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