1 | /* |
2 | * Copyright (c) 2010-2021 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | |
29 | #include <string.h> |
30 | #include <stdint.h> |
31 | #include <stdbool.h> |
32 | |
33 | #include <mach/mach_types.h> |
34 | |
35 | #include <kern/kalloc.h> |
36 | #include <kern/locks.h> |
37 | #include <kern/debug.h> |
38 | |
39 | #include <sys/kernel.h> |
40 | #include <sys/param.h> |
41 | #include <sys/sockio.h> |
42 | #include <sys/socket.h> |
43 | #include <sys/queue.h> |
44 | #include <sys/cdefs.h> |
45 | #include <sys/kern_control.h> |
46 | #include <sys/mbuf.h> |
47 | #include <sys/sysctl.h> |
48 | |
49 | #include <net/if_types.h> |
50 | #include <net/if.h> |
51 | #include <net/kpi_interface.h> |
52 | #include <net/bpf.h> |
53 | #include <net/remote_vif.h> |
54 | |
55 | #include <libkern/libkern.h> |
56 | #include <libkern/OSAtomic.h> |
57 | |
58 | #include <os/log.h> |
59 | |
60 | #define RVI_IF_NAME "rvi" |
61 | |
62 | #define RVI_DIR_IN IFF_LINK0 |
63 | #define RVI_DIR_OUT IFF_LINK1 |
64 | #define RVI_DIR_INOUT (RVI_DIR_IN | RVI_DIR_OUT) |
65 | |
66 | #define RVI_IF_FAMILY IFNET_FAMILY_LOOPBACK |
67 | #define RVI_IF_TYPE IFT_OTHER |
68 | #define RVI_IF_FLAGS (IFF_UP | IFF_DEBUG | RVI_DIR_INOUT) |
69 | |
70 | struct rvi_client_t { |
71 | LIST_ENTRY(rvi_client_t) _cle; |
72 | ifnet_t _ifp; |
73 | uint32_t _unit; |
74 | uint32_t _vif; |
75 | uint32_t _raw_count; |
76 | uint32_t _pktap_count; |
77 | }; |
78 | |
79 | static LIST_HEAD(, rvi_client_t) _s_rvi_clients; |
80 | |
81 | static LCK_GRP_DECLARE(rvi_grp, "remote virtual interface lock" ); |
82 | static LCK_RW_DECLARE(rvi_mtx, &rvi_grp); |
83 | |
84 | static kern_ctl_ref rvi_kernctl = NULL; |
85 | |
86 | kern_return_t rvi_start(kmod_info_t *, void *); |
87 | kern_return_t rvi_stop(kmod_info_t *, void *); |
88 | |
89 | static void rvi_insert_client(struct rvi_client_t *); |
90 | static errno_t rvi_create_if(struct rvi_client_t *); |
91 | static errno_t rvi_destroy_if(struct rvi_client_t *); |
92 | |
93 | static inline void rvi_lock_shared(lck_rw_t *); |
94 | static inline void rvi_lock_exclusive(lck_rw_t *); |
95 | static inline void rvi_lock_done_shared(lck_rw_t *); |
96 | static inline void rvi_lock_done_exclusive(lck_rw_t *); |
97 | |
98 | static errno_t rvi_output(ifnet_t, mbuf_t); |
99 | static errno_t rvi_demux(ifnet_t, mbuf_t, char *, protocol_family_t *); |
100 | static errno_t rvi_ioctl(ifnet_t, unsigned long, void *); |
101 | static errno_t rvi_add_proto(ifnet_t, protocol_family_t, const struct ifnet_demux_desc *, uint32_t); |
102 | static errno_t rvi_del_proto(ifnet_t, protocol_family_t); |
103 | static errno_t rvi_set_bpf_tap(ifnet_t, uint32_t, bpf_tap_mode); |
104 | static void rvi_detach(ifnet_t); |
105 | |
106 | static errno_t rvi_bpf_tap(ifnet_t, mbuf_t, int, struct rvi_client_t *, struct pktap_header *); |
107 | |
108 | static errno_t rvi_register_control(void); |
109 | static errno_t rvi_ctl_connect(kern_ctl_ref, struct sockaddr_ctl *, void **); |
110 | static errno_t rvi_ctl_send(kern_ctl_ref, uint32_t, void *, mbuf_t, int); |
111 | static errno_t rvi_ctl_disconnect(kern_ctl_ref, uint32_t, void *); |
