nmap/nselib/nmap.luadoc

--- Interface with Nmap internals.
-- \n\n
-- The nmap module is an interface with Nmap's internal functions and data
-- structures. The API provides target host details such as port states and
-- version detection results. It also offers an interface to the Nsock library
-- for efficient network I/O. 

module "nmap"

--- Returns the debugging level as a non-negative integer.
-- \n\n
-- The debugging level can be set with the -d option.
-- @return The debugging level.
-- @usage if nmap.debugging() > 0 then ... end
function nmap.debugging()

--- Determines whether Nmap was compiled with SSL support.
-- \n\n
-- This can be used to avoid sending SSL probes when SSL is not available. 
-- @return true if Nmap was compiled with SSL support, false otherwise.
function nmap.have_ssl()

--- Returns the verbosity level as a non-negative integer.
-- \n\n
-- The verbosity level can be set with the -v option.
-- @return The verbosity level.
-- @usage if nmap.verbosity() > 0 then ... end
function nmap.verbosity()

--- Searches for the specified file and returns a string containing its path if
-- it is found and readable (to the process).
-- \n\n
-- If the file is not found, not readable, or is a directory, nil is returned.
-- The call nmap.fetchfile("nmap-rpc") will search for the data file nmap-rpc
-- and, assuming it's found (which it should be), return a string like
-- "/usr/local/share/nmap/nmap-rpc".
-- @param filename Filename to search for.
-- @return String representing the full path to the file or nil.
function nmap.fetchfile(filename)

--- Returns the timing level as a non-negative integer. Possible return values
-- vary from 0 to 5, corresponding to the six built-in Nmap timing templates.
-- The timing level can be set with the -T option.
-- @return The timing level.
function nmap.timing_level()

--- Gets a port table for a port on a given host.
-- \n\n
-- This function takes a host table and a port table and returns a port table
-- for the queried port. The port table returned is similar in structure to the
-- ones passed to the rule and action functions.
-- \n\n
-- You can of course reuse the host and port tables passed to the port rule
-- function. The purpose of this call is to be able to match scripts against
-- more than one open port. For example if the target host has an open port 22
-- and a running identd server, then you can write a script which will only fire
-- if both ports are open and there is an identification server on port 113.
-- While it is possible to specify IP addresses different to the currently
-- scanned target, the result will only be correct if the target is in the
-- currently scanned group of hosts.
-- @param host Host table, containing an "ip" field.
-- @param port Port table, containing "number" and "protocol" fields.
-- @param protocol Protocol string ("tcp" or "udp")
-- @return A new port table holding the status and information for the port.
-- @usage p = nmap.get_port_state({ip="127.0.0.1"}, {number="80", protocol="tcp"})
function nmap.get_port_state(host, port)

--- Sets the state of a port on a given host.
-- \n\n
-- Using this function, the final port state, reflected in Nmap's results,
-- can be changed for a target. This is useful when Nmap detects a port as
-- "open|filtered", but the script successfully connects to that port. In this
-- case, the script can set the port state to "open". Note that the port.state
-- value, which is passed to the script's action function will not be changed by
-- this call.
-- @param host Host table, containing an "ip" field.
-- @param port Port table, containing "number" and "protocol" fields.
-- @param state Port state, like "open" or "closed".
function nmap.set_port_state(host, port, state)

--- Sets version information on a port.
-- \n\n
-- NSE scripts are sometimes able to determine the service name and application
-- version listening on a port. A whole script category (version) was designed
-- for this purpose. set_port_version function is used to record version
-- information when it is discovered.
-- \n\n
-- The host and port arguments to this function should either be the tables
-- passed to the action method or they should have the same structure. The port
-- argument specifies the port to operate on through its "number" and "protocol"
-- fields. and also contains the new version information to set. The version
-- detection fields this function looks at are "name", "product", "version",
-- "extrainfo", "hostname", "ostype", "devicetype", and "service_tunnel". All
-- these keys are optional.
-- \n\n
-- The probestate argument describes the state in which the script completed. It
-- is a string, one of: "hardmatched", "softmatched", "nomatch", "tcpwrapped",
-- or "incomplete". "hardmatched" is almost always used, as it signifies a
-- successful match. The other possible states are generally only used for
-- standard version detection rather than the NSE enhancement.
-- @param host Host table, containing and "ip" field.
-- @param port Port table, containing "number" and "protocol" fields, as well as
-- any additional version information fields.
-- @param probestate The state of the probe: "hardmatched", "softmatched",
-- "nomatch", "tcpwrapped", or "incomplete".
function nmap.set_port_version(host, port, probestate)

--- Returns the current date and time in milliseconds.
-- @return The number of milliseconds since the epoch (on most systems this is
-- 01/01/1970).
function nmap.clock_ms()

