X-Git-Url: http://git.ozlabs.org/?p=petitboot;a=blobdiff_plain;f=discover%2Fgrub2%2Fscript.c;h=0618297784499f5d60ac0e597e03ff8602ee05d7;hp=67b4b7801f8717d51df2cdbfc68edab97988f082;hb=37bff93c8b0a71432613f41f2319dc073ca64619;hpb=882f61e8eb44ec9f9becc32328667c65f364d066

diff --git a/discover/grub2/script.c b/discover/grub2/script.c
index 67b4b78..0618297 100644
--- a/discover/grub2/script.c
+++ b/discover/grub2/script.c
@@ -1,7 +1,9 @@
 
 #include <sys/types.h>
 #include <string.h>
+#include <stdlib.h>
 
+#include <log/log.h>
 #include <types/types.h>
 #include <talloc/talloc.h>
 
@@ -9,18 +11,22 @@
 
 #define to_stmt_simple(stmt) \
 	container_of(stmt, struct grub2_statement_simple, st)
+#define to_stmt_block(stmt) \
+	container_of(stmt, struct grub2_statement_block, 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)
 #define to_stmt_function(stmt) \
 	container_of(stmt, struct grub2_statement_function, st)
+#define to_stmt_for(stmt) \
+	container_of(stmt, struct grub2_statement_for, st)
 #define to_stmt_conditional(stmt) \
 	container_of(stmt, struct grub2_statement_conditional, st)
 
 struct env_entry {
-	const char		*name;
-	const char		*value;
+	char			*name;
+	char			*value;
 	struct list_item	list;
 };
 
@@ -31,6 +37,8 @@ struct grub2_symtab_entry {
 	struct list_item	list;
 };
 
+static const char *default_prefix = "/boot/grub";
+
 static struct grub2_symtab_entry *script_lookup_function(
 		struct grub2_script *script, const char *name)
 {
@@ -69,14 +77,16 @@ void script_env_set(struct grub2_script *script,
 
 	if (!entry) {
 		entry = talloc(script, struct env_entry);
-		entry->name = name;
+		entry->name = talloc_strdup(entry, name);
 		list_add(&script->environment, &entry->list);
+	} else {
+		talloc_free(entry->value);
 	}
 
-	entry->value = value;
+	entry->value = talloc_strdup(entry, value);
 }
 
-static bool expand_var(struct grub2_script *script, struct grub2_word *word)
+static char *expand_var(struct grub2_script *script, struct grub2_word *word)
 {
 	const char *val;
 
@@ -84,9 +94,7 @@ static bool expand_var(struct grub2_script *script, struct grub2_word *word)
 	if (!val)
 		val = "";
 
-	word->text = talloc_strdup(script, val);
-
-	return true;
+	return talloc_strdup(script, val);
 }
 
 static bool is_delim(char c)
@@ -94,125 +102,133 @@ static bool is_delim(char c)
 	return c == ' ' || c == '\t';
 }
 
-/* For non-double-quoted variable expansions, we may need to split the
- * variable's value into multiple argv items.
- *
- * This function sets the word->text to the initial set of non-delimiter chars
- * in the expanded var value. We then skip any delimiter chars, and (if
- * required), create the new argv item with the remaining text, and
- * add it to the argv list, after top_word.
- */
-static void process_split(struct grub2_script *script,
-		struct grub2_word *top_word,
-		struct grub2_word *word)
+static bool option_is_default(struct grub2_script *script,
+		struct discover_boot_option *opt, const char *id)
 {
-	int i, len, delim_start = -1, delim_end = -1;
-	struct grub2_word *new_word;
-	char *remainder;
+	unsigned int default_idx;
+	const char *var;
+	char *end;
 
-	len = strlen(word->text);
+	var = script_env_get(script, "default");
+	if (!var)
+		return false;
 
-	/* Scan our string for the start of a delim (delim_start), and the
-	 * start of any new text (delim_end). */
-	for (i = 0; i < len; i++) {
-		if (is_delim(word->text[i])) {
-			if (delim_start == -1)
-				delim_start = i;
-		} else if (delim_start != -1) {
-			delim_end = i;
-			break;
-		}
+	default_idx = strtoul(var, &end, 10);
+	if (end != var && *end == '\0')
+		return default_idx == script->n_options;
+
+	/* if we don't have an explicit id for this option, fall back to
+	 * the name */
+	if (!id)
+		id = opt->option->name;
+
+	return !strcmp(id, var);
+}
+
+static void append_text_to_current_arg(struct grub2_argv *argv,
+		const char *text, int len)
+{
+	char *cur = argv->argv[argv->argc - 1];
+
+	if (cur) {
+		int curlen = strlen(cur);
+		cur = talloc_realloc(argv->argv, cur, char, len + curlen + 1);
+		memcpy(cur + curlen, text, len);
+		cur[len + curlen] = '\0';
+
+	} else {
+		cur = talloc_strndup(argv->argv, text, len);
 	}
 
-	/* No delim? nothing to do. The process_expansions loop will
-	 * append this word's text to the top word, if necessary
-	 */
-	if (delim_start == -1)
+	argv->argv[argv->argc-1] = cur;
+}
+
+/* Add a word to the argv array. Depending on the word type, and presence of
+ * delimiter characters, we may add multiple items to the array.
+ */
+static void append_word_to_argv(struct grub2_script *script,
+		struct grub2_argv *argv, struct grub2_word *word)
+{
+	const char *text, *pos;
+	int i, len;
+
+	/* If it's a variable, perform substitution */
+	if (word->type == GRUB2_WORD_VAR)
+		text = expand_var(script, word);
+	else
+		text = word->text;
+
+	len = strlen(text);
+
+	/* If we have no text, we leave the current word as-is. The caller
+	 * has allocated an empty string for the case where this is the
+	 * first text token */
+	if (!len)
 		return;
 
-	/* Set this word's text value to the text before the delimiter.
-	 * this will get appended to the top word
-	 */
-	word->text[delim_start] = '\0';
-
-	/* No trailing text? If there are no following word tokens, we're done.
-	 * Otherwise, we need to start a new argv item with those tokens */
-	if (delim_end == -1) {
-		if (!word->next)
-			return;
-		remainder = "";
-	} else {
-		remainder = word->text + delim_end;
+	/* If we're not splitting, we just add the entire block to the
+	 * current argv item */
+	if (!word->split) {
+		append_text_to_current_arg(argv, text, len);
+		return;
 	}
 
-	new_word = talloc(script, struct grub2_word);
-	new_word->type = GRUB2_WORD_TEXT;
-	/* if there's no trailing text, we know we don't need to re-split */
-	new_word->split = delim_end != -1;
-	new_word->next = word->next;
-	new_word->last = NULL;
-	new_word->text = talloc_strdup(new_word, remainder);
+	/* Scan for delimiters. If we find a word-end boundary, add the word
+	 * to the argv array, and start a new argv item */
+	pos = !is_delim(text[0]) ? text : NULL;
+	for (i = 0; i < len; i++) {
 
-	/* stitch it into the argv list before this word */
-	list_insert_after(&top_word->argv_list,
-			   &new_word->argv_list);
+		/* first delimiter after a word: add the accumulated word to
+		 * argv */
+		if (pos && is_delim(text[i])) {
+			append_text_to_current_arg(argv, pos,
+					text + i - pos);
+			pos = NULL;
+
+		/* first non-delimeter after a delimiter: record the starting
+		 * position, and create another argv item */
+		} else if (!pos && !is_delim(text[i])) {
+			pos = text + i;
+			argv->argc++;
+			argv->argv = talloc_realloc(argv, argv->argv, char *,
+					argv->argc);
+			argv->argv[argv->argc - 1] = NULL;
+		}
+	}
 
-	/* terminate this word */
-	word->next = NULL;
+	/* add remaining word characters */
+	if (pos)
+		append_text_to_current_arg(argv, pos, text + len - pos);
 }
 
-/* iterate through the words in an argv_list, looking for GRUB2_WORD_VAR
+/* Transform an argv word-token list (returned from the parser) into an
+ * expanded argv array (as used by the script execution code). We do this by
+ * iterating 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
  */
 static void process_expansions(struct grub2_script *script,
 		struct grub2_argv *argv)
 {
 	struct grub2_word *top_word, *word;
-	int i;
 
 	argv->argc = 0;
+	argv->argv = NULL;
 
 	list_for_each_entry(&argv->words, top_word, argv_list) {
 		argv->argc++;
-
-		/* expand vars and squash the list of words into the head
-		 * of the argv word list */
-		for (word = top_word; word; word = word->next) {
-
-			/* if it's a variable, perform the substitution */
-			if (word->type == GRUB2_WORD_VAR) {
-				expand_var(script, word);
-				word->type = GRUB2_WORD_TEXT;
-			}
-
-			/* split; this will potentially insert argv
-			 * entries after top_word. */
-			if (word->split)
-				process_split(script, top_word, word);
-
-			/* accumulate word text into the top word, so
-			 * we end up with a shallow tree of argv data */
-			/* todo: don't do this in process_split */
-			if (word != top_word) {
-				top_word->text = talloc_asprintf_append(
-							top_word->text,
-							"%s", word->text);
-			}
-
-
-		}
-		top_word->next = NULL;
+		argv->argv = talloc_realloc(argv, argv->argv, char *,
+				argv->argc);
+		/* because we've parsed a separate word here, we know that
+		 * we need at least an empty string */
+		argv->argv[argv->argc - 1] = talloc_strdup(argv->argv, "");
+
+		for (word = top_word; word; word = word->next)
+			append_word_to_argv(script, argv, word);
 	}
 
-	/* convert the list to an argv array, to pass to the function */
-	argv->argv = talloc_array(script, char *, argv->argc);
-	i = 0;
-
-	list_for_each_entry(&argv->words, word, argv_list)
-		argv->argv[i++] = word->text;
+	/* we may have allocated an extra argv element but not populated it */
+	if (!argv->argv[argv->argc - 1])
+		argv->argc--;
 }
 
 static int statements_execute(struct grub2_script *script,
@@ -233,6 +249,7 @@ int statement_simple_execute(struct grub2_script *script,
 {
 	struct grub2_statement_simple *st = to_stmt_simple(statement);
 	struct grub2_symtab_entry *entry;
+	char *pos;
 	int rc;
 
 	if (!st->argv)
@@ -243,10 +260,21 @@ int statement_simple_execute(struct grub2_script *script,
 	if (!st->argv->argc)
 		return 0;
 
+	/* is this a var=value assignment? */
+	pos = strchr(st->argv->argv[0], '=');
+	if (pos) {
+		char *name, *value;
+		name = st->argv->argv[0];
+		name = talloc_strndup(st, name, pos - name);
+		value = pos + 1;
+		script_env_set(script, name, value);
+		return 0;
+	}
+
 	entry = script_lookup_function(script, st->argv->argv[0]);
 	if (!entry) {
-		fprintf(stderr, "undefined function '%s'\n", st->argv->argv[0]);
-		return 0;
+		pb_log("grub2: undefined function '%s'\n", st->argv->argv[0]);
+		return 1;
 	}
 
 	rc = entry->fn(script, entry->data, st->argv->argc, st->argv->argv);
@@ -254,6 +282,13 @@ int statement_simple_execute(struct grub2_script *script,
 	return rc;
 }
 
+int statement_block_execute(struct grub2_script *script,
+		struct grub2_statement *statement)
+{
+	struct grub2_statement_block *st = to_stmt_block(statement);
+	return statements_execute(script, st->statements);
+}
+
 /* returns 0 if the statement was executed, 1 otherwise */
 static int statement_conditional_execute(struct grub2_script *script,
 		struct grub2_statement *statement, bool *executed)
@@ -275,7 +310,7 @@ int statement_if_execute(struct grub2_script *script,
 	struct grub2_statement_if *st = to_stmt_if(statement);
 	struct grub2_statement *conditional;
 	bool executed;
-	int rc;
+	int rc = 0;
 
 	list_for_each_entry(&st->conditionals->list, conditional, list) {
 		rc = statement_conditional_execute(script,
@@ -295,24 +330,42 @@ int statement_menuentry_execute(struct grub2_script *script,
 {
 	struct grub2_statement_menuentry *st = to_stmt_menuentry(statement);
 	struct discover_boot_option *opt;
+	const char *id = NULL;
+	int i;
 
 	process_expansions(script, st->argv);
 
 	opt = discover_boot_option_create(script->ctx, script->ctx->device);
-	if (st->argv->argc > 0) {
+
+	/* XXX: --options=values need to be parsed properly; this is a simple
+	 * implementation to get --id= working.
+	 */
+	for (i = 1; i < st->argv->argc; ++i) {
+		if (strncmp("--id=", st->argv->argv[i], 5) == 0) {
+			id = st->argv->argv[i] + 5;
+			break;
+		}
+	}
+	if (st->argv->argc > 0)
 		opt->option->name = talloc_strdup(opt, st->argv->argv[0]);
-	} else {
+	else
 		opt->option->name = talloc_strdup(opt, "(unknown)");
-	}
+
 	opt->option->id = talloc_asprintf(opt->option, "%s#%s",
 			script->ctx->device->device->id,
-			opt->option->name);
+			id ? id : opt->option->name);
 
 	script->opt = opt;
 
 	statements_execute(script, st->statements);
 
+	if (!opt->boot_image)
+		return -1;
+
+	opt->option->is_default = option_is_default(script, opt, id);
+
 	discover_context_add_boot_option(script->ctx, opt);
+	script->n_options++;
 	script->opt = NULL;
 
 	return 0;
@@ -341,25 +394,60 @@ int statement_function_execute(struct grub2_script *script,
 	const char *name;
 
 	if (st->name->type == GRUB2_WORD_VAR)
-		expand_var(script, st->name);
+		name = expand_var(script, st->name);
+	else
+		name = st->name->text;
 
-	name = st->name->text;
 	script_register_function(script, name, function_invoke, st);
 
 	return 0;
 }
 
+int statement_for_execute(struct grub2_script *script,
+		struct grub2_statement *statement)
+{
+	struct grub2_statement_for *st = to_stmt_for(statement);
+	const char *varname;
+	int i, rc = 0;
+
+	if (st->var->type == GRUB2_WORD_VAR)
+		expand_var(script, st->var);
+	varname = st->var->text;
+
+	process_expansions(script, st->list);
+
+	for (i = 0; i < st->list->argc; ++i) {
+		script_env_set(script, varname, st->list->argv[i]);
+		rc = statements_execute(script, st->body);
+	}
+
+	return rc;
+}
+
 static void init_env(struct grub2_script *script)
 {
 	struct env_entry *env;
+	char *prefix, *sep;
 
 	list_init(&script->environment);
 
+	/* use location of the parsed config file to determine the prefix */
 	env = talloc(script, struct env_entry);
-	env->name = talloc_strdup(env, "prefix");
-	env->value = talloc_strdup(env, "/");
 
-	list_add(&script->environment, &env->list);
+	prefix = NULL;
+	if (script->filename) {
+		sep = strrchr(script->filename, '/');
+		if (sep)
+			prefix = talloc_strndup(env, script->filename,
+					sep - script->filename);
+	}
+
+	script_env_set(script, "prefix", prefix ? : default_prefix);
+	if (prefix)
+		talloc_free(prefix);
+
+	/* establish feature settings */
+	script_env_set(script, "feature_menuentry_id", "y");
 }
 
 void script_register_function(struct grub2_script *script,
@@ -378,6 +466,7 @@ void script_register_function(struct grub2_script *script,
 
 void script_execute(struct grub2_script *script)
 {
+	init_env(script);
 	statements_execute(script, script->statements);
 }
 
@@ -386,11 +475,9 @@ struct grub2_script *create_script(struct grub2_parser *parser,
 {
 	struct grub2_script *script;
 
-	script = talloc(parser, struct grub2_script);
+	script = talloc_zero(parser, struct grub2_script);
 
-	init_env(script);
 	script->ctx = ctx;
-	script->opt = NULL;
 
 	list_init(&script->symtab);
 	register_builtins(script);