1 /*
2 * SysDB - src/frontend/connection.c
3 * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #include "sysdb.h"
29 #include "core/object.h"
30 #include "core/plugin.h"
31 #include "frontend/connection-private.h"
32 #include "frontend/parser.h"
33 #include "utils/error.h"
34 #include "utils/strbuf.h"
35 #include "utils/proto.h"
37 #include <assert.h>
38 #include <errno.h>
40 #include <arpa/inet.h>
41 #include <fcntl.h>
43 #include <stdlib.h>
44 #include <string.h>
46 #include <pthread.h>
48 /*
49 * private variables
50 */
52 static pthread_key_t conn_ctx_key;
53 static _Bool conn_ctx_key_initialized = 0;
55 /*
56 * private types
57 */
59 /* name of connection objects */
60 #define CONN_FD_PREFIX "conn#"
61 #define CONN_FD_PLACEHOLDER "XXXXXXX"
63 static int
64 connection_init(sdb_object_t *obj, va_list ap)
65 {
66 sdb_conn_t *conn;
67 int sock_fd;
68 int sock_fl;
70 assert(obj);
71 conn = CONN(obj);
73 sock_fd = va_arg(ap, int);
75 conn->buf = sdb_strbuf_create(/* size = */ 128);
76 if (! conn->buf) {
77 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate a read buffer "
78 "for a new connection");
79 return -1;
80 }
81 conn->errbuf = sdb_strbuf_create(0);
82 if (! conn->errbuf) {
83 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate an error buffer "
84 "for a new connection");
85 return -1;
86 }
88 conn->client_addr_len = sizeof(conn->client_addr);
89 conn->fd = accept(sock_fd, (struct sockaddr *)&conn->client_addr,
90 &conn->client_addr_len);
92 if (conn->fd < 0) {
93 char buf[1024];
94 sdb_log(SDB_LOG_ERR, "frontend: Failed to accept remote "
95 "connection: %s", sdb_strerror(errno,
96 buf, sizeof(buf)));
97 return -1;
98 }
100 if (conn->client_addr.ss_family != AF_UNIX) {
101 sdb_log(SDB_LOG_ERR, "frontend: Accepted connection using "
102 "unexpected family type %d", conn->client_addr.ss_family);
103 return -1;
104 }
106 sock_fl = fcntl(conn->fd, F_GETFL);
107 if (fcntl(conn->fd, F_SETFL, sock_fl | O_NONBLOCK)) {
108 char buf[1024];
109 sdb_log(SDB_LOG_ERR, "frontend: Failed to switch connection conn#%i "
110 "to non-blocking mode: %s", conn->fd,
111 sdb_strerror(errno, buf, sizeof(buf)));
112 return -1;
113 }
115 sdb_log(SDB_LOG_DEBUG, "frontend: Accepted connection on fd=%i",
116 conn->fd);
118 conn->cmd = CONNECTION_IDLE;
119 conn->cmd_len = 0;
121 /* update the object name */
122 snprintf(obj->name + strlen(CONN_FD_PREFIX),
123 strlen(CONN_FD_PLACEHOLDER), "%i", conn->fd);
124 return 0;
125 } /* connection_init */
127 static void
128 connection_destroy(sdb_object_t *obj)
129 {
130 sdb_conn_t *conn;
131 size_t len;
133 assert(obj);
134 conn = CONN(obj);
136 if (conn->buf) {
137 len = sdb_strbuf_len(conn->buf);
138 if (len)
139 sdb_log(SDB_LOG_INFO, "frontend: Discarding incomplete command "
140 "(%zu byte%s left in buffer)", len, len == 1 ? "" : "s");
141 }
143 sdb_log(SDB_LOG_DEBUG, "frontend: Closing connection on fd=%i",
144 conn->fd);
145 if (conn->fd >= 0)
146 close(conn->fd);
147 conn->fd = -1;
149 sdb_strbuf_destroy(conn->buf);
150 conn->buf = NULL;
151 sdb_strbuf_destroy(conn->errbuf);
152 conn->errbuf = NULL;
153 } /* connection_destroy */
155 static sdb_type_t connection_type = {
156 /* size = */ sizeof(sdb_conn_t),
157 /* init = */ connection_init,
158 /* destroy = */ connection_destroy,
159 };
161 /*
162 * private helper functions
163 */
165 static void
166 sdb_conn_ctx_destructor(void *c)
167 {
168 sdb_object_t *conn = c;
170 if (! conn)
171 return;
172 sdb_object_deref(conn);
173 } /* sdb_conn_ctx_destructor */
175 static void
176 sdb_conn_ctx_init(void)
177 {
178 if (conn_ctx_key_initialized)
179 return;
181 pthread_key_create(&conn_ctx_key, sdb_conn_ctx_destructor);
182 conn_ctx_key_initialized = 1;
183 } /* sdb_conn_ctx_init */
185 static void
186 sdb_conn_set_ctx(sdb_conn_t *conn)
187 {
188 sdb_conn_t *old;
190 sdb_conn_ctx_init();
192 old = pthread_getspecific(conn_ctx_key);
193 if (old)
194 sdb_object_deref(SDB_OBJ(old));
195 if (conn)
196 sdb_object_ref(SDB_OBJ(conn));
197 pthread_setspecific(conn_ctx_key, conn);
198 } /* sdb_conn_set_ctx */
200 static sdb_conn_t *
201 sdb_conn_get_ctx(void)
202 {
203 if (! conn_ctx_key_initialized)
204 return NULL;
205 return pthread_getspecific(conn_ctx_key);
206 } /* sdb_conn_get_ctx */
208 /*
209 * connection handler functions
210 */
212 /*
213 * connection_log:
214 * Send a log message originating from the current thread to the client.
