* New module for checking emails inside messages (rules based, like multimap)

* Emails now are separated from urls and urls checks
* Add ability to check text attachements if option is presented in a configuration

Version is 0.3.6 now

1 files changed, 167 insertions, 0 deletions

diff --git a/src/plugins/lua/emails.lua b/src/plugins/lua/emails.lua
new file mode 100644
index 000000000..969c762ec
--- /dev/null
+++ b/src/plugins/lua/emails.lua
@@ -0,0 +1,167 @@
+-- Emails is module for different checks for emails inside messages
+
+-- Rules format:
+-- symbol = sym, map = file:///path/to/file, domain_only = yes
+-- symbol = sym2, dnsbl = bl.somehost.com, domain_only = no
+local rules = {}
+
+function split(str, delim, maxNb)
+	-- Eliminate bad cases...
+	if string.find(str, delim) == nil then
+		return { str }
+	end
+	if maxNb == nil or maxNb < 1 then
+		maxNb = 0    -- No limit
+	end
+	local result = {}
+	local pat = "(.-)" .. delim .. "()"
+	local nb = 0
+	local lastPos
+	for part, pos in string.gfind(str, pat) do
+		nb = nb + 1
+		result[nb] = part
+		lastPos = pos
+		if nb == maxNb then break end
+	end
+	-- Handle the last field
+	if nb ~= maxNb then
+		result[nb + 1] = string.sub(str, lastPos)
+	end
+	return result
+end
+
+function emails_dns_cb(task, to_resolve, results, err, symbol)
+	if results then
+		task:insert_result(symbol, 1)
+	end
+end
+
+-- Check rule for a single email
+function check_email_rule(task, rule, addr)
+	if rule['dnsbl'] then
+		local to_resolve = ''
+		if rule['domain_only'] then
+			to_resolve = string.format('%s.%s', addr:get_host(), rule['dnsbl'])
+		else
+			to_resolve = string.format('%s.%s.%s', addr:get_user(), addr:get_host(), rule['dnsbl'])
+		end
+		task:resolve_dns_a(to_resolve, 'emails_dns_cb', rule['symbol'])
+	elseif rule['map'] then
+		if rule['domain_only'] then
+			if rule['map']:get_key(addr:get_host()) then
+				task:insert_result(rule['symbol'], 1)
+			end
+		else
+			if rule['map']:get_key(string.format('%s@%s', addr:get_user(), addr:get_host())) then
+				task:insert_result(rule['symbol'], 1)
+			end
+		end
+	end
+end
+
+-- Check email
+function check_emails(task)
+	local emails = task:get_emails()
+	local checked = {}
+	if emails then
+		for _,addr in ipairs(emails) do
+			local to_check = string.format('%s@%s', addr:get_user(), addr:get_host())
+			if not checked['to_check'] then
+				for _,rule in ipairs(rules) do
+					check_email_rule(task, rule, addr)
+				end
+				checked[to_check] = true
+			end 
+		end
+	end
+end
+
+-- Add rule to ruleset
+local function add_emails_rule(params)
+	local newrule = {
+		name = nil,
+		dnsbl = nil,
+		map = nil,
+		domain_only = false,
+		symbol = nil
+	}
+	for _,param in ipairs(params) do
+		local _,_,name,value = string.find(param, '([a-zA-Z_0-9]+)%s*=%s*(.+)')
+		if not name or not value then
+			rspamd_logger:err('invalid rule: '..param)
+			return nil
+		end
+		if name == 'dnsbl' then
+			newrule['dnsbl'] = value
+			newrule['name'] = value
+		elseif name == 'map' then
+			newrule['name'] = value
+			newrule['map'] = rspamd_config:add_hash_map (newrule['name'])
+		elseif name == 'symbol' then
+			newrule['symbol'] = value
+		elseif name == 'domain_only' then
+			if value == 'yes' or value == 'true' or value == '1' then
+				newrule['domain_only'] = true
+			end
+		else	
+			rspamd_logger:err('invalid rule option: '.. name)
+			return nil
+		end
+
+	end
+	if not newrule['symbol'] or (not newrule['map'] and not newrule['dnsbl']) then
+		rspamd_logger:err('incomplete rule')
+		return nil
+	end
+	table.insert(rules, newrule)
+	return newrule
+end
+
+
+-- Registration
+if type(rspamd_config.get_api_version) ~= 'nil' then
+	if rspamd_config:get_api_version() >= 2 then
+		rspamd_config:register_module_option('emails', 'rule', 'string')
+	else
+		rspamd_logger:err('Invalid rspamd version for this plugin')
+	end
+end
+
+local opts =  rspamd_config:get_all_opt('emails')
+if opts then
+	local strrules = opts['rule']
+	if strrules then
+		if type(strrules) == 'table' then 
+			for _,value in ipairs(strrules) do
+				local params = split(value, ',')
+				local rule = add_emails_rule (params)
+				if not rule then
+					rspamd_logger:err('cannot add rule: "'..value..'"')
+				else
+					if type(rspamd_config.get_api_version) ~= 'nil' then
+						rspamd_config:register_virtual_symbol(rule['symbol'], 1.0)
+					end
+				end
+			end
+		elseif type(strrules) == 'string' then
+			local params = split(strrules, ',')
+			local rule = add_emails_rule (params)
+			if not rule then
+				rspamd_logger:err('cannot add rule: "'..strrules..'"')
+			else
+				if type(rspamd_config.get_api_version) ~= 'nil' then
+					rspamd_config:register_virtual_symbol(rule['symbol'], 1.0)
+				end
+			end
+		end
+	end
+end
+
+if table.maxn(rules) > 0 then
+	-- add fake symbol to check all maps inside a single callback
+	if type(rspamd_config.get_api_version) ~= 'nil' then
+		rspamd_config:register_callback_symbol('EMAILS', 1.0, 'check_emails')
+	else
+		rspamd_config:register_symbol('EMAILS', 1.0, 'check_emails')
+	end
+end