Add gc_arena to struct argv to save allocations

With the private gc_arena we do not have to allocate the strings
found during parsing again, since we know the arena they are
allocated in is valid as long as the argv vector is.

Signed-off-by: Heiko Hund <heiko.hund@sophos.com>
Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20200206132103.15977-4-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg19376.html

3 files changed, 45 insertions, 29 deletions

diff --git a/src/openvpn/argv.c b/src/openvpn/argv.c
index 4f7aa4e..7d949d2 100644
--- a/src/openvpn/argv.c
+++ b/src/openvpn/argv.c
@@ -47,12 +47,11 @@ argv_extend(struct argv *a, const size_t newcap)
     {
         char **newargv;
         size_t i;
-        ALLOC_ARRAY_CLEAR(newargv, char *, newcap);
+        ALLOC_ARRAY_CLEAR_GC(newargv, char *, newcap, &a->gc);
         for (i = 0; i < a->argc; ++i)
         {
             newargv[i] = a->argv[i];
         }
-        free(a->argv);
         a->argv = newargv;
         a->capacity = newcap;
     }
@@ -64,6 +63,7 @@ argv_init(struct argv *a)
     a->capacity = 0;
     a->argc = 0;
     a->argv = NULL;
+    a->gc = gc_new();
     argv_extend(a, 8);
 }
 
@@ -78,24 +78,21 @@ argv_new(void)
 void
 argv_free(struct argv *a)
 {
-    size_t i;
-    for (i = 0; i < a->argc; ++i)
-    {
-        free(a->argv[i]);
-    }
-    free(a->argv);
+    gc_free(&a->gc);
 }
 
 static void
 argv_reset(struct argv *a)
 {
-    size_t i;
-    for (i = 0; i < a->argc; ++i)
+    if (a->argc)
     {
-        free(a->argv[i]);
-        a->argv[i] = NULL;
+        size_t i;
+        for (i = 0; i < a->argc; ++i)
+        {
+            a->argv[i] = NULL;
+        }
+        a->argc = 0;
     }
-    a->argc = 0;
 }
 
 static void
@@ -107,7 +104,7 @@ argv_grow(struct argv *a, const size_t add)
 }
 
 static void
-argv_append(struct argv *a, char *str)  /* str must have been malloced or be NULL */
+argv_append(struct argv *a, char *str)  /* str must have been gc_malloced or be NULL */
 {
     argv_grow(a, 1);
     a->argv[a->argc++] = str;
@@ -127,7 +124,7 @@ argv_clone(const struct argv *a, const size_t headroom)
     {
         for (size_t i = 0; i < a->argc; ++i)
         {
-            argv_append(&r, string_alloc(a->argv[i], NULL));
+            argv_append(&r, string_alloc(a->argv[i], &r.gc));
         }
     }
     return r;
@@ -138,7 +135,7 @@ argv_insert_head(const struct argv *a, const char *head)
 {
     struct argv r;
     r = argv_clone(a, 1);
-    r.argv[0] = string_alloc(head, NULL);
+    r.argv[0] = string_alloc(head, &r.gc);
     return r;
 }
 
@@ -222,7 +219,6 @@ argv_prep_format(const char *format, const char delim, size_t *count, struct gc_
 static bool
 argv_printf_arglist(struct argv *a, const char *format, va_list arglist)
 {
-    struct gc_arena gc = gc_new();
     const char delim = 0x1D;  /* ASCII Group Separator (GS) */
     bool res = false;
 
@@ -236,7 +232,7 @@ argv_printf_arglist(struct argv *a, const char *format, va_list arglist)
      *
      */
     size_t argc = a->argc;
-    char *f = argv_prep_format(format, delim, &argc, &gc);
+    char *f = argv_prep_format(format, delim, &argc, &a->gc);
     if (f == NULL)
     {
         goto out;
@@ -256,8 +252,8 @@ argv_printf_arglist(struct argv *a, const char *format, va_list arglist)
      *  Do the actual vsnprintf() operation, which expands the format
      *  string with the provided arguments.
      */
-    size_t size = len + 1;
-    char *buf = gc_malloc(size, false, &gc);
+    size_t size = adjust_power_of_2(len + 1);
+    char *buf = gc_malloc(size, false, &a->gc);
     len = vsnprintf(buf, size, f, arglist);
     if (len < 0 || len >= size)
     {
@@ -272,11 +268,11 @@ argv_printf_arglist(struct argv *a, const char *format, va_list arglist)
     while (end)
     {
         *end = '\0';
-        argv_append(a, string_alloc(buf, NULL));
+        argv_append(a, buf);
         buf = end + 1;
         end = strchr(buf, delim);
     }
-    argv_append(a, string_alloc(buf, NULL));
+    argv_append(a, buf);
 
     if (a->argc != argc)
     {
@@ -287,7 +283,6 @@ argv_printf_arglist(struct argv *a, const char *format, va_list arglist)
     res = true;
 
 out:
-    gc_free(&gc);
     return res;
 }
 
@@ -321,21 +316,18 @@ argv_parse_cmd(struct argv *a, const char *s)
 {
     argv_reset(a);
 
-    struct gc_arena gc = gc_new();
     char *parms[MAX_PARMS + 1] = { 0 };
-    int nparms = parse_line(s, parms, MAX_PARMS, "SCRIPT-ARGV", 0, D_ARGV_PARSE_CMD, &gc);
+    int nparms = parse_line(s, parms, MAX_PARMS, "SCRIPT-ARGV", 0, D_ARGV_PARSE_CMD, &a->gc);
     if (nparms)
     {
         int i;
         for (i = 0; i < nparms; ++i)
         {
-            argv_append(a, string_alloc(parms[i], NULL));
+            argv_append(a, parms[i]);
         }
     }
     else
     {
-        argv_append(a, string_alloc(s, NULL));
+        argv_append(a, string_alloc(s, &a->gc));
     }
-
-    gc_free(&gc);
 }
diff --git a/src/openvpn/argv.h b/src/openvpn/argv.h
index 989cd29..943c78e 100644
--- a/src/openvpn/argv.h
+++ b/src/openvpn/argv.h
@@ -33,6 +33,7 @@
 #include "buffer.h"
 
 struct argv {
+    struct gc_arena gc;
     size_t capacity;
     size_t argc;
     char **argv;
diff --git a/tests/unit_tests/openvpn/test_argv.c b/tests/unit_tests/openvpn/test_argv.c
index fde0ba4..25e80c1 100644
--- a/tests/unit_tests/openvpn/test_argv.c
+++ b/tests/unit_tests/openvpn/test_argv.c
@@ -118,6 +118,28 @@ argv_printf__empty_parameter__argc_correct(void **state)
 }
 
 static void
+argv_printf__long_args__data_correct(void **state)
+{
+    int i;
+    struct argv a = argv_new();
+    const char *args[] = {
+        "good_tools_have_good_names_even_though_it_might_impair_typing",
+        "--long-opt=looooooooooooooooooooooooooooooooooooooooooooooooong",
+        "--long-cat=loooooooooooooooooooooooooooooooooooooooooooooooooooonger",
+        "file_with_very_descriptive_filename_that_leaves_no_questions_open.jpg.exe"
+    };
+
+    argv_printf(&a, "%s %s %s %s", args[0], args[1], args[2], args[3]);
+    assert_int_equal(a.argc, 4);
+    for (i = 0; i < a.argc; i++)
+    {
+        assert_string_equal(a.argv[i], args[i]);
+    }
+
+    argv_free(&a);
+}
+
+static void
 argv_parse_cmd__command_string__argc_correct(void **state)
 {
     struct argv a = argv_new();
@@ -237,6 +259,7 @@ main(void)
         cmocka_unit_test(argv_printf__group_sep_in_arg__fail_no_ouput),
         cmocka_unit_test(argv_printf__combined_path_with_spaces__argc_correct),
         cmocka_unit_test(argv_printf__empty_parameter__argc_correct),
+        cmocka_unit_test(argv_printf__long_args__data_correct),
         cmocka_unit_test(argv_parse_cmd__command_string__argc_correct),
         cmocka_unit_test(argv_parse_cmd__command_and_extra_options__argc_correct),
         cmocka_unit_test(argv_printf_cat__used_twice__argc_correct),