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 "frontend/connection-private.h"
31 #include "utils/error.h"
32 #include "utils/strbuf.h"
33 #include "utils/proto.h"
35 #include <assert.h>
36 #include <errno.h>
38 #include <arpa/inet.h>
39 #include <fcntl.h>
41 #include <string.h>
43 /*
44 * private data types
45 */
47 /* name of connection objects */
48 #define CONN_FD_PREFIX "conn#"
49 #define CONN_FD_PLACEHOLDER "XXXXXXX"
51 static int
52 connection_init(sdb_object_t *obj, va_list ap)
53 {
54 sdb_conn_t *conn;
55 int sock_fd;
56 int sock_fl;
58 assert(obj);
59 conn = CONN(obj);
61 sock_fd = va_arg(ap, int);
63 conn->buf = sdb_strbuf_create(/* size = */ 128);
64 if (! conn->buf) {
65 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate a read buffer "
66 "for a new connection");
67 return -1;
68 }
69 conn->errbuf = sdb_strbuf_create(0);
70 if (! conn->errbuf) {
71 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate an error buffer "
72 "for a new connection");
73 return -1;
74 }
76 conn->client_addr_len = sizeof(conn->client_addr);
77 conn->fd = accept(sock_fd, (struct sockaddr *)&conn->client_addr,
78 &conn->client_addr_len);
80 if (conn->fd < 0) {
81 char buf[1024];
82 sdb_log(SDB_LOG_ERR, "frontend: Failed to accept remote "
83 "connection: %s", sdb_strerror(errno,
84 buf, sizeof(buf)));
85 return -1;
86 }
88 if (conn->client_addr.ss_family != AF_UNIX) {
89 sdb_log(SDB_LOG_ERR, "frontend: Accepted connection using "
90 "unexpected family type %d", conn->client_addr.ss_family);
91 return -1;
92 }
94 sock_fl = fcntl(conn->fd, F_GETFL);
95 if (fcntl(conn->fd, F_SETFL, sock_fl | O_NONBLOCK)) {
96 char buf[1024];
97 sdb_log(SDB_LOG_ERR, "frontend: Failed to switch connection conn#%i "
98 "to non-blocking mode: %s", conn->fd,
99 sdb_strerror(errno, buf, sizeof(buf)));
100 return -1;
101 }
103 sdb_log(SDB_LOG_DEBUG, "frontend: Accepted connection on fd=%i",
104 conn->fd);
106 conn->cmd = CONNECTION_IDLE;
107 conn->cmd_len = 0;
109 /* update the object name */
110 snprintf(obj->name + strlen(CONN_FD_PREFIX),
111 strlen(CONN_FD_PLACEHOLDER), "%i", conn->fd);
112 return 0;
113 } /* connection_init */
115 static void
116 connection_destroy(sdb_object_t *obj)
117 {
118 sdb_conn_t *conn;
119 size_t len;
121 assert(obj);
122 conn = CONN(obj);
124 if (conn->buf) {
125 len = sdb_strbuf_len(conn->buf);
126 if (len)
127 sdb_log(SDB_LOG_INFO, "frontend: Discarding incomplete command "
128 "(%zu byte%s left in buffer)", len, len == 1 ? "" : "s");
129 }
131 sdb_log(SDB_LOG_DEBUG, "frontend: Closing connection on fd=%i",
132 conn->fd);
133 close(conn->fd);
134 conn->fd = -1;
136 sdb_strbuf_destroy(conn->buf);
137 conn->buf = NULL;
138 sdb_strbuf_destroy(conn->errbuf);
139 conn->errbuf = NULL;
140 } /* connection_destroy */
142 static sdb_type_t connection_type = {
143 /* size = */ sizeof(sdb_conn_t),
144 /* init = */ connection_init,
145 /* destroy = */ connection_destroy,
146 };
148 /*
149 * connection handler functions
150 */
152 static uint32_t
153 connection_get_int32(sdb_conn_t *conn, size_t offset)
154 {
155 const char *data;
156 uint32_t n;
158 assert(conn && (sdb_strbuf_len(conn->buf) >= offset + sizeof(uint32_t)));
160 data = sdb_strbuf_string(conn->buf);
161 memcpy(&n, data + offset, sizeof(n));
162 n = ntohl(n);
163 return n;
164 } /* connection_get_int32 */
166 static int
167 command_handle(sdb_conn_t *conn)
168 {
169 int status = -1;
171 assert(conn && (conn->cmd != CONNECTION_IDLE));
173 sdb_log(SDB_LOG_DEBUG, "frontend: Handling command %u (len: %u)",
174 conn->cmd, conn->cmd_len);
176 if ((! conn->username) && (conn->cmd != CONNECTION_STARTUP)) {
177 const char *errmsg = "Authentication required";
178 sdb_connection_send(conn, CONNECTION_ERROR,
179 (uint32_t)strlen(errmsg), errmsg);
180 return -1;
181 }
183 /* reset */
184 sdb_strbuf_sprintf(conn->errbuf, "");
186 switch (conn->cmd) {
187 case CONNECTION_PING:
188 status = sdb_connection_ping(conn);
189 break;
190 case CONNECTION_STARTUP:
191 status = sdb_fe_session_start(conn);
192 break;
194 case CONNECTION_QUERY:
195 {
196 sdb_llist_t *parsetree;
197 sdb_conn_node_t *node = NULL;
199 parsetree = sdb_fe_parse(sdb_strbuf_string(conn->buf),
