1 files changed, 650 insertions, 0 deletions

diff --git a/fs/smb/client/link.c b/fs/smb/client/link.c
new file mode 100644
index 000000000000..c66be4904e1f
--- /dev/null
+++ b/fs/smb/client/link.c
@@ -0,0 +1,650 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ *
+ *   Copyright (C) International Business Machines  Corp., 2002,2008
+ *   Author(s): Steve French (sfrench@us.ibm.com)
+ *
+ */
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include "cifsfs.h"
+#include "cifspdu.h"
+#include "cifsglob.h"
+#include "cifsproto.h"
+#include "cifs_debug.h"
+#include "cifs_fs_sb.h"
+#include "cifs_unicode.h"
+#include "smb2proto.h"
+#include "cifs_ioctl.h"
+
+/*
+ * M-F Symlink Functions - Begin
+ */
+
+#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
+#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
+#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
+#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
+#define CIFS_MF_SYMLINK_FILE_SIZE \
+	(CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
+
+#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
+#define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
+#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
+
+static int
+symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
+{
+	int rc;
+	struct shash_desc *md5 = NULL;
+
+	rc = cifs_alloc_hash("md5", &md5);
+	if (rc)
+		goto symlink_hash_err;
+
+	rc = crypto_shash_init(md5);
+	if (rc) {
+		cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
+		goto symlink_hash_err;
+	}
+	rc = crypto_shash_update(md5, link_str, link_len);
+	if (rc) {
+		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
+		goto symlink_hash_err;
+	}
+	rc = crypto_shash_final(md5, md5_hash);
+	if (rc)
+		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
+
+symlink_hash_err:
+	cifs_free_hash(&md5);
+	return rc;
+}
+
+static int
+parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
+		 char **_link_str)
+{
+	int rc;
+	unsigned int link_len;
+	const char *md5_str1;
+	const char *link_str;
+	u8 md5_hash[16];
+	char md5_str2[34];
+
+	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
+		return -EINVAL;
+
+	md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
+	link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
+
+	rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
+	if (rc != 1)
+		return -EINVAL;
+
+	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
+		return -EINVAL;
+
+	rc = symlink_hash(link_len, link_str, md5_hash);
+	if (rc) {
+		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
+		return rc;
+	}
+
+	scnprintf(md5_str2, sizeof(md5_str2),
+		  CIFS_MF_SYMLINK_MD5_FORMAT,
+		  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
+
+	if (strncmp(md5_str1, md5_str2, 17) != 0)
+		return -EINVAL;
+
+	if (_link_str) {
+		*_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
+		if (!*_link_str)
+			return -ENOMEM;
+	}
+
+	*_link_len = link_len;
+	return 0;
+}
+
+static int
+format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
+{
+	int rc;
+	unsigned int link_len;
+	unsigned int ofs;
+	u8 md5_hash[16];
+
+	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
+		return -EINVAL;
+
+	link_len = strlen(link_str);
+
+	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
+		return -ENAMETOOLONG;
+
+	rc = symlink_hash(link_len, link_str, md5_hash);
+	if (rc) {
+		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
+		return rc;
+	}
+
+	scnprintf(buf, buf_len,
+		  CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
+		  link_len,
+		  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
+
+	ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
+	memcpy(buf + ofs, link_str, link_len);
+
+	ofs += link_len;
+	if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
+		buf[ofs] = '\n';
+		ofs++;
+	}
+
+	while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
+		buf[ofs] = ' ';
+		ofs++;
+	}
+
+	return 0;
+}
+
+bool
+couldbe_mf_symlink(const struct cifs_fattr *fattr)
+{
+	if (!S_ISREG(fattr->cf_mode))
+		/* it's not a symlink */
+		return false;
+
+	if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
+		/* it's not a symlink */
+		return false;
+
+	return true;
+}
+
+static int
+create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
+		  struct cifs_sb_info *cifs_sb, const char *fromName,
+		  const char *toName)
+{
+	int rc;
+	u8 *buf;
+	unsigned int bytes_written = 0;
+
+	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
+	if (rc)
+		goto out;
+
+	if (tcon->ses->server->ops->create_mf_symlink)
+		rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
+					cifs_sb, fromName, buf, &bytes_written);
+	else
+		rc = -EOPNOTSUPP;
+
+	if (rc)
+		goto out;
+
+	if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
+		rc = -EIO;
+out:
+	kfree(buf);
+	return rc;
+}
+
+int
+check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
+		 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
+		 const unsigned char *path)
+{
+	int rc;
+	u8 *buf = NULL;
+	unsigned int link_len = 0;
+	unsigned int bytes_read = 0;
+	char *symlink = NULL;
+
+	if (!couldbe_mf_symlink(fattr))
+		/* it's not a symlink */
+		return 0;
+
+	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	if (tcon->ses->server->ops->query_mf_symlink)
+		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
+					      cifs_sb, path, buf, &bytes_read);
+	else
+		rc = -ENOSYS;
+
+	if (rc)
+		goto out;
+
+	if (bytes_read == 0) /* not a symlink */
+		goto out;
+
+	rc = parse_mf_symlink(buf, bytes_read, &link_len, &symlink);
+	if (rc == -EINVAL) {
+		/* it's not a symlink */
+		rc = 0;
+		goto out;
+	}
+
+	if (rc != 0)
+		goto out;
+
+	/* it is a symlink */
+	fattr->cf_eof = link_len;
+	fattr->cf_mode &= ~S_IFMT;
+	fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
+	fattr->cf_dtype = DT_LNK;
+	fattr->cf_symlink_target = symlink;
+out:
+	kfree(buf);
+	return rc;
+}
+
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
+/*
+ * SMB 1.0 Protocol specific functions
+ */
+
+int
+cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
+		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
+		      char *pbuf, unsigned int *pbytes_read)
+{
+	int rc;
+	int oplock = 0;
+	struct cifs_fid fid;
+	struct cifs_open_parms oparms;
+	struct cifs_io_parms io_parms = {0};
+	int buf_type = CIFS_NO_BUFFER;
+	FILE_ALL_INFO file_info;
+
+	oparms = (struct cifs_open_parms) {
+		.tcon = tcon,
+		.cifs_sb = cifs_sb,
+		.desired_access = GENERIC_READ,
+		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
+		.disposition = FILE_OPEN,
+		.path = path,
+		.fid = &fid,
+	};
+
+	rc = CIFS_open(xid, &oparms, &oplock, &file_info);
+	if (rc)
+		return rc;
+
+	if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
+		rc = -ENOENT;
+		/* it's not a symlink */
+		goto out;
+	}
+
+	io_parms.netfid = fid.netfid;
+	io_parms.pid = current->tgid;
+	io_parms.tcon = tcon;
+	io_parms.offset = 0;
+	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+
+	rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
+out:
+	CIFSSMBClose(xid, tcon, fid.netfid);
+	return rc;
+}
+
+int
+cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
+		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
+		       char *pbuf, unsigned int *pbytes_written)
+{
+	int rc;
+	int oplock = 0;
+	struct cifs_fid fid;
+	struct cifs_open_parms oparms;
+	struct cifs_io_parms io_parms = {0};
+
+	oparms = (struct cifs_open_parms) {
+		.tcon = tcon,
+		.cifs_sb = cifs_sb,
+		.desired_access = GENERIC_WRITE,
+		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
+		.disposition = FILE_CREATE,
+		.path = path,
+		.fid = &fid,
+	};
+
+	rc = CIFS_open(xid, &oparms, &oplock, NULL);
+	if (rc)
+		return rc;
+
+	io_parms.netfid = fid.netfid;
+	io_parms.pid = current->tgid;
+	io_parms.tcon = tcon;
+	io_parms.offset = 0;
+	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+
+	rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
+	CIFSSMBClose(xid, tcon, fid.netfid);
+	return rc;
+}
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
+
+/*
+ * SMB 2.1/SMB3 Protocol specific functions
+ */
+int
+smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
+		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
+		      char *pbuf, unsigned int *pbytes_read)
+{
+	int rc;
+	struct cifs_fid fid;
+	struct cifs_open_parms oparms;
+	struct cifs_io_parms io_parms = {0};
+	int buf_type = CIFS_NO_BUFFER;
+	__le16 *utf16_path;
+	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
+	struct smb2_file_all_info *pfile_info = NULL;
+
+	oparms = (struct cifs_open_parms) {
+		.tcon = tcon,
+		.cifs_sb = cifs_sb,
+		.path = path,
+		.desired_access = GENERIC_READ,
+		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
+		.disposition = FILE_OPEN,
+		.fid = &fid,
+	};
+
+	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
+	if (utf16_path == NULL)
+		return -ENOMEM;
+
+	pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
+			     GFP_KERNEL);
+
+	if (pfile_info == NULL) {
+		kfree(utf16_path);
+		return  -ENOMEM;
+	}
+
+	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
+		       NULL, NULL);
+	if (rc)
+		goto qmf_out_open_fail;
+
+	if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
+		/* it's not a symlink */
+		rc = -ENOENT; /* Is there a better rc to return? */
+		goto qmf_out;
+	}
+
+	io_parms.netfid = fid.netfid;
+	io_parms.pid = current->tgid;
+	io_parms.tcon = tcon;
+	io_parms.offset = 0;
+	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+	io_parms.persistent_fid = fid.persistent_fid;
+	io_parms.volatile_fid = fid.volatile_fid;
+	rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
+qmf_out:
+	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
+qmf_out_open_fail:
+	kfree(utf16_path);
+	kfree(pfile_info);
+	return rc;
+}
+
+int
+smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
+		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
+		       char *pbuf, unsigned int *pbytes_written)
+{
+	int rc;
+	struct cifs_fid fid;
+	struct cifs_open_parms oparms;
+	struct cifs_io_parms io_parms = {0};
+	__le16 *utf16_path;
+	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
+	struct kvec iov[2];
+
+	cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
+
+	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
+	if (!utf16_path)
+		return -ENOMEM;
+
+	oparms = (struct cifs_open_parms) {
+		.tcon = tcon,
+		.cifs_sb = cifs_sb,
+		.path = path,
+		.desired_access = GENERIC_WRITE,
+		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
+		.disposition = FILE_CREATE,
+		.fid = &fid,
+		.mode = 0644,
+	};
+
+	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
+		       NULL, NULL);
+	if (rc) {
+		kfree(utf16_path);
+		return rc;
+	}
+
+	io_parms.netfid = fid.netfid;
+	io_parms.pid = current->tgid;
+	io_parms.tcon = tcon;
+	io_parms.offset = 0;
+	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+	io_parms.persistent_fid = fid.persistent_fid;
+	io_parms.volatile_fid = fid.volatile_fid;
+
+	/* iov[0] is reserved for smb header */
+	iov[1].iov_base = pbuf;
+	iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
+
+	rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
+
+	/* Make sure we wrote all of the symlink data */
+	if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
+		rc = -EIO;
+
+	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
+
+	kfree(utf16_path);
+	return rc;
+}
+
+/*
+ * M-F Symlink Functions - End
+ */
+
+int
+cifs_hardlink(struct dentry *old_file, struct inode *inode,
+	      struct dentry *direntry)
+{
+	int rc = -EACCES;
+	unsigned int xid;
+	const char *from_name, *to_name;
+	void *page1, *page2;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+	struct tcon_link *tlink;
+	struct cifs_tcon *tcon;
+	struct TCP_Server_Info *server;
+	struct cifsInodeInfo *cifsInode;
+
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+	tcon = tlink_tcon(tlink);
+
+	xid = get_xid();
+	page1 = alloc_dentry_path();
+	page2 = alloc_dentry_path();
+
+	from_name = build_path_from_dentry(old_file, page1);
