mirror of
https://github.com/openappsec/attachment.git
synced 2025-12-31 13:49:09 +03:00
339 lines
13 KiB
Lua
Executable File
339 lines
13 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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NanoHandler.sessions = {}
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NanoHandler.processed_requests = {}
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function NanoHandler.init_worker()
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nano.init_attachment()
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end
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-- **Handles Request Headers (DecodeHeaders Equivalent)**
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function NanoHandler.access(conf)
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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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if NanoHandler.processed_requests[session_id] then
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kong.ctx.plugin.blocked = true
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return
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end
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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.log.err("Failed to initialize session - failing open")
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return
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end
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kong.ctx.plugin.session_data = session_data
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kong.ctx.plugin.session_id = session_id
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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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return
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end
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local req_headers = nano.handleHeaders(headers)
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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.DROP then
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nano.fini_session(session_data)
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.cleanup_all()
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return result
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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.DROP then
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nano.fini_session(session_data)
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.cleanup_all()
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return result
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end
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else
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kong.log.debug("Request body not in memory, attempting to read from buffer/file")
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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.DROP then
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nano.fini_session(session_data)
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kong.ctx.plugin.blocked = true
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return nano.handle_custom_response(session_data, response)
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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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kong.log.debug("Reading request body from file: ", body_file)
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local file = io.open(body_file, "rb")
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if file then
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local entire_body = file:read("*all")
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file:close()
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if entire_body and #entire_body > 0 then
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kong.log.debug("Sending entire body of size ", #entire_body, " bytes to C module")
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verdict, response = nano.send_body(session_id, session_data, entire_body, nano.HttpChunkType.HTTP_REQUEST_BODY)
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if verdict == nano.AttachmentVerdict.DROP then
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nano.fini_session(session_data)
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.cleanup_all()
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return result
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end
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else
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kong.log.debug("Empty body file")
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end
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end
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else
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kong.log.warn("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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nano.fini_session(session_data)
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nano.cleanup_all()
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return
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end
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if verdict == nano.AttachmentVerdict.DROP then
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nano.fini_session(session_data)
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.cleanup_all()
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return result
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end
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else
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verdict, response = nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_REQUEST_END)
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if verdict == nano.AttachmentVerdict.DROP then
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nano.fini_session(session_data)
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.cleanup_all()
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return result
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end
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end
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NanoHandler.processed_requests[session_id] = true
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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 ctx.blocked then
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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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if not session_id or not session_data then
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kong.log.err("No session data found in header_filter")
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return
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end
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local headers = kong.response.get_headers()
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local header_data = nano.handleHeaders(headers)
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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.DROP then
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kong.ctx.plugin.blocked = true
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nano.fini_session(session_data)
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nano.cleanup_all()
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return nano.handle_custom_response(session_data, response)
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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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if ctx.blocked then
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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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if not session_id or not session_data or ctx.session_finalized then
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return
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end
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-- Initialize chunk counter and timeout tracking on first call
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if not ctx.body_buffer_chunk then
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ctx.body_buffer_chunk = 0
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ctx.body_filter_start_time = ngx.now() * 1000
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ctx.body_filter_timeout = false
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ctx.failed_nano_send = false
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ctx.num_body_filter_calls = 0
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ctx.last_chunk_hash = nil
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end
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ctx.num_body_filter_calls = ctx.num_body_filter_calls + 1
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if ctx.failed_nano_send then
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return
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end
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local current_time = ngx.now() * 1000
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if current_time - ctx.body_filter_start_time > 150000 then
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if not ctx.body_filter_timeout then
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ctx.body_filter_timeout = true
