xref: /openbmc/linux/arch/um/drivers/vector_user.c (revision 852a53a0)
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 <limits.h>
33 #include <um_malloc.h>
34 #include "vector_user.h"
35 
36 #define ID_GRE 0
37 #define ID_L2TPV3 1
38 #define ID_BESS 2
39 #define ID_MAX 2
40 
41 #define TOKEN_IFNAME "ifname"
42 
43 #define TRANS_RAW "raw"
44 #define TRANS_RAW_LEN strlen(TRANS_RAW)
45 
46 #define TRANS_FD "fd"
47 #define TRANS_FD_LEN strlen(TRANS_FD)
48 
49 #define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
50 #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
51 #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
52 #define UNIX_BIND_FAIL "unix_open : could not bind socket err=%i"
53 #define BPF_ATTACH_FAIL "Failed to attach filter size %d prog %px to %d, err %d\n"
54 #define BPF_DETACH_FAIL "Failed to detach filter size %d prog %px to %d, err %d\n"
55 
56 #define MAX_UN_LEN 107
57 
58 /* This is very ugly and brute force lookup, but it is done
59  * only once at initialization so not worth doing hashes or
60  * anything more intelligent
61  */
62 
63 char *uml_vector_fetch_arg(struct arglist *ifspec, char *token)
64 {
65 	int i;
66 
67 	for (i = 0; i < ifspec->numargs; i++) {
68 		if (strcmp(ifspec->tokens[i], token) == 0)
69 			return ifspec->values[i];
70 	}
71 	return NULL;
72 
73 }
74 
75 struct arglist *uml_parse_vector_ifspec(char *arg)
76 {
77 	struct arglist *result;
78 	int pos, len;
79 	bool parsing_token = true, next_starts = true;
80 
81 	if (arg == NULL)
82 		return NULL;
83 	result = uml_kmalloc(sizeof(struct arglist), UM_GFP_KERNEL);
84 	if (result == NULL)
85 		return NULL;
86 	result->numargs = 0;
87 	len = strlen(arg);
88 	for (pos = 0; pos < len; pos++) {
89 		if (next_starts) {
90 			if (parsing_token) {
91 				result->tokens[result->numargs] = arg + pos;
92 			} else {
93 				result->values[result->numargs] = arg + pos;
94 				result->numargs++;
95 			}
96 			next_starts = false;
97 		}
98 		if (*(arg + pos) == '=') {
99 			if (parsing_token)
100 				parsing_token = false;
101 			else
102 				goto cleanup;
103 			next_starts = true;
104 			(*(arg + pos)) = '\0';
105 		}
106 		if (*(arg + pos) == ',') {
107 			parsing_token = true;
108 			next_starts = true;
109 			(*(arg + pos)) = '\0';
110 		}
111 	}
112 	return result;
113 cleanup:
114 	printk(UM_KERN_ERR "vector_setup - Couldn't parse '%s'\n", arg);
115 	kfree(result);
116 	return NULL;
117 }
118 
119 /*
120  * Socket/FD configuration functions. These return an structure
121  * of rx and tx descriptors to cover cases where these are not
122  * the same (f.e. read via raw socket and write via tap).
