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pxar::fuse: add support to read ACLs.

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ACLs are stored separately in the pxar archive. This implements the functionality
needed to read the ACLs and return them as extended attributes in the getxattr
callback.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
This commit is contained in:
Christian Ebner 2020-01-28 12:42:23 +01:00 committed by Wolfgang Bumiller
parent 0502ce6da3
commit 72677fb0a5
1 changed files with 71 additions and 11 deletions
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82
src/pxar/fuse.rs
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@ -16,6 +16,7 @@ use libc;
use libc::{c_char, c_int, c_void, size_t};
use crate::tools::lru_cache::{Cacher, LruCache};
use crate::tools::acl;
use super::binary_search_tree::search_binary_tree_by;
use super::decoder::{Decoder, DirectoryEntry};
use super::format_definition::PxarGoodbyeItem;
@ -643,19 +644,77 @@ impl Session {
let entry = entry_cache.access(ino_offset, &mut EntryCacher { decoder, map })
.map_err(|_| libc::EIO)?
.ok_or_else(|| libc::EIO)?;
// security.capability is stored separately, check it first
if name.to_bytes() == b"security.capability" {
match &mut entry.xattr.fcaps {
None => return Err(libc::ENODATA),
Some(fcaps) => return Self::xattr_reply_value(req, &mut fcaps.data, size),
// Some of the extended attributes are stored separately in the archive,
// so check if requested name matches one of those.
match name.to_bytes() {
b"security.capability" => {
match &mut entry.xattr.fcaps {
None => return Err(libc::ENODATA),
Some(fcaps) => return Self::xattr_reply_value(req, &mut fcaps.data, size),
}
}
b"system.posix_acl_access" => {
// Make sure to return if there are no matching extended attributes in the archive
if entry.xattr.acl_group_obj.is_none()
&& entry.xattr.acl_user.is_empty()
&& entry.xattr.acl_group.is_empty() {
return Err(libc::ENODATA);
}
let mut buffer = acl::ACLXAttrBuffer::new(acl::ACL_EA_VERSION);
buffer.add_entry(acl::ACL_USER_OBJ, None, acl::mode_user_to_acl_permissions(entry.entry.mode));
match &entry.xattr.acl_group_obj {
Some(group_obj) => {
buffer.add_entry(acl::ACL_MASK, None, acl::mode_group_to_acl_permissions(entry.entry.mode));
buffer.add_entry(acl::ACL_GROUP_OBJ, None, group_obj.permissions);
}
None => {
buffer.add_entry(acl::ACL_GROUP_OBJ, None, acl::mode_group_to_acl_permissions(entry.entry.mode));
}
}
buffer.add_entry(acl::ACL_OTHER, None, acl::mode_other_to_acl_permissions(entry.entry.mode));
for user in &mut entry.xattr.acl_user {
buffer.add_entry(acl::ACL_USER, Some(user.uid), user.permissions);
}
for group in &mut entry.xattr.acl_group {
buffer.add_entry(acl::ACL_GROUP, Some(group.gid), group.permissions);
}
return Self::xattr_reply_value(req, buffer.as_mut_slice(), size);
}
b"system.posix_acl_default" => {
if let Some(default) = &entry.xattr.acl_default {
let mut buffer = acl::ACLXAttrBuffer::new(acl::ACL_EA_VERSION);
buffer.add_entry(acl::ACL_USER_OBJ, None, default.user_obj_permissions);
buffer.add_entry(acl::ACL_GROUP_OBJ, None, default.group_obj_permissions);
buffer.add_entry(acl::ACL_OTHER, None, default.other_permissions);
if default.mask_permissions != std::u64::MAX {
buffer.add_entry(acl::ACL_MASK, None, default.mask_permissions);
}
for user in &mut entry.xattr.acl_default_user {
buffer.add_entry(acl::ACL_USER, Some(user.uid), user.permissions);
}
for group in &mut entry.xattr.acl_default_group {
buffer.add_entry(acl::ACL_GROUP, Some(group.gid), group.permissions);
}
if buffer.len() > 0 {
return Self::xattr_reply_value(req, buffer.as_mut_slice(), size);
}
}
}
name => {
for xattr in &mut entry.xattr.xattrs {
if name == xattr.name.as_slice() {
return Self::xattr_reply_value(req, &mut xattr.value, size);
}
}
}
}
for xattr in &mut entry.xattr.xattrs {
if name.to_bytes() == xattr.name.as_slice() {
return Self::xattr_reply_value(req, &mut xattr.value, size);
}
}
Err(libc::ENODATA)
});
@ -677,13 +736,14 @@ impl Session {
buffer.append(&mut xattr.name);
buffer.push(b'\0');
}
Self::xattr_reply_value(req, &mut buffer, size)
});
}
/// Helper function used to respond to get- and listxattr calls in order to
/// de-duplicate code.
fn xattr_reply_value(req: Request, value: &mut Vec<u8>, size: size_t) -> Result<(), i32> {
fn xattr_reply_value(req: Request, value: &mut [u8], size: size_t) -> Result<(), i32> {
let len = value.len();
if size == 0 {