/*
* security/tomoyo/realpath.c
*
- * Get the canonicalized absolute pathnames. The basis for TOMOYO.
- *
- * Copyright (C) 2005-2009 NTT DATA CORPORATION
- *
- * Version: 2.2.0 2009/04/01
+ * Pathname calculation functions for TOMOYO.
*
+ * Copyright (C) 2005-2010 NTT DATA CORPORATION
*/
#include <linux/types.h>
#include <linux/mount.h>
#include <linux/mnt_namespace.h>
#include <linux/fs_struct.h>
-#include <linux/hash.h>
#include <linux/magic.h>
#include <linux/slab.h>
+#include <net/sock.h>
#include "common.h"
/**
* tomoyo_encode: Convert binary string to ascii string.
*
- * @buffer: Buffer for ASCII string.
- * @buflen: Size of @buffer.
- * @str: Binary string.
+ * @str: String in binary format.
+ *
+ * Returns pointer to @str in ascii format on success, NULL otherwise.
*
- * Returns 0 on success, -ENOMEM otherwise.
+ * This function uses kzalloc(), so caller must kfree() if this function
+ * didn't return NULL.
*/
-int tomoyo_encode(char *buffer, int buflen, const char *str)
+char *tomoyo_encode(const char *str)
{
- while (1) {
- const unsigned char c = *(unsigned char *) str++;
+ int len = 0;
+ const char *p = str;
+ char *cp;
+ char *cp0;
- if (tomoyo_is_valid(c)) {
- if (--buflen <= 0)
- break;
- *buffer++ = (char) c;
- if (c != '\\')
- continue;
- if (--buflen <= 0)
- break;
- *buffer++ = (char) c;
- continue;
- }
- if (!c) {
- if (--buflen <= 0)
- break;
- *buffer = '\0';
- return 0;
+ if (!p)
+ return NULL;
+ while (*p) {
+ const unsigned char c = *p++;
+ if (c == '\\')
+ len += 2;
+ else if (c > ' ' && c < 127)
+ len++;
+ else
+ len += 4;
+ }
+ len++;
+ /* Reserve space for appending "/". */
+ cp = kzalloc(len + 10, GFP_NOFS);
+ if (!cp)
+ return NULL;
+ cp0 = cp;
+ p = str;
+ while (*p) {
+ const unsigned char c = *p++;
+
+ if (c == '\\') {
+ *cp++ = '\\';
+ *cp++ = '\\';
+ } else if (c > ' ' && c < 127) {
+ *cp++ = c;
+ } else {
+ *cp++ = '\\';
+ *cp++ = (c >> 6) + '0';
+ *cp++ = ((c >> 3) & 7) + '0';
+ *cp++ = (c & 7) + '0';
}
- buflen -= 4;
- if (buflen <= 0)
- break;
- *buffer++ = '\\';
- *buffer++ = (c >> 6) + '0';
- *buffer++ = ((c >> 3) & 7) + '0';
- *buffer++ = (c & 7) + '0';
}
- return -ENOMEM;
+ return cp0;
}
/**
- * tomoyo_realpath_from_path2 - Returns realpath(3) of the given dentry but ignores chroot'ed root.
+ * tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root.
*
- * @path: Pointer to "struct path".
- * @newname: Pointer to buffer to return value in.
- * @newname_len: Size of @newname.
+ * @path: Pointer to "struct path".
*
- * Returns 0 on success, negative value otherwise.
+ * Returns the realpath of the given @path on success, NULL otherwise.
*
* If dentry is a directory, trailing '/' is appended.
* Characters out of 0x20 < c < 0x7F range are converted to
* \ooo style octal string.
* Character \ is converted to \\ string.
+ *
+ * These functions use kzalloc(), so the caller must call kfree()
+ * if these functions didn't return NULL.
