Sha256: 1864eb14502c3e3d478f3726829606f8e550c171619750deb332aa3a49a20b4b
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Versions: 12
Compression:
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Contents
# Some commands are supposed to occur in sequence. For example, USER
# must be immediately followed by PASS. This class keeps track of
# when a specific command either must arrive or must not arrive, and
# raises a "bad sequence" error when commands arrive in the wrong
# sequence.
module Ftpd
class CommandSequenceChecker
include Error
def initialize
@must_expect = []
@expected_command = nil
end
# Set the command to expect next. If not set, then any command
# will be accepted, so long as it hasn't been registered using
# {#must_expect}. Otherwise, the set command must be next or a
# sequence error will result.
#
# @param command [String] The command. Must be lowercase.
def expect(command)
@expected_command = command
end
# Register a command that must be expected. When that command is
# received without {#expect} having been called for it, a sequence
# error will result.
def must_expect(command)
@must_expect << command
end
# Check a command. If expecting a specific command and this
# command isn't it, then raise an error that will cause a "503 Bad
# sequence" error to be sent. After checking, the expected
# command is cleared and any command will be accepted until
# {#expect} is called again.
#
# @param command [String] The command. Must be lowercase.
# @raise [CommandError] A "503 Bad sequence" error
def check(command)
if @expected_command
begin
sequence_error unless command == @expected_command
ensure
@expected_command = nil
end
else
sequence_error if @must_expect.include?(command)
end
end
end
end
Version data entries
12 entries across 12 versions & 1 rubygems