Asynchronous DNS queries on iplist.

[apps/pfixtools.git] / common / rbl.c

diff --git a/common/rbl.c b/common/rbl.c
index 1f2f442..f0b5d55 100644 (file)
--- a/common/rbl.c
+++ b/common/rbl.c
@@ -33,27 +33,128 @@
  * Copyright © 2008 Florent Bruneau
  */
 
+#include <unbound.h>
 #include <netdb.h>
+#include "array.h"
+#include "epoll.h"
+#include "server.h"
 #include "rbl.h"
 
-static inline rbl_result_t rbl_dns_check(const char *hostname)
+
+typedef struct rbl_context_t {
+    rbl_result_t *result;
+    rbl_result_callback_t call;
+    void *data;
+} rbl_context_t;
+ARRAY(rbl_context_t);
+
+static struct ub_ctx *ctx = NULL;
+static PA(rbl_context_t) ctx_pool = ARRAY_INIT;
+
+static rbl_context_t *rbl_context_new(void)
+{
+    return p_new(rbl_context_t, 1);
+}
+
+static void rbl_context_delete(rbl_context_t **context)
+{
+    if (*context) {
+        p_delete(context);
+    }
+}
+
+static void rbl_context_wipe(rbl_context_t *context)
+{
+    p_clear(context, 1);
+}
+
+static rbl_context_t *rbl_context_acquire(void)
+{
+    if (array_len(ctx_pool) > 0) {
+        return array_pop_last(ctx_pool);
+    } else {
+        return rbl_context_new();
+    }
+}
+
+static void rbl_context_release(rbl_context_t *context)
+{
+    rbl_context_wipe(context);
+    array_add(ctx_pool, context);
+}
+
+static void rbl_exit(void)
+{
+    if (ctx != NULL) {
+        ub_ctx_delete(ctx);
+        ctx = NULL;
+    }
+    array_deep_wipe(ctx_pool, rbl_context_delete);
+}
+module_exit(rbl_exit);
+
+static void rbl_callback(void *arg, int err, struct ub_result *result)
 {
-    debug("looking up for %s", hostname);
-    struct hostent *host = gethostbyname(hostname);
-    if (host != NULL) {
-        debug("host found");
-        return RBL_FOUND;
+    rbl_context_t *context = arg;
+    if (err != 0) {
+        debug("asynchronous request led to an error");
+        *context->result = RBL_ERROR;
+    } else if (result->nxdomain) {
+        debug("asynchronous request done, %s NOT FOUND", result->qname);
+        *context->result = RBL_NOTFOUND;
+    } else {
+        debug("asynchronous request done, %s FOUND", result->qname);
+        *context->result = RBL_FOUND;
+    }
+    if (context->call != NULL) {
+        debug("calling callback");
+        context->call(context->result, context->data);
     } else {
-        if (h_errno == HOST_NOT_FOUND) {
-            debug("host not found: %s", hostname);
-            return RBL_NOTFOUND;
+        debug("no callback defined");
+    }
+    ub_resolve_free(result);
+    rbl_context_release(context);
+}
+
+static int rbl_handler(server_t *event, void *config)
+{
+    int retval = 0;
+    debug("rbl_handler called: ub_fd triggered");
+    epoll_modify(event->fd, 0, event);
+    if ((retval = ub_process(ctx)) != 0) {
+        err("error in DNS resolution: %s", ub_strerror(retval));
+    }
+    epoll_modify(event->fd, EPOLLIN, event);
+    return 0;
+}
+
+static inline bool rbl_dns_check(const char *hostname, rbl_result_t *result,
+                                 rbl_result_callback_t callback, void *data)
+{
+    if (ctx == NULL) {
+        ctx = ub_ctx_create();
+        ub_ctx_async(ctx, true);
+        if (server_register(ub_fd(ctx), rbl_handler, NULL) == NULL) {
+            crit("cannot register asynchronous DNS event handler");
+            abort();
         }
-        debug("dns error: %m");
-        return RBL_ERROR;
+    }
+    rbl_context_t *context = rbl_context_acquire();
+    context->result = result;
+    context->call   = callback;
+    context->data   = data;
+    if (ub_resolve_async(ctx, (char*)hostname, 1, 1, context, rbl_callback, NULL) == 0) {
+        *result = RBL_ASYNC;
+        return true;
+    } else {
+        *result = RBL_ERROR;
+        rbl_context_release(context);
+        return false;
     }
 }
 
-rbl_result_t rbl_check(const char *rbl, uint32_t ip)
+bool rbl_check(const char *rbl, uint32_t ip, rbl_result_t *result,
+               rbl_result_callback_t callback, void *data)
 {
     char host[257];
     int len;
@@ -65,10 +166,11 @@ rbl_result_t rbl_check(const char *rbl, uint32_t ip)
         return RBL_ERROR;
     if (host[len - 2] == '.')
         host[len - 1] = '\0';
-    return rbl_dns_check(host);
+    return rbl_dns_check(host, result, callback, data);
 }
 
-rbl_result_t rhbl_check(const char *rhbl, const char *hostname)
+bool rhbl_check(const char *rhbl, const char *hostname, rbl_result_t *result,
+                rbl_result_callback_t callback, void *data)
 {
     char host[257];
     int len;
@@ -78,5 +180,5 @@ rbl_result_t rhbl_check(const char *rhbl, const char *hostname)
         return RBL_ERROR;
     if (host[len - 2] == '.')
         host[len - 1] = '\0';
-    return rbl_dns_check(host);
+    return rbl_dns_check(host, result, callback, data);
 }