Commit 2f6324a3 authored by Magnus Karlsson's avatar Magnus Karlsson Committed by Daniel Borkmann
Browse files

libbpf: Support shared umems between queues and devices 



Add support for shared umems between hardware queues and devices to
the AF_XDP part of libbpf. This so that zero-copy can be achieved in
applications that want to send and receive packets between HW queues
on one device or between different devices/netdevs.

In order to create sockets that share a umem between hardware queues
and devices, a new function has been added called
xsk_socket__create_shared(). It takes the same arguments as
xsk_socket_create() plus references to a fill ring and a completion
ring. So for every socket that share a umem, you need to have one more
set of fill and completion rings. This in order to maintain the
single-producer single-consumer semantics of the rings.

You can create all the sockets via the new xsk_socket__create_shared()
call, or create the first one with xsk_socket__create() and the rest
with xsk_socket__create_shared(). Both methods work.

Signed-off-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/1598603189-32145-14-git-send-email-magnus.karlsson@intel.com
parent a1132430

tools/lib/bpf/libbpf.map

+1 −0
Original line number Diff line number Diff line
@@ -306,4 +306,5 @@ LIBBPF_0.2.0 { 
		perf_buffer__buffer_fd;

		perf_buffer__epoll_fd;

		perf_buffer__consume_buffer;

		xsk_socket__create_shared;

} LIBBPF_0.1.0;

tools/lib/bpf/xsk.c

+244 −132
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/if_ether.h>

#include <linux/if_packet.h>

#include <linux/if_xdp.h>

#include <linux/list.h>

#include <linux/sockios.h>

#include <net/if.h>

#include <sys/ioctl.h>
@@ -45,26 +46,35 @@ 
#endif



struct xsk_umem {

	struct xsk_ring_prod *fill;

	struct xsk_ring_cons *comp;

	struct xsk_ring_prod *fill_save;

	struct xsk_ring_cons *comp_save;

	char *umem_area;

	struct xsk_umem_config config;

	int fd;

	int refcount;

	struct list_head ctx_list;

};



struct xsk_ctx {

	struct xsk_ring_prod *fill;

	struct xsk_ring_cons *comp;

	__u32 queue_id;

	struct xsk_umem *umem;

	int refcount;

	int ifindex;

	struct list_head list;

	int prog_fd;

	int xsks_map_fd;

	char ifname[IFNAMSIZ];

};



struct xsk_socket {

	struct xsk_ring_cons *rx;

	struct xsk_ring_prod *tx;

	__u64 outstanding_tx;

	struct xsk_umem *umem;

	struct xsk_ctx *ctx;

	struct xsk_socket_config config;

	int fd;

	int ifindex;

	int prog_fd;

	int xsks_map_fd;

	__u32 queue_id;

	char ifname[IFNAMSIZ];

};



struct xsk_nl_info {
@@ -200,15 +210,73 @@ static int xsk_get_mmap_offsets(int fd, struct xdp_mmap_offsets *off) 
	return -EINVAL;

}



static int xsk_create_umem_rings(struct xsk_umem *umem, int fd,

				 struct xsk_ring_prod *fill,

				 struct xsk_ring_cons *comp)

{

	struct xdp_mmap_offsets off;

	void *map;

	int err;



	err = setsockopt(fd, SOL_XDP, XDP_UMEM_FILL_RING,

			 &umem->config.fill_size,

			 sizeof(umem->config.fill_size));

	if (err)

		return -errno;



	err = setsockopt(fd, SOL_XDP, XDP_UMEM_COMPLETION_RING,

			 &umem->config.comp_size,

			 sizeof(umem->config.comp_size));

	if (err)

		return -errno;



	err = xsk_get_mmap_offsets(fd, &off);

	if (err)

		return -errno;



	map = mmap(NULL, off.fr.desc + umem->config.fill_size * sizeof(__u64),

		   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,

		   XDP_UMEM_PGOFF_FILL_RING);

	if (map == MAP_FAILED)

		return -errno;



	fill->mask = umem->config.fill_size - 1;

	fill->size = umem->config.fill_size;

	fill->producer = map + off.fr.producer;

	fill->consumer = map + off.fr.consumer;

	fill->flags = map + off.fr.flags;

	fill->ring = map + off.fr.desc;

	fill->cached_cons = umem->config.fill_size;



	map = mmap(NULL, off.cr.desc + umem->config.comp_size * sizeof(__u64),

		   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,

		   XDP_UMEM_PGOFF_COMPLETION_RING);

	if (map == MAP_FAILED) {

		err = -errno;

		goto out_mmap;

