arping: make help text clearer

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2015-08-16 19:56:16 +02:00
parent 26ccd3d062
commit fb52769f4a

View File

@ -13,11 +13,11 @@
//usage: "\n -f Quit on first ARP reply"
//usage: "\n -q Quiet"
//usage: "\n -b Keep broadcasting, don't go unicast"
//usage: "\n -D Duplicated address detection mode"
//usage: "\n -D Exit with 1 if DST_IP replies"
//usage: "\n -U Unsolicited ARP mode, update your neighbors"
//usage: "\n -A ARP answer mode, update your neighbors"
//usage: "\n -c N Stop after sending N ARP requests"
//usage: "\n -w TIMEOUT Time to wait for ARP reply, seconds"
//usage: "\n -w TIMEOUT Seconds to wait for ARP reply"
//usage: "\n -I IFACE Interface to use (default eth0)"
//usage: "\n -s SRC_IP Sender IP address"
//usage: "\n DST_IP Target IP address"
@ -162,7 +162,7 @@ static void catcher(void)
alarm(1);
}
static bool recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
static void recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
{
struct arphdr *ah = (struct arphdr *) buf;
unsigned char *p = (unsigned char *) (ah + 1);
@ -181,33 +181,33 @@ static bool recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
if (FROM->sll_pkttype != PACKET_HOST
&& FROM->sll_pkttype != PACKET_BROADCAST
&& FROM->sll_pkttype != PACKET_MULTICAST)
return false;
return;
/* Only these types are recognized */
if (ah->ar_op != htons(ARPOP_REQUEST) && ah->ar_op != htons(ARPOP_REPLY))
return false;
return;
/* ARPHRD check and this darned FDDI hack here :-( */
if (ah->ar_hrd != htons(FROM->sll_hatype)
&& (FROM->sll_hatype != ARPHRD_FDDI || ah->ar_hrd != htons(ARPHRD_ETHER)))
return false;
return;
/* Protocol must be IP. */
if (ah->ar_pro != htons(ETH_P_IP)
|| (ah->ar_pln != 4)
|| (ah->ar_hln != me.sll_halen)
|| (len < (int)(sizeof(*ah) + 2 * (4 + ah->ar_hln))))
return false;
return;
move_from_unaligned32(src_ip.s_addr, p + ah->ar_hln);
move_from_unaligned32(dst_ip.s_addr, p + ah->ar_hln + 4 + ah->ar_hln);
if (dst.s_addr != src_ip.s_addr)
return false;
return;
if (!(option_mask32 & DAD)) {
if ((src.s_addr != dst_ip.s_addr)
|| (memcmp(p + ah->ar_hln + 4, &me.sll_addr, ah->ar_hln)))
return false;
|| (memcmp(p + ah->ar_hln + 4, &me.sll_addr, ah->ar_hln)))
return;
} else {
/* DAD packet was:
src_ip = 0 (or some src)
@ -224,7 +224,7 @@ static bool recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
*/
if ((memcmp(p, &me.sll_addr, me.sll_halen) == 0)
|| (src.s_addr && src.s_addr != dst_ip.s_addr))
return false;
return;
}
if (!(option_mask32 & QUIET)) {
int s_printed = 0;
@ -264,7 +264,6 @@ static bool recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
memcpy(he.sll_addr, p, me.sll_halen);
option_mask32 |= UNICASTING;
}
return true;
}
int arping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;