xref: /openbmc/linux/arch/um/drivers/vector_user.c (revision e1cd7b80)
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 prog %px to %d, err %d\n"
50 #define BPF_DETACH_FAIL "Failed to detach filter size %d prog %px to %d, err %d\n"
51 
52 #define MAX_UN_LEN 107
53 
54 /* This is very ugly and brute force lookup, but it is done
55  * only once at initialization so not worth doing hashes or
56  * anything more intelligent
57  */
58 
59 char *uml_vector_fetch_arg(struct arglist *ifspec, char *token)
60 {
61 	int i;
62 
63 	for (i = 0; i < ifspec->numargs; i++) {
64 		if (strcmp(ifspec->tokens[i], token) == 0)
65 			return ifspec->values[i];
66 	}
67 	return NULL;
68 
69 }
70 
71 struct arglist *uml_parse_vector_ifspec(char *arg)
72 {
73 	struct arglist *result;
74 	int pos, len;
75 	bool parsing_token = true, next_starts = true;
76 
77 	if (arg == NULL)
78 		return NULL;
79 	result = uml_kmalloc(sizeof(struct arglist), UM_GFP_KERNEL);
80 	if (result == NULL)
81 		return NULL;
82 	result->numargs = 0;
83 	len = strlen(arg);
84 	for (pos = 0; pos < len; pos++) {
85 		if (next_starts) {
86 			if (parsing_token) {
87 				result->tokens[result->numargs] = arg + pos;
88 			} else {
89 				result->values[result->numargs] = arg + pos;
90 				result->numargs++;
91 			}
92 			next_starts = false;
93 		}
94 		if (*(arg + pos) == '=') {
95 			if (parsing_token)
96 				parsing_token = false;
97 			else
98 				goto cleanup;
99 			next_starts = true;
100 			(*(arg + pos)) = '\0';
101 		}
102 		if (*(arg + pos) == ',') {
103 			parsing_token = true;
104 			next_starts = true;
105 			(*(arg + pos)) = '\0';
106 		}
107 	}
108 	return result;
109 cleanup:
110 	printk(UM_KERN_ERR "vector_setup - Couldn't parse '%s'\n", arg);
111 	kfree(result);
112 	return NULL;
113 }
114 
115 /*
116  * Socket/FD configuration functions. These return an structure
117  * of rx and tx descriptors to cover cases where these are not
118  * the same (f.e. read via raw socket and write via tap).
119  */
120 
121 #define PATH_NET_TUN "/dev/net/tun"
122 
123 
124 static int create_tap_fd(char *iface)
125 {
126 	struct ifreq ifr;
127 	int fd = -1;
128 	int err = -ENOMEM, offload;
129 
130 	fd = open(PATH_NET_TUN, O_RDWR);
131 	if (fd < 0) {
132 		printk(UM_KERN_ERR "uml_tap: failed to open tun device\n");
133 		goto tap_fd_cleanup;
134 	}
135 	memset(&ifr, 0, sizeof(ifr));
136 	ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
137 	strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
138 
139 	err = ioctl(fd, TUNSETIFF, (void *) &ifr);
140 	if (err != 0) {
141 		printk(UM_KERN_ERR "uml_tap: failed to select tap interface\n");
142 		goto tap_fd_cleanup;
143 	}
144 
145 	offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6;
146 	ioctl(fd, TUNSETOFFLOAD, offload);
147 	return fd;
148 tap_fd_cleanup:
149 	if (fd >= 0)
150 		os_close_file(fd);
151 	return err;
152 }
153 
154 static int create_raw_fd(char *iface, int flags, int proto)
155 {
156 	struct ifreq ifr;
157 	int fd = -1;
158 	struct sockaddr_ll sock;
159 	int err = -ENOMEM;
160 
161 	fd = socket(AF_PACKET, SOCK_RAW, flags);
162 	if (fd == -1) {
163 		err = -errno;
164 		goto raw_fd_cleanup;
165 	}
166 	memset(&ifr, 0, sizeof(ifr));
167 	strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
168 	if (ioctl(fd, SIOCGIFINDEX, (void *) &ifr) < 0) {
