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authorSascha Hauer <s.hauer@pengutronix.de>2018-08-30 12:19:42 +0200
committerSascha Hauer <s.hauer@pengutronix.de>2018-08-30 12:40:20 +0200
commit3f245bc37d71e3a86db3cc78a615eb7c8ce8ba1c (patch)
tree3e9b611269c47731d89b94a9487f5e9098ec08f9
parentc45c74edc20386af8fe12fecb97b5953ba9716b0 (diff)
downloadbarebox-3f245bc37d71e3a86db3cc78a615eb7c8ce8ba1c.tar.gz
fs: tftp: hide files which are actually not present on the server
In tftp_lookup we claimed that every desired file is there. This leads to problems when a user only tests if a file is present and makes decisions upon this information. Rather than claiming that all files are present do a tftp_do_open() on the files and see if it is really there. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
-rw-r--r--fs/tftp.c33
1 files changed, 25 insertions, 8 deletions
diff --git a/fs/tftp.c b/fs/tftp.c
index 0baf0c2..9274e93 100644
--- a/fs/tftp.c
+++ b/fs/tftp.c
@@ -391,14 +391,6 @@ static struct file_priv *tftp_do_open(struct device_d *dev,
case O_WRONLY:
priv->push = 1;
priv->state = STATE_WRQ;
- if (!(accmode & O_TRUNC)) {
- /*
- * TFTP always truncates the existing file, so this
- * flag is mandatory when opening a file for writing.
- */
- ret = -ENOSYS;
- goto out;
- }
break;
case O_RDWR:
ret = -ENOSYS;
@@ -646,10 +638,34 @@ static struct inode *tftp_get_inode(struct super_block *sb, const struct inode *
return inode;
}
+static int tftp_create(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ struct inode *inode;
+
+ inode = tftp_get_inode(dir->i_sb, dir, mode);
+ if (!inode)
+ return -EPERM;
+
+ inode->i_size = 0;
+
+ d_instantiate(dentry, inode);
+
+ return 0;
+}
+
static struct dentry *tftp_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
+ struct super_block *sb = dir->i_sb;
+ struct fs_device_d *fsdev = container_of(sb, struct fs_device_d, sb);
struct inode *inode;
+ struct file_priv *priv;
+
+ priv = tftp_do_open(&fsdev->dev, O_RDONLY, dentry);
+ if (IS_ERR(priv))
+ return NULL;
+
+ tftp_do_close(priv);
inode = tftp_get_inode(dir->i_sb, dir, S_IFREG | S_IRWXUGO);
if (!inode)
@@ -663,6 +679,7 @@ static struct dentry *tftp_lookup(struct inode *dir, struct dentry *dentry,
static const struct inode_operations tftp_dir_inode_operations =
{
.lookup = tftp_lookup,
+ .create = tftp_create,
};
static const struct super_operations tftp_ops;