| mini_httpd(8) | System Manager's Manual | mini_httpd(8) |
mini_httpd - small HTTP server
mini_httpd [-C configfile] [-p port] [-d dir] [-dd data_dir] [-c cgipat] [-u user] [-h hostname] [-r] [-v] [-l logfile] [-i pidfile] [-T charset] [-P P3P] [-M maxage] [-S] [-E certfile] [-Y cipher] [-D] [-V]
mini_httpd is a small HTTP server. Its performance is not great, but for low or medium traffic sites it's quite adequate. It implements all the basic features of an HTTP server, including:
It can also be configured to do SSL/HTTPS.
mini_httpd was written for a couple reasons. One, as an experiment to see just how slow an old-fashioned forking web server would be with today's operating systems. The answer is, surprisingly, not that slow - on FreeBSD 3.2, mini_httpd benchmarks at about 90% the speed of Apache. The other main reason for writing mini_httpd was to get a simple platform for experimenting with new web server technology, for instance SSL.
mini_httpd supports the CGI 1.1 spec.
In order for a CGI program to be run, its name must match the pattern you specify with the -c flag This is a simple shell-style filename pattern. You can use * to match any string not including a slash, or ** to match any string including slashes, or ? to match any single character. You can also use multiple such patterns separated by |. The patterns get checked against the filename part of the incoming URL. Don't forget to quote any wildcard characters so that the shell doesn't mess with them.
Basic Authentication uses a password file called ".htpasswd", in the directory to be protected. This file is formatted as the familiar colon-separated username/encrypted-password pair, records delimited by newlines. The protection does not carry over to subdirectories. The utility program htpasswd(1) is included to help create and modify .htpasswd files.
chroot() is a system call that restricts the program's view of the filesystem to the current directory and directories below it. It becomes impossible for remote users to access any file outside of the initial directory. The restriction is inherited by child processes, so CGI programs get it too. This is a very strong security measure, and is recommended. The only downside is that only root can call chroot(), so this means the program must be started as root. However, the last thing it does during initialization is to give up root access by becoming another user, so this is safe.
Note that with some other web servers, such as NCSA httpd, setting up a directory tree for use with chroot() is complicated, involving creating a bunch of special directories and copying in various files. With mini_httpd it's a lot easier, all you have to do is make sure any shells, utilities, and config files used by your CGI programs and scripts are available. If you have CGI disabled, or if you make a policy that all CGI programs must be written in a compiled language such as C and statically linked, then you probably don't have to do any setup at all.
However, one thing you should do is tell syslogd about the chroot tree, so that mini_httpd can still generate syslog messages. Check your system's syslodg man page for how to do this. In FreeBSD you would put something like this in /etc/rc.conf:
Substitute in your own chroot tree's pathname, of course. Don't worry about creating the log socket, syslogd wants to do that itself. (You may need to create the dev directory.) In Linux the flag is -a instead of -l, and there may be other differences.
syslogd_flags="-l /usr/local/www/data/dev/log"
Multihoming means using one machine to serve multiple hostnames. For instance, if you're an internet provider and you want to let all of your customers have customized web addresses, you might have www.joe.acme.com, www.jane.acme.com, and your own www.acme.com, all running on the same physical hardware. This feature is also known as "virtual hosts". There are three steps to setting this up.
One, make DNS entries for all of the hostnames. The current way to do this, allowed by HTTP/1.1, is to use CNAME aliases, like so:
However, this is incompatible with older HTTP/1.0 browsers. If you want to stay compatible, there's a different way - use A records instead, each with a different IP address, like so:
www.acme.com IN A 192.100.66.1
www.joe.acme.com IN CNAME www.acme.com
www.jane.acme.com IN CNAME www.acme.com
This is bad because it uses extra IP addresses, a somewhat scarce resource. But if you want people with older browsers to be able to visit your sites, you still have to do it this way.
www.acme.com IN A 192.100.66.1
www.joe.acme.com IN A 192.100.66.200
www.jane.acme.com IN A 192.100.66.201
Step two. If you're using the modern CNAME method of multihoming, then you can skip this step. Otherwise, using the older multiple-IP-address method you must set up IP aliases or multiple interfaces for the extra addresses. You can use ifconfig(8)'s alias command to tell the machine to answer to all of the different IP addresses. Example:
If your OS's version of ifconfig doesn't have an alias command, you're probably out of luck.
