sys/lib/libsa/bootcfg.c

   1 /*      $NetBSD: bootcfg.c,v 1.2 2014/08/10 07:40:49 isaki 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 void
  98 perform_bootcfg(const char *conf, bootcfg_command command, const off_t maxsz)
  99 {
 100         char *bc, *c;
 101         int cmenu, cbanner, len;
 102         int fd, err, off;
 103         struct stat st;
 104         char *next, *key, *value, *v2;
 105
 106         /* clear bootcfg structure */
 107         memset(&bootcfg_info, 0, sizeof(bootcfg_info));
 108
 109         /* set default timeout */
 110         bootcfg_info.timeout = DEFAULT_TIMEOUT;
 111
 112         /* automatically switch between letter and numbers on menu */
 113         bootcfg_info.menuformat = DEFAULT_FORMAT;
 114
 115         fd = open(conf, 0);
 116         if (fd < 0)
 117                 return;
 118
 119         err = fstat(fd, &st);
 120         if (err == -1) {
 121                 close(fd);
 122                 return;
 123         }
 124
 125         /* if a maximum size is being requested for the boot.cfg enforce it. */
 126         if (0 < maxsz && st.st_size > maxsz) {
 127                 close(fd);
 128                 return;
 129         }
 130
 131         bc = alloc(st.st_size + 1);
 132         if (bc == NULL) {
 133                 printf("Could not allocate memory for boot configuration\n");
 134                 close(fd);
 135                 return;
 136         }
 137
 138         /*
 139          * XXX original code, assumes error or eof return from read()
 140          *     results in the entire boot.cfg being buffered.
 141          *     - should bail out on read() failing.
 142          *     - assumption is made that the file size doesn't change between
 143          *       fstat() and read()ing.  probably safe in this context
 144          *       arguably should check that reading the file won't overflow
 145          *       the storage anyway.
 146          */
 147         off = 0;
 148         do {
 149                 len = read(fd, bc + off, 1024);
 150                 if (len <= 0)
 151                         break;
 152                 off += len;
 153         } while (len > 0);
 154         bc[off] = '\0';
 155
 156         close(fd);
 157
 158         /* bc is now assumed to contain the whole boot.cfg file (see above) */
 159
 160         cmenu = 0;
 161         cbanner = 0;
 162         for (c = bc; *c; c = next) {
 163                 key = c;
 164                 /* find end of line */
 165                 for (; *c && *c != '\n'; c++)
 166                         /* zero terminate line on start of comment */
 167                         if (*c == '#')
 168                                 *c = 0;
 169                 /* zero terminate line */
 170                 if (*(next = c))
 171                         *next++ = 0;
 172                 /* Look for = separator between key and value */
 173                 for (c = key; *c && *c != '='; c++)
 174                         continue;
 175                 /* Ignore lines with no key=value pair */
 176                 if (*c == '\0')
 177                         continue;
 178
 179                 /* zero terminate key which points to keyword */
 180                 *c++ = 0;
 181                 value = c;
 182                 /* Look for end of line (or file) and zero terminate value */
 183                 for (; *c && *c != '\n'; c++)
 184                         continue;
 185                 *c = 0;
 186
 187                 if (!strncmp(key, "menu", 4)) {
 188                         /*
 189                          * Parse "menu=<description>:<command>".  If the
 190                          * description is empty ("menu=:<command>)",
 191                          * then re-use the command as the description.
 192                          * Note that the command may contain embedded
 193                          * colons.
 194                          */
 195                         if (cmenu >= BOOTCFG_MAXMENU)
 196                                 continue;
 197                         bootcfg_info.desc[cmenu] = value;
 198                         for (v2 = value; *v2 && *v2 != ':'; v2++)
 199                                 continue;
 200                         if (*v2) {
 201                                 *v2++ = 0;
 202                                 bootcfg_info.command[cmenu] = v2;
 203                                 if (! *value)
 204                                         bootcfg_info.desc[cmenu] = v2;
 205                                 cmenu++;
 206                         } else {
 207                                 /* No delimiter means invalid line */
 208                                 bootcfg_info.desc[cmenu] = NULL;
 209                         }
 210                 } else if (!strncmp(key, "banner", 6)) {
 211                         if (cbanner < BOOTCFG_MAXBANNER)
 212                                 bootcfg_info.banner[cbanner++] = value;
 213                 } else if (!strncmp(key, "timeout", 7)) {
 214                         if (!isdigit(*value))
 215                                 bootcfg_info.timeout = -1;
 216                         else
 217                                 bootcfg_info.timeout = atoi(value);
 218                 } else if (!strncmp(key, "default", 7)) {
 219                         bootcfg_info.def = atoi(value) - 1;
 220                 } else if (!strncmp(key, "consdev", 7)) {
 221                         bootcfg_info.consdev = value;
 222                 } else if (!strncmp(key, BOOTCFG_CMD_LOAD, 4)) {
 223                         command(BOOTCFG_CMD_LOAD, value);
 224                 } else if (!strncmp(key, "format", 6)) {
 225                         printf("value:%c\n", *value);
 226                         switch (*value) {
 227                         case 'a':
 228                         case 'A':
 229                                 bootcfg_info.menuformat = MENUFORMAT_AUTO;
 230                                 break;
 231
 232                         case 'n':
 233                         case 'N':
 234                         case 'd':
 235                         case 'D':
 236                                 bootcfg_info.menuformat = MENUFORMAT_NUMBER;
 237                                 break;
 238
 239                         case 'l':
 240                         case 'L':
 241                                 bootcfg_info.menuformat = MENUFORMAT_LETTER;
 242                                 break;
 243                         }
 244                 } else if (!strncmp(key, "clear", 5)) {
 245                         bootcfg_info.clear = !!atoi(value);
 246                 } else if (!strncmp(key, BOOTCFG_CMD_USERCONF, 8)) {
 247                         command(BOOTCFG_CMD_USERCONF, value);
 248                 } else {
 249                         command(key, value);
 250                 }
 251         }
 252
 253         switch (bootcfg_info.menuformat) {
 254         case MENUFORMAT_AUTO:
 255                 if (cmenu > 9 && bootcfg_info.timeout > 0)
 256                         bootcfg_info.menuformat = MENUFORMAT_LETTER;
 257                 else
 258                         bootcfg_info.menuformat = MENUFORMAT_NUMBER;
 259                 break;
 260
 261         case MENUFORMAT_NUMBER:
 262                 if (cmenu > 9 && bootcfg_info.timeout > 0)
 263                         cmenu = 9;
 264                 break;
 265         }
 266
 267         bootcfg_info.nummenu = cmenu;
 268         if (bootcfg_info.def < 0)
 269                 bootcfg_info.def = 0;
 270         if (bootcfg_info.def >= cmenu)
 271                 bootcfg_info.def = cmenu - 1;
 272 }