1 /*
2  * Copyright (C) 2011 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  * Syslog protocol
29  *
30  */
31 
32 #include <stdint.h>
33 #include <stdlib.h>
34 #include <ctype.h>
35 #include <byteswap.h>
36 #include <ipxe/xfer.h>
37 #include <ipxe/open.h>
38 #include <ipxe/tcpip.h>
39 #include <ipxe/dhcp.h>
40 #include <ipxe/dhcpv6.h>
41 #include <ipxe/settings.h>
42 #include <ipxe/console.h>
43 #include <ipxe/lineconsole.h>
44 #include <ipxe/syslog.h>
45 #include <config/console.h>
46 
47 /* Set default console usage if applicable */
48 #if ! ( defined ( CONSOLE_SYSLOG ) && CONSOLE_EXPLICIT ( CONSOLE_SYSLOG ) )
49 #undef CONSOLE_SYSLOG
50 #define CONSOLE_SYSLOG ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )
51 #endif
52 
53 /** The syslog server */
54 static union {
55 	struct sockaddr sa;
56 	struct sockaddr_tcpip st;
57 	struct sockaddr_in sin;
58 	struct sockaddr_in6 sin6;
59 } logserver = {
60 	.st = {
61 		.st_port = htons ( SYSLOG_PORT ),
62 	},
63 };
64 
65 /** Syslog UDP interface operations */
66 static struct interface_operation syslogger_operations[] = {};
67 
68 /** Syslog UDP interface descriptor */
69 static struct interface_descriptor syslogger_desc =
70 	INTF_DESC_PURE ( syslogger_operations );
71 
72 /** The syslog UDP interface */
73 static struct interface syslogger = INTF_INIT ( syslogger_desc );
74 
75 /******************************************************************************
76  *
77  * Console driver
78  *
79  ******************************************************************************
80  */
81 
82 /** Host name (for log messages) */
83 static char *syslog_hostname;
84 
85 /** Domain name (for log messages) */
86 static char *syslog_domain;
87 
88 /**
89  * Transmit formatted syslog message
90  *
91  * @v xfer		Data transfer interface
92  * @v severity		Severity
93  * @v message		Message
94  * @v terminator	Message terminator
95  * @ret rc		Return status code
96  */
syslog_send(struct interface * xfer,unsigned int severity,const char * message,const char * terminator)97 int syslog_send ( struct interface *xfer, unsigned int severity,
98 		  const char *message, const char *terminator ) {
99 	const char *hostname = ( syslog_hostname ? syslog_hostname : "" );
100 	const char *domain = ( ( hostname[0] && syslog_domain ) ?
101 			       syslog_domain : "" );
102 
103 	return xfer_printf ( xfer, "<%d>%s%s%s%sipxe: %s%s",
104 			     SYSLOG_PRIORITY ( SYSLOG_DEFAULT_FACILITY,
105 					       severity ), hostname,
106 			     ( domain[0] ? "." : "" ), domain,
107 			     ( hostname[0] ? " " : "" ), message, terminator );
108 }
109 
110 /******************************************************************************
111  *
112  * Console driver
113  *
114  ******************************************************************************
115  */
116 
117 /** Syslog line buffer */
118 static char syslog_buffer[SYSLOG_BUFSIZE];
119 
120 /** Syslog severity */
121 static unsigned int syslog_severity = SYSLOG_DEFAULT_SEVERITY;
122 
123 /**
124  * Handle ANSI set syslog priority (private sequence)
125  *
126  * @v ctx		ANSI escape sequence context
127  * @v count		Parameter count
128  * @v params		List of graphic rendition aspects
129  */
syslog_handle_priority(struct ansiesc_context * ctx __unused,unsigned int count __unused,int params[])130 static void syslog_handle_priority ( struct ansiesc_context *ctx __unused,
131 				     unsigned int count __unused,
132 				     int params[] ) {
133 	if ( params[0] >= 0 ) {
134 		syslog_severity = params[0];
135 	} else {
136 		syslog_severity = SYSLOG_DEFAULT_SEVERITY;
137 	}
138 }
139 
140 /** Syslog ANSI escape sequence handlers */
141 static struct ansiesc_handler syslog_handlers[] = {
142 	{ ANSIESC_LOG_PRIORITY, syslog_handle_priority },
143 	{ 0, NULL }
144 };
145 
146 /** Syslog line console */
147 static struct line_console syslog_line = {
148 	.buffer = syslog_buffer,
149 	.len = sizeof ( syslog_buffer ),
150 	.ctx = {
151 		.handlers = syslog_handlers,
152 	},
153 };
154 
155 /** Syslog recursion marker */
156 static int syslog_entered;
157 
158 /**
159  * Print a character to syslog console
160  *
161  * @v character		Character to be printed
