Question

First of all I am showing the PHP code ….

<?php 

 echo ("hello");

 echo exec("sendip -v -p ipv6 -6s 2001::100 -p tcp -ts 21 -td 21 2001::200 2> 
 &1");

 echo ("hi");

 ?>

When I entered the command through linux command line it is working fine.The command is sending a tcp ipv6 packet on 2001::200 machine from 2001::100.

[root@udit-pc]# sendip -v  -p ipv6 -6s 2001::100 -p tcp -ts 21 
-td 21 2001::200 > /dev/null &

/* (-v for verbose) */    

Output of above command …

 Added 34 options
 Initializing module ipv6
 Initializing module tcp
 Finalizing module tcp
 Finalizing module ipv6
 Final packet data:
 60 00 00 00   `...
 /*

  here other packet 
  contents gets printed

  */

 7D 62 00 00   }b..
 61 62 63 64   abcd
 Sent 64 bytes to 2001::200
 Freeing module ipv6
 Freeing module tcp

When I execute the php script through command line…

[root@udit-pc]# php test.php
Freeing module tcp

hellohi gets printed and packet arrived at 2001::200.

But problem arise when I try to run php script through browser…

 http:://localhost/test.php

hellohi gets printed but packet does not arrive at other machine.

 sh: sendip: command not found

Also in both case packet contents are not printed at terminal although using verbose option but when directly using command verbose option works fine.

I tried with many things although I do not think they would help like……

1. I added /usr/local/lib and usr/local/bin to PATH variable but no benefit.

2. chmod +s /usr/local/bin/sendip .Sticky bit set but again no benefit.

3. paste the /usr/local/bin/sendip itself in /var/www/html folder although I have changed the PATH variable but as i said i m just using hit n trial getting no clue…..

There are some output snapshots which may further help ….

[root@cc html]# echo $PATH
/usr/lib/qt-3.3/bin:/usr/kerberos/sbin:/usr/kerberos/bin:
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin: 
/usr/X11R6/bin:/root/bin:/usr/local/lib

[root@cc html]# locate sendip
.....
/usr/local/bin/sendip
/usr/local/lib/sendip
.....

 [root@cc bin]# chmod +s sendip
 [root@cc bin]# ls -l sendip
 -rwsrwsrwx 1 apache apache 41071 Sep 26 19:41 sendip

 [root@cc bin]# cd /usr/local/lib/
 [root@cc lib]# ls -ld sendip
 drwxrwxrwx 2 root root 4096 Sep 28 22:48 sendip
 [root@cc lib]# chmod +s sendip
 [root@cc lib]# ls -ld sendip
 drwsrwsrwx 2 root root 4096 Sep 28 22:48 sendip

When file contents are changed …….

 <?php
 echo exec("/usr/bin/sendip ........  2 > &1");
 ?>

Then oputput is :

 [root@cc html]# php test.php
 Freeing module tcp[root@cc html]# 

On browser….
No error gets printed but packet still not arrived.

I am stuck in between.Please suggest me what else should I rather try ??????/

Answer 1

is sendip() in the path of the shell being invoked by PHP? You’re not checking for error conditions, so possibly you’re not actually executing sendip, and just getting a “no such program or file” type errors.

Instead of redirecting the exec()’d command’s output to null, redirect it all to the browser so you can see what happens:

echo exec("sendiip yada yada yada 2>&1");