169 		err = -errno;
170 		goto raw_fd_cleanup;
171 	}
172 
173 	sock.sll_family = AF_PACKET;
174 	sock.sll_protocol = htons(proto);
175 	sock.sll_ifindex = ifr.ifr_ifindex;
176 
177 	if (bind(fd,
178 		(struct sockaddr *) &sock, sizeof(struct sockaddr_ll)) < 0) {
179 		err = -errno;
180 		goto raw_fd_cleanup;
181 	}
182 	return fd;
183 raw_fd_cleanup:
184 	printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
185 	if (fd >= 0)
186 		os_close_file(fd);
187 	return err;
188 }
189 
190 static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
191 {
192 	int fd = -1;
193 	char *iface;
194 	struct vector_fds *result = NULL;
195 
196 	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
197 	if (iface == NULL) {
198 		printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
199 		goto tap_cleanup;
200 	}
201 
202 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
203 	if (result == NULL) {
204 		printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
205 		goto tap_cleanup;
206 	}
207 	result->rx_fd = -1;
208 	result->tx_fd = -1;
209 	result->remote_addr = NULL;
210 	result->remote_addr_size = 0;
211 
212 	/* TAP */
213 
214 	fd = create_tap_fd(iface);
215 	if (fd < 0) {
216 		printk(UM_KERN_ERR "uml_tap: failed to create tun interface\n");
217 		goto tap_cleanup;
218 	}
219 	result->tx_fd = fd;
220 	result->rx_fd = fd;
221 	return result;
222 tap_cleanup:
223 	printk(UM_KERN_ERR "user_init_tap: init failed, error %d", fd);
224 	if (result != NULL)
225 		kfree(result);
226 	return NULL;
227 }
228 
229 static struct vector_fds *user_init_hybrid_fds(struct arglist *ifspec)
230 {
231 	char *iface;
232 	struct vector_fds *result = NULL;
233 
234 	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
235 	if (iface == NULL) {
236 		printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
237 		goto hybrid_cleanup;
238 	}
239 
240 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
241 	if (result == NULL) {
242 		printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
243 		goto hybrid_cleanup;
244 	}
245 	result->rx_fd = -1;
246 	result->tx_fd = -1;
247 	result->remote_addr = NULL;
248 	result->remote_addr_size = 0;
249 
250 	/* TAP */
251 
252 	result->tx_fd = create_tap_fd(iface);
253 	if (result->tx_fd < 0) {
254 		printk(UM_KERN_ERR "uml_tap: failed to create tun interface: %i\n", result->tx_fd);
255 		goto hybrid_cleanup;
256 	}
257 
258 	/* RAW */
259 
260 	result->rx_fd = create_raw_fd(iface, ETH_P_ALL, ETH_P_ALL);
261 	if (result->rx_fd == -1) {
262 		printk(UM_KERN_ERR
263 			"uml_tap: failed to create paired raw socket: %i\n", result->rx_fd);
264 		goto hybrid_cleanup;
265 	}
266 	return result;
267 hybrid_cleanup:
268 	printk(UM_KERN_ERR "user_init_hybrid: init failed");
269 	if (result != NULL)
270 		kfree(result);
271 	return NULL;
272 }
273 
274 static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
275 {
276 	int fd = -1;
277 	int socktype;
278 	char *src, *dst;
279 	struct vector_fds *result = NULL;
280 	struct sockaddr_un *local_addr = NULL, *remote_addr = NULL;
281 
282 	src = uml_vector_fetch_arg(ifspec, "src");
283 	dst = uml_vector_fetch_arg(ifspec, "dst");
284 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
285 	if (result == NULL) {
286 		printk(UM_KERN_ERR "unix open:cannot allocate remote addr");
