From: "Mickaël Salaün" <mic@digikod.net>
To: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Cc: willemdebruijn.kernel@gmail.com, gnoack3000@gmail.com,
linux-security-module@vger.kernel.org, netdev@vger.kernel.org,
netfilter-devel@vger.kernel.org, yusongping@huawei.com,
hukeping@huawei.com, anton.sirazetdinov@huawei.com
Subject: Re: [PATCH v7 04/18] landlock: move helper functions
Date: Tue, 6 Sep 2022 10:07:31 +0200 [thread overview]
Message-ID: <2299f034-e6f2-051c-97e3-bf93a0916a50@digikod.net> (raw)
In-Reply-To: <20220829170401.834298-5-konstantin.meskhidze@huawei.com>
You can make the subject more informative with "landlock: Move
unmask_layers() and init_layer_masks()".
On 29/08/2022 19:03, Konstantin Meskhidze wrote:
> This patch moves unmask_layers() and init_layer_masks() helpers
> to ruleset.c to share with landlock network implementation in
> following commits.
>
> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
> ---
>
> Changes since v6:
> * Moves get_handled_accesses() helper from ruleset.c back to fs.c,
> cause it's not used in coming network commits.
>
> Changes since v5:
> * Splits commit.
> * Moves init_layer_masks() and get_handled_accesses() helpers
> to ruleset.c and makes then non-static.
> * Formats code with clang-format-14.
>
> ---
> security/landlock/fs.c | 85 -------------------------------------
> security/landlock/ruleset.c | 84 ++++++++++++++++++++++++++++++++++++
> security/landlock/ruleset.h | 10 +++++
> 3 files changed, 94 insertions(+), 85 deletions(-)
>
> diff --git a/security/landlock/fs.c b/security/landlock/fs.c
> index cca87fcd222d..b03d6153f628 100644
> --- a/security/landlock/fs.c
> +++ b/security/landlock/fs.c
> @@ -215,60 +215,6 @@ find_rule(const struct landlock_ruleset *const domain,
> return rule;
> }
>
> -/*
> - * @layer_masks is read and may be updated according to the access request and
> - * the matching rule.
> - *
> - * Returns true if the request is allowed (i.e. relevant layer masks for the
> - * request are empty).
> - */
> -static inline bool
> -unmask_layers(const struct landlock_rule *const rule,
> - const access_mask_t access_request,
> - layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
> -{
> - size_t layer_level;
> -
> - if (!access_request || !layer_masks)
> - return true;
> - if (!rule)
> - return false;
> -
> - /*
> - * An access is granted if, for each policy layer, at least one rule
> - * encountered on the pathwalk grants the requested access,
> - * regardless of its position in the layer stack. We must then check
> - * the remaining layers for each inode, from the first added layer to
> - * the last one. When there is multiple requested accesses, for each
> - * policy layer, the full set of requested accesses may not be granted
> - * by only one rule, but by the union (binary OR) of multiple rules.
> - * E.g. /a/b <execute> + /a <read> => /a/b <execute + read>
> - */
> - for (layer_level = 0; layer_level < rule->num_layers; layer_level++) {
> - const struct landlock_layer *const layer =
> - &rule->layers[layer_level];
> - const layer_mask_t layer_bit = BIT_ULL(layer->level - 1);
> - const unsigned long access_req = access_request;
> - unsigned long access_bit;
> - bool is_empty;
> -
> - /*
> - * Records in @layer_masks which layer grants access to each
> - * requested access.
> - */
> - is_empty = true;
> - for_each_set_bit(access_bit, &access_req,
> - ARRAY_SIZE(*layer_masks)) {
> - if (layer->access & BIT_ULL(access_bit))
> - (*layer_masks)[access_bit] &= ~layer_bit;
> - is_empty = is_empty && !(*layer_masks)[access_bit];
> - }
> - if (is_empty)
> - return true;
> - }
> - return false;
> -}
> -
> /*
> * Allows access to pseudo filesystems that will never be mountable (e.g.
> * sockfs, pipefs), but can still be reachable through
> @@ -303,37 +249,6 @@ get_handled_accesses(const struct landlock_ruleset *const domain)
> return access_dom;
> }
>
> -static inline access_mask_t
> -init_layer_masks(const struct landlock_ruleset *const domain,
> - const access_mask_t access_request,
> - layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
> -{
> - access_mask_t handled_accesses = 0;
> - size_t layer_level;
> -
> - memset(layer_masks, 0, sizeof(*layer_masks));
> - /* An empty access request can happen because of O_WRONLY | O_RDWR. */
> - if (!access_request)
> - return 0;
> -
> - /* Saves all handled accesses per layer. */
> - for (layer_level = 0; layer_level < domain->num_layers; layer_level++) {
> - const unsigned long access_req = access_request;
> - unsigned long access_bit;
> -
> - for_each_set_bit(access_bit, &access_req,
> - ARRAY_SIZE(*layer_masks)) {
> - if (landlock_get_fs_access_mask(domain, layer_level) &
> - BIT_ULL(access_bit)) {
> - (*layer_masks)[access_bit] |=
> - BIT_ULL(layer_level);
> - handled_accesses |= BIT_ULL(access_bit);
> - }
> - }
> - }
> - return handled_accesses;
> -}
> -
> /*
> * Check that a destination file hierarchy has more restrictions than a source
> * file hierarchy. This is only used for link and rename actions.
> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
> index 3a5ef356aaa3..671a95e2a345 100644
> --- a/security/landlock/ruleset.c
> +++ b/security/landlock/ruleset.c
> @@ -564,3 +564,87 @@ landlock_find_rule(const struct landlock_ruleset *const ruleset,
> }
> return NULL;
> }
> +
> +/*
> + * @layer_masks is read and may be updated according to the access request and
> + * the matching rule.
> + *
> + * Returns true if the request is allowed (i.e. relevant layer masks for the
> + * request are empty).
> + */
> +bool unmask_layers(const struct landlock_rule *const rule,
> + const access_mask_t access_request,
> + layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
> +{
> + size_t layer_level;
> +
> + if (!access_request || !layer_masks)
> + return true;
> + if (!rule)
> + return false;
> +
> + /*
> + * An access is granted if, for each policy layer, at least one rule
> + * encountered on the pathwalk grants the requested access,
> + * regardless of its position in the layer stack. We must then check
> + * the remaining layers for each inode, from the first added layer to
> + * the last one. When there is multiple requested accesses, for each
> + * policy layer, the full set of requested accesses may not be granted
> + * by only one rule, but by the union (binary OR) of multiple rules.
> + * E.g. /a/b <execute> + /a <read> => /a/b <execute + read>
> + */
> + for (layer_level = 0; layer_level < rule->num_layers; layer_level++) {
> + const struct landlock_layer *const layer =
> + &rule->layers[layer_level];
> + const layer_mask_t layer_bit = BIT_ULL(layer->level - 1);
> + const unsigned long access_req = access_request;
> + unsigned long access_bit;
> + bool is_empty;
> +
> + /*
> + * Records in @layer_masks which layer grants access to each
> + * requested access.
> + */
> + is_empty = true;
> + for_each_set_bit(access_bit, &access_req,
> + ARRAY_SIZE(*layer_masks)) {
> + if (layer->access & BIT_ULL(access_bit))
> + (*layer_masks)[access_bit] &= ~layer_bit;
> + is_empty = is_empty && !(*layer_masks)[access_bit];
> + }
> + if (is_empty)
> + return true;
> + }
> + return false;
> +}
> +
> +access_mask_t
> +init_layer_masks(const struct landlock_ruleset *const domain,
> + const access_mask_t access_request,
> + layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
> +{
> + access_mask_t handled_accesses = 0;
> + size_t layer_level;
> +
> + memset(layer_masks, 0, sizeof(*layer_masks));
> + /* An empty access request can happen because of O_WRONLY | O_RDWR. */
> + if (!access_request)
> + return 0;
> +
> + /* Saves all handled accesses per layer. */
> + for (layer_level = 0; layer_level < domain->num_layers; layer_level++) {
> + const unsigned long access_req = access_request;
> + unsigned long access_bit;
> +
> + for_each_set_bit(access_bit, &access_req,
> + ARRAY_SIZE(*layer_masks)) {
> + if (landlock_get_fs_access_mask(domain, layer_level) &
> + BIT_ULL(access_bit)) {
> + (*layer_masks)[access_bit] |=
> + BIT_ULL(layer_level);
> + handled_accesses |= BIT_ULL(access_bit);
> + }
> + }
> + }
> + return handled_accesses;
> +}
> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
> index bb1408cc8dd2..d7d9b987829c 100644
> --- a/security/landlock/ruleset.h
> +++ b/security/landlock/ruleset.h
> @@ -235,4 +235,14 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset,
> LANDLOCK_SHIFT_ACCESS_FS) &
> LANDLOCK_MASK_ACCESS_FS;
> }
> +
> +bool unmask_layers(const struct landlock_rule *const rule,
> + const access_mask_t access_request,
> + layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
> +
> +access_mask_t
> +init_layer_masks(const struct landlock_ruleset *const domain,
> + const access_mask_t access_request,
> + layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
> +
