1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6 #include <stdio.h>
7 #include <unistd.h>
8 #include <stdarg.h>
9 #include <errno.h>
10 #include <stddef.h>
11 #include <string.h>
12 #include <sys/ioctl.h>
13 #include <net/if.h>
14 #include <linux/if_tun.h>
15 #include <arpa/inet.h>
16 #include <sys/types.h>
17 #include <sys/stat.h>
18 #include <fcntl.h>
19 #include <sys/socket.h>
20 #include <sys/un.h>
21 #include <net/ethernet.h>
22 #include <netinet/ip.h>
23 #include <netinet/ether.h>
24 #include <linux/if_ether.h>
25 #include <linux/if_packet.h>
26 #include <sys/wait.h>
27 #include <sys/uio.h>
28 #include <linux/virtio_net.h>
29 #include <netdb.h>
30 #include <stdlib.h>
31 #include <os.h>
32 #include <um_malloc.h>
33 #include "vector_user.h"
34
35 #define ID_GRE 0
36 #define ID_L2TPV3 1
37 #define ID_BESS 2
38 #define ID_MAX 2
39
40 #define TOKEN_IFNAME "ifname"
41
42 #define TRANS_RAW "raw"
43 #define TRANS_RAW_LEN strlen(TRANS_RAW)
44
45 #define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
46 #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
47 #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
48 #define UNIX_BIND_FAIL "unix_open : could not bind socket err=%i"
49 #define BPF_ATTACH_FAIL "Failed to attach filter size %d to %d, err %d\n"
50
51 #define MAX_UN_LEN 107
52
53 /* This is very ugly and brute force lookup, but it is done
54 * only once at initialization so not worth doing hashes or
55 * anything more intelligent
56 */
57
uml_vector_fetch_arg(struct arglist * ifspec,char * token)58 char *uml_vector_fetch_arg(struct arglist *ifspec, char *token)
59 {
60 int i;
61
62 for (i = 0; i < ifspec->numargs; i++) {
63 if (strcmp(ifspec->tokens[i], token) == 0)
64 return ifspec->values[i];
65 }
66 return NULL;
67
68 }
69
uml_parse_vector_ifspec(char * arg)70 struct arglist *uml_parse_vector_ifspec(char *arg)
71 {
72 struct arglist *result;
73 int pos, len;
74 bool parsing_token = true, next_starts = true;
75
76 if (arg == NULL)
77 return NULL;
78 result = uml_kmalloc(sizeof(struct arglist), UM_GFP_KERNEL);
79 if (result == NULL)
80 return NULL;
81 result->numargs = 0;
82 len = strlen(arg);
83 for (pos = 0; pos < len; pos++) {
84 if (next_starts) {
85 if (parsing_token) {
86 result->tokens[result->numargs] = arg + pos;
87 } else {
88 result->values[result->numargs] = arg + pos;
89 result->numargs++;
90 }
91 next_starts = false;
92 }
93 if (*(arg + pos) == '=') {
94 if (parsing_token)
95 parsing_token = false;
96 else
97 goto cleanup;
98 next_starts = true;
99 (*(arg + pos)) = '\0';
100 }
101 if (*(arg + pos) == ',') {
102 parsing_token = true;
103 next_starts = true;
104 (*(arg + pos)) = '\0';
105 }
106 }
107 return result;
108 cleanup:
109 printk(UM_KERN_ERR "vector_setup - Couldn't parse '%s'\n", arg);
110 kfree(result);
111 return NULL;
112 }
113
114 /*
115 * Socket/FD configuration functions. These return an structure
116 * of rx and tx descriptors to cover cases where these are not
117 * the same (f.e. read via raw socket and write via tap).