--- Gets the link-level hardware type of an interface.
-- \n\n
-- This function takes a dnet-style interface name and returns a string
-- representing the hardware type of the interface. Possible return values are
-- "ethernet", "loopback", "p2p", or nil if none of the other types apply.
-- @param interface_name The name of the interface.
-- @return "ethernet", "loopback", "p2p", or nil.
function nmap.get_interface_link(interface_name)

--- Create a mutex on an object.
-- \n\n
-- This function returns another function that works as a mutex on the object
-- passed. This object can be any Lua data type except nil, booleans, and
-- numbers. The returned function allows you to lock, try to lock, and release
-- the mutex. The returned function takes only one argument, which must be one
-- of\n
-- "lock": makes a blocking lock on the mutex. If the mutex is busy then
-- the thread will yield and wait. The function returns with the mutex locked.\n
-- "trylock": makes a non-blocking lock on the mutex. If the mutex is
-- busy then it immediately returns with a return value of false. Otherwise,
-- the mutex locks the mutex and returns true.\n
-- "done": releases the mutex and allows another thread to lock it. If
-- the thread does not have a lock on the mutex, an error will be raised.\n
-- "running": returns the thread locked on the mutex or nil if no thread
-- is locked. This should only be used for debugging as it interferes with
-- finished threads from being collected.
-- @param object Object to create a mutex for.
-- @return Mutex function which takes one of the following arguments: "lock",
-- "trylock", "done", or "running".
-- @usage
-- id = "My Script's Unique ID";\n
-- \n
-- local mutex = nmap.mutex(id);\n
-- function action(host, port)\n
--   mutex "lock";\n
--   -- do stuff\n
--   mutex "done";\n
--   return script_output;\n
-- end
function nmap.mutex(object)

--- Creates a new exception handler.
-- \n\n
-- This function returns another function, an exception handler. The returned
-- function takes a variable number of arguments, which are assumed to be the
-- return values of another function. It checks the return values for an
-- exception, which is signalled when the first return value is false. If there
-- is an exception, the script will stop immediately and produce no output. An
-- optional handler function can be called before the script is stopped. In the
-- error handler function you can perform any clean-up operations, such as
-- closing a socket.
-- @param handler Exception handler function (optional).
-- @usage
-- local result, socket, try, catch\n
-- \n
-- result = ""\n
-- socket = nmap.new_socket()\n
-- catch = function()\n
--   socket:close()\n
-- end\n
-- try = nmap.new_try(catch)\n
-- try(socket:connect(host.ip, port.number))\n
-- result = try(socket:receive_lines(1))\n
-- try(socket:send(result))
function nmap.new_try(handler)

--- Returns a new NSE socket object.
-- \n\n
-- To allow for efficient and parallelizable network I/O, NSE provides an
-- interface to Nsock, the Nmap socket library. The smart callback mechanism
-- Nsock uses is fully transparent to NSE scripts. The main benefit of NSE's
-- sockets is that they never block on I/O operations, allowing many scripts to
-- be run in parallel. The I/O parallelism is fully transparent to authors of
-- NSE scripts. In NSE you can either program as if you were using a single non
-- blocking socket or you can program as if your connection is blocking.
-- Seemingly blocking I/O calls still return once a specified timeout has been
-- exceeded.
-- \n\n
-- NSE sockets are the recommended way to do network I/O. They support
-- connect-style sending and receiving over TCP and UDP (and SSL), as well as
-- raw socket receiving.
-- @return A new NSE socket.
-- @see nmap.new_dnet
function nmap.new_socket()

--- Establishes a connection.
-- \n\n
-- The connect puts a socket in a state ready for communication. It takes as
-- arguments a host descriptor (either an IP address or a hostname), a port
-- number and optionally a protocol. The protocol must be one of "tcp", "udp" or
-- "ssl"; it is "tcp" if not specified.
-- \n\n
-- On success the function returns true. On failure it returns false and an
-- error string. Those strings are taken from the gai_strerror C function. They
-- are (with the error code in parentheses):\n
-- "Address family for hostname not supported" (EAI_ADDRFAMILY)\n
-- "Temporary failure in name resolution" (EAI_AGAIN)\n
-- "Bad value for ai_flags" (EAI_BADFLAGS)\n
-- "Non-recoverable failure in name resolution" (EAI_FAIL)\n
-- "ai_family not supported" (EAI_FAMILY)\n
-- "Memory allocation failure" (EAI_MEMORY)\n
-- "No address associated with hostname" (EAI_NODATA)\n
-- "Name or service not known" (EAI_NONAME)\n
-- "Servname not supported for ai_socktype" (EAI_SERVICE)\n
-- "ai_socktype not supported" (EAI_SOCKTYPE)\n
-- "System error" (EAI_SYSTEM)\n
-- In addition to these standard system error based messages are the following
-- two NSE-specific errors:\n
-- "Sorry, you don't have OpenSSL" occurs if the protocol is "ssl" but but Nmap
-- was compiled without OpenSSL support.\n
-- "invalid connection method" occurs if the second parameter is not one of
-- "tcp", "udp", and "ssl".
-- @param hostid Hostname or IP address.
-- @param port Port number.
-- @param protocol "tcp", "udp", or "ssl" (default "tcp").
-- @return Status (true or false).
-- @return Error code (if status is false).
function socket:connect(hostid, port, protocol)

