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 40 /* 41 * Developed by the TrustedBSD Project. 42 * 43 * Experiment with a partition-like model. 44 */ 45 46 #include <sys/param.h> 47 #include <sys/kernel.h> 48 #include <sys/module.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/sbuf.h> 52 #include <sys/socket.h> 53 #include <sys/socketvar.h> 54 #include <sys/systm.h> 55 #include <sys/sysctl.h> 56 57 #include <net/route.h> 58 #include <netinet/in.h> 59 #include <netinet/in_pcb.h> 60 61 #include <security/mac/mac_policy.h> 62 #include <security/mac_partition/mac_partition.h> 63 64 SYSCTL_DECL(_security_mac); 65 66 static SYSCTL_NODE(_security_mac, OID_AUTO, partition, 67 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 68 "TrustedBSD mac_partition policy controls"); 69 70 static int partition_enabled = 1; 71 SYSCTL_INT(_security_mac_partition, OID_AUTO, enabled, CTLFLAG_RW, 72 &partition_enabled, 0, "Enforce partition policy"); 73 74 static int partition_slot; 75 #define SLOT(l) mac_label_get((l), partition_slot) 76 #define SLOT_SET(l, v) mac_label_set((l), partition_slot, (v)) 77 78 static int 79 partition_check(struct label *subject, struct label *object) 80 { 81 82 if (partition_enabled == 0) 83 return (0); 84 85 if (subject == NULL) 86 return (0); 87 88 if (SLOT(subject) == 0) 89 return (0); 90 91 /* 92 * If the object label hasn't been allocated, then it's effectively 93 * not in a partition, and we know the subject is as it has a label 94 * and it's not 0, so reject. 95 */ 96 if (object == NULL) 97 return (EPERM); 98 99 if (SLOT(subject) == SLOT(object)) 100 return (0); 101 102 return (EPERM); 103 } 104 105 /* 106 * Object-specific entry points are sorted alphabetically by object type name 107 * and then by operation. 108 */ 109 static int 110 partition_cred_check_relabel(struct ucred *cred, struct label *newlabel) 111 { 112 int error; 113 114 error = 0; 115 116 /* 117 * Treat "0" as a no-op request because it reflects an unset 118 * partition label. If we ever want to support switching back to an 119 * unpartitioned state for a process, we'll need to differentiate the 120 * "not in a partition" and "no partition defined during internalize" 121 * conditions. 122 */ 123 if (SLOT(newlabel) != 0) { 124 /* 125 * Require BSD privilege in order to change the partition. 126 * Originally we also required that the process not be in a 127 * partition in the first place, but this didn't interact 128 * well with sendmail. 129 */ 130 error = priv_check_cred(cred, PRIV_MAC_PARTITION); 131 } 132 133 return (error); 134 } 135 136 static int 137 partition_cred_check_visible(struct ucred *cr1, struct ucred *cr2) 138 { 139 int error; 140 141 error = partition_check(cr1->cr_label, cr2->cr_label); 142 143 return (error == 0 ? 0 : ESRCH); 144 } 145 146 static void 147 partition_cred_copy_label(struct label *src, struct label *dest) 148 { 149 150 if (src != NULL && dest != NULL) 151 SLOT_SET(dest, SLOT(src)); 152 else if (dest != NULL) 153 SLOT_SET(dest, 0); 154 } 155 156 static void 157 partition_cred_create_init(struct ucred *cred) 158 { 159 160 SLOT_SET(cred->cr_label, 0); 161 } 162 163 static void 164 partition_cred_create_swapper(struct ucred *cred) 165 { 166 167 SLOT_SET(cred->cr_label, 0); 168 } 169 170 static void 171 partition_cred_destroy_label(struct label *label) 172 { 173 174 SLOT_SET(label, 0); 175 } 176 177 static int 178 partition_cred_externalize_label(struct label *label, char *element_name, 179 struct sbuf *sb, int *claimed) 180 { 181 182 if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0) 183 return (0); 184 185 (*claimed)++; 186 187 if (label != NULL) { 188 if (sbuf_printf(sb, "%jd", (intmax_t)SLOT(label)) == -1) 189 return (EINVAL); 190 } else { 191 if (sbuf_printf(sb, "0") == -1) 192 return (EINVAL); 193 } 194 return (0); 195 } 196 197 static void 198 partition_cred_init_label(struct label *label) 199 { 200 201 SLOT_SET(label, 0); 202 } 203 204 static int 205 partition_cred_internalize_label(struct label *label, char *element_name, 206 char *element_data, int *claimed) 207 { 208 209 if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0) 210 return (0); 211 212 (*claimed)++; 213 SLOT_SET(label, strtol(element_data, NULL, 10)); 214 return (0); 215 } 216 217 static void 218 partition_cred_relabel(struct ucred *cred, struct label *newlabel) 219 { 220 221 if (newlabel != NULL && SLOT(newlabel) != 0) 222 SLOT_SET(cred->cr_label, SLOT(newlabel)); 223 } 224 225 static int 226 partition_inpcb_check_visible(struct ucred *cred, struct inpcb *inp, 227 struct label *inplabel) 228 { 229 int error; 230 231 error = partition_check(cred->cr_label, inp->inp_cred->cr_label); 232 233 return (error ? ENOENT : 0); 234 } 235 236 static int 237 partition_proc_check_debug(struct ucred *cred, struct proc *p) 238 { 239 int error; 240 241 error = partition_check(cred->cr_label, p->p_ucred->cr_label); 242 243 return (error ? ESRCH : 0); 244 } 245 246 static int 247 partition_proc_check_sched(struct ucred *cred, struct proc *p) 248 { 249 int error; 250 251 error = partition_check(cred->cr_label, p->p_ucred->cr_label); 252 253 return (error ? ESRCH : 0); 254 } 255 256 static int 257 partition_proc_check_signal(struct ucred *cred, struct proc *p, 258 int signum) 259 { 260 int error; 261 262 error = partition_check(cred->cr_label, p->p_ucred->cr_label); 263 264 return (error ? ESRCH : 0); 265 } 266 267 static int 268 partition_socket_check_visible(struct ucred *cred, struct socket *so, 269 struct label *solabel) 270 { 271 int error; 272 273 error = partition_check(cred->cr_label, so->so_cred->cr_label); 274 275 return (error ? ENOENT : 0); 276 } 277 278 static int 279 partition_vnode_check_exec(struct ucred *cred, struct vnode *vp, 280 struct label *vplabel, struct image_params *imgp, 281 struct label *execlabel) 282 { 283 284 if (execlabel != NULL) { 285 /* 286 * We currently don't permit labels to be changed at 287 * exec-time as part of the partition model, so disallow 288 * non-NULL partition label changes in execlabel. 289 */ 290 if (SLOT(execlabel) != 0) 291 return (EINVAL); 292 } 293 294 return (0); 295 } 296 297 static struct mac_policy_ops partition_ops = 298 { 299 .mpo_cred_check_relabel = partition_cred_check_relabel, 300 .mpo_cred_check_visible = partition_cred_check_visible, 301 .mpo_cred_copy_label = partition_cred_copy_label, 302 .mpo_cred_create_init = partition_cred_create_init, 303 .mpo_cred_create_swapper = partition_cred_create_swapper, 304 .mpo_cred_destroy_label = partition_cred_destroy_label, 305 .mpo_cred_externalize_label = partition_cred_externalize_label, 306 .mpo_cred_init_label = partition_cred_init_label, 307 .mpo_cred_internalize_label = partition_cred_internalize_label, 308 .mpo_cred_relabel = partition_cred_relabel, 309 .mpo_inpcb_check_visible = partition_inpcb_check_visible, 310 .mpo_proc_check_debug = partition_proc_check_debug, 311 .mpo_proc_check_sched = partition_proc_check_sched, 312 .mpo_proc_check_signal = partition_proc_check_signal, 313 .mpo_socket_check_visible = partition_socket_check_visible, 314 .mpo_vnode_check_exec = partition_vnode_check_exec, 315 }; 316 317 MAC_POLICY_SET(&partition_ops, mac_partition, "TrustedBSD MAC/Partition", 318 MPC_LOADTIME_FLAG_UNLOADOK, &partition_slot); 319