Curl hangs my apache server when doing POST to https - php

I have this very weird issue with curl, when I do a post request to my ubuntu apache server the apache server hangs, if I debug my php code I can see that
$fp = curl_exec($ch);
Never returns. I think the actual post request is correct because I can successfully do the same POST request with postman.
Below are my curl options :
$ch = curl_init();
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER , 0);
curl_setopt($ch,CURLOPT_URL, $this->url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch,CURLOPT_POST,true);
curl_setopt($ch,CURLOPT_HTTPHEADER,$testHeader);
curl_setopt($ch,CURLOPT_POSTFIELDS,$post_data);
$fp = curl_exec($ch);
One weird thing is that if im quick, and reload my apache server
sudo service apache reload
while its in this hanged state the curl_exec immediately returns and I get my data. Im not a real web developer and more of a windows guy so any help would be greatly appreciated. :)
UPDATE
I can see no error reporting from Curl since the process hangs. It never comes to the point where it can give me the error. When I reload the apache server the request returns and then there are no errors reported. I added the CURLOPT_VERBOSE option.
UPDATE 2:
OK I can also run the post from curl commandline both from the host and the client. Worth mentioning is that my host is a virtual machine. Beginning to think its more of a network thing.

OK I finally solved this stupid error with the help of this thread
PHP curl exec fail on php script same domain
The solution was to add:
session_write_close();
before the curl_exec
and then
session_start();
After. I hope I can help someone by writing it here.

Related

cURL not working sometimes and gives empty result

I used cURL to get data from another website. Sometimes it shows data and sometimes empty result
Here is my Code
function get_data($url) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
$agent=$_SERVER["HTTP_USER_AGENT"];
curl_setopt($ch,CURLOPT_USERAGENT, $agent);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER, false);
$data = curl_exec($ch);
curl_close($ch);
return $data;
}
$returned_content = get_data('www.example.com');
echo $returned_content;
Possibly you call too many connections from your curl_init to one Ip Address, So the server blocks the connection and causes the on/off errors.
Not receiving any content back could be due to one or more out of many different reasons and you need to figure out which.
Use curl_error($ch) in your code after the transfer has been performed to see if curl has told you about a problem.
Investigate the response headers. A HTTP transfer can be successful and not return any error but might only respond with HTTP headers and no body at all. The HTTP headers may then contain clues as to why. Perhaps it is a redirect you should follow, perhaps it requires HTTP authentication or perhaps the server indicates a temporary server glitch.
Curl in PHP returns null on AWS EC2 instance
I had similar issue and I fixed it by making sure versions and settings in php.ini file which is in PHP5 and Apache2 folders were same. If its not then Apache2 tries to execute versions set inside the php.ini settings. Also make sure PHP5-libcurl is installed. Its important too.
Possibly the intermittent failures are due to flaky DNS servers, even if it isn't, you'll still benefit from using Google's DNS servers..
See: https://developers.google.com/speed/public-dns/docs/using
Solution
Make sure you have no space for any variables or in url. Like "$user_name = "Lokman Hosen"". You have to give urldecode "$user_name = "Lokman_Hosen"" or "$user_name = "Lokman%20Hosen"". You can use
urldecode()
Function to remove space. Now cURL dont allow any space.

PHP curl call not working when the caller script is called from outside the LAN

So I am encountering a strange situation with a php curl request.
It works perfectly when the script is called from the same local network as the server which is running it but when somebody calls it from outside is not working anymore.
This is my code:
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, ROOT_DIR."directory/someScript.php");
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 1);
$output = curl_exec($ch);
curl_close($ch);
When I run someScript.php manually even from outside the LAN it works just fine. The issue occurs only when it I try to run it by calling it with curl via another php script.
Anybody have any idea? The curl library is enabled. And both scripts are on the same server.
I am using port forwarding on port 80 to make the server visible in the Internet.
I decided to post the solution in case somebody else has the same problem.
In the end I found the cause for this. The problem was that I was calling the script using the external IP instead of the internal one. Further more because of this XAMPP redirected the call to its default page and because I didn't use the output I did not noticed that.

How to resolve cURL Error (7): couldn't connect to host?

I send an item code to a web service in xml format using cUrl(php). I get the correct response in localhost, but when do it server it shows
cURL Error (7): couldn't connect to host
And here's my code:
function xml_post($post_xml, $url)
{
$user_agent = $_SERVER['HTTP_USER_AGENT'];
$ch = curl_init(); // initialize curl handle
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_FAILONERROR, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_TIMEOUT, 50);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_xml);
curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);
// curl_setopt($ch, CURLOPT_PORT, $port);
$data = curl_exec($ch);
$curl_errno = curl_errno($ch);
$curl_error = curl_error($ch);
if ($curl_errno > 0) {
echo "cURL Error ($curl_errno): $curl_error\n";
} else {
echo "Data received\n";
}
curl_close($ch);
echo $data;
}
I send the item code to the tally and fetch the details from it. I tried using both the versions php 4+ and php5+, nothing works out Any solution.
CURL error code 7 (CURLE_COULDNT_CONNECT)
is very explicit ... it means Failed to connect() to host or proxy.
The following code would work on any system:
$ch = curl_init("http://google.com"); // initialize curl handle
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$data = curl_exec($ch);
print($data);
If you can not see google page then .. your URL is wrong or you have some firewall or restriction issue.
“CURL ERROR 7 Failed to connect to Permission denied” error is caused, when for any reason curl request is blocked by some firewall or similar thing.
you will face this issue when ever the curl request is not with standard ports.
for example if you do curl to some URL which is on port 1234, you will face this issue where as URL with port 80 will give you results easily.
Most commonly this error has been seen on CentOS and any other OS with ‘SElinux’.
you need to either disable or change ’SElinux’ to permissive
have a look on this one
http://www.akashif.co.uk/php/curl-error-7-failed-to-connect-to-permission-denied
Hope this helps
If you have tried all the ways and failed, try this one command:
setsebool -P httpd_can_network_connect on
In PHP, If your network under proxy. You should set the proxy URL and port
curl_setopt($ch, CURLOPT_PROXY, "http://url.com"); //your proxy url
curl_setopt($ch, CURLOPT_PROXYPORT, "80"); // your proxy port number
This is solves my problem
In my case I had something like cURL Error (7): ... Operation Timed Out. I'm using the network connection of the company I'm working for. I needed to create some environment variables. The next worked for me:
In Linux terminal:
$ export https_proxy=yourProxy:80
$ export http_proxy=yourProxy:80
In windows I created (the same) environment variables in the windows way.
I hope it helps!
Regards!
Are you able to hit that URL by browser or by PHP script? The error shown is that you could not connect. So first confirm that the URL is accessible.
Check if port 80 and 443 are blocked. or enter - IP graph.facebook.com and enter it in etc/hosts file
you can also get this if you are trying to hit the same URL with multiple HTTP request at the same time.Many curl requests wont be able to connect and so return with error
This issue can also be caused by making curl calls to https when it is not configured on the remote device. Calling over http can resolve this problem in these situations, at least until you configure ssl on the remote.
In my case, the problem was caused by the hosting provider I was using blocking http packets addressed to their IP block that originated from within their IP block. Un-frickin-believable!!!
For a couple of days I was totally blocked on this. I'm very very new to networking/vms but was keen to try set it up myself instead of paying a hosting company to do it for me.
Context
I'm rebuilding the server side for an app that uses php routines to return various bits of data from internal sources as well as external APIs for a map based app. I have started an Oracle VM instance and have installed/set up Apache and php. All running totally fine, until one of my php routines tries to execute a cURL. I start implementing error logging to find that I don't even get a message - just '7', despite implementation being very similar to the above. My php routine accessing an internal file for data was running successfully so I was fairly sure it wasn't an Apache or php issue. I also checked my Apache error logs, nothing telling.
Solution
I nearly gave up - there's talk on disabling SELinux above and in other articles, I tried that and it did work for my purposes, but here's a really good article on why you shouldn't disable SELinux https://www.electronicdesign.com/technologies/embedded-revolution/article/21807408/dont-do-it-disabling-selinux
If temporarily disabling it works and like me you don't want to do this (but it confirms that SELinux is blocking you!), I found a neat little command that actually prints out any SELinux issues in a more readable fashion:
sealert -a /var/log/audit/audit.log
This returned the following:
found 1 alerts in /var/log/audit/audit.log
--------------------------------------------------------------------------------
SELinux is preventing php-fpm from name_connect access on the tcp_socket port 443.
Great, I now get a bit more information than just '7'. Reading further down, I can see it actually makes suggestions:
***** Plugin catchall_boolean (24.7 confidence) suggests ******************
If you want to allow httpd to can network connect
Then you must tell SELinux about this by enabling the 'httpd_can_network_connect' boolean.
Do
setsebool -P httpd_can_network_connect 1
This has been mentioned further above but now I have a bit more context and an explanation as to what it does. I run the command, and I'm in business. Furthermore, my SELinux is still set to enforcing, meaning my machine is more secure.
There are many other suggestions logged out, if you're blocked it might be worth logging out/checking out /var/log/audit/audit.log.

curl_exec($ch) not executing on external domains anymore, why?

I was using cURL to scrape content from a site and just recently my page stated hanging when it reached curl_exec($ch). After some tests I noticed that it could load any other page from my own domain but when attempting to load from anything external I'll get a connect() timeout! error.
Here's a simplified version of what I was using:
<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,'http://www.google.com');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 0);
$contents = curl_exec ($ch);
curl_close ($ch);
echo $contents;
?>
Here's some info I have about my host from my phpinfo():
PHP Version 5.3.1
cURL support enabled
cURL Information 7.19.7
Host i686-pc-linux-gnu
I don't have access to SSH or modifying the php.ini file (however I can read it). But is there a way to tell if something was recently set to block cURL access to external domains? Or is there something else I might have missed?
Thanks,
Dave
I'm not aware about any setting like that, it would not make much sense.
As you said you are on a remote webserver without console access I guess that your activity has been detected by the host or more likely it caused issues and so they firewalled you.
A silent iptables DROP would cause this.
When scraping google you need to use proxies for more than a few hand full of requests and you should never abuse your webservers primary IP if it's not your own. That's likely a breach of their TOS and could even result in legal action if they get banned from Google (which can happen).
Take a look at Google rank checker that's a PHP script that does exactly what you want using CURL and proper IP management.
I can't think of anything that's causing a timeout than a firewall on your side.
I'm not sure why you're getting a connect() timeout! error, but the following line:
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 0);
If it's not set to 1, it will not return any of the page's content back into your $contents.

getting the POST request from web server

I'm having troubles debugging a POST request I'm making from my web server to another web server.
I'm trying to communicate with a SOAP web service but from some reason a code that worked well from local machine fails when executing on my server
Looking for a way to see the post request my server make to the web service server
web server OS - CentOs
using PHP curl to make the request
Ideas anyone?
Wireshark? If you've got to connect to the remote end using SSL, then run a stunnel client on the soap client and route requests through that tapping in between.
I had the same problem, and using CURLINFO_HEADER_OUT made outgoing request headers show up in debug info.
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLINFO_HEADER_OUT, true);
$data = curl_exec($ch);
var_dump($data);
$details = curl_getinfo($ch);
var_dump($details);
To see the POST on the server
$h=fopen('out.txt','w');
fwrite($h,var_export($_POST,true));
Maybe the curl is disabled on your server
Or point your client at:
<?php print_r($_POST); ?>
C.
Redirect the post request to a server you control. You can then read the posted data using echo file_get_contents('php://input');

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