xref: /netbsd-src/usr.sbin/npf/npftest/libnpftest/npf_mbuf_subr.c (revision b899bfd96fd2cbaf2befc9ce4aaed9b9c230837a)
1 /*
2  * NPF testing - helper routines.
3  *
4  * Public Domain.
5  */
6 
7 #ifdef _KERNEL
8 #include <sys/types.h>
9 #include <sys/kmem.h>
10 #endif
11 
12 #include "npf_impl.h"
13 #include "npf_test.h"
14 
15 
16 #if defined(_NPF_STANDALONE)
17 struct mbuf *
npfkern_m_get(npf_t * npf __unused,unsigned flags,size_t space)18 npfkern_m_get(npf_t *npf __unused, unsigned flags, size_t space)
19 {
20 	unsigned mlen = offsetof(struct mbuf, m_data0[space]);
21 	struct mbuf *m;
22 
23 	m = calloc(1, mlen);
24 	if (m) {
25 		m->m_type = 1;
26 		m->m_flags = flags;
27 		m->m_data = m->m_data0;
28 	}
29 	return m;
30 }
31 #else
32 struct mbuf *
npfkern_m_get(npf_t * npf __unused,unsigned flags,size_t space)33 npfkern_m_get(npf_t *npf __unused, unsigned flags, size_t space)
34 {
35 	return m_get(flags, space);
36 }
37 #endif
38 
39 static void *
npfkern_m_getdata(const struct mbuf * m)40 npfkern_m_getdata(const struct mbuf *m)
41 {
42 	return m->m_data;
43 }
44 
45 static struct mbuf *
npfkern_m_next(struct mbuf * m)46 npfkern_m_next(struct mbuf *m)
47 {
48 	return m->m_next;
49 }
50 
51 static size_t
npfkern_m_buflen(const struct mbuf * m)52 npfkern_m_buflen(const struct mbuf *m)
53 {
54 	return m->m_len;
55 }
56 
57 size_t
npfkern_m_length(const struct mbuf * m)58 npfkern_m_length(const struct mbuf *m)
59 {
60 	const struct mbuf *m0;
61 	unsigned pktlen = 0;
62 
63 	if ((m->m_flags & M_PKTHDR) != 0)
64 		return m->m_pkthdr.len;
65 	for (m0 = m; m0 != NULL; m0 = m0->m_next)
66 		pktlen += m0->m_len;
67 	return pktlen;
68 }
69 
70 void
npfkern_m_freem(struct mbuf * m)71 npfkern_m_freem(struct mbuf *m)
72 {
73 #ifdef _NPF_STANDALONE
74 	struct mbuf *n;
75 
76 	do {
77 		n = m->m_next;
78 		m->m_type = MT_FREE;
79 		free(m);
80 		m = n;
81 	} while (m);
82 #else
83 	m_freem(m);
84 #endif
85 }
86 
87 static bool
npfkern_m_ensure_contig(struct mbuf ** m0,size_t len)88 npfkern_m_ensure_contig(struct mbuf **m0, size_t len)
89 {
90 	struct mbuf *m1;
91 	unsigned tlen;
92 	char *dptr;
93 
94 	tlen = npfkern_m_length(*m0);
95 	if ((m1 = npfkern_m_get(NULL, M_PKTHDR, tlen)) == NULL) {
96 		return false;
97 	}
98 	m1->m_pkthdr.len = m1->m_len = tlen;
99 	dptr = m1->m_data;
100 	for (struct mbuf *m = *m0; m != NULL; m = m->m_next) {
101 		memcpy(dptr, m->m_data, m->m_len);
102 		dptr += m->m_len;
103 	}
104 	npfkern_m_freem(*m0);
105 	*m0 = m1;
106 	(void)len;
107 	return true;
108 }
109 
110 
111 struct mbuf *
mbuf_getwithdata(const void * data,size_t len)112 mbuf_getwithdata(const void *data, size_t len)
113 {
114 	struct mbuf *m;
115 	void *dst;
116 
117 	m = m_gethdr(M_WAITOK, MT_HEADER);
118 	assert(m != NULL);
119 	dst = mtod(m, void *);
120 	memcpy(dst, data, len);
121 	m->m_pkthdr.len = len;
122 	m->m_len = len;
123 	return m;
124 }
125 
126 struct mbuf *
mbuf_construct_ether(int proto)127 mbuf_construct_ether(int proto)
128 {
129 	struct mbuf *m0, *m1;
130 	struct ether_header *ethdr;
131 
132 	m0 = m_gethdr(M_WAITOK, MT_HEADER);
133 	ethdr = mtod(m0, struct ether_header *);
134 	ethdr->ether_type = htons(ETHERTYPE_IP);
135 	m0->m_pkthdr.len = sizeof(struct ether_header);
136 	m0->m_len = sizeof(struct ether_header);
137 
138 	m1 = mbuf_construct(proto);
139 	m0->m_next = m1;
140 	m1->m_next = NULL;
141 	return m0;
142 }
143 
144 static int
mbuf_fill_proto(int proto,void * l4data)145 mbuf_fill_proto(int proto, void *l4data)
146 {
147 	struct tcphdr *th;
148 	int size = 0;
149 
150 	switch (proto) {
151 	case IPPROTO_TCP:
152 		th = l4data;
153 		th->th_off = sizeof(struct tcphdr) >> 2;
154 		size = sizeof(struct tcphdr);
155 		break;
156 	case IPPROTO_UDP:
157 		size = sizeof(struct udphdr);
158 		break;
159 	case IPPROTO_ICMP:
160 		size = offsetof(struct icmp, icmp_data);
161 		break;
162 	}
163 	return size;
164 }
165 
166 struct mbuf *
mbuf_construct(int proto)167 mbuf_construct(int proto)
168 {
169 	struct mbuf *m;
170 	struct ip *iphdr;
171 	void *l4data;
172 	int size;
173 
174 	m = m_gethdr(M_WAITOK, MT_HEADER);
175 	iphdr = mtod(m, struct ip *);
176 
177 	iphdr->ip_v = IPVERSION;
178 	iphdr->ip_hl = sizeof(struct ip) >> 2;
179 	iphdr->ip_off = 0;
180 	iphdr->ip_ttl = 64;
181 	iphdr->ip_p = proto;
182 
183 	size = sizeof(struct ip);
184 	l4data = (void *)(iphdr + 1);
185 	size += mbuf_fill_proto(proto, l4data);
186 	iphdr->ip_len = htons(size);
187 
188 	m->m_pkthdr.len = size;
189 	m->m_len = size;
190 	m->m_next = NULL;
191 	return m;
192 }
193 
194 struct mbuf *
mbuf_construct6(int proto)195 mbuf_construct6(int proto)
196 {
197 	struct mbuf *m;
198 	struct ip6_hdr *ip6;
199 	void *l4data;
200 	int size;
201 
202 	m = m_gethdr(M_WAITOK, MT_HEADER);
203 	ip6 = mtod(m, struct ip6_hdr *);
204 
205 	ip6->ip6_vfc = IPV6_VERSION;
206 	ip6->ip6_nxt = proto;
207 	ip6->ip6_hlim = 64;
208 
209 	size = sizeof(struct ip6_hdr);
210 	l4data = (void *)(ip6 + 1);
211 	size += mbuf_fill_proto(proto, l4data);
212 	ip6->ip6_plen = htons(size);
213 
214 	m->m_pkthdr.len = size;
215 	m->m_len = size;
216 	m->m_next = NULL;
217 	return m;
218 }
219 
220 void *
mbuf_return_hdrs(struct mbuf * m,bool ether,struct ip ** ip)221 mbuf_return_hdrs(struct mbuf *m, bool ether, struct ip **ip)
222 {
223 	struct ip *iphdr;
224 
225 	if (ether) {
226 		struct mbuf *mn = m->m_next;
227 		iphdr = mtod(mn, struct ip *);
228 	} else {
229 		iphdr = mtod(m, struct ip *);
230 	}
231 	*ip = iphdr;
232 	return (void *)(iphdr + 1);
233 }
234 
235 void *
mbuf_return_hdrs6(struct mbuf * m,struct ip6_hdr ** ip6)236 mbuf_return_hdrs6(struct mbuf *m, struct ip6_hdr **ip6)
237 {
238 	struct ip6_hdr *ip6hdr = mtod(m, struct ip6_hdr *);
239 
240 	*ip6 = ip6hdr;
241 	return (void *)(ip6hdr + 1);
242 }
243 
244 void
mbuf_icmp_append(struct mbuf * m,struct mbuf * m_orig)245 mbuf_icmp_append(struct mbuf *m, struct mbuf *m_orig)
246 {
247 	struct ip *iphdr = mtod(m, struct ip *);
248 	const size_t hlen = iphdr->ip_hl << 2;
249 	void *p = (uint8_t *)iphdr + hlen;
250 	struct icmp *ic = (struct icmp *)p;
251 	const size_t addlen = m_length(m_orig);
252 
253 	iphdr->ip_len = htons(ntohs(iphdr->ip_len) + addlen);
254 	memcpy(&ic->icmp_ip, mtod(m_orig, struct ip *), addlen);
255 	m->m_pkthdr.len += addlen;
256 	m->m_len += addlen;
257 	m_freem(m_orig);
258 }
259 
260 struct mbuf *
mbuf_get_pkt(int af,int proto,const char * src,const char * dst,int sport,int dport)261 mbuf_get_pkt(int af, int proto, const char *src, const char *dst,
262     int sport, int dport)
263 {
264 	struct mbuf *m;
265 	struct ip *ip;
266 	struct ip6_hdr *ip6;
267 	struct tcphdr *th;
268 	struct udphdr *uh;
269 	void *p, *ipsrc, *ipdst;
270 
271 	switch (af) {
272 	case AF_INET6:
273 		m = mbuf_construct6(proto);
274 		p = mbuf_return_hdrs6(m, &ip6);
275 		ipsrc = &ip6->ip6_src;
276 		ipdst = &ip6->ip6_dst;
277 		break;
278 	case AF_INET:
279 	default:
280 		m = mbuf_construct(proto);
281 		p = mbuf_return_hdrs(m, false, &ip);
282 		ipsrc = &ip->ip_src.s_addr;
283 		ipdst = &ip->ip_dst.s_addr;
284 	}
285 
286 	npf_inet_pton(af, src, ipsrc);
287 	npf_inet_pton(af, dst, ipdst);
288 
289 	switch (proto) {
290 	case IPPROTO_TCP:
291 		th = p;
292 		th->th_sport = htons(sport);
293 		th->th_dport = htons(dport);
294 		break;
295 	case IPPROTO_UDP:
296 		uh = p;
297 		uh->uh_sport = htons(sport);
298 		uh->uh_dport = htons(dport);
299 		break;
300 	default:
301 		KASSERT(false);
302 	}
303 	return m;
304 }
305 
306 npf_cache_t *
get_cached_pkt(struct mbuf * m,const char * ifname)307 get_cached_pkt(struct mbuf *m, const char *ifname)
308 {
309 	ifnet_t *ifp = npf_test_getif(ifname ? ifname : IFNAME_DUMMY);
310 	npf_cache_t *npc = kmem_zalloc(sizeof(npf_cache_t), KM_SLEEP);
311 	nbuf_t *nbuf = kmem_zalloc(sizeof(nbuf_t), KM_SLEEP);
312 	int ret;
313 
314 	npc->npc_info = 0;
315 	npc->npc_ctx = npf_getkernctx();
316 
317 	nbuf_init(npc->npc_ctx, nbuf, m, ifp);
318 	npc->npc_nbuf = nbuf;
319 	ret = npf_cache_all(npc);
320 	assert(ret); (void)ret;
321 
322 	return npc;
323 }
324 
325 void
put_cached_pkt(npf_cache_t * npc)326 put_cached_pkt(npf_cache_t *npc)
327 {
328 	struct mbuf *m = nbuf_head_mbuf(npc->npc_nbuf);
329 	kmem_free(npc->npc_nbuf, sizeof(nbuf_t));
330 	kmem_free(npc, sizeof(npf_cache_t));
331 	m_freem(m);
332 }
333 
334 const npf_mbufops_t npftest_mbufops = {
335 	.alloc			= npfkern_m_get,
336 	.free			= npfkern_m_freem,
337 	.getdata		= npfkern_m_getdata,
338 	.getnext		= npfkern_m_next,
339 	.getlen			= npfkern_m_buflen,
340 	.getchainlen		= npfkern_m_length,
341 	.ensure_contig		= npfkern_m_ensure_contig,
342 	.ensure_writable	= NULL,
343 };
344