| /* |
| * Implementation of the security services. |
| * |
| * Authors : Stephen Smalley, <sds@epoch.ncsc.mil> |
| * James Morris <jmorris@redhat.com> |
| * |
| * 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 |
| * |
| * Updated: Hewlett-Packard <paul.moore@hp.com> |
| * |
| * Added support for NetLabel |
| * |
| * Updated: Chad Sellers <csellers@tresys.com> |
| * |
| * 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 <jmorris@redhat.com> |
| * 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 |
| * the Free Software Foundation, version 2. |
| */ |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| #include <linux/spinlock.h> |
| #include <linux/rcupdate.h> |
| #include <linux/errno.h> |
| #include <linux/in.h> |
| #include <linux/sched.h> |
| #include <linux/audit.h> |
| #include <linux/mutex.h> |
| #include <net/sock.h> |
| #include <net/netlabel.h> |
| |
| #include "flask.h" |
| #include "avc.h" |
| #include "avc_ss.h" |
| #include "security.h" |
| #include "context.h" |
| #include "policydb.h" |
| #include "sidtab.h" |
| #include "services.h" |
| #include "conditional.h" |
| #include "mls.h" |
| #include "objsec.h" |
| #include "selinux_netlabel.h" |
| #include "xfrm.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 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; |
| int ss_initialized = 0; |
| |
| /* |
| * The largest sequence number that has been used when |
| * providing an access decision to the access vector cache. |
| * The sequence number only changes when a policy change |
| * occurs. |
| */ |
| static u32 latest_granting = 0; |
| |
| /* Forward declaration. */ |
| static int context_struct_to_string(struct context *context, char **scontext, |
| u32 *scontext_len); |
| |
| /* |
| * Return the boolean value of a constraint expression |
| * when it is applied to the specified source and target |
| * security contexts. |
| * |
| * xcontext is a special beast... It is used by the validatetrans rules |
| * only. For these rules, scontext is the context before the transition, |
| * tcontext is the context after the transition, and xcontext is the context |
| * of the process performing the transition. All other callers of |
| * constraint_expr_eval should pass in NULL for xcontext. |
| */ |
| static int constraint_expr_eval(struct context *scontext, |
| struct context *tcontext, |
| struct context *xcontext, |
| struct constraint_expr *cexpr) |
| { |
| u32 val1, val2; |
| struct context *c; |
| struct role_datum *r1, *r2; |
| struct mls_level *l1, *l2; |
| struct constraint_expr *e; |
| int s[CEXPR_MAXDEPTH]; |
| int sp = -1; |
| |
| for (e = cexpr; e; e = e->next) { |
| switch (e->expr_type) { |
| case CEXPR_NOT: |
| BUG_ON(sp < 0); |
| s[sp] = !s[sp]; |
| break; |
| case CEXPR_AND: |
| BUG_ON(sp < 1); |
| sp--; |
| s[sp] &= s[sp+1]; |
| break; |
| case CEXPR_OR: |
| BUG_ON(sp < 1); |
| sp--; |
| s[sp] |= s[sp+1]; |
| break; |
| case CEXPR_ATTR: |
| if (sp == (CEXPR_MAXDEPTH-1)) |
| return 0; |
| switch (e->attr) { |
| case CEXPR_USER: |
| val1 = scontext->user; |
| val2 = tcontext->user; |
| break; |
| case CEXPR_TYPE: |
| val1 = scontext->type; |
| val2 = tcontext->type; |
| break; |
| case CEXPR_ROLE: |
| val1 = scontext->role; |
| val2 = tcontext->role; |
| r1 = policydb.role_val_to_struct[val1 - 1]; |
| r2 = policydb.role_val_to_struct[val2 - 1]; |
| switch (e->op) { |
| case CEXPR_DOM: |
| s[++sp] = ebitmap_get_bit(&r1->dominates, |
| val2 - 1); |
| continue; |
| case CEXPR_DOMBY: |
| s[++sp] = ebitmap_get_bit(&r2->dominates, |
| val1 - 1); |
| continue; |
| case CEXPR_INCOMP: |
| s[++sp] = ( !ebitmap_get_bit(&r1->dominates, |
| val2 - 1) && |
| !ebitmap_get_bit(&r2->dominates, |
| val1 - 1) ); |
| continue; |
| default: |
| break; |
| } |
| break; |
| case CEXPR_L1L2: |
| l1 = &(scontext->range.level[0]); |
| l2 = &(tcontext->range.level[0]); |
| goto mls_ops; |
| case CEXPR_L1H2: |
| l1 = &(scontext->range.level[0]); |
| l2 = &(tcontext->range.level[1]); |
| goto mls_ops; |
| case CEXPR_H1L2: |
| l1 = &(scontext->range.level[1]); |
| l2 = &(tcontext->range.level[0]); |
| goto mls_ops; |
| case CEXPR_H1H2: |
| l1 = &(scontext->range.level[1]); |
| l2 = &(tcontext->range.level[1]); |
| goto mls_ops; |
| case CEXPR_L1H1: |
| l1 = &(scontext->range.level[0]); |
| l2 = &(scontext->range.level[1]); |
| goto mls_ops; |
| case CEXPR_L2H2: |
| l1 = &(tcontext->range.level[0]); |
| l2 = &(tcontext->range.level[1]); |
| goto mls_ops; |
| mls_ops: |
| switch (e->op) { |
| case CEXPR_EQ: |
| s[++sp] = mls_level_eq(l1, l2); |
| continue; |
| case CEXPR_NEQ: |
| s[++sp] = !mls_level_eq(l1, l2); |
| continue; |
| case CEXPR_DOM: |
| s[++sp] = mls_level_dom(l1, l2); |
| continue; |
| case CEXPR_DOMBY: |
| s[++sp] = mls_level_dom(l2, l1); |
| continue; |
| case CEXPR_INCOMP: |
| s[++sp] = mls_level_incomp(l2, l1); |
| continue; |
| default: |
| BUG(); |
| return 0; |
| } |
| break; |
| default: |
| BUG(); |
| return 0; |
| } |
| |
| switch (e->op) { |
| case CEXPR_EQ: |
| s[++sp] = (val1 == val2); |
| break; |
| case CEXPR_NEQ: |
| s[++sp] = (val1 != val2); |
| break; |
| default: |
| BUG(); |
| return 0; |
| } |
| break; |
| case CEXPR_NAMES: |
| if (sp == (CEXPR_MAXDEPTH-1)) |
| return 0; |
| c = scontext; |
| if (e->attr & CEXPR_TARGET) |
| c = tcontext; |
| else if (e->attr & CEXPR_XTARGET) { |
| c = xcontext; |
| if (!c) { |
| BUG(); |
| return 0; |
| } |
| } |
| if (e->attr & CEXPR_USER) |
| val1 = c->user; |
| else if (e->attr & CEXPR_ROLE) |
| val1 = c->role; |
