1 // This module handles HTTP transactions.
3 // Copyright (c) 1996-2022 by the citadel.org team
5 // This program is open source software. It runs great on the
6 // Linux operating system (and probably elsewhere). You can use,
7 // copy, and run it under the terms of the GNU General Public
10 // This program is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 // GNU General Public License for more details.
17 // Write data to the HTTP client. Encrypt if necessary.
18 int client_write(struct client_handle *ch, char *buf, int nbytes) {
20 return client_write_ssl(ch, buf, nbytes);
23 return write(ch->sock, buf, nbytes);
28 // Read data from the HTTP client. Decrypt if necessary.
29 // Returns number of bytes read, or -1 to indicate an error.
30 int client_read(struct client_handle *ch, char *buf, int nbytes) {
32 return client_read_ssl(ch, buf, nbytes);
35 int bytes_received = 0;
36 int bytes_this_block = 0;
37 while (bytes_received < nbytes) {
38 bytes_this_block = read(ch->sock, &buf[bytes_received], nbytes - bytes_received);
39 if (bytes_this_block < 1) {
42 bytes_received += bytes_this_block;
49 // Read a newline-terminated line of text from the client.
50 // Implemented in terms of client_read() and is therefore transparent...
51 // Returns the string length or -1 for error.
52 int client_readline(struct client_handle *ch, char *buf, int maxbytes) {
60 while (len < maxbytes) {
61 c = client_read(ch, &buf[len], 1);
63 syslog(LOG_DEBUG, "Socket error or zero-length read");
66 if (buf[len] == '\n') {
67 if ((len > 0) && (buf[len - 1] == '\r')) {
79 // printf() type function to send data to the web client.
80 void client_printf(struct client_handle *ch, const char *format, ...) {
82 StrBuf *Buf = NewStrBuf();
84 va_start(arg_ptr, format);
85 StrBufVAppendPrintf(Buf, format, arg_ptr);
88 client_write(ch, (char *) ChrPtr(Buf), StrLength(Buf));
93 // Push one new header into the response of an HTTP request.
94 // When completed, the HTTP transaction now owns the memory allocated for key and val.
95 void add_response_header(struct http_transaction *h, char *key, char *val) {
96 struct keyval new_response_header;
97 new_response_header.key = key;
98 new_response_header.val = val;
99 array_append(h->response_headers, &new_response_header);
103 // Entry point for this layer. Socket is connected. If running as an HTTPS
104 // server, SSL has already been negotiated. Now perform one transaction.
105 void perform_one_http_transaction(struct client_handle *ch) {
109 struct http_transaction h;
111 struct sockaddr_in sin;
112 int i; // general purpose iterator variable
114 memset(&h, 0, sizeof h);
115 h.request_headers = array_new(sizeof(struct keyval));
116 h.request_parms = array_new(sizeof(struct keyval));
117 h.response_headers = array_new(sizeof(struct keyval));
119 while (len = client_readline(ch, buf, sizeof buf), (len > 0)) {
122 if (lines_read == 1) { // First line is method and URL.
123 c = strchr(buf, ' '); // IGnore the HTTP-version.
125 h.method = strdup("NULL");
130 h.method = strdup(buf);
141 else { // Subsequent lines are headers.
142 c = strchr(buf, ':'); // Header line folding is obsolete so we don't support it.
145 struct keyval new_request_header;
147 new_request_header.key = strdup(buf);
149 new_request_header.val = strdup(c);
150 striplt(new_request_header.key);
151 striplt(new_request_header.val);
152 array_append(h.request_headers, &new_request_header);
154 syslog(LOG_DEBUG, "\033[1m\033[35m{ %s: %s\033[0m", new_request_header.key, new_request_header.val);
161 // If the URL had any query parameters in it, parse them out now.
162 char *p = (h.url ? strchr(h.url, '?') : NULL);
164 *p++ = 0; // insert a null to remove parameters from the URL
165 char *tok, *saveptr = NULL;
166 for (tok = strtok_r(p, "&", &saveptr); tok!=NULL; tok = strtok_r(NULL, "&", &saveptr)) {
167 char *eq = strchr(tok, '=');
172 kv.key = strdup(tok);
174 array_append(h.request_parms, &kv);
176 syslog(LOG_DEBUG, "\033[1m\033[33m| %s = %s\033[0m", kv.key, kv.val);
182 // build up the site prefix, such as https://foo.bar.com:4343
183 h.site_prefix = malloc(256);
184 strcpy(h.site_prefix, (is_https ? "https://" : "http://"));
185 char *hostheader = header_val(&h, "Host");
187 strcat(h.site_prefix, hostheader);
190 strcat(h.site_prefix, "127.0.0.1");
192 socklen_t llen = sizeof(sin);
193 if (getsockname(ch->sock, (struct sockaddr *) &sin, &llen) >= 0) {
194 sprintf(&h.site_prefix[strlen(h.site_prefix)], ":%d", ntohs(sin.sin_port));
197 // Now try to read in the request body (if one is present)
199 syslog(LOG_DEBUG, "Client disconnected");
203 syslog(LOG_DEBUG, "\033[33m\033[1m< %s %s\033[0m", h.method, h.url);
206 // If there is a request body, read it now.
