X-Git-Url: https://git.ozlabs.org/?p=petitboot;a=blobdiff_plain;f=discover%2Fgrub2%2Fscript.c;h=8a9d91dac987c36680283f8b9c95cfdf6ac15fb5;hp=65cab1523ec00038c2d9c38f66d8b40c756deeae;hb=7edc34c4ee8dc0913ea1a4ec64d3fbe6d64afc6d;hpb=561bedfedc9565764f71ac95957accabfdc677ab

diff --git a/discover/grub2/script.c b/discover/grub2/script.c
index 65cab15..8a9d91d 100644
--- a/discover/grub2/script.c
+++ b/discover/grub2/script.c
@@ -1,91 +1,235 @@
 
 #include <sys/types.h>
-#include <regex.h>
 #include <string.h>
+#include <stdlib.h>
 
+#include <log/log.h>
+#include <types/types.h>
 #include <talloc/talloc.h>
 
 #include "grub2.h"
 
 #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 {
+	char			*name;
+	char			*value;
+	struct list_item	list;
+};
+
+struct grub2_symtab_entry {
 	const char		*name;
-	const char		*value;
+	grub2_function		fn;
+	void			*data;
 	struct list_item	list;
 };
 
-static const char *env_lookup(struct grub2_script *script,
-		const char *name, int name_len)
+static const char *default_prefix = "/boot/grub";
+
+static struct grub2_symtab_entry *script_lookup_function(
+		struct grub2_script *script, const char *name)
 {
-	struct env_entry *entry;
+	struct grub2_symtab_entry *entry;
+
+	list_for_each_entry(&script->symtab, entry, list) {
+		if (!strcmp(entry->name, name))
+			return entry;
+	}
+
+	return NULL;
+}
 
-	printf("%s: %.*s\n", __func__, name_len, name);
+const char *script_env_get(struct grub2_script *script, const char *name)
+{
+	struct env_entry *entry;
 
 	list_for_each_entry(&script->environment, entry, list)
-		if (!strncmp(entry->name, name, name_len)
-				&& entry->name[name_len] == '\0')
+		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, i;
+	struct env_entry *e, *entry = NULL;
 
-	src = word->text;
+	list_for_each_entry(&script->environment, e, list) {
+		if (!strcmp(e->name, name)) {
+			entry = e;
+			break;
+		}
+	}
 
-	n = regexec(&script->var_re, src, 1, &match, 0);
-	printf("%s %s: %d\n", __func__, word->text, n);
-	if (n != 0)
-		return false;
+	if (!entry) {
+		entry = talloc(script, struct env_entry);
+		entry->name = talloc_strdup(entry, name);
+		list_add(&script->environment, &entry->list);
+	} else {
+		talloc_free(entry->value);
+	}
+
+	entry->value = talloc_strdup(entry, value);
+}
 
-	i = 0;
-	if (src[match.rm_so + 1] == '{')
-		i++;
+static char *expand_var(struct grub2_script *script, struct grub2_word *word)
+{
+	const char *val;
 
-	val = env_lookup(script, src + match.rm_so + 1 + i,
-				 match.rm_eo - match.rm_so - 1 - (i * 2));
+	val = script_env_get(script, word->name);
 	if (!val)
 		val = "";
 
-	printf("repl: %s\n", val);
+	return talloc_strdup(script, val);
+}
+
+static bool is_delim(char c)
+{
+	return c == ' ' || c == '\t';
+}
+
+static bool option_is_default(struct grub2_script *script,
+			      struct discover_boot_option *opt, const char *id)
+{
+	unsigned int default_idx;
+	const char *var;
+	char *end;
+
+	var = script_env_get(script, "default");
+	if (!var)
+		return false;
+
+	default_idx = strtoul(var, &end, 10);
+	if (end != var && *end == '\0')
+		return default_idx == script->n_options;
 
-	dest = talloc_strndup(script, src, match.rm_so);
-	dest = talloc_asprintf_append(dest, "%s%s", val, src + match.rm_eo);
+	if (id && !strcmp(id, var))
+		return true;
 
-	word->text = dest;
-	return true;
+	return !strcmp(opt->option->name, var);
 }
 
-/* iterate through the words in an argv, looking for expansions. If a
- * word is marked with expand == true, then we process any variable
- * substitutions.
- *
- * Once that's done, we may (if split == true) have to split the word to create
- * new argv items
+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);
+	}
+
+	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;
+
+	/* 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;
+	}
+
+	/* 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++) {
+
+		/* 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;
+		}
+	}
+
+	/* add remaining word characters */
+	if (pos)
+		append_text_to_current_arg(argv, pos, text + len - pos);
+}
+
+/* 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.
  */
 static void process_expansions(struct grub2_script *script,
 		struct grub2_argv *argv)
 {
-	struct grub2_word *word;
+	struct grub2_word *top_word, *word;
+
+	argv->argc = 0;
+	argv->argv = NULL;
 
-	list_for_each_entry(&argv->words, word, argv_list) {
-		if (!word->expand)
-			continue;
+	list_for_each_entry(&argv->words, top_word, argv_list) {
+		argv->argc++;
+		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, "");
 
-		expand_word(script, word);
+		for (word = top_word; word; word = word->next)
+			append_word_to_argv(script, argv, word);
 	}
+
+	/* we may have allocated an extra argv element but not populated it */
+	if (argv->argv && !argv->argv[argv->argc - 1])
+		argv->argc--;
 }
 
-int statements_execute(struct grub2_script *script,
+static int statements_execute(struct grub2_script *script,
 		struct grub2_statements *stmts)
 {
 	struct grub2_statement *stmt;
@@ -102,33 +246,185 @@ int statement_simple_execute(struct grub2_script *script,
 		struct grub2_statement *statement)
 {
 	struct grub2_statement_simple *st = to_stmt_simple(statement);
+	struct grub2_symtab_entry *entry;
+	char *pos;
+	int rc;
 
 	if (!st->argv)
 		return 0;
 
 	process_expansions(script, st->argv);
 
-	return 0;
+	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) {
+		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);
+
+	return rc;
 }
 
-int statement_if_execute(struct grub2_script *script,
+int statement_block_execute(struct grub2_script *script,
 		struct grub2_statement *statement)
 {
-	struct grub2_statement_if *st = to_stmt_if(statement);
-	struct grub2_statements *case_stmts;
+	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)
+{
+	struct grub2_statement_conditional *st = to_stmt_conditional(statement);
 	int rc;
 
 	rc = st->condition->exec(script, st->condition);
+	*executed = (!rc);
+	if (*executed)
+		rc = statements_execute(script, st->statements);
+
+	return rc;
+}
 
-	if (rc == 0)
-		case_stmts = st->true_case;
+int statement_if_execute(struct grub2_script *script,
+		struct grub2_statement *statement)
+{
+	struct grub2_statement_if *st = to_stmt_if(statement);
+	struct grub2_statement *conditional;
+	bool executed = false;
+	int rc = 0;
+
+	list_for_each_entry(&st->conditionals->list, conditional, list) {
+		rc = statement_conditional_execute(script,
+				conditional, &executed);
+		if (executed)
+			break;
+	}
+
+	if (!executed && st->else_case)
+		rc = statements_execute(script, st->else_case);
+
+	return rc;
+}
+
+int statement_menuentry_execute(struct grub2_script *script,
+		struct grub2_statement *statement)
+{
+	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);
+
+	/* 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], strlen("--id")) == 0) {
+			if (strlen(st->argv->argv[i]) > strlen("--id=")) {
+				id = st->argv->argv[i] + strlen("--id=");
+				break;
+			}
+
+			if (i + 1 < st->argv->argc) {
+				id = st->argv->argv[i + 1];
+				break;
+			}
+		}
+	}
+	if (st->argv->argc > 0)
+		opt->option->name = talloc_strdup(opt, st->argv->argv[0]);
 	else
-		case_stmts = st->false_case;
+		opt->option->name = talloc_strdup(opt, "(unknown)");
+
+	opt->option->id = talloc_asprintf(opt->option, "%s#%s",
+			script->ctx->device->device->id,
+			id ? id : opt->option->name);
+
+	script->opt = opt;
+
+	statements_execute(script, st->statements);
 
