// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)

/*
 * AF_XDP user-space access library.
 *
 * Copyright(c) 2018 - 2019 Intel Corporation.
 *
 * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
 */

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <asm/barrier.h>
#include <linux/compiler.h>
#include <linux/ethtool.h>
#include <linux/filter.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <linux/if_xdp.h>
#include <linux/sockios.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>

#include "bpf.h"
#include "libbpf.h"
#include "libbpf_internal.h"
#include "xsk.h"

/* make sure libbpf doesn't use kernel-only integer typedefs */
#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64

#ifndef SOL_XDP
 #define SOL_XDP 283
#endif

#ifndef AF_XDP
 #define AF_XDP 44
#endif

#ifndef PF_XDP
 #define PF_XDP AF_XDP
#endif

struct xsk_umem {
        struct xsk_ring_prod *fill;
        struct xsk_ring_cons *comp;
        char *umem_area;
        struct xsk_umem_config config;
        int fd;
        int refcount;
};

struct xsk_socket {
        struct xsk_ring_cons *rx;
        struct xsk_ring_prod *tx;
        __u64 outstanding_tx;
        struct xsk_umem *umem;
        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 {
        bool xdp_prog_attached;
        int ifindex;
        int fd;
};

/* Up until and including Linux 5.3 */
struct xdp_ring_offset_v1 {
        __u64 producer;
        __u64 consumer;
        __u64 desc;
};

/* Up until and including Linux 5.3 */
struct xdp_mmap_offsets_v1 {
        struct xdp_ring_offset_v1 rx;
        struct xdp_ring_offset_v1 tx;
        struct xdp_ring_offset_v1 fr;
        struct xdp_ring_offset_v1 cr;
};

int xsk_umem__fd(const struct xsk_umem *umem)
{
        return umem ? umem->fd : -EINVAL;
}

int xsk_socket__fd(const struct xsk_socket *xsk)
{
        return xsk ? xsk->fd : -EINVAL;
}

static bool xsk_page_aligned(void *buffer)
{
        unsigned long addr = (unsigned long)buffer;

        return !(addr & (getpagesize() - 1));
}

static void xsk_set_umem_config(struct xsk_umem_config *cfg,
                                const struct xsk_umem_config *usr_cfg)
{
        if (!usr_cfg) {
                cfg->fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
                cfg->comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
                cfg->frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
                cfg->frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM;
                cfg->flags = XSK_UMEM__DEFAULT_FLAGS;
                return;
        }

        cfg->fill_size = usr_cfg->fill_size;
        cfg->comp_size = usr_cfg->comp_size;
        cfg->frame_size = usr_cfg->frame_size;
        cfg->frame_headroom = usr_cfg->frame_headroom;
        cfg->flags = usr_cfg->flags;
}

static int xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
                                     const struct xsk_socket_config *usr_cfg)
{
        if (!usr_cfg) {
                cfg->rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
                cfg->tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
                cfg->libbpf_flags = 0;
                cfg->xdp_flags = 0;
                cfg->bind_flags = 0;
                return 0;
        }

        if (usr_cfg->libbpf_flags & ~XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)
                return -EINVAL;

        cfg->rx_size = usr_cfg->rx_size;
        cfg->tx_size = usr_cfg->tx_size;
        cfg->libbpf_flags = usr_cfg->libbpf_flags;
        cfg->xdp_flags = usr_cfg->xdp_flags;
        cfg->bind_flags = usr_cfg->bind_flags;

        return 0;
}

static void xsk_mmap_offsets_v1(struct xdp_mmap_offsets *off)
{
        struct xdp_mmap_offsets_v1 off_v1;

        /* getsockopt on a kernel <= 5.3 has no flags fields.
         * Copy over the offsets to the correct places in the >=5.4 format
         * and put the flags where they would have been on that kernel.
         */
        memcpy(&off_v1, off, sizeof(off_v1));

        off->rx.producer = off_v1.rx.producer;
        off->rx.consumer = off_v1.rx.consumer;
        off->rx.desc = off_v1.rx.desc;
        off->rx.flags = off_v1.rx.consumer + sizeof(__u32);

        off->tx.producer = off_v1.tx.producer;
        off->tx.consumer = off_v1.tx.consumer;
        off->tx.desc = off_v1.tx.desc;
        off->tx.flags = off_v1.tx.consumer + sizeof(__u32);

        off->fr.producer = off_v1.fr.producer;
        off->fr.consumer = off_v1.fr.consumer;
        off->fr.desc = off_v1.fr.desc;
        off->fr.flags = off_v1.fr.consumer + sizeof(__u32);

        off->cr.producer = off_v1.cr.producer;
        off->cr.consumer = off_v1.cr.consumer;
        off->cr.desc = off_v1.cr.desc;
        off->cr.flags = off_v1.cr.consumer + sizeof(__u32);
}

static int xsk_get_mmap_offsets(int fd, struct xdp_mmap_offsets *off)
{
        socklen_t optlen;
        int err;

        optlen = sizeof(*off);
        err = getsockopt(fd, SOL_XDP, XDP_MMAP_OFFSETS, off, &optlen);
        if (err)
                return err;

        if (optlen == sizeof(*off))
                return 0;

        if (optlen == sizeof(struct xdp_mmap_offsets_v1)) {
                xsk_mmap_offsets_v1(off);
                return 0;
        }

        return -EINVAL;
}

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)
                return -EFAULT;
        if (!size && !xsk_page_aligned(umem_area))
                return -EINVAL;

        umem = calloc(1, sizeof(*umem));
        if (!umem)
                return -ENOMEM;

        umem->fd = socket(AF_XDP, SOCK_RAW, 0);
        if (umem->fd < 0) {
                err = -errno;
                goto out_umem_alloc;
        }

        umem->umem_area = umem_area;
        xsk_set_umem_config(&umem->config, usr_config);

        memset(&mr, 0, sizeof(mr));
        mr.addr = (uintptr_t)umem_area;
        mr.len = size;
        mr.chunk_size = umem->config.frame_size;
        mr.headroom = umem->config.frame_headroom;
        mr.flags = umem->config.flags;

        err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr));
        if (err) {
                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;
                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_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, 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;

        *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:
        free(umem);
        return err;
}

struct xsk_umem_config_v1 {
        __u32 fill_size;
        __u32 comp_size;
        __u32 frame_size;
        __u32 frame_headroom;
};

int xsk_umem__create_v0_0_2(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 xsk_umem_config config;

        memcpy(&config, usr_config, sizeof(struct xsk_umem_config_v1));
        config.flags = 0;

        return xsk_umem__create_v0_0_4(umem_ptr, umem_area, size, fill, comp,
                                        &config);
}
COMPAT_VERSION(xsk_umem__create_v0_0_2, xsk_umem__create, LIBBPF_0.0.2)
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;
        char log_buf[log_buf_size];
        int err, prog_fd;

        /* This is the C-program:
         * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
         * {
         *     int ret, index = ctx->rx_queue_index;
         *
         *     // A set entry here means that the correspnding queue_id
         *     // has an active AF_XDP socket bound to it.
         *     ret = bpf_redirect_map(&xsks_map, index, XDP_PASS);
         *     if (ret > 0)
         *         return ret;
         *
         *     // Fallback for pre-5.3 kernels, not supporting default
         *     // action in the flags parameter.
         *     if (bpf_map_lookup_elem(&xsks_map, &index))
         *         return bpf_redirect_map(&xsks_map, index, 0);
         *     return XDP_PASS;
         * }
         */
        struct bpf_insn prog[] = {
                /* r2 = *(u32 *)(r1 + 16) */
                BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 16),
                /* *(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),
                /* r3 = XDP_PASS */
                BPF_MOV64_IMM(BPF_REG_3, 2),
                /* call bpf_redirect_map */
                BPF_EMIT_CALL(BPF_FUNC_redirect_map),
                /* if w0 != 0 goto pc+13 */
                BPF_JMP32_IMM(BPF_JSGT, BPF_REG_0, 0, 13),
                /* r2 = r10 */
                BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
                /* r2 += -4 */
                BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
                /* r1 = xskmap[] */
                BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd),
                /* call bpf_map_lookup_elem */
                BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
                /* r1 = r0 */
                BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
                /* r0 = XDP_PASS */
                BPF_MOV64_IMM(BPF_REG_0, 2),
                /* if r1 == 0 goto pc+5 */
                BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5),
                /* 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),
                /* r3 = 0 */
                BPF_MOV64_IMM(BPF_REG_3, 0),
                /* call bpf_redirect_map */
                BPF_EMIT_CALL(BPF_FUNC_redirect_map),
                /* The jumps are to this instruction */
                BPF_EXIT_INSN(),
        };
        size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);

        prog_fd = bpf_load_program(BPF_PROG_TYPE_XDP, prog, insns_cnt,
                                   "LGPL-2.1 or BSD-2-Clause", 0, log_buf,
                                   log_buf_size);
        if (prog_fd < 0) {
                pr_warn("BPF log buffer:\n%s", log_buf);
                return prog_fd;
        }

        err = bpf_set_link_xdp_fd(xsk->ifindex, prog_fd, xsk->config.xdp_flags);
        if (err) {
                close(prog_fd);
                return err;
        }