287 		goto unix_cleanup;
288 	}
289 	remote_addr = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
290 	if (remote_addr == NULL) {
291 		printk(UM_KERN_ERR "unix open:cannot allocate remote addr");
292 		goto unix_cleanup;
293 	}
294 
295 	switch (id) {
296 	case ID_BESS:
297 		socktype = SOCK_SEQPACKET;
298 		if ((src != NULL) && (strlen(src) <= MAX_UN_LEN)) {
299 			local_addr = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
300 			if (local_addr == NULL) {
301 				printk(UM_KERN_ERR "bess open:cannot allocate local addr");
302 				goto unix_cleanup;
303 			}
304 			local_addr->sun_family = AF_UNIX;
305 			memcpy(local_addr->sun_path, src, strlen(src) + 1);
306 		}
307 		if ((dst == NULL) || (strlen(dst) > MAX_UN_LEN))
308 			goto unix_cleanup;
309 		remote_addr->sun_family = AF_UNIX;
310 		memcpy(remote_addr->sun_path, dst, strlen(dst) + 1);
311 		break;
312 	default:
313 		printk(KERN_ERR "Unsupported unix socket type\n");
314 		return NULL;
315 	}
316 
317 	fd = socket(AF_UNIX, socktype, 0);
318 	if (fd == -1) {
319 		printk(UM_KERN_ERR
320 			"unix open: could not open socket, error = %d",
321 			-errno
322 		);
323 		goto unix_cleanup;
324 	}
325 	if (local_addr != NULL) {
326 		if (bind(fd, (struct sockaddr *) local_addr, sizeof(struct sockaddr_un))) {
327 			printk(UM_KERN_ERR UNIX_BIND_FAIL, errno);
328 			goto unix_cleanup;
329 		}
330 	}
331 	switch (id) {
332 	case ID_BESS:
333 		if (connect(fd, remote_addr, sizeof(struct sockaddr_un)) < 0) {
334 			printk(UM_KERN_ERR "bess open:cannot connect to %s %i", remote_addr->sun_path, -errno);
335 			goto unix_cleanup;
336 		}
337 		break;
338 	}
339 	result->rx_fd = fd;
340 	result->tx_fd = fd;
341 	result->remote_addr_size = sizeof(struct sockaddr_un);
342 	result->remote_addr = remote_addr;
343 	return result;
344 unix_cleanup:
345 	if (fd >= 0)
346 		os_close_file(fd);
347 	if (remote_addr != NULL)
348 		kfree(remote_addr);
349 	if (result != NULL)
350 		kfree(result);
351 	return NULL;
352 }
353 
354 static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
355 {
356 	int rxfd = -1, txfd = -1;
357 	int err = -ENOMEM;
358 	char *iface;
359 	struct vector_fds *result = NULL;
360 
361 	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
362 	if (iface == NULL)
363 		goto raw_cleanup;
364 
365 	rxfd = create_raw_fd(iface, ETH_P_ALL, ETH_P_ALL);
366 	if (rxfd == -1) {
367 		err = -errno;
368 		goto raw_cleanup;
369 	}
370 	txfd = create_raw_fd(iface, 0, ETH_P_IP); /* Turn off RX on this fd */
371 	if (txfd == -1) {
372 		err = -errno;
373 		goto raw_cleanup;
374 	}
375 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
376 	if (result != NULL) {
377 		result->rx_fd = rxfd;
378 		result->tx_fd = txfd;
379 		result->remote_addr = NULL;
380 		result->remote_addr_size = 0;
381 	}
382 	return result;
383 raw_cleanup:
384 	printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
385 	if (result != NULL)
386 		kfree(result);
387 	return NULL;
388 }
389 
390 
391 bool uml_raw_enable_qdisc_bypass(int fd)
392 {
393 	int optval = 1;
394 
395 	if (setsockopt(fd,
396 		SOL_PACKET, PACKET_QDISC_BYPASS,
397 		&optval, sizeof(optval)) != 0) {
398 		return false;
399 	}
400 	return true;
401 }
402 
403 bool uml_raw_enable_vnet_headers(int fd)
404 {
405 	int optval = 1;
406 
407 	if (setsockopt(fd,
