1 files changed, 114 insertions, 312 deletions

diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index d1b96f019621..ed8ccd680102 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -1,174 +1,164 @@
 /*
  * 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};
-
+		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;
 		spin_lock(&dcache_lock);
 		/* go to whatever namespace root we are under */
-		sp = __d_path(path, &ns_root, newname, newname_len);
+		pos = __d_path(path, &ns_root, buf, buf_len);
 		spin_unlock(&dcache_lock);
 		/* 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;
 }
 
 /**
@@ -189,191 +179,3 @@ char *tomoyo_realpath_nofollow(const char *pathname)
 	}
 	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;
-}