/*
* 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"
-#include "realpath.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 0 on success, -ENOMEM otherwise.
+ * Returns pointer to @str in ascii format on success, NULL 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 {
- /* Taken from d_namespace_path(). */
- struct path root;
- struct path ns_root = { };
- struct path tmp;
-
- read_lock(¤t->fs->lock);
- root = current->fs->root;
- path_get(&root);
- read_unlock(¤t->fs->lock);
- spin_lock(&vfsmount_lock);
- if (root.mnt && root.mnt->mnt_ns)
- ns_root.mnt = mntget(root.mnt->mnt_ns->root);
- if (ns_root.mnt)
- ns_root.dentry = dget(ns_root.mnt->mnt_root);
- spin_unlock(&vfsmount_lock);
- spin_lock(&dcache_lock);
- tmp = ns_root;
- sp = __d_path(path, &tmp, newname, newname_len);
- spin_unlock(&dcache_lock);
- path_put(&root);
- path_put(&ns_root);
+ 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 */
+ 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_parent == path->mnt) &&
+ 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 tomoyo_alloc(), so the caller must call tomoyo_free()
- * if these functions didn't return NULL.
- */
-char *tomoyo_realpath_from_path(struct path *path)
-{
- char *buf = tomoyo_alloc(sizeof(struct tomoyo_page_buffer));
-
- 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;
- tomoyo_free(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;
+ kfree(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 unsigned int tomoyo_allocated_memory_for_elements;
-/* Quota for holding non-string data. */
-static unsigned int tomoyo_quota_for_elements;
-
-/**
- * tomoyo_alloc_element - Allocate permanent memory for structures.
- *
- * @size: Size in bytes.
- *
- * Returns pointer to allocated memory on success, NULL otherwise.
- *
- * Memory has to be zeroed.
- * The RAM is chunked, so NEVER try to kfree() the returned pointer.
- */
-void *tomoyo_alloc_element(const unsigned int size)
-{
- static char *buf;
- static DEFINE_MUTEX(lock);
- static unsigned int buf_used_len = PATH_MAX;
- char *ptr = NULL;
- /*Assumes sizeof(void *) >= sizeof(long) is true. */
- const unsigned int word_aligned_size
- = roundup(size, max(sizeof(void *), sizeof(long)));
- if (word_aligned_size > PATH_MAX)
- return NULL;
- mutex_lock(&lock);
- if (buf_used_len + word_aligned_size > PATH_MAX) {
- if (!tomoyo_quota_for_elements ||
- tomoyo_allocated_memory_for_elements
- + PATH_MAX <= tomoyo_quota_for_elements)
- ptr = kzalloc(PATH_MAX, GFP_KERNEL);
- if (!ptr) {
- printk(KERN_WARNING "ERROR: Out of memory "
- "for tomoyo_alloc_element().\n");
- if (!tomoyo_policy_loaded)
- panic("MAC Initialization failed.\n");
- } else {
- buf = ptr;
- tomoyo_allocated_memory_for_elements += PATH_MAX;
- buf_used_len = word_aligned_size;
- ptr = buf;
- }
- } else if (word_aligned_size) {
- int i;
- ptr = buf + buf_used_len;
- buf_used_len += word_aligned_size;
- for (i = 0; i < word_aligned_size; i++) {
- if (!ptr[i])
- continue;
- printk(KERN_ERR "WARNING: Reserved memory was tainted! "
- "The system might go wrong.\n");
- ptr[i] = '\0';
- }
- }
- mutex_unlock(&lock);
- return ptr;
-}
-
-/* Memory allocated for string data in bytes. */
-static unsigned int tomoyo_allocated_memory_for_savename;
-/* Quota for holding string data in bytes. */
-static unsigned int tomoyo_quota_for_savename;
-
-/*
- * TOMOYO uses this hash only when appending a string into the string
- * table. Frequency of appending strings is very low. So we don't need
- * large (e.g. 64k) hash size. 256 will be sufficient.
- */
-#define TOMOYO_HASH_BITS 8
-#define TOMOYO_MAX_HASH (1u<<TOMOYO_HASH_BITS)
-
-/*
- * tomoyo_name_entry is a structure which is used for linking
- * "struct tomoyo_path_info" into tomoyo_name_list .
- *
- * Since tomoyo_name_list manages a list of strings which are shared by
- * multiple processes (whereas "struct tomoyo_path_info" inside
- * "struct tomoyo_path_info_with_data" is not shared), a reference counter will
- * be added to "struct tomoyo_name_entry" rather than "struct tomoyo_path_info"
- * when TOMOYO starts supporting garbage collector.
- */
-struct tomoyo_name_entry {
- struct list_head list;
- struct tomoyo_path_info entry;
-};
-
-/* Structure for available memory region. */
-struct tomoyo_free_memory_block_list {
- struct list_head list;
- char *ptr; /* Pointer to a free area. */
- int len; /* Length of the area. */
-};
-
-/*
- * 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 *".
- */
-static struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
-
-/**
- * tomoyo_save_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.
