[deliverable/linux.git] / security / tomoyo / audit.c

/*
 * security/tomoyo/audit.c
 *
 * Pathname restriction functions.
 *
 * Copyright (C) 2005-2010  NTT DATA CORPORATION
 */

#include "common.h"
#include <linux/slab.h>

/**
 * tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
 *
 * @bprm: Pointer to "struct linux_binprm".
 * @dump: Pointer to "struct tomoyo_page_dump".
 *
 * Returns the contents of @bprm on success, NULL otherwise.
 *
 * This function uses kzalloc(), so caller must kfree() if this function
 * didn't return NULL.
 */
static char *tomoyo_print_bprm(struct linux_binprm *bprm,
			       struct tomoyo_page_dump *dump)
{
	static const int tomoyo_buffer_len = 4096 * 2;
	char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
	char *cp;
	char *last_start;
	int len;
	unsigned long pos = bprm->p;
	int offset = pos % PAGE_SIZE;
	int argv_count = bprm->argc;
	int envp_count = bprm->envc;
	bool truncated = false;
	if (!buffer)
		return NULL;
	len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
	cp = buffer + len;
	if (!argv_count) {
		memmove(cp, "} envp[]={ ", 11);
		cp += 11;
	}
	last_start = cp;
	while (argv_count || envp_count) {
		if (!tomoyo_dump_page(bprm, pos, dump))
			goto out;
		pos += PAGE_SIZE - offset;
		/* Read. */
		while (offset < PAGE_SIZE) {
			const char *kaddr = dump->data;
			const unsigned char c = kaddr[offset++];
			if (cp == last_start)
				*cp++ = '"';
			if (cp >= buffer + tomoyo_buffer_len - 32) {
				/* Reserve some room for "..." string. */
				truncated = true;
			} else if (c == '\\') {
				*cp++ = '\\';
				*cp++ = '\\';
			} else if (c > ' ' && c < 127) {
				*cp++ = c;
			} else if (!c) {
				*cp++ = '"';
				*cp++ = ' ';
				last_start = cp;
			} else {
				*cp++ = '\\';
				*cp++ = (c >> 6) + '0';
				*cp++ = ((c >> 3) & 7) + '0';
				*cp++ = (c & 7) + '0';
			}
			if (c)
				continue;
			if (argv_count) {
				if (--argv_count == 0) {
					if (truncated) {
						cp = last_start;
						memmove(cp, "... ", 4);
						cp += 4;
					}
					memmove(cp, "} envp[]={ ", 11);
					cp += 11;
					last_start = cp;
					truncated = false;
				}
			} else if (envp_count) {
				if (--envp_count == 0) {
					if (truncated) {
						cp = last_start;
						memmove(cp, "... ", 4);
						cp += 4;
					}
				}
			}
			if (!argv_count && !envp_count)
				break;
		}
		offset = 0;
	}
	*cp++ = '}';
	*cp = '\0';
	return buffer;
out:
	snprintf(buffer, tomoyo_buffer_len - 1,
		 "argv[]={ ... } envp[]= { ... }");
	return buffer;
}

/**
 * tomoyo_filetype - Get string representation of file type.
 *
 * @mode: Mode value for stat().
 *
 * Returns file type string.
 */
static inline const char *tomoyo_filetype(const mode_t mode)
{
	switch (mode & S_IFMT) {
	case S_IFREG:
	case 0:
		return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE];
	case S_IFDIR:
		return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY];
	case S_IFLNK:
		return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK];
	case S_IFIFO:
		return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO];
	case S_IFSOCK:
		return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET];
	case S_IFBLK:
		return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV];
	case S_IFCHR:
		return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV];
	}
	return "unknown"; /* This should not happen. */
}

