summaryrefslogtreecommitdiffstats
path: root/fs/smb/client/link.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/smb/client/link.c')
-rw-r--r--fs/smb/client/link.c650
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 000000000..c0f101fc1
--- /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 user_namespace *mnt_userns, 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-15 09:03:23 +0000