diff options
Diffstat (limited to 'tools/lib/bpf/xsk.c')
-rw-r--r-- | tools/lib/bpf/xsk.c | 735 |
1 files changed, 735 insertions, 0 deletions
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c new file mode 100644 index 000000000000..38667b62f1fe --- /dev/null +++ b/tools/lib/bpf/xsk.c @@ -0,0 +1,735 @@ +// 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" + +#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 xsks_map; + int ifindex; + int prog_fd; + int qidconf_map_fd; + int xsks_map_fd; + __u32 queue_id; + char ifname[IFNAMSIZ]; +}; + +struct xsk_nl_info { + bool xdp_prog_attached; + int ifindex; + int fd; +}; + +/* For 32-bit systems, we need to use mmap2 as the offsets are 64-bit. + * Unfortunately, it is not part of glibc. + */ +static inline void *xsk_mmap(void *addr, size_t length, int prot, int flags, + int fd, __u64 offset) +{ +#ifdef __NR_mmap2 + unsigned int page_shift = __builtin_ffs(getpagesize()) - 1; + long ret = syscall(__NR_mmap2, addr, length, prot, flags, fd, + (off_t)(offset >> page_shift)); + + return (void *)ret; +#else + return mmap(addr, length, prot, flags, fd, offset); +#endif +} + +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; + 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; +} + +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; +} + +int xsk_umem__create(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; + socklen_t optlen; + 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); + + mr.addr = (uintptr_t)umem_area; + mr.len = size; + mr.chunk_size = umem->config.frame_size; + mr.headroom = umem->config.frame_headroom; + + 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; + } + + optlen = sizeof(off); + err = getsockopt(umem->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen); + if (err) { + err = -errno; + goto out_socket; + } + + map = xsk_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->ring = map + off.fr.desc; + fill->cached_cons = umem->config.fill_size; + + map = xsk_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->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; +} + +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 *qidconf, index = ctx->rx_queue_index; + * + * // A set entry here means that the correspnding queue_id + * // has an active AF_XDP socket bound to it. + * qidconf = bpf_map_lookup_elem(&qidconf_map, &index); + * if (!qidconf) + * return XDP_ABORTED; + * + * if (*qidconf) + * return bpf_redirect_map(&xsks_map, index, 0); + * + * return XDP_PASS; + * } + */ + struct bpf_insn prog[] = { + /* r1 = *(u32 *)(r1 + 16) */ + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 16), + /* *(u32 *)(r10 - 4) = r1 */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_1, -4), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), + BPF_LD_MAP_FD(BPF_REG_1, xsk->qidconf_map_fd), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV32_IMM(BPF_REG_0, 0), + /* if r1 == 0 goto +8 */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 8), + BPF_MOV32_IMM(BPF_REG_0, 2), + /* r1 = *(u32 *)(r1 + 0) */ + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 0), + /* if r1 == 0 goto +5 */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5), + /* r2 = *(u32 *)(r10 - 4) */ + BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd), + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_10, -4), + BPF_MOV32_IMM(BPF_REG_3, 0), + 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_warning("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; + struct ifreq ifr; + int fd, err, ret; + + fd = socket(AF_INET, SOCK_DGRAM, 0); + if (fd < 0) + return -errno; + + channels.cmd = ETHTOOL_GCHANNELS; + ifr.ifr_data = (void *)&channels; + strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ); + err = ioctl(fd, SIOCETHTOOL, &ifr); + if (err && errno != EOPNOTSUPP) { + ret = -errno; + goto out; + } + + if (channels.max_combined == 0 || errno == EOPNOTSUPP) + /* If