---
-- A smallish httpspider library providing basic spidering capabilities
-- It consists of the following classes:
--
-- * <code>Options</code>
-- ** This class is responsible for handling library options.
--
-- * <code>LinkExtractor</code>
-- ** This class contains code responsible for extracting urls from web pages.
--
-- * <code>URL</code>
-- ** This class contains code to parse and process URLs.
--
-- * <code>UrlQueue</code>
-- ** This class contains a queue of the next links to process.
--
-- * <code>Crawler</code>
-- ** This class is responsible for the actual crawling.
--
-- The following sample code shows how the spider could be used:
-- <code>
-- local crawler = httpspider.Crawler:new( host, port, '/', { scriptname = SCRIPT_NAME } )
-- crawler:set_timeout(10000)
--
-- local result
-- while(true) do
-- local status, r = crawler:crawl()
-- if ( not(status) ) then
-- break
-- end
-- if ( r.response.body:match(str_match) ) then
-- crawler:stop()
-- result = r.url
-- break
-- end
-- end
--
-- return result
-- </code>
--
-- @author Patrik Karlsson <patrik@cqure.net>
--
-- @args httpspider.maxdepth the maximum amount of directories beneath
-- the initial url to spider. A negative value disables the limit.
-- (default: 3)
-- @args httpspider.maxpagecount the maximum amount of pages to visit.
-- A negative value disables the limit (default: 20)
-- @args httpspider.url the url to start spidering. This is a URL
-- relative to the scanned host eg. /default.html (default: /)
-- @args httpspider.withinhost only spider URLs within the same host.
-- (default: true)
-- @args httpspider.withindomain only spider URLs within the same
-- domain. This widens the scope from <code>withinhost</code> and can
-- not be used in combination. (default: false)
-- @args httpspider.noblacklist if set, doesn't load the default blacklist
-- @args httpspider.useheadfornonwebfiles if set, the crawler would use
-- HEAD instead of GET for files that do not have extensions indicating
-- that they are webpages (the list of webpage extensions is located in
-- nselib/data/http-web-files-extensions.lst)
--
local coroutine = require "coroutine"
local http = require "http"
local io = require "io"
local nmap = require "nmap"
local stdnse = require "stdnse"
local string = require "string"
local table = require "table"
local url = require "url"
_ENV = stdnse.module("httpspider", stdnse.seeall)
local LIBRARY_NAME = "httpspider"
local PREFETCH_SIZE = 5
-- The Options class, handling all spidering options
Options = {
new = function(self, options)
local o = { }
-- copy all options as class members
for k, v in pairs(options) do o[k] = v end
-- set a few default values
o.timeout = options.timeout or 10000
o.whitelist = o.whitelist or {}
o.blacklist = o.blacklist or {}
local removewww = function(url) return string.gsub(url, "^www%.", "") end
if ( o.withinhost == true or o.withindomain == true ) then
-- set up the appropriate matching functions
if ( o.withinhost ) then
o.withinhost = function(u)
local parsed_u = url.parse(tostring(u))
if ( o.base_url:getPort() ~= 80 and o.base_url:getPort() ~= 443 ) then
if ( tonumber(parsed_u.port) ~= tonumber(o.base_url:getPort()) ) then
return false
end
elseif ( parsed_u.scheme ~= o.base_url:getProto() ) then
return false
-- if urls don't match only on the "www" prefix, then they are probably the same
elseif ( parsed_u.host == nil or removewww(parsed_u.host:lower()) ~= removewww(o.base_url:getHost():lower()) ) then
return false
end
return true
end
else
o.withindomain = function(u)
local parsed_u = url.parse(tostring(u))
if ( o.base_url:getPort() ~= 80 and o.base_url:getPort() ~= 443 ) then
if ( tonumber(parsed_u.port) ~= tonumber(o.base_url:getPort()) ) then
return false
end
elseif ( parsed_u.scheme ~= o.base_url:getProto() ) then
return false
elseif ( parsed_u.host == nil or parsed_u.host:sub(-#o.base_url:getDomain()):lower() ~= o.base_url:getDomain():lower() ) then
return false
end
return true
end
end
end
setmetatable(o, self)
self.__index = self
return o
end,
addWhitelist = function(self, func) table.insert(self.whitelist, func) end,
addBlacklist = function(self, func) table.insert(self.blacklist, func) end,
}
-- Placeholder for form extraction code
FormExtractor = {
}
LinkExtractor = {
-- Creates a new instance of LinkExtractor
-- @return o instance of LinkExtractor
new = function(self, url, html, options)
local o = {
url = url,
html = html,
links = {},
options = options,
}
setmetatable(o, self)
self.__index = self
o:parse()
return o
end,
-- is the link absolute or not?
