Code

frontend: Force-close the connection in sdb_connection_close().
[sysdb.git] / src / frontend / connection.c
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)
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 %s", obj->name);
144         if (conn->fd >= 0)
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)
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)
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)
187         sdb_conn_t *old;
189         sdb_conn_ctx_init();
191         old = pthread_getspecific(conn_ctx_key);
192         if (old)
193                 sdb_object_deref(SDB_OBJ(old));
194         if (conn)
195                 sdb_object_ref(SDB_OBJ(conn));
196         pthread_setspecific(conn_ctx_key, conn);
197 } /* sdb_conn_set_ctx */
199 static sdb_conn_t *
200 sdb_conn_get_ctx(void)
202         if (! conn_ctx_key_initialized)
203                 return NULL;
204         return pthread_getspecific(conn_ctx_key);
205 } /* sdb_conn_get_ctx */
207 /*
208  * connection handler functions
209  */
211 /*
212  * connection_log:
213  * Send a log message originating from the current thread to the client.
214  */
215 static int
216 connection_log(int prio, const char *msg,
217                 sdb_object_t __attribute__((unused)) *user_data)
219         sdb_conn_t *conn;
221         conn = sdb_conn_get_ctx();
222         /* no connection associated to this thread
223          * or user not authenticated yet => don't leak any information */
224         if ((! conn) || (! conn->username))
225                 return 0;
227         /* XXX: make the log-level configurable by the client at runtime */
228         if (prio >= SDB_LOG_DEBUG)
229                 return 0;
231         /* TODO: Use CONNECTION_LOG_<prio>? */
232         if (sdb_connection_send(conn, CONNECTION_LOG,
233                                 (uint32_t)strlen(msg), msg) < 0)
234                 return -1;
235         return 0;
236 } /* connection_log */
238 static uint32_t
239 connection_get_int32(sdb_conn_t *conn, size_t offset)
241         const char *data;
242         uint32_t n;
244         assert(conn && (sdb_strbuf_len(conn->buf) >= offset + sizeof(uint32_t)));
246         data = sdb_strbuf_string(conn->buf);
247         memcpy(&n, data + offset, sizeof(n));
248         n = ntohl(n);
249         return n;
250 } /* connection_get_int32 */
252 static int
253 command_handle(sdb_conn_t *conn)
255         int status = -1;
257         assert(conn && (conn->cmd != CONNECTION_IDLE));
259         sdb_log(SDB_LOG_DEBUG, "frontend: Handling command %u (len: %u)",
260                         conn->cmd, conn->cmd_len);
262         if ((! conn->username) && (conn->cmd != CONNECTION_STARTUP)) {
263                 const char *errmsg = "Authentication required";
264                 sdb_connection_send(conn, CONNECTION_ERROR,
265                                 (uint32_t)strlen(errmsg), errmsg);
266                 return -1;
267         }
269         /* reset */
270         sdb_strbuf_sprintf(conn->errbuf, "");
272         switch (conn->cmd) {
273                 case CONNECTION_PING:
274                         status = sdb_connection_ping(conn);
275                         break;
276                 case CONNECTION_STARTUP:
277                         status = sdb_fe_session_start(conn);
278                         break;
280                 case CONNECTION_QUERY:
281                 {
282                         sdb_llist_t *parsetree;
283                         sdb_conn_node_t *node = NULL;
285                         parsetree = sdb_fe_parse(sdb_strbuf_string(conn->buf),
286                                         (int)conn->cmd_len);
287                         if (! parsetree) {
288                                 sdb_log(SDB_LOG_ERR, "frontend: Failed to parse query '%s'",
289                                                 sdb_strbuf_string(conn->buf));
290                                 status = -1;
291                                 break;
292                         }
294                         switch (sdb_llist_len(parsetree)) {
295                                 case 0:
296                                         /* skipping empty command */
297                                         break;
298                                 case 1:
299                                         node = SDB_CONN_NODE(sdb_llist_get(parsetree, 0));
300                                         break;
302                                 default:
303                                         sdb_log(SDB_LOG_WARNING, "frontend: Ignoring %d command%s "
304                                                         "in multi-statement query '%s'",
305                                                         sdb_llist_len(parsetree) - 1,
306                                                         sdb_llist_len(parsetree) == 2 ? "" : "s",
307                                                         sdb_strbuf_string(conn->buf));
308                                         node = SDB_CONN_NODE(sdb_llist_get(parsetree, 0));
309                         }
311                         if (node) {
312                                 status = sdb_fe_exec(conn, node);
313                                 sdb_object_deref(SDB_OBJ(node));
314                         }
316                         sdb_llist_destroy(parsetree);
317                         break;
318                 }
320                 case CONNECTION_FETCH:
321                         status = sdb_fe_fetch(conn, sdb_strbuf_string(conn->buf));
322                         break;
323                 case CONNECTION_LIST:
324                         status = sdb_fe_list(conn);
325                         break;
326                 case CONNECTION_LOOKUP:
327                 {
328                         sdb_store_matcher_t *m;
330                         m = sdb_fe_parse_matcher(sdb_strbuf_string(conn->buf),
331                                         (int)conn->cmd_len);