	}



	comp->mask = umem->config.comp_size - 1;

	comp->size = umem->config.comp_size;

	comp->producer = map + off.cr.producer;

	comp->consumer = map + off.cr.consumer;

	comp->flags = map + off.cr.flags;

	comp->ring = map + off.cr.desc;



	return 0;



out_mmap:

	munmap(map, off.fr.desc + umem->config.fill_size * sizeof(__u64));

	return err;

}



int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area,

			    __u64 size, struct xsk_ring_prod *fill,

			    struct xsk_ring_cons *comp,

			    const struct xsk_umem_config *usr_config)

{

	struct xdp_mmap_offsets off;

	struct xdp_umem_reg mr;

	struct xsk_umem *umem;

	void *map;

	int err;



	if (!umem_area || !umem_ptr || !fill || !comp)
@@ -227,6 +295,7 @@ int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area, 
	}



	umem->umem_area = umem_area;

	INIT_LIST_HEAD(&umem->ctx_list);

	xsk_set_umem_config(&umem->config, usr_config);



	memset(&mr, 0, sizeof(mr));
@@ -241,71 +310,16 @@ int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area, 
		err = -errno;

		goto out_socket;

	}

	err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_FILL_RING,

			 &umem->config.fill_size,

			 sizeof(umem->config.fill_size));

	if (err) {

		err = -errno;

		goto out_socket;

	}

	err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_COMPLETION_RING,

			 &umem->config.comp_size,

			 sizeof(umem->config.comp_size));

	if (err) {

		err = -errno;

		goto out_socket;

	}



	err = xsk_get_mmap_offsets(umem->fd, &off);

	if (err) {

		err = -errno;

		goto out_socket;

	}



	map = mmap(NULL, off.fr.desc + umem->config.fill_size * sizeof(__u64),

		   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, umem->fd,

		   XDP_UMEM_PGOFF_FILL_RING);

	if (map == MAP_FAILED) {

		err = -errno;

	err = xsk_create_umem_rings(umem, umem->fd, fill, comp);

	if (err)

		goto out_socket;

	}



	umem->fill = fill;

	fill->mask = umem->config.fill_size - 1;

	fill->size = umem->config.fill_size;

	fill->producer = map + off.fr.producer;

	fill->consumer = map + off.fr.consumer;

	fill->flags = map + off.fr.flags;

	fill->ring = map + off.fr.desc;

	fill->cached_prod = *fill->producer;

	/* cached_cons is "size" bigger than the real consumer pointer

	 * See xsk_prod_nb_free

	 */

	fill->cached_cons = *fill->consumer + umem->config.fill_size;



	map = mmap(NULL, off.cr.desc + umem->config.comp_size * sizeof(__u64),

		   PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, umem->fd,

		   XDP_UMEM_PGOFF_COMPLETION_RING);

	if (map == MAP_FAILED) {

		err = -errno;

		goto out_mmap;

	}



	umem->comp = comp;

	comp->mask = umem->config.comp_size - 1;

	comp->size = umem->config.comp_size;

	comp->producer = map + off.cr.producer;

	comp->consumer = map + off.cr.consumer;

	comp->flags = map + off.cr.flags;

	comp->ring = map + off.cr.desc;

	comp->cached_prod = *comp->producer;

	comp->cached_cons = *comp->consumer;



	umem->fill_save = fill;

	umem->comp_save = comp;

	*umem_ptr = umem;

	return 0;



out_mmap:

	munmap(map, off.fr.desc + umem->config.fill_size * sizeof(__u64));

out_socket:

	close(umem->fd);

out_umem_alloc:
@@ -339,6 +353,7 @@ DEFAULT_VERSION(xsk_umem__create_v0_0_4, xsk_umem__create, LIBBPF_0.0.4) 
static int xsk_load_xdp_prog(struct xsk_socket *xsk)

{

	static const int log_buf_size = 16 * 1024;

	struct xsk_ctx *ctx = xsk->ctx;

	char log_buf[log_buf_size];

	int err, prog_fd;
@@ -366,7 +381,7 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) 
		/* *(u32 *)(r10 - 4) = r2 */

		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -4),

		/* r1 = xskmap[] */

		BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd),

		BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),

		/* r3 = XDP_PASS */

		BPF_MOV64_IMM(BPF_REG_3, 2),

		/* call bpf_redirect_map */
@@ -378,7 +393,7 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) 
		/* r2 += -4 */

		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),

		/* r1 = xskmap[] */

		BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd),

		BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),

		/* call bpf_map_lookup_elem */

		BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),

		/* r1 = r0 */
@@ -390,7 +405,7 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) 
		/* r2 = *(u32 *)(r10 - 4) */

		BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_10, -4),

		/* r1 = xskmap[] */

		BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd),

		BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),

		/* r3 = 0 */

		BPF_MOV64_IMM(BPF_REG_3, 0),

		/* call bpf_redirect_map */
@@ -408,19 +423,21 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) 
		return prog_fd;

	}



	err = bpf_set_link_xdp_fd(xsk->ifindex, prog_fd, xsk->config.xdp_flags);

	err = bpf_set_link_xdp_fd(xsk->ctx->ifindex, prog_fd,

				  xsk->config.xdp_flags);

	if (err) {

		close(prog_fd);

		return err;

	}



	xsk->prog_fd = prog_fd;

	ctx->prog_fd = prog_fd;

	return 0;

}



static int xsk_get_max_queues(struct xsk_socket *xsk)

{

	struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };

	struct xsk_ctx *ctx = xsk->ctx;

	struct ifreq ifr = {};

	int fd, err, ret;
@@ -429,7 +446,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk) 
		return -errno;



	ifr.ifr_data = (void *)&channels;

	memcpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);

	memcpy(ifr.ifr_name, ctx->ifname, IFNAMSIZ - 1);

	ifr.ifr_name[IFNAMSIZ - 1] = '\0';

	err = ioctl(fd, SIOCETHTOOL, &ifr);

	if (err && errno != EOPNOTSUPP) {
@@ -457,6 +474,7 @@ out: 


static int xsk_create_bpf_maps(struct xsk_socket *xsk)

{

	struct xsk_ctx *ctx = xsk->ctx;

	int max_queues;

	int fd;
@@ -469,15 +487,17 @@ static int xsk_create_bpf_maps(struct xsk_socket *xsk) 
	if (fd < 0)

		return fd;



	xsk->xsks_map_fd = fd;

	ctx->xsks_map_fd = fd;



	return 0;

}



static void xsk_delete_bpf_maps(struct xsk_socket *xsk)

{

	bpf_map_delete_elem(xsk->xsks_map_fd, &xsk->queue_id);

	close(xsk->xsks_map_fd);

	struct xsk_ctx *ctx = xsk->ctx;



	bpf_map_delete_elem(ctx->xsks_map_fd, &ctx->queue_id);

	close(ctx->xsks_map_fd);

}



static int xsk_lookup_bpf_maps(struct xsk_socket *xsk)
@@ -485,10 +505,11 @@ static int xsk_lookup_bpf_maps(struct xsk_socket *xsk) 
	__u32 i, *map_ids, num_maps, prog_len = sizeof(struct bpf_prog_info);

	__u32 map_len = sizeof(struct bpf_map_info);

	struct bpf_prog_info prog_info = {};

	struct xsk_ctx *ctx = xsk->ctx;

	struct bpf_map_info map_info;

	int fd, err;



	err = bpf_obj_get_info_by_fd(xsk->prog_fd, &prog_info, &prog_len);

	err = bpf_obj_get_info_by_fd(ctx->prog_fd, &prog_info, &prog_len);

	if (err)

		return err;
@@ -502,11 +523,11 @@ static int xsk_lookup_bpf_maps(struct xsk_socket *xsk) 
	prog_info.nr_map_ids = num_maps;

	prog_info.map_ids = (__u64)(unsigned long)map_ids;



	err = bpf_obj_get_info_by_fd(xsk->prog_fd, &prog_info, &prog_len);

	err = bpf_obj_get_info_by_fd(ctx->prog_fd, &prog_info, &prog_len);

	if (err)

		goto out_map_ids;



	xsk->xsks_map_fd = -1;

	ctx->xsks_map_fd = -1;



	for (i = 0; i < prog_info.nr_map_ids; i++) {

		fd = bpf_map_get_fd_by_id(map_ids[i]);
@@ -520,7 +541,7 @@ static int xsk_lookup_bpf_maps(struct xsk_socket *xsk) 
		}



		if (!strcmp(map_info.name, "xsks_map")) {

			xsk->xsks_map_fd = fd;

			ctx->xsks_map_fd = fd;

			continue;

		}
@@ -528,7 +549,7 @@ static int xsk_lookup_bpf_maps(struct xsk_socket *xsk) 
	}



	err = 0;

	if (xsk->xsks_map_fd == -1)

	if (ctx->xsks_map_fd == -1)

		err = -ENOENT;



out_map_ids:
@@ -538,16 +559,19 @@ out_map_ids: 


static int xsk_set_bpf_maps(struct xsk_socket *xsk)

{

	return bpf_map_update_elem(xsk->xsks_map_fd, &xsk->queue_id,

	struct xsk_ctx *ctx = xsk->ctx;



	return bpf_map_update_elem(ctx->xsks_map_fd, &ctx->queue_id,

				   &xsk->fd, 0);

}



static int xsk_setup_xdp_prog(struct xsk_socket *xsk)

{

	struct xsk_ctx *ctx = xsk->ctx;

	__u32 prog_id = 0;

	int err;



	err = bpf_get_link_xdp_id(xsk->ifindex, &prog_id,

	err = bpf_get_link_xdp_id(ctx->ifindex, &prog_id,

				  xsk->config.xdp_flags);

	if (err)

		return err;
@@ -563,12 +587,12 @@ static int xsk_setup_xdp_prog(struct xsk_socket *xsk) 
			return err;

		}

	} else {

		xsk->prog_fd = bpf_prog_get_fd_by_id(prog_id);

		if (xsk->prog_fd < 0)

		ctx->prog_fd = bpf_prog_get_fd_by_id(prog_id);

		if (ctx->prog_fd < 0)

			return -errno;

		err = xsk_lookup_bpf_maps(xsk);

		if (err) {

			close(xsk->prog_fd);

			close(ctx->prog_fd);

			return err;

		}

	}
@@ -577,25 +601,110 @@ static int xsk_setup_xdp_prog(struct xsk_socket *xsk) 
		err = xsk_set_bpf_maps(xsk);

	if (err) {

		xsk_delete_bpf_maps(xsk);

		close(xsk->prog_fd);

		close(ctx->prog_fd);

		return err;

	}



	return 0;

}



int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,

static struct xsk_ctx *xsk_get_ctx(struct xsk_umem *umem, int ifindex,

				   __u32 queue_id)

{

	struct xsk_ctx *ctx;



	if (list_empty(&umem->ctx_list))

		return NULL;



	list_for_each_entry(ctx, &umem->ctx_list, list) {

		if (ctx->ifindex == ifindex && ctx->queue_id == queue_id) {

			ctx->refcount++;

			return ctx;

		}

	}



	return NULL;

}



static void xsk_put_ctx(struct xsk_ctx *ctx)

{

	struct xsk_umem *umem = ctx->umem;

	struct xdp_mmap_offsets off;

	int err;



	if (--ctx->refcount == 0) {

		err = xsk_get_mmap_offsets(umem->fd, &off);

		if (!err) {

			munmap(ctx->fill->ring - off.fr.desc,

			       off.fr.desc + umem->config.fill_size *

			       sizeof(__u64));

			munmap(ctx->comp->ring - off.cr.desc,

			       off.cr.desc + umem->config.comp_size *

			       sizeof(__u64));

		}



		list_del(&ctx->list);

		free(ctx);

	}

}



static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk,

				      struct xsk_umem *umem, int ifindex,

				      const char *ifname, __u32 queue_id,

				      struct xsk_ring_prod *fill,

				      struct xsk_ring_cons *comp)

{

	struct xsk_ctx *ctx;

	int err;



	ctx = calloc(1, sizeof(*ctx));

	if (!ctx)

		return NULL;



	if (!umem->fill_save) {

		err = xsk_create_umem_rings(umem, xsk->fd, fill, comp);

		if (err) {

			free(ctx);

			return NULL;

