From 4c62ab9c538bc09c38093fa079e6902ea4d42b98 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Tue, 16 Nov 2010 09:50:47 -0800 Subject: [PATCH] irda: irttp: allow zero byte packets Sending zero byte packets is not neccessarily an error (AF_INET accepts it, too), so just apply a shortcut. This was discovered because of a non-working software with WINE. See http://bugs.winehq.org/show_bug.cgi?id=19397#c86 http://thread.gmane.org/gmane.linux.irda.general/1643 for very detailed debugging information and a testcase. Kudos to Wolfgang for those! Reported-by: Wolfgang Schwotzer Signed-off-by: Wolfram Sang Tested-by: Mike Evans Signed-off-by: David S. Miller --- net/irda/irttp.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/net/irda/irttp.c b/net/irda/irttp.c index 285761e77d90..6cfaeaf2a370 100644 --- a/net/irda/irttp.c +++ b/net/irda/irttp.c @@ -550,16 +550,23 @@ EXPORT_SYMBOL(irttp_close_tsap); */ int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb) { + int ret = -1; + IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;); IRDA_ASSERT(skb != NULL, return -1;); IRDA_DEBUG(4, "%s()\n", __func__); + /* Take shortcut on zero byte packets */ + if (skb->len == 0) { + ret = 0; + goto err; + } + /* Check that nothing bad happens */ - if ((skb->len == 0) || (!self->connected)) { - IRDA_DEBUG(1, "%s(), No data, or not connected\n", - __func__); + if (!self->connected) { + IRDA_DEBUG(1, "%s(), Not connected\n", __func__); goto err; } @@ -576,7 +583,7 @@ int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb) err: dev_kfree_skb(skb); - return -1; + return ret; } EXPORT_SYMBOL(irttp_udata_request); @@ -599,9 +606,15 @@ int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb) IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__, skb_queue_len(&self->tx_queue)); + /* Take shortcut on zero byte packets */ + if (skb->len == 0) { + ret = 0; + goto err; + } + /* Check that nothing bad happens */ - if ((skb->len == 0) || (!self->connected)) { - IRDA_WARNING("%s: No data, or not connected\n", __func__); + if (!self->connected) { + IRDA_WARNING("%s: Not connected\n", __func__); ret = -ENOTCONN; goto err; } -- GitLab