unbound.c pipe code.

git-svn-id: file:///svn/unbound/trunk@883 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -1,3 +1,6 @@
+22 January 2008: Wouter
+	- library code for async in libunbound/unbound.c.
+
 21 January 2008: Wouter
 	- libworker work, netevent raw commpoints, write_msg, serialize.
 

libunbound/context.c

@@ -102,13 +102,13 @@ static int
 find_id(struct ub_val_ctx* ctx, int* id)
 {
 	size_t tries = 0;
+	ctx->next_querynum++;
 	while(rbtree_search(&ctx->queries, &ctx->next_querynum)) {
 		ctx->next_querynum++; /* numerical wraparound is fine */
 		if(tries++ > NUM_ID_TRIES)
 			return 0;
 	}
 	*id = ctx->next_querynum;
-	ctx->next_querynum++;
 	return 1;
 }
 

libunbound/context.h

@@ -170,7 +170,9 @@ enum ub_ctx_err {
 	/** cfg change after finalize() */
 	UB_AFTERFINAL = -6,
 	/** initialization failed (bad settings) */
-	UB_INITFAIL = -7
+	UB_INITFAIL = -7,
+	/** error in pipe communication with async bg worker */
+	UB_PIPE = -8
 };
 
 /**

libunbound/unbound.c

@@ -50,6 +50,7 @@
 #include "util/config_file.h"
 #include "util/alloc.h"
 #include "util/module.h"
+#include "util/regional.h"
 #include "util/log.h"
 #include "services/modstack.h"
 #include "services/localzone.h"
@@ -104,14 +105,22 @@ ub_val_ctx_create()
 	return ctx;
 }
 
+/** delete context query */
+static void
+context_query_delete(struct ctx_query* q) 
+{
+	if(!q) return;
+	ub_val_result_free(q->res);
+	free(q->msg);
+	free(q);
+}
+
 /** delete q */
 static void
 delq(rbnode_t* n, void* ATTR_UNUSED(arg))
 {
 	struct ctx_query* q = (struct ctx_query*)n;
-	if(!q) return;
-	ub_val_result_free(q->res);
-	free(q);
+	context_query_delete(q);
 }
 
 void 
@@ -275,13 +284,15 @@ ub_val_ctx_poll(struct ub_val_ctx* ctx)
 int 
 ub_val_ctx_wait(struct ub_val_ctx* ctx)
 {
+	int r;
 	lock_basic_lock(&ctx->cfglock);
 	while(ctx->num_async > 0) {
-		lock_basic_lock(&ctx->rrpipe_lock);
 		lock_basic_unlock(&ctx->cfglock);
-		(void)pollit(ctx, NULL);
+		lock_basic_lock(&ctx->rrpipe_lock);
+		r = pollit(ctx, NULL);
 		lock_basic_unlock(&ctx->rrpipe_lock);
-		ub_val_ctx_process(ctx);
+		if(r)
+			ub_val_ctx_process(ctx);
 		lock_basic_lock(&ctx->cfglock);
 	}
 	lock_basic_unlock(&ctx->cfglock);
@@ -291,15 +302,93 @@ ub_val_ctx_wait(struct ub_val_ctx* ctx)
 int 
 ub_val_ctx_fd(struct ub_val_ctx* ctx)
 {
-	return ctx->rrpipe[0];
+	int fd;
+	lock_basic_lock(&ctx->rrpipe_lock);
+	fd = ctx->rrpipe[0];
+	lock_basic_unlock(&ctx->rrpipe_lock);
+	return fd;
+}
+
+/** process answer from bg worker */
+static int
+process_answer(struct ub_val_ctx* ctx, uint8_t* msg, uint32_t len)
+{
+	int err;
+	struct ctx_query* q;
+	ub_val_callback_t cb;
+	void* cbarg;
+	struct ub_val_result* res;
+	if(context_serial_getcmd(msg, len) != UB_LIBCMD_ANSWER) {
+		log_err("error: bad data from bg worker %d",
+			(int)context_serial_getcmd(msg, len));
+		return 0;
+	}
+
+	lock_basic_lock(&ctx->cfglock);
+	q = context_deserialize_answer(ctx, msg, len, &err);
+	if(!q) {
+		lock_basic_unlock(&ctx->cfglock);
+		return 0;
+	}
+	log_assert(q->async);
+
+	/* grab cb while locked */
+	cb = q->cb;
+	cbarg = q->cb_arg;
+	if(err) {
+		res = NULL;
+		ub_val_result_free(q->res);
+	} else {
+		/* parse the message, extract rcode, fill result */
+		ldns_buffer* buf = ldns_buffer_new(q->msg_len);
+		struct regional* region = regional_create();
+		res = q->res;
+		res->rcode = LDNS_RCODE_SERVFAIL;
+		if(region && buf) {
+			ldns_buffer_clear(buf);
+			ldns_buffer_write(buf, q->msg, q->msg_len);
+			ldns_buffer_flip(buf);
+			libworker_enter_result(res, buf, region,
+				q->msg_security);
+		}
+		ldns_buffer_free(buf);
+		regional_destroy(region);
+	}
+	q->res = NULL;
+	/* delete the q from list */
+	(void)rbtree_delete(&ctx->queries, q->node.key);
+	ctx->num_async--;
+	context_query_delete(q);
+	lock_basic_unlock(&ctx->cfglock);
+
+	/* no locks held while calling callback, so that library is
+	 * re-entrant. */
+	(*cb)(cbarg, err, res);
+
+	return 1;
 }
 