118 */
119
120 #define PATH_NET_TUN "/dev/net/tun"
121
122
create_tap_fd(char * iface)123 static int create_tap_fd(char *iface)
124 {
125 struct ifreq ifr;
126 int fd = -1;
127 int err = -ENOMEM, offload;
128
129 fd = open(PATH_NET_TUN, O_RDWR);
130 if (fd < 0) {
131 printk(UM_KERN_ERR "uml_tap: failed to open tun device\n");
132 goto tap_fd_cleanup;
133 }
134 memset(&ifr, 0, sizeof(ifr));
135 ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
136 strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
137
138 err = ioctl(fd, TUNSETIFF, (void *) &ifr);
139 if (err != 0) {
140 printk(UM_KERN_ERR "uml_tap: failed to select tap interface\n");
141 goto tap_fd_cleanup;
142 }
143
144 offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6;
145 ioctl(fd, TUNSETOFFLOAD, offload);
146 return fd;
147 tap_fd_cleanup:
148 if (fd >= 0)
149 os_close_file(fd);
150 return err;
151 }
152
create_raw_fd(char * iface,int flags,int proto)153 static int create_raw_fd(char *iface, int flags, int proto)
154 {
155 struct ifreq ifr;
156 int fd = -1;
157 struct sockaddr_ll sock;
158 int err = -ENOMEM;
159
160 fd = socket(AF_PACKET, SOCK_RAW, flags);
161 if (fd == -1) {
162 err = -errno;
163 goto raw_fd_cleanup;
164 }
165 memset(&ifr, 0, sizeof(ifr));
166 strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
167 if (ioctl(fd, SIOCGIFINDEX, (void *) &ifr) < 0) {
168 err = -errno;
169 goto raw_fd_cleanup;
170 }
171
172 sock.sll_family = AF_PACKET;
173 sock.sll_protocol = htons(proto);
174 sock.sll_ifindex = ifr.ifr_ifindex;
175
176 if (bind(fd,
177 (struct sockaddr *) &sock, sizeof(struct sockaddr_ll)) < 0) {
178 err = -errno;
179 goto raw_fd_cleanup;
180 }
181 return fd;
182 raw_fd_cleanup:
183 printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
184 if (fd >= 0)
185 os_close_file(fd);
186 return err;
187 }
188
user_init_tap_fds(struct arglist * ifspec)189 static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
190 {
191 int fd = -1;
192 char *iface;
193 struct vector_fds *result = NULL;
194
195 iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
196 if (iface == NULL) {
197 printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
198 goto tap_cleanup;
199 }
200
201 result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
202 if (result == NULL) {
203 printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
204 goto tap_cleanup;
205 }
206 result->rx_fd = -1;
207 result->tx_fd = -1;
208 result->remote_addr = NULL;
209 result->remote_addr_size = 0;
210
211 /* TAP */
212
213 fd = create_tap_fd(iface);
214 if (fd < 0) {
215 printk(UM_KERN_ERR "uml_tap: failed to create tun interface\n");
216 goto tap_cleanup;
217 }
218 result->tx_fd = fd;
219 result->rx_fd = fd;
220 return result;
221 tap_cleanup:
222 printk(UM_KERN_ERR "user_init_tap: init failed, error %d", fd);
223 if (result != NULL)
224 kfree(result);
225 return NULL;
226 }
227
user_init_hybrid_fds(struct arglist * ifspec)228 static struct vector_fds *user_init_hybrid_fds(struct arglist *ifspec)
229 {
230 char *iface;
231 struct vector_fds *result = NULL;
232
233 iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
234 if (iface == NULL) {
235 printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
236 goto hybrid_cleanup;
237 }
238
