148 lines
4.3 KiB
Ruby
148 lines
4.3 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
# Downloads a remote file. If no filename is given, it'll use the remote filename
|
|
module BulkImports
|
|
class FileDownloadService
|
|
ServiceError = Class.new(StandardError)
|
|
|
|
REMOTE_FILENAME_PATTERN = %r{filename="(?<filename>[^"]+)"}.freeze
|
|
FILENAME_SIZE_LIMIT = 255 # chars before the extension
|
|
|
|
def initialize(configuration:, relative_url:, dir:, file_size_limit:, allowed_content_types:, filename: nil)
|
|
@configuration = configuration
|
|
@relative_url = relative_url
|
|
@filename = filename
|
|
@dir = dir
|
|
@file_size_limit = file_size_limit
|
|
@allowed_content_types = allowed_content_types
|
|
end
|
|
|
|
def execute
|
|
validate_dir
|
|
validate_url
|
|
validate_content_type
|
|
validate_content_length
|
|
|
|
download_file
|
|
|
|
validate_symlink
|
|
|
|
filepath
|
|
end
|
|
|
|
private
|
|
|
|
attr_reader :configuration, :relative_url, :dir, :file_size_limit, :allowed_content_types
|
|
|
|
def download_file
|
|
File.open(filepath, 'wb') do |file|
|
|
bytes_downloaded = 0
|
|
|
|
http_client.stream(relative_url) do |chunk|
|
|
bytes_downloaded += chunk.size
|
|
|
|
validate_size!(bytes_downloaded)
|
|
raise(ServiceError, "File download error #{chunk.code}") unless chunk.code == 200
|
|
|
|
file.write(chunk)
|
|
end
|
|
end
|
|
rescue StandardError => e
|
|
File.delete(filepath) if File.exist?(filepath)
|
|
|
|
raise e
|
|
end
|
|
|
|
def http_client
|
|
@http_client ||= BulkImports::Clients::HTTP.new(
|
|
url: configuration.url,
|
|
token: configuration.access_token
|
|
)
|
|
end
|
|
|
|
def allow_local_requests?
|
|
::Gitlab::CurrentSettings.allow_local_requests_from_web_hooks_and_services?
|
|
end
|
|
|
|
def headers
|
|
@headers ||= http_client.head(relative_url).headers
|
|
end
|
|
|
|
def validate_dir
|
|
raise(ServiceError, 'Invalid target directory') unless dir.start_with?(Dir.tmpdir)
|
|
end
|
|
|
|
def validate_symlink
|
|
if File.lstat(filepath).symlink?
|
|
File.delete(filepath)
|
|
|
|
raise(ServiceError, 'Invalid downloaded file')
|
|
end
|
|
end
|
|
|
|
def validate_url
|
|
::Gitlab::UrlBlocker.validate!(
|
|
http_client.resource_url(relative_url),
|
|
allow_localhost: allow_local_requests?,
|
|
allow_local_network: allow_local_requests?,
|
|
schemes: %w(http https)
|
|
)
|
|
end
|
|
|
|
def validate_content_length
|
|
validate_size!(headers['content-length'])
|
|
end
|
|
|
|
def validate_size!(size)
|
|
if size.blank?
|
|
raise ServiceError, 'Missing content-length header'
|
|
elsif size.to_i > file_size_limit
|
|
raise ServiceError, "File size %{size} exceeds limit of %{limit}" % {
|
|
size: ActiveSupport::NumberHelper.number_to_human_size(size),
|
|
limit: ActiveSupport::NumberHelper.number_to_human_size(file_size_limit)
|
|
}
|
|
end
|
|
end
|
|
|
|
def validate_content_type
|
|
content_type = headers['content-type']
|
|
|
|
raise(ServiceError, 'Invalid content type') if content_type.blank? || allowed_content_types.exclude?(content_type)
|
|
end
|
|
|
|
def filepath
|
|
@filepath ||= File.join(@dir, filename)
|
|
end
|
|
|
|
def filename
|
|
@filename.presence || remote_filename
|
|
end
|
|
|
|
# Fetch the remote filename information from the request content-disposition header
|
|
# - Raises if the filename does not exist
|
|
# - If the filename is longer then 255 chars truncate it
|
|
# to be a total of 255 chars (with the extension)
|
|
def remote_filename
|
|
@remote_filename ||=
|
|
headers['content-disposition'].to_s
|
|
.match(REMOTE_FILENAME_PATTERN) # matches the filename pattern
|
|
.then { |match| match&.named_captures || {} } # ensures the match is a hash
|
|
.fetch('filename') # fetches the 'filename' key or raise KeyError
|
|
.then(&File.method(:basename)) # Ensures to remove path from the filename (../ for instance)
|
|
.then(&method(:ensure_filename_size)) # Ensures the filename is within the FILENAME_SIZE_LIMIT
|
|
rescue KeyError
|
|
raise ServiceError, 'Remote filename not provided in content-disposition header'
|
|
end
|
|
|
|
def ensure_filename_size(filename)
|
|
if filename.length <= FILENAME_SIZE_LIMIT
|
|
filename
|
|
else
|
|
extname = File.extname(filename)
|
|
basename = File.basename(filename, extname)[0, FILENAME_SIZE_LIMIT]
|
|
|
|
"#{basename}#{extname}"
|
|
end
|
|
end
|
|
end
|
|
end
|