12812c7132b20e35da6954757ddbcb5f6f2e7a7d
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 close(conn->fd);
146 conn->fd = -1;
148 sdb_strbuf_destroy(conn->buf);
149 conn->buf = NULL;
150 sdb_strbuf_destroy(conn->errbuf);
151 conn->errbuf = NULL;
152 } /* connection_destroy */
154 static sdb_type_t connection_type = {
155 /* size = */ sizeof(sdb_conn_t),
156 /* init = */ connection_init,
157 /* destroy = */ connection_destroy,
158 };
160 /*
161 * private helper functions
162 */
164 static void
165 sdb_conn_ctx_destructor(void *c)
166 {
167 sdb_object_t *conn = c;
169 if (! conn)
170 return;
171 sdb_object_deref(conn);
172 } /* sdb_conn_ctx_destructor */
174 static void
175 sdb_conn_ctx_init(void)
176 {
177 if (conn_ctx_key_initialized)
178 return;
180 pthread_key_create(&conn_ctx_key, sdb_conn_ctx_destructor);
181 conn_ctx_key_initialized = 1;
182 } /* sdb_conn_ctx_init */
184 static void
185 sdb_conn_set_ctx(sdb_conn_t *conn)
186 {
187 sdb_conn_ctx_init();
188 if (conn)
189 sdb_object_ref(SDB_OBJ(conn));
190 pthread_setspecific(conn_ctx_key, conn);
191 } /* sdb_conn_set_ctx */
193 static sdb_conn_t *
194 sdb_conn_get_ctx(void)
195 {
196 if (! conn_ctx_key_initialized)
197 return NULL;
198 return pthread_getspecific(conn_ctx_key);
199 } /* sdb_conn_get_ctx */
201 /*
202 * connection handler functions
203 */
205 /*
206 * connection_log:
207 * Send a log message originating from the current thread to the client.
208 */
209 static int
210 connection_log(int prio, const char *msg,
211 sdb_object_t __attribute__((unused)) *user_data)
212 {
213 sdb_conn_t *conn;
215 conn = sdb_conn_get_ctx();
216 /* no connection associated to this thread
217 * or user not authenticated yet => don't leak any information */
218 if ((! conn) || (! conn->username))
219 return 0;
221 /* XXX: make the log-level configurable by the client at runtime */
222 if (prio >= SDB_LOG_DEBUG)
223 return 0;
225 /* TODO: Use CONNECTION_LOG_<prio>? */
226 if (sdb_connection_send(conn, CONNECTION_LOG,
227 (uint32_t)strlen(msg), msg) < 0)
228 return -1;
229 return 0;
230 } /* connection_log */
232 static uint32_t
233 connection_get_int32(sdb_conn_t *conn, size_t offset)
234 {
235 const char *data;
236 uint32_t n;
238 assert(conn && (sdb_strbuf_len(conn->buf) >= offset + sizeof(uint32_t)));
240 data = sdb_strbuf_string(conn->buf);
241 memcpy(&n, data + offset, sizeof(n));
242 n = ntohl(n);
243 return n;
244 } /* connection_get_int32 */
246 static int
247 command_handle(sdb_conn_t *conn)
248 {
249 int status = -1;
251 assert(conn && (conn->cmd != CONNECTION_IDLE));
253 sdb_log(SDB_LOG_DEBUG, "frontend: Handling command %u (len: %u)",
254 conn->cmd, conn->cmd_len);
256 if ((! conn->username) && (conn->cmd != CONNECTION_STARTUP)) {
257 const char *errmsg = "Authentication required";
258 sdb_connection_send(conn, CONNECTION_ERROR,
259 (uint32_t)strlen(errmsg), errmsg);
260 return -1;
261 }
263 /* reset */
264 sdb_strbuf_sprintf(conn->errbuf, "");
266 switch (conn->cmd) {
267 case CONNECTION_PING:
268 status = sdb_connection_ping(conn);
269 break;
270 case CONNECTION_STARTUP:
271 status = sdb_fe_session_start(conn);
272 break;
274 case CONNECTION_QUERY:
275 {
276 sdb_llist_t *parsetree;
277 sdb_conn_node_t *node = NULL;
279 parsetree = sdb_fe_parse(sdb_strbuf_string(conn->buf),
280 (int)conn->cmd_len);
281 if (! parsetree) {
282 sdb_log(SDB_LOG_ERR, "frontend: Failed to parse query '%s'",
283 sdb_strbuf_string(conn->buf));
284 status = -1;
285 break;
286 }
288 switch (sdb_llist_len(parsetree)) {
289 case 0:
290 /* skipping empty command */
291 break;
292 case 1:
293 node = SDB_CONN_NODE(sdb_llist_get(parsetree, 0));
294 break;
296 default:
297 sdb_log(SDB_LOG_WARNING, "frontend: Ignoring %d command%s "
298 "in multi-statement query '%s'",
299 sdb_llist_len(parsetree) - 1,
300 sdb_llist_len(parsetree) == 2 ? "" : "s",
301 sdb_strbuf_string(conn->buf));
302 node = SDB_CONN_NODE(sdb_llist_get(parsetree, 0));
303 }
305 if (node) {
306 status = sdb_fe_exec(conn, node);
307 sdb_object_deref(SDB_OBJ(node));
308 }
310 sdb_llist_destroy(parsetree);
311 break;
312 }
314 case CONNECTION_FETCH:
315 status = sdb_fe_fetch(conn, sdb_strbuf_string(conn->buf));
316 break;
317 case CONNECTION_LIST:
318 status = sdb_fe_list(conn);
319 break;
320 case CONNECTION_LOOKUP:
321 {
322 sdb_store_matcher_t *m;
324 m = sdb_fe_parse_matcher(sdb_strbuf_string(conn->buf),
325 (int)conn->cmd_len);
326 if (! m) {
327 sdb_log(SDB_LOG_ERR, "frontend: Failed to parse expression '%s'",
328 sdb_strbuf_string(conn->buf));
329 status = -1;
330 break;
331 }
333 status = sdb_fe_lookup(conn, m);
334 sdb_object_deref(SDB_OBJ(m));
335 break;
336 }
338 default:
339 {
340 sdb_log(SDB_LOG_WARNING, "frontend: Ignoring invalid command %#x",
341 conn->cmd);
342 sdb_strbuf_sprintf(conn->errbuf, "Invalid command %#x", conn->cmd);
343 status = -1;
344 break;
345 }
346 }
348 if (status)
349 sdb_connection_send(conn, CONNECTION_ERROR,
350 (uint32_t)sdb_strbuf_len(conn->errbuf),
351 sdb_strbuf_string(conn->errbuf));
353 /* remove the command from the buffer */
354 if (conn->cmd_len)
355 sdb_strbuf_skip(conn->buf, 0, conn->cmd_len);
356 conn->cmd = CONNECTION_IDLE;
357 conn->cmd_len = 0;
358 return status;
359 } /* command_handle */
361 /* initialize the connection state information */
362 static int
363 command_init(sdb_conn_t *conn)
364 {
365 size_t len;
367 assert(conn && (conn->cmd == CONNECTION_IDLE) && (! conn->cmd_len));
369 conn->cmd = connection_get_int32(conn, 0);
370 conn->cmd_len = connection_get_int32(conn, sizeof(uint32_t));
372 len = 2 * sizeof(uint32_t);
373 if (conn->cmd == CONNECTION_IDLE)
374 len += conn->cmd_len;
375 sdb_strbuf_skip(conn->buf, 0, len);
376 return 0;
377 } /* command_init */
379 /* returns negative value on error, 0 on EOF, number of octets else */
380 static ssize_t
381 connection_read(sdb_conn_t *conn)
382 {
383 ssize_t n = 0;
385 while (42) {
386 ssize_t status;
388 errno = 0;
389 status = sdb_strbuf_read(conn->buf, conn->fd, 1024);
390 if (status < 0) {
391 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
392 break;
393 return (int)status;
394 }
395 else if (! status) /* EOF */
396 break;
398 n += status;
399 }
401 return n;
402 } /* connection_read */
404 /*
405 * public API
406 */
408 int
409 sdb_connection_enable_logging(void)
410 {
411 return sdb_plugin_register_log("connection-logger", connection_log,
412 /* user_data = */ NULL);
413 } /* sdb_connection_enable_logging */
415 sdb_conn_t *
416 sdb_connection_accept(int fd)
417 {
418 if (fd < 0)
419 return NULL;
421 /* the placeholder will be replaced with the accepted file
422 * descriptor when initializing the object */
423 return CONN(sdb_object_create(CONN_FD_PREFIX CONN_FD_PLACEHOLDER,
424 connection_type, fd));
425 } /* sdb_connection_create */
427 void
428 sdb_connection_close(sdb_conn_t *conn)
429 {
430 sdb_object_deref(SDB_OBJ(conn));
431 } /* sdb_connection_close */
433 ssize_t
434 sdb_connection_read(sdb_conn_t *conn)
435 {
436 ssize_t n = 0;
438 sdb_conn_set_ctx(conn);
440 while (42) {
441 ssize_t status = connection_read(conn);
443 if ((conn->cmd == CONNECTION_IDLE) && (! conn->cmd_len)
444 && (sdb_strbuf_len(conn->buf) >= 2 * sizeof(int32_t)))
445 command_init(conn);
446 if ((conn->cmd != CONNECTION_IDLE)
447 && (sdb_strbuf_len(conn->buf) >= conn->cmd_len))
448 command_handle(conn);
450 if (status <= 0)
451 break;
453 n += status;
454 }
456 sdb_conn_set_ctx(NULL);
457 return n;
458 } /* sdb_connection_read */
460 ssize_t
461 sdb_connection_send(sdb_conn_t *conn, uint32_t code,
462 uint32_t msg_len, const char *msg)
463 {
464 ssize_t status;
466 if ((! conn) || (conn->fd < 0))
467 return -1;
469 status = sdb_proto_send_msg(conn->fd, code, msg_len, msg);
470 if (status < 0) {
471 char errbuf[1024];
473 sdb_log(SDB_LOG_ERR, "frontend: Failed to send msg "
474 "(code: %u, len: %u) to client: %s", code, msg_len,
475 sdb_strerror(errno, errbuf, sizeof(errbuf)));
476 }
477 return status;
478 } /* sdb_connection_send */
480 int
481 sdb_connection_ping(sdb_conn_t *conn)
482 {
483 if ((! conn) || (conn->cmd != CONNECTION_PING))
484 return -1;
486 /* we're alive */
487 sdb_connection_send(conn, CONNECTION_OK, 0, NULL);
488 return 0;
489 } /* sdb_connection_ping */
491 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */