1 // This module sits directly above the HTTP layer. By the time we get here,
2 // an HTTP request has been fully received and parsed. Control is passed up
3 // to this layer to actually perform the request. We then fill in the response
4 // and pass control back down to the HTTP layer to output the response back to
7 // Copyright (c) 1996-2023 by the citadel.org team
9 // This program is open source software. Use, duplication, or
10 // disclosure are subject to the GNU General Public License v3.
15 // Not found! Wowzers.
16 void do_404(struct http_transaction *h) {
17 h->response_code = 404;
18 h->response_string = strdup("NOT FOUND");
19 add_response_header(h, strdup("Content-type"), strdup("text/plain"));
20 h->response_body = strdup("404 NOT FOUND\r\n");
21 h->response_body_length = strlen(h->response_body);
25 // Precondition failed (such as if-match)
26 void do_412(struct http_transaction *h) {
27 h->response_code = 412;
28 h->response_string = strdup("PRECONDITION FAILED");
32 // Succeed with no output
33 void do_204(struct http_transaction *h) {
34 h->response_code = 204;
35 h->response_string = strdup("No content");
39 // We throw an HTTP error "502 bad gateway" when we need to connect to Citadel, but can't.
40 void do_502(struct http_transaction *h) {
41 h->response_code = 502;
42 h->response_string = strdup("bad gateway");
43 add_response_header(h, strdup("Content-type"), strdup("text/plain"));
44 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."));
45 h->response_body_length = strlen(h->response_body);
49 // Tell the client to authenticate using HTTP-AUTH (RFC 2617)
50 void request_http_authenticate(struct http_transaction *h) {
51 h->response_code = 401;
52 h->response_string = strdup("Unauthorized");
53 add_response_header(h, strdup("WWW-Authenticate"), strdup("Basic realm=\"Citadel Server\""));
57 // Easy and fun utility function to throw a redirect.
58 void http_redirect(struct http_transaction *h, char *to_where) {
59 syslog(LOG_DEBUG, "Redirecting to: %s", to_where);
60 h->response_code = 302;
61 h->response_string = strdup("Moved Temporarily");
62 add_response_header(h, strdup("Location"), strdup(to_where));
63 add_response_header(h, strdup("Content-type"), strdup("text/plain"));
64 h->response_body = strdup(to_where);
65 h->response_body_length = strlen(h->response_body);
69 // perform_request() is the entry point for *every* HTTP transaction.
70 void perform_request(struct http_transaction *h) {
71 struct ctdlsession *c;
73 // Determine which code path to take based on the beginning of the URL.
74 // This is implemented as a series of strncasecmp() calls rather than a
75 // lookup table in order to make the code more readable.
77 if (IsEmptyStr(h->url)) { // Sanity check
82 // Right about here is where we should try to handle anything that doesn't start
83 // with the /ctdl/ prefix.
86 if ((!strcmp(h->url, "/")) && (!strcasecmp(h->method, "GET"))) {
87 http_redirect(h, "/ctdl/s/index.html");
91 // Legacy URL patterns (/readnew?gotoroom=xxx&start_reading_at=yyy) ...
92 // Direct room name (/my%20blog) ...
94 // HTTP-01 challenge [RFC5785 section 3, RFC8555 section 9.2]
95 if (!strncasecmp(h->url, HKEY("/.well-known"))) { // Static content
100 if (!strcasecmp(h->url, "/favicon.ico")) {
105 // Everything below this line is strictly REST URL patterns.
107 if (strncasecmp(h->url, HKEY("/ctdl/"))) { // Reject non-REST
112 if (!strncasecmp(h->url, HKEY("/ctdl/s/"))) { // Static content
117 if (h->url[7] != '/') {
122 // Anything below this line:
123 // 1. Is in the format of /ctdl/?/*
124 // 2. Requires a connection to a Citadel server.
126 c = connect_to_citadel(h);
132 // WebDAV methods like OPTIONS and PROPFIND *require* a logged-in session,
133 // even if the Citadel server allows anonymous access.
134 if (IsEmptyStr(c->auth)) {
135 if ( (!strcasecmp(h->method, "OPTIONS"))
136 || (!strcasecmp(h->method, "PROPFIND"))
137 || (!strcasecmp(h->method, "REPORT"))
138 || (!strcasecmp(h->method, "DELETE"))
139 || (!strcasecmp(h->method, "MOVE"))
140 || (!strcasecmp(h->method, "COPY"))
142 request_http_authenticate(h);
143 disconnect_from_citadel(c);
148 // Break down the URL by path and send the request to the appropriate part of the program.
150 case 'a': // /ctdl/a/ == RESTful path to admin functions
153 case 'c': // /ctdl/c/ == misc Citadel server commands
156 case 'f': // /ctdl/f/ == RESTful path to floors
159 case 'r': // /ctdl/r/ == RESTful path to rooms
162 case 'u': // /ctdl/u/ == RESTful path to users
169 // Are we in an authenticated session? If so, set a cookie so we stay logged in.
170 if (!IsEmptyStr(c->auth)) {
171 char koekje[AUTH_MAX];
172 char *exp = http_datestring(time(NULL) + (86400 * 30));
173 snprintf(koekje, AUTH_MAX, "wcauth=%s; path=/ctdl/; Expires=%s", c->auth, exp); // warn
175 add_response_header(h, strdup("Set-Cookie"), strdup(koekje));
178 // Durlng development we are foiling the browser cache completely. In production we'll be more selective.
179 add_response_header(h, strdup("Cache-Control"), strdup("no-store, must-revalidate"));
180 add_response_header(h, strdup("Pragma"), strdup("no-cache"));
181 add_response_header(h, strdup("Expires"), strdup("0"));
183 // Unbind from our Citadel server connection.
184 disconnect_from_citadel(c);