xdpsock_user.c

/* Use of this source code is governed by the Apache 2.0 license
 *
 * Originally based upon the linux kernel samples/bpf/xdpsock_user.c code:
 * Copyright(c) 2017 - 2018 Intel Corporation.
 */

#include <assert.h>
#include <errno.h>
#include <libgen.h>
#include <linux/bpf.h>
#include <linux/if_link.h>
#include <linux/if_xdp.h>
#include <linux/if_ether.h>
#include <net/if.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <net/ethernet.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/mman.h>
#include <time.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/types.h>
#include <poll.h>

#include <bpf/libbpf.h>
#include <bpf/bpf.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

#define NUM_FRAMES 131072
#define FRAME_HEADROOM 0
#define FRAME_SHIFT 11
#define FRAME_SIZE 2048
#define NUM_DESCS 1024
#define BATCH_SIZE 1

#define FQ_NUM_DESCS 1024
#define CQ_NUM_DESCS 1024

#define DEBUG_HEXDUMP 1

typedef __u64 u64;
typedef __u32 u32;

static u32 opt_xdp_flags;
static int opt_interval = 1;
static int opt_queue = 0;
static u32 opt_xdp_bind_flags;

struct xdp_umem_uqueue {
	u32 cached_prod;
	u32 cached_cons;
	u32 mask;
	u32 size;
	u32 *producer;
	u32 *consumer;
	u64 *ring;
	void *map;
};

struct xdp_umem {
	char *frames;
	struct xdp_umem_uqueue fq;
	struct xdp_umem_uqueue cq;
	int fd;
};

struct xdp_uqueue {
	u32 cached_prod;
	u32 cached_cons;
	u32 mask;
	u32 size;
	u32 *producer;
	u32 *consumer;
	struct xdp_desc *ring;
	void *map;
};

struct xdpsock {
	struct xdp_uqueue rx;
	struct xdp_uqueue tx;
	int sfd;
	struct xdp_umem *umem;
	u32 outstanding_tx;
	unsigned long rx_npkts;
	unsigned long tx_npkts;
	unsigned long prev_rx_npkts;
	unsigned long prev_tx_npkts;
};

struct data_val {
    char **data;
    int *sz;
    int numb_packs;
};

#define lassert(expr)							\
	do {								\
		if (!(expr)) {						\
			fprintf(stderr, "%s:%s:%i: Assertion failed: "	\
				#expr ": errno: %d/\"%s\"\n",		\
				__FILE__, __func__, __LINE__,		\
				errno, strerror(errno));		\
			exit(EXIT_FAILURE);				\
		}							\
	} while (0)

#define barrier() __asm__ __volatile__("": : :"memory")
#ifdef __aarch64__
#define u_smp_rmb() __asm__ __volatile__("dmb ishld": : :"memory")
#define u_smp_wmb() __asm__ __volatile__("dmb ishst": : :"memory")
#else
#define u_smp_rmb() barrier()
#define u_smp_wmb() barrier()
#endif

static void hex_dump(void *pkt, size_t length, u64 addr)
{
	const unsigned char *address = (unsigned char *)pkt;
	const unsigned char *line = address;
	size_t line_size = 32;
	unsigned char c;
	char buf[32];
	int i = 0;

	sprintf(buf, "addr=%lu", addr);
	printf("length = %zu\n", length);
	printf("%s | ", buf);
	while (length-- > 0) {
		printf("%02X ", *address++);
		if (!(++i % line_size) || (length == 0 && i % line_size)) {
			if (length == 0) {
				while (i++ % line_size)
					printf("__ ");
			}
			printf(" | ");	/* right close */
			while (line < address) {
				c = *line++;
				printf("%c", (c < 33 || c == 255) ? 0x2E : c);
			}
			printf("\n");
			if (length > 0)
				printf("%s | ", buf);
		}
	}
	printf("\n");
}

static inline u32 umem_nb_free(struct xdp_umem_uqueue *q, u32 nb)
{
	u32 free_entries = q->cached_cons - q->cached_prod;

	if (free_entries >= nb)
		return free_entries;

