Bug#705223: netcat-openbsd: May send raw LF line endings even if the -C option is used

2013-04-13 Thread Jörgen Grahn 
On Fri Apr 12 13:45:28 2013, happyaron...@gmail.com wrote:
 Hi,
 
 Can you try netcat-openbsd in Wheezy? It contains quite some fixes and
 there is something related to CRLF handling.

Good suggestion. I experimented with it (netcat-openbsd_1.105-7_powerpc)
this morning. It /may/ behave slightly differently -- hard to tell,
since timing, ARP cache and so on is involved.  But in the end, my
complaint seems to apply to Wheezy too.

Here's part of the strace for netcat-openbsd_1.105-7 being fed by the
shell script.

  poll([{fd=3, events=POLLIN}, {fd=0, events=POLLIN}], 2, -1) = 1 ([{fd=0, 
revents=POLLIN}])
  read(0, foobar\nfoobar\nfoobar\nfoobar\nfoob..., 2048) = 42
  write(3, foobar\nfoobar\nfoobar\nfoobar\nfoob..., 41) = 41
  write(3, \r\n, 2) = 2
  poll([{fd=3, events=POLLIN}, {fd=0, events=POLLIN}], 2, -1) = 1 ([{fd=0, 
revents=POLLIN}])
  read(0, foobar\n, 2048)   = 7
  write(3, foobar, 6)   = 6
  write(3, \r\n, 2) = 2
  poll([{fd=3, events=POLLIN}, {fd=0, events=POLLIN}], 2, -1) = 1 ([{fd=0, 
revents=POLLIN}])
  read(0, foobar\n, 2048)   = 7
  write(3, foobar, 6)   = 6
  write(3, \r\n, 2) = 2
  poll([{fd=3, events=POLLIN}, {fd=0, events=POLLIN}], 2, -1) = 1 ([{fd=0, 
revents=POLLIN}])
  read(0, foobar\n, 2048)   = 7
  write(3, foobar, 6)   = 6
  write(3, \r\n, 2) = 2
  ...

I.e. when nc has connected to the server and is ready to transmit,
at least 42 bytes (6 lines) are already waiting on stdin.  But
nc assumes it's one line and just does one LF-CRLF translation.

I suspect the same thing could happen later in the stream, except nc is
fast enough in this scenario, and stdin is consumed line by line.

BR,
/Jorgen

-- 
  // Jörgen Grahn  | mot du jour: Daughter of Pomira  
\X/ gr...@snipabacken.se |  


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Bug#705223: netcat-openbsd: May send raw LF line endings even if the -C option is used

2013-04-11 Thread Jorgen Grahn 
Package: netcat-openbsd
Version: 1.89-4
Severity: normal


I was using this shell script to stress-test a TCP server I'm working on:

 #!/bin/bash
 
 action() {
 local delay=$1; shift
 local n=$1; shift
 
 while [ $((n--)) -gt 0 ] ; do
 echo foobar
 sleep $delay
 done
 }
 
 action $1 $2 | nc -C some-host some-port | wc

The server takes CRLF-separated commands/requests, and I was puzzled when
I found that it reported receiving fewer commands than I sent.

After debugging the server for a while with no luck, I finally saw that
the TCP stream from netcat contained some foobar\nfoobar\r\n patterns, e.g.
immediately after connection.

Whatever method the -C option uses to ensure translation of CR to CRLF, it's
not foolproof.  Maybe only slow manual input was considered.

My workaround was to stop using -C, and to add CRLF explicitly using
echo -ne foobar\r\n instead.

BR,
Jorgen

-- System Information:
Debian Release: 6.0.7
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: powerpc (ppc)

Kernel: Linux 3.4.10
Locale: LANG=sv_SE, LC_CTYPE=sv_SE (charmap=ISO-8859-1)
Shell: /bin/sh linked to /bin/dash

Versions of packages netcat-openbsd depends on:
ii  libc6 2.11.3-4   Embedded GNU C Library: Shared lib
ii  libglib2.0-0  2.24.2-1   The GLib library of C routines

netcat-openbsd recommends no packages.

netcat-openbsd suggests no packages.

-- no debconf information


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Bug#705223: netcat-openbsd: May send raw LF line endings even if the -C option is used

2013-04-11 Thread Aron Xu 
Hi,

Can you try netcat-openbsd in Wheezy? It contains quite some fixes and
there is something related to CRLF handling.



On Thu, Apr 11, 2013 at 9:37 PM, Jorgen Grahn
grahn+deb...@snipabacken.se wrote:
 Package: netcat-openbsd
 Version: 1.89-4
 Severity: normal


 I was using this shell script to stress-test a TCP server I'm working on:

 #!/bin/bash

 action() {
 local delay=$1; shift
 local n=$1; shift

 while [ $((n--)) -gt 0 ] ; do
 echo foobar
 sleep $delay
 done
 }

 action $1 $2 | nc -C some-host some-port | wc

 The server takes CRLF-separated commands/requests, and I was puzzled when
 I found that it reported receiving fewer commands than I sent.

 After debugging the server for a while with no luck, I finally saw that
 the TCP stream from netcat contained some foobar\nfoobar\r\n patterns, e.g.
 immediately after connection.

 Whatever method the -C option uses to ensure translation of CR to CRLF, it's
 not foolproof.  Maybe only slow manual input was considered.

 My workaround was to stop using -C, and to add CRLF explicitly using
 echo -ne foobar\r\n instead.

 BR,
 Jorgen

 -- System Information:
 Debian Release: 6.0.7
   APT prefers stable
   APT policy: (500, 'stable')
 Architecture: powerpc (ppc)

 Kernel: Linux 3.4.10
 Locale: LANG=sv_SE, LC_CTYPE=sv_SE (charmap=ISO-8859-1)
 Shell: /bin/sh linked to /bin/dash

 Versions of packages netcat-openbsd depends on:
 ii  libc6 2.11.3-4   Embedded GNU C Library: Shared 
 lib
 ii  libglib2.0-0  2.24.2-1   The GLib library of C routines

 netcat-openbsd recommends no packages.

 netcat-openbsd suggests no packages.

 -- no debconf information



-- 
Regards,
Aron Xu


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