408 		SOL_PACKET, PACKET_VNET_HDR,
409 		&optval, sizeof(optval)) != 0) {
410 		printk(UM_KERN_INFO VNET_HDR_FAIL, fd);
411 		return false;
412 	}
413 	return true;
414 }
415 bool uml_tap_enable_vnet_headers(int fd)
416 {
417 	unsigned int features;
418 	int len = sizeof(struct virtio_net_hdr);
419 
420 	if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
421 		printk(UM_KERN_INFO TUN_GET_F_FAIL, strerror(errno));
422 		return false;
423 	}
424 	if ((features & IFF_VNET_HDR) == 0) {
425 		printk(UM_KERN_INFO "tapraw: No VNET HEADER support");
426 		return false;
427 	}
428 	ioctl(fd, TUNSETVNETHDRSZ, &len);
429 	return true;
430 }
431 
432 static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
433 {
434 	int err = -ENOMEM;
435 	int fd = -1, gairet;
436 	struct addrinfo srchints;
437 	struct addrinfo dsthints;
438 	bool v6, udp;
439 	char *value;
440 	char *src, *dst, *srcport, *dstport;
441 	struct addrinfo *gairesult = NULL;
442 	struct vector_fds *result = NULL;
443 
444 
445 	value = uml_vector_fetch_arg(ifspec, "v6");
446 	v6 = false;
447 	udp = false;
448 	if (value != NULL) {
449 		if (strtol((const char *) value, NULL, 10) > 0)
450 			v6 = true;
451 	}
452 
453 	value = uml_vector_fetch_arg(ifspec, "udp");
454 	if (value != NULL) {
455 		if (strtol((const char *) value, NULL, 10) > 0)
456 			udp = true;
457 	}
458 	src = uml_vector_fetch_arg(ifspec, "src");
459 	dst = uml_vector_fetch_arg(ifspec, "dst");
460 	srcport = uml_vector_fetch_arg(ifspec, "srcport");
461 	dstport = uml_vector_fetch_arg(ifspec, "dstport");
462 
463 	memset(&dsthints, 0, sizeof(dsthints));
464 
465 	if (v6)
466 		dsthints.ai_family = AF_INET6;
467 	else
468 		dsthints.ai_family = AF_INET;
469 
470 	switch (id) {
471 	case ID_GRE:
472 		dsthints.ai_socktype = SOCK_RAW;
473 		dsthints.ai_protocol = IPPROTO_GRE;
474 		break;
475 	case ID_L2TPV3:
476 		if (udp) {
477 			dsthints.ai_socktype = SOCK_DGRAM;
478 			dsthints.ai_protocol = 0;
479 		} else {
480 			dsthints.ai_socktype = SOCK_RAW;
481 			dsthints.ai_protocol = IPPROTO_L2TP;
482 		}
483 		break;
484 	default:
485 		printk(KERN_ERR "Unsupported socket type\n");
486 		return NULL;
487 	}
488 	memcpy(&srchints, &dsthints, sizeof(struct addrinfo));
489 
490 	gairet = getaddrinfo(src, srcport, &dsthints, &gairesult);
491 	if ((gairet != 0) || (gairesult == NULL)) {
492 		printk(UM_KERN_ERR
493 			"socket_open : could not resolve src, error = %s",
494 			gai_strerror(gairet)
495 		);
496 		return NULL;
497 	}
498 	fd = socket(gairesult->ai_family,
499 		gairesult->ai_socktype, gairesult->ai_protocol);
500 	if (fd == -1) {
501 		printk(UM_KERN_ERR
502 			"socket_open : could not open socket, error = %d",
503 			-errno
504 		);
505 		goto cleanup;
506 	}
507 	if (bind(fd,
508 		(struct sockaddr *) gairesult->ai_addr,
509 		gairesult->ai_addrlen)) {
510 		printk(UM_KERN_ERR L2TPV3_BIND_FAIL, errno);
511 		goto cleanup;
512 	}
513 
514 	if (gairesult != NULL)
515 		freeaddrinfo(gairesult);
516 
517 	gairesult = NULL;
518 
519 	gairet = getaddrinfo(dst, dstport, &dsthints, &gairesult);
520 	if ((gairet != 0) || (gairesult == NULL)) {
521 		printk(UM_KERN_ERR
522 			"socket_open : could not resolve dst, error = %s",
523 			gai_strerror(gairet)
524 		);
525 		return NULL;
526 	}
527 
528 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
