diff options
Diffstat (limited to 'security/tomoyo/memory.c')
-rw-r--r-- | security/tomoyo/memory.c | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/security/tomoyo/memory.c b/security/tomoyo/memory.c new file mode 100644 index 00000000000..297612669c7 --- /dev/null +++ b/security/tomoyo/memory.c @@ -0,0 +1,282 @@ +/* + * security/tomoyo/memory.c + * + * Memory management functions for TOMOYO. + * + * Copyright (C) 2005-2010 NTT DATA CORPORATION + */ + +#include <linux/hash.h> +#include <linux/slab.h> +#include "common.h" + +/** + * tomoyo_warn_oom - Print out of memory warning message. + * + * @function: Function's name. + */ +void tomoyo_warn_oom(const char *function) +{ + /* Reduce error messages. */ + static pid_t tomoyo_last_pid; + const pid_t pid = current->pid; + if (tomoyo_last_pid != pid) { + printk(KERN_WARNING "ERROR: Out of memory at %s.\n", + function); + tomoyo_last_pid = pid; + } + if (!tomoyo_policy_loaded) + panic("MAC Initialization failed.\n"); +} + +/* Memory allocated for policy. */ +static atomic_t tomoyo_policy_memory_size; +/* Quota for holding policy. */ +static unsigned int tomoyo_quota_for_policy; + +/** + * tomoyo_memory_ok - Check memory quota. + * + * @ptr: Pointer to allocated memory. + * + * Returns true on success, false otherwise. + * + * Returns true if @ptr is not NULL and quota not exceeded, false otherwise. + */ +bool tomoyo_memory_ok(void *ptr) +{ + size_t s = ptr ? ksize(ptr) : 0; + atomic_add(s, &tomoyo_policy_memory_size); + if (ptr && (!tomoyo_quota_for_policy || + atomic_read(&tomoyo_policy_memory_size) + <= tomoyo_quota_for_policy)) { + memset(ptr, 0, s); + return true; + } + atomic_sub(s, &tomoyo_policy_memory_size); + tomoyo_warn_oom(__func__); + return false; +} + +/** + * tomoyo_commit_ok - Check memory quota. + * + * @data: Data to copy from. + * @size: Size in byte. + * + * Returns pointer to allocated memory on success, NULL otherwise. + * @data is zero-cleared on success. + */ +void *tomoyo_commit_ok(void *data, const unsigned int size) +{ + void *ptr = kzalloc(size, GFP_NOFS); + if (tomoyo_memory_ok(ptr)) { + memmove(ptr, data, size); + memset(data, 0, size); + return ptr; + } + return NULL; +} + +/** + * tomoyo_memory_free - Free memory for elements. + * + * @ptr: Pointer to allocated memory. + */ +void tomoyo_memory_free(void *ptr) +{ + atomic_sub(ksize(ptr), &tomoyo_policy_memory_size); + kfree(ptr); +} + +/** + * tomoyo_get_group - Allocate memory for "struct tomoyo_path_group"/"struct tomoyo_number_group". + * + * @group_name: The name of address group. + * @idx: Index number. + * + * Returns pointer to "struct tomoyo_group" on success, NULL otherwise. + */ +struct tomoyo_group *tomoyo_get_group(const char *group_name, const u8 idx) +{ + struct tomoyo_group e = { }; + struct tomoyo_group *group = NULL; + bool found = false; + if (!tomoyo_correct_word(group_name) || idx >= TOMOYO_MAX_GROUP) + return NULL; + e.group_name = tomoyo_get_name(group_name); + if (!e.group_name) + return NULL; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + goto out; + list_for_each_entry(group, &tomoyo_group_list[idx], list) { + if (e.group_name != group->group_name) + continue; + atomic_inc(&group->users); + found = true; + break; + } + if (!found) { + struct tomoyo_group *entry = tomoyo_commit_ok(&e, sizeof(e)); + if (entry) { + INIT_LIST_HEAD(&entry->member_list); + atomic_set(&entry->users, 1); + list_add_tail_rcu(&entry->list, + &tomoyo_group_list[idx]); + group = entry; + found = true; + } + } + mutex_unlock(&tomoyo_policy_lock); + out: + tomoyo_put_name(e.group_name); + return found ? group : NULL; +} + +/* + * tomoyo_name_list is used for holding string data used by TOMOYO. + * Since same string data is likely used for multiple times (e.g. + * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of + * "const struct tomoyo_path_info *". + */ +struct list_head tomoyo_name_list[TOMOYO_MAX_HASH]; + +/** + * tomoyo_get_name - Allocate permanent memory for string data. + * + * @name: The string to store into the permernent memory. + * + * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise. + */ +const struct tomoyo_path_info *tomoyo_get_name(const char *name) +{ + struct tomoyo_name *ptr; + unsigned int hash; + int len; + int allocated_len; + struct list_head *head; + + if (!name) + return NULL; + len = strlen(name) + 1; + hash = full_name_hash((const unsigned char *) name, len - 1); + head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)]; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + return NULL; + list_for_each_entry(ptr, head, list) { + if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name)) + continue; + atomic_inc(&ptr->users); + goto out; + } + ptr = kzalloc(sizeof(*ptr) + len, GFP_NOFS); + allocated_len = ptr ? ksize(ptr) : 0; + if (!ptr || (tomoyo_quota_for_policy && + atomic_read(&tomoyo_policy_memory_size) + allocated_len + > tomoyo_quota_for_policy)) { + kfree(ptr); + ptr = NULL; + tomoyo_warn_oom(__func__); + goto out; + } + atomic_add(allocated_len, &tomoyo_policy_memory_size); + ptr->entry.name = ((char *) ptr) + sizeof(*ptr); + memmove((char *) ptr->entry.name, name, len); + atomic_set(&ptr->users, 1); + tomoyo_fill_path_info(&ptr->entry); + list_add_tail(&ptr->list, head); + out: + mutex_unlock(&tomoyo_policy_lock); + return ptr ? &ptr->entry : NULL; +} + +/** + * tomoyo_mm_init - Initialize mm related code. + */ +void __init tomoyo_mm_init(void) +{ + int idx; + + for (idx = 0; idx < TOMOYO_MAX_POLICY; idx++) + INIT_LIST_HEAD(&tomoyo_policy_list[idx]); + for (idx = 0; idx < TOMOYO_MAX_GROUP; idx++) + INIT_LIST_HEAD(&tomoyo_group_list[idx]); + for (idx = 0; idx < TOMOYO_MAX_HASH; idx++) + INIT_LIST_HEAD(&tomoyo_name_list[idx]); + INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list); + tomoyo_kernel_domain.domainname = tomoyo_get_name(TOMOYO_ROOT_NAME); + list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list); + idx = tomoyo_read_lock(); + if (tomoyo_find_domain(TOMOYO_ROOT_NAME) != &tomoyo_kernel_domain) + panic("Can't register tomoyo_kernel_domain"); + { + /* Load built-in policy. */ + tomoyo_write_transition_control("/sbin/hotplug", false, + TOMOYO_TRANSITION_CONTROL_INITIALIZE); + tomoyo_write_transition_control("/sbin/modprobe", false, + TOMOYO_TRANSITION_CONTROL_INITIALIZE); + } + tomoyo_read_unlock(idx); +} + + +/* Memory allocated for query lists. */ +unsigned int tomoyo_query_memory_size; +/* Quota for holding query lists. */ +unsigned int tomoyo_quota_for_query; + +/** + * tomoyo_read_memory_counter - Check for memory usage in bytes. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns memory usage. + */ +void tomoyo_read_memory_counter(struct tomoyo_io_buffer *head) +{ + if (!head->r.eof) { + const unsigned int policy + = atomic_read(&tomoyo_policy_memory_size); + const unsigned int query = tomoyo_query_memory_size; + char buffer[64]; + + memset(buffer, 0, sizeof(buffer)); + if (tomoyo_quota_for_policy) + snprintf(buffer, sizeof(buffer) - 1, + " (Quota: %10u)", + tomoyo_quota_for_policy); + else + buffer[0] = '\0'; + tomoyo_io_printf(head, "Policy: %10u%s\n", policy, + buffer); + if (tomoyo_quota_for_query) + snprintf(buffer, sizeof(buffer) - 1, + " (Quota: %10u)", + tomoyo_quota_for_query); + else + buffer[0] = '\0'; + tomoyo_io_printf(head, "Query lists: %10u%s\n", query, + buffer); + tomoyo_io_printf(head, "Total: %10u\n", policy + query); + head->r.eof = true; + } +} + +/** + * tomoyo_write_memory_quota - Set memory quota. + * + * @head: Pointer to "struct tomoyo_io_buffer". + * + * Returns 0. + */ +int tomoyo_write_memory_quota(struct tomoyo_io_buffer *head) +{ + char *data = head->write_buf; + unsigned int size; + + if (sscanf(data, "Policy: %u", &size) == 1) + tomoyo_quota_for_policy = size; + else if (sscanf(data, "Query lists: %u", &size) == 1) + tomoyo_quota_for_query = size; + return 0; +} |