ip: stop propagating argc; optimize ip_parse_common_args

function                                             old     new   delta
find_pair                                            167     187     +20
static.families                                        -      17     +17
die_must_be_on_off                                     -      11     +11
...
on_off                                                33      22     -11
do_ipaddr                                            103      90     -13
do_iptunnel                                         1001     986     -15
iproute_list_or_flush                               1237    1217     -20
static.ip_common_commands                             43      22     -21
do_iproute                                          2217    2193     -24
parse_args                                          1444    1414     -30
ip_do                                                 47      16     -31
do_iprule                                            994     963     -31
ip_main                                              153     113     -40
ipaddr_modify                                       1357    1305     -52
ipaddr_list_or_flush                                2543    2490     -53
ip_parse_common_args                                 294     159    -135
------------------------------------------------------------------------------
(add/remove: 4/1 grow/shrink: 4/24 up/down: 85/-563)         Total: -478 bytes
   text    data     bss     dec     hex filename
 775561     966    9236  785763   bfd63 busybox_old
 775073     962    9236  785271   bfb77 busybox_unstripped

networking/libiproute/iprule.c

@@ -161,7 +161,7 @@ static int print_rule(struct sockaddr_nl *who ATTRIBUTE_UNUSED,
 }
 
 /* Return value becomes exitcode. It's okay to not return at all */
-static int iprule_list(int argc, char **argv)
+static int iprule_list(char **argv)
 {
 	struct rtnl_handle rth;
 	int af = preferred_family;
@@ -169,9 +169,9 @@ static int iprule_list(int argc, char **argv)
 	if (af == AF_UNSPEC)
 		af = AF_INET;
 
-	if (argc > 0) {
+	if (*argv) {
 		//bb_error_msg("\"rule show\" needs no arguments");
-		bb_warn_ignoring_args(argc);
+		bb_warn_ignoring_args(1);
 		return -1;
 	}
 
@@ -184,7 +184,7 @@ static int iprule_list(int argc, char **argv)
 }
 
 /* Return value becomes exitcode. It's okay to not return at all */
-static int iprule_modify(int cmd, int argc, char **argv)
+static int iprule_modify(int cmd, char **argv)
 {
 	static const char keywords[] ALIGN1 =
 		"from\0""to\0""preference\0""order\0""priority\0"
@@ -220,7 +220,7 @@ static int iprule_modify(int cmd, int argc, char **argv)
 		req.r.rtm_type = RTN_UNICAST;
 	}
 
-	while (argc > 0) {
+	while (*argv) {
 		key = index_in_substrings(keywords, *argv) + 1;
 		if (key == 0) /* no match found in keywords array, bail out. */
 			bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
@@ -291,7 +291,6 @@ static int iprule_modify(int cmd, int argc, char **argv)
 				invarg(*argv, "type");
 			req.r.rtm_type = type;
 		}
-		argc--;
 		argv++;
 	}
 
@@ -310,17 +309,16 @@ static int iprule_modify(int cmd, int argc, char **argv)
 }
 
 /* Return value becomes exitcode. It's okay to not return at all */
-int do_iprule(int argc, char **argv)
+int do_iprule(char **argv)
 {
 	static const char ip_rule_commands[] ALIGN1 =
 		"add\0""delete\0""list\0""show\0";
 	int cmd = 2; /* list */
 
-	if (argc < 1)
-		return iprule_list(0, NULL);
-	if (*argv)
-		cmd = index_in_substrings(ip_rule_commands, *argv);
+	if (!*argv)
+		return iprule_list(argv);
 
+	cmd = index_in_substrings(ip_rule_commands, *argv);
 	switch (cmd) {
 		case 0: /* add */
 			cmd = RTM_NEWRULE;
@@ -330,10 +328,10 @@ int do_iprule(int argc, char **argv)
 			break;
 		case 2: /* list */
 		case 3: /* show */
-			return iprule_list(argc-1, argv+1);
+			return iprule_list(argv+1);
 			break;
 		default:
 			bb_error_msg_and_die("unknown command %s", *argv);
 	}
-	return iprule_modify(cmd, argc-1, argv+1);
+	return iprule_modify(cmd, argv+1);
 }