> #endif /* _SECURITY_LANDLOCK_RULESET_H */
> --
> 2.25.1
>
next prev parent reply other threads:[~2022-09-06 8:07 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-29 17:03 [PATCH v7 00/18] Network support for Landlock Konstantin Meskhidze
2022-08-29 17:03 ` [PATCH v7 01/18] landlock: rename access mask Konstantin Meskhidze
2022-09-06 8:06 ` Mickaël Salaün
2022-09-09 10:42 ` Konstantin Meskhidze (A)
2022-09-12 17:16 ` Mickaël Salaün
2022-08-29 17:03 ` [PATCH v7 02/18] landlock: refactor landlock_find_rule/insert_rule Konstantin Meskhidze
2022-09-06 8:07 ` Mickaël Salaün
2022-09-09 10:48 ` Konstantin Meskhidze (A)
2022-09-12 17:17 ` Mickaël Salaün
2022-10-12 8:37 ` Konstantin Meskhidze (A)
2022-10-12 10:06 ` Mickaël Salaün
2022-10-12 11:13 ` Konstantin Meskhidze (A)
2022-08-29 17:03 ` [PATCH v7 03/18] landlock: refactor merge/inherit_ruleset functions Konstantin Meskhidze
2022-09-06 8:07 ` Mickaël Salaün
2022-09-09 14:53 ` Konstantin Meskhidze (A)
2022-09-12 17:17 ` Mickaël Salaün
2022-08-29 17:03 ` [PATCH v7 04/18] landlock: move helper functions Konstantin Meskhidze
2022-09-06 8:07 ` Mickaël Salaün [this message]
2022-09-10 16:50 ` Konstantin Meskhidze (A)
2022-08-29 17:03 ` [PATCH v7 05/18] landlock: refactor " Konstantin Meskhidze
2022-09-06 8:07 ` Mickaël Salaün
2022-09-10 17:20 ` Konstantin Meskhidze (A)
2022-09-12 17:18 ` Mickaël Salaün
2022-08-29 17:03 ` [PATCH v7 06/18] landlock: refactor landlock_add_rule syscall Konstantin Meskhidze
2022-08-29 17:03 ` [PATCH v7 07/18] landlock: user space API network support Konstantin Meskhidze
2022-09-06 8:08 ` Mickaël Salaün
2022-09-10 17:25 ` Konstantin Meskhidze (A)
2022-08-29 17:03 ` [PATCH v7 08/18] landlock: add network rules support Konstantin Meskhidze
2022-09-06 8:08 ` Mickaël Salaün
2022-09-10 18:27 ` Konstantin Meskhidze (A)
2022-09-12 17:18 ` Mickaël Salaün
2022-08-29 17:03 ` [PATCH v7 09/18] landlock: implement TCP network hooks Konstantin Meskhidze
2022-09-06 8:08 ` Mickaël Salaün
2022-09-10 20:28 ` Konstantin Meskhidze (A)
2022-09-12 17:18 ` Mickaël Salaün
2022-08-29 17:03 ` [PATCH v7 10/18] seltests/landlock: move helper function Konstantin Meskhidze
2022-09-06 8:09 ` Mickaël Salaün
2022-09-10 20:29 ` Konstantin Meskhidze (A)
2022-08-29 17:03 ` [PATCH v7 11/18] seltests/landlock: add tests for bind() hooks Konstantin Meskhidze
2022-09-06 8:09 ` Mickaël Salaün
2022-09-10 20:47 ` Konstantin Meskhidze (A)
2022-08-29 17:03 ` [PATCH v7 12/18] seltests/landlock: add tests for connect() hooks Konstantin Meskhidze
2022-08-29 17:03 ` [PATCH v7 13/18] seltests/landlock: add AF_UNSPEC family test Konstantin Meskhidze
2022-09-06 8:09 ` Mickaël Salaün
2022-09-10 20:48 ` Konstantin Meskhidze (A)
2022-08-29 17:03 ` [PATCH v7 14/18] seltests/landlock: add rules overlapping test Konstantin Meskhidze
2022-09-06 8:09 ` Mickaël Salaün
2022-09-10 20:49 ` Konstantin Meskhidze (A)
2022-08-29 17:03 ` [PATCH v7 15/18] seltests/landlock: add ruleset expanding test Konstantin Meskhidze
2022-08-29 17:03 ` [PATCH v7 16/18] seltests/landlock: add invalid input data test Konstantin Meskhidze
2022-09-06 8:09 ` Mickaël Salaün
2022-09-10 20:51 ` Konstantin Meskhidze (A)
2022-09-12 17:22 ` Mickaël Salaün
2022-10-10 10:37 ` Mickaël Salaün
2022-10-11 7:55 ` Konstantin Meskhidze (A)
2022-10-11 8:32 ` Mickaël Salaün
2022-08-29 17:04 ` [PATCH v7 17/18] samples/landlock: add network demo Konstantin Meskhidze
2022-09-06 8:10 ` Mickaël Salaün
2022-09-10 20:59 ` Konstantin Meskhidze (A)
2022-09-12 17:23 ` Mickaël Salaün
2022-08-29 17:04 ` [PATCH v7 18/18] landlock: Document Landlock's network support Konstantin Meskhidze
2022-09-06 8:12 ` Mickaël Salaün
2022-09-10 21:14 ` Konstantin Meskhidze (A)
2022-09-12 17:23 ` Mickaël Salaün
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