123  */
124 
125 #define PATH_NET_TUN "/dev/net/tun"
126 
127 
128 static int create_tap_fd(char *iface)
129 {
130 	struct ifreq ifr;
131 	int fd = -1;
132 	int err = -ENOMEM, offload;
133 
134 	fd = open(PATH_NET_TUN, O_RDWR);
135 	if (fd < 0) {
136 		printk(UM_KERN_ERR "uml_tap: failed to open tun device\n");
137 		goto tap_fd_cleanup;
138 	}
139 	memset(&ifr, 0, sizeof(ifr));
140 	ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
141 	strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
142 
143 	err = ioctl(fd, TUNSETIFF, (void *) &ifr);
144 	if (err != 0) {
145 		printk(UM_KERN_ERR "uml_tap: failed to select tap interface\n");
146 		goto tap_fd_cleanup;
147 	}
148 
149 	offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6;
150 	ioctl(fd, TUNSETOFFLOAD, offload);
151 	return fd;
152 tap_fd_cleanup:
153 	if (fd >= 0)
154 		os_close_file(fd);
155 	return err;
156 }
157 
158 static int create_raw_fd(char *iface, int flags, int proto)
159 {
160 	struct ifreq ifr;
161 	int fd = -1;
162 	struct sockaddr_ll sock;
163 	int err = -ENOMEM;
164 
165 	fd = socket(AF_PACKET, SOCK_RAW, flags);
166 	if (fd == -1) {
167 		err = -errno;
168 		goto raw_fd_cleanup;
169 	}
170 	memset(&ifr, 0, sizeof(ifr));
171 	strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
172 	if (ioctl(fd, SIOCGIFINDEX, (void *) &ifr) < 0) {
173 		err = -errno;
174 		goto raw_fd_cleanup;
175 	}
176 
177 	sock.sll_family = AF_PACKET;
178 	sock.sll_protocol = htons(proto);
179 	sock.sll_ifindex = ifr.ifr_ifindex;
180 
181 	if (bind(fd,
182 		(struct sockaddr *) &sock, sizeof(struct sockaddr_ll)) < 0) {
183 		err = -errno;
184 		goto raw_fd_cleanup;
185 	}
186 	return fd;
187 raw_fd_cleanup:
188 	printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
189 	if (fd >= 0)
190 		os_close_file(fd);
191 	return err;
192 }
193 
194 static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
195 {
196 	int fd = -1;
197 	char *iface;
198 	struct vector_fds *result = NULL;
199 
200 	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
201 	if (iface == NULL) {
202 		printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
203 		goto tap_cleanup;
204 	}
205 
206 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
207 	if (result == NULL) {
208 		printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
209 		goto tap_cleanup;
210 	}
211 	result->rx_fd = -1;
212 	result->tx_fd = -1;
213 	result->remote_addr = NULL;
214 	result->remote_addr_size = 0;
215 
216 	/* TAP */
217 
218 	fd = create_tap_fd(iface);
219 	if (fd < 0) {
220 		printk(UM_KERN_ERR "uml_tap: failed to create tun interface\n");
221 		goto tap_cleanup;
222 	}
223 	result->tx_fd = fd;
224 	result->rx_fd = fd;
225 	return result;
226 tap_cleanup:
227 	printk(UM_KERN_ERR "user_init_tap: init failed, error %d", fd);
228 	kfree(result);
229 	return NULL;
230 }
231 
232 static struct vector_fds *user_init_hybrid_fds(struct arglist *ifspec)
233 {
234 	char *iface;
235 	struct vector_fds *result = NULL;
236 
237 	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
238 	if (iface == NULL) {
239 		printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
240 		goto hybrid_cleanup;
241 	}
242 
243 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
244 	if (result == NULL) {
245 		printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
246 		goto hybrid_cleanup;
247 	}
248 	result->rx_fd = -1;
249 	result->tx_fd = -1;
250 	result->remote_addr = NULL;
251 	result->remote_addr_size = 0;
252 
253 	/* TAP */
254 
255 	result->tx_fd = create_tap_fd(iface);
256 	if (result->tx_fd < 0) {
257 		printk(UM_KERN_ERR "uml_tap: failed to create tun interface: %i\n", result->tx_fd);
258 		goto hybrid_cleanup;
259 	}
260 
261 	/* RAW */
262 
263 	result->rx_fd = create_raw_fd(iface, ETH_P_ALL, ETH_P_ALL);
264 	if (result->rx_fd == -1) {
265 		printk(UM_KERN_ERR
266 			"uml_tap: failed to create paired raw socket: %i\n", result->rx_fd);
267 		goto hybrid_cleanup;
268 	}
269 	return result;
270 hybrid_cleanup:
271 	printk(UM_KERN_ERR "user_init_hybrid: init failed");
272 	kfree(result);
273 	return NULL;
274 }
275 
276 static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
277 {
278 	int fd = -1;
279 	int socktype;
280 	char *src, *dst;
281 	struct vector_fds *result = NULL;
282 	struct sockaddr_un *local_addr = NULL, *remote_addr = NULL;
283 
284 	src = uml_vector_fetch_arg(ifspec, "src");
285 	dst = uml_vector_fetch_arg(ifspec, "dst");
286 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
287 	if (result == NULL) {
288 		printk(UM_KERN_ERR "unix open:cannot allocate remote addr");
289 		goto unix_cleanup;
290 	}
291 	remote_addr = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
292 	if (remote_addr == NULL) {
293 		printk(UM_KERN_ERR "unix open:cannot allocate remote addr");
294 		goto unix_cleanup;
295 	}
296 
297 	switch (id) {
298 	case ID_BESS:
299 		socktype = SOCK_SEQPACKET;
300 		if ((src != NULL) && (strlen(src) <= MAX_UN_LEN)) {
301 			local_addr = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
302 			if (local_addr == NULL) {
303 				printk(UM_KERN_ERR "bess open:cannot allocate local addr");
304 				goto unix_cleanup;
305 			}
306 			local_addr->sun_family = AF_UNIX;
307 			memcpy(local_addr->sun_path, src, strlen(src) + 1);
308 		}
309 		if ((dst == NULL) || (strlen(dst) > MAX_UN_LEN))
310 			goto unix_cleanup;
311 		remote_addr->sun_family = AF_UNIX;
312 		memcpy(remote_addr->sun_path, dst, strlen(dst) + 1);
313 		break;
314 	default:
315 		printk(KERN_ERR "Unsupported unix socket type\n");
316 		return NULL;
317 	}
318 
319 	fd = socket(AF_UNIX, socktype, 0);
320 	if (fd == -1) {
321 		printk(UM_KERN_ERR
322 			"unix open: could not open socket, error = %d",
323 			-errno
324 		);
325 		goto unix_cleanup;
326 	}
327 	if (local_addr != NULL) {
328 		if (bind(fd, (struct sockaddr *) local_addr, sizeof(struct sockaddr_un))) {
329 			printk(UM_KERN_ERR UNIX_BIND_FAIL, errno);
330 			goto unix_cleanup;
331 		}
332 	}
333 	switch (id) {
334 	case ID_BESS:
335 		if (connect(fd, remote_addr, sizeof(struct sockaddr_un)) < 0) {
336 			printk(UM_KERN_ERR "bess open:cannot connect to %s %i", remote_addr->sun_path, -errno);
337 			goto unix_cleanup;
338 		}
339 		break;
340 	}
341 	result->rx_fd = fd;
342 	result->tx_fd = fd;
343 	result->remote_addr_size = sizeof(struct sockaddr_un);
