[patch] shrink arping a bit, #2
Bernhard Fischer
rep.nop at aon.at
Thu Mar 30 09:47:50 PST 2006
On Thu, Mar 30, 2006 at 07:10:28PM +0200, Bernhard Fischer wrote:
>On Thu, Mar 30, 2006 at 06:57:08PM +0200, Bernhard Fischer wrote:
>>Hi,
>>
>> text data bss dec hex filename
>> 3627 4 120 3751 ea7 networking/arping.o.oorig
>> 3592 4 120 3716 e84 networking/arping.o
>>
>>The attached patchlet doesn't use bb_getopt_ulflags yet and i don't plan
>>to convert it during the next couple of days, so if anyone wants to
>>help..
>>
>>Apparently we have yet another arping() impl in udhcpd which could be
>>dropped unless udhcp is built in standalone-mode
>>
>>It's irritating that our arping wants the interface specified as capital
>>'I' while the big version which ships with my desktop uses a lowercase
>>'i'. I'd like to change ours to lowercase too.
>>
>>Objections or comments?
>
>hmz. I'll of course mv setting the default retval _after_ the last
>bb_show_usage..
Corrected version which is also a little smaller than the first
proposal:
text data bss dec hex filename
3627 4 120 3751 ea7 networking/arping.o.oorig
3577 4 96 3677 e5d networking/arping.o
-------------- next part --------------
Index: networking/arping.c
===================================================================
--- networking/arping.c (revision 14706)
+++ networking/arping.c (working copy)
@@ -1,10 +1,8 @@
+/* vi:set ts=4:*/
/*
* arping.c - Ping hosts by ARP requests/replies
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
* Author: Alexey Kuznetsov <kuznet at ms2.inr.ac.ru>
* Busybox port: Nick Fedchik <nick at fedchik.org.ua>
@@ -26,29 +24,32 @@
#include "busybox.h"
-#define APPLET_NAME "arping"
-
static struct in_addr src;
static struct in_addr dst;
static struct sockaddr_ll me;
static struct sockaddr_ll he;
static struct timeval last;
-static int dad;
-static int unsolicited;
-static int advert;
-static int quiet;
-static int quit_on_reply = 0;
+struct cfg_s {
+ int dad:1;
+ int unsolicited:1;
+ int advert:1;
+ int quiet:1;
+ int quit_on_reply:1;
+ int unicasting:1;
+ int broadcast_only:1;
+};
+static struct cfg_s cfg;
+
+static int s;
static int count = -1;
static int timeout;
-static int unicasting;
-static int s;
-static int broadcast_only;
static int sent;
static int brd_sent;
static int received;
static int brd_recv;
static int req_recv;
+
#define MS_TDIFF(tv1,tv2) ( ((tv1).tv_sec-(tv2).tv_sec)*1000 + \
((tv1).tv_usec-(tv2).tv_usec)/1000 )
#if 0
@@ -69,7 +70,7 @@
{
int err;
struct timeval now;
- unsigned char buf[256];
+ RESERVE_CONFIG_UBUFFER(buf, 256);
struct arphdr *ah = (struct arphdr *) buf;
unsigned char *p = (unsigned char *) (ah + 1);
@@ -78,7 +79,7 @@
ah->ar_pro = htons(ETH_P_IP);
ah->ar_hln = ME->sll_halen;
ah->ar_pln = 4;
- ah->ar_op = advert ? htons(ARPOP_REPLY) : htons(ARPOP_REQUEST);
+ ah->ar_op = cfg.advert ? htons(ARPOP_REPLY) : htons(ARPOP_REQUEST);
memcpy(p, &ME->sll_addr, ah->ar_hln);
p += ME->sll_halen;
@@ -86,7 +87,7 @@
memcpy(p, src_addr, 4);
p += 4;
- if (advert)
+ if (cfg.advert)
memcpy(p, &ME->sll_addr, ah->ar_hln);
else
memcpy(p, &HE->sll_addr, ah->ar_hln);
@@ -100,15 +101,16 @@
if (err == p - buf) {
last = now;
sent++;
- if (!unicasting)
+ if (!cfg.unicasting)
brd_sent++;
}
+ RELEASE_CONFIG_BUFFER(buf);
return err;
}
static void finish(void)
{
- if (!quiet) {
+ if (!cfg.quiet) {
printf("Sent %d probes (%d broadcast(s))\n", sent, brd_sent);
printf("Received %d repl%s", received, (received > 1) ? "ies" : "y");
if (brd_recv || req_recv) {
@@ -122,9 +124,9 @@
putchar('\n');
fflush(stdout);
}
- if (dad)
+ if (cfg.dad)
exit(!!received);
- if (unsolicited)
+ if (cfg.unsolicited)
exit(0);
exit(!received);
}
@@ -145,7 +147,7 @@
if (last.tv_sec == 0 || MS_TDIFF(tv, last) > 500) {
send_pack(s, &src, &dst, &me, &he);
- if (count == 0 && unsolicited)
+ if (count == 0 && cfg.unsolicited)
finish();
}
alarm(1);
@@ -153,13 +155,10 @@
static int recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
{
- struct timeval tv;
struct arphdr *ah = (struct arphdr *) buf;
unsigned char *p = (unsigned char *) (ah + 1);
struct in_addr src_ip, dst_ip;
- gettimeofday(&tv, NULL);
-
/* Filter out wild packets */
if (FROM->sll_pkttype != PACKET_HOST &&
FROM->sll_pkttype != PACKET_BROADCAST &&
@@ -187,7 +186,7 @@
return 0;
memcpy(&src_ip, p + ah->ar_hln, 4);
memcpy(&dst_ip, p + ah->ar_hln + 4 + ah->ar_hln, 4);
- if (!dad) {
+ if (!cfg.dad) {
if (src_ip.s_addr != dst.s_addr)
return 0;
if (src.s_addr != dst_ip.s_addr)
@@ -215,9 +214,12 @@
if (src.s_addr && src.s_addr != dst_ip.s_addr)
return 0;
}
- if (!quiet) {
+ if (!cfg.quiet) {
int s_printed = 0;
+ struct timeval tv;
+ gettimeofday(&tv, NULL);
+
printf("%s ",
FROM->sll_pkttype == PACKET_HOST ? "Unicast" : "Broadcast");
printf("%s from ",
@@ -234,6 +236,7 @@
printf("[%s]",
ether_ntoa((struct ether_addr *) p + ah->ar_hln + 4));
}
+
if (last.tv_sec) {
long usecs = (tv.tv_sec - last.tv_sec) * 1000000 +
tv.tv_usec - last.tv_usec;
@@ -251,48 +254,46 @@
brd_recv++;
if (ah->ar_op == htons(ARPOP_REQUEST))
req_recv++;
- if (quit_on_reply)
+ if (cfg.quit_on_reply)
finish();
- if (!broadcast_only) {
+ if (!cfg.broadcast_only) {
memcpy(he.sll_addr, p, me.sll_halen);
- unicasting = 1;
+ cfg.unicasting = 1;
}
return 1;
}
int arping_main(int argc, char **argv)
{
- int socket_errno;
int ch;
- uid_t uid = getuid();
char *device = "eth0";
- int ifindex = 0;
+ int ifindex;
char *source = NULL;
char *target;
s = socket(PF_PACKET, SOCK_DGRAM, 0);
- socket_errno = errno;
+ ifindex = errno;
- setuid(uid);
+ setuid(getuid());
while ((ch = getopt(argc, argv, "h?bfDUAqc:w:s:I:")) != EOF) {
switch (ch) {
case 'b':
- broadcast_only = 1;
+ cfg.broadcast_only = 1;
break;
case 'D':
- dad++;
- quit_on_reply = 1;
+ cfg.dad = 1;
+ cfg.quit_on_reply = 1;
break;
case 'U':
- unsolicited++;
+ cfg.unsolicited = 1;
break;
case 'A':
- advert++;
- unsolicited++;
+ cfg.advert = 1;
+ cfg.unsolicited = 1;
break;
case 'q':
- quiet++;
+ cfg.quiet = 1;
break;
case 'c':
count = atoi(optarg);
@@ -304,14 +305,13 @@
if (optarg == NULL)
bb_show_usage();
if (bb_strlen(optarg) > IF_NAMESIZE) {
- bb_error_msg("Interface name `%s' must be less than %d", optarg,
- IF_NAMESIZE);
- exit(2);
+ bb_error_msg_and_die("Interface name `%s' must be less than %d",
+ optarg, IF_NAMESIZE);
}
device = optarg;
break;
case 'f':
- quit_on_reply = 1;
+ cfg.quit_on_reply = 1;
break;
case 's':
source = optarg;
@@ -329,11 +329,11 @@
bb_show_usage();
target = *argv;
+ bb_default_error_retval = 2;
-
if (s < 0) {
- bb_error_msg("socket");
- exit(socket_errno);
+ bb_perror_msg("socket");
+ exit(ifindex);
}
{
@@ -342,22 +342,19 @@
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, device, IFNAMSIZ - 1);
if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
- bb_error_msg("Interface %s not found", device);
- exit(2);
+ bb_error_msg_and_die("Interface %s not found", device);
}
ifindex = ifr.ifr_ifindex;
if (ioctl(s, SIOCGIFFLAGS, (char *) &ifr)) {
- bb_error_msg("SIOCGIFFLAGS");
- exit(2);
+ bb_error_msg_and_die("SIOCGIFFLAGS");
}
if (!(ifr.ifr_flags & IFF_UP)) {
- bb_error_msg("Interface %s is down", device);
- exit(2);
+ bb_error_msg_and_die("Interface %s is down", device);
}
if (ifr.ifr_flags & (IFF_NOARP | IFF_LOOPBACK)) {
bb_error_msg("Interface %s is not ARPable", device);
- exit(dad ? 0 : 2);
+ exit(cfg.dad ? 0 : 2);
}
}
@@ -366,27 +363,24 @@
hp = gethostbyname2(target, AF_INET);
if (!hp) {
- bb_error_msg("invalid or unknown target %s", target);
- exit(2);
+ bb_error_msg_and_die("invalid or unknown target %s", target);
}
memcpy(&dst, hp->h_addr, 4);
}
if (source && !inet_aton(source, &src)) {
- bb_error_msg("invalid source address %s", source);
- exit(2);
+ bb_error_msg_and_die("invalid source address %s", source);
}
- if (!dad && unsolicited && src.s_addr == 0)
+ if (!cfg.dad && cfg.unsolicited && src.s_addr == 0)
src = dst;
- if (!dad || src.s_addr) {
+ if (!cfg.dad || src.s_addr) {
struct sockaddr_in saddr;
int probe_fd = socket(AF_INET, SOCK_DGRAM, 0);
if (probe_fd < 0) {
- bb_error_msg("socket");
- exit(2);
+ bb_error_msg_and_die("socket");
}
if (device) {
if (setsockopt
@@ -399,10 +393,9 @@
if (src.s_addr) {
saddr.sin_addr = src;
if (bind(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr)) == -1) {
- bb_error_msg("bind");
- exit(2);
+ bb_error_msg_and_die("bind");
}
- } else if (!dad) {
+ } else if (!cfg.dad) {
int on = 1;
socklen_t alen = sizeof(saddr);
@@ -412,16 +405,14 @@
if (setsockopt
(probe_fd, SOL_SOCKET, SO_DONTROUTE, (char *) &on,
sizeof(on)) == -1)
- perror("WARNING: setsockopt(SO_DONTROUTE)");
+ bb_perror_msg("WARNING: setsockopt(SO_DONTROUTE)");
if (connect(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr))
== -1) {
- bb_error_msg("connect");
- exit(2);
+ bb_error_msg_and_die("connect");
}
if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) ==
-1) {
- bb_error_msg("getsockname");
- exit(2);
+ bb_error_msg_and_die("getsockname");
}
src = saddr.sin_addr;
}
@@ -432,34 +423,31 @@
me.sll_ifindex = ifindex;
me.sll_protocol = htons(ETH_P_ARP);
if (bind(s, (struct sockaddr *) &me, sizeof(me)) == -1) {
- bb_error_msg("bind");
- exit(2);
+ bb_error_msg_and_die("bind");
}
{
socklen_t alen = sizeof(me);
if (getsockname(s, (struct sockaddr *) &me, &alen) == -1) {
- bb_error_msg("getsockname");
- exit(2);
+ bb_error_msg_and_die("getsockname");
}
}
if (me.sll_halen == 0) {
bb_error_msg("Interface \"%s\" is not ARPable (no ll address)", device);
- exit(dad ? 0 : 2);
+ exit(cfg.dad ? 0 : 2);
}
he = me;
memset(he.sll_addr, -1, he.sll_halen);
- if (!quiet) {
+ if (!cfg.quiet) {
printf("ARPING to %s", inet_ntoa(dst));
printf(" from %s via %s\n", inet_ntoa(src),
device ? device : "unknown");
}
- if (!src.s_addr && !dad) {
- bb_error_msg("no src address in the non-DAD mode");
- exit(2);
+ if (!src.s_addr && !cfg.dad) {
+ bb_error_msg_and_die("no src address in the non-DAD mode");
}
{
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