xref: /freebsd/lib/libfetch/fetch.3 (revision 576ee62dd2e5e0454a5316eb9207f4ebaa543171)
1.\"-
2.\" Copyright (c) 1998-2013 Dag-Erling Smørgrav
3.\" Copyright (c) 2013-2016 Michael Gmelin <freebsd@grem.de>
4.\" All rights reserved.
5.\"
6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions
8.\" are met:
9.\" 1. Redistributions of source code must retain the above copyright
10.\"    notice, this list of conditions and the following disclaimer.
11.\" 2. Redistributions in binary form must reproduce the above copyright
12.\"    notice, this list of conditions and the following disclaimer in the
13.\"    documentation and/or other materials provided with the distribution.
14.\"
15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25.\" SUCH DAMAGE.
26.\"
27.Dd January 22, 2026
28.Dt FETCH 3
29.Os
30.Sh NAME
31.Nm fetchMakeURL ,
32.Nm fetchParseURL ,
33.Nm fetchFreeURL ,
34.Nm fetchXGetURL ,
35.Nm fetchGetURL ,
36.Nm fetchPutURL ,
37.Nm fetchStatURL ,
38.Nm fetchListURL ,
39.Nm fetchXGet ,
40.Nm fetchGet ,
41.Nm fetchPut ,
42.Nm fetchStat ,
43.Nm fetchList ,
44.Nm fetchXGetFile ,
45.Nm fetchGetFile ,
46.Nm fetchPutFile ,
47.Nm fetchStatFile ,
48.Nm fetchListFile ,
49.Nm fetchXGetHTTP ,
50.Nm fetchGetHTTP ,
51.Nm fetchPutHTTP ,
52.Nm fetchStatHTTP ,
53.Nm fetchListHTTP ,
54.Nm fetchReqHTTP ,
55.Nm fetchXGetFTP ,
56.Nm fetchGetFTP ,
57.Nm fetchPutFTP ,
58.Nm fetchStatFTP ,
59.Nm fetchListFTP
60.Nd file transfer functions
61.Sh LIBRARY
62.Lb libfetch
63.Sh SYNOPSIS
64.In sys/param.h
65.In stdio.h
66.In fetch.h
67.Ft struct url *
68.Fn fetchMakeURL "const char *scheme" "const char *host" "int port" "const char *doc" "const char *user" "const char *pwd"
69.Ft struct url *
70.Fn fetchParseURL "const char *URL"
71.Ft void
72.Fn fetchFreeURL "struct url *u"
73.Ft FILE *
74.Fn fetchXGetURL "const char *URL" "struct url_stat *us" "const char *flags"
75.Ft FILE *
76.Fn fetchGetURL "const char *URL" "const char *flags"
77.Ft FILE *
78.Fn fetchPutURL "const char *URL" "const char *flags"
79.Ft int
80.Fn fetchStatURL "const char *URL" "struct url_stat *us" "const char *flags"
81.Ft struct url_ent *
82.Fn fetchListURL "const char *URL" "const char *flags"
83.Ft FILE *
84.Fn fetchXGet "struct url *u" "struct url_stat *us" "const char *flags"
85.Ft FILE *
86.Fn fetchGet "struct url *u" "const char *flags"
87.Ft FILE *
88.Fn fetchPut "struct url *u" "const char *flags"
89.Ft int
90.Fn fetchStat "struct url *u" "struct url_stat *us" "const char *flags"
91.Ft struct url_ent *
92.Fn fetchList "struct url *u" "const char *flags"
93.Ft FILE *
94.Fn fetchXGetFile "struct url *u" "struct url_stat *us" "const char *flags"
95.Ft FILE *
96.Fn fetchGetFile "struct url *u" "const char *flags"
97.Ft FILE *
98.Fn fetchPutFile "struct url *u" "const char *flags"
99.Ft int
100.Fn fetchStatFile "struct url *u" "struct url_stat *us" "const char *flags"
101.Ft struct url_ent *
102.Fn fetchListFile "struct url *u" "const char *flags"
103.Ft FILE *
104.Fn fetchXGetHTTP "struct url *u" "struct url_stat *us" "const char *flags"
105.Ft FILE *
106.Fn fetchGetHTTP "struct url *u" "const char *flags"
107.Ft FILE *
108.Fn fetchPutHTTP "struct url *u" "const char *flags"
109.Ft int
110.Fn fetchStatHTTP "struct url *u" "struct url_stat *us" "const char *flags"
111.Ft struct url_ent *
112.Fn fetchListHTTP "struct url *u" "const char *flags"
113.Ft FILE *
114.Fn fetchReqHTTP "struct url *u" "const char *method" "const char *flags" "const char *content_type" "const char *body"
115.Ft FILE *
116.Fn fetchXGetFTP "struct url *u" "struct url_stat *us" "const char *flags"
117.Ft FILE *
118.Fn fetchGetFTP "struct url *u" "const char *flags"
119.Ft FILE *
120.Fn fetchPutFTP "struct url *u" "const char *flags"
121.Ft int
122.Fn fetchStatFTP "struct url *u" "struct url_stat *us" "const char *flags"
123.Ft struct url_ent *
124.Fn fetchListFTP "struct url *u" "const char *flags"
125.Sh DESCRIPTION
126These functions implement a high-level library for retrieving and
127uploading files using Uniform Resource Locators (URLs).
