.\" Copyright (c) 2022, 2023, 2024 Omar Polo .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .Dd June 6, 2024 .Dt GMID.CONF 5 .Os .Sh NAME .Nm gmid.conf .Nd gmid Gemini server configuration file .Sh DESCRIPTION .Nm is the configuration file format for the .Xr gmid 8 Gemini server. .Pp The configuration file is divided into the following sections: .Bl -tag -width Ds .It Sy Macros User-defined variables may be defined and used later, simplifying the configuration file. .It Sy Global Options Global settings for .Xr gmid 8 . .It Sy Types Media types and extensions. .It Sy Servers Virtual hosts definition. .El .Pp Within the sections, empty lines are ignored and comments can be put anywhere in the file using a hash mark .Pq Sq # and extend to the end of the current line. A boolean is either the symbol .Sq on or .Sq off . A string is a sequence of characters wrapped in double quotes, .Dq like this . Multiple strings one next to the other are joined into a single string: .Bd -literal -offset indent # equivalent to "temporary-failure" block return 40 "temporary" "-" "failure" .Ed .Pp Furthermore, quoting is necessary only when a string needs to contain special characters .Pq like spaces or punctuation , something that looks like a number or a reserved keyword. The last example could have been written also as: .Bd -literal -offset indent block return 40 temporary "-" failure .Ed .Pp Strict ordering of the sections is not enforced, so that is possible to mix macros, options and .Ic server blocks. However, defining all the .Ic server blocks after the macros and the global options is recommended. .Pp Newlines are often optional, except around top-level instructions, and semicolons .Dq \&; can also be optionally used to separate options. .Pp Additional configuration files can be included with the .Ic include keyword, for example: .Bd -literal -offset indent include "/etc/gmid.conf.local" .Ed .Ss Macros Macros can be defined that will later be expanded in context. Macro names must start with a letter, digit or underscore and may contain any of those characters. Macros names may not be reserved words. Macros are not expanded inside quotes. .Pp Two kinds of macros are supported: variable-like and proper macros. When a macro is invoked with a .Dq $ before its name its expanded as a string, whereas when it's invoked with a .Dq @ its expanded in-place. .Pp For example: .Bd -literal -offset indent ext_ip = "10.0.0.1" dir = "/var/gemini" certdir = "/etc/keys" common = "lang it; auto index on" server "foo" { listen on $ext_ip root $dir "/foo" # "/var/gemini/foo" cert $certdir "/foo.pem" # "/etc/keys/foo.pem" key $certdir "/foo.key" # "/etc/keys/foo.key" @common } .Ed .Ss Global Options .Bl -tag -width 12m .It Ic chroot Ar path .Xr chroot 2 the process to the given .Ar path . The daemon has to be run with root privileges and thus the option .Ic user needs to be provided too, so privileges can be dropped afterwards. All the paths in the configuration file are relative to the chroot directory, except for the .Ic cert , .Ic key and .Ic ocsp paths. Defaults to the .Ic user home directory, if provided. .It Ic log Ar options Specify logging options. Multiple options may be provided within curly braces. The available options are as follows: .Bl -tag -width Ds .It Ic access Ar file Log the requests to .Ar file . The path is relative to the .Ic chroot . .It Ic style Ar style Set the logging style, defaults to .Ic legacy . The .Ar style can be one of: .Bl -tag -width Ds .It Ic common Attempt to be compatible with the default Apache httpd log format. Each line is formatted as follows: the matching host name, the remote IP address, one dash .Sq - , Common Name of the client certificate .Pq if provided, '-' otherwise , the timestamp of the request, the request URI wrapped in double quotes, the response code and the size of the response. .It Ic combined Attempt to be compatible with the default nginx log format. Each line is formatted as follows: the remote IP address, one dash .Sq - , Common Name of the client certificate .Pq if provided, '-' otherwise , the timestamp wrapped in square brackets, the request URI wrapped in double quotes, the response code, the size of the response, a dash wrapped in double quotes and "". The strangness of these two last fields is because Gemini doesn't have the notion of the .Dq Referer header nor the .Dq User-agent . .