diff options
| -rw-r--r-- | fs/cifs/cifsproto.h | 4 | ||||
| -rw-r--r-- | fs/cifs/link.c | 79 |
2 files changed, 83 insertions, 0 deletions
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 588612867451..8604a45c1107 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -409,4 +409,8 @@ extern int CIFSSMBSetPosixACL(const int xid, struct cifsTconInfo *tcon, extern int CIFSGetExtAttr(const int xid, struct cifsTconInfo *tcon, const int netfid, __u64 *pExtAttrBits, __u64 *pMask); extern void cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb); +extern bool CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr); +extern int CIFSCheckMFSymlink(struct cifs_fattr *fattr, + const unsigned char *path, + struct cifs_sb_info *cifs_sb, int xid); #endif /* _CIFSPROTO_H */ diff --git a/fs/cifs/link.c b/fs/cifs/link.c index 12eb491d4c52..bec212b09a02 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -91,6 +91,85 @@ CIFSParseMFSymlink(const u8 *buf, return 0; } +bool +CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr) +{ + if (!(fattr->cf_mode & S_IFREG)) + /* 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; +} + +int +CIFSCheckMFSymlink(struct cifs_fattr *fattr, + const unsigned char *path, + struct cifs_sb_info *cifs_sb, int xid) +{ + int rc; + int oplock = 0; + __u16 netfid = 0; + struct cifsTconInfo *pTcon = cifs_sb->tcon; + u8 *buf; + char *pbuf; + unsigned int bytes_read = 0; + int buf_type = CIFS_NO_BUFFER; + unsigned int link_len = 0; + FILE_ALL_INFO file_info; + + if (!CIFSCouldBeMFSymlink(fattr)) + /* it's not a symlink */ + return 0; + + rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ, + CREATE_NOT_DIR, &netfid, &oplock, &file_info, + cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & + CIFS_MOUNT_MAP_SPECIAL_CHR); + if (rc != 0) + return rc; + + if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) { + CIFSSMBClose(xid, pTcon, netfid); + /* it's not a symlink */ + return 0; + } + + buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + pbuf = buf; + + rc = CIFSSMBRead(xid, pTcon, netfid, + CIFS_MF_SYMLINK_FILE_SIZE /* length */, + 0 /* offset */, + &bytes_read, &pbuf, &buf_type); + CIFSSMBClose(xid, pTcon, netfid); + if (rc != 0) { + kfree(buf); + return rc; + } + + rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL); + kfree(buf); + if (rc == -EINVAL) + /* it's not a symlink */ + return 0; + if (rc != 0) + return rc; + + /* 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; + return 0; +} + int cifs_hardlink(struct dentry *old_file, struct inode *inode, struct dentry *direntry) |