--- /dev/null
+/*
+ * This module sits directly above the HTTP layer. By the time we get here,
+ * an HTTP request has been fully received and parsed. Control is passed up
+ * to this layer to actually perform the request. We then fill in the response
+ * and pass control back down to the HTTP layer to output the response back to
+ * the client.
+ *
+ * Copyright (c) 1996-2016 by the citadel.org team
+ *
+ * This program is open source software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include "webcit.h"
+
+
+/*
+ * Not found! Wowzers.
+ */
+void do_404(struct http_transaction *h)
+{
+ h->response_code = 404;
+ h->response_string = strdup("NOT FOUND");
+ add_response_header(h, strdup("Content-type"), strdup("text/plain"));
+ h->response_body = strdup("404 NOT FOUND\r\n");
+ h->response_body_length = strlen(h->response_body);
+}
+
+
+/*
+ * Precondition failed (such as if-match)
+ */
+void do_412(struct http_transaction *h)
+{
+ h->response_code = 412;
+ h->response_string = strdup("PRECONDITION FAILED");
+}
+
+
+/*
+ * We throw an HTTP error "502 bad gateway" when we need to connect to Citadel, but can't.
+ */
+void do_502(struct http_transaction *h)
+{
+ h->response_code = 502;
+ h->response_string = strdup("bad gateway");
+ add_response_header(h, strdup("Content-type"), strdup("text/plain"));
+ h->response_body = strdup(_("This program was unable to connect or stay connected to the Citadel server. Please report this problem to your system administrator."));
+ h->response_body_length = strlen(h->response_body);
+}
+
+
+/*
+ * Tell the client to authenticate using HTTP-AUTH (RFC 2617)
+ */
+void request_http_authenticate(struct http_transaction *h)
+{
+ h->response_code = 401;
+ h->response_string = strdup("Unauthorized");
+ add_response_header(h, strdup("WWW-Authenticate"), strdup("Basic realm=\"Citadel Server\""));
+}
+
+
+/*
+ * Easy and fun utility function to throw a redirect.
+ */
+void http_redirect(struct http_transaction *h, char *to_where)
+{
+ syslog(LOG_DEBUG, "Redirecting to: %s", to_where);
+ h->response_code = 302;
+ h->response_string = strdup("Moved Temporarily");
+ add_response_header(h, strdup("Location"), strdup(to_where));
+ add_response_header(h, strdup("Content-type"), strdup("text/plain"));
+ h->response_body = strdup(to_where);
+ h->response_body_length = strlen(h->response_body);
+}
+
+
+/*
+ * perform_request() is the entry point for *every* HTTP transaction.
+ */
+void perform_request(struct http_transaction *h)
+{
+ struct ctdlsession *c;
+
+ // Determine which code path to take based on the beginning of the URI.
+ // This is implemented as a series of strncasecmp() calls rather than a
+ // lookup table in order to make the code more readable.
+
+ if (IsEmptyStr(h->uri)) { // Sanity check
+ do_404(h);
+ return;
+ }
+
+ // Right about here is where we should try to handle anything that doesn't start
+ // with the /ctdl/ prefix.
+ // Root (/) ...
+
+ if ( (!strcmp(h->uri, "/")) && (!strcasecmp(h->method, "GET")) ) {
+ http_redirect(h, "/ctdl/s/index.html");
+ return;
+ }
+
+ // Legacy URI patterns (/readnew?gotoroom=xxx&start_reading_at=yyy) ...
+ // Direct room name (/my%20blog) ...
+
+ // Everything below this line is strictly REST URI patterns.
+
+ if (strncasecmp(h->uri, HKEY("/ctdl/"))) { // Reject non-REST
+ do_404(h);
+ return;
+ }
+
+ if (!strncasecmp(h->uri, HKEY("/ctdl/s/"))) { // Static content
+ output_static(h);
+ return;
+ }
+
+ if (h->uri[7] != '/') {
+ do_404(h);
+ return;
+ }
+
+ // Anything below this line:
+ // 1. Is in the format of /ctdl/?/*
+ // 2. Requires a connection to a Citadel server.
+
+ c = connect_to_citadel(h);
+ if (c == NULL) {
+ do_502(h);
+ return;
+ }
+
+ // WebDAV methods like OPTIONS and PROPFIND *require* a logged-in session,
+ // even if the Citadel server allows anonymous access.
+ if (IsEmptyStr(c->auth)) {
+ if ( (!strcasecmp(h->method, "OPTIONS"))
+ || (!strcasecmp(h->method, "PROPFIND"))
+ || (!strcasecmp(h->method, "REPORT"))
+ || (!strcasecmp(h->method, "DELETE"))
+ ) {
+ request_http_authenticate(h);
+ disconnect_from_citadel(c);
+ return;
+ }
+ }
+
+ // Break down the URI by path and send the request to the appropriate part of the program.
+ //
+ switch(h->uri[6]) {
+ case 'a': // /ctdl/a/ == RESTful path to admin functions
+ ctdl_a(h, c);
+ break;
+ case 'c': // /ctdl/c/ == misc Citadel server commands
+ ctdl_c(h, c);
+ break;
+ case 'r': // /ctdl/r/ == RESTful path to rooms
+ ctdl_r(h, c);
+ break;
+ case 'u': // /ctdl/u/ == RESTful path to users
+ do_404(h);
+ break;
+ default:
+ do_404(h);
+ }
+
+ // Are we in an authenticated session? If so, set a cookie so we stay logged in.
+ if (!IsEmptyStr(c->auth)) {
+ char koekje[AUTH_MAX];
+ char *exp = http_datestring(time(NULL) + (86400 * 30));
+ snprintf(koekje, AUTH_MAX, "wcauth=%s; path=/ctdl/; Expires=%s", c->auth, exp);
+ free(exp);
+ add_response_header(h, strdup("Set-Cookie"), strdup(koekje));
+ }
+
+ // During development we are foiling the browser cache completely. In production we'll be more selective.
+ add_response_header(h, strdup("Cache-Control"), strdup("no-store, must-revalidate"));
+ add_response_header(h, strdup("Pragma"), strdup("no-cache"));
+ add_response_header(h, strdup("Expires"), strdup("0"));
+
+ // Unbind from our Citadel server connection.
+ disconnect_from_citadel(c);
+}
projects / citadel.git / blobdiff