| else if (e->attr & CEXPR_TYPE) |
| val1 = c->type; |
| else { |
| BUG(); |
| return 0; |
| } |
| |
| switch (e->op) { |
| case CEXPR_EQ: |
| s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); |
| break; |
| case CEXPR_NEQ: |
| s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); |
| break; |
| default: |
| BUG(); |
| return 0; |
| } |
| break; |
| default: |
| BUG(); |
| return 0; |
| } |
| } |
| |
| BUG_ON(sp != 0); |
| return s[0]; |
| } |
| |
| /* |
| * Compute access vectors based on a context structure pair for |
| * the permissions in a particular class. |
| */ |
| static int context_struct_compute_av(struct context *scontext, |
| struct context *tcontext, |
| u16 tclass, |
| u32 requested, |
| struct av_decision *avd) |
| { |
| struct constraint_node *constraint; |
| struct role_allow *ra; |
| struct avtab_key avkey; |
| struct avtab_node *node; |
| struct class_datum *tclass_datum; |
| struct ebitmap *sattr, *tattr; |
| struct ebitmap_node *snode, *tnode; |
| unsigned int i, j; |
| |
| /* |
| * Remap extended Netlink classes for old policy versions. |
| * Do this here rather than socket_type_to_security_class() |
| * in case a newer policy version is loaded, allowing sockets |
| * to remain in the correct class. |
| */ |
| if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) |
| if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && |
| tclass <= SECCLASS_NETLINK_DNRT_SOCKET) |
| tclass = SECCLASS_NETLINK_SOCKET; |
| |
| if (!tclass || tclass > policydb.p_classes.nprim) { |
| printk(KERN_ERR "security_compute_av: unrecognized class %d\n", |
| tclass); |
| return -EINVAL; |
| } |
| tclass_datum = policydb.class_val_to_struct[tclass - 1]; |
| |
| /* |
| * Initialize the access vectors to the default values. |
| */ |
| avd->allowed = 0; |
| avd->decided = 0xffffffff; |
| avd->auditallow = 0; |
| avd->auditdeny = 0xffffffff; |
| avd->seqno = latest_granting; |
| |
| /* |
| * If a specific type enforcement rule was defined for |
| * this permission check, then use it. |
| */ |
| avkey.target_class = tclass; |
| avkey.specified = AVTAB_AV; |
| sattr = &policydb.type_attr_map[scontext->type - 1]; |
| tattr = &policydb.type_attr_map[tcontext->type - 1]; |
| ebitmap_for_each_bit(sattr, snode, i) { |
| if (!ebitmap_node_get_bit(snode, i)) |
| continue; |
| ebitmap_for_each_bit(tattr, tnode, j) { |
| if (!ebitmap_node_get_bit(tnode, j)) |
| continue; |
| avkey.source_type = i + 1; |
| avkey.target_type = j + 1; |
| for (node = avtab_search_node(&policydb.te_avtab, &avkey); |
| node != NULL; |
| node = avtab_search_node_next(node, avkey.specified)) { |
| if (node->key.specified == AVTAB_ALLOWED) |
| avd->allowed |= node->datum.data; |
| else if (node->key.specified == AVTAB_AUDITALLOW) |
| avd->auditallow |= node->datum.data; |
| else if (node->key.specified == AVTAB_AUDITDENY) |
| avd->auditdeny &= node->datum.data; |
| } |
| |
| /* Check conditional av table for additional permissions */ |
| cond_compute_av(&policydb.te_cond_avtab, &avkey, avd); |
| |
| } |
| } |
| |
| /* |
| * Remove any permissions prohibited by a constraint (this includes |
| * the MLS policy). |
| */ |
| constraint = tclass_datum->constraints; |
| while (constraint) { |
| if ((constraint->permissions & (avd->allowed)) && |
| !constraint_expr_eval(scontext, tcontext, NULL, |
| constraint->expr)) { |
| avd->allowed = (avd->allowed) & ~(constraint->permissions); |
| } |
| constraint = constraint->next; |
| } |
| |
| /* |
| * If checking process transition permission and the |
| * role is changing, then check the (current_role, new_role) |
| * pair. |
| */ |
| if (tclass == SECCLASS_PROCESS && |
| (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) && |
| scontext->role != tcontext->role) { |
| for (ra = policydb.role_allow; ra; ra = ra->next) { |
| if (scontext->role == ra->role && |
| tcontext->role == ra->new_role) |
| break; |
| } |
| if (!ra) |
| avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION | |
| PROCESS__DYNTRANSITION); |
| } |
| |
| return 0; |
| } |
| |
| static int security_validtrans_handle_fail(struct context *ocontext, |
| struct context *ncontext, |
| struct context *tcontext, |
| u16 tclass) |
| { |
| char *o = NULL, *n = NULL, *t = NULL; |
| u32 olen, nlen, tlen; |
| |
| if (context_struct_to_string(ocontext, &o, &olen) < 0) |
| goto out; |
| if (context_struct_to_string(ncontext, &n, &nlen) < 0) |
| goto out; |
| if (context_struct_to_string(tcontext, &t, &tlen) < 0) |
| goto out; |
| audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, |
| "security_validate_transition: denied for" |
| " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", |
| o, n, t, policydb.p_class_val_to_name[tclass-1]); |
| out: |
| kfree(o); |
| kfree(n); |
| kfree(t); |
| |
| if (!selinux_enforcing) |
| return 0; |
| return -EPERM; |
| } |
| |
| int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, |
| u16 tclass) |
| { |
| struct context *ocontext; |
| struct context *ncontext; |
| struct context *tcontext; |
| struct class_datum *tclass_datum; |
| struct constraint_node *constraint; |
| int rc = 0; |
| |
| if (!ss_initialized) |
| return 0; |
| |
| POLICY_RDLOCK; |
| |
| /* |
| * Remap extended Netlink classes for old policy versions. |
| * Do this here rather than socket_type_to_security_class() |
| * in case a newer policy version is loaded, allowing sockets |
| * to remain in the correct class. |
| */ |
| if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) |
