From: Andreas Gruenbacher <andreas.gruenbacher@gmail.com> To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-api@vger.kernel.org, samba-technical@lists.samba.org, linux-security-module@vger.kernel.org Subject: [RFC v4 13/31] richacl: Check if an acl is equivalent to a file mode Date: Wed, 24 Jun 2015 23:57:02 +0200 [thread overview] Message-ID: <1435183040-22726-14-git-send-email-agruenba@redhat.com> (raw) In-Reply-To: <1435183040-22726-1-git-send-email-agruenba@redhat.com> ACLs are considered equivalent to file modes if they only consist of owner@, group@, and everyone@ entries, the owner@ permissions do not depend on whether the owner is a member in the owning group, and no inheritance flags are set. This test is used to avoid storing richacls if the acl can be computed from the file permission bits. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> --- fs/richacl_base.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/richacl.h | 1 + 2 files changed, 96 insertions(+) diff --git a/fs/richacl_base.c b/fs/richacl_base.c index 5da092b..1ef3bf3 100644 --- a/fs/richacl_base.c +++ b/fs/richacl_base.c @@ -365,3 +365,98 @@ richacl_chmod(struct richacl *acl, mode_t mode) return clone; } EXPORT_SYMBOL_GPL(richacl_chmod); + +/** + * richacl_equiv_mode - compute the mode equivalent of @acl + * + * An acl is considered equivalent to a file mode if it only consists of + * owner@, group@, and everyone@ entries and the owner@ permissions do not + * depend on whether the owner is a member in the owning group. + */ +int +richacl_equiv_mode(const struct richacl *acl, mode_t *mode_p) +{ + mode_t mode = *mode_p; + + /* + * The RICHACE_DELETE_CHILD flag is meaningless for non-directories, so + * we ignore it. + */ + unsigned int x = S_ISDIR(mode) ? 0 : RICHACE_DELETE_CHILD; + struct { + unsigned int allowed; + unsigned int defined; /* allowed or denied */ + } owner = { + .defined = RICHACE_POSIX_ALWAYS_ALLOWED | RICHACE_POSIX_OWNER_ALLOWED | x, + }, group = { + .defined = RICHACE_POSIX_ALWAYS_ALLOWED | x, + }, everyone = { + .defined = RICHACE_POSIX_ALWAYS_ALLOWED | x, + }; + const struct richace *ace; + + if (acl->a_flags & ~RICHACL_MASKED) + return -1; + + richacl_for_each_entry(ace, acl) { + if (ace->e_flags & ~RICHACE_SPECIAL_WHO) + return -1; + + if (richace_is_owner(ace) || richace_is_everyone(ace)) { + x = ace->e_mask & ~owner.defined; + if (richace_is_allow(ace)) { + unsigned int group_denied = group.defined & ~group.allowed; + + if (x & group_denied) + return -1; + owner.allowed |= x; + } else /* if (richace_is_deny(ace)) */ { + if (x & group.allowed) + return -1; + } + owner.defined |= x; + + if (richace_is_everyone(ace)) { + x = ace->e_mask; + if (richace_is_allow(ace)) { + group.allowed |= x & ~group.defined; + everyone.allowed |= x & ~everyone.defined; + } + group.defined |= x; + everyone.defined |= x; + } + } else if (richace_is_group(ace)) { + x = ace->e_mask & ~group.defined; + if (richace_is_allow(ace)) + group.allowed |= x; + group.defined |= x; + } else + return -1; + } + + if (group.allowed & ~owner.defined) + return -1; + + if (acl->a_flags & RICHACL_MASKED) { + owner.allowed = acl->a_owner_mask; + group.allowed &= acl->a_group_mask; + everyone.allowed = acl->a_other_mask; + } + + mode = (mode & ~S_IRWXUGO) | + (richacl_mask_to_mode(owner.allowed) << 6) | + (richacl_mask_to_mode(group.allowed) << 3) | + richacl_mask_to_mode(everyone.allowed); + + /* Mask flags we can ignore */ + x = S_ISDIR(mode) ? 0 : RICHACE_DELETE_CHILD; + + if (((richacl_mode_to_mask(mode >> 6) ^ owner.allowed) & ~x) || + ((richacl_mode_to_mask(mode >> 3) ^ group.allowed) & ~x) || + ((richacl_mode_to_mask(mode) ^ everyone.allowed) & ~x)) + return -1; + + *mode_p = mode; + return 0; +} +EXPORT_SYMBOL_GPL(richacl_equiv_mode); diff --git a/include/linux/richacl.h b/include/linux/richacl.h index 1b66cd5..2357d6b 100644 --- a/include/linux/richacl.h +++ b/include/linux/richacl.h @@ -307,6 +307,7 @@ extern unsigned int richacl_mode_to_mask(mode_t); extern unsigned int richacl_want_to_mask(unsigned int); extern void richacl_compute_max_masks(struct richacl *, kuid_t); extern struct richacl *richacl_chmod(struct richacl *, mode_t); +extern int richacl_equiv_mode(const struct richacl *, mode_t *); /* richacl_inode.c */ extern int richacl_permission(struct inode *, const struct richacl *, int); -- 2.4.2
