[syslinux:master] dns: don't get stuck on no packet received

[syslinux-bot for H. Peter Anvin]

Commit-ID:  14b77079a892dc42219217688684ed9d6c4d0e3d
Gitweb:     http://syslinux.zytor.com/commit/14b77079a892dc42219217688684ed9d6c4d0e3d
Author:     H. Peter Anvin <hpa at zytor.com>
AuthorDate: Mon, 21 Jun 2010 10:11:59 -0700
Committer:  H. Peter Anvin <hpa at zytor.com>
CommitDate: Mon, 21 Jun 2010 10:11:59 -0700

dns: don't get stuck on no packet received

Make sure the timeout actually gets processed.  The right thing to do
for the receive loop is to check for timeout, then try to receive, and
loop until an acceptable packet has been received; we might as well do
that explicitly.

Signed-off-by: H. Peter Anvin <hpa at zytor.com>


---
 core/fs/pxe/dnsresolv.c |   15 +++++----------
 1 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/core/fs/pxe/dnsresolv.c b/core/fs/pxe/dnsresolv.c
index 76a905a..2b263fa 100644
--- a/core/fs/pxe/dnsresolv.c
+++ b/core/fs/pxe/dnsresolv.c
@@ -247,7 +247,10 @@ uint32_t dns_resolv(const char *name)
             continue;
 
         oldtime = jiffies();
-	while (1) {
+	do {
+	    if (jiffies() - oldtime >= timeout)
+		goto again;
+
             udp_read.status      = 0;
             udp_read.src_ip      = srv;
             udp_read.dest_ip     = IPInfo.myip;
@@ -256,16 +259,8 @@ uint32_t dns_resolv(const char *name)
             udp_read.buffer_size = PKTBUF_SIZE;
             udp_read.buffer      = FAR_PTR(DNSRecvBuf);
             err = pxe_call(PXENV_UDP_READ, &udp_read);
-            if (err || udp_read.status)
-                continue;
-
-            /* Got a packet, deal with it... */
-            if (hd2->id == hd1->id)
-                break;
+	} while (err || udp_read.status || hd2->id != hd1->id);
 
-	    if (jiffies() - oldtime >= timeout)
-		goto again;
-        }
         if ((hd2->flags ^ 0x80) & htons(0xf80f))
             goto badness;