npf_nat_test.c revision 1.5 1 /* $NetBSD: npf_nat_test.c,v 1.5 2014/02/05 03:30:13 rmind Exp $ */
2
3 /*
4 * NPF NAT test.
5 *
6 * Public Domain.
7 */
8
9 #include <sys/types.h>
10
11 #include "npf_impl.h"
12 #include "npf_test.h"
13
14 #define RESULT_PASS 0
15 #define RESULT_BLOCK ENETUNREACH
16
17 #define NPF_BINAT (NPF_NATIN | NPF_NATOUT)
18
19 #define RANDOM_PORT 45600
20
21 static const struct test_case {
22 const char * src;
23 in_port_t sport;
24 const char * dst;
25 in_port_t dport;
26 int ttype;
27 const char * ifname;
28 int di;
29 int ret;
30 const char * taddr;
31 in_port_t tport;
32 } test_cases[] = {
33
34 /*
35 * Traditional NAPT (outbound NAT):
36 * map $ext_if dynamic $local_net -> $pub_ip1
37 */
38 {
39 LOCAL_IP1, 15000, REMOTE_IP1, 7000,
40 NPF_NATOUT, IFNAME_EXT, PFIL_OUT,
41 RESULT_PASS, PUB_IP1, RANDOM_PORT
42 },
43 {
44 LOCAL_IP1, 15000, REMOTE_IP1, 7000,
45 NPF_NATOUT, IFNAME_EXT, PFIL_OUT,
46 RESULT_PASS, PUB_IP1, RANDOM_PORT
47 },
48 {
49 LOCAL_IP1, 15000, REMOTE_IP1, 7000,
50 NPF_NATOUT, IFNAME_EXT, PFIL_IN,
51 RESULT_BLOCK, NULL, 0
52 },
53 {
54 REMOTE_IP1, 7000, LOCAL_IP1, 15000,
55 NPF_NATOUT, IFNAME_EXT, PFIL_IN,
56 RESULT_BLOCK, NULL, 0
57 },
58 {
59 REMOTE_IP1, 7000, PUB_IP1, RANDOM_PORT,
60 NPF_NATOUT, IFNAME_INT, PFIL_IN,
61 RESULT_BLOCK, NULL, 0
62 },
63 {
64 REMOTE_IP1, 7000, PUB_IP1, RANDOM_PORT,
65 NPF_NATOUT, IFNAME_EXT, PFIL_IN,
66 RESULT_PASS, LOCAL_IP1, 15000
67 },
68
69 /*
70 * NAT redirect (inbound NAT):
71 * map $ext_if dynamic $local_ip1 port 8000 <- $pub_ip1 port 8000
72 */
73 {
74 REMOTE_IP2, 16000, PUB_IP1, 8000,
75 NPF_NATIN, IFNAME_EXT, PFIL_IN,
76 RESULT_PASS, LOCAL_IP1, 6000
77 },
78 {
79 LOCAL_IP1, 6000, REMOTE_IP2, 16000,
80 NPF_NATIN, IFNAME_EXT, PFIL_OUT,
81 RESULT_PASS, PUB_IP1, 8000
82 },
83
84 /*
85 * Bi-directional NAT (inbound + outbound NAT):
86 * map $ext_if dynamic $local_ip2 <-> $pub_ip2
87 */
88 {
89 REMOTE_IP2, 17000, PUB_IP2, 9000,
90 NPF_BINAT, IFNAME_EXT, PFIL_IN,
91 RESULT_PASS, LOCAL_IP2, 9000
92 },
93 {
94 LOCAL_IP2, 9000, REMOTE_IP2, 17000,
95 NPF_BINAT, IFNAME_EXT, PFIL_OUT,
96 RESULT_PASS, PUB_IP2, 9000
97 },
98 {
99 LOCAL_IP2, 18000, REMOTE_IP2, 9000,
100 NPF_BINAT, IFNAME_EXT, PFIL_OUT,
101 RESULT_PASS, PUB_IP2, 18000
102 },
103 {
104 REMOTE_IP2, 9000, PUB_IP2, 18000,
105 NPF_BINAT, IFNAME_EXT, PFIL_IN,
106 RESULT_PASS, LOCAL_IP2, 18000
107 },
108
109 };
110
111 static bool
112 nmatch_addr(const char *saddr, const struct in_addr *addr2)
113 {
114 const in_addr_t addr1 = inet_addr(saddr);
115 return memcmp(&addr1, &addr2->s_addr, sizeof(in_addr_t)) != 0;
116 }
117
118 static bool
119 checkresult(bool verbose, unsigned i, struct mbuf *m, ifnet_t *ifp, int error)
120 {
121 const struct test_case *t = &test_cases[i];
122 npf_cache_t npc = { .npc_info = 0 };
123 nbuf_t nbuf;
124
125 if (verbose) {
126 printf("packet %d (expected %d ret %d)\n", i+1, t->ret, error);
127 }
128 if (error) {
129 return error == t->ret;
130 }
131
132 nbuf_init(&nbuf, m, ifp);
133 if (!npf_cache_all(&npc, &nbuf)) {
134 printf("error: could not fetch the packet data");
135 return false;
136 }
137
138 const struct ip *ip = npc.npc_ip.v4;
139 const struct udphdr *uh = npc.npc_l4.udp;
140
141 if (verbose) {
142 printf("\tpost-translation: src %s (%d)",
143 inet_ntoa(ip->ip_src), ntohs(uh->uh_sport));
144 printf(" dst %s (%d)\n",
145 inet_ntoa(ip->ip_dst), ntohs(uh->uh_dport));
146 }
147 if (error != t->ret) {
148 return false;
149 }
150
151 const bool forw = t->di == PFIL_OUT;
152 const char *saddr = forw ? t->taddr : t->src;
153 const char *daddr = forw ? t->dst : t->taddr;
154 in_addr_t sport = forw ? t->tport : t->sport;
155 in_addr_t dport = forw ? t->dport : t->tport;
156
157 bool defect = false;
158 defect |= nmatch_addr(saddr, &ip->ip_src);
159 defect |= sport != ntohs(uh->uh_sport);
160 defect |= nmatch_addr(daddr, &ip->ip_dst);
161 defect |= dport != ntohs(uh->uh_dport);
162 return !defect;
163 }
164
165 static struct mbuf *
166 fill_packet(const struct test_case *t)
167 {
168 struct mbuf *m;
169 struct ip *ip;
170 struct udphdr *uh;
171
172 m = mbuf_construct(IPPROTO_UDP);
173 uh = mbuf_return_hdrs(m, false, &ip);
174 ip->ip_src.s_addr = inet_addr(t->src);
175 ip->ip_dst.s_addr = inet_addr(t->dst);
176 uh->uh_sport = htons(t->sport);
177 uh->uh_dport = htons(t->dport);
178 return m;
179 }
180
181 bool
182 npf_nat_test(bool verbose)
183 {
184 for (unsigned i = 0; i < __arraycount(test_cases); i++) {
185 const struct test_case *t = &test_cases[i];
186 ifnet_t *ifp = ifunit(t->ifname);
187 struct mbuf *m = fill_packet(t);
188 int error;
189 bool ret;
190
191 if (ifp == NULL) {
192 printf("Interface %s is not configured.\n", t->ifname);
193 return false;
194 }
195 error = npf_packet_handler(NULL, &m, ifp, t->di);
196 ret = checkresult(verbose, i, m, ifp, error);
197 if (m) {
198 m_freem(m);
199 }
200 if (!ret) {
201 return false;
202 }
203 }
204 return true;
205 }
206