529 	if (result != NULL) {
530 		result->rx_fd = fd;
531 		result->tx_fd = fd;
532 		result->remote_addr = uml_kmalloc(
533 			gairesult->ai_addrlen, UM_GFP_KERNEL);
534 		if (result->remote_addr == NULL)
535 			goto cleanup;
536 		result->remote_addr_size = gairesult->ai_addrlen;
537 		memcpy(
538 			result->remote_addr,
539 			gairesult->ai_addr,
540 			gairesult->ai_addrlen
541 		);
542 	}
543 	freeaddrinfo(gairesult);
544 	return result;
545 cleanup:
546 	if (gairesult != NULL)
547 		freeaddrinfo(gairesult);
548 	printk(UM_KERN_ERR "user_init_socket: init failed, error %d", err);
549 	if (fd >= 0)
550 		os_close_file(fd);
551 	if (result != NULL) {
552 		kfree(result->remote_addr);
553 		kfree(result);
554 	}
555 	return NULL;
556 }
557 
558 struct vector_fds *uml_vector_user_open(
559 	int unit,
560 	struct arglist *parsed
561 )
562 {
563 	char *transport;
564 
565 	if (parsed == NULL) {
566 		printk(UM_KERN_ERR "no parsed config for unit %d\n", unit);
567 		return NULL;
568 	}
569 	transport = uml_vector_fetch_arg(parsed, "transport");
570 	if (transport == NULL) {
571 		printk(UM_KERN_ERR "missing transport for unit %d\n", unit);
572 		return NULL;
573 	}
574 	if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
575 		return user_init_raw_fds(parsed);
576 	if (strncmp(transport, TRANS_HYBRID, TRANS_HYBRID_LEN) == 0)
577 		return user_init_hybrid_fds(parsed);
578 	if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
579 		return user_init_tap_fds(parsed);
580 	if (strncmp(transport, TRANS_GRE, TRANS_GRE_LEN) == 0)
581 		return user_init_socket_fds(parsed, ID_GRE);
582 	if (strncmp(transport, TRANS_L2TPV3, TRANS_L2TPV3_LEN) == 0)
583 		return user_init_socket_fds(parsed, ID_L2TPV3);
584 	if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
585 		return user_init_unix_fds(parsed, ID_BESS);
586 	return NULL;
587 }
588 
589 
590 int uml_vector_sendmsg(int fd, void *hdr, int flags)
591 {
592 	int n;
593 
594 	CATCH_EINTR(n = sendmsg(fd, (struct msghdr *) hdr,  flags));
595 	if ((n < 0) && (errno == EAGAIN))
596 		return 0;
597 	if (n >= 0)
598 		return n;
599 	else
600 		return -errno;
601 }
602 
603 int uml_vector_recvmsg(int fd, void *hdr, int flags)
604 {
605 	int n;
606 	struct msghdr *msg = (struct msghdr *) hdr;
607 
608 	CATCH_EINTR(n = readv(fd, msg->msg_iov, msg->msg_iovlen));
609 	if ((n < 0) && (errno == EAGAIN))
610 		return 0;
611 	if (n >= 0)
612 		return n;
613 	else
614 		return -errno;
615 }
616 
617 int uml_vector_writev(int fd, void *hdr, int iovcount)
618 {
619 	int n;
620 
621 	CATCH_EINTR(n = writev(fd, (struct iovec *) hdr,  iovcount));
622 	if ((n < 0) && ((errno == EAGAIN) || (errno == ENOBUFS)))
623 		return 0;
624 	if (n >= 0)
625 		return n;
626 	else
627 		return -errno;
628 }
629 
630 int uml_vector_sendmmsg(
631 	int fd,
632 	void *msgvec,
633 	unsigned int vlen,
634 	unsigned int flags)
635 {
636 	int n;
637 
638 	CATCH_EINTR(n = sendmmsg(fd, (struct mmsghdr *) msgvec, vlen, flags));
639 	if ((n < 0) && ((errno == EAGAIN) || (errno == ENOBUFS)))
640 		return 0;
641 	if (n >= 0)
642 		return n;
643 	else
644 		return -errno;
645 }
646 
647 int uml_vector_recvmmsg(
648 	int fd,
649 	void *msgvec,
650 	unsigned int vlen,
651 	unsigned int flags)
652 {
653 	int n;
654 
655 	CATCH_EINTR(
656 		n = recvmmsg(fd, (struct mmsghdr *) msgvec, vlen, flags, 0));
657 	if ((n < 0) && (errno == EAGAIN))
658 		return 0;
659 	if (n >= 0)
660 		return n;
661 	else
662 		return -errno;
663 }
664 int uml_vector_attach_bpf(int fd, void *bpf)
665 {
666 	struct sock_fprog *prog = bpf;
667 
668 	int err = setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, bpf, sizeof(struct sock_fprog));
669 
670 	if (err < 0)
671 		printk(KERN_ERR BPF_ATTACH_FAIL, prog->len, prog->filter, fd, -errno);
672 	return err;
673 }
674 
675 int uml_vector_detach_bpf(int fd, void *bpf)
676 {
677 	struct sock_fprog *prog = bpf;
678 
679 	int err = setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, bpf, sizeof(struct sock_fprog));
680 	if (err < 0)
681 		printk(KERN_ERR BPF_DETACH_FAIL, prog->len, prog->filter, fd, -errno);
682 	return err;
683 }
684 void *uml_vector_default_bpf(void *mac)
685 {
686 	struct sock_filter *bpf;
687 	uint32_t *mac1 = (uint32_t *)(mac + 2);
688 	uint16_t *mac2 = (uint16_t *) mac;
689 	struct sock_fprog *bpf_prog;
690 
691 	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
692 	if (bpf_prog) {
693 		bpf_prog->len = DEFAULT_BPF_LEN;
694 		bpf_prog->filter = NULL;
695 	} else {
696 		return NULL;
697 	}
698 	bpf = uml_kmalloc(
699 		sizeof(struct sock_filter) * DEFAULT_BPF_LEN, UM_GFP_KERNEL);
700 	if (bpf) {
701 		bpf_prog->filter = bpf;
702 		/* ld	[8] */
703 		bpf[0] = (struct sock_filter){ 0x20, 0, 0, 0x00000008 };
704 		/* jeq	#0xMAC[2-6] jt 2 jf 5*/
705 		bpf[1] = (struct sock_filter){ 0x15, 0, 3, ntohl(*mac1)};
706 		/* ldh	[6] */
707 		bpf[2] = (struct sock_filter){ 0x28, 0, 0, 0x00000006 };
708 		/* jeq	#0xMAC[0-1] jt 4 jf 5 */
709 		bpf[3] = (struct sock_filter){ 0x15, 0, 1, ntohs(*mac2)};
710 		/* ret	#0 */
711 		bpf[4] = (struct sock_filter){ 0x6, 0, 0, 0x00000000 };
712 		/* ret	#0x40000 */
713 		bpf[5] = (struct sock_filter){ 0x6, 0, 0, 0x00040000 };
714 	} else {
715 		kfree(bpf_prog);
716 		bpf_prog = NULL;
717 	}
718 	return bpf_prog;
719 }
720 
721 /* Note - this function requires a valid mac being passed as an arg */
722 
723 void *uml_vector_user_bpf(char *filename)
724 {
725 	struct sock_filter *bpf;
726 	struct sock_fprog *bpf_prog;
727 	struct stat statbuf;
728 	int res, ffd = -1;
729 
730 	if (filename == NULL)
731 		return NULL;
732 
733 	if (stat(filename, &statbuf) < 0) {
734 		printk(KERN_ERR "Error %d reading bpf file", -errno);
735 		return false;
736 	}
737 	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
738 	if (bpf_prog != NULL) {
739 		bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
740 		bpf_prog->filter = NULL;
741 	}
742 	ffd = os_open_file(filename, of_read(OPENFLAGS()), 0);
743 	if (ffd < 0) {
744 		printk(KERN_ERR "Error %d opening bpf file", -errno);
745 		goto bpf_failed;
746 	}
747 	bpf = uml_kmalloc(statbuf.st_size, UM_GFP_KERNEL);
748 	if (bpf == NULL) {
749 		printk(KERN_ERR "Failed to allocate bpf buffer");
750 		goto bpf_failed;
751 	}
752 	bpf_prog->filter = bpf;
753 	res = os_read_file(ffd, bpf, statbuf.st_size);
754 	if (res < statbuf.st_size) {
755 		printk(KERN_ERR "Failed to read bpf program %s, error %d", filename, res);
756 		kfree(bpf);
757 		goto bpf_failed;
758 	}
759 	os_close_file(ffd);
760 	return bpf_prog;
761 bpf_failed:
762 	if (ffd > 0)
763 		os_close_file(ffd);
764 	kfree(bpf_prog);
765 	return NULL;
766 }
767