1 /* $NetBSD: bootcfg.c,v 1.4 2019/03/31 20:08:45 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/types.h> 30 #include <sys/reboot.h> 31 32 #include <lib/libsa/stand.h> 33 #include <lib/libsa/bootcfg.h> 34 #include <lib/libkern/libkern.h> 35 36 #define MENUFORMAT_AUTO 0 37 #define MENUFORMAT_NUMBER 1 38 #define MENUFORMAT_LETTER 2 39 40 #define DEFAULT_FORMAT MENUFORMAT_AUTO 41 #define DEFAULT_TIMEOUT 10 42 43 struct bootcfg_def bootcfg_info; 44 45 void 46 bootcfg_do_noop(const char *cmd, char *arg) 47 { 48 /* noop, do nothing */ 49 } 50 51 /* 52 * This function parses a boot.cfg file in the root of the filesystem 53 * (if present) and populates the global boot configuration. 54 * 55 * The file consists of a number of lines each terminated by \n 56 * The lines are in the format keyword=value. There should not be spaces 57 * around the = sign. 58 * 59 * perform_bootcfg(conf, command, maxsz) 60 * 61 * conf Path to boot.cfg to be passed verbatim to open() 62 * 63 * command Pointer to a function that will be called when 64 * perform_bootcfg() encounters a key (command) it does not 65 * recognize. 66 * The command function is provided both the keyword and 67 * value parsed as arguments to the function. 68 * 69 * maxsz Limit the size of the boot.cfg perform_bootcfg() will parse. 70 * - If maxsz is < 0 boot.cfg will not be processed. 71 * - If maxsz is = 0 no limit will be imposed but parsing may 72 * fail due to platform or other constraints e.g. maximum 73 * segment size. 74 * - If 0 < maxsz and boot.cfg exceeds maxsz it will not be 75 * parsed, otherwise it will be parsed. 76 * 77 * The recognised keywords are: 78 * banner: text displayed instead of the normal welcome text 79 * menu: Descriptive text:command to use 80 * timeout: Timeout in seconds (overrides that set by installboot) 81 * default: the default menu option to use if Return is pressed 82 * consdev: the console device to use 83 * format: how menu choices are displayed: (a)utomatic, (n)umbers or (l)etters 84 * clear: whether to clear the screen or not 85 * 86 * Example boot.cfg file: 87 * banner=Welcome to NetBSD 88 * banner=Please choose the boot type from the following menu 89 * menu=Boot NetBSD:boot netbsd 90 * menu=Boot into single user mode:boot netbsd -s 91 * menu=:boot hd1a:netbsd -cs 92 * menu=Goto boot comand line:prompt 93 * timeout=10 94 * consdev=com0 95 * default=1 96 */ 97 int 98 perform_bootcfg(const char *conf, bootcfg_command command, const off_t maxsz) 99 { 100 char *bc, *c; 101 int cmenu, cbanner; 102 ssize_t len, off; 103 int fd, err; 104 struct stat st; 105 char *next, *key, *value, *v2; 106 107 /* clear bootcfg structure */ 108 memset(&bootcfg_info, 0, sizeof(bootcfg_info)); 109 110 /* set default timeout */ 111 bootcfg_info.timeout = DEFAULT_TIMEOUT; 112 113 /* automatically switch between letter and numbers on menu */ 114 bootcfg_info.menuformat = DEFAULT_FORMAT; 115 116 fd = open(conf, 0); 117 if (fd < 0) 118 return ENOENT; 119 120 err = fstat(fd, &st); 121 if (err == -1) { 122 close(fd); 123 return EIO; 124 } 125 126 /* if a maximum size is being requested for the boot.cfg enforce it. */ 127 if (0 < maxsz && st.st_size > maxsz) { 128 close(fd); 129 return EFBIG; 130 } 131 132 bc = alloc((size_t)st.st_size + 1); 133 if (bc == NULL) { 134 printf("Could not allocate memory for boot configuration\n"); 135 close(fd); 136 return ENOMEM; 137 } 138 139 /* 140 * XXX original code, assumes error or eof return from read() 141 * results in the entire boot.cfg being buffered. 142 * - should bail out on read() failing. 143 * - assumption is made that the file size doesn't change between 144 * fstat() and read()ing. probably safe in this context 145 * arguably should check that reading the file won't overflow 146 * the storage anyway. 147 */ 148 off = 0; 149 do { 150 len = read(fd, bc + off, 1024); 151 if (len <= 0) 152 break; 153 off += len; 154 } while (len > 0); 155 bc[off] = '\0'; 156 157 close(fd); 158 159 /* bc is now assumed to contain the whole boot.cfg file (see above) */ 160 161 cmenu = 0; 162 cbanner = 0; 163 for (c = bc; *c; c = next) { 164 key = c; 165 /* find end of line */ 166 for (; *c && *c != '\n'; c++) 167 /* zero terminate line on start of comment */ 168 if (*c == '#') 169 *c = 0; 170 /* zero terminate line */ 171 if (*(next = c)) 172 *next++ = 0; 173 /* Look for = separator between key and value */ 174 for (c = key; *c && *c != '='; c++) 175 continue; 176 /* Ignore lines with no key=value pair */ 177 if (*c == '\0') 178 continue; 179 180 /* zero terminate key which points to keyword */ 181 *c++ = 0; 182 value = c; 183 /* Look for end of line (or file) and zero terminate value */ 184 for (; *c && *c != '\n'; c++) 185 continue; 186 *c = 0; 187 188 if (!strncmp(key, "menu", 4)) { 189 /* 190 * Parse "menu=<description>:<command>". If the 191 * description is empty ("menu=:<command>)", 192 * then re-use the command as the description. 193 * Note that the command may contain embedded 194 * colons. 195 */ 196 if (cmenu >= BOOTCFG_MAXMENU) 197 continue; 198 bootcfg_info.desc[cmenu] = value; 199 for (v2 = value; *v2 && *v2 != ':'; v2++) 200 continue; 201 if (*v2) { 202 *v2++ = 0; 203 bootcfg_info.command[cmenu] = v2; 204 if (! *value) 205 bootcfg_info.desc[cmenu] = v2; 206 cmenu++; 207 } else { 208 /* No delimiter means invalid line */ 209 bootcfg_info.desc[cmenu] = NULL; 210 } 211 } else if (!strncmp(key, "banner", 6)) { 212 if (cbanner < BOOTCFG_MAXBANNER) 213 bootcfg_info.banner[cbanner++] = value; 214 } else if (!strncmp(key, "timeout", 7)) { 215 if (!isdigit(*value)) 216 bootcfg_info.timeout = -1; 217 else 218 bootcfg_info.timeout = atoi(value); 219 } else if (!strncmp(key, "default", 7)) { 220 bootcfg_info.def = atoi(value) - 1; 221 } else if (!strncmp(key, "consdev", 7)) { 222 bootcfg_info.consdev = value; 223 } else if (!strncmp(key, BOOTCFG_CMD_LOAD, 4)) { 224 command(BOOTCFG_CMD_LOAD, value); 225 } else if (!strncmp(key, "format", 6)) { 226 printf("value:%c\n", *value); 227 switch (*value) { 228 case 'a': 229 case 'A': 230 bootcfg_info.menuformat = MENUFORMAT_AUTO; 231 break; 232 233 case 'n': 234 case 'N': 235 case 'd': 236 case 'D': 237 bootcfg_info.menuformat = MENUFORMAT_NUMBER; 238 break; 239 240 case 'l': 241 case 'L': 242 bootcfg_info.menuformat = MENUFORMAT_LETTER; 243 break; 244 } 245 } else if (!strncmp(key, "clear", 5)) { 246 bootcfg_info.clear = !!atoi(value); 247 } else if (!strncmp(key, BOOTCFG_CMD_USERCONF, 8)) { 248 command(BOOTCFG_CMD_USERCONF, value); 249 } else { 250 command(key, value); 251 } 252 } 253 254 switch (bootcfg_info.menuformat) { 255 case MENUFORMAT_AUTO: 256 if (cmenu > 9 && bootcfg_info.timeout > 0) 257 bootcfg_info.menuformat = MENUFORMAT_LETTER; 258 else 259 bootcfg_info.menuformat = MENUFORMAT_NUMBER; 260 break; 261 262 case MENUFORMAT_NUMBER: 263 if (cmenu > 9 && bootcfg_info.timeout > 0) 264 cmenu = 9; 265 break; 266 } 267 268 bootcfg_info.nummenu = cmenu; 269 if (bootcfg_info.def < 0) 270 bootcfg_info.def = 0; 271 if (bootcfg_info.def >= cmenu) 272 bootcfg_info.def = cmenu - 1; 273 274 return 0; 275 } 276