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mod_pubsub_feeds/mod_pubsub_feeds.lua @ 5603:d2561c1d26f5
mod_client_management: Allow revoking a specific client version
Could be useful in case of a security issue affecting a particular
version. Even if in that case, the more likely use case is revoking all
older versions except the fixed one(s), this can be done with a loop or
improved later.
author | Kim Alvefur <zash@zash.se> |
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date | Fri, 14 Jul 2023 15:16:06 +0200 (17 months ago) |
parent | 5579:bc292c84f56c |
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-- Fetches Atom feeds and publishes to PubSub nodes local pubsub = module:depends"pubsub"; local time = os.time; local dt_parse, dt_datetime = require "util.datetime".parse, require "util.datetime".datetime; local uuid = require "util.uuid".generate; local hmac_sha1 = require "util.hashes".hmac_sha1; local parse_xml = require "util.xml".parse; local st = require "util.stanza"; local translate_rss = module:require("feeds").translate_rss; local xmlns_atom = "http://www.w3.org/2005/Atom"; local function parse_feed(data) local feed, err = parse_xml(data, { allow_processing_instructions = true; allow_comments = true }); if not feed then return feed, err; end if feed.attr.xmlns == xmlns_atom then return feed; elseif feed.attr.xmlns == nil and feed.name == "rss" then return translate_rss(feed); end return nil, "unsupported-format"; end local use_pubsubhubub = module:get_option_boolean("use_pubsubhubub", false); if use_pubsubhubub then module:depends"http"; end local http = require "net.http"; local formdecode = http.formdecode; local formencode = http.formencode; local feed_list = module:shared("feed_list"); local legacy_refresh_interval = module:get_option_number("feed_pull_interval", 15); local refresh_interval = module:get_option_number("feed_pull_interval_seconds", legacy_refresh_interval*60); local lease_length = tostring(math.floor(module:get_option_number("feed_lease_length", 86400))); function module.load() local config = module:get_option("feeds", { }); local ok, nodes = pubsub.service:get_nodes(true); if not ok then nodes = {}; end local new_feed_list = {}; for node, url in pairs(config) do if type(node) == "number" then node = url; end new_feed_list[node] = true; if not feed_list[node] then local ok, err = pubsub.service:create(node, true); if ok or err == "conflict" then feed_list[node] = { url = url; node = node; last_update = 0 }; else module:log("error", "Could not create node %s: %s", node, err); end else feed_list[node].url = url; end if not nodes[node] then feed_list[node].last_update = 0; end end for node in pairs(feed_list) do if not new_feed_list[node] then feed_list[node] = nil; end end end function update_entry(item, data) local node = item.node; module:log("debug", "parsing %d bytes of data in node %s", #data or 0, node) local feed, err = parse_feed(data); if not feed then module:log("error", "Could not parse feed %q: %s", item.url, err); module:log("debug", "Feed data:\n%s\n.", data); return; end local entries = {}; for entry in feed:childtags("entry") do table.insert(entries, entry); end local ok, last_id = pubsub.service:get_last_item(node, true); if not ok then module:log("error", "PubSub node %q missing: %s", node, last_id); return end local start_from = #entries; for i, entry in ipairs(entries) do local id = entry:get_child_text("id"); if not id then local link = entry:get_child("link"); if link then module:log("debug", "Feed %q item %s is missing an id, using <link> instead", item.url, entry:top_tag()); id = link and link.attr.href; else module:log("error", "Feed %q item %s is missing both id and link, this feed is unusable", item.url, entry:top_tag()); return; end entry:text_tag("id", id); end if last_id == id then -- This should be the first item that we already have. start_from = i-1; break end end for i = start_from, 1, -1 do -- Feeds are usually in reverse order local entry = entries[i]; entry.attr.xmlns = xmlns_atom; local id = entry:get_child_text("id"); local timestamp = dt_parse(entry:get_child_text("published")); if not timestamp then timestamp = time(); entry:text_tag("published", dt_datetime(timestamp)); end if not timestamp or not item.last_update or timestamp > item.last_update then local xitem = st.stanza("item", { id = id, xmlns = "http://jabber.org/protocol/pubsub" }):add_child(entry); -- TODO Put data from /feed into item/source local ok, err = pubsub.service:publish(node, true, id, xitem); if not ok then module:log("error", "Publishing to node %s failed: %s", node, err); elseif timestamp then item.last_update = timestamp; end end end if item.lease_expires and item.lease_expires > time() then item.subscription = nil; item.lease_expires = nil; end if use_pubsubhubub and not item.subscription then --module:log("debug", "check if %s has a hub", item.node); for link in feed:childtags("link") do if link.attr.rel == "hub" then item.hub = link.attr.href; module:log("debug", "Node %s has a hub: %s", item.node, item.hub); return subscribe(item); end end end end function fetch(item, callback) -- HTTP Pull local headers = { ["If-None-Match"] = item.etag; ["Accept"] = "application/atom+xml, application/x-rss+xml, application/xml"; }; http.request(item.url, { headers = headers }, function(data, code, resp) if code == 200 then if callback then callback(item, data) end if resp.headers then item.etag = resp.headers.etag end elseif code == 304 then module:log("debug", "No updates to %q", item.url); elseif code == 301 and resp.headers.location then module:log("info", "Feed %q has moved to %q", item.url, resp.headers.location); elseif code <= 100 then module:log("error", "Error fetching %q: %q[%d]", item.url, data, code); else module:log("debug", "Unhandled status code %d when fetching %q", code, item.url); end end); end function refresh_feeds(now) --module:log("debug", "Refreshing feeds"); for _, item in pairs(feed_list) do if item.subscription ~= "subscribe" and item.last_update + refresh_interval < now then --module:log("debug", "checking %s", item.node); fetch(item, update_entry); end end return refresh_interval; end local function format_url(node) return module:http_url(nil, "/callback") .. "?" .. formencode({ node = node }); end function subscribe(feed, want) want = want or "subscribe"; feed.secret = feed.secret or uuid(); local body = formencode{ ["hub.callback"] = format_url(feed.node); ["hub.mode"] = want; ["hub.topic"] = feed.url; ["hub.verify"] = "async"; -- COMPAT this is REQUIRED in the 0.3 draft but removed in 0.4 ["hub.secret"] = feed.secret; ["hub.lease_seconds"] = lease_length; }; --module:log("debug", "subscription request, body: %s", body); --FIXME The subscription states and related stuff feed.subscription = want; http.request(feed.hub, { body = body }, function(data, code) module:log("debug", "subscription to %s submitted, status %s", feed.node, tostring(code)); if code >= 400 then module:log("error", "There was something wrong with our subscription request, body: %s", tostring(data)); feed.subscription = "failed"; end end); end function handle_http_request(event) local request = event.request; local method = request.method; local body = request.body; local query = request.url.query or {}; --FIXME if query and type(query) == "string" then query = formdecode(query); end local feed = feed_list[query.node]; if not feed then if query["hub.mode"] == "unsubscribe" then -- Unsubscribe from unknown feed module:log("debug", "Unsubscribe from unknown feed %s -- %s", query["hub.topic"], formencode(query)); return query["hub.challenge"]; end module:log("debug", "Push for unknown feed %s -- %s", query["hub.topic"], formencode(query)); return 404; end if method == "GET" then if query.node then if query["hub.topic"] ~= feed.url then module:log("debug", "Invalid topic: %s", tostring(query["hub.topic"])) return 404 end if query["hub.mode"] == "denied" then module:log("info", "Subscription denied: %s", tostring(query["hub.reason"] or "No reason given")) feed.subscription = "denied"; return "Ok then :("; elseif query["hub.mode"] == feed.subscription then module:log("debug", "Confirming %s request to %s", feed.subscription, feed.url) else module:log("debug", "Invalid mode: %s", tostring(query["hub.mode"])) return 400 end local lease_seconds = tonumber(query["hub.lease_seconds"]); if lease_seconds then feed.lease_expires = time() + lease_seconds - refresh_interval * 2; end return query["hub.challenge"]; end return 400; elseif method == "POST" then if #body > 0 then module:log("debug", "got %d bytes PuSHed for %s", #body, query.node); local signature = request.headers.x_hub_signature; if feed.secret then local localsig = "sha1=" .. hmac_sha1(feed.secret, body, true); if localsig ~= signature then module:log("debug", "Invalid signature, got %s but wanted %s", tostring(signature), tostring(localsig)); return 401; end module:log("debug", "Valid signature"); end update_entry(feed, body); return 202; end return 400; end return 501; end if use_pubsubhubub then module:provides("http", { default_path = "/callback"; route = { GET = handle_http_request; POST = handle_http_request; -- This all? }; }); end module:add_timer(1, refresh_feeds);