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 */
syslogs_close(struct interface * intf,int rc)65 static void syslogs_close ( struct interface *intf, int rc ) {
66
67 DBG ( "SYSLOGS console disconnected: %s\n", strerror ( rc ) );
68 intf_restart ( intf, rc );
69 }
70
71 /**
72 * Handle encrypted syslog TLS interface window change
73 *
74 * @v intf Interface
75 */
syslogs_window_changed(struct interface * intf)76 static void syslogs_window_changed ( struct interface *intf ) {
77
78 /* Mark console as enabled when window first opens, indicating
79 * that TLS negotiation is complete. (Do not disable console
80 * when window closes again, since TCP will close the window
81 * whenever there is unACKed data.)
82 */
83 if ( xfer_window ( intf ) ) {
84 if ( syslogs_console.disabled )
85 DBG ( "SYSLOGS console connected\n" );
86 syslogs_console.disabled = 0;
87 }
88 }
89
90 /** Encrypted syslog TLS interface operations */
91 static struct interface_operation syslogs_operations[] = {
92 INTF_OP ( xfer_window_changed, struct interface *,
93 syslogs_window_changed ),
94 INTF_OP ( intf_close, struct interface *, syslogs_close ),
95 };
96
97 /** Encrypted syslog TLS interface descriptor */
98 static struct interface_descriptor syslogs_desc =
99 INTF_DESC_PURE ( syslogs_operations );
100
101 /** The encrypted syslog TLS interface */
102 static struct interface syslogs = INTF_INIT ( syslogs_desc );
103
104 /******************************************************************************
105 *
106 * Console driver
107 *
108 ******************************************************************************
109 */
110
111 /** Encrypted syslog line buffer */
112 static char syslogs_buffer[SYSLOG_BUFSIZE];
113
114 /** Encrypted syslog severity */
115 static unsigned int syslogs_severity = SYSLOG_DEFAULT_SEVERITY;
116
117 /**
118 * Handle ANSI set encrypted syslog priority (private sequence)
119 *
120 * @v ctx ANSI escape sequence context
121 * @v count Parameter count
122 * @v params List of graphic rendition aspects
123 */
syslogs_handle_priority(struct ansiesc_context * ctx __unused,unsigned int count __unused,int params[])124 static void syslogs_handle_priority ( struct ansiesc_context *ctx __unused,
125 unsigned int count __unused,
126 int params[] ) {
127 if ( params[0] >= 0 ) {
128 syslogs_severity = params[0];
129 } else {
130 syslogs_severity = SYSLOG_DEFAULT_SEVERITY;
131 }
132 }
133
134 /** Encrypted syslog ANSI escape sequence handlers */
135 static struct ansiesc_handler syslogs_handlers[] = {
136 { ANSIESC_LOG_PRIORITY, syslogs_handle_priority },
137 { 0, NULL }
138 };
139
140 /** Encrypted syslog line console */
141 static struct line_console syslogs_line = {
142 .buffer = syslogs_buffer,
143 .len = sizeof ( syslogs_buffer ),
144 .ctx = {
145 .handlers = syslogs_handlers,
146 },
147 };
148
149 /** Encrypted syslog recursion marker */
150 static int syslogs_entered;
151
152 /**
153 * Print a character to encrypted syslog console
154 *
155 * @v character Character to be printed
156 */
syslogs_putchar(int character)157 static void syslogs_putchar ( int character ) {
158 int rc;
159
160 /* Ignore if we are already mid-logging */
161 if ( syslogs_entered )
162 return;
163
164 /* Fill line buffer */
165 if ( line_putchar ( &syslogs_line, character ) == 0 )
166 return;
167
168 /* Guard against re-entry */
169 syslogs_entered = 1;
170
171 /* Send log message */
172 if ( ( rc = syslog_send ( &syslogs, syslogs_severity,
173 syslogs_buffer, "\n" ) ) != 0 ) {
174 DBG ( "SYSLOGS could not send log message: %s\n",
175 strerror ( rc ) );
176 }
177
178 /* Clear re-entry flag */
179 syslogs_entered = 0;
180 }
181
182 /** Encrypted syslog console driver */
183 struct console_driver syslogs_console __console_driver = {
184 .putchar = syslogs_putchar,
185 .disabled = CONSOLE_DISABLED,
186 .usage = CONSOLE_SYSLOGS,
187 };
188
189 /******************************************************************************
190 *
191 * Settings
192 *
193 ******************************************************************************
194 */
195
196 /** Encrypted syslog server setting */
197 const struct setting syslogs_setting __setting ( SETTING_MISC, syslogs ) = {
198 .name = "syslogs",
199 .description = "Encrypted syslog server",
200 .tag = DHCP_EB_SYSLOGS_SERVER,
201 .type = &setting_type_string,
202 };
203
204 /**
205 * Apply encrypted syslog settings
206 *
207 * @ret rc Return status code
208 */
apply_syslogs_settings(void)209 static int apply_syslogs_settings ( void ) {
210 static char *old_server;
211 char *server;
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 DBG ( "SYSLOGS using log server %s\n", server );
238
239 /* Connect to log server */
240 if ( ( rc = xfer_open_named_socket ( &syslogs, SOCK_STREAM,
241 (( struct sockaddr *) &logserver ),
242 server, NULL ) ) != 0 ) {
243 DBG ( "SYSLOGS cannot connect to log server: %s\n",
244 strerror ( rc ) );
245 goto err_open_named_socket;
246 }
247
248 /* Add TLS filter */
249 if ( ( rc = add_tls ( &syslogs, server, NULL, NULL ) ) != 0 ) {
250 DBG ( "SYSLOGS cannot create TLS filter: %s\n",
251 strerror ( rc ) );
252 goto err_add_tls;
253 }
254
255 /* Record log server */
256 old_server = server;
257
258 return 0;
259
260 err_add_tls:
261 err_open_named_socket:
262 syslogs_close ( &syslogs, rc );
263 out_no_server:
264 out_no_change:
265 free ( server );
266 return rc;
267 }
268
269 /** Encrypted syslog settings applicator */
270 struct settings_applicator syslogs_applicator __settings_applicator = {
271 .apply = apply_syslogs_settings,
272 };
273