security/tomoyo/condition.c - kernel/msm-4.9 - Gitiles

 /*
  * security/tomoyo/condition.c
  *
  * Copyright (C) 2005-2011  NTT DATA CORPORATION
  */

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

 /* List of "struct tomoyo_condition". */
 LIST_HEAD(tomoyo_condition_list);

 /**
  * tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry.
  *
  * @a: Pointer to "struct tomoyo_condition".
  * @b: Pointer to "struct tomoyo_condition".
  *
  * Returns true if @a == @b, false otherwise.
  */
 static inline bool tomoyo_same_condition(const struct tomoyo_condition *a,
 					 const struct tomoyo_condition *b)
 {
 	return a->size == b->size && a->condc == b->condc &&
 		a->numbers_count == b->numbers_count &&
 		!memcmp(a + 1, b + 1, a->size - sizeof(*a));
 }

 /**
  * tomoyo_condition_type - Get condition type.
  *
  * @word: Keyword string.
  *
  * Returns one of values in "enum tomoyo_conditions_index" on success,
  * TOMOYO_MAX_CONDITION_KEYWORD otherwise.
  */
 static u8 tomoyo_condition_type(const char *word)
 {
 	u8 i;
 	for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) {
 		if (!strcmp(word, tomoyo_condition_keyword[i]))
 			break;
 	}
 	return i;
 }

 /* Define this to enable debug mode. */
 /* #define DEBUG_CONDITION */

 #ifdef DEBUG_CONDITION
 #define dprintk printk
 #else
 #define dprintk(...) do { } while (0)
 #endif

 /**
  * tomoyo_commit_condition - Commit "struct tomoyo_condition".
  *
  * @entry: Pointer to "struct tomoyo_condition".
  *
  * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
  *
  * This function merges duplicated entries. This function returns NULL if
  * @entry is not duplicated but memory quota for policy has exceeded.
  */
 static struct tomoyo_condition *tomoyo_commit_condition
 (struct tomoyo_condition *entry)
 {
 	struct tomoyo_condition *ptr;
 	bool found = false;
 	if (mutex_lock_interruptible(&tomoyo_policy_lock)) {
 		dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
 		ptr = NULL;
 		found = true;
 		goto out;
 	}
 	list_for_each_entry_rcu(ptr, &tomoyo_condition_list, head.list) {
 		if (!tomoyo_same_condition(ptr, entry))
 			continue;
 		/* Same entry found. Share this entry. */
 		atomic_inc(&ptr->head.users);
 		found = true;
 		break;
 	}
 	if (!found) {
 		if (tomoyo_memory_ok(entry)) {
 			atomic_set(&entry->head.users, 1);
 			list_add_rcu(&entry->head.list,
 				     &tomoyo_condition_list);
 		} else {
 			found = true;
 			ptr = NULL;
 		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
 out:
 	if (found) {
 		tomoyo_del_condition(&entry->head.list);
 		kfree(entry);
 		entry = ptr;
 	}
 	return entry;
 }

