1/*
2 * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#include <stdarg.h>
30#include <sys/errno.h>
31#include <sys/types.h>
32#include <sys/malloc.h>
33#include <sys/buf.h>
34#include <sys/time.h>
35#include <sys/kauth.h>
36#include <sys/mount.h>
37#include <sys/vnode.h>
38#include <sys/syslog.h>		/* for vaddlog() */
39#include <sys/vnode_internal.h>
40#include <dev/random/randomdev.h>
41
42#include <sys/fslog.h>
43#include <sys/mount_internal.h>
44
45#include <uuid/uuid.h>
46
47/* String to append as format modifier for each key-value pair */
48#define FSLOG_KEYVAL_FMT	"[%s %s] "
49#define FSLOG_KEYVAL_FMT_LEN	(sizeof(FSLOG_KEYVAL_FMT) - 1)
50
51#define FSLOG_NEWLINE_CHAR	"\n"
52#define FSLOG_NEWLINE_CHAR_LEN	(sizeof(FSLOG_NEWLINE_CHAR) - 1)
53
54/* Length of entire ASL message in 10 characters.  Kernel defaults to zero */
55#define FSLOG_ASL_MSG_LEN	"         0"
56
57/* Length of default format string to be used by printf */
58#define MAX_FMT_LEN		256
59
60/* Internal function to print input values as key-value pairs in format
61 * identifiable by Apple system log (ASL) facility.   All key-value pairs
62 * are assumed to be pointer to strings and are provided using two ways -
63 * (a) va_list argument which is a list of varying number of arguments
64 *     created by the caller of this function.
65 * (b) variable number of arguments passed to this function.
66 *
67 * Parameters -
68 * 	level 	  - Priority level for this ASL message
69 *	facility  - Facility for this ASL message.
70 *	num_pairs - Number of key-value pairs provided by vargs argument.
71 *	vargs 	  - List of key-value pairs.
72 *	... 	  - Additional key-value pairs (apart from vargs) as variable
73 *	      	    argument list.  A NULL value indicates the end of the
74 *	      	    variable argument list.
75 *
76 * Returns -
77 *	zero	- On success, when it prints all key-values pairs provided.
78 *	E2BIG	- When it cannot print all key-value pairs provided and had
79 *		  to truncate the output.
80 */
81static int fslog_asl_msg(int level, const char *facility, int num_pairs, va_list vargs, ...)
82{
83	int err = 0;
84	char fmt[MAX_FMT_LEN];	/* Format string to use with vaddlog */
85	int calc_pairs = 0;
86	size_t len;
87	int i;
88	va_list ap;
89	char *ptr;
90
91	/* Mask extra bits, if any, from priority level */
92	level = LOG_PRI(level);
93
94	/* Create the first part of format string consisting of ASL
95	 * message length, level, and facility.
96	 */
97	if (facility) {
98		snprintf(fmt, MAX_FMT_LEN, "%s [%s %d] [%s %d] [%s %s] ",
99			FSLOG_ASL_MSG_LEN,
100			FSLOG_KEY_LEVEL, level,
101			FSLOG_KEY_READ_UID, FSLOG_VAL_READ_UID,
102			FSLOG_KEY_FACILITY, facility);
103	} else {
104		snprintf(fmt, MAX_FMT_LEN, "%s [%s %d] [%s %d] ",
105			FSLOG_ASL_MSG_LEN,
106			FSLOG_KEY_LEVEL, level,
107			FSLOG_KEY_READ_UID, FSLOG_VAL_READ_UID);
108	}
109
110	/* Determine the number of key-value format string [%s %s] that
111	 * should be added in format string for every key-value pair provided
112	 * in va_list.  Calculate maximum number of format string that can be
113	 * accommodated in the remaining format buffer (after saving space
114	 * for newline character).  If the caller provided pairs in va_list
115	 * is more than calculated pairs, truncate extra pairs.
