1/*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright 2021 Lutz Donnerhacke
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 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above
13 *    copyright notice, this list of conditions and the following
14 *    disclaimer in the documentation and/or other materials provided
15 *    with the distribution.
16 * 3. Neither the name of the copyright holder nor the names of its
17 *    contributors may be used to endorse or promote products derived
18 *    from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
21 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
22 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
27 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
29 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
30 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
31 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34#include <stdio.h>
35#include <stdlib.h>
36
37#include <netinet/in.h>
38
39#include "util.h"
40
41/* common ip ranges */
42struct in_addr masq = { htonl(0x01020304) };
43struct in_addr pub  = { htonl(0x0102dead) };
44struct in_addr prv1 = { htonl(0x0a00dead) };
45struct in_addr prv2 = { htonl(0xac10dead) };
46struct in_addr prv3 = { htonl(0xc0a8dead) };
47struct in_addr cgn  = { htonl(0x6440dead) };
48struct in_addr ext  = { htonl(0x12345678) };
49struct in_addr ANY_ADDR = { 0 };
50
51#define REQUIRE(x)	do {				\
52	if (!(x)) {					\
53		fprintf(stderr, "Failed in %s %s:%d.\n",\
54		    __FUNCTION__, __FILE__, __LINE__);	\
55		exit(-1);				\
56	}						\
57} while(0)
58
59int
60randcmp(const void *a, const void *b)
61{
62	int res, r = rand();
63
64	(void)a;
65	(void)b;
66	res = (r/4 < RAND_MAX/9) ? 1
67	    : (r/5 < RAND_MAX/9) ? 0
68	    : -1;
69	return (res);
70}
71
72void
73hexdump(void *p, size_t len)
74{
75	size_t i;
76	unsigned char *c = p;
77
78	for (i = 0; i < len; i++) {
79		printf(" %02x", c[i]);
80		switch (i & 0xf) {
81		case 0xf: printf("\n"); break;
82		case 0x7: printf(" "); break;
83		default:  break;
84		}
85	}
86	if ((i & 0xf) != 0x0)
87		printf("\n");
88}
89
90struct ip *
91ip_packet(u_char protocol, size_t len)
92{
93	struct ip * p;
94
95	REQUIRE(len >= 64 && len <= IP_MAXPACKET);
96
97	p = calloc(1, len);
98	REQUIRE(p != NULL);
99
100	p->ip_v = IPVERSION;
101	p->ip_hl = sizeof(*p)/4;
102	p->ip_len = htons(len);
103	p->ip_ttl = IPDEFTTL;
104	p->ip_p = protocol;
105	REQUIRE(p->ip_hl == 5);
106
107	return (p);
108}
109
110struct udphdr *
111set_udp(struct ip *p, u_short sport, u_short dport) {
112	int hlen = p->ip_hl << 2;
113	struct udphdr *u = (struct udphdr *)((uintptr_t)p + hlen);
114	int payload = ntohs(p->ip_len) - hlen;
115
116	REQUIRE(payload >= (int)sizeof(*u));
117	p->ip_p = IPPROTO_UDP;
118	u->uh_sport = htons(sport);
119	u->uh_dport = htons(dport);
120	u->uh_ulen = htons(payload);
121	return (u);
122}
123