Introduce binfmt support

This will allow to execute any file and detect it's type to handle it.
This will allow to use shell for bootp bootfile or dfu.

You can register multiple hook for the same filetype. They will be execute
in the invert order of register. If a hook does not handle the file you just
return -ERESTARTNOHAND;

This is only available with hush parser.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

common/Kconfig

@@ -43,6 +43,10 @@ config HAVE_NOSHELL
 config FILETYPE
 	bool
 
+config BINFMT
+	bool
+	select FILETYPE
+
 menu "General Settings              "
 
 config LOCALVERSION
@@ -275,6 +279,7 @@ choice
 		select ENVIRONMENT_VARIABLES
 		select COMMAND_SUPPORT
 		select PARAMETER
+		select BINFMT
 		help
 		  Enable hush support. This is the most advanced shell available
 		  for barebox.

common/Makefile

@@ -1,3 +1,4 @@
+obj-$(CONFIG_BINFMT)		+= binfmt.o
 obj-$(CONFIG_SHELL_HUSH)	+= hush.o
 obj-$(CONFIG_SHELL_SIMPLE)	+= parser.o
 obj-$(CONFIG_GREGORIAN_CALENDER) += date.o

common/binfmt.c

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ *
+ * GPL v2
+ */
+
+#include <common.h>
+#include <binfmt.h>
+#include <libbb.h>
+#include <malloc.h>
+#include <command.h>
+#include <errno.h>
+
+static LIST_HEAD(binfmt_hooks);
+
+static int binfmt_run(char *file, int argc, char **argv)
+{
+	struct binfmt_hook *b;
+	enum filetype type = file_name_detect_type(file);
+	int ret;
+
+	list_for_each_entry(b, &binfmt_hooks, list) {
+		if (b->type != type)
+			continue;
+
+		ret = b->hook(b, file, argc, argv);
+		if (ret != -ERESTARTNOHAND)
+			return ret;
+	}
+	return -ENOENT;
+}
+
+/*
+ * This converts the original '/executable <args>' into
+ * 'barebox_cmd <args> /executable'
+ */
+static int binfmt_exec_excute(struct binfmt_hook *b, char *file, int argc, char **argv)
+{
+	char **newargv = xzalloc(sizeof(char*) * (argc + 1));
+	int ret, i;
+
+	newargv[0] = b->exec;
+
+	for (i = 1 ; i < argc; i++)
+		newargv[i] = argv[i];
+	newargv[i] = file;
+
+	ret = execute_binfmt(argc + 1, newargv);
+
+	free(newargv);
+
+	return ret;
+}
+
+int execute_binfmt(int argc, char **argv)
+{
+	int ret;
+	char *path;
+
+	if (strchr(argv[0], '/'))
+		return binfmt_run(argv[0], argc, argv);
+
+	path = find_execable(argv[0]);
+	if (path) {
+		ret = binfmt_run(path, argc, argv);
+		free(path);
+		return ret;
+	}
+
+	return execute_command(argc, &argv[0]);
+}
+
+int binfmt_register(struct binfmt_hook *b)
+{
+	if (!b || !b->type)
+		return -EIO;
+
+	if (!b->hook && !b->exec)
+		return -EIO;
+
+	if (b->exec)
+		b->hook = binfmt_exec_excute;
+
+	list_add_tail(&b->list, &binfmt_hooks);
+
+	return 0;
+}
+
+void binfmt_unregister(struct binfmt_hook *b)
+{
+	if (!b)
+		return;
+
+	list_del(&b->list);
+}

common/hush.c

@@ -124,6 +124,8 @@
 #include <libbb.h>
 #include <magicvar.h>
 #include <linux/list.h>
+#include <binfmt.h>
+#include <init.h>
 
 /*cmd_boot.c*/
 extern int do_bootd(int flag, int argc, char *argv[]);      /* do_bootd */
@@ -572,8 +574,6 @@ static int run_pipe_real(struct p_context *ctx, struct pipe *pi)
 	int nextin;
 	struct child_prog *child;
 	char *p;
-	char *path;
-	int ret;
 # if __GNUC__
 	/* Avoid longjmp clobbering */
 	(void) &i;
@@ -642,16 +642,7 @@ static int run_pipe_real(struct p_context *ctx, struct pipe *pi)
 		if (!strcmp(child->argv[i], "getopt"))
 			return builtin_getopt(ctx, child);
 #endif
-		if (strchr(child->argv[i], '/')) {
-			return execute_script(child->argv[i], child->argc-i, &child->argv[i]);
-		}
-		if ((path = find_execable(child->argv[i]))) {
-			ret = execute_script(path, child->argc-i, &child->argv[i]);
-			free(path);
-			return ret;
-		}
-
-		return execute_command(child->argc - i, &child->argv[i]);
+		return execute_binfmt(child->argc - i, &child->argv[i]);
 	}
 	return -1;
 }
@@ -1749,6 +1740,22 @@ BAREBOX_MAGICVAR(PATH, "colon seperated list of pathes to search for executables
 BAREBOX_MAGICVAR(PS1, "hush prompt");
 #endif
 
+static int binfmt_sh_excute(struct binfmt_hook *b, char *file, int argc, char **argv)
+{
+	return execute_script(file, argc, argv);
+}
+
+static struct binfmt_hook binfmt_sh_hook = {
+	.type = filetype_sh,
+	.hook = binfmt_sh_excute,
+};
+
+static int binfmt_sh_init(void)
+{
+	return binfmt_register(&binfmt_sh_hook);
+}
+fs_initcall(binfmt_sh_init);
+
 /**
  * @file
  * @brief A prototype Bourne shell grammar parser

include/binfmt.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ *
+ * GPL v2
+ */
+
+#ifndef __BFMT_H__
+#define __BFMT_H__
+
+#include <filetype.h>
+#include <linux/list.h>
+
+struct binfmt_hook {
+	enum filetype type;
+	int (*hook)(struct binfmt_hook *b, char *file, int argc, char **argv);
+	char *exec;
+
+	struct list_head list;
+};
+
+#ifdef CONFIG_BINFMT
+int binfmt_register(struct binfmt_hook *b);
+void binfmt_unregister(struct binfmt_hook *b);
+
+int execute_binfmt(int argc, char **argv);
+#else
+static inline int binfmt_register(struct binfmt_hook *b)
+{
+	return -EINVAL;
+}
+static inline void binfmt_unregister(struct binfmt_hook *b) {}
+
+static inline int execute_binfmt(int argc, char **argv)
+{
+	return 1;
+}
+#endif
+
+#endif /* __BFMT_H__ */