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1 .\" Copyright (c) 2022, 2023 Omar Polo <op@omarpolo.com>
2 .\"
3 .\" Permission to use, copy, modify, and distribute this software for any
4 .\" purpose with or without fee is hereby granted, provided that the above
5 .\" copyright notice and this permission notice appear in all copies.
6 .\"
7 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
10 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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12 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
13 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14 .Dd July 24, 2023
15 .Dt GMID.CONF 5
16 .Os
17 .Sh NAME
18 .Nm gmid.conf
19 .Nd gmid Gemini server configuration file
20 .Sh DESCRIPTION
21 .Nm
22 is the configuration file format for the
23 .Xr gmid 8
24 Gemini server.
25 .Pp
26 The configuration file is divided into the following sections:
27 .Bl -tag -width Ds
28 .It Sy Macros
29 User-defined variables may be defined and used later, simplifying the
30 configuration file.
31 .It Sy Global Options
32 Global settings for
33 .Xr gmid 8 .
34 .It Sy Servers
35 Virtual hosts definition.
36 .It Sy Types
37 Media types and extensions.
38 .El
39 .Pp
40 Within the sections, empty lines are ignored and comments can be put
41 anywhere in the file using a hash mark
42 .Pq Sq #
43 and extend to the end of the current line.
44 A boolean is either the symbol
45 .Sq on
46 or
47 .Sq off .
48 A string is a sequence of characters wrapped in double quotes,
49 .Dq like this .
50 Multiple strings one next to the other are joined into a single
51 string:
52 .Bd -literal -offset indent
53 # equivalent to "temporary-failure"
54 block return 40 "temporary" "-" "failure"
55 .Ed
56 .Pp
57 Furthermore, quoting is necessary only when a string needs to contain
58 special characters
59 .Pq like spaces or punctuation ,
60 something that looks like a number or a reserved keyword.
61 The last example could have been written also as:
62 .Bd -literal -offset indent
63 block return 40 temporary "-" failure
64 .Ed
65 .Pp
66 Strict ordering of the sections is not enforced, so that is possible
67 to mix macros, options and
68 .Ic server
69 blocks.
70 However, defining all the
71 .Ic server
72 blocks after the macros and the global options is recommended.
73 .Pp
74 Newlines are often optional, except around top-level instructions, and
75 semicolons
76 .Dq \&;
77 can also be optionally used to separate options.
78 .Pp
79 Additional configuration files can be included with the
80 .Ic include
81 keyword, for example:
82 .Bd -literal -offset indent
83 include "/etc/gmid.conf.local"
84 .Ed
85 .Ss Macros
86 Macros can be defined that will later be expanded in context.
87 Macro names must start with a letter, digit or underscore and may
88 contain any of those characters.
89 Macros names may not be reserved words.
90 Macros are not expanded inside quotes.
91 .Pp
92 Two kinds of macros are supported: variable-like and proper macros.
93 When a macro is invoked with a
94 .Dq $
95 before its name its expanded as a string, whereas when it's invoked
96 with a
97 .Dq @
98 its expanded in-place.
99 .Pp
100 For example:
101 .Bd -literal -offset indent
102 ext_ip = "10.0.0.1"
103 dir = "/var/gemini"
104 certdir = "/etc/keys"
105 common = "lang it; auto index on"
107 server "foo" {
108 listen on $ext_ip
109 root $dir "/foo" # "/var/gemini/foo"
110 cert $certdir "/foo.pem" # "/etc/keys/foo.pem"
111 key $certdir "/foo.key" # "/etc/keys/foo.key"
112 @common
114 .Ed
115 .Ss Global Options
116 .Bl -tag -width 12m
117 .It Ic chroot Ar path
118 .Xr chroot 2
119 the process to the given
120 .Ar path .
121 The daemon has to be run with root privileges and thus the option
122 .Ic user
123 needs to be provided too, so privileges can be dropped afterwards.
124 All the paths in the configuration file are relative to the chroot
125 directory, except for the
126 .Ic cert ,
127 .Ic key
128 and
129 .Ic ocsp
130 paths.
131 Defaults to the
132 .Ic user
133 home directory, if provided.
134 .It Ic log Ar options
135 Specify logging options.
136 Multiple options may be provided within curly braces.
137 The available options are as follows:
138 .Bl -tag -width Ds
139 .It Ic access Ar file
140 Log the requests to
141 .Ar file .
142 The path is relative to the
143 .Ic chroot .
