xref: /freebsd/lib/libfetch/fetch.3 (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1.\"-
2.\" Copyright (c) 1998-2013 Dag-Erling Smørgrav
3.\" Copyright (c) 2013 Michael Gmelin <freebsd@grem.de>
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27.\" $FreeBSD$
28.\"
29.Dd July 30, 2013
30.Dt FETCH 3
31.Os
32.Sh NAME
33.Nm fetchMakeURL ,
34.Nm fetchParseURL ,
35.Nm fetchFreeURL ,
36.Nm fetchXGetURL ,
37.Nm fetchGetURL ,
38.Nm fetchPutURL ,
39.Nm fetchStatURL ,
40.Nm fetchListURL ,
41.Nm fetchXGet ,
42.Nm fetchGet ,
43.Nm fetchPut ,
44.Nm fetchStat ,
45.Nm fetchList ,
46.Nm fetchXGetFile ,
47.Nm fetchGetFile ,
48.Nm fetchPutFile ,
49.Nm fetchStatFile ,
50.Nm fetchListFile ,
51.Nm fetchXGetHTTP ,
52.Nm fetchGetHTTP ,
53.Nm fetchPutHTTP ,
54.Nm fetchStatHTTP ,
55.Nm fetchListHTTP ,
56.Nm fetchXGetFTP ,
57.Nm fetchGetFTP ,
58.Nm fetchPutFTP ,
59.Nm fetchStatFTP ,
60.Nm fetchListFTP
61.Nd file transfer functions
62.Sh LIBRARY
63.Lb libfetch
64.Sh SYNOPSIS
65.In sys/param.h
66.In stdio.h
67.In fetch.h
68.Ft struct url *
69.Fn fetchMakeURL "const char *scheme" "const char *host" "int port" "const char *doc" "const char *user" "const char *pwd"
70.Ft struct url *
71.Fn fetchParseURL "const char *URL"
72.Ft void
73.Fn fetchFreeURL "struct url *u"
74.Ft FILE *
75.Fn fetchXGetURL "const char *URL" "struct url_stat *us" "const char *flags"
76.Ft FILE *
77.Fn fetchGetURL "const char *URL" "const char *flags"
78.Ft FILE *
79.Fn fetchPutURL "const char *URL" "const char *flags"
80.Ft int
81.Fn fetchStatURL "const char *URL" "struct url_stat *us" "const char *flags"
82.Ft struct url_ent *
83.Fn fetchListURL "const char *URL" "const char *flags"
84.Ft FILE *
85.Fn fetchXGet "struct url *u" "struct url_stat *us" "const char *flags"
86.Ft FILE *
87.Fn fetchGet "struct url *u" "const char *flags"
88.Ft FILE *
89.Fn fetchPut "struct url *u" "const char *flags"
90.Ft int
91.Fn fetchStat "struct url *u" "struct url_stat *us" "const char *flags"
92.Ft struct url_ent *
93.Fn fetchList "struct url *u" "const char *flags"
94.Ft FILE *
95.Fn fetchXGetFile "struct url *u" "struct url_stat *us" "const char *flags"
96.Ft FILE *
97.Fn fetchGetFile "struct url *u" "const char *flags"
98.Ft FILE *
99.Fn fetchPutFile "struct url *u" "const char *flags"
100.Ft int
101.Fn fetchStatFile "struct url *u" "struct url_stat *us" "const char *flags"
102.Ft struct url_ent *
103.Fn fetchListFile "struct url *u" "const char *flags"
104.Ft FILE *
105.Fn fetchXGetHTTP "struct url *u" "struct url_stat *us" "const char *flags"
106.Ft FILE *
107.Fn fetchGetHTTP "struct url *u" "const char *flags"
108.Ft FILE *
109.Fn fetchPutHTTP "struct url *u" "const char *flags"
110.Ft int
111.Fn fetchStatHTTP "struct url *u" "struct url_stat *us" "const char *flags"
112.Ft struct url_ent *
113.Fn fetchListHTTP "struct url *u" "const char *flags"
114.Ft FILE *
115.Fn fetchXGetFTP "struct url *u" "struct url_stat *us" "const char *flags"
116.Ft FILE *
117.Fn fetchGetFTP "struct url *u" "const char *flags"
118.Ft FILE *
119.Fn fetchPutFTP "struct url *u" "const char *flags"
120.Ft int
121.Fn fetchStatFTP "struct url *u" "struct url_stat *us" "const char *flags"
122.Ft struct url_ent *
123.Fn fetchListFTP "struct url *u" "const char *flags"
124.Sh DESCRIPTION
125These functions implement a high-level library for retrieving and
126uploading files using Uniform Resource Locators (URLs).
