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-rw-r--r--plugins/mod_http_file_share.lua506
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diff --git a/plugins/mod_http_file_share.lua b/plugins/mod_http_file_share.lua
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+-- Prosody IM
+-- Copyright (C) 2021 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- XEP-0363: HTTP File Upload
+-- Again, from the top!
+
+local t_insert = table.insert;
+local jid = require "util.jid";
+local st = require "util.stanza";
+local url = require "socket.url";
+local dm = require "core.storagemanager".olddm;
+local jwt = require "util.jwt";
+local errors = require "util.error";
+local dataform = require "util.dataforms".new;
+local dt = require "util.datetime";
+local hi = require "util.human.units";
+local cache = require "util.cache";
+local lfs = require "lfs";
+
+local namespace = "urn:xmpp:http:upload:0";
+
+module:depends("disco");
+
+module:add_identity("store", "file", module:get_option_string("name", "HTTP File Upload"));
+module:add_feature(namespace);
+
+local uploads = module:open_store("uploads", "archive");
+-- id, <request>, time, owner
+
+local secret = module:get_option_string(module.name.."_secret", require"util.id".long());
+local external_base_url = module:get_option_string(module.name .. "_base_url");
+local file_size_limit = module:get_option_number(module.name .. "_size_limit", 10 * 1024 * 1024); -- 10 MB
+local file_types = module:get_option_set(module.name .. "_allowed_file_types", {});
+local safe_types = module:get_option_set(module.name .. "_safe_file_types", {"image/*","video/*","audio/*","text/plain"});
+local expiry = module:get_option_number(module.name .. "_expires_after", 7 * 86400);
+local daily_quota = module:get_option_number(module.name .. "_daily_quota", file_size_limit*10); -- 100 MB / day
+
+local access = module:get_option_set(module.name .. "_access", {});
+
+if not external_base_url then
+ module:depends("http");
+end
+
+module:add_extension(dataform {
+ { name = "FORM_TYPE", type = "hidden", value = namespace },
+ { name = "max-file-size", type = "text-single" },
+}:form({ ["max-file-size"] = tostring(file_size_limit) }, "result"));
+
+local upload_errors = errors.init(module.name, namespace, {
+ access = { type = "auth"; condition = "forbidden" };
+ filename = { type = "modify"; condition = "bad-request"; text = "Invalid filename" };
+ filetype = { type = "modify"; condition = "not-acceptable"; text = "File type not allowed" };
+ filesize = { type = "modify"; condition = "not-acceptable"; text = "File too large";
+ extra = {tag = st.stanza("file-too-large", {xmlns = namespace}):tag("max-file-size"):text(tostring(file_size_limit)) };
+ };
+ filesizefmt = { type = "modify"; condition = "bad-request"; text = "File size must be positive integer"; };
+ quota = { type = "wait"; condition = "resource-constraint"; text = "Daily quota reached"; };
+});
+
+local upload_cache = cache.new(1024);
+local quota_cache = cache.new(1024);
+
+local measure_upload_cache_size = module:measure("upload_cache", "amount");
+local measure_quota_cache_size = module:measure("quota_cache", "amount");
+
+module:hook_global("stats-update", function ()
+ measure_upload_cache_size(upload_cache:count());
+ measure_quota_cache_size(quota_cache:count());
+end);
+
+local measure_uploads = module:measure("upload", "sizes");
+
+-- Convenience wrapper for logging file sizes
+local function B(bytes) return hi.format(bytes, "B", "b"); end
+
+local function get_filename(slot, create)
+ return dm.getpath(slot, module.host, module.name, "bin", create)
+end
+
+function get_daily_quota(uploader)
+ local now = os.time();
+ local max_age = now - 86400;
+ local cached = quota_cache:get(uploader);
+ if cached and cached.time > max_age then
+ return cached.size;
+ end
+ local iter, err = uploads:find(nil, {with = uploader; start = max_age });
+ if not iter then return iter, err; end
+ local total_bytes = 0;
+ local oldest_upload = now;
+ for _, slot, when in iter do
+ local size = tonumber(slot.attr.size);
+ if size then total_bytes = total_bytes + size; end
+ if when < oldest_upload then oldest_upload = when; end
+ end
+ -- If there were no uploads then we end up caching [now, 0], which is fine
+ -- since we increase the size on new uploads
+ quota_cache:set(uploader, { time = oldest_upload, size = total_bytes });
+ return total_bytes;
+end
+
+function may_upload(uploader, filename, filesize, filetype) -- > boolean, error
+ local uploader_host = jid.host(uploader);
+ if not ((access:empty() and prosody.hosts[uploader_host]) or access:contains(uploader) or access:contains(uploader_host)) then
+ return false, upload_errors.new("access");
+ end
+
+ if not filename or filename:find"/" then
+ -- On Linux, only '/' and '\0' are invalid in filenames and NUL can't be in XML
+ return false, upload_errors.new("filename");
+ end
+
+ if not filesize or filesize < 0 or filesize % 1 ~= 0 then
+ return false, upload_errors.new("filesizefmt");
+ end
+ if filesize > file_size_limit then
+ return false, upload_errors.new("filesize");
+ end
+
+ local uploader_quota = get_daily_quota(uploader);
+ if uploader_quota + filesize > daily_quota then
+ return false, upload_errors.new("quota");
+ end
+
+ if not ( file_types:empty() or file_types:contains(filetype) or file_types:contains(filetype:gsub("/.*", "/*")) ) then
+ return false, upload_errors.new("filetype");
+ end
+
+ return true;
+end
+
+function get_authz(slot, uploader, filename, filesize, filetype)
+local now = os.time();
+ return jwt.sign(secret, {
+ -- token properties
+ sub = uploader;
+ iat = now;
+ exp = now+300;
+
+ -- slot properties
+ slot = slot;
+ expires = expiry >= 0 and (now+expiry) or nil;
+ -- file properties
+ filename = filename;
+ filesize = filesize;
+ filetype = filetype;
+ });
+end
+
+function get_url(slot, filename)
+ local base_url = external_base_url or module:http_url();
+ local slot_url = url.parse(base_url);
+ slot_url.path = url.parse_path(slot_url.path or "/");
+ t_insert(slot_url.path, slot);
+ if filename then
+ t_insert(slot_url.path, filename);
+ slot_url.path.is_directory = false;
+ else
+ slot_url.path.is_directory = true;
+ end
+ slot_url.path = url.build_path(slot_url.path);
+ return url.build(slot_url);
+end
+
+function handle_slot_request(event)
+ local stanza, origin = event.stanza, event.origin;
+
+ local request = st.clone(stanza.tags[1], true);
+ local filename = request.attr.filename;
+ local filesize = tonumber(request.attr.size);
+ local filetype = request.attr["content-type"] or "application/octet-stream";
+ local uploader = jid.bare(stanza.attr.from);
+
+ local may, why_not = may_upload(uploader, filename, filesize, filetype);
+ if not may then
+ origin.send(st.error_reply(stanza, why_not));
+ return true;
+ end
+
+ module:log("info", "Issuing upload slot to %s for %s", uploader, B(filesize));
+ local slot, storage_err = errors.coerce(uploads:append(nil, nil, request, os.time(), uploader))
+ if not slot then
+ origin.send(st.error_reply(stanza, storage_err));
+ return true;
+ end
+
+ local cached_quota = quota_cache:get(uploader);
+ if cached_quota and cached_quota.time > os.time()-86400 then
+ cached_quota.size = cached_quota.size + filesize;
+ quota_cache:set(uploader, cached_quota);
+ end
+
+ local authz = get_authz(slot, uploader, filename, filesize, filetype);
+ local slot_url = get_url(slot, filename);
+ local upload_url = slot_url;
+
+ local reply = st.reply(stanza)
+ :tag("slot", { xmlns = namespace })
+ :tag("get", { url = slot_url }):up()
+ :tag("put", { url = upload_url })
+ :text_tag("header", "Bearer "..authz, {name="Authorization"})
+ :reset();
+
+ origin.send(reply);
+ return true;
+end
+
+function handle_upload(event, path) -- PUT /upload/:slot
+ local request = event.request;
+ local authz = request.headers.authorization;
+ if authz then
+ authz = authz:match("^Bearer (.*)")
+ end
+ if not authz then
+ module:log("debug", "Missing or malformed Authorization header");
+ event.response.headers.www_authenticate = "Bearer";
+ return 403;
+ end
+ local authed, upload_info = jwt.verify(secret, authz);
+ if not (authed and type(upload_info) == "table" and type(upload_info.exp) == "number") then
+ module:log("debug", "Unauthorized or invalid token: %s, %q", authed, upload_info);
+ return 401;
+ end
+ if not request.body_sink and upload_info.exp < os.time() then
+ module:log("debug", "Authorization token expired on %s", dt.datetime(upload_info.exp));
+ return 410;
+ end
+ if not path or upload_info.slot ~= path:match("^[^/]+") then
+ module:log("debug", "Invalid upload slot: %q, path: %q", upload_info.slot, path);
+ return 400;
+ end
+ if request.headers.content_length and tonumber(request.headers.content_length) ~= upload_info.filesize then
+ return 413;
+ -- Note: We don't know the size if the upload is streamed in chunked encoding,
+ -- so we also check the final file size on completion.
+ end
+
+ local filename = get_filename(upload_info.slot, true);
+
+ do
+ -- check if upload has been completed already
+ -- we want to allow retry of a failed upload attempt, but not after it's been completed
+ local f = io.open(filename, "r");
+ if f then
+ f:close();
+ return 409;
+ end
+ end
+
+ if not request.body_sink then
+ module:log("debug", "Preparing to receive upload into %q, expecting %s", filename, B(upload_info.filesize));
+ local fh, err = io.open(filename.."~", "w");
+ if not fh then
+ module:log("error", "Could not open file for writing: %s", err);
+ return 500;
+ end
+ request.body_sink = fh;
+ if request.body == false then
+ if request.headers.expect == "100-continue" then
+ request.conn:write("HTTP/1.1 100 Continue\r\n\r\n");
+ end
+ return true;
+ end
+ end
+
+ if request.body then
+ module:log("debug", "Complete upload available, %s", B(#request.body));
+ -- Small enough to have been uploaded already
+ local written, err = errors.coerce(request.body_sink:write(request.body));
+ if not written then
+ return err;
+ end
+ request.body = nil;
+ end
+
+ if request.body_sink then
+ local final_size = request.body_sink:seek();
+ local uploaded, err = errors.coerce(request.body_sink:close());
+ if final_size ~= upload_info.filesize then
+ -- Could be too short as well, but we say the same thing
+ uploaded, err = false, 413;
+ end
+ if uploaded then
+ module:log("debug", "Upload of %q completed, %s", filename, B(final_size));
+ assert(os.rename(filename.."~", filename));
+ measure_uploads(final_size);
+
+ upload_cache:set(upload_info.slot, {
+ name = upload_info.filename;
+ size = tostring(upload_info.filesize);
+ type = upload_info.filetype;
+ time = os.time();
+ });
+ return 201;
+ else
+ assert(os.remove(filename.."~"));
+ return err;
+ end
+ end
+
+end
+
+local download_cache_hit = module:measure("download_cache_hit", "rate");
+local download_cache_miss = module:measure("download_cache_miss", "rate");
+
+function handle_download(event, path) -- GET /uploads/:slot+filename
+ local request, response = event.request, event.response;
+ local slot_id = path:match("^[^/]+");
+ local basename, filetime, filetype, filesize;
+ local cached = upload_cache:get(slot_id);
+ if cached then
+ module:log("debug", "Cache hit");
+ download_cache_hit();
+ basename = cached.name;
+ filesize = cached.size;
+ filetype = cached.type;
+ filetime = cached.time;
+ upload_cache:set(slot_id, cached);
+ -- TODO cache negative hits?
+ else
+ module:log("debug", "Cache miss");
+ download_cache_miss();
+ local slot, when = errors.coerce(uploads:get(nil, slot_id));
+ if not slot then
+ module:log("debug", "uploads:get(%q) --> not-found, %s", slot_id, when);
+ else
+ module:log("debug", "uploads:get(%q) --> %s, %d", slot_id, slot, when);
+ basename = slot.attr.filename;
+ filesize = slot.attr.size;
+ filetype = slot.attr["content-type"];
+ filetime = when;
+ upload_cache:set(slot_id, {
+ name = basename;
+ size = slot.attr.size;
+ type = filetype;
+ time = when;
+ });
+ end
+ end
+ if not basename then
+ return 404;
+ end
+ local last_modified = os.date('!%a, %d %b %Y %H:%M:%S GMT', filetime);
+ if request.headers.if_modified_since == last_modified then
+ return 304;
+ end
+ local filename = get_filename(slot_id);
+ local handle, ferr = io.open(filename);
+ if not handle then
+ module:log("error", "Could not open file for reading: %s", ferr);
+ -- This can be because the upload slot wasn't used, or the file disappeared
+ -- somehow, or permission issues.
+ return 410;
+ end
+
+ if not filetype then
+ filetype = "application/octet-stream";
+ end
+ local disposition = "attachment";
+ if safe_types:contains(filetype) or safe_types:contains(filetype:gsub("/.*", "/*")) then
+ disposition = "inline";
+ end
+
+ response.headers.last_modified = last_modified;
+ response.headers.content_length = filesize;
+ response.headers.content_type = filetype;
+ response.headers.content_disposition = string.format("%s; filename=%q", disposition, basename);
+
+ response.headers.cache_control = "max-age=31556952, immutable";
+ response.headers.content_security_policy = "default-src 'none'; frame-ancestors 'none';"
+ response.headers.strict_transport_security = "max-age=31556952";
+ response.headers.x_content_type_options = "nosniff";
+ response.headers.x_frame_options = "DENY"; -- replaced by frame-ancestors in CSP?
+ response.headers.x_xss_protection = "1; mode=block";
+
+ return response:send_file(handle);
+end
+
+if expiry >= 0 and not external_base_url then
+ -- TODO HTTP DELETE to the external endpoint?
+ local array = require "util.array";
+ local async = require "util.async";
+ local ENOENT = require "util.pposix".ENOENT;
+
+ local function sleep(t)
+ local wait, done = async.waiter();
+ module:add_timer(t, done)
+ wait();
+ end
+
+ local reaper_task = async.runner(function(boundary_time)
+ local prune_done = module:measure("prune", "times");
+ local iter, total = assert(uploads:find(nil, {["end"] = boundary_time; total = true}));
+
+ if total == 0 then
+ module:log("info", "No expired uploaded files to prune");
+ prune_done();
+ return;
+ end
+
+ module:log("info", "Pruning expired files uploaded earlier than %s", dt.datetime(boundary_time));
+
+ local obsolete_uploads = array();
+ local i = 0;
+ for slot_id in iter do
+ i = i + 1;
+ obsolete_uploads:push(slot_id);
+ upload_cache:set(slot_id, nil);
+ end
+
+ sleep(0.1);
+ local n = 0;
+ local problem_deleting = false;
+ obsolete_uploads:filter(function(slot_id)
+ n = n + 1;
+ if i % 100 == 0 then sleep(0.1); end
+ local filename = get_filename(slot_id);
+ local deleted, err, errno = os.remove(filename);
+ if deleted or errno == ENOENT then
+ return true;
+ else
+ module:log("error", "Could not delete file %q: %s", filename, err);
+ problem_deleting = true;
+ return false;
+ end
+ end);
+ -- obsolete_uploads now contains slot ids for which the files have been
+ -- deleted and that needs to be cleared from the database
+
+ local deletion_query = {["end"] = boundary_time};
+ if not problem_deleting then
+ module:log("info", "All (%d) expired files successfully deleted", n);
+ -- we can delete based on time
+ else
+ module:log("warn", "%d out of %d expired files could not be deleted", n-#obsolete_uploads, n);
+ -- we'll need to delete only those entries where the files were
+ -- successfully deleted, and then try again with the failed ones.
+ -- eventually the admin ought to notice and fix the permissions or
+ -- whatever the problem is.
+ deletion_query = {ids = obsolete_uploads};
+ end
+
+ if #obsolete_uploads == 0 then
+ module:log("debug", "No metadata to remove");
+ else
+ local removed, err = uploads:delete(nil, deletion_query);
+
+ if removed == true or removed == n or removed == #obsolete_uploads then
+ module:log("debug", "Removed all metadata for expired uploaded files");
+ else
+ module:log("error", "Problem removing metadata for deleted files: %s", err);
+ end
+ end
+
+ prune_done();
+ end);
+
+ module:add_timer(1, function ()
+ reaper_task:run(os.time()-expiry);
+ return 60*60;
+ end);
+end
+
+-- Reachable from the console
+function check_files(query)
+ local issues = {};
+ local iter = assert(uploads:find(nil, query));
+ for slot_id, file in iter do
+ local filename = get_filename(slot_id);
+ local size, err = lfs.attributes(filename, "size");
+ if not size then
+ issues[filename] = err;
+ elseif tonumber(file.attr.size) ~= size then
+ issues[filename] = "file size mismatch";
+ end
+ end
+
+ return next(issues) == nil, issues;
+end
+
+module:hook("iq-get/host/urn:xmpp:http:upload:0:request", handle_slot_request);
+
+if not external_base_url then
+module:provides("http", {
+ streaming_uploads = true;
+ cors = {
+ credentials = true;
+ };
+ route = {
+ ["PUT /*"] = handle_upload;
+ ["GET /*"] = handle_download;
+ ["GET /"] = function (event)
+ return prosody.events.fire_event("http-message", {
+ response = event.response;
+ ---
+ title = "Prosody HTTP Upload endpoint";
+ message = "This is where files will be uploaded to, and served from.";
+ warning = not (event.request.secure) and "This endpoint is not considered secure!" or nil;
+ }) or "This is the Prosody HTTP Upload endpoint.";
+ end
+ }
+ });
+end