2 // Functions that handle communication with a Citadel Server
4 // Copyright (c) 1987-2021 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 struct ctdlsession *cpool = NULL; // linked list of connections to the Citadel server
19 pthread_mutex_t cpool_mutex = PTHREAD_MUTEX_INITIALIZER; // Lock it before modifying
22 // Read a specific number of bytes of binary data from the Citadel server.
23 // Returns the number of bytes read or -1 for error.
24 int ctdl_read_binary(struct ctdlsession *ctdl, char *buf, int bytes_requested) {
28 while (bytes_read < bytes_requested) {
29 c = read(ctdl->sock, &buf[bytes_read], bytes_requested-bytes_read);
31 syslog(LOG_DEBUG, "Socket error or zero-length read");
40 // Read a newline-terminated line of text from the Citadel server.
41 // Returns the string length or -1 for error.
42 int ctdl_readline(struct ctdlsession *ctdl, char *buf, int maxbytes) {
49 while (len < maxbytes) {
50 c = read(ctdl->sock, &buf[len], 1);
52 syslog(LOG_DEBUG, "Socket error or zero-length read");
55 if (buf[len] == '\n') {
56 if ((len > 0) && (buf[len - 1] == '\r')) {
60 // syslog(LOG_DEBUG, "\033[33m[ %s\033[0m", buf);
65 // syslog(LOG_DEBUG, "\033[33m[ %s\033[0m", buf);
70 // Read lines of text from the Citadel server until a 000 terminator is received.
71 // Implemented in terms of ctdl_readline() and is therefore transparent...
72 // Returns a newly allocated StrBuf or NULL for error.
73 StrBuf *ctdl_readtextmsg(struct ctdlsession * ctdl) {
75 StrBuf *sj = NewStrBuf();
80 while ((ctdl_readline(ctdl, buf, sizeof(buf)) >= 0) && (strcmp(buf, "000"))) {
81 StrBufAppendPrintf(sj, "%s\n", buf);
88 // Write to the Citadel server. For now we're just wrapping write() in case we
89 // need to add anything else later.
90 ssize_t ctdl_write(struct ctdlsession * ctdl, const void *buf, size_t count) {
91 return write(ctdl->sock, buf, count);
95 // printf() type function to send data to the Citadel Server.
96 void ctdl_printf(struct ctdlsession *ctdl, const char *format, ...) {
98 StrBuf *Buf = NewStrBuf();
100 va_start(arg_ptr, format);
101 StrBufVAppendPrintf(Buf, format, arg_ptr);
104 syslog(LOG_DEBUG, "\033[32m] %s\033[0m", ChrPtr(Buf));
105 ctdl_write(ctdl, (char *) ChrPtr(Buf), StrLength(Buf));
106 ctdl_write(ctdl, "\n", 1);
111 // Client side - connect to a unix domain socket
112 int uds_connectsock(char *sockpath) {
113 struct sockaddr_un addr;
116 memset(&addr, 0, sizeof(addr));
117 addr.sun_family = AF_UNIX;
118 strncpy(addr.sun_path, sockpath, sizeof addr.sun_path);
120 s = socket(AF_UNIX, SOCK_STREAM, 0);
122 syslog(LOG_WARNING, "Can't create socket [%s]: %s", sockpath, strerror(errno));
126 if (connect(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
127 syslog(LOG_WARNING, "Can't connect [%s]: %s", sockpath, strerror(errno));
135 // TCP client - connect to a host/port
136 int tcp_connectsock(char *host, char *service) {
137 struct in6_addr serveraddr;
138 struct addrinfo hints;
139 struct addrinfo *res = NULL;
140 struct addrinfo *ai = NULL;
144 if ((host == NULL) || IsEmptyStr(host))
146 if ((service == NULL) || IsEmptyStr(service))
149 syslog(LOG_DEBUG, "tcp_connectsock(%s,%s)", host, service);
151 memset(&hints, 0x00, sizeof(hints));
152 hints.ai_flags = AI_NUMERICSERV;
153 hints.ai_family = AF_UNSPEC;
154 hints.ai_socktype = SOCK_STREAM;
156 // Handle numeric IPv4 and IPv6 addresses
157 rc = inet_pton(AF_INET, host, &serveraddr);
158 if (rc == 1) { // dotted quad
159 hints.ai_family = AF_INET;
160 hints.ai_flags |= AI_NUMERICHOST;
163 rc = inet_pton(AF_INET6, host, &serveraddr);
164 if (rc == 1) { // IPv6 address
165 hints.ai_family = AF_INET6;
166 hints.ai_flags |= AI_NUMERICHOST;
170 // Begin the connection process
172 rc = getaddrinfo(host, service, &hints, &res);
174 syslog(LOG_DEBUG, "%s: %s", host, gai_strerror(rc));
179 // Try all available addresses until we connect to one or until we run out.
180 for (ai = res; ai != NULL; ai = ai->ai_next) {
182 if (ai->ai_family == AF_INET)
183 syslog(LOG_DEBUG, "Trying IPv4");
184 else if (ai->ai_family == AF_INET6)
185 syslog(LOG_DEBUG, "Trying IPv6");
187 syslog(LOG_WARNING, "This is going to fail.");
189 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
191 syslog(LOG_WARNING, "socket() failed: %s", strerror(errno));
195 rc = connect(s, ai->ai_addr, ai->ai_addrlen);
200 fdflags = fcntl(rc, F_GETFL);
202 syslog(LOG_ERR, "unable to get socket %d flags! %s", rc, strerror(errno));
206 fdflags = fdflags | O_NONBLOCK;
207 if (fcntl(rc, F_SETFL, fdflags) < 0) {
208 syslog(LOG_ERR, "unable to set socket %d nonblocking flags! %s", rc, strerror(errno));
216 syslog(LOG_WARNING, "connect() failed: %s", strerror(errno));
225 // Extract from the headers, the username and password the client is attempting to use.
