1 /*- 2 * Copyright (c) 2010 The FreeBSD Foundation 3 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net> 4 * All rights reserved. 5 * 6 * This software was developed by Pawel Jakub Dawidek under sponsorship from 7 * the FreeBSD Foundation. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #ifdef HAVE_CAPSICUM 35 #include <sys/capability.h> 36 #endif 37 #include <sys/param.h> 38 #include <sys/disk.h> 39 #include <sys/ioctl.h> 40 #include <sys/jail.h> 41 #include <sys/stat.h> 42 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <pwd.h> 46 #include <stdarg.h> 47 #include <stdbool.h> 48 #include <stdio.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 #include <pjdlog.h> 53 54 #include "hast.h" 55 #include "subr.h" 56 57 int 58 vsnprlcat(char *str, size_t size, const char *fmt, va_list ap) 59 { 60 size_t len; 61 62 len = strlen(str); 63 return (vsnprintf(str + len, size - len, fmt, ap)); 64 } 65 66 int 67 snprlcat(char *str, size_t size, const char *fmt, ...) 68 { 69 va_list ap; 70 int result; 71 72 va_start(ap, fmt); 73 result = vsnprlcat(str, size, fmt, ap); 74 va_end(ap); 75 return (result); 76 } 77 78 int 79 provinfo(struct hast_resource *res, bool dowrite) 80 { 81 struct stat sb; 82 83 PJDLOG_ASSERT(res->hr_localpath != NULL && 84 res->hr_localpath[0] != '\0'); 85 86 if (res->hr_localfd == -1) { 87 res->hr_localfd = open(res->hr_localpath, 88 dowrite ? O_RDWR : O_RDONLY); 89 if (res->hr_localfd < 0) { 90 KEEP_ERRNO(pjdlog_errno(LOG_ERR, "Unable to open %s", 91 res->hr_localpath)); 92 return (-1); 93 } 94 } 95 if (fstat(res->hr_localfd, &sb) < 0) { 96 KEEP_ERRNO(pjdlog_errno(LOG_ERR, "Unable to stat %s", 97 res->hr_localpath)); 98 return (-1); 99 } 100 if (S_ISCHR(sb.st_mode)) { 101 /* 102 * If this is character device, it is most likely GEOM provider. 103 */ 104 if (ioctl(res->hr_localfd, DIOCGMEDIASIZE, 105 &res->hr_local_mediasize) < 0) { 106 KEEP_ERRNO(pjdlog_errno(LOG_ERR, 107 "Unable obtain provider %s mediasize", 108 res->hr_localpath)); 109 return (-1); 110 } 111 if (ioctl(res->hr_localfd, DIOCGSECTORSIZE, 112 &res->hr_local_sectorsize) < 0) { 113 KEEP_ERRNO(pjdlog_errno(LOG_ERR, 114 "Unable obtain provider %s sectorsize", 115 res->hr_localpath)); 116 return (-1); 117 } 118 } else if (S_ISREG(sb.st_mode)) { 119 /* 120 * We also support regular files for which we hardcode 121 * sector size of 512 bytes. 122 */ 123 res->hr_local_mediasize = sb.st_size; 124 res->hr_local_sectorsize = 512; 125 } else { 126 /* 127 * We support no other file types. 128 */ 129 pjdlog_error("%s is neither GEOM provider nor regular file.", 130 res->hr_localpath); 131 errno = EFTYPE; 132 return (-1); 133 } 134 return (0); 135 } 136 137 const char * 138 role2str(int role) 139 { 140 141 switch (role) { 142 case HAST_ROLE_INIT: 143 return ("init"); 144 case HAST_ROLE_PRIMARY: 145 return ("primary"); 146 case HAST_ROLE_SECONDARY: 147 return ("secondary"); 148 } 149 return ("unknown"); 150 } 151 152 int 153 drop_privs(struct hast_resource *res) 154 { 155 char jailhost[sizeof(res->hr_name) * 2]; 156 struct jail jailst; 157 struct passwd *pw; 158 uid_t ruid, euid, suid; 159 gid_t rgid, egid, sgid; 160 gid_t gidset[1]; 161 bool capsicum, jailed; 162 163 /* 164 * According to getpwnam(3) we have to clear errno before calling the 165 * function to be able to distinguish between an error and missing 166 * entry (with is not treated as error by getpwnam(3)). 