From 0299119625fe0067998fffdff9bdf721379f3131 Mon Sep 17 00:00:00 2001 From: Harry Ciao Date: Tue, 16 Aug 2011 16:08:52 +0800 Subject: [PATCH] libsepol: Skip writing role attributes for policy.X and downgraded pp. Role attributes are redundant for policy.X, their destiny has been fulfilled in the expand phase when their types.types ebitmap have been populated to that of their sub regular roles. When pp is downgraded, role_datum_t's the flavor flag and roles ebitmap would be discarded, resulting in role attributes useless at all. So for such case they should also be skipped. Deduct the number of role attributes from p_roles.table->nel when they are skipped. Last, uncount attributes number before converting endianness. Signed-off-by: Harry Ciao Signed-off-by: Eric Paris Acked-by: Dan Walsh --- libsepol/src/write.c | 42 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 41 insertions(+), 1 deletion(-) diff --git a/libsepol/src/write.c b/libsepol/src/write.c index 290e0365..7257b0b8 100644 --- a/libsepol/src/write.c +++ b/libsepol/src/write.c @@ -972,6 +972,19 @@ static int role_write(hashtab_key_t key, hashtab_datum_t datum, void *ptr) role = (role_datum_t *) datum; + /* + * Role attributes are redundant for policy.X, skip them + * when writing the roles symbol table. They are also skipped + * when pp is downgraded. + * + * Their numbers would be deducted in policydb_write(). + */ + if ((role->flavor == ROLE_ATTRIB) && + ((p->policy_type == POLICY_KERN) || + (p->policy_type != POLICY_KERN && + p->policyvers < MOD_POLICYDB_VERSION_ROLEATTRIB))) + return POLICYDB_SUCCESS; + len = strlen(key); items = 0; buf[items++] = cpu_to_le32(len); @@ -1795,6 +1808,19 @@ static int type_attr_uncount(hashtab_key_t key __attribute__ ((unused)), return 0; } +static int role_attr_uncount(hashtab_key_t key __attribute__ ((unused)), + hashtab_datum_t datum, void *args) +{ + role_datum_t *role = datum; + uint32_t *p_nel = args; + + if (role->flavor == ROLE_ATTRIB) { + /* uncount attribute from total number of roles */ + (*p_nel)--; + } + return 0; +} + /* * Write the configuration data in a policy database * structure to a policy database binary representation @@ -1926,7 +1952,7 @@ int policydb_write(policydb_t * p, struct policy_file *fp) num_syms = info->sym_num; for (i = 0; i < num_syms; i++) { buf[0] = cpu_to_le32(p->symtab[i].nprim); - buf[1] = cpu_to_le32(p->symtab[i].table->nel); + buf[1] = p->symtab[i].table->nel; /* * A special case when writing type/attribute symbol table. @@ -1939,6 +1965,20 @@ int policydb_write(policydb_t * p, struct policy_file *fp) p->policy_type == POLICY_KERN) { hashtab_map(p->symtab[i].table, type_attr_uncount, &buf[1]); } + + /* + * Another special case when writing role/attribute symbol + * table, role attributes are redundant for policy.X, or + * when the pp's version is not big enough. So deduct + * their numbers from p_roles.table->nel. + */ + if ((i == SYM_ROLES) && + ((p->policy_type == POLICY_KERN) || + (p->policy_type != POLICY_KERN && + p->policyvers < MOD_POLICYDB_VERSION_ROLEATTRIB))) + hashtab_map(p->symtab[i].table, role_attr_uncount, &buf[1]); + + buf[1] = cpu_to_le32(buf[1]); items = put_entry(buf, sizeof(uint32_t), 2, fp); if (items != 2) return POLICYDB_ERROR;