/*- * Copyright (c) 2005 Tom Rhodes * Copyright (c) 1999-2002 Robert N. M. Watson * Copyright (c) 2001-2005 Networks Associates Technology, Inc. * All rights reserved. * * This software was developed by Robert Watson for the TrustedBSD Project. * It was later enhanced by Tom Rhodes for the TrustedBSD Project. * * This software was developed for the FreeBSD Project in part by Network * Associates Laboratories, the Security Research Division of Network * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), * as part of the DARPA CHATS research program. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD$ */ /* * Developed by the TrustedBSD Project. * "BSD Extended" MAC policy, allowing the administrator to impose * mandatory rules regarding users and some system objects. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct mtx mac_bsdextended_mtx; SYSCTL_DECL(_security_mac); SYSCTL_NODE(_security_mac, OID_AUTO, bsdextended, CTLFLAG_RW, 0, "TrustedBSD extended BSD MAC policy controls"); static int mac_bsdextended_enabled = 1; SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, enabled, CTLFLAG_RW, &mac_bsdextended_enabled, 0, "Enforce extended BSD policy"); TUNABLE_INT("security.mac.bsdextended.enabled", &mac_bsdextended_enabled); MALLOC_DEFINE(M_MACBSDEXTENDED, "mac_bsdextended", "BSD Extended MAC rule"); #define MAC_BSDEXTENDED_MAXRULES 250 static struct mac_bsdextended_rule *rules[MAC_BSDEXTENDED_MAXRULES]; static int rule_count = 0; static int rule_slots = 0; SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_count, CTLFLAG_RD, &rule_count, 0, "Number of defined rules\n"); SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_slots, CTLFLAG_RD, &rule_slots, 0, "Number of used rule slots\n"); /* * This is just used for logging purposes, eventually we would like * to log much more then failed requests. */ static int mac_bsdextended_logging; SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, logging, CTLFLAG_RW, &mac_bsdextended_logging, 0, "Log failed authorization requests"); /* * This tunable is here for compatibility. It will allow the user * to switch between the new mode (first rule matches) and the old * functionality (all rules match). */ static int mac_bsdextended_firstmatch_enabled; SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, firstmatch_enabled, CTLFLAG_RW, &mac_bsdextended_firstmatch_enabled, 1, "Disable/enable match first rule functionality"); static int mac_bsdextended_rule_valid(struct mac_bsdextended_rule *rule) { if ((rule->mbr_subject.mbi_flags | MBI_BITS) != MBI_BITS) return (EINVAL); if ((rule->mbr_object.mbi_flags | MBI_BITS) != MBI_BITS) return (EINVAL); if ((rule->mbr_mode | MBI_ALLPERM) != MBI_ALLPERM) return (EINVAL); return (0); } static int sysctl_rule(SYSCTL_HANDLER_ARGS) { struct mac_bsdextended_rule temprule, *ruleptr; u_int namelen; int error, index, *name; error = 0; name = (int *)arg1; namelen = arg2; /* printf("bsdextended sysctl handler (namelen %d)\n", namelen); */ if (namelen != 1) return (EINVAL); index = name[0]; if (index >= MAC_BSDEXTENDED_MAXRULES) return (ENOENT); ruleptr = NULL; if (req->newptr && req->newlen != 0) { error = SYSCTL_IN(req, &temprule, sizeof(temprule)); if (error) return (error); MALLOC(ruleptr, struct mac_bsdextended_rule *, sizeof(*ruleptr), M_MACBSDEXTENDED, M_WAITOK | M_ZERO); } mtx_lock(&mac_bsdextended_mtx); if (req->oldptr) { if (index < 0 || index > rule_slots + 1) { error = ENOENT; goto out; } if (rules[index] == NULL) { error = ENOENT; goto out; } temprule = *rules[index]; } if (req->newptr && req->newlen == 0) { /* printf("deletion\n"); */ KASSERT(ruleptr == NULL, ("sysctl_rule: ruleptr != NULL")); ruleptr = rules[index]; if (ruleptr == NULL) { error = ENOENT; goto out; } rule_count--; rules[index] = NULL; } else if (req->newptr) { error = mac_bsdextended_rule_valid(&temprule); if (error) goto out; if (rules[index] == NULL) { /* printf("addition\n"); */ *ruleptr = temprule; rules[index] = ruleptr; ruleptr = NULL; if (index + 1 > rule_slots) rule_slots = index + 1; rule_count++; } else { /* printf("replacement\n"); */ *rules[index] = temprule; } } out: mtx_unlock(&mac_bsdextended_mtx); if (ruleptr != NULL) FREE(ruleptr, M_MACBSDEXTENDED); if (req->oldptr && error == 0) error = SYSCTL_OUT(req, &temprule, sizeof(temprule)); return (error); } SYSCTL_NODE(_security_mac_bsdextended, OID_AUTO, rules, CTLFLAG_RW, sysctl_rule, "BSD extended MAC rules"); static void mac_bsdextended_init(struct mac_policy_conf *mpc) { /* Initialize ruleset lock. */ mtx_init(&mac_bsdextended_mtx, "mac_bsdextended lock", NULL, MTX_DEF); /* Register dynamic sysctl's for rules. */ } static void mac_bsdextended_destroy(struct mac_policy_conf *mpc) { /* Destroy ruleset lock. */ mtx_destroy(&mac_bsdextended_mtx); /* Tear down sysctls. */ } static int mac_bsdextended_rulecheck(struct mac_bsdextended_rule *rule, struct ucred *cred, uid_t object_uid, gid_t object_gid, int acc_mode) { int match; /* * Is there a subject match? */ mtx_assert(&mac_bsdextended_mtx, MA_OWNED); if (rule->mbr_subject.mbi_flags & MBI_UID_DEFINED) { match = (rule->mbr_subject.mbi_uid == cred->cr_uid || rule->mbr_subject.mbi_uid == cred->cr_ruid || rule->mbr_subject.mbi_uid == cred->cr_svuid); if (rule->mbr_subject.mbi_flags & MBI_NEGATED) match = !match; if (!match) return (0); } if (rule->mbr_subject.mbi_flags & MBI_GID_DEFINED) { match = (groupmember(rule->mbr_subject.mbi_gid, cred) || rule->mbr_subject.mbi_gid == cred->cr_rgid || rule->mbr_subject.mbi_gid == cred->cr_svgid); if (rule->mbr_subject.mbi_flags & MBI_NEGATED) match = !match; if (!match) return (0); } /* * Is there an object match? */ if (rule->mbr_object.mbi_flags & MBI_UID_DEFINED) { match = (rule->mbr_object.mbi_uid == object_uid); if (rule->mbr_object.mbi_flags & MBI_NEGATED) match = !match; if (!match) return (0); } if (rule->mbr_object.mbi_flags & MBI_GID_DEFINED) { match = (rule->mbr_object.mbi_gid == object_gid); if (rule->mbr_object.mbi_flags & MBI_NEGATED) match = !match; if (!match) return (0); } /* * Is the access permitted? */ if ((rule->mbr_mode & acc_mode) != acc_mode) { if (mac_bsdextended_logging) log(LOG_AUTHPRIV, "mac_bsdextended: %d:%d request %d" " on %d:%d failed. \n", cred->cr_ruid, cred->cr_rgid, acc_mode, object_uid, object_gid); return (EACCES); /* Matching rule denies access */ } /* * If the rule matched, permits access, and first match is enabled, * return success. */ if (mac_bsdextended_firstmatch_enabled) return (EJUSTRETURN); else return(0); } static int mac_bsdextended_check(struct ucred *cred, uid_t object_uid, gid_t object_gid, int acc_mode) { int error, i; if (suser_cred(cred, 0) == 0) return (0); mtx_lock(&mac_bsdextended_mtx); for (i = 0; i < rule_slots; i++) { if (rules[i] == NULL) continue; /* * Since we do not separately handle append, map append to * write. */ if (acc_mode & MBI_APPEND) { acc_mode &= ~MBI_APPEND; acc_mode |= MBI_WRITE; } error = mac_bsdextended_rulecheck(rules[i], cred, object_uid, object_gid, acc_mode); if (error == EJUSTRETURN) break; if (error) { mtx_unlock(&mac_bsdextended_mtx); return (error); } } mtx_unlock(&mac_bsdextended_mtx); return (0); } static int mac_bsdextended_check_system_swapon(struct ucred *cred, struct vnode *vp, struct label *label) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE)); } static int mac_bsdextended_check_vnode_access(struct ucred *cred, struct vnode *vp, struct label *label, int acc_mode) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, acc_mode)); } static int mac_bsdextended_check_vnode_chdir(struct ucred *cred, struct vnode *dvp, struct label *dlabel) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_EXEC)); } static int mac_bsdextended_check_vnode_chroot(struct ucred *cred, struct vnode *dvp, struct label *dlabel) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_EXEC)); } static int mac_bsdextended_check_create_vnode(struct ucred *cred, struct vnode *dvp, struct label *dlabel, struct componentname *cnp, struct vattr *vap) { struct vattr dvap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &dvap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, dvap.va_uid, dvap.va_gid, MBI_WRITE)); } static int mac_bsdextended_check_vnode_delete(struct ucred *cred, struct vnode *dvp, struct label *dlabel, struct vnode *vp, struct label *label, struct componentname *cnp) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &vap, cred, curthread); if (error) return (error); error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE); if (error) return (error); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE)); } static int mac_bsdextended_check_vnode_deleteacl(struct ucred *cred, struct vnode *vp, struct label *label, acl_type_t type) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_ADMIN)); } static int mac_bsdextended_check_vnode_deleteextattr(struct ucred *cred, struct vnode *vp, struct label *label, int attrnamespace, const char *name) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE)); } static int mac_bsdextended_check_vnode_exec(struct ucred *cred, struct vnode *vp, struct label *label, struct image_params *imgp, struct label *execlabel) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_READ|MBI_EXEC)); } static int mac_bsdextended_check_vnode_getacl(struct ucred *cred, struct vnode *vp, struct label *label, acl_type_t type) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_STAT)); } static int mac_bsdextended_check_vnode_getextattr(struct ucred *cred, struct vnode *vp, struct label *label, int attrnamespace, const char *name, struct uio *uio) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_READ)); } static int mac_bsdextended_check_vnode_link(struct ucred *cred, struct vnode *dvp, struct label *dlabel, struct vnode *vp, struct label *label, struct componentname *cnp) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &vap, cred, curthread); if (error) return (error); error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE); if (error) return (error); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE); if (error) return (error); return (0); } static int mac_bsdextended_check_vnode_listextattr(struct ucred *cred, struct vnode *vp, struct label *label, int attrnamespace) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_READ)); } static int mac_bsdextended_check_vnode_lookup(struct ucred *cred, struct vnode *dvp, struct label *dlabel, struct componentname *cnp) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_EXEC)); } static int mac_bsdextended_check_vnode_open(struct ucred *cred, struct vnode *vp, struct label *filelabel, int acc_mode) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, acc_mode)); } static int mac_bsdextended_check_vnode_readdir(struct ucred *cred, struct vnode *dvp, struct label *dlabel) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_READ)); } static int mac_bsdextended_check_vnode_readdlink(struct ucred *cred, struct vnode *vp, struct label *label) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_READ)); } static int mac_bsdextended_check_vnode_rename_from(struct ucred *cred, struct vnode *dvp, struct label *dlabel, struct vnode *vp, struct label *label, struct componentname *cnp) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &vap, cred, curthread); if (error) return (error); error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE); if (error) return (error); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE); return (error); } static int mac_bsdextended_check_vnode_rename_to(struct ucred *cred, struct vnode *dvp, struct label *dlabel, struct vnode *vp, struct label *label, int samedir, struct componentname *cnp) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(dvp, &vap, cred, curthread); if (error) return (error); error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE); if (error) return (error); if (vp != NULL) { error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE); } return (error); } static int mac_bsdextended_check_vnode_revoke(struct ucred *cred, struct vnode *vp, struct label *label) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_ADMIN)); } static int mac_bsdextended_check_setacl_vnode(struct ucred *cred, struct vnode *vp, struct label *label, acl_type_t type, struct acl *acl) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_ADMIN)); } static int mac_bsdextended_check_vnode_setextattr(struct ucred *cred, struct vnode *vp, struct label *label, int attrnamespace, const char *name, struct uio *uio) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_WRITE)); } static int mac_bsdextended_check_vnode_setflags(struct ucred *cred, struct vnode *vp, struct label *label, u_long flags) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_ADMIN)); } static int mac_bsdextended_check_vnode_setmode(struct ucred *cred, struct vnode *vp, struct label *label, mode_t mode) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_ADMIN)); } static int mac_bsdextended_check_vnode_setowner(struct ucred *cred, struct vnode *vp, struct label *label, uid_t uid, gid_t gid) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_ADMIN)); } static int mac_bsdextended_check_vnode_setutimes(struct ucred *cred, struct vnode *vp, struct label *label, struct timespec atime, struct timespec utime) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, cred, curthread); if (error) return (error); return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, MBI_ADMIN)); } static int mac_bsdextended_check_vnode_stat(struct ucred *active_cred, struct ucred *file_cred, struct vnode *vp, struct label *label) { struct vattr vap; int error; if (!mac_bsdextended_enabled) return (0); error = VOP_GETATTR(vp, &vap, active_cred, curthread); if (error) return (error); return (mac_bsdextended_check(active_cred, vap.va_uid, vap.va_gid, MBI_STAT)); } static struct mac_policy_ops mac_bsdextended_ops = { .mpo_destroy = mac_bsdextended_destroy, .mpo_init = mac_bsdextended_init, .mpo_check_system_swapon = mac_bsdextended_check_system_swapon, .mpo_check_vnode_access = mac_bsdextended_check_vnode_access, .mpo_check_vnode_chdir = mac_bsdextended_check_vnode_chdir, .mpo_check_vnode_chroot = mac_bsdextended_check_vnode_chroot, .mpo_check_vnode_create = mac_bsdextended_check_create_vnode, .mpo_check_vnode_delete = mac_bsdextended_check_vnode_delete, .mpo_check_vnode_deleteacl = mac_bsdextended_check_vnode_deleteacl, .mpo_check_vnode_deleteextattr = mac_bsdextended_check_vnode_deleteextattr, .mpo_check_vnode_exec = mac_bsdextended_check_vnode_exec, .mpo_check_vnode_getacl = mac_bsdextended_check_vnode_getacl, .mpo_check_vnode_getextattr = mac_bsdextended_check_vnode_getextattr, .mpo_check_vnode_link = mac_bsdextended_check_vnode_link, .mpo_check_vnode_listextattr = mac_bsdextended_check_vnode_listextattr, .mpo_check_vnode_lookup = mac_bsdextended_check_vnode_lookup, .mpo_check_vnode_open = mac_bsdextended_check_vnode_open, .mpo_check_vnode_readdir = mac_bsdextended_check_vnode_readdir, .mpo_check_vnode_readlink = mac_bsdextended_check_vnode_readdlink, .mpo_check_vnode_rename_from = mac_bsdextended_check_vnode_rename_from, .mpo_check_vnode_rename_to = mac_bsdextended_check_vnode_rename_to, .mpo_check_vnode_revoke = mac_bsdextended_check_vnode_revoke, .mpo_check_vnode_setacl = mac_bsdextended_check_setacl_vnode, .mpo_check_vnode_setextattr = mac_bsdextended_check_vnode_setextattr, .mpo_check_vnode_setflags = mac_bsdextended_check_vnode_setflags, .mpo_check_vnode_setmode = mac_bsdextended_check_vnode_setmode, .mpo_check_vnode_setowner = mac_bsdextended_check_vnode_setowner, .mpo_check_vnode_setutimes = mac_bsdextended_check_vnode_setutimes, .mpo_check_vnode_stat = mac_bsdextended_check_vnode_stat, }; MAC_POLICY_SET(&mac_bsdextended_ops, mac_bsdextended, "TrustedBSD MAC/BSD Extended", MPC_LOADTIME_FLAG_UNLOADOK, NULL);