diff options
Diffstat (limited to 'fs/cifs/link.c')
| -rw-r--r-- | fs/cifs/link.c | 571 |
1 files changed, 480 insertions, 91 deletions
diff --git a/fs/cifs/link.c b/fs/cifs/link.c index fc1e0487eae..68559fd557f 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -20,6 +20,7 @@ */ #include <linux/fs.h> #include <linux/stat.h> +#include <linux/slab.h> #include <linux/namei.h> #include "cifsfs.h" #include "cifspdu.h" @@ -28,78 +29,465 @@ #include "cifs_debug.h" #include "cifs_fs_sb.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 \ + "%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; + + rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon, cifs_sb, + fromName, buf, &bytes_written); + 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)) + /* 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; +} + +/* + * M-F Symlink Functions - End + */ + int cifs_hardlink(struct dentry *old_file, struct inode *inode, struct dentry *direntry) { int rc = -EACCES; - int xid; - char *fromName = NULL; - char *toName = NULL; - struct cifs_sb_info *cifs_sb_target; - struct cifsTconInfo *pTcon; + 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; - xid = GetXid(); - - cifs_sb_target = CIFS_SB(inode->i_sb); - pTcon = cifs_sb_target->tcon; + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) + return PTR_ERR(tlink); + tcon = tlink_tcon(tlink); -/* No need to check for cross device links since server will do that - BB note DFS case in future though (when we may have to check) */ + xid = get_xid(); - fromName = build_path_from_dentry(old_file); - toName = build_path_from_dentry(direntry); - if ((fromName == NULL) || (toName == NULL)) { + 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 (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)*/ - if (pTcon->unix_ext) - rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName, - cifs_sb_target->local_nls, - cifs_sb_target->mnt_cifs_flags & + if (tcon->unix_ext) + rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name, + cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); else { - rc = CIFSCreateHardLink(xid, pTcon, fromName, toName, - cifs_sb_target->local_nls, - cifs_sb_target->mnt_cifs_flags & - CIFS_MOUNT_MAP_SPECIAL_CHR); + 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 source file is cached (oplocked) revalidate will not go to server + * until the file is closed or oplock broken so update nlinks locally + */ if (old_file->d_inode) { cifsInode = CIFS_I(old_file->d_inode); if (rc == 0) { - old_file->d_inode->i_nlink++; -/* BB should we make this contingent on superblock flag NOATIME? */ -/* old_file->d_inode->i_ctime = CURRENT_TIME;*/ - /* 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? */ + spin_lock(&old_file->d_inode->i_lock); + inc_nlink(old_file->d_inode); + spin_unlock(&old_file->d_inode->i_lock); + /* + * BB should we make this contingent on superblock flag + * NOATIME? + */ + /* old_file->d_inode->i_ctime = CURRENT_TIME; */ + /* + * 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 */ + /* + * if not oplocked will force revalidate to get info on source + * file from srv + */ 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; */ + /* + * 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(fromName); - kfree(toName); - FreeXid(xid); + kfree(from_name); + kfree(to_name); + free_xid(xid); + cifs_put_tlink(tlink); return rc; } @@ -108,40 +496,44 @@ cifs_follow_link(struct dentry *direntry, struct nameidata *nd) { struct inode *inode = direntry->d_inode; int rc = -ENOMEM; - int xid; + unsigned int xid; char *full_path = NULL; char *target_path = NULL; struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); - struct cifsTconInfo *tcon = cifs_sb->tcon; + struct tcon_link *tlink = NULL; + struct cifs_tcon *tcon; + struct TCP_Server_Info *server; - xid = GetXid(); + xid = get_xid(); - /* - * For now, we just handle symlinks with unix extensions enabled. - * Eventually we should handle NTFS reparse points, and MacOS - * symlink support. For instance... - * - * rc = CIFSSMBQueryReparseLinkInfo(...) - * - * For now, just return -EACCES when the server doesn't support posix - * extensions. Note that we still allow querying symlinks when posix - * extensions are manually disabled. We could disable these as well - * but there doesn't seem to be any harm in allowing the client to - * read them. - */ - if (!(tcon->ses->capabilities & CAP_UNIX)) { - rc = -EACCES; + 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; - cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode)); + 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); - rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path, - cifs_sb->local_nls); kfree(full_path); out: if (rc != 0) { @@ -149,7 +541,9 @@ out: target_path = ERR_PTR(rc); } - FreeXid(xid); + free_xid(xid); + if (tlink) + cifs_put_tlink(tlink); nd_set_link(nd, target_path); return NULL; } @@ -158,30 +552,35 @@ int cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname) { int rc = -EOPNOTSUPP; - int xid; - struct cifs_sb_info *cifs_sb; - struct cifsTconInfo *pTcon; + 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 = GetXid(); + xid = get_xid(); - cifs_sb = CIFS_SB(inode->i_sb); - pTcon = cifs_sb->tcon; + 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; - FreeXid(xid); - return rc; + goto symlink_exit; } - cFYI(1, ("Full path: %s", full_path)); - cFYI(1, ("symname is %s", symname)); + 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 (pTcon->unix_ext) + 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); /* else @@ -197,25 +596,15 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname) inode->i_sb, xid, NULL); if (rc != 0) { - cFYI(1, ("Create symlink ok, getinodeinfo fail rc = %d", - rc)); + cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n", + rc); } else { - if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; - else - direntry->d_op = &cifs_dentry_ops; d_instantiate(direntry, newinode); } } - +symlink_exit: kfree(full_path); - FreeXid(xid); + cifs_put_tlink(tlink); + free_xid(xid); return rc; } - -void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie) -{ - char *p = nd_get_link(nd); - if (!IS_ERR(p)) - kfree(p); -} |