	/* Refresh the local tail pointer */
	q->cached_cons = *q->consumer + q->size;

	return q->cached_cons - q->cached_prod;
}

static inline u32 xq_nb_free(struct xdp_uqueue *q, u32 ndescs)
{
	u32 free_entries = q->cached_cons - q->cached_prod;

	if (free_entries >= ndescs)
		return free_entries;

	/* Refresh the local tail pointer */
	q->cached_cons = *q->consumer + q->size;
	return q->cached_cons - q->cached_prod;
}

static inline u32 umem_nb_avail(struct xdp_umem_uqueue *q, u32 nb)
{
	u32 entries = q->cached_prod - q->cached_cons;

	if (entries == 0) {
		q->cached_prod = *q->producer;
		entries = q->cached_prod - q->cached_cons;
	}

	return (entries > nb) ? nb : entries;
}

static inline u32 xq_nb_avail(struct xdp_uqueue *q, u32 ndescs)
{
	u32 entries = q->cached_prod - q->cached_cons;

	if (entries == 0) {
		q->cached_prod = *q->producer;
		entries = q->cached_prod - q->cached_cons;
	}

	return (entries > ndescs) ? ndescs : entries;
}

static inline int umem_fill_to_kernel_ex(struct xdp_umem_uqueue *fq,
					 struct xdp_desc *d,
					 size_t nb)
{
	u32 i;

	if (umem_nb_free(fq, nb) < nb)
		return -ENOSPC;

	for (i = 0; i < nb; i++) {
		u32 idx = fq->cached_prod++ & fq->mask;

		fq->ring[idx] = d[i].addr;
	}

	u_smp_wmb();

	*fq->producer = fq->cached_prod;

	return 0;
}

static inline int umem_fill_to_kernel(struct xdp_umem_uqueue *fq, u64 *d,
				      size_t nb)
{
	u32 i;

	if (umem_nb_free(fq, nb) < nb)
		return -ENOSPC;

	for (i = 0; i < nb; i++) {
		u32 idx = fq->cached_prod++ & fq->mask;

		fq->ring[idx] = d[i];
	}

	u_smp_wmb();

	*fq->producer = fq->cached_prod;

	return 0;
}

static inline size_t umem_complete_from_kernel(struct xdp_umem_uqueue *cq,
					       u64 *d, size_t nb)
{
	u32 idx, i, entries = umem_nb_avail(cq, nb);

	u_smp_rmb();

	for (i = 0; i < entries; i++) {
		idx = cq->cached_cons++ & cq->mask;
		d[i] = cq->ring[idx];
	}

	if (entries > 0) {
		u_smp_wmb();

		*cq->consumer = cq->cached_cons;
	}

	return entries;
}

static inline void *xq_get_data(struct xdpsock *xsk, u64 addr)
{
	return &xsk->umem->frames[addr];
}

static inline int xq_deq(struct xdp_uqueue *uq,
			 struct xdp_desc *descs,
			 int ndescs)
{
	struct xdp_desc *r = uq->ring;
	unsigned int idx;
	int i, entries;

	entries = xq_nb_avail(uq, ndescs);

	u_smp_rmb();

	for (i = 0; i < entries; i++) {
		idx = uq->cached_cons++ & uq->mask;
		descs[i] = r[idx];
	}

	if (entries > 0) {
		u_smp_wmb();

		*uq->consumer = uq->cached_cons;
	}

	return entries;
}

static struct xdp_umem *xdp_umem_configure(int sfd)
{
	int fq_size = FQ_NUM_DESCS, cq_size = CQ_NUM_DESCS;
	struct xdp_mmap_offsets off;
	struct xdp_umem_reg mr;
	struct xdp_umem *umem;
	socklen_t optlen;
	void *bufs;

	umem = calloc(1, sizeof(*umem));
	lassert(umem);

	lassert(posix_memalign(&bufs, getpagesize(), /* PAGE_SIZE aligned */
			       NUM_FRAMES * FRAME_SIZE) == 0);

	mr.addr = (__u64)bufs;
	mr.len = NUM_FRAMES * FRAME_SIZE;
	mr.chunk_size = FRAME_SIZE;
	mr.headroom = FRAME_HEADROOM;

