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-rw-r--r--guix/nar.scm229
1 files changed, 221 insertions, 8 deletions
diff --git a/guix/nar.scm b/guix/nar.scm
index ea119a25fe..4bc2deb229 100644
--- a/guix/nar.scm
+++ b/guix/nar.scm
@@ -1,5 +1,5 @@
;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2014 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
@@ -19,23 +19,40 @@
(define-module (guix nar)
#:use-module (guix utils)
#:use-module (guix serialization)
- #:use-module ((guix build utils) #:select (with-directory-excursion))
+ #:use-module ((guix build utils)
+ #:select (delete-file-recursively with-directory-excursion))
+ #:use-module (guix store)
+ #:use-module (guix ui) ; for '_'
+ #:use-module (guix hash)
+ #:use-module (guix pki)
+ #:use-module (guix pk-crypto)
#:use-module (rnrs bytevectors)
#:use-module (rnrs io ports)
#:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-35)
#:use-module (ice-9 ftw)
#:use-module (ice-9 match)
#:export (nar-error?
+ nar-error-port
+ nar-error-file
+
nar-read-error?
- nar-read-error-file
- nar-read-error-port
nar-read-error-token
+ nar-invalid-hash-error?
+ nar-invalid-hash-error-expected
+ nar-invalid-hash-error-actual
+
+ nar-signature-error?
+ nar-signature-error-signature
+
write-file
- restore-file))
+ restore-file
+
+ restore-file-set))
;;; Comment:
;;;
@@ -44,15 +61,24 @@
;;; Code:
(define-condition-type &nar-error &error ; XXX: inherit from &nix-error ?
- nar-error?)
+ nar-error?
+ (file nar-error-file) ; file we were restoring, or #f
+ (port nar-error-port)) ; port from which we read
(define-condition-type &nar-read-error &nar-error
nar-read-error?
- (port nar-read-error-port) ; port from which we read
- (file nar-read-error-file) ; file we were restoring, or #f
(token nar-read-error-token)) ; faulty token, or #f
+(define-condition-type &nar-signature-error &nar-error
+ nar-signature-error?
+ (signature nar-signature-error-signature)) ; faulty signature or #f
+(define-condition-type &nar-invalid-hash-error &nar-signature-error
+ nar-invalid-hash-error?
+ (expected nar-invalid-hash-error-expected) ; expected hash (a bytevector)
+ (actual nar-invalid-hash-error-actual)) ; actual hash
+
+
(define (dump in out size)
"Copy SIZE bytes from IN to OUT."
(define buf-size 65536)
@@ -239,4 +265,191 @@ Restore it as FILE."
(&message (message "unsupported nar entry type"))
(&nar-read-error (port port) (file file) (token x))))))))
+
+;;;
+;;; Restoring a file set into the store.
+;;;
+
+;; The code below accesses the store directly and is meant to be run from
+;; "build hooks", which cannot invoke the daemon's 'import-paths' RPC since
+;; (1) the locks on the files to be restored as already held, and (2) the
+;; $NIX_HELD_LOCKS hackish environment variable cannot be set.
+;;
+;; So we're really duplicating that functionality of the daemon (well, until
+;; most of the daemon is in Scheme :-)). But note that we do use a couple of
+;; RPCs for functionality not available otherwise, like 'valid-path?'.
+
+(define (lock-store-file file)
+ "Acquire exclusive access to FILE, a store file."
+ (call-with-output-file (string-append file ".lock")
+ (cut fcntl-flock <> 'write-lock)))
+
+(define (unlock-store-file file)
+ "Release access to FILE."
+ (call-with-input-file (string-append file ".lock")
+ (cut fcntl-flock <> 'unlock)))
+
+(define* (finalize-store-file source target
+ #:key (references '()) deriver (lock? #t))
+ "Rename SOURCE to TARGET and register TARGET as a valid store item, with
+REFERENCES and DERIVER. When LOCK? is true, acquire exclusive locks on TARGET
+before attempting to register it; otherwise, assume TARGET's locks are already
+held."
+
+ ;; XXX: Currently we have to call out to the daemon to check whether TARGET
+ ;; is valid.
+ (with-store store
+ (unless (valid-path? store target)
+ (when lock?
+ (lock-store-file target))
+
+ (unless (valid-path? store target)
+ ;; If FILE already exists, delete it (it's invalid anyway.)
+ (when (file-exists? target)
+ (delete-file-recursively target))
+
+ ;; Install the new TARGET.
+ (rename-file source target)
+
+ ;; Register TARGET. As a side effect, it resets the timestamps of all
+ ;; its files, recursively. However, it doesn't attempt to deduplicate
+ ;; its files like 'importPaths' does (FIXME).