-	if (case_stmts)
-		statements_execute(script, case_stmts);
+	if (!opt->boot_image)
+		return -1;
+
+	opt->option->is_default = option_is_default(script, opt, id);
+
+	list_add_tail(&script->options, &opt->list);
+	script->n_options++;
+	script->opt = NULL;
+
+	return 0;
+}
+
+static int function_invoke(struct grub2_script *script,
+		void *data, int argc, char **argv)
+{
+	struct grub2_statement_function *fn = data;
+	char *name;
+	int i;
+
+	/* set positional parameters */
+	for (i = 1; i < argc; i++) {
+		name = talloc_asprintf(script, "%d", i);
+		script_env_set(script, name, argv[i]);
+	}
+
+	return statements_execute(script, fn->body);
+}
+
+int statement_function_execute(struct grub2_script *script,
+		struct grub2_statement *statement)
+{
+	struct grub2_statement_function *st = to_stmt_function(statement);
+	const char *name;
+
+	if (st->name->type == GRUB2_WORD_VAR)
+		name = expand_var(script, st->name);
 	else
-		rc = 0;
+		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;
 }
@@ -136,50 +432,96 @@ int statement_if_execute(struct grub2_script *script,
 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);
 
-void script_execute(struct grub2_script *script)
-{
-	statements_execute(script, script->statements);
+	/* establish feature settings */
+	script_env_set(script, "feature_menuentry_id", "y");
 }
 
-static int script_destroy(void *p)
+void script_register_function(struct grub2_script *script,
+		const char *name, grub2_function fn,
+		void *data)
 {
-	struct grub2_script *script = p;
-	regfree(&script->var_re);
-	return 0;
+	struct grub2_symtab_entry *entry;
+
+	entry = talloc(script, struct grub2_symtab_entry);
+	entry->fn = fn;
+	entry->name = name;
+	entry->data = data;
+	list_add(&script->symtab, &entry->list);
 }
 
-struct grub2_script *create_script(void *ctx)
+static void set_fallback_default(struct grub2_script *script)
 {
-	struct grub2_script *script;
-	int rc;
+	struct discover_boot_option *opt, *first = NULL;
+	bool have_default = false;
 
-	script = talloc(ctx, struct grub2_script);
+	list_for_each_entry(&script->options, opt, list) {
+		if (!first)
+			first = opt;
+		have_default = have_default || opt->option->is_default;
+	}
 
-	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 (!have_default && first) {
+		const char *env = script_env_get(script, "default");
 
+		pb_log("grub: no explicit default (env default=%s), "
+				"falling back to first option (%s)\n",
+				env ?: "unset", first->option->name);
+
+		first->option->is_default = true;
 	}
-	talloc_set_destructor(script, script_destroy);
+}
+
+void script_execute(struct grub2_script *script)
+{
+	struct discover_boot_option *opt, *tmp;
+
+	if (!script)
+		return;
 
 	init_env(script);
+	statements_execute(script, script->statements);
+
+	set_fallback_default(script);
+
+	list_for_each_entry_safe(&script->options, opt, tmp, list)
+		discover_context_add_boot_option(script->ctx, opt);
+
+	/* Our option list will be invalid, as we've added all options to the
+	 * discover context */
+	list_init(&script->options);
+}
+
+struct grub2_script *create_script(struct grub2_parser *parser,
+		struct discover_context *ctx)
+{
+	struct grub2_script *script;
+
+	script = talloc_zero(parser, struct grub2_script);
+
+	script->ctx = ctx;
+
+	list_init(&script->symtab);
+	list_init(&script->options);
+	register_builtins(script);
 
 	return script;
 }