	lassert(setsockopt(sfd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr)) == 0);
	lassert(setsockopt(sfd, SOL_XDP, XDP_UMEM_FILL_RING, &fq_size,
			   sizeof(int)) == 0);
	lassert(setsockopt(sfd, SOL_XDP, XDP_UMEM_COMPLETION_RING, &cq_size,
			   sizeof(int)) == 0);

	optlen = sizeof(off);
	lassert(getsockopt(sfd, SOL_XDP, XDP_MMAP_OFFSETS, &off,
			   &optlen) == 0);

	umem->fq.map = mmap(0, off.fr.desc +
			    FQ_NUM_DESCS * sizeof(u64),
			    PROT_READ | PROT_WRITE,
			    MAP_SHARED | MAP_POPULATE, sfd,
			    XDP_UMEM_PGOFF_FILL_RING);
	lassert(umem->fq.map != MAP_FAILED);

	umem->fq.mask = FQ_NUM_DESCS - 1;
	umem->fq.size = FQ_NUM_DESCS;
	umem->fq.producer = umem->fq.map + off.fr.producer;
	umem->fq.consumer = umem->fq.map + off.fr.consumer;
	umem->fq.ring = umem->fq.map + off.fr.desc;
	umem->fq.cached_cons = FQ_NUM_DESCS;

	umem->cq.map = mmap(0, off.cr.desc +
			     CQ_NUM_DESCS * sizeof(u64),
			     PROT_READ | PROT_WRITE,
			     MAP_SHARED | MAP_POPULATE, sfd,
			     XDP_UMEM_PGOFF_COMPLETION_RING);
	lassert(umem->cq.map != MAP_FAILED);

	umem->cq.mask = CQ_NUM_DESCS - 1;
	umem->cq.size = CQ_NUM_DESCS;
	umem->cq.producer = umem->cq.map + off.cr.producer;
	umem->cq.consumer = umem->cq.map + off.cr.consumer;
	umem->cq.ring = umem->cq.map + off.cr.desc;

	umem->frames = bufs;
	umem->fd = sfd;

	return umem;
}

static struct xdpsock *xsk_configure(struct xdp_umem *umem, int opt_ifindex)
{
	struct sockaddr_xdp sxdp = {};
	struct xdp_mmap_offsets off;
	int sfd, ndescs = NUM_DESCS;
	struct xdpsock *xsk;
	bool shared = true;
	socklen_t optlen;
	u64 i;

	sfd = socket(PF_XDP, SOCK_RAW, 0);
	lassert(sfd >= 0);

	xsk = calloc(1, sizeof(*xsk));
	lassert(xsk);

	xsk->sfd = sfd;
	xsk->outstanding_tx = 0;

	if (!umem) {
		shared = false;
		xsk->umem = xdp_umem_configure(sfd);
	} else {
		xsk->umem = umem;
	}

	lassert(setsockopt(sfd, SOL_XDP, XDP_RX_RING,
			   &ndescs, sizeof(int)) == 0);
	lassert(setsockopt(sfd, SOL_XDP, XDP_TX_RING,
			   &ndescs, sizeof(int)) == 0);
	optlen = sizeof(off);
	lassert(getsockopt(sfd, SOL_XDP, XDP_MMAP_OFFSETS, &off,
			   &optlen) == 0);

	/* Rx */
	xsk->rx.map = mmap(NULL,
			   off.rx.desc +
			   NUM_DESCS * sizeof(struct xdp_desc),
			   PROT_READ | PROT_WRITE,
			   MAP_SHARED | MAP_POPULATE, sfd,
			   XDP_PGOFF_RX_RING);
	lassert(xsk->rx.map != MAP_FAILED);

	if (!shared) {
		for (i = 0; i < NUM_DESCS * FRAME_SIZE; i += FRAME_SIZE)
			lassert(umem_fill_to_kernel(&xsk->umem->fq, &i, 1)
				== 0);
	}

	/* Tx */
	xsk->tx.map = mmap(NULL,
			   off.tx.desc +
			   NUM_DESCS * sizeof(struct xdp_desc),
			   PROT_READ | PROT_WRITE,
			   MAP_SHARED | MAP_POPULATE, sfd,
			   XDP_PGOFF_TX_RING);
	lassert(xsk->tx.map != MAP_FAILED);

	xsk->rx.mask = NUM_DESCS - 1;
	xsk->rx.size = NUM_DESCS;
	xsk->rx.producer = xsk->rx.map + off.rx.producer;
	xsk->rx.consumer = xsk->rx.map + off.rx.consumer;
	xsk->rx.ring = xsk->rx.map + off.rx.desc;

	xsk->tx.mask = NUM_DESCS - 1;
	xsk->tx.size = NUM_DESCS;
	xsk->tx.producer = xsk->tx.map + off.tx.producer;
	xsk->tx.consumer = xsk->tx.map + off.tx.consumer;
	xsk->tx.ring = xsk->tx.map + off.tx.desc;
	xsk->tx.cached_cons = NUM_DESCS;

	sxdp.sxdp_family = PF_XDP;
	sxdp.sxdp_ifindex = opt_ifindex;
	sxdp.sxdp_queue_id = opt_queue;

	if (shared) {
		sxdp.sxdp_flags = XDP_SHARED_UMEM;
		sxdp.sxdp_shared_umem_fd = umem->fd;
	} else {
		sxdp.sxdp_flags = opt_xdp_bind_flags;
	}

	lassert(bind(sfd, (struct sockaddr *)&sxdp, sizeof(sxdp)) == 0);

	return xsk;
}

void close_sock(int opt_ifindex)
{
	bpf_set_link_xdp_fd(opt_ifindex, -1, opt_xdp_flags);
}

static void kick_tx(int fd)
{
	int ret;

	ret = sendto(fd, NULL, 0, MSG_DONTWAIT, NULL, 0);
	if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN || errno == EBUSY)
		return;
	lassert(0);
}

static inline void complete_tx_only(struct xdpsock *xsk)
{
	u64 descs[BATCH_SIZE];
	unsigned int rcvd;

	if (!xsk->outstanding_tx)
		return;

	kick_tx(xsk->sfd);

	rcvd = umem_complete_from_kernel(&xsk->umem->cq, descs, BATCH_SIZE);
	if (rcvd > 0) {
		xsk->outstanding_tx -= rcvd;
		xsk->tx_npkts += rcvd;
	}
}

static inline int xq_enq_tx_only(struct xdpsock *xsk, struct xdp_uqueue *uq,
				 unsigned int id, unsigned int ndescs, char *data, int len)
{
	struct xdp_desc *r = uq->ring;
	unsigned int i;

	if (xq_nb_free(uq, ndescs) < ndescs)
		return -ENOSPC;

	for (i = 0; i < ndescs; i++) {
		u32 idx = uq->cached_prod++ & uq->mask;

		r[idx].addr	= (id + i) << FRAME_SHIFT;
		r[idx].len	= len;

	char *pkt = xq_get_data(xsk, r[idx].addr);
	memcpy(pkt, data, len);
	printf("Writing = %d\n", pkt);
	hex_dump(pkt, r[idx].len, r[idx].addr);
	}

	u_smp_wmb();

	*uq->producer = uq->cached_prod;
	return 0;
}

int write_sock(struct xdpsock *xsk, char *pkt, int l)
{
	static unsigned int idx = NUM_DESCS;

	if (xq_nb_free(&xsk->tx, BATCH_SIZE) >= BATCH_SIZE) {
		lassert(xq_enq_tx_only(xsk, &xsk->tx, idx, BATCH_SIZE, pkt, l) == 0);
		xsk->outstanding_tx += BATCH_SIZE;
		idx += BATCH_SIZE;
		idx %= NUM_FRAMES;
		if (idx == 0) {
			idx = NUM_DESCS;
		}
		printf("idx = %d\n", idx);
	}

	complete_tx_only(xsk); 

    return l;
}


struct data_val* read_sock(struct xdpsock *xsk)
{
	struct xdp_desc descs[BATCH_SIZE];
	struct data_val* dval = malloc(sizeof(struct data_val));
	unsigned int rcvd, i;


	dval->numb_packs = 0;
	rcvd = xq_deq(&xsk->rx, descs, BATCH_SIZE);
	if (!rcvd){ 
		return dval;
	}

	dval->data = malloc(rcvd * sizeof(char*));
	dval->sz = malloc(rcvd * sizeof(int));
	dval->numb_packs = rcvd;
	for (i = 0; i < rcvd; i++) {
		char *pkt = xq_get_data(xsk, descs[i].addr);
		printf("Reading = %d\n", pkt);
		hex_dump(pkt, descs[i].len, descs[i].addr);
	dval->data[i] = malloc(descs[i].len * sizeof(char));
	memcpy(dval->data[i], pkt, descs[i].len);
	dval->sz[i] = descs[i].len;
	
