public inbox for linux-bluetooth@vger.kernel.org
 help / color / mirror / Atom feed
From: Tuomas Suutari <thsuut@utu.fi>
To: bluez-devel@lists.sourceforge.net
Subject: [Bluez-devel] rfcomm_sock_sendmsg with len==0 (in Linux 2.6.18)
Date: Tue, 19 Dec 2006 11:03:20 +0200	[thread overview]
Message-ID: <200612191103.20942.thsuut@utu.fi> (raw)

Hello.

I've made a buffer for socket connections to use with C++ iostreams. 
It's quite simple; just uses send and recv to fill and empty the buffer 
when needed.

It worked fine for a while, but yesterday some strange errors occured 
with it. After few hours of debugging I found that code responsible was 
using syscall send() to Bluetooth socket with buffer length set to 0. 
Problem was that I assumed it to return either -1 on error or 0 when 
success, but instead it returned positive values sometimes. 

Ok, it was stupid calling send() with len==0 anyway, but still (at least 
according to manual) send shouldn't return anything positive then. So I 
traced what kernel code is responsible and found it's 
rfcomm_sock_sendmsg() in net/bluetooth/rfcomm/sock.c. It returns 
uninitialized variable err, if called with len==0.

Simple fix is to initialize err to 0.

-- 
Tuomas Suutari | +358 50 3806983 | thsuut@utu.fi

-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys - and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel

             reply	other threads:[~2006-12-19  9:03 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-19  9:03 Tuomas Suutari [this message]
2006-12-19  9:39 ` [Bluez-devel] rfcomm_sock_sendmsg with len==0 (in Linux 2.6.18) Marcel Holtmann
2006-12-19  9:47   ` Tuomas Suutari
2006-12-19 10:31     ` Marcel Holtmann
2006-12-19 10:41       ` Luciano Coelho
2006-12-19 10:57       ` Tuomas Suutari

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=200612191103.20942.thsuut@utu.fi \
    --to=thsuut@utu.fi \
    --cc=bluez-devel@lists.sourceforge.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox