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

1 files changed, 40 insertions, 44 deletions

diff --git a/networking/libiproute/ip_parse_common_args.c b/networking/libiproute/ip_parse_common_args.c
index ff333993f..294bde540 100644
--- a/networking/libiproute/ip_parse_common_args.c
+++ b/networking/libiproute/ip_parse_common_args.c
@@ -18,71 +18,67 @@
 #include "ip_common.h"  /* #include "libbb.h" is inside */
 #include "utils.h"
 
-int preferred_family = AF_UNSPEC;
+family_t preferred_family = AF_UNSPEC;
 smallint oneline;
 char _SL_;
 
-void ip_parse_common_args(int *argcp, char ***argvp)
+char **ip_parse_common_args(char **argv)
 {
-	int argc = *argcp;
-	char **argv = *argvp;
 	static const char ip_common_commands[] ALIGN1 =
-		"-family\0""inet\0""inet6\0""link\0"
-		"-4\0""-6\0""-0\0""-oneline\0";
+		"oneline" "\0"
+		"family" "\0"
+		"4" "\0"
+		"6" "\0"
+		"0" "\0"
+		;
 	enum {
-		ARG_family = 1,
-		ARG_inet,
-		ARG_inet6,
-		ARG_link,
+		ARG_oneline,
+		ARG_family,
 		ARG_IPv4,
 		ARG_IPv6,
 		ARG_packet,
-		ARG_oneline
 	};
-	smalluint arg;
+	static const family_t af_numbers[] = { AF_INET, AF_INET6, AF_PACKET };
+	int arg;
 
-	while (argc > 1) {
-		char *opt = argv[1];
+	while (*argv) {
+		char *opt = *argv;
 
-		if (strcmp(opt,"--") == 0) {
-			argc--;
-			argv++;
-			break;
-		}
 		if (opt[0] != '-')
 			break;
-		if (opt[1] == '-')
+		opt++;
+		if (opt[0] == '-') {
 			opt++;
-		arg = index_in_strings(ip_common_commands, opt) + 1;
+			if (!opt[0]) { /* "--" */
+				argv++;
+				break;
+			}
+		}
+		arg = index_in_strings(ip_common_commands, opt);
+		if (arg < 0)
+			bb_show_usage();
+		if (arg == ARG_oneline) {
+			oneline = 1;
+			argv++;
+			continue;
+		}
 		if (arg == ARG_family) {
-			argc--;
+			static const char families[] ALIGN1 =
+				"inet" "\0" "inet6" "\0" "link" "\0";
 			argv++;
-			if (!argv[1])
+			if (!*argv)
 				bb_show_usage();
-			arg = index_in_strings(ip_common_commands, argv[1]) + 1;
-			if (arg == ARG_inet)
-				preferred_family = AF_INET;
-			else if (arg == ARG_inet6)
-				preferred_family = AF_INET6;
-			else if (arg == ARG_link)
-				preferred_family = AF_PACKET;
-			else
-				invarg(argv[1], "protocol family");
-		} else if (arg == ARG_IPv4) {
-			preferred_family = AF_INET;
-		} else if (arg == ARG_IPv6) {
-			preferred_family = AF_INET6;
-		} else if (arg == ARG_packet) {
-			preferred_family = AF_PACKET;
-		} else if (arg == ARG_oneline) {
-			++oneline;
+			arg = index_in_strings(families, *argv);
+			if (arg < 0)
+				invarg(*argv, "protocol family");
+			/* now arg == 0, 1 or 2 */
 		} else {
-			bb_show_usage();
+			arg -= ARG_IPv4;
+			/* now arg == 0, 1 or 2 */
 		}
-		argc--;
+		preferred_family = af_numbers[arg];
 		argv++;
 	}
 	_SL_ = oneline ? '\\' : '\n';
-	*argcp = argc;
-	*argvp = argv;
+	return argv;
 }