]> git.ozlabs.org Git - petitboot/blobdiff - discover/grub2/script.c
discover/grub2: Add initial command execution
[petitboot] / discover / grub2 / script.c
index 067b0c9440857f48b0ce4c0ad84c3e3e559484ac..fce4f0afde487f8fc623ccc2ab519bf2d4ecee0e 100644 (file)
@@ -1,62 +1,72 @@
 
 #include <sys/types.h>
-#include <regex.h>
 #include <string.h>
 
 #include <talloc/talloc.h>
 
 #include "grub2.h"
 
+#define to_stmt_simple(stmt) \
+       container_of(stmt, struct grub2_statement_simple, st)
+#define to_stmt_if(stmt) \
+       container_of(stmt, struct grub2_statement_if, st)
+#define to_stmt_menuentry(stmt) \
+       container_of(stmt, struct grub2_statement_menuentry, st)
+
 struct env_entry {
        const char              *name;
        const char              *value;
        struct list_item        list;
 };
 
-static const char *env_lookup(struct grub2_script *script,
-               const char *name, int name_len)
+const char *script_env_get(struct grub2_script *script, const char *name)
 {
        struct env_entry *entry;
-       const char *str;
-
-       str = talloc_strndup(script, name, name_len);
-       printf("%s: %s\n", __func__, str);
 
        list_for_each_entry(&script->environment, entry, list)
-               if (!strncmp(entry->name, name, name_len))
+               if (!strcmp(entry->name, name))
                        return entry->value;
 
        return NULL;
 }
 
-static bool expand_word(struct grub2_script *script, struct grub2_word *word)
+void script_env_set(struct grub2_script *script,
+               const char *name, const char *value)
 {
-       const char *val, *src;
-       char *dest = NULL;
-       regmatch_t match;
-       int n;
+       struct env_entry *e, *entry = NULL;
+
+       list_for_each_entry(&script->environment, e, list) {
+               if (!strcmp(e->name, name)) {
+                       entry = e;
+                       break;
+               }
+       }
 
-       src = word->text;
+       if (!entry) {
+               entry = talloc(script, struct env_entry);
+               entry->name = name;
+               list_add(&script->environment, &entry->list);
+       }
+
+       entry->value = value;
+}
 
-       n = regexec(&script->var_re, src, 1, &match, 0);
-       if (n == 0)
-               return false;
+static bool expand_var(struct grub2_script *script, struct grub2_word *word)
+{
+       const char *val;
 
-       val = env_lookup(script, src + match.rm_so,
-                                match.rm_eo - match.rm_so);
-       if (val)
+       val = script_env_get(script, word->var.name);
+       if (!val)
                val = "";
 
-       dest = talloc_strndup(script, src, match.rm_so);
-       dest = talloc_asprintf_append(dest, "%s%s", val, src + match.rm_eo);
+       word->type = GRUB2_WORD_TEXT;
+       word->text = talloc_strdup(script, val);
 
-       word->text = dest;
        return true;
 }
 
-/* iterate through the words in an argv, looking for expansions. If a
- * word is marked with expand == true, then we process any variable
- * substitutions.
+/* iterate through the words in an argv_list, looking for GRUB2_WORD_VAR
+ * expansions.
  *
  * Once that's done, we may (if split == true) have to split the word to create
  * new argv items
@@ -64,45 +74,157 @@ static bool expand_word(struct grub2_script *script, struct grub2_word *word)
 static void process_expansions(struct grub2_script *script,
                struct grub2_argv *argv)
 {
-       struct grub2_word *word;
+       struct grub2_word *top_word, *word;
+       int i;
 
-       list_for_each_entry(&argv->words, word, argv_list) {
-               if (!word->expand)
-                       continue;
+       argv->argc = 0;
 
-               expand_word(script, word);
+       list_for_each_entry(&argv->words, top_word, argv_list) {
+               argv->argc++;
+
+               /* expand vars and squash the list of words into the top struct.
+                * todo: splitting
+                */
+               for (word = top_word; word; word = word->next) {
+                       if (word->type == GRUB2_WORD_VAR)
+                               expand_var(script, word);
+
+                       if (word == top_word)
+                               continue;
+
+                       top_word->text = talloc_asprintf_append(top_word->text,
+                                       "%s", word->text);
+               }
+               top_word->next = NULL;
        }
+
+       argv->argv = talloc_array(script, char *, argv->argc);
+       i = 0;
+
+       list_for_each_entry(&argv->words, word, argv_list)
+               argv->argv[i++] = word->text;
 }
 