200 (int)conn->cmd_len);
201 if (! parsetree) {
202 sdb_log(SDB_LOG_ERR, "frontend: Failed to parse query '%s'",
203 sdb_strbuf_string(conn->buf));
204 status = -1;
205 break;
206 }
208 switch (sdb_llist_len(parsetree)) {
209 case 0:
210 /* skipping empty command */
211 break;
212 case 1:
213 node = SDB_CONN_NODE(sdb_llist_get(parsetree, 0));
214 break;
216 default:
217 sdb_log(SDB_LOG_WARNING, "frontend: Ignoring %d command%s "
218 "in multi-statement query '%s'",
219 sdb_llist_len(parsetree) - 1,
220 sdb_llist_len(parsetree) == 2 ? "" : "s",
221 sdb_strbuf_string(conn->buf));
222 node = SDB_CONN_NODE(sdb_llist_get(parsetree, 0));
223 }
225 if (node)
226 status = sdb_fe_exec(conn, node);
228 sdb_llist_destroy(parsetree);
229 break;
230 }
232 case CONNECTION_LIST:
233 status = sdb_fe_list(conn);
234 break;
236 default:
237 {
238 sdb_log(SDB_LOG_WARNING, "frontend: Ignoring invalid command %#x",
239 conn->cmd);
240 sdb_strbuf_sprintf(conn->errbuf, "Invalid command %#x", conn->cmd);
241 status = -1;
242 break;
243 }
244 }
246 if (status)
247 sdb_connection_send(conn, CONNECTION_ERROR,
248 (uint32_t)sdb_strbuf_len(conn->errbuf),
249 sdb_strbuf_string(conn->errbuf));
251 /* remove the command from the buffer */
252 if (conn->cmd_len)
253 sdb_strbuf_skip(conn->buf, 0, conn->cmd_len);
254 conn->cmd = CONNECTION_IDLE;
255 conn->cmd_len = 0;
256 return status;
257 } /* command_handle */
259 /* initialize the connection state information */
260 static int
261 command_init(sdb_conn_t *conn)
262 {
263 size_t len;
265 assert(conn && (conn->cmd == CONNECTION_IDLE) && (! conn->cmd_len));
267 conn->cmd = connection_get_int32(conn, 0);
268 conn->cmd_len = connection_get_int32(conn, sizeof(uint32_t));
270 len = 2 * sizeof(uint32_t);
271 if (conn->cmd == CONNECTION_IDLE)
272 len += conn->cmd_len;
273 sdb_strbuf_skip(conn->buf, 0, len);
274 return 0;
275 } /* command_init */
277 /* returns negative value on error, 0 on EOF, number of octets else */
278 static ssize_t
279 connection_read(sdb_conn_t *conn)
280 {
281 ssize_t n = 0;
283 while (42) {
284 ssize_t status;
286 errno = 0;
287 status = sdb_strbuf_read(conn->buf, conn->fd, 1024);
288 if (status < 0) {
289 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
290 break;
291 return (int)status;
292 }
293 else if (! status) /* EOF */
294 break;
296 n += status;
297 }
299 return n;
300 } /* connection_read */
302 /*
303 * public API
304 */
306 sdb_conn_t *
307 sdb_connection_accept(int fd)
308 {
309 if (fd < 0)
310 return NULL;
312 /* the placeholder will be replaced with the accepted file
313 * descriptor when initializing the object */
314 return CONN(sdb_object_create(CONN_FD_PREFIX CONN_FD_PLACEHOLDER,
315 connection_type, fd));
316 } /* sdb_connection_create */
318 void
319 sdb_connection_close(sdb_conn_t *conn)
320 {
321 sdb_object_deref(SDB_OBJ(conn));
322 } /* sdb_connection_close */
324 ssize_t
325 sdb_connection_read(sdb_conn_t *conn)
326 {
327 ssize_t n = 0;
329 while (42) {
330 ssize_t status = connection_read(conn);
332 if ((conn->cmd == CONNECTION_IDLE) && (! conn->cmd_len)
333 && (sdb_strbuf_len(conn->buf) >= 2 * sizeof(int32_t)))
334 command_init(conn);
335 if ((conn->cmd != CONNECTION_IDLE)
336 && (sdb_strbuf_len(conn->buf) >= conn->cmd_len))
337 command_handle(conn);
339 if (status <= 0)
340 break;
342 n += status;
343 }
344 return n;
345 } /* sdb_connection_read */
347 ssize_t
348 sdb_connection_send(sdb_conn_t *conn, uint32_t code,
349 uint32_t msg_len, const char *msg)
350 {
351 ssize_t status;
353 if ((! conn) || (conn->fd < 0))
354 return -1;
356 status = sdb_proto_send_msg(conn->fd, code, msg_len, msg);
357 if (status < 0) {
358 char errbuf[1024];
360 sdb_log(SDB_LOG_ERR, "frontend: Failed to send msg "
361 "(code: %u, len: %u) to client: %s", code, msg_len,
362 sdb_strerror(errno, errbuf, sizeof(errbuf)));
363 }
364 return status;
365 } /* sdb_connection_send */
367 int
368 sdb_connection_ping(sdb_conn_t *conn)
369 {
370 if ((! conn) || (conn->cmd != CONNECTION_PING))
371 return -1;
373 /* we're alive */
374 sdb_connection_send(conn, CONNECTION_OK, 0, NULL);
375 return 0;
376 } /* sdb_connection_ping */
378 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */