proc.c

linux 内核源代码

/*
 * Code common to mkdir and rmdir.
 */
static int
smb_proc_generic_command(struct dentry *dentry, __u8 command)
{
	struct smb_sb_info *server = server_from_dentry(dentry);
	char *p;
	int result;
	struct smb_request *req;

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, PAGE_SIZE)))
		goto out;

	p = smb_setup_header(req, command, 0, 0);
	result = smb_simple_encode_path(req, &p, dentry, NULL);
	if (result < 0)
		goto out_free;
	smb_setup_bcc(req, p);

	result = smb_request_ok(req, command, 0, 0);
	if (result < 0)
		goto out_free;
	result = 0;

out_free:
	smb_rput(req);
out:
	return result;
}

int
smb_proc_mkdir(struct dentry *dentry)
{
	return smb_proc_generic_command(dentry, SMBmkdir);
}

int
smb_proc_rmdir(struct dentry *dentry)
{
	return smb_proc_generic_command(dentry, SMBrmdir);
}

#if SMBFS_POSIX_UNLINK
/*
 * Removes readonly attribute from a file. Used by unlink to give posix
 * semantics.
 */
static int
smb_set_rw(struct dentry *dentry,struct smb_sb_info *server)
{
	int result;
	struct smb_fattr fattr;

	/* FIXME: cifsUE should allow removing a readonly file. */

	/* first get current attribute */
	smb_init_dirent(server, &fattr);
	result = server->ops->getattr(server, dentry, &fattr);
	smb_finish_dirent(server, &fattr);
	if (result < 0)
		return result;

	/* if RONLY attribute is set, remove it */
	if (fattr.attr & aRONLY) {  /* read only attribute is set */
		fattr.attr &= ~aRONLY;
		result = smb_proc_setattr_core(server, dentry, fattr.attr);
	}
	return result;
}
#endif

int
smb_proc_unlink(struct dentry *dentry)
{
	struct smb_sb_info *server = server_from_dentry(dentry);
	int flag = 0;
	char *p;
	int result;
	struct smb_request *req;

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, PAGE_SIZE)))
		goto out;

      retry:
	p = smb_setup_header(req, SMBunlink, 1, 0);
	WSET(req->rq_header, smb_vwv0, aSYSTEM | aHIDDEN);
	result = smb_simple_encode_path(req, &p, dentry, NULL);
	if (result < 0)
		goto out_free;
	smb_setup_bcc(req, p);

	if ((result = smb_request_ok(req, SMBunlink, 0, 0)) < 0) {
#if SMBFS_POSIX_UNLINK
		if (result == -EACCES && !flag) {
			/* Posix semantics is for the read-only state
			   of a file to be ignored in unlink(). In the
			   SMB world a unlink() is refused on a
			   read-only file. To make things easier for
			   unix users we try to override the files
			   permission if the unlink fails with the
			   right error.
			   This introduces a race condition that could
			   lead to a file being written by someone who
			   shouldn't have access, but as far as I can
			   tell that is unavoidable */

			/* remove RONLY attribute and try again */
			result = smb_set_rw(dentry,server);
			if (result == 0) {
				flag = 1;
				req->rq_flags = 0;
				goto retry;
			}
		}
#endif
		goto out_free;
	}
	result = 0;

out_free:
	smb_rput(req);
out:
	return result;
}

int
smb_proc_flush(struct smb_sb_info *server, __u16 fileid)
{
	int result;
	struct smb_request *req;

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, 0)))
		goto out;

	smb_setup_header(req, SMBflush, 1, 0);
	WSET(req->rq_header, smb_vwv0, fileid);
	req->rq_flags |= SMB_REQ_NORETRY;
	result = smb_request_ok(req, SMBflush, 0, 0);

	smb_rput(req);
out:
	return result;
}

static int
smb_proc_trunc32(struct inode *inode, loff_t length)
{
	/*
	 * Writing 0bytes is old-SMB magic for truncating files.
	 * MAX_NON_LFS should prevent this from being called with a too
	 * large offset.
	 */
	return smb_proc_write(inode, length, 0, NULL);
}

static int
smb_proc_trunc64(struct inode *inode, loff_t length)
{
	struct smb_sb_info *server = server_from_inode(inode);
	int result;
	char *param;
	char *data;
	struct smb_request *req;