112 | static errno_t rvi_ctl_getopt(kern_ctl_ref, uint32_t, void *, int, void *, size_t *); |
113 | |
114 | int |
115 | rvi_init() |
116 | { |
117 | int error = 0; |
118 | |
119 | if ((error = rvi_register_control()) != 0) { |
120 | os_log(OS_LOG_DEFAULT, "rvi_start failed: rvi_register_control failure" ); |
121 | return error; |
122 | } |
123 | |
124 | return 0; |
125 | } |
126 | |
127 | static inline void |
128 | rvi_lock_shared(lck_rw_t *mtx) |
129 | { |
130 | lck_rw_lock_shared(lck: mtx); |
131 | } |
132 | |
133 | static inline void |
134 | rvi_lock_exclusive(lck_rw_t *mtx) |
135 | { |
136 | lck_rw_lock_exclusive(lck: mtx); |
137 | } |
138 | |
139 | static inline void |
140 | rvi_lock_done_shared(lck_rw_t *mtx) |
141 | { |
142 | lck_rw_unlock_shared(lck: mtx); |
143 | } |
144 | |
145 | static inline void |
146 | rvi_lock_done_exclusive(lck_rw_t *mtx) |
147 | { |
148 | lck_rw_unlock_exclusive(lck: mtx); |
149 | } |
150 | |
151 | static errno_t |
152 | rvi_create_if(struct rvi_client_t *client) |
153 | { |
154 | errno_t err = 0; |
155 | struct ifnet_init_params rvi_ifinit; |
156 | |
157 | memset(s: &rvi_ifinit, c: 0x0, n: sizeof(rvi_ifinit)); |
158 | rvi_ifinit.name = RVI_IF_NAME; |
159 | rvi_ifinit.unit = client->_vif; |
160 | rvi_ifinit.type = RVI_IF_TYPE; |
161 | rvi_ifinit.family = RVI_IF_FAMILY; |
162 | rvi_ifinit.output = rvi_output; |
163 | rvi_ifinit.demux = rvi_demux; |
164 | rvi_ifinit.add_proto = rvi_add_proto; |
165 | rvi_ifinit.del_proto = rvi_del_proto; |
166 | rvi_ifinit.ioctl = rvi_ioctl; |
167 | rvi_ifinit.detach = rvi_detach; |
168 | rvi_ifinit.softc = client; |
169 | |
170 | err = ifnet_allocate(&rvi_ifinit, &client->_ifp); |
171 | if (err != 0) { |
172 | os_log(OS_LOG_DEFAULT, "%s: ifnet_allocate for %s%d failed - %d" , |
173 | __func__, RVI_IF_NAME, client->_vif, err); |
174 | goto done; |
175 | } |
176 | |
177 | ifnet_set_flags(interface: client->_ifp, RVI_IF_FLAGS, RVI_IF_FLAGS); |
178 | |
179 | err = ifnet_attach(interface: client->_ifp, NULL); |
180 | if (err != 0) { |
181 | os_log(OS_LOG_DEFAULT, "%s: ifnet_attach for %s%d failed - %d" , |
182 | __func__, RVI_IF_NAME, client->_vif, err); |
183 | ifnet_release(interface: client->_ifp); |
184 | goto done; |
185 | } |
186 | |
187 | bpf_attach(interface: client->_ifp, DLT_PKTAP, header_length: sizeof(struct pktap_header), NULL, |
188 | tap: rvi_set_bpf_tap); |
189 | bpf_attach(interface: client->_ifp, DLT_RAW, header_length: 0, NULL, tap: rvi_set_bpf_tap); |
190 | done: |
191 | return err; |
192 | } |
193 | |
194 | static errno_t |
195 | rvi_destroy_if(struct rvi_client_t *client) |
196 | { |
197 | errno_t err = 0; |
198 | |
199 | if (client == NULL) { |
200 | goto done; |
201 | } |
202 | |
203 | err = ifnet_detach(interface: client->_ifp); |
204 | if (err != 0) { |
205 | os_log(OS_LOG_DEFAULT, "%s: ifnet_detach for %s%d failed - %d" , |
206 | __func__, RVI_IF_NAME, client->_vif, err); |
207 | } |
208 | done: |
209 | return err; |
210 | } |
211 | |
212 | static void |
213 | rvi_detach(ifnet_t ifp) |
214 | { |
215 | struct rvi_client_t *client; |
