Hi,
As suggested by theo@, it is probably time to make the async resolver
API public, so that people can start using it.
So, here is a diff that does two things (will be committed separately).
First, move asr.h to include/ and install the manpages. It only
exposes the API that has been in libc for a while now, so there is no
new symbol strictly speaking, but maybe it still deserves a minor bump.
The other thing is to add a simple wrapper to our libevent, so that
libevent programs can immediatly and easily benefit from the async
resolver.
You have to run "make includes" in /usr/src/include before building.
Comments welcome.
Eric.
Index: include/Makefile
===================================================================
RCS file: /cvs/src/include/Makefile,v
retrieving revision 1.181
diff -u -p -r1.181 Makefile
--- include/Makefile 8 Dec 2013 17:05:09 -0000 1.181
+++ include/Makefile 26 Dec 2013 16:50:20 -0000
@@ -9,7 +9,7 @@
.include <bsd.own.mk>
-FILES= a.out.h ar.h assert.h bitstring.h blf.h bm.h bsd_auth.h \
+FILES= a.out.h ar.h asr.h assert.h bitstring.h blf.h bm.h bsd_auth.h \
complex.h cpio.h ctype.h curses.h db.h dbm.h des.h dirent.h disktab.h \
dlfcn.h elf_abi.h err.h errno.h fenv.h float.h fnmatch.h fstab.h fts.h \
ftw.h getopt.h glob.h grp.h ifaddrs.h inttypes.h iso646.h kvm.h \
Index: include/asr.h
===================================================================
RCS file: include/asr.h
diff -N include/asr.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ include/asr.h 26 Dec 2013 16:50:20 -0000
@@ -0,0 +1,100 @@
+/* $OpenBSD: asr.h,v 1.7 2013/07/12 14:36:21 eric Exp $ */
+/*
+ * Copyright (c) 2012 Eric Faurot <e...@openbsd.org>
+ *
+ * Permission to use, copy, modify, and 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <netinet/in.h>
+
+/*
+ * This part is the generic API for the async mechanism. It could be useful
+ * beyond the resolver.
+ */
+
+/* Return values for async_run() */
+#define ASYNC_COND 0 /* wait for fd condition */
+#define ASYNC_YIELD 1 /* partial result */
+#define ASYNC_DONE 2 /* done */
+
+/* Expected fd conditions */
+#define ASYNC_READ 1
+#define ASYNC_WRITE 2
+
+/* This opaque structure holds an async query state. */
+struct async;
+
+/*
+ * This is the structure through which async_run() returns async
+ * results to the caller.
+ */
+struct async_res {
+ int ar_cond;
+ int ar_fd;
+ int ar_timeout;
+
+ int ar_errno;
+ int ar_h_errno;
+ int ar_gai_errno;
+ int ar_rrset_errno;
+
+ int ar_count;
+
+ int ar_rcode;
+ void *ar_data;
+ int ar_datalen;
+ union {
+ struct sockaddr sa;
+ struct sockaddr_in sain;
+ struct sockaddr_in6 sain6;
+ } ar_sa;
+
+ struct addrinfo *ar_addrinfo;
+ struct rrsetinfo *ar_rrsetinfo;
+ struct hostent *ar_hostent;
+ struct netent *ar_netent;
+};
+
+int asr_async_run(struct async *, struct async_res *);
+int asr_async_run_sync(struct async *, struct async_res *);
+void asr_async_abort(struct async *);
+
+/* This opaque structure holds an async resolver context. */
+struct asr;
+
+struct asr *asr_resolver(const char *);
+void asr_resolver_done(struct asr *);
+
+/* Async version of the resolver API */
+
+struct async *res_send_async(const unsigned char *, int, struct asr *);
+struct async *res_query_async(const char *, int, int, struct asr *);
+struct async *res_search_async(const char *, int, int, struct asr *);
+
+struct async *getrrsetbyname_async(const char *, unsigned int, unsigned int,
+ unsigned int, struct asr *);
+
+struct async *gethostbyname_async(const char *, struct asr *);
+struct async *gethostbyname2_async(const char *, int, struct asr *);
+struct async *gethostbyaddr_async(const void *, socklen_t, int, struct asr *);
+
+struct async *getnetbyname_async(const char *, struct asr *);
+struct async *getnetbyaddr_async(in_addr_t, int, struct asr *);
+
+struct async *getaddrinfo_async(const char *, const char *,
+ const struct addrinfo *, struct asr *);
+struct async *getnameinfo_async(const struct sockaddr *, socklen_t, char *,
+ size_t, char *, size_t, int, struct asr *);