isAbsolute = function(url)
-- at this point we don't care about the protocol
-- also, we don't add // to cover stuff like:
-- feed:http://example.com/rss.xml
return ( url:match('^%w*:') ~= nil )
end,
-- Creates an absolute link from a relative one based on the base_url
-- The functionality is very simple and does not take any ../../ in
-- consideration.
--
-- @param base_url URL containing the page url from which the links were
-- extracted
-- @param rel_url string containing the relative portion of the URL
-- @return link string containing the absolute link
createAbsolute = function(base_url, rel_url, base_href)
-- is relative with leading slash? ie /dir1/foo.html
local leading_slash = rel_url:match("^/")
rel_url = rel_url:match("^/?(.*)") or '/'
-- check for tailing slash
if ( base_href and not(base_href:match("/$") ) ) then
base_href = base_href .. '/'
end
if ( ( base_url:getProto() == 'https' and base_url:getPort() == 443 ) or
( base_url:getProto() == 'http' and base_url:getPort() == 80 ) ) then
if ( leading_slash ) then
return ("%s://%s/%s"):format(base_url:getProto(), base_url:getHost(), rel_url)
else
if ( base_href ) then
return ("%s%s"):format(base_href, rel_url)
else
return ("%s://%s%s%s"):format(base_url:getProto(), base_url:getHost(), base_url:getDir(), rel_url)
end
end
else
if ( leading_slash ) then
return ("%s://%s:%d/%s"):format(base_url:getProto(), base_url:getHost(), base_url:getPort(), rel_url)
else
if ( base_href ) then
return ("%s%s"):format(base_href, rel_url)
else
return ("%s://%s:%d%s%s"):format(base_url:getProto(), base_url:getHost(), base_href or base_url:getPort(), base_url:getDir(), rel_url)
end
end
end
end,
-- Gets the depth of the link, relative to our base url eg.
-- base_url = http://www.cqure.net/wp/
-- url = http://www.cqure.net/wp/ - depth: 0
-- url = http://www.cqure.net/wp/index.php - depth: 0
-- url = http://www.cqure.net/wp/2011/index.php - depth: 1
-- url = http://www.cqure.net/index.html - depth: -1
--
-- @param url instance of URL
-- @return depth number containing the depth relative to the base_url
getDepth = function(self, url)
local base_dir, url_dir = self.options.base_url:getDir(), url:getDir()
if ( url_dir and base_dir ) then
local m = url_dir:match(base_dir.."(.*)")
if ( not(m) ) then
return -1
else
local _, depth = m:gsub("/", "/")
return depth
end
end
end,
validate_link = function(self, url)
local valid = true
-- if our url is nil, abort, this could be due to a number of
-- reasons such as unsupported protocols: javascript, mail ... or
-- that the URL failed to parse for some reason
if ( url == nil or tostring(url) == nil ) then
return false
end
-- linkdepth trumps whitelisting
if ( self.options.maxdepth and self.options.maxdepth >= 0 ) then
local depth = self:getDepth( url )
if ( -1 == depth or depth > self.options.maxdepth ) then
stdnse.print_debug(3, "%s: Skipping link depth: %d; b_url=%s; url=%s", LIBRARY_NAME, depth, tostring(self.options.base_url), tostring(url))
return false
end
end
-- withindomain trumps any whitelisting
if ( self.options.withindomain ) then
if ( not(self.options.withindomain(url)) ) then
stdnse.print_debug(2, "%s: Link is not within domain: %s", LIBRARY_NAME, tostring(url))
return false
end
end
-- withinhost trumps any whitelisting
if ( self.options.withinhost ) then
if ( not(self.options.withinhost(url)) ) then
stdnse.print_debug(2, "%s: Link is not within host: %s", LIBRARY_NAME, tostring(url))
return false
end
end
-- run through all blacklists
if ( #self.options.blacklist > 0 ) then
for _, func in ipairs(self.options.blacklist) do
if ( func(url) ) then
stdnse.print_debug(2, "%s: Blacklist match: %s", LIBRARY_NAME, tostring(url))
valid = false
break
end
end
end
-- check the url against our whitelist
if ( #self.options.whitelist > 0 ) then
valid = false
for _, func in ipairs(self.options.whitelist) do
if ( func(url) ) then
stdnse.print_debug(2, "%s: Whitelist match: %s", LIBRARY_NAME, tostring(url))
valid = true
break
end
end
end
return valid
end,
-- Parses a HTML response and extracts all links it can find
-- The function currently supports href, src and action links
-- Also all behaviour options, such as depth, white- and black-list are
-- processed in here.
parse = function(self)
local links = {}
local patterns = {
'[hH][rR][eE][fF]%s*=%s*[\'"]%s*([^"^\']-)%s*[\'"]',
'[hH][rR][eE][fF]%s*=%s*([^\'\"][^%s>]+)',
'[sS][rR][cC]%s*=%s*[\'"]%s*([^"^\']-)%s*[\'"]',
'[sS][rR][cC]%s*=%s*([^\'\"][^%s>]+)',
'[aA][cC][tT][iI][oO][nN]%s*=%s*[\'"]%s*([^"^\']+%s*)[\'"]',
}
local base_hrefs = {
'[Bb][Aa][Ss][Ee]%s*[Hh][Rr][Ee][Ff]%s*=%s*[\'"](%s*[^"^\']+%s*)[\'"]',
'[Bb][Aa][Ss][Ee]%s*[Hh][Rr][Ee][Ff]%s*=%s*([^\'\"][^%s>]+)'
}
local base_href
for _, pattern in ipairs(base_hrefs) do
base_href = self.html:match(pattern)
if ( base_href ) then
break
end
end
for _, pattern in ipairs(patterns) do
for l in self.html:gmatch(pattern) do
local link = l
if ( not(LinkExtractor.isAbsolute(l)) ) then
link = LinkExtractor.createAbsolute(self.url, l, base_href)
end
local url = URL:new(link)
local valid = self:validate_link(url)
if ( valid ) then
stdnse.print_debug(3, "%s: Adding link: %s", LIBRARY_NAME, tostring(url))
links[tostring(url)] = true
elseif ( tostring(url) ) then
stdnse.print_debug(3, "%s: Skipping url: %s", LIBRARY_NAME, link)
end
end
end
for link in pairs(links) do
table.insert(self.links, link)
end
end,
-- Gets a table containing all of the retrieved URLs, after filtering
-- has been applied.
getLinks = function(self) return self.links end,
}
-- The URL class, containing code to process URLS
-- This class is heavily inspired by the Java URL class
URL = {
-- Creates a new instance of URL
-- @param url string containing the text representation of a URL
-- @return o instance of URL, in case of parsing being successful
-- nil in case parsing fails
new = function(self, url)
local o = {
raw = url,
}
setmetatable(o, self)
self.__index = self
if ( o:parse() ) then
return o
end
end,
-- Parses the string representation of the URL and splits it into different
-- URL components
-- @return status true on success, false on failure
parse = function(self)
self.proto, self.host, self.port, self.file = self.raw:match("^(http[s]?)://([^:/]*)[:]?(%d*)")
if ( self.proto and self.host ) then
self.file = self.raw:match("^http[s]?://[^:/]*[:]?%d*(/[^#]*)") or '/'
self.port = tonumber(self.port)
if ( not(self.port) ) then
if ( self.proto:match("https") ) then
self.port = 443
elseif ( self.proto:match("http")) then
self.port = 80
end
end
self.path = self.file:match("^([^?]*)[%?]?")