344 	result->remote_addr = remote_addr;
345 	return result;
346 unix_cleanup:
347 	if (fd >= 0)
348 		os_close_file(fd);
349 	kfree(remote_addr);
350 	kfree(result);
351 	return NULL;
352 }
353 
354 static int strtofd(const char *nptr)
355 {
356 	long fd;
357 	char *endptr;
358 
359 	if (nptr == NULL)
360 		return -1;
361 
362 	errno = 0;
363 	fd = strtol(nptr, &endptr, 10);
364 	if (nptr == endptr ||
365 		errno != 0 ||
366 		*endptr != '\0' ||
367 		fd < 0 ||
368 		fd > INT_MAX) {
369 		return -1;
370 	}
371 	return fd;
372 }
373 
374 static struct vector_fds *user_init_fd_fds(struct arglist *ifspec)
375 {
376 	int fd = -1;
377 	char *fdarg = NULL;
378 	struct vector_fds *result = NULL;
379 
380 	fdarg = uml_vector_fetch_arg(ifspec, "fd");
381 	fd = strtofd(fdarg);
382 	if (fd == -1) {
383 		printk(UM_KERN_ERR "fd open: bad or missing fd argument");
384 		goto fd_cleanup;
385 	}
386 
387 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
388 	if (result == NULL) {
389 		printk(UM_KERN_ERR "fd open: allocation failed");
390 		goto fd_cleanup;
391 	}
392 
393 	result->rx_fd = fd;
394 	result->tx_fd = fd;
395 	result->remote_addr_size = 0;
396 	result->remote_addr = NULL;
397 	return result;
398 
399 fd_cleanup:
400 	if (fd >= 0)
401 		os_close_file(fd);
402 	if (result != NULL)
403 		kfree(result);
404 	return NULL;
405 }
406 
407 static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
408 {
409 	int rxfd = -1, txfd = -1;
410 	int err = -ENOMEM;
411 	char *iface;
412 	struct vector_fds *result = NULL;
413 
414 	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
415 	if (iface == NULL)
416 		goto raw_cleanup;
417 
418 	rxfd = create_raw_fd(iface, ETH_P_ALL, ETH_P_ALL);
419 	if (rxfd == -1) {
420 		err = -errno;
421 		goto raw_cleanup;
422 	}
423 	txfd = create_raw_fd(iface, 0, ETH_P_IP); /* Turn off RX on this fd */
424 	if (txfd == -1) {
425 		err = -errno;
426 		goto raw_cleanup;
427 	}
428 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
429 	if (result != NULL) {
430 		result->rx_fd = rxfd;
431 		result->tx_fd = txfd;
432 		result->remote_addr = NULL;
433 		result->remote_addr_size = 0;
434 	}
435 	return result;
436 raw_cleanup:
437 	printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
438 	kfree(result);
439 	return NULL;
440 }
441 
442 
443 bool uml_raw_enable_qdisc_bypass(int fd)
444 {
445 	int optval = 1;
446 
447 	if (setsockopt(fd,
448 		SOL_PACKET, PACKET_QDISC_BYPASS,
449 		&optval, sizeof(optval)) != 0) {
450 		return false;
451 	}
452 	return true;
453 }
454 
455 bool uml_raw_enable_vnet_headers(int fd)
456 {
457 	int optval = 1;
458 
459 	if (setsockopt(fd,
460 		SOL_PACKET, PACKET_VNET_HDR,
461 		&optval, sizeof(optval)) != 0) {
462 		printk(UM_KERN_INFO VNET_HDR_FAIL, fd);
463 		return false;
464 	}
465 	return true;
466 }
467 bool uml_tap_enable_vnet_headers(int fd)
468 {
469 	unsigned int features;
470 	int len = sizeof(struct virtio_net_hdr);
471 
472 	if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
473 		printk(UM_KERN_INFO TUN_GET_F_FAIL, strerror(errno));
474 		return false;
475 	}
476 	if ((features & IFF_VNET_HDR) == 0) {
477 		printk(UM_KERN_INFO "tapraw: No VNET HEADER support");
478 		return false;
479 	}
480 	ioctl(fd, TUNSETVNETHDRSZ, &len);
481 	return true;
482 }
483 
484 static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
485 {
486 	int err = -ENOMEM;
487 	int fd = -1, gairet;
488 	struct addrinfo srchints;
489 	struct addrinfo dsthints;
490 	bool v6, udp;
491 	char *value;
492 	char *src, *dst, *srcport, *dstport;
493 	struct addrinfo *gairesult = NULL;
494 	struct vector_fds *result = NULL;
495 
496 
497 	value = uml_vector_fetch_arg(ifspec, "v6");
498 	v6 = false;
499 	udp = false;
500 	if (value != NULL) {
501 		if (strtol((const char *) value, NULL, 10) > 0)
502 			v6 = true;
503 	}
504 
505 	value = uml_vector_fetch_arg(ifspec, "udp");
506 	if (value != NULL) {
507 		if (strtol((const char *) value, NULL, 10) > 0)
508 			udp = true;
509 	}
510 	src = uml_vector_fetch_arg(ifspec, "src");
511 	dst = uml_vector_fetch_arg(ifspec, "dst");
512 	srcport = uml_vector_fetch_arg(ifspec, "srcport");
513 	dstport = uml_vector_fetch_arg(ifspec, "dstport");
514 
515 	memset(&dsthints, 0, sizeof(dsthints));
516 
517 	if (v6)
518 		dsthints.ai_family = AF_INET6;
519 	else
520 		dsthints.ai_family = AF_INET;
521 
522 	switch (id) {
523 	case ID_GRE:
524 		dsthints.ai_socktype = SOCK_RAW;
525 		dsthints.ai_protocol = IPPROTO_GRE;
526 		break;
527 	case ID_L2TPV3:
528 		if (udp) {
529 			dsthints.ai_socktype = SOCK_DGRAM;
530 			dsthints.ai_protocol = 0;
531 		} else {
532 			dsthints.ai_socktype = SOCK_RAW;
533 			dsthints.ai_protocol = IPPROTO_L2TP;
534 		}
535 		break;
536 	default:
537 		printk(KERN_ERR "Unsupported socket type\n");
538 		return NULL;
539 	}
540 	memcpy(&srchints, &dsthints, sizeof(struct addrinfo));
541 
542 	gairet = getaddrinfo(src, srcport, &dsthints, &gairesult);
543 	if ((gairet != 0) || (gairesult == NULL)) {
544 		printk(UM_KERN_ERR
545 			"socket_open : could not resolve src, error = %s",
546 			gai_strerror(gairet)
547 		);
548 		return NULL;
549 	}
550 	fd = socket(gairesult->ai_family,
551 		gairesult->ai_socktype, gairesult->ai_protocol);
552 	if (fd == -1) {
553 		printk(UM_KERN_ERR
554 			"socket_open : could not open socket, error = %d",
555 			-errno
556 		);
557 		goto cleanup;
558 	}
559 	if (bind(fd,
560 		(struct sockaddr *) gairesult->ai_addr,
561 		gairesult->ai_addrlen)) {
562 		printk(UM_KERN_ERR L2TPV3_BIND_FAIL, errno);
563 		goto cleanup;
564 	}
565 
566 	if (gairesult != NULL)
567 		freeaddrinfo(gairesult);
568 
569 	gairesult = NULL;
570 
571 	gairet = getaddrinfo(dst, dstport, &dsthints, &gairesult);
572 	if ((gairet != 0) || (gairesult == NULL)) {
573 		printk(UM_KERN_ERR
574 			"socket_open : could not resolve dst, error = %s",
575 			gai_strerror(gairet)
576 		);
577 		return NULL;
578 	}
579 
580 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
581 	if (result != NULL) {
582 		result->rx_fd = fd;
583 		result->tx_fd = fd;
584 		result->remote_addr = uml_kmalloc(
585 			gairesult->ai_addrlen, UM_GFP_KERNEL);
586 		if (result->remote_addr == NULL)
587 			goto cleanup;
588 		result->remote_addr_size = gairesult->ai_addrlen;
589 		memcpy(
590 			result->remote_addr,
591 			gairesult->ai_addr,
592 			gairesult->ai_addrlen
593 		);
594 	}
595 	freeaddrinfo(gairesult);
596 	return result;
597 cleanup:
598 	if (gairesult != NULL)
599 		freeaddrinfo(gairesult);
600 	printk(UM_KERN_ERR "user_init_socket: init failed, error %d", err);
601 	if (fd >= 0)
602 		os_close_file(fd);
603 	if (result != NULL) {
604 		kfree(result->remote_addr);
605 		kfree(result);
606 	}
607 	return NULL;
608 }
609 
610 struct vector_fds *uml_vector_user_open(
611 	int unit,
612 	struct arglist *parsed
613 )
614 {
615 	char *transport;
616 
617 	if (parsed == NULL) {
618 		printk(UM_KERN_ERR "no parsed config for unit %d\n", unit);
619 		return NULL;
620 	}
621 	transport = uml_vector_fetch_arg(parsed, "transport");
622 	if (transport == NULL) {
623 		printk(UM_KERN_ERR "missing transport for unit %d\n", unit);
624 		return NULL;
625 	}
626 	if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
627 		return user_init_raw_fds(parsed);
628 	if (strncmp(transport, TRANS_HYBRID, TRANS_HYBRID_LEN) == 0)
629 		return user_init_hybrid_fds(parsed);
630 	if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
631 		return user_init_tap_fds(parsed);
632 	if (strncmp(transport, TRANS_GRE, TRANS_GRE_LEN) == 0)
633 		return user_init_socket_fds(parsed, ID_GRE);
634 	if (strncmp(transport, TRANS_L2TPV3, TRANS_L2TPV3_LEN) == 0)
635 		return user_init_socket_fds(parsed, ID_L2TPV3);
636 	if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
637 		return user_init_unix_fds(parsed, ID_BESS);
638 	if (strncmp(transport, TRANS_FD, TRANS_FD_LEN) == 0)
639 		return user_init_fd_fds(parsed);
640 	return NULL;
641 }
642 
643 
644 int uml_vector_sendmsg(int fd, void *hdr, int flags)
645 {
646 	int n;
647 
648 	CATCH_EINTR(n = sendmsg(fd, (struct msghdr *) hdr,  flags));
649 	if ((n < 0) && (errno == EAGAIN))
650 		return 0;
651 	if (n >= 0)
652 		return n;
653 	else
654 		return -errno;
655 }
656 
657 int uml_vector_recvmsg(int fd, void *hdr, int flags)
658 {
659 	int n;
660 	struct msghdr *msg = (struct msghdr *) hdr;
661 
662 	CATCH_EINTR(n = readv(fd, msg->msg_iov, msg->msg_iovlen));
663 	if ((n < 0) && (errno == EAGAIN))
664 		return 0;
665 	if (n >= 0)
666 		return n;
667 	else
668 		return -errno;
669 }
670 
671 int uml_vector_writev(int fd, void *hdr, int iovcount)
672 {
673 	int n;
674 
675 	CATCH_EINTR(n = writev(fd, (struct iovec *) hdr,  iovcount));
676 	if ((n < 0) && ((errno == EAGAIN) || (errno == ENOBUFS)))
677 		return 0;
678 	if (n >= 0)
679 		return n;
680 	else
681 		return -errno;
682 }
683 
684 int uml_vector_sendmmsg(
685 	int fd,
686 	void *msgvec,
687 	unsigned int vlen,
688 	unsigned int flags)
689 {
690 	int n;
691 
692 	CATCH_EINTR(n = sendmmsg(fd, (struct mmsghdr *) msgvec, vlen, flags));
693 	if ((n < 0) && ((errno == EAGAIN) || (errno == ENOBUFS)))
694 		return 0;
695 	if (n >= 0)
696 		return n;
697 	else
698 		return -errno;
699 }
700 
701 int uml_vector_recvmmsg(
702 	int fd,
703 	void *msgvec,
704 	unsigned int vlen,
705 	unsigned int flags)
706 {
707 	int n;
708 
709 	CATCH_EINTR(
710 		n = recvmmsg(fd, (struct mmsghdr *) msgvec, vlen, flags, 0));
711 	if ((n < 0) && (errno == EAGAIN))
712 		return 0;
713 	if (n >= 0)
714 		return n;
715 	else
716 		return -errno;
717 }
718 int uml_vector_attach_bpf(int fd, void *bpf)
719 {
720 	struct sock_fprog *prog = bpf;
721 
722 	int err = setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, bpf, sizeof(struct sock_fprog));
723 
724 	if (err < 0)
725 		printk(KERN_ERR BPF_ATTACH_FAIL, prog->len, prog->filter, fd, -errno);
726 	return err;
727 }
728 
729 int uml_vector_detach_bpf(int fd, void *bpf)
730 {
731 	struct sock_fprog *prog = bpf;
732 
733 	int err = setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, bpf, sizeof(struct sock_fprog));
734 	if (err < 0)
735 		printk(KERN_ERR BPF_DETACH_FAIL, prog->len, prog->filter, fd, -errno);
736 	return err;
737 }
738 void *uml_vector_default_bpf(void *mac)
739 {
740 	struct sock_filter *bpf;
741 	uint32_t *mac1 = (uint32_t *)(mac + 2);
742 	uint16_t *mac2 = (uint16_t *) mac;
743 	struct sock_fprog *bpf_prog;
744 
745 	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
746 	if (bpf_prog) {
747 		bpf_prog->len = DEFAULT_BPF_LEN;
748 		bpf_prog->filter = NULL;
749 	} else {
750 		return NULL;
751 	}
752 	bpf = uml_kmalloc(
753 		sizeof(struct sock_filter) * DEFAULT_BPF_LEN, UM_GFP_KERNEL);
754 	if (bpf) {
755 		bpf_prog->filter = bpf;
756 		/* ld	[8] */
757 		bpf[0] = (struct sock_filter){ 0x20, 0, 0, 0x00000008 };
758 		/* jeq	#0xMAC[2-6] jt 2 jf 5*/
759 		bpf[1] = (struct sock_filter){ 0x15, 0, 3, ntohl(*mac1)};
760 		/* ldh	[6] */
761 		bpf[2] = (struct sock_filter){ 0x28, 0, 0, 0x00000006 };
762 		/* jeq	#0xMAC[0-1] jt 4 jf 5 */
763 		bpf[3] = (struct sock_filter){ 0x15, 0, 1, ntohs(*mac2)};
764 		/* ret	#0 */
765 		bpf[4] = (struct sock_filter){ 0x6, 0, 0, 0x00000000 };
766 		/* ret	#0x40000 */
767 		bpf[5] = (struct sock_filter){ 0x6, 0, 0, 0x00040000 };
768 	} else {
769 		kfree(bpf_prog);
770 		bpf_prog = NULL;
771 	}
772 	return bpf_prog;
773 }
774 
775 /* Note - this function requires a valid mac being passed as an arg */
776 
777 void *uml_vector_user_bpf(char *filename)
778 {
779 	struct sock_filter *bpf;
780 	struct sock_fprog *bpf_prog;
781 	struct stat statbuf;
782 	int res, ffd = -1;
783 
784 	if (filename == NULL)
785 		return NULL;
786 
787 	if (stat(filename, &statbuf) < 0) {
788 		printk(KERN_ERR "Error %d reading bpf file", -errno);
789 		return false;
790 	}
791 	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
792 	if (bpf_prog != NULL) {
793 		bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
794 		bpf_prog->filter = NULL;
795 	}
796 	ffd = os_open_file(filename, of_read(OPENFLAGS()), 0);
797 	if (ffd < 0) {
798 		printk(KERN_ERR "Error %d opening bpf file", -errno);
799 		goto bpf_failed;
800 	}
801 	bpf = uml_kmalloc(statbuf.st_size, UM_GFP_KERNEL);
802 	if (bpf == NULL) {
803 		printk(KERN_ERR "Failed to allocate bpf buffer");
804 		goto bpf_failed;
805 	}
806 	bpf_prog->filter = bpf;
807 	res = os_read_file(ffd, bpf, statbuf.st_size);
808 	if (res < statbuf.st_size) {
809 		printk(KERN_ERR "Failed to read bpf program %s, error %d", filename, res);
810 		kfree(bpf);
811 		goto bpf_failed;
812 	}
813 	os_close_file(ffd);
814 	return bpf_prog;
815 bpf_failed:
816 	if (ffd > 0)
817 		os_close_file(ffd);
818 	kfree(bpf_prog);
819 	return NULL;
820 }
821