215 */
216 static int
217 connection_log(int prio, const char *msg,
218 sdb_object_t __attribute__((unused)) *user_data)
219 {
220 sdb_conn_t *conn;
222 conn = sdb_conn_get_ctx();
223 /* no connection associated to this thread
224 * or user not authenticated yet => don't leak any information */
225 if ((! conn) || (! conn->username))
226 return 0;
228 /* XXX: make the log-level configurable by the client at runtime */
229 if (prio >= SDB_LOG_DEBUG)
230 return 0;
232 /* TODO: Use CONNECTION_LOG_<prio>? */
233 if (sdb_connection_send(conn, CONNECTION_LOG,
234 (uint32_t)strlen(msg), msg) < 0)
235 return -1;
236 return 0;
237 } /* connection_log */
239 static uint32_t
240 connection_get_int32(sdb_conn_t *conn, size_t offset)
241 {
242 const char *data;
243 uint32_t n;
245 assert(conn && (sdb_strbuf_len(conn->buf) >= offset + sizeof(uint32_t)));
247 data = sdb_strbuf_string(conn->buf);
248 memcpy(&n, data + offset, sizeof(n));
249 n = ntohl(n);
250 return n;
251 } /* connection_get_int32 */
253 static int
254 command_handle(sdb_conn_t *conn)
255 {
256 int status = -1;
258 assert(conn && (conn->cmd != CONNECTION_IDLE));
260 sdb_log(SDB_LOG_DEBUG, "frontend: Handling command %u (len: %u)",
261 conn->cmd, conn->cmd_len);
263 if ((! conn->username) && (conn->cmd != CONNECTION_STARTUP)) {
264 const char *errmsg = "Authentication required";
265 sdb_connection_send(conn, CONNECTION_ERROR,
266 (uint32_t)strlen(errmsg), errmsg);
267 return -1;
268 }
270 /* reset */
271 sdb_strbuf_sprintf(conn->errbuf, "");
273 switch (conn->cmd) {
274 case CONNECTION_PING:
275 status = sdb_connection_ping(conn);
276 break;
277 case CONNECTION_STARTUP:
278 status = sdb_fe_session_start(conn);
279 break;
281 case CONNECTION_QUERY:
282 {
283 sdb_llist_t *parsetree;
284 sdb_conn_node_t *node = NULL;
286 parsetree = sdb_fe_parse(sdb_strbuf_string(conn->buf),
287 (int)conn->cmd_len);
288 if (! parsetree) {
289 sdb_log(SDB_LOG_ERR, "frontend: Failed to parse query '%s'",
290 sdb_strbuf_string(conn->buf));
291 status = -1;
292 break;
293 }
295 switch (sdb_llist_len(parsetree)) {
296 case 0:
297 /* skipping empty command */
298 break;
299 case 1:
300 node = SDB_CONN_NODE(sdb_llist_get(parsetree, 0));
301 break;
303 default:
304 sdb_log(SDB_LOG_WARNING, "frontend: Ignoring %d command%s "
305 "in multi-statement query '%s'",
306 sdb_llist_len(parsetree) - 1,
307 sdb_llist_len(parsetree) == 2 ? "" : "s",
308 sdb_strbuf_string(conn->buf));
309 node = SDB_CONN_NODE(sdb_llist_get(parsetree, 0));
310 }
312 if (node) {
313 status = sdb_fe_exec(conn, node);
314 sdb_object_deref(SDB_OBJ(node));
315 }
317 sdb_llist_destroy(parsetree);
318 break;
319 }
321 case CONNECTION_FETCH:
322 status = sdb_fe_fetch(conn, sdb_strbuf_string(conn->buf));
323 break;
324 case CONNECTION_LIST:
325 status = sdb_fe_list(conn);
326 break;
327 case CONNECTION_LOOKUP:
328 {
329 sdb_store_matcher_t *m;
331 m = sdb_fe_parse_matcher(sdb_strbuf_string(conn->buf),
332 (int)conn->cmd_len);
333 if (! m) {
334 sdb_log(SDB_LOG_ERR, "frontend: Failed to parse expression '%s'",
335 sdb_strbuf_string(conn->buf));
336 status = -1;
337 break;
338 }
340 status = sdb_fe_lookup(conn, m);
341 sdb_object_deref(SDB_OBJ(m));
342 break;
343 }
345 default:
346 {
347 sdb_log(SDB_LOG_WARNING, "frontend: Ignoring invalid command %#x",
348 conn->cmd);
349 sdb_strbuf_sprintf(conn->errbuf, "Invalid command %#x", conn->cmd);
350 status = -1;
351 break;
352 }
353 }
355 if (status)
356 sdb_connection_send(conn, CONNECTION_ERROR,
357 (uint32_t)sdb_strbuf_len(conn->errbuf),
358 sdb_strbuf_string(conn->errbuf));