self.dir = self.path:match("^(.+%/)") or "/"
self.domain= self.host:match("^[^%.]-%.(.*)")
return true
elseif( self.raw:match("^javascript:") ) then
stdnse.print_debug(2, "%s: Skipping javascript url: %s", LIBRARY_NAME, self.raw)
elseif( self.raw:match("^mailto:") ) then
stdnse.print_debug(2, "%s: Skipping mailto link: %s", LIBRARY_NAME, self.raw)
else
stdnse.print_debug(2, "%s: WARNING: Failed to parse url: %s", LIBRARY_NAME, self.raw)
end
return false
end,
-- Get's the host portion of the URL
-- @return host string containing the hostname
getHost = function(self) return self.host end,
-- Get's the protocol representation of the URL
-- @return proto string containing the protocol (ie. http, https)
getProto = function(self) return self.proto end,
-- Returns the filename component of the URL.
-- @return file string containing the path and query components of the url
getFile = function(self) return self.file end,
-- Gets the port component of the URL
-- @return port number containing the port of the URL
getPort = function(self) return self.port end,
-- Gets the path component of the URL
-- @return the full path and filename of the URL
getPath = function(self) return self.path end,
-- Gets the directory component of the URL
-- @return directory string containing the directory part of the URL
getDir = function(self) return self.dir end,
-- Gets the domain component of the URL
-- @return domain string containing the hosts domain
getDomain = function(self)
if ( self.domain ) then
return self.domain
-- fallback to the host, if we can't find a domain
else
return self.host
end
end,
-- Converts the URL to a string
-- @return url string containing the string representation of the url
__tostring = function(self) return self.raw end,
}
-- An UrlQueue
UrlQueue = {
-- creates a new instance of UrlQueue
-- @param options table containing options
-- @return o new instance of UrlQueue
new = function(self, options)
local o = {
urls = {},
options = options
}
setmetatable(o, self)
self.__index = self
return o
end,
-- get's the next available url in the queue
getNext = function(self)
return table.remove(self.urls,1)
end,
-- adds a new url to the queue
-- @param url can be either a string or a URL or a table of URLs
add = function(self, url)
assert( type(url) == 'string' or type(url) == 'table', "url was neither a string or table")
local urls = ( 'string' == type(url) ) and URL:new(url) or url
-- if it's a table, it can be either a single URL or an array of URLs
if ( 'table' == type(url) and url.raw ) then
urls = { url }
end
for _, u in ipairs(urls) do
u = ( 'string' == type(u) ) and URL:new(u) or u
if ( u ) then
table.insert(self.urls, u)
else
stdnse.print_debug("ERROR: Invalid URL: %s", url)
end
end
end,
-- dumps the contents of the UrlQueue
dump = function(self)
for _, url in ipairs(self.urls) do
print("url:", url)
end
end,
}
-- The Crawler class
Crawler = {
-- creates a new instance of the Crawler instance
-- @param host table as received by the action method
-- @param port table as received by the action method
-- @param url string containing the relative URL
-- @param options table of options:
-- <code>noblacklist</code> - do not load default blacklist
-- <code>base_url</code> - start url to crawl
-- <code>timeout</code> - timeout for the http request
-- <code>maxdepth</code> - the maximum directory depth to crawl
-- <code>maxpagecount</code> - the maximum amount of pages to retrieve
-- <code>withinhost</code> - stay within the host of the base_url
-- <code>withindomain</code> - stay within the base_url domain
-- <code>scriptname</code> - should be set to SCRIPT_NAME to enable
-- script specific arguments.