Index: lib/libc/shlib_version
===================================================================
RCS file: /cvs/src/lib/libc/shlib_version,v
retrieving revision 1.157
diff -u -p -r1.157 shlib_version
--- lib/libc/shlib_version 17 Dec 2013 16:34:27 -0000 1.157
+++ lib/libc/shlib_version 26 Dec 2013 16:50:21 -0000
@@ -1,4 +1,4 @@
major=72
-minor=0
+minor=1
# note: If changes were made to include/thread_private.h or if system
# calls were added/changed then librthread/shlib_version also be updated.
Index: lib/libc/asr/Makefile.inc
===================================================================
RCS file: /cvs/src/lib/libc/asr/Makefile.inc,v
retrieving revision 1.6
diff -u -p -r1.6 Makefile.inc
--- lib/libc/asr/Makefile.inc 8 Aug 2013 06:55:42 -0000 1.6
+++ lib/libc/asr/Makefile.inc 26 Dec 2013 16:50:22 -0000
@@ -8,11 +8,13 @@ SRCS+= asr.c asr_debug.c asr_utils.c \
gethostnamadr_async.c getnetnamadr_async.c \
getaddrinfo_async.c getnameinfo_async.c
-MLINKS+ = \
+MAN+= asr_resolver.3
+
+MLINKS+= \
asr_resolver.3 asr_resolver_done.3 \
asr_resolver.3 asr_async_run.3 \
asr_resolver.3 asr_async_run_sync.3 \
- asr_resolver.3 asr_async_abort.3 \
+ asr_resolver.3 asr_async_abort.3 \
asr_resolver.3 res_send_async.3 \
asr_resolver.3 res_query_async.3 \
asr_resolver.3 res_search_async.3 \
Index: lib/libc/asr/asr.h
===================================================================
RCS file: lib/libc/asr/asr.h
diff -N lib/libc/asr/asr.h
--- lib/libc/asr/asr.h 12 Jul 2013 14:36:21 -0000 1.7
+++ /dev/null 1 Jan 1970 00:00:00 -0000
@@ -1,100 +0,0 @@
-/* $OpenBSD: asr.h,v 1.7 2013/07/12 14:36:21 eric Exp $ */
-/*
- * Copyright (c) 2012 Eric Faurot <e...@openbsd.org>
- *
- * Permission to use, copy, modify, and 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
- */
-
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netdb.h>
-#include <netinet/in.h>
-
-/*
- * This part is the generic API for the async mechanism. It could be useful
- * beyond the resolver.
- */
-
-/* Return values for async_run() */
-#define ASYNC_COND 0 /* wait for fd condition */
-#define ASYNC_YIELD 1 /* partial result */
-#define ASYNC_DONE 2 /* done */
-
-/* Expected fd conditions */
-#define ASYNC_READ 1
-#define ASYNC_WRITE 2
-
-/* This opaque structure holds an async query state. */
-struct async;
-
-/*
- * This is the structure through which async_run() returns async
- * results to the caller.