127.Pp
128.Fn fetchParseURL
129takes a URL in the form of a null-terminated string and splits it into
130its components function according to the Common Internet Scheme Syntax
131detailed in RFC1738.
132A regular expression which produces this syntax is:
133.Bd -literal
134    <scheme>:(//(<user>(:<pwd>)?@)?<host>(:<port>)?)?/(<document>)?
135.Ed
136.Pp
137If the URL does not seem to begin with a scheme name, the following
138syntax is assumed:
139.Bd -literal
140    ((<user>(:<pwd>)?@)?<host>(:<port>)?)?/(<document>)?
141.Ed
142.Pp
143Note that some components of the URL are not necessarily relevant to
144all URL schemes.
145For instance, the file scheme only needs the <scheme> and <document>
146components.
147.Pp
148.Fn fetchMakeURL
149and
150.Fn fetchParseURL
151return a pointer to a
152.Vt url
153structure, which is defined as follows in
154.In fetch.h :
155.Bd -literal
156#define URL_SCHEMELEN 16
157#define URL_USERLEN 256
158#define URL_PWDLEN 256
159
160struct url {
161    char	 scheme[URL_SCHEMELEN+1];
162    char	 user[URL_USERLEN+1];
163    char	 pwd[URL_PWDLEN+1];
164    char	 host[MAXHOSTNAMELEN+1];
165    int		 port;
166    char	*doc;
167    off_t	 offset;
168    size_t	 length;
169    time_t	 ims_time;
170};
171.Ed
172.Pp
173The
174.Va ims_time
175field stores the time value for
176.Li If-Modified-Since
177HTTP requests.
178.Pp
179The pointer returned by
180.Fn fetchMakeURL
181or
182.Fn fetchParseURL
183should be freed using
184.Fn fetchFreeURL .
185.Pp
186.Fn fetchXGetURL ,
187.Fn fetchGetURL ,
188and
189.Fn fetchPutURL
190constitute the recommended interface to the
191.Nm fetch
192library.
193They examine the URL passed to them to determine the transfer
194method, and call the appropriate lower-level functions to perform the
195actual transfer.
196.Fn fetchXGetURL
197also returns the remote document's metadata in the
198.Vt url_stat
199structure pointed to by the
200.Fa us
201argument.
202.Pp
203The
204.Fa flags
205argument is a string of characters which specify transfer options.
206The
207meaning of the individual flags is scheme-dependent, and is detailed
208in the appropriate section below.
209.Pp
210.Fn fetchStatURL
211attempts to obtain the requested document's metadata and fill in the
212structure pointed to by its second argument.
213The
214.Vt url_stat
215structure is defined as follows in
216.In fetch.h :
217.Bd -literal
218struct url_stat {
219    off_t	 size;
220    time_t	 atime;
221    time_t	 mtime;
222};
223.Ed
224.Pp
225If the size could not be obtained from the server, the
226.Fa size
227field is set to -1.
228If the modification time could not be obtained from the server, the
229.Fa mtime
230field is set to the epoch.
231If the access time could not be obtained from the server, the
232.Fa atime
233field is set to the modification time.
234.Pp
235.Fn fetchListURL
236attempts to list the contents of the directory pointed to by the URL
237provided.
238If successful, it returns a malloced array of
239.Vt url_ent
240structures.
241The
242.Vt url_ent
243structure is defined as follows in
244.In fetch.h :
245.Bd -literal
246struct url_ent {
247    char         name[PATH_MAX];
248    struct url_stat stat;
249};
250.Ed
251.Pp
252The list is terminated by an entry with an empty name.
253.Pp
254The pointer returned by
255.Fn fetchListURL
256should be freed using
257.Fn free .
258.Pp
259.Fn fetchXGet ,
260.Fn fetchGet ,
261.Fn fetchPut
262and
263.Fn fetchStat
264are similar to
265.Fn fetchXGetURL ,
266.Fn fetchGetURL ,
267.Fn fetchPutURL
268and
269.Fn fetchStatURL ,
270except that they expect a pre-parsed URL in the form of a pointer to
271a
272.Vt struct url
273rather than a string.
274.Pp
275All of the
276.Fn fetchXGetXXX ,
277.Fn fetchGetXXX
278and
279.Fn fetchPutXXX
280functions return a pointer to a stream which can be used to read or
281write data from or to the requested document, respectively.