/**
 * tomoyo_print_header - Get header line of audit log.
 *
 * @r: Pointer to "struct tomoyo_request_info".
 *
 * Returns string representation.
 *
 * This function uses kmalloc(), so caller must kfree() if this function
 * didn't return NULL.
 */
static char *tomoyo_print_header(struct tomoyo_request_info *r)
{
	struct tomoyo_time stamp;
	const pid_t gpid = task_pid_nr(current);
	struct tomoyo_obj_info *obj = r->obj;
	static const int tomoyo_buffer_len = 4096;
	char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
	int pos;
	u8 i;
	if (!buffer)
		return NULL;
	{
		struct timeval tv;
		do_gettimeofday(&tv);
		tomoyo_convert_time(tv.tv_sec, &stamp);
	}
	pos = snprintf(buffer, tomoyo_buffer_len - 1,
		       "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
		       "granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
		       "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
		       "fsuid=%u fsgid=%u }", stamp.year, stamp.month,
		       stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile,
		       tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid,
		       tomoyo_sys_getpid(), tomoyo_sys_getppid(),
		       current_uid(), current_gid(), current_euid(),
		       current_egid(), current_suid(), current_sgid(),
		       current_fsuid(), current_fsgid());
	if (!obj)
		goto no_obj_info;
	if (!obj->validate_done) {
		tomoyo_get_attributes(obj);
		obj->validate_done = true;
	}
	for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
		struct tomoyo_mini_stat *stat;
		unsigned int dev;
		mode_t mode;
		if (!obj->stat_valid[i])
			continue;
		stat = &obj->stat[i];
		dev = stat->dev;
		mode = stat->mode;
		if (i & 1) {
			pos += snprintf(buffer + pos,
					tomoyo_buffer_len - 1 - pos,
					" path%u.parent={ uid=%u gid=%u "
					"ino=%lu perm=0%o }", (i >> 1) + 1,
					stat->uid, stat->gid, (unsigned long)
					stat->ino, stat->mode & S_IALLUGO);
			continue;
		}
		pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
				" path%u={ uid=%u gid=%u ino=%lu major=%u"
				" minor=%u perm=0%o type=%s", (i >> 1) + 1,
				stat->uid, stat->gid, (unsigned long)
				stat->ino, MAJOR(dev), MINOR(dev),
				mode & S_IALLUGO, tomoyo_filetype(mode));
		if (S_ISCHR(mode) || S_ISBLK(mode)) {
			dev = stat->rdev;
			pos += snprintf(buffer + pos,
					tomoyo_buffer_len - 1 - pos,
					" dev_major=%u dev_minor=%u",
					MAJOR(dev), MINOR(dev));
		}
		pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
				" }");
	}
no_obj_info:
	if (pos < tomoyo_buffer_len - 1)
		return buffer;
	kfree(buffer);
	return NULL;
}

/**
 * tomoyo_init_log - Allocate buffer for audit logs.
 *
 * @r:    Pointer to "struct tomoyo_request_info".
 * @len:  Buffer size needed for @fmt and @args.
 * @fmt:  The printf()'s format string.
 * @args: va_list structure for @fmt.
 *
 * Returns pointer to allocated memory.
 *
 * This function uses kzalloc(), so caller must kfree() if this function
 * didn't return NULL.
 */
char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
		      va_list args)
{
	char *buf = NULL;
	char *bprm_info = NULL;
	const char *header = NULL;
	char *realpath = NULL;
	const char *symlink = NULL;
	int pos;
	const char *domainname = r->domain->domainname->name;
	header = tomoyo_print_header(r);
	if (!header)
		return NULL;
	/* +10 is for '\n' etc. and '\0'. */
	len += strlen(domainname) + strlen(header) + 10;
	if (r->ee) {
		struct file *file = r->ee->bprm->file;
		realpath = tomoyo_realpath_from_path(&file->f_path);
		bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
		if (!realpath || !bprm_info)
			goto out;
		/* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
		len += strlen(realpath) + 80 + strlen(bprm_info);
	} else if (r->obj && r->obj->symlink_target) {
		symlink = r->obj->symlink_target->name;
		/* +18 is for " symlink.target=\"%s\"" */
		len += 18 + strlen(symlink);
	}
	len = tomoyo_round2(len);
	buf = kzalloc(len, GFP_NOFS);
	if (!buf)
		goto out;
	len--;
	pos = snprintf(buf, len, "%s", header);
	if (realpath) {
		struct linux_binprm *bprm = r->ee->bprm;
		pos += snprintf(buf + pos, len - pos,
				" exec={ realpath=\"%s\" argc=%d envc=%d %s }",
				realpath, bprm->argc, bprm->envc, bprm_info);
	} else if (symlink)
		pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
				symlink);
	pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
	vsnprintf(buf + pos, len - pos, fmt, args);
out:
	kfree(realpath);
	kfree(bprm_info);
	kfree(header);
	return buf;
}