+	if (IS_ERR(from_name)) {
+		rc = PTR_ERR(from_name);
+		goto cifs_hl_exit;
+	}
+	to_name = build_path_from_dentry(direntry, page2);
+	if (IS_ERR(to_name)) {
+		rc = PTR_ERR(to_name);
+		goto cifs_hl_exit;
+	}
+
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
+	if (tcon->unix_ext)
+		rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
+					    cifs_sb->local_nls,
+					    cifs_remap(cifs_sb));
+	else {
+#else
+	{
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
+		server = tcon->ses->server;
+		if (!server->ops->create_hardlink) {
+			rc = -ENOSYS;
+			goto cifs_hl_exit;
+		}
+		rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
+						  cifs_sb);
+		if ((rc == -EIO) || (rc == -EINVAL))
+			rc = -EOPNOTSUPP;
+	}
+
+	d_drop(direntry);	/* force new lookup from server of target */
+
+	/*
+	 * if source file is cached (oplocked) revalidate will not go to server
+	 * until the file is closed or oplock broken so update nlinks locally
+	 */
+	if (d_really_is_positive(old_file)) {
+		cifsInode = CIFS_I(d_inode(old_file));
+		if (rc == 0) {
+			spin_lock(&d_inode(old_file)->i_lock);
+			inc_nlink(d_inode(old_file));
+			spin_unlock(&d_inode(old_file)->i_lock);
+
+			/*
+			 * parent dir timestamps will update from srv within a
+			 * second, would it really be worth it to set the parent
+			 * dir cifs inode time to zero to force revalidate
+			 * (faster) for it too?
+			 */
+		}
+		/*
+		 * if not oplocked will force revalidate to get info on source
+		 * file from srv.  Note Samba server prior to 4.2 has bug -
+		 * not updating src file ctime on hardlinks but Windows servers
+		 * handle it properly
+		 */
+		cifsInode->time = 0;
+
+		/*
+		 * Will update parent dir timestamps from srv within a second.
+		 * Would it really be worth it to set the parent dir (cifs
+		 * inode) time field to zero to force revalidate on parent
+		 * directory faster ie
+		 *
+		 * CIFS_I(inode)->time = 0;
+		 */
+	}
+
+cifs_hl_exit:
+	free_dentry_path(page1);
+	free_dentry_path(page2);
+	free_xid(xid);
+	cifs_put_tlink(tlink);
+	return rc;
+}
+
+int
+cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
+	     struct dentry *direntry, const char *symname)
+{
+	int rc = -EOPNOTSUPP;
+	unsigned int xid;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+	struct tcon_link *tlink;
+	struct cifs_tcon *pTcon;
+	const char *full_path;
+	void *page;
+	struct inode *newinode = NULL;
+
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
+	page = alloc_dentry_path();
+	if (!page)
+		return -ENOMEM;
+
+	xid = get_xid();
+
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink)) {
+		rc = PTR_ERR(tlink);
+		goto symlink_exit;
+	}
+	pTcon = tlink_tcon(tlink);
+
+	full_path = build_path_from_dentry(direntry, page);
+	if (IS_ERR(full_path)) {
+		rc = PTR_ERR(full_path);
+		goto symlink_exit;
+	}
+
+	cifs_dbg(FYI, "Full path: %s\n", full_path);
+	cifs_dbg(FYI, "symname is %s\n", symname);
+
+	/* BB what if DFS and this volume is on different share? BB */
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
+		rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
+	else if (pTcon->unix_ext)
+		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
+					   cifs_sb->local_nls,
+					   cifs_remap(cifs_sb));
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
+	/* else
+	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
+					cifs_sb_target->local_nls); */
+
+	if (rc == 0) {
+		if (pTcon->posix_extensions)
+			rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
+		else if (pTcon->unix_ext)
+			rc = cifs_get_inode_info_unix(&newinode, full_path,
+						      inode->i_sb, xid);
+		else
+			rc = cifs_get_inode_info(&newinode, full_path, NULL,
+						 inode->i_sb, xid, NULL);
+
+		if (rc != 0) {
+			cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
+				 rc);
+		} else {
+			d_instantiate(direntry, newinode);
+		}
+	}
+symlink_exit:
+	free_dentry_path(page);
+	cifs_put_tlink(tlink);
+	free_xid(xid);
+	return rc;
+}