utmpx.c revision 1.4
1 /* $NetBSD: utmpx.c,v 1.4 2002/03/11 03:29:49 simonb Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 #include <sys/cdefs.h> 39 40 #if defined(LIBC_SCCS) && !defined(lint) 41 __RCSID("$NetBSD: utmpx.c,v 1.4 2002/03/11 03:29:49 simonb Exp $"); 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <sys/types.h> 45 #include <sys/param.h> 46 #include <sys/wait.h> 47 #include <sys/socket.h> 48 #include <sys/time.h> 49 #include <sys/stat.h> 50 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <vis.h> 55 #include <utmpx.h> 56 #include <unistd.h> 57 #include <fcntl.h> 58 59 static FILE *fp; 60 static struct utmpx ut; 61 static char utfile[MAXPATHLEN] = _PATH_UTMPX; 62 63 static struct utmpx *utmp_update(const struct utmpx *); 64 65 static const char vers[] = "utmpx-1.00"; 66 67 void 68 setutxent() 69 { 70 (void)memset(&ut, 0, sizeof(ut)); 71 if (fp == NULL) 72 return; 73 (void)fseeko(fp, (off_t)sizeof(ut), SEEK_SET); 74 } 75 76 77 void 78 endutxent() 79 { 80 (void)memset(&ut, 0, sizeof(ut)); 81 if (fp != NULL) 82 (void)fclose(fp); 83 } 84 85 86 struct utmpx * 87 getutxent() 88 { 89 if (fp == NULL) { 90 struct stat st; 91 92 if ((fp = fopen(utfile, "r+")) == NULL) 93 if ((fp = fopen(utfile, "r")) == NULL) 94 goto fail; 95 96 /* get file size in order to check if new file */ 97 if (fstat(fileno(fp), &st) == -1) 98 goto failclose; 99 100 if (st.st_size == 0) { 101 /* new file, add signature record */ 102 (void)memset(&ut, 0, sizeof(ut)); 103 ut.ut_type = SIGNATURE; 104 (void)memcpy(ut.ut_user, vers, sizeof(vers)); 105 if (fwrite(&ut, sizeof(ut), 1, fp) != sizeof(ut)) 106 goto failclose; 107 } else { 108 /* old file, read signature record */ 109 if (fread(&ut, sizeof(ut), 1, fp) != sizeof(ut)) 110 goto failclose; 111 if (memcmp(ut.ut_user, vers, sizeof(vers)) != 0 || 112 ut.ut_type != SIGNATURE) 113 goto failclose; 114 } 115 } 116 117 if (fread(&ut, sizeof(ut), 1, fp) != sizeof(ut)) 118 goto fail; 119 120 return &ut; 121 failclose: 122 (void)fclose(fp); 123 fail: 124 (void)memset(&ut, 0, sizeof(ut)); 125 return NULL; 126 } 127 128 129 struct utmpx * 130 getutxid(const struct utmpx *utx) 131 { 132 if (utx->ut_type == EMPTY) 133 return NULL; 134 135 do { 136 if (ut.ut_type == EMPTY) 137 continue; 138 switch (utx->ut_type) { 139 case EMPTY: 140 return NULL; 141 case RUN_LVL: 142 case BOOT_TIME: 143 case OLD_TIME: 144 case NEW_TIME: 145 if (ut.ut_type == utx->ut_type) 146 return &ut; 147 break; 148 case INIT_PROCESS: 149 case LOGIN_PROCESS: 150 case USER_PROCESS: 151 case DEAD_PROCESS: 152 switch (ut.ut_type) { 153 case INIT_PROCESS: 154 case LOGIN_PROCESS: 155 case USER_PROCESS: 156 case DEAD_PROCESS: 157 if (memcmp(ut.ut_id, utx->ut_id, 158 sizeof(ut.ut_id)) == 0) 159 return &ut; 160 break; 161 default: 162 break; 163 } 164 break; 165 default: 166 return NULL; 167 } 168 } 169 while (getutxent() != NULL); 170 return NULL; 171 } 172 173 174 