[master] add JSON statistics channel

3524.	[func]		Added an alternate statistics channel in JSON format,
			when the server is built with the json-c library:
			http://[address]:[port]/json.  [RT #32630]

CHANGES

+3524.	[func]		Added an alternate statistics channel in JSON format,
+			when the server is built with the json-c library:
+			http://[address]:[port]/json.  [RT #32630]
+
 3523.	[contrib]	Ported filesystem and ldap DLZ drivers to
 			dynamically-loadable modules, and added the
 			"wildcard" module based on a contribution from

README

@@ -230,6 +230,12 @@ Building
 	a nonstandard prefix, you can tell configure where to
 	look for it using "--with-openssl=/prefix".
 
+        To support the HTTP statistics channel, the server must
+        be linked with at least one of the following: libxml2
+        (http://xmlsoft.org) or json-c (https://github.com/json-c).
+        If these are installed at a nonstandard prefix, use
+        "--with-libxml2=/prefix" or "--with-libjson=/prefix".
+
 	On some platforms it is necessary to explictly request large
 	file support to handle files bigger than 2GB.  This can be
 	done by "--enable-largefile" on the configure command line.

config.h.in

@@ -239,6 +239,9 @@ int sigwait(const unsigned int *set, int *sig);
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 
+/* Define if libjson was found */
+#undef HAVE_JSON
+
 /* Define to 1 if you have the <kerberosv5/krb5.h> header file. */
 #undef HAVE_KERBEROSV5_KRB5_H
 

configure

@@ -1467,6 +1467,7 @@ with_gssapi
 with_randomdev
 enable_threads
 with_libxml2
+with_libjson
 enable_largefile
 with_purify
 with_libtool
@@ -2177,6 +2178,7 @@ Optional Packages:
   --with-gssapi=PATH      Specify path for system-supplied GSSAPI [default=yes]
   --with-randomdev=PATH   Specify path for random device
   --with-libxml2=PATH     Build with libxml2 library yes|no|path
+  --with-libjson=PATH     Build with libjson0 library yes|no|path
   --with-purify=PATH      use Rational purify
   --with-libtool          use GNU libtool
   --with-export-libdir=PATH
@@ -16011,6 +16013,59 @@ else
 $as_echo "no" >&6; }
 fi
 
+#
+# was --with-libjson specified?
+#
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for json library" >&5
+$as_echo_n "checking for json library... " >&6; }
+
+# Check whether --with-libjson was given.
+if test "${with_libjson+set}" = set; then :
+  withval=$with_libjson; use_libjson="$withval"
+else
+  use_libjson="auto"
+fi
+
+
+case "$use_libjson" in
+	no)
+		libjson_libs=""
+		;;
+	auto|yes)
+		if test -f "/usr/include/json/json.h"
+                then
+			libjson_libs="-ljson"
+			libjson_cflags="-I /usr/include/json"
+                else
+			libjson_libs=""
+                fi
+		;;
+	*)
+		if test -f "${use_libjson}/include/json/json.h"
+                then
+			libjson_libs="-L${use_libjson}/lib -ljson"
+			libjson_cflags="-I${use_libjson}/include/json"
+                else
+			as_fn_error $? "$use_libjson/include/json.h not found." "$LINENO" 5
+		fi
+		;;
+esac
+HERE
+
+if test "X${libjson_libs}" != "X"
+then
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+	CFLAGS="$CFLAGS $libjson_cflags"
+	LIBS="$LIBS $libjson_libs"
+
+$as_echo "#define HAVE_JSON 1" >>confdefs.h
+
+else
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
 #
 # In solaris 10, SMF can manage named service
 #

