diff options
Diffstat (limited to 'fs/cifs/link.c')
| -rw-r--r-- | fs/cifs/link.c | 746 |
1 files changed, 746 insertions, 0 deletions
diff --git a/fs/cifs/link.c b/fs/cifs/link.c new file mode 100644 index 000000000..e6c707cc6 --- /dev/null +++ b/fs/cifs/link.c @@ -0,0 +1,746 @@ +/* + * fs/cifs/link.c + * + * Copyright (C) International Business Machines Corp., 2002,2008 + * Author(s): Steve French (sfrench@us.ibm.com) + * + * This library is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published + * by the Free Software Foundation; either version 2.1 of the License, or + * (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#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" +#ifdef CONFIG_CIFS_SMB2 +#include "smb2proto.h" +#endif + +/* + * 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 \ + "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n" +#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \ + md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \ + md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \ + md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\ + md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15] + +static int +symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash) +{ + int rc; + unsigned int size; + struct crypto_shash *md5; + struct sdesc *sdescmd5; + + md5 = crypto_alloc_shash("md5", 0, 0); + if (IS_ERR(md5)) { + rc = PTR_ERR(md5); + cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n", + __func__, rc); + return rc; + } + size = sizeof(struct shash_desc) + crypto_shash_descsize(md5); + sdescmd5 = kmalloc(size, GFP_KERNEL); + if (!sdescmd5) { + rc = -ENOMEM; + goto symlink_hash_err; + } + sdescmd5->shash.tfm = md5; + sdescmd5->shash.flags = 0x0; + + rc = crypto_shash_init(&sdescmd5->shash); + if (rc) { + cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__); + goto symlink_hash_err; + } + rc = crypto_shash_update(&sdescmd5->shash, 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(&sdescmd5->shash, md5_hash); + if (rc) + cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__); + +symlink_hash_err: + crypto_free_shash(md5); + kfree(sdescmd5); + + 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; + + rc = symlink_hash(link_len, link_str, md5_hash); + if (rc) { + cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc); + return rc; + } + + snprintf(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; + } + + snprintf(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; +} + +static int +query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, const unsigned char *path, + char **symlinkinfo) +{ + int rc; + u8 *buf = NULL; + unsigned int link_len = 0; + unsigned int bytes_read = 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 */ + rc = -EINVAL; + goto out; + } + + rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo); +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; + + 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, NULL); + 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; +out: + kfree(buf); + return rc; +} + +/* + * 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; + int buf_type = CIFS_NO_BUFFER; + FILE_ALL_INFO file_info; + + oparms.tcon = tcon; + oparms.cifs_sb = cifs_sb; + oparms.desired_access = GENERIC_READ; + oparms.create_options = CREATE_NOT_DIR; + oparms.disposition = FILE_OPEN; + oparms.path = path; + oparms.fid = &fid; + oparms.reconnect = false; + + 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; + int create_options = CREATE_NOT_DIR; + + if (backup_cred(cifs_sb)) + create_options |= CREATE_OPEN_BACKUP_INTENT; + + oparms.tcon = tcon; + oparms.cifs_sb = cifs_sb; + oparms.desired_access = GENERIC_WRITE; + oparms.create_options = create_options; + oparms.disposition = FILE_CREATE; + oparms.path = path; + oparms.fid = &fid; + oparms.reconnect = false; + + 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, NULL, 0); + CIFSSMBClose(xid, tcon, fid.netfid); + return rc; +} + +/* + * SMB 2.1/SMB3 Protocol specific functions + */ +#ifdef CONFIG_CIFS_SMB2 +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; + int buf_type = CIFS_NO_BUFFER; + __le16 *utf16_path; + __u8 oplock = SMB2_OPLOCK_LEVEL_II; + struct smb2_file_all_info *pfile_info = NULL; + + oparms.tcon = tcon; + oparms.cifs_sb = cifs_sb; + oparms.desired_access = GENERIC_READ; + oparms.create_options = CREATE_NOT_DIR; + if (backup_cred(cifs_sb)) + oparms.create_options |= CREATE_OPEN_BACKUP_INTENT; + oparms.disposition = FILE_OPEN; + oparms.fid = &fid; + oparms.reconnect = false; + + 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); + 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; + int create_options = CREATE_NOT_DIR; + __le16 *utf16_path; + __u8 oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE; + struct kvec iov[2]; + + if (backup_cred(cifs_sb)) + create_options |= CREATE_OPEN_BACKUP_INTENT; + + 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.tcon = tcon; + oparms.cifs_sb = cifs_sb; + oparms.desired_access = GENERIC_WRITE; + oparms.create_options = create_options; + oparms.disposition = FILE_CREATE; + oparms.fid = &fid; + oparms.reconnect = false; + + rc = SMB2_open(xid, &oparms, utf16_path, &oplock, 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; +} +#endif /* CONFIG_CIFS_SMB2 */ + +/* + * M-F Symlink Functions - End + */ + +int +cifs_hardlink(struct dentry *old_file, struct inode *inode, + struct dentry *direntry) +{ + int rc = -EACCES; + unsigned int xid; + char *from_name = NULL; + char *to_name = NULL; + 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; + + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) + return PTR_ERR(tlink); + tcon = tlink_tcon(tlink); + + xid = get_xid(); + + from_name = build_path_from_dentry(old_file); + to_name = build_path_from_dentry(direntry); + if ((from_name == NULL) || (to_name == NULL)) { + rc = -ENOMEM; + goto cifs_hl_exit; + } + + if (tcon->unix_ext) + rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name, + cifs_sb->local_nls, + cifs_remap(cifs_sb)); + else { + 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: + kfree(from_name); + kfree(to_name); + free_xid(xid); + cifs_put_tlink(tlink); + return rc; +} + +void * +cifs_follow_link(struct dentry *direntry, struct nameidata *nd) +{ + struct inode *inode = d_inode(direntry); + int rc = -ENOMEM; + unsigned int xid; + char *full_path = NULL; + char *target_path = NULL; + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct tcon_link *tlink = NULL; + struct cifs_tcon *tcon; + struct TCP_Server_Info *server; + + xid = get_xid(); + + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) { + rc = PTR_ERR(tlink); + tlink = NULL; + goto out; + } + tcon = tlink_tcon(tlink); + server = tcon->ses->server; + + full_path = build_path_from_dentry(direntry); + if (!full_path) + goto out; + + cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode); + + rc = -EACCES; + /* + * First try Minshall+French Symlinks, if configured + * and fallback to UNIX Extensions Symlinks. + */ + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) + rc = query_mf_symlink(xid, tcon, cifs_sb, full_path, + &target_path); + + if (rc != 0 && server->ops->query_symlink) + rc = server->ops->query_symlink(xid, tcon, full_path, + &target_path, cifs_sb); + + kfree(full_path); +out: + if (rc != 0) { + kfree(target_path); + target_path = ERR_PTR(rc); + } + + free_xid(xid); + if (tlink) + cifs_put_tlink(tlink); + nd_set_link(nd, target_path); + return NULL; +} + +int +cifs_symlink(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; + char *full_path = NULL; + struct inode *newinode = NULL; + + 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); + if (full_path == NULL) { + rc = -ENOMEM; + 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); + else if (pTcon->unix_ext) + rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname, + cifs_sb->local_nls, + cifs_remap(cifs_sb)); + /* else + rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName, + cifs_sb_target->local_nls); */ + + if (rc == 0) { + 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: + kfree(full_path); + cifs_put_tlink(tlink); + free_xid(xid); + return rc; +} |