Mirror of GNU Guix
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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix build download)
#:use-module (web uri)
#:use-module ((web client) #:hide (open-socket-for-uri))
#:use-module (web response)
#:use-module (guix ftp-client)
#:use-module (guix build utils)
#:use-module (rnrs io ports)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-19)
#:use-module (srfi srfi-26)
#:use-module (ice-9 match)
#:use-module (ice-9 format)
#:export (open-socket-for-uri
open-connection-for-uri
resolve-uri-reference
maybe-expand-mirrors
url-fetch
progress-proc
uri-abbreviation))
;;; Commentary:
;;;
;;; Fetch data such as tarballs over HTTP or FTP (builder-side code).
;;;
;;; Code:
(define %http-receive-buffer-size
;; Size of the HTTP receive buffer.
65536)
(define (duration->seconds duration)
"Return the number of seconds represented by DURATION, a 'time-duration'
object, as an inexact number."
(+ (time-second duration)
(/ (time-nanosecond duration) 1e9)))
(define (throughput->string throughput)
"Given THROUGHPUT, measured in bytes per second, return a string
representing it in a human-readable way."
(if (> throughput 3e6)
(format #f "~,2f MiB/s" (/ throughput (expt 2. 20)))
(format #f "~,0f KiB/s" (/ throughput 1024.0))))
(define* (progress-proc file size #:optional (log-port (current-output-port)))
"Return a procedure to show the progress of FILE's download, which is
SIZE byte long. The returned procedure is suitable for use as an
argument to `dump-port'. The progress report is written to LOG-PORT."
;; XXX: Because of <http://bugs.gnu.org/19939> this procedure is often not
;; called as frequently as we'd like too; this is especially bad with Nginx
;; on hydra.gnu.org, which returns whole nars as a single chunk.
(let ((start-time #f))
(let-syntax ((with-elapsed-time
(syntax-rules ()
((_ elapsed body ...)
(let* ((now (current-time time-monotonic))
(elapsed (and start-time
(duration->seconds
(time-difference now
start-time)))))
(unless start-time
(set! start-time now))
body ...)))))
(if (number? size)
(lambda (transferred cont)
(with-elapsed-time elapsed
(let ((% (* 100.0 (/ transferred size)))
(throughput (if elapsed
(/ transferred elapsed)
0)))
(display #\cr log-port)
(format log-port "~a\t~5,1f% of ~,1f KiB (~a)"
file % (/ size 1024.0)
(throughput->string throughput))
(flush-output-port log-port)
(cont))))
(lambda (transferred cont)
(with-elapsed-time elapsed
(let ((throughput (if elapsed
(/ transferred elapsed)
0)))
(display #\cr log-port)
(format log-port "~a\t~6,1f KiB transferred (~a)"
file (/ transferred 1024.0)
(throughput->string throughput))
(flush-output-port log-port)
(cont))))))))
(define* (uri-abbreviation uri #:optional (max-length 42))
"If URI's string representation is larger than MAX-LENGTH, return an
abbreviation of URI showing the scheme, host, and basename of the file."
(define uri-as-string
(uri->string uri))
(define (elide-path)
(let ((path (uri-path uri)))
(string-append (symbol->string (uri-scheme uri)) "://"
;; `file' URIs have no host part.
(or (uri-host uri) "")
(string-append "/.../" (basename path)))))
(if (> (string-length uri-as-string) max-length)
(let ((short (elide-path)))
(if (< (string-length short) (string-length uri-as-string))
short
uri-as-string))
uri-as-string))
(define (ftp-fetch uri file)
"Fetch data from URI and write it to FILE. Return FILE on success."
(let* ((conn (ftp-open (uri-host uri)))
(size (false-if-exception (ftp-size conn (uri-path uri))))
(in (ftp-retr conn (basename (uri-path uri))
(dirname (uri-path uri)))))
(call-with-output-file file
(lambda (out)
(dump-port in out
#:buffer-size %http-receive-buffer-size
#:progress (progress-proc (uri-abbreviation uri) size))))
(ftp-close conn))
(newline)
file)
;; Autoload GnuTLS so that this module can be used even when GnuTLS is
;; not available. At compile time, this yields "possibly unbound
;; variable" warnings, but these are OK: we know that the variables will
;; be bound if we need them, because (guix download) adds GnuTLS as an
;; input in that case.
;; XXX: Use this hack instead of #:autoload to avoid compilation errors.
;; See <http://bugs.gnu.org/12202>.
(module-autoload! (current-module)
'(gnutls) '(make-session connection-end/client))
(define add-weak-reference
(let ((table (make-weak-key-hash-table)))
(lambda (from to)
"Hold a weak reference from FROM to TO."
(hashq-set! table from to))))
(define (tls-wrap port server)
"Return PORT wrapped in a TLS connection to SERVER. SERVER must be a DNS
host name without trailing dot."
(define (log level str)
(format (current-error-port)
"gnutls: [~a|~a] ~a" (getpid) level str))
(let ((session (make-session connection-end/client)))
;; Some servers such as 'cloud.github.com' require the client to support
;; the 'SERVER NAME' extension. However, 'set-session-server-name!' is
;; not available in older GnuTLS releases. See
;; <http://bugs.gnu.org/18526> for details.
(if (module-defined? (resolve-interface '(gnutls))
'set-session-server-name!)
(set-session-server-name! session server-name-type/dns server)
(format (current-error-port)
"warning: TLS 'SERVER NAME' extension not supported~%"))
(set-session-transport-fd! session (fileno port))
(set-session-default-priority! session)
(set-session-credentials! session (make-certificate-credentials))
;; Uncomment the following lines in case of debugging emergency.
;;(set-log-level! 10)
;;(set-log-procedure! log)
(handshake session)
(let ((record (session-record-port session)))
;; Since we use `fileno' above, the file descriptor behind PORT would be
;; closed when PORT is GC'd. If we used `port->fdes', it would instead
;; never be closed. So we use `fileno', but keep a weak reference to
;; PORT, so the file descriptor gets closed when RECORD is GC'd.
(add-weak-reference record port)
record)))
(define (open-socket-for-uri uri)
"Return an open port for URI. This variant works around
<http://bugs.gnu.org/15368> which affects Guile's 'open-socket-for-uri' up to
2.0.11 included."
(define rmem-max
;; The maximum size for a receive buffer on Linux, see socket(7).
"/proc/sys/net/core/rmem_max")
(define buffer-size
(if (file-exists? rmem-max)
(call-with-input-file rmem-max read)
126976)) ;the default for Linux, per 'rmem_default'
(let ((s ((@ (web client) open-socket-for-uri) uri)))
;; Work around <http://bugs.gnu.org/15368> by restoring a decent
;; buffer size.
(setsockopt s SOL_SOCKET SO_RCVBUF buffer-size)
s))
(define (open-connection-for-uri uri)
"Like 'open-socket-for-uri', but also handle HTTPS connections."
(define https?
(eq? 'https (uri-scheme uri)))
(let-syntax ((with-https-proxy
(syntax-rules ()
((_ exp)
;; For HTTPS URIs, honor 'https_proxy', not 'http_proxy'.
;; FIXME: Proxying is not supported for https.
(let ((thunk (lambda () exp)))
(if (and https?
(module-variable
(resolve-interface '(web client))
'current-http-proxy))
(parameterize ((current-http-proxy #f))
(when (getenv "https_proxy")
(format (current-error-port)
"warning: 'https_proxy' is ignored~%"))
(thunk))
(thunk)))))))
(with-https-proxy
(let ((s (open-socket-for-uri uri)))
;; Buffer input and output on this port.
(setvbuf s _IOFBF %http-receive-buffer-size)
(if https?
(tls-wrap s (uri-host uri))
s)))))
;; XXX: This is an awful hack to make sure the (set-port-encoding! p
;; "ISO-8859-1") call in `read-response' passes, even during bootstrap
;; where iconv is not available.
(module-define! (resolve-module '(web response))
'set-port-encoding!
(lambda (p e) #f))
;; XXX: Work around <http://bugs.gnu.org/13095>, present in Guile
;; up to 2.0.7.
(module-define! (resolve-module '(web client))
'shutdown (const #f))
;; XXX: Work around <http://bugs.gnu.org/19840>, present in Guile
;; up to 2.0.11.
(unless (or (> (string->number (major-version)) 2)
(> (string->number (minor-version)) 0)
(> (string->number (micro-version)) 11))
(let ((var (module-variable (resolve-module '(web http))
'declare-relative-uri-header!)))
;; If 'declare-relative-uri-header!' doesn't exist, forget it.
(when (and var (variable-bound? var))
(let ((declare-relative-uri-header! (variable-ref var)))
(declare-relative-uri-header! "Location")))))
(define (resolve-uri-reference ref base)
"Resolve the URI reference REF, interpreted relative to the BASE URI, into a
target URI, according to the algorithm specified in RFC 3986 section 5.2.2.
Return the resulting target URI."
(define (merge-paths base-path rel-path)
(let* ((base-components (string-split base-path #\/))
(base-directory-components (match base-components
((components ... last) components)
(() '())))
(base-directory (string-join base-directory-components "/")))
(string-append base-directory "/" rel-path)))
(define (remove-dot-segments path)
(let loop ((in
;; Drop leading "." and ".." components from a relative path.
;; (absolute paths will start with a "" component)
(drop-while (match-lambda
((or "." "..") #t)
(_ #f))
(string-split path #\/)))
(out '()))
(match in
(("." . rest)
(loop rest out))
((".." . rest)
(match out
((or () (""))
(error "remove-dot-segments: too many '..' components" path))
(_
(loop rest (cdr out)))))
((component . rest)
(loop rest (cons component out)))
(()
(string-join (reverse out) "/")))))
(cond ((or (uri-scheme ref)
(uri-host ref))
(build-uri (or (uri-scheme ref)
(uri-scheme base))
#:userinfo (uri-userinfo ref)
#:host (uri-host ref)
#:port (uri-port ref)
#:path (remove-dot-segments (uri-path ref))
#:query (uri-query ref)
#:fragment (uri-fragment ref)))
((string-null? (uri-path ref))
(build-uri (uri-scheme base)
#:userinfo (uri-userinfo base)
#:host (uri-host base)
#:port (uri-port base)
#:path (remove-dot-segments (uri-path base))
#:query (or (uri-query ref)
(uri-query base))
#:fragment (uri-fragment ref)))
(else
(build-uri (uri-scheme base)
#:userinfo (uri-userinfo base)
#:host (uri-host base)
#:port (uri-port base)
#:path (remove-dot-segments
(if (string-prefix? "/" (uri-path ref))
(uri-path ref)
(merge-paths (uri-path base)
(uri-path ref))))
#:query (uri-query ref)
#:fragment (uri-fragment ref)))))
(define (http-fetch uri file)
"Fetch data from URI and write it to FILE. Return FILE on success."
(define post-2.0.7?
(or (> (string->number (major-version)) 2)
(> (string->number (minor-version)) 0)
(> (string->number (micro-version)) 7)
(string>? (version) "2.0.7")))
(define headers
'(;; Some web sites, such as http://dist.schmorp.de, would block you if
;; there's no 'User-Agent' header, presumably on the assumption that
;; you're a spammer. So work around that.
(User-Agent . "GNU Guile")
;; Some servers, such as https://alioth.debian.org, return "406 Not
;; Acceptable" when not explicitly told that everything is accepted.
(Accept . "*/*")))
(let*-values (((connection)
(open-connection-for-uri uri))
((resp bv-or-port)
;; XXX: `http-get*' was introduced in 2.0.7, and replaced by
;; #:streaming? in 2.0.8. We know we're using it within the
;; chroot, but `guix-download' might be using a different
;; version. So keep this compatibility hack for now.
(if post-2.0.7?
(http-get uri #:port connection #:decode-body? #f
#:streaming? #t
#:headers headers)
(if (module-defined? (resolve-interface '(web client))
'http-get*)
(http-get* uri #:port connection #:decode-body? #f
#:headers headers)
(http-get uri #:port connection #:decode-body? #f
#:extra-headers headers))))
((code)
(response-code resp))
((size)
(response-content-length resp)))
(case code
((200) ; OK
(begin
(call-with-output-file file
(lambda (p)
(if (port? bv-or-port)
(begin
(dump-port bv-or-port p
#:buffer-size %http-receive-buffer-size
#:progress (progress-proc (uri-abbreviation uri)
size))
(newline))
(put-bytevector p bv-or-port))))
file))
((301 ; moved permanently
302) ; found (redirection)
(let ((uri (resolve-uri-reference (response-location resp) uri)))
(format #t "following redirection to `~a'...~%"
(uri->string uri))
(close connection)
(http-fetch uri file)))
(else
(error "download failed" (uri->string uri)
code (response-reason-phrase resp))))))
(define-syntax-rule (false-if-exception* body ...)
"Like `false-if-exception', but print the exception on the error port."
(catch #t
(lambda ()
body ...)
(lambda (key . args)
#f)
(lambda (key . args)
(print-exception (current-error-port) #f key args))))
(define (uri-vicinity dir file)
"Concatenate DIR, slash, and FILE, keeping only one slash in between.
This is required by some HTTP servers."
(string-append (string-trim-right dir #\/) "/"
(string-trim file #\/)))
(define (maybe-expand-mirrors uri mirrors)
"If URI uses the 'mirror' scheme, expand it according to the MIRRORS alist.
Return a list of URIs."
(case (uri-scheme uri)
((mirror)
(let ((kind (string->symbol (uri-host uri)))
(path (uri-path uri)))
(match (assoc-ref mirrors kind)
((mirrors ..1)
(map (compose string->uri (cut uri-vicinity <> path))
mirrors))
(_
(error "unsupported URL mirror kind" kind uri)))))
(else
(list uri))))
(define* (url-fetch url file #:key (mirrors '()))
"Fetch FILE from URL; URL may be either a single string, or a list of
string denoting alternate URLs for FILE. Return #f on failure, and FILE
on success."
(define uri
(append-map (cut maybe-expand-mirrors <> mirrors)
(match url
((_ ...) (map string->uri url))
(_ (list (string->uri url))))))
(define (fetch uri file)
(format #t "starting download of `~a' from `~a'...~%"
file (uri->string uri))
(case (uri-scheme uri)
((http https)
(false-if-exception* (http-fetch uri file)))
((ftp)
(false-if-exception* (ftp-fetch uri file)))
(else
(format #t "skipping URI with unsupported scheme: ~s~%"
uri)
#f)))
;; Make this unbuffered so 'progress-proc' works as expected. _IOLBF means
;; '\n', not '\r', so it's not appropriate here.
(setvbuf (current-output-port) _IONBF)
(setvbuf (current-error-port) _IOLBF)
(let try ((uri uri))
(match uri
((uri tail ...)
(or (fetch uri file)
(try tail)))
(()
(format (current-error-port) "failed to download ~s from ~s~%"
file url)
#f))))
;;; Local Variables:
;;; eval: (put 'with-elapsed-time 'scheme-indent-function 1)
;;; End:
;;; download.scm ends here