 int 
 ub_val_ctx_process(struct ub_val_ctx* ctx)
 {
-	/* TODO */
-	/* ctx->num_asynx-- when handled; */
-	return UB_NOMEM;
+	int r;
+	uint8_t* msg = NULL;
+	uint32_t len = 0;
+	while(1) {
+		lock_basic_lock(&ctx->rrpipe_lock);
+		r = libworker_read_msg(ctx->rrpipe[0], &msg, &len, 1);
+		lock_basic_unlock(&ctx->rrpipe_lock);
+		if(r == 0)
+			return UB_PIPE;
+		else if(r == -1)
+			return UB_NOERROR;
+		if(!process_answer(ctx, msg, len)) {
+			free(msg);
+			return UB_PIPE;
+		}
+		free(msg);
+	}
+	return UB_NOERROR;
 }
 
 int 
@@ -327,15 +416,14 @@ ub_val_resolve(struct ub_val_ctx* ctx, char* name, int rrtype,
 
 	r = libworker_fg(ctx, q);
 	if(r) {
-		ub_val_result_free(q->res);
-		free(q);
+		context_query_delete(q);
 		return r;
 	}
 	*result = q->res;
+	q->res = NULL;
 
 	(void)rbtree_delete(&ctx->queries, q->node.key);
-	free(q->msg);
-	free(q);
+	context_query_delete(q);
 	return UB_NOERROR;
 }
 
@@ -344,7 +432,10 @@ ub_val_resolve_async(struct ub_val_ctx* ctx, char* name, int rrtype,
 	int rrclass, void* mydata, ub_val_callback_t callback, int* async_id)
 {
 	struct ctx_query* q;
+	uint8_t* msg = NULL;
+	uint32_t len = 0;
 
+	*async_id = 0;
 	lock_basic_lock(&ctx->cfglock);
 	if(!ctx->finalized) {
 		int r = context_finalize(ctx);
@@ -367,27 +458,59 @@ ub_val_resolve_async(struct ub_val_ctx* ctx, char* name, int rrtype,
 	q = context_new(ctx, name, rrtype, rrclass, callback, mydata);
 	if(!q)
 		return UB_NOMEM;
-	/* TODO write over pipe to background worker */
+
+	/* write over pipe to background worker */
+	lock_basic_lock(&ctx->cfglock);
+	msg = context_serialize_new_query(q, &len);
+	if(!msg) {
+		(void)rbtree_delete(&ctx->queries, q->node.key);
+		ctx->num_async--;
+		context_query_delete(q);
+		lock_basic_unlock(&ctx->cfglock);
+		return UB_NOMEM;
+	}
 	*async_id = q->querynum;
-	return UB_NOMEM;
+	lock_basic_unlock(&ctx->cfglock);
+	
+	lock_basic_lock(&ctx->qqpipe_lock);
+	libworker_write_msg(ctx->qqpipe[1], msg, len, 0);
+	lock_basic_unlock(&ctx->qqpipe_lock);
+	free(msg);
+	return UB_NOERROR;
 }
 
