From 42345b68c2e3e2b6549fc34b937ff44240dfc3b6 Mon Sep 17 00:00:00 2001 From: Joshua Brindle Date: Wed, 4 Sep 2019 14:03:23 -0700 Subject: selinux: default_range glblub implementation A policy developer can now specify glblub as a default_range default and the computed transition will be the intersection of the mls range of the two contexts. The glb (greatest lower bound) lub (lowest upper bound) of a range is calculated as the greater of the low sensitivities and the lower of the high sensitivities and the and of each category bitmap. This can be used by MLS solution developers to compute a context that satisfies, for example, the range of a network interface and the range of a user logging in. Some examples are: User Permitted Range | Network Device Label | Computed Label ---------------------|----------------------|---------------- s0-s1:c0.c12 | s0 | s0 s0-s1:c0.c12 | s0-s1:c0.c1023 | s0-s1:c0.c12 s0-s4:c0.c512 | s1-s1:c0.c1023 | s1-s1:c0.c512 s0-s15:c0,c2 | s4-s6:c0.c128 | s4-s6:c0,c2 s0-s4 | s2-s6 | s2-s4 s0-s4 | s5-s8 | INVALID s5-s8 | s0-s4 | INVALID Signed-off-by: Joshua Brindle [PM: subject lines and checkpatch.pl fixes] Signed-off-by: Paul Moore --- security/selinux/ss/ebitmap.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'security/selinux/ss/ebitmap.c') diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c index 09929fc5ab47..c8c3663111e2 100644 --- a/security/selinux/ss/ebitmap.c +++ b/security/selinux/ss/ebitmap.c @@ -77,6 +77,24 @@ int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src) return 0; } +int ebitmap_and(struct ebitmap *dst, struct ebitmap *e1, struct ebitmap *e2) +{ + struct ebitmap_node *n; + int bit, rc; + + ebitmap_init(dst); + + ebitmap_for_each_positive_bit(e1, n, bit) { + if (ebitmap_get_bit(e2, bit)) { + rc = ebitmap_set_bit(dst, bit, 1); + if (rc < 0) + return rc; + } + } + return 0; +} + + #ifdef CONFIG_NETLABEL /** * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap -- cgit v1.2.3