configure.in

@@ -1483,6 +1483,49 @@ else
 	AC_MSG_RESULT(no)
 fi
 
+#
+# was --with-libjson specified?
+#
+AC_MSG_CHECKING(for json library)
+AC_ARG_WITH(libjson,
+[  --with-libjson[=PATH]     Build with libjson0 library [yes|no|path]],
+    use_libjson="$withval", use_libjson="auto")
+
+case "$use_libjson" in
+	no)
+		libjson_libs=""
+		;;
+	auto|yes)
+		if test -f "/usr/include/json/json.h"
+                then
+			libjson_libs="-ljson"
+			libjson_cflags="-I /usr/include/json"
+                else
+			libjson_libs=""
+                fi
+		;;
+	*)
+		if test -f "${use_libjson}/include/json/json.h"
+                then
+			libjson_libs="-L${use_libjson}/lib -ljson"
+			libjson_cflags="-I${use_libjson}/include/json"
+                else
+			AC_MSG_ERROR([$use_libjson/include/json.h not found.])
+		fi
+		;;
+esac
+HERE
+
+if test "X${libjson_libs}" != "X"
+then
+	AC_MSG_RESULT(yes)
+	CFLAGS="$CFLAGS $libjson_cflags"
+	LIBS="$LIBS $libjson_libs"
+	AC_DEFINE(HAVE_JSON, 1, [Define if libjson was found])
+else
+	AC_MSG_RESULT(no)
+fi
+
 #
 # In solaris 10, SMF can manage named service
 #

doc/arm/Bv9ARM-book.xml

@@ -10504,8 +10504,9 @@ ns.domain.com.rpz-nsdname   CNAME   .
 	  This statement intends to be flexible to support multiple
 	  communication protocols in the future, but currently only
 	  HTTP access is supported.
-	  It requires that BIND 9 be compiled with libxml2;
-	  the <command>statistics-channels</command> statement is
+          It requires that BIND 9 be compiled with libxml2 and/or
+          json-c (also known as libjson0); the
+          <command>statistics-channels</command> statement is
 	  still accepted even if it is built without the library,
 	  but any HTTP access will fail with an error.
         </para>
@@ -10514,7 +10515,8 @@ ns.domain.com.rpz-nsdname   CNAME   .
           An <command>inet</command> control channel is a TCP socket
 	  listening at the specified <command>ip_port</command> on the
 	  specified <command>ip_addr</command>, which can be an IPv4 or IPv6
-	  address.  An <command>ip_addr</command> of <literal>*</literal> (asterisk) is
+          address.  An <command>ip_addr</command> of <literal>*</literal>
+          (asterisk) is
 	  interpreted as the IPv4 wildcard address; connections will be
 	  accepted on any of the system's IPv4 addresses.
 	  To listen on the IPv6 wildcard address,
@@ -10545,6 +10547,41 @@ ns.domain.com.rpz-nsdname   CNAME   .
           <command>named</command> will not open any communication channels.
         </para>
 
+        <para>
+          The statistics are available in various formats and views
+          depending on the URI used to access them.  For example, if
+          the statistics channel is configured to listen on 127.0.0.1
+          port 8888, then the statistics are accessible in XML format at
+          <ulink url="http://127.0.0.1:8888/"
+                  >http://127.0.0.1:8888/</ulink> or
+          <ulink url="http://127.0.0.1:8888/xml"
+                  >http://127.0.0.1:8888/xml</ulink>. A CSS file is
+          included which can format the XML statistics into tables 
+          when viewed with a stylesheet-capable browser, and into 
+          charts and graphs when using a javascript-capable browser.
+        </para>
+
+        <para>
+          The full set of statistics can also be read in JSON format at
+          <ulink url="http://127.0.0.1:8888/json"
+                  >http://127.0.0.1:8888/json</ulink>.
+          Broken-out subsets of the statistics can be viewed at
+          <ulink url="http://127.0.0.1:8888/json/server"
+                  >http://127.0.0.1:8888/json/server</ulink>
+          (server and resolver statistics),
+          <ulink url="http://127.0.0.1:8888/json/zones"
+                  >http://127.0.0.1:8888/json/zones</ulink>
+          (zone statistics),
+          <ulink url="http://127.0.0.1:8888/json/net"
+                  >http://127.0.0.1:8888/json/net</ulink>
+          (network status and socket statistics),
+          <ulink url="http://127.0.0.1:8888/json/mem"
+                  >http://127.0.0.1:8888/json/mem</ulink>
+          (memory manager statistics),
+          <ulink url="http://127.0.0.1:8888/json/tasks"
+                  >http://127.0.0.1:8888/json/tasks</ulink>
+          (task manager statistics).
+        </para>
       </sect2>
 
 	<sect2 id="trusted-keys">

lib/dns/cache.c

@@ -21,6 +21,7 @@
 
 #include <config.h>
 
+#include <isc/json.h>
 #include <isc/mem.h>
 #include <isc/print.h>
 #include <isc/string.h>
@@ -29,6 +30,7 @@
 #include <isc/time.h>
 #include <isc/timer.h>
 #include <isc/util.h>
+#include <isc/xml.h>
 