 int 
 ub_val_cancel(struct ub_val_ctx* ctx, int async_id)
 {
 	struct ctx_query* q;
+	uint8_t* msg = NULL;
+	uint32_t len = 0;
 	lock_basic_lock(&ctx->cfglock);
 	q = (struct ctx_query*)rbtree_search(&ctx->queries, &async_id);
-	lock_basic_unlock(&ctx->cfglock);
-	if(!q || !q->async) /* it is not there, so nothing to do */
+	if(!q || !q->async) {
+		/* it is not there, so nothing to do */
+		lock_basic_unlock(&ctx->cfglock);
 		return UB_NOERROR;
-	/* TODO ; send cancel to background worker */
-
-	lock_basic_lock(&ctx->cfglock);
-	(void)rbtree_delete(&ctx->queries, &async_id);
+	}
+	log_assert(q->async);
+	msg = context_serialize_cancel(q, &len);
+	if(!msg) {
+		lock_basic_unlock(&ctx->cfglock);
+		return UB_NOMEM;
+	}
+	
+	/* delete it */
+	(void)rbtree_delete(&ctx->queries, q->node.key);
 	ctx->num_async--;
+	context_query_delete(q);
 	lock_basic_unlock(&ctx->cfglock);
-	return UB_NOMEM;
+
+	/* send cancel to background worker */
+	lock_basic_lock(&ctx->qqpipe_lock);
+	libworker_write_msg(ctx->qqpipe[1], msg, len, 0);
+	lock_basic_unlock(&ctx->qqpipe_lock);
+	free(msg);
+	return UB_NOERROR;
 }
 
 void 
@@ -418,6 +541,7 @@ ub_val_strerror(int err)
 		case UB_FORKFAIL: return "could not fork";
 		case UB_INITFAIL: return "initialization failure";
 		case UB_AFTERFINAL: return "setting change after finalize";
+		case UB_PIPE: return "error in pipe communication with async";
 		default: return "unknown error";
 	}
 }

libunbound/unbound.h

@@ -179,8 +179,7 @@ struct ub_val_result {
 /**
  * Callback for results of async queries.
  * The readable function definition looks like:
- * void my_callback(void* my_arg, int err, int secure, int havedata,
- *	struct ub_val_result* result);
+ * void my_callback(void* my_arg, int err, struct ub_val_result* result);
  * It is called with
  *	void* my_arg: your pointer to a (struct of) data of your choice, 
  *		or NULL.
@@ -333,7 +332,7 @@ int ub_val_resolve(struct ub_val_ctx* ctx, char* name, int rrtype,
 /**
  * Perform resolution and validation of the target name.
  * Asynchronous, after a while, the callback will be called with your
- * data and the result + secure status.
+ * data and the result.
  * @param ctx: context.
  *	If no thread or process has been created yet to perform the
  *	work in the background, it is created now.
@@ -345,8 +344,7 @@ int ub_val_resolve(struct ub_val_ctx* ctx, char* name, int rrtype,
  * 	and is passed on to the callback function.
  * @param callback: this is called on completion of the resolution.
  * 	It is called as:
- * 	void callback(void* mydata, int err, int secure, int havedata, 
- * 		struct ub_val_result* result)
+ * 	void callback(void* mydata, int err, struct ub_val_result* result)
  * 	with mydata: the same as passed here, you may pass NULL,
  * 	with err: is 0 when a result has been found.
  * 	with result: a newly allocated result structure.

libunbound/worker.c

@@ -368,12 +368,37 @@ fill_res(struct ub_val_result* res, struct ub_packed_rrset_key* answer,
 	return 1;
 }
 
