arphold.c revision 281887 
1/*
2 * Copyright (c) 2010 Hudson River Trading LLC
3 * Written by George Neville-Neil gnn@freebsd.org
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * Description: The following is a test of the arp entry packet queues
28 * which replaced the single packet hold entry that existed in the BSDs
29 * since time immemorial.  The test process is:
30 *
31 * 1) Find out the current system limit (maxhold)
32 * 2) Using an IP address for which we do not yet have an entry
33 *    load up an ARP entry packet queue with exactly that many packets.
34 * 3) Check the arp dropped stat to make sure that we have not dropped
35 *    any packets as yet.
36 * 4) Add one more packet to the queue.
37 * 5) Make sure that only one packet was dropped.
38 *
39 * CAVEAT: The ARP timer will flush the queue after 1 second so it is
40 * important not to run this code in a fast loop or the test will
41 * fail.
42 *
43 * $FreeBSD: head/tools/regression/netinet/arphold/arphold.c 281887 2015-04-23 14:22:20Z jhb $
44 */
45
46#include <unistd.h>
47#include <stdio.h>
48#include <stdlib.h>
49#include <string.h>
50#include <sys/types.h>
51#include <sys/sysctl.h>
52#include <sys/socket.h>
53#include <netinet/in.h>
54#include <arpa/inet.h>
55#include <net/if_arp.h>
56
57#define MSG_SIZE 1024
58#define PORT 6969
59
60int
61main(int argc, char **argv)
62{
63
64	int sock;
65	int maxhold;
66	size_t size = sizeof(maxhold);
67	struct sockaddr_in dest;
68	char message[MSG_SIZE];
69	struct arpstat arpstat;
70	size_t len = sizeof(arpstat);
71	unsigned long dropped = 0;
72
73	memset(&message, 1, sizeof(message));
74
75	if (sysctlbyname("net.link.ether.inet.maxhold", &maxhold, &size,
76			 NULL, 0) < 0) {
77		perror("not ok 1 - sysctlbyname failed");
78		exit(1);
79	}
80
81#ifdef DEBUG
82	printf("maxhold is %d\n", maxhold);
83#endif /* DEBUG */
84
85	if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
86		perror("not ok 1 - could not open socket");
87		exit(1);
88	}
89
90	bzero(&dest, sizeof(dest));
91	if (inet_pton(AF_INET, argv[1], &dest.sin_addr.s_addr) != 1) {
92		perror("not ok 1 - could not parse address");
93		exit(1);
94	}
95	dest.sin_len = sizeof(dest);
96	dest.sin_family = AF_INET;
97	dest.sin_port = htons(PORT);
98
99	if (sysctlbyname("net.link.ether.arp.stats", &arpstat, &len,
100			 NULL, 0) < 0) {
101		perror("not ok 1 - could not get initial arp stats");
102		exit(1);
103	}
104
105	dropped = arpstat.dropped;
106#ifdef DEBUG
107	printf("dropped before %ld\n", dropped);
108#endif /* DEBUG */
109
110	/*
111	 * Load up the queue in the ARP entry to the maximum.
112	 * We should not drop any packets at this point.
113	 */
114
115	while (maxhold > 0) {
116		if (sendto(sock, message, sizeof(message), 0,
117			   (struct sockaddr *)&dest, sizeof(dest)) < 0) {
118			perror("not ok 1 - could not send packet");
119			exit(1);
120		}
121		maxhold--;
122	}
123
124	if (sysctlbyname("net.link.ether.arp.stats", &arpstat, &len,
125			 NULL, 0) < 0) {
126		perror("not ok 1 - could not get new arp stats");
127		exit(1);
128	}
129
130#ifdef DEBUG
131	printf("dropped after %ld\n", arpstat.dropped);
132#endif /* DEBUG */
133
134	if (arpstat.dropped != dropped) {
135		printf("not ok 1 - Failed, drops changed:"
136		       "before %ld after %ld\n", dropped, arpstat.dropped);
137		exit(1);
138	}
139
140	dropped = arpstat.dropped;
141
142	/* Now add one extra and make sure it is dropped. */
143	if (sendto(sock, message, sizeof(message), 0,
144		   (struct sockaddr *)&dest, sizeof(dest)) < 0) {
145		perror("not ok 1 - could not send packet");
146		exit(1);
147	}
148
149	if (sysctlbyname("net.link.ether.arp.stats", &arpstat, &len,
150			 NULL, 0) < 0) {
151		perror("not ok 1 - could not get new arp stats");
152		exit(1);
153	}
154
155	if (arpstat.dropped != (dropped + 1)) {
156		printf("not ok 1 - Failed to drop one packet: before"
157		       " %ld after %ld\n", dropped, arpstat.dropped);
158		exit(1);
159	}
160
161	printf("ok\n");
162	return (0);
163}
164