 #include <dns/cache.h>
 #include <dns/db.h>
@@ -1448,3 +1450,85 @@ error:
 	return (xmlrc);
 }
 #endif
+
+#ifdef HAVE_JSON
+#define CHECKMEM(m) do { \
+	if (m == NULL) { \
+		result = ISC_R_NOMEMORY;\
+		goto error;\
+	} \
+} while(0)
+
+isc_result_t
+dns_cache_renderjson(dns_cache_t *cache, json_object *cstats) {
+	isc_result_t result = ISC_R_SUCCESS;
+	int indices[dns_cachestatscounter_max];
+	isc_uint64_t values[dns_cachestatscounter_max];
+	json_object *obj;
+
+	REQUIRE(VALID_CACHE(cache));
+
+	getcounters(cache->stats, isc_statsformat_file,
+		    dns_cachestatscounter_max, indices, values);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_hits]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "CacheHits", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_misses]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "CacheMisses", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_queryhits]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "QueryHits", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_querymisses]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "QueryMisses", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_deletelru]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "DeleteLRU", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_deletettl]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "DeleteTTL", obj);
+
+	obj = json_object_new_int64(dns_db_nodecount(cache->db));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "CacheNodes", obj);
+
+	obj = json_object_new_int64(dns_db_hashsize(cache->db));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "CacheBuckets", obj);
+
+	obj = json_object_new_int64(isc_mem_total(cache->mctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "TreeMemTotal", obj);
+
+	obj = json_object_new_int64(isc_mem_inuse(cache->mctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "TreeMemInUse", obj);
+
+	obj = json_object_new_int64(isc_mem_maxinuse(cache->mctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "HeapMemMax", obj);
+
+	obj = json_object_new_int64(isc_mem_total(cache->hmctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "HeapMemTotal", obj);
+
+	obj = json_object_new_int64(isc_mem_inuse(cache->hmctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "HeapMemInUse", obj);
+
+	obj = json_object_new_int64(isc_mem_maxinuse(cache->hmctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "HeapMemMax", obj);
+
+	result = ISC_R_SUCCESS;
+error:
+	return (result);
+}
+#endif

lib/dns/include/dns/cache.h

@@ -49,6 +49,7 @@
  ***	Imports
  ***/
 
+#include <isc/json.h>
 #include <isc/lang.h>
 #include <isc/stats.h>
 #include <isc/stdtime.h>
@@ -327,6 +328,14 @@ dns_cache_renderxml(dns_cache_t *cache, xmlTextWriterPtr writer);
  */
 #endif /* HAVE_LIBXML2 */
 
+#ifdef HAVE_JSON
+isc_result_t
+dns_cache_renderjson(dns_cache_t *cache, json_object *cstats);
+/*
+ * Render cache statistics and status in JSON
+ */
+#endif /* HAVE_JSON */
+
 ISC_LANG_ENDDECLS
 
 #endif /* DNS_CACHE_H */

lib/isc/httpd.c

@@ -938,9 +938,10 @@ isc_httpd_senddone(isc_task_t *task, isc_event_t *ev)
 	 */
 	if (httpd->freecb != NULL) {
 		isc_buffer_t *b = NULL;
-		if (isc_buffer_length(&httpd->bodybuffer) > 0)
+		if (isc_buffer_length(&httpd->bodybuffer) > 0) {
 			b = &httpd->bodybuffer;
-		httpd->freecb(b, httpd->freecb_arg);
+			httpd->freecb(b, httpd->freecb_arg);
+		}
 		NOTICE("senddone free callback performed");
 	}
 	if (ISC_LINK_LINKED(&httpd->bodybuffer, link)) {

lib/isc/include/isc/json.h

+/*
+ * Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISC_JSON_H
+#define ISC_JSON_H 1
+
+/*
+ * This file is here mostly to make it easy to add additional libjson header
+ * files as needed across all the users of this file.  Rather than place
+ * these libjson includes in each file, one include makes it easy to handle
+ * the ifdef as well as adding the ability to add additional functions
+ * which may be useful.
+ */
+
+#ifdef HAVE_JSON
+#include <json/json.h>
+#endif
+
+#define ISC_JSON_RENDERCONFIG		0x00000001 /* render config data */
+#define ISC_JSON_RENDERSTATS		0x00000002 /* render stats */
+#define ISC_JSON_RENDERALL		0x000000ff /* render everything */
+
+#endif /* ISC_JSON_H */

lib/isc/include/isc/mem.h

@@ -24,6 +24,7 @@
 
 #include <stdio.h>
 
+#include <isc/json.h>
 #include <isc/lang.h>
 #include <isc/mutex.h>
 #include <isc/platform.h>
@@ -554,6 +555,15 @@ isc_mem_renderxml(xmlTextWriterPtr writer);
  */
 #endif /* HAVE_LIBXML2 */
 