239 result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
240 if (result == NULL) {
241 printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
242 goto hybrid_cleanup;
243 }
244 result->rx_fd = -1;
245 result->tx_fd = -1;
246 result->remote_addr = NULL;
247 result->remote_addr_size = 0;
248
249 /* TAP */
250
251 result->tx_fd = create_tap_fd(iface);
252 if (result->tx_fd < 0) {
253 printk(UM_KERN_ERR "uml_tap: failed to create tun interface: %i\n", result->tx_fd);
254 goto hybrid_cleanup;
255 }
256
257 /* RAW */
258
259 result->rx_fd = create_raw_fd(iface, ETH_P_ALL, ETH_P_ALL);
260 if (result->rx_fd == -1) {
261 printk(UM_KERN_ERR
262 "uml_tap: failed to create paired raw socket: %i\n", result->rx_fd);
263 goto hybrid_cleanup;
264 }
265 return result;
266 hybrid_cleanup:
267 printk(UM_KERN_ERR "user_init_hybrid: init failed");
268 if (result != NULL)
269 kfree(result);
270 return NULL;
271 }
272
user_init_unix_fds(struct arglist * ifspec,int id)273 static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
274 {
275 int fd = -1;
276 int socktype;
277 char *src, *dst;
278 struct vector_fds *result = NULL;
279 struct sockaddr_un *local_addr = NULL, *remote_addr = NULL;
280
281 src = uml_vector_fetch_arg(ifspec, "src");
282 dst = uml_vector_fetch_arg(ifspec, "dst");
283 result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
284 if (result == NULL) {
285 printk(UM_KERN_ERR "unix open:cannot allocate remote addr");
286 goto unix_cleanup;
287 }
288 remote_addr = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
289 if (remote_addr == NULL) {
290 printk(UM_KERN_ERR "unix open:cannot allocate remote addr");
291 goto unix_cleanup;
292 }
293
294 switch (id) {
295 case ID_BESS:
296 socktype = SOCK_SEQPACKET;
297 if ((src != NULL) && (strlen(src) <= MAX_UN_LEN)) {
298 local_addr = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
299 if (local_addr == NULL) {
300 printk(UM_KERN_ERR "bess open:cannot allocate local addr");
301 goto unix_cleanup;
302 }
303 local_addr->sun_family = AF_UNIX;
304 memcpy(local_addr->sun_path, src, strlen(src) + 1);
305 }
306 if ((dst == NULL) || (strlen(dst) > MAX_UN_LEN))
307 goto unix_cleanup;
308 remote_addr->sun_family = AF_UNIX;
309 memcpy(remote_addr->sun_path, dst, strlen(dst) + 1);
310 break;
311 default:
312 printk(KERN_ERR "Unsupported unix socket type\n");
313 return NULL;
314 }
315
316 fd = socket(AF_UNIX, socktype, 0);
317 if (fd == -1) {
318 printk(UM_KERN_ERR
319 "unix open: could not open socket, error = %d",
320 -errno
321 );
322 goto unix_cleanup;
323 }
324 if (local_addr != NULL) {
325 if (bind(fd, (struct sockaddr *) local_addr, sizeof(struct sockaddr_un))) {
326 printk(UM_KERN_ERR UNIX_BIND_FAIL, errno);
327 goto unix_cleanup;
328 }
329 }
330 switch (id) {
331 case ID_BESS:
332 if (connect(fd, remote_addr, sizeof(struct sockaddr_un)) < 0) {
333 printk(UM_KERN_ERR "bess open:cannot connect to %s %i", remote_addr->sun_path, -errno);
334 goto unix_cleanup;
335 }
336 break;
337 }
338 result->rx_fd = fd;
339 result->tx_fd = fd;
340 result->remote_addr_size = sizeof(struct sockaddr_un);
341 result->remote_addr = remote_addr;
342 return result;
343 unix_cleanup:
344 if (fd >= 0)
345 os_close_file(fd);
346 if (remote_addr != NULL)
347 kfree(remote_addr);
348 if (result != NULL)
