1 /*- 2 * Copyright (c) 1999-2002, 2007-2008 Robert N. M. Watson 3 * Copyright (c) 2001-2002 Networks Associates Technology, Inc. 4 * Copyright (c) 2006 SPARTA, Inc. 5 * Copyright (c) 2008 Apple Inc. 6 * All rights reserved. 7 * 8 * This software was developed by Robert Watson for the TrustedBSD Project. 9 * 10 * This software was developed for the FreeBSD Project in part by Network 11 * Associates Laboratories, the Security Research Division of Network 12 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 13 * as part of the DARPA CHATS research program. 14 * 15 * This software was enhanced by SPARTA ISSO under SPAWAR contract 16 * N66001-04-C-6019 ("SEFOS"). 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * $FreeBSD$ 40 */ 41 42 /* 43 * Developed by the TrustedBSD Project. 44 * 45 * Experiment with a partition-like model. 46 */ 47 48 #include <sys/param.h> 49 #include <sys/kernel.h> 50 #include <sys/module.h> 51 #include <sys/priv.h> 52 #include <sys/proc.h> 53 #include <sys/sbuf.h> 54 #include <sys/socket.h> 55 #include <sys/socketvar.h> 56 #include <sys/systm.h> 57 #include <sys/sysctl.h> 58 59 #include <net/route.h> 60 #include <netinet/in.h> 61 #include <netinet/in_pcb.h> 62 63 #include <security/mac/mac_policy.h> 64 #include <security/mac_partition/mac_partition.h> 65 66 SYSCTL_DECL(_security_mac); 67 68 SYSCTL_NODE(_security_mac, OID_AUTO, partition, CTLFLAG_RW, 0, 69 "TrustedBSD mac_partition policy controls"); 70 71 static int partition_enabled = 1; 72 SYSCTL_INT(_security_mac_partition, OID_AUTO, enabled, CTLFLAG_RW, 73 &partition_enabled, 0, "Enforce partition policy"); 74 75 static int partition_slot; 76 #define SLOT(l) mac_label_get((l), partition_slot) 77 #define SLOT_SET(l, v) mac_label_set((l), partition_slot, (v)) 78 79 static int 80 partition_check(struct label *subject, struct label *object) 81 { 82 83 if (partition_enabled == 0) 84 return (0); 85 86 if (subject == NULL) 87 return (0); 88 89 if (SLOT(subject) == 0) 90 return (0); 91 92 /* 93 * If the object label hasn't been allocated, then it's effectively 94 * not in a partition, and we know the subject is as it has a label 95 * and it's not 0, so reject. 96 */ 97 if (object == NULL) 98 return (EPERM); 99 100 if (SLOT(subject) == SLOT(object)) 101 return (0); 102 103 return (EPERM); 104 } 105 106 /* 107 * Object-specific entry points are sorted alphabetically by object type name 108 * and then by operation. 109 */ 110 static int 111 partition_cred_check_relabel(struct ucred *cred, struct label *newlabel) 112 { 113 int error; 114 115 error = 0; 116 117 /* 118 * Treat "0" as a no-op request because it reflects an unset 119 * partition label. If we ever want to support switching back to an 120 * unpartitioned state for a process, we'll need to differentiate the 121 * "not in a partition" and "no partition defined during internalize" 122 * conditions. 123 */ 124 if (SLOT(newlabel) != 0) { 125 /* 126 * Require BSD privilege in order to change the partition. 127 * Originally we also required that the process not be in a 128 * partition in the first place, but this didn't interact 129 * well with sendmail. 130 */ 131 error = priv_check_cred(cred, PRIV_MAC_PARTITION, 0); 132 } 133 134 return (error); 135 } 136 137 static int 138 partition_cred_check_visible(struct ucred *cr1, struct ucred *cr2) 139 { 140 int error; 141 142 error = partition_check(cr1->cr_label, cr2->cr_label); 143 144 return (error == 0 ? 0 : ESRCH); 145 } 146 147 static void 148 partition_cred_copy_label(struct label *src, struct label *dest) 149 { 150 151 if (src != NULL && dest != NULL) 152 SLOT_SET(dest, SLOT(src)); 153 else if (dest != NULL) 154 SLOT_SET(dest, 0); 155 } 156 157 static void 158 partition_cred_create_init(struct ucred *cred) 159 { 160 161 SLOT_SET(cred->cr_label, 0); 162 } 163 164 static void 165 partition_cred_create_swapper(struct ucred *cred) 166 { 167 168 SLOT_SET(cred->cr_label, 0); 169 } 170 171 static void 172 partition_cred_destroy_label(struct label *label) 173 { 174 175 SLOT_SET(label, 0); 176 } 177 178 static int 179 partition_cred_externalize_label(struct label *label, char *element_name, 180 struct sbuf *sb, int *claimed) 181 { 182 183 if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0) 184 return (0); 185 186 (*claimed)++; 187 188 if (label != NULL) { 189 if (sbuf_printf(sb, "%jd", (intmax_t)SLOT(label)) == -1) 190 return (EINVAL); 191 } else { 192 if (sbuf_printf(sb, "0") == -1) 193 return (EINVAL); 194 } 195 return (0); 196 } 197 198 static void 199 partition_cred_init_label(struct label *label) 200 { 201 202 SLOT_SET(label, 0); 203 } 204 205 static int 206 partition_cred_internalize_label(struct label *label, char *element_name, 207 char *element_data, int *claimed) 208 { 209 210 if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0) 211 return (0); 212 213 (*claimed)++; 214 SLOT_SET(label, strtol(element_data, NULL, 10)); 215 return (0); 216 } 217 218 static void 219 partition_cred_relabel(struct ucred *cred, struct label *newlabel) 220 { 221 222 if (newlabel != NULL && SLOT(newlabel) != 0) 223 SLOT_SET(cred->cr_label, SLOT(newlabel)); 224 } 225 226 static int 227 partition_inpcb_check_visible(struct ucred *cred, struct inpcb *inp, 228 struct label *inplabel) 229 { 230 int error; 231 232 error = partition_check(cred->cr_label, inp->inp_cred->cr_label); 233 234 return (error ? ENOENT : 0); 235 } 236 237 static int 238 partition_proc_check_debug(struct ucred *cred, struct proc *p) 239 { 240 int error; 241 242 error = partition_check(cred->cr_label, p->p_ucred->cr_label); 243 244 return (error ? ESRCH : 0); 245 } 246 247 static int 248 partition_proc_check_sched(struct ucred *cred, struct proc *p) 249 { 250 int error; 251 252 error = partition_check(cred->cr_label, p->p_ucred->cr_label); 253 254 return (error ? ESRCH : 0); 255 } 256 257 static int 258 partition_proc_check_signal(struct ucred *cred, struct proc *p, 259 int signum) 260 { 261 int error; 262 263 error = partition_check(cred->cr_label, p->p_ucred->cr_label); 264 265 return (error ? ESRCH : 0); 266 } 267 268 static int 269 partition_socket_check_visible(struct ucred *cred, struct socket *so, 270 struct label *solabel) 271 { 272 int error; 273 274 error = partition_check(cred->cr_label, so->so_cred->cr_label); 275 276 return (error ? ENOENT : 0); 277 } 278 279 static int 280 partition_vnode_check_exec(struct ucred *cred, struct vnode *vp, 281 struct label *vplabel, struct image_params *imgp, 282 struct label *execlabel) 283 { 284 285 if (execlabel != NULL) { 286 /* 287 * We currently don't permit labels to be changed at 288 * exec-time as part of the partition model, so disallow 289 * non-NULL partition label changes in execlabel. 290 */ 291 if (SLOT(execlabel) != 0) 292 return (EINVAL); 293 } 294 295 return (0); 296 } 297 298 static struct mac_policy_ops partition_ops = 299 { 300 .mpo_cred_check_relabel = partition_cred_check_relabel, 301 .mpo_cred_check_visible = partition_cred_check_visible, 302 .mpo_cred_copy_label = partition_cred_copy_label, 303 .mpo_cred_create_init = partition_cred_create_init, 304 .mpo_cred_create_swapper = partition_cred_create_swapper, 305 .mpo_cred_destroy_label = partition_cred_destroy_label, 306 .mpo_cred_externalize_label = partition_cred_externalize_label, 307 .mpo_cred_init_label = partition_cred_init_label, 308 .mpo_cred_internalize_label = partition_cred_internalize_label, 309 .mpo_cred_relabel = partition_cred_relabel, 310 .mpo_inpcb_check_visible = partition_inpcb_check_visible, 311 .mpo_proc_check_debug = partition_proc_check_debug, 312 .mpo_proc_check_sched = partition_proc_check_sched, 313 .mpo_proc_check_signal = partition_proc_check_signal, 314 .mpo_socket_check_visible = partition_socket_check_visible, 315 .mpo_vnode_check_exec = partition_vnode_check_exec, 316 }; 317 318 MAC_POLICY_SET(&partition_ops, mac_partition, "TrustedBSD MAC/Partition", 319 MPC_LOADTIME_FLAG_UNLOADOK, &partition_slot); 320