[http] Cleanly shut down potentially looped interfaces
[ipxe.git] / src / net / tcp / syslogs.c
1 /*
2 * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 */
23
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 /** @file
27 *
28 * Encrypted syslog protocol
29 *
30 */
31
32 #include <stdint.h>
33 #include <stdlib.h>
34 #include <byteswap.h>
35 #include <ipxe/xfer.h>
36 #include <ipxe/open.h>
37 #include <ipxe/tcpip.h>
38 #include <ipxe/dhcp.h>
39 #include <ipxe/settings.h>
40 #include <ipxe/console.h>
41 #include <ipxe/lineconsole.h>
42 #include <ipxe/tls.h>
43 #include <ipxe/syslog.h>
44 #include <config/console.h>
45
46 /* Set default console usage if applicable */
47 #if ! ( defined ( CONSOLE_SYSLOGS ) && CONSOLE_EXPLICIT ( CONSOLE_SYSLOGS ) )
48 #undef CONSOLE_SYSLOGS
49 #define CONSOLE_SYSLOGS ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )
50 #endif
51
52 struct console_driver syslogs_console __console_driver;
53
54 /** The encrypted syslog server */
55 static struct sockaddr_tcpip logserver = {
56 .st_port = htons ( SYSLOG_PORT ),
57 };
58
59 /**
60 * Handle encrypted syslog TLS interface close
61 *
62 * @v intf Interface
63 * @v rc Reason for close
64 */
65 static void syslogs_close ( struct interface *intf __unused, int rc ) {
66
67 DBG ( "SYSLOGS console disconnected: %s\n", strerror ( rc ) );
68 }
69
70 /**
71 * Handle encrypted syslog TLS interface window change
72 *
73 * @v intf Interface
74 */
75 static void syslogs_window_changed ( struct interface *intf ) {
76
77 /* Mark console as enabled when window first opens, indicating
78 * that TLS negotiation is complete. (Do not disable console
79 * when window closes again, since TCP will close the window
80 * whenever there is unACKed data.)
81 */
82 if ( xfer_window ( intf ) ) {
83 if ( syslogs_console.disabled )
84 DBG ( "SYSLOGS console connected\n" );
85 syslogs_console.disabled = 0;
86 }
87 }
88
89 /** Encrypted syslog TLS interface operations */
90 static struct interface_operation syslogs_operations[] = {
91 INTF_OP ( xfer_window_changed, struct interface *,
92 syslogs_window_changed ),
93 INTF_OP ( intf_close, struct interface *, syslogs_close ),
94 };
95
96 /** Encrypted syslog TLS interface descriptor */
97 static struct interface_descriptor syslogs_desc =
98 INTF_DESC_PURE ( syslogs_operations );
99
100 /** The encrypted syslog TLS interface */
101 static struct interface syslogs = INTF_INIT ( syslogs_desc );
102
103 /******************************************************************************
104 *
105 * Console driver
106 *
107 ******************************************************************************
108 */
109
110 /** Encrypted syslog line buffer */
111 static char syslogs_buffer[SYSLOG_BUFSIZE];
112
113 /** Encrypted syslog severity */
114 static unsigned int syslogs_severity = SYSLOG_DEFAULT_SEVERITY;
115
116 /**
117 * Handle ANSI set encrypted syslog priority (private sequence)
118 *
119 * @v ctx ANSI escape sequence context
120 * @v count Parameter count
121 * @v params List of graphic rendition aspects
122 */
123 static void syslogs_handle_priority ( struct ansiesc_context *ctx __unused,
124 unsigned int count __unused,
125 int params[] ) {
126 if ( params[0] >= 0 ) {
127 syslogs_severity = params[0];
128 } else {
129 syslogs_severity = SYSLOG_DEFAULT_SEVERITY;
130 }
131 }
132
133 /** Encrypted syslog ANSI escape sequence handlers */
134 static struct ansiesc_handler syslogs_handlers[] = {
135 { ANSIESC_LOG_PRIORITY, syslogs_handle_priority },
136 { 0, NULL }
137 };
138
139 /** Encrypted syslog line console */