WARNING: multiple messages have this Message-ID (diff)
From: Andreas Gruenbacher <andreas.gruenbacher-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, samba-technical-w/Ol4Ecudpl8XjKLYN78aQ@public.gmane.org, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Subject: [RFC v4 13/31] richacl: Check if an acl is equivalent to a file mode Date: Wed, 24 Jun 2015 23:57:02 +0200 [thread overview] Message-ID: <1435183040-22726-14-git-send-email-agruenba@redhat.com> (raw) In-Reply-To: <1435183040-22726-1-git-send-email-agruenba-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> ACLs are considered equivalent to file modes if they only consist of owner@, group@, and everyone@ entries, the owner@ permissions do not depend on whether the owner is a member in the owning group, and no inheritance flags are set. This test is used to avoid storing richacls if the acl can be computed from the file permission bits. Signed-off-by: Andreas Gruenbacher <agruenba-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> --- fs/richacl_base.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/richacl.h | 1 + 2 files changed, 96 insertions(+) diff --git a/fs/richacl_base.c b/fs/richacl_base.c index 5da092b..1ef3bf3 100644 --- a/fs/richacl_base.c +++ b/fs/richacl_base.c @@ -365,3 +365,98 @@ richacl_chmod(struct richacl *acl, mode_t mode) return clone; } EXPORT_SYMBOL_GPL(richacl_chmod); + +/** + * richacl_equiv_mode - compute the mode equivalent of @acl + * + * An acl is considered equivalent to a file mode if it only consists of + * owner@, group@, and everyone@ entries and the owner@ permissions do not + * depend on whether the owner is a member in the owning group. + */ +int +richacl_equiv_mode(const struct richacl *acl, mode_t *mode_p) +{ + mode_t mode = *mode_p; + + /* + * The RICHACE_DELETE_CHILD flag is meaningless for non-directories, so + * we ignore it. + */ + unsigned int x = S_ISDIR(mode) ? 0 : RICHACE_DELETE_CHILD; + struct { + unsigned int allowed; + unsigned int defined; /* allowed or denied */ + } owner = { + .defined = RICHACE_POSIX_ALWAYS_ALLOWED | RICHACE_POSIX_OWNER_ALLOWED | x, + }, group = { + .defined = RICHACE_POSIX_ALWAYS_ALLOWED | x, + }, everyone = { + .defined = RICHACE_POSIX_ALWAYS_ALLOWED | x, + }; + const struct richace *ace; + + if (acl->a_flags & ~RICHACL_MASKED) + return -1; + + richacl_for_each_entry(ace, acl) { + if (ace->e_flags & ~RICHACE_SPECIAL_WHO) + return -1; + + if (richace_is_owner(ace) || richace_is_everyone(ace)) { + x = ace->e_mask & ~owner.defined; + if (richace_is_allow(ace)) { + unsigned int group_denied = group.defined & ~group.allowed; + + if (x & group_denied) + return -1; + owner.allowed |= x; + } else /* if (richace_is_deny(ace)) */ { + if (x & group.allowed) + return -1; + } + owner.defined |= x; + + if (richace_is_everyone(ace)) { + x = ace->e_mask; + if (richace_is_allow(ace)) { + group.allowed |= x & ~group.defined; + everyone.allowed |= x & ~everyone.defined; + } + group.defined |= x; + everyone.defined |= x; + } + } else if (richace_is_group(ace)) { + x = ace->e_mask & ~group.defined; + if (richace_is_allow(ace)) + group.allowed |= x; + group.defined |= x; + } else + return -1; + } + + if (group.allowed & ~owner.defined) + return -1; + + if (acl->a_flags & RICHACL_MASKED) { + owner.allowed = acl->a_owner_mask; + group.allowed &= acl->a_group_mask; + everyone.allowed = acl->a_other_mask; + } + + mode = (mode & ~S_IRWXUGO) | + (richacl_mask_to_mode(owner.allowed) << 6) | + (richacl_mask_to_mode(group.allowed) << 3) | + richacl_mask_to_mode(everyone.allowed); + + /* Mask flags we can ignore */ + x = S_ISDIR(mode) ? 0 : RICHACE_DELETE_CHILD; + + if (((richacl_mode_to_mask(mode >> 6) ^ owner.allowed) & ~x) || + ((richacl_mode_to_mask(mode >> 3) ^ group.allowed) & ~x) || + ((richacl_mode_to_mask(mode) ^ everyone.allowed) & ~x)) + return -1; + + *mode_p = mode; + return 0; +} +EXPORT_SYMBOL_GPL(richacl_equiv_mode); diff --git a/include/linux/richacl.h b/include/linux/richacl.h index 1b66cd5..2357d6b 100644 --- a/include/linux/richacl.h +++ b/include/linux/richacl.h @@ -307,6 +307,7 @@ extern unsigned int richacl_mode_to_mask(mode_t); extern unsigned int richacl_want_to_mask(unsigned int); extern void richacl_compute_max_masks(struct richacl *, kuid_t); extern struct richacl *richacl_chmod(struct richacl *, mode_t); +extern int richacl_equiv_mode(const struct richacl *, mode_t *); /* richacl_inode.c */ extern int richacl_permission(struct inode *, const struct richacl *, int); -- 2.