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1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2
3/*
4 * AF_XDP user-space access library.
5 *
6 * Copyright(c) 2018 - 2019 Intel Corporation.
7 *
8 * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
9 */
10
11#include <errno.h>
12#include <stdlib.h>
13#include <string.h>
14#include <unistd.h>
15#include <arpa/inet.h>
16#include <asm/barrier.h>
17#include <linux/compiler.h>
18#include <linux/ethtool.h>
19#include <linux/filter.h>
20#include <linux/if_ether.h>
21#include <linux/if_packet.h>
22#include <linux/if_xdp.h>
23#include <linux/sockios.h>
24#include <net/if.h>
25#include <sys/ioctl.h>
26#include <sys/mman.h>
27#include <sys/socket.h>
28#include <sys/types.h>
29
30#include "bpf.h"
31#include "libbpf.h"
32#include "libbpf_internal.h"
33#include "xsk.h"
34
35/* make sure libbpf doesn't use kernel-only integer typedefs */
36#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
37
38#ifndef SOL_XDP
39 #define SOL_XDP 283
40#endif
41
42#ifndef AF_XDP
43 #define AF_XDP 44
44#endif
45
46#ifndef PF_XDP
47 #define PF_XDP AF_XDP
48#endif
49
50struct xsk_umem {
51 struct xsk_ring_prod *fill;
52 struct xsk_ring_cons *comp;
53 char *umem_area;
54 struct xsk_umem_config config;
55 int fd;
56 int refcount;
57};
58
59struct xsk_socket {
60 struct xsk_ring_cons *rx;
61 struct xsk_ring_prod *tx;
62 __u64 outstanding_tx;
63 struct xsk_umem *umem;
64 struct xsk_socket_config config;
65 int fd;
66 int ifindex;
67 int prog_fd;
68 int xsks_map_fd;
69 __u32 queue_id;
70 char ifname[IFNAMSIZ];
71};
72
73struct xsk_nl_info {
74 bool xdp_prog_attached;
75 int ifindex;
76 int fd;
77};
78
79/* Up until and including Linux 5.3 */
80struct xdp_ring_offset_v1 {
81 __u64 producer;
82 __u64 consumer;
83 __u64 desc;
84};
85
86/* Up until and including Linux 5.3 */
87struct xdp_mmap_offsets_v1 {
88 struct xdp_ring_offset_v1 rx;
89 struct xdp_ring_offset_v1 tx;
90 struct xdp_ring_offset_v1 fr;
91 struct xdp_ring_offset_v1 cr;
92};
93
94int xsk_umem__fd(const struct xsk_umem *umem)
95{
96 return umem ? umem->fd : -EINVAL;
97}
98
99int xsk_socket__fd(const struct xsk_socket *xsk)
100{
101 return xsk ? xsk->fd : -EINVAL;
102}
103
104static bool xsk_page_aligned(void *buffer)
105{
106 unsigned long addr = (unsigned long)buffer;
107
108 return !(addr & (getpagesize() - 1));
109}
110
111static void xsk_set_umem_config(struct xsk_umem_config *cfg,
112 const struct xsk_umem_config *usr_cfg)
113{
114 if (!usr_cfg) {
115 cfg->fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
116 cfg->comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
117 cfg->frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
118 cfg->frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM;
119 cfg->flags = XSK_UMEM__DEFAULT_FLAGS;
120 return;
121 }
122
123 cfg->fill_size = usr_cfg->fill_size;
124 cfg->comp_size = usr_cfg->comp_size;
125 cfg->frame_size = usr_cfg->frame_size;
126 cfg->frame_headroom = usr_cfg->frame_headroom;
127 cfg->flags = usr_cfg->flags;
128}
129
130static int xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
131 const struct xsk_socket_config *usr_cfg)
132{
133 if (!usr_cfg) {
134 cfg->rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
135 cfg->tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
136 cfg->libbpf_flags = 0;
137 cfg->xdp_flags = 0;
138 cfg->bind_flags = 0;
139 return 0;
140 }
141
142 if (usr_cfg->libbpf_flags & ~XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)
143 return -EINVAL;
144
145 cfg->rx_size = usr_cfg->rx_size;
146 cfg->tx_size = usr_cfg->tx_size;
147 cfg->libbpf_flags = usr_cfg->libbpf_flags;
148 cfg->xdp_flags = usr_cfg->xdp_flags;
149 cfg->bind_flags = usr_cfg->bind_flags;
150
151 return 0;
152}
153
154static void xsk_mmap_offsets_v1(struct xdp_mmap_offsets *off)
155{
156 struct xdp_mmap_offsets_v1 off_v1;
157
158 /* getsockopt on a kernel <= 5.3 has no flags fields.
159 * Copy over the offsets to the correct places in the >=5.4 format
160 * and put the flags where they would have been on that kernel.
161 */
162 memcpy(&off_v1, off, sizeof(off_v1));
163
164 off->rx.producer = off_v1.rx.producer;
165 off->rx.consumer = off_v1.rx.consumer;
166 off->rx.desc = off_v1.rx.desc;
167 off->rx.flags = off_v1.rx.consumer + sizeof(__u32);
168
169 off->tx.producer = off_v1.tx.producer;
170 off->tx.consumer = off_v1.tx.consumer;
171 off->tx.desc = off_v1.tx.desc;
172 off->tx.flags = off_v1.tx.consumer + sizeof(__u32);
173
174 off->fr.producer = off_v1.fr.producer;
175 off->fr.consumer = off_v1.fr.consumer;
176 off->fr.desc = off_v1.fr.desc;
177 off->fr.flags = off_v1.fr.consumer + sizeof(__u32);
178
179 off->cr.producer = off_v1.cr.producer;
180 off->cr.consumer = off_v1.cr.consumer;
181 off->cr.desc = off_v1.cr.desc;
182 off->cr.flags = off_v1.cr.consumer + sizeof(__u32);
183}
184
185static int xsk_get_mmap_offsets(int fd, struct xdp_mmap_offsets *off)
186{
187 socklen_t optlen;
188 int err;
189
190 optlen = sizeof(*off);
191 err = getsockopt(fd, SOL_XDP, XDP_MMAP_OFFSETS, off, &optlen);
192 if (err)
193 return err;
194
195 if (optlen == sizeof(*off))
196 return 0;
197
198 if (optlen == sizeof(struct xdp_mmap_offsets_v1)) {
199 xsk_mmap_offsets_v1(off);
200 return 0;
201 }
202
203 return -EINVAL;
204}
205
206int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area,
207 __u64 size, struct xsk_ring_prod *fill,
208 struct xsk_ring_cons *comp,
209 const struct xsk_umem_config *usr_config)
210{
211 struct xdp_mmap_offsets off;
212 struct xdp_umem_reg mr;
213 struct xsk_umem *umem;
214 void *map;
215 int err;
216
217 if (!umem_area || !umem_ptr || !fill || !comp)
218 return -EFAULT;
219 if (!size && !xsk_page_aligned(umem_area))
220 return -EINVAL;
221
222 umem = calloc(1, sizeof(*umem));
223 if (!umem)
224 return -ENOMEM;
225
226 umem->fd = socket(AF_XDP, SOCK_RAW, 0);
227 if (umem->fd < 0) {
228 err = -errno;
229 goto out_umem_alloc;
230 }
231
232 umem->umem_area = umem_area;
233 xsk_set_umem_config(&umem->config, usr_config);
234
235 memset(&mr, 0, sizeof(mr));
236 mr.addr = (uintptr_t)umem_area;
237 mr.len = size;
238 mr.chunk_size = umem->config.frame_size;
239 mr.headroom = umem->config.frame_headroom;
240 mr.flags = umem->config.flags;
241
242 err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr));
243 if (err) {
244 err = -errno;
245 goto out_socket;
246 }
247 err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_FILL_RING,
248 &umem->config.fill_size,
249 sizeof(umem->config.fill_size));
250 if (err) {
251 err = -errno;
252 goto out_socket;
253 }
254 err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_COMPLETION_RING,
255 &umem->config.comp_size,
256 sizeof(umem->config.comp_size));
257 if (err) {
258 err = -errno;
259 goto out_socket;
260 }
261
262 err = xsk_get_mmap_offsets(umem->fd, &off);
263 if (err) {
264 err = -errno;
265 goto out_socket;
266 }
267
268 map = mmap(NULL, off.fr.desc + umem->config.fill_size * sizeof(__u64),
269 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, umem->fd,
270 XDP_UMEM_PGOFF_FILL_RING);
271 if (map == MAP_FAILED) {
272 err = -errno;
273 goto out_socket;
274 }
275
276 umem->fill = fill;
277 fill->mask = umem->config.fill_size - 1;
278 fill->size = umem->config.fill_size;
279 fill->producer = map + off.fr.producer;
280 fill->consumer = map + off.fr.consumer;
281 fill->flags = map + off.fr.flags;
282 fill->ring = map + off.fr.desc;
283 fill->cached_prod = *fill->producer;
284 /* cached_cons is "size" bigger than the real consumer pointer
285 * See xsk_prod_nb_free
286 */
287 fill->cached_cons = *fill->consumer + umem->config.fill_size;
288
289 map = mmap(NULL, off.cr.desc + umem->config.comp_size * sizeof(__u64),
290 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, umem->fd,
291 XDP_UMEM_PGOFF_COMPLETION_RING);
292 if (map == MAP_FAILED) {
293 err = -errno;
294 goto out_mmap;
295 }
296
297 umem->comp = comp;
298 comp->mask = umem->config.comp_size - 1;
299 comp->size = umem->config.comp_size;
300 comp->producer = map + off.cr.producer;
301 comp->consumer = map + off.cr.consumer;
302 comp->flags = map + off.cr.flags;
303 comp->ring = map + off.cr.desc;
304 comp->cached_prod = *comp->producer;
305 comp->cached_cons = *comp->consumer;
306
307 *umem_ptr = umem;
308 return 0;
309
310out_mmap:
311 munmap(map, off.fr.desc + umem->config.fill_size * sizeof(__u64));
312out_socket:
313 close(umem->fd);
314out_umem_alloc:
315 free(umem);
316 return err;
317}
318
319struct xsk_umem_config_v1 {
320 __u32 fill_size;
321 __u32 comp_size;
322 __u32 frame_size;
323 __u32 frame_headroom;
324};
325
326int xsk_umem__create_v0_0_2(struct xsk_umem **umem_ptr, void *umem_area,
327 __u64 size, struct xsk_ring_prod *fill,
328 struct xsk_ring_cons *comp,
329 const struct xsk_umem_config *usr_config)
330{
331 struct xsk_umem_config config;
332
333 memcpy(&config, usr_config, sizeof(struct xsk_umem_config_v1));
334 config.flags = 0;
335
336 return xsk_umem__create_v0_0_4(umem_ptr, umem_area, size, fill, comp,
337 &config);
338}
339COMPAT_VERSION(xsk_umem__create_v0_0_2, xsk_umem__create, LIBBPF_0.0.2)
340DEFAULT_VERSION(xsk_umem__create_v0_0_4, xsk_umem__create, LIBBPF_0.0.4)
341
342static int xsk_load_xdp_prog(struct xsk_socket *xsk)
343{
344 static const int log_buf_size = 16 * 1024;
345 char log_buf[log_buf_size];
346 int err, prog_fd;
347
348 /* This is the C-program:
349 * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
350 * {
351 * int ret, index = ctx->rx_queue_index;
352 *
353 * // A set entry here means that the correspnding queue_id
354 * // has an active AF_XDP socket bound to it.
355 * ret = bpf_redirect_map(&xsks_map, index, XDP_PASS);
356 * if (ret > 0)
357 * return ret;
358 *
359 * // Fallback for pre-5.3 kernels, not supporting default
360 * // action in the flags parameter.
361 * if (bpf_map_lookup_elem(&xsks_map, &index))
362 * return bpf_redirect_map(&xsks_map, index, 0);
363 * return XDP_PASS;
364 * }
365 */
366 struct bpf_insn prog[] = {
367 /* r2 = *(u32 *)(r1 + 16) */
368 BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 16),
369 /* *(u32 *)(r10 - 4) = r2 */
370 BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -4),
371 /* r1 = xskmap[] */
372 BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd),
373 /* r3 = XDP_PASS */
374 BPF_MOV64_IMM(BPF_REG_3, 2),
375 /* call bpf_redirect_map */
376 BPF_EMIT_CALL(BPF_FUNC_redirect_map),
377 /* if w0 != 0 goto pc+13 */
378 BPF_JMP32_IMM(BPF_JSGT, BPF_REG_0, 0, 13),
379 /* r2 = r10 */
380 BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
381 /* r2 += -4 */
382 BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
383 /* r1 = xskmap[] */
384 BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd),
385 /* call bpf_map_lookup_elem */
386 BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