- */
-struct async_res {
- int ar_cond;
- int ar_fd;
- int ar_timeout;
-
- int ar_errno;
- int ar_h_errno;
- int ar_gai_errno;
- int ar_rrset_errno;
-
- int ar_count;
-
- int ar_rcode;
- void *ar_data;
- int ar_datalen;
- union {
- struct sockaddr sa;
- struct sockaddr_in sain;
- struct sockaddr_in6 sain6;
- } ar_sa;
-
- struct addrinfo *ar_addrinfo;
- struct rrsetinfo *ar_rrsetinfo;
- struct hostent *ar_hostent;
- struct netent *ar_netent;
-};
-
-int asr_async_run(struct async *, struct async_res *);
-int asr_async_run_sync(struct async *, struct async_res *);
-void asr_async_abort(struct async *);
-
-/* This opaque structure holds an async resolver context. */
-struct asr;
-
-struct asr *asr_resolver(const char *);
-void asr_resolver_done(struct asr *);
-
-/* Async version of the resolver API */
-
-struct async *res_send_async(const unsigned char *, int, struct asr *);
-struct async *res_query_async(const char *, int, int, struct asr *);
-struct async *res_search_async(const char *, int, int, struct asr *);
-
-struct async *getrrsetbyname_async(const char *, unsigned int, unsigned int,
- unsigned int, struct asr *);
-
-struct async *gethostbyname_async(const char *, struct asr *);
-struct async *gethostbyname2_async(const char *, int, struct asr *);
-struct async *gethostbyaddr_async(const void *, socklen_t, int, struct asr *);
-
-struct async *getnetbyname_async(const char *, struct asr *);
-struct async *getnetbyaddr_async(in_addr_t, int, struct asr *);
-
-struct async *getaddrinfo_async(const char *, const char *,
- const struct addrinfo *, struct asr *);
-struct async *getnameinfo_async(const struct sockaddr *, socklen_t, char *,
- size_t, char *, size_t, int, struct asr *);
Index: lib/libevent/Makefile
===================================================================
RCS file: /cvs/src/lib/libevent/Makefile,v
retrieving revision 1.31
diff -u -p -r1.31 Makefile
--- lib/libevent/Makefile 2 Aug 2012 13:38:38 -0000 1.31
+++ lib/libevent/Makefile 26 Dec 2013 16:50:24 -0000
@@ -26,6 +26,8 @@ MLINKS= event.3 bufferevent_base_set.3 \
event.3 evbuffer_readline.3 \
event.3 evbuffer_write.3 \
event.3 event_add.3 \
+ event.3 event_async.3 \
+ event.3 event_async_cancel.3 \
event.3 event_base_dispatch.3 \
event.3 event_base_free.3 \
event.3 event_base_loop.3 \
Index: lib/libevent/event.3
===================================================================
RCS file: /cvs/src/lib/libevent/event.3,v
retrieving revision 1.41
diff -u -p -r1.41 event.3
--- lib/libevent/event.3 22 Apr 2010 16:35:45 -0000 1.41
+++ lib/libevent/event.3 26 Dec 2013 16:50:25 -0000
@@ -45,6 +45,8 @@
.Nm event_base_once ,
.Nm event_pending ,
.Nm event_initialized ,
+.Nm event_async ,
+.Nm event_async_cancel,
.Nm event_priority_init ,
.Nm event_priority_set ,
.Nm evtimer_set ,
@@ -121,6 +123,10 @@
.Fn "event_priority_init" "int npriorities"
.Ft int
.Fn "event_priority_set" "struct event *ev" "int priority"
+.Ft "struct event_async *"
+.Fn "event_async" "struct async *as" "void (*fn)(int, struct async_res *, void
*)" "void *"
+.Ft void
+.Fn "event_async_cancel" "struct event_async *eva"
.Ft void
.Fn "evtimer_set" "struct event *ev" "void (*fn)(int, short, void *)" "void
*arg"
.Ft void
@@ -398,6 +404,39 @@ will proceed normally.
.Pp
It is the responsibility of the caller to provide these functions with
pre-allocated event structures.
+.Sh ASYNC RESOLVER QUERIES
+This version of
+.Nm libevent
+provides helper functions to run asr async queries.
+.Pp
+The
+.Nm event_async
+function is used to setup the
+.Fa async
+query (created through the asr API) to run within
+.Nm libevent .
+All necessary events are handled internally.
+When the query is done, the user callback
+.Fa fn
+is called with the return value of the last call to
+.Xr asr_async_run 3 ,
+a structure filled with the result, and the user-provided data pointer
+.Fa arg .
+The caller is expected to clear the results as for
+.Xr asr_async_run 3 ,
+but the structure itself must not be freed.
+This functions returns an opaque handle to the internal
+.Nm libevent
+context for this query.
+.Pp
+The
+.Nm event_async_cancel
+function cancels the
+.Fa eva
+async query context previously created with
+.Nm event_async .
+This function will abort the underlying async query.
+It must not be called if the callback has already been fired.