ifconfig le0 www.acme.com
ifconfig le0 www.joe.acme.com alias
ifconfig le0 www.jane.acme.com alias
Third and last, you must set up mini_httpd to handle the multiple hosts. The easiest way is with the -v flag. This works with either CNAME multihosting or multiple-IP multihosting. What it does is send each incoming request to a subdirectory based on the hostname it's intended for. All you have to do in order to set things up is to create those subdirectories in the directory where mini_httpd will run. With the example above, you'd do like so:
If you're using old-style multiple-IP multihosting, you should also create symbolic links from the numeric addresses to the names, like so:
mkdir www.acme.com www.joe.acme.com www.jane.acme.com
This lets the older HTTP/1.0 browsers find the right subdirectory.
ln -s www.acme.com 192.100.66.1
ln -s www.joe.acme.com 192.100.66.200
ln -s www.jane.acme.com 192.100.66.201
There's an optional alternate step three if you're using multiple-IP multihosting: run a separate mini_httpd process for each hostname, using the -h flag to specify which one is which. This gives you more flexibility, since you can run each of these processes in separate directories or with different options. Example:
But remember, this multiple-process method does not work with CNAME multihosting ‐ for that, you must use a single mini_httpd process with the -v flag.
( cd /usr/www ; mini_httpd -h www.acme.com )
( cd /usr/www/joe ; mini_httpd -u joe -h www.joe.acme.com )
( cd /usr/www/jane ; mini_httpd -u jane -h www.jane.acme.com )
mini_httpd lets you define your own custom error pages for the various HTTP errors. There's a separate file for each error number, all stored in one special directory. The directory name is "errors", at the top of the web directory tree. The error files should be named "errNNN.html", where NNN is the error number. So for example, to make a custom error page for the authentication failure error, which is number 401, you would put your HTML into the file "errors/err401.html". If no custom error file is found for a given error number, then the usual built-in error page is generated.
If you're using the virtual hosts option, you can also have different custom error pages for each different virtual host. In this case you put another "errors" directory in the top of that virtual host's web tree. mini_httpd will look first in the virtual host errors directory, and then in the server-wide errors directory, and if neither of those has an appropriate error file then it will generate the built-in error.
Sometimes another site on the net will embed your image files in their HTML files, which basically means they're stealing your bandwidth. You can prevent them from doing this by using non-local referrer filtering. With this option, certain files can only be fetched via a local referrer. The files have to be referenced by a local web page. If a web page on some other site references the files, that fetch will be blocked. There are three config-file variables for this feature:
For most sites, that one setting is all you need to enable referrer filtering.
urlpat=**.jpg|**.gif|**.au|**.wav
mini_httpd will terminate cleanly upon receipt of a number of different signals, which you can send via the standard Unix kill(1) command. Any of SIGTERM, SIGINT, or SIGUSR1 will do the trick. All requests in progress will be completed. The network socket used to accept new connections gets closed immediately, which means a fresh mini_httpd can be started up right away. This is convenient when you're rotating your log files.
In addition, a SIGHUP will attempt to close and re-open the log file. This is a little tricky to set up correctly, for instance if you are using chroot() then the log file must be within the chroot tree, but it's definitely doable.
If you're going to serve SSL/HTTPS you will need a server certificate. There are a bunch of companies that will issue one for you; see the lists at http://www.apache-ssl.org/#Digital_Certificates and http://www.modssl.org/docs/2.4/ssl_faq.html#ToC23
You can also create one for yourself, using the openssl tool. Step one - create the key and certificate request:
Step two ‐ remove the passphrase from the key:
openssl req -new > cert.csr
Step three ‐ convert the certificate request into a signed certificate:
openssl rsa -in privkey.pem -out key.pem
This creates four files. The ones you want are cert.pem and key.pem. You don't need cert.csr and privkey.pem, and may remove them.
openssl x509 -in cert.csr -out cert.pem -req -signkey key.pem -days 365
Copyright © 1999,2000 by Jef Poskanzer <jef@mail.acme.com>. All rights reserved.
| 05 October 1999 |