util/nvramtool/input_file.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include "common.h"
   4 #include "input_file.h"
   5 #include "layout.h"
   6 #include "cmos_ops.h"
   7 #include "cmos_lowlevel.h"
   8 #include "reg_expr.h"
   9
  10 static int get_input_file_line(FILE * f, char line[], int line_buf_size);
  11 static unsigned long long try_prepare_cmos_write(const cmos_entry_t * e,
  12                                                  const char value_str[]);
  13
  14 /* matches either a blank line or a comment line */
  15 static const char blank_or_comment_regex[] =
  16     /* a blank line */
  17     "(^[[:space:]]+$)" "|"      /* or ... */
  18     /* a line consisting of: optional whitespace followed by */
  19     "(^[[:space:]]*"
  20     /* a '#' character and optionally, additional characters */
  21     "#.*$)";
  22
  23 /* matches an assignment line */
  24 const char assignment_regex[] =
  25     /* optional whitespace */
  26     "^[[:space:]]*"
  27     /* followed by a coreboot parameter name */
  28     "([^[:space:]]+)"
  29     /* followed by optional whitespace */
  30     "[[:space:]]*"
  31     /* followed by an '=' character */
  32     "="
  33     /* followed by optional whitespace */
  34     "[[:space:]]*"
  35     /* followed by a value that may contain embedded whitespace */
  36     "([^[:space:]]+([[:space:]]+[^[:space:]]+)*)+"
  37     /* followed by optional whitespace */
  38     "[[:space:]]*$";
  39
  40 static int line_num;
  41
  42 /****************************************************************************
  43  * process_input_file
  44  *
  45  * Read the contents of file 'f' and return a pointer to a list of pending
  46  * write operations.  Perform sanity checking on all write operations and
  47  * exit with an error message if there is a problem.
  48  ****************************************************************************/
  49 cmos_write_t *process_input_file(FILE * f)
  50 {
  51         static const int LINE_BUF_SIZE = 256;
  52         static const size_t N_MATCHES = 4;
  53         char line[LINE_BUF_SIZE];
  54         const char *name, *value;
  55         cmos_write_t *list, *item, **p;
  56         regex_t blank_or_comment, assignment;
  57         regmatch_t match[N_MATCHES];
  58         const cmos_entry_t *e;
  59
  60         list = NULL;
  61         p = &list;
  62
  63         compile_reg_expr(REG_EXTENDED | REG_NEWLINE, blank_or_comment_regex, &blank_or_comment);
  64         compile_reg_expr(REG_EXTENDED | REG_NEWLINE, assignment_regex, &assignment);
  65
  66         /* each iteration processes one line from input file */
  67         for (line_num = 1; get_input_file_line(f, line, LINE_BUF_SIZE) == OK; line_num++) {     /* skip comments and blank lines */
  68                 if (!regexec(&blank_or_comment, line, 0, NULL, 0))
  69                         continue;
  70
  71                 /* Is this a valid assignment line?  If not, then it's a syntax
  72                  * error.
  73                  */
  74                 if (regexec(&assignment, line, N_MATCHES, match, 0)) {
  75                         fprintf(stderr,
  76                                 "%s: Syntax error on line %d of input file.\n",
  77                                 prog_name, line_num);
  78                         exit(1);
  79                 }
  80
  81                 /* OK, we found an assignment.  Break the line into substrings
  82                  * representing the lefthand and righthand sides of the assignment.
  83                  */
  84                 line[match[1].rm_eo] = '\0';
  85                 line[match[2].rm_eo] = '\0';
  86                 name = &line[match[1].rm_so];
  87                 value = &line[match[2].rm_so];
  88
  89                 /* now look up the coreboot parameter name */
  90                 if (is_checksum_name(name)
  91                     || (e = find_cmos_entry(name)) == NULL) {
  92                         fprintf(stderr,
  93                                 "%s: Error on line %d of input file: CMOS parameter "
  94                                 "%s not found.\n", prog_name, line_num, name);
  95                         exit(1);
  96                 }
  97
  98                 /* At this point, we figure out what numeric value needs to be written
  99                  * to which location.  At the same time, we perform sanity checking on
 100                  * the write operation.
 101                  */
 102
 103                 if ((item = (cmos_write_t *) malloc(sizeof(*item))) == NULL)
 104                         out_of_memory();
 105
 106                 item->bit = e->bit;
 107                 item->length = e->length;
 108                 item->config = e->config;
 109                 item->value = try_prepare_cmos_write(e, value);
 110
 111                 /* Append write operation to pending write list. */
 112                 item->next = NULL;
 113                 *p = item;
 114                 p = &item->next;
 115         }
 116
 117         regfree(&blank_or_comment);
 118         regfree(&assignment);
 119         return list;
 120 }
 121
 122 /****************************************************************************
 123  * do_cmos_writes
 124  *
 125  * 'list' is a linked list of pending CMOS write operations that have passed
 126  * all sanity checks.  Perform all write operations, destroying the list as
 127  * we go.
 128  ****************************************************************************/
 129 void do_cmos_writes(cmos_write_t * list)
 130 {
 131         cmos_write_t *item;
 132
 133         set_iopl(3);
 134
 135         while (list != NULL) {
 136                 cmos_entry_t e;
 137                 item = list;
 138                 e.bit = item->bit;
 139                 e.length = item->length;
 140                 e.config = item->config;
 141                 list = item->next;
 142                 cmos_write(&e, item->value);
 143                 free(item);
 144         }
 145
 146         cmos_checksum_write(cmos_checksum_compute());
 147         set_iopl(0);
 148 }
 149
 150 /****************************************************************************
 151  * get_input_file_line
 152  *
 153  * Get a line of input from file 'f'.  Store result in 'line' which is an
 154  * array of 'line_buf_size' bytes.  Return OK on success or an error code on
 155  * error.
 156  ****************************************************************************/
 157 static int get_input_file_line(FILE * f, char line[], int line_buf_size)
 158 {
 159         switch (get_line_from_file(f, line, line_buf_size)) {
 160         case OK:
 161                 return OK;
 162
 163         case LINE_EOF:
 164                 return LINE_EOF;
 165
 166         case LINE_TOO_LONG:
 167                 fprintf(stderr,
 168                         "%s: Error on line %d of input file: Maximum line "
 169                         "length exceeded.  Max is %d characters.\n", prog_name,
 170                         line_num, line_buf_size - 2);
 171                 break;
 172
 173         default:
 174                 BUG();
 175         }
 176
 177         exit(1);
 178         return 1;               /* keep compiler happy */
 179 }
 180
 181 /****************************************************************************
 182  * try_prepare_cmos_write
 183  *
 184  * Attempt to convert 'value_str' to an integer representation for storage in
 185  * CMOS memory.  On success, return the converted value.  On error, exit with
 186  * an error message.
 187  ****************************************************************************/
 188 static unsigned long long try_prepare_cmos_write(const cmos_entry_t * e,
 189                                                  const char value_str[])
 190 {
 191         unsigned long long value;
 192
 193         switch (prepare_cmos_write(e, value_str, &value)) {
 194         case OK:
 195                 return value;
 196
 197         case CMOS_OP_BAD_ENUM_VALUE:
 198                 fprintf(stderr,
 199                         "%s: Error on line %d of input file: Bad value for "
 200                         "parameter %s.", prog_name, line_num, e->name);
 201                 break;
 202
 203         case CMOS_OP_NEGATIVE_INT:
 204                 fprintf(stderr,
 205                         "%s: Error on line %d of input file: This program "
 206                         "does not support assignment of negative numbers to "
 207                         "coreboot parameters.", prog_name, line_num);
 208                 break;
 209
 210         case CMOS_OP_INVALID_INT:
 211                 fprintf(stderr,
 212                         "%s: Error on line %d of input file: %s is not a "
 213                         "valid integer.", prog_name, line_num, value_str);
 214                 break;
 215
 216         case CMOS_OP_RESERVED:
 217                 fprintf(stderr,
 218                         "%s: Error on line %d of input file: Can not modify "
 219                         "reserved coreboot parameter %s.", prog_name, line_num,
 220                         e->name);
 221                 break;
 222
 223         case CMOS_OP_VALUE_TOO_WIDE:
 224                 fprintf(stderr,
 225                         "%s: Error on line %d of input file: Can not write "
 226                         "value %s to CMOS parameter %s that is only %d bits wide.",
 227                         prog_name, line_num, value_str, e->name, e->length);
 228                 break;
 229
 230         case CMOS_OP_NO_MATCHING_ENUM:
 231                 fprintf(stderr,
 232                         "%s: coreboot parameter %s has no matching enums.",
 233                         prog_name, e->name);
 234                 break;
 235
 236         case CMOS_AREA_OUT_OF_RANGE:
 237                 fprintf(stderr,
 238                         "%s: The CMOS area specified by the layout info for "
 239                         "coreboot parameter %s is out of range.", prog_name,
 240                         e->name);
 241                 break;
 242
 243         case CMOS_AREA_OVERLAPS_RTC:
 244                 fprintf(stderr,
 245                         "%s: The CMOS area specified by the layout info for "
 246                         "coreboot parameter %s overlaps the realtime clock area.",
 247                         prog_name, e->name);
 248                 break;
 249
 250         case CMOS_AREA_TOO_WIDE:
 251                 fprintf(stderr,
 252                         "%s: The CMOS area specified by the layout info for "
 253                         "coreboot parameter %s is too wide.", prog_name,
 254                         e->name);
 255                 break;
 256
 257         default:
 258                 fprintf(stderr,
 259                         "%s: Unknown error encountered while attempting to modify "
 260                         "coreboot parameter %s.", prog_name, e->name);
 261                 break;
 262         }
 263
 264         fprintf(stderr, "  No CMOS writes performed.\n");
 265         exit(1);
 266         return 0;               /* keep compiler happy */
 267 }