X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=security%2Fselinux%2Fss%2Fservices.c;h=ca9154dc5d825bea7f680de2f42b0979e4a930a6;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=6375dd578b39c69d6929d7ef421044757506d5be;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 6375dd578..ca9154dc5 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -7,13 +7,23 @@ * Updated: Trusted Computer Solutions, Inc. * * Support for enhanced MLS infrastructure. + * Support for context based audit filters. * * Updated: Frank Mayer and Karl MacMillan * * Added conditional policy language extensions * - * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. - * Copyright (C) 2003 - 2004 Tresys Technology, LLC + * Updated: Hewlett-Packard + * + * Added support for NetLabel + * + * Updated: Chad Sellers + * + * Added validation of kernel classes and permissions + * + * Copyright (C) 2006 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC * Copyright (C) 2003 Red Hat, Inc., James Morris * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -23,11 +33,15 @@ #include #include #include +#include #include #include #include #include -#include +#include +#include +#include + #include "flask.h" #include "avc.h" #include "avc_ss.h" @@ -38,19 +52,28 @@ #include "services.h" #include "conditional.h" #include "mls.h" +#include "objsec.h" +#include "selinux_netlabel.h" +#include "xfrm.h" +#include "ebitmap.h" extern void selnl_notify_policyload(u32 seqno); unsigned int policydb_loaded_version; +/* + * This is declared in avc.c + */ +extern const struct selinux_class_perm selinux_class_perm; + static DEFINE_RWLOCK(policy_rwlock); #define POLICY_RDLOCK read_lock(&policy_rwlock) #define POLICY_WRLOCK write_lock_irq(&policy_rwlock) #define POLICY_RDUNLOCK read_unlock(&policy_rwlock) #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock) -static DECLARE_MUTEX(load_sem); -#define LOAD_LOCK down(&load_sem) -#define LOAD_UNLOCK up(&load_sem) +static DEFINE_MUTEX(load_mutex); +#define LOAD_LOCK mutex_lock(&load_mutex) +#define LOAD_UNLOCK mutex_unlock(&load_mutex) static struct sidtab sidtab; struct policydb policydb; @@ -831,6 +854,8 @@ static int security_compute_sid(u32 ssid, goto out; } + context_init(&newcontext); + POLICY_RDLOCK; scontext = sidtab_search(&sidtab, ssid); @@ -848,8 +873,6 @@ static int security_compute_sid(u32 ssid, goto out_unlock; } - context_init(&newcontext); - /* Set the user identity. */ switch (specified) { case AVTAB_TRANSITION: @@ -1008,86 +1031,112 @@ int security_change_sid(u32 ssid, } /* - * Verify that each permission that is defined under the - * existing policy is still defined with the same value - * in the new policy. + * Verify that each kernel class that is defined in the + * policy is correct */ -static int validate_perm(void *key, void *datum, void *p) +static int validate_classes(struct policydb *p) { - struct hashtab *h; - struct perm_datum *perdatum, *perdatum2; - int rc = 0; - - - h = p; - perdatum = datum; - - perdatum2 = hashtab_search(h, key); - if (!perdatum2) { - printk(KERN_ERR "security: permission %s disappeared", - (char *)key); - rc = -ENOENT; - goto out; - } - if (perdatum->value != perdatum2->value) { - printk(KERN_ERR "security: the value of permission %s changed", - (char *)key); - rc = -EINVAL; - } -out: - return rc; -} - -/* - * Verify that each class that is defined under the - * existing policy is still defined with the same - * attributes in the new policy. - */ -static int validate_class(void *key, void *datum, void *p) -{ - struct policydb *newp; - struct class_datum *cladatum, *cladatum2; - int rc; - - newp = p; - cladatum = datum; - - cladatum2 = hashtab_search(newp->p_classes.table, key); - if (!cladatum2) { - printk(KERN_ERR "security: class %s disappeared\n", - (char *)key); - rc = -ENOENT; - goto out; - } - if (cladatum->value != cladatum2->value) { - printk(KERN_ERR "security: the value of class %s changed\n", - (char *)key); - rc = -EINVAL; - goto out; + int i, j; + struct class_datum *cladatum; + struct perm_datum *perdatum; + u32 nprim, tmp, common_pts_len, perm_val, pol_val; + u16 