+ (register-path target
+ #:references references
+ #:deriver deriver))
+
+ (when lock?
+ (unlock-store-file target)))))
+
+(define (temporary-store-directory)
+ "Return the file name of a temporary directory created in the store that is
+protected from garbage collection."
+ (let* ((template (string-append (%store-prefix) "/guix-XXXXXX"))
+ (port (mkstemp! template)))
+ (close-port port)
+ (with-store store
+ (add-temp-root store template))
+
+ ;; There's a small window during which the GC could delete the file. Try
+ ;; again if that happens.
+ (if (file-exists? template)
+ (begin
+ ;; It's up to the caller to create that file or directory.
+ (delete-file template)
+ template)
+ (temporary-store-directory))))
+
+(define* (restore-file-set port
+ #:key (verify-signature? #t) (lock? #t)
+ (log-port (current-error-port)))
+ "Restore the file set read from PORT to the store. The format of the data
+on PORT must be as created by 'export-paths'---i.e., a series of Nar-formatted
+archives with interspersed meta-data joining them together, possibly with a
+digital signature at the end. Log progress to LOG-PORT. Return the list of
+files restored.
+
+When LOCK? is #f, assume locks for the files to be restored are already held.
+This is the case when the daemon calls a build hook.
+
+Note that this procedure accesses the store directly, so it's only meant to be
+used by the daemon's build hooks since they cannot call back to the daemon
+while the locks are held."
+ (define %export-magic
+ ;; Number used to identify genuine file set archives.
+ #x4558494e)
+
+ (define port*
+ ;; Keep that one around, for error conditions.
+ port)
+
+ (define (assert-valid-signature signature hash file)
+ ;; Bail out if SIGNATURE, an sexp, doesn't match HASH, a bytevector
+ ;; containing the expected hash for FILE.
+ (let* ((signature (catch 'gcry-error
+ (lambda ()
+ (string->canonical-sexp signature))
+ (lambda (err . _)
+ (raise (condition
+ (&message
+ (message "signature is not a valid \
+s-expression"))
+ (&nar-signature-error
+ (file file)
+ (signature signature) (port port)))))))
+ (subject (signature-subject signature))
+ (data (signature-signed-data signature)))
+ (if (and data subject)
+ (if (authorized-key? subject)
+ (if (equal? (hash-data->bytevector data) hash)
+ (unless (valid-signature? signature)
+ (raise (condition
+ (&message (message "invalid signature"))
+ (&nar-signature-error
+ (file file) (signature signature) (port port)))))
+ (raise (condition (&message (message "invalid hash"))
+ (&nar-invalid-hash-error
+ (port port) (file file)
+ (signature signature)
+ (expected (hash-data->bytevector data))
+ (actual hash)))))
+ (raise (condition (&message (message "unauthorized public key"))
+ (&nar-signature-error
+ (signature signature) (file file) (port port)))))
+ (raise (condition
+ (&message (message "corrupt signature data"))
+ (&nar-signature-error
+ (signature signature) (file file) (port port)))))))
+
+ (let loop ((n (read-long-long port))
+ (files '()))
+ (case n
+ ((0)
+ (reverse files))
+ ((1)
+ (let-values (((port get-hash)
+ (open-sha256-input-port port)))
+ (let ((temp (temporary-store-directory)))
+ (restore-file port temp)
+ (let ((magic (read-int port)))
+ (unless (= magic %export-magic)
+ (raise (condition
+ (&message (message "corrupt file set archive"))
+ (&nar-read-error
+ (port port*) (file #f) (token #f))))))
+
+ (let ((file (read-store-path port))
+ (refs (read-store-path-list port))
+ (deriver (read-string port))
+ (hash (get-hash))
+ (has-sig? (= 1 (read-int port))))
+ (format log-port
+ (_ "importing file or directory '~a'...~%")
+ file)
+
+ (let ((sig (and has-sig? (read-string port))))
+ (when verify-signature?
+ (if sig
+ (begin
+ (assert-valid-signature sig hash file)
+ (format log-port
+ (_ "found valid signature for '~a'~%")
+ file)
+ (finalize-store-file temp file
+ #:references refs
+ #:deriver deriver
+ #:lock? lock?)
+ (loop (read-long-long port)
+ (cons file files)))
+ (raise (condition
+ (&message (message "imported file lacks \
+a signature"))
+ (&nar-signature-error
+ (port port*) (file file) (signature #f)))))))))))
+ (else
+ ;; Neither 0 nor 1.
+ (raise (condition
+ (&message (message "invalid inter-file archive mark"))
+ (&nar-read-error
+ (port port) (file #f) (token #f))))))))
+
;;; nar.scm ends here
generated by cgit v1.2.3 (git 2.45.0) at 2024-11-29 09:46:17 +0000