167 */ 168 errno = 0; 169 pw = getpwnam(HAST_USER); 170 if (pw == NULL) { 171 if (errno != 0) { 172 KEEP_ERRNO(pjdlog_errno(LOG_ERR, 173 "Unable to find info about '%s' user", HAST_USER)); 174 return (-1); 175 } else { 176 pjdlog_error("'%s' user doesn't exist.", HAST_USER); 177 errno = ENOENT; 178 return (-1); 179 } 180 } 181 182 bzero(&jailst, sizeof(jailst)); 183 jailst.version = JAIL_API_VERSION; 184 jailst.path = pw->pw_dir; 185 if (res == NULL) { 186 (void)snprintf(jailhost, sizeof(jailhost), "hastctl"); 187 } else { 188 (void)snprintf(jailhost, sizeof(jailhost), "hastd: %s (%s)", 189 res->hr_name, role2str(res->hr_role)); 190 } 191 jailst.hostname = jailhost; 192 jailst.jailname = NULL; 193 jailst.ip4s = 0; 194 jailst.ip4 = NULL; 195 jailst.ip6s = 0; 196 jailst.ip6 = NULL; 197 if (jail(&jailst) >= 0) { 198 jailed = true; 199 } else { 200 jailed = false; 201 pjdlog_errno(LOG_WARNING, 202 "Unable to jail to directory to %s", pw->pw_dir); 203 if (chroot(pw->pw_dir) == -1) { 204 KEEP_ERRNO(pjdlog_errno(LOG_ERR, 205 "Unable to change root directory to %s", 206 pw->pw_dir)); 207 return (-1); 208 } 209 } 210 PJDLOG_VERIFY(chdir("/") == 0); 211 gidset[0] = pw->pw_gid; 212 if (setgroups(1, gidset) == -1) { 213 KEEP_ERRNO(pjdlog_errno(LOG_ERR, 214 "Unable to set groups to gid %u", 215 (unsigned int)pw->pw_gid)); 216 return (-1); 217 } 218 if (setgid(pw->pw_gid) == -1) { 219 KEEP_ERRNO(pjdlog_errno(LOG_ERR, "Unable to set gid to %u", 220 (unsigned int)pw->pw_gid)); 221 return (-1); 222 } 223 if (setuid(pw->pw_uid) == -1) { 224 KEEP_ERRNO(pjdlog_errno(LOG_ERR, "Unable to set uid to %u", 225 (unsigned int)pw->pw_uid)); 226 return (-1); 227 } 228 229 /* 230 * Until capsicum doesn't allow ioctl(2) we cannot use it to sandbox 231 * primary and secondary worker processes, as primary uses GGATE 232 * ioctls and secondary uses ioctls to handle BIO_DELETE and BIO_FLUSH. 233 * For now capsicum is only used to sandbox hastctl. 234 */ 235 #ifdef HAVE_CAPSICUM 236 if (res == NULL) { 237 capsicum = (cap_enter() == 0); 238 if (!capsicum) { 239 pjdlog_common(LOG_DEBUG, 1, errno, 240 "Unable to sandbox using capsicum"); 241 } 242 } else 243 #endif 244 capsicum = false; 245 246 /* 247 * Better be sure that everything succeeded. 248 */ 249 PJDLOG_VERIFY(getresuid(&ruid, &euid, &suid) == 0); 250 PJDLOG_VERIFY(ruid == pw->pw_uid); 251 PJDLOG_VERIFY(euid == pw->pw_uid); 252 PJDLOG_VERIFY(suid == pw->pw_uid); 253 PJDLOG_VERIFY(getresgid(&rgid, &egid, &sgid) == 0); 254 PJDLOG_VERIFY(rgid == pw->pw_gid); 255 PJDLOG_VERIFY(egid == pw->pw_gid); 256 PJDLOG_VERIFY(sgid == pw->pw_gid); 257 PJDLOG_VERIFY(getgroups(0, NULL) == 1); 258 PJDLOG_VERIFY(getgroups(1, gidset) == 1); 259 PJDLOG_VERIFY(gidset[0] == pw->pw_gid); 260 261 pjdlog_debug(1, 262 "Privileges successfully dropped using %s%s+setgid+setuid.", 263 capsicum ? "capsicum+" : "", jailed ? "jail" : "chroot"); 264 265 return (0); 266 } 267