cli: hush_modern: Enable variables expansion for modern hush

Enables variables expansion for modern hush, both for local and environment
variables.
So the following commands:
foo=bar
echo $foo
setenv bar foo
echo $bar
leads to "bar" and "foo" being printed on console output.

Signed-off-by: Francis Laniel <francis.laniel@amarulasolutions.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/common/cli_hush_modern.c b/common/cli_hush_modern.c
index 626fed089b2d1aaf4c9d267bc75721f2e5440f9a..15bb1f0d9245d0643254326b65c3b503ca7ba175 100644 (file)
--- a/common/cli_hush_modern.c
+++ b/common/cli_hush_modern.c
@@ -207,6 +207,23 @@ static const char* endofname(const char *name)
        return name;
 }
 
+/**
+ * list_size() - returns the number of elements in char ** before NULL.
+ *
+ * Argument must contain NULL to signalize its end.
+ *
+ * @list The list to count the number of element.
+ * @return The number of element in list.
+ */
+static size_t list_size(char **list)
+{
+       size_t size;
+
+       for (size = 0; list[size] != NULL; size++);
+
+       return size;
+}
+
 struct in_str;
 static int u_boot_cli_readline(struct in_str *i);
 

diff --git a/common/cli_hush_upstream.c b/common/cli_hush_upstream.c
index 4b6ab20f3b1cd788a20059f48b7abd7ef5c2a308..ff4a57c6e3a453c70f2bd29c33fddb7cb49895c1 100644 (file)
--- a/common/cli_hush_upstream.c
+++ b/common/cli_hush_upstream.c
@@ -3485,7 +3485,6 @@ static int o_get_last_ptr(o_string *o, int n)
        return ((int)(uintptr_t)list[n-1]) + string_start;
 }
 
-#ifndef __U_BOOT__
 /*
  * Globbing routines.
  *
@@ -3740,8 +3739,10 @@ static int glob_needed(const char *s)
  */
 static int perform_glob(o_string *o, int n)
 {
+#ifndef __U_BOOT__
        glob_t globdata;
        int gr;
+#endif /* __U_BOOT__ */
        char *pattern;
 
        debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
@@ -3750,13 +3751,16 @@ static int perform_glob(o_string *o, int n)
        pattern = o->data + o_get_last_ptr(o, n);
        debug_printf_glob("glob pattern '%s'\n", pattern);
        if (!glob_needed(pattern)) {
+#ifndef __U_BOOT__
  literal:
+#endif /* __U_BOOT__ */
                /* unbackslash last string in o in place, fix length */
                o->length = unbackslash(pattern) - o->data;
                debug_printf_glob("glob pattern '%s' is literal\n", pattern);
                return o_save_ptr_helper(o, n);
        }
 
+#ifndef __U_BOOT__
        memset(&globdata, 0, sizeof(globdata));
        /* Can't use GLOB_NOCHECK: it does not unescape the string.
         * If we glob "*.\*" and don't find anything, we need
@@ -3792,16 +3796,22 @@ static int perform_glob(o_string *o, int n)
        if (DEBUG_GLOB)
                debug_print_list("perform_glob returning", o, n);
        return n;
+#else /* __U_BOOT__ */
+       /*
+        * NOTE We only use perform glob to call unbackslash to remove backslash
+        * from string once expanded.
+        * So, it seems OK to return this if no previous return was done.
+        */
+       return o_save_ptr_helper(o, n);
+#endif /* __U_BOOT__ */
 }
 
-#endif /* !__U_BOOT__ */
 #endif /* !HUSH_BRACE_EXPANSION */
 
 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
  * Otherwise, just finish current list[] and start new */
 static int o_save_ptr(o_string *o, int n)
 {
-#ifndef __U_BOOT__
        if (o->o_expflags & EXP_FLAG_GLOB) {
                /* If o->has_empty_slot, list[n] was already globbed
                 * (if it was requested back then when it was filled)
@@ -3809,7 +3819,6 @@ static int o_save_ptr(o_string *o, int n)
                if (!o->has_empty_slot)
                        return perform_glob(o, n); /* o_save_ptr_helper is inside */
        }
-#endif /* !__U_BOOT__ */
        return o_save_ptr_helper(o, n);
 }
 