116	 */
117	len = MAX_FMT_LEN - strlen(fmt) - FSLOG_NEWLINE_CHAR_LEN - 1;
118	calc_pairs = len / FSLOG_KEYVAL_FMT_LEN;
119	if (num_pairs <= calc_pairs) {
120		calc_pairs = num_pairs;
121	} else {
122		err = E2BIG;
123	}
124
125	/* Append format strings [%s %s] for the key-value pairs in vargs */
126	len = MAX_FMT_LEN - FSLOG_NEWLINE_CHAR_LEN;
127	for (i = 0; i < calc_pairs; i++) {
128		(void) strlcat(fmt, FSLOG_KEYVAL_FMT, len);
129	}
130
131	/* Count number of variable arguments provided to this function
132	 * and determine total number of key-value pairs.
133	 */
134	calc_pairs = 0;
135	va_start(ap, vargs);
136	ptr = va_arg(ap, char *);
137	while (ptr) {
138		calc_pairs++;
139		ptr = va_arg(ap, char *);
140	}
141	calc_pairs /= 2;
142	va_end(ap);
143
144	/* If user provided variable number of arguments, append them as
145	 * as real key-value "[k v]" into the format string.  If the format
146	 * string is too small, ignore the key-value pair completely.
147	 */
148	if (calc_pairs) {
149		char *key, *val;
150		size_t pairlen;
151		int offset;
152
153		/* Calculate bytes available for key-value pairs after reserving
154		 * bytes for newline character and NULL terminator
155		 */
156		len = MAX_FMT_LEN - strlen(fmt) - FSLOG_NEWLINE_CHAR_LEN - 1;
157		offset = strlen(fmt);
158
159		va_start(ap, vargs);
160		for (i = 0; i < calc_pairs; i++) {
161			key = va_arg(ap, char *);
162			val = va_arg(ap, char *);
163
164			/* Calculate bytes required to store next key-value pair as
165			 * "[key val] " including space for '[', ']', and two spaces.
166			 */
167			pairlen = strlen(key) + strlen(val) + 4;
168			if (pairlen > len) {
169				err = E2BIG;
170				break;
171			}
172
173			/* len + 1 because one byte has been set aside for NULL
174			 * terminator in calculation of 'len' above
175			 */
176			snprintf((fmt + offset), len + 1, FSLOG_KEYVAL_FMT, key, val);
177			offset += pairlen;
178			len -= pairlen;
179		}
180		va_end(ap);
181	}
182
183	/* Append newline */
184	(void) strlcat(fmt, FSLOG_NEWLINE_CHAR, MAX_FMT_LEN);
185
186	/* Print the key-value pairs in ASL format */
187	vaddlog(fmt, vargs);
188
189	return err;
190}
191
192/* Log file system related error in key-value format identified by Apple
193 * system log (ASL) facility.  The key-value pairs are string pointers
194 * (char *) and are provided as variable arguments list.  A NULL value
195 * indicates end of the list.
196 *
197 * Keys can not contain '[', ']', space, and newline.  Values can not
198 * contain '[', ']', and newline.  If any key-value contains any of the
199 * reserved characters, the behavior is undefined.  The caller of the
200 * function should escape any occurrences of '[' and ']' by prefixing
201 * it with '\'.
202 *
203 * The function takes a message ID which can be used to logically group
204 * different ASL messages.  Messages in same logical group have same message
205 * ID and have information to describe order of the message --- first,
206 * middle, or last.
207 *
208 * The following message IDs have special meaning -
209 * FSLOG_MSG_FIRST - This message is the first message in its logical
210 *	group.  This generates a unique message ID, creates two key-value
211 *	pairs with message ID and order of the message as "First".
212 * FSLOG_MSG_LAST - This is really a MASK which should be logically OR'ed
213 *	with message ID to indicate the last message for a logical group.
214 *	This also creates two key-value pairs with message ID and order of
215 *	message as "Last".