| if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && |
| tclass <= SECCLASS_NETLINK_DNRT_SOCKET) |
| tclass = SECCLASS_NETLINK_SOCKET; |
| |
| if (!tclass || tclass > policydb.p_classes.nprim) { |
| printk(KERN_ERR "security_validate_transition: " |
| "unrecognized class %d\n", tclass); |
| rc = -EINVAL; |
| goto out; |
| } |
| tclass_datum = policydb.class_val_to_struct[tclass - 1]; |
| |
| ocontext = sidtab_search(&sidtab, oldsid); |
| if (!ocontext) { |
| printk(KERN_ERR "security_validate_transition: " |
| " unrecognized SID %d\n", oldsid); |
| rc = -EINVAL; |
| goto out; |
| } |
| |
| ncontext = sidtab_search(&sidtab, newsid); |
| if (!ncontext) { |
| printk(KERN_ERR "security_validate_transition: " |
| " unrecognized SID %d\n", newsid); |
| rc = -EINVAL; |
| goto out; |
| } |
| |
| tcontext = sidtab_search(&sidtab, tasksid); |
| if (!tcontext) { |
| printk(KERN_ERR "security_validate_transition: " |
| " unrecognized SID %d\n", tasksid); |
| rc = -EINVAL; |
| goto out; |
| } |
| |
| constraint = tclass_datum->validatetrans; |
| while (constraint) { |
| if (!constraint_expr_eval(ocontext, ncontext, tcontext, |
| constraint->expr)) { |
| rc = security_validtrans_handle_fail(ocontext, ncontext, |
| tcontext, tclass); |
| goto out; |
| } |
| constraint = constraint->next; |
| } |
| |
| out: |
| POLICY_RDUNLOCK; |
| return rc; |
| } |
| |
| /** |
| * security_compute_av - Compute access vector decisions. |
| * @ssid: source security identifier |
| * @tsid: target security identifier |
| * @tclass: target security class |
| * @requested: requested permissions |
| * @avd: access vector decisions |
| * |
| * Compute a set of access vector decisions based on the |
| * SID pair (@ssid, @tsid) for the permissions in @tclass. |
| * Return -%EINVAL if any of the parameters are invalid or %0 |
| * if the access vector decisions were computed successfully. |
| */ |
| int security_compute_av(u32 ssid, |
| u32 tsid, |
| u16 tclass, |
| u32 requested, |
| struct av_decision *avd) |
| { |
| struct context *scontext = NULL, *tcontext = NULL; |
| int rc = 0; |
| |
| if (!ss_initialized) { |
| avd->allowed = 0xffffffff; |
| avd->decided = 0xffffffff; |
| avd->auditallow = 0; |
| avd->auditdeny = 0xffffffff; |
| avd->seqno = latest_granting; |
| return 0; |
| } |
| |
| POLICY_RDLOCK; |
| |
| scontext = sidtab_search(&sidtab, ssid); |
| if (!scontext) { |
| printk(KERN_ERR "security_compute_av: unrecognized SID %d\n", |
| ssid); |
| rc = -EINVAL; |
| goto out; |
| } |
| tcontext = sidtab_search(&sidtab, tsid); |
| if (!tcontext) { |
| printk(KERN_ERR "security_compute_av: unrecognized SID %d\n", |
| tsid); |
| rc = -EINVAL; |
| goto out; |
| } |
| |
| rc = context_struct_compute_av(scontext, tcontext, tclass, |
| requested, avd); |
| out: |
| POLICY_RDUNLOCK; |
| return rc; |
| } |
| |
| /* |
| * Write the security context string representation of |
| * the context structure `context' into a dynamically |
| * allocated string of the correct size. Set `*scontext' |
| * to point to this string and set `*scontext_len' to |
| * the length of the string. |
| */ |
| static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) |
| { |
| char *scontextp; |
| |
| *scontext = NULL; |
| *scontext_len = 0; |
| |
| /* Compute the size of the context. */ |
| *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1; |
| *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1; |
| *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1; |
| *scontext_len += mls_compute_context_len(context); |
| |
| /* Allocate space for the context; caller must free this space. */ |
| scontextp = kmalloc(*scontext_len, GFP_ATOMIC); |
| if (!scontextp) { |
| return -ENOMEM; |
| } |
| *scontext = scontextp; |
| |
| /* |
| * Copy the user name, role name and type name into the context. |
| */ |
| sprintf(scontextp, "%s:%s:%s", |
| policydb.p_user_val_to_name[context->user - 1], |
| policydb.p_role_val_to_name[context->role - 1], |
| policydb.p_type_val_to_name[context->type - 1]); |
| scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) + |
| 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) + |
| 1 + strlen(policydb.p_type_val_to_name[context->type - 1]); |
| |
| mls_sid_to_context(context, &scontextp); |
| |
| *scontextp = 0; |
| |
| return 0; |
| } |
| |
| #include "initial_sid_to_string.h" |
| |
| /** |
| * security_sid_to_context - Obtain a context for a given SID. |
| * @sid: security identifier, SID |
| * @scontext: security context |
| * @scontext_len: length in bytes |
| * |
| * Write the string representation of the context associated with @sid |
| * into a dynamically allocated string of the correct size. Set @scontext |
| * to point to this string and set @scontext_len to the length of the string. |
| */ |
| int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) |
| { |
| struct context *context; |
| int rc = 0; |
| |
| if (!ss_initialized) { |
| if (sid <= SECINITSID_NUM) { |
| char *scontextp; |
| |
| *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; |
| } |
| printk(KERN_ERR "security_sid_to_context: called before initial " |
| "load_policy on unknown SID %d\n", sid); |
| rc = -EINVAL; |
| goto out; |
| } |
| POLICY_RDLOCK; |
| context = sidtab_search(&sidtab, sid); |
| if (!context) { |
| printk(KERN_ERR "security_sid_to_context: unrecognized SID " |
| "%d\n", sid); |
| rc = -EINVAL; |
| goto out_unlock; |
| } |
| rc = context_struct_to_string(context, scontext, scontext_len); |
| out_unlock: |
| POLICY_RDUNLOCK; |