		}

	} else if (umem->fill_save != fill || umem->comp_save != comp) {

		/* Copy over rings to new structs. */

		memcpy(fill, umem->fill_save, sizeof(*fill));

		memcpy(comp, umem->comp_save, sizeof(*comp));

	}



	ctx->ifindex = ifindex;

	ctx->refcount = 1;

	ctx->umem = umem;

	ctx->queue_id = queue_id;

	memcpy(ctx->ifname, ifname, IFNAMSIZ - 1);

	ctx->ifname[IFNAMSIZ - 1] = '\0';



	umem->fill_save = NULL;

	umem->comp_save = NULL;

	ctx->fill = fill;

	ctx->comp = comp;

	list_add(&ctx->list, &umem->ctx_list);

	return ctx;

}



int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,

			      const char *ifname,

			      __u32 queue_id, struct xsk_umem *umem,

		       struct xsk_ring_cons *rx, struct xsk_ring_prod *tx,

			      struct xsk_ring_cons *rx,

			      struct xsk_ring_prod *tx,

			      struct xsk_ring_prod *fill,

			      struct xsk_ring_cons *comp,

			      const struct xsk_socket_config *usr_config)

{

	void *rx_map = NULL, *tx_map = NULL;

	struct sockaddr_xdp sxdp = {};

	struct xdp_mmap_offsets off;

	struct xsk_socket *xsk;

	int err;

	struct xsk_ctx *ctx;

	int err, ifindex;



	if (!umem || !xsk_ptr || !(rx || tx))

	if (!umem || !xsk_ptr || !(rx || tx) || !fill || !comp)

		return -EFAULT;



	xsk = calloc(1, sizeof(*xsk));
@@ -606,10 +715,10 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, 
	if (err)

		goto out_xsk_alloc;



	if (umem->refcount &&

	    !(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {

		pr_warn("Error: shared umems not supported by libbpf supplied XDP program.\n");

		err = -EBUSY;

	xsk->outstanding_tx = 0;

	ifindex = if_nametoindex(ifname);

	if (!ifindex) {

		err = -errno;

		goto out_xsk_alloc;

	}
@@ -623,16 +732,16 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, 
		xsk->fd = umem->fd;

	}



	xsk->outstanding_tx = 0;

	xsk->queue_id = queue_id;

	xsk->umem = umem;

	xsk->ifindex = if_nametoindex(ifname);

	if (!xsk->ifindex) {

		err = -errno;

	ctx = xsk_get_ctx(umem, ifindex, queue_id);

	if (!ctx) {

		ctx = xsk_create_ctx(xsk, umem, ifindex, ifname, queue_id,

				     fill, comp);

		if (!ctx) {

			err = -ENOMEM;

			goto out_socket;

		}

	memcpy(xsk->ifname, ifname, IFNAMSIZ - 1);

	xsk->ifname[IFNAMSIZ - 1] = '\0';

	}

	xsk->ctx = ctx;



	if (rx) {

		err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING,
@@ -640,7 +749,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, 
				 sizeof(xsk->config.rx_size));

		if (err) {

			err = -errno;

			goto out_socket;

			goto out_put_ctx;

		}

	}

	if (tx) {
@@ -649,14 +758,14 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, 
				 sizeof(xsk->config.tx_size));

		if (err) {

			err = -errno;

			goto out_socket;

			goto out_put_ctx;

		}

	}



	err = xsk_get_mmap_offsets(xsk->fd, &off);

	if (err) {

		err = -errno;

		goto out_socket;

		goto out_put_ctx;

	}



	if (rx) {
@@ -666,7 +775,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, 
			      xsk->fd, XDP_PGOFF_RX_RING);

		if (rx_map == MAP_FAILED) {

			err = -errno;

			goto out_socket;

			goto out_put_ctx;

		}



		rx->mask = xsk->config.rx_size - 1;
@@ -705,10 +814,10 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, 
	xsk->tx = tx;



	sxdp.sxdp_family = PF_XDP;

	sxdp.sxdp_ifindex = xsk->ifindex;

	sxdp.sxdp_queue_id = xsk->queue_id;

	sxdp.sxdp_ifindex = ctx->ifindex;

	sxdp.sxdp_queue_id = ctx->queue_id;

	if (umem->refcount > 1) {

		sxdp.sxdp_flags = XDP_SHARED_UMEM;

		sxdp.sxdp_flags |= XDP_SHARED_UMEM;

		sxdp.sxdp_shared_umem_fd = umem->fd;