        xsk->prog_fd = prog_fd;
        return 0;
}

static int xsk_get_max_queues(struct xsk_socket *xsk)
{
        struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
        struct ifreq ifr = {};
        int fd, err, ret;

        fd = socket(AF_INET, SOCK_DGRAM, 0);
        if (fd < 0)
                return -errno;

        ifr.ifr_data = (void *)&channels;
        memcpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
        ifr.ifr_name[IFNAMSIZ - 1] = '\0';
        err = ioctl(fd, SIOCETHTOOL, &ifr);
        if (err && errno != EOPNOTSUPP) {
                ret = -errno;
                goto out;
        }

        if (err) {
                /* If the device says it has no channels, then all traffic
                 * is sent to a single stream, so max queues = 1.
                 */
                ret = 1;
        } else {
                /* Take the max of rx, tx, combined. Drivers return
                 * the number of channels in different ways.
                 */
                ret = max(channels.max_rx, channels.max_tx);
                ret = max(ret, (int)channels.max_combined);
        }

out:
        close(fd);
        return ret;
}

static int xsk_create_bpf_maps(struct xsk_socket *xsk)
{
        int max_queues;
        int fd;

        max_queues = xsk_get_max_queues(xsk);
        if (max_queues < 0)
                return max_queues;

        fd = bpf_create_map_name(BPF_MAP_TYPE_XSKMAP, "xsks_map",
                                 sizeof(int), sizeof(int), max_queues, 0);
        if (fd < 0)
                return fd;

        xsk->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);
}

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 bpf_map_info map_info;
        int fd, err;

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

        num_maps = prog_info.nr_map_ids;

        map_ids = calloc(prog_info.nr_map_ids, sizeof(*map_ids));
        if (!map_ids)
                return -ENOMEM;

        memset(&prog_info, 0, prog_len);
        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);
        if (err)
                goto out_map_ids;

        xsk->xsks_map_fd = -1;

        for (i = 0; i < prog_info.nr_map_ids; i++) {
                fd = bpf_map_get_fd_by_id(map_ids[i]);
                if (fd < 0)
                        continue;

                err = bpf_obj_get_info_by_fd(fd, &map_info, &map_len);
                if (err) {
                        close(fd);
                        continue;
                }

                if (!strcmp(map_info.name, "xsks_map")) {
                        xsk->xsks_map_fd = fd;
                        continue;
                }

                close(fd);
        }

        err = 0;
        if (xsk->xsks_map_fd == -1)
                err = -ENOENT;

out_map_ids:
        free(map_ids);
        return err;
}

static int xsk_set_bpf_maps(struct xsk_socket *xsk)
{
        return bpf_map_update_elem(xsk->xsks_map_fd, &xsk->queue_id,
                                   &xsk->fd, 0);
}

static int xsk_setup_xdp_prog(struct xsk_socket *xsk)
{
        __u32 prog_id = 0;
        int err;

        err = bpf_get_link_xdp_id(xsk->ifindex, &prog_id,
                                  xsk->config.xdp_flags);
        if (err)
                return err;

        if (!prog_id) {
                err = xsk_create_bpf_maps(xsk);
                if (err)
                        return err;

                err = xsk_load_xdp_prog(xsk);
                if (err) {
                        xsk_delete_bpf_maps(xsk);
                        return err;
                }
        } else {
                xsk->prog_fd = bpf_prog_get_fd_by_id(prog_id);
                if (xsk->prog_fd < 0)
                        return -errno;
                err = xsk_lookup_bpf_maps(xsk);
                if (err) {
                        close(xsk->prog_fd);
                        return err;
                }
        }

        if (xsk->rx)
                err = xsk_set_bpf_maps(xsk);
        if (err) {
                xsk_delete_bpf_maps(xsk);
                close(xsk->prog_fd);
                return err;
        }

        return 0;
}

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)
{
        void *rx_map = NULL, *tx_map = NULL;
        struct sockaddr_xdp sxdp = {};
        struct xdp_mmap_offsets off;
        struct xsk_socket *xsk;
        int err;

        if (!umem || !xsk_ptr || !(rx || tx))
                return -EFAULT;

        xsk = calloc(1, sizeof(*xsk));
        if (!xsk)
                return -ENOMEM;

        err = xsk_set_xdp_socket_config(&xsk->config, usr_config);
        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;
                goto out_xsk_alloc;
        }

        if (umem->refcount++ > 0) {
                xsk->fd = socket(AF_XDP, SOCK_RAW, 0);
                if (xsk->fd < 0) {
                        err = -errno;
                        goto out_xsk_alloc;
                }
        } else {
                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;
                goto out_socket;
        }
        memcpy(xsk->ifname, ifname, IFNAMSIZ - 1);
        xsk->ifname[IFNAMSIZ - 1] = '\0';