| out: |
| return rc; |
| |
| } |
| |
| static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid) |
| { |
| char *scontext2; |
| struct context context; |
| struct role_datum *role; |
| struct type_datum *typdatum; |
| struct user_datum *usrdatum; |
| char *scontextp, *p, oldc; |
| int rc = 0; |
| |
| if (!ss_initialized) { |
| int i; |
| |
| for (i = 1; i < SECINITSID_NUM; i++) { |
| if (!strcmp(initial_sid_to_string[i], scontext)) { |
| *sid = i; |
| goto out; |
| } |
| } |
| *sid = SECINITSID_KERNEL; |
| goto out; |
| } |
| *sid = SECSID_NULL; |
| |
| /* Copy the string so that we can modify the copy as we parse it. |
| The string should already by null terminated, but we append a |
| null suffix to the copy to avoid problems with the existing |
| attr package, which doesn't view the null terminator as part |
| of the attribute value. */ |
| scontext2 = kmalloc(scontext_len+1,GFP_KERNEL); |
| if (!scontext2) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| memcpy(scontext2, scontext, scontext_len); |
| scontext2[scontext_len] = 0; |
| |
| context_init(&context); |
| *sid = SECSID_NULL; |
| |
| POLICY_RDLOCK; |
| |
| /* Parse the security context. */ |
| |
| rc = -EINVAL; |
| scontextp = (char *) scontext2; |
| |
| /* Extract the user. */ |
| p = scontextp; |
| while (*p && *p != ':') |
| p++; |
| |
| if (*p == 0) |
| goto out_unlock; |
| |
| *p++ = 0; |
| |
| usrdatum = hashtab_search(policydb.p_users.table, scontextp); |
| if (!usrdatum) |
| goto out_unlock; |
| |
| context.user = usrdatum->value; |
| |
| /* Extract role. */ |
| scontextp = p; |
| while (*p && *p != ':') |
| p++; |
| |
| if (*p == 0) |
| goto out_unlock; |
| |
| *p++ = 0; |
| |
| role = hashtab_search(policydb.p_roles.table, scontextp); |
| if (!role) |
| goto out_unlock; |
| context.role = role->value; |
| |
| /* Extract type. */ |
| scontextp = p; |
| while (*p && *p != ':') |
| p++; |
| oldc = *p; |
| *p++ = 0; |
| |
| typdatum = hashtab_search(policydb.p_types.table, scontextp); |
| if (!typdatum) |
| goto out_unlock; |
| |
| context.type = typdatum->value; |
| |
| rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid); |
| if (rc) |
| goto out_unlock; |
| |
| if ((p - scontext2) < scontext_len) { |
| rc = -EINVAL; |
| goto out_unlock; |
| } |
| |
| /* Check the validity of the new context. */ |
| if (!policydb_context_isvalid(&policydb, &context)) { |
| rc = -EINVAL; |
| goto out_unlock; |
| } |
| /* Obtain the new sid. */ |
| rc = sidtab_context_to_sid(&sidtab, &context, sid); |
| out_unlock: |
| POLICY_RDUNLOCK; |
| context_destroy(&context); |
| kfree(scontext2); |
| out: |
| return rc; |
| } |
| |
| /** |
| * security_context_to_sid - Obtain a SID for a given security context. |
| * @scontext: security context |
| * @scontext_len: length in bytes |
| * @sid: security identifier, SID |
| * |
| * Obtains a SID associated with the security context that |
| * has the string representation specified by @scontext. |
| * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient |
| * memory is available, or 0 on success. |
| */ |
| int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid) |
| { |
| return security_context_to_sid_core(scontext, scontext_len, |
| sid, SECSID_NULL); |
| } |
| |
| /** |
| * security_context_to_sid_default - Obtain a SID for a given security context, |
| * falling back to specified default if needed. |
| * |
| * @scontext: security context |
| * @scontext_len: length in bytes |
| * @sid: security identifier, SID |
| * @def_sid: default SID to assign on errror |
| * |
| * Obtains a SID associated with the security context that |
| * has the string representation specified by @scontext. |
| * The default SID is passed to the MLS layer to be used to allow |
| * kernel labeling of the MLS field if the MLS field is not present |
| * (for upgrading to MLS without full relabel). |
| * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient |
| * memory is available, or 0 on success. |
| */ |
| int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid) |
| { |
| return security_context_to_sid_core(scontext, scontext_len, |
| sid, def_sid); |
| } |
| |
| static int compute_sid_handle_invalid_context( |
| struct context *scontext, |
| struct context *tcontext, |
| u16 tclass, |
| struct context *newcontext) |
| { |
| char *s = NULL, *t = NULL, *n = NULL; |
| u32 slen, tlen, nlen; |
| |
| if (context_struct_to_string(scontext, &s, &slen) < 0) |
| goto out; |
| if (context_struct_to_string(tcontext, &t, &tlen) < 0) |
| goto out; |
| if (context_struct_to_string(newcontext, &n, &nlen) < 0) |
| goto out; |
| audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, |
| "security_compute_sid: invalid context %s" |
| " for scontext=%s" |
| " tcontext=%s" |
| " tclass=%s", |
| n, s, t, policydb.p_class_val_to_name[tclass-1]); |
| out: |
| kfree(s); |
| kfree(t); |
| kfree(n); |
| if (!selinux_enforcing) |
| return 0; |
| return -EACCES; |
| } |
| |
| static int security_compute_sid(u32 ssid, |
| u32 tsid, |
| u16 tclass, |
| u32 specified, |
| u32 *out_sid) |
| { |
| struct context *scontext = NULL, *tcontext = NULL, newcontext; |
| struct role_trans *roletr = NULL; |
| struct avtab_key avkey; |
| struct avtab_datum *avdatum; |
| struct avtab_node *node; |
| int rc = 0; |
| |
| if (!ss_initialized) { |
| switch (tclass) { |
| case SECCLASS_PROCESS: |
| *out_sid = ssid; |
| break; |
| default: |
| *out_sid = tsid; |
| break; |
| } |
| goto out; |
| } |
| |
| context_init(&newcontext); |
