January 2004
Intermediate to advanced
464 pages
14h 47m
English
Content preview from Squid: The Definitive Guide
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Name
deny_info
Synopsis
This directive allows you to show specific error messages to users when a request matches certain ACL elements. This is more informative than sending a generic “access denied” error message, as happens by default.
When Squid checks its access control rules to see whether or not a particular request is allowed or denied, it remembers the ACL element that causes the search to terminate. You can use these ACL element names in a deny_info line to correlate error messages with a specific request characteristic. Consider, for example, this configuration:
acl Unsafe_Ports 7 9 19 22 23 25 53 109 110 119 ... http_access deny Unsafe_Ports ... deny_info ERR_PORT_IS_UNSAFE Unsafe_Ports
When a user makes a request to an origin server on one of the ports listed in the Unsafe_Ports ACL, Squid denies the request. Furthermore, Squid generates an error message from the ERR_PORT_IS_UNSAFE file, found in the error_directory directory.
Alternatively, you can specify a URI instead of an error message template. In this case, Squid sends an HTTP 302 (Moved Temporarily) redirect to the given URI.
Finally, if you specify TCP_RESET as the error message template,
Squid closes the client’s connection in a way that generates a TCP
reset.
Syntax | deny_info |
Default | No default |
Example | deny_info ERR_PORT_IS_UNSAFE Unsafe_Ports |
Related | error_directory, acl |
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.