1 /*
2  * NPF initialisation and handler routines.
3  *
4  * Public Domain.
5  */
6 
7 #ifdef _KERNEL
8 #include <sys/types.h>
9 #include <sys/cprng.h>
10 #include <sys/kmem.h>
11 #include <net/if.h>
12 #include <net/if_types.h>
13 #endif
14 
15 #include "npf_impl.h"
16 #include "npf_test.h"
17 
18 /* State of the current stream. */
19 static npf_state_t  cstream_state;
20 static void *                 cstream_ptr;
21 static bool                   cstream_retval;
22 
23 static long                   (*_random_func)(void);
24 static int                    (*_pton_func)(int, const char *, void *);
25 static const char * (*_ntop_func)(int, const void *, char *, socklen_t);
26 
27 static void                   npf_state_sample(npf_state_t *, bool);
28 
29 static void                   load_npf_config_ifs(nvlist_t *, bool);
30 
31 #ifndef __NetBSD__
32 /*
33  * Standalone NPF: we define the same struct ifnet members
34  * to reduce the npf_ifops_t implementation differences.
35  */
36 struct ifnet {
37           char                if_xname[32];
38           void *              if_softc;
39           TAILQ_ENTRY(ifnet) if_list;
40 };
41 #endif
42 
43 static TAILQ_HEAD(, ifnet) npftest_ifnet_list =
44     TAILQ_HEAD_INITIALIZER(npftest_ifnet_list);
45 
46 static const char * npftest_ifop_getname(npf_t *, ifnet_t *);
47 static ifnet_t *    npftest_ifop_lookup(npf_t *, const char *);
48 static void                   npftest_ifop_flush(npf_t *, void *);
49 static void *                 npftest_ifop_getmeta(npf_t *, const ifnet_t *);
50 static void                   npftest_ifop_setmeta(npf_t *, ifnet_t *, void *);
51 
52 const npf_ifops_t npftest_ifops = {
53           .getname  = npftest_ifop_getname,
54           .lookup             = npftest_ifop_lookup,
55           .flush              = npftest_ifop_flush,
56           .getmeta  = npftest_ifop_getmeta,
57           .setmeta  = npftest_ifop_setmeta,
58 };
59 
60 void
npf_test_init(int (* pton_func)(int,const char *,void *),const char * (* ntop_func)(int,const void *,char *,socklen_t),long (* rndfunc)(void))61 npf_test_init(int (*pton_func)(int, const char *, void *),
62     const char *(*ntop_func)(int, const void *, char *, socklen_t),
63     long (*rndfunc)(void))
64 {
65           npf_t *npf;
66 
67 #ifdef __NetBSD__
68           // XXX: Workaround for npf_init()
69           if ((npf = npf_getkernctx()) != NULL) {
70                     npf_worker_discharge(npf);
71                     npf_worker_sysfini();
72           }
73 #endif
74           npf = npfk_create(0, &npftest_mbufops, &npftest_ifops, NULL);
75           npfk_thread_register(npf);
76           npf_setkernctx(npf);
77 
78           npf_state_setsampler(npf_state_sample);
79           _pton_func = pton_func;
80           _ntop_func = ntop_func;
81           _random_func = rndfunc;
82 
83           (void)npf_test_addif(IFNAME_DUMMY, false, false);
84 }
85 
86 void
npf_test_fini(void)87 npf_test_fini(void)
88 {
89           npf_t *npf = npf_getkernctx();
90 
91           npfk_thread_unregister(npf);
92           npfk_destroy(npf);
93 }
94 
95 int
npf_test_load(const void * buf,size_t len,bool verbose)96 npf_test_load(const void *buf, size_t len, bool verbose)
97 {
98           nvlist_t *npf_dict;
99           npf_error_t error;
100           int ret;
101 
102           npf_dict = nvlist_unpack(buf, len, 0);
103           if (!npf_dict) {
104                     printf("%s: could not unpack the nvlist\n", __func__);
105                     return EINVAL;
106           }
107           load_npf_config_ifs(npf_dict, verbose);
108           ret = npfk_load(npf_getkernctx(), npf_dict, &error);
109           nvlist_destroy(npf_dict);
110           return ret;
111 }
112 
113 ifnet_t *
npf_test_addif(const char * ifname,bool reg,bool verbose)114 npf_test_addif(const char *ifname, bool reg, bool verbose)
115 {
116           npf_t *npf = npf_getkernctx();
117           ifnet_t *ifp = kmem_zalloc(sizeof(*ifp), KM_SLEEP);
118 
119           /*
120            * This is a "fake" interface with explicitly set index.
121            * Note: test modules may not setup pfil(9) hooks and if_attach()
122            * may not trigger npf_ifmap_attach(), so we call it manually.
123            */
124           strlcpy(ifp->if_xname, ifname, sizeof(ifp->if_xname));
125           TAILQ_INSERT_TAIL(&npftest_ifnet_list, ifp, if_list);
126 
127           npfk_ifmap_attach(npf, ifp);
128           if (reg) {
129                     npf_ifmap_register(npf, ifname);
130           }
131 
132           if (verbose) {
133                     printf("+ Interface %s\n", ifname);
134           }
135           return ifp;
136 }
137 
138 ifnet_t *
npf_test_getif(const char * ifname)139 npf_test_getif(const char *ifname)
140 {
141           ifnet_t *ifp;
142 
143           TAILQ_FOREACH(ifp, &npftest_ifnet_list, if_list) {
144                     if (!strcmp(ifp->if_xname, ifname))
145                               return ifp;
146           }
147           return NULL;
148 }
149 
150 static void
load_npf_config_ifs(nvlist_t * npf_dict,bool verbose)151 load_npf_config_ifs(nvlist_t *npf_dict, bool verbose)
152 {
153           const nvlist_t * const *iflist;
154           const nvlist_t *dbg_dict;
155           size_t nitems;
156 
157           dbg_dict = dnvlist_get_nvlist(npf_dict, "debug", NULL);
158           if (!dbg_dict) {
159                     return;
160           }
161           if (!nvlist_exists_nvlist_array(dbg_dict, "interfaces")) {
162                     return;
163           }
164           iflist = nvlist_get_nvlist_array(dbg_dict, "interfaces", &nitems);
165           for (unsigned i = 0; i < nitems; i++) {
166                     const nvlist_t *ifdict = iflist[i];
167                     const char *ifname;
168 
169                     if ((ifname = nvlist_get_string(ifdict, "name")) != NULL) {
170                               (void)npf_test_addif(ifname, true, verbose);
171                     }
172           }
173 }
174 
175 static const char *
npftest_ifop_getname(npf_t * npf __unused,ifnet_t * ifp)176 npftest_ifop_getname(npf_t *npf __unused, ifnet_t *ifp)
177 {
178           return ifp->if_xname;
179 }
180 
181 static ifnet_t *
npftest_ifop_lookup(npf_t * npf __unused,const char * ifname)182 npftest_ifop_lookup(npf_t *npf __unused, const char *ifname)
183 {
184           return npf_test_getif(ifname);
185 }
186 
187 static void
npftest_ifop_flush(npf_t * npf __unused,void * arg)188 npftest_ifop_flush(npf_t *npf __unused, void *arg)
189 {
190           ifnet_t *ifp;
191 
192           TAILQ_FOREACH(ifp, &npftest_ifnet_list, if_list)
193                     ifp->if_softc = arg;
194 }
195 
196 static void *
npftest_ifop_getmeta(npf_t * npf __unused,const ifnet_t * ifp)197 npftest_ifop_getmeta(npf_t *npf __unused, const ifnet_t *ifp)
198 {
199           return ifp->if_softc;
200 }
201 
202 static void
npftest_ifop_setmeta(npf_t * npf __unused,ifnet_t * ifp,void * arg)203 npftest_ifop_setmeta(npf_t *npf __unused, ifnet_t *ifp, void *arg)
204 {
205           ifp->if_softc = arg;
206 }
207 
208 /*
209  * State sampler - this routine is called from inside of NPF state engine.
210  */
211 static void
npf_state_sample(npf_state_t * nst,bool retval)212 npf_state_sample(npf_state_t *nst, bool retval)
213 {
214           /* Pointer will serve as an ID. */
215           cstream_ptr = nst;
216           memcpy(&cstream_state, nst, sizeof(npf_state_t));
217           cstream_retval = retval;
218 }
219 
220 int
npf_test_statetrack(const void * data,size_t len,ifnet_t * ifp,bool forw,int64_t * result)221 npf_test_statetrack(const void *data, size_t len, ifnet_t *ifp,
222     bool forw, int64_t *result)
223 {
224           npf_t *npf = npf_getkernctx();
225           struct mbuf *m;
226           int i = 0, error;
227 
228           m = mbuf_getwithdata(data, len);
229           error = npfk_packet_handler(npf, &m, ifp, forw ? PFIL_OUT : PFIL_IN);
230           if (error) {
231                     assert(m == NULL);
232                     return error;
233           }
234           assert(m != NULL);
235           m_freem(m);
236 
237           const int di = forw ? NPF_FLOW_FORW : NPF_FLOW_BACK;
238           npf_tcpstate_t *fstate = &cstream_state.nst_tcpst[di];
239           npf_tcpstate_t *tstate = &cstream_state.nst_tcpst[!di];
240 
241           result[i++] = (intptr_t)cstream_ptr;
242           result[i++] = cstream_retval;
243           result[i++] = cstream_state.nst_state;
244 
245           result[i++] = fstate->nst_end;
246           result[i++] = fstate->nst_maxend;
247           result[i++] = fstate->nst_maxwin;
248           result[i++] = fstate->nst_wscale;
249 
250           result[i++] = tstate->nst_end;
251           result[i++] = tstate->nst_maxend;
252           result[i++] = tstate->nst_maxwin;
253           result[i++] = tstate->nst_wscale;
254 
255           return 0;
256 }
257 
258 int
npf_inet_pton(int af,const char * src,void * dst)259 npf_inet_pton(int af, const char *src, void *dst)
260 {
261           return _pton_func(af, src, dst);
262 }
263 
264 const char *
npf_inet_ntop(int af,const void * src,char * dst,socklen_t size)265 npf_inet_ntop(int af, const void *src, char *dst, socklen_t size)
266 {
267           return _ntop_func(af, src, dst, size);
268 }
269 
270 #ifdef _KERNEL
271 /*
272  * Need to override cprng_fast32() -- we need deterministic PRNG.
273  */
274 uint32_t
cprng_fast32(void)275 cprng_fast32(void)
276 {
277           return (uint32_t)(_random_func ? _random_func() : random());
278 }
279 #endif
280