1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * This module contains functions used for reading and writing the scratch zone 31 * translation files. These files are used by Live Upgrade to keep track of 32 * mappings between actual kernel zone names and the zones in an alternate boot 33 * environment. 34 * 35 * The functions are MT-safe. 36 * 37 * The file format looks like this: 38 * 39 * <zonename> <kernel-zonename> <alt-root> 40 * 41 * The expected usage model is: 42 * 43 * fp = zonecfg_open_scratch("", B_TRUE); 44 * zonecfg_lock_scratch(fp); 45 * if (zonecfg_find_scratch(fp, zonename, altroot, NULL, 0) == 0) { 46 * handle error; zone already mounted 47 * } 48 * mount zone here 49 * zonecfg_add_scratch(fp, zonename, kernname, altroot); 50 * zonecfg_close_scratch(fp); 51 * fp = zonecfg_open_scratch(zoneroot, B_TRUE); 52 * ftruncate(fileno(fp), 0); 53 * zonecfg_add_scratch(fp, zonename, kernname, "/"); 54 * zonecfg_close_scratch(fp); 55 */ 56 57 #include <stdio.h> 58 #include <unistd.h> 59 #include <fcntl.h> 60 #include <errno.h> 61 #include <string.h> 62 #include <sys/types.h> 63 #include <sys/stat.h> 64 #include <sys/param.h> 65 #include <libzonecfg.h> 66 67 #define PATH_MAPFILE "tmp/.alt.lu-zone-map" 68 69 static int 70 lock_op(int fd, int type) 71 { 72 struct flock lock; 73 74 lock.l_type = type; 75 lock.l_whence = SEEK_SET; 76 lock.l_start = 0; 77 lock.l_len = 0; 78 79 return (fcntl(fd, F_SETLKW, &lock)); 80 } 81 82 FILE * 83 zonecfg_open_scratch(const char *rootpath, boolean_t createfile) 84 { 85 mode_t oldmask = umask(0); 86 struct stat lbuf, fbuf; 87 int fd, flags; 88 FILE *fp; 89 char mapfile[MAXPATHLEN]; 90 91 (void) snprintf(mapfile, sizeof (mapfile), "%s/" PATH_MAPFILE, 92 rootpath); 93 94 flags = O_RDWR | O_NOFOLLOW | O_NOLINKS; 95 if (createfile) 96 flags |= O_EXCL | O_CREAT; 97 if ((fd = open(mapfile, flags, 0644)) == -1) { 98 if (!createfile) { 99 errno = ENOENT; 100 goto failure; 101 } 102 if (lstat(mapfile, &lbuf) == -1) 103 goto failure; 104 if (!S_ISREG(lbuf.st_mode) || lbuf.st_nlink != 1 || 105 lbuf.st_uid != 0) { 106 errno = EINVAL; 107 goto failure; 108 } 109 fd = open(mapfile, O_RDWR); 110 if (fd == -1) 111 goto failure; 112 if (fstat(fd, &fbuf) == -1) 113 goto failure; 114 if (lbuf.st_ino != fbuf.st_ino || lbuf.st_dev != fbuf.st_dev) { 115 errno = EINVAL; 116 goto failure; 117 } 118 } 119 if (lock_op(fd, F_RDLCK) == -1) 120 goto failure; 121 (void) umask(oldmask); 122 if ((fp = fdopen(fd, "r+")) == NULL) 123 (void) close(fd); 124 return (fp); 125 126 failure: 127 if (fd != -1) 128 (void) close(fd); 129 (void) umask(oldmask); 130 return (NULL); 131 } 132 133 int 134 zonecfg_lock_scratch(FILE *fp) 135 { 136 if (fflush(fp) != 0) 137 return (-1); 138 return (lock_op(fileno(fp), F_WRLCK)); 139 } 140 141 void 142 zonecfg_close_scratch(FILE *fp) 143 { 144 (void) fclose(fp); 145 } 146 147 int 148 zonecfg_get_scratch(FILE *fp, char *zonename, size_t namelen, char *kernname, 149 size_t kernlen, char *altroot, size_t altlen) 150 { 151 char line[2 * ZONENAME_MAX + MAXPATHLEN + 2]; 152 char *cp, *cp2; 153 154 /* We always hold at least a read lock on the file */ 155 for (;;) { 156 if (fgets(line, sizeof (line), fp) == NULL) 157 return (-1); 158 if ((cp = strchr(line, '\n')) == NULL) 159 return (-1); 160 *cp = '\0'; 161 if ((cp = strchr(line, ' ')) == NULL) 162 cp = line + strlen(line); 163 else 164 *cp++ = '\0'; 165 if (zonename != NULL && 166 strlcpy(zonename, line, namelen) >= namelen) 167 continue; 168 if ((cp2 = strchr(cp, ' ')) == NULL) 169 cp2 = cp + strlen(cp); 170 else 171 *cp2++ = '\0'; 172 if (kernname != NULL && 173 strlcpy(kernname, cp, kernlen) >= kernlen) 174 continue; 175 if (altroot != NULL && strlcpy(altroot, cp2, altlen) >= altlen) 176 continue; 177 break; 178 } 179 return (0); 180 } 181 182 int 183 zonecfg_find_scratch(FILE *fp, const char *zonename, const char *altroot, 184 char *kernzone, size_t kernlen) 185 { 186 char zone[ZONENAME_MAX]; 187 char aroot[MAXPATHLEN]; 188 189 rewind(fp); 190 while (zonecfg_get_scratch(fp, zone, sizeof (zone), kernzone, kernlen, 191 aroot, sizeof (aroot)) == 0) { 192 if (strcmp(zone, zonename) == 0 && strcmp(altroot, aroot) == 0) 193 return (0); 194 } 195 return (-1); 196 } 197 198 int 199 zonecfg_reverse_scratch(FILE *fp, const char *kernzone, char *zonename, 200 size_t namelen, char *altroot, size_t altlen) 201 { 202 char kzone[ZONENAME_MAX]; 203 204 rewind(fp); 205 while (zonecfg_get_scratch(fp, zonename, namelen, kzone, 206 sizeof (kzone), altroot, altlen) == 0) { 207 if (strcmp(kzone, kernzone) == 0) 208 return (0); 209 } 210 return (-1); 211 } 212 213 int 214 zonecfg_add_scratch(FILE *fp, const char *zonename, const char *kernzone, 215 const char *altroot) 216 { 217 if (fseek(fp, 0, SEEK_END) == -1) 218 return (-1); 219 if (fprintf(fp, "%s %s %s\n", zonename, kernzone, altroot) == EOF) 220 return (-1); 221 if (fflush(fp) != 0) 222 return (-1); 223 return (0); 224 } 225 226 int 227 zonecfg_delete_scratch(FILE *fp, const char *kernzone) 228 { 229 char zone[ZONENAME_MAX]; 230 char kzone[ZONENAME_MAX]; 231 char aroot[MAXPATHLEN]; 232 long roffs, woffs; 233 234 /* 235 * The implementation here is intentionally quite simple. We could 236 * allocate a buffer that's big enough to hold the data up to 237 * stat.st_size and then write back out the part we need to, but there 238 * seems to be little point. 239 */ 240 rewind(fp); 241 roffs = 0; 242 do { 243 woffs = roffs; 244 if (zonecfg_get_scratch(fp, NULL, 0, kzone, sizeof (kzone), 245 NULL, 0) != 0) 246 return (-1); 247 roffs = ftell(fp); 248 } while (strcmp(kzone, kernzone) != 0); 249 while (zonecfg_get_scratch(fp, zone, sizeof (zone), kzone, 250 sizeof (kzone), aroot, sizeof aroot) == 0) { 251 roffs = ftell(fp); 252 if (fseek(fp, woffs, SEEK_SET) == -1) 253 break; 254 if (fprintf(fp, "%s %s %s\n", zone, kzone, aroot) == EOF) 255 break; 256 woffs = ftell(fp); 257 if (fseek(fp, roffs, SEEK_SET) == -1) 258 break; 259 } 260 (void) ftruncate(fileno(fp), woffs); 261 return (0); 262 } 263 264 boolean_t 265 zonecfg_is_scratch(const char *kernzone) 266 { 267 return (strncmp(kernzone, "SUNWlu", 6) == 0); 268 } 269