--- Sends data on an open socket.
-- \n\n
-- The send method sends the data contained in the data string through an open
-- connection. On success the returns true. If the send
-- operation has failed, the function returns true along with an error string.
-- The error strings are:\n
-- "Trying to send through a closed socket": there was no call to socket:connect
-- before the send operation.\n
-- "TIMEOUT": the operation took longer than the specified timeout for the
-- socket.\n
-- "ERROR": an error occurred inside the underlying Nsock library.\n
-- "CANCELLED": the operation was cancelled.\n
-- "KILL": for example the script scan is aborted due to a faulty script.\n
-- "EOF": an EOF was read (probably will not occur for a send operation).\n
-- @param data The data to send.
-- @return Status (true or false).
-- @return Error code (if status is false).
function socket:send(data)

--- Receives data from an open socket.
-- \n\n
-- The receive method does a non-blocking receive operation on an open socket.
-- On success the function returns true along with the received data. If
-- receiving data has failed, the function returns false along with an error
-- string. A failure occurs for example if receive is called on a closed socket.
-- The receive call returns to the NSE script all the data currently stored in
-- the receive buffer of the socket. Error conditions are the same as for the
-- send operation.
-- @return Status (true or false).
-- @return Data (if status is true) or error string (if status is false).
function socket:receive()

--- Receives lines from an open connection.
-- \n\n
-- Tries to receive at least n lines from an open connection. A line is a string
-- delimited with \n characters.  If it was not possible to receive at least n
-- lines before the operation times out a "TIMEOUT" error occurs. On the other
-- hand, if more than n lines were received, all are returned, not just n. Use
-- stdnse.make_buffer to guarantee one line is returned per call.
-- \n\n
-- On success the function returns true along with the received data. If
-- receiving data has failed, the function returns false along with an error
-- string. Error conditions are the same as for the send operation.
-- @param n Minimum number of lines to read.
-- @return Status (true or false).
-- @return Data (if status is true) or error string (if status is false).
function socket:receive_lines(n)

--- Receives bytes from an open connection.
-- \n\n
-- Tries to receive at least n bytes from an open connection. Like in
-- receive_lines, n is the minimum amount of characters we would like to
-- receive. If more arrive, we get all of them. If fewer than n characters
-- arrive before the operation times out, a "TIMEOUT" error occurs.
-- \n\n
-- On success the function returns true along with the received data. If
-- receiving data has failed, the function returns false along with an error
-- string. Error conditions are the same as for the send operation.
-- @param n Minimum number of bytes to read.
-- @return Status (true or false).
-- @return Data (if status is true) or error string (if status is false).
function socket:receive_bytes(n)

--- Reads from a socket using a buffer and an arbitrary delimiter.
-- \n\n
-- The receive_buf method reads data from the network until it encounters the
-- given delimiter string (or matches the function passed in). This function
-- continues to read from the network until the delimiter is found or the
-- function times out.  If data is read beyond the delimiter, that data is saved
-- in a buffer for the next call to receive_buf.  This buffer is cleared on
-- subsequent calls to other Network I/O API functions.
-- \n\n
-- The first argument may be either a pattern or a function. If a pattern, that
-- pattern is used to separate the data. If a function, it must take exactly one
-- parameter (the buffer) and its return values must be in the same format as
-- string.find (offsets to the start and the end of the delimiter inside the
-- buffer, or nil if the delimiter is not found).  The nselib match.lua module
-- provides functions for matching against regular expressions or byte counts.
-- These functions are suitable as arguments to receive_buf.
-- \n\n
-- The second argument to receive_buf is a Boolean value controlling whether the
-- delimiting string is returned along with the received data (true) or
-- discarded (false).
-- \n\n
-- On success the function returns true along with the received data. If
-- receiving data has failed, the function returns false along with an error
-- string. Possible error messages are the same as those that the other receive
-- function can return, with the addition of\n
-- "Error inside splitting-function": the first argument was a function which
-- caused an error while being called.\n
-- "Error in string.find (nsockobj:receive_buf)!": a string was provided as the
-- first argument, and string.find() yielded an error while being called.\n
-- "Expected either a function or a string!": the first argument was neither a
-- function nor a string.\n
-- "Delimiter has negative size!": the returned start offset is greater than the
-- end offset.\n
-- @param delimiter A Lua pattern or a function with return values like those of
-- string.find.
-- @param keeppattern Whether to return the delimiter string with any returned
-- data.
-- @return Status (true or false).
-- @return Data (if status is true) or error string (if status is false).
function socket:receive_buf(delimiter, keeppattern)

