discover/grub2: Implement load_env

[petitboot] / discover / grub2 / env.c

diff --git a/discover/grub2/env.c b/discover/grub2/env.c
new file mode 100644 (file)
index 0000000..e28c9fe
--- /dev/null
+++ b/discover/grub2/env.c
@@ -0,0 +1,107 @@
+
+#include <stdio.h>
+#include <string.h>
+
+#include <log/log.h>
+#include <types/types.h>
+#include <talloc/talloc.h>
+#include <array-size/array-size.h>
+
+#include <discover/parser.h>
+#include <discover/file.h>
+
+#include "grub2.h"
+
+static const char *default_envfile = "grubenv";
+static const char *signature = "# GRUB Environment Block\n";
+
+static int parse_buf_to_env(struct grub2_script *script, void *buf, int len)
+{
+       char *tmp, *line, *sep;
+       int siglen;
+
+       siglen = strlen(signature);
+
+       if (len < siglen) {
+               pb_log("grub environment block too small\n");
+               return -1;
+       }
+
+       if (memcmp(buf, signature, siglen)) {
+               pb_log("grub environment block has invalid signature\n");
+               return -1;
+       }
+
+       buf += siglen;
+
+       for (line = strtok_r(buf, "\n", &tmp); line;
+                               line = strtok_r(NULL, "\n", &tmp)) {
+
+               if (*line == '#')
+                       continue;
+
+               sep = strchr(line, '=');
+               if (!sep)
+                       continue;
+               if (sep == line)
+                       continue;
+
+               *sep = '\0';
+               script_env_set(script, line, sep + 1);
+       }
+
+       return 0;
+}
+
+int builtin_load_env(struct grub2_script *script,
+               void *data __attribute__((unused)),
+               int argc, char *argv[]);
+
+int builtin_load_env(struct grub2_script *script,
+               void *data __attribute__((unused)),
+               int argc, char *argv[])
+{
+       struct discover_device *dev = script->ctx->device;
+       const char *envfile;
+       char *buf, *envpath;
+       int rc, len;
+
+       /* we only support local filesystems */
+       if (!dev->mounted) {
+               pb_log("load_env: can't load from a non-mounted device (%s)\n",
+                               dev->device->id);
+               return -1;
+       }
+
+       if (argc == 3 && !strcmp(argv[1], "-f"))
+               envfile = argv[2];
+       else
+               envfile = default_envfile;
+
+       envpath = talloc_asprintf(script, "%s/%s",
+                               script_env_get(script, "prefix") ? : "",
+                               envfile);
+
+       rc = parser_request_file(script->ctx, dev, envpath, &buf, &len);
+
+       if (!rc)
+               rc = parse_buf_to_env(script, buf, len);
+
+       talloc_free(buf);
+
+       return 0;
+}
+
+int builtin_save_env(struct grub2_script *script,
+               void *data __attribute__((unused)),
+               int argc, char *argv[]);
+
+int builtin_save_env(struct grub2_script *script __attribute__((unused)),
+               void *data __attribute__((unused)),
+               int argc __attribute__((unused)),
+               char *argv[] __attribute__((unused)))
+{
+       /* todo: save */
+       return 0;
+}
+