git.ozlabs.org Git - petitboot/blob - discover/grub2/env.c

   1
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 #include <log/log.h>
   6 #include <types/types.h>
   7 #include <talloc/talloc.h>
   8 #include <array-size/array-size.h>
   9
  10 #include <discover/parser.h>
  11 #include <discover/file.h>
  12
  13 #include "grub2.h"
  14
  15 static const char *default_envfile = "grubenv";
  16 static const char *signature = "# GRUB Environment Block\n";
  17
  18 static int parse_buf_to_env(struct grub2_script *script, void *buf, int len)
  19 {
  20         char *tmp, *line, *sep;
  21         int siglen;
  22
  23         siglen = strlen(signature);
  24
  25         if (len < siglen) {
  26                 pb_log("grub environment block too small\n");
  27                 return -1;
  28         }
  29
  30         if (memcmp(buf, signature, siglen)) {
  31                 pb_log("grub environment block has invalid signature\n");
  32                 return -1;
  33         }
  34
  35         buf += siglen;
  36
  37         for (line = strtok_r(buf, "\n", &tmp); line;
  38                                 line = strtok_r(NULL, "\n", &tmp)) {
  39
  40                 if (*line == '#')
  41                         continue;
  42
  43                 sep = strchr(line, '=');
  44                 if (!sep)
  45                         continue;
  46                 if (sep == line)
  47                         continue;
  48
  49                 *sep = '\0';
  50                 script_env_set(script, line, sep + 1);
  51         }
  52
  53         return 0;
  54 }
  55
  56 int builtin_load_env(struct grub2_script *script,
  57                 void *data __attribute__((unused)),
  58                 int argc, char *argv[]);
  59
  60 int builtin_load_env(struct grub2_script *script,
  61                 void *data __attribute__((unused)),
  62                 int argc, char *argv[])
  63 {
  64         struct discover_device *dev = script->ctx->device;
  65         const char *envfile;
  66         char *buf, *envpath;
  67         int rc, len;
  68
  69         /* we only support local filesystems */
  70         if (!dev->mounted) {
  71                 pb_log("load_env: can't load from a non-mounted device (%s)\n",
  72                                 dev->device->id);
  73                 return -1;
  74         }
  75
  76         if (argc == 3 && !strcmp(argv[1], "-f"))
  77                 envfile = argv[2];
  78         else
  79                 envfile = default_envfile;
  80
  81         envpath = talloc_asprintf(script, "%s/%s",
  82                                 script_env_get(script, "prefix") ? : "",
  83                                 envfile);
  84
  85         rc = parser_request_file(script->ctx, dev, envpath, &buf, &len);
  86
  87         if (!rc)
  88                 rc = parse_buf_to_env(script, buf, len);
  89
  90         talloc_free(buf);
  91
  92         return 0;
  93 }
  94
  95 int builtin_save_env(struct grub2_script *script,
  96                 void *data __attribute__((unused)),
  97                 int argc, char *argv[]);
  98
  99 int builtin_save_env(struct grub2_script *script __attribute__((unused)),
 100                 void *data __attribute__((unused)),
 101                 int argc __attribute__((unused)),
 102                 char *argv[] __attribute__((unused)))
 103 {
 104         /* todo: save */
 105         return 0;
 106 }
 107