--- Closes an open connection.
-- \n\n
-- On success the function returns true. If the close fails, the function
-- returns false and an error string. Currently the only error message is
-- "Trying to close a closed socket", which is issued if the socket has already
-- been closed.
-- \n\n
-- Sockets are subject to garbage collection. Should you forget to close a
-- socket, it will get closed before it gets deleted (on the next occasion Lua's
-- garbage collector is run). However since garbage collection cycles are
-- difficult to predict, it is considered good practice to close opened sockets.
-- @return Status (true or false).
-- @return Error code (if status is false).
function socket:close()

--- Gets information about a socket.
-- \n\n
-- This function returns information about the socket object. It returns 5
-- values. If an error occurred, the first value is nil and the second value
-- describes the error condition. Otherwise the first value describes the
-- success of the operation and the remaining 4 values describe both endpoints
-- of the TCP connection. If you put the call in a try() statement the status
-- value is consumed. The call can be used for example if you want to query an
-- authentication server.
-- @return Status (true or false).
-- @return Local IP address (if status is true) or error string (if status is
-- false).
-- @return Local port number (if status is true).
-- @return Remote IP address (if status is true).
-- @return Remote port number (if status is true).
function socket:get_info()

--- Sets a timeout for socket input and output operations.
-- \n\n
-- After this time, given in milliseconds, socket operations will time out and
-- return. The default value is 30,000 (30 seconds). The lowest allowed value is
-- 10 ms, since this is the granularity of NSE network I/O.
-- @param t Timeout in milliseconds.
function socket:set_timeout(t)

--- Opens a socket for raw packet capture.
-- \n\n
-- The callback function is a function that receives a packet with headers and
-- computes a "packet hash"--some value derived from the packet. For example,
-- the callback function could extract the source IP address from a packet. The
-- hash of each packet received is compared against all the strings registered
-- with the pcap_register function.
-- @param device The dnet-style interface name of the device you want to capture
-- from.
-- @param snaplen The length of each packet you want to capture (similar to the
-- -s option to tcpdump)\n
-- @param promisc Should be set to 1 if the interface should activate
-- promiscuous mode, and 0 otherwise.
-- @param test_function Callback function used to compute the packet hash.
-- @param bpf A string describing a Berkeley packet filter expression (like
-- those provided to tcpdump).
-- @see socket:pcap_register
function socket:pcap_open(device, snaplen, promisc, test_function, bpf)

--- Starts listening for incoming packages.
-- \n\n
-- The provided packet_hash is a binary string which has to match the hash
-- returned by the test_function parameter provided to pcap_open(). If you want
-- to receive all packets, just provide the empty string (""). There has to be a
-- call to pcap_register() before a call to pcap_receive().
-- @param packet_hash A binary string that is compared against packet hashes.
-- @see socket:pcap_open
function socket:pcap_register(packet_hash)

--- Receives a captured packet.
-- \n\n
-- If an error or timeout occurs, the function returns false and an error
-- message. Otherwise, the function returns true followed by the packet length,
-- the layer two header, and the layer three header.
-- @return Status (true or false).
-- @return The length of the captured packet (this may be smaller than the
-- actual packet length since packets are truncated when the Libpcap snaplen
-- parameter is smaller than the total packet length).
-- @return Data from the second OSI layer (e.g. ethernet headers).
-- @return Data from the third OSI layer (e.g. IPv4 headers).
function socket:pcap_receive()

--- Closes the pcap device.
function socket:pcap_close()

--- Creates a new dnet object, used to send raw packets.
function nmap.new_dnet()

--- Opens an ethernet interface for raw packet sending.
-- \n\n
-- An error ("device is not valid ethernet interface") is thrown in case the
-- provided argument is not valid.
-- @param interface_name The dnet-style name of the interface to open.
function dnet:ethernet_open(interface_name)

--- Sends a raw ethernet frame.
-- \n\n
-- The dnet object must be associated with a previously opened interface. The
-- packet must include the IP and ethernet headers. including IP header and
-- ethernet header. If there was no previous valid call to ethernet_open() an
-- error is thrown ("dnet is not valid opened ethernet interface").
-- @param packet
function dnet:ethernet_send(packet)

--- Closes an ethernet interface.
-- \n\n
-- An error ("device is not valid ethernet interface") is thrown in case the
-- provided argument is not valid.
function dnet:ethernet_close()