387 /* r1 = r0 */
388 BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
389 /* r0 = XDP_PASS */
390 BPF_MOV64_IMM(BPF_REG_0, 2),
391 /* if r1 == 0 goto pc+5 */
392 BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5),
393 /* r2 = *(u32 *)(r10 - 4) */
394 BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_10, -4),
395 /* r1 = xskmap[] */
396 BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd),
397 /* r3 = 0 */
398 BPF_MOV64_IMM(BPF_REG_3, 0),
399 /* call bpf_redirect_map */
400 BPF_EMIT_CALL(BPF_FUNC_redirect_map),
401 /* The jumps are to this instruction */
402 BPF_EXIT_INSN(),
403 };
404 size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
405
406 prog_fd = bpf_load_program(BPF_PROG_TYPE_XDP, prog, insns_cnt,
407 "LGPL-2.1 or BSD-2-Clause", 0, log_buf,
408 log_buf_size);
409 if (prog_fd < 0) {
410 pr_warn("BPF log buffer:\n%s", log_buf);
411 return prog_fd;
412 }
413
414 err = bpf_set_link_xdp_fd(xsk->ifindex, prog_fd, xsk->config.xdp_flags);
415 if (err) {
416 close(prog_fd);
417 return err;
418 }
419
420 xsk->prog_fd = prog_fd;
421 return 0;
422}
423
424static int xsk_get_max_queues(struct xsk_socket *xsk)
425{
426 struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
427 struct ifreq ifr = {};
428 int fd, err, ret;
429
430 fd = socket(AF_INET, SOCK_DGRAM, 0);
431 if (fd < 0)
432 return -errno;
433
434 ifr.ifr_data = (void *)&channels;
435 memcpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
436 ifr.ifr_name[IFNAMSIZ - 1] = '\0';
437 err = ioctl(fd, SIOCETHTOOL, &ifr);
438 if (err && errno != EOPNOTSUPP) {
439 ret = -errno;
440 goto out;
441 }
442
443 if (err) {
444 /* If the device says it has no channels, then all traffic
445 * is sent to a single stream, so max queues = 1.
446 */
447 ret = 1;
448 } else {
449 /* Take the max of rx, tx, combined. Drivers return
450 * the number of channels in different ways.
451 */
452 ret = max(channels.max_rx, channels.max_tx);
453 ret = max(ret, (int)channels.max_combined);
454 }
455
456out:
457 close(fd);
458 return ret;
459}
460
461static int xsk_create_bpf_maps(struct xsk_socket *xsk)
462{
463 int max_queues;
464 int fd;
465
466 max_queues = xsk_get_max_queues(xsk);
467 if (max_queues < 0)
468 return max_queues;
469
470 fd = bpf_create_map_name(BPF_MAP_TYPE_XSKMAP, "xsks_map",
471 sizeof(int), sizeof(int), max_queues, 0);
472 if (fd < 0)
473 return fd;
474
475 xsk->xsks_map_fd = fd;
476
477 return 0;
478}
479
480static void xsk_delete_bpf_maps(struct xsk_socket *xsk)
481{
482 bpf_map_delete_elem(xsk->xsks_map_fd, &xsk->queue_id);
483 close(xsk->xsks_map_fd);
484}
485
486static int xsk_lookup_bpf_maps(struct xsk_socket *xsk)
487{
488 __u32 i, *map_ids, num_maps, prog_len = sizeof(struct bpf_prog_info);
489 __u32 map_len = sizeof(struct bpf_map_info);
490 struct bpf_prog_info prog_info = {};
491 struct bpf_map_info map_info;
492 int fd, err;
493
494 err = bpf_obj_get_info_by_fd(xsk->prog_fd, &prog_info, &prog_len);
495 if (err)
496 return err;
497
498 num_maps = prog_info.nr_map_ids;
499
500 map_ids = calloc(prog_info.nr_map_ids, sizeof(*map_ids));
501 if (!map_ids)
502 return -ENOMEM;
503
504 memset(&prog_info, 0, prog_len);
505 prog_info.nr_map_ids = num_maps;
506 prog_info.map_ids = (__u64)(unsigned long)map_ids;
507
508 err = bpf_obj_get_info_by_fd(xsk->prog_fd, &prog_info, &prog_len);
509 if (err)
510 goto out_map_ids;
511
512 xsk->xsks_map_fd = -1;
513
514 for (i = 0; i < prog_info.nr_map_ids; i++) {
515 fd = bpf_map_get_fd_by_id(map_ids[i]);
516 if (fd < 0)
517 continue;
518
519 err = bpf_obj_get_info_by_fd(fd, &map_info, &map_len);
520 if (err) {
521 close(fd);
522 continue;
523 }
524
525 if (!strcmp(map_info.name, "xsks_map")) {
526 xsk->xsks_map_fd = fd;
527 continue;
528 }
529
530 close(fd);
531 }
532
533 err = 0;
534 if (xsk->xsks_map_fd == -1)
535 err = -ENOENT;
536
537out_map_ids:
538 free(map_ids);
539 return err;
540}
541
542static int xsk_set_bpf_maps(struct xsk_socket *xsk)
543{
544 return bpf_map_update_elem(xsk->xsks_map_fd, &xsk->queue_id,
545 &xsk->fd, 0);
546}
547
548static int xsk_setup_xdp_prog(struct xsk_socket *xsk)
549{
550 __u32 prog_id = 0;
551 int err;
552
553 err = bpf_get_link_xdp_id(xsk->ifindex, &prog_id,
554 xsk->config.xdp_flags);
555 if (err)
556 return err;
557
558 if (!prog_id) {
559 err = xsk_create_bpf_maps(xsk);
560 if (err)
561 return err;
562
563 err = xsk_load_xdp_prog(xsk);
564 if (err) {
565 xsk_delete_bpf_maps(xsk);
566 return err;
567 }
568 } else {
569 xsk->prog_fd = bpf_prog_get_fd_by_id(prog_id);
570 if (xsk->prog_fd < 0)
571 return -errno;
572 err = xsk_lookup_bpf_maps(xsk);
573 if (err) {
574 close(xsk->prog_fd);
575 return err;
576 }
577 }
578
579 if (xsk->rx)
580 err = xsk_set_bpf_maps(xsk);
581 if (err) {
582 xsk_delete_bpf_maps(xsk);
583 close(xsk->prog_fd);
584 return err;
585 }
586
587 return 0;
588}
589
590int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
591 __u32 queue_id, struct xsk_umem *umem,
592 struct xsk_ring_cons *rx, struct xsk_ring_prod *tx,
593 const struct xsk_socket_config *usr_config)
594{
595 void *rx_map = NULL, *tx_map = NULL;
596 struct sockaddr_xdp sxdp = {};
597 struct xdp_mmap_offsets off;
598 struct xsk_socket *xsk;
599 int err;
600
601 if (!umem || !xsk_ptr || !(rx || tx))
602 return -EFAULT;
603
604 xsk = calloc(1, sizeof(*xsk));
605 if (!xsk)
606 return -ENOMEM;
607
608 err = xsk_set_xdp_socket_config(&xsk->config, usr_config);
609 if (err)
610 goto out_xsk_alloc;
611
612 if (umem->refcount &&
613 !(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
614 pr_warn("Error: shared umems not supported by libbpf supplied XDP program.\n");
615 err = -EBUSY;
616 goto out_xsk_alloc;
617 }
618
619 if (umem->refcount++ > 0) {
620 xsk->fd = socket(AF_XDP, SOCK_RAW, 0);
621 if (xsk->fd < 0) {
622 err = -errno;
623 goto out_xsk_alloc;
624 }
625 } else {
626 xsk->fd = umem->fd;
627 }
628
629 xsk->outstanding_tx = 0;
630 xsk->queue_id = queue_id;
631 xsk->umem = umem;
632 xsk->ifindex = if_nametoindex(ifname);
633 if (!xsk->ifindex) {
634 err = -errno;
635 goto out_socket;
636 }
637 memcpy(xsk->ifname, ifname, IFNAMSIZ - 1);
638 xsk->ifname[IFNAMSIZ - 1] = '\0';
639
640 if (rx) {
641 err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING,
642 &xsk->config.rx_size,
643 sizeof(xsk->config.rx_size));
644 if (err) {
645 err = -errno;
646 goto out_socket;
647 }
648 }
649 if (tx) {
650 err = setsockopt(xsk->fd, SOL_XDP, XDP_TX_RING,
651 &xsk->config.tx_size,
652 sizeof(xsk->config.tx_size));
653 if (err) {
654 err = -errno;
655 goto out_socket;
656 }
657 }
658
659 err = xsk_get_mmap_offsets(xsk->fd, &off);
660 if (err) {
661 err = -errno;
662 goto out_socket;
663 }
664
665 if (rx) {
666 rx_map = mmap(NULL, off.rx.desc +
667 xsk->config.rx_size * sizeof(struct xdp_desc),
668 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
669 xsk->fd, XDP_PGOFF_RX_RING);