128.Pp
129.Fn fetchParseURL
130takes a URL in the form of a null-terminated string and splits it into
131its components function according to the Common Internet Scheme Syntax
132detailed in RFC1738.
133A regular expression which produces this syntax is:
134.Bd -literal
135    <scheme>:(//(<user>(:<pwd>)?@)?<host>(:<port>)?)?/(<document>)?
136.Ed
137.Pp
138If the URL does not seem to begin with a scheme name, the following
139syntax is assumed:
140.Bd -literal
141    ((<user>(:<pwd>)?@)?<host>(:<port>)?)?/(<document>)?
142.Ed
143.Pp
144Note that some components of the URL are not necessarily relevant to
145all URL schemes.
146For instance, the file scheme only needs the <scheme> and <document>
147components.
148.Pp
149.Fn fetchMakeURL
150and
151.Fn fetchParseURL
152return a pointer to a
153.Vt url
154structure, which is defined as follows in
155.In fetch.h :
156.Bd -literal
157#define URL_SCHEMELEN 16
158#define URL_USERLEN 256
159#define URL_PWDLEN 256
160
161struct url {
162    char	 scheme[URL_SCHEMELEN+1];
163    char	 user[URL_USERLEN+1];
164    char	 pwd[URL_PWDLEN+1];
165    char	 host[MAXHOSTNAMELEN+1];
166    int		 port;
167    char	*doc;
168    off_t	 offset;
169    size_t	 length;
170    time_t	 ims_time;
171};
172.Ed
173.Pp
174The
175.Va ims_time
176field stores the time value for
177.Li If-Modified-Since
178HTTP requests.
179.Pp
180The pointer returned by
181.Fn fetchMakeURL
182or
183.Fn fetchParseURL
184should be freed using
185.Fn fetchFreeURL .
186.Pp
187.Fn fetchXGetURL ,
188.Fn fetchGetURL ,
189and
190.Fn fetchPutURL
191constitute the recommended interface to the
192.Nm fetch
193library.
194They examine the URL passed to them to determine the transfer
195method, and call the appropriate lower-level functions to perform the
196actual transfer.
197.Fn fetchXGetURL
198also returns the remote document's metadata in the
199.Vt url_stat
200structure pointed to by the
201.Fa us
202argument.
203.Pp
204The
205.Fa flags
206argument is a string of characters which specify transfer options.
207The
208meaning of the individual flags is scheme-dependent, and is detailed
209in the appropriate section below.
210.Pp
211.Fn fetchStatURL
212attempts to obtain the requested document's metadata and fill in the
213structure pointed to by its second argument.
214The
215.Vt url_stat
216structure is defined as follows in
217.In fetch.h :
218.Bd -literal
219struct url_stat {
220    off_t	 size;
221    time_t	 atime;
222    time_t	 mtime;
223};
224.Ed
225.Pp
226If the size could not be obtained from the server, the
227.Fa size
228field is set to -1.
229If the modification time could not be obtained from the server, the
230.Fa mtime
231field is set to the epoch.
232If the access time could not be obtained from the server, the
233.Fa atime
234field is set to the modification time.
235.Pp
236.Fn fetchListURL
237attempts to list the contents of the directory pointed to by the URL
238provided.
239If successful, it returns a malloced array of
240.Vt url_ent
241structures.
242The
243.Vt url_ent
244structure is defined as follows in
245.In fetch.h :
246.Bd -literal
247struct url_ent {
248    char         name[PATH_MAX];
249    struct url_stat stat;
250};
251.Ed
252.Pp
253The list is terminated by an entry with an empty name.
254.Pp
255The pointer returned by
256.Fn fetchListURL
257should be freed using
258.Fn free .
259.Pp
260.Fn fetchXGet ,
261.Fn fetchGet ,
262.Fn fetchPut
263and
264.Fn fetchStat
265are similar to
266.Fn fetchXGetURL ,
267.Fn fetchGetURL ,
268.Fn fetchPutURL
269and
270.Fn fetchStatURL ,
271except that they expect a pre-parsed URL in the form of a pointer to
272a
273.Vt struct url
274rather than a string.
275.Pp
276All of the
277.Fn fetchXGetXXX ,
278.Fn fetchGetXXX
279and
280.Fn fetchPutXXX
281functions return a pointer to a stream which can be used to read or
282write data from or to the requested document, respectively.
283Note that
284although the implementation details of the individual access methods
285vary, it can generally be assumed that a stream returned by one of the
286.Fn fetchXGetXXX
287or
288.Fn fetchGetXXX
289functions is read-only, and that a stream returned by one of the
290.Fn fetchPutXXX
291functions is write-only.
292.Sh FILE SCHEME
293.Fn fetchXGetFile ,
294.Fn fetchGetFile
295and
296.Fn fetchPutFile
297provide access to documents which are files in a locally mounted file
298system.
299Only the <document> component of the URL is used.
300.Pp
301.Fn fetchXGetFile
302and
303.Fn fetchGetFile
304do not accept any flags.
305.Pp
306.Fn fetchPutFile
307accepts the
308.Ql a
309(append to file) flag.
310If that flag is specified, the data written to
311the stream returned by
312.Fn fetchPutFile
313will be appended to the previous contents of the file, instead of
314replacing them.
315.Sh FTP SCHEME
316.Fn fetchXGetFTP ,
317.Fn fetchGetFTP
318and
319.Fn fetchPutFTP
320implement the FTP protocol as described in RFC959.
321.Pp
322If the
323.Ql P
324(not passive) flag is specified, an active (rather than passive)
325connection will be attempted.
326.Pp
327The
328.Ql p
329flag is supported for compatibility with earlier versions where active
330connections were the default.
331It has precedence over the
332.Ql P
333flag, so if both are specified,
334.Nm
335will use a passive connection.
336.Pp
337If the
338.Ql l
339(low) flag is specified, data sockets will be allocated in the low (or
340default) port range instead of the high port range (see
341.Xr ip 4 ) .
342.Pp
343If the
344.Ql d
345(direct) flag is specified,
346.Fn fetchXGetFTP ,
347.Fn fetchGetFTP
348and
349.Fn fetchPutFTP
350will use a direct connection even if a proxy server is defined.
351.Pp
352If no user name or password is given, the
353.Nm fetch
354library will attempt an anonymous login, with user name "anonymous"
355and password "anonymous@<hostname>".
356.Sh HTTP SCHEME
357The
358.Fn fetchXGetHTTP ,
359.Fn fetchGetHTTP ,
360.Fn fetchPutHTTP
361and
362.Fn fetchReqHTTP
363functions implement the HTTP/1.1 protocol.
364With a little luck, there is
365even a chance that they comply with RFC2616 and RFC2617.
366.Pp
367If the
368.Ql d
369(direct) flag is specified,
370.Fn fetchXGetHTTP ,
371.Fn fetchGetHTTP
372and
373.Fn fetchPutHTTP
374will use a direct connection even if a proxy server is defined.
375.Pp
376If the
377.Ql i
378(if-modified-since) flag is specified, and
379the
380.Va ims_time
381field is set in
382.Vt "struct url" ,
383then
384.Fn fetchXGetHTTP
385and
386.Fn fetchGetHTTP
387will send a conditional
388.Li If-Modified-Since
389HTTP header to only fetch the content if it is newer than
390.Va ims_time .
391.Pp
392The function
393.Fn fetchReqHTTP
394can be used to make requests with an arbitrary HTTP verb,
395including POST, DELETE, CONNECT, OPTIONS, TRACE or PATCH.
396This can be done by setting the argument
397.Fa method
398to the intended verb, such as
399.Ql POST ,
400and
401.Fa body
402to the content.
403.Pp
404Since there seems to be no good way of implementing the HTTP PUT
405method in a manner consistent with the rest of the
406.Nm fetch
407library,
408.Fn fetchPutHTTP
409is currently unimplemented.
410.Sh HTTPS SCHEME
411Based on HTTP SCHEME.
412The CA bundle used for peer verification can be changed by setting the
413environment variables
414.Ev SSL_CA_CERT_FILE
415to point to a concatenated bundle of trusted certificates and
416.Ev SSL_CA_CERT_PATH
417to point to a directory containing hashes of trusted CAs (see
418.Xr verify 1 ) .
419.Pp
420A certificate revocation list (CRL) can be used by setting the
421environment variable
422.Ev SSL_CRL_FILE
423(see
424.Xr crl 1 ) .
425.Pp
426Peer verification can be disabled by setting the environment variable
427.Ev SSL_NO_VERIFY_PEER .
428Note that this also disables CRL checking.
429.Pp
430By default the service identity is verified according to the rules
431detailed in RFC6125 (also known as hostname verification).
432This feature can be disabled by setting the environment variable
433.Ev SSL_NO_VERIFY_HOSTNAME .
434.Pp
435Client certificate based authentication is supported.
436The environment variable
437.Ev SSL_CLIENT_CERT_FILE
438should be set to point to a file containing key and client certificate
439to be used in PEM format.
440When a PEM-format key is in a separate file from the client certificate,
441the environment variable
442.Ev SSL_CLIENT_KEY_FILE
443can be set to point to the key file.
444In case the key uses a password, the user will be prompted on standard
445input.
446.Pp
447By default
448.Nm libfetch
449allows TLSv1 and newer when negotiating the connecting with the remote
450peer.
451You can change this behavior by setting the
452.Ev SSL_NO_TLS1 ,
453.Ev SSL_NO_TLS1_1 ,
454.Ev SSL_NO_TLS1_2 and
455.Ev SSL_NO_TLS1_3
456environment variables to disable TLS 1.0, 1.1, 1.2 and 1.3
457respectively.
458.Sh AUTHENTICATION
459Apart from setting the appropriate environment variables and
460specifying the user name and password in the URL or the
461.Vt struct url ,
462the calling program has the option of defining an authentication
463function with the following prototype:
464.Pp
465.Ft int
466.Fn myAuthMethod "struct url *u"
467.Pp
468The callback function should fill in the
469.Fa user
470and
471.Fa pwd
472fields in the provided
473.Vt struct url
474and return 0 on success, or any other value to indicate failure.
475.Pp
476To register the authentication callback, simply set
477.Va fetchAuthMethod
478to point at it.
479The callback will be used whenever a site requires authentication and
480the appropriate environment variables are not set.
481.Pp
482This interface is experimental and may be subject to change.
483.Sh RETURN VALUES
484.Fn fetchParseURL
485returns a pointer to a
486.Vt struct url
487containing the individual components of the URL.
488If it is
489unable to allocate memory, or the URL is syntactically incorrect,
490.Fn fetchParseURL
491returns a NULL pointer.
492.Pp
493The
494.Fn fetchStat
495functions return 0 on success and -1 on failure.
496.Pp
497All other functions return a stream pointer which may be used to
498access the requested document, or NULL if an error occurred.
499.Pp
500The following error codes are defined in
501.In fetch.h :
502.Bl -tag -width 18n
503.It Bq Er FETCH_ABORT
504Operation aborted
505.It Bq Er FETCH_AUTH
506Authentication failed
507.It Bq Er FETCH_DOWN
508Service unavailable
509.It Bq Er FETCH_EXISTS
510File exists
511.It Bq Er FETCH_FULL
512File system full
513.It Bq Er FETCH_INFO
514Informational response
515.It Bq Er FETCH_MEMORY
516Insufficient memory
517.It Bq Er FETCH_MOVED
518File has moved
519.It Bq Er FETCH_NETWORK
520Network error
521.It Bq Er FETCH_OK
522No error
523.It Bq Er FETCH_PROTO
524Protocol error
525.It Bq Er FETCH_RESOLV
526Resolver error
527.It Bq Er FETCH_SERVER
528Server error
529.It Bq Er FETCH_TEMP
530Temporary error
531.It Bq Er FETCH_TIMEOUT
532Operation timed out
533.It Bq Er FETCH_UNAVAIL
534File is not available
535.It Bq Er FETCH_UNKNOWN
536Unknown error
537.It Bq Er FETCH_URL
538Invalid URL
539.El
540.Pp
541The accompanying error message includes a protocol-specific error code
542and message, like "File is not available (404 Not Found)"
543.Sh ENVIRONMENT
544.Bl -tag -width ".Ev FETCH_BIND_ADDRESS"
545.It Ev FETCH_BIND_ADDRESS
546Specifies a hostname or IP address to which sockets used for outgoing
547connections will be bound.
548.It Ev FTP_LOGIN
549Default FTP login if none was provided in the URL.
550.It Ev FTP_PASSIVE_MODE
551If set to
552.Ql no ,
553forces the FTP code to use active mode.
554If set to any other value, forces passive mode even if the application
555requested active mode.
556.It Ev FTP_PASSWORD
557Default FTP password if the remote server requests one and none was
558provided in the URL.
559.It Ev FTP_PROXY
560URL of the proxy to use for FTP requests.
561The document part is ignored.
562FTP and HTTP proxies are supported; if no scheme is specified, FTP is
563assumed.
564If the proxy is an FTP proxy,
565.Nm libfetch
566will send
567.Ql user@host
568as user name to the proxy, where
569.Ql user
570is the real user name, and
571.Ql host
572is the name of the FTP server.
573.Pp
574If this variable is set to an empty string, no proxy will be used for
575FTP requests, even if the
576.Ev HTTP_PROXY
577variable is set.
578.It Ev ftp_proxy
579Same as
580.Ev FTP_PROXY ,
581for compatibility.
582.It Ev HTTP_ACCEPT
583Specifies the value of the
584.Va Accept
585header for HTTP requests.
586If empty, no
587.Va Accept
588header is sent.
589The default is
590.Dq */* .
591.It Ev HTTP_AUTH
592Specifies HTTP authorization parameters as a colon-separated list of
593items.
594The first and second item are the authorization scheme and realm
595respectively; further items are scheme-dependent.
596Currently, the
597.Dq basic
598and
599.Dq digest
600authorization methods are supported.
601.Pp
602Both methods require two parameters: the user name and
603password, in that order.
604.Pp
605This variable is only used if the server requires authorization and
606no user name or password was specified in the URL.
607.It Ev HTTP_PROXY
608URL of the proxy to use for HTTP requests.
609The document part is ignored.
610Only HTTP proxies are supported for HTTP requests.
611If no port number is specified, the default is 3128.
612.Pp
613Note that this proxy will also be used for FTP documents, unless the
614.Ev FTP_PROXY
615variable is set.
616.It Ev http_proxy
617Same as
618.Ev HTTP_PROXY ,
619for compatibility.
620.It Ev HTTP_PROXY_AUTH
621Specifies authorization parameters for the HTTP proxy in the same
622format as the
623.Ev HTTP_AUTH
624variable.
625.Pp
626This variable is used if and only if connected to an HTTP proxy, and
627is ignored if a user and/or a password were specified in the proxy
628URL.
629.It Ev HTTP_REFERER
630Specifies the referrer URL to use for HTTP requests.
631If set to
632.Dq auto ,
633the document URL will be used as referrer URL.
634.It Ev HTTP_USER_AGENT
635Specifies the User-Agent string to use for HTTP requests.
636This can be useful when working with HTTP origin or proxy servers that
637differentiate between user agents.
638If defined but empty, no User-Agent header is sent.
639.It Ev NETRC
640Specifies a file to use instead of
641.Pa ~/.netrc
642to look up login names and passwords for FTP and HTTP sites as well as
643HTTP proxies.
644See
645.Xr ftp 1
646for a description of the file format.
647.It Ev NO_PROXY
648Either a single asterisk, which disables the use of proxies
649altogether, or a comma- or whitespace-separated list of hosts for
650which proxies should not be used.
651.It Ev no_proxy
652Same as
653.Ev NO_PROXY ,
654for compatibility.
655.It Ev SOCKS5_PROXY
656Uses SOCKS version 5 to make connection.
657The format must be the IP or hostname followed by a colon for the port.
658IPv6 addresses must enclose the address in brackets.
659If no port is specified, the default is 1080.
660This setting will supercede a connection to an
661.Ev HTTP_PROXY .
662.It Ev SSL_CA_CERT_FILE
663CA certificate bundle containing trusted CA certificates.
664Default value: See HTTPS SCHEME above.
665.It Ev SSL_CA_CERT_PATH
666Path containing trusted CA hashes.
667.It Ev SSL_CLIENT_CERT_FILE
668PEM encoded client certificate/key which will be used in
669client certificate authentication.
670.It Ev SSL_CLIENT_KEY_FILE
671PEM encoded client key in case key and client certificate
672are stored separately.
673.It Ev SSL_CRL_FILE
674File containing certificate revocation list.
675.It Ev SSL_NO_TLS1
676Do not allow TLS version 1.0 when negotiating the connection.
677.It Ev SSL_NO_TLS1_1
678Do not allow TLS version 1.1 when negotiating the connection.
679.It Ev SSL_NO_TLS1_2
680Do not allow TLS version 1.2 when negotiating the connection.
681.It Ev SSL_NO_TLS1_3
682Do not allow TLS version 1.3 when negotiating the connection.
683.It Ev SSL_NO_VERIFY_HOSTNAME
684If set, do not verify that the hostname matches the subject of the
685certificate presented by the server.
686.It Ev SSL_NO_VERIFY_PEER
687If set, do not verify the peer certificate against trusted CAs.
688.El
689.Sh EXAMPLES
690To access a proxy server on
691.Pa proxy.example.com
692port 8080, set the
693.Ev HTTP_PROXY
694environment variable in a manner similar to this:
695.Pp
696.Dl HTTP_PROXY=http://proxy.example.com:8080
697.Pp
698If the proxy server requires authentication, there are
699two options available for passing the authentication data.
700The first method is by using the proxy URL:
701.Pp
702.Dl HTTP_PROXY=http://<user>:<pwd>@proxy.example.com:8080
703.Pp
704The second method is by using the
705.Ev HTTP_PROXY_AUTH
706environment variable:
707.Bd -literal -offset indent
708HTTP_PROXY=http://proxy.example.com:8080
709HTTP_PROXY_AUTH=basic:*:<user>:<pwd>
710.Ed
711.Pp
712To disable the use of a proxy for an HTTP server running on the local
713host, define
714.Ev NO_PROXY
715as follows:
716.Bd -literal -offset indent
717NO_PROXY=localhost,127.0.0.1
718.Ed
719.Pp
720To use a SOCKS5 proxy, set the
721.Ev SOCKS5_PROXY
722environment variable to a
723valid host or IP followed by an optional colon and the port.
724IPv6 addresses must be enclosed in brackets.
725The following are examples of valid settings:
726.Bd -literal -offset indent
727SOCKS5_PROXY=proxy.example.com
728SOCKS5_PROXY=proxy.example.com:1080
729SOCKS5_PROXY=192.0.2.0
730SOCKS5_PROXY=198.51.100.0:1080
731SOCKS5_PROXY=[2001:db8::1]
732SOCKS5_PROXY=[2001:db8::2]:1080
733.Ed
734.Pp
735Access HTTPS website without any certificate verification whatsoever:
736.Bd -literal -offset indent
737SSL_NO_VERIFY_PEER=1
738SSL_NO_VERIFY_HOSTNAME=1
739.Ed
740.Pp
741Access HTTPS website using client certificate based authentication
742and a private CA:
743.Bd -literal -offset indent
744SSL_CLIENT_CERT_FILE=/path/to/client.pem
745SSL_CA_CERT_FILE=/path/to/myca.pem
746.Ed
747.Sh SEE ALSO
748.Xr fetch 1 ,
749.Xr ip 4
750.Rs
751.%A J. Postel
752.%A J. K. Reynolds
753.%D October 1985
754.%B File Transfer Protocol
755.%O RFC959
756.Re
757.Rs
758.%A P. Deutsch
759.%A A. Emtage
760.%A A. Marine.
761.%D May 1994
762.%T How to Use Anonymous FTP
763.%O RFC1635
764.Re
765.Rs
766.%A T. Berners-Lee
767.%A L. Masinter
768.%A M. McCahill
769.%D December 1994
770.%T Uniform Resource Locators (URL)
771.%O RFC1738
772.Re
773.Rs
774.%A R. Fielding
775.%A J. Gettys
776.%A J. Mogul
777.%A H. Frystyk
778.%A L. Masinter
779.%A P. Leach
780.%A T. Berners-Lee
781.%D January 1999
782.%B Hypertext Transfer Protocol -- HTTP/1.1
783.%O RFC2616
784.Re
785.Rs
786.%A J. Franks
787.%A P. Hallam-Baker
788.%A J. Hostetler
789.%A S. Lawrence
790.%A P. Leach
791.%A A. Luotonen
792.%A L. Stewart
793.%D June 1999
794.%B HTTP Authentication: Basic and Digest Access Authentication
795.%O RFC2617
796.Re
797.Sh HISTORY
798The
799.Nm fetch
800library first appeared in
801.Fx 3.0 .
802.Sh AUTHORS
803.An -nosplit
804The
805.Nm fetch
806library was mostly written by
807.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org
808with numerous suggestions and contributions from
809.An Jordan K. Hubbard Aq Mt jkh@FreeBSD.org ,
810.An Eugene Skepner Aq Mt eu@qub.com ,
811.An Hajimu Umemoto Aq Mt ume@FreeBSD.org ,
812.An Henry Whincup Aq Mt henry@techiebod.com ,
813.An Jukka A. Ukkonen Aq Mt jau@iki.fi ,
814.An Jean-Fran\(,cois Dockes Aq Mt jf@dockes.org ,
815.An Michael Gmelin Aq Mt freebsd@grem.de
816and others.
817It replaces the older
818.Nm ftpio
819library written by
820.An Poul-Henning Kamp Aq Mt phk@FreeBSD.org
821and
822.An Jordan K. Hubbard Aq Mt jkh@FreeBSD.org .
823.Pp
824This manual page was written by
825.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org
826and
827.An Michael Gmelin Aq Mt freebsd@grem.de .
828.Sh BUGS
829Some parts of the library are not yet implemented.
830The most notable
831examples of this are
832.Fn fetchPutHTTP ,
833.Fn fetchListHTTP ,
834.Fn fetchListFTP
835and FTP proxy support.
836.Pp
837There is no way to select a proxy at run-time other than setting the
838.Ev HTTP_PROXY
839or
840.Ev FTP_PROXY
841environment variables as appropriate.
842.Pp
843.Nm libfetch
844does not understand or obey 305 (Use Proxy) replies.
845.Pp
846Error numbers are unique only within a certain context; the error
847codes used for FTP and HTTP overlap, as do those used for resolver and
848system errors.
849For instance, error code 202 means "Command not
850implemented, superfluous at this site" in an FTP context and
851"Accepted" in an HTTP context.
852.Pp
853.Fn fetchStatFTP
854does not check that the result of an MDTM command is a valid date.
855.Pp
856In case password protected keys are used for client certificate based
857authentication the user is prompted for the password on each and every
858fetch operation.
859.Pp
860The man page is incomplete, poorly written and produces badly
861formatted text.
862.Pp
863The error reporting mechanism is unsatisfactory.
864.Pp
865Some parts of the code are not fully reentrant.
866