security/tomoyo/audit.c - arm/linux-arm64-legacy - Git at Google

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

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

 /**
  * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
  *
  * @time:  Seconds since 1970/01/01 00:00:00.
  * @stamp: Pointer to "struct tomoyo_time".
  *
  * Returns nothing.
  *
  * This function does not handle Y2038 problem.
  */
 static void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
 {
 	static const u16 tomoyo_eom[2][12] = {
 		{ 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
 		{ 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
 	};
 	u16 y;
 	u8 m;
 	bool r;
 	stamp->sec = time % 60;
 	time /= 60;
 	stamp->min = time % 60;
 	time /= 60;
 	stamp->hour = time % 24;
 	time /= 24;
 	for (y = 1970; ; y++) {
 		const unsigned short days = (y & 3) ? 365 : 366;
 		if (time < days)
 			break;
 		time -= days;
 	}
 	r = (y & 3) == 0;
 	for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
 		;
 	if (m)
 		time -= tomoyo_eom[r][m - 1];
 	stamp->year = y;
 	stamp->month = ++m;
 	stamp->day = ++time;
 }

 /**
  * 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);
 	static const int tomoyo_buffer_len = 4096;
 	char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
 	pid_t ppid;
 	if (!buffer)
 		return NULL;
 	{
 		struct timeval tv;
 		do_gettimeofday(&tv);
 		tomoyo_convert_time(tv.tv_sec, &stamp);
 	}
 	rcu_read_lock();
 	ppid = task_tgid_vnr(current->real_parent);
 	rcu_read_unlock();
 	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, task_tgid_vnr(current), ppid,
 		 current_uid(), current_gid(), current_euid(), current_egid(),
 		 current_suid(), current_sgid(), current_fsuid(),
 		 current_fsgid());
 	return buffer;
 }

 /**
  * 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;
 	const char *header = NULL;
 	int pos;
 	const char *domainname = tomoyo_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;
 	len = tomoyo_round2(len);
 	buf = kzalloc(len, GFP_NOFS);
 	if (!buf)
 		goto out;
 	len--;
 	pos = snprintf(buf, len, "%s", header);
 	pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
 	vsnprintf(buf + pos, len - pos, fmt, args);
 out:
 	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;
 }
	/*
	* security/tomoyo/audit.c
	*
	* Pathname restriction functions.
	*
	* Copyright (C) 2005-2010 NTT DATA CORPORATION
	*/

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

	/**
	* tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
	*
	* @time: Seconds since 1970/01/01 00:00:00.
	* @stamp: Pointer to "struct tomoyo_time".
	*
	* Returns nothing.
	*
	* This function does not handle Y2038 problem.
	*/
	static void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
	{
	static const u16 tomoyo_eom[2][12] = {
	{ 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
	{ 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
	};
	u16 y;
	u8 m;
	bool r;
	stamp->sec = time % 60;
	time /= 60;
	stamp->min = time % 60;
	time /= 60;
	stamp->hour = time % 24;
	time /= 24;
	for (y = 1970; ; y++) {
	const unsigned short days = (y & 3) ? 365 : 366;
	if (time < days)
	break;
	time -= days;
	}
	r = (y & 3) == 0;
	for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
	;
	if (m)
	time -= tomoyo_eom[r][m - 1];
	stamp->year = y;
	stamp->month = ++m;
	stamp->day = ++time;
	}

	/**
	* 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);
	static const int tomoyo_buffer_len = 4096;
	char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
	pid_t ppid;
	if (!buffer)
	return NULL;
	{
	struct timeval tv;
	do_gettimeofday(&tv);
	tomoyo_convert_time(tv.tv_sec, &stamp);
	}
	rcu_read_lock();
	ppid = task_tgid_vnr(current->real_parent);
	rcu_read_unlock();
	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, task_tgid_vnr(current), ppid,
	current_uid(), current_gid(), current_euid(), current_egid(),
	current_suid(), current_sgid(), current_fsuid(),
	current_fsgid());
	return buffer;
	}

	/**
	* 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;
	const char *header = NULL;
	int pos;
	const char *domainname = tomoyo_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;
	len = tomoyo_round2(len);
	buf = kzalloc(len, GFP_NOFS);
	if (!buf)
	goto out;
	len--;
	pos = snprintf(buf, len, "%s", header);
	pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
	vsnprintf(buf + pos, len - pos, fmt, args);
	out:
	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;
	}