From 1fccdae563757464969865f3147bc7770387c187 Mon Sep 17 00:00:00 2001 From: Juraj Marcin Date: Fri, 2 Sep 2022 16:09:00 +0200 Subject: [PATCH] libsepol: implement new module binary format of avrule Implement a new module policy format that closely matches the new internal representation of avrule introduced in the previous patch. This patch bumps the maximum module policy version and implements reading/writing functions such that the module binary policy structure matches its internal representation, namely, the object name attribute used for the filename transition rules. These changes have no significant effect on the size of the module policy file (tested with Fedora policy). Signed-off-by: Juraj Marcin --- libsepol/include/sepol/policydb/policydb.h | 3 ++- libsepol/src/policydb.c | 28 ++++++++++++++++++++++ libsepol/src/write.c | 24 ++++++++++++++++--- 3 files changed, 51 insertions(+), 4 deletions(-) diff --git a/libsepol/include/sepol/policydb/policydb.h b/libsepol/include/sepol/policydb/policydb.h index 16f1e95206..ebc0791da1 100644 --- a/libsepol/include/sepol/policydb/policydb.h +++ b/libsepol/include/sepol/policydb/policydb.h @@ -748,9 +748,10 @@ extern int policydb_set_target_platform(policydb_t *p, int platform); #define MOD_POLICYDB_VERSION_INFINIBAND 19 #define MOD_POLICYDB_VERSION_GLBLUB 20 #define MOD_POLICYDB_VERSION_SELF_TYPETRANS 21 +#define MOD_POLICYDB_VERSION_AVRULE_FTRANS 22 #define MOD_POLICYDB_VERSION_MIN MOD_POLICYDB_VERSION_BASE -#define MOD_POLICYDB_VERSION_MAX MOD_POLICYDB_VERSION_SELF_TYPETRANS +#define MOD_POLICYDB_VERSION_MAX MOD_POLICYDB_VERSION_AVRULE_FTRANS #define POLICYDB_CONFIG_MLS 1 diff --git a/libsepol/src/policydb.c b/libsepol/src/policydb.c index 5ed3554f34..dfce31f87e 100644 --- a/libsepol/src/policydb.c +++ b/libsepol/src/policydb.c @@ -341,6 +341,13 @@ static const struct policydb_compat_info policydb_compat[] = { .ocon_num = OCON_IBENDPORT + 1, .target_platform = SEPOL_TARGET_SELINUX, }, + { + .type = POLICY_BASE, + .version = MOD_POLICYDB_VERSION_AVRULE_FTRANS, + .sym_num = SYM_NUM, + .ocon_num = OCON_IBENDPORT + 1, + .target_platform = SEPOL_TARGET_SELINUX, + }, { .type = POLICY_MOD, .version = MOD_POLICYDB_VERSION_BASE, @@ -467,6 +474,13 @@ static const struct policydb_compat_info policydb_compat[] = { .ocon_num = 0, .target_platform = SEPOL_TARGET_SELINUX, }, + { + .type = POLICY_MOD, + .version = MOD_POLICYDB_VERSION_AVRULE_FTRANS, + .sym_num = SYM_NUM, + .ocon_num = 0, + .target_platform = SEPOL_TARGET_SELINUX, + }, }; #if 0 @@ -3202,6 +3216,19 @@ static avrule_t *avrule_read(policydb_t * p, struct policy_file *fp) tail = cur; } + if (p->policyvers >= MOD_POLICYDB_VERSION_AVRULE_FTRANS && + avrule->specified & AVRULE_TRANSITION) { + rc = next_entry(buf, fp, sizeof(uint32_t)); + if (rc < 0) + goto bad; + len = le32_to_cpu(*buf); + if (len) { + rc = str_read(&avrule->object_name, fp, len); + if (rc < 0) + goto bad; + } + } + if (avrule->specified & AVRULE_XPERMS) { uint8_t buf8; size_t nel = ARRAY_SIZE(avrule->xperms->perms); @@ -3638,6 +3665,7 @@ static int avrule_decl_read(policydb_t * p, avrule_decl_t * decl, } if (p->policyvers >= MOD_POLICYDB_VERSION_FILENAME_TRANS && + p->policyvers < MOD_POLICYDB_VERSION_AVRULE_FTRANS && filename_trans_rule_read(p, &decl->avrules, fp)) return -1; diff --git a/libsepol/src/write.c b/libsepol/src/write.c index 161d20c4e5..67e06cfe90 100644 --- a/libsepol/src/write.c +++ b/libsepol/src/write.c @@ -2024,8 +2024,9 @@ static int avrule_write(policydb_t *p, avrule_t * avrule, uint32_t buf[32], len; class_perm_node_t *cur; - /* skip filename transitions for now */ - if (avrule->specified & AVRULE_TRANSITION && avrule->object_name) + /* skip filename transitions if writing older version without name */ + if (p->policyvers < MOD_POLICYDB_VERSION_AVRULE_FTRANS && + avrule->specified & AVRULE_TRANSITION && avrule->object_name) return POLICYDB_SUCCESS; if (p->policyvers < MOD_POLICYDB_VERSION_SELF_TYPETRANS && @@ -2072,6 +2073,21 @@ static int avrule_write(policydb_t *p, avrule_t * avrule, cur = cur->next; } + if (p->policyvers >= MOD_POLICYDB_VERSION_AVRULE_FTRANS && + avrule->specified & AVRULE_TRANSITION) { + len = avrule->object_name ? strlen(avrule->object_name) : 0; + *buf = cpu_to_le32(len); + items = put_entry(buf, sizeof(uint32_t), 1, fp); + if (items != 1) + return POLICYDB_ERROR; + if (avrule->object_name) { + items = put_entry(avrule->object_name, sizeof(char), + len, fp); + if (items != len) + return POLICYDB_ERROR; + } + } + if (avrule->specified & AVRULE_XPERMS) { size_t nel = ARRAY_SIZE(avrule->xperms->perms); uint32_t buf32[nel]; @@ -2121,7 +2137,8 @@ static int avrule_write_list(policydb_t *p, avrule_t * avrules, avrule = avrules; len = 0; while (avrule) { - if (!(avrule->specified & AVRULE_TRANSITION && + if (p->policyvers >= MOD_POLICYDB_VERSION_AVRULE_FTRANS || + !(avrule->specified & AVRULE_TRANSITION && avrule->object_name)) len++; avrule = avrule->next; @@ -2356,6 +2373,7 @@ static int avrule_decl_write(avrule_decl_t * decl, int num_scope_syms, } if (p->policyvers >= MOD_POLICYDB_VERSION_FILENAME_TRANS && + p->policyvers < MOD_POLICYDB_VERSION_AVRULE_FTRANS && filename_trans_rule_write(p, decl->avrules, fp)) return POLICYDB_ERROR;