| |
| POLICY_RDLOCK; |
| |
| scontext = sidtab_search(&sidtab, ssid); |
| if (!scontext) { |
| printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n", |
| ssid); |
| rc = -EINVAL; |
| goto out_unlock; |
| } |
| tcontext = sidtab_search(&sidtab, tsid); |
| if (!tcontext) { |
| printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n", |
| tsid); |
| rc = -EINVAL; |
| goto out_unlock; |
| } |
| |
| /* Set the user identity. */ |
| switch (specified) { |
| case AVTAB_TRANSITION: |
| case AVTAB_CHANGE: |
| /* Use the process user identity. */ |
| newcontext.user = scontext->user; |
| break; |
| case AVTAB_MEMBER: |
| /* Use the related object owner. */ |
| newcontext.user = tcontext->user; |
| break; |
| } |
| |
| /* Set the role and type to default values. */ |
| switch (tclass) { |
| case SECCLASS_PROCESS: |
| /* Use the current role and type of process. */ |
| newcontext.role = scontext->role; |
| newcontext.type = scontext->type; |
| break; |
| default: |
| /* Use the well-defined object role. */ |
| newcontext.role = OBJECT_R_VAL; |
| /* Use the type of the related object. */ |
| newcontext.type = tcontext->type; |
| } |
| |
| /* Look for a type transition/member/change rule. */ |
| avkey.source_type = scontext->type; |
| avkey.target_type = tcontext->type; |
| avkey.target_class = tclass; |
| avkey.specified = specified; |
| avdatum = avtab_search(&policydb.te_avtab, &avkey); |
| |
| /* If no permanent rule, also check for enabled conditional rules */ |
| if(!avdatum) { |
| node = avtab_search_node(&policydb.te_cond_avtab, &avkey); |
| for (; node != NULL; node = avtab_search_node_next(node, specified)) { |
| if (node->key.specified & AVTAB_ENABLED) { |
| avdatum = &node->datum; |
| break; |
| } |
| } |
| } |
| |
| if (avdatum) { |
| /* Use the type from the type transition/member/change rule. */ |
| newcontext.type = avdatum->data; |
| } |
| |
| /* Check for class-specific changes. */ |
| switch (tclass) { |
| case SECCLASS_PROCESS: |
| if (specified & AVTAB_TRANSITION) { |
| /* Look for a role transition rule. */ |
| for (roletr = policydb.role_tr; roletr; |
| roletr = roletr->next) { |
| if (roletr->role == scontext->role && |
| roletr->type == tcontext->type) { |
| /* Use the role transition rule. */ |
| newcontext.role = roletr->new_role; |
| break; |
| } |
| } |
| } |
| break; |
| default: |
| break; |
| } |
| |
| /* Set the MLS attributes. |
| This is done last because it may allocate memory. */ |
| rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext); |
| if (rc) |
| goto out_unlock; |
| |
| /* Check the validity of the context. */ |
| if (!policydb_context_isvalid(&policydb, &newcontext)) { |
| rc = compute_sid_handle_invalid_context(scontext, |
| tcontext, |
| tclass, |
| &newcontext); |
| if (rc) |
| goto out_unlock; |
| } |
| /* Obtain the sid for the context. */ |
| rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); |
| out_unlock: |
| POLICY_RDUNLOCK; |
| context_destroy(&newcontext); |
| out: |
| return rc; |
| } |
| |
| /** |
| * security_transition_sid - Compute the SID for a new subject/object. |
| * @ssid: source security identifier |
| * @tsid: target security identifier |
| * @tclass: target security class |
| * @out_sid: security identifier for new subject/object |
| * |
| * Compute a SID to use for labeling a new subject or object in the |
| * class @tclass based on a SID pair (@ssid, @tsid). |
| * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM |
| * if insufficient memory is available, or %0 if the new SID was |
| * computed successfully. |
| */ |
| int security_transition_sid(u32 ssid, |
| u32 tsid, |
| u16 tclass, |
| u32 *out_sid) |
| { |
| return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid); |
| } |
| |
| /** |
| * security_member_sid - Compute the SID for member selection. |
| * @ssid: source security identifier |
| * @tsid: target security identifier |
| * @tclass: target security class |
| * @out_sid: security identifier for selected member |
| * |
| * Compute a SID to use when selecting a member of a polyinstantiated |
| * object of class @tclass based on a SID pair (@ssid, @tsid). |
| * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM |
| * if insufficient memory is available, or %0 if the SID was |
| * computed successfully. |
| */ |
| int security_member_sid(u32 ssid, |
| u32 tsid, |
| u16 tclass, |
| u32 *out_sid) |
| { |
| return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid); |
| } |
| |
| /** |
| * security_change_sid - Compute the SID for object relabeling. |
| * @ssid: source security identifier |
| * @tsid: target security identifier |
| * @tclass: target security class |
| * @out_sid: security identifier for selected member |
| * |
| * Compute a SID to use for relabeling an object of class @tclass |
| * based on a SID pair (@ssid, @tsid). |
| * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM |
| * if insufficient memory is available, or %0 if the SID was |
| * computed successfully. |
| */ |
| int security_change_sid(u32 ssid, |
| u32 tsid, |
| u16 tclass, |
| u32 *out_sid) |
| { |
| return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid); |
| } |
| |
| /* |
| * Verify that each kernel class that is defined in the |
| * policy is correct |
| */ |
| static int validate_classes(struct policydb *p) |
| { |
| 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; |
| } |
| } |
| 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; |
| } |
| } |
| 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; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* Clone the SID into the new SID table. */ |
| static int clone_sid(u32 sid, |
| struct context *context, |
| void *arg) |
| { |
| struct sidtab *s = arg; |
| |
| return sidtab_insert(s, sid, context); |
| } |
| |
| static inline int convert_context_handle_invalid_context(struct context *context) |
| { |
| int rc = 0; |
| |
| if (selinux_enforcing) { |
| rc = -EINVAL; |
| } else { |
| char *s; |
| u32 len; |
| |
| context_struct_to_string(context, &s, &len); |
| printk(KERN_ERR "security: context %s is invalid\n", s); |
| kfree(s); |
| } |
| return rc; |
| } |
| |
| struct convert_context_args { |
| struct policydb *oldp; |
| struct policydb *newp; |
| }; |
| |
| /* |
| * Convert the values in the security context |
| * structure `c' from the values specified |
| * in the policy `p->oldp' to the values specified |
| * in the policy `p->newp'. Verify that the |
| * context is valid under the new policy. |
| */ |
| static int convert_context(u32 key, |
| struct context *c, |
| void *p) |
| { |
| struct convert_context_args *args; |
| struct context oldc; |
| struct role_datum *role; |
| struct type_datum *typdatum; |
| struct user_datum *usrdatum; |
| char *s; |
| u32 len; |
| int rc; |
| |
| args = p; |
| |
| rc = context_cpy(&oldc, c); |
| if (rc) |
| goto out; |
| |
| rc = -EINVAL; |
| |
| /* Convert the user. */ |
| usrdatum = hashtab_search(args->newp->p_users.table, |
| args->oldp->p_user_val_to_name[c->user - 1]); |
| if (!usrdatum) { |
| goto bad; |
| } |
| c->user = usrdatum->value; |
| |
| /* Convert the role. */ |
| role = hashtab_search(args->newp->p_roles.table, |
| args->oldp->p_role_val_to_name[c->role - 1]); |
| if (!role) { |
| goto bad; |
| } |
| c->role = role->value; |
| |
| /* Convert the type. */ |
| typdatum = hashtab_search(args->newp->p_types.table, |
| args->oldp->p_type_val_to_name[c->type - 1]); |
| if (!typdatum) { |
| goto bad; |
| } |
| c->type = typdatum->value; |
| |
| rc = mls_convert_context(args->oldp, args->newp, c); |
| if (rc) |
| goto bad; |
| |
| /* Check the validity of the new context. */ |
| if (!policydb_context_isvalid(args->newp, c)) { |
| rc = convert_context_handle_invalid_context(&oldc); |
| if (rc) |
| goto bad; |
| } |
| |
| context_destroy(&oldc); |
| out: |
| return rc; |
| bad: |
| context_struct_to_string(&oldc, &s, &len); |
| context_destroy(&oldc); |
| printk(KERN_ERR "security: invalidating context %s\n", s); |
| kfree(s); |
| goto out; |
| } |
| |
| extern void selinux_complete_init(void); |
| |
| /** |
| * security_load_policy - Load a security policy configuration. |
| * @data: binary policy data |
| * @len: length of data in bytes |
| * |
| * Load a new set of security policy configuration data, |
| * validate it and convert the SID table as necessary. |
| * This function will flush the access vector cache after |
| * loading the new policy. |
| */ |
| int security_load_policy(void *data, size_t len) |
| { |
| struct policydb oldpolicydb, newpolicydb; |
| struct sidtab oldsidtab, newsidtab; |
| struct convert_context_args args; |
| u32 seqno; |
| int rc = 0; |
| struct policy_file file = { data, len }, *fp = &file; |
| |
| LOAD_LOCK; |
| |
| if (!ss_initialized) { |
| avtab_cache_init(); |
| if (policydb_read(&policydb, fp)) { |
| LOAD_UNLOCK; |
| avtab_cache_destroy(); |
| return -EINVAL; |
| } |
| if (policydb_load_isids(&policydb, &sidtab)) { |
| LOAD_UNLOCK; |
| policydb_destroy(&policydb); |
| 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; |
| LOAD_UNLOCK; |
| selinux_complete_init(); |
| avc_ss_reset(seqno); |
| selnl_notify_policyload(seqno); |
| selinux_netlbl_cache_invalidate(); |
| return 0; |
| } |
| |
| #if 0 |
| sidtab_hash_eval(&sidtab, "sids"); |
| #endif |
| |
| if (policydb_read(&newpolicydb, fp)) { |
| LOAD_UNLOCK; |
| return -EINVAL; |
| } |
| |
| sidtab_init(&newsidtab); |
| |
| /* 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; |
| } |
| |
| /* Clone the SID table. */ |
| sidtab_shutdown(&sidtab); |
| if (sidtab_map(&sidtab, clone_sid, &newsidtab)) { |
| rc = -ENOMEM; |
| goto err; |
| } |
| |
| /* Convert the internal representations of contexts |
| in the new SID table and remove invalid SIDs. */ |
| args.oldp = &policydb; |
| args.newp = &newpolicydb; |
| sidtab_map_remove_on_error(&newsidtab, convert_context, &args); |
| |
| /* Save the old policydb and SID table to free later. */ |
| memcpy(&oldpolicydb, &policydb, sizeof policydb); |
| sidtab_set(&oldsidtab, &sidtab); |
| |
| /* Install the new policydb and SID table. */ |
| POLICY_WRLOCK; |
| memcpy(&policydb, &newpolicydb, sizeof policydb); |
| sidtab_set(&sidtab, &newsidtab); |
| seqno = ++latest_granting; |
| policydb_loaded_version = policydb.policyvers; |
| POLICY_WRUNLOCK; |
| LOAD_UNLOCK; |
| |
| /* Free the old policydb and SID table. */ |
| policydb_destroy(&oldpolicydb); |
| sidtab_destroy(&oldsidtab); |
| |
| avc_ss_reset(seqno); |
| selnl_notify_policyload(seqno); |
| selinux_netlbl_cache_invalidate(); |
| |
| return 0; |
| |
| err: |
| LOAD_UNLOCK; |
| sidtab_destroy(&newsidtab); |
| policydb_destroy(&newpolicydb); |
| return rc; |
| |
| } |
| |
| /** |
| * security_port_sid - Obtain the SID for a port. |
| * @domain: communication domain aka address family |
| * @type: socket type |
| * @protocol: protocol number |
| * @port: port number |
| * @out_sid: security identifier |
| */ |
| int security_port_sid(u16 domain, |
| u16 type, |
| u8 protocol, |