226 // This could be HTTP AUTH or it could be in the cookies.
227 void extract_auth(struct http_transaction *h, char *authbuf, int authbuflen) {
232 char *authheader = header_val(h, "Authorization");
234 if (!strncasecmp(authheader, "Basic ", 6)) {
235 safestrncpy(authbuf, &authheader[6], authbuflen);
236 return; // HTTP-AUTH was found -- stop here
240 char *cookieheader = header_val(h, "Cookie");
242 char *wcauth = strstr(cookieheader, "wcauth=");
244 safestrncpy(authbuf, &cookieheader[7], authbuflen);
245 char *semicolon = strchr(authbuf, ';');
246 if (semicolon != NULL) {
249 if (strlen(authbuf) < 3) { // impossibly small
252 return; // Cookie auth was found -- stop here
255 // no authorization found in headers ... this is an anonymous session
259 // Log in to the Citadel server. Returns 0 on success or nonzero on error.
261 // 'auth' should be a base64-encoded "username:password" combination (like in http-auth)
263 // If 'resultbuf' is not NULL, it should be a buffer of at least 1024 characters,
264 // and will be filled with the result from a Citadel server command.
265 int login_to_citadel(struct ctdlsession *c, char *auth, char *resultbuf) {
269 char supplied_username[AUTH_MAX];
270 char supplied_password[AUTH_MAX];
272 if (resultbuf != NULL) {
279 buflen = CtdlDecodeBase64(buf, auth, strlen(auth));
280 extract_token(supplied_username, buf, 0, ':', sizeof supplied_username);
281 extract_token(supplied_password, buf, 1, ':', sizeof supplied_password);
282 syslog(LOG_DEBUG, "Supplied credentials: username=%s, pwlen=%d", supplied_username, (int) strlen(supplied_password));
284 ctdl_printf(c, "USER %s", supplied_username);
285 ctdl_readline(c, buf, 1024);
287 syslog(LOG_DEBUG, "No such user: %s", buf);
288 return (1); // no such user; resultbuf will explain why
291 ctdl_printf(c, "PASS %s", supplied_password);
292 ctdl_readline(c, buf, 1024);
295 strcpy(c->auth, auth);
296 extract_token(c->whoami, &buf[4], 0, '|', sizeof c->whoami);
297 syslog(LOG_DEBUG, "Login succeeded: %s", buf);
301 syslog(LOG_DEBUG, "Login failed: %s", buf);
302 return (1); // login failed; resultbuf will explain why
306 // Hunt for, or create, a connection to our Citadel Server
307 struct ctdlsession *connect_to_citadel(struct http_transaction *h) {
308 struct ctdlsession *cptr = NULL;
309 struct ctdlsession *my_session = NULL;
310 int is_new_session = 0;
315 // Does the request carry a username and password?
316 extract_auth(h, auth, sizeof auth);
317 syslog(LOG_DEBUG, "Session auth: %s", auth); // remove this log when development is done
319 // Lock the connection pool while we claim our connection
320 pthread_mutex_lock(&cpool_mutex);
322 for (cptr = cpool; ((cptr != NULL) && (my_session == NULL)); cptr = cptr->next) {
323 if ((cptr->is_bound == 0) && (!strcmp(cptr->auth, auth))) {
325 my_session->is_bound = 1;
328 if (my_session == NULL) {
329 syslog(LOG_DEBUG, "No qualifying sessions , starting a new one");
330 my_session = malloc(sizeof(struct ctdlsession));
331 if (my_session != NULL) {
332 memset(my_session, 0, sizeof(struct ctdlsession));
334 my_session->next = cpool;
336 my_session->is_bound = 1;
339 pthread_mutex_unlock(&cpool_mutex);
340 if (my_session == NULL) {
341 return (NULL); // oh well
344 if (my_session->sock < 3) {
347 else { // make sure our Citadel session is still good
349 test_conn = ctdl_write(my_session, HKEY("NOOP\n"));
351 syslog(LOG_DEBUG, "Citadel session is broken , must reconnect");
352 close(my_session->sock);
353 my_session->sock = 0;
357 test_conn = ctdl_readline(my_session, buf, sizeof(buf));
359 syslog(LOG_DEBUG, "Citadel session is broken , must reconnect");
360 close(my_session->sock);
361 my_session->sock = 0;
367 if (is_new_session) {
368 strcpy(my_session->room, "");
369 my_session->sock = tcp_connectsock(ctdlhost, ctdlport);
370 ctdl_readline(my_session, buf, sizeof(buf)); // skip past the server greeting banner
372 if (!IsEmptyStr(auth)) { // do we need to log in to Citadel?
373 r = login_to_citadel(my_session, auth, NULL); // FIXME figure out what happens if login failed
376 ctdl_printf(my_session, "NOOP");
377 ctdl_readline(my_session, buf, sizeof(buf));
378 my_session->last_access = time(NULL);
379 ++my_session->num_requests_handled;
385 // Release our Citadel Server connection back into the pool.
386 void disconnect_from_citadel(struct ctdlsession *ctdl) {
387 pthread_mutex_lock(&cpool_mutex);
389 pthread_mutex_unlock(&cpool_mutex);