This is an old revision of the document!
Table of Contents
Web Server
The Synchronet Web Server serves static (e.g. files) and dynamic content to HTTP clients (e.g. web browsers).
Introduction
The Synchronet Web Server is a mostly HTTP 1.1 compliant web server capable of handing basic web servicing tasks. It has most of the basic features of a general-purpose web server one would come to expect, including (Fast)CGI.
It also, through Server-Side JavaScript (SSJS), allows dynamic pages to be created which can access BBS data directly.
Configure
The Synchronet Web Server can be configured via SCFG->Servers->Web Server:
╔══════════════════════════════════════════════════════════════════════╗ ║ Web Server ║ ╠══════════════════════════════════════════════════════════════════════╣ ║ │Enabled Yes ║ ║ │Log Level Informational ║ ║ │HTTP Interfaces 0.0.0.0, :: ║ ║ │HTTP Port 80 ║ ║ │HTTPS Support Yes ║ ║ │HTTPS Interfaces 0.0.0.0 ║ ║ │HTTPS Port 443 ║ ║ │SSJS File Extension .ssjs ║ ║ │Index Filenames index.html, index.ssjs, index.php, ind║ ║ │Content Root Directory ../webv4/root ║ ║ │Error Sub-directory error ║ ║ │Strict Transport Security No ║ ║ │Virtual Host Support Yes ║ ║ │Access Logging <disabled> ║ ║ │Max Clients 100 ║ ║ │Max Inactivity 1 minute ║ ║ │Filebase Index Script webfileindex.ssjs ║ ║ │Filebase VPath Prefix /files/ ║ ║ │Filebase VPath for VHosts Yes ║ ║ │Authentication Methods Basic,Digest,TLS-PSK ║ ║ │Output Buffer Drain Timeout 10 ms ║ ║ │Lookup Client Hostname No ║ ║ │CGI Support No ║ ╚══════════════════════════════════════════════════════════════════════╝
... or via SBBSCTRL->Web->Configure:
sbbs.ini
The [Web] section of your sbbs.ini file supports the following configuration settings (keys):
| Key | Default | Description |
|---|---|---|
| AutoStart | true | Automatically start-up the server when Synchronet is started |
| HostName | none | Override system hostname |
| LogLevel | Informational | Default minimum severity of log messages to view or log-to-disk |
| TLSErrorLevel | Emergency | Maximum severity of TLS-related log messages |
| Interface | 0.0.0.0,:: | Comma-separated list of IPv4 and IPv6 addresses of network interfaces and optional port numbers to listen for incoming HTTP/TCP connections |
| TLSInterface | Interface | ... for incoming HTTPS/TLS connections |
| Port | 80 | Default TCP port to listen for incoming HTTP connections |
| TLSPort | 443 | Default TCP port to listen for incoming HTTPS/TLS connections |
| BindRetryCount | 2 | Default number of network interface/port bind retry attempts |
| BindRetryDelay | 15 | Default number of seconds to wait between bind attempts |
| MaxClients | unlimited | Maximum number of simultaneous connections supported (0 = unlimited) |
| MaxInactivity | 2m | Maximum duration of client inactivity before disconnection |
| MaxCgiInactivity | 2m | Maximum duration of CGI application inactivity |
| SemFileCheckFrequency | global (2) | Seconds between semaphore file checks |
| IndexFileNames | index.html,index.ssjs | Index filenames to search for and serve up (when no file name was requested) |
| RootDirectory | ../web/root | Files are served out of this directory tree |
| ErrorDirectory | error | Sub-directory of RootDirectory where error files are served from |
| CGIDirectory | cgi-bin | Sub-directory of RootDirectory where CGI applications are served from |
| DefaultCGIContent | text/plain | Default MIME-type of CGI content |
| CGIExtensions | .cgi | Comma-separate list of file extensions (suffixes) used to recognize CGI application files |
| JavaScriptExtension | .ssjs | File extension used to recognize Server-side JavaScript content files |
| Authentication | Basic,Digest,TLS-PSK | Authentication methods supported |
| HttpLogFile | data/logs/http- | Path prefix for HTTP access log files |
| FileIndexScript | “” | Server-side JavaScript to execute to provide HTML/CSS library and directory listings of virtual file paths |
| FileVPathPrefix | “” | Virtual path for file base access, suggested value: /files/ |
| FileVPathForVHosts | false | If you'd like your virtual hosts to have virtual file path access, set this to true |
| OutbufDrainTimeout | 10 | Number of milliseconds to wait for output buffer to drain |
| TempDirectory | ../temp/ | Override default temporary file directory |
| Options | See below for details |
Options
Default value: NO_HOST_LOOKUP | HTTP_LOGGING
The Options key is set to a | separated list of options to enable. In addition to the standard options, the web server also supports the following:
DEBUG_RX
Log all received data to the console log, as well as various extra bits related to receiving data.