@@ -5455,7 +5464,20 @@ static int parse_dollar(o_string *as_string,
                        nommu_addchr(as_string, ch);
                        if (ch == '}')
                                break;
+#ifndef __U_BOOT__
                        if (!isalnum(ch) && ch != '_') {
+#else /* __U_BOOT__ */
+                       /*
+                        * In several places in U-Boot, we use variable like
+                        * foo# (e.g. serial#), particularly in env.
+                        * So, we need to authorize # to appear inside
+                        * variable name and then expand this variable.
+                        * NOTE Having # in variable name is not permitted in
+                        * upstream hush but expansion will be done (even though
+                        * the result will be empty).
+                        */
+                       if (!isalnum(ch) && ch != '_' && ch != '#') {
+#endif /* __U_BOOT__ */
                                unsigned end_ch;
 #ifndef __U_BOOT__
                                unsigned char last_ch;
@@ -7030,7 +7052,20 @@ static NOINLINE int expand_one_var(o_string *output, int n,
                }
 #endif /* !__U_BOOT__ */
                default:
+#ifndef __U_BOOT__
                        val = get_local_var_value(var);
+#else /* __U_BOOT__ */
+                       /*
+                        * Environment variable set with setenv* have to be
+                        * expanded.
+                        * So, we first search if the variable exists in
+                        * environment, if this is not the case, we default to
+                        * local value.
+                        */
+                       val = env_get(var);
+                       if (!val)
+                               val = get_local_var_value(var);
+#endif /* __U_BOOT__ */
                }
        }
 
@@ -7375,7 +7410,11 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
                case '*':
                case '@': {
                        int i;
+#ifndef __U_BOOT__
                        if (!G.global_argv[1])
+#else /* __U_BOOT__ */
+                       if (!G.global_argv || !G.global_argv[1])
+#endif /* __U_BOOT__ */
                                break;
                        i = 1;
                        cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
@@ -9976,7 +10015,30 @@ static NOINLINE int run_pipe(struct pipe *pi)
 #endif /* !__U_BOOT__ */
                command = &pi->cmds[cmd_no];
                cmd_no++;
-               if (command->argv) {
+
+#ifdef __U_BOOT__
+               /* Replace argv and argc by expanded if it exists. */
+               if (argv_expanded) {
+                       /*
+                        * We need to save a pointer to argv, we will restore it
+                        * later, so it will be freed when pipe is freed.
+                        */
+                       argv = command->argv;
+
+                       /*
+                        * After expansion, there can be more or less argument, so we need to
+                        * update argc, for example:
+                        * - More arguments:
+                        *   foo='bar quuz'
+                        *   echo $foo
+                        * - Less arguments:
+                        *   echo $foo (if foo was never set)
+                        */
+                       command->argc = list_size(argv_expanded);
+                       command->argv = argv_expanded;
+               }
+#endif /* __U_BOOT__ */
+                       if (command->argv) {
                        debug_printf_exec(": pipe member '%s' '%s'...\n",
                                        command->argv[0], command->argv[1]);
                } else {
@@ -10091,6 +10153,25 @@ static NOINLINE int run_pipe(struct pipe *pi)
                rcode = cmd_process(G.do_repeat ? CMD_FLAG_REPEAT : 0,
                                    command->argc, command->argv,
                                    &(G.flag_repeat), NULL);
+
+               if (argv_expanded) {
+                       /*
+                        * expand_strvec_to_strvec() allocates memory to expand
+                        * argv, we need to free it.
+                        */
+                       free(argv_expanded);
+
+                       /*
+                        * We also restore command->argv to its original value
+                        * so no memory leak happens.
+                        */
+                       command->argv = argv;
+
+                       /*
+                        * NOTE argc exists only in U-Boot, so argv freeing does
+                        * not rely on it as this code exists in BusyBox.
+                        */
+               }
 #endif /* __U_BOOT__ */
        }