+/** fill result from parsed message, on error fills servfail */
+void
+libworker_enter_result(struct ub_val_result* res, ldns_buffer* buf,
+	struct regional* temp, enum sec_status msg_security)
+{
+	struct query_info rq;
+	struct reply_info* rep;
+	res->rcode = LDNS_RCODE_SERVFAIL;
+	rep = parse_reply(buf, temp, &rq);
+	if(!rep) {
+		return; /* error parsing buf, or out of memory */
+	}
+	if(!fill_res(res, reply_find_answer_rrset(&rq, rep), 
+		reply_find_final_cname_target(&rq, rep), &rq))
+		return; /* out of memory */
+	/* rcode, havedata, nxdomain, secure, bogus */
+	res->rcode = (int)FLAGS_GET_RCODE(rep->flags);
+	if(res->data && res->data[0])
+		res->havedata = 1;
+	if(res->rcode == LDNS_RCODE_NXDOMAIN)
+		res->nxdomain = 1;
+	if(msg_security == sec_status_secure)
+		res->secure = 1;
+	if(msg_security == sec_status_bogus)
+		res->bogus = 1;
+}
+
 /** callback with fg results */
 static void
 libworker_fg_done_cb(void* arg, int rcode, ldns_buffer* buf, enum sec_status s)
 {
-	struct query_info rq; /* replied query */
-	struct reply_info* rep;
 	struct libworker_fg_data* d = (struct libworker_fg_data*)arg;
 	/* fg query is done; exit comm base */
 	comm_base_exit(d->w->base);
@@ -389,29 +414,13 @@ libworker_fg_done_cb(void* arg, int rcode, ldns_buffer* buf, enum sec_status s)
 	d->q->msg = memdup(ldns_buffer_begin(buf), ldns_buffer_limit(buf));
 	d->q->msg_len = ldns_buffer_limit(buf);
 	if(!d->q->msg) {
-		return; /* error in rcode */
+		return; /* the error is in the rcode */
 	}
 
 	/* canonname and results */
-	rep = parse_reply(buf, d->w->env->scratch, &rq);
-	if(!rep) {
-		return; /* error parsing buf, or out of memory */
-	}
-	if(!fill_res(d->q->res, reply_find_answer_rrset(&rq, rep), 
-		reply_find_final_cname_target(&rq, rep), &rq))
-		return; /* out of memory */
-	/* rcode, havedata, nxdomain, secure, bogus */
-	d->q->res->rcode = (int)LDNS_RCODE_WIRE(d->q->msg);
-	if(d->q->res->data && d->q->res->data[0])
-		d->q->res->havedata = 1;
-	if(d->q->res->rcode == LDNS_RCODE_NXDOMAIN)
-		d->q->res->nxdomain = 1;
-	if(s == sec_status_secure)
-		d->q->res->secure = 1;
-	if(s == sec_status_bogus)
-		d->q->res->bogus = 1;
-
 	d->q->msg_security = s;
+
+	libworker_enter_result(d->q->res, buf, d->w->env->scratch, s);
 }
 
 /** setup qinfo and edns */

libunbound/worker.h

@@ -44,6 +44,7 @@
 #ifndef LIBUNBOUND_WORKER_H
 #define LIBUNBOUND_WORKER_H
 struct ub_val_ctx;
+struct ub_val_result;
 struct module_env;
 struct comm_base;
 struct outside_network;
@@ -54,6 +55,8 @@ struct module_qstate;
 struct comm_point;
 struct comm_reply;
 struct libworker_res_list;
+struct regional;
+enum sec_status;
 
 /** 
  * The library-worker status structure
@@ -217,4 +220,16 @@ int libworker_write_msg(int fd, uint8_t* buf, uint32_t len, int nonblock);
  */
 int libworker_read_msg(int fd, uint8_t** buf, uint32_t* len, int nonblock);
 
+/** 
+ * fill result from parsed message, on error fills servfail 
+ * @param res: is clear at start, filled in at end.
+ * @param buf: contains DNS message.
+ * @param temp: temporary buffer for parse.
+ * @param msg_security: security status of the DNS message.
+ *   On error, the res may contain a different status 
+ *   (out of memory is not secure, not bogus).
+ */
+void libworker_enter_result(struct ub_val_result* res, ldns_buffer* buf,
+	struct regional* temp, enum sec_status msg_security);
+
 #endif /* LIBUNBOUND_WORKER_H */