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, 14)))
		goto out;

	param = req->rq_buffer;
	data = req->rq_buffer + 6;

	/* FIXME: must we also set allocation size? winNT seems to do that */
	WSET(param, 0, SMB_I(inode)->fileid);
	WSET(param, 2, SMB_SET_FILE_END_OF_FILE_INFO);
	WSET(param, 4, 0);
	LSET(data, 0, length);

	req->rq_trans2_command = TRANSACT2_SETFILEINFO;
	req->rq_ldata = 8;
	req->rq_data  = data;
	req->rq_lparm = 6;
	req->rq_parm  = param;
	req->rq_flags |= SMB_REQ_NORETRY;
	result = smb_add_request(req);
	if (result < 0)
		goto out_free;

	result = 0;
	if (req->rq_rcls != 0)
		result = smb_errno(req);

out_free:
	smb_rput(req);
out:
	return result;
}

static int
smb_proc_trunc95(struct inode *inode, loff_t length)
{
	struct smb_sb_info *server = server_from_inode(inode);
	int result = smb_proc_trunc32(inode, length);
 
	/*
	 * win9x doesn't appear to update the size immediately.
	 * It will return the old file size after the truncate,
	 * confusing smbfs. So we force an update.
	 *
	 * FIXME: is this still necessary?
	 */
	smb_proc_flush(server, SMB_I(inode)->fileid);
	return result;
}

static void
smb_init_dirent(struct smb_sb_info *server, struct smb_fattr *fattr)
{
	memset(fattr, 0, sizeof(*fattr));

	fattr->f_nlink = 1;
	fattr->f_uid = server->mnt->uid;
	fattr->f_gid = server->mnt->gid;
	fattr->f_unix = 0;
}

static void
smb_finish_dirent(struct smb_sb_info *server, struct smb_fattr *fattr)
{
	if (fattr->f_unix)
		return;

	fattr->f_mode = server->mnt->file_mode;
	if (fattr->attr & aDIR) {
		fattr->f_mode = server->mnt->dir_mode;
		fattr->f_size = SMB_ST_BLKSIZE;
	}
	/* Check the read-only flag */
	if (fattr->attr & aRONLY)
		fattr->f_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);

	/* How many 512 byte blocks do we need for this file? */
	fattr->f_blocks = 0;
	if (fattr->f_size != 0)
		fattr->f_blocks = 1 + ((fattr->f_size-1) >> 9);
	return;
}

void
smb_init_root_dirent(struct smb_sb_info *server, struct smb_fattr *fattr,
		     struct super_block *sb)
{
	smb_init_dirent(server, fattr);
	fattr->attr = aDIR;
	fattr->f_ino = 2; /* traditional root inode number */
	fattr->f_mtime = current_fs_time(sb);
	smb_finish_dirent(server, fattr);
}

/*
 * Decode a dirent for old protocols
 *
 * qname is filled with the decoded, and possibly translated, name.
 * fattr receives decoded attributes
 *
 * Bugs Noted:
 * (1) Pathworks servers may pad the name with extra spaces.
 */
static char *
smb_decode_short_dirent(struct smb_sb_info *server, char *p,
			struct qstr *qname, struct smb_fattr *fattr,
			unsigned char *name_buf)
{
	int len;

	/*
	 * SMB doesn't have a concept of inode numbers ...
	 */
	smb_init_dirent(server, fattr);
	fattr->f_ino = 0;	/* FIXME: do we need this? */

	p += SMB_STATUS_SIZE;	/* reserved (search_status) */
	fattr->attr = *p;
	fattr->f_mtime.tv_sec = date_dos2unix(server, WVAL(p, 3), WVAL(p, 1));
	fattr->f_mtime.tv_nsec = 0;
	fattr->f_size = DVAL(p, 5);
	fattr->f_ctime = fattr->f_mtime;
	fattr->f_atime = fattr->f_mtime;
	qname->name = p + 9;
	len = strnlen(qname->name, 12);

	/*
	 * Trim trailing blanks for Pathworks servers
	 */
	while (len > 2 && qname->name[len-1] == ' ')
		len--;

	smb_finish_dirent(server, fattr);

#if 0
	/* FIXME: These only work for ascii chars, and recent smbmount doesn't
	   allow the flag to be set anyway. It kills const. Remove? */
	switch (server->opt.case_handling) {
	case SMB_CASE_UPPER:
		str_upper(entry->name, len);
		break;
	case SMB_CASE_LOWER:
		str_lower(entry->name, len);
		break;
	default:
		break;
	}
#endif

	qname->len = 0;
	len = server->ops->convert(name_buf, SMB_MAXNAMELEN,
				   qname->name, len,
				   server->remote_nls, server->local_nls);
	if (len > 0) {
		qname->len = len;
		qname->name = name_buf;
		DEBUG1("len=%d, name=%.*s\n",qname->len,qname->len,qname->name);
	}

	return p + 22;
}

/*
 * This routine is used to read in directory entries from the network.
 * Note that it is for short directory name seeks, i.e.: protocol <
 * SMB_PROTOCOL_LANMAN2
 */
static int
smb_proc_readdir_short(struct file *filp, void *dirent, filldir_t filldir,
		       struct smb_cache_control *ctl)
{
	struct dentry *dir = filp->f_path.dentry;
	struct smb_sb_info *server = server_from_dentry(dir);
	struct qstr qname;
	struct smb_fattr fattr;
	char *p;
	int result;
	int i, first, entries_seen, entries;
	int entries_asked = (server->opt.max_xmit - 100) / SMB_DIRINFO_SIZE;
	__u16 bcc;
	__u16 count;
	char status[SMB_STATUS_SIZE];
	static struct qstr mask = {
		.name	= "*.*",
		.len	= 3,
	};
	unsigned char *last_status;
	struct smb_request *req;
	unsigned char *name_buf;

	VERBOSE("%s/%s\n", DENTRY_PATH(dir));

	lock_kernel();

	result = -ENOMEM;
	if (! (name_buf = kmalloc(SMB_MAXNAMELEN, GFP_KERNEL)))
		goto out;

	first = 1;
	entries = 0;
	entries_seen = 2; /* implicit . and .. */

	result = -ENOMEM;
	if (! (req = smb_alloc_request(server, server->opt.max_xmit)))
		goto out_name;

	while (1) {
		p = smb_setup_header(req, SMBsearch, 2, 0);
		WSET(req->rq_header, smb_vwv0, entries_asked);
		WSET(req->rq_header, smb_vwv1, aDIR);
		if (first == 1) {
			result = smb_simple_encode_path(req, &p, dir, &mask);
			if (result < 0)
				goto out_free;
			if (p + 3 > (char *)req->rq_buffer + req->rq_bufsize) {
				result = -ENAMETOOLONG;
				goto out_free;
			}
			*p++ = 5;
			WSET(p, 0, 0);
			p += 2;
			first = 0;
		} else {
			if (p + 5 + SMB_STATUS_SIZE >
			    (char *)req->rq_buffer + req->rq_bufsize) {
				result = -ENAMETOOLONG;
				goto out_free;
			}
				
			*p++ = 4;
			*p++ = 0;
			*p++ = 5;
			WSET(p, 0, SMB_STATUS_SIZE);
			p += 2;
			memcpy(p, status, SMB_STATUS_SIZE);
			p += SMB_STATUS_SIZE;
		}

		smb_setup_bcc(req, p);

		result = smb_request_ok(req, SMBsearch, 1, -1);
		if (result < 0) {
			if ((req->rq_rcls == ERRDOS) && 
			    (req->rq_err  == ERRnofiles))
				break;
			goto out_free;
		}
		count = WVAL(req->rq_header, smb_vwv0);
		if (count <= 0)
			break;

		result = -EIO;
		bcc = smb_bcc(req->rq_header);
		if (bcc != count * SMB_DIRINFO_SIZE + 3)
			goto out_free;
		p = req->rq_buffer + 3;


