"     /* Local errors */
#define L_AUTH "\006"    /* Authorization failed etc. */
#define L_FATAL "\007"   /* Fatal errors */
#define L_BUG "\010"     /* BIRD bugs */

Introduced bug() which is like die(), but with level L_BUG. Protocols
should _never_ call die() as it should be used only during initialization
and on irrecoverable catastrophic events like out of memory.

Also introduced ASSERT() which behaves like normal assert(), but it calls
bug() when assertion fails. When !defined(DEBUGGING), it gets ignored.

TODO

@@ -1,12 +1,12 @@
 Core
 ~~~~
 * right usage of DBG vs. debug
-* cleanup debugging calls!
+* cleanup debugging calls
+* logging and tracing; use appropriate log levels
+* check log calls for trailing newlines
 
 - TOS not supported by kernel -> automatically drop routes with TOS<>0
 
-- use -freg-struct-return ?
-
 - fake multipath?
 - replace all NUM's by expr's
 - config file: define ipaddr constants?
@@ -25,6 +25,8 @@ Core
 - static: check validity of route destination?
 - static: device routes
 
+- device: configuration of interface patterns
+
 - filter: logging of dropped routes (?)
 - limitation of memory consumption: per-process and total (?)
 - adding of route: check whether all bits not covered by masklen are zero

lib/birdlib.h

@@ -27,13 +27,17 @@
 
 void log(char *msg, ...);
 void die(char *msg, ...) NORET;
+void bug(char *msg, ...) NORET;
 
 #define L_DEBUG "\001"			/* Debugging messages */
-#define L_INFO "\002"			/* Informational messages */
+#define L_TRACE "\002"			/* Protocol tracing */
-#define L_WARN "\003"			/* Warnings */
+#define L_INFO "\003"			/* Informational messages */
-#define L_ERR "\004"			/* Errors */
+#define L_REMOTE "\004"			/* Remote protocol errors */
-#define L_AUTH "\005"			/* Authorization failed etc. */
+#define L_WARN "\004"			/* Local warnings */
-#define L_FATAL "\006"			/* Fatal errors */
+#define L_ERR "\005"			/* Local errors */
+#define L_AUTH "\006"			/* Authorization failed etc. */
+#define L_FATAL "\007"			/* Fatal errors */
+#define L_BUG "\010"			/* BIRD bugs */
 
 void log_init(char *);			/* Initialize logging to given file (NULL=stderr, ""=syslog) */
 void log_init_debug(char *);		/* Initialize debug dump to given file (NULL=stderr, ""=off) */
@@ -48,4 +52,10 @@ void debug(char *msg, ...);		/* Printf to debug output */
 #define DBG(x, y...)
 #endif
 
+#ifdef DEBUGGING
+#define ASSERT(x) do { if (!(x)) bug("Assertion `%s' failed at %s:%d", #x, __FILE__, __LINE__); } while(0)
+#else
+#define ASSERT(x) do { } while(0)
+#endif
+
 #endif

sysdep/unix/log.c

@@ -107,19 +107,29 @@ log(char *msg, ...)
   va_list args;
 
   va_start(args, msg);
-  if (*msg >= 1 && *msg <= 6)
+  if (*msg >= 1 && *msg <= 8)
     class = *msg++;
   vlog(class, msg, args);
   va_end(args);
 }
 
+void
+bug(char *msg, ...)
+{
+  va_list args;
+
+  va_start(args, msg);
+  vlog(L_BUG[0], msg, args);
+  exit(1);
+}
+
 void
 die(char *msg, ...)
 {
   va_list args;
 
   va_start(args, msg);
-  vlog(6, msg, args);
+  vlog(L_FATAL[0], msg, args);
   exit(1);
 }