| u16 port, |
| u32 *out_sid) |
| { |
| struct ocontext *c; |
| int rc = 0; |
| |
| POLICY_RDLOCK; |
| |
| c = policydb.ocontexts[OCON_PORT]; |
| while (c) { |
| if (c->u.port.protocol == protocol && |
| c->u.port.low_port <= port && |
| c->u.port.high_port >= port) |
| break; |
| c = c->next; |
| } |
| |
| if (c) { |
| if (!c->sid[0]) { |
| rc = sidtab_context_to_sid(&sidtab, |
| &c->context[0], |
| &c->sid[0]); |
| if (rc) |
| goto out; |
| } |
| *out_sid = c->sid[0]; |
| } else { |
| *out_sid = SECINITSID_PORT; |
| } |
| |
| out: |
| POLICY_RDUNLOCK; |
| return rc; |
| } |
| |
| /** |
| * security_netif_sid - Obtain the SID for a network interface. |
| * @name: interface name |
| * @if_sid: interface SID |
| * @msg_sid: default SID for received packets |
| */ |
| int security_netif_sid(char *name, |
| u32 *if_sid, |
| u32 *msg_sid) |
| { |
| int rc = 0; |
| struct ocontext *c; |
| |
| POLICY_RDLOCK; |
| |
| c = policydb.ocontexts[OCON_NETIF]; |
| while (c) { |
| if (strcmp(name, c->u.name) == 0) |
| break; |
| c = c->next; |
| } |
| |
| if (c) { |
| if (!c->sid[0] || !c->sid[1]) { |
| rc = sidtab_context_to_sid(&sidtab, |
| &c->context[0], |
| &c->sid[0]); |
| if (rc) |
| goto out; |
| rc = sidtab_context_to_sid(&sidtab, |
| &c->context[1], |
| &c->sid[1]); |
| if (rc) |
| goto out; |
| } |
| *if_sid = c->sid[0]; |
| *msg_sid = c->sid[1]; |
| } else { |
| *if_sid = SECINITSID_NETIF; |
| *msg_sid = SECINITSID_NETMSG; |
| } |
| |
| out: |
| POLICY_RDUNLOCK; |
| return rc; |
| } |
| |
| static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) |
| { |
| int i, fail = 0; |
| |
| for(i = 0; i < 4; i++) |
| if(addr[i] != (input[i] & mask[i])) { |
| fail = 1; |
| break; |
| } |
| |
| return !fail; |
| } |
| |
| /** |
| * security_node_sid - Obtain the SID for a node (host). |
| * @domain: communication domain aka address family |
| * @addrp: address |
| * @addrlen: address length in bytes |
| * @out_sid: security identifier |
| */ |
| int security_node_sid(u16 domain, |
| void *addrp, |
| u32 addrlen, |
| u32 *out_sid) |
| { |
| int rc = 0; |
| struct ocontext *c; |
| |
| POLICY_RDLOCK; |
| |
| switch (domain) { |
| case AF_INET: { |
| u32 addr; |
| |
| if (addrlen != sizeof(u32)) { |
| rc = -EINVAL; |
| goto out; |
| } |
| |
| addr = *((u32 *)addrp); |
| |
| c = policydb.ocontexts[OCON_NODE]; |
| while (c) { |
| if (c->u.node.addr == (addr & c->u.node.mask)) |
| break; |
| c = c->next; |
| } |
| break; |
| } |
| |
| case AF_INET6: |
| if (addrlen != sizeof(u64) * 2) { |
| rc = -EINVAL; |
| goto out; |
| } |
| c = policydb.ocontexts[OCON_NODE6]; |
| while (c) { |
| if (match_ipv6_addrmask(addrp, c->u.node6.addr, |
| c->u.node6.mask)) |
| break; |
| c = c->next; |
| } |
| break; |
| |
| default: |
| *out_sid = SECINITSID_NODE; |
| goto out; |
| } |
| |
| if (c) { |
| if (!c->sid[0]) { |
| rc = sidtab_context_to_sid(&sidtab, |
| &c->context[0], |
| &c->sid[0]); |
| if (rc) |
| goto out; |
| } |
| *out_sid = c->sid[0]; |
| } else { |
| *out_sid = SECINITSID_NODE; |
| } |
| |
| out: |
| POLICY_RDUNLOCK; |
| return rc; |
| } |
| |
| #define SIDS_NEL 25 |
| |
| /** |
| * security_get_user_sids - Obtain reachable SIDs for a user. |
| * @fromsid: starting SID |
| * @username: username |
| * @sids: array of reachable SIDs for user |
| * @nel: number of elements in @sids |
| * |
| * Generate the set of SIDs for legal security contexts |
| * for a given user that can be reached by @fromsid. |
| * Set *@sids to point to a dynamically allocated |
| * array containing the set of SIDs. Set *@nel to the |
| * number of elements in the array. |
| */ |
| |
| int security_get_user_sids(u32 fromsid, |
| char *username, |
| u32 **sids, |
| u32 *nel) |
| { |
| struct context *fromcon, usercon; |
| u32 *mysids, *mysids2, sid; |
| u32 mynel = 0, maxnel = SIDS_NEL; |
| struct user_datum *user; |
| struct role_datum *role; |
| struct av_decision avd; |
| struct ebitmap_node *rnode, *tnode; |
| int rc = 0, i, j; |
| |
| if (!ss_initialized) { |
| *sids = NULL; |
| *nel = 0; |
| goto out; |
| } |
| |
| POLICY_RDLOCK; |
| |
| fromcon = sidtab_search(&sidtab, fromsid); |
| if (!fromcon) { |
| rc = -EINVAL; |
| goto out_unlock; |
| } |
| |
| user = hashtab_search(policydb.p_users.table, username); |
| if (!user) { |
| rc = -EINVAL; |
| goto out_unlock; |
| } |
| usercon.user = user->value; |
| |
| mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); |
| if (!mysids) { |
| rc = -ENOMEM; |
| goto out_unlock; |
| } |
| |
| ebitmap_for_each_bit(&user->roles, rnode, i) { |
| if (!ebitmap_node_get_bit(rnode, i)) |
| continue; |
| role = policydb.role_val_to_struct[i]; |
| usercon.role = i+1; |
| ebitmap_for_each_bit(&role->types, tnode, j) { |
| if (!ebitmap_node_get_bit(tnode, j)) |
| continue; |
| usercon.type = j+1; |
| |
| if (mls_setup_user_range(fromcon, user, &usercon)) |
| continue; |
| |
| rc = context_struct_compute_av(fromcon, &usercon, |
| SECCLASS_PROCESS, |
| PROCESS__TRANSITION, |
| &avd); |
| if (rc || !(avd.allowed & PROCESS__TRANSITION)) |
| continue; |
| rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); |
| if (rc) { |
| kfree(mysids); |
| goto out_unlock; |
| } |
| if (mynel < maxnel) { |
| mysids[mynel++] = sid; |
| } else { |
| maxnel += SIDS_NEL; |
| mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); |
| if (!mysids2) { |
| rc = -ENOMEM; |
| kfree(mysids); |
| goto out_unlock; |
| } |
| memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); |
| kfree(mysids); |
| mysids = mysids2; |