	}

	xsk->rx_npkts += rcvd;
	umem_fill_to_kernel_ex(&xsk->umem->fq, descs, rcvd);

    return dval;
}


struct xdpsock** get_sock(int opt_ifindex){
	struct xdpsock **xsks = malloc(2*sizeof(struct xdpsock));
	struct bpf_prog_load_attr prog_load_attr = {
		.prog_type	= BPF_PROG_TYPE_XDP,
	};
	int prog_fd, qidconf_map, xsks_map;
	struct bpf_object *obj;
	char xdp_filename[256];
	struct bpf_map *map;
	int i, ret, key = 0;
	int num_socks = 0;
	pthread_t pt;

	if (!opt_ifindex) {
		fprintf(stderr, "ERROR: interface does not exist\n");
		exit(-1);
	}

	snprintf(xdp_filename, sizeof(xdp_filename), "xdpsock/xdpsock_user_kern.o");
	prog_load_attr.file = xdp_filename;

	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
		exit(EXIT_FAILURE);
	if (prog_fd < 0) {
		fprintf(stderr, "ERROR: no program found: %s\n",
			strerror(prog_fd));
		exit(EXIT_FAILURE);
	}

	map = bpf_object__find_map_by_name(obj, "qidconf_map");
	qidconf_map = bpf_map__fd(map);
	if (qidconf_map < 0) {
		fprintf(stderr, "ERROR: no qidconf map found: %s\n",
			strerror(qidconf_map));
		exit(EXIT_FAILURE);
	}

	map = bpf_object__find_map_by_name(obj, "xsks_map");
	xsks_map = bpf_map__fd(map);
	if (xsks_map < 0) {
		fprintf(stderr, "ERROR: no xsks map found: %s\n",
			strerror(xsks_map));
		exit(EXIT_FAILURE);
	}

	if (bpf_set_link_xdp_fd(opt_ifindex, prog_fd, opt_xdp_flags) < 0) {
		fprintf(stderr, "ERROR: link set xdp fd failed\n");
		exit(EXIT_FAILURE);
	}

	ret = bpf_map_update_elem(qidconf_map, &key, &opt_queue, 0);
	if (ret) {
		fprintf(stderr, "ERROR: bpf_map_update_elem qidconf\n");
		exit(EXIT_FAILURE);
	}

	xsks[num_socks++] = xsk_configure(NULL, opt_ifindex);
	for (i = 0; i < 1; i++){
		xsks[num_socks++] = xsk_configure(xsks[0]->umem, opt_ifindex);}

	for (i = 0; i < num_socks; i++) {
		key = i;
		ret = bpf_map_update_elem(xsks_map, &key, &xsks[i]->sfd, 0);
		if (ret) {
			fprintf(stderr, "ERROR: bpf_map_update_elem %d\n", i);
			exit(EXIT_FAILURE);
		}
	}

	return xsks;
}

int main(int argc, char **argv)
{
	struct xdpsock **xsks;
	struct xdpsock *sock1, *sock2;
	int ifindex = -1;
	char data[] = {1, 1, 1, 1, 1, 1, 4, 1, 3, 2, 18, 93, 8, 6, 0, 1, 8, 0,
			6, 4, 0, 1, 54, 21, -3, 42, -18, -93, -64, -88, 8, 100,
			0, 0, 0, 0, 0, 0, -40, 58, -44, 100};
	int len = 42;
	
	if (argc < 2) {
		printf("Usage:\n\t%s net_iface\n", argv[0]);
		return 0;
	}
	
	ifindex = if_nametoindex(argv[1]);
	
	xsks = get_sock(ifindex);
	sock1 = xsks[0];
	sock2 = xsks[1];
	
	write_sock(sock1, data, len);
	read_sock(sock2);

	close_sock(ifindex);
}