/* Wait queue for /sys/kernel/security/tomoyo/audit. */
static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);

/* Structure for audit log. */
struct tomoyo_log {
	struct list_head list;
	char *log;
	int size;
};

/* The list for "struct tomoyo_log". */
static LIST_HEAD(tomoyo_log);

/* Lock for "struct list_head tomoyo_log". */
static DEFINE_SPINLOCK(tomoyo_log_lock);

/* Length of "stuct list_head tomoyo_log". */
static unsigned int tomoyo_log_count;

/**
 * tomoyo_get_audit - Get audit mode.
 *
 * @ns:          Pointer to "struct tomoyo_policy_namespace".
 * @profile:     Profile number.
 * @index:       Index number of functionality.
 * @is_granted:  True if granted log, false otherwise.
 *
 * Returns true if this request should be audited, false otherwise.
 */
static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
			     const u8 profile, const u8 index,
			     const bool is_granted)
{
	u8 mode;
	const u8 category = tomoyo_index2category[index] +
		TOMOYO_MAX_MAC_INDEX;
	struct tomoyo_profile *p;
	if (!tomoyo_policy_loaded)
		return false;
	p = tomoyo_profile(ns, profile);
	if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
		return false;
	mode = p->config[index];
	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
		mode = p->config[category];
	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
		mode = p->default_config;
	if (is_granted)
		return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
	return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
}

/**
 * tomoyo_write_log2 - Write an audit log.
 *
 * @r:    Pointer to "struct tomoyo_request_info".
 * @len:  Buffer size needed for @fmt and @args.
 * @fmt:  The printf()'s format string.
 * @args: va_list structure for @fmt.
 *
 * Returns nothing.
 */
void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
		       va_list args)
{
	char *buf;
	struct tomoyo_log *entry;
	bool quota_exceeded = false;
	if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, r->granted))
		goto out;
	buf = tomoyo_init_log(r, len, fmt, args);
	if (!buf)
		goto out;
	entry = kzalloc(sizeof(*entry), GFP_NOFS);
	if (!entry) {
		kfree(buf);
		goto out;
	}
	entry->log = buf;
	len = tomoyo_round2(strlen(buf) + 1);
	/*
	 * The entry->size is used for memory quota checks.
	 * Don't go beyond strlen(entry->log).
	 */
	entry->size = len + tomoyo_round2(sizeof(*entry));
	spin_lock(&tomoyo_log_lock);
	if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
	    tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
	    tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
		quota_exceeded = true;
	} else {
		tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
		list_add_tail(&entry->list, &tomoyo_log);
		tomoyo_log_count++;
	}
	spin_unlock(&tomoyo_log_lock);
	if (quota_exceeded) {
		kfree(buf);
		kfree(entry);
		goto out;
	}
	wake_up(&tomoyo_log_wait);
out:
	return;
}

/**
 * tomoyo_write_log - Write an audit log.
 *
 * @r:   Pointer to "struct tomoyo_request_info".
 * @fmt: The printf()'s format string, followed by parameters.
 *
 * Returns nothing.
 */
void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
{
	va_list args;
	int len;
	va_start(args, fmt);
	len = vsnprintf((char *) &len, 1, fmt, args) + 1;
	va_end(args);
	va_start(args, fmt);
	tomoyo_write_log2(r, len, fmt, args);
	va_end(args);
}

/**
 * tomoyo_read_log - Read an audit log.
 *
 * @head: Pointer to "struct tomoyo_io_buffer".
 *
 * Returns nothing.
 */
void tomoyo_read_log(struct tomoyo_io_buffer *head)
{
	struct tomoyo_log *ptr = NULL;
	if (head->r.w_pos)
		return;
	kfree(head->read_buf);
	head->read_buf = NULL;
	spin_lock(&tomoyo_log_lock);
	if (!list_empty(&tomoyo_log)) {
		ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
		list_del(&ptr->list);
		tomoyo_log_count--;
		tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
	}
	spin_unlock(&tomoyo_log_lock);
	if (ptr) {
		head->read_buf = ptr->log;
		head->r.w[head->r.w_pos++] = head->read_buf;
		kfree(ptr);
	}
}

/**
 * tomoyo_poll_log - Wait for an audit log.
 *
 * @file: Pointer to "struct file".
 * @wait: Pointer to "poll_table".
 *
 * Returns POLLIN | POLLRDNORM when ready to read an audit log.
 */
int tomoyo_poll_log(struct file *file, poll_table *wait)
{
	if (tomoyo_log_count)
		return POLLIN | POLLRDNORM;
	poll_wait(file, &tomoyo_log_wait, wait);
	if (tomoyo_log_count)
		return POLLIN | POLLRDNORM;
	return 0;
}
Commit	Line	Data
eadd99cc TH	1	/*
	2	* security/tomoyo/audit.c
	3	*
	4	* Pathname restriction functions.
	5	*
	6	* Copyright (C) 2005-2010 NTT DATA CORPORATION
	7	*/
	8
	9	#include "common.h"
	10	#include <linux/slab.h>
	11
5b636857 TH	12	/**
	13	* tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
	14	*
	15	* @bprm: Pointer to "struct linux_binprm".
	16	* @dump: Pointer to "struct tomoyo_page_dump".
	17	*
	18	* Returns the contents of @bprm on success, NULL otherwise.
	19	*
	20	* This function uses kzalloc(), so caller must kfree() if this function
	21	* didn't return NULL.
	22	*/
	23	static char tomoyo_print_bprm(struct linux_binprm bprm,
	24	struct tomoyo_page_dump *dump)
	25	{
	26	static const int tomoyo_buffer_len = 4096 * 2;
	27	char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
	28	char *cp;
	29	char *last_start;
	30	int len;
	31	unsigned long pos = bprm->p;
	32	int offset = pos % PAGE_SIZE;
	33	int argv_count = bprm->argc;
	34	int envp_count = bprm->envc;
	35	bool truncated = false;
	36	if (!buffer)
	37	return NULL;
	38	len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
	39	cp = buffer + len;
	40	if (!argv_count) {
	41	memmove(cp, "} envp[]={ ", 11);
	42	cp += 11;
	43	}
	44	last_start = cp;
	45	while (argv_count \|\| envp_count) {
	46	if (!tomoyo_dump_page(bprm, pos, dump))
	47	goto out;
	48	pos += PAGE_SIZE - offset;
	49	/* Read. */
	50	while (offset < PAGE_SIZE) {
	51	const char *kaddr = dump->data;
	52	const unsigned char c = kaddr[offset++];
	53	if (cp == last_start)
	54	*cp++ = '"';
	55	if (cp >= buffer + tomoyo_buffer_len - 32) {
	56	/* Reserve some room for "..." string. */
	57	truncated = true;
	58	} else if (c == '\\') {
	59	*cp++ = '\\';
	60	*cp++ = '\\';
	61	} else if (c > ' ' && c < 127) {
	62	*cp++ = c;
	63	} else if (!c) {
	64	*cp++ = '"';
	65	*cp++ = ' ';
	66	last_start = cp;
	67	} else {
	68	*cp++ = '\\';
	69	*cp++ = (c >> 6) + '0';
	70	*cp++ = ((c >> 3) & 7) + '0';
	71	*cp++ = (c & 7) + '0';
	72	}
	73	if (c)
	74	continue;
	75	if (argv_count) {
76	if (--argv_count == 0) {
77	if (truncated) {
78	cp = last_start;
79	memmove(cp, "... ", 4);
80	cp += 4;
81	}
82	memmove(cp, "} envp[]={ ", 11);
83	cp += 11;
84	last_start = cp;
85	truncated = false;
86	}
87	} else if (envp_count) {
88	if (--envp_count == 0) {
89	if (truncated) {
90	cp = last_start;
91	memmove(cp, "... ", 4);
92	cp += 4;
93	}
94	}
95	}
96	if (!argv_count && !envp_count)
97	break;
98	}
99	offset = 0;
100	}
101	*cp++ = '}';
102	*cp = '\0';
103	return buffer;
104	out:
105	snprintf(buffer, tomoyo_buffer_len - 1,
106	"argv[]={ ... } envp[]= { ... }");
107	return buffer;
108	}
109
8761afd4 TH	110	/**
	111	* tomoyo_filetype - Get string representation of file type.
	112	*
	113	* @mode: Mode value for stat().
	114	*
	115	* Returns file type string.
	116	*/
	117	static inline const char *tomoyo_filetype(const mode_t mode)
	118	{
	119	switch (mode & S_IFMT) {
	120	case S_IFREG:
	121	case 0:
	122	return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE];
	123	case S_IFDIR:
	124	return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY];
	125	case S_IFLNK:
	126	return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK];
	127	case S_IFIFO:
	128	return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO];
	129	case S_IFSOCK:
	130	return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET];
	131	case S_IFBLK:
	132	return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV];
	133	case S_IFCHR:
	134	return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV];
	135	}
	136	return "unknown"; /* This should not happen. */
	137	}
	138
eadd99cc TH	139	/**
	140	* tomoyo_print_header - Get header line of audit log.
	141	*
	142	* @r: Pointer to "struct tomoyo_request_info".
	143	*
	144	* Returns string representation.
	145	*
	146	* This function uses kmalloc(), so caller must kfree() if this function
	147	* didn't return NULL.
	148	*/
	149	static char tomoyo_print_header(struct tomoyo_request_info r)
	150	{
	151	struct tomoyo_time stamp;
	152	const pid_t gpid = task_pid_nr(current);
8761afd4	153	struct tomoyo_obj_info *obj = r->obj;
eadd99cc TH	154	static const int tomoyo_buffer_len = 4096;
eadd99cc TH	155	char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
2066a361	156	int pos;
8761afd4	157	u8 i;
eadd99cc TH	158	if (!buffer)
	159	return NULL;
	160	{
	161	struct timeval tv;
	162	do_gettimeofday(&tv);
	163	tomoyo_convert_time(tv.tv_sec, &stamp);
	164	}
2066a361 TH	165	pos = snprintf(buffer, tomoyo_buffer_len - 1,
	166	"#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
	167	"granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
	168	"uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
	169	"fsuid=%u fsgid=%u }", stamp.year, stamp.month,
	170	stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile,
	171	tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid,
	172	tomoyo_sys_getpid(), tomoyo_sys_getppid(),
	173	current_uid(), current_gid(), current_euid(),
	174	current_egid(), current_suid(), current_sgid(),
	175	current_fsuid(), current_fsgid());
8761afd4 TH	176	if (!obj)
	177	goto no_obj_info;
	178	if (!obj->validate_done) {
	179	tomoyo_get_attributes(obj);
	180	obj->validate_done = true;
	181	}
	182	for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
	183	struct tomoyo_mini_stat *stat;
	184	unsigned int dev;
	185	mode_t mode;
	186	if (!obj->stat_valid[i])
	187	continue;
	188	stat = &obj->stat[i];
	189	dev = stat->dev;
	190	mode = stat->mode;
	191	if (i & 1) {
	192	pos += snprintf(buffer + pos,
	193	tomoyo_buffer_len - 1 - pos,
	194	" path%u.parent={ uid=%u gid=%u "
	195	"ino=%lu perm=0%o }", (i >> 1) + 1,
	196	stat->uid, stat->gid, (unsigned long)
	197	stat->ino, stat->mode & S_IALLUGO);
	198	continue;
	199	}
	200	pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
	201	" path%u={ uid=%u gid=%u ino=%lu major=%u"
	202	" minor=%u perm=0%o type=%s", (i >> 1) + 1,
	203	stat->uid, stat->gid, (unsigned long)
	204	stat->ino, MAJOR(dev), MINOR(dev),
	205	mode & S_IALLUGO, tomoyo_filetype(mode));
	206	if (S_ISCHR(mode) \|\| S_ISBLK(mode)) {
	207	dev = stat->rdev;
	208	pos += snprintf(buffer + pos,
	209	tomoyo_buffer_len - 1 - pos,
	210	" dev_major=%u dev_minor=%u",
	211	MAJOR(dev), MINOR(dev));
	212	}
	213	pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
	214	" }");
	215	}
	216	no_obj_info:
2066a361 TH	217	if (pos < tomoyo_buffer_len - 1)
	218	return buffer;
	219	kfree(buffer);
	220	return NULL;
eadd99cc TH	221	}
	222
	223	/**
	224	* tomoyo_init_log - Allocate buffer for audit logs.
	225	*
	226	* @r: Pointer to "struct tomoyo_request_info".
	227	* @len: Buffer size needed for @fmt and @args.
	228	* @fmt: The printf()'s format string.
	229	* @args: va_list structure for @fmt.
	230	*
	231	* Returns pointer to allocated memory.
	232	*
	233	* This function uses kzalloc(), so caller must kfree() if this function
	234	* didn't return NULL.
	235	*/
	236	char tomoyo_init_log(struct tomoyo_request_info r, int len, const char *fmt,
	237	va_list args)
	238	{
	239	char *buf = NULL;
5b636857	240	char *bprm_info = NULL;
eadd99cc	241	const char *header = NULL;
2ca9bf45 TH	242	char *realpath = NULL;
2ca9bf45 TH	243	const char *symlink = NULL;
eadd99cc	244	int pos;
ea504819	245	const char *domainname = r->domain->domainname->name;
eadd99cc TH	246	header = tomoyo_print_header(r);
	247	if (!header)
	248	return NULL;
	249	/* +10 is for '\n' etc. and '\0'. */
	250	len += strlen(domainname) + strlen(header) + 10;
2ca9bf45 TH	251	if (r->ee) {
	252	struct file *file = r->ee->bprm->file;
	253	realpath = tomoyo_realpath_from_path(&file->f_path);
5b636857 TH	254	bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
5b636857 TH	255	if (!realpath \|\| !bprm_info)
2ca9bf45	256	goto out;
5b636857 TH	257	/* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
5b636857 TH	258	len += strlen(realpath) + 80 + strlen(bprm_info);
2ca9bf45 TH	259	} else if (r->obj && r->obj->symlink_target) {
	260	symlink = r->obj->symlink_target->name;
	261	/* +18 is for " symlink.target=\"%s\"" */
	262	len += 18 + strlen(symlink);
	263	}
eadd99cc TH	264	len = tomoyo_round2(len);
	265	buf = kzalloc(len, GFP_NOFS);
	266	if (!buf)
	267	goto out;
	268	len--;
	269	pos = snprintf(buf, len, "%s", header);
2ca9bf45	270	if (realpath) {
5b636857	271	struct linux_binprm *bprm = r->ee->bprm;
2ca9bf45	272	pos += snprintf(buf + pos, len - pos,
5b636857 TH	273	" exec={ realpath=\"%s\" argc=%d envc=%d %s }",
5b636857 TH	274	realpath, bprm->argc, bprm->envc, bprm_info);
2ca9bf45 TH	275	} else if (symlink)
	276	pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
	277	symlink);
eadd99cc TH	278	pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
	279	vsnprintf(buf + pos, len - pos, fmt, args);
	280	out:
2ca9bf45	281	kfree(realpath);
5b636857	282	kfree(bprm_info);
eadd99cc TH	283	kfree(header);
	284	return buf;
	285	}
	286
	287	/* Wait queue for /sys/kernel/security/tomoyo/audit. */
	288	static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
	289
	290	/* Structure for audit log. */
	291	struct tomoyo_log {
	292	struct list_head list;
	293	char *log;
	294	int size;
	295	};
	296
	297	/* The list for "struct tomoyo_log". */
	298	static LIST_HEAD(tomoyo_log);
	299
	300	/* Lock for "struct list_head tomoyo_log". */
	301	static DEFINE_SPINLOCK(tomoyo_log_lock);
	302
	303	/* Length of "stuct list_head tomoyo_log". */
	304	static unsigned int tomoyo_log_count;
	305
	306	/**
	307	* tomoyo_get_audit - Get audit mode.
	308	*
bd03a3e4	309	* @ns: Pointer to "struct tomoyo_policy_namespace".
eadd99cc TH	310	* @profile: Profile number.
	311	* @index: Index number of functionality.
	312	* @is_granted: True if granted log, false otherwise.
	313	*
	314	* Returns true if this request should be audited, false otherwise.
	315	*/
bd03a3e4 TH	316	static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
bd03a3e4 TH	317	const u8 profile, const u8 index,
eadd99cc TH	318	const bool is_granted)
	319	{
	320	u8 mode;
2c47ab93 TH	321	const u8 category = tomoyo_index2category[index] +
2c47ab93 TH	322	TOMOYO_MAX_MAC_INDEX;
eadd99cc TH	323	struct tomoyo_profile *p;
	324	if (!tomoyo_policy_loaded)
	325	return false;
bd03a3e4	326	p = tomoyo_profile(ns, profile);
eadd99cc TH	327	if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
	328	return false;
	329	mode = p->config[index];
	330	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
