From: Stefan Metzmacher <metze@samba.org>
Date: Tue, 2 Oct 2012 10:20:26 +0000 (+0200)
Subject: lib/tsocket: fix loop in tdgram_bsd_recvfrom() (bug #9184)
X-Git-Url: http://git.samba.org/?p=metze%2Fsamba%2Fwip.git;a=commitdiff_plain;h=730d4e5e7c66f4f296e7e4c2919ce9ce53370792

lib/tsocket: fix loop in tdgram_bsd_recvfrom() (bug #9184)

If the socket is not readable yet, we need to retry
if tsocket_bsd_pending() returns 0.

See also
https://lists.samba.org/archive/samba-technical/2012-October/087164.html

metze
---

diff --git a/lib/tsocket/tsocket_bsd.c b/lib/tsocket/tsocket_bsd.c
index d5721b4d94ef..135fd027aa56 100644
--- a/lib/tsocket/tsocket_bsd.c
+++ b/lib/tsocket/tsocket_bsd.c
@@ -792,7 +792,7 @@ static int tdgram_bsd_set_writeable_handler(struct tdgram_bsd *bsds,
 
 struct tdgram_bsd_recvfrom_state {
 	struct tdgram_context *dgram;
-
+	bool first_try;
 	uint8_t *buf;
 	size_t len;
 	struct tsocket_address *src;
@@ -826,6 +826,7 @@ static struct tevent_req *tdgram_bsd_recvfrom_send(TALLOC_CTX *mem_ctx,
 	}
 
 	state->dgram	= dgram;
+	state->first_try= true;
 	state->buf	= NULL;
 	state->len	= 0;
 	state->src	= NULL;
@@ -876,6 +877,13 @@ static void tdgram_bsd_recvfrom_handler(void *private_data)
 	bool retry;
 
 	ret = tsocket_bsd_pending(bsds->fd);
+	if (state->first_try && ret == 0) {
+		state->first_try = false;
+		/* retry later */
+		return;
+	}
+	state->first_try = false;
+
 	err = tsocket_bsd_error_from_errno(ret, errno, &retry);
 	if (retry) {
 		/* retry later */