282Note that
283although the implementation details of the individual access methods
284vary, it can generally be assumed that a stream returned by one of the
285.Fn fetchXGetXXX
286or
287.Fn fetchGetXXX
288functions is read-only, and that a stream returned by one of the
289.Fn fetchPutXXX
290functions is write-only.
291.Sh FILE SCHEME
292.Fn fetchXGetFile ,
293.Fn fetchGetFile
294and
295.Fn fetchPutFile
296provide access to documents which are files in a locally mounted file
297system.
298Only the <document> component of the URL is used.
299.Pp
300.Fn fetchXGetFile
301and
302.Fn fetchGetFile
303do not accept any flags.
304.Pp
305.Fn fetchPutFile
306accepts the
307.Ql a
308(append to file) flag.
309If that flag is specified, the data written to
310the stream returned by
311.Fn fetchPutFile
312will be appended to the previous contents of the file, instead of
313replacing them.
314.Sh FTP SCHEME
315.Fn fetchXGetFTP ,
316.Fn fetchGetFTP
317and
318.Fn fetchPutFTP
319implement the FTP protocol as described in RFC959.
320.Pp
321If the
322.Ql P
323(not passive) flag is specified, an active (rather than passive)
324connection will be attempted.
325.Pp
326The
327.Ql p
328flag is supported for compatibility with earlier versions where active
329connections were the default.
330It has precedence over the
331.Ql P
332flag, so if both are specified,
333.Nm
334will use a passive connection.
335.Pp
336If the
337.Ql l
338(low) flag is specified, data sockets will be allocated in the low (or
339default) port range instead of the high port range (see
340.Xr ip 4 ) .
341.Pp
342If the
343.Ql d
344(direct) flag is specified,
345.Fn fetchXGetFTP ,
346.Fn fetchGetFTP
347and
348.Fn fetchPutFTP
349will use a direct connection even if a proxy server is defined.
350.Pp
351If no user name or password is given, the
352.Nm fetch
353library will attempt an anonymous login, with user name "anonymous"
354and password "anonymous@<hostname>".
355.Sh HTTP SCHEME
356The
357.Fn fetchXGetHTTP ,
358.Fn fetchGetHTTP
359and
360.Fn fetchPutHTTP
361functions implement the HTTP/1.1 protocol.
362With a little luck, there is
363even a chance that they comply with RFC2616 and RFC2617.
364.Pp
365If the
366.Ql d
367(direct) flag is specified,
368.Fn fetchXGetHTTP ,
369.Fn fetchGetHTTP
370and
371.Fn fetchPutHTTP
372will use a direct connection even if a proxy server is defined.
373.Pp
374If the
375.Ql i
376(if-modified-since) flag is specified, and
377the
378.Va ims_time
379field is set in
380.Vt "struct url" ,
381then
382.Fn fetchXGetHTTP
383and
384.Fn fetchGetHTTP
385will send a conditional
386.Li If-Modified-Since
387HTTP header to only fetch the content if it is newer than
388.Va ims_time .
389.Pp
390Since there seems to be no good way of implementing the HTTP PUT
391method in a manner consistent with the rest of the
392.Nm fetch
393library,
394.Fn fetchPutHTTP
395is currently unimplemented.
396.Sh HTTPS SCHEME
397Based on HTTP SCHEME.
398By default the peer is verified using the CA bundle located in
399.Pa /etc/ssl/cert.pem .
400The file may contain multiple CA certificates.
401A common source of a current CA bundle is
402.Pa \%security/ca_root_nss .
403.Pp
404The CA bundle used for peer verification can be changed by setting the
405environment variables
406.Ev SSL_CA_CERT_FILE
407to point to a concatenated bundle of trusted certificates and
408.Ev SSL_CA_CERT_PATH
409to point to a directory containing hashes of trusted CAs (see
410.Xr verify 1 ) .
411.Pp
412A certificate revocation list (CRL) can be used by setting the
413environment variable
414.Ev SSL_CRL_FILE
415(see
416.Xr crl 1 ) .
417.Pp
418Peer verification can be disabled by setting the environment variable
419.Ev SSL_NO_VERIFY_PEER .
420Note that this also disables CRL checking.
421.Pp
422By default the service identity is verified according to the rules
423detailed in RFC6125 (also known as hostname verification).
424This feature can be disabled by setting the environment variable
425.Ev SSL_NO_VERIFY_HOSTNAME .
426.Pp
427Client certificate based authentication is supported.