140 static struct line_console syslogs_line = {
141 .buffer = syslogs_buffer,
142 .len = sizeof ( syslogs_buffer ),
143 .ctx = {
144 .handlers = syslogs_handlers,
145 },
146 };
147
148 /** Encrypted syslog recursion marker */
149 static int syslogs_entered;
150
151 /**
152 * Print a character to encrypted syslog console
153 *
154 * @v character Character to be printed
155 */
156 static void syslogs_putchar ( int character ) {
157 int rc;
158
159 /* Ignore if we are already mid-logging */
160 if ( syslogs_entered )
161 return;
162
163 /* Fill line buffer */
164 if ( line_putchar ( &syslogs_line, character ) == 0 )
165 return;
166
167 /* Guard against re-entry */
168 syslogs_entered = 1;
169
170 /* Send log message */
171 if ( ( rc = syslog_send ( &syslogs, syslogs_severity,
172 syslogs_buffer, "\n" ) ) != 0 ) {
173 DBG ( "SYSLOGS could not send log message: %s\n",
174 strerror ( rc ) );
175 }
176
177 /* Clear re-entry flag */
178 syslogs_entered = 0;
179 }
180
181 /** Encrypted syslog console driver */
182 struct console_driver syslogs_console __console_driver = {
183 .putchar = syslogs_putchar,
184 .disabled = CONSOLE_DISABLED,
185 .usage = CONSOLE_SYSLOGS,
186 };
187
188 /******************************************************************************
189 *
190 * Settings
191 *
192 ******************************************************************************
193 */
194
195 /** Encrypted syslog server setting */
196 const struct setting syslogs_setting __setting ( SETTING_MISC, syslogs ) = {
197 .name = "syslogs",
198 .description = "Encrypted syslog server",
199 .tag = DHCP_EB_SYSLOGS_SERVER,
200 .type = &setting_type_string,
201 };
202
203 /**
204 * Apply encrypted syslog settings
205 *
206 * @ret rc Return status code
207 */
208 static int apply_syslogs_settings ( void ) {
209 static char *old_server;
210 char *server;
211 struct interface *socket;
212 int rc;
213
214 /* Fetch log server */
215 fetch_string_setting_copy ( NULL, &syslogs_setting, &server );
216
217 /* Do nothing unless log server has changed */
218 if ( ( ( server == NULL ) && ( old_server == NULL ) ) ||
219 ( ( server != NULL ) && ( old_server != NULL ) &&
220 ( strcmp ( server, old_server ) == 0 ) ) ) {
221 rc = 0;
222 goto out_no_change;
223 }
224 free ( old_server );
225 old_server = NULL;
226
227 /* Reset encrypted syslog connection */
228 syslogs_console.disabled = CONSOLE_DISABLED;
229 intf_restart ( &syslogs, 0 );
230
231 /* Do nothing unless we have a log server */
232 if ( ! server ) {
233 DBG ( "SYSLOGS has no log server\n" );
234 rc = 0;
235 goto out_no_server;
236 }
237
238 /* Add TLS filter */
239 if ( ( rc = add_tls ( &syslogs, server, &socket ) ) != 0 ) {
240 DBG ( "SYSLOGS cannot create TLS filter: %s\n",
241 strerror ( rc ) );
242 goto err_add_tls;
243 }
244
245 /* Connect to log server */
246 if ( ( rc = xfer_open_named_socket ( socket, SOCK_STREAM,
247 (( struct sockaddr *) &logserver ),
248 server, NULL ) ) != 0 ) {
249 DBG ( "SYSLOGS cannot connect to log server: %s\n",
250 strerror ( rc ) );
251 goto err_open_named_socket;
252 }
253 DBG ( "SYSLOGS using log server %s\n", server );
254
255 /* Record log server */
256 old_server = server;
257 server = NULL;
258
259 /* Success */
260 rc = 0;
261
262 err_open_named_socket:
263 err_add_tls:
264 out_no_server:
265 out_no_change:
266 free ( server );
267 return rc;
268 }
269
270 /** Encrypted syslog settings applicator */
271 struct settings_applicator syslogs_applicator __settings_applicator = {
272 .apply = apply_syslogs_settings,
273 };