 /**
  * tomoyo_get_condition - Parse condition part.
  *
  * @param: Pointer to "struct tomoyo_acl_param".
  *
  * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
  */
 struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param)
 {
 	struct tomoyo_condition *entry = NULL;
 	struct tomoyo_condition_element *condp = NULL;
 	struct tomoyo_number_union *numbers_p = NULL;
 	struct tomoyo_condition e = { };
 	char * const start_of_string = param->data;
 	char * const end_of_string = start_of_string + strlen(start_of_string);
 	char *pos;
 rerun:
 	pos = start_of_string;
 	while (1) {
 		u8 left = -1;
 		u8 right = -1;
 		char *left_word = pos;
 		char *cp;
 		char *right_word;
 		bool is_not;
 		if (!*left_word)
 			break;
 		/*
 		 * Since left-hand condition does not allow use of "path_group"
 		 * or "number_group" and environment variable's names do not
 		 * accept '=', it is guaranteed that the original line consists
 		 * of one or more repetition of $left$operator$right blocks
 		 * where "$left is free from '=' and ' '" and "$operator is
 		 * either '=' or '!='" and "$right is free from ' '".
 		 * Therefore, we can reconstruct the original line at the end
 		 * of dry run even if we overwrite $operator with '\0'.
 		 */
 		cp = strchr(pos, ' ');
 		if (cp) {
 			*cp = '\0'; /* Will restore later. */
 			pos = cp + 1;
 		} else {
 			pos = "";
 		}
 		right_word = strchr(left_word, '=');
 		if (!right_word || right_word == left_word)
 			goto out;
 		is_not = *(right_word - 1) == '!';
 		if (is_not)
 			*(right_word++ - 1) = '\0'; /* Will restore later. */
 		else if (*(right_word + 1) != '=')
 			*right_word++ = '\0'; /* Will restore later. */
 		else
 			goto out;
 		dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word,
 			is_not ? "!" : "", right_word);
 		left = tomoyo_condition_type(left_word);
 		dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word,
 			left);
 		if (left == TOMOYO_MAX_CONDITION_KEYWORD) {
 			if (!numbers_p) {
 				e.numbers_count++;
 			} else {
 				e.numbers_count--;
 				left = TOMOYO_NUMBER_UNION;
 				param->data = left_word;
 				if (*left_word == '@' ||
 				    !tomoyo_parse_number_union(param,
 							       numbers_p++))
 					goto out;
 			}
 		}
 		if (!condp)
 			e.condc++;
 		else
 			e.condc--;
 		right = tomoyo_condition_type(right_word);
 		if (right == TOMOYO_MAX_CONDITION_KEYWORD) {
 			if (!numbers_p) {
 				e.numbers_count++;
 			} else {
 				e.numbers_count--;
 				right = TOMOYO_NUMBER_UNION;
 				param->data = right_word;
 				if (!tomoyo_parse_number_union(param,
 							       numbers_p++))
 					goto out;
 			}
 		}
 		if (!condp) {
 			dprintk(KERN_WARNING "%u: dry_run left=%u right=%u "
 				"match=%u\n", __LINE__, left, right, !is_not);
 			continue;
 		}
 		condp->left = left;
 		condp->right = right;
 		condp->equals = !is_not;
 		dprintk(KERN_WARNING "%u: left=%u right=%u match=%u\n",
 			__LINE__, condp->left, condp->right,
 			condp->equals);
 		condp++;
 	}
 	dprintk(KERN_INFO "%u: cond=%u numbers=%u\n",
 		__LINE__, e.condc, e.numbers_count);
 	if (entry) {
 		BUG_ON(e.numbers_count | e.condc);
 		return tomoyo_commit_condition(entry);
 	}
 	e.size = sizeof(*entry)
 		+ e.condc * sizeof(struct tomoyo_condition_element)
 		+ e.numbers_count * sizeof(struct tomoyo_number_union);
 	entry = kzalloc(e.size, GFP_NOFS);
 	if (!entry)
 		return NULL;
 	*entry = e;
 	condp = (struct tomoyo_condition_element *) (entry + 1);
 	numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
 	{
 		bool flag = false;
 		for (pos = start_of_string; pos < end_of_string; pos++) {
 			if (*pos)
 				continue;
 			if (flag) /* Restore " ". */
 				*pos = ' ';
 			else if (*(pos + 1) == '=') /* Restore "!=". */
 				*pos = '!';
 			else /* Restore "=". */
 				*pos = '=';
 			flag = !flag;
 		}
 	}
 	goto rerun;
 out:
 	dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
 	if (entry) {
 		tomoyo_del_condition(&entry->head.list);
 		kfree(entry);
 	}
 	return NULL;
 }

 /**
  * tomoyo_condition - Check condition part.
  *
  * @r:    Pointer to "struct tomoyo_request_info".
  * @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
  *
  * Returns true on success, false otherwise.
  *
  * Caller holds tomoyo_read_lock().
  */
 bool tomoyo_condition(struct tomoyo_request_info *r,
 		      const struct tomoyo_condition *cond)
 {
 	u32 i;
 	unsigned long min_v[2] = { 0, 0 };
 	unsigned long max_v[2] = { 0, 0 };
 	const struct tomoyo_condition_element *condp;
 	const struct tomoyo_number_union *numbers_p;
 	u16 condc;
 	if (!cond)
 		return true;
 	condc = cond->condc;
 	condp = (struct tomoyo_condition_element *) (cond + 1);
 	numbers_p = (const struct tomoyo_number_union *) (condp + condc);
 	for (i = 0; i < condc; i++) {
 		const bool match = condp->equals;
 		const u8 left = condp->left;
 		const u8 right = condp->right;
 		u8 j;
 		condp++;
 		/* Check numeric or bit-op expressions. */
 		for (j = 0; j < 2; j++) {
 			const u8 index = j ? right : left;
 			unsigned long value = 0;
 			switch (index) {
 			case TOMOYO_TASK_UID:
 				value = current_uid();
 				break;
 			case TOMOYO_TASK_EUID:
 				value = current_euid();
 				break;
 			case TOMOYO_TASK_SUID:
 				value = current_suid();
 				break;
 			case TOMOYO_TASK_FSUID:
 				value = current_fsuid();
 				break;
 			case TOMOYO_TASK_GID:
 				value = current_gid();
 				break;
 			case TOMOYO_TASK_EGID:
 				value = current_egid();
 				break;
 			case TOMOYO_TASK_SGID:
 				value = current_sgid();
 				break;
 			case TOMOYO_TASK_FSGID:
 				value = current_fsgid();
 				break;
 			case TOMOYO_TASK_PID:
 				value = tomoyo_sys_getpid();
 				break;
 			case TOMOYO_TASK_PPID:
 				value = tomoyo_sys_getppid();
 				break;
 			case TOMOYO_NUMBER_UNION:
 				/* Fetch values later. */
 				break;
 			default:
 				break;
 			}
 			max_v[j] = value;
 			min_v[j] = value;
 		}
 		if (left == TOMOYO_NUMBER_UNION) {
 			/* Fetch values now. */
 			const struct tomoyo_number_union *ptr = numbers_p++;
 			min_v[0] = ptr->values[0];
 			max_v[0] = ptr->values[1];
 		}
 		if (right == TOMOYO_NUMBER_UNION) {
 			/* Fetch values now. */
 			const struct tomoyo_number_union *ptr = numbers_p++;
 			if (ptr->group) {
 				if (tomoyo_number_matches_group(min_v[0],
 								max_v[0],
 								ptr->group)
 				    == match)
 					continue;
 			} else {
 				if ((min_v[0] <= ptr->values[1] &&
 				     max_v[0] >= ptr->values[0]) == match)
 					continue;
 			}
 			goto out;
 		}
 		/* Normal value range comparison. */
 		if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
 			continue;
 out:
 		return false;
 	}
 	return true;
 }
	/*
	* security/tomoyo/condition.c
	*
	* Copyright (C) 2005-2011 NTT DATA CORPORATION
	*/

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

	/* List of "struct tomoyo_condition". */
	LIST_HEAD(tomoyo_condition_list);

	/**
	* tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry.
	*
	* @a: Pointer to "struct tomoyo_condition".
	* @b: Pointer to "struct tomoyo_condition".
	*
	* Returns true if @a == @b, false otherwise.
	*/
	static inline bool tomoyo_same_condition(const struct tomoyo_condition *a,
	const struct tomoyo_condition *b)
	{
	return a->size == b->size && a->condc == b->condc &&
	a->numbers_count == b->numbers_count &&
	!memcmp(a + 1, b + 1, a->size - sizeof(*a));
	}

	/**
	* tomoyo_condition_type - Get condition type.
	*
	* @word: Keyword string.
	*
	* Returns one of values in "enum tomoyo_conditions_index" on success,
	* TOMOYO_MAX_CONDITION_KEYWORD otherwise.
	*/
	static u8 tomoyo_condition_type(const char *word)
	{
	u8 i;
	for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) {
	if (!strcmp(word, tomoyo_condition_keyword[i]))
	break;
	}
	return i;
	}

	/* Define this to enable debug mode. */
	/* #define DEBUG_CONDITION */

	#ifdef DEBUG_CONDITION
	#define dprintk printk
	#else
	#define dprintk(...) do { } while (0)
	#endif