| mysids[mynel++] = sid; |
| } |
| } |
| } |
| |
| *sids = mysids; |
| *nel = mynel; |
| |
| out_unlock: |
| POLICY_RDUNLOCK; |
| out: |
| return rc; |
| } |
| |
| /** |
| * security_genfs_sid - Obtain a SID for a file in a filesystem |
| * @fstype: filesystem type |
| * @path: path from root of mount |
| * @sclass: file security class |
| * @sid: SID for path |
| * |
| * Obtain a SID to use for a file in a filesystem that |
| * cannot support xattr or use a fixed labeling behavior like |
| * transition SIDs or task SIDs. |
| */ |
| int security_genfs_sid(const char *fstype, |
| char *path, |
| u16 sclass, |
| u32 *sid) |
| { |
| int len; |
| struct genfs *genfs; |
| struct ocontext *c; |
| int rc = 0, cmp = 0; |
| |
| POLICY_RDLOCK; |
| |
| for (genfs = policydb.genfs; genfs; genfs = genfs->next) { |
| cmp = strcmp(fstype, genfs->fstype); |
| if (cmp <= 0) |
| break; |
| } |
| |
| if (!genfs || cmp) { |
| *sid = SECINITSID_UNLABELED; |
| rc = -ENOENT; |
| goto out; |
| } |
| |
| for (c = genfs->head; c; c = c->next) { |
| len = strlen(c->u.name); |
| if ((!c->v.sclass || sclass == c->v.sclass) && |
| (strncmp(c->u.name, path, len) == 0)) |
| break; |
| } |
| |
| if (!c) { |
| *sid = SECINITSID_UNLABELED; |
| rc = -ENOENT; |
| goto out; |
| } |
| |
| if (!c->sid[0]) { |
| rc = sidtab_context_to_sid(&sidtab, |
| &c->context[0], |
| &c->sid[0]); |
| if (rc) |
| goto out; |
| } |
| |
| *sid = c->sid[0]; |
| out: |
| POLICY_RDUNLOCK; |
| return rc; |
| } |
| |
| /** |
| * security_fs_use - Determine how to handle labeling for a filesystem. |
| * @fstype: filesystem type |
| * @behavior: labeling behavior |
| * @sid: SID for filesystem (superblock) |
| */ |
| int security_fs_use( |
| const char *fstype, |
| unsigned int *behavior, |
| u32 *sid) |
| { |
| int rc = 0; |
| struct ocontext *c; |
| |
| POLICY_RDLOCK; |
| |
| c = policydb.ocontexts[OCON_FSUSE]; |
| while (c) { |
| if (strcmp(fstype, c->u.name) == 0) |
| break; |
| c = c->next; |
| } |
| |
| if (c) { |
| *behavior = c->v.behavior; |
| if (!c->sid[0]) { |
| rc = sidtab_context_to_sid(&sidtab, |
| &c->context[0], |
| &c->sid[0]); |
| if (rc) |
| goto out; |
| } |
| *sid = c->sid[0]; |
| } else { |
| rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid); |
| if (rc) { |
| *behavior = SECURITY_FS_USE_NONE; |
| rc = 0; |
| } else { |
| *behavior = SECURITY_FS_USE_GENFS; |
| } |
| } |
| |
| out: |
| POLICY_RDUNLOCK; |
| return rc; |
| } |
| |
| int security_get_bools(int *len, char ***names, int **values) |
| { |
| int i, rc = -ENOMEM; |
| |
| POLICY_RDLOCK; |
| *names = NULL; |
| *values = NULL; |
| |
| *len = policydb.p_bools.nprim; |
| if (!*len) { |
| rc = 0; |
| goto out; |
| } |
| |
| *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC); |
| if (!*names) |
| goto err; |
| |
| *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); |
| if (!*values) |
| goto err; |
| |
| for (i = 0; i < *len; i++) { |
| size_t name_len; |
| (*values)[i] = policydb.bool_val_to_struct[i]->state; |
| name_len = strlen(policydb.p_bool_val_to_name[i]) + 1; |
| (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC); |
| if (!(*names)[i]) |
| goto err; |
| strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len); |
| (*names)[i][name_len - 1] = 0; |
| } |
| rc = 0; |
| out: |
| POLICY_RDUNLOCK; |
| return rc; |
| err: |
| if (*names) { |
| for (i = 0; i < *len; i++) |
| kfree((*names)[i]); |
| } |
| kfree(*values); |
| goto out; |
| } |
| |
| |
| int security_set_bools(int len, int *values) |
| { |
| int i, rc = 0; |
| int lenp, seqno = 0; |
| struct cond_node *cur; |
| |
| POLICY_WRLOCK; |
| |
| lenp = policydb.p_bools.nprim; |
| if (len != lenp) { |
| rc = -EFAULT; |
| goto out; |
| } |
| |
| 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; |
| } |
| } |
| |
| for (cur = policydb.cond_list; cur != NULL; cur = cur->next) { |
| rc = evaluate_cond_node(&policydb, cur); |
| if (rc) |
| goto out; |
| } |
| |
| seqno = ++latest_granting; |
| |
| out: |
| POLICY_WRUNLOCK; |
| if (!rc) { |
| avc_ss_reset(seqno); |
| selnl_notify_policyload(seqno); |
| } |
| return rc; |
| } |
| |
| int security_get_bool_value(int bool) |
| { |
| int rc = 0; |
| int len; |
| |
| POLICY_RDLOCK; |
| |
| len = policydb.p_bools.nprim; |
| if (bool >= len) { |
| rc = -EFAULT; |
| goto out; |
| } |
| |
| rc = policydb.bool_val_to_struct[bool]->state; |
| 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_copy_context(&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_lvl(&ctx_new, secattr->mls_lvl, secattr->mls_lvl); |
| if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
| if (mls_import_cat(&ctx_new, |
| secattr->mls_cat, |
| secattr->mls_cat_len, |
| NULL, |
| 0) != 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); |
| mls_export_lvl(ctx, &secattr.mls_lvl, NULL); |
| rc = mls_export_cat(ctx, |
| &secattr.mls_cat, |
| &secattr.mls_cat_len, |
| NULL, |
| NULL); |
| if (rc != 0) |
| goto netlbl_socket_setsid_return; |
| |
| secattr.flags |= NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; |
| if (secattr.mls_cat) |
| secattr.flags |= NETLBL_SECATTR_MLS_CAT; |
| |
| rc = netlbl_socket_setattr(sock, &secattr); |
| if (rc == 0) { |
| spin_lock(&sksec->nlbl_lock); |
| sksec->nlbl_state = NLBL_LABELED; |
| spin_unlock(&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; |
| } |
| lock_sock(sock->sk); |
| rc = selinux_netlbl_socket_setsid(sock, sksec->sid); |
| release_sock(sock->sk); |
| 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 */ |