DEBUG_TX
Log all transmitted data except the reply body itself, as well as various extra bits of information related to transmitted data.
DEBUG_SSJS
Log server-side JavaScript execution details.
VIRTUAL_HOSTS
Supports name-based virtual hosts. If your system has multiple
host names, you can have each host name return unique content
depending on which hostname is used. ie: if
freebsd.synchro.net and nix.synchro.net both resolved to your
system, you could have FreeBSD-specific pages on one, and
general *nix stuff on the other.
A virtual host is added by simply putting the desired content
into a sub-directory of RootDirectory with the desired hostname
ie: web/root/freebsd.synchro.net/ if the browser doesn't send
the request host name (very old browsers, or some automated
tools) they will be served out of document root.
It is therefore a good idea to put links to your various
virtual hosts in an index.html page in RootDirectory something
like this:
<html> <head> <title>Old Browser</title> </head> <body> Your browser is either too old to support name-based virtual hosts, or you have visited a virtual hosts that is not yet configured. The following are hosted here:<br> <a href="freebsd.synchro.net">freebsd.synchro.net</a><br> <a href="nix.synchro.net">nix.synchro.net</a><br> </body> </html>
NO_CGI
Disable CGI script execution.
HTTP_LOGGING
Enable logging to a Common Logfile Format log as described in the HttpLogFile section. Usefull for running log analysis programs (like Webalizer: http://www.mrunix.net/webalizer/)
NO_JAVASCRIPT
Disable SSJS execution.
ALLOW_TLS
Enable TLS support.
HSTS_SAFE
Indicates that all URLs available via http are also available via https and redirects clients who want a TLS session to the https location.
Reference
Web Server configuration settings reference:
RootDirectory
Default value: ../web/root
This is the root directory of your web server... a request to
http://yourbbs.synchro.net/index.html will be served out of this directory.
NOTE: Older versions of Synchronet had this value default to ../web/html
ErrorDirectory
Default value: error
The directory relative to RootDirectory where the various error
message files are located. The error message files are named by the
numeric HTTP error code they will represent and may be either .html
or .ssjs files (.ssjs files take precedence over .html files for the
same error).
IndexFileNames
Default value: index.html,index.ssjs
A comma-separated list of filenames in order of preference to serve as
the default document in a directory. Many Sysops change this to:
index.html,index.htm,index.ssjs.
Do not remove the index.ssjs unless you are not using the stock
web pages at all.
Authorization
Default value: Basic,Digest
A comma-separated list of authentication mechanisms in order of preference. The standards say that Basic must come first, but no browser currently appears to use Digest if Basic is listed first. Supported values are Basic and Digest. Digest is more secure as the users password is not sent in the clear over the wire.
CGIDirectory
Default value: cgi-bin
A directory relative to RootDirectory where any files found will be considered CGI-executable. Be careful what files you put in this directory.
CGIExtensions
Default value: .cgi
A comma-separated list of file extensions/suffixes. Files with these extensions will be considered CGI-executable and the web server will attempt to execute them as such.
Other probably values include: .pl,.php,.exe
DefaultCGIContent
Default value: text/plain
If the CGI program does not generate a content-type header, this value will be used for the MIME content-type specified in the HTTP response.
JavaScriptExtension
Default value: .ssjs
Files with this extension will be considered SSJS files. On all systems, this will be attempted to run with the JavaScript interpreter.
MaxInactivity
Default value: 120
If a client holds a connection open for this many seconds without a request, the web server will shut down the connection.
MaxCgiInactivity
Defalut value: 120
If a CGI script runs for more than this many seconds without any output, it will be terminated and the connection will be shut down.
HttpLogFile
Default value: ../data/logs/http-
The prefix of log files if HTTP_LOGGING is enabled (See next item) to
store Common Logfile Format logs in. The current virtual host
(if enabled, see next item), date, and .log are appended to this (e.g.http-2005-03-12.log).
