zeek/scripts/base/frameworks/notice/extend-email/hostnames.bro
2011-12-19 16:28:30 -06:00

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##! Loading this script extends the :bro:enum:`Notice::ACTION_EMAIL` action
##! by appending to the email the hostnames associated with
##! :bro:type:`Notice::Info`'s *src* and *dst* fields as determined by a
##! DNS lookup.
@load ../main
module Notice;
# We have to store references to the notices here because the when statement
# clones the frame which doesn't give us access to modify values outside
# of it's execution scope. (we get a clone of the notice instead of a
# reference to the original notice)
global tmp_notice_storage: table[string] of Notice::Info &create_expire=max_email_delay+10secs;
event Notice::notice(n: Notice::Info) &priority=10
{
if ( ! n?$src && ! n?$dst )
return;
# This should only be done for notices that are being sent to email.
if ( ACTION_EMAIL !in n$actions )
return;
# I'm not recovering gracefully from the when statements because I want
# the notice framework to detect that something has exceeded the maximum
# allowed email delay and tell the user.
local uid = unique_id("");
tmp_notice_storage[uid] = n;
local output = "";
if ( n?$src )
{
add n$email_delay_tokens["hostnames-src"];
when ( local src_name = lookup_addr(n$src) )
{
output = string_cat("orig/src hostname: ", src_name, "\n");
tmp_notice_storage[uid]$email_body_sections[|tmp_notice_storage[uid]$email_body_sections|] = output;
delete tmp_notice_storage[uid]$email_delay_tokens["hostnames-src"];
}
}
if ( n?$dst )
{
add n$email_delay_tokens["hostnames-dst"];
when ( local dst_name = lookup_addr(n$dst) )
{
output = string_cat("resp/dst hostname: ", dst_name, "\n");
tmp_notice_storage[uid]$email_body_sections[|tmp_notice_storage[uid]$email_body_sections|] = output;
delete tmp_notice_storage[uid]$email_delay_tokens["hostnames-dst"];
}
}
}