[PATCH v7 07/18] landlock: user space API network support

[Konstantin Meskhidze (A)]

9/6/2022 11:08 AM, Mickaël Salaün пишет:
> You can squash this commit into 8/18.

   I got it. Will be squashed.
> 
> You need to increment the Landlock ABI version here.
> 
   Ok. Thanks for the tip.
> 
> On 29/08/2022 19:03, Konstantin Meskhidze wrote:
>> Refactors user space API to support network actions. Adds new network
>> access flags, network rule and network attributes.
>> 
>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze at huawei.com>
>> ---
>> 
>> Changes since v6:
>> * None.
>> 
>> Changes since v5:
>> * Formats code with clang-format-14.
>> 
>> Changes since v4:
>> * None
>> 
>> Changes since v3:
>> * Splits commit.
>> * Refactors User API for network rule type.
>> 
>> ---
>>   include/uapi/linux/landlock.h | 49 +++++++++++++++++++++++++++++++++++
>>   security/landlock/syscalls.c  |  3 ++-
>>   2 files changed, 51 insertions(+), 1 deletion(-)
>> 
>> diff --git a/include/uapi/linux/landlock.h b/include/uapi/linux/landlock.h
>> index 735b1fe8326e..1ce2be6a78af 100644
>> --- a/include/uapi/linux/landlock.h
>> +++ b/include/uapi/linux/landlock.h
>> @@ -31,6 +31,13 @@ struct landlock_ruleset_attr {
>>   	 * this access right.
>>   	 */
>>   	__u64 handled_access_fs;
>> +
>> +	/**
>> +	 * @handled_access_net: Bitmask of actions (cf. `Network flags`_)
>> +	 * that is handled by this ruleset and should then be forbidden if no
>> +	 * rule explicitly allow them.
>> +	 */
>> +	__u64 handled_access_net;
>>   };
>> 
>>   /*
>> @@ -54,6 +61,11 @@ enum landlock_rule_type {
>>   	 * landlock_path_beneath_attr .
>>   	 */
>>   	LANDLOCK_RULE_PATH_BENEATH = 1,
>> +	/**
>> +	 * @LANDLOCK_RULE_NET_SERVICE: Type of a &struct
>> +	 * landlock_net_service_attr .
>> +	 */
>> +	LANDLOCK_RULE_NET_SERVICE = 2,
>>   };
>> 
>>   /**
>> @@ -79,6 +91,24 @@ struct landlock_path_beneath_attr {
>>   	 */
>>   } __attribute__((packed));
>> 
>> +/**
>> + * struct landlock_net_service_attr - TCP subnet definition
>> + *
>> + * Argument of sys_landlock_add_rule().
>> + */
>> +struct landlock_net_service_attr {
>> +	/**
>> +	 * @allowed_access: Bitmask of allowed access network for services
>> +	 * (cf. `Network flags`_).
>> +	 */
>> +	__u64 allowed_access;
>> +	/**
>> +	 * @port: Network port.
>> +	 */
>> +	__u16 port;
>> +
>> +} __attribute__((packed));
>> +
>>   /**
>>    * DOC: fs_access
>>    *
>> @@ -169,4 +199,23 @@ struct landlock_path_beneath_attr {
>>   #define LANDLOCK_ACCESS_FS_TRUNCATE			(1ULL << 14)
>>   /* clang-format on */
>> 
>> +/**
>> + * DOC: net_access
>> + *
>> + * Network flags
>> + * ~~~~~~~~~~~~~~~~
>> + *
>> + * These flags enable to restrict a sandboxed process to a set of network
>> + * actions.
>> + *
>> + * TCP sockets with allowed actions:
>> + *
>> + * - %LANDLOCK_ACCESS_NET_BIND_TCP: Bind a TCP socket to a local port.
>> + * - %LANDLOCK_ACCESS_NET_CONNECT_TCP: Connect an active TCP socket to
>> + *   a remote port.
>> + */
>> +/* clang-format off */
>> +#define LANDLOCK_ACCESS_NET_BIND_TCP			(1ULL << 0)
>> +#define LANDLOCK_ACCESS_NET_CONNECT_TCP			(1ULL << 1)
>> +/* clang-format on */
>>   #endif /* _UAPI_LINUX_LANDLOCK_H */
>> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
>> index 28acc4cef3e8..ffd5805eddd9 100644
>> --- a/security/landlock/syscalls.c
>> +++ b/security/landlock/syscalls.c
>> @@ -82,8 +82,9 @@ static void build_check_abi(void)
>>   	 * struct size.
>>   	 */
>>   	ruleset_size = sizeof(ruleset_attr.handled_access_fs);
>> +	ruleset_size += sizeof(ruleset_attr.handled_access_net);
>>   	BUILD_BUG_ON(sizeof(ruleset_attr) != ruleset_size);
>> -	BUILD_BUG_ON(sizeof(ruleset_attr) != 8);
>> +	BUILD_BUG_ON(sizeof(ruleset_attr) != 16);
>> 
>>   	path_beneath_size = sizeof(path_beneath_attr.allowed_access);
>>   	path_beneath_size += sizeof(path_beneath_attr.parent_fd);
>> --
>> 2.25.1
>> 
> .