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, 54 insertions, 44 deletions

diff --git a/networking/libiproute/iplink.c b/networking/libiproute/iplink.c
index e1c9c6043..494b223bf 100644
--- a/networking/libiproute/iplink.c
+++ b/networking/libiproute/iplink.c
@@ -21,12 +21,6 @@
 /* taken from linux/sockios.h */
 #define SIOCSIFNAME     0x8923          /* set interface name */
 
-static void on_off(const char *msg) ATTRIBUTE_NORETURN;
-static void on_off(const char *msg)
-{
-        bb_error_msg_and_die("error: argument of \"%s\" must be \"on\" or \"off\"", msg);
-}
-
 /* Exits on error */
 static int get_ctl_fd(void)
 {
@@ -158,8 +152,14 @@ static void set_address(struct ifreq *ifr, int brd)
 }
 
 
+static void die_must_be_on_off(const char *msg) ATTRIBUTE_NORETURN;
+static void die_must_be_on_off(const char *msg)
+{
+        bb_error_msg_and_die("argument of \"%s\" must be \"on\" or \"off\"", msg);
+}
+
 /* Return value becomes exitcode. It's okay to not return at all */
-static int do_set(int argc, char **argv)
+static int do_set(char **argv)
 {
         char *dev = NULL;
         uint32_t mask = 0;
@@ -172,53 +172,63 @@ static int do_set(int argc, char **argv)
         char *newname = NULL;
         int htype, halen;
         static const char keywords[] ALIGN1 =
-                "up\0""down\0""name\0""mtu\0""multicast\0""arp\0""addr\0""dev\0"
-                "on\0""off\0";
-        enum { ARG_up = 1, ARG_down, ARG_name, ARG_mtu, ARG_multicast, ARG_arp,
-                ARG_addr, ARG_dev, PARM_on, PARM_off };
+                "up\0""down\0""name\0""mtu\0""multicast\0""arp\0""addr\0""dev\0";
+        enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_multicast, ARG_arp,
+                ARG_addr, ARG_dev };
+        static const char str_on_off[] ALIGN1 = "on\0""off\0";
+        enum { PARM_on = 0, PARM_off };
         smalluint key;
 
-        while (argc > 0) {
-                key = index_in_strings(keywords, *argv) + 1;
+        while (*argv) {
+                key = index_in_strings(keywords, *argv);
                 if (key == ARG_up) {
                         mask |= IFF_UP;
                         flags |= IFF_UP;
-                } else if (key == ARG_down) {
+                }
+                if (key == ARG_down) {
                         mask |= IFF_UP;
                         flags &= ~IFF_UP;
-                } else if (key == ARG_name) {
+                }
+                if (key == ARG_name) {
                         NEXT_ARG();
                         newname = *argv;
-                } else if (key == ARG_mtu) {
+                }
+                if (key == ARG_mtu) {
                         NEXT_ARG();
                         if (mtu != -1)
                                 duparg("mtu", *argv);
                         if (get_integer(&mtu, *argv, 0))
                                 invarg(*argv, "mtu");
-                } else if (key == ARG_multicast) {
+                }
+                if (key == ARG_multicast) {
+                        int param;
                         NEXT_ARG();
                         mask |= IFF_MULTICAST;
-                        key = index_in_strings(keywords, *argv) + 1;
-                        if (key == PARM_on) {
+                        param = index_in_strings(str_on_off, *argv);
+                        if (param < 0)
+                                die_must_be_on_off("multicast");
+                        if (param == PARM_on)
                                 flags |= IFF_MULTICAST;
-                        } else if (key == PARM_off) {
+                        else
                                 flags &= ~IFF_MULTICAST;
-                        } else
-                                on_off("multicast");
-                } else if (key == ARG_arp) {
+                }
+                if (key == ARG_arp) {
+                        int param;
                         NEXT_ARG();
                         mask |= IFF_NOARP;
-                        key = index_in_strings(keywords, *argv) + 1;
-                        if (key == PARM_on) {
+                        param = index_in_strings(str_on_off, *argv);
+                        if (param < 0)
+                                die_must_be_on_off("arp");
+                        if (param == PARM_on)
                                 flags &= ~IFF_NOARP;
-                        } else if (key == PARM_off) {
+                        else
                                 flags |= IFF_NOARP;
-                        } else
-                                on_off("arp");
-                } else if (key == ARG_addr) {
+                }
+                if (key == ARG_addr) {
                         NEXT_ARG();
                         newaddr = *argv;
-                } else {
+                }
+                if (key >= ARG_dev) {
                         if (key == ARG_dev) {
                                 NEXT_ARG();
                         }
@@ -226,7 +236,7 @@ static int do_set(int argc, char **argv)
                                 duparg2("dev", *argv);
                         dev = *argv;
                 }
-                argc--; argv++;
+                argv++;
         }
 
         if (!dev) {
@@ -266,26 +276,26 @@ static int do_set(int argc, char **argv)
         return 0;
 }
 
-static int ipaddr_list_link(int argc, char **argv)
+static int ipaddr_list_link(char **argv)
 {
         preferred_family = AF_PACKET;
-        return ipaddr_list_or_flush(argc, argv, 0);
+        return ipaddr_list_or_flush(argv, 0);
 }
 
 /* Return value becomes exitcode. It's okay to not return at all */
-int do_iplink(int argc, char **argv)
+int do_iplink(char **argv)
 {
         static const char keywords[] ALIGN1 =
                 "set\0""show\0""lst\0""list\0";
-        smalluint key;
-        if (argc <= 0)
-                return ipaddr_list_link(0, NULL);
-        key = index_in_substrings(keywords, *argv) + 1;
-        if (key == 0)
+        int key;
+        if (!*argv)
+                return ipaddr_list_link(argv);
+        key = index_in_substrings(keywords, *argv);
+        if (key < 0)
                 bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
-        argc--; argv++;
-        if (key == 1) /* set */
-                return do_set(argc, argv);
-        else /* show, lst, list */
-                return ipaddr_list_link(argc, argv);
+        argv++;
+        if (key == 0) /* set */
+                return do_set(argv);
+        /* show, lst, list */
+        return ipaddr_list_link(argv);
 }