#!/usr/bin/env ruby

=begin
Purpose:
	Performs HTTP trace of a given urls. It's useful if you want to
	trace through set of pages while keeping state (cookies).
Author: Wejn <wejn at box dot cz>
License: GPLv2 (without the "latter" option)
Requires: Ruby >= 1.9
TS: 20141105104700

Example:

Let's say you need to track what happens when you click through
some affiliate link and then what happens when you go to "order"
page.

You call this script like this:

./trace-http http://link.$OC/link.e/s28119/ph/main2/ http://link.$OC/join.e/ph

and get result like this:

*** Tracing URL: http://link.$OC/link.e/s28119/ph/main2/ ***

Req: http://link.$OC/link.e/s28119/ph/main2/
  Sets cookie: referreR s28119%2Fph%2Fmain2
  Sets cookie: affil_id s28119
  Redirect 302 -> http://click.$OC:8080/ct?id=28119&bn=2202&url=s28119/ph/main2

Req: http://click.$OC:8080/ct?id=28119&bn=2202&url=s28119/ph/main2
  Sets cookie: ezpartner 28119:2202:0:1199293054:
  Redirect 302 -> http://link.$OC/tp.e/s28119/ph/main2

Req: http://link.$OC/tp.e/s28119/ph/main2
  Redirect 302 -> http://$PH/preview/

Req: http://$PH/preview/
  Redirect 302 -> http://pvw.$PH/preview/

Req: http://pvw.$PH/preview/
  Success 200, body: 20935 bytes.

*** Tracing URL: http://link.$OC/join.e/ph ***

Req: http://link.$OC/join.e/ph
  Redirect 302 -> http://click.$OC:8080/signup?link=http://link.$OC/joincb.e?site=ph

Req: http://click.$OC:8080/signup?link=http://link.$OC/joincb.e?site=ph
  Redirect 302 -> http://link.$OC/joincb.e?site=ph&webmaster=28119:54802

Req: http://link.$OC/joincb.e?site=ph&webmaster=28119:54802
  Redirect 302 -> https://secure.$VXS/ezbill.php3?methods=1&site=593&webmaster=28119:54802&user_1=yb:e2cac15a&user_2=czI4MTE5L3BoL21haW4y

Req: https://secure.$VXS/ezbill.php3?methods=1&site=593&webmaster=28119:54802&user_1=yb:e2cac15a&user_2=czI4MTE5L3BoL21haW4y
  Success 200, body: 13669 bytes.

*** The end ***

which makes it VERY easy to see what's going on.
=end

require 'net/https'
require 'net/http'
require 'uri'
require 'cgi'
require 'time'

# Sanity check # {{{1
if ARGV.size < 1
	$stderr.puts "Usage: #{File.basename($0)} <url>+"
	exit 1
end
# }}}1

uris = []

# verify urls # {{{1
for url in ARGV
	url += '/' unless url.index('/')
	url = "http://" + url unless url =~ /^(f|ht)tps?:\/\//

	uri = URI.parse(url)

	unless uri.kind_of?(URI::HTTP) || uri.kind_of?(URI::HTTPS)
		$stderr.puts "Not a http style url"
		exit 1
	end

	uris << uri
end
# }}}1

# Simple cookie jar implementation, enabling to simulate sessions in http
class CookieJar # {{{1
	def initialize
		@jar = Hash.new
	end

	def set_cookie(cookie, domain)
		vals = cookie.split(/;\s*/)
		vals.map! { |x| x.split(/=/,2) }
		name, value = vals.shift

		# XXX: Gaping security hole -- we allow cross-domain cookie setting
		domain = vals.assoc("domain").last if vals.assoc("domain")

		path = (vals.assoc("path") || []).last
		expires = (vals.assoc("expires") || []).last
		secure = (vals.assoc("secure") || []).last
		
		@jar[domain] ||= {}

		cook = { "name" => name, "value" => value }
		cook["path"] = path if path
		cook["domain"] = domain if domain
		cook["expires"] = Time.parse(expires) if expires
		cook["secure"] = secure if secure

		@jar[domain][name] = cook
	end

	def cookies_for(domain, path)
		cookies = {}

		parts = domain.split(".").reverse

		# get cookies
		1.upto(parts.size) do |i|
			d = parts[0,i].reverse.join('.')
			d = "." + d unless d == domain

			for name, cook in (@jar[d] || {})
				# domain ok
				if !cook["expires"] || cook["expires"] > Time.now
					# not expired
					if !cook["path"] || (path.index(cook["path"]) || 1).zero?
						# path matches
						# XXX: we ignore "secure" flag
						cookies[name] = cook
					end
				end
			end
		end

		# output
		out = []
		for name, cook in cookies
			out << name + "=" + cook["value"]
		end
		out.join("; ")
	end
end # }}}1

cj = CookieJar.new

# do the trace(s) # {{{1
for uri in uris
	puts
	puts "*** Tracing URL: #{uri.to_s} ***"
	puts

	loop do
		puts "Req: #{uri.to_s}"
		req = uri.path.empty? ? "/" : uri.path
		req += "?" + uri.query if uri.query
		http = Net::HTTP.new(uri.host, uri.port)
		if uri.kind_of?(URI::HTTPS)
			http.use_ssl = true
			http.verify_mode = OpenSSL::SSL::VERIFY_NONE
		end

		headers = { "User-Agent" => "TraceHTTP/0.1 (X11; U; Linux i686; en-US; rv:0.0.1) coded by Wejn" }

		if cookies = cj.cookies_for(uri.host, uri.path)
			headers['Cookie'] = cookies
		end

		resp = http.get(req, headers)
		cook = resp.get_fields("Set-Cookie")

		if cook && !cook.empty?
			cook.each do |v|
				cj.set_cookie(v, uri.host)
				puts "  Sets cookie: #{v.sub(/;.*/,'').sub(/=/, ' ')}"
			end
		end

		case resp
		when Net::HTTPSuccess
			puts "  Success #{resp.code}, body: #{resp.body.to_s.size} bytes."
			break
		when Net::HTTPRedirection
			puts "  Redirect #{resp.code} -> #{resp['Location']}"
			puts
			if resp['Location'] =~ /^(f|ht)tps?:\/\//
				uri = URI.parse(resp['Location'])
			else
				pfx = uri.scheme + "://" + uri.host
				pfx += ":" + uri.port.to_s unless uri.default_port == uri.port
				if resp['Location'][0,1] == '/'
					uri = URI.parse(pfx + resp['Location'])
				else
					if uri.path.rindex('/')
						pth = uri.path[(0...uri.path.rindex('/'))]
					else
						pth = '/'
					end
					uri = URI.parse(pfx + pth + '/' + resp['Location'])
				end
			end
		when Net::HTTPClientError
			puts "  Client Error #{resp.code}."
			break
		when Net::HTTPServerError
			puts "  Server Error #{resp.code}."
			break
		else
			puts "Unknown response (WTF?): #{resp.code}."
			break
		end
	end

end
# }}}1

puts
puts "*** The end ***"