216 * FSLOG_MSG_SINGLE - This signifies that the message is the only message
217 * 	in its logical group.  Therefore no extra key-values are generated
218 *	for this option.
219 * For all other values of message IDs, it regards them as intermediate
220 * message and generates two key-value pairs with message ID and order of
221 * message as "Middle".
222 *
223 * Returns -
224 *	Message ID of the ASL message printed.  The caller should use
225 * 	this value to print intermediate messages or end the logical message
226 *	group.
227 *	For FSLOG_MSG_SINGLE option, it returns FSLOG_MSG_SINGLE.
228 */
229unsigned long fslog_err(unsigned long msg_id, ... )
230{
231	va_list ap;
232	int num_pairs;
233	char msg_id_str[21]; /* To convert 64-bit number to string with NULL char */
234	char *arg;
235	const char *msg_order_ptr;
236
237	/* Count number of arguments and key-value pairs provided by user */
238	num_pairs = 0;
239	va_start(ap, msg_id);
240	arg = va_arg(ap, char *);
241	while (arg) {
242		num_pairs++;
243		arg = va_arg(ap, char *);
244	}
245	num_pairs /= 2;
246	va_end(ap);
247
248	va_start(ap, msg_id);
249	if (msg_id == FSLOG_MSG_SINGLE) {
250		/* Single message, do not print message ID and message order */
251		(void) fslog_asl_msg(FSLOG_VAL_LEVEL, FSLOG_VAL_FACILITY,
252				num_pairs, ap, NULL);
253	} else {
254		if (msg_id == FSLOG_MSG_FIRST) {
255			/* First message, generate random message ID */
256			while ((msg_id == FSLOG_MSG_FIRST) ||
257			       (msg_id == FSLOG_MSG_LAST) ||
258			       (msg_id == FSLOG_MSG_SINGLE)) {
259				msg_id = RandomULong();
260				/* MSB is reserved for indicating last message
261				 * in sequence.  Clear the MSB while generating
262				 * new message ID.
263				 */
264				msg_id = msg_id >> 1;
265			}
266			msg_order_ptr = FSLOG_VAL_ORDER_FIRST;
267		} else if (msg_id & FSLOG_MSG_LAST) {
268			/* MSB set to indicate last message for this ID */
269			msg_order_ptr = FSLOG_VAL_ORDER_LAST;
270			/* MSB of message ID is set to indicate last message
271			 * in sequence.  Clear the bit to get real message ID.
272			 */
273			msg_id = msg_id & ~FSLOG_MSG_LAST;
274		} else {
275			/* Intermediate message for this ID */
276			msg_order_ptr = FSLOG_VAL_ORDER_MIDDLE;
277		}
278
279		snprintf(msg_id_str, sizeof(msg_id_str), "%lu", msg_id);
280		(void) fslog_asl_msg(FSLOG_VAL_LEVEL, FSLOG_VAL_FACILITY,
281			 num_pairs, ap,
282			 FSLOG_KEY_MSG_ID, msg_id_str,
283			 FSLOG_KEY_MSG_ORDER, msg_order_ptr, NULL);
284	}
285	va_end(ap);
286	return msg_id;
287}
288
289/* Search if given string contains '[' and ']'.  If any, escape it by
290 * prefixing with a '\'.  If the length of the string is not big enough,
291 * no changes are done and error is returned.
292 *
293 * Parameters -
294 * 	str - string that can contain '[' or ']', should be NULL terminated
295 *	len - length, in bytes, of valid data, including NULL character.