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ctx.failed_nano_send = true
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kong.log.warn("body_filter timeout exceeded (2.5 minutes), failing open")
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-- Finalize session on timeout
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if not ctx.session_finalized then
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nano.fini_session(session_data)
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nano.cleanup_all()
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ctx.session_finalized = true
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end
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end
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return
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end
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local chunk = ngx.arg[1]
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local eof = ngx.arg[2]
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local full_body = kong.response.get_raw_body()
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local is_streaming = (full_body == nil and chunk ~= nil)
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-- Return early for empty/nil chunks that aren't EOF
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if not eof and (not chunk or (type(chunk) == "string" and #chunk == 0)) and not full_body then
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kong.log.debug("Skipping empty chunk, call #", ctx.num_body_filter_calls)
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return
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end
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local chunk_size = chunk and type(chunk) == "string" and #chunk or 0
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kong.log.debug("body_filter call #", ctx.num_body_filter_calls, ", chunk size: ", chunk_size, ", eof: ", eof, ", sent: ", ctx.body_buffer_chunk, " chunks")
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if full_body and not ctx.body_seen then
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ctx.body_seen = true
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local ok, result = pcall(function()
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return {nano.send_body(session_id, session_data, full_body, nano.HttpChunkType.HTTP_RESPONSE_BODY)}
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end)
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if ok and result and result[1] then
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local verdict = result[1]
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local response = result[2]
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local modifications = result[3]
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if modifications then
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full_body = nano.handle_body_modifications(full_body, modifications, ctx.body_buffer_chunk)
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kong.response.set_raw_body(full_body)
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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.DROP then
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nano.fini_session(session_data)
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ctx.session_finalized = true
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local custom_result = nano.handle_custom_response(session_data, response)
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nano.cleanup_all()
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return custom_result
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end
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else
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kong.log.warn("nano.send_body failed for in-memory body: ", result)
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ctx.body_buffer_chunk = ctx.body_buffer_chunk + 1
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ctx.failed_nano_send = true
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end
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elseif is_streaming and chunk and type(chunk) == "string" and #chunk > 0 then
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ctx.body_seen = true
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local chunk_hash = ngx.crc32_long(chunk)
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if chunk_hash == ctx.last_chunk_hash then
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kong.log.debug("Duplicate chunk detected (same hash as previous), skipping")
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return
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end
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local ok, result = pcall(function()
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return {nano.send_body(session_id, session_data, chunk, nano.HttpChunkType.HTTP_RESPONSE_BODY)}
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end)
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if ok and result and result[1] then
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ctx.last_chunk_hash = chunk_hash
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ctx.body_buffer_chunk = ctx.body_buffer_chunk + 1
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local verdict = result[1]
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local response = result[2]
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local modifications = result[3]
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if modifications then
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chunk = nano.handle_body_modifications(chunk, modifications, ctx.body_buffer_chunk)
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ngx.arg[1] = chunk
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end
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if verdict == nano.AttachmentVerdict.DROP then
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nano.fini_session(session_data)
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ctx.session_finalized = true
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local custom_result = nano.handle_custom_response(session_data, response)
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nano.cleanup_all()
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return custom_result
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end
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else
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-- Nano send failed - fail open, pass chunk through uninspected
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kong.log.warn("nano.send_body failed, failing open: ", result)
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ctx.body_buffer_chunk = ctx.body_buffer_chunk + 1
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ctx.failed_nano_send = true
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ctx.last_chunk_hash = chunk_hash
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-- CRITICAL: Pass chunk through to client
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-- ngx.arg[1] is already set to chunk by Kong, don't need to modify
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end
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end
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if eof or (ctx.expect_body == false and not ctx.body_seen) then
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if not ctx.body_filter_timeout and not ctx.failed_nano_send then
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local ok, result = pcall(function()
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return {nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_RESPONSE_END)}
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end)
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if ok and result and result[1] then
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local verdict = result[1]
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local response = result[2]
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if verdict == nano.AttachmentVerdict.DROP then
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nano.fini_session(session_data)
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ctx.session_finalized = true
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ngx.arg[1] = nil
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ngx.arg[2] = true
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local custom_result = nano.handle_custom_response(session_data, response)
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nano.cleanup_all()
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return custom_result
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end
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else
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kong.log.warn("nano.end_inspection failed: ", result)
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end
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nano.fini_session(session_data)
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nano.cleanup_all()
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ctx.session_finalized = true
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end
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end
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end
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return NanoHandler |