1 // This module handles HTTP transactions.
3 // Copyright (c) 1996-2023 by the citadel.org team
5 // This program is open source software. Use, duplication, or disclosure is subject to the GNU General Public License v3.
9 // Write data to the HTTP client. Encrypt if necessary.
10 int client_write(struct client_handle *ch, char *buf, int nbytes) {
12 return client_write_ssl(ch, buf, nbytes);
15 return write(ch->sock, buf, nbytes);
20 // Read data from the HTTP client. Decrypt if necessary.
21 // Returns number of bytes read, or -1 to indicate an error.
22 int client_read(struct client_handle *ch, char *buf, int nbytes) {
24 return client_read_ssl(ch, buf, nbytes);
27 int bytes_received = 0;
28 int bytes_this_block = 0;
29 while (bytes_received < nbytes) {
30 bytes_this_block = read(ch->sock, &buf[bytes_received], nbytes - bytes_received);
31 if (bytes_this_block < 1) {
34 bytes_received += bytes_this_block;
41 // Read a newline-terminated line of text from the client.
42 // Implemented in terms of client_read() and is therefore transparent...
43 // Returns the string length or -1 for error.
44 int client_readline(struct client_handle *ch, char *buf, int maxbytes) {
52 while (len < maxbytes) {
53 c = client_read(ch, &buf[len], 1);
55 syslog(LOG_DEBUG, "Socket error or zero-length read");
58 if (buf[len] == '\n') {
59 if ((len > 0) && (buf[len - 1] == '\r')) {
71 // printf() type function to send data to the web client.
72 void client_printf(struct client_handle *ch, const char *format, ...) {
74 StrBuf *Buf = NewStrBuf();
76 va_start(arg_ptr, format);
77 StrBufVAppendPrintf(Buf, format, arg_ptr);
80 client_write(ch, (char *) ChrPtr(Buf), StrLength(Buf));
85 // Push one new header into the response of an HTTP request.
86 // When completed, the HTTP transaction now owns the memory allocated for key and val.
87 void add_response_header(struct http_transaction *h, char *key, char *val) {
88 struct keyval new_response_header;
89 new_response_header.key = key;
90 new_response_header.val = val;
91 array_append(h->response_headers, &new_response_header);
95 // Entry point for this layer. Socket is connected. If running as an HTTPS
96 // server, SSL has already been negotiated. Now perform one transaction.
97 void perform_one_http_transaction(struct client_handle *ch) {
101 struct http_transaction h;
103 struct sockaddr_in sin;
104 int i; // general purpose iterator variable
106 memset(&h, 0, sizeof h);
107 h.request_headers = array_new(sizeof(struct keyval));
108 h.request_parms = array_new(sizeof(struct keyval));
109 h.response_headers = array_new(sizeof(struct keyval));
111 while (len = client_readline(ch, buf, sizeof buf), (len > 0)) {
114 if (lines_read == 1) { // First line is method and URL.
115 c = strchr(buf, ' '); // IGnore the HTTP-version.
117 h.method = strdup("NULL");
122 h.method = strdup(buf);
133 else { // Subsequent lines are headers.
134 c = strchr(buf, ':'); // Header line folding is obsolete so we don't support it.
137 struct keyval new_request_header;
139 new_request_header.key = strdup(buf);
141 new_request_header.val = strdup(c);
142 string_trim(new_request_header.key);
143 string_trim(new_request_header.val);
144 array_append(h.request_headers, &new_request_header);
146 syslog(LOG_DEBUG, "{ %s: %s", new_request_header.key, new_request_header.val);
153 // If the URL had any query parameters in it, parse them out now.
154 char *p = (h.url ? strchr(h.url, '?') : NULL);
156 *p++ = 0; // insert a null to remove parameters from the URL
157 char *tok, *saveptr = NULL;
158 for (tok = strtok_r(p, "&", &saveptr); tok!=NULL; tok = strtok_r(NULL, "&", &saveptr)) {
159 char *eq = strchr(tok, '=');
164 kv.key = strdup(tok);
166 array_append(h.request_parms, &kv);
168 syslog(LOG_DEBUG, "| %s = %s", kv.key, kv.val);
174 // build up the site prefix, such as https://foo.bar.com:4343
175 h.site_prefix = malloc(256);
176 strcpy(h.site_prefix, (is_https ? "https://" : "http://"));
177 char *hostheader = header_val(&h, "Host");
179 strcat(h.site_prefix, hostheader);
182 strcat(h.site_prefix, "127.0.0.1");
184 socklen_t llen = sizeof(sin);
185 if (getsockname(ch->sock, (struct sockaddr *) &sin, &llen) >= 0) {
186 sprintf(&h.site_prefix[strlen(h.site_prefix)], ":%d", ntohs(sin.sin_port));
189 // Now try to read in the request body (if one is present)
191 syslog(LOG_DEBUG, "Client disconnected");
195 syslog(LOG_DEBUG, "< %s %s", h.method, h.url);
198 // If there is a request body, read it now.
