diff options
Diffstat (limited to 'security/selinux/ss/services.c')
| -rw-r--r-- | security/selinux/ss/services.c | 239 |
1 files changed, 238 insertions, 1 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 6149248..c284dbb 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -7,12 +7,13 @@ * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> * * Support for enhanced MLS infrastructure. + * Support for context based audit filters. * * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> * * Added conditional policy language extensions * - * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. * Copyright (C) 2003 - 2004 Tresys Technology, LLC * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> * This program is free software; you can redistribute it and/or modify @@ -593,6 +594,10 @@ int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) *scontext_len = strlen(initial_sid_to_string[sid]) + 1; scontextp = kmalloc(*scontext_len,GFP_ATOMIC); + if (!scontextp) { + rc = -ENOMEM; + goto out; + } strcpy(scontextp, initial_sid_to_string[sid]); *scontext = scontextp; goto out; @@ -1811,3 +1816,235 @@ out: POLICY_RDUNLOCK; return rc; } + +struct selinux_audit_rule { + u32 au_seqno; + struct context au_ctxt; +}; + +void selinux_audit_rule_free(struct selinux_audit_rule *rule) +{ + if (rule) { + context_destroy(&rule->au_ctxt); + kfree(rule); + } +} + +int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, + struct selinux_audit_rule **rule) +{ + struct selinux_audit_rule *tmprule; + struct role_datum *roledatum; + struct type_datum *typedatum; + struct user_datum *userdatum; + int rc = 0; + + *rule = NULL; + + if (!ss_initialized) + return -ENOTSUPP; + + switch (field) { + case AUDIT_SE_USER: + case AUDIT_SE_ROLE: + case AUDIT_SE_TYPE: + /* only 'equals' and 'not equals' fit user, role, and type */ + if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL) + return -EINVAL; + break; + case AUDIT_SE_SEN: + case AUDIT_SE_CLR: + /* we do not allow a range, indicated by the presense of '-' */ + if (strchr(rulestr, '-')) + return -EINVAL; + break; + default: + /* only the above fields are valid */ + return -EINVAL; + } + + tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); + if (!tmprule) + return -ENOMEM; + + context_init(&tmprule->au_ctxt); + + POLICY_RDLOCK; + + tmprule->au_seqno = latest_granting; + + switch (field) { + case AUDIT_SE_USER: + userdatum = hashtab_search(policydb.p_users.table, rulestr); + if (!userdatum) + rc = -EINVAL; + else + tmprule->au_ctxt.user = userdatum->value; + break; + case AUDIT_SE_ROLE: + roledatum = hashtab_search(policydb.p_roles.table, rulestr); + if (!roledatum) + rc = -EINVAL; + else + tmprule->au_ctxt.role = roledatum->value; + break; + case AUDIT_SE_TYPE: + typedatum = hashtab_search(policydb.p_types.table, rulestr); + if (!typedatum) + rc = -EINVAL; + else + tmprule->au_ctxt.type = typedatum->value; + break; + case AUDIT_SE_SEN: + case AUDIT_SE_CLR: + rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC); + break; + } + + POLICY_RDUNLOCK; + + if (rc) { + selinux_audit_rule_free(tmprule); + tmprule = NULL; + } + + *rule = tmprule; + + return rc; +} + +int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op, + struct selinux_audit_rule *rule, + struct audit_context *actx) +{ + struct context *ctxt; + struct mls_level *level; + int match = 0; + + if (!rule) { + audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, + "selinux_audit_rule_match: missing rule\n"); + return -ENOENT; + } + + POLICY_RDLOCK; + + if (rule->au_seqno < latest_granting) { + audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, + "selinux_audit_rule_match: stale rule\n"); + match = -ESTALE; + goto out; + } + + ctxt = sidtab_search(&sidtab, ctxid); + if (!ctxt) { + audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, + "selinux_audit_rule_match: unrecognized SID %d\n", + ctxid); + match = -ENOENT; + goto out; + } + + /* a field/op pair that is not caught here will simply fall through + without a match */ + switch (field) { + case AUDIT_SE_USER: + switch (op) { + case AUDIT_EQUAL: + match = (ctxt->user == rule->au_ctxt.user); + break; + case AUDIT_NOT_EQUAL: + match = (ctxt->user != rule->au_ctxt.user); + break; + } + break; + case AUDIT_SE_ROLE: + switch (op) { + case AUDIT_EQUAL: + match = (ctxt->role == rule->au_ctxt.role); + break; + case AUDIT_NOT_EQUAL: + match = (ctxt->role != rule->au_ctxt.role); + break; + } + break; + case AUDIT_SE_TYPE: + switch (op) { + case AUDIT_EQUAL: + match = (ctxt->type == rule->au_ctxt.type); + break; + case AUDIT_NOT_EQUAL: + match = (ctxt->type != rule->au_ctxt.type); + break; + } + break; + case AUDIT_SE_SEN: + case AUDIT_SE_CLR: + level = (op == AUDIT_SE_SEN ? + &ctxt->range.level[0] : &ctxt->range.level[1]); + switch (op) { + case AUDIT_EQUAL: + match = mls_level_eq(&rule->au_ctxt.range.level[0], + level); + break; + case AUDIT_NOT_EQUAL: + match = !mls_level_eq(&rule->au_ctxt.range.level[0], + level); + break; + case AUDIT_LESS_THAN: + match = (mls_level_dom(&rule->au_ctxt.range.level[0], + level) && + !mls_level_eq(&rule->au_ctxt.range.level[0], + level)); + break; + case AUDIT_LESS_THAN_OR_EQUAL: + match = mls_level_dom(&rule->au_ctxt.range.level[0], + level); + break; + case AUDIT_GREATER_THAN: + match = (mls_level_dom(level, + &rule->au_ctxt.range.level[0]) && + !mls_level_eq(level, + &rule->au_ctxt.range.level[0])); + break; + case AUDIT_GREATER_THAN_OR_EQUAL: + match = mls_level_dom(level, + &rule->au_ctxt.range.level[0]); + break; + } + } + +out: + POLICY_RDUNLOCK; + return match; +} + +static int (*aurule_callback)(void) = NULL; + +static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid, + u16 class, u32 perms, u32 *retained) +{ + int err = 0; + + if (event == AVC_CALLBACK_RESET && aurule_callback) + err = aurule_callback(); + return err; +} + +static int __init aurule_init(void) +{ + int err; + + err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET, + SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0); + if (err) + panic("avc_add_callback() failed, error %d\n", err); + + return err; +} +__initcall(aurule_init); + +void selinux_audit_set_callback(int (*callback)(void)) +{ + aurule_callback = callback; +} |