360 /* remove the command from the buffer */
361 if (conn->cmd_len)
362 sdb_strbuf_skip(conn->buf, 0, conn->cmd_len);
363 conn->cmd = CONNECTION_IDLE;
364 conn->cmd_len = 0;
365 return status;
366 } /* command_handle */
368 /* initialize the connection state information */
369 static int
370 command_init(sdb_conn_t *conn)
371 {
372 size_t len;
374 assert(conn && (conn->cmd == CONNECTION_IDLE) && (! conn->cmd_len));
376 conn->cmd = connection_get_int32(conn, 0);
377 conn->cmd_len = connection_get_int32(conn, sizeof(uint32_t));
379 len = 2 * sizeof(uint32_t);
380 if (conn->cmd == CONNECTION_IDLE)
381 len += conn->cmd_len;
382 sdb_strbuf_skip(conn->buf, 0, len);
383 return 0;
384 } /* command_init */
386 /* returns negative value on error, 0 on EOF, number of octets else */
387 static ssize_t
388 connection_read(sdb_conn_t *conn)
389 {
390 ssize_t n = 0;
392 if ((! conn) || (conn->fd < 0))
393 return -1;
395 while (42) {
396 ssize_t status;
398 errno = 0;
399 status = sdb_strbuf_read(conn->buf, conn->fd, 1024);
400 if (status < 0) {
401 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
402 break;
404 close(conn->fd);
405 conn->fd = -1;
406 return (int)status;
407 }
408 else if (! status) /* EOF */
409 break;
411 n += status;
412 }
414 return n;
415 } /* connection_read */
417 /*
418 * public API
419 */
421 int
422 sdb_connection_enable_logging(void)
423 {
424 return sdb_plugin_register_log("connection-logger", connection_log,
425 /* user_data = */ NULL);
426 } /* sdb_connection_enable_logging */
428 sdb_conn_t *
429 sdb_connection_accept(int fd)
430 {
431 if (fd < 0)
432 return NULL;
434 /* the placeholder will be replaced with the accepted file
435 * descriptor when initializing the object */
436 return CONN(sdb_object_create(CONN_FD_PREFIX CONN_FD_PLACEHOLDER,
437 connection_type, fd));
438 } /* sdb_connection_create */
440 void
441 sdb_connection_close(sdb_conn_t *conn)
442 {
443 sdb_object_deref(SDB_OBJ(conn));
444 } /* sdb_connection_close */
446 ssize_t
447 sdb_connection_read(sdb_conn_t *conn)
448 {
449 ssize_t n = 0;
451 sdb_conn_set_ctx(conn);
453 while (42) {
454 ssize_t status = connection_read(conn);
456 if ((conn->cmd == CONNECTION_IDLE) && (! conn->cmd_len)
457 && (sdb_strbuf_len(conn->buf) >= 2 * sizeof(int32_t)))
458 command_init(conn);
459 if ((conn->cmd != CONNECTION_IDLE)
460 && (sdb_strbuf_len(conn->buf) >= conn->cmd_len))
461 command_handle(conn);
463 if (status <= 0)
464 break;
466 n += status;
467 }
469 sdb_conn_set_ctx(NULL);
470 return n;
471 } /* sdb_connection_read */
473 ssize_t
474 sdb_connection_send(sdb_conn_t *conn, uint32_t code,
475 uint32_t msg_len, const char *msg)
476 {
477 ssize_t status;
479 if ((! conn) || (conn->fd < 0))
480 return -1;
482 status = sdb_proto_send_msg(conn->fd, code, msg_len, msg);
483 if (status < 0) {
484 char errbuf[1024];
486 /* tell other code that there was a problem and, more importantly,
487 * make sure we don't try to send further logs to the connection */
488 close(conn->fd);
489 conn->fd = -1;
491 sdb_log(SDB_LOG_ERR, "frontend: Failed to send msg "
492 "(code: %u, len: %u) to client: %s", code, msg_len,
493 sdb_strerror(errno, errbuf, sizeof(errbuf)));
494 }
495 return status;
496 } /* sdb_connection_send */
498 int
499 sdb_connection_ping(sdb_conn_t *conn)
500 {
501 if ((! conn) || (conn->cmd != CONNECTION_PING))
502 return -1;
504 /* we're alive */
505 sdb_connection_send(conn, CONNECTION_OK, 0, NULL);
506 return 0;
507 } /* sdb_connection_ping */
509 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */