xref: /netbsd-src/usr.sbin/npf/npftest/libnpftest/npf_nbuf_test.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: npf_nbuf_test.c,v 1.6 2016/12/26 23:05:05 christos Exp $	*/
2 
3 /*
4  * NPF nbuf interface test.
5  *
6  * Public Domain.
7  */
8 
9 #ifdef _KERNEL
10 #include <sys/types.h>
11 #include <sys/kmem.h>
12 #endif
13 
14 #include "npf_impl.h"
15 #include "npf_test.h"
16 
17 #define	MBUF_CHAIN_LEN		128
18 
19 CTASSERT((MBUF_CHAIN_LEN % sizeof(uint32_t)) == 0);
20 
21 static void
22 mbuf_consistency_check(nbuf_t *nbuf)
23 {
24 	struct mbuf *m = nbuf_head_mbuf(nbuf);
25 
26 	while (m) {
27 		assert(m->m_type != MT_FREE);
28 		m = m->m_next;
29 	}
30 }
31 
32 static char *
33 parse_nbuf_chain(struct mbuf *m)
34 {
35 	ifnet_t *dummy_ifp = npf_test_addif(IFNAME_TEST, false, false);
36 	char *s = kmem_zalloc(MBUF_CHAIN_LEN + 1, KM_SLEEP);
37 	nbuf_t nbuf;
38 	void *nptr;
39 	int n;
40 
41 	nbuf_init(npf_getkernctx(), &nbuf, m, dummy_ifp);
42 
43 	nptr = nbuf_advance(&nbuf, (random() % 16) + 1, (random() % 16) + 1);
44 	mbuf_consistency_check(&nbuf);
45 	assert(nptr != NULL);
46 	nbuf_reset(&nbuf);
47 
48 	for (n = 0; ; ) {
49 		char d[4 + 1];
50 
51 		nptr = nbuf_ensure_contig(&nbuf, sizeof(uint32_t));
52 		if (nptr == NULL) {
53 			break;
54 		}
55 		mbuf_consistency_check(&nbuf);
56 		memcpy(&d, nptr, sizeof(uint32_t));
57 
58 		d[sizeof(d) - 1] = '\0';
59 		strcat(s, d);
60 
61 		if (n + sizeof(uint32_t) == MBUF_CHAIN_LEN) {
62 			assert(nbuf_advance(&nbuf, sizeof(uint32_t) - 1, 0));
63 			assert(!nbuf_advance(&nbuf, 1, 0));
64 			break;
65 		}
66 		if (!nbuf_advance(&nbuf, sizeof(uint32_t), 0)) {
67 			break;
68 		}
69 		n += sizeof(uint32_t);
70 	}
71 	mbuf_consistency_check(&nbuf);
72 	return s;
73 }
74 
75 static char *
76 mbuf_getstring(struct mbuf *m)
77 {
78 	char *s = kmem_zalloc(MBUF_CHAIN_LEN + 1, KM_SLEEP);
79 	u_int tlen = 0;
80 
81 	while (m) {
82 		int len = m->m_len;
83 		char *d = m->m_data;
84 		while (len--) {
85 			s[tlen++] = *d++;
86 		}
87 		m = m->m_next;
88 	}
89 	return s;
90 }
91 
92 static struct mbuf *
93 mbuf_alloc_with_off(size_t off, int len)
94 {
95 	struct mbuf *m;
96 
97 	KASSERT(off + len < MLEN);
98 	m = m_get(M_WAITOK, MT_DATA);
99 	m->m_data = (char *)m->m_data + off;
100 	m->m_len = len;
101 	return m;
102 }
103 
104 /*
105  * Create an mbuf chain, each of 1 byte size.
106  */
107 static struct mbuf *
108 mbuf_bytesize(size_t clen)
109 {
110 	struct mbuf *m0 = NULL, *m = NULL;
111 	u_int i, n;
112 
113 	/* Chain of clen (e.g. 128) mbufs, each storing 1 byte of data. */
114 	for (i = 0, n = 0; i < clen; i++) {
115 		/* Range of offset: 0 .. 15. */
116 		m0 = mbuf_alloc_with_off(n & 0xf, 1);
117 
118 		/* Fill data with letters from 'a' to 'z'. */
119 		memset(m0->m_data, 'a' + n, 1);
120 		n = ('a' + n) < 'z' ? n + 1 : 0;
121 
122 		/* Next mbuf.. */
123 		m0->m_next = m;
124 		m = m0;
125 	}
126 
127 	m0 = m_gethdr(M_WAITOK, MT_HEADER);
128 	m0->m_pkthdr.len = clen;
129 	m0->m_len = 0;
130 	m0->m_next = m;
131 	return m0;
132 }
133 
134 /*
135  * Generate random amount of mbufs, with random offsets and lengths.
136  */
137 static struct mbuf *
138 mbuf_random_len(size_t chain_len)
139 {
140 	struct mbuf *m0 = NULL, *m = NULL;
141 	u_int tlen = 0, n = 0;
142 
143 	while (tlen < chain_len) {
144 		u_int off, len;
145 		char *d;
146 
147 		/* Random offset and length range: 1 .. 16. */
148 		off = (random() % 16) + 1;
149 		len = (random() % 16) + 1;
150 
151 		/* Do not exceed 128 bytes of total length. */
152 		if (tlen + len > chain_len) {
153 			len = chain_len - tlen;
154 		}
155 		tlen += len;
156 
157 		/* Consistently fill data with letters from 'a' to 'z'. */
158 		m0 = mbuf_alloc_with_off(off, len);
159 		d = m0->m_data;
160 		while (len--) {
161 			*d++ = ('a' + n);
162 			n = ('a' + n) < 'z' ? n + 1 : 0;
163 		}
164 
165 		/* Next mbuf.. */
166 		m0->m_next = m;
167 		m = m0;
168 	}
169 	KASSERT(tlen == chain_len);
170 
171 	m0 = m_gethdr(M_WAITOK, MT_HEADER);
172 	m0->m_pkthdr.len = tlen;
173 	m0->m_next = m;
174 	m0->m_len = 0;
175 	return m0;
176 }
177 
178 static bool
179 validate_mbuf_data(bool verbose, char *bufa, char *bufb)
180 {
181 	bool ret = (strcmp(bufa, bufb) == 0);
182 
183 	if (verbose) {
184 		printf("Buffer A: %s\nBuffer B: %s\n", bufa, bufb);
185 	}
186 	kmem_free(bufa, MBUF_CHAIN_LEN + 1);
187 	kmem_free(bufb, MBUF_CHAIN_LEN + 1);
188 	return ret;
189 }
190 
191 bool
192 npf_nbuf_test(bool verbose)
193 {
194 	struct mbuf *m1, *m2;
195 	char *bufa, *bufb;
196 	bool fail = false;
197 
198 	m1 = mbuf_random_len(MBUF_CHAIN_LEN);
199 	bufa = mbuf_getstring(m1);
200 	bufb = parse_nbuf_chain(m1);
201 	fail |= !validate_mbuf_data(verbose, bufa, bufb);
202 
203 	m2 = mbuf_bytesize(MBUF_CHAIN_LEN);
204 	bufa = mbuf_getstring(m2);
205 	bufb = parse_nbuf_chain(m2);
206 	fail |= !validate_mbuf_data(verbose, bufa, bufb);
207 
208 	return !fail;
209 }
210