-- <code>redirect_ok</code> - redirect_ok closure to pass to http.get function
-- <code>no_cache</code> - no_cache option to pass to http.get function
-- @return o new instance of Crawler or nil on failure
new = function(self, host, port, url, options)
local o = {
host = host,
port = port,
url = url,
options = options or {},
basethread = stdnse.base(),
}
setmetatable(o, self)
self.__index = self
o:loadScriptArguments()
o:loadLibraryArguments()
o:loadDefaultArguments()
local response = http.get(o.host, o.port, '/', { timeout = o.options.timeout, redirect_ok = o.options.redirect_ok, no_cache = o.options.no_cache } )
if ( not(response) or 'table' ~= type(response) ) then
return
end
o.url = o.url:match("/?(.*)")
local u_host = o.host.targetname or o.host.name
if ( not(u_host) or 0 == #u_host ) then
u_host = o.host.ip
end
local u = ("%s://%s:%d/%s"):format(response.ssl and "https" or "http", u_host, o.port.number, o.url)
o.options.base_url = URL:new(u)
o.options = Options:new(o.options)
o.urlqueue = UrlQueue:new(o.options)
o.urlqueue:add(o.options.base_url)
o.options.timeout = o.options.timeout or 10000
o.processed = {}
-- script arguments have precedense
if ( not(o.options.maxdepth) ) then
o.options.maxdepth = tonumber(stdnse.get_script_args("httpspider.maxdepth"))
end
-- script arguments have precedense
if ( not(o.options.maxpagecount) ) then
o.options.maxpagecount = tonumber(stdnse.get_script_args("httpspider.maxpagecount"))
end
if ( not(o.options.noblacklist) ) then
o:addDefaultBlacklist()
end
if ( o.options.useheadfornonwebfiles ) then
-- Load web files extensitons from a file in nselib/data folder.
-- For more information on individual file formats, see
-- http://en.wikipedia.org/wiki/List_of_file_formats.
o.web_files_extensions = {}
local f = nmap.fetchfile("nselib/data/http-web-files-extensions.lst")
if f then
for l in io.lines(f) do
table.insert(o.web_files_extensions, l)
end
end
end
stdnse.print_debug(2, "%s: %s", LIBRARY_NAME, o:getLimitations())
return o
end,
-- Set's the timeout used by the http library
-- @param timeout number containing the timeout in ms.
set_timeout = function(self, timeout)
self.options.timeout = timeout
end,
-- Get's the amount of pages that has been retrieved
-- @return count number of pages retrieved by the instance
getPageCount = function(self)
local count = 1
for url in pairs(self.processed) do
count = count + 1
end
return count
end,
-- Adds a default blacklist blocking binary files such as images,
-- compressed archives and executable files
addDefaultBlacklist = function(self)
local extensions = {
image_extensions = {"png","jpg","jpeg","gif","bmp"},
video_extensions = {"avi","flv","ogg","mp4","wmv"},
audio_extensions = {"aac","m4a","mp3","wav"},
doc_extensions = {"pdf", "doc", "docx", "docm", "xls", "xlsx", "xlsm",
"ppt", "pptx", "pptm", "odf", "ods", "odp", "ps", "xps"},
archive_extensions = {"zip", "tar.gz", "gz", "rar", "7z", "sit", "sitx",
"tgz", "tar.bz", "tar", "iso"},
exe_extensions = {"exe", "com", "msi", "bin","dmg"}
}
local blacklist = {}
for _, cat in pairs(extensions) do
for _, ext in ipairs(cat) do
table.insert(blacklist, string.format(".%s$", ext))
end
end
self.options:addBlacklist( function(url)
local p = url:getPath():lower()
for _, pat in ipairs(blacklist) do
if ( p:match(pat) ) then
return true
end
end
end )
end,
-- does the heavy crawling
--
-- The crawler may exit due to a number of different reasons, including
-- invalid options, reaching max count or simply running out of links
-- We return a false status for all of these and in case the error was
-- unexpected or requires attention we set the error property accordingly.
-- This way the script can alert the user of the details by calling
-- getError()
crawl_thread = function(self, response_queue)
local condvar = nmap.condvar(response_queue)
if ( false ~= self.options.withinhost and false ~= self.options.withindomain ) then
table.insert(response_queue, { false, { err = true, reason = "Invalid options: withinhost and withindomain can't both be true" } })
condvar "signal"
return
end
while(true) do
if ( self.quit or coroutine.status(self.basethread) == 'dead' ) then
table.insert(response_queue, {false, { err = false, msg = "Quit signalled by crawler" } })
break
end
-- in case the user set a max page count to retrieve check how many
-- pages we have retrieved so far
local count = self:getPageCount()
if ( self.options.maxpagecount and
( count > self.options.maxpagecount ) ) then
table.insert(response_queue, { false, { err = false, msg = "Reached max page count" } })
condvar "signal"
return
end
-- pull links from the queue until we get a valid one
local url
repeat
url = self.urlqueue:getNext()
until( not(url) or not(self.processed[tostring(url)]) )
-- if no url could be retrieved from the queue, abort ...
if ( not(url) ) then
table.insert(response_queue, { false, { err = false, msg = "No more urls" } })
condvar "signal"
return
end
if ( self.options.maxpagecount ) then
stdnse.print_debug(2, "%s: Fetching url [%d of %d]: %s", LIBRARY_NAME, count, self.options.maxpagecount, tostring(url))
else
stdnse.print_debug(2, "%s: Fetching url: %s", LIBRARY_NAME, tostring(url))
end
local response
-- in case we want to use HEAD rather than GET for files with certain extensions
if ( self.options.useheadfornonwebfiles ) then
local is_web_file = false
local file = url:getPath():lower()
-- check if we are at a URL with 'no extension', for example: nmap.org/6
if string.match(file,".*(/[^/%.]*)$") or string.match(file, "/$") then is_web_file = true end
if not is_web_file then
for _,v in pairs(self.web_files_extensions) do
if string.match(file, "%."..v.."$") then
is_web_file = true
break
end
end
end
if is_web_file then
stdnse.print_debug(2, "%s: Using GET: %s", LIBRARY_NAME, file)
response = http.get(url:getHost(), url:getPort(), url:getFile(), { timeout = self.options.timeout, redirect_ok = self.options.redirect_ok, no_cache = self.options.no_cache } )
else
stdnse.print_debug(2, "%s: Using HEAD: %s", LIBRARY_NAME, file)
response = http.head(url:getHost(), url:getPort(), url:getFile())
end
else
-- fetch the url, and then push it to the processed table
response = http.get(url:getHost(), url:getPort(), url:getFile(), { timeout = self.options.timeout, redirect_ok = self.options.redirect_ok, no_cache = self.options.no_cache } )
end
self.processed[tostring(url)] = true
if ( response ) then
-- were we redirected?
if ( response.location ) then
-- was the link absolute?
local link = response.location[#response.location]
if ( link:match("^http") ) then
url = URL:new(link)
-- guess not
else
url.path = link
end
end
-- if we have a response, proceed scraping it
if ( response.body ) then
local links = LinkExtractor:new(url, response.body, self.options):getLinks()
self.urlqueue:add(links)
end
else
response = { body = "", headers = {} }
end
table.insert(response_queue, { true, { url = url, response = response } } )
while ( PREFETCH_SIZE < #response_queue ) do
stdnse.print_debug(2, "%s: Response queue full, waiting ...", LIBRARY_NAME)
condvar "wait"
end
condvar "signal"
end
condvar "signal"
end,
-- Loads the argument set on a script level
loadScriptArguments = function(self)
local sn = self.options.scriptname
if ( not(sn) ) then
stdnse.print_debug("%s: WARNING: Script argument could not be loaded as scriptname was not set", LIBRARY_NAME)
return
end
if ( nil == self.options.maxdepth ) then
self.options.maxdepth = tonumber(stdnse.get_script_args(sn .. ".maxdepth"))
end
if ( nil == self.options.maxpagecount ) then
self.options.maxpagecount = tonumber(stdnse.get_script_args(sn .. ".maxpagecount"))
end
if ( nil == self.url ) then
self.url = stdnse.get_script_args(sn .. ".url")
end
if ( nil == self.options.withinhost ) then
self.options.withinhost = stdnse.get_script_args(sn .. ".withinhost")
end
if ( nil == self.options.withindomain ) then
self.options.withindomain = stdnse.get_script_args(sn .. ".withindomain")
end
if ( nil == self.options.noblacklist ) then
self.options.noblacklist = stdnse.get_script_args(sn .. ".noblacklist")
end
if ( nil == self.options.useheadfornonwebfiles ) then
self.options.useheadfornonwebfiles = stdnse.get_script_args(sn .. ".useheadfornonwebfiles")
end
end,
-- Loads the argument on a library level
loadLibraryArguments = function(self)
local ln = LIBRARY_NAME
if ( nil == self.options.maxdepth ) then
self.options.maxdepth = tonumber(stdnse.get_script_args(ln .. ".maxdepth"))
end
if ( nil == self.options.maxpagecount ) then
self.options.maxpagecount = tonumber(stdnse.get_script_args(ln .. ".maxpagecount"))
end
if ( nil == self.url ) then
self.url = stdnse.get_script_args(ln .. ".url")
end
if ( nil == self.options.withinhost ) then
self.options.withinhost = stdnse.get_script_args(ln .. ".withinhost")
end
if ( nil == self.options.withindomain ) then
self.options.withindomain = stdnse.get_script_args(ln .. ".withindomain")
end
if ( nil == self.options.noblacklist ) then
self.options.noblacklist = stdnse.get_script_args(ln .. ".noblacklist")
end
if ( nil == self.options.useheadfornonwebfiles ) then
self.options.useheadfornonwebfiles = stdnse.get_script_args(ln .. ".useheadfornonwebfiles")
end
end,
-- Loads any defaults for arguments that were not set
loadDefaultArguments = function(self)
local function tobool(b)
if ( nil == b ) then
return
end
assert("string" == type(b) or "boolean" == type(b) or "number" == type(b), "httpspider: tobool failed, unsupported type")
if ( "string" == type(b) ) then
if ( "true" == b ) then
return true
else
return false
end
elseif ( "number" == type(b) ) then
if ( 1 == b ) then
return true
else
return false
end
end
return b
end
-- fixup some booleans to make sure they're actually booleans
self.options.withinhost = tobool(self.options.withinhost)
self.options.withindomain = tobool(self.options.withindomain)
self.options.noblacklist = tobool(self.options.noblacklist)
self.options.useheadfornonwebfiles = tobool(self.options.useheadfornonwebfiles)
if ( self.options.withinhost == nil ) then
if ( self.options.withindomain ~= true ) then
self.options.withinhost = true
else
self.options.withinhost = false
end
end
if ( self.options.withindomain == nil ) then
self.options.withindomain = false
end
self.options.maxdepth = self.options.maxdepth or 3
self.options.maxpagecount = self.options.maxpagecount or 20
self.url = self.url or '/'
end,
-- gets a string of limitations imposed on the crawl
getLimitations = function(self)
local o = self.options
local limits = {}
if ( o.maxdepth > 0 or o.maxpagecount > 0 or
o.withinhost or o.withindomain ) then
if ( o.maxdepth > 0 ) then
table.insert(limits, ("maxdepth=%d"):format(o.maxdepth))
end
if ( o.maxpagecount > 0 ) then
table.insert(limits, ("maxpagecount=%d"):format(o.maxpagecount))
end
if ( o.withindomain ) then
table.insert(limits, ("withindomain=%s"):format(o.base_url:getDomain() or o.base_url:getHost()))
end
if ( o.withinhost ) then
table.insert(limits, ("withinhost=%s"):format(o.base_url:getHost()))
end
end
if ( #limits > 0 ) then
return ("Spidering limited to: %s"):format(stdnse.strjoin("; ", limits))
end
end,
-- does the crawling
crawl = function(self)
self.response_queue = self.response_queue or {}
local condvar = nmap.condvar(self.response_queue)
if ( not(self.thread) ) then
self.thread = stdnse.new_thread(self.crawl_thread, self, self.response_queue)
end
if ( #self.response_queue == 0 and coroutine.status(self.thread) ~= 'dead') then
condvar "wait"
end
condvar "signal"
if ( #self.response_queue == 0 ) then
return false, { err = false, msg = "No more urls" }
else
return table.unpack(table.remove(self.response_queue, 1))
end
end,
-- signals the crawler to stop
stop = function(self)
local condvar = nmap.condvar(self.response_queue)
self.quit = true
condvar "signal"
if ( coroutine.status(self.thread) == "dead" ) then
return
end
condvar "wait"
end
}
return _ENV;
@KyuuKazami