144 .It Ic style Ar style
145 Set the logging style, defaults to
146 .Ic legacy .
147 The
148 .Ar style
149 can be one of:
150 .Bl -tag -width Ds
151 .It Ic common
152 Attempt to be compatible with the default Apache httpd log format.
153 Each line is formatted as follows: the matching host name,
154 the remote IP address, one dash
155 .Sq - ,
156 Common Name of the client certificate
157 .Pq if provided, '-' otherwise ,
158 the timestamp of the request, the request URI wrapped in double quotes,
159 the response code and the size of the response.
160 .It Ic combined
161 Attempt to be compatible with the default nginx log format.
162 Each line is formatted as follows: the remote IP address, one dash
163 .Sq - ,
164 Common Name of the client certificate
165 .Pq if provided, '-' otherwise ,
166 the timestamp wrapped in square brackets, the request URI wrapped in
167 double quotes, the response code, the size of the response, a dash
168 wrapped in double quotes and "".
169 The strangness of these two last fields is because Gemini doesn't have
170 the notion of the
171 .Dq Referer
172 header nor the
173 .Dq User-agent .
174 .\" .It Ic condensed
175 .\" The native
176 .\" .Xr gmid 8
177 .\" format since 2.0.
178 .\" Each line is formatted as follows: RFC 3339 date time,
179 .\" remote IP address, Common Name of the client certificate
180 .\" .Pq if provided, '-' otherwise ,
181 .\" the matching host name, the request URI, the size of the request,
182 .\" the size of the response, the response code and meta.
183 .It Ic legacy
184 Each line is formatted as follows: the remote IP address and port, the
185 .Sq GET
186 keyword, the request URI, the response code and meta.
187 .El
188 .It Ic syslog Op Ic off
189 Log to syslog.
190 It is enabled by default, use the
191 .Ic off
192 argument to disable.
193 .It Ic syslog facility Ar facility
194 Log to
195 .Xr syslog 3
196 using specified
197 .Ar facility .
198 Available facilities are as follows: daemon, ftp, local0 through local7 and
199 user.
200 These are case insensitive and can be prefixed with
201 .Sq LOG_ .
202 Not all level may be available on all operating systems.
203 The default facility is
204 .Ev LOG_DAEMON .
205 .El
206 .It Ic prefork Ar number
207 Run the specified number of server processes.
208 This increases the performance and prevents delays when connecting to
209 a server.
210 .Xr gmid 8
211 runs 3 server processes by default.
212 The maximum number allowed is 16.
213 .It Ic protocols Ar string
214 Specify the TLS protocols to enable.
215 Refer to
216 .Xr tls_config_parse_protocols 3
217 for the valid protocol string values.
218 By default, both TLSv1.3 and TLSv1.2 are enabled.
219 Use
220 .Dq tlsv1.3
221 to enable only TLSv1.3.
222 .It Ic user Ar string
223 Run the daemon as the given user.
224 Mandatory if the
225 .Ic chroot
226 option is used.
227 .El
228 .Ss Servers
229 Every virtual host is defined by a
230 .Ic server
231 block:
232 .Bl -tag -width Ds
233 .It Ic server Ar hostname Brq ...
234 Match the server name using shell globbing rules.
235 It can be an explicit name,
236 .Ar www.example.com ,
237 or a name including a wildcards,
238 .Ar *.example.com .
239 .El
240 .Pp
241 Followed by a block of options that is enclosed in curly brackets:
242 .Bl -tag -width Ds
243 .It Ic alias Ar name
244 Specify an additional alias
245 .Ar name
246 for this server.
247 .It Ic auto Ic index Ar bool
248 If no index file is found, automatically generate a directory listing.
249 Disabled by default.
250 .It Ic block Op Ic return Ar code Op Ar meta
251 Send a reply and close the connection;
252 by default
253 .Ar code
254 is 40
255 and
256 .Ar meta
257 is
258 .Dq temporary failure .
259 If
260 .Ar code
261 is in the 3x range, then
262 .Ar meta
263 is mandatory.
264 Inside
265 .Ar meta ,
266 the following special sequences are supported:
267 .Bl -tag -width Ds -compact
268 .It \&%\&%
269 is replaced with a single
270 .Sq \&% .
271 .It \&%p
272 is replaced with the request path.
273 .It \&%q
274 is replaced with the query string of the request.
275 .It \&%P
276 is replaced with the server port.
277 .It \&%N
278 is replaced with the server name.