+#ifdef HAVE_JSON
+isc_result_t
+isc_mem_renderjson(json_object *memobj);
+/*%<
+ * Render all contexts' statistics and status in JSON.
+ */
+#endif /* HAVE_JSON */
+
+
 /*
  * Memory pools
  */

lib/isc/include/isc/socket.h

@@ -57,13 +57,14 @@
  *** Imports
  ***/
 
-#include <isc/lang.h>
-#include <isc/types.h>
 #include <isc/event.h>
 #include <isc/eventclass.h>
-#include <isc/time.h>
+#include <isc/lang.h>
+#include <isc/json.h>
 #include <isc/region.h>
 #include <isc/sockaddr.h>
+#include <isc/time.h>
+#include <isc/types.h>
 #include <isc/xml.h>
 
 ISC_LANG_BEGINDECLS
@@ -1143,15 +1144,21 @@ isc__socketmgr_maxudp(isc_socketmgr_t *mgr, int maxudp);
  */
 
 #ifdef HAVE_LIBXML2
-
 int
 isc_socketmgr_renderxml(isc_socketmgr_t *mgr, xmlTextWriterPtr writer);
 /*%<
  * Render internal statistics and other state into the XML document.
  */
-
 #endif /* HAVE_LIBXML2 */
 
+#ifdef HAVE_JSON
+isc_result_t
+isc_socketmgr_renderjson(isc_socketmgr_t *mgr, json_object *stats);
+/*%<
+ * Render internal statistics and other state into JSON format.
+ */
+#endif /* HAVE_JSON */
+
 #ifdef USE_SOCKETIMPREGISTER
 /*%<
  * See isc_socketmgr_create() above.

lib/isc/include/isc/task.h

@@ -81,6 +81,7 @@
  ***/
 
 #include <isc/eventclass.h>
+#include <isc/json.h>
 #include <isc/lang.h>
 #include <isc/stdtime.h>
 #include <isc/types.h>
@@ -787,10 +788,13 @@ isc_taskmgr_excltask(isc_taskmgr_t *mgr, isc_task_t **taskp);
 
 
 #ifdef HAVE_LIBXML2
-
 int
 isc_taskmgr_renderxml(isc_taskmgr_t *mgr, xmlTextWriterPtr writer);
+#endif
 
+#ifdef HAVE_JSON
+isc_result_t
+isc_taskmgr_renderjson(isc_taskmgr_t *mgr, json_object *tasksobj);
 #endif
 
 /*%<

lib/isc/include/isc/types.h

@@ -129,7 +129,8 @@ typedef enum {
 /*% Statistics formats (text file or XML) */
 typedef enum {
 	isc_statsformat_file,
-	isc_statsformat_xml
+	isc_statsformat_xml,
+	isc_statsformat_json
 } isc_statsformat_t;
 
 #endif /* ISC_TYPES_H */

lib/isc/mem.c

@@ -27,6 +27,7 @@
 
 #include <limits.h>
 
+#include <isc/json.h>
 #include <isc/magic.h>
 #include <isc/mem.h>
 #include <isc/msgs.h>
@@ -2379,18 +2380,21 @@ isc_mem_references(isc_mem_t *ctx0) {
 	return (references);
 }
 
-#ifdef HAVE_LIBXML2
-
+#if defined(HAVE_LIBXML2) || defined(HAVE_JSON)
 typedef struct summarystat {
 	isc_uint64_t	total;
 	isc_uint64_t	inuse;
 	isc_uint64_t	blocksize;
 	isc_uint64_t	contextsize;
 } summarystat_t;
+#endif
 
+#ifdef HAVE_LIBXML2
 #define TRY0(a) do { xmlrc = (a); if (xmlrc < 0) goto error; } while(0)
 static int
-renderctx(isc__mem_t *ctx, summarystat_t *summary, xmlTextWriterPtr writer) {
+xml_renderctx(isc__mem_t *ctx, summarystat_t *summary,
+	      xmlTextWriterPtr writer)
+{
 	int xmlrc;
 
