Make evdns use the regular logging system by default

Once, for reasons that made sense at the time, we had evdns.c use its
own logging subsystem with two levels, "warn" and "debug".  This leads
to problems, since setting a log handler for Libevent wouldn't actually
trap these messages, since they weren't on by default, and since some of
the warns should really be msgs.

This patch changes the default behavior of evdns.c to log to
event_(debugx,warnx,msgx) by default, and adds a new (internal-use-only)
log level of EVDNS_LOG_MSG.  Programs that set a evdns logging
function will see no change.  Programs that don't will now see evdns
warnings reported like other warnings.

diff --git a/evdns.c b/evdns.c
index 3219aa5b2e02274dec2dc9ae94a145d79e3c2e36..e9cbec76e978ac03bac69d2104423afce64cb62a 100644 (file)
--- a/evdns.c
+++ b/evdns.c
@@ -105,6 +105,7 @@
 
 #define EVDNS_LOG_DEBUG 0
 #define EVDNS_LOG_WARN 1
+#define EVDNS_LOG_MSG 2
 
 #ifndef HOST_NAME_MAX
 #define HOST_NAME_MAX 255
@@ -435,12 +436,23 @@ debug_ntop(const struct sockaddr *sa)
        return "<unknown>";
 }
 
+static void
+default_evdns_log_fn(int warning, const char *buf)
+{
+       if (warning == EVDNS_LOG_WARN)
+               event_warnx("[evdns] %s", buf);
+       else if (warning == EVDNS_LOG_MSG)
+               event_msgx("[evdns] %s", buf);
+       else
+               event_debug(("[evdns] %s", buf));
+}
+
 static evdns_debug_log_fn_type evdns_log_fn = NULL;
 
 void
 evdns_set_log_fn(evdns_debug_log_fn_type fn)
 {
-  evdns_log_fn = fn;
+       evdns_log_fn = fn;
 }
 
 #ifdef __GNUC__
@@ -459,8 +471,15 @@ _evdns_log(int warn, const char *fmt, ...)
                return;
        va_start(args,fmt);
        evutil_vsnprintf(buf, sizeof(buf), fmt, args);
-       evdns_log_fn(warn, buf);
        va_end(args);
+       if (evdns_log_fn) {
+               if (warn == EVDNS_LOG_MSG)
+                       warn = EVDNS_LOG_WARN;
+               evdns_log_fn(warn, buf);
+       } else {
+               default_evdns_log_fn(warn, buf);
+       }
+
 }
 
 #define log _evdns_log
@@ -555,12 +574,12 @@ nameserver_failed(struct nameserver *const ns, const char *msg) {
        /* then don't do anything */
        if (!ns->state) return;
 
-       log(EVDNS_LOG_WARN, "Nameserver %s has failed: %s",
+       log(EVDNS_LOG_MSG, "Nameserver %s has failed: %s",
                debug_ntop((struct sockaddr*)&ns->address), msg);
        base->global_good_nameservers--;
        EVUTIL_ASSERT(base->global_good_nameservers >= 0);
        if (base->global_good_nameservers == 0) {
-               log(EVDNS_LOG_WARN, "All nameservers have failed");
+               log(EVDNS_LOG_MSG, "All nameservers have failed");
        }
 
        ns->state = 0;
@@ -602,7 +621,7 @@ nameserver_up(struct nameserver *const ns)
 {
        ASSERT_LOCKED(ns->base);
        if (ns->state) return;
-       log(EVDNS_LOG_WARN, "Nameserver %s is back up",
+       log(EVDNS_LOG_MSG, "Nameserver %s is back up",
            debug_ntop((struct sockaddr *)&ns->address));
        evtimer_del(&ns->timeout_event);
        if (ns->probe_request) {
@@ -1288,8 +1307,9 @@ server_port_read(struct evdns_server_port *s) {
                        int err = evutil_socket_geterror(s->socket);
                        if (EVUTIL_ERR_RW_RETRIABLE(err))
                                return;
-                       log(EVDNS_LOG_WARN, "Error %s (%d) while reading request.",
-                               evutil_socket_error_to_string(err), err);
+                       log(EVDNS_LOG_WARN,
+                           "Error %s (%d) while reading request.",
+                           evutil_socket_error_to_string(err), err);
                        return;
                }
                request_parse(packet, r, s, (struct sockaddr*) &addr, addrlen);

diff --git a/include/event2/dns.h b/include/event2/dns.h
index be0ec56350352371ca5195c632f8ef31dd9aa3dd..a954066f130472682ff6fe5bda48e4fe6b91127c 100644 (file)
--- a/include/event2/dns.h
+++ b/include/event2/dns.h
@@ -476,7 +476,9 @@ typedef void (*evdns_debug_log_fn_type)(int is_warning, const char *msg);
 
 
 /**
-  Set the callback function to handle log messages.
+  Set the callback function to handle DNS log messages.  If this
+  callback is not set, evdns log messages are handled with the regular
+  Libevent logging system.
 
   @param fn the callback to be invoked when a log message is generated
  */