login: disable input console if password wrong

so we guarantee that barebox is secured again user interaction

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands/login.c

@@ -24,6 +24,7 @@
 #include <globalvar.h>
 #include <magicvar.h>
 #include <init.h>
+#include <console.h>
 
 #define PASSWD_MAX_LENGTH	(128 + 1)
 
@@ -44,6 +45,7 @@ static int do_login(int argc, char *argv[])
 	int timeout = login_timeout;
 	char *timeout_cmd = "boot";
 
+	console_allow_input(true);
 	if (!is_passwd_enable()) {
 		puts("login: password not set\n");
 		return 0;
@@ -64,8 +66,10 @@ static int do_login(int argc, char *argv[])
 		puts("Password: ");
 		passwd_len = password(passwd, PASSWD_MAX_LENGTH, LOGIN_MODE, timeout);
 
-		if (passwd_len < 0)
+		if (passwd_len < 0) {
+			console_allow_input(false);
 			run_command(timeout_cmd, 0);
+		}
 
 		if (check_passwd(passwd, passwd_len))
 			return 0;

common/console.c

@@ -236,6 +236,9 @@ int getc(void)
 	unsigned char ch;
 	uint64_t start;
 
+	if (unlikely(!console_is_input_allow()))
+		return -EPERM;
+
 	/*
 	 * For 100us we read the characters from the serial driver
 	 * into a kfifo. This helps us not to lose characters
@@ -270,6 +273,9 @@ EXPORT_SYMBOL(fgetc);
 
 int tstc(void)
 {
+	if (unlikely(!console_is_input_allow()))
+		return 0;
+
 	return kfifo_len(console_input_fifo) || tstc_raw();
 }
 EXPORT_SYMBOL(tstc);

common/console_common.c

@@ -21,9 +21,42 @@
 #include <common.h>
 #include <fs.h>
 #include <errno.h>
+#include <console.h>
+#include <init.h>
+#include <environment.h>
+#include <globalvar.h>
+#include <magicvar.h>
+#include <password.h>
 
 #ifndef CONFIG_CONSOLE_NONE
 
+static int console_input_allow;
+
+static int console_global_init(void)
+{
+	if (IS_ENABLED(CONFIG_CMD_LOGIN) && is_passwd_enable())
+		console_input_allow = 0;
+	else
+		console_input_allow = 1;
+
+	globalvar_add_simple_bool("console.input_allow", &console_input_allow);
+
+	return 0;
+}
+late_initcall(console_global_init);
+
+BAREBOX_MAGICVAR_NAMED(global_console_input_allow, global.console.input_allow, "console input allowed");
+
+bool console_is_input_allow(void)
+{
+	return console_input_allow;
+}
+
+void console_allow_input(bool val)
+{
+	console_input_allow = val;
+}
+
 int printf(const char *fmt, ...)
 {
 	va_list args;

common/console_simple.c

@@ -3,6 +3,7 @@
 #include <fs.h>
 #include <errno.h>
 #include <debug_ll.h>
+#include <console.h>
 
 LIST_HEAD(console_list);
 EXPORT_SYMBOL(console_list);
@@ -40,6 +41,9 @@ EXPORT_SYMBOL(console_putc);
 
 int tstc(void)
 {
+	if (unlikely(!console_is_input_allow()))
+		return 0;
+
 	if (!console)
 		return 0;
 
@@ -49,6 +53,9 @@ EXPORT_SYMBOL(tstc);
 
 int getc(void)
 {
+	if (unlikely(!console_is_input_allow()))
+		return -EPERM;
+
 	if (!console)
 		return -EINVAL;
 	return console->getc(console);

common/startup.c

@@ -138,6 +138,8 @@ void __noreturn start_barebox(void)
 			run_command("source /env/bin/init", 0);
 		} else {
 			pr_err("/env/bin/init not found\n");
+			if (IS_ENABLED(CONFIG_CMD_LOGIN))
+				while(run_command("login -t 0", 0));
 		}
 	}
 

include/console.h

@@ -54,4 +54,7 @@ extern struct list_head console_list;
 
 #define CFG_PBSIZE (CONFIG_CBSIZE+sizeof(CONFIG_PROMPT)+16)
 
+bool console_is_input_allow(void);
+void console_allow_input(bool val);
+
 #endif