From f5d50fbd2f1814b9f4dbaeec6818d66989a43a5c Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 11 Feb 2018 13:27:54 +0100 Subject: [PATCH] arping: code shrink Do not clear extra bits on option_mask32, it's not necessary. Move DAD bit to 2, this makes exit logic simpler. function old new delta arping_main 1655 1629 -26 Signed-off-by: Denys Vlasenko --- networking/arping.c | 56 ++++++++++++++++++++++----------------------- 1 file changed, 28 insertions(+), 28 deletions(-) diff --git a/networking/arping.c b/networking/arping.c index f9967d81e..fd2f52cdb 100644 --- a/networking/arping.c +++ b/networking/arping.c @@ -11,7 +11,6 @@ //config: select PLATFORM_LINUX //config: help //config: Ping hosts by ARP packets. -//config: //applet:IF_ARPING(APPLET(arping, BB_DIR_USR_SBIN, BB_SUID_DROP)) @@ -45,14 +44,23 @@ #define MONOTONIC_US() ((unsigned)monotonic_us()) enum { - DAD = 1, - UNSOLICITED = 2, - ADVERT = 4, - QUIET = 8, - QUIT_ON_REPLY = 16, - BCAST_ONLY = 32, - UNICASTING = 64 + UNSOLICITED = 1 << 0, + DAD = 1 << 1, + ADVERT = 1 << 2, + QUIET = 1 << 3, + QUIT_ON_REPLY = 1 << 4, + BCAST_ONLY = 1 << 5, + UNICASTING = 1 << 6, + TIMEOUT = 1 << 7, }; +#define GETOPT32(str_timeout, device, source) \ + getopt32(argv, "^" \ + "UDAqfbc:+w:I:s:" \ + /* Dad also sets quit_on_reply, */ \ + /* Advert also sets unsolicited: */ \ + "\0" "=1:Df:AU", \ + &count, &str_timeout, &device, &source \ + ); struct globals { struct in_addr src; @@ -92,21 +100,15 @@ struct globals { count = -1; \ } while (0) -// If GNUisms are not available... -//static void *mempcpy(void *_dst, const void *_src, int n) -//{ -// memcpy(_dst, _src, n); -// return (char*)_dst + n; -//} - static int send_pack(struct in_addr *src_addr, - struct in_addr *dst_addr, struct sockaddr_ll *ME, + struct in_addr *dst_addr, + struct sockaddr_ll *ME, struct sockaddr_ll *HE) { int err; unsigned char buf[256]; struct arphdr *ah = (struct arphdr *) buf; - unsigned char *p = (unsigned char *) (ah + 1); + unsigned char *p; ah->ar_hrd = htons(ARPHRD_ETHER); ah->ar_pro = htons(ETH_P_IP); @@ -114,6 +116,7 @@ static int send_pack(struct in_addr *src_addr, ah->ar_pln = 4; ah->ar_op = option_mask32 & ADVERT ? htons(ARPOP_REPLY) : htons(ARPOP_REQUEST); + p = (unsigned char *) (ah + 1); p = mempcpy(p, &ME->sll_addr, ah->ar_hln); p = mempcpy(p, src_addr, 4); @@ -303,16 +306,9 @@ int arping_main(int argc UNUSED_PARAM, char **argv) unsigned opt; char *str_timeout; - /* Dad also sets quit_on_reply. - * Advert also sets unsolicited. - */ - opt = getopt32(argv, "^" "DUAqfbc:+w:I:s:" "\0" "=1:Df:AU", - &count, &str_timeout, &device, &source - ); - if (opt & 0x80) /* -w: timeout */ + opt = GETOPT32(str_timeout, device, source); + if (opt & TIMEOUT) timeout_us = xatou_range(str_timeout, 0, INT_MAX/2000000) * 1000000 + 500000; - //if (opt & 0x200) /* -s: source */ - option_mask32 &= 0x3f; /* set respective flags */ } target = argv[optind]; @@ -336,7 +332,9 @@ int arping_main(int argc UNUSED_PARAM, char **argv) } if (ifr.ifr_flags & (IFF_NOARP | IFF_LOOPBACK)) { bb_error_msg(err_str, "is not ARPable"); - return (option_mask32 & DAD ? 0 : 2); + BUILD_BUG_ON(DAD != 2); + /* exit 0 if DAD, else exit 2 */ + return (~option_mask32 & DAD); } } @@ -401,7 +399,9 @@ int arping_main(int argc UNUSED_PARAM, char **argv) } if (me.sll_halen == 0) { bb_error_msg(err_str, "is not ARPable (no ll address)"); - return (option_mask32 & DAD ? 0 : 2); + BUILD_BUG_ON(DAD != 2); + /* exit 0 if DAD, else exit 2 */ + return (~option_mask32 & DAD); } he = me; memset(he.sll_addr, -1, he.sll_halen); -- 2.25.1