fff69fb03d
Add network rules support in the ruleset management helpers and the landlock_create_ruleset() syscall. Extend user space API to support network actions: * Add new network access rights: LANDLOCK_ACCESS_NET_BIND_TCP and LANDLOCK_ACCESS_NET_CONNECT_TCP. * Add a new network rule type: LANDLOCK_RULE_NET_PORT tied to struct landlock_net_port_attr. The allowed_access field contains the network access rights, and the port field contains the port value according to the controlled protocol. This field can take up to a 64-bit value but the maximum value depends on the related protocol (e.g. 16-bit value for TCP). Network port is in host endianness [1]. * Add a new handled_access_net field to struct landlock_ruleset_attr that contains network access rights. * Increment the Landlock ABI version to 4. Implement socket_bind() and socket_connect() LSM hooks, which enable to control TCP socket binding and connection to specific ports. Expand access_masks_t from u16 to u32 to be able to store network access rights alongside filesystem access rights for rulesets' handled access rights. Access rights are not tied to socket file descriptors but checked at bind() or connect() call time against the caller's Landlock domain. For the filesystem, a file descriptor is a direct access to a file/data. However, for network sockets, we cannot identify for which data or peer a newly created socket will give access to. Indeed, we need to wait for a connect or bind request to identify the use case for this socket. Likewise a directory file descriptor may enable to open another file (i.e. a new data item), but this opening is also restricted by the caller's domain, not the file descriptor's access rights [2]. [1] https://lore.kernel.org/r/278ab07f-7583-a4e0-3d37-1bacd091531d@digikod.net [2] https://lore.kernel.org/r/263c1eb3-602f-57fe-8450-3f138581bee7@digikod.net Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> Link: https://lore.kernel.org/r/20231026014751.414649-9-konstantin.meskhidze@huawei.com [mic: Extend commit message, fix typo in comments, and specify endianness in the documentation] Co-developed-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Mickaël Salaün <mic@digikod.net>
34 lines
1.0 KiB
C
34 lines
1.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Landlock LSM - Limits for different components
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*
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* Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net>
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* Copyright © 2018-2020 ANSSI
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*/
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#ifndef _SECURITY_LANDLOCK_LIMITS_H
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#define _SECURITY_LANDLOCK_LIMITS_H
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#include <linux/bitops.h>
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#include <linux/limits.h>
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#include <uapi/linux/landlock.h>
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/* clang-format off */
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#define LANDLOCK_MAX_NUM_LAYERS 16
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#define LANDLOCK_MAX_NUM_RULES U32_MAX
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#define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_TRUNCATE
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#define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1)
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#define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS)
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#define LANDLOCK_SHIFT_ACCESS_FS 0
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#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP
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#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1)
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#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET)
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#define LANDLOCK_SHIFT_ACCESS_NET LANDLOCK_NUM_ACCESS_FS
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/* clang-format on */
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#endif /* _SECURITY_LANDLOCK_LIMITS_H */
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