Telnet: PHP and bash together

[Ravendark]

Hello,

 

I wrote a bash script that opens a telnet connection to a machine. Then again it opens another telnet connection within that machine (telnets to a card which has a local IP) and runs an uptime command. The script is:

 

#!/bin/bash

MSAN_IP=$1
SLOT_IP=$2
ARGS=2

if [ $# -ne $ARGS ]; then
echo "`basename $0`: Wrong number or parameter supplied"
echo "`basename $0`: Usage: `basename $0` <MSAN_IP> <SLOT_LOCAL_IP>"
exit 0;
else
expect << EOF

set timeout 5

spawn telnet $MSAN_IP 2323

expect "IPCP login: "

send "root\r"

expect "Password: "

send "***\r"

expect "~ # "

send "telnet 10.1.3.$SLOT_IP\r"

expect "60xADSL login: "

send "root\r"

expect "Password: "

send "weblin1\r"

expect "60xADSL# "

send "uptime\r"

expect "60xADSL# "

send "exit\r"

expect “~ # ”

send "exit\r"

exit

EOF
fi

 

Now...I have a php webpage as an interface for this script.

This is the code that calls the bash script:

 

exec("/var/www/html/slot_uptime/telnet_pots.sh $msan_ip $slot > /var/www/html/slot_uptime/uptime_pots.txt");
		$uptime = exec("cat /var/www/html/slot_uptime/uptime_pots.txt | grep load | awk -F \", load\" '{print \$1}'| awk -F \"up\" '{print \$2}'"); // | awk -F \", load\" '{print \$1}'
		if ($uptime == "") {
			echo "<h2>Could not retrieve uptime</h2><br>";
		}

 

The script works fine if I run it from the command line.

It even works fine when the php script calls it.

 

Though, there are 2 machines out of many that when the PHP script calls the bash script, the host closes the connection.

 

Successful output:

 

./telnet_adsl.sh 10.193.0.3 4
spawn telnet 10.193.0.3 2323
Trying 10.193.0.3...
Connected to 10.193.0.3.
Escape character is '^]'.

You are logging into Marconi IP Common Part "IPCP"

IPCP login: root
Password: 
~ # telnet 10.1.3.4

Entering character mode
Escape character is '^]'.


Linux 2.4.20_mvl31-wds-mips_fp_be (60xADSL) (0)

60xADSL login: root
Password: 

this is motd file to inform any information to user


BusyBox v1.00-rc2 (2004.08.03-10:23+0000) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

60xADSL# uptime
06:58:28 up 15 days,  8:10, load average: 0.00, 0.00, 0.00
60xADSL# exit
Connection closed by foreign host.

 

Not successful:

 

spawn telnet 10.193.0.5 2323
Trying 10.193.0.5...
Connected to 10.193.0.5.
Escape character is '^]'.
Connection closed by foreign host.

 

All the machines have the exactly the same software running on them (some sort or linux distro).

Any ideas?

 

Thanks in advance!

[requinix]

Though, there are 2 machines out of many that when the PHP script calls the bash script, the host closes the connection.

So it works when you try the bash script manually? What if you try manually running the exact same command the PHP script runs?

[Ravendark]

Do you mean running the php command from the command line?

[requinix]

Running the same command PHP tries to run:

$ /var/www/html/slot_uptime/telnet_pots.sh $msan_ip $slot > /var/www/html/slot_uptime/uptime_pots.txt

(after substituting values for those two variables, of course).

 

And as a sanity check, echo out that command and make sure it is what you expect.

[Ravendark]

yes it works fine

[requinix]

Does the remote software offer any logs you can look at? Are the two machines the last in the "list" or are they located at random within? If you shuffle the "list" does the situation change?

 

In your shoes I would be trying three things: finding more information (eg, logs, adding whatever debugging/verbosity options you have available), looking for patterns and similarities and differences (eg, two machines on a different subnet, not all running the same software with the same settings), and trying to change the outcome by manipulating the circumstances (eg, running the commands manually, rearranging lists).

[Ravendark]

Well it seems that I found what was wrong.

I forced the php "exec" to use bash

 

$uptime = exec("/bin/bash /var/www/html/slot_uptime/telnet_pots.sh $msan_ip $slot | grep load | awk -F \", load\" '{print \$1}' | awk -F \"up\" '{print \$2}'");

 

works ok now, thanks for all the help!