-static int script_destroy(void *p)
+int statements_execute(struct grub2_script *script,
+               struct grub2_statements *stmts)
 {
-       struct grub2_script *script = p;
-       regfree(&script->var_re);
-       return 0;
+       struct grub2_statement *stmt;
+       int rc = 0;
+
+       list_for_each_entry(&stmts->list, stmt, list) {
+               if (stmt->exec)
+                       rc = stmt->exec(script, stmt);
+       }
+       return rc;
 }
 
-struct grub2_script *create_script(void *ctx)
+int statement_simple_execute(struct grub2_script *script,
+               struct grub2_statement *statement)
 {
-       struct grub2_script *script;
+       struct grub2_statement_simple *st = to_stmt_simple(statement);
+       struct grub2_command *cmd;
        int rc;
 
-       script = talloc(ctx, struct grub2_script);
+       if (!st->argv)
+               return 0;
+
+       process_expansions(script, st->argv);
 
-       rc = regcomp(&script->var_re,
-               "\\$\\{?([[:alpha:]][_[:alnum:]]*|[0-9]|[\\?@\\*#])\\}?",
-                       REG_EXTENDED);
-       if (rc) {
-               char err[200];
-               regerror(rc, &script->var_re, err, sizeof(err));
-               fprintf(stderr, "RE error %d: %s\n", rc, err);
-               talloc_free(script);
-               return NULL;
+       if (!st->argv->argc)
+               return 0;
 
+       cmd = script_lookup_command(script, st->argv->argv[0]);
+       if (!cmd) {
+               fprintf(stderr, "undefined command '%s'\n", st->argv->argv[0]);
+               return 0;
        }
-       talloc_set_destructor(script, script_destroy);
+
+       rc = cmd->exec(script, st->argv->argc, st->argv->argv);
+
+       return rc;
+}
+
+int statement_if_execute(struct grub2_script *script,
+               struct grub2_statement *statement)
+{
+       struct grub2_statement_if *st = to_stmt_if(statement);
+       struct grub2_statements *case_stmts;
+       int rc;
+
+       rc = st->condition->exec(script, st->condition);
+
+       if (rc == 0)
+               case_stmts = st->true_case;
+       else
+               case_stmts = st->false_case;
+
+       if (case_stmts)
+               statements_execute(script, case_stmts);
+       else
+               rc = 0;
+
+       return rc;
+}
+
+int statement_menuentry_execute(struct grub2_script *script,
+               struct grub2_statement *statement)
+{
+       struct grub2_statement_menuentry *st = to_stmt_menuentry(statement);
+
+       process_expansions(script, st->argv);
+       statements_execute(script, st->statements);
+
+       return 0;
+}
+
+static void init_env(struct grub2_script *script)
+{
+       struct env_entry *env;
 
        list_init(&script->environment);
 
+       env = talloc(script, struct env_entry);
+       env->name = talloc_strdup(env, "prefix");
+       env->value = talloc_strdup(env, "/");
+
+       list_add(&script->environment, &env->list);
+}
+
+struct grub2_command *script_lookup_command(struct grub2_script *script,
+               const char *name)
+{
+       struct grub2_command *command;
+
+       list_for_each_entry(&script->commands, command, list) {
+               if (!strcmp(command->name, name))
+                       return command;
+       }
+
+       return NULL;
+}
+
+void script_register_command(struct grub2_script *script,
+               struct grub2_command *command)
+{
+       list_add(&script->commands, &command->list);
+}
+
+
+void script_execute(struct grub2_script *script)
+{
+       statements_execute(script, script->statements);
+}
+
+struct grub2_script *create_script(void *ctx)
+{
+       struct grub2_script *script;
+
+       script = talloc(ctx, struct grub2_script);
+
+       init_env(script);
+       list_init(&script->commands);
+       register_builtins(script);
+
        return script;
 }