216 | |
217 | rvi_lock_exclusive(mtx: &rvi_mtx); |
218 | |
219 | client = ifnet_softc(interface: ifp); |
220 | LIST_REMOVE(client, _cle); |
221 | |
222 | ifnet_release(interface: ifp); |
223 | |
224 | rvi_lock_done_exclusive(mtx: &rvi_mtx); |
225 | |
226 | kfree_type(struct rvi_client_t, client); |
227 | } |
228 | |
229 | static void |
230 | rvi_insert_client(struct rvi_client_t *client) |
231 | { |
232 | struct rvi_client_t *itr = NULL; |
233 | uint32_t ph = 0; |
234 | |
235 | rvi_lock_exclusive(mtx: &rvi_mtx); |
236 | |
237 | if (LIST_EMPTY(&_s_rvi_clients)) { |
238 | LIST_INSERT_HEAD(&_s_rvi_clients, client, _cle); |
239 | } else { |
240 | LIST_FOREACH(itr, &_s_rvi_clients, _cle) { |
241 | if (ph != itr->_vif) { |
242 | LIST_INSERT_BEFORE(itr, client, _cle); |
243 | break; |
244 | } |
245 | |
246 | ph++; |
247 | |
248 | if (LIST_NEXT(itr, _cle) == NULL) { |
249 | LIST_INSERT_AFTER(itr, client, _cle); |
250 | break; |
251 | } |
252 | } |
253 | } |
254 | |
255 | rvi_lock_done_exclusive(mtx: &rvi_mtx); |
256 | |
257 | client->_vif = ph; |
258 | } |
259 | |
260 | static void |
261 | rvi_remove_client(uint32_t unit) |
262 | { |
263 | struct rvi_client_t *client = NULL; |
264 | |
265 | rvi_lock_shared(mtx: &rvi_mtx); |
266 | |
267 | LIST_FOREACH(client, &_s_rvi_clients, _cle) { |
268 | if (client->_unit == unit) { |
269 | break; |
270 | } |
271 | } |
272 | |
273 | rvi_lock_done_shared(mtx: &rvi_mtx); |
274 | |
275 | if (client == NULL) { |
276 | panic("rvi_ctl_disconnect: received a disconnect notification without a cache entry" ); |
277 | } |
278 | |
279 | (void)rvi_destroy_if(client); |
280 | } |
281 | |
282 | |
283 | static errno_t |
284 | rvi_register_control(void) |
285 | { |
286 | errno_t err = 0; |
287 | struct kern_ctl_reg kern_ctl; |
288 | |
289 | bzero(s: &kern_ctl, n: sizeof(kern_ctl)); |
290 | strlcpy(dst: kern_ctl.ctl_name, RVI_CONTROL_NAME, n: sizeof(kern_ctl.ctl_name)); |
291 | kern_ctl.ctl_name[sizeof(kern_ctl.ctl_name) - 1] = 0; |
292 | kern_ctl.ctl_flags = CTL_FLAG_PRIVILEGED; |
293 | kern_ctl.ctl_sendsize = RVI_BUFFERSZ; |
294 | kern_ctl.ctl_recvsize = RVI_BUFFERSZ; |
295 | kern_ctl.ctl_connect = rvi_ctl_connect; |
296 | kern_ctl.ctl_disconnect = rvi_ctl_disconnect; |
297 | kern_ctl.ctl_send = rvi_ctl_send; |
298 | kern_ctl.ctl_setopt = NULL; |
299 | kern_ctl.ctl_getopt = rvi_ctl_getopt; |
300 | |
301 | err = ctl_register(userkctl: &kern_ctl, kctlref: &rvi_kernctl); |
302 | |
303 | return err; |
304 | } |
305 | |
306 | static errno_t |
307 | rvi_ctl_connect(kern_ctl_ref kctlref, struct sockaddr_ctl *sac, void **unitinfo) |
308 | { |
309 | #pragma unused(kctlref) |
310 | errno_t err = 0; |
311 | struct rvi_client_t *client = NULL; |
312 | |
313 | client = kalloc_type(struct rvi_client_t, Z_WAITOK | Z_ZERO | Z_NOFAIL); |
314 | |
315 | client->_unit = sac->sc_unit; |
316 | rvi_insert_client(client); |
317 | |
318 | err = rvi_create_if(client); |
319 | if (err != 0) { |
320 | os_log(OS_LOG_DEFAULT, "%s: failure to create virtual interface %d" , |
321 | __func__, err); |
322 | } |
323 | *unitinfo = client; |
324 | |
325 | return err; |
326 | } |
327 | |
328 | static errno_t |
329 | rvi_ctl_disconnect(kern_ctl_ref kctlref, uint32_t unit, void *unitinfo) |
330 | { |
331 | #pragma unused(kctlref) |
332 | #pragma unused(unitinfo) |
333 | errno_t err = 0; |
334 | |
335 | rvi_remove_client(unit); |
336 | |
337 | return err; |
338 | } |
339 | |
340 | static errno_t |
341 | rvi_ctl_getopt(kern_ctl_ref kctlref, uint32_t unit, void *unitinfo, |
342 | int opt, void *data, size_t *len) |
343 | { |
344 | #pragma unused(kctlref) |
345 | #pragma unused(unit) |
346 | errno_t err = 0; |
347 | int n; |
348 | struct rvi_client_t *client = (struct rvi_client_t *)unitinfo; |
349 | |
350 | rvi_lock_shared(mtx: &rvi_mtx); |
351 | |
352 | switch (opt) { |
353 | case RVI_COMMAND_GET_INTERFACE: |
354 | if (data == NULL || len == NULL) { |
355 | err = EINVAL; |
356 | break; |
357 | } |
358 | n = scnprintf(data, count: *len, "%s%u" , ifnet_name(interface: client->_ifp), |
359 | ifnet_unit(interface: client->_ifp)); |
360 | |
361 | *len = n + 1; |
362 | break; |
363 | |
364 | case RVI_COMMAND_VERSION: |
365 | if (data == NULL || len == NULL || *len < sizeof(int)) { |
366 | err = EINVAL; |
367 | break; |
368 | } |
369 | *(int *)data = RVI_VERSION_CURRENT; |
370 | *len = sizeof(int); |
371 | break; |
372 | |
373 | default: |
374 | err = ENOPROTOOPT; |
375 | break; |
376 | } |
377 | |
378 | rvi_lock_done_shared(mtx: &rvi_mtx); |
379 | |
380 | return err; |
381 | } |
382 | |
383 | static errno_t |
384 | rvi_ctl_send(kern_ctl_ref kctlref, uint32_t unit, void *unitinfo, mbuf_t m, int flags) |
385 | { |
386 | #pragma unused(kctlref) |
387 | #pragma unused(unit) |
388 | #pragma unused(flags) |
389 | errno_t err = 0; |
390 | struct rvi_client_t *client = (struct rvi_client_t *)unitinfo; |
391 | struct pktap_header pktap_hdr; |
392 | uint32_t hdr_length; |
393 | |
394 | err = mbuf_copydata(mbuf: m, offset: 0, length: sizeof(struct pktap_header), out_data: (void *)&pktap_hdr); |
395 | if (err != 0) { |
396 | os_log(OS_LOG_DEFAULT, "%s: mbuf_copydata failed %d" , __func__, err); |
397 | goto done; |
398 | } |
399 | hdr_length = pktap_hdr.pth_length; |
400 | |
401 | mbuf_adj(mbuf: m, len: hdr_length); |
402 | |
403 | rvi_lock_shared(mtx: &rvi_mtx); |
404 | |
405 | err = rvi_bpf_tap(client->_ifp, m, |
406 | pktap_hdr.pth_flags & PTH_FLAG_DIR_OUT ? 1 : 0, |
407 | client, &pktap_hdr); |
408 | |
409 | rvi_lock_done_shared(mtx: &rvi_mtx); |
410 | done: |
411 | mbuf_freem(mbuf: m); |
412 | return err; |
413 | } |
414 | |
415 | static errno_t |
416 | rvi_output(ifnet_t ifp, mbuf_t m) |
417 | { |
418 | #pragma unused(ifp) |
419 | |
420 | mbuf_freem(mbuf: m); |
421 | return 0; |
422 | } |
423 | |
424 | static errno_t |
425 | rvi_demux(ifnet_t ifp, mbuf_t m, char *, protocol_family_t *ppf) |
426 | { |
427 | #pragma unused(ifp) |
428 | #pragma unused(m) |
429 | #pragma unused(header) |
430 | #pragma unused(ppf) |
431 | |
432 | return ENOTSUP; |
433 | } |
434 | |
435 | static errno_t |
436 | rvi_add_proto( ifnet_t ifp, protocol_family_t pf, |
437 | const struct ifnet_demux_desc *dmx, uint32_t cnt) |
438 | { |
439 | #pragma unused(ifp) |
