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 static _Thread_local FILE *uf = NULL; 44 static _Thread_local int udb; 45 46 int 47 setutxdb(int db, const char *file) 48 { 49 struct stat sb; 50 51 switch (db) { 52 case UTXDB_ACTIVE: 53 if (file == NULL) 54 file = _PATH_UTX_ACTIVE; 55 break; 56 case UTXDB_LASTLOGIN: 57 if (file == NULL) 58 file = _PATH_UTX_LASTLOGIN; 59 break; 60 case UTXDB_LOG: 61 if (file == NULL) 62 file = _PATH_UTX_LOG; 63 break; 64 default: 65 errno = EINVAL; 66 return (-1); 67 } 68 69 if (uf != NULL) 70 fclose(uf); 71 uf = fopen(file, "re"); 72 if (uf == NULL) 73 return (-1); 74 75 if (db != UTXDB_LOG) { 76 /* Safety check: never use broken files. */ 77 if (_fstat(fileno(uf), &sb) != -1 && 78 sb.st_size % sizeof(struct futx) != 0) { 79 fclose(uf); 80 uf = NULL; 81 errno = EFTYPE; 82 return (-1); 83 } 84 /* Prevent reading of partial records. */ 85 (void)setvbuf(uf, NULL, _IOFBF, 86 rounddown(BUFSIZ, sizeof(struct futx))); 87 } 88 89 udb = db; 90 return (0); 91 } 92 93 void 94 setutxent(void) 95 { 96 97 setutxdb(UTXDB_ACTIVE, NULL); 98 } 99 100 void 101 endutxent(void) 102 { 103 104 if (uf != NULL) { 105 fclose(uf); 106 uf = NULL; 107 } 108 } 109 110 static int 111 getfutxent(struct futx *fu) 112 { 113 114 if (uf == NULL) 115 setutxent(); 116 if (uf == NULL) 117 return (-1); 118 119 if (udb == UTXDB_LOG) { 120 uint16_t len; 121 122 retry: 123 if (fread(&len, sizeof(len), 1, uf) != 1) 124 return (-1); 125 len = be16toh(len); 126 if (len == 0) { 127 /* 128 * XXX: Though zero-size records are valid in theory, 129 * they can never occur in practice. Zero-size records 130 * indicate file corruption. Seek one byte forward, to 131 * see if we can find a record there. 132 */ 133 ungetc('\0', uf); 134 goto retry; 135 } 136 if (len > sizeof *fu) { 137 /* Forward compatibility. */ 138 if (fread(fu, sizeof(*fu), 1, uf) != 1) 139 return (-1); 140 fseek(uf, len - sizeof(*fu), SEEK_CUR); 141 } else { 142 /* Partial record. */ 143 memset(fu, 0, sizeof(*fu)); 144 if (fread(fu, len, 1, uf) != 1) 145 return (-1); 146 } 147 } else { 148 if (fread(fu, sizeof(*fu), 1, uf) != 1) 149 return (-1); 150 } 151 return (0); 152 } 153 154 struct utmpx * 155 getutxent(void) 156 { 157 struct futx fu; 158 159 if (getfutxent(&fu) != 0) 160 return (NULL); 161 return (futx_to_utx(&fu)); 162 } 163 164 struct utmpx * 165 getutxid(const struct utmpx *id) 166 { 167 struct futx fu; 168 169 for (;;) { 170 if (getfutxent(&fu) != 0) 171 return (NULL); 172 173 switch (fu.fu_type) { 174 case USER_PROCESS: 175 case INIT_PROCESS: 176 case LOGIN_PROCESS: 177 case DEAD_PROCESS: 178 switch (id->ut_type) { 179 case USER_PROCESS: 180 case INIT_PROCESS: 181 case LOGIN_PROCESS: 182 case DEAD_PROCESS: 183 if (memcmp(fu.fu_id, id->ut_id, 184 MIN(sizeof(fu.fu_id), sizeof(id->ut_id))) == 185 0) 186 goto found; 187 } 188 break; 189 default: 190 if (fu.fu_type == id->ut_type) 191 goto found; 192 break; 193 } 194 } 195 196 found: 197 return (futx_to_utx(&fu)); 198 } 199 200 struct utmpx * 201 getutxline(const struct utmpx *line) 202 { 203 struct futx fu; 204 205 for (;;) { 206 if (getfutxent(&fu) != 0) 207 return (NULL); 208 209 switch (fu.fu_type) { 210 case USER_PROCESS: 211 case LOGIN_PROCESS: 212 if (strncmp(fu.fu_line, line->ut_line, 213 MIN(sizeof(fu.fu_line), sizeof(line->ut_line))) == 214 0) 215 goto found; 216 break; 217 } 218 } 219 220 found: 221 return (futx_to_utx(&fu)); 222 } 223 224 struct utmpx * 225 getutxuser(const char *user) 226 { 227 struct futx fu; 228 229 for (;;) { 230 if (getfutxent(&fu) != 0) 231 return (NULL); 232 233 switch (fu.fu_type) { 234 case USER_PROCESS: 235 if (strncmp(fu.fu_user, user, sizeof(fu.fu_user)) == 0) 236 goto found; 237 break; 238 } 239 } 240 241 found: 242 return (futx_to_utx(&fu)); 243 } 244