349 kfree(result);
350 return NULL;
351 }
352
user_init_raw_fds(struct arglist * ifspec)353 static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
354 {
355 int rxfd = -1, txfd = -1;
356 int err = -ENOMEM;
357 char *iface;
358 struct vector_fds *result = NULL;
359
360 iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
361 if (iface == NULL)
362 goto raw_cleanup;
363
364 rxfd = create_raw_fd(iface, ETH_P_ALL, ETH_P_ALL);
365 if (rxfd == -1) {
366 err = -errno;
367 goto raw_cleanup;
368 }
369 txfd = create_raw_fd(iface, 0, ETH_P_IP); /* Turn off RX on this fd */
370 if (txfd == -1) {
371 err = -errno;
372 goto raw_cleanup;
373 }
374 result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
375 if (result != NULL) {
376 result->rx_fd = rxfd;
377 result->tx_fd = txfd;
378 result->remote_addr = NULL;
379 result->remote_addr_size = 0;
380 }
381 return result;
382 raw_cleanup:
383 printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
384 if (result != NULL)
385 kfree(result);
386 return NULL;
387 }
388
389
uml_raw_enable_qdisc_bypass(int fd)390 bool uml_raw_enable_qdisc_bypass(int fd)
391 {
392 int optval = 1;
393
394 if (setsockopt(fd,
395 SOL_PACKET, PACKET_QDISC_BYPASS,
396 &optval, sizeof(optval)) != 0) {
397 return false;
398 }
399 return true;
400 }
401
uml_raw_enable_vnet_headers(int fd)402 bool uml_raw_enable_vnet_headers(int fd)
403 {
404 int optval = 1;
405
406 if (setsockopt(fd,
407 SOL_PACKET, PACKET_VNET_HDR,
408 &optval, sizeof(optval)) != 0) {
409 printk(UM_KERN_INFO VNET_HDR_FAIL, fd);
410 return false;
411 }
412 return true;
413 }
uml_tap_enable_vnet_headers(int fd)414 bool uml_tap_enable_vnet_headers(int fd)
415 {
416 unsigned int features;
417 int len = sizeof(struct virtio_net_hdr);
418
419 if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
420 printk(UM_KERN_INFO TUN_GET_F_FAIL, strerror(errno));
421 return false;
422 }
423 if ((features & IFF_VNET_HDR) == 0) {
424 printk(UM_KERN_INFO "tapraw: No VNET HEADER support");
425 return false;
426 }
427 ioctl(fd, TUNSETVNETHDRSZ, &len);
428 return true;
429 }
430
user_init_socket_fds(struct arglist * ifspec,int id)431 static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
432 {
433 int err = -ENOMEM;
434 int fd = -1, gairet;
435 struct addrinfo srchints;
436 struct addrinfo dsthints;
437 bool v6, udp;
438 char *value;
439 char *src, *dst, *srcport, *dstport;
440 struct addrinfo *gairesult = NULL;
441 struct vector_fds *result = NULL;
442
443
444 value = uml_vector_fetch_arg(ifspec, "v6");
445 v6 = false;
446 udp = false;
447 if (value != NULL) {
448 if (strtol((const char *) value, NULL, 10) > 0)
449 v6 = true;
450 }
451
452 value = uml_vector_fetch_arg(ifspec, "udp");
453 if (value != NULL) {
454 if (strtol((const char *) value, NULL, 10) > 0)
455 udp = true;
456 }
457 src = uml_vector_fetch_arg(ifspec, "src");
458 dst = uml_vector_fetch_arg(ifspec, "dst");
459 srcport = uml_vector_fetch_arg(ifspec, "srcport");
460 dstport = uml_vector_fetch_arg(ifspec, "dstport");
461
462 memset(&dsthints, 0, sizeof(dsthints));
463
464 if (v6)
465 dsthints.ai_family = AF_INET6;
466 else
467 dsthints.ai_family = AF_INET;
468
469 switch (id) {
470 case ID_GRE:
471 dsthints.ai_socktype = SOCK_RAW;
472 dsthints.ai_protocol = IPPROTO_GRE;
