2 // This module handles HTTP transactions.
4 // Copyright (c) 1996-2021 by the citadel.org team
6 // This program is open source software. It runs great on the
7 // Linux operating system (and probably elsewhere). You can use,
8 // copy, and run it under the terms of the GNU General Public
11 // This program is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
18 // Write data to the HTTP client. Encrypt if necessary.
19 int client_write(struct client_handle *ch, char *buf, int nbytes) {
21 return client_write_ssl(ch, buf, nbytes);
24 return write(ch->sock, buf, nbytes);
29 // Read data from the HTTP client. Decrypt if necessary.
30 // Returns number of bytes read, or -1 to indicate an error.
31 int client_read(struct client_handle *ch, char *buf, int nbytes) {
33 return client_read_ssl(ch, buf, nbytes);
36 int bytes_received = 0;
37 int bytes_this_block = 0;
38 while (bytes_received < nbytes) {
39 bytes_this_block = read(ch->sock, &buf[bytes_received], nbytes - bytes_received);
40 if (bytes_this_block < 1) {
43 bytes_received += bytes_this_block;
50 // Read a newline-terminated line of text from the client.
51 // Implemented in terms of client_read() and is therefore transparent...
52 // Returns the string length or -1 for error.
53 int client_readline(struct client_handle *ch, char *buf, int maxbytes) {
61 while (len < maxbytes) {
62 c = client_read(ch, &buf[len], 1);
64 syslog(LOG_DEBUG, "Socket error or zero-length read");
67 if (buf[len] == '\n') {
68 if ((len > 0) && (buf[len - 1] == '\r')) {
80 // printf() type function to send data to the web client.
81 void client_printf(struct client_handle *ch, const char *format, ...) {
83 StrBuf *Buf = NewStrBuf();
85 va_start(arg_ptr, format);
86 StrBufVAppendPrintf(Buf, format, arg_ptr);
89 client_write(ch, (char *) ChrPtr(Buf), StrLength(Buf));
94 // Push one new header into the response of an HTTP request.
95 // When completed, the HTTP transaction now owns the memory allocated for key and val.
96 void add_response_header(struct http_transaction *h, char *key, char *val) {
97 struct keyval new_response_header;
98 new_response_header.key = key;
99 new_response_header.val = val;
100 array_append(h->response_headers, &new_response_header);
104 // Entry point for this layer. Socket is connected. If running as an HTTPS
105 // server, SSL has already been negotiated. Now perform one transaction.
106 void perform_one_http_transaction(struct client_handle *ch) {
110 struct http_transaction h;
112 struct sockaddr_in sin;
113 int i; // general purpose iterator variable
115 memset(&h, 0, sizeof h);
116 h.request_headers = 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 // build up the site prefix, such as https://foo.bar.com:4343
162 h.site_prefix = malloc(256);
163 strcpy(h.site_prefix, (is_https ? "https://" : "http://"));
164 char *hostheader = header_val(&h, "Host");
166 strcat(h.site_prefix, hostheader);
169 strcat(h.site_prefix, "127.0.0.1");
171 socklen_t llen = sizeof(sin);
172 if (getsockname(ch->sock, (struct sockaddr *) &sin, &llen) >= 0) {
173 sprintf(&h.site_prefix[strlen(h.site_prefix)], ":%d", ntohs(sin.sin_port));
176 // Now try to read in the request body (if one is present)
178 syslog(LOG_DEBUG, "Client disconnected");
181 syslog(LOG_DEBUG, "\033[33m\033[1m< %s %s\033[0m", h.method, h.url);
183 // If there is a request body, read it now.
184 char *ccl = header_val(&h, "Content-Length");
186 h.request_body_length = atol(ccl);
188 if (h.request_body_length > 0) {
189 syslog(LOG_DEBUG, "Reading request body (%ld bytes)", h.request_body_length);
190 h.request_body = malloc(h.request_body_length);
191 client_read(ch, h.request_body, h.request_body_length);
193 //write(2, HKEY("\033[31m"));
194 //write(2, h.request_body, h.request_body_length);
195 //write(2, HKEY("\033[0m\n"));
198 // Now pass control up to the next layer to perform the request.
201 // Output the results back to the client.
202 //write(2, HKEY("\033[32m"));
203 //write(2, h.response_body, h.response_body_length);
204 //write(2, HKEY("\033[0m\n"));
206 syslog(LOG_DEBUG, "> %03d %s", h.response_code, h.response_string);
207 client_printf(ch, "HTTP/1.1 %03d %s\r\n", h.response_code, h.response_string);
208 client_printf(ch, "Connection: close\r\n");
209 client_printf(ch, "Content-Length: %ld\r\n", h.response_body_length);
210 char *datestring = http_datestring(time(NULL));
212 client_printf(ch, "Date: %s\r\n", datestring);
216 client_printf(ch, "Content-encoding: identity\r\n"); // change if we gzip/deflate
217 int number_of_response_headers = array_len(h.response_headers);
218 for (i=0; i<number_of_response_headers; ++i) {
219 struct keyval *kv = array_get_element_at(h.response_headers, i);
221 syslog(LOG_DEBUG, "\033[1m\033[35m} %s: %s\033[0m", kv->key, kv->val);
223 client_printf(ch, "%s: %s\r\n", kv->key, kv->val);
225 client_printf(ch, "\r\n");
226 if ((h.response_body_length > 0) && (h.response_body != NULL)) {
227 client_write(ch, h.response_body, h.response_body_length);
231 // free the transaction memory
232 while (array_len(h.request_headers) > 0) {
233 struct keyval *kv = array_get_element_at(h.request_headers, 0);
234 if (kv->key) free(kv->key);
235 if (kv->val) free(kv->val);
236 array_delete_element_at(h.request_headers, 0);
238 array_free(h.request_headers);
239 while (array_len(h.response_headers) > 0) {
240 struct keyval *kv = array_get_element_at(h.response_headers, 0);
241 if (kv->key) free(kv->key);
242 if (kv->val) free(kv->val);
243 array_delete_element_at(h.response_headers, 0);
245 array_free(h.response_headers);
252 if (h.request_body) {
253 free(h.request_body);
255 if (h.response_string) {
256 free(h.response_string);
264 // Utility function to fetch a specific header from a completely read-in request.
265 // Returns the value of the requested header, or NULL if the specified header was not sent.
266 // The caller does NOT own the memory of the returned pointer, but can count on the pointer
267 // to still be valid through the end of the transaction.
268 char *header_val(struct http_transaction *h, char *requested_header) {
271 for (i=0; i<array_len(h->request_headers); ++i) {
272 kv = array_get_element_at(h->request_headers, i);
273 if (!strcasecmp(kv->key, requested_header)) {