428The environment variable
429.Ev SSL_CLIENT_CERT_FILE
430should be set to point to a file containing key and client certificate
431to be used in PEM format. In case the key is stored in a separate
432file, the environment variable
433.Ev SSL_CLIENT_KEY_FILE
434can be set to point to the key in PEM format.
435In case the key uses a password, the user will be prompted on standard
436input (see
437.Xr PEM 3 ) .
438.Pp
439By default
440.Nm libfetch
441allows SSLv3 and TLSv1 when negotiating the connecting with the remote
442peer.
443You can change this behavior by setting the environment variable
444.Ev SSL_ALLOW_SSL2
445to allow SSLv2 (not recommended) and
446.Ev SSL_NO_SSL3
447or
448.Ev SSL_NO_TLS1
449to disable the respective methods.
450.Sh AUTHENTICATION
451Apart from setting the appropriate environment variables and
452specifying the user name and password in the URL or the
453.Vt struct url ,
454the calling program has the option of defining an authentication
455function with the following prototype:
456.Pp
457.Ft int
458.Fn myAuthMethod "struct url *u"
459.Pp
460The callback function should fill in the
461.Fa user
462and
463.Fa pwd
464fields in the provided
465.Vt struct url
466and return 0 on success, or any other value to indicate failure.
467.Pp
468To register the authentication callback, simply set
469.Va fetchAuthMethod
470to point at it.
471The callback will be used whenever a site requires authentication and
472the appropriate environment variables are not set.
473.Pp
474This interface is experimental and may be subject to change.
475.Sh RETURN VALUES
476.Fn fetchParseURL
477returns a pointer to a
478.Vt struct url
479containing the individual components of the URL.
480If it is
481unable to allocate memory, or the URL is syntactically incorrect,
482.Fn fetchParseURL
483returns a NULL pointer.
484.Pp
485The
486.Fn fetchStat
487functions return 0 on success and -1 on failure.
488.Pp
489All other functions return a stream pointer which may be used to
490access the requested document, or NULL if an error occurred.
491.Pp
492The following error codes are defined in
493.In fetch.h :
494.Bl -tag -width 18n
495.It Bq Er FETCH_ABORT
496Operation aborted
497.It Bq Er FETCH_AUTH
498Authentication failed
499.It Bq Er FETCH_DOWN
500Service unavailable
501.It Bq Er FETCH_EXISTS
502File exists
503.It Bq Er FETCH_FULL
504File system full
505.It Bq Er FETCH_INFO
506Informational response
507.It Bq Er FETCH_MEMORY
508Insufficient memory
509.It Bq Er FETCH_MOVED
510File has moved
511.It Bq Er FETCH_NETWORK
512Network error
513.It Bq Er FETCH_OK
514No error
515.It Bq Er FETCH_PROTO
516Protocol error
517.It Bq Er FETCH_RESOLV
518Resolver error
519.It Bq Er FETCH_SERVER
520Server error
521.It Bq Er FETCH_TEMP
522Temporary error
523.It Bq Er FETCH_TIMEOUT
524Operation timed out
525.It Bq Er FETCH_UNAVAIL
526File is not available
527.It Bq Er FETCH_UNKNOWN
528Unknown error
529.It Bq Er FETCH_URL
530Invalid URL
531.El
532.Pp
533The accompanying error message includes a protocol-specific error code
534and message, e.g.\& "File is not available (404 Not Found)"
535.Sh ENVIRONMENT
536.Bl -tag -width ".Ev FETCH_BIND_ADDRESS"
537.It Ev FETCH_BIND_ADDRESS
538Specifies a hostname or IP address to which sockets used for outgoing
539connections will be bound.
540.It Ev FTP_LOGIN
541Default FTP login if none was provided in the URL.
542.It Ev FTP_PASSIVE_MODE
543If set to
544.Ql no ,
545forces the FTP code to use active mode.
546If set to any other value, forces passive mode even if the application
547requested active mode.
548.It Ev FTP_PASSWORD
549Default FTP password if the remote server requests one and none was
550provided in the URL.
551.It Ev FTP_PROXY
552URL of the proxy to use for FTP requests.
553The document part is ignored.
554FTP and HTTP proxies are supported; if no scheme is specified, FTP is
555assumed.
556If the proxy is an FTP proxy,
557.Nm libfetch
558will send
559.Ql user@host
560as user name to the proxy, where
561.Ql user
562is the real user name, and
563.Ql host
564is the name of the FTP server.