class_val; + const struct selinux_class_perm *kdefs = &selinux_class_perm; + const char *def_class, *def_perm, *pol_class; + struct symtab *perms; + + for (i = 1; i < kdefs->cts_len; i++) { + def_class = kdefs->class_to_string[i]; + if (i > p->p_classes.nprim) { + printk(KERN_INFO + "security: class %s not defined in policy\n", + def_class); + continue; + } + pol_class = p->p_class_val_to_name[i-1]; + if (strcmp(pol_class, def_class)) { + printk(KERN_ERR + "security: class %d is incorrect, found %s but should be %s\n", + i, pol_class, def_class); + return -EINVAL; + } } - if ((cladatum->comdatum && !cladatum2->comdatum) || - (!cladatum->comdatum && cladatum2->comdatum)) { - printk(KERN_ERR "security: the inherits clause for the access " - "vector definition for class %s changed\n", (char *)key); - rc = -EINVAL; - goto out; + for (i = 0; i < kdefs->av_pts_len; i++) { + class_val = kdefs->av_perm_to_string[i].tclass; + perm_val = kdefs->av_perm_to_string[i].value; + def_perm = kdefs->av_perm_to_string[i].name; + if (class_val > p->p_classes.nprim) + continue; + pol_class = p->p_class_val_to_name[class_val-1]; + cladatum = hashtab_search(p->p_classes.table, pol_class); + BUG_ON(!cladatum); + perms = &cladatum->permissions; + nprim = 1 << (perms->nprim - 1); + if (perm_val > nprim) { + printk(KERN_INFO + "security: permission %s in class %s not defined in policy\n", + def_perm, pol_class); + continue; + } + perdatum = hashtab_search(perms->table, def_perm); + if (perdatum == NULL) { + printk(KERN_ERR + "security: permission %s in class %s not found in policy\n", + def_perm, pol_class); + return -EINVAL; + } + pol_val = 1 << (perdatum->value - 1); + if (pol_val != perm_val) { + printk(KERN_ERR + "security: permission %s in class %s has incorrect value\n", + def_perm, pol_class); + return -EINVAL; + } } - if (cladatum->comdatum) { - rc = hashtab_map(cladatum->comdatum->permissions.table, validate_perm, - cladatum2->comdatum->permissions.table); - if (rc) { - printk(" in the access vector definition for class " - "%s\n", (char *)key); - goto out; + for (i = 0; i < kdefs->av_inherit_len; i++) { + class_val = kdefs->av_inherit[i].tclass; + if (class_val > p->p_classes.nprim) + continue; + pol_class = p->p_class_val_to_name[class_val-1]; + cladatum = hashtab_search(p->p_classes.table, pol_class); + BUG_ON(!cladatum); + if (!cladatum->comdatum) { + printk(KERN_ERR + "security: class %s should have an inherits clause but does not\n", + pol_class); + return -EINVAL; + } + tmp = kdefs->av_inherit[i].common_base; + common_pts_len = 0; + while (!(tmp & 0x01)) { + common_pts_len++; + tmp >>= 1; + } + perms = &cladatum->comdatum->permissions; + for (j = 0; j < common_pts_len; j++) { + def_perm = kdefs->av_inherit[i].common_pts[j]; + if (j >= perms->nprim) { + printk(KERN_INFO + "security: permission %s in class %s not defined in policy\n", + def_perm, pol_class); + continue; + } + perdatum = hashtab_search(perms->table, def_perm); + if (perdatum == NULL) { + printk(KERN_ERR + "security: permission %s in class %s not found in policy\n", + def_perm, pol_class); + return -EINVAL; + } + if (perdatum->value != j + 1) { + printk(KERN_ERR + "security: permission %s in class %s has incorrect value\n", + def_perm, pol_class); + return -EINVAL; + } } } - rc = hashtab_map(cladatum->permissions.table, validate_perm, - cladatum2->permissions.table); - if (rc) - printk(" in access vector definition for class %s\n", - (char *)key); -out: - return rc; + return 0; } /* Clone the SID into the new SID table. */ @@ -1232,6 +1281,16 @@ int security_load_policy(void *data, size_t len) avtab_cache_destroy(); return -EINVAL; } + /* Verify that the kernel defined classes are correct. */ + if (validate_classes(&policydb)) { + printk(KERN_ERR + "security: the definition of a class is incorrect\n"); + LOAD_UNLOCK; + sidtab_destroy(&sidtab); + policydb_destroy(&policydb); + avtab_cache_destroy(); + return -EINVAL; + } policydb_loaded_version = policydb.policyvers; ss_initialized = 1; seqno = ++latest_granting; @@ -1239,6 +1298,8 @@ int security_load_policy(void *data, size_t len) selinux_complete_init(); avc_ss_reset(seqno); selnl_notify_policyload(seqno); + selinux_netlbl_cache_invalidate(); + selinux_xfrm_notify_policyload(); return 0; } @@ -1253,10 +1314,10 @@ int security_load_policy(void *data, size_t len) sidtab_init(&newsidtab); - /* Verify that the existing classes did not change. */ - if (hashtab_map(policydb.p_classes.table, validate_class, &newpolicydb)) { - printk(KERN_ERR "security: the definition of an existing " - "class changed\n"); + /* Verify that the kernel defined classes are correct. */ + if (validate_classes(&newpolicydb)) { + printk(KERN_ERR + "security: the definition of a class is incorrect\n"); rc = -EINVAL; goto err; } @@ -1293,6 +1354,8 @@ int security_load_policy(void *data, size_t len) avc_ss_reset(seqno); selnl_notify_policyload(seqno); + selinux_netlbl_cache_invalidate(); + selinux_xfrm_notify_policyload(); return 0; @@ -1762,19 +1825,22 @@ int security_set_bools(int len, int *values) goto out; } - printk(KERN_INFO "security: committed booleans { "); for (i = 0; i < len; i++) { + if (!!values[i] != policydb.bool_val_to_struct[i]->state) { + audit_log(current->audit_context, GFP_ATOMIC, + AUDIT_MAC_CONFIG_CHANGE, + "bool=%s val=%d old_val=%d auid=%u", + policydb.p_bool_val_to_name[i], + !!values[i], + policydb.bool_val_to_struct[i]->state, + audit_get_loginuid(current->audit_context)); + } if (values[i]) { policydb.bool_val_to_struct[i]->state = 1; } else { policydb.bool_val_to_struct[i]->state = 0; } - if (i != 0) - printk(", "); - printk("%s:%d", policydb.p_bool_val_to_name[i], - policydb.bool_val_to_struct[i]->state); } - printk(" }\n"); for (cur = policydb.cond_list; cur != NULL; cur = cur->next) { rc = evaluate_cond_node(&policydb, cur); @@ -1789,6 +1855,7 @@ out: if (!rc) { avc_ss_reset(seqno); selnl_notify_policyload(seqno); + selinux_xfrm_notify_policyload(); } return rc; } @@ -1811,3 +1878,884 @@ out: POLICY_RDUNLOCK; return rc; } + +/* + * security_sid_mls_copy() - computes a new sid based on the given + * sid and the mls portion of mls_sid. + */ +int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) +{ + struct context *context1; + struct context *context2; + struct context newcon; + char *s; + u32 len; + int rc = 0; + + if (!ss_initialized || !selinux_mls_enabled) { + *new_sid = sid; + goto out; + } + + context_init(&newcon); + + POLICY_RDLOCK; + context1 = sidtab_search(&sidtab, sid); + if (!context1) { + printk(KERN_ERR "security_sid_mls_copy: unrecognized SID " + "%d\n", sid); + rc = -EINVAL; + goto out_unlock; + } + + context2 = sidtab_search(&sidtab, mls_sid); + if (!context2) { + printk(KERN_ERR "security_sid_mls_copy: unrecognized SID " + "%d\n", mls_sid); + rc = -EINVAL; + goto out_unlock; + } + + newcon.user = context1->user; + newcon.role = context1->role; + newcon.type = context1->type; + rc = mls_context_cpy(&newcon, context2); + if (rc) + goto out_unlock; + + /* Check the validity of the new context. */ + if (!policydb_context_isvalid(&policydb, &newcon)) { + rc = convert_context_handle_invalid_context(&newcon); + if (rc) + goto bad; + } + + rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid); + goto out_unlock; + +bad: + if (!context_struct_to_string(&newcon, &s, &len)) { + audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, + "security_sid_mls_copy: invalid context %s", s); + kfree(s); + } + +out_unlock: + POLICY_RDUNLOCK; + context_destroy(&newcon); +out: + 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_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + /* only 'equals' and 'not equals' fit user, role, and type */ + if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL) + return -EINVAL; + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + /* 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_SUBJ_USER: + case AUDIT_OBJ_USER: + userdatum = hashtab_search(policydb.p_users.table, rulestr); + if (!userdatum) + rc = -EINVAL; + else + tmprule->au_ctxt.user = userdatum->value; + break; + case AUDIT_SUBJ_ROLE: + case AUDIT_OBJ_ROLE: + roledatum = hashtab_search(policydb.p_roles.table, rulestr); + if (!roledatum) + rc = -EINVAL; + else + tmprule->au_ctxt.role = roledatum->value; + break; + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_TYPE: + typedatum = hashtab_search(policydb.p_types.table, rulestr); + if (!typedatum) + rc = -EINVAL; + else + tmprule->au_ctxt.type = typedatum->value; + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + 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 sid, 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, sid); + if (!ctxt) { + audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, + "selinux_audit_rule_match: unrecognized SID %d\n", + sid); + match = -ENOENT; + goto out; + } + + /* a field/op pair that is not caught here will simply fall through + without a match */ + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_OBJ_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_SUBJ_ROLE: + case AUDIT_OBJ_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_SUBJ_TYPE: + case AUDIT_OBJ_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_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + level = ((field == AUDIT_SUBJ_SEN || + field == AUDIT_OBJ_LEV_LOW) ? + &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; +} + +/** + * security_skb_extlbl_sid - Determine the external label of a packet + * @skb: the packet + * @base_sid: the SELinux SID to use as a context for MLS only external labels + * @sid: the packet's SID + * + * Description: + * Check the various different forms of external packet labeling and determine + * the external SID for the packet. + * + */ +void security_skb_extlbl_sid(struct sk_buff *skb, u32 base_sid, u32 *sid) +{ + u32 xfrm_sid; + u32 nlbl_sid; + + selinux_skb_xfrm_sid(skb, &xfrm_sid); + if (selinux_netlbl_skbuff_getsid(skb, + (xfrm_sid == SECSID_NULL ? + base_sid : xfrm_sid), + &nlbl_sid) != 0) + nlbl_sid = SECSID_NULL; + + *sid = (nlbl_sid == SECSID_NULL ? xfrm_sid : nlbl_sid); +} + +#ifdef CONFIG_NETLABEL +/* + * This is the structure we store inside the NetLabel cache block. + */ +#define NETLBL_CACHE(x) ((struct netlbl_cache *)(x)) +#define NETLBL_CACHE_T_NONE 0 +#define NETLBL_CACHE_T_SID 1 +#define NETLBL_CACHE_T_MLS 2 +struct netlbl_cache { + u32 type; + union { + u32 sid; + struct mls_range mls_label; + } data; +}; + +/** + * selinux_netlbl_cache_free - Free the NetLabel cached data + * @data: the data to free + * + * Description: + * This function is intended to be used as the free() callback inside the + * netlbl_lsm_cache structure. + * + */ +static void selinux_netlbl_cache_free(const void *data) +{ + struct netlbl_cache *cache; + + if (data == NULL) + return; + + cache = NETLBL_CACHE(data); + switch (cache->type) { + case NETLBL_CACHE_T_MLS: + ebitmap_destroy(&cache->data.mls_label.level[0].cat); + break; + } + kfree(data); +} + +/** + * selinux_netlbl_cache_add - Add an entry to the NetLabel cache + * @skb: the packet + * @ctx: the SELinux context + * + * Description: + * Attempt to cache the context in @ctx, which was derived from the packet in + * @skb, in the NetLabel subsystem cache. + * + */ +static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx) +{ + struct netlbl_cache *cache = NULL; + struct netlbl_lsm_secattr secattr; + + netlbl_secattr_init(&secattr); + secattr.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); + if (secattr.cache == NULL) + goto netlbl_cache_add_return; + + cache = kzalloc(sizeof(*cache), GFP_ATOMIC); + if (cache == NULL) + goto netlbl_cache_add_return; + + cache->type = NETLBL_CACHE_T_MLS; + if (ebitmap_cpy(&cache->data.mls_label.level[0].cat, + &ctx->range.level[0].cat) != 0) + goto netlbl_cache_add_return; + cache->data.mls_label.level[1].cat.highbit = + cache->data.mls_label.level[0].cat.highbit; + cache->data.mls_label.level[1].cat.node = + cache->data.mls_label.level[0].cat.node; + cache->data.mls_label.level[0].sens = ctx->range.level[0].sens; + cache->data.mls_label.level[1].sens = ctx->range.level[0].sens; + + secattr.cache->free = selinux_netlbl_cache_free; + secattr.cache->data = (void *)cache; + secattr.flags = NETLBL_SECATTR_CACHE; + + netlbl_cache_add(skb, &secattr); + +netlbl_cache_add_return: + netlbl_secattr_destroy(&secattr); +} + +/** + * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache + * + * Description: + * Invalidate the NetLabel security attribute mapping cache. + * + */ +void selinux_netlbl_cache_invalidate(void) +{ + netlbl_cache_invalidate(); +} + +/** + * selinux_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID + * @skb: the network packet + * @secattr: the NetLabel packet security attributes + * @base_sid: the SELinux SID to use as a context for MLS only attributes + * @sid: the SELinux SID + * + * Description: + * Convert the given NetLabel packet security attributes in @secattr into a + * SELinux SID. If the @secattr field does not contain a full SELinux + * SID/context then use the context in @base_sid as the foundation. If @skb + * is not NULL attempt to cache as much data as possibile. Returns zero on + * success, negative values on failure. + * + */ +static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb, + struct netlbl_lsm_secattr *secattr, + u32 base_sid, + u32 *sid) +{ + int rc = -EIDRM; + struct context *ctx; + struct context ctx_new; + struct netlbl_cache *cache; + + POLICY_RDLOCK; + + if (secattr->flags & NETLBL_SECATTR_CACHE) { + cache = NETLBL_CACHE(secattr->cache->data); + switch (cache->type) { + case NETLBL_CACHE_T_SID: + *sid = cache->data.sid; + rc = 0; + break; + case NETLBL_CACHE_T_MLS: + ctx = sidtab_search(&sidtab, base_sid); + if (ctx == NULL) + goto netlbl_secattr_to_sid_return; + + ctx_new.user = ctx->user; + ctx_new.role = ctx->role; + ctx_new.type = ctx->type; + ctx_new.range.level[0].sens = + cache->data.mls_label.level[0].sens; + ctx_new.range.level[0].cat.highbit = + cache->data.mls_label.level[0].cat.highbit; + ctx_new.range.level[0].cat.node = + cache->data.mls_label.level[0].cat.node; + ctx_new.range.level[1].sens = + cache->data.mls_label.level[1].sens; + ctx_new.range.level[1].cat.highbit = + cache->data.mls_label.level[1].cat.highbit; + ctx_new.range.level[1].cat.node = + cache->data.mls_label.level[1].cat.node; + + rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); + break; + default: + goto netlbl_secattr_to_sid_return; + } + } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { + ctx = sidtab_search(&sidtab, base_sid); + if (ctx == NULL) + goto netlbl_secattr_to_sid_return; + + ctx_new.user = ctx->user; + ctx_new.role = ctx->role; + ctx_new.type = ctx->type; + mls_import_netlbl_lvl(&ctx_new, secattr); + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat, + secattr->mls_cat) != 0) + goto netlbl_secattr_to_sid_return; + ctx_new.range.level[1].cat.highbit = + ctx_new.range.level[0].cat.highbit; + ctx_new.range.level[1].cat.node = + ctx_new.range.level[0].cat.node; + } else { + ebitmap_init(&ctx_new.range.level[0].cat); + ebitmap_init(&ctx_new.range.level[1].cat); + } + if (mls_context_isvalid(&policydb, &ctx_new) != 1) + goto netlbl_secattr_to_sid_return_cleanup; + + rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); + if (rc != 0) + goto netlbl_secattr_to_sid_return_cleanup; + + if (skb != NULL) + selinux_netlbl_cache_add(skb, &ctx_new); + ebitmap_destroy(&ctx_new.range.level[0].cat); + } else { + *sid = SECSID_NULL; + rc = 0; + } + +netlbl_secattr_to_sid_return: + POLICY_RDUNLOCK; + return rc; +netlbl_secattr_to_sid_return_cleanup: + ebitmap_destroy(&ctx_new.range.level[0].cat); + goto netlbl_secattr_to_sid_return; +} + +/** + * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel + * @skb: the packet + * @base_sid: the SELinux SID to use as a context for MLS only attributes + * @sid: the SID + * + * Description: + * Call the NetLabel mechanism to get the security attributes of the given + * packet and use those attributes to determine the correct context/SID to + * assign to the packet. Returns zero on success, negative values on failure. + * + */ +int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid) +{ + int rc; + struct netlbl_lsm_secattr secattr; + + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, &secattr); + if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) + rc = selinux_netlbl_secattr_to_sid(skb, + &secattr, + base_sid, + sid); + else + *sid = SECSID_NULL; + netlbl_secattr_destroy(&secattr); + + return rc; +} + +/** + * selinux_netlbl_socket_setsid - Label a socket using the NetLabel mechanism + * @sock: the socket to label + * @sid: the SID to use + * + * Description: + * Attempt to label a socket using the NetLabel mechanism using the given + * SID. Returns zero values on success, negative values on failure. The + * caller is responsibile for calling rcu_read_lock() before calling this + * this function and rcu_read_unlock() after this function returns. + * + */ +static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid) +{ + int rc = -ENOENT; + struct sk_security_struct *sksec = sock->sk->sk_security; + struct netlbl_lsm_secattr secattr; + struct context *ctx; + + if (!ss_initialized) + return 0; + + netlbl_secattr_init(&secattr); + + POLICY_RDLOCK; + + ctx = sidtab_search(&sidtab, sid); + if (ctx == NULL) + goto netlbl_socket_setsid_return; + + secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1], + GFP_ATOMIC); + secattr.flags |= NETLBL_SECATTR_DOMAIN; + mls_export_netlbl_lvl(ctx, &secattr); + rc = mls_export_netlbl_cat(ctx, &secattr); + if (rc != 0) + goto netlbl_socket_setsid_return; + + rc = netlbl_socket_setattr(sock, &secattr); + if (rc == 0) { + spin_lock_bh(&sksec->nlbl_lock); + sksec->nlbl_state = NLBL_LABELED; + spin_unlock_bh(&sksec->nlbl_lock); + } + +netlbl_socket_setsid_return: + POLICY_RDUNLOCK; + netlbl_secattr_destroy(&secattr); + return rc; +} + +/** + * selinux_netlbl_sk_security_reset - Reset the NetLabel fields + * @ssec: the sk_security_struct + * @family: the socket family + * + * Description: + * Called when the NetLabel state of a sk_security_struct needs to be reset. + * The caller is responsibile for all the NetLabel sk_security_struct locking. + * + */ +void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec, + int family) +{ + if (family == PF_INET) + ssec->nlbl_state = NLBL_REQUIRE; + else + ssec->nlbl_state = NLBL_UNSET; +} + +/** + * selinux_netlbl_sk_security_init - Setup the NetLabel fields + * @ssec: the sk_security_struct + * @family: the socket family + * + * Description: + * Called when a new sk_security_struct is allocated to initialize the NetLabel + * fields. + * + */ +void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec, + int family) +{ + /* No locking needed, we are the only one who has access to ssec */ + selinux_netlbl_sk_security_reset(ssec, family); + spin_lock_init(&ssec->nlbl_lock); +} + +/** + * selinux_netlbl_sk_security_clone - Copy the NetLabel fields + * @ssec: the original sk_security_struct + * @newssec: the cloned sk_security_struct + * + * Description: + * Clone the NetLabel specific sk_security_struct fields from @ssec to + * @newssec. + * + */ +void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec, + struct sk_security_struct *newssec) +{ + /* We don't need to take newssec->nlbl_lock because we are the only + * thread with access to newssec, but we do need to take the RCU read + * lock as other threads could have access to ssec */ + rcu_read_lock(); + selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family); + newssec->sclass = ssec->sclass; + rcu_read_unlock(); +} + +/** + * selinux_netlbl_socket_post_create - Label a socket using NetLabel + * @sock: the socket to label + * + * Description: + * Attempt to label a socket using the NetLabel mechanism using the given + * SID. Returns zero values on success, negative values on failure. + * + */ +int selinux_netlbl_socket_post_create(struct socket *sock) +{ + int rc = 0; + struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; + struct sk_security_struct *sksec = sock->sk->sk_security; + + sksec->sclass = isec->sclass; + + rcu_read_lock(); + if (sksec->nlbl_state == NLBL_REQUIRE) + rc = selinux_netlbl_socket_setsid(sock, sksec->sid); + rcu_read_unlock(); + + return rc; +} + +/** + * selinux_netlbl_sock_graft - Netlabel the new socket + * @sk: the new connection + * @sock: the new socket + * + * Description: + * The connection represented by @sk is being grafted onto @sock so set the + * socket's NetLabel to match the SID of @sk. + * + */ +void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) +{ + struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr secattr; + u32 nlbl_peer_sid; + + sksec->sclass = isec->sclass; + + rcu_read_lock(); + + if (sksec->nlbl_state != NLBL_REQUIRE) { + rcu_read_unlock(); + return; + } + + netlbl_secattr_init(&secattr); + if (netlbl_sock_getattr(sk, &secattr) == 0 && + secattr.flags != NETLBL_SECATTR_NONE && + selinux_netlbl_secattr_to_sid(NULL, + &secattr, + SECINITSID_UNLABELED, + &nlbl_peer_sid) == 0) + sksec->peer_sid = nlbl_peer_sid; + netlbl_secattr_destroy(&secattr); + + /* Try to set the NetLabel on the socket to save time later, if we fail + * here we will pick up the pieces in later calls to + * selinux_netlbl_inode_permission(). */ + selinux_netlbl_socket_setsid(sock, sksec->sid); + + rcu_read_unlock(); +} + +/** + * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled + * @inode: the file descriptor's inode + * @mask: the permission mask + * + * Description: + * Looks at a file's inode and if it is marked as a socket protected by + * NetLabel then verify that the socket has been labeled, if not try to label + * the socket now with the inode's SID. Returns zero on success, negative + * values on failure. + * + */ +int selinux_netlbl_inode_permission(struct inode *inode, int mask) +{ + int rc; + struct sk_security_struct *sksec; + struct socket *sock; + + if (!S_ISSOCK(inode->i_mode) || + ((mask & (MAY_WRITE | MAY_APPEND)) == 0)) + return 0; + sock = SOCKET_I(inode); + sksec = sock->sk->sk_security; + + rcu_read_lock(); + if (sksec->nlbl_state != NLBL_REQUIRE) { + rcu_read_unlock(); + return 0; + } + local_bh_disable(); + bh_lock_sock_nested(sock->sk); + rc = selinux_netlbl_socket_setsid(sock, sksec->sid); + bh_unlock_sock(sock->sk); + local_bh_enable(); + rcu_read_unlock(); + + return rc; +} + +/** + * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel + * @sksec: the sock's sk_security_struct + * @skb: the packet + * @ad: the audit data + * + * Description: + * Fetch the NetLabel security attributes from @skb and perform an access check + * against the receiving socket. Returns zero on success, negative values on + * error. + * + */ +int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, + struct sk_buff *skb, + struct avc_audit_data *ad) +{ + int rc; + u32 netlbl_sid; + u32 recv_perm; + + rc = selinux_netlbl_skbuff_getsid(skb, + SECINITSID_UNLABELED, + &netlbl_sid); + if (rc != 0) + return rc; + + if (netlbl_sid == SECSID_NULL) + return 0; + + switch (sksec->sclass) { + case SECCLASS_UDP_SOCKET: + recv_perm = UDP_SOCKET__RECVFROM; + break; + case SECCLASS_TCP_SOCKET: + recv_perm = TCP_SOCKET__RECVFROM; + break; + default: + recv_perm = RAWIP_SOCKET__RECVFROM; + } + + rc = avc_has_perm(sksec->sid, + netlbl_sid, + sksec->sclass, + recv_perm, + ad); + if (rc == 0) + return 0; + + netlbl_skbuff_err(skb, rc); + return rc; +} + +/** + * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel + * @sock: the socket + * @level: the socket level or protocol + * @optname: the socket option name + * + * Description: + * Check the setsockopt() call and if the user is trying to replace the IP + * options on a socket and a NetLabel is in place for the socket deny the + * access; otherwise allow the access. Returns zero when the access is + * allowed, -EACCES when denied, and other negative values on error. + * + */ +int selinux_netlbl_socket_setsockopt(struct socket *sock, + int level, + int optname) +{ + int rc = 0; + struct sk_security_struct *sksec = sock->sk->sk_security; + struct netlbl_lsm_secattr secattr; + + rcu_read_lock(); + if (level == IPPROTO_IP && optname == IP_OPTIONS && + sksec->nlbl_state == NLBL_LABELED) { + netlbl_secattr_init(&secattr); + rc = netlbl_socket_getattr(sock, &secattr); + if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) + rc = -EACCES; + netlbl_secattr_destroy(&secattr); + } + rcu_read_unlock(); + + return rc; +} +#endif /* CONFIG_NETLABEL */