Hi, all! This is a new bunch of RFC patches related to Landlock LSM network confinement. Here are previous discussions: 1. https://lore.kernel.org/linux-security-module/20211210072123.386713-1-konstantin.meskhidze@xxxxxxxxxx/ 2. https://lore.kernel.org/linux-security-module/20211228115212.703084-1-konstantin.meskhidze@xxxxxxxxxx/ As in previous RFCs, 2 hooks are supported: - hook_socket_bind() - hook_socket_connect() Selftest are provided in tools/testing/selftests/landlock/network_test.c; Implementation was tested in QEMU invironment with 5.13 kernel version: 1. base_test - passed all tests 2. fs_test - passed 44/46 tests. 2 tests related to overlayfs failed. Probably, I have wrong config options for overlayfs. 3. network_test - passed all tests. Please give your suggestions about test cover in network_test.c Implementation related issues ============================= 1. Access masks array refactored into 1D one and changed to 32 bits. Filesystem masks occupy 16 lower bits and network masks reside in 16 upper bits. struct landlock_ruleset { ... ... u32 access_masks[]; } 2. Refactor API functions in ruleset.c: 1. Add (void *)object argument. 2. Add u16 rule_type argument. - In filesystem case the "object" is defined by underlying inode. In network case the "object" is defined by a port. There is a union containing either a struct landlock_object pointer or a raw data (here a u16 port): union { struct landlock_object *ptr; uintptr_t data; } object; - Everytime when a rule is inserted it's needed to provide a rule type: landlock_insert_rule(ruleset, (void *)object, access, rule_type) 1. A rule_type could be or LANDLOCK_RULE_NET_SERVICE or LANDLOCK_RULE_PATH_BENEATH; 2. (void *) object - is either landlock_object *ptr or port value; 3. Use two rb_trees in ruleset structure: 1. root_inode - for filesystem objects (inodes). 2. root_net_port - for network port objects. Konstantin Meskhidze (2): landlock: TCP network hooks implementation landlock: selftests for bind and connect hooks include/uapi/linux/landlock.h | 52 +++ security/landlock/Makefile | 2 +- security/landlock/fs.c | 12 +- security/landlock/limits.h | 6 + security/landlock/net.c | 175 +++++++++ security/landlock/net.h | 21 ++ security/landlock/ruleset.c | 167 ++++++--- security/landlock/ruleset.h | 40 +- security/landlock/setup.c | 3 + security/landlock/syscalls.c | 142 ++++--- .../testing/selftests/landlock/network_test.c | 346 ++++++++++++++++++ 11 files changed, 860 insertions(+), 106 deletions(-) create mode 100644 security/landlock/net.c create mode 100644 security/landlock/net.h create mode 100644 tools/testing/selftests/landlock/network_test.c -- 2.25.1
