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 http_header *new_response_header = malloc(sizeof(struct http_header));
98 new_response_header->key = key;
99 new_response_header->val = val;
100 new_response_header->next = h->response_headers;
101 h->response_headers = new_response_header;
105 // Entry point for this layer. Socket is connected. If running as an HTTPS
106 // server, SSL has already been negotiated. Now perform one transaction.
107 void perform_one_http_transaction(struct client_handle *ch) {
111 struct http_transaction h;
113 struct sockaddr_in sin;
114 struct http_header *clh; // general purpose iterator variable
116 memset(&h, 0, sizeof h);
118 while (len = client_readline(ch, buf, sizeof buf), (len > 0)) {
121 if (lines_read == 1) { // First line is method and URI.
122 c = strchr(buf, ' '); // IGnore the HTTP-version.
124 h.method = strdup("NULL");
129 h.method = strdup(buf);
140 else { // Subsequent lines are headers.
141 c = strchr(buf, ':'); // Header line folding is obsolete so we don't support it.
143 struct http_header *new_request_header = malloc(sizeof(struct http_header));
145 new_request_header->key = strdup(buf);
147 new_request_header->val = strdup(c);
148 striplt(new_request_header->key);
149 striplt(new_request_header->val);
150 new_request_header->next = h.request_headers;
151 h.request_headers = new_request_header;
153 syslog(LOG_DEBUG, "{ %s: %s", new_request_header->key, new_request_header->val);
160 // build up the site prefix, such as https://foo.bar.com:4343
161 h.site_prefix = malloc(256);
162 strcpy(h.site_prefix, (is_https ? "https://" : "http://"));
163 char *hostheader = header_val(&h, "Host");
165 strcat(h.site_prefix, hostheader);
168 strcat(h.site_prefix, "127.0.0.1");
170 socklen_t llen = sizeof(sin);
171 if (getsockname(ch->sock, (struct sockaddr *) &sin, &llen) >= 0) {
172 sprintf(&h.site_prefix[strlen(h.site_prefix)], ":%d", ntohs(sin.sin_port));
175 // Now try to read in the request body (if one is present)
177 syslog(LOG_DEBUG, "Client disconnected");
180 syslog(LOG_DEBUG, "\033[33m\033[1m< %s %s\033[0m", h.method, h.uri);
182 // If there is a request body, read it now.
183 char *ccl = header_val(&h, "Content-Length");
185 h.request_body_length = atol(ccl);
187 if (h.request_body_length > 0) {
188 syslog(LOG_DEBUG, "Reading request body (%ld bytes)", h.request_body_length);
189 h.request_body = malloc(h.request_body_length);
190 client_read(ch, h.request_body, h.request_body_length);
192 //write(2, HKEY("\033[31m"));
193 //write(2, h.request_body, h.request_body_length);
194 //write(2, HKEY("\033[0m\n"));
197 // Now pass control up to the next layer to perform the request.
200 // Output the results back to the client.
201 //write(2, HKEY("\033[32m"));
202 //write(2, h.response_body, h.response_body_length);
203 //write(2, HKEY("\033[0m\n"));
205 syslog(LOG_DEBUG, "> %03d %s", h.response_code, h.response_string);
206 client_printf(ch, "HTTP/1.1 %03d %s\r\n", h.response_code, h.response_string);
207 client_printf(ch, "Connection: close\r\n");
208 client_printf(ch, "Content-Length: %ld\r\n", h.response_body_length);
209 char *datestring = http_datestring(time(NULL));
211 client_printf(ch, "Date: %s\r\n", datestring);
215 client_printf(ch, "Content-encoding: identity\r\n"); // change if we gzip/deflate
216 for (clh = h.response_headers; clh != NULL; clh = clh->next) {
218 syslog(LOG_DEBUG, "} %s: %s", clh->key, clh->val);
220 client_printf(ch, "%s: %s\r\n", clh->key, clh->val);
222 client_printf(ch, "\r\n");
223 if ((h.response_body_length > 0) && (h.response_body != NULL)) {
224 client_write(ch, h.response_body, h.response_body_length);
228 // free the transaction memory
229 while (h.request_headers) {
230 if (h.request_headers->key)
231 free(h.request_headers->key);
232 if (h.request_headers->val)
233 free(h.request_headers->val);
234 clh = h.request_headers->next;
235 free(h.request_headers);
236 h.request_headers = clh;
238 while (h.response_headers) {
239 if (h.response_headers->key)
240 free(h.response_headers->key);
241 if (h.response_headers->val)
242 free(h.response_headers->val);
243 clh = h.response_headers->next;
244 free(h.response_headers);
245 h.response_headers = clh;
252 free(h.request_body);
253 if (h.response_string)
254 free(h.response_string);
260 // Utility function to fetch a specific header from a completely read-in request.
261 // Returns the value of the requested header, or NULL if the specified header was not sent.
262 // The caller does NOT own the memory of the returned pointer, but can count on the pointer
263 // to still be valid through the end of the transaction.
264 char *header_val(struct http_transaction *h, char *requested_header) {
265 struct http_header *clh; // general purpose iterator variable
266 for (clh = h->request_headers; clh != NULL; clh = clh->next) {
267 if (!strcasecmp(clh->key, requested_header)) {