	} else {

		sxdp.sxdp_flags = xsk->config.bind_flags;
@@ -720,7 +829,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, 
		goto out_mmap_tx;

	}



	xsk->prog_fd = -1;

	ctx->prog_fd = -1;



	if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {

		err = xsk_setup_xdp_prog(xsk);
@@ -739,6 +848,8 @@ out_mmap_rx: 
	if (rx)

		munmap(rx_map, off.rx.desc +

		       xsk->config.rx_size * sizeof(struct xdp_desc));

out_put_ctx:

	xsk_put_ctx(ctx);

out_socket:

	if (--umem->refcount)

		close(xsk->fd);
@@ -747,25 +858,24 @@ out_xsk_alloc: 
	return err;

}



int xsk_umem__delete(struct xsk_umem *umem)

int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,

		       __u32 queue_id, struct xsk_umem *umem,

		       struct xsk_ring_cons *rx, struct xsk_ring_prod *tx,

		       const struct xsk_socket_config *usr_config)

{

	struct xdp_mmap_offsets off;

	int err;

	return xsk_socket__create_shared(xsk_ptr, ifname, queue_id, umem,

					 rx, tx, umem->fill_save,

					 umem->comp_save, usr_config);

}



int xsk_umem__delete(struct xsk_umem *umem)

{

	if (!umem)

		return 0;



	if (umem->refcount)

		return -EBUSY;



	err = xsk_get_mmap_offsets(umem->fd, &off);

	if (!err) {

		munmap(umem->fill->ring - off.fr.desc,

		       off.fr.desc + umem->config.fill_size * sizeof(__u64));

		munmap(umem->comp->ring - off.cr.desc,

		       off.cr.desc + umem->config.comp_size * sizeof(__u64));

	}



	close(umem->fd);

	free(umem);
@@ -775,15 +885,16 @@ int xsk_umem__delete(struct xsk_umem *umem) 
void xsk_socket__delete(struct xsk_socket *xsk)

{

	size_t desc_sz = sizeof(struct xdp_desc);

	struct xsk_ctx *ctx = xsk->ctx;

	struct xdp_mmap_offsets off;

	int err;



	if (!xsk)

		return;



	if (xsk->prog_fd != -1) {

	if (ctx->prog_fd != -1) {

		xsk_delete_bpf_maps(xsk);

		close(xsk->prog_fd);

		close(ctx->prog_fd);

	}



	err = xsk_get_mmap_offsets(xsk->fd, &off);
@@ -796,14 +907,15 @@ void xsk_socket__delete(struct xsk_socket *xsk) 
			munmap(xsk->tx->ring - off.tx.desc,

			       off.tx.desc + xsk->config.tx_size * desc_sz);

		}



	}



	xsk->umem->refcount--;

	xsk_put_ctx(ctx);



	ctx->umem->refcount--;

	/* Do not close an fd that also has an associated umem connected

	 * to it.

	 */

	if (xsk->fd != xsk->umem->fd)

	if (xsk->fd != ctx->umem->fd)

		close(xsk->fd);

	free(xsk);

}

tools/lib/bpf/xsk.h

+9 −0
Original line number Diff line number Diff line
@@ -234,6 +234,15 @@ LIBBPF_API int xsk_socket__create(struct xsk_socket **xsk, 
				  struct xsk_ring_cons *rx,

				  struct xsk_ring_prod *tx,

				  const struct xsk_socket_config *config);

LIBBPF_API int

xsk_socket__create_shared(struct xsk_socket **xsk_ptr,

			  const char *ifname,

			  __u32 queue_id, struct xsk_umem *umem,

			  struct xsk_ring_cons *rx,

			  struct xsk_ring_prod *tx,

			  struct xsk_ring_prod *fill,

			  struct xsk_ring_cons *comp,

			  const struct xsk_socket_config *config);



/* Returns 0 for success and -EBUSY if the umem is still in use. */

LIBBPF_API int xsk_umem__delete(struct xsk_umem *umem);

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