\" .It Ic condensed .\" The native .\" .Xr gmid 8 .\" format since 2.0. .\" Each line is formatted as follows: RFC 3339 date time, .\" remote IP address, Common Name of the client certificate .\" .Pq if provided, '-' otherwise , .\" the matching host name, the request URI, the size of the request, .\" the size of the response, the response code and meta. .It Ic legacy Each line is formatted as follows: the remote IP address and port, the .Sq GET keyword, the request URI, the response code and meta. .El .It Ic syslog Op Ic off Log to syslog. It is enabled by default, use the .Ic off argument to disable. .It Ic syslog facility Ar facility Log to .Xr syslog 3 using specified .Ar facility . Available facilities are as follows: daemon, ftp, local0 through local7 and user. These are case insensitive and can be prefixed with .Sq LOG_ . Not all level may be available on all operating systems. The default facility is .Ev LOG_DAEMON . .El .It Ic prefork Ar number Run the specified number of server processes. This increases the performance and prevents delays when connecting to a server. .Xr gmid 8 runs 3 server processes by default. The maximum number allowed is 16. .It Ic protocols Ar string Specify the TLS protocols to enable. Refer to .Xr tls_config_parse_protocols 3 for the valid protocol string values. By default, both TLSv1.3 and TLSv1.2 are enabled. Use .Dq tlsv1.3 to enable only TLSv1.3. .It Ic user Ar string Run the daemon as the given user. Mandatory if the .Ic chroot option is used. .El .Ss Servers Every virtual host is defined by a .Ic server block: .Bl -tag -width Ds .It Ic server Ar hostname Brq ... Match the server name using shell globbing rules. It can be an explicit name, .Ar www.example.com , or a name including wildcards, .Ar *.example.com . .El .Pp Followed by a block of options that is enclosed in curly brackets: .Bl -tag -width Ds .It Ic alias Ar name Specify an additional alias .Ar name for this server. .It Ic auto Ic index Ar bool If no index file is found, automatically generate a directory listing. Disabled by default. .It Ic block Op Ic return Ar code Op Ar meta Send a reply and close the connection; by default .Ar code is 40 and .Ar meta is .Dq temporary failure . If .Ar code is in the 3x range, then .Ar meta is mandatory. Inside .Ar meta , the following special sequences are supported: .Bl -tag -width Ds -compact .It \&%\&% is replaced with a single .Sq \&% . .It \&%p is replaced with the request path. .It \&%q is replaced with the query string of the request. .It \&%P is replaced with the server port. .It \&%N is replaced with the server name. .El .It Ic cert Ar file Path to the certificate to use for this server. .Ar file should contain a PEM encoded certificate. This option is mandatory. .It Ic default type Ar string Set the default media type that is used if the media type for a specified extension is not found. If not specified, the .Ic default type is set to .Dq application/octet-stream . .It Ic fastcgi Ar option Enable FastCGI instead of serving files. Multiple options may be specified within curly braces. Valid options are: .Bl -tag -width Ds .It Ic param Ar name Cm = Ar value Set the param .Ar name to .Ar value . .It Ic socket Oo Ic tcp Oc Ar socket Oo Cm port Ar port Oc The .Ar socket can either be a UNIX-domain socket or a TCP socket. If the FastCGI application is listening on a UNIX domain socket, .Ar socket is a local path name within the .Xr chroot 2 root directory of .Xr gmid 8 . Otherwise, the .Ic tcp keyword must be provided and .Ar socket is interpreted as a hostname or an IP address. .Ar port can be either a port number or the name of a service enclosed in double quotes. If not specified defaults to 9000. .It Ic strip Ar number Strip .Ar number leading path components from the request URL before splitting it in .Ev SCRIPT_NAME and .Ev PATH_INFO . .El .Pp The FastCGI handler will be given the following variables by default: .Bl -tag -width 24m .\" .It Ev GEMINI_DOCUMENT_ROOT .