FileVPathPrefix
Default value: “”
Suggested value: /files/
A virtual sub-directory of your web root to provide direct HTTP[S] access to your file bases. HTTP-AUTH is used for conditional access/restrictions, when necessary. The trailing slash is important.
FileVPathForVHosts
Default value: false
By default, virtual hosts will not have the virtual file path (if enabled). Set this to true if you would like your virtual hosts to support the virtual file paths as well.
FileIndexScript
Default value: “”
Suggested value: webfileindex.ssjs
A Server-side JavaScript (SSJS) file to execute and provide HTML/CSS indexes to file libraries and directories accessed via virtual file paths.
Other configuration files
In addition to the [Web] keys in the sbbs.ini file, the web server
also uses some other configuration files:
ctrl/mime_types.ini
Contains the file extension to mime-type mapping. Each line is in the format “extension = mime-type” ie: “html = text/html” The extensions are case-insensitive and do not include the '.'.
ctrl/webicons.ini
Contains the URLs to the icons used by the default 404.ssjs script for each file type/extension. Format is “extension = URL”. Example: “html=/icons/layout.gif”. Two “magical” extensions exist: DIRECTORY which is used for directories and DefaultIcon which is used for extensions which don't exist in the list.
ctrl/web_handler.ini
This file contains 2 sections where a list of file extensions and their associated content-creation handlers are specified:
[CGI]
The [CGI] section is for natively-executed CGI handlers (e.g. “pl = perl” indicates “perl” will be used to handle “.pl” files).
[JavaScript]
The [JavaScript] section is used for JS-executed content handlers (e.g. “xjs = xjs_handler.js”).
ctrl/cgi_env.ini
Contains a list of system environment variables to pass to CGI processes. Each variable can have an optionally specified default value, over-ridden value, and prepended or appended text.
webctrl.ini
Each directory under the RootDirectory may have a webctrl.ini file which overrides certain settings for
the directory it's in and all child directories. Configuration keys may be set
either globally, in a per-filename group, or, in version 3.17 or greater, a per-directory-name group.
Using the * and ? wildcards as the group name such as [*.html] or [dirname/]. The following keys may be used in these files:
AccessRequirements
Specifies an ARS string which all users must match to be able to access files in this directory. Will force an HTTP login.
For example, to require a login, but allow any user to access files in a
directory, but only a sysop to access *.log files and .git directories, the following could be used:
AccessRequirements=level 0 [*.log] AccessRequirements=level 90 [*.git] AccessRequirements=level 90
Realm
Sets the realm that is displayed to the user for the HTTP login. Default is the BBS name.
DigestRealm
Sets the realm that is displayed to the user for the HTTP login when Digest authentication is being used. Default is the Realm value.
Authorization
A comma-separated list of authentication mechanisms in order of
preference. The standards say that Basic must come first, but no
browser currently appears to use Digest if Basic is listed first.
Supported values are Basic and Digest. Digest is more secure as the
users password is never sent over the wire.
ErrorDirectory
Specifies a different directory to check for error pages. If the error page is not found, will still check the global error directory.
CGIDirectory
Specify an alternate CGI directory to check for CGI files.
PathInfoIndex
Specifies that the index files can be ran for unlocated pages in the current directory. This effecively works like a custom 404 page.
FastCGISocket
Specifies the socket address of a FastCGI listener in either <Address>:<Port> format (e.g. 127.0.0.1:9000) or unix:/path/to/unix/socket format. Should be used with wildcard sections like this:
[*.php] FastCGISocket=127.0.0.1:9000
See php for details on using with PHP.
Rewrite*
Specifies a Javascript snippet which can modify the http_request.request_string. This allows internal redirects like the RewriteRule feature in Apache .htaccess files. The key must *begin* with the string “Rewrite” which may be followed by any legal INI key characters. The order of execution is not guaranteed.
RewriteDetail=var n=http_request.request_string.replace(/_detail\/(.*)/,"lib/exe/detail.php?media=$1"); if(n != http_request.request_string) { http_request.request_string=n; true }
If the expression returns “true”, reparses http_request.request_string as an internal redirect.
Added on November 3rd, 2015 to CVS (in 3.17a). (Commit)
JSPreExec
A JavaScript snippet which is executed in the same context as Rewrite* lines, but before any Rewrites are executed. This allows load()ing some common code before execution... ie: JSPreExec=load(js.startup_dir+'/rewrite_lib.js');.
Added on November 3rd, 2015 to CVS (in 3.17a).
JavaScript Objects
In addition to the standard JavaScript objects, the web server provides the following:
http_request object
The http_request object contains information from the client that was included during this request. This objects properties are as follows:
path_info
Contains extra path information that was included with the
request AFTER the URI which identified this script. For
example, if the request was for
http://www.synchro.net/script.ssjs/test/this then path_info
would contain the string “/test/this”
method
Contains the HTTP method used to run the script. As of this writing, the available methods are “HEAD”, “GET”, “POST”, and “OPTIONS”
virtual_path
The virtual path that this URI was reached by. This is the portion of the URI from the end of the host to the end of the filename.
query
This object contains the values of any form data which was submitted with the request. This is an associative “array” of name/value pairs. THE VALUES ARE ARRAYS OF STRINGS. The reason for this is that it is legal and often useful to have multiple form fields with the same name.
query_string
If a query string was included, this is the raw, unparsed query string.
post_data
As with query_string but for data which was POSTed.
header
An associative array of header name/value pairs.
cookie
Much like the query object, this object contains key/value pairs of set cookies. Once again, this is an array of strings since multiple values for the same key can be set for cookies.
real_path
The real OS's complete path to this script.
ars
The ARS string which applies to this request.
request_string
The raw request string sent by the client.
host
The value of the host header for this request.
vhost
The virtual host serving this request.
http_ver
The HTTP version used for this request as a string.
remote_ip
The IP address of the client.
remote_host
If the web server does host lookups (disabled by default), this is the remote hostname.
scheme
“https” if TLS is in use, “http” otherwise.
http_reply object
The http_reply object is used to pass information about the reply back to the Synchronet web server. The properties are as follows:
status
HTTP status string. The default is generally “200 Ok”
header
An associative array of headers to include with the reply. The only pre-defined one is “Content-Type” which defaults to “text/html”.
fast
This optional property can be set to “true” to make write()s go directly to the client for HTTP/1.0 connections. This prevents keep-alives from working but generally appears faster to the client. Since HTTP/1.1 requests use chunked mode, this isn't required for HTTP/1.1.
Extra global methods
The web server also adds a new global JavaScript method that requests that the specified cookie be set:
set_cookie(string key,
string value
[, time_t expires
[, string domain
[, string path
[, bool secure ]]]])
Extra global variables
web_root_dir
The path to the web server's document root directory.
See also: the RootDirectory key under [Web] in sbbs.ini.
XJS files
XJS files, handled by exec/xjs_handler.js are what many people consider to be
an easier method of generating SSJS files. XJS files are HTML files with JS
commands embedded in them using special tags much like PHP. XJS files are
translated on-the-fly to .ssjs files using the same name with .ssjs appended.
For example, a file named test.xjs will, when ran, generate a test.xjs.ssjs
file.
XJS syntax
In an XJS file, everything not within a special xjs tag is send to the remote host unmodified, and everything inside the xjs tag is interpreted as JS statements to be executed at that point in the file. The xjs tag begins with either “<?xjs” or “<?” and ends with “?>”. A simple example would be:
<html><head><title><?xjs write(system.name) ?></title></head> <body> Your SysOp "<?xjs write(system.operator) ?>" welcomes you to <?xjs write(system.name) ?> </body> </html>
This would send the following web page to the remote system:
<html><head><title>My Brand New BBS</title></head> <body> Your SysOp "Sysop" welcomes you to My Brand New BBS </body> </html>
Looping constructs are permitted, however, not using brackets can result in unexpected effects. Because of this, it is reccomended to *always* use brackets with looping and flow control items.
The following example displays the numbers from one to 10.
<html><head><title>Counter</title></head> <body> <?xjs var i; for(i=1; i<=10; i++) { ?> <?xjs write(i) ?><br> <?xjs } ?> </body> </html>
XJS-specific global methods and properties
The following JavaScript methods and properties are available to XJS files only.
xjs_load(filename)
Runs the specified xjs file at the current position. Local variables
are NOT visible to xjs_load()ed pages. The filename is assumed to be
relative to the including file (or absolute.)
cwd
Contains the path that the current xjs script was loaded from and which
parameters to xjs_load() are assumed to be relative to. If you change
the value of cwd, it will change the location where xjs_load() will
check for files.