473 break;
474 case ID_L2TPV3:
475 if (udp) {
476 dsthints.ai_socktype = SOCK_DGRAM;
477 dsthints.ai_protocol = 0;
478 } else {
479 dsthints.ai_socktype = SOCK_RAW;
480 dsthints.ai_protocol = IPPROTO_L2TP;
481 }
482 break;
483 default:
484 printk(KERN_ERR "Unsupported socket type\n");
485 return NULL;
486 }
487 memcpy(&srchints, &dsthints, sizeof(struct addrinfo));
488
489 gairet = getaddrinfo(src, srcport, &dsthints, &gairesult);
490 if ((gairet != 0) || (gairesult == NULL)) {
491 printk(UM_KERN_ERR
492 "socket_open : could not resolve src, error = %s",
493 gai_strerror(gairet)
494 );
495 return NULL;
496 }
497 fd = socket(gairesult->ai_family,
498 gairesult->ai_socktype, gairesult->ai_protocol);
499 if (fd == -1) {
500 printk(UM_KERN_ERR
501 "socket_open : could not open socket, error = %d",
502 -errno
503 );
504 goto cleanup;
505 }
506 if (bind(fd,
507 (struct sockaddr *) gairesult->ai_addr,
508 gairesult->ai_addrlen)) {
509 printk(UM_KERN_ERR L2TPV3_BIND_FAIL, errno);
510 goto cleanup;
511 }
512
513 if (gairesult != NULL)
514 freeaddrinfo(gairesult);
515
516 gairesult = NULL;
517
518 gairet = getaddrinfo(dst, dstport, &dsthints, &gairesult);
519 if ((gairet != 0) || (gairesult == NULL)) {
520 printk(UM_KERN_ERR
521 "socket_open : could not resolve dst, error = %s",
522 gai_strerror(gairet)
523 );
524 return NULL;
525 }
526
527 result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
528 if (result != NULL) {
529 result->rx_fd = fd;
530 result->tx_fd = fd;
531 result->remote_addr = uml_kmalloc(
532 gairesult->ai_addrlen, UM_GFP_KERNEL);
533 if (result->remote_addr == NULL)
534 goto cleanup;
535 result->remote_addr_size = gairesult->ai_addrlen;
536 memcpy(
537 result->remote_addr,
538 gairesult->ai_addr,
539 gairesult->ai_addrlen
540 );
541 }
542 freeaddrinfo(gairesult);
543 return result;
544 cleanup:
545 if (gairesult != NULL)
546 freeaddrinfo(gairesult);
547 printk(UM_KERN_ERR "user_init_socket: init failed, error %d", err);
548 if (fd >= 0)
549 os_close_file(fd);
550 if (result != NULL) {
551 kfree(result->remote_addr);
552 kfree(result);
553 }
554 return NULL;
555 }
556
uml_vector_user_open(int unit,struct arglist * parsed)557 struct vector_fds *uml_vector_user_open(
558 int unit,
559 struct arglist *parsed
560 )
561 {
562 char *transport;
563
564 if (parsed == NULL) {
565 printk(UM_KERN_ERR "no parsed config for unit %d\n", unit);
566 return NULL;
567 }
568 transport = uml_vector_fetch_arg(parsed, "transport");
569 if (transport == NULL) {
570 printk(UM_KERN_ERR "missing transport for unit %d\n", unit);
571 return NULL;
572 }
573 if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
574 return user_init_raw_fds(parsed);
575 if (strncmp(transport, TRANS_HYBRID, TRANS_HYBRID_LEN) == 0)
576 return user_init_hybrid_fds(parsed);
577 if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
578 return user_init_tap_fds(parsed);
579 if (strncmp(transport, TRANS_GRE, TRANS_GRE_LEN) == 0)
580 return user_init_socket_fds(parsed, ID_GRE);
581 if (strncmp(transport, TRANS_L2TPV3, TRANS_L2TPV3_LEN) == 0)
582 return user_init_socket_fds(parsed, ID_L2TPV3);
583 if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
584 return user_init_unix_fds(parsed, ID_BESS);
585 return NULL;
586 }
587
588