the device says it has no channels, then all traffic + * is sent to a single stream, so max queues = 1. + */ + ret = 1; + else + ret = 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_ARRAY, "qidconf_map", + sizeof(int), sizeof(int), max_queues, 0); + if (fd < 0) + return fd; + xsk->qidconf_map_fd = fd; + + fd = bpf_create_map_name(BPF_MAP_TYPE_XSKMAP, "xsks_map", + sizeof(int), sizeof(int), max_queues, 0); + if (fd < 0) { + close(xsk->qidconf_map_fd); + return fd; + } + xsk->xsks_map_fd = fd; + + return 0; +} + +static void xsk_delete_bpf_maps(struct xsk_socket *xsk) +{ + close(xsk->qidconf_map_fd); + close(xsk->xsks_map_fd); + xsk->qidconf_map_fd = -1; + xsk->xsks_map_fd = -1; +} + +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; + + for (i = 0; i < prog_info.nr_map_ids; i++) { + if (xsk->qidconf_map_fd != -1 && xsk->xsks_map_fd != -1) + break; + + 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, "qidconf_map")) { + xsk->qidconf_map_fd = fd; + continue; + } + + if (!strcmp(map_info.name, "xsks_map")) { + xsk->xsks_map_fd = fd; + continue; + } + + close(fd); + } + + err = 0; + if (xsk->qidconf_map_fd < 0 || xsk->xsks_map_fd < 0) { + err = -ENOENT; + xsk_delete_bpf_maps(xsk); + } + +out_map_ids: + free(map_ids); + return err; +} + +static void xsk_clear_bpf_maps(struct xsk_socket *xsk) +{ + int qid = false; + + bpf_map_update_elem(xsk->qidconf_map_fd, &xsk->queue_id, &qid, 0); + bpf_map_delete_elem(xsk->xsks_map_fd, &xsk->queue_id); +} + +static int xsk_set_bpf_maps(struct xsk_socket *xsk) +{ + int qid = true, fd = xsk->fd, err; + + err = bpf_map_update_elem(xsk->qidconf_map_fd, &xsk->queue_id, &qid, 0); + if (err) + goto out; + + err = bpf_map_update_elem(xsk->xsks_map_fd, &xsk->queue_id, &fd, 0); + if (err) + goto out; + + return 0; +out: + xsk_clear_bpf_maps(xsk); + return err; +} + +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) + goto out_maps; + } else { + xsk->prog_fd = bpf_prog_get_fd_by_id(prog_id); + err = xsk_lookup_bpf_maps(xsk); + if (err) + goto out_load; + } + + err = xsk_set_bpf_maps(xsk); + if (err) + goto out_load; + + return 0; + +out_load: + close(xsk->prog_fd); +out_maps: + xsk_delete_bpf_maps(xsk); + return err; +} + +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; + socklen_t optlen; + int err; + + if (!umem || !xsk_ptr || !rx || !tx) + return -EFAULT; + + if (umem->refcount) { + pr_warning("Error: shared umems not supported by libbpf.\n"); + return -EBUSY; + } + + xsk = calloc(1, sizeof(*xsk)); + if (!xsk) + return -ENOMEM; + + 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; + } + strncpy(xsk->ifname, ifname, IFNAMSIZ); + + err = xsk_set_xdp_socket_config(&xsk->config, usr_config); + if (err) + goto out_socket; + + 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; + } + } + + optlen = sizeof(off); + err = getsockopt(xsk->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen); + if (err) { + err = -errno; + goto out_socket; + } + + if (rx) { + rx_map = xsk_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->ring = rx_map + off.rx.desc; + } + xsk->rx = rx; + + if (tx) { + tx_map = xsk_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->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; + 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->qidconf_map_fd = -1; + xsk->xsks_map_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; + socklen_t optlen; + int err; + + if (!umem) + return 0; + + if (umem->refcount) + return -EBUSY; + + optlen = sizeof(off); + err = getsockopt(umem->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen); + 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; + socklen_t optlen; + int err; + + if (!xsk) + return; + + xsk_clear_bpf_maps(xsk); + xsk_delete_bpf_maps(xsk); + + optlen = sizeof(off); + err = getsockopt(xsk->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen); + 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); +} |