Ensure that message are logged to syslog when appropriate, even in child handlers.
[ashd.git] / doc / htparser.doc
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1htparser(1)
2===========
3
4NAME
5----
e7e3e593 6htparser - Root HTTP server for use with ashd(7)
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7
8SYNOPSIS
9--------
10*htparser* [*-hSf*] [*-u* 'USER'] [*-r* 'ROOT'] [*-p* 'PIDFILE'] 'PORTSPEC'... `--` 'ROOT' ['ARGS'...]
11
12DESCRIPTION
13-----------
14
15The *htparser* program is the root HTTP server of *ashd*(7). It
16listens to specified TCP ports, speaks HTTP with connecting clients,
17and passes requests on to the root handler program.
18
19When *htparser* starts, it will first begin listening to all ports
20specified by 'PORTSPEC'. Once all ports have been bound successfully,
21it will fork off and start the root handler specified by 'ROOT',
22searching the *PATH* environment variable if necessary, and passing it
23all the 'ARGS' as command-line arguments. Only after that will
24*htparser* do any daemonizing or chrooting as specified by options.
25
26The root handler must be a persistent program as specified in
27*ashd*(7). If the handler program exits, *htparser* will exit too.
28
29PORT SPECIFICATION
30------------------
31
32'PORTSPEC' is given in the form
33'HANDLER'[*:*'PAR'[*=*'VAL'][(*,*'PAR'[*=*'VAL'])...]]. The
34'PAR'='VAL' pairs are used for specifying key-value arguments to the
35'HANDLER'. An example of a valid 'PORTSPEC' is `plain:port=8080`.
36
37Currently, the available 'HANDLERs' are *plain* and *ssl*, for
38handling plain TCP connections and SSL/TLS-protected connections,
39respectively. For details regarding the arguments that each handler
40accept, simply run *htparser* with 'HANDLER':*help*. For example, the
41command "`htparser ssl:help`" will display help for the *ssl* handler to
42standard output and then exit.
43
44The port specifications must be followed by the `--` argument to
45distinguish them from the root handler specification.
46
47OPTIONS
48-------
49
50*-h*::
51
52 Print a brief usage message on standard output and exit.
53
54*-S*::
55
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56 Log messages to *syslog*(3) instead of standard error. Also
57 sets the environment ASHD_USESYSLOG environment variable in
58 the root handler process, which indicates to the standard ashd
59 programs to do the same thing.
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60
61*-f*::
62
63 Daemonize after all specified ports have been successfully
64 bound and the root handler has been started.
65
66*-u*::
67
68 Change UID to 'USER' once all specified ports have been
69 successfully bound and the root handler has been
70 started. 'USER' must be specified symbolically (i.e. not as a
71 numeric UID).
72
73*-r*::
74
75 Change root directory to 'ROOT' once all specified ports have
76 been successfully bound and the root handler has been started.
77
78*-p*::
79
80 After having daemonized, write the PID of the new process to
81 'PIDFILE'.
82
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83EXAMPLES
84--------
85
86`htparser plain -- dirplex /srv/www`::
87
88 This simple invocation will simply listen for HTTP requests on
89 port 80 and use *dirplex*(1) to serve files from the /srv/www
90 directory.
91
92`htparser plain:port=8080 -- dirplex /srv/www`::
93
94 The same as the previous example, but uses port 8080 instead,
95 so that it can be started without root privileges.]
96
97`htparser plain ssl:cert=/etc/ssl/private/web.pem -- dirplex /srv/www`::
98
99 The same as above, but will listen on port 443 for SSL
100 connections as well. The file `/etc/ssl/privte/web.pem` needs
101 to contain both the server certificate and its private key.
102
103`htparser plain -- sudo -u www-user dirplex /srv/www`::
104
105 The same as above, but uses *sudo*(8) to ensure that *dirplex*
106 runs as a non-privileged user.
107
108`htparser -f -u nobody -r /var/empty plain -- patplex /etc/ashd/rootpat`::
109
110 Will listen to port 80 for plain HTTP requests and use the
111 *patplex*(1) program to serve requests based on patterns
112 specified in the `/etc/ashd/rootpat` file. *htparser* will
113 daemonize, change user-ID to `nobody` and change its root
114 directory to `/var/empty` once *patplex* has been
115 started. Note that *patplex* still runs as root in the normal
116 file system, so that it can start other handler programs as
117 needed.
118
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119X-ASH HEADERS
120-------------
121
122*htparser* strips away all headers from incoming requests that begin
123 with the `X-Ash-` prefix, and adds the following headers to requests:
124
125*X-Ash-Address*::
126
127 The IP address that the client connected from. May be an IPv6
128 address.
129
130*X-Ash-Port*::
131
132 The client-side port number of the TCP connection.
133
134*X-Ash-Server-Address*::
135
136 The IP address of the server where the connection was
137 accepted. May be an IPv6 address.
138
139*X-Ash-Server-Port*::
140
141 The server-side port number of the TCP connection.
142
143*X-Ash-Protocol*::
144
145 Either *http* or *https*, depending on whether the request was
146 received by the *plain* or the *ssl* handler.
147
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148AUTHOR
149------
150Fredrik Tolf <fredrik@dolda2000.com>
151
152SEE ALSO
153--------
154*ashd*(7)