        if (rx) {
                err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING,
                                 &xsk->config.rx_size,
                                 sizeof(xsk->config.rx_size));
                if (err) {
                        err = -errno;
                        goto out_socket;
                }
        }
        if (tx) {
                err = setsockopt(xsk->fd, SOL_XDP, XDP_TX_RING,
                                 &xsk->config.tx_size,
                                 sizeof(xsk->config.tx_size));
                if (err) {
                        err = -errno;
                        goto out_socket;
                }
        }

        err = xsk_get_mmap_offsets(xsk->fd, &off);
        if (err) {
                err = -errno;
                goto out_socket;
        }

        if (rx) {
                rx_map = mmap(NULL, off.rx.desc +
                              xsk->config.rx_size * sizeof(struct xdp_desc),
                              PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
                              xsk->fd, XDP_PGOFF_RX_RING);
                if (rx_map == MAP_FAILED) {
                        err = -errno;
                        goto out_socket;
                }

                rx->mask = xsk->config.rx_size - 1;
                rx->size = xsk->config.rx_size;
                rx->producer = rx_map + off.rx.producer;
                rx->consumer = rx_map + off.rx.consumer;
                rx->flags = rx_map + off.rx.flags;
                rx->ring = rx_map + off.rx.desc;
        }
        xsk->rx = rx;

        if (tx) {
                tx_map = mmap(NULL, off.tx.desc +
                              xsk->config.tx_size * sizeof(struct xdp_desc),
                              PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
                              xsk->fd, XDP_PGOFF_TX_RING);
                if (tx_map == MAP_FAILED) {
                        err = -errno;
                        goto out_mmap_rx;
                }

                tx->mask = xsk->config.tx_size - 1;
                tx->size = xsk->config.tx_size;
                tx->producer = tx_map + off.tx.producer;
                tx->consumer = tx_map + off.tx.consumer;
                tx->flags = tx_map + off.tx.flags;
                tx->ring = tx_map + off.tx.desc;
                tx->cached_cons = xsk->config.tx_size;
        }
        xsk->tx = tx;

        sxdp.sxdp_family = PF_XDP;
        sxdp.sxdp_ifindex = xsk->ifindex;
        sxdp.sxdp_queue_id = xsk->queue_id;
        if (umem->refcount > 1) {
                sxdp.sxdp_flags = XDP_SHARED_UMEM;
                sxdp.sxdp_shared_umem_fd = umem->fd;
        } else {
                sxdp.sxdp_flags = xsk->config.bind_flags;
        }

        err = bind(xsk->fd, (struct sockaddr *)&sxdp, sizeof(sxdp));
        if (err) {
                err = -errno;
                goto out_mmap_tx;
        }

        xsk->prog_fd = -1;

        if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
                err = xsk_setup_xdp_prog(xsk);
                if (err)
                        goto out_mmap_tx;
        }

        *xsk_ptr = xsk;
        return 0;

out_mmap_tx:
        if (tx)
                munmap(tx_map, off.tx.desc +
                       xsk->config.tx_size * sizeof(struct xdp_desc));
out_mmap_rx:
        if (rx)
                munmap(rx_map, off.rx.desc +
                       xsk->config.rx_size * sizeof(struct xdp_desc));
out_socket:
        if (--umem->refcount)
                close(xsk->fd);
out_xsk_alloc:
        free(xsk);
        return err;
}

int xsk_umem__delete(struct xsk_umem *umem)
{
        struct xdp_mmap_offsets off;
        int err;

        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);

        return 0;
}

void xsk_socket__delete(struct xsk_socket *xsk)
{
        size_t desc_sz = sizeof(struct xdp_desc);
        struct xdp_mmap_offsets off;
        int err;

        if (!xsk)
                return;

        if (xsk->prog_fd != -1) {
                xsk_delete_bpf_maps(xsk);
                close(xsk->prog_fd);
        }

        err = xsk_get_mmap_offsets(xsk->fd, &off);
        if (!err) {
                if (xsk->rx) {
                        munmap(xsk->rx->ring - off.rx.desc,
                               off.rx.desc + xsk->config.rx_size * desc_sz);
                }
                if (xsk->tx) {
                        munmap(xsk->tx->ring - off.tx.desc,
                               off.tx.desc + xsk->config.tx_size * desc_sz);
                }

        }

        xsk->umem->refcount--;
        /* Do not close an fd that also has an associated umem connected
         * to it.
         */
        if (xsk->fd != xsk->umem->fd)
                close(xsk->fd);
        free(xsk);
}