670 if (rx_map == MAP_FAILED) {
671 err = -errno;
672 goto out_socket;
673 }
674
675 rx->mask = xsk->config.rx_size - 1;
676 rx->size = xsk->config.rx_size;
677 rx->producer = rx_map + off.rx.producer;
678 rx->consumer = rx_map + off.rx.consumer;
679 rx->flags = rx_map + off.rx.flags;
680 rx->ring = rx_map + off.rx.desc;
681 rx->cached_prod = *rx->producer;
682 rx->cached_cons = *rx->consumer;
683 }
684 xsk->rx = rx;
685
686 if (tx) {
687 tx_map = mmap(NULL, off.tx.desc +
688 xsk->config.tx_size * sizeof(struct xdp_desc),
689 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
690 xsk->fd, XDP_PGOFF_TX_RING);
691 if (tx_map == MAP_FAILED) {
692 err = -errno;
693 goto out_mmap_rx;
694 }
695
696 tx->mask = xsk->config.tx_size - 1;
697 tx->size = xsk->config.tx_size;
698 tx->producer = tx_map + off.tx.producer;
699 tx->consumer = tx_map + off.tx.consumer;
700 tx->flags = tx_map + off.tx.flags;
701 tx->ring = tx_map + off.tx.desc;
702 tx->cached_prod = *tx->producer;
703 /* cached_cons is r->size bigger than the real consumer pointer
704 * See xsk_prod_nb_free
705 */
706 tx->cached_cons = *tx->consumer + xsk->config.tx_size;
707 }
708 xsk->tx = tx;
709
710 sxdp.sxdp_family = PF_XDP;
711 sxdp.sxdp_ifindex = xsk->ifindex;
712 sxdp.sxdp_queue_id = xsk->queue_id;
713 if (umem->refcount > 1) {
714 sxdp.sxdp_flags = XDP_SHARED_UMEM;
715 sxdp.sxdp_shared_umem_fd = umem->fd;
716 } else {
717 sxdp.sxdp_flags = xsk->config.bind_flags;
718 }
719
720 err = bind(xsk->fd, (struct sockaddr *)&sxdp, sizeof(sxdp));
721 if (err) {
722 err = -errno;
723 goto out_mmap_tx;
724 }
725
726 xsk->prog_fd = -1;
727
728 if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
729 err = xsk_setup_xdp_prog(xsk);
730 if (err)
731 goto out_mmap_tx;
732 }
733
734 *xsk_ptr = xsk;
735 return 0;
736
737out_mmap_tx:
738 if (tx)
739 munmap(tx_map, off.tx.desc +
740 xsk->config.tx_size * sizeof(struct xdp_desc));
741out_mmap_rx:
742 if (rx)
743 munmap(rx_map, off.rx.desc +
744 xsk->config.rx_size * sizeof(struct xdp_desc));
745out_socket:
746 if (--umem->refcount)
747 close(xsk->fd);
748out_xsk_alloc:
749 free(xsk);
750 return err;
751}
752
753int xsk_umem__delete(struct xsk_umem *umem)
754{
755 struct xdp_mmap_offsets off;
756 int err;
757
758 if (!umem)
759 return 0;
760
761 if (umem->refcount)
762 return -EBUSY;
763
764 err = xsk_get_mmap_offsets(umem->fd, &off);
765 if (!err) {
766 munmap(umem->fill->ring - off.fr.desc,
767 off.fr.desc + umem->config.fill_size * sizeof(__u64));
768 munmap(umem->comp->ring - off.cr.desc,
769 off.cr.desc + umem->config.comp_size * sizeof(__u64));
770 }
771
772 close(umem->fd);
773 free(umem);
774
775 return 0;
776}
777
778void xsk_socket__delete(struct xsk_socket *xsk)
779{
780 size_t desc_sz = sizeof(struct xdp_desc);
781 struct xdp_mmap_offsets off;
782 int err;
783
784 if (!xsk)
785 return;
786
787 if (xsk->prog_fd != -1) {
788 xsk_delete_bpf_maps(xsk);
789 close(xsk->prog_fd);
790 }
791
792 err = xsk_get_mmap_offsets(xsk->fd, &off);
793 if (!err) {
794 if (xsk->rx) {
795 munmap(xsk->rx->ring - off.rx.desc,
796 off.rx.desc + xsk->config.rx_size * desc_sz);
797 }
798 if (xsk->tx) {
799 munmap(xsk->tx->ring - off.tx.desc,
800 off.tx.desc + xsk->config.tx_size * desc_sz);
801 }
802
803 }
804
805 xsk->umem->refcount--;
806 /* Do not close an fd that also has an associated umem connected
807 * to it.
808 */
809 if (xsk->fd != xsk->umem->fd)
810 close(xsk->fd);
811 free(xsk);
812}