1 /* $NetBSD: creds.c,v 1.13 2007/10/18 13:48:04 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2006 Antti Kantee. All Rights Reserved. 5 * 6 * Development of this software was supported by the Ulla Tuominen Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 18 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 #if !defined(lint) 32 __RCSID("$NetBSD: creds.c,v 1.13 2007/10/18 13:48:04 pooka Exp $"); 33 #endif /* !lint */ 34 35 /* 36 * Interface for dealing with credits. 37 */ 38 39 #include <sys/types.h> 40 #include <sys/param.h> 41 42 #include <errno.h> 43 #include <puffs.h> 44 #include <stdbool.h> 45 #include <string.h> 46 47 #include "puffs_priv.h" 48 49 #define UUCCRED(a) (a->pkcr_type == PUFFCRED_TYPE_UUC) 50 #define INTCRED(a) (a->pkcr_type == PUFFCRED_TYPE_INTERNAL) 51 52 int 53 puffs_cred_getuid(const struct puffs_cred *pcr, uid_t *ruid) 54 { 55 PUFFS_MAKEKCRED(pkcr, pcr); 56 57 if (!UUCCRED(pkcr)) { 58 errno = EOPNOTSUPP; 59 return -1; 60 } 61 *ruid = pkcr->pkcr_uuc.cr_uid; 62 63 return 0; 64 } 65 66 int 67 puffs_cred_getgid(const struct puffs_cred *pcr, gid_t *rgid) 68 { 69 PUFFS_MAKEKCRED(pkcr, pcr); 70 71 if (!UUCCRED(pkcr)) { 72 errno = EOPNOTSUPP; 73 return -1; 74 } 75 *rgid = pkcr->pkcr_uuc.cr_gid; 76 77 return 0; 78 } 79 80 int 81 puffs_cred_getgroups(const struct puffs_cred *pcr, gid_t *rgids, short *ngids) 82 { 83 PUFFS_MAKEKCRED(pkcr, pcr); 84 size_t ncopy; 85 86 if (!UUCCRED(pkcr)) { 87 errno = EOPNOTSUPP; 88 return -1; 89 } 90 91 ncopy = MIN(*ngids, NGROUPS); 92 (void)memcpy(rgids, pkcr->pkcr_uuc.cr_groups, sizeof(gid_t) * ncopy); 93 *ngids = (short)ncopy; 94 95 return 0; 96 } 97 98 bool 99 puffs_cred_isuid(const struct puffs_cred *pcr, uid_t uid) 100 { 101 PUFFS_MAKEKCRED(pkcr, pcr); 102 103 return UUCCRED(pkcr) && pkcr->pkcr_uuc.cr_uid == uid; 104 } 105 106 bool 107 puffs_cred_hasgroup(const struct puffs_cred *pcr, gid_t gid) 108 { 109 PUFFS_MAKEKCRED(pkcr, pcr); 110 short i; 111 112 if (!UUCCRED(pkcr)) 113 return false; 114 115 if (pkcr->pkcr_uuc.cr_gid == gid) 116 return true; 117 for (i = 0; i < pkcr->pkcr_uuc.cr_ngroups; i++) 118 if (pkcr->pkcr_uuc.cr_groups[i] == gid) 119 return true; 120 121 return false; 122 } 123 124 bool 125 puffs_cred_isregular(const struct puffs_cred *pcr) 126 { 127 PUFFS_MAKEKCRED(pkcr, pcr); 128 129 return UUCCRED(pkcr); 130 } 131 132 bool 133 puffs_cred_iskernel(const struct puffs_cred *pcr) 134 { 135 PUFFS_MAKEKCRED(pkcr, pcr); 136 137 return INTCRED(pkcr) && pkcr->pkcr_internal == PUFFCRED_CRED_NOCRED; 138 } 139 140 bool 141 puffs_cred_isfs(const struct puffs_cred *pcr) 142 { 143 PUFFS_MAKEKCRED(pkcr, pcr); 144 145 return INTCRED(pkcr) && pkcr->pkcr_internal == PUFFCRED_CRED_FSCRED; 146 } 147 148 bool 149 puffs_cred_isjuggernaut(const struct puffs_cred *pcr) 150 { 151 152 return puffs_cred_isuid(pcr, 0) || puffs_cred_iskernel(pcr) 153 || puffs_cred_isfs(pcr); 154 } 155 156 int 157 puffs_cid_getpid(const struct puffs_cid *pcid, pid_t *pid) 158 { 159 PUFFS_MAKEKCID(pkcid, pcid); 160 161 if (pkcid->pkcid_type == PUFFCID_TYPE_REAL) { 162 *pid = pkcid->pkcid_pid; 163 return 0; 164 } else { 165 errno = ESRCH; 166 return -1; 167 } 168 } 169 170 int 171 puffs_cid_getlwpid(const struct puffs_cid *pcid, lwpid_t *lid) 172 { 173 PUFFS_MAKEKCID(pkcid, pcid); 174 175 if (pkcid->pkcid_type == PUFFCID_TYPE_REAL) { 176 *lid = pkcid->pkcid_lwpid; 177 return 0; 178 } else { 179 errno = ESRCH; 180 return -1; 181 } 182 } 183 184 bool 185 puffs_cid_isequal(const struct puffs_cid *pc1, const struct puffs_cid *pc2) 186 { 187 PUFFS_MAKEKCID(pkc1, pc1); 188 PUFFS_MAKEKCID(pkc2, pc2); 189 190 if (pkc1->pkcid_type != PUFFCID_TYPE_REAL 191 || pkc2->pkcid_type != PUFFCID_TYPE_REAL) 192 return false; 193 194 if (pkc1->pkcid_lwpid == pkc1->pkcid_lwpid 195 && pkc2->pkcid_pid == pkc2->pkcid_pid) 196 return true; 197 198 return false; 199 } 200 201 /* 202 * Generic routine for checking file access rights. Modeled after 203 * vaccess() in the kernel. 204 */ 205 int 206 puffs_access(enum vtype type, mode_t file_mode, uid_t uid, gid_t gid, 207 mode_t acc_mode, const struct puffs_cred *pcr) 208 { 209 mode_t mask; 210 211 /* megapower */ 212 if (puffs_cred_iskernel(pcr) || puffs_cred_isfs(pcr)) 213 return 0; 214 215 /* superuser, allow all except exec if *ALL* exec bits are unset */ 216 if (puffs_cred_isuid(pcr, 0)) { 217 if ((acc_mode & PUFFS_VEXEC) && type != VDIR && 218 (file_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) 219 return EACCES; 220 return 0; 221 } 222 223 mask = 0; 224 /* owner */ 225 if (puffs_cred_isuid(pcr, uid)) { 226 if (acc_mode & PUFFS_VEXEC) 227 mask |= S_IXUSR; 228 if (acc_mode & PUFFS_VREAD) 229 mask |= S_IRUSR; 230 if (acc_mode & PUFFS_VWRITE) 231 mask |= S_IWUSR; 232 /* group */ 233 } else if (puffs_cred_hasgroup(pcr, gid)) { 234 if (acc_mode & PUFFS_VEXEC) 235 mask |= S_IXGRP; 236 if (acc_mode & PUFFS_VREAD) 237 mask |= S_IRGRP; 238 if (acc_mode & PUFFS_VWRITE) 239 mask |= S_IWGRP; 240 /* other */ 241 } else { 242 if (acc_mode & PUFFS_VEXEC) 243 mask |= S_IXOTH; 244 if (acc_mode & PUFFS_VREAD) 245 mask |= S_IROTH; 246 if (acc_mode & PUFFS_VWRITE) 247 mask |= S_IWOTH; 248 } 249 250 if ((file_mode & mask) == mask) 251 return 0; 252 else 253 return EACCES; 254 } 255 256 int 257 puffs_access_chown(uid_t owner, gid_t group, uid_t newowner, gid_t newgroup, 258 const struct puffs_cred *pcr) 259 { 260 261 if (newowner == (uid_t)PUFFS_VNOVAL) 262 newowner = owner; 263 if (newgroup == (gid_t)PUFFS_VNOVAL) 264 newgroup = group; 265 266 if ((!puffs_cred_isuid(pcr, owner) || newowner != owner || 267 ((newgroup != group && !puffs_cred_hasgroup(pcr, newgroup)))) 268 && !puffs_cred_isjuggernaut(pcr)) 269 return EPERM; 270 271 return 0; 272 } 273 274 int 275 puffs_access_chmod(uid_t owner, gid_t group, enum vtype type, mode_t mode, 276 const struct puffs_cred *pcr) 277 { 278 279 if (!puffs_cred_isuid(pcr, owner) && !puffs_cred_isjuggernaut(pcr)) 280 return EPERM; 281 282 if (!puffs_cred_isjuggernaut(pcr)) { 283 if (type != VDIR && (mode & S_ISTXT)) 284 return EFTYPE; 285 if (!puffs_cred_hasgroup(pcr, group) && (mode & S_ISGID)) 286 return EPERM; 287 } 288 289 return 0; 290 } 291 292 int 293 puffs_access_times(uid_t uid, gid_t gid, mode_t mode, int va_utimes_null, 294 const struct puffs_cred *pcr) 295 { 296 297 if (!puffs_cred_isuid(pcr, uid) && !puffs_cred_isjuggernaut(pcr) 298 && (va_utimes_null == 0 299 || puffs_access(VNON, mode, uid, gid, PUFFS_VWRITE, pcr) != 0)) 300 return EPERM; 301 302 return 0; 303 } 304