uml_vector_sendmsg(int fd,void * hdr,int flags)589 int uml_vector_sendmsg(int fd, void *hdr, int flags)
590 {
591 int n;
592
593 CATCH_EINTR(n = sendmsg(fd, (struct msghdr *) hdr, flags));
594 if ((n < 0) && (errno == EAGAIN))
595 return 0;
596 if (n >= 0)
597 return n;
598 else
599 return -errno;
600 }
601
uml_vector_recvmsg(int fd,void * hdr,int flags)602 int uml_vector_recvmsg(int fd, void *hdr, int flags)
603 {
604 int n;
605 struct msghdr *msg = (struct msghdr *) hdr;
606
607 CATCH_EINTR(n = readv(fd, msg->msg_iov, msg->msg_iovlen));
608 if ((n < 0) && (errno == EAGAIN))
609 return 0;
610 if (n >= 0)
611 return n;
612 else
613 return -errno;
614 }
615
uml_vector_writev(int fd,void * hdr,int iovcount)616 int uml_vector_writev(int fd, void *hdr, int iovcount)
617 {
618 int n;
619
620 CATCH_EINTR(n = writev(fd, (struct iovec *) hdr, iovcount));
621 if ((n < 0) && ((errno == EAGAIN) || (errno == ENOBUFS)))
622 return 0;
623 if (n >= 0)
624 return n;
625 else
626 return -errno;
627 }
628
uml_vector_sendmmsg(int fd,void * msgvec,unsigned int vlen,unsigned int flags)629 int uml_vector_sendmmsg(
630 int fd,
631 void *msgvec,
632 unsigned int vlen,
633 unsigned int flags)
634 {
635 int n;
636
637 CATCH_EINTR(n = sendmmsg(fd, (struct mmsghdr *) msgvec, vlen, flags));
638 if ((n < 0) && ((errno == EAGAIN) || (errno == ENOBUFS)))
639 return 0;
640 if (n >= 0)
641 return n;
642 else
643 return -errno;
644 }
645
uml_vector_recvmmsg(int fd,void * msgvec,unsigned int vlen,unsigned int flags)646 int uml_vector_recvmmsg(
647 int fd,
648 void *msgvec,
649 unsigned int vlen,
650 unsigned int flags)
651 {
652 int n;
653
654 CATCH_EINTR(
655 n = recvmmsg(fd, (struct mmsghdr *) msgvec, vlen, flags, 0));
656 if ((n < 0) && (errno == EAGAIN))
657 return 0;
658 if (n >= 0)
659 return n;
660 else
661 return -errno;
662 }
uml_vector_attach_bpf(int fd,void * bpf,int bpf_len)663 int uml_vector_attach_bpf(int fd, void *bpf, int bpf_len)
664 {
665 int err = setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, bpf, bpf_len);
666
667 if (err < 0)
668 printk(KERN_ERR BPF_ATTACH_FAIL, bpf_len, fd, -errno);
669 return err;
670 }
671
672 #define DEFAULT_BPF_LEN 6
673
uml_vector_default_bpf(int fd,void * mac)674 void *uml_vector_default_bpf(int fd, void *mac)
675 {
676 struct sock_filter *bpf;
677 uint32_t *mac1 = (uint32_t *)(mac + 2);
678 uint16_t *mac2 = (uint16_t *) mac;
679 struct sock_fprog bpf_prog = {
680 .len = 6,
681 .filter = NULL,
682 };
683
684 bpf = uml_kmalloc(
685 sizeof(struct sock_filter) * DEFAULT_BPF_LEN, UM_GFP_KERNEL);
686 if (bpf != NULL) {
687 bpf_prog.filter = bpf;
688 /* ld [8] */
689 bpf[0] = (struct sock_filter){ 0x20, 0, 0, 0x00000008 };
690 /* jeq #0xMAC[2-6] jt 2 jf 5*/
691 bpf[1] = (struct sock_filter){ 0x15, 0, 3, ntohl(*mac1)};
692 /* ldh [6] */
693 bpf[2] = (struct sock_filter){ 0x28, 0, 0, 0x00000006 };
694 /* jeq #0xMAC[0-1] jt 4 jf 5 */
695 bpf[3] = (struct sock_filter){ 0x15, 0, 1, ntohs(*mac2)};
696 /* ret #0 */
697 bpf[4] = (struct sock_filter){ 0x6, 0, 0, 0x00000000 };
698 /* ret #0x40000 */
699 bpf[5] = (struct sock_filter){ 0x6, 0, 0, 0x00040000 };
700 if (uml_vector_attach_bpf(
701 fd, &bpf_prog, sizeof(struct sock_fprog)) < 0) {
702 kfree(bpf);
703 bpf = NULL;
704 }
705 }
706 return bpf;
707 }
708
709