296 *	buflen - size of buffer that contains the string
297 */
298static int escape_str(char *str, int len, int buflen)
299{
300	int count;
301	char *src, *dst;
302
303	/* Count number of characters to escape */
304	src = str;
305	count = 0;
306	do {
307		if ((*src == '[') || (*src == ']')) {
308			count++;
309		}
310	} while (*src++);
311
312	if (count) {
313		/* Check if the buffer has enough space to escape all characters */
314		if ((buflen - len) < count) {
315			return ENOSPC;
316		}
317
318		src = str + len;
319		dst = src + count;
320		while (count) {
321			*dst-- = *src;
322			if ((*src == '[') || (*src == ']')) {
323				/* Last char copied needs to be escaped */
324				*dst-- = '\\';
325				count--;
326			}
327			src--;
328		}
329	}
330
331	return 0;
332}
333
334/* Log information about runtime file system corruption detected by
335 * the file system.  It takes the VFS mount structure as
336 * parameter which is used to access the mount point of the
337 * corrupt volume.  If no mount structure or mount point string
338 * string exists, nothing is logged to ASL database.
339 *
340 * Currently prints following information -
341 * 	1. Mount Point
342 */
343void fslog_fs_corrupt(struct mount *mnt)
344{
345	if (mnt != NULL) {
346		fslog_err(FSLOG_MSG_SINGLE,
347			  FSLOG_KEY_ERR_TYPE, FSLOG_VAL_ERR_TYPE_FS,
348			  FSLOG_KEY_MNTPT, mnt->mnt_vfsstat.f_mntonname,
349			  NULL);
350	}
351
352	return;
353}
354
355/* Log information about IO error detected in buf_biodone()
356 * Currently prints following information -
357 * 	1. Physical block number
358 *	2. Logical block number
359 *	3. Device node
360 *	4. Mount point
361 *	5. Path for file, if any
362 *	6. Error number
363 *	7. Type of IO (read/write)
364 */
365void fslog_io_error(const buf_t bp)
366{
367	int err;
368	unsigned long msg_id;
369	char blknum_str[21];
370	char lblknum_str[21];
371	char errno_str[6];
372	const char *iotype;
373	unsigned char print_last = 0;
374	vnode_t	vp;
375
376	if (buf_error(bp) == 0) {
377		return;
378	}
379
380	/* Convert error number to string */
381	snprintf (errno_str, sizeof(errno_str), "%d", buf_error(bp));
382
383	/* Determine type of IO operation */
384	if (buf_flags(bp) & B_READ) {
385		iotype = FSLOG_VAL_IOTYPE_READ;
386	} else {
387		iotype = FSLOG_VAL_IOTYPE_WRITE;
388	}
389
390	/* Convert physical block number to string */
391	snprintf (blknum_str, sizeof(blknum_str), "%lld", buf_blkno(bp));
392
393	/* Convert logical block number to string */
394	snprintf (lblknum_str, sizeof(lblknum_str), "%lld", buf_lblkno(bp));
395
396	msg_id = fslog_err(FSLOG_MSG_FIRST,
397				FSLOG_KEY_ERR_TYPE, FSLOG_VAL_ERR_TYPE_IO,
398				FSLOG_KEY_ERRNO, errno_str,
399				FSLOG_KEY_IOTYPE, iotype,
400				FSLOG_KEY_PHYS_BLKNUM, blknum_str,
401				FSLOG_KEY_LOG_BLKNUM, lblknum_str,
402				NULL);
403
404	/* Access the vnode for this buffer */
405	vp = buf_vnode(bp);
406	if (vp) {
407		struct vfsstatfs *sp;
408		mount_t	mp;
409		char *path;
410		int len;
411		struct vfs_context context;
412
413		mp = vnode_mount(vp);
414		/* mp should be NULL only for bdevvp during boot */
415		if (mp == NULL) {
416			goto out;
417		}
418		sp = vfs_statfs(mp);
419
420		/* Access the file path */
421		MALLOC(path, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
422		if (path) {
423			len = MAXPATHLEN;
424			context.vc_thread = current_thread();
425			context.vc_ucred = kauth_cred_get();
426			/* Find path without entering file system */
427			err = build_path(vp, path, len, &len, BUILDPATH_NO_FS_ENTER,
428					 &context);
429			if (!err) {
430				err = escape_str(path, len, MAXPATHLEN);
431				if (!err) {
432					/* Print device node, mount point, path */
433					msg_id = fslog_err(msg_id | FSLOG_MSG_LAST,
434						FSLOG_KEY_DEVNODE, sp->f_mntfromname,
435						FSLOG_KEY_MNTPT, sp->f_mntonname,
436						FSLOG_KEY_PATH, path,
437						NULL);
438					print_last = 1;
439				}
440			}
441			FREE(path, M_TEMP);
442		}
443
444		if (print_last == 0) {
445			/* Print device node and mount point */
446			msg_id = fslog_err(msg_id | FSLOG_MSG_LAST,
447					FSLOG_KEY_DEVNODE, sp->f_mntfromname,
448					FSLOG_KEY_MNTPT, sp->f_mntonname,
449					NULL);
450			print_last = 1;
451		}
452	}
453
454out:
455	if (print_last == 0) {
456		msg_id = fslog_err(msg_id | FSLOG_MSG_LAST, NULL);
457	}
458
459	return;
460}
461
462static void
463_fslog_extmod_msgtracer_internal(int level, const char *facility, int num_pairs, ...)
