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 is 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);
26 void do_405(struct http_transaction *h) {
27 h->response_code = 412;
28 h->response_string = strdup("METHOD NOT ALLOWED");
32 // Precondition failed (such as if-match)
33 void do_412(struct http_transaction *h) {
34 h->response_code = 412;
35 h->response_string = strdup("PRECONDITION FAILED");
39 // Succeed with no output
40 void do_204(struct http_transaction *h) {
41 h->response_code = 204;
42 h->response_string = strdup("No content");
46 // We throw an HTTP error "502 bad gateway" when we need to connect to Citadel, but can't.
47 void do_502(struct http_transaction *h) {
48 h->response_code = 502;
49 h->response_string = strdup("bad gateway");
50 add_response_header(h, strdup("Content-type"), strdup("text/plain"));
51 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."));
52 h->response_body_length = strlen(h->response_body);
56 // Tell the client to authenticate using HTTP-AUTH (RFC 2617)
57 void request_http_authenticate(struct http_transaction *h) {
58 h->response_code = 401;
59 h->response_string = strdup("Unauthorized");
60 add_response_header(h, strdup("WWW-Authenticate"), strdup("Basic realm=\"Citadel Server\""));
64 // Easy and fun utility function to throw a redirect.
65 void http_redirect(struct http_transaction *h, char *to_where) {
66 syslog(LOG_DEBUG, "Redirecting to: %s", to_where);
67 h->response_code = 302;
68 h->response_string = strdup("Moved Temporarily");
69 add_response_header(h, strdup("Location"), strdup(to_where));
70 add_response_header(h, strdup("Content-type"), strdup("text/plain"));
71 h->response_body = strdup(to_where);
72 h->response_body_length = strlen(h->response_body);
76 // perform_request() is the entry point for *every* HTTP transaction.
77 void perform_request(struct http_transaction *h) {
78 struct ctdlsession *c;
80 // Determine which code path to take based on the beginning of the URL.
81 // This is implemented as a series of strncasecmp() calls rather than a
82 // lookup table in order to make the code more readable.
84 if (IsEmptyStr(h->url)) { // Sanity check
89 // Right about here is where we should try to handle anything that doesn't start
90 // with the /ctdl/ prefix.
93 if ((!strcmp(h->url, "/")) && (!strcasecmp(h->method, "GET"))) {
94 http_redirect(h, "/ctdl/s/index.html");
98 // Legacy URL patterns (/readnew?gotoroom=xxx&start_reading_at=yyy) ...
99 // Direct room name (/my%20blog) ...
101 // HTTP-01 challenge [RFC5785 section 3, RFC8555 section 9.2]
102 if (!strncasecmp(h->url, HKEY("/.well-known"))) { // Static content
107 if (!strcasecmp(h->url, "/favicon.ico")) {
112 // Everything below this line is strictly REST URL patterns.
114 if (strncasecmp(h->url, HKEY("/ctdl/"))) { // Reject non-REST
119 if (!strncasecmp(h->url, HKEY("/ctdl/s/"))) { // Static content
124 if (h->url[7] != '/') {
129 // Anything below this line:
130 // 1. Is in the format of /ctdl/?/*
131 // 2. Requires a connection to a Citadel server.
133 c = connect_to_citadel(h);
139 // WebDAV methods like OPTIONS and PROPFIND *require* a logged-in session,
140 // even if the Citadel server allows anonymous access.
141 if (IsEmptyStr(c->auth)) {
142 if ( (!strcasecmp(h->method, "OPTIONS"))
143 || (!strcasecmp(h->method, "PROPFIND"))
144 || (!strcasecmp(h->method, "REPORT"))
145 || (!strcasecmp(h->method, "DELETE"))
146 || (!strcasecmp(h->method, "MOVE"))
147 || (!strcasecmp(h->method, "COPY"))
149 request_http_authenticate(h);
150 disconnect_from_citadel(c);
155 // Break down the URL by path and send the request to the appropriate part of the program.
157 case 'a': // /ctdl/a/ == RESTful path to admin functions
160 case 'c': // /ctdl/c/ == misc Citadel server commands
163 case 'f': // /ctdl/f/ == RESTful path to floors
166 case 'r': // /ctdl/r/ == RESTful path to rooms
169 case 'u': // /ctdl/u/ == RESTful path to users
172 case 'p': // /ctdl/p/ == RESTful path to upload functions
179 // Are we in an authenticated session? If so, set a cookie so we stay logged in.
180 if (!IsEmptyStr(c->auth)) {
181 char koekje[AUTH_MAX];
182 char *exp = http_datestring(time(NULL) + (86400 * 30));
183 snprintf(koekje, AUTH_MAX, "wcauth=%s; path=/ctdl/; Expires=%s", c->auth, exp); // warn
185 add_response_header(h, strdup("Set-Cookie"), strdup(koekje));
188 // Durlng development we are foiling the browser cache completely. In production we'll be more selective.
189 add_response_header(h, strdup("Cache-Control"), strdup("no-store, must-revalidate"));
190 add_response_header(h, strdup("Pragma"), strdup("no-cache"));
191 add_response_header(h, strdup("Expires"), strdup("0"));
193 // Unbind from our Citadel server connection.
194 disconnect_from_citadel(c);