util/smmstoretool/storage.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 #include "storage.h"
   4
   5 #include <assert.h>
   6 #include <stdio.h>
   7
   8 #include "commonlib/bsd/compiler.h"
   9 #include "fmap.h"
  10
  11 #include "fv.h"
  12 #include "utils.h"
  13
  14 bool storage_open(const char store_file[], struct storage_t *storage, bool rw)
  15 {
  16         storage->rw = rw;
  17
  18         storage->file = map_file(store_file, rw);
  19         if (storage->file.start == NULL) {
  20                 fprintf(stderr, "Failed to load smm-store-file \"%s\"\n",
  21                         store_file);
  22                 return false;
  23         }
  24
  25         /* If we won't find FMAP with SMMSTORE, use the whole file, but fail if
  26          * FMAP is there without SMMSTORE. */
  27         storage->region = storage->file;
  28
  29         long fmap_offset = fmap_find(storage->file.start, storage->file.length);
  30         if (fmap_offset >= 0) {
  31                 struct fmap *fmap = (void *)(storage->file.start + fmap_offset);
  32                 const struct fmap_area *area = fmap_find_area(fmap, "SMMSTORE");
  33                 if (area == NULL) {
  34                         fprintf(stderr,
  35                                 "Found FMAP without SMMSTORE in \"%s\"\n",
  36                                 store_file);
  37                         return false;
  38                 }
  39
  40                 storage->region.start += area->offset;
  41                 storage->region.length = area->size;
  42         }
  43
  44         bool auth_vars;
  45         if (!fv_parse(storage->region, &storage->store_area, &auth_vars)) {
  46                 if (!rw) {
  47                         fprintf(stderr,
  48                                 "Failed to find variable store in \"%s\"\n",
  49                                 store_file);
  50                         goto error;
  51                 }
  52
  53                 if (!fv_init(storage->region)) {
  54                         fprintf(stderr,
  55                                 "Failed to create variable store in \"%s\"\n",
  56                                 store_file);
  57                         goto error;
  58                 }
  59
  60                 if (!fv_parse(storage->region, &storage->store_area, &auth_vars)) {
  61                         fprintf(stderr,
  62                                 "Failed to parse newly formatted store in \"%s\"\n",
  63                                 store_file);
  64                         goto error;
  65                 }
  66
  67                 fprintf(stderr,
  68                         "Successfully created variable store in \"%s\"\n",
  69                         store_file);
  70         }
  71
  72         storage->vs = vs_load(storage->store_area, auth_vars);
  73         return true;
  74
  75 error:
  76         unmap_file(storage->file);
  77         return false;
  78 }
  79
  80 bool storage_write_back(struct storage_t *storage)
  81 {
  82         assert(storage->rw && "Only RW storage can be updated.");
  83
  84         bool success = vs_store(&storage->vs, storage->store_area);
  85         if (!success)
  86                 fprintf(stderr, "Failed to update variable store\n");
  87         storage_drop(storage);
  88         return success;
  89 }
  90
  91 void storage_drop(struct storage_t *storage)
  92 {
  93         unmap_file(storage->file);
  94         vs_free(&storage->vs);
  95 }