mirror of
https://github.com/openappsec/attachment.git
synced 2025-12-31 05:39:07 +03:00
364 lines
14 KiB
Lua
Executable File
364 lines
14 KiB
Lua
Executable File
local module_name = ...
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local prefix = module_name:match("^(.-)handler$")
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local nano = require(prefix .. "nano_ffi")
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local kong = kong
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local NanoHandler = {}
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NanoHandler.PRIORITY = 3000
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NanoHandler.VERSION = "1.0.0"
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function NanoHandler.init_worker()
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nano.init_attachment()
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end
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function NanoHandler.access(conf)
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local ctx = kong.ctx.plugin
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local headers = kong.request.get_headers()
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local session_id = nano.generate_session_id()
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kong.service.request.set_header("x-session-id", tostring(session_id))
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local session_data = nano.init_session(session_id)
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if not session_data then
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kong.ctx.plugin.cleanup_needed = false
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return
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end
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ctx.session_data = session_data
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ctx.session_id = session_id
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if nano.is_session_finalized(session_id) then
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kong.log.debug("Session has already been inspected, no need for further inspection")
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return
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end
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local meta_data = nano.handle_start_transaction()
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if not meta_data then
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kong.log.err("Failed to handle start transaction - failing open")
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ctx.cleanup_needed = true
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return
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end
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local req_headers = nano.handleHeaders(headers)
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if not req_headers then
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kong.log.err("Failed to handle request headers - failing open")
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ctx.cleanup_needed = true
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return
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end
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local has_content_length = tonumber(ngx.var.http_content_length) and tonumber(ngx.var.http_content_length) > 0
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local contains_body = has_content_length and 1 or 0
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local verdict, response = nano.send_data(session_id, session_data, meta_data, req_headers, contains_body, nano.HttpChunkType.HTTP_REQUEST_FILTER)
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if verdict ~= nano.AttachmentVerdict.INSPECT then
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ctx.cleanup_needed = true
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if verdict == nano.AttachmentVerdict.DROP then
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return nano.handle_custom_response(session_data, response)
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end
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return
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end
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if contains_body == 1 then
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local body = kong.request.get_raw_body()
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if body and #body > 0 then
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verdict, response = nano.send_body(session_id, session_data, body, nano.HttpChunkType.HTTP_REQUEST_BODY)
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if verdict ~= nano.AttachmentVerdict.INSPECT then
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ctx.cleanup_needed = true
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if verdict == nano.AttachmentVerdict.DROP then
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return nano.handle_custom_response(session_data, response)
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end
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return
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end
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else
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local body_data = ngx.var.request_body
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if body_data and #body_data > 0 then
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kong.log.debug("Found request body in nginx var, size: ", #body_data)
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verdict, response = nano.send_body(session_id, session_data, body_data, nano.HttpChunkType.HTTP_REQUEST_BODY)
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if verdict ~= nano.AttachmentVerdict.INSPECT then
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ctx.cleanup_needed = true
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if verdict == nano.AttachmentVerdict.DROP then
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return nano.handle_custom_response(session_data, response)
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end
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return
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end
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else
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local body_file = ngx.var.request_body_file
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if body_file then
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local file = io.open(body_file, "rb")
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if file then
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local chunk_size = 8192
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local chunk_count = 0
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local start_time = ngx.now()
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local timeout_sec = nano.get_request_processing_timeout_sec()
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kong.log.debug("Request body reading timeout set to ", timeout_sec, " seconds")
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while true do
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ngx.update_time()
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local current_time = ngx.now()
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local elapsed = current_time - start_time
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if elapsed > timeout_sec then
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kong.log.warn("Request body reading timeout after ", elapsed, " seconds")
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file:close()
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return
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end
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local chunk = file:read(chunk_size)
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if not chunk or #chunk == 0 then
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kong.log.debug("End of request body file reached")
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break
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end
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chunk_count = chunk_count + 1
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kong.log.debug("Sending request body chunk ", chunk_count, " of size ", #chunk, " bytes to C module")
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verdict, response = nano.send_body(session_id, session_data, chunk, nano.HttpChunkType.HTTP_REQUEST_BODY)
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if verdict ~= nano.AttachmentVerdict.INSPECT then
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file:close()
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ctx.cleanup_needed = true
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if verdict == nano.AttachmentVerdict.DROP then
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return nano.handle_custom_response(session_data, response)
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end
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return
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end
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end
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file:close()
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kong.log.debug("Sent ", chunk_count, " chunks from request body file")
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end
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else
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kong.log.err("Request body expected but no body data or file available")
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end
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end
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end
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local ok, verdict, response = pcall(function()
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return nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_REQUEST_END)
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end)
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if not ok then
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kong.log.err("Error ending request inspection: ", verdict, " - failing open")
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ctx.cleanup_needed = true
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return
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end
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if verdict ~= nano.AttachmentVerdict.INSPECT then
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ctx.cleanup_needed = true
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if verdict == nano.AttachmentVerdict.DROP then
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return nano.handle_custom_response(session_data, response)
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end
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return
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end
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end
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end
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function NanoHandler.header_filter(conf)
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local ctx = kong.ctx.plugin
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if nano.is_session_finalized(ctx.session_data) then
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kong.log.debug("Session has already been inspected, no need for further inspection")
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return
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end
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if ctx.cleanup_needed then
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kong.log.debug("cleanup in header_filter, passing through")
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return
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end
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local session_id = ctx.session_id
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local session_data = ctx.session_data
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local headers = kong.response.get_headers()
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local header_data = nano.handleHeaders(headers)
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if not header_data then
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kong.log.err("Failed to handle response headers - failing open")
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ctx.cleanup_needed = true
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return
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end
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local status_code = kong.response.get_status()
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local content_length = tonumber(headers["content-length"]) or 0
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local verdict, response = nano.send_response_headers(session_id, session_data, header_data, status_code, content_length)
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if verdict ~= nano.AttachmentVerdict.INSPECT then
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ctx.cleanup_needed = true
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if verdict == nano.AttachmentVerdict.DROP then
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kong.log.debug("DROP verdict in header_filter - will replace response in body_filter")
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ctx.blocked = true
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ctx.block_response = response
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end
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return
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end
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ctx.expect_body = not (status_code == 204 or status_code == 304 or (100 <= status_code and status_code < 200) or content_length == 0)
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end
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function NanoHandler.body_filter(conf)
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local ctx = kong.ctx.plugin
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local chunk = ngx.arg[1]
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local eof = ngx.arg[2]
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local session_id = ctx.session_id
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local session_data = ctx.session_data
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if ctx.blocked then
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kong.log.debug("Sending custom block response in body_filter")
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if ctx.block_response then
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kong.log.debug("Block response data available, preparing custom response")
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local code, body, headers = nano.get_custom_response_data(session_data, ctx.block_response)
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ngx.status = code
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for header_name, header_value in pairs(headers) do
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ngx.header[header_name] = header_value
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end
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if body and #body > 0 then
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ngx.header["Content-Length"] = #body
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ngx.arg[1] = body
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else
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ngx.header["Content-Length"] = 0
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ngx.arg[1] = ""
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end
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else
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kong.log.err("Missing session_data or block_response, sending empty response")
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ngx.status = 403
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ngx.arg[1] = ""
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end
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ngx.arg[2] = true
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ctx.cleanup_needed = true
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return
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end
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if nano.is_session_finalized(session_data) then
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kong.log.debug("Session has already been inspected, no need for further inspection")
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return
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end
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if ctx.cleanup_needed then
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kong.log.debug("cleanup chunk without inspection, passing through")
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return
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end
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if not ctx.body_filter_start_time then
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ctx.body_filter_start_time = ngx.now()
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ctx.body_filter_timeout_sec = nano.get_response_processing_timeout_sec()
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kong.log.debug("body_filter timeout set to ", ctx.body_filter_timeout_sec, " seconds")
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end
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local elapsed_time = ngx.now() - ctx.body_filter_start_time