464{
465	va_list ap;
466
467	va_start(ap, num_pairs);
468	(void) fslog_asl_msg(level, facility,
469				num_pairs, ap, NULL);
470	va_end(ap);
471}
472
473/* Log information about external modification of a process,
474 * using MessageTracer formatting. Assumes that both the caller
475 * and target are appropriately locked.
476 * Currently prints following information -
477 * 	1. Caller process name (truncated to 16 characters)
478 *	2. Caller process Mach-O UUID
479 *  3. Target process name (truncated to 16 characters)
480 *  4. Target process Mach-O UUID
481 */
482void
483fslog_extmod_msgtracer(proc_t caller, proc_t target)
484{
485	if ((caller != PROC_NULL) && (target != PROC_NULL)) {
486
487		/*
488		 * Print into buffer large enough for "ThisIsAnApplicat(BC223DD7-B314-42E0-B6B0-C5D2E6638337)",
489		 * including space for escaping, and NUL byte included in sizeof(uuid_string_t).
490		 */
491
492		uuid_string_t uuidstr;
493		char c_name[2*MAXCOMLEN + 2 /* () */ + sizeof(uuid_string_t)];
494		char t_name[2*MAXCOMLEN + 2 /* () */ + sizeof(uuid_string_t)];
495
496		strlcpy(c_name, caller->p_comm, sizeof(c_name));
497		uuid_unparse_upper(caller->p_uuid, uuidstr);
498		strlcat(c_name, "(", sizeof(c_name));
499		strlcat(c_name, uuidstr, sizeof(c_name));
500		strlcat(c_name, ")", sizeof(c_name));
501		if (0 != escape_str(c_name, strlen(c_name), sizeof(c_name))) {
502			return;
503		}
504
505		strlcpy(t_name, target->p_comm, sizeof(t_name));
506		uuid_unparse_upper(target->p_uuid, uuidstr);
507		strlcat(t_name, "(", sizeof(t_name));
508		strlcat(t_name, uuidstr, sizeof(t_name));
509		strlcat(t_name, ")", sizeof(t_name));
510		if (0 != escape_str(t_name, strlen(t_name), sizeof(t_name))) {
511			return;
512		}
513
514#if DEBUG
515		printf("EXTMOD: %s(%d) -> %s(%d)\n",
516			   c_name,
517			   proc_pid(caller),
518			   t_name,
519			   proc_pid(target));
520#endif
521
522		_fslog_extmod_msgtracer_internal(LOG_DEBUG, "messagetracer",
523							4,
524							"com.apple.message.domain", "com.apple.kernel.external_modification", /* 0 */
525							"com.apple.message.signature", c_name, /* 1 */
526							"com.apple.message.signature2", t_name, /* 2 */
527							"com.apple.message.result", "noop", /* 3 */
528							NULL);
529	}
530}
531