		/* Make sure the response fits in the buffer. Fixed sized 
		   entries means we don't have to check in the decode loop. */

		last_status = req->rq_buffer + 3 + (count-1) * SMB_DIRINFO_SIZE;

		if (last_status + SMB_DIRINFO_SIZE >=
		    req->rq_buffer + req->rq_bufsize) {
			printk(KERN_ERR "smb_proc_readdir_short: "
			       "last dir entry outside buffer! "
			       "%d@%p  %d@%p\n", SMB_DIRINFO_SIZE, last_status,
			       req->rq_bufsize, req->rq_buffer);
			goto out_free;
		}

		/* Read the last entry into the status field. */
		memcpy(status, last_status, SMB_STATUS_SIZE);


		/* Now we are ready to parse smb directory entries. */

		for (i = 0; i < count; i++) {
			p = smb_decode_short_dirent(server, p, 
						    &qname, &fattr, name_buf);
			if (qname.len == 0)
				continue;

			if (entries_seen == 2 && qname.name[0] == '.') {
				if (qname.len == 1)
					continue;
				if (qname.name[1] == '.' && qname.len == 2)
					continue;
			}
			if (!smb_fill_cache(filp, dirent, filldir, ctl, 
					    &qname, &fattr))
				;	/* stop reading? */
			entries_seen++;
		}
	}
	result = entries;

out_free:
	smb_rput(req);
out_name:
	kfree(name_buf);
out:
	unlock_kernel();
	return result;
}

static void smb_decode_unix_basic(struct smb_fattr *fattr, struct smb_sb_info *server, char *p)
{
	u64 size, disk_bytes;

	/* FIXME: verify nls support. all is sent as utf8? */

	fattr->f_unix = 1;
	fattr->f_mode = 0;

	/* FIXME: use the uniqueID from the remote instead? */
	/* 0 L file size in bytes */
	/* 8 L file size on disk in bytes (block count) */
	/* 40 L uid */
	/* 48 L gid */
	/* 56 W file type */
	/* 60 L devmajor */
	/* 68 L devminor */
	/* 76 L unique ID (inode) */
	/* 84 L permissions */
	/* 92 L link count */

	size = LVAL(p, 0);
	disk_bytes = LVAL(p, 8);

	/*
	 * Some samba versions round up on-disk byte usage
	 * to 1MB boundaries, making it useless. When seeing
	 * that, use the size instead.
	 */
	if (!(disk_bytes & 0xfffff))
		disk_bytes = size+511;

	fattr->f_size = size;
	fattr->f_blocks = disk_bytes >> 9;
	fattr->f_ctime = smb_ntutc2unixutc(LVAL(p, 16));
	fattr->f_atime = smb_ntutc2unixutc(LVAL(p, 24));
	fattr->f_mtime = smb_ntutc2unixutc(LVAL(p, 32));

	if (server->mnt->flags & SMB_MOUNT_UID)
		fattr->f_uid = server->mnt->uid;
	else
		fattr->f_uid = LVAL(p, 40);

	if (server->mnt->flags & SMB_MOUNT_GID)
		fattr->f_gid = server->mnt->gid;
	else
		fattr->f_gid = LVAL(p, 48);

	fattr->f_mode |= smb_filetype_to_mode(WVAL(p, 56));

	if (S_ISBLK(fattr->f_mode) || S_ISCHR(fattr->f_mode)) {
		__u64 major = LVAL(p, 60);
		__u64 minor = LVAL(p, 68);

		fattr->f_rdev = MKDEV(major & 0xffffffff, minor & 0xffffffff);
		if (MAJOR(fattr->f_rdev) != (major & 0xffffffff) ||
	    	MINOR(fattr->f_rdev) != (minor & 0xffffffff))
			fattr->f_rdev = 0;
	}