	331	mode = p->config[category];
	332	if (mode == TOMOYO_CONFIG_USE_DEFAULT)
	333	mode = p->default_config;
	334	if (is_granted)
	335	return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
	336	return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
	337	}
	338
	339	/**
	340	* tomoyo_write_log2 - Write an audit log.
	341	*
	342	* @r: Pointer to "struct tomoyo_request_info".
	343	* @len: Buffer size needed for @fmt and @args.
	344	* @fmt: The printf()'s format string.
	345	* @args: va_list structure for @fmt.
	346	*
	347	* Returns nothing.
	348	*/
	349	void tomoyo_write_log2(struct tomoyo_request_info r, int len, const char fmt,
	350	va_list args)
	351	{
	352	char *buf;
	353	struct tomoyo_log *entry;
	354	bool quota_exceeded = false;
bd03a3e4	355	if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, r->granted))
eadd99cc TH	356	goto out;
	357	buf = tomoyo_init_log(r, len, fmt, args);
	358	if (!buf)
	359	goto out;
	360	entry = kzalloc(sizeof(*entry), GFP_NOFS);
	361	if (!entry) {
	362	kfree(buf);
	363	goto out;
	364	}
	365	entry->log = buf;
	366	len = tomoyo_round2(strlen(buf) + 1);
	367	/*
	368	* The entry->size is used for memory quota checks.
	369	* Don't go beyond strlen(entry->log).
	370	*/
	371	entry->size = len + tomoyo_round2(sizeof(*entry));
	372	spin_lock(&tomoyo_log_lock);
	373	if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
	374	tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
	375	tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
	376	quota_exceeded = true;
	377	} else {
	378	tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
	379	list_add_tail(&entry->list, &tomoyo_log);
	380	tomoyo_log_count++;
	381	}
	382	spin_unlock(&tomoyo_log_lock);
	383	if (quota_exceeded) {
	384	kfree(buf);
	385	kfree(entry);
	386	goto out;
	387	}
	388	wake_up(&tomoyo_log_wait);
	389	out:
	390	return;
	391	}
	392
	393	/**
	394	* tomoyo_write_log - Write an audit log.
	395	*
	396	* @r: Pointer to "struct tomoyo_request_info".
	397	* @fmt: The printf()'s format string, followed by parameters.
	398	*
	399	* Returns nothing.
	400	*/
	401	void tomoyo_write_log(struct tomoyo_request_info r, const char fmt, ...)
	402	{
	403	va_list args;
	404	int len;
	405	va_start(args, fmt);
	406	len = vsnprintf((char *) &len, 1, fmt, args) + 1;
	407	va_end(args);
	408	va_start(args, fmt);
	409	tomoyo_write_log2(r, len, fmt, args);
	410	va_end(args);
	411	}
	412
	413	/**
	414	* tomoyo_read_log - Read an audit log.
	415	*
	416	* @head: Pointer to "struct tomoyo_io_buffer".
	417	*
	418	* Returns nothing.
	419	*/
420	void tomoyo_read_log(struct tomoyo_io_buffer *head)
421	{
422	struct tomoyo_log *ptr = NULL;
423	if (head->r.w_pos)
424	return;
425	kfree(head->read_buf);
426	head->read_buf = NULL;
427	spin_lock(&tomoyo_log_lock);
428	if (!list_empty(&tomoyo_log)) {
429	ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
430	list_del(&ptr->list);
431	tomoyo_log_count--;
432	tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
433	}
434	spin_unlock(&tomoyo_log_lock);
435	if (ptr) {
436	head->read_buf = ptr->log;
437	head->r.w[head->r.w_pos++] = head->read_buf;
438	kfree(ptr);
439	}
440	}
441
442	/**
443	* tomoyo_poll_log - Wait for an audit log.
444	*
445	* @file: Pointer to "struct file".
446	* @wait: Pointer to "poll_table".
447	*
448	* Returns POLLIN \| POLLRDNORM when ready to read an audit log.
449	*/
450	int tomoyo_poll_log(struct file file, poll_table wait)
451	{
452	if (tomoyo_log_count)
453	return POLLIN \| POLLRDNORM;
454	poll_wait(file, &tomoyo_log_wait, wait);
455	if (tomoyo_log_count)
456	return POLLIN \| POLLRDNORM;
457	return 0;
458	}