279 .El
280 .It Ic cert Ar file
281 Path to the certificate to use for this server.
282 .Ar file
283 should contain a PEM encoded certificate.
284 This option is mandatory.
285 .It Ic default type Ar string
286 Set the default media type that is used if the media type for a
287 specified extension is not found.
288 If not specified, the
289 .Ic default type
290 is set to
291 .Dq application/octet-stream .
292 .It Ic fastcgi Ar option
293 Enable FastCGI instead of serving files.
294 Multiple options may be specified within curly braces.
295 Valid options are:
296 .Bl -tag -width Ds
297 .It Ic param Ar name Cm = Ar value
298 Set the param
299 .Ar name
300 to
301 .Ar value .
302 .It Ic socket Oo Ic tcp Oc Ar socket Oo Cm port Ar port Oc
303 The
304 .Ar socket
305 can either be a UNIX-domain socket or a TCP socket.
306 If the FastCGI application is listening on a UNIX domain socket,
307 .Ar socket
308 is a local path name within the
309 .Xr chroot 2
310 root directory of
311 .Xr gmid 8 .
312 Otherwise, the
313 .Ic tcp
314 keyword must be provided and
315 .Ar socket
316 is interpreted as a hostname or an IP address.
317 .Ar port
318 can be either a port number or the name of a service enclosed in
319 double quotes.
320 If not specified defaults to 9000.
321 .It Ic strip Ar number
322 Strip
323 .Ar number
324 leading path components from the
325 .El
326 .Pp
327 The FastCGI handler will be given the following variables by default:
328 .Bl -tag -width 24m
329 .It Ev GATEWAY_INTERFACE
330 .Dq CGI/1.1
331 .It Ev GEMINI_DOCUMENT_ROOT
332 The root directory of the virtual host.
333 .It Ev GEMINI_SCRIPT_FILENAME
334 Full path to the FastCGI script being executed.
335 .It Ev GEMINI_URL
336 The full IRI of the request.
337 .It Ev GEMINI_URL_PATH
338 The path of the request.
339 .It Ev GEMINI_SEARCH_STRING
340 The decoded
341 .Ev QUERY_STRING
342 if defined in the request and if it doesn't contain any unencoded
343 .Sq =
344 characters, otherwise unset.
345 .It Ev PATH_INFO
346 The portion of the requested path that is derived from the the IRI
347 path hierarchy following the part that identifies the script itself.
348 Can be unset.
349 .It Ev PATH_TRANSLATED
350 Present if and only if
351 .Ev PATH_INFO
352 is set.
353 It represent the translation of the
354 .Ev PATH_INFO .
355 .Nm gmid
356 builds this by appending the
357 .Ev PATH_INFO
358 to the virtual host directory root.
359 .It Ev QUERY_STRING
360 The URL-encoded search or parameter string.
361 .It Ev REMOTE_ADDR , Ev REMOTE_HOST
362 Textual representation of the client IP.
363 .It Ev REQUEST_METHOD
364 This is present only for RFC3875 (CGI) compliance.
365 It's always set to the empty string.
366 .It Ev SCRIPT_NAME
367 The virtual URI path to the script.
368 .It Ev SERVER_NAME
369 The name of the server
370 .It Ev SERVER_PORT
371 The port the server is listening on.
372 .It Ev SERVER_PROTOCOL
373 .Dq GEMINI
374 .It Ev SERVER_SOFTWARE
375 The name and version of the server, i.e.
376 .Dq gmid/1.8.4
377 .It Ev AUTH_TYPE
378 The string "Certificate" if the client used a certificate, otherwise
379 unset.
380 .It Ev REMOTE_USER
381 The subject of the client certificate if provided, otherwise unset.
382 .It Ev TLS_CLIENT_ISSUER
383 The is the issuer of the client certificate if provided, otherwise
384 unset.
385 .It Ev TLS_CLIENT_HASH
386 The hash of the client certificate if provided, otherwise unset.
387 The format is
388 .Dq ALGO:HASH .
389 .It Ev TLS_VERSION
390 The TLS version negotiated with the peer.
391 .It Ev TLS_CIPHER
392 The cipher suite negotiated with the peer.
393 .It Ev TLS_CIPHER_STRENGTH
394 The strength in bits for the symmetric cipher that is being used with
395 the peer.
396 .It Ev TLS_CLIENT_NOT_AFTER
397 The time corresponding to the end of the validity period of the peer
398 certificate in the ISO 8601 format
399 .Pq e.g. Dq 2021-02-07T20:17:41Z .
400 .It Ev TLS_CLIENT_NOT_BEFORE
401 The time corresponding to the start of the validity period of the peer
402 certificate in the ISO 8601 format.
403 .El
404 .It Ic fastcgi off
405 Disable FastCGI handling in the current location.
406 .It Ic index Ar string
407 Set the directory index file.
408 If not specified, it defaults to
409 .Pa index.gmi .
410 .It Ic key Ar file
411 Specify the private key to use for this server.
412 .Ar file
413 should contain a PEM encoded private key.
414 This option is mandatory.
415 .It Ic lang Ar string
416 Specify the language tag for the text/gemini content served.
417 If not specified, no
418 .Dq lang
419 parameter will be added in the response.
420 .It Ic listen on Ar address Op Ic port Ar number
421 Set the listen
422 .Ar address
423 and
424 .Ar port
425 which defaults to
426 .Sq 1965 .
427 This statement can be specified multiple times.
428 If
429 .Ar address
430 is
431 .Sq *
432 then
433 .Xr gmid 8
434 will listen on all IPv4 and IPv6 addresses.
435 .Ar 0.0.0.0
436 can be used to listen on all IPv4 addresses and
437 .Ar ::
438 on all IPv6 addresses.
439 .It Ic location Ar path Brq ...
440 Specify server configuration rules for a specific location.
441 .Ar path
442 argument will be matched against the request path with shell globbing
443 rules.
444 In case of multiple location statements in the same context, the first
445 matching location will be put into effect and the later ones ignored.
446 Therefore is advisable to match for more specific paths first and for
447 generic ones later on.
449 .Ic location
450 section may include most of the server configuration rules
451 except
452 .Ic alias , Ic cert , Ic key , Ic listen , Ic location
453 and
454 .Ic proxy .
455 .It Ic log Ar bool
456 Enable or disable the logging for the current server or location block.
457 .It Ic ocsp Ar file
458 Specify an OCSP response to be stapled during TLS handshakes
459 with this server.
460 The
461 .Ar file
462 should contain a DER-format OCSP response retrieved from an
463 OCSP server for the
464 .Ic cert
465 in use.
466 If the OCSP response in
467 .Ar file
468 is empty, OCSP stapling will not be used.
469 The default is to not use OCSP stapling.
470 .It Ic proxy Oo Cm proto Ar name Oc Oo Cm for-host Ar host Oo Cm port Ar port Oc Oc Brq ...
471 Set up a reverse proxy.
472 The optional matching rules
473 .Cm proto
474 and
475 .Cm for-host
476 can be used to enable proxying only for protocols matching
477 .Ar name
478 .Po Dq gemini
479 by default
480 .Pc
481 and/or whose request IRI matches
482 .Ar host
483 and
484 .Ar port
485 .Pq 1965 by default .
486 Matching happens using shell globbing rules.
487 .Pp
488 In case of multiple matching proxy blocks in the same context, the
489 first matching proxy will be put into effect and the later ones
490 ignored.
491 .Pp
492 Valid options are:
493 .Bl -tag -width Ds
494 .It Ic cert Ar file
495 Specify the client certificate to use when making requests.
496 .It Ic key Ar file
497 Specify the client certificate key to use when making requests.
498 .It Ic protocols Ar string
499 Specify the TLS protocols allowed when making remote requests.
500 Refer to the
501 .Xr tls_config_parse_protocols 3
502 function for the valid protocol string values.
503 By default, both TLSv1.2 and TLSv1.3 are enabled.
504 .It Ic relay-to Ar host Op Cm port Ar port
505 Relay the request to the given
506 .Ar host
507 at the given
508 .Ar port ,
509 1965 by default.
510 This is the only mandatory option in a
511 .Ic proxy
512 block.
513 .It Ic require Ic client Ic ca Ar file
514 Allow the proxying only from clients that provide a certificate
515 signed by the CA certificate in
516 .Ar file .
517 .It Ic sni Ar hostname
518 Use the given
519 .Ar hostname
520 instead of the one extracted from the
521 .Ic relay-to
522 rule for the TLS handshake with the proxied gemini server.
523 .It Ic use-tls Ar bool
524 Specify whether to use TLS when connecting to the proxied host.
525 Enabled by default.
526 .It Ic verifyname Ar bool
527 Enable or disable the TLS server name verification.
528 Enabled by default.
529 .El
530 .It Ic root Ar directory
531 Specify the root directory for this server
532 .Pq alas the current Dq document root .
533 It's relative to the chroot if enabled.
534 .It Ic require Ic client Ic ca Ar path
535 Allow requests only from clients that provide a certificate signed by
536 the CA certificate in
537 .Ar path .
538 It needs to be a PEM-encoded certificate and it's not relative to the
539 chroot.
540 .It Ic strip Ar number
541 Strip
542 .Ar number
543 components from the beginning of the path before doing a lookup in the
544 root directory.
545 It's also considered for the
546 .Ar meta
547 parameter in the scope of a
548 .Ic block return .
549 .El
550 .Ss Types
551 The
552 .Ic types
553 section must include one or more lines of the following syntax, enclosed
554 in curly brances:
555 .Bl -tag -width Ds
556 .It Ar type Ns / Ns Ar subtype Ar name Op Ar name ...
557 Set the media
558 .Ar type
559 and
560 .Ar subtype
561 to the specified extension
562 .Ar name .
563 One or more names can be specified per line.
564 Earch line may end with an optional semicolon.
565 .It Ic include Ar file
566 Include types definition from an external file, for example
567 .Pa /usr/share/misc/mime.types .
568 .El
569 .Pp
570 By default
571 .Nm gmid
572 uses the following mapping if no
573 .Ic types
574 block is defined:
575 .Pp
576 .Bl -tag -offset indent -width 15m -compact
577 .It application/pdf
578 pdf
579 .It image/gif
580 gif
581 .It image/jpeg
582 jpg jpeg
583 .It image/png
584 png
585 .It image/svg+xml
586 svg
587 .It text/gemini
588 gemini gmi
589 .It text/markdown
590 markdown md
591 .It text/x-patch
592 diff patch
593 .It text/xml
594 xml
595 .El
596 .Pp
597 As an exception,
598 .Nm gmid
599 uses the MIME type
600 .Ar text/gemini
601 for file extensions
602 .Ar gemini
603 or
604 .Ar gmi
605 if no mapping was found.
606 .Sh EXAMPLES
607 The following is an example of a possible configuration for a site
608 that enables only TLSv1.3, adds the MIME types mapping from
609 .Pa /usr/share/misc/mime.types
610 and defines two virtual host:
611 .Bd -literal -offset indent
612 protocols "tlsv1.3"
614 types {
615 include "/usr/share/misc/mime.types"
618 server "example.com" {
619 listen on * port 1965
620 cert "/etc/ssl/example.com.pem"
621 key "/etc/ssl/private/example.com.key"
622 root "/var/gemini/example.com"
625 server "example.it" {
626 listen on * port 1965
627 cert "/etc/ssl/example.it.pem"
628 key "/etc/ssl/private/example.it.key"
629 root "/var/gemini/example.it"
631 # set the language for text/gemini files
632 lang "it"
634 .Ed
635 .Pp
636 Yet another example, showing how to enable a
637 .Ic chroot
638 and use
639 .Ic location
640 rule
641 .Bd -literal -offset indent
642 chroot "/var/gemini"
643 user "_gmid"
645 server "example.com" {
646 listen on * port 1965
648 # absolute paths:
649 cert "/etc/ssl/example.com.pem"
650 key "/etc/ssl/private/example.com.key"
652 # relative to the chroot:
653 root "/example.com"
655 location "/static/*" {
656 # load the following rules only for
657 # requests that matches "/static/*"
659 auto index on
660 index "index.gemini"
663 .Ed
664 .Pp
665 This shows how to set up a reverse proxy: all request for
666 .Sq example.com
667 will be forwarded to 10.0.0.6 transparently.
668 Proxying establish a new TLS connection, so any client-certificates used
669 to connect to
670 .Xr gmid 8
671 cannot be provided to the proxied server as well.
672 .Bd -literal -offset indent
673 server "example.com" {
674 listen on * port 1965
675 cert "/etc/ssl/example.com.pem"
676 key "/etc/ssl/private/example.com.key"
677 proxy {
678 relay-to 10.0.0.6 port 1965
681 .Ed
682 .Sh SEE ALSO
683 .Xr gmid 8 ,
684 .Xr slowcgi 8
685 .Sh AUTHORS
686 .An -nosplit
687 The
688 .Nm gmid
689 program was written by
690 .An Omar Polo Aq Mt op@omarpolo.com .