162  */
syslog_putchar(int character)163 static void syslog_putchar ( int character ) {
164 	int rc;
165 
166 	/* Ignore if we are already mid-logging */
167 	if ( syslog_entered )
168 		return;
169 
170 	/* Fill line buffer */
171 	if ( line_putchar ( &syslog_line, character ) == 0 )
172 		return;
173 
174 	/* Guard against re-entry */
175 	syslog_entered = 1;
176 
177 	/* Send log message */
178 	if ( ( rc = syslog_send ( &syslogger, syslog_severity,
179 				  syslog_buffer, "" ) ) != 0 ) {
180 		DBG ( "SYSLOG could not send log message: %s\n",
181 		      strerror ( rc ) );
182 	}
183 
184 	/* Clear re-entry flag */
185 	syslog_entered = 0;
186 }
187 
188 /** Syslog console driver */
189 struct console_driver syslog_console __console_driver = {
190 	.putchar = syslog_putchar,
191 	.disabled = CONSOLE_DISABLED,
192 	.usage = CONSOLE_SYSLOG,
193 };
194 
195 /******************************************************************************
196  *
197  * Settings
198  *
199  ******************************************************************************
200  */
201 
202 /** IPv4 syslog server setting */
203 const struct setting syslog_setting __setting ( SETTING_MISC, syslog ) = {
204 	.name = "syslog",
205 	.description = "Syslog server",
206 	.tag = DHCP_LOG_SERVERS,
207 	.type = &setting_type_ipv4,
208 };
209 
210 /** IPv6 syslog server setting */
211 const struct setting syslog6_setting __setting ( SETTING_MISC, syslog6 ) = {
212 	.name = "syslog6",
213 	.description = "Syslog server",
214 	.tag = DHCPV6_LOG_SERVERS,
215 	.type = &setting_type_ipv6,
216 	.scope = &dhcpv6_scope,
217 };
218 
219 /**
220  * Strip invalid characters from host/domain name
221  *
222  * @v name		Name to strip
223  */
syslog_fix_name(char * name)224 static void syslog_fix_name ( char *name ) {
225 	char *fixed = name;
226 	int c;
227 
228 	/* Do nothing if name does not exist */
229 	if ( ! name )
230 		return;
231 
232 	/* Strip any non-printable or whitespace characters from the name */
233 	do {
234 		c = *(name++);
235 		*fixed = c;
236 		if ( isprint ( c ) && ! isspace ( c ) )
237 			fixed++;
238 	} while ( c );
239 }
240 
241 /**
242  * Apply syslog settings
243  *
244  * @ret rc		Return status code
245  */
apply_syslog_settings(void)246 static int apply_syslog_settings ( void ) {
247 	struct sockaddr old_logserver;
248 	int rc;
249 
250 	/* Fetch hostname and domain name */
251 	free ( syslog_hostname );
252 	fetch_string_setting_copy ( NULL, &hostname_setting, &syslog_hostname );
253 	syslog_fix_name ( syslog_hostname );
254 	free ( syslog_domain );
255 	fetch_string_setting_copy ( NULL, &domain_setting, &syslog_domain );
256 	syslog_fix_name ( syslog_domain );
257 
258 	/* Fetch log server */
259 	syslog_console.disabled = CONSOLE_DISABLED;
260 	memcpy ( &old_logserver, &logserver, sizeof ( old_logserver ) );
261 	logserver.sa.sa_family = 0;
262 	if ( fetch_ipv6_setting ( NULL, &syslog6_setting,
263 				  &logserver.sin6.sin6_addr ) >= 0 ) {
264 		logserver.sin6.sin6_family = AF_INET6;
265 	} else if ( fetch_ipv4_setting ( NULL, &syslog_setting,
266 					 &logserver.sin.sin_addr ) >= 0 ) {
267 		logserver.sin.sin_family = AF_INET;
268 	}
269 	if ( logserver.sa.sa_family ) {
270 		syslog_console.disabled = 0;
271 		DBG ( "SYSLOG using log server %s\n",
272 		      sock_ntoa ( &logserver.sa ) );
273 	}
274 
275 	/* Do nothing unless log server has changed */
276 	if ( memcmp ( &logserver, &old_logserver, sizeof ( logserver ) ) == 0 )
277 		return 0;
278 
279 	/* Reset syslog connection */
280 	intf_restart ( &syslogger, 0 );
281 
282 	/* Do nothing unless we have a log server */
283 	if ( syslog_console.disabled ) {
284 		DBG ( "SYSLOG has no log server\n" );
285 		return 0;
286 	}
287 
288 	/* Connect to log server */
289 	if ( ( rc = xfer_open_socket ( &syslogger, SOCK_DGRAM,
290 				       &logserver.sa, NULL ) ) != 0 ) {
291 		DBG ( "SYSLOG cannot connect to log server: %s\n",
292 		      strerror ( rc ) );
293 		return rc;
294 	}
295 
296 	return 0;
297 }
298 
299 /** Syslog settings applicator */
300 struct settings_applicator syslog_applicator __settings_applicator = {
301 	.apply = apply_syslog_settings,
302 };
303