565.Pp
566If this variable is set to an empty string, no proxy will be used for
567FTP requests, even if the
568.Ev HTTP_PROXY
569variable is set.
570.It Ev ftp_proxy
571Same as
572.Ev FTP_PROXY ,
573for compatibility.
574.It Ev HTTP_ACCEPT
575Specifies the value of the
576.Va Accept
577header for HTTP requests.
578If empty, no
579.Va Accept
580header is sent.
581The default is
582.Dq */* .
583.It Ev HTTP_AUTH
584Specifies HTTP authorization parameters as a colon-separated list of
585items.
586The first and second item are the authorization scheme and realm
587respectively; further items are scheme-dependent.
588Currently, the
589.Dq basic
590and
591.Dq digest
592authorization methods are supported.
593.Pp
594Both methods require two parameters: the user name and
595password, in that order.
596.Pp
597This variable is only used if the server requires authorization and
598no user name or password was specified in the URL.
599.It Ev HTTP_PROXY
600URL of the proxy to use for HTTP requests.
601The document part is ignored.
602Only HTTP proxies are supported for HTTP requests.
603If no port number is specified, the default is 3128.
604.Pp
605Note that this proxy will also be used for FTP documents, unless the
606.Ev FTP_PROXY
607variable is set.
608.It Ev http_proxy
609Same as
610.Ev HTTP_PROXY ,
611for compatibility.
612.It Ev HTTP_PROXY_AUTH
613Specifies authorization parameters for the HTTP proxy in the same
614format as the
615.Ev HTTP_AUTH
616variable.
617.Pp
618This variable is used if and only if connected to an HTTP proxy, and
619is ignored if a user and/or a password were specified in the proxy
620URL.
621.It Ev HTTP_REFERER
622Specifies the referrer URL to use for HTTP requests.
623If set to
624.Dq auto ,
625the document URL will be used as referrer URL.
626.It Ev HTTP_USER_AGENT
627Specifies the User-Agent string to use for HTTP requests.
628This can be useful when working with HTTP origin or proxy servers that
629differentiate between user agents.
630.It Ev NETRC
631Specifies a file to use instead of
632.Pa ~/.netrc
633to look up login names and passwords for FTP sites.
634See
635.Xr ftp 1
636for a description of the file format.
637This feature is experimental.
638.It Ev NO_PROXY
639Either a single asterisk, which disables the use of proxies
640altogether, or a comma- or whitespace-separated list of hosts for
641which proxies should not be used.
642.It Ev no_proxy
643Same as
644.Ev NO_PROXY ,
645for compatibility.
646.It Ev SSL_ALLOW_SSL2
647Allow SSL version 2 when negotiating the connection (not recommended).
648.It Ev SSL_CA_CERT_FILE
649CA certificate bundle containing trusted CA certificates.
650Default value:
651.Pa /etc/ssl/cert.pem .
652.It Ev SSL_CA_CERT_PATH
653Path containing trusted CA hashes.
654.It Ev SSL_CLIENT_CERT_FILE
655PEM encoded client certificate/key which will be used in
656client certificate authentication.
657.It Ev SSL_CLIENT_KEY_FILE
658PEM encoded client key in case key and client certificate
659are stored separately.
660.It Ev SSL_CRL_FILE
661File containing certificate revocation list.
662.It Ev SSL_NO_SSL3
663Don't allow SSL version 3 when negotiating the connection.
664.It Ev SSL_NO_TLS1
665Don't allow TLV version 1 when negotiating the connection.
666.It Ev SSL_NO_VERIFY_HOSTNAME
667If set, do not verify that the hostname matches the subject of the
668certificate presented by the server.
669.It Ev SSL_NO_VERIFY_PEER
670If set, do not verify the peer certificate against trusted CAs.
671.El
672.Sh EXAMPLES
673To access a proxy server on
674.Pa proxy.example.com
675port 8080, set the
676.Ev HTTP_PROXY
677environment variable in a manner similar to this:
678.Pp
679.Dl HTTP_PROXY=http://proxy.example.com:8080
680.Pp
681If the proxy server requires authentication, there are
682two options available for passing the authentication data.
683The first method is by using the proxy URL:
684.Pp
685.Dl HTTP_PROXY=http://<user>:<pwd>@proxy.example.com:8080
686.Pp
687The second method is by using the
688.Ev HTTP_PROXY_AUTH
689environment variable:
690.Bd -literal -offset indent
691HTTP_PROXY=http://proxy.example.com:8080
692HTTP_PROXY_AUTH=basic:*:<user>:<pwd>
693.Ed
694.Pp
695To disable the use of a proxy for an HTTP server running on the local
696host, define
697.Ev NO_PROXY
698as follows:
699.Bd -literal -offset indent
700NO_PROXY=localhost,127.0.0.1
701.Ed
702.Pp
703Access HTTPS website without any certificate verification whatsoever:
704.Bd -literal -offset indent
705SSL_NO_VERIFY_PEER=1
706SSL_NO_VERIFY_HOSTNAME=1
707.Ed
708.Pp
709Access HTTPS website using client certificate based authentication
710and a private CA:
711.Bd -literal -offset indent
712SSL_CLIENT_CERT_FILE=/path/to/client.pem
713SSL_CA_CERT_FILE=/path/to/myca.pem
714.Ed
715.Sh SEE ALSO
716.Xr fetch 1 ,
717.Xr ftpio 3 ,
718.Xr ip 4
719.Rs
720.%A J. Postel
721.%A J. K. Reynolds
722.%D October 1985
723.%B File Transfer Protocol
724.%O RFC959
725.Re
726.Rs
727.%A P. Deutsch
728.%A A. Emtage
729.%A A. Marine.
730.%D May 1994
731.%T How to Use Anonymous FTP
732.%O RFC1635
733.Re
734.Rs
735.%A T. Berners-Lee
736.%A L. Masinter
737.%A M. McCahill
738.%D December 1994
739.%T Uniform Resource Locators (URL)
740.%O RFC1738
741.Re
742.Rs
743.%A R. Fielding
744.%A J. Gettys
745.%A J. Mogul
746.%A H. Frystyk
747.%A L. Masinter
748.%A P. Leach
749.%A T. Berners-Lee
750.%D January 1999
751.%B Hypertext Transfer Protocol -- HTTP/1.1
752.%O RFC2616
753.Re
754.Rs
755.%A J. Franks
756.%A P. Hallam-Baker
757.%A J. Hostetler
758.%A S. Lawrence
759.%A P. Leach
760.%A A. Luotonen
761.%A L. Stewart
762.%D June 1999
763.%B HTTP Authentication: Basic and Digest Access Authentication
764.%O RFC2617
765.Re
766.Sh HISTORY
767The
768.Nm fetch
769library first appeared in
770.Fx 3.0 .
771.Sh AUTHORS
772.An -nosplit
773The
774.Nm fetch
775library was mostly written by
776.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org
777with numerous suggestions and contributions from
778.An Jordan K. Hubbard Aq jkh@FreeBSD.org ,
779.An Eugene Skepner Aq eu@qub.com ,
780.An Hajimu Umemoto Aq ume@FreeBSD.org ,
781.An Henry Whincup Aq henry@techiebod.com ,
782.An Jukka A. Ukkonen Aq jau@iki.fi ,
783.An Jean-Fran\(,cois Dockes Aq jf@dockes.org ,
784.An Michael Gmelin Aq freebsd@grem.de
785and others.
786It replaces the older
787.Nm ftpio
788library written by
789.An Poul-Henning Kamp Aq phk@FreeBSD.org
790and
791.An Jordan K. Hubbard Aq jkh@FreeBSD.org .
792.Pp
793This manual page was written by
794.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org
795and
796.An Michael Gmelin Aq freebsd@grem.de .
797.Sh BUGS
798Some parts of the library are not yet implemented.
799The most notable
800examples of this are
801.Fn fetchPutHTTP ,
802.Fn fetchListHTTP ,
803.Fn fetchListFTP
804and FTP proxy support.
805.Pp
806There is no way to select a proxy at run-time other than setting the
807.Ev HTTP_PROXY
808or
809.Ev FTP_PROXY
810environment variables as appropriate.
811.Pp
812.Nm libfetch
813does not understand or obey 305 (Use Proxy) replies.
814.Pp
815Error numbers are unique only within a certain context; the error
816codes used for FTP and HTTP overlap, as do those used for resolver and
817system errors.
818For instance, error code 202 means "Command not
819implemented, superfluous at this site" in an FTP context and
820"Accepted" in an HTTP context.
821.Pp
822.Fn fetchStatFTP
823does not check that the result of an MDTM command is a valid date.
824.Pp
825In case password protected keys are used for client certificate based
826authentication the user is prompted for the password on each and every
827fetch operation.
828.Pp
829The man page is incomplete, poorly written and produces badly
830formatted text.
831.Pp
832The error reporting mechanism is unsatisfactory.
833.Pp
834Some parts of the code are not fully reentrant.
835