*/
-int tomoyo_realpath_from_path2(struct path *path, char *newname,
- int newname_len)
+char *tomoyo_realpath_from_path(struct path *path)
{
- int error = -ENOMEM;
+ char *buf = NULL;
+ char *name = NULL;
+ unsigned int buf_len = PAGE_SIZE / 2;
struct dentry *dentry = path->dentry;
- char *sp;
-
- if (!dentry || !path->mnt || !newname || newname_len <= 2048)
- return -EINVAL;
- if (dentry->d_op && dentry->d_op->d_dname) {
+ bool is_dir;
+ if (!dentry)
+ return NULL;
+ is_dir = dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode);
+ while (1) {
+ struct path ns_root = { .mnt = NULL, .dentry = NULL };
+ char *pos;
+ buf_len <<= 1;
+ kfree(buf);
+ buf = kmalloc(buf_len, GFP_NOFS);
+ if (!buf)
+ break;
+ /* Get better name for socket. */
+ if (dentry->d_sb && dentry->d_sb->s_magic == SOCKFS_MAGIC) {
+ struct inode *inode = dentry->d_inode;
+ struct socket *sock = inode ? SOCKET_I(inode) : NULL;
+ struct sock *sk = sock ? sock->sk : NULL;
+ if (sk) {
+ snprintf(buf, buf_len - 1, "socket:[family=%u:"
+ "type=%u:protocol=%u]", sk->sk_family,
+ sk->sk_type, sk->sk_protocol);
+ } else {
+ snprintf(buf, buf_len - 1, "socket:[unknown]");
+ }
+ name = tomoyo_encode(buf);
+ break;
+ }
/* For "socket:[\$]" and "pipe:[\$]". */
- static const int offset = 1536;
- sp = dentry->d_op->d_dname(dentry, newname + offset,
- newname_len - offset);
- } else {
- struct path ns_root = {.mnt = NULL, .dentry = NULL};
-
- spin_lock(&dcache_lock);
+ if (dentry->d_op && dentry->d_op->d_dname) {
+ pos = dentry->d_op->d_dname(dentry, buf, buf_len - 1);
+ if (IS_ERR(pos))
+ continue;
+ name = tomoyo_encode(pos);
+ break;
+ }
+ /* If we don't have a vfsmount, we can't calculate. */
+ if (!path->mnt)
+ break;
/* go to whatever namespace root we are under */
- sp = __d_path(path, &ns_root, newname, newname_len);
- spin_unlock(&dcache_lock);
+ pos = __d_path(path, &ns_root, buf, buf_len);
/* Prepend "/proc" prefix if using internal proc vfs mount. */
- if (!IS_ERR(sp) && (path->mnt->mnt_flags & MNT_INTERNAL) &&
+ if (!IS_ERR(pos) && (path->mnt->mnt_flags & MNT_INTERNAL) &&
(path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) {
- sp -= 5;
- if (sp >= newname)
- memcpy(sp, "/proc", 5);
+ pos -= 5;
+ if (pos >= buf)
+ memcpy(pos, "/proc", 5);
else
- sp = ERR_PTR(-ENOMEM);
- }
- }
- if (IS_ERR(sp))
- error = PTR_ERR(sp);
- else
- error = tomoyo_encode(newname, sp - newname, sp);
- /* Append trailing '/' if dentry is a directory. */
- if (!error && dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)
- && *newname) {
- sp = newname + strlen(newname);
- if (*(sp - 1) != '/') {
- if (sp < newname + newname_len - 4) {
- *sp++ = '/';
- *sp = '\0';
- } else {
- error = -ENOMEM;
- }
+ pos = ERR_PTR(-ENOMEM);
}
+ if (IS_ERR(pos))
+ continue;
+ name = tomoyo_encode(pos);
+ break;
}
- if (error)
- printk(KERN_WARNING "tomoyo_realpath: Pathname too long.\n");
- return error;
-}
-
-/**
- * tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root.
- *
- * @path: Pointer to "struct path".
- *
- * Returns the realpath of the given @path on success, NULL otherwise.
- *
- * These functions use kzalloc(), so the caller must call kfree()
- * if these functions didn't return NULL.