	/**
	* tomoyo_commit_condition - Commit "struct tomoyo_condition".
	*
	* @entry: Pointer to "struct tomoyo_condition".
	*
	* Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
	*
	* This function merges duplicated entries. This function returns NULL if
	* @entry is not duplicated but memory quota for policy has exceeded.
	*/
	static struct tomoyo_condition *tomoyo_commit_condition
	(struct tomoyo_condition *entry)
	{
	struct tomoyo_condition *ptr;
	bool found = false;
	if (mutex_lock_interruptible(&tomoyo_policy_lock)) {
	dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
	ptr = NULL;
	found = true;
	goto out;
	}
	list_for_each_entry_rcu(ptr, &tomoyo_condition_list, head.list) {
	if (!tomoyo_same_condition(ptr, entry))
	continue;
	/* Same entry found. Share this entry. */
	atomic_inc(&ptr->head.users);
	found = true;
	break;
	}
	if (!found) {
	if (tomoyo_memory_ok(entry)) {
	atomic_set(&entry->head.users, 1);
	list_add_rcu(&entry->head.list,
	&tomoyo_condition_list);
	} else {
	found = true;
	ptr = NULL;
	}
	}
	mutex_unlock(&tomoyo_policy_lock);
	out:
	if (found) {
	tomoyo_del_condition(&entry->head.list);
	kfree(entry);
	entry = ptr;
	}
	return entry;
	}

	/**
	* tomoyo_get_condition - Parse condition part.
	*
	* @param: Pointer to "struct tomoyo_acl_param".
	*
	* Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
	*/
	struct tomoyo_condition tomoyo_get_condition(struct tomoyo_acl_param param)
	{
	struct tomoyo_condition *entry = NULL;
	struct tomoyo_condition_element *condp = NULL;
	struct tomoyo_number_union *numbers_p = NULL;
	struct tomoyo_condition e = { };
	char * const start_of_string = param->data;
	char * const end_of_string = start_of_string + strlen(start_of_string);
	char *pos;
	rerun:
	pos = start_of_string;
	while (1) {
	u8 left = -1;
	u8 right = -1;
	char *left_word = pos;
	char *cp;
	char *right_word;
	bool is_not;
	if (!*left_word)
	break;
	/*
	* Since left-hand condition does not allow use of "path_group"
	* or "number_group" and environment variable's names do not
	* accept '=', it is guaranteed that the original line consists
	* of one or more repetition of $left$operator$right blocks
	* where "$left is free from '=' and ' '" and "$operator is
	* either '=' or '!='" and "$right is free from ' '".
	* Therefore, we can reconstruct the original line at the end
	* of dry run even if we overwrite $operator with '\0'.
	*/
	cp = strchr(pos, ' ');
	if (cp) {
	cp = '\0'; / Will restore later. */
	pos = cp + 1;
	} else {
	pos = "";
	}
	right_word = strchr(left_word, '=');
	if (!right_word \|\| right_word == left_word)
	goto out;
	is_not = *(right_word - 1) == '!';
	if (is_not)
	(right_word++ - 1) = '\0'; / Will restore later. */
	else if (*(right_word + 1) != '=')
	right_word++ = '\0'; / Will restore later. */
	else
	goto out;
	dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word,
	is_not ? "!" : "", right_word);
	left = tomoyo_condition_type(left_word);
	dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word,
	left);
	if (left == TOMOYO_MAX_CONDITION_KEYWORD) {
	if (!numbers_p) {
	e.numbers_count++;
	} else {
	e.numbers_count--;
	left = TOMOYO_NUMBER_UNION;
	param->data = left_word;
	if (*left_word == '@' \|\|
	!tomoyo_parse_number_union(param,
	numbers_p++))
	goto out;
	}
	}
	if (!condp)
	e.condc++;
	else
	e.condc--;
	right = tomoyo_condition_type(right_word);
	if (right == TOMOYO_MAX_CONDITION_KEYWORD) {
	if (!numbers_p) {
	e.numbers_count++;
	} else {
	e.numbers_count--;
	right = TOMOYO_NUMBER_UNION;
	param->data = right_word;
	if (!tomoyo_parse_number_union(param,
	numbers_p++))
	goto out;
	}
	}
	if (!condp) {
	dprintk(KERN_WARNING "%u: dry_run left=%u right=%u "
	"match=%u\n", __LINE__, left, right, !is_not);
	continue;
	}
	condp->left = left;
	condp->right = right;
	condp->equals = !is_not;
	dprintk(KERN_WARNING "%u: left=%u right=%u match=%u\n",
	__LINE__, condp->left, condp->right,
	condp->equals);
	condp++;
	}
	dprintk(KERN_INFO "%u: cond=%u numbers=%u\n",
	__LINE__, e.condc, e.numbers_count);
	if (entry) {
	BUG_ON(e.numbers_count \| e.condc);
	return tomoyo_commit_condition(entry);
	}
	e.size = sizeof(*entry)
	+ e.condc * sizeof(struct tomoyo_condition_element)
	+ e.numbers_count * sizeof(struct tomoyo_number_union);
	entry = kzalloc(e.size, GFP_NOFS);
	if (!entry)
	return NULL;
	*entry = e;
	condp = (struct tomoyo_condition_element *) (entry + 1);
	numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
	{
	bool flag = false;
	for (pos = start_of_string; pos < end_of_string; pos++) {
	if (*pos)
	continue;
	if (flag) /* Restore " ". */
	*pos = ' ';
	else if ((pos + 1) == '=') / Restore "!=". */
	*pos = '!';
	else /* Restore "=". */
	*pos = '=';
	flag = !flag;
	}
	}
	goto rerun;
	out:
	dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
	if (entry) {
	tomoyo_del_condition(&entry->head.list);
	kfree(entry);
	}
	return NULL;
	}

	/**
	* tomoyo_condition - Check condition part.
	*
	* @r: Pointer to "struct tomoyo_request_info".
	* @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
	*
	* Returns true on success, false otherwise.
	*
	* Caller holds tomoyo_read_lock().
	*/
	bool tomoyo_condition(struct tomoyo_request_info *r,
	const struct tomoyo_condition *cond)
	{
	u32 i;
	unsigned long min_v[2] = { 0, 0 };
	unsigned long max_v[2] = { 0, 0 };
	const struct tomoyo_condition_element *condp;
	const struct tomoyo_number_union *numbers_p;
	u16 condc;
	if (!cond)
	return true;
	condc = cond->condc;
	condp = (struct tomoyo_condition_element *) (cond + 1);
	numbers_p = (const struct tomoyo_number_union *) (condp + condc);
	for (i = 0; i < condc; i++) {
	const bool match = condp->equals;
	const u8 left = condp->left;
	const u8 right = condp->right;
	u8 j;
	condp++;
	/* Check numeric or bit-op expressions. */
	for (j = 0; j < 2; j++) {
	const u8 index = j ? right : left;
	unsigned long value = 0;
	switch (index) {
	case TOMOYO_TASK_UID:
	value = current_uid();
	break;
	case TOMOYO_TASK_EUID:
	value = current_euid();
	break;
	case TOMOYO_TASK_SUID:
	value = current_suid();
	break;
	case TOMOYO_TASK_FSUID:
	value = current_fsuid();
	break;
	case TOMOYO_TASK_GID:
	value = current_gid();
	break;
	case TOMOYO_TASK_EGID:
	value = current_egid();
	break;
	case TOMOYO_TASK_SGID:
	value = current_sgid();
	break;
	case TOMOYO_TASK_FSGID:
	value = current_fsgid();
	break;
	case TOMOYO_TASK_PID:
	value = tomoyo_sys_getpid();
	break;
	case TOMOYO_TASK_PPID:
	value = tomoyo_sys_getppid();
	break;
	case TOMOYO_NUMBER_UNION:
	/* Fetch values later. */
	break;
	default:
	break;
	}
	max_v[j] = value;
	min_v[j] = value;
	}
	if (left == TOMOYO_NUMBER_UNION) {
	/* Fetch values now. */
	const struct tomoyo_number_union *ptr = numbers_p++;
	min_v[0] = ptr->values[0];
	max_v[0] = ptr->values[1];
	}
	if (right == TOMOYO_NUMBER_UNION) {
	/* Fetch values now. */
	const struct tomoyo_number_union *ptr = numbers_p++;
	if (ptr->group) {
	if (tomoyo_number_matches_group(min_v[0],
	max_v[0],
	ptr->group)
	== match)
	continue;
	} else {
	if ((min_v[0] <= ptr->values[1] &&
	max_v[0] >= ptr->values[0]) == match)
	continue;
	}
	goto out;
	}
	/* Normal value range comparison. */
	if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
	continue;
	out:
	return false;
	}
	return true;
	}