332                         if (! m) {
333                                 sdb_log(SDB_LOG_ERR, "frontend: Failed to parse expression '%s'",
334                                                 sdb_strbuf_string(conn->buf));
335                                 status = -1;
336                                 break;
337                         }
339                         status = sdb_fe_lookup(conn, m);
340                         sdb_object_deref(SDB_OBJ(m));
341                         break;
342                 }
344                 default:
345                 {
346                         sdb_log(SDB_LOG_WARNING, "frontend: Ignoring invalid command %#x",
347                                         conn->cmd);
348                         sdb_strbuf_sprintf(conn->errbuf, "Invalid command %#x", conn->cmd);
349                         status = -1;
350                         break;
351                 }
352         }
354         if (status)
355                 sdb_connection_send(conn, CONNECTION_ERROR,
356                                 (uint32_t)sdb_strbuf_len(conn->errbuf),
357                                 sdb_strbuf_string(conn->errbuf));
359         /* remove the command from the buffer */
360         if (conn->cmd_len)
361                 sdb_strbuf_skip(conn->buf, 0, conn->cmd_len);
362         conn->cmd = CONNECTION_IDLE;
363         conn->cmd_len = 0;
364         return status;
365 } /* command_handle */
367 /* initialize the connection state information */
368 static int
369 command_init(sdb_conn_t *conn)
371         size_t len;
373         assert(conn && (conn->cmd == CONNECTION_IDLE) && (! conn->cmd_len));
375         conn->cmd = connection_get_int32(conn, 0);
376         conn->cmd_len = connection_get_int32(conn, sizeof(uint32_t));
378         len = 2 * sizeof(uint32_t);
379         if (conn->cmd == CONNECTION_IDLE)
380                 len += conn->cmd_len;
381         sdb_strbuf_skip(conn->buf, 0, len);
382         return 0;
383 } /* command_init */
385 /* returns negative value on error, 0 on EOF, number of octets else */
386 static ssize_t
387 connection_read(sdb_conn_t *conn)
389         ssize_t n = 0;
391         if ((! conn) || (conn->fd < 0))
392                 return -1;
394         while (42) {
395                 ssize_t status;
397                 errno = 0;
398                 status = sdb_strbuf_read(conn->buf, conn->fd, 1024);
399                 if (status < 0) {
400                         if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
401                                 break;
403                         close(conn->fd);
404                         conn->fd = -1;
405                         return (int)status;
406                 }
407                 else if (! status) /* EOF */
408                         break;
410                 n += status;
411         }
413         return n;
414 } /* connection_read */
416 /*
417  * public API
418  */
420 int
421 sdb_connection_enable_logging(void)
423         return sdb_plugin_register_log("connection-logger", connection_log,
424                         /* user_data = */ NULL);
425 } /* sdb_connection_enable_logging */
427 sdb_conn_t *
428 sdb_connection_accept(int fd)
430         if (fd < 0)
431                 return NULL;
433         /* the placeholder will be replaced with the accepted file
434          * descriptor when initializing the object */
435         return CONN(sdb_object_create(CONN_FD_PREFIX CONN_FD_PLACEHOLDER,
436                                 connection_type, fd));
437 } /* sdb_connection_create */
439 void
440 sdb_connection_close(sdb_conn_t *conn)
442         if (! conn)
443                 return;
445         /* close the connection even if someone else still references it */
446         if (conn->fd >= 0)
447                 close(conn->fd);
448         conn->fd = -1;
450         sdb_object_deref(SDB_OBJ(conn));
451 } /* sdb_connection_close */
453 ssize_t
454 sdb_connection_read(sdb_conn_t *conn)
456         ssize_t n = 0;
458         sdb_conn_set_ctx(conn);
460         while (42) {
461                 ssize_t status = connection_read(conn);
463                 if ((conn->cmd == CONNECTION_IDLE) && (! conn->cmd_len)
464                                 && (sdb_strbuf_len(conn->buf) >= 2 * sizeof(int32_t)))
465                         command_init(conn);
466                 if ((conn->cmd != CONNECTION_IDLE)
467                                 && (sdb_strbuf_len(conn->buf) >= conn->cmd_len))
468                         command_handle(conn);
470                 if (status <= 0)
471                         break;
473                 n += status;
474         }
476         sdb_conn_set_ctx(NULL);
477         return n;
478 } /* sdb_connection_read */
480 ssize_t
481 sdb_connection_send(sdb_conn_t *conn, uint32_t code,
482                 uint32_t msg_len, const char *msg)
484         ssize_t status;
486         if ((! conn) || (conn->fd < 0))
487                 return -1;
489         status = sdb_proto_send_msg(conn->fd, code, msg_len, msg);
490         if (status < 0) {
491                 char errbuf[1024];
493                 /* tell other code that there was a problem and, more importantly,
494                  * make sure we don't try to send further logs to the connection */
495                 close(conn->fd);
496                 conn->fd = -1;
498                 sdb_log(SDB_LOG_ERR, "frontend: Failed to send msg "
499                                 "(code: %u, len: %u) to client: %s", code, msg_len,
500                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
501         }
502         return status;
503 } /* sdb_connection_send */
505 int
506 sdb_connection_ping(sdb_conn_t *conn)
508         if ((! conn) || (conn->cmd != CONNECTION_PING))
509                 return -1;
511         /* we're alive */
512         sdb_connection_send(conn, CONNECTION_OK, 0, NULL);
513         return 0;
514 } /* sdb_connection_ping */
516 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */