;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2020 Ludovic Courtès ;;; Copyright © 2015 Mark H Weaver ;;; Copyright © 2012, 2015 Free Software Foundation, Inc. ;;; Copyright © 2017 Tobias Geerinckx-Rice ;;; ;;; 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 . (define-module (guix http-client) #:use-module (web uri) #:use-module (web http) #:use-module ((web client) #:hide (open-socket-for-uri)) #:use-module (web request) #:use-module (web response) #:use-module (srfi srfi-1) #:use-module (srfi srfi-11) #:use-module (srfi srfi-19) #:use-module (srfi srfi-26) #:use-module (srfi srfi-34) #:use-module (srfi srfi-35) #:use-module (ice-9 match) #:use-module (ice-9 binary-ports) #:use-module (rnrs bytevectors) #:use-module (guix ui) #:use-module (guix utils) #:use-module (guix base64) #:autoload (gcrypt hash) (sha256) #:autoload (gnutls) (error/invalid-session) #:use-module ((guix build utils) #:select (mkdir-p dump-port)) #:use-module ((guix build download) #:select (open-socket-for-uri (open-connection-for-uri . guix:open-connection-for-uri) resolve-uri-reference)) #:re-export (open-socket-for-uri) #:export (&http-get-error http-get-error? http-get-error-uri http-get-error-code http-get-error-reason http-fetch http-multiple-get %http-cache-ttl http-fetch/cached)) ;;; Commentary: ;;; ;;; HTTP client portable among Guile versions, and with proper error condition ;;; reporting. ;;; ;;; Code: ;; HTTP GET error. (define-condition-type &http-get-error &error http-get-error? (uri http-get-error-uri) ; URI (code http-get-error-code) ; integer (reason http-get-error-reason)) ; string (define* (http-fetch uri #:key port (text? #f) (buffered? #t) (open-connection guix:open-connection-for-uri) (keep-alive? #f) (verify-certificate? #t) (headers '((user-agent . "GNU Guile"))) timeout) "Return an input port containing the data at URI, and the HTTP response from the server. If TEXT? is true, the data at URI is considered to be textual. Follow any HTTP redirection. When BUFFERED? is #f, return an unbuffered port, suitable for use in `filtered-port'. HEADERS is an alist of extra HTTP headers. When KEEP-ALIVE? is true, the connection is marked as 'keep-alive' and PORT is not closed upon completion. When VERIFY-CERTIFICATE? is true, verify HTTPS server certificates. TIMEOUT specifies the timeout in seconds for connection establishment; when TIMEOUT is #f, connection establishment never times out. Raise an '&http-get-error' condition if downloading fails." (let loop ((uri (if (string? uri) (string->uri uri) uri))) (let ((port (or port (open-connection uri #:verify-certificate? verify-certificate? #:timeout timeout))) (headers (match (uri-userinfo uri) ((? string? str) (cons (cons 'Authorization (string-append "Basic " (base64-encode (string->utf8 str)))) headers)) (_ headers)))) (unless (or buffered? (not (file-port? port))) (setvbuf port 'none)) (let*-values (((resp data) (http-get uri #:streaming? #t #:port port #:keep-alive? keep-alive? #:headers headers)) ((code) (response-code resp))) (case code ((200) (values data resp)) ((301 ; moved permanently 302 ; found (redirection) 303 ; see other 307 ; temporary redirection 308) ; permanent redirection (let ((uri (resolve-uri-reference (response-location resp) uri))) (close-port port) (format (current-error-port) (G_ "following redirection to `~a'...~%") (uri->string uri)) (loop uri))) (else (raise (condition (&http-get-error (uri uri) (code code) (reason (response-reason-phrase resp))) (&message (message (format #f (G_ "~a: HTTP download failed: ~a (~s)") (uri->string uri) code (response-reason-phrase resp)))))))))))) (define* (http-multiple-get base-uri proc seed requests #:key port (verify-certificate? #t) (open-connection guix:open-connection-for-uri) (keep-alive? #t) (batch-size 1000)) "Send all of REQUESTS to the server at BASE-URI. Call PROC for each response, passing it the request object, the response, a port from which to read the response body, and the previous result, starting with SEED, à la 'fold'. Return the final result. When PORT is specified, use it as the initial connection on which HTTP requests are sent; otherwise call OPEN-CONNECTION to open a new connection for a URI. When KEEP-ALIVE? is false, close the connection port before returning." (let connect ((port port) (requests requests) (result seed)) (define batch (if (>= batch-size (length requests)) requests (take requests batch-size))) ;; (format (current-error-port) "connecting (~a requests left)..." ;; (length requests)) (let ((p (or port (open-connection base-uri #:verify-certificate? verify-certificate?)))) ;; For HTTPS, P is not a file port and does not support 'setvbuf'. (when (file-port? p) (setvbuf p 'block (expt 2 16))) ;; Send BATCH in a row. ;; XXX: Do our own caching to work around inefficiencies when ;; communicating over TLS: . (let-values (((buffer get) (open-bytevector-output-port))) ;; Inherit the HTTP proxying property from P. (set-http-proxy-port?! buffer (http-proxy-port? p)) (catch #t (lambda () (for-each (cut write-request <> buffer) batch) (put-bytevector p (get)) (force-output p)) (lambda (key . args) ;; If PORT becomes unusable, open a fresh connection and ;; retry. (if (or (and (eq? key 'system-error) (= EPIPE (system-error-errno `(,key ,@args)))) (and (eq? key 'gnutls-error) (eq? (first args) error/invalid-session))) (begin (close-port p) ; close the broken port (connect #f requests result)) (apply throw key args))))) ;; Now start processing responses. (let loop ((sent batch) (processed 0) (result result)) (match sent (() (match (drop requests processed) (() (unless keep-alive? (close-port p)) (reverse result)) (remainder (connect p remainder result)))) ((head tail ...) (catch #t (lambda () (let* ((resp (read-response p)) (body (response-body-port resp)) (result (proc head resp body result))) ;; The server can choose to stop responding at any time, ;; in which case we have to try again. Check whether ;; that is the case. Note that even upon "Connection: ;; close", we can read from BODY. (match (assq 'connection (response-headers resp)) (('connection 'close) (close-port p) (connect #f ;try again (drop requests (+ 1 processed)) result)) (_ (loop tail (+ 1 processed) result))))) ;keep going (lambda (key . args) ;; If PORT was cached and the server closed the connection ;; in the meantime, we get EPIPE. In that case, open a ;; fresh connection and retry. We might also get ;; 'bad-response or a similar exception from (web response) ;; later on, once we've sent the request, or a ;; ERROR/INVALID-SESSION from GnuTLS. (if (or (and (eq? key 'system-error) (= EPIPE (system-error-errno `(,key ,@args)))) (and (eq? key 'gnutls-error) (eq? (first args) error/invalid-session)) (memq key '(bad-response bad-header bad-header-component))) (begin (close-port p) (connect #f ; try again (drop requests (+ 1 processed)) result)) (apply throw key args)))))))))) ;;; ;;; Caching. ;;; (define %http-cache-ttl ;; Time-to-live in seconds of the HTTP cache of in ~/.cache/guix. (make-parameter (* 3600 (or (and=> (getenv "GUIX_HTTP_CACHE_TTL") string->number*) 36)))) (define (cache-file-for-uri uri) "Return the name of the file in the cache corresponding to URI." (let ((digest (sha256 (string->utf8 (uri->string uri))))) ;; Use the "URL" alphabet because it does not contain "/". (string-append (cache-directory) "/http/" (base64-encode digest 0 (bytevector-length digest) #f #f base64url-alphabet)))) (define* (http-fetch/cached uri #:key (ttl (%http-cache-ttl)) text? (write-cache dump-port) (cache-miss (const #t)) (timeout 10)) "Like 'http-fetch', return an input port, but cache its contents in ~/.cache/guix. The cache remains valid for TTL seconds. Call WRITE-CACHE with the HTTP input port and the cache output port to write the data to cache. Call CACHE-MISS with URI just before fetching data from URI. TIMEOUT specifies the timeout in seconds for connection establishment." (let ((file (cache-file-for-uri uri))) (define (update-cache cache-port) (define cache-time (and cache-port (stat:mtime (stat cache-port)))) (define headers `((user-agent . "GNU Guile") ,@(if cache-time `((if-modified-since . ,(time-utc->date (make-time time-utc 0 cache-time)))) '()))) ;; Update the cache and return an input port. (guard (c ((http-get-error? c) (if (= 304 (http-get-error-code c)) ;"Not Modified" (begin (utime file) ;update FILE's mtime cache-port) (raise c)))) (let ((port (http-fetch uri #:text? text? #:headers headers #:timeout timeout))) (cache-miss uri) (mkdir-p (dirname file)) (when cache-port (close-port cache-port)) (with-atomic-file-output file (cut write-cache port <>)) (close-port port) (open-input-file file)))) (define (old? port) ;; Return true if PORT has passed TTL. (let* ((s (stat port)) (now (current-time time-utc))) (< (+ (stat:mtime s) ttl) (time-second now)))) (catch 'system-error (lambda () (let ((port (open-input-file file))) (if (old? port) (update-cache port) port))) (lambda args (if (= ENOENT (system-error-errno args)) (update-cache #f) (apply throw args)))))) ;;; http-client.scm ends here