- *
- * The RAM is shared, so NEVER try to modify or kfree() the returned name.
- */
-const struct tomoyo_path_info *tomoyo_save_name(const char *name)
-{
- static LIST_HEAD(fmb_list);
- static DEFINE_MUTEX(lock);
- struct tomoyo_name_entry *ptr;
- unsigned int hash;
- /* fmb contains available size in bytes.
- fmb is removed from the fmb_list when fmb->len becomes 0. */
- struct tomoyo_free_memory_block_list *fmb;
- int len;
- char *cp;
- struct list_head *head;
-
- if (!name)
- return NULL;
- len = strlen(name) + 1;
- if (len > TOMOYO_MAX_PATHNAME_LEN) {
- printk(KERN_WARNING "ERROR: Name too long "
- "for tomoyo_save_name().\n");
- return NULL;
- }
- hash = full_name_hash((const unsigned char *) name, len - 1);
- head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
-
- mutex_lock(&lock);
- list_for_each_entry(ptr, head, list) {
- if (hash == ptr->entry.hash && !strcmp(name, ptr->entry.name))
- goto out;
- }
- list_for_each_entry(fmb, &fmb_list, list) {
- if (len <= fmb->len)
- goto ready;
- }
- if (!tomoyo_quota_for_savename ||
- tomoyo_allocated_memory_for_savename + PATH_MAX
- <= tomoyo_quota_for_savename)
- cp = kzalloc(PATH_MAX, GFP_KERNEL);
- else
- cp = NULL;
- fmb = kzalloc(sizeof(*fmb), GFP_KERNEL);
- if (!cp || !fmb) {
- kfree(cp);
- kfree(fmb);
- printk(KERN_WARNING "ERROR: Out of memory "
- "for tomoyo_save_name().\n");
- if (!tomoyo_policy_loaded)
- panic("MAC Initialization failed.\n");
- ptr = NULL;
- goto out;
- }
- tomoyo_allocated_memory_for_savename += PATH_MAX;
- list_add(&fmb->list, &fmb_list);
- fmb->ptr = cp;
- fmb->len = PATH_MAX;
- ready:
- ptr = tomoyo_alloc_element(sizeof(*ptr));
- if (!ptr)
- goto out;
- ptr->entry.name = fmb->ptr;
- memmove(fmb->ptr, name, len);
- tomoyo_fill_path_info(&ptr->entry);
- fmb->ptr += len;
- fmb->len -= len;
- list_add_tail(&ptr->list, head);
- if (fmb->len == 0) {
- list_del(&fmb->list);
- kfree(fmb);
- }
- out:
- mutex_unlock(&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_save_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");
-}
-
-/* Memory allocated for temporary purpose. */
-static atomic_t tomoyo_dynamic_memory_size;
-
-/**
- * tomoyo_alloc - Allocate memory for temporary purpose.
- *
- * @size: Size in bytes.
- *
- * Returns pointer to allocated memory on success, NULL otherwise.
- */
-void *tomoyo_alloc(const size_t size)
-{
- void *p = kzalloc(size, GFP_KERNEL);
- if (p)
- atomic_add(ksize(p), &tomoyo_dynamic_memory_size);
- return p;
-}
-
-/**
- * tomoyo_free - Release memory allocated by tomoyo_alloc().
- *
- * @p: Pointer returned by tomoyo_alloc(). May be NULL.
- *
- * Returns nothing.
- */
-void tomoyo_free(const void *p)
-{
- if (p) {
- atomic_sub(ksize(p), &tomoyo_dynamic_memory_size);
- kfree(p);
- }
-}
-
-/**
- * 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 shared
- = tomoyo_allocated_memory_for_savename;
- const unsigned int private
- = tomoyo_allocated_memory_for_elements;
- const unsigned int dynamic
- = atomic_read(&tomoyo_dynamic_memory_size);
- char buffer[64];
-
- memset(buffer, 0, sizeof(buffer));
- if (tomoyo_quota_for_savename)
- snprintf(buffer, sizeof(buffer) - 1,
- " (Quota: %10u)",
- tomoyo_quota_for_savename);
- else
- buffer[0] = '\0';
- tomoyo_io_printf(head, "Shared: %10u%s\n", shared, buffer);
- if (tomoyo_quota_for_elements)
- snprintf(buffer, sizeof(buffer) - 1,
- " (Quota: %10u)",
- tomoyo_quota_for_elements);
- else
- buffer[0] = '\0';
- tomoyo_io_printf(head, "Private: %10u%s\n", private, buffer);
- tomoyo_io_printf(head, "Dynamic: %10u\n", dynamic);
- tomoyo_io_printf(head, "Total: %10u\n",
- shared + private + dynamic);
- 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, "Shared: %u", &size) == 1)
- tomoyo_quota_for_savename = size;
- else if (sscanf(data, "Private: %u", &size) == 1)
- tomoyo_quota_for_elements = size;
- return 0;
-}
projects / linux-flexiantxendom0-natty.git / blobdiff