207 char *ccl = header_val(&h, "Content-Length");
209 h.request_body_length = atol(ccl);
211 if (h.request_body_length > 0) {
212 syslog(LOG_DEBUG, "Reading request body (%ld bytes)", h.request_body_length);
213 h.request_body = malloc(h.request_body_length);
214 client_read(ch, h.request_body, h.request_body_length);
216 // Write the entire request body to stderr -- not what you want during normal operation.
217 #ifdef BODY_TO_STDERR
218 write(2, HKEY("\033[31m"));
219 write(2, h.request_body, h.request_body_length);
220 write(2, HKEY("\033[0m\n"));
225 // Now pass control up to the next layer to perform the request.
228 // Write the entire response body to stderr -- not what you want during normal operation.
229 #ifdef BODY_TO_STDERR
230 write(2, HKEY("\033[32m"));
231 write(2, h.response_body, h.response_body_length);
232 write(2, HKEY("\033[0m\n"));
235 // Output the results back to the client.
237 syslog(LOG_DEBUG, "\033[33m\033[1m> %03d %s\033[0m", h.response_code, h.response_string);
239 client_printf(ch, "HTTP/1.1 %03d %s\r\n", h.response_code, h.response_string);
240 client_printf(ch, "Connection: close\r\n");
241 client_printf(ch, "Content-Length: %ld\r\n", h.response_body_length);
242 char *datestring = http_datestring(time(NULL));
244 client_printf(ch, "Date: %s\r\n", datestring);
248 client_printf(ch, "Content-encoding: identity\r\n"); // change if we gzip/deflate
249 int number_of_response_headers = array_len(h.response_headers);
250 for (i=0; i<number_of_response_headers; ++i) {
251 struct keyval *kv = array_get_element_at(h.response_headers, i);
253 syslog(LOG_DEBUG, "\033[1m\033[35m} %s: %s\033[0m", kv->key, kv->val);
255 client_printf(ch, "%s: %s\r\n", kv->key, kv->val);
257 client_printf(ch, "\r\n");
258 if ((h.response_body_length > 0) && (h.response_body != NULL)) {
259 client_write(ch, h.response_body, h.response_body_length);
263 // free the transaction memory
264 while (array_len(h.request_headers) > 0) {
265 struct keyval *kv = array_get_element_at(h.request_headers, 0);
266 if (kv->key) free(kv->key);
267 if (kv->val) free(kv->val);
268 array_delete_element_at(h.request_headers, 0);
270 array_free(h.request_headers);
271 while (array_len(h.request_parms) > 0) {
272 struct keyval *kv = array_get_element_at(h.request_parms, 0);
273 if (kv->key) free(kv->key);
274 if (kv->val) free(kv->val);
275 array_delete_element_at(h.request_parms, 0);
277 array_free(h.request_parms);
278 while (array_len(h.response_headers) > 0) {
279 struct keyval *kv = array_get_element_at(h.response_headers, 0);
280 if (kv->key) free(kv->key);
281 if (kv->val) free(kv->val);
282 array_delete_element_at(h.response_headers, 0);
284 array_free(h.response_headers);
291 if (h.request_body) {
292 free(h.request_body);
294 if (h.response_string) {
295 free(h.response_string);
303 // Utility function to fetch a specific header from a completely read-in request.
304 // Returns the value of the requested header, or NULL if the specified header was not sent.
305 // The caller does NOT own the memory of the returned pointer, but can count on the pointer
306 // to still be valid through the end of the transaction.
307 char *header_val(struct http_transaction *h, char *requested_header) {
310 for (i=0; i<array_len(h->request_headers); ++i) {
311 kv = array_get_element_at(h->request_headers, i);
312 if (!strcasecmp(kv->key, requested_header)) {
320 // Utility function to fetch a specific URL parameter from a completely read-in request.
321 // Returns the value of the requested parameter, or NULL if the specified parameter was not sent.
322 // The caller does NOT own the memory of the returned pointer, but can count on the pointer
323 // to still be valid through the end of the transaction.
324 char *get_url_param(struct http_transaction *h, char *requested_param) {
327 for (i=0; i<array_len(h->request_parms); ++i) {
328 kv = array_get_element_at(h->request_parms, i);
329 if (!strcasecmp(kv->key, requested_param)) {