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 "namespace.h" 30 #include <sys/endian.h> 31 #include <sys/param.h> 32 #include <sys/stat.h> 33 #include <errno.h> 34 #include <stdio.h> 35 #include <string.h> 36 #include <utmpx.h> 37 #include "utxdb.h" 38 #include "un-namespace.h" 39 40 static _Thread_local FILE *uf = NULL; 41 static _Thread_local int udb; 42 43 int 44 setutxdb(int db, const char *file) 45 { 46 struct stat sb; 47 48 switch (db) { 49 case UTXDB_ACTIVE: 50 if (file == NULL) 51 file = _PATH_UTX_ACTIVE; 52 break; 53 case UTXDB_LASTLOGIN: 54 if (file == NULL) 55 file = _PATH_UTX_LASTLOGIN; 56 break; 57 case UTXDB_LOG: 58 if (file == NULL) 59 file = _PATH_UTX_LOG; 60 break; 61 default: 62 errno = EINVAL; 63 return (-1); 64 } 65 66 if (uf != NULL) 67 fclose(uf); 68 uf = fopen(file, "re"); 69 if (uf == NULL) 70 return (-1); 71 72 if (db != UTXDB_LOG) { 73 /* Safety check: never use broken files. */ 74 if (_fstat(fileno(uf), &sb) != -1 && 75 sb.st_size % sizeof(struct futx) != 0) { 76 fclose(uf); 77 uf = NULL; 78 errno = EFTYPE; 79 return (-1); 80 } 81 /* Prevent reading of partial records. */ 82 (void)setvbuf(uf, NULL, _IOFBF, 83 rounddown(BUFSIZ, sizeof(struct futx))); 84 } 85 86 udb = db; 87 return (0); 88 } 89 90 void 91 setutxent(void) 92 { 93 94 setutxdb(UTXDB_ACTIVE, NULL); 95 } 96 97 void 98 endutxent(void) 99 { 100 101 if (uf != NULL) { 102 fclose(uf); 103 uf = NULL; 104 } 105 } 106 107 static int 108 getfutxent(struct futx *fu) 109 { 110 111 if (uf == NULL) 112 setutxent(); 113 if (uf == NULL) 114 return (-1); 115 116 if (udb == UTXDB_LOG) { 117 uint16_t len; 118 119 retry: 120 if (fread(&len, sizeof(len), 1, uf) != 1) 121 return (-1); 122 len = be16toh(len); 123 if (len == 0) { 124 /* 125 * XXX: Though zero-size records are valid in theory, 126 * they can never occur in practice. Zero-size records 127 * indicate file corruption. Seek one byte forward, to 128 * see if we can find a record there. 129 */ 130 ungetc('\0', uf); 131 goto retry; 132 } 133 if (len > sizeof *fu) { 134 /* Forward compatibility. */ 135 if (fread(fu, sizeof(*fu), 1, uf) != 1) 136 return (-1); 137 fseek(uf, len - sizeof(*fu), SEEK_CUR); 138 } else { 139 /* Partial record. */ 140 memset(fu, 0, sizeof(*fu)); 141 if (fread(fu, len, 1, uf) != 1) 142 return (-1); 143 } 144 } else { 145 if (fread(fu, sizeof(*fu), 1, uf) != 1) 146 return (-1); 147 } 148 return (0); 149 } 150 151 struct utmpx * 152 getutxent(void) 153 { 154 struct futx fu; 155 156 if (getfutxent(&fu) != 0) 157 return (NULL); 158 return (futx_to_utx(&fu)); 159 } 160 161 struct utmpx * 162 getutxid(const struct utmpx *id) 163 { 164 struct futx fu; 165 166 for (;;) { 167 if (getfutxent(&fu) != 0) 168 return (NULL); 169 170 switch (fu.fu_type) { 171 case USER_PROCESS: 172 case INIT_PROCESS: 173 case LOGIN_PROCESS: 174 case DEAD_PROCESS: 175 switch (id->ut_type) { 176 case USER_PROCESS: 177 case INIT_PROCESS: 178 case LOGIN_PROCESS: 179 case DEAD_PROCESS: 180 if (memcmp(fu.fu_id, id->ut_id, 181 MIN(sizeof(fu.fu_id), sizeof(id->ut_id))) == 182 0) 183 goto found; 184 } 185 break; 186 default: 187 if (fu.fu_type == id->ut_type) 188 goto found; 189 break; 190 } 191 } 192 193 found: 194 return (futx_to_utx(&fu)); 195 } 196 197 struct utmpx * 198 getutxline(const struct utmpx *line) 199 { 200 struct futx fu; 201 202 for (;;) { 203 if (getfutxent(&fu) != 0) 204 return (NULL); 205 206 switch (fu.fu_type) { 207 case USER_PROCESS: 208 case LOGIN_PROCESS: 209 if (strncmp(fu.fu_line, line->ut_line, 210 MIN(sizeof(fu.fu_line), sizeof(line->ut_line))) == 211 0) 212 goto found; 213 break; 214 } 215 } 216 217 found: 218 return (futx_to_utx(&fu)); 219 } 220 221 struct utmpx * 222 getutxuser(const char *user) 223 { 224 struct futx fu; 225 226 for (;;) { 227 if (getfutxent(&fu) != 0) 228 return (NULL); 229 230 switch (fu.fu_type) { 231 case USER_PROCESS: 232 if (strncmp(fu.fu_user, user, sizeof(fu.fu_user)) == 0) 233 goto found; 234 break; 235 } 236 } 237 238 found: 239 return (futx_to_utx(&fu)); 240 } 241