From: Vincent Bernat <bernat@luffy.cx>
Date: Sat, 30 Mar 2013 14:42:51 +0000 (+0100)
Subject: lib: fix sync_recv to handle segmentation
X-Git-Tag: 0.7.2~19
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e581ec3043d528cadb56c5d49b1b29c92fa78d83;p=thirdparty%2Flldpd.git

lib: fix sync_recv to handle segmentation

While it should not happen with Unix sockets, a read() can return only
partial data. Therefore, we continue to poll until we get the
appropriate length.

This fix was proposed by Chris Yang. Closes #31.
---

diff --git a/src/lib/connection.c b/src/lib/connection.c
index 3b3227cc..2fe7c44d 100644
--- a/src/lib/connection.c
+++ b/src/lib/connection.c
@@ -68,6 +68,7 @@ sync_recv(lldpctl_conn_t *lldpctl,
 {
 	struct lldpctl_conn_sync_t *conn = user_data;
 	size_t nb;
+	size_t remain, offset = 0;
 
 	if (conn->fd == -1 &&
 	    ((conn->fd = sync_connect(lldpctl)) == -1)) {
@@ -75,14 +76,17 @@ sync_recv(lldpctl_conn_t *lldpctl,
 		return LLDPCTL_ERR_CANNOT_CONNECT;
 	}
 
-	while ((nb = read(conn->fd, (void*)data, length)) == -1) {
-		if (errno == EAGAIN || errno == EINTR) continue;
-		return LLDPCTL_ERR_CALLBACK_FAILURE;
-	}
-	return nb;
+	remain = length;
+	do {
+		if ((nb = read(conn->fd, (void*)data + offset, remain)) == -1 &&
+		    (errno == EAGAIN || errno == EINTR))
+			continue;
+		remain -= nb;
+		offset += nb;
+	} while (remain > 0 && nb > 0);
+	return offset;
 }
 
-
 lldpctl_conn_t*
 lldpctl_new(lldpctl_send_callback send, lldpctl_recv_callback recv, void *user_data)
 {