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 57int 58vsnprlcat(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 66int 67snprlcat(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 78int 79provinfo(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 == -1) { 90 pjdlog_errno(LOG_ERR, "Unable to open %s", 91 res->hr_localpath); 92 return (-1); 93 } 94 } 95 if (fstat(res->hr_localfd, &sb) == -1) { 96 pjdlog_errno(LOG_ERR, "Unable to stat %s", res->hr_localpath); 97 return (-1); 98 } 99 if (S_ISCHR(sb.st_mode)) { 100 /* 101 * If this is character device, it is most likely GEOM provider. 102 */ 103 if (ioctl(res->hr_localfd, DIOCGMEDIASIZE, 104 &res->hr_local_mediasize) == -1) { 105 pjdlog_errno(LOG_ERR, 106 "Unable obtain provider %s mediasize", 107 res->hr_localpath); 108 return (-1); 109 } 110 if (ioctl(res->hr_localfd, DIOCGSECTORSIZE, 111 &res->hr_local_sectorsize) == -1) { 112 pjdlog_errno(LOG_ERR, 113 "Unable obtain provider %s sectorsize", 114 res->hr_localpath); 115 return (-1); 116 } 117 } else if (S_ISREG(sb.st_mode)) { 118 /* 119 * We also support regular files for which we hardcode 120 * sector size of 512 bytes. 121 */ 122 res->hr_local_mediasize = sb.st_size; 123 res->hr_local_sectorsize = 512; 124 } else { 125 /* 126 * We support no other file types. 127 */ 128 pjdlog_error("%s is neither GEOM provider nor regular file.", 129 res->hr_localpath); 130 errno = EFTYPE; 131 return (-1); 132 } 133 return (0); 134} 135 136const char * 137role2str(int role) 138{ 139 140 switch (role) { 141 case HAST_ROLE_INIT: 142 return ("init"); 143 case HAST_ROLE_PRIMARY: 144 return ("primary"); 145 case HAST_ROLE_SECONDARY: 146 return ("secondary"); 147 } 148 return ("unknown"); 149} 150 151int 152drop_privs(const struct hast_resource *res) 153{ 154 char jailhost[sizeof(res->hr_name) * 2]; 155 struct jail jailst; 156 struct passwd *pw; 157 uid_t ruid, euid, suid; 158 gid_t rgid, egid, sgid; 159 gid_t gidset[1]; 160 bool capsicum, jailed; 161 162 /* 163 * According to getpwnam(3) we have to clear errno before calling the 164 * function to be able to distinguish between an error and missing 165 * entry (with is not treated as error by getpwnam(3)). 166 */ 167 errno = 0; 168 pw = getpwnam(HAST_USER); 169 if (pw == NULL) { 170 if (errno != 0) { 171 pjdlog_errno(LOG_ERR, 172 "Unable to find info about '%s' user", HAST_USER); 173 return (-1); 174 } else { 175 pjdlog_error("'%s' user doesn't exist.", HAST_USER); 176 errno = ENOENT; 177 return (-1); 178 } 179 } 180 181 bzero(&jailst, sizeof(jailst)); 182 jailst.version = JAIL_API_VERSION; 183 jailst.path = pw->pw_dir; 184 if (res == NULL) { 185 (void)snprintf(jailhost, sizeof(jailhost), "hastctl"); 186 } else { 187 (void)snprintf(jailhost, sizeof(jailhost), "hastd: %s (%s)", 188 res->hr_name, role2str(res->hr_role)); 189 } 190 jailst.hostname = jailhost; 191 jailst.jailname = NULL; 192 jailst.ip4s = 0; 193 jailst.ip4 = NULL; 194 jailst.ip6s = 0; 195 jailst.ip6 = NULL; 196 if (jail(&jailst) >= 0) { 197 jailed = true; 198 } else { 199 jailed = false; 200 pjdlog_errno(LOG_WARNING, 201 "Unable to jail to directory to %s", pw->pw_dir); 202 if (chroot(pw->pw_dir) == -1) { 203 pjdlog_errno(LOG_ERR, 204 "Unable to change root directory to %s", 205 pw->pw_dir); 206 return (-1); 207 } 208 } 209 PJDLOG_VERIFY(chdir("/") == 0); 210 gidset[0] = pw->pw_gid; 211 if (setgroups(1, gidset) == -1) { 212 pjdlog_errno(LOG_ERR, "Unable to set groups to gid %u", 213 (unsigned int)pw->pw_gid); 214 return (-1); 215 } 216 if (setgid(pw->pw_gid) == -1) { 217 pjdlog_errno(LOG_ERR, "Unable to set gid to %u", 218 (unsigned int)pw->pw_gid); 219 return (-1); 220 } 221 if (setuid(pw->pw_uid) == -1) { 222 pjdlog_errno(LOG_ERR, "Unable to set uid to %u", 223 (unsigned int)pw->pw_uid); 224 return (-1); 225 } 226 227 /* 228 * Until capsicum doesn't allow ioctl(2) we cannot use it to sandbox 229 * primary and secondary worker processes, as primary uses GGATE 230 * ioctls and secondary uses ioctls to handle BIO_DELETE and BIO_FLUSH. 231 * For now capsicum is only used to sandbox hastctl. 232 */ 233#ifdef HAVE_CAPSICUM 234 if (res == NULL) { 235 capsicum = (cap_enter() == 0); 236 if (!capsicum) { 237 pjdlog_common(LOG_DEBUG, 1, errno, 238 "Unable to sandbox using capsicum"); 239 } 240 } else 241#endif 242 capsicum = false; 243 244 /* 245 * Better be sure that everything succeeded. 246 */ 247 PJDLOG_VERIFY(getresuid(&ruid, &euid, &suid) == 0); 248 PJDLOG_VERIFY(ruid == pw->pw_uid); 249 PJDLOG_VERIFY(euid == pw->pw_uid); 250 PJDLOG_VERIFY(suid == pw->pw_uid); 251 PJDLOG_VERIFY(getresgid(&rgid, &egid, &sgid) == 0); 252 PJDLOG_VERIFY(rgid == pw->pw_gid); 253 PJDLOG_VERIFY(egid == pw->pw_gid); 254 PJDLOG_VERIFY(sgid == pw->pw_gid); 255 PJDLOG_VERIFY(getgroups(0, NULL) == 1); 256 PJDLOG_VERIFY(getgroups(1, gidset) == 1); 257 PJDLOG_VERIFY(gidset[0] == pw->pw_gid); 258 259 pjdlog_debug(1, 260 "Privileges successfully dropped using %s%s+setgid+setuid.", 261 capsicum ? "capsicum+" : "", jailed ? "jail" : "chroot"); 262 263 return (0); 264} 265