[tarantool-patches] [PATCH 4/6] swim: wrap sio_strfaddr()

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

SIO provides a function sio_strfaddr() to obtain string
representation of arbitrary struct sockaddr. And it uses
singleton buffer to store results, because some of them can't
fit into tt_static_buf() according to POSIX name limits.

SWIM uses only AF_INET addresses, they are short enough to fit
into tt_static_buf(). Also SWIM is going to call sio_strfaddr()
on more than 1 address in a row in subsequent patches, and
singleton buffer does not work here - each call will overwrite
result of the previous. Besides, SWIM never uses struct sockaddr
type. All these reasons are sufficient to wrap sio_strfaddr()
with encapsulated cast to struct sockaddr *, and copying on
tt_static_buf().

Part of #3234
---
 src/lib/swim/swim.c       | 10 +++-------
 src/lib/swim/swim_io.c    |  5 ++---
 src/lib/swim/swim_proto.c |  8 ++++++++
 src/lib/swim/swim_proto.h | 10 ++++++++++
 4 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/src/lib/swim/swim.c b/src/lib/swim/swim.c
index 230ec52d4..bb1ded713 100644
--- a/src/lib/swim/swim.c
+++ b/src/lib/swim/swim.c
@@ -1086,8 +1086,7 @@ swim_send_fd_msg(struct swim *swim, struct swim_task *task,
 	assert(map_size == 2);
 	mp_encode_map(header, map_size);
 	say_verbose("SWIM %d: schedule %s to %s", swim_fd(swim),
-		    swim_fd_msg_type_strs[type],
-		    sio_strfaddr((struct sockaddr *) dst, sizeof(*dst)));
+		    swim_fd_msg_type_strs[type], swim_inaddr_str(dst));
 	swim_task_send(task, dst, &swim->scheduler);
 }
 
@@ -1732,9 +1731,7 @@ swim_info(struct swim *swim, struct info_handler *info)
 	     node = mh_next(swim->members, node)) {
 		struct swim_member *m =
 			*mh_swim_table_node(swim->members, node);
-		info_table_begin(info,
-				 sio_strfaddr((struct sockaddr *) &m->addr,
-					      sizeof(m->addr)));
+		info_table_begin(info, swim_inaddr_str(&m->addr));
 		info_append_str(info, "status",
 				swim_member_status_strs[m->status]);
 		info_append_str(info, "uuid", swim_uuid_str(&m->uuid));
@@ -1888,8 +1885,7 @@ swim_iterator_close(struct swim_iterator *iterator)
 const char *
 swim_member_uri(const struct swim_member *member)
 {
-	return sio_strfaddr((const struct sockaddr *) &member->addr,
-			    sizeof(member->addr));
+	return swim_inaddr_str(&member->addr);
 }
 
 const struct tt_uuid *
diff --git a/src/lib/swim/swim_io.c b/src/lib/swim/swim_io.c
index 7d6addf02..a55c15f30 100644
--- a/src/lib/swim/swim_io.c
+++ b/src/lib/swim/swim_io.c
@@ -321,8 +321,7 @@ swim_scheduler_on_output(struct ev_loop *loop, struct ev_io *io, int events)
 		rlist_shift_entry(&scheduler->queue_output, struct swim_task,
 				  in_queue_output);
 	say_verbose("SWIM %d: send %s to %s", swim_scheduler_fd(scheduler),
-		    task->desc, sio_strfaddr((struct sockaddr *) &task->dst,
-					     sizeof(task->dst)));
+		    task->desc, swim_inaddr_str(&task->dst));
 	swim_packet_build_meta(&task->packet, &scheduler->transport.addr);
 	int rc = swim_transport_send(&scheduler->transport, task->packet.buf,
 				     task->packet.pos - task->packet.buf,
@@ -353,7 +352,7 @@ swim_scheduler_on_input(struct ev_loop *loop, struct ev_io *io, int events)
 		return;
 	}
 	say_verbose("SWIM %d: received from %s", swim_scheduler_fd(scheduler),
-		    sio_strfaddr((struct sockaddr *) &src, len));
+		    swim_inaddr_str(&src));
 	struct swim_meta_def meta;
 	const char *pos = buf, *end = pos + size;
 	if (swim_meta_def_decode(&meta, &pos, end) < 0)
diff --git a/src/lib/swim/swim_proto.c b/src/lib/swim/swim_proto.c
index 91500518d..796559e8e 100644
--- a/src/lib/swim/swim_proto.c
+++ b/src/lib/swim/swim_proto.c
@@ -33,8 +33,16 @@
 #include "say.h"
 #include "version.h"
 #include "diag.h"
+#include "sio.h"
 #include <sys/socket.h> /* AF_INET for FreeBSD. */
 
+const char *
+swim_inaddr_str(const struct sockaddr_in *addr)
+{
+	return tt_sprintf("%s", sio_strfaddr((struct sockaddr *) addr,
+					     sizeof(*addr)));
+}
+
 const char *swim_member_status_strs[] = {
 	"alive",
 	"dead",
diff --git a/src/lib/swim/swim_proto.h b/src/lib/swim/swim_proto.h
index 59a4d2086..ddf9e28db 100644
--- a/src/lib/swim/swim_proto.h
+++ b/src/lib/swim/swim_proto.h
@@ -540,4 +540,14 @@ swim_inaddr_eq(const struct sockaddr_in *a1, const struct sockaddr_in *a2)
 	       a1->sin_addr.s_addr == a2->sin_addr.s_addr;
 }
 
+/**
+ * A wrapper around sio_strfaddr() so as to 1) do not clog SWIM
+ * code with huge casts to 'struct sockaddr *' and passes of
+ * sizeof(struct sockaddr_in); 2) copy on tt_static_buf instead of
+ * internal singleton sio buffer - otherwise non-first invocation
+ * of sio_strfaddr() rewrites the previous one.
+ */
+const char *
+swim_inaddr_str(const struct sockaddr_in *addr);
+
 #endif /* TARANTOOL_SWIM_PROTO_H_INCLUDED */
-- 
2.20.1 (Apple Git-117)