199 char *ccl = header_val(&h, "Content-Length");
201 h.request_body_length = atol(ccl);
203 if (h.request_body_length > 0) {
204 syslog(LOG_DEBUG, "Reading request body (%ld bytes)", h.request_body_length);
206 // Sometimes we need the request body by itself, sometimes we need it with headers.
207 // So we save it with synthetic headers, and also provide a pointer into the place where the body begins.
209 char *cct = header_val(&h, "Content-Type");
211 h.request_body_with_synth_headers = malloc(h.request_body_length + 1024);
212 memset(h.request_body_with_synth_headers, h.request_body_length + 1024, 0);
213 sprintf(h.request_body_with_synth_headers, "Content-Type: %s\r\n\r\n", cct);
214 h.request_body = h.request_body_with_synth_headers + strlen(h.request_body_with_synth_headers);
216 else { // a request body absent a Content-Type: header is invalid, but handle it anyway.
217 h.request_body_with_synth_headers = malloc(h.request_body_length);
218 memset(h.request_body_with_synth_headers, h.request_body_length, 0);
219 h.request_body = h.request_body_with_synth_headers;
222 client_read(ch, h.request_body, h.request_body_length);
224 // Write the entire request body to stderr -- not what you want during normal operation.
225 #ifdef REQUEST_BODY_TO_STDERR
226 write(2, HKEY("--- REQUEST BODY BEGIN ---\n"));
227 write(2, h.request_body, h.request_body_length);
228 write(2, HKEY("--- REQUEST BODY END ---\n"));
233 // Now pass control up to the next layer to perform the request.
236 // Write the entire response body to stderr -- not what you want during normal operation.
237 #ifdef RESPONSE_BODY_TO_STDERR
238 write(2, HKEY("--- RESPONSE BODY BEGIN ---\n"));
239 write(2, h.response_body, h.response_body_length);
240 write(2, HKEY("--- RESPONSE BODY END ---\n"));
243 // Output the results back to the client.
245 syslog(LOG_DEBUG, "> %03d %s", h.response_code, h.response_string);
247 client_printf(ch, "HTTP/1.1 %03d %s\r\n", h.response_code, h.response_string);
248 client_printf(ch, "Connection: close\r\n");
249 client_printf(ch, "Content-Length: %ld\r\n", h.response_body_length);
250 char *datestring = http_datestring(time(NULL));
252 client_printf(ch, "Date: %s\r\n", datestring);
256 client_printf(ch, "Content-encoding: identity\r\n"); // change if we gzip/deflate
257 int number_of_response_headers = array_len(h.response_headers);
258 for (i=0; i<number_of_response_headers; ++i) {
259 struct keyval *kv = array_get_element_at(h.response_headers, i);
261 syslog(LOG_DEBUG, "} %s: %s", kv->key, kv->val);
263 client_printf(ch, "%s: %s\r\n", kv->key, kv->val);
265 client_printf(ch, "\r\n");
266 if ((h.response_body_length > 0) && (h.response_body != NULL)) {
267 client_write(ch, h.response_body, h.response_body_length);
271 // free the transaction memory
272 while (array_len(h.request_headers) > 0) {
273 struct keyval *kv = array_get_element_at(h.request_headers, 0);
274 if (kv->key) free(kv->key);
275 if (kv->val) free(kv->val);
276 array_delete_element_at(h.request_headers, 0);
278 array_free(h.request_headers);
279 while (array_len(h.request_parms) > 0) {
280 struct keyval *kv = array_get_element_at(h.request_parms, 0);
281 if (kv->key) free(kv->key);
282 if (kv->val) free(kv->val);
283 array_delete_element_at(h.request_parms, 0);
285 array_free(h.request_parms);
286 while (array_len(h.response_headers) > 0) {
287 struct keyval *kv = array_get_element_at(h.response_headers, 0);
288 if (kv->key) free(kv->key);
289 if (kv->val) free(kv->val);
290 array_delete_element_at(h.response_headers, 0);
292 array_free(h.response_headers);
299 if (h.request_body_with_synth_headers) {
300 free(h.request_body_with_synth_headers);
302 if (h.response_string) {
303 free(h.response_string);
311 // Utility function to fetch a specific header from a completely read-in request.
312 // Returns the value of the requested header, or NULL if the specified header was not sent.
313 // The caller does NOT own the memory of the returned pointer, but can count on the pointer
314 // to still be valid through the end of the transaction.
315 char *header_val(struct http_transaction *h, char *requested_header) {
318 for (i=0; i<array_len(h->request_headers); ++i) {
319 kv = array_get_element_at(h->request_headers, i);
320 if (!strcasecmp(kv->key, requested_header)) {
328 // Utility function to fetch a specific URL parameter from a completely read-in request.
329 // Returns the value of the requested parameter, or NULL if the specified parameter was not sent.
330 // The caller does NOT own the memory of the returned pointer, but can count on the pointer
331 // to still be valid through the end of the transaction.
332 char *get_url_param(struct http_transaction *h, char *requested_param) {
335 for (i=0; i<array_len(h->request_parms); ++i) {
336 kv = array_get_element_at(h->request_parms, i);
337 if (!strcasecmp(kv->key, requested_param)) {