- */
-char *tomoyo_realpath_from_path(struct path *path)
-{
- char *buf = kzalloc(sizeof(struct tomoyo_page_buffer), GFP_NOFS);
-
- BUILD_BUG_ON(sizeof(struct tomoyo_page_buffer)
- <= TOMOYO_MAX_PATHNAME_LEN - 1);
- if (!buf)
- return NULL;
- if (tomoyo_realpath_from_path2(path, buf,
- TOMOYO_MAX_PATHNAME_LEN - 1) == 0)
- return buf;
kfree(buf);
- return NULL;
-}
-
-/**
- * tomoyo_realpath - Get realpath of a pathname.
- *
- * @pathname: The pathname to solve.
- *
- * Returns the realpath of @pathname on success, NULL otherwise.
- */
-char *tomoyo_realpath(const char *pathname)
-{
- struct path path;
-
- if (pathname && kern_path(pathname, LOOKUP_FOLLOW, &path) == 0) {
- char *buf = tomoyo_realpath_from_path(&path);
- path_put(&path);
- return buf;
+ if (!name)
+ tomoyo_warn_oom(__func__);
+ else if (is_dir && *name) {
+ /* Append trailing '/' if dentry is a directory. */
+ char *pos = name + strlen(name) - 1;
+ if (*pos != '/')
+ /*
+ * This is OK because tomoyo_encode() reserves space
+ * for appending "/".
+ */
+ *++pos = '/';
}
- return NULL;
+ return name;
}
/**
}
return NULL;
}
-
-/* Memory allocated for non-string data. */
-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.
- *
- * Caller holds tomoyo_policy_lock.
- * Memory pointed by @ptr will be zeroed on success.
- */
-bool tomoyo_memory_ok(void *ptr)
-{
- int allocated_len = ptr ? ksize(ptr) : 0;
- atomic_add(allocated_len, &tomoyo_policy_memory_size);
- if (ptr && (!tomoyo_quota_for_policy ||
- atomic_read(&tomoyo_policy_memory_size)
- <= tomoyo_quota_for_policy)) {
- memset(ptr, 0, allocated_len);
- return true;
- }
- printk(KERN_WARNING "ERROR: Out of memory "
- "for tomoyo_alloc_element().\n");
- if (!tomoyo_policy_loaded)
- panic("MAC Initialization failed.\n");
- 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.
- */
-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_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_entry *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);
- printk(KERN_WARNING "ERROR: Out of memory "
- "for tomoyo_get_name().\n");
- if (!tomoyo_policy_loaded)
- panic("MAC Initialization failed.\n");
- ptr = NULL;
- 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_realpath_init - Initialize realpath related code.
- */
-void __init tomoyo_realpath_init(void)
-{
- int i;
-
- BUILD_BUG_ON(TOMOYO_MAX_PATHNAME_LEN > PATH_MAX);
- for (i = 0; i < TOMOYO_MAX_HASH; i++)
- INIT_LIST_HEAD(&tomoyo_name_list[i]);
- INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list);
- tomoyo_kernel_domain.domainname = tomoyo_get_name(TOMOYO_ROOT_NAME);
- /*
- * tomoyo_read_lock() is not needed because this function is
- * called before the first "delete" request.
- */
- list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
- if (tomoyo_find_domain(TOMOYO_ROOT_NAME) != &tomoyo_kernel_domain)
- panic("Can't register tomoyo_kernel_domain");
-}
-
-/**
- * tomoyo_read_memory_counter - Check for memory usage in bytes.
- *
- * @head: Pointer to "struct tomoyo_io_buffer".
- *
- * Returns memory usage.
- */
-int tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
-{
- if (!head->read_eof) {
- const unsigned int policy
- = atomic_read(&tomoyo_policy_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);
- tomoyo_io_printf(head, "Total: %10u\n", policy);
- head->read_eof = true;
- }
- return 0;
-}
-
-/**
- * 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;
- return 0;
-}
projects / linux-flexiantxendom0-natty.git / blobdiff