1 /*- 2 * Copyright (c) 1999-2002, 2007 Robert N. M. Watson 3 * Copyright (c) 2001-2002 Networks Associates Technology, Inc. 4 * All rights reserved. 5 * 6 * This software was developed by Robert Watson for the TrustedBSD Project. 7 * 8 * This software was developed for the FreeBSD Project in part by Network 9 * Associates Laboratories, the Security Research Division of Network 10 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 11 * as part of the DARPA CHATS research program. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $FreeBSD$ 35 */ 36 37 /* 38 * Developed by the TrustedBSD Project. 39 * Experiment with a partition-like model. 40 */ 41 42 #include <sys/param.h> 43 #include <sys/kernel.h> 44 #include <sys/module.h> 45 #include <sys/priv.h> 46 #include <sys/proc.h> 47 #include <sys/sbuf.h> 48 #include <sys/systm.h> 49 #include <sys/sysctl.h> 50 51 #include <security/mac/mac_policy.h> 52 #include <security/mac_partition/mac_partition.h> 53 54 SYSCTL_DECL(_security_mac); 55 56 SYSCTL_NODE(_security_mac, OID_AUTO, partition, CTLFLAG_RW, 0, 57 "TrustedBSD mac_partition policy controls"); 58 59 static int mac_partition_enabled = 1; 60 SYSCTL_INT(_security_mac_partition, OID_AUTO, enabled, CTLFLAG_RW, 61 &mac_partition_enabled, 0, "Enforce partition policy"); 62 63 static int partition_slot; 64 #define SLOT(l) mac_label_get((l), partition_slot) 65 #define SLOT_SET(l, v) mac_label_set((l), partition_slot, (v)) 66 67 static void 68 mac_partition_init_label(struct label *label) 69 { 70 71 SLOT_SET(label, 0); 72 } 73 74 static void 75 mac_partition_destroy_label(struct label *label) 76 { 77 78 SLOT_SET(label, 0); 79 } 80 81 static void 82 mac_partition_copy_label(struct label *src, struct label *dest) 83 { 84 85 SLOT_SET(dest, SLOT(src)); 86 } 87 88 static int 89 mac_partition_externalize_label(struct label *label, char *element_name, 90 struct sbuf *sb, int *claimed) 91 { 92 93 if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0) 94 return (0); 95 96 (*claimed)++; 97 98 if (sbuf_printf(sb, "%jd", (intmax_t)SLOT(label)) == -1) 99 return (EINVAL); 100 else 101 return (0); 102 } 103 104 static int 105 mac_partition_internalize_label(struct label *label, char *element_name, 106 char *element_data, int *claimed) 107 { 108 109 if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0) 110 return (0); 111 112 (*claimed)++; 113 SLOT_SET(label, strtol(element_data, NULL, 10)); 114 return (0); 115 } 116 117 static void 118 mac_partition_create_proc0(struct ucred *cred) 119 { 120 121 SLOT_SET(cred->cr_label, 0); 122 } 123 124 static void 125 mac_partition_create_proc1(struct ucred *cred) 126 { 127 128 SLOT_SET(cred->cr_label, 0); 129 } 130 131 static void 132 mac_partition_relabel_cred(struct ucred *cred, struct label *newlabel) 133 { 134 135 if (SLOT(newlabel) != 0) 136 SLOT_SET(cred->cr_label, SLOT(newlabel)); 137 } 138 139 static int 140 label_on_label(struct label *subject, struct label *object) 141 { 142 143 if (mac_partition_enabled == 0) 144 return (0); 145 146 if (SLOT(subject) == 0) 147 return (0); 148 149 if (SLOT(subject) == SLOT(object)) 150 return (0); 151 152 return (EPERM); 153 } 154 155 static int 156 mac_partition_check_cred_relabel(struct ucred *cred, struct label *newlabel) 157 { 158 int error; 159 160 error = 0; 161 162 /* Treat "0" as a no-op request. */ 163 if (SLOT(newlabel) != 0) { 164 /* 165 * Require BSD privilege in order to change the partition. 166 * Originally we also required that the process not be 167 * in a partition in the first place, but this didn't 168 * interact well with sendmail. 169 */ 170 error = priv_check_cred(cred, PRIV_MAC_PARTITION, 0); 171 } 172 173 return (error); 174 } 175 176 static int 177 mac_partition_check_cred_visible(struct ucred *u1, struct ucred *u2) 178 { 179 int error; 180 181 error = label_on_label(u1->cr_label, u2->cr_label); 182 183 return (error == 0 ? 0 : ESRCH); 184 } 185 186 static int 187 mac_partition_check_proc_debug(struct ucred *cred, struct proc *proc) 188 { 189 int error; 190 191 error = label_on_label(cred->cr_label, proc->p_ucred->cr_label); 192 193 return (error ? ESRCH : 0); 194 } 195 196 static int 197 mac_partition_check_proc_sched(struct ucred *cred, struct proc *proc) 198 { 199 int error; 200 201 error = label_on_label(cred->cr_label, proc->p_ucred->cr_label); 202 203 return (error ? ESRCH : 0); 204 } 205 206 static int 207 mac_partition_check_proc_signal(struct ucred *cred, struct proc *proc, 208 int signum) 209 { 210 int error; 211 212 error = label_on_label(cred->cr_label, proc->p_ucred->cr_label); 213 214 return (error ? ESRCH : 0); 215 } 216 217 static int 218 mac_partition_check_socket_visible(struct ucred *cred, struct socket *socket, 219 struct label *socketlabel) 220 { 221 int error; 222 223 error = label_on_label(cred->cr_label, socketlabel); 224 225 return (error ? ENOENT : 0); 226 } 227 228 static int 229 mac_partition_check_vnode_exec(struct ucred *cred, struct vnode *vp, 230 struct label *label, struct image_params *imgp, struct label *execlabel) 231 { 232 233 if (execlabel != NULL) { 234 /* 235 * We currently don't permit labels to be changed at 236 * exec-time as part of the partition model, so disallow 237 * non-NULL partition label changes in execlabel. 238 */ 239 if (SLOT(execlabel) != 0) 240 return (EINVAL); 241 } 242 243 return (0); 244 } 245 246 static struct mac_policy_ops mac_partition_ops = 247 { 248 .mpo_init_cred_label = mac_partition_init_label, 249 .mpo_destroy_cred_label = mac_partition_destroy_label, 250 .mpo_copy_cred_label = mac_partition_copy_label, 251 .mpo_externalize_cred_label = mac_partition_externalize_label, 252 .mpo_internalize_cred_label = mac_partition_internalize_label, 253 .mpo_create_proc0 = mac_partition_create_proc0, 254 .mpo_create_proc1 = mac_partition_create_proc1, 255 .mpo_relabel_cred = mac_partition_relabel_cred, 256 .mpo_check_cred_relabel = mac_partition_check_cred_relabel, 257 .mpo_check_cred_visible = mac_partition_check_cred_visible, 258 .mpo_check_proc_debug = mac_partition_check_proc_debug, 259 .mpo_check_proc_sched = mac_partition_check_proc_sched, 260 .mpo_check_proc_signal = mac_partition_check_proc_signal, 261 .mpo_check_socket_visible = mac_partition_check_socket_visible, 262 .mpo_check_vnode_exec = mac_partition_check_vnode_exec, 263 }; 264 265 MAC_POLICY_SET(&mac_partition_ops, mac_partition, "TrustedBSD MAC/Partition", 266 MPC_LOADTIME_FLAG_UNLOADOK, &partition_slot); 267