\" The root directory of the virtual host. .It Ev GEMINI_URL_PATH Full path of the request. .It Ev GEMINI_SEARCH_STRING The decoded .Ev QUERY_STRING if defined in the request and if it doesn't contain any unencoded .Sq = characters, otherwise unset. .It Ev GATEWAY_INTERFACE .Dq CGI/1.1 .It Ev AUTH_TYPE The string "Certificate" if the client used a certificate, otherwise unset. .It Ev PATH_INFO The portion of the requested path that is derived from the the IRI path hierarchy following .Ev SCRIPT_NAME . Can be unset. .It Ev PATH_TRANSLATED Present if and only if .Ev PATH_INFO is set. It represent the translation of the .Ev PATH_INFO . .Nm gmid builds this by appending the .Ev PATH_INFO to the virtual host directory root. .It Ev QUERY_STRING The URL-encoded search or parameter string. .It Ev REMOTE_ADDR , Ev REMOTE_HOST Textual representation of the client IP. .It Ev REQUEST_METHOD This is present only for RFC3875 (CGI) compliance. It's always set to .Dq GET . .It Ev SCRIPT_NAME The virtual URI path to the script. Since it's impossible to determine in all cases the correct .Ev SCRIPT_NAME programmatically .Nm gmid assumes it's the empty string. It is recommended to manually specify this parameter when serving a sub-tree of a virtual host via FastCGI. .It Ev SERVER_NAME The name of the server .It Ev SERVER_PORT The port the server is listening on. .It Ev SERVER_PROTOCOL .Dq GEMINI .It Ev SERVER_SOFTWARE The name and version of the server, i.e. .Dq gmid/2.0.4 .It Ev REMOTE_USER The subject of the client certificate if provided, otherwise unset. .It Ev TLS_CLIENT_ISSUER The is the issuer of the client certificate if provided, otherwise unset. .It Ev TLS_CLIENT_HASH The hash of the client certificate if provided, otherwise unset. The format is .Dq ALGO:HASH . .It Ev TLS_VERSION The TLS version negotiated with the peer. .It Ev TLS_CIPHER The cipher suite negotiated with the peer. .It Ev TLS_CIPHER_STRENGTH The strength in bits for the symmetric cipher that is being used with the peer. .It Ev TLS_CLIENT_NOT_AFTER The time corresponding to the end of the validity period of the peer certificate in the ISO 8601 format .Pq e.g. Dq 2021-02-07T20:17:41Z . .It Ev TLS_CLIENT_NOT_BEFORE The time corresponding to the start of the validity period of the peer certificate in the ISO 8601 format. .El .It Ic fastcgi off Disable FastCGI handling in the current location. .It Ic index Ar string Set the directory index file. If not specified, it defaults to .Pa index.gmi . .It Ic key Ar file Specify the private key to use for this server. .Ar file should contain a PEM encoded private key. This option is mandatory. .It Ic lang Ar string Specify the language tag for the text/gemini content served. If not specified, no .Dq lang parameter will be added in the response. .It Ic listen on Ar address Op Ic port Ar number Set the listen .Ar address and .Ar port which defaults to .Sq 1965 . This statement can be specified multiple times. If .Ar address is .Sq * then .Xr gmid 8 will listen on all IPv4 and IPv6 addresses. .Ar 0.0.0.0 can be used to listen on all IPv4 addresses and .Ar :: on all IPv6 addresses. .It Ic location Ar path Brq ... Specify server configuration rules for a specific location. .Ar path argument will be matched against the request path with shell globbing rules. In case of multiple location statements in the same context, the first matching location will be put into effect and the later ones ignored. Therefore is advisable to match for more specific paths first and for generic ones later on. A .Ic location section may include most of the server configuration rules except .Ic alias , Ic cert , Ic key , Ic listen , Ic location and .Ic proxy . .It Ic log Ar bool Enable or disable the logging for the current server or location block. .It Ic ocsp Ar file Specify an OCSP response to be stapled during TLS handshakes with this server. The .Ar file should contain a DER-format OCSP response retrieved from an OCSP server for the .Ic cert in use. If the OCSP response in .Ar file is empty, OCSP stapling will not be used. The default is to not use OCSP stapling. .It Ic proxy Oo Cm proto Ar name Oc Oo Cm for-host Ar host Oo Cm port Ar port Oc Oc Brq ... Set up a reverse proxy. The optional matching rules .Cm proto and .Cm for-host can be used to enable proxying only for protocols matching .Ar name .Po Dq gemini by default .Pc and/or whose request IRI matches .Ar host and .Ar port .Pq 1965 by default . Matching happens using shell globbing rules. .Pp In case of multiple matching proxy blocks in the same context, the first matching proxy will be put into effect and the later ones ignored. .Pp Valid options are: .Bl -tag -width Ds .It Ic cert Ar file Specify the client certificate to use when making requests. .It Ic key Ar file Specify the client certificate key to use when making requests. .It Ic protocols Ar string Specify the TLS protocols allowed when making remote requests. Refer to the .Xr tls_config_parse_protocols 3 function for the valid protocol string values. By default, both TLSv1.2 and TLSv1.3 are enabled. .It Ic relay-to Ar host Op Cm port Ar port Relay the request to the given .Ar host at the given .Ar port , 1965 by default. This is the only mandatory option in a .Ic proxy block. .It Ic require Ic client Ic ca Ar file Allow the proxying only from clients that provide a certificate signed by the CA certificate in .Ar file . .It Ic sni Ar hostname Use the given .Ar hostname instead of the one extracted from the .Ic relay-to rule for the TLS handshake with the proxied gemini server. .It Ic use-tls Ar bool Specify whether to use TLS when connecting to the proxied host. Enabled by default. .It Ic verifyname Ar bool Enable or disable the TLS server name verification. Enabled by default. .El .It Ic root Ar directory Specify the root directory for this server .Pq alas the current Dq document root . It's relative to the chroot if enabled. .It Ic require Ic client Ic ca Ar path Allow requests only from clients that provide a certificate signed by the CA certificate in .Ar path . It needs to be a PEM-encoded certificate and it's not relative to the chroot. .It Ic strip Ar number Strip .Ar number components from the beginning of the path before doing a lookup in the root directory. It's also considered for the .Ar meta parameter in the scope of a .Ic block return . .El .Ss Types The .Ic types section must include one or more lines of the following syntax, enclosed in curly brances: .Bl -tag -width Ds .It Ar type Ns / Ns Ar subtype Ar name Op Ar name ... Set the media .Ar type and .Ar subtype to the specified extension .Ar name . One or more names can be specified per line. Earch line may end with an optional semicolon. .It Ic include Ar file Include types definition from an external file, for example .Pa /usr/share/misc/mime.types . .El .Pp By default .Nm gmid uses the following mapping if no .Ic types block is defined: .Pp .Bl -tag -offset indent -width 15m -compact .It application/pdf pdf .It image/gif gif .It image/jpeg jpg jpeg .It image/png png .It image/svg+xml svg .It text/gemini gemini gmi .It text/markdown markdown md .It text/x-patch diff patch .It text/xml xml .El .Pp As an exception, .Nm gmid uses the MIME type .Ar text/gemini for file extensions .Ar gemini or .Ar gmi if no mapping was found. .Sh EXAMPLES The following is an example of a possible configuration for a site that enables only TLSv1.3, adds the MIME types mapping from .Pa /usr/share/misc/mime.types and defines two virtual host: .Bd -literal -offset indent protocols "tlsv1.3" types { include "/usr/share/misc/mime.types" } server "example.com" { listen on * port 1965 cert "/etc/ssl/example.com.pem" key "/etc/ssl/private/example.com.key" root "/var/gemini/example.com" } server "example.it" { listen on * port 1965 cert "/etc/ssl/example.it.pem" key "/etc/ssl/private/example.it.key" root "/var/gemini/example.it" # set the language for text/gemini files lang "it" } .Ed .Pp Yet another example, showing how to enable a .Ic chroot and use .Ic location rule .Bd -literal -offset indent chroot "/var/gemini" user "_gmid" server "example.com" { listen on * port 1965 # absolute paths: cert "/etc/ssl/example.com.pem" key "/etc/ssl/private/example.com.key" # relative to the chroot: root "/example.com" location "/static/*" { # load the following rules only for # requests that matches "/static/*" auto index on index "index.gemini" } } .Ed .Pp This shows how to set up a reverse proxy: all request for .Sq example.com will be forwarded to 10.0.0.6 transparently. Proxying establish a new TLS connection, so any client-certificates used to connect to .Xr gmid 8 cannot be provided to the proxied server as well. .Bd -literal -offset indent server "example.com" { listen on * port 1965 cert "/etc/ssl/example.com.pem" key "/etc/ssl/private/example.com.key" proxy { relay-to 10.0.0.6 port 1965 } } .Ed .Sh SEE ALSO .Xr gmid 8 , .Xr slowcgi 8 .Sh AUTHORS .An -nosplit The .Nm gmid program was written by .An Omar Polo Aq Mt op@omarpolo.com .