440 | #pragma unused(pf) |
441 | #pragma unused(dmx) |
442 | #pragma unused(cnt) |
443 | |
444 | return EINVAL; |
445 | } |
446 | |
447 | static errno_t |
448 | rvi_del_proto(ifnet_t ifp, protocol_family_t pf) |
449 | { |
450 | #pragma unused(ifp) |
451 | #pragma unused(pf) |
452 | |
453 | return EINVAL; |
454 | } |
455 | |
456 | static errno_t |
457 | rvi_ioctl(ifnet_t ifp, unsigned long cmd, void *data) |
458 | { |
459 | #pragma unused(ifp) |
460 | #pragma unused(cmd) |
461 | #pragma unused(data) |
462 | |
463 | return ENOTSUP; |
464 | } |
465 | |
466 | static errno_t |
467 | rvi_set_bpf_tap(ifnet_t ifp, uint32_t dlt, bpf_tap_mode mode) |
468 | { |
469 | struct rvi_client_t *client; |
470 | |
471 | rvi_lock_shared(mtx: &rvi_mtx); |
472 | |
473 | client = ifnet_softc(interface: ifp); |
474 | if (client == NULL) { |
475 | os_log(OS_LOG_DEFAULT, "%s: ifnet_softc is NULL for ifp %p" , __func__, ifp); |
476 | goto done; |
477 | } |
478 | switch (dlt) { |
479 | case DLT_RAW: |
480 | if (mode == 0) { |
481 | if (client->_raw_count > 0) { |
482 | client->_raw_count--; |
483 | } |
484 | } else { |
485 | client->_raw_count++; |
486 | } |
487 | break; |
488 | case DLT_PKTAP: |
489 | if (mode == 0) { |
490 | if (client->_pktap_count > 0) { |
491 | client->_pktap_count--; |
492 | } |
493 | } else { |
494 | client->_pktap_count++; |
495 | } |
496 | break; |
497 | } |
498 | done: |
499 | rvi_lock_done_shared(mtx: &rvi_mtx); |
500 | |
501 | return 0; |
502 | } |
503 | |
504 | /* |
505 | * Note: called with the rvi lock taken as shared |
506 | */ |
507 | static errno_t |
508 | rvi_bpf_tap(ifnet_t ifp, mbuf_t m, int outgoing, struct rvi_client_t *client, |
509 | struct pktap_header *pktap_hdr) |
510 | { |
511 | #pragma unused(ifp) |
512 | errno_t err = 0; |
513 | void (*bpf_tap_fn)(ifnet_t, uint32_t, mbuf_t, void *, size_t ) = |
514 | outgoing ? bpf_tap_out : bpf_tap_in; |
515 | |
516 | if (client->_pktap_count > 0) { |
517 | bpf_tap_fn(client->_ifp, DLT_PKTAP, m, pktap_hdr, |
518 | sizeof(struct pktap_header)); |
519 | } |
520 | |
521 | if (client->_raw_count > 0 && |
522 | (pktap_hdr->pth_protocol_family == AF_INET || |
523 | pktap_hdr->pth_protocol_family == AF_INET6)) { |
524 | /* |
525 | * We can play just with the length of the first mbuf in the |
526 | * chain because bpf_tap_imp() disregard the packet length |
527 | * of the mbuf packet header. |
528 | */ |
529 | if (pktap_hdr->pth_frame_pre_length > mbuf_len(mbuf: m)) { |
530 | err = mbuf_pullup(mbuf: &m, len: pktap_hdr->pth_frame_pre_length); |
531 | if (err != 0) { |
532 | os_log(OS_LOG_DEFAULT, "%s mbuf_pullup failed" , __func__); |
533 | return 0; |
534 | } |
535 | } |
536 | |
537 | if (mbuf_setdata(mbuf: m, data: m_mtod_current(m) + pktap_hdr->pth_frame_pre_length, |
538 | len: m->m_len - pktap_hdr->pth_frame_pre_length) == 0) { |
539 | bpf_tap_fn(client->_ifp, DLT_RAW, m, NULL, 0); |
540 | mbuf_setdata(mbuf: m, data: m_mtod_current(m) - pktap_hdr->pth_frame_pre_length, |
541 | len: m->m_len + pktap_hdr->pth_frame_pre_length); |
542 | } |
543 | } |
544 | |
545 | return err; |
546 | } |
547 | |