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2015-06-24 22:04 UTC|newest] Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-06-24 21:56 [RFC v4 00/31] Richacls Andreas Gruenbacher 2015-06-24 21:56 ` Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 01/31] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 02/31] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher 2015-06-24 21:56 ` Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 03/31] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD " Andreas Gruenbacher 2015-06-24 21:56 ` Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 04/31] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 05/31] vfs: Add permission flags for setting file attributes Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 06/31] richacl: In-memory representation and helper functions Andreas Gruenbacher 2015-06-25 19:58 ` Stefan (metze) Metzmacher 2015-06-25 21:06 ` Andreas Grünbacher 2015-06-25 21:40 ` Stefan (metze) Metzmacher 2015-06-25 21:40 ` Stefan (metze) Metzmacher 2015-06-26 7:55 ` Andreas Grünbacher 2015-06-26 7:55 ` Andreas Grünbacher 2015-06-24 21:56 ` [RFC v4 07/31] richacl: Permission mapping functions Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 08/31] richacl: Compute maximum file masks from an acl Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 09/31] richacl: Update the file masks in chmod() Andreas Gruenbacher 2015-06-24 21:56 ` Andreas Gruenbacher 2015-06-24 21:56 ` [RFC v4 10/31] richacl: Permission check algorithm Andreas Gruenbacher 2015-06-24 21:56 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 11/31] vfs: Cache base_acl objects in inodes Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 12/31] vfs: Cache richacl in struct inode Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher [this message] 2015-06-24 21:57 ` [RFC v4 13/31] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 14/31] richacl: Create-time inheritance Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 15/31] richacl: Automatic Inheritance Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 16/31] richacl: xattr mapping functions Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 17/31] vfs: Add richacl permission checking Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 18/31] ext4: Add richacl support Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 19/31] ext4: Add richacl feature flag Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 20/31] richacl: acl editing helper functions Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 21/31] richacl: Move everyone@ aces down the acl Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 22/31] richacl: Propagate everyone@ permissions to other aces Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 23/31] richacl: Set the owner permissions to the owner mask Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 24/31] richacl: Set the other permissions to the other mask Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 25/31] richacl: Isolate the owner and group classes Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 26/31] richacl: Apply the file masks to a richacl Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 27/31] richacl: Create richacl from mode values Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 28/31] nfsd: Keep list of acls to dispose of in compoundargs Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 29/31] nfsd: Use richacls as internal acl representation Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 30/31] nfsd: Add richacl support Andreas Gruenbacher 2015-06-24 21:57 ` [RFC v4 31/31] nfsd: Add support for the v4.1 dacl attribute Andreas Gruenbacher 2015-06-24 21:57 ` Andreas Gruenbacher
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1435183040-22726-14-git-send-email-agruenba@redhat.com \ --to=andreas.gruenbacher@gmail.com \ --cc=linux-api@vger.kernel.org \ --cc=linux-fsdevel@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-nfs@vger.kernel.org \ --cc=linux-security-module@vger.kernel.org \ --cc=samba-technical@lists.samba.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.