 	REQUIRE(VALID_CONTEXT(ctx));
@@ -2501,7 +2505,7 @@ isc_mem_renderxml(xmlTextWriterPtr writer) {
 	for (ctx = ISC_LIST_HEAD(contexts);
 	     ctx != NULL;
 	     ctx = ISC_LIST_NEXT(ctx, link)) {
-		xmlrc = renderctx(ctx, &summary, writer);
+		xmlrc = xml_renderctx(ctx, &summary, writer);
 		if (xmlrc < 0) {
 			UNLOCK(&lock);
 			goto error;
@@ -2549,4 +2553,160 @@ isc_mem_renderxml(xmlTextWriterPtr writer) {
 }
 
 #endif /* HAVE_LIBXML2 */
+
+#ifdef HAVE_JSON
+#define CHECKMEM(m) do { \
+	if (m == NULL) { \
+		result = ISC_R_NOMEMORY;\
+		goto error;\
+	} \
+} while(0)
+
+static isc_result_t
+json_renderctx(isc__mem_t *ctx, summarystat_t *summary, json_object *array) {
+	isc_result_t result = ISC_R_FAILURE;
+	json_object *ctxobj, *obj;
+	char buf[1024];
+
+	REQUIRE(VALID_CONTEXT(ctx));
+	REQUIRE(summary != NULL);
+	REQUIRE(array != NULL);
+
+	MCTXLOCK(ctx, &ctx->lock);
+
+	summary->contextsize += sizeof(*ctx) +
+		(ctx->max_size + 1) * sizeof(struct stats) +
+		ctx->max_size * sizeof(element *) +
+		ctx->basic_table_count * sizeof(char *);
+	summary->total += ctx->total;
+	summary->inuse += ctx->inuse;
+	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0)
+		summary->blocksize += ctx->basic_table_count *
+			NUM_BASIC_BLOCKS * ctx->mem_target;
+#if ISC_MEM_TRACKLINES
+	if (ctx->debuglist != NULL) {
+		summary->contextsize +=
+			(ctx->max_size + 1) * sizeof(debuglist_t) +
+			ctx->debuglistcnt * sizeof(debuglink_t);
+	}
+#endif
+
+	ctxobj = json_object_new_object();
+	CHECKMEM(ctxobj);
+
+	sprintf(buf, "%p", ctx);
+	obj = json_object_new_string(buf);
+	CHECKMEM(obj);
+	json_object_object_add(ctxobj, "id", obj);
+
+	if (ctx->name[0] != 0) {
+		obj = json_object_new_string(ctx->name);
+		CHECKMEM(obj);
+		json_object_object_add(ctxobj, "name", obj);
+	}
+
+	obj = json_object_new_int64(ctx->references);
+	CHECKMEM(obj);
+	json_object_object_add(ctxobj, "references", obj);
+
+	obj = json_object_new_int64(ctx->total);
+	CHECKMEM(obj);
+	json_object_object_add(ctxobj, "total", obj);
+
+	obj = json_object_new_int64(ctx->inuse);
+	CHECKMEM(obj);
+	json_object_object_add(ctxobj, "inuse", obj);
+
+	obj = json_object_new_int64(ctx->maxinuse);
+	CHECKMEM(obj);
+	json_object_object_add(ctxobj, "maxinuse", obj);
+
+	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
+		isc_uint64_t blocksize;
+		blocksize = ctx->basic_table_count * NUM_BASIC_BLOCKS *
+			ctx->mem_target;
+		obj = json_object_new_int64(blocksize);
+		CHECKMEM(obj);
+		json_object_object_add(ctxobj, "blocksize", obj);
+	}
+
+	obj = json_object_new_int64(ctx->poolcnt);
+	CHECKMEM(obj);
+	json_object_object_add(ctxobj, "pools", obj);
+
+	obj = json_object_new_int64(ctx->hi_water);
+	CHECKMEM(obj);
+	json_object_object_add(ctxobj, "hiwater", obj);
+
+	obj = json_object_new_int64(ctx->lo_water);
+	CHECKMEM(obj);
+	json_object_object_add(ctxobj, "lowater", obj);
+
+	MCTXUNLOCK(ctx, &ctx->lock);
+	json_object_array_add(array, ctxobj);
+	return (ISC_R_SUCCESS);
+