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if elapsed_time > ctx.body_filter_timeout_sec then
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kong.log.warn("Body filter timeout after ", elapsed_time, " seconds - failing open")
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ctx.cleanup_needed = true
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if ctx.response_buffer and #ctx.response_buffer > 0 then
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local buffered_data = table.concat(ctx.response_buffer)
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local original_content_length = tonumber(ngx.header["Content-Length"]) or #buffered_data
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local total_diff = ctx.content_length_diff or 0
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ngx.header["Content-Length"] = original_content_length + total_diff
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ngx.arg[1] = buffered_data
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end
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return
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end
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if not ctx.response_buffer then
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ctx.response_buffer = {}
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end
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if chunk and #chunk > 0 then
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ctx.body_buffer_chunk = ctx.body_buffer_chunk or 0
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ctx.content_length_diff = ctx.content_length_diff or 0
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ctx.body_seen = true
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table.insert(ctx.response_buffer, chunk)
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local verdict, response, modifications = nano.send_body(session_id, session_data, chunk, nano.HttpChunkType.HTTP_RESPONSE_BODY)
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if modifications then
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local original_length = #chunk
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chunk = nano.handle_body_modifications(chunk, modifications, ctx.body_buffer_chunk)
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local modified_length = #chunk
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ctx.content_length_diff = ctx.content_length_diff + (modified_length - original_length)
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ctx.response_buffer[#ctx.response_buffer] = chunk
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end
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ctx.body_buffer_chunk = ctx.body_buffer_chunk + 1
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if verdict ~= nano.AttachmentVerdict.INSPECT then
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ctx.cleanup_needed = true
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if verdict == nano.AttachmentVerdict.DROP then
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local code, body, headers = nano.get_custom_response_data(session_data, response)
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ngx.status = code
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for header_name, header_value in pairs(headers) do
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ngx.header[header_name] = header_value
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end
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if body and #body > 0 then
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ngx.header["Content-Length"] = #body
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ngx.arg[1] = body
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else
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ngx.header["Content-Length"] = 0
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ngx.arg[1] = ""
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end
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ngx.arg[2] = true
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return
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else
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local buffered_data = table.concat(ctx.response_buffer)
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ngx.arg[1] = buffered_data
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ctx.response_buffer = nil
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return
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end
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end
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ngx.arg[1] = ""
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return
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end
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if eof then
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if ctx.body_seen or ctx.expect_body == false then
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local verdict, response = nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_RESPONSE_END)
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if verdict ~= nano.AttachmentVerdict.INSPECT then
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kong.log.debug("Final verdict after end_inspection: ", verdict)
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ctx.cleanup_needed = true
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if verdict == nano.AttachmentVerdict.DROP then
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kong.log.warn("DROP verdict at EOF - replacing with custom response")
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local code, body, headers = nano.get_custom_response_data(session_data, response)
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ngx.status = code
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for header_name, header_value in pairs(headers) do
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ngx.header[header_name] = header_value
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end
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if body and #body > 0 then
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ngx.header["Content-Length"] = #body
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ngx.arg[1] = body
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else
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ngx.header["Content-Length"] = 0
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ngx.arg[1] = ""
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end
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ngx.arg[2] = true
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return
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end
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end
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end
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if ctx.response_buffer and #ctx.response_buffer > 0 then
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local buffered_data = table.concat(ctx.response_buffer)
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local original_content_length = tonumber(ngx.header["Content-Length"]) or #buffered_data
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local total_diff = ctx.content_length_diff or 0
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ngx.header["Content-Length"] = original_content_length + total_diff
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ngx.arg[1] = buffered_data
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else
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kong.log.debug("No buffered chunks to flush (empty response)")
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ngx.header["Content-Length"] = 0
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end
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ngx.arg[2] = true
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ctx.cleanup_needed = true
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end
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end
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function NanoHandler.log(conf)
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local ctx = kong.ctx.plugin
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if ctx.cleanup_needed then
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nano.fini_session(ctx.session_data)
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nano.cleanup_all()
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ctx.session_data = nil
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ctx.session_id = nil
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collectgarbage("collect")
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end
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end
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return NanoHandler |