1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include "namespace.h" 31 #include <sys/endian.h> 32 #include <sys/param.h> 33 #include <sys/stat.h> 34 #include <errno.h> 35 #include <stdio.h> 36 #include <string.h> 37 #include <utmpx.h> 38 #include "utxdb.h" 39 #include "un-namespace.h" 40 41 static _Thread_local FILE *uf = NULL; 42 static _Thread_local int udb; 43 44 int 45 setutxdb(int db, const char *file) 46 { 47 struct stat sb; 48 49 switch (db) { 50 case UTXDB_ACTIVE: 51 if (file == NULL) 52 file = _PATH_UTX_ACTIVE; 53 break; 54 case UTXDB_LASTLOGIN: 55 if (file == NULL) 56 file = _PATH_UTX_LASTLOGIN; 57 break; 58 case UTXDB_LOG: 59 if (file == NULL) 60 file = _PATH_UTX_LOG; 61 break; 62 default: 63 errno = EINVAL; 64 return (-1); 65 } 66 67 if (uf != NULL) 68 fclose(uf); 69 uf = fopen(file, "re"); 70 if (uf == NULL) 71 return (-1); 72 73 if (db != UTXDB_LOG) { 74 /* Safety check: never use broken files. */ 75 if (_fstat(fileno(uf), &sb) != -1 && 76 sb.st_size % sizeof(struct futx) != 0) { 77 fclose(uf); 78 uf = NULL; 79 errno = EFTYPE; 80 return (-1); 81 } 82 /* Prevent reading of partial records. */ 83 (void)setvbuf(uf, NULL, _IOFBF, 84 rounddown(BUFSIZ, sizeof(struct futx))); 85 } 86 87 udb = db; 88 return (0); 89 } 90 91 void 92 setutxent(void) 93 { 94 95 setutxdb(UTXDB_ACTIVE, NULL); 96 } 97 98 void 99 endutxent(void) 100 { 101 102 if (uf != NULL) { 103 fclose(uf); 104 uf = NULL; 105 } 106 } 107 108 static int 109 getfutxent(struct futx *fu) 110 { 111 112 if (uf == NULL) 113 setutxent(); 114 if (uf == NULL) 115 return (-1); 116 117 if (udb == UTXDB_LOG) { 118 uint16_t len; 119 120 retry: 121 if (fread(&len, sizeof(len), 1, uf) != 1) 122 return (-1); 123 len = be16toh(len); 124 if (len == 0) { 125 /* 126 * XXX: Though zero-size records are valid in theory, 127 * they can never occur in practice. Zero-size records 128 * indicate file corruption. Seek one byte forward, to 129 * see if we can find a record there. 130 */ 131 ungetc('\0', uf); 132 goto retry; 133 } 134 if (len > sizeof *fu) { 135 /* Forward compatibility. */ 136 if (fread(fu, sizeof(*fu), 1, uf) != 1) 137 return (-1); 138 fseek(uf, len - sizeof(*fu), SEEK_CUR); 139 } else { 140 /* Partial record. */ 141 memset(fu, 0, sizeof(*fu)); 142 if (fread(fu, len, 1, uf) != 1) 143 return (-1); 144 } 145 } else { 146 if (fread(fu, sizeof(*fu), 1, uf) != 1) 147 return (-1); 148 } 149 return (0); 150 } 151 152 struct utmpx * 153 getutxent(void) 154 { 155 struct futx fu; 156 157 if (getfutxent(&fu) != 0) 158 return (NULL); 159 return (futx_to_utx(&fu)); 160 } 161 162 struct utmpx * 163 getutxid(const struct utmpx *id) 164 { 165 struct futx fu; 166 167 for (;;) { 168 if (getfutxent(&fu) != 0) 169 return (NULL); 170 171 switch (fu.fu_type) { 172 case USER_PROCESS: 173 case INIT_PROCESS: 174 case LOGIN_PROCESS: 175 case DEAD_PROCESS: 176 switch (id->ut_type) { 177 case USER_PROCESS: 178 case INIT_PROCESS: 179 case LOGIN_PROCESS: 180 case DEAD_PROCESS: 181 if (memcmp(fu.fu_id, id->ut_id, 182 MIN(sizeof(fu.fu_id), sizeof(id->ut_id))) == 183 0) 184 goto found; 185 } 186 break; 187 default: 188 if (fu.fu_type == id->ut_type) 189 goto found; 190 break; 191 } 192 } 193 194 found: 195 return (futx_to_utx(&fu)); 196 } 197 198 struct utmpx * 199 getutxline(const struct utmpx *line) 200 { 201 struct futx fu; 202 203 for (;;) { 204 if (getfutxent(&fu) != 0) 205 return (NULL); 206 207 switch (fu.fu_type) { 208 case USER_PROCESS: 209 case LOGIN_PROCESS: 210 if (strncmp(fu.fu_line, line->ut_line, 211 MIN(sizeof(fu.fu_line), sizeof(line->ut_line))) == 212 0) 213 goto found; 214 break; 215 } 216 } 217 218 found: 219 return (futx_to_utx(&fu)); 220 } 221 222 struct utmpx * 223 getutxuser(const char *user) 224 { 225 struct futx fu; 226 227 for (;;) { 228 if (getfutxent(&fu) != 0) 229 return (NULL); 230 231 switch (fu.fu_type) { 232 case USER_PROCESS: 233 if (strncmp(fu.fu_user, user, sizeof(fu.fu_user)) == 0) 234 goto found; 235 break; 236 } 237 } 238 239 found: 240 return (futx_to_utx(&fu)); 241 } 242