.Sh EVENT PRIORITIES
By default
.Nm libevent
Index: lib/libevent/event.c
===================================================================
RCS file: /cvs/src/lib/libevent/event.c,v
retrieving revision 1.27
diff -u -p -r1.27 event.c
--- lib/libevent/event.c 17 Apr 2013 15:31:49 -0000 1.27
+++ lib/libevent/event.c 26 Dec 2013 16:50:26 -0000
@@ -52,6 +52,7 @@
#include <string.h>
#include <assert.h>
#include <time.h>
+#include <asr.h>
#include "event.h"
#include "event-internal.h"
@@ -1032,4 +1033,71 @@ const char *
event_get_method(void)
{
return (current_base->evsel->name);
+}
+
+/*
+ * libevent wrapper for asr async dns lookups
+ *
+ */
+
+struct event_async {
+ struct event ev;
+ struct async *async;
+ void (*cb)(int, struct async_res *, void *);
+ void *arg;
+};
+
+static void event_async_cb(int, short, void *);
+
+struct event_async *
+event_async(struct async * async, void (*cb)(int, struct async_res *, void *),
+ void *arg)
+{
+ struct event_async *eva;
+ struct timeval tv;
+
+ eva = calloc(1, sizeof *eva);
+ if (eva == NULL)
+ return (NULL);
+ eva->async = async;
+ eva->cb = cb;
+ eva->arg = arg;
+ tv.tv_sec = 0;
+ tv.tv_usec = 0;
+ evtimer_set(&eva->ev, event_async_cb, eva);
+ evtimer_add(&eva->ev, &tv);
+ return (eva);
+}
+
+void
+event_async_cancel(struct event_async *eva)
+{
+ event_del(&eva->ev);
+ asr_async_abort(eva->async);
+ free(eva);
+}
+
+static void
+event_async_cb(int fd, short ev, void *arg)
+{
+ struct event_async *eva = arg;
+ struct async_res ar;
+ int r;
+ struct timeval tv;
+
+ while ((r = asr_async_run(eva->async, &ar)) == ASYNC_YIELD)
+ eva->cb(r, &ar, eva->arg);
+
+ event_del(&eva->ev);
+ if (r == ASYNC_COND) {
+ event_set(&eva->ev, ar.ar_fd,
+ ar.ar_cond == ASYNC_READ ? EV_READ : EV_WRITE,
+ event_async_cb, eva);
+ tv.tv_sec = ar.ar_timeout / 1000;
+ tv.tv_usec = (ar.ar_timeout % 1000) * 1000;
+ event_add(&eva->ev, &tv);
+ } else { /* ASYNC_DONE */
+ eva->cb(r, &ar, eva->arg);
+ free(eva);
+ }
}
Index: lib/libevent/event.h
===================================================================
RCS file: /cvs/src/lib/libevent/event.h,v
retrieving revision 1.25
diff -u -p -r1.25 event.h
--- lib/libevent/event.h 28 Aug 2012 09:09:56 -0000 1.25
+++ lib/libevent/event.h 26 Dec 2013 16:50:27 -0000
@@ -702,6 +702,33 @@ int event_base_priority_init(struct even
*/
int event_priority_set(struct event *, int);
+/* These functions are helpers to use the async */
+
+struct async;
+struct async_res;
+struct event_async;
+
+/**
+ Run an async resolver query within libevent.
+
+ @param async an async request built with the asr API
+ @param cb the function to call when the query is done
+ @param arg additionnal user data
+ @return NULL on error, a pointer to a libevent internal structure
+ representing the async query context
+ */
+struct event_async *event_async(struct async *,
+ void (*)(int, struct async_res *, void *), void *);
+
+/**
+ Cancel a running event_async query.
+
+ The underlying async query is also canceled.
+
+ @param eva a pointer to a async query event as returned by event_async()
+ */
+void event_async_cancel(struct event_async *);
+
/* These functions deal with buffering input and output */
Index: lib/libevent/shlib_version
===================================================================
RCS file: /cvs/src/lib/libevent/shlib_version,v
retrieving revision 1.9
diff -u -p -r1.9 shlib_version
--- lib/libevent/shlib_version 13 Aug 2013 05:52:13 -0000 1.9
+++ lib/libevent/shlib_version 26 Dec 2013 16:50:27 -0000
@@ -1,2 +1,2 @@
major=4
-minor=0
+minor=1