struct utmpx * 175 getutxline(const struct utmpx *utx) 176 { 177 do { 178 switch (ut.ut_type) { 179 case EMPTY: 180 break; 181 case LOGIN_PROCESS: 182 case USER_PROCESS: 183 if (strncmp(ut.ut_line, utx->ut_line, 184 sizeof(ut.ut_line)) == 0) 185 return &ut; 186 break; 187 default: 188 break; 189 } 190 } 191 while (getutxent() != NULL); 192 return NULL; 193 } 194 195 196 struct utmpx * 197 pututxline(const struct utmpx *utx) 198 { 199 struct utmpx temp, *u = NULL; 200 int gotlock = 0; 201 202 if (strcmp(_PATH_UTMPX, utfile) == 0 && geteuid() != 0) 203 return utmp_update(utx); 204 205 if (utx == NULL) 206 return NULL; 207 208 (void)memcpy(&temp, utx, sizeof(temp)); 209 210 if (fp == NULL) { 211 (void)getutxent(); 212 if (fp == NULL) 213 return NULL; 214 } 215 216 if (getutxid(&temp) == NULL) { 217 setutxent(); 218 if (getutxid(&temp) == NULL) { 219 if (lockf(fileno(fp), F_LOCK, (off_t)0) == -1) 220 return NULL; 221 gotlock++; 222 if (fseeko(fp, (off_t)0, SEEK_END) == -1) 223 goto fail; 224 } 225 } 226 227 if (!gotlock) { 228 /* we are not appending */ 229 if (fseeko(fp, -(off_t)sizeof(ut), SEEK_CUR) == -1) 230 return NULL; 231 } 232 233 if (fwrite(&temp, sizeof (temp), 1, fp) != 1) 234 goto fail; 235 236 if (fflush(fp) == -1) 237 goto fail; 238 239 u = memcpy(&ut, &temp, sizeof(ut)); 240 fail: 241 if (gotlock) { 242 if (lockf(fileno(fp), F_ULOCK, (off_t)0) == -1) 243 return NULL; 244 } 245 return u; 246 } 247 248 249 static struct utmpx * 250 utmp_update(const struct utmpx *utx) 251 { 252 char buf[sizeof(*utx) * 4 + 1]; 253 pid_t pid; 254 int status; 255 256 (void)strvisx(buf, (const char *)(const void *)utx, sizeof(*utx), 257 VIS_WHITE); 258 switch (pid = fork()) { 259 case 0: 260 (void)execl(_PATH_UTMP_UPDATE, 261 strrchr(_PATH_UTMP_UPDATE, '/') + 1, buf); 262 exit(1); 263 /*NOTREACHED*/ 264 case -1: 265 return NULL; 266 default: 267 if (waitpid(pid, &status, 0) == -1) 268 return NULL; 269 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) 270 return memcpy(&ut, utx, sizeof(ut)); 271 return NULL; 272 } 273 274 } 275 276 void 277 updwtmpx(const char *file, const struct utmpx *utx) 278 { 279 int fd = open(file, O_WRONLY | O_APPEND); 280 if (fd == -1) { 281 if ((fd = open(file, O_CREAT | O_WRONLY, 0644)) == -1) 282 return; 283 (void)memset(&ut, 0, sizeof(ut)); 284 ut.ut_type = SIGNATURE; 285 (void)memcpy(ut.ut_user, vers, sizeof(vers)); 286 (void)write(fd, &ut, sizeof(ut)); 287 } 288 (void)write(fd, utx, sizeof(*utx)); 289 (void)close(fd); 290 } 291 292 293 /* 294 * The following are extensions and not part of the X/Open spec 295 */ 296 int 297 utmpxname(const char *fname) 298 { 299 size_t len = strlen(fname); 300 301 if (len >= sizeof(utfile)) 302 return 0; 303 304 /* must end in x! */ 305 if (fname[len - 1] != 'x') 306 return 0; 307 308 (void)strcpy(utfile, fname); 309 endutxent(); 310 return 1; 311 } 312
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