1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2010 Ed Schouten <ed@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "namespace.h" 33 #include <sys/endian.h> 34 #include <sys/param.h> 35 #include <sys/stat.h> 36 #include <errno.h> 37 #include <stdio.h> 38 #include <string.h> 39 #include <utmpx.h> 40 #include "utxdb.h" 41 #include "un-namespace.h" 42 43 #ifdef __NO_TLS 44 static FILE *uf = NULL; 45 static int udb; 46 #else 47 static _Thread_local FILE *uf = NULL; 48 static _Thread_local int udb; 49 #endif 50 51 int 52 setutxdb(int db, const char *file) 53 { 54 struct stat sb; 55 56 switch (db) { 57 case UTXDB_ACTIVE: 58 if (file == NULL) 59 file = _PATH_UTX_ACTIVE; 60 break; 61 case UTXDB_LASTLOGIN: 62 if (file == NULL) 63 file = _PATH_UTX_LASTLOGIN; 64 break; 65 case UTXDB_LOG: 66 if (file == NULL) 67 file = _PATH_UTX_LOG; 68 break; 69 default: 70 errno = EINVAL; 71 return (-1); 72 } 73 74 if (uf != NULL) 75 fclose(uf); 76 uf = fopen(file, "re"); 77 if (uf == NULL) 78 return (-1); 79 80 if (db != UTXDB_LOG) { 81 /* Safety check: never use broken files. */ 82 if (_fstat(fileno(uf), &sb) != -1 && 83 sb.st_size % sizeof(struct futx) != 0) { 84 fclose(uf); 85 uf = NULL; 86 errno = EFTYPE; 87 return (-1); 88 } 89 /* Prevent reading of partial records. */ 90 (void)setvbuf(uf, NULL, _IOFBF, 91 rounddown(BUFSIZ, sizeof(struct futx))); 92 } 93 94 udb = db; 95 return (0); 96 } 97 98 void 99 setutxent(void) 100 { 101 102 setutxdb(UTXDB_ACTIVE, NULL); 103 } 104 105 void 106 endutxent(void) 107 { 108 109 if (uf != NULL) { 110 fclose(uf); 111 uf = NULL; 112 } 113 } 114 115 static int 116 getfutxent(struct futx *fu) 117 { 118 119 if (uf == NULL) 120 setutxent(); 121 if (uf == NULL) 122 return (-1); 123 124 if (udb == UTXDB_LOG) { 125 uint16_t len; 126 127 retry: 128 if (fread(&len, sizeof(len), 1, uf) != 1) 129 return (-1); 130 len = be16toh(len); 131 if (len == 0) { 132 /* 133 * XXX: Though zero-size records are valid in theory, 134 * they can never occur in practice. Zero-size records 135 * indicate file corruption. Seek one byte forward, to 136 * see if we can find a record there. 137 */ 138 ungetc('\0', uf); 139 goto retry; 140 } 141 if (len > sizeof *fu) { 142 /* Forward compatibility. */ 143 if (fread(fu, sizeof(*fu), 1, uf) != 1) 144 return (-1); 145 fseek(uf, len - sizeof(*fu), SEEK_CUR); 146 } else { 147 /* Partial record. */ 148 memset(fu, 0, sizeof(*fu)); 149 if (fread(fu, len, 1, uf) != 1) 150 return (-1); 151 } 152 } else { 153 if (fread(fu, sizeof(*fu), 1, uf) != 1) 154 return (-1); 155 } 156 return (0); 157 } 158 159 struct utmpx * 160 getutxent(void) 161 { 162 struct futx fu; 163 164 if (getfutxent(&fu) != 0) 165 return (NULL); 166 return (futx_to_utx(&fu)); 167 } 168 169 struct utmpx * 170 getutxid(const struct utmpx *id) 171 { 172 struct futx fu; 173 174 for (;;) { 175 if (getfutxent(&fu) != 0) 176 return (NULL); 177 178 switch (fu.fu_type) { 179 case USER_PROCESS: 180 case INIT_PROCESS: 181 case LOGIN_PROCESS: 182 case DEAD_PROCESS: 183 switch (id->ut_type) { 184 case USER_PROCESS: 185 case INIT_PROCESS: 186 case LOGIN_PROCESS: 187 case DEAD_PROCESS: 188 if (memcmp(fu.fu_id, id->ut_id, 189 MIN(sizeof(fu.fu_id), sizeof(id->ut_id))) == 190 0) 191 goto found; 192 } 193 break; 194 default: 195 if (fu.fu_type == id->ut_type) 196 goto found; 197 break; 198 } 199 } 200 201 found: 202 return (futx_to_utx(&fu)); 203 } 204 205 struct utmpx * 206 getutxline(const struct utmpx *line) 207 { 208 struct futx fu; 209 210 for (;;) { 211 if (getfutxent(&fu) != 0) 212 return (NULL); 213 214 switch (fu.fu_type) { 215 case USER_PROCESS: 216 case LOGIN_PROCESS: 217 if (strncmp(fu.fu_line, line->ut_line, 218 MIN(sizeof(fu.fu_line), sizeof(line->ut_line))) == 219 0) 220 goto found; 221 break; 222 } 223 } 224 225 found: 226 return (futx_to_utx(&fu)); 227 } 228 229 struct utmpx * 230 getutxuser(const char *user) 231 { 232 struct futx fu; 233 234 for (;;) { 235 if (getfutxent(&fu) != 0) 236 return (NULL); 237 238 switch (fu.fu_type) { 239 case USER_PROCESS: 240 if (strncmp(fu.fu_user, user, sizeof(fu.fu_user)) == 0) 241 goto found; 242 break; 243 } 244 } 245 246 found: 247 return (futx_to_utx(&fu)); 248 } 249