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| -rw-r--r-- | Documentation/networking/af_xdp.rst | 297 | ||||
| -rw-r--r-- | Documentation/networking/index.rst | 1 | ||||
| -rw-r--r-- | samples/bpf/Makefile | 4 | ||||
| -rw-r--r-- | samples/bpf/xdpsock.h | 11 | ||||
| -rw-r--r-- | samples/bpf/xdpsock_kern.c | 56 | ||||
| -rw-r--r-- | samples/bpf/xdpsock_user.c | 948 |
6 files changed, 1317 insertions, 0 deletions
diff --git a/Documentation/networking/af_xdp.rst b/Documentation/networking/af_xdp.rst new file mode 100644 index 000000000000..91928d9ee4bf --- /dev/null +++ b/Documentation/networking/af_xdp.rst @@ -0,0 +1,297 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====== +AF_XDP +====== + +Overview +======== + +AF_XDP is an address family that is optimized for high performance +packet processing. + +This document assumes that the reader is familiar with BPF and XDP. If +not, the Cilium project has an excellent reference guide at +http://cilium.readthedocs.io/en/doc-1.0/bpf/. + +Using the XDP_REDIRECT action from an XDP program, the program can +redirect ingress frames to other XDP enabled netdevs, using the +bpf_redirect_map() function. AF_XDP sockets enable the possibility for +XDP programs to redirect frames to a memory buffer in a user-space +application. + +An AF_XDP socket (XSK) is created with the normal socket() +syscall. Associated with each XSK are two rings: the RX ring and the +TX ring. A socket can receive packets on the RX ring and it can send +packets on the TX ring. These rings are registered and sized with the +setsockopts XDP_RX_RING and XDP_TX_RING, respectively. It is mandatory +to have at least one of these rings for each socket. An RX or TX +descriptor ring points to a data buffer in a memory area called a +UMEM. RX and TX can share the same UMEM so that a packet does not have +to be copied between RX and TX. Moreover, if a packet needs to be kept +for a while due to a possible retransmit, the descriptor that points +to that packet can be changed to point to another and reused right +away. This again avoids copying data. + +The UMEM consists of a number of equally size frames and each frame +has a unique frame id. A descriptor in one of the rings references a +frame by referencing its frame id. The user space allocates memory for +this UMEM using whatever means it feels is most appropriate (malloc, +mmap, huge pages, etc). This memory area is then registered with the +kernel using the new setsockopt XDP_UMEM_REG. The UMEM also has two +rings: the FILL ring and the COMPLETION ring. The fill ring is used by +the application to send down frame ids for the kernel to fill in with +RX packet data. References to these frames will then appear in the RX +ring once each packet has been received. The completion ring, on the +other hand, contains frame ids that the kernel has transmitted +completely and can now be used again by user space, for either TX or +RX. Thus, the frame ids appearing in the completion ring are ids that +were previously transmitted using the TX ring. In summary, the RX and +FILL rings are used for the RX path and the TX and COMPLETION rings +are used for the TX path. + +The socket is then finally bound with a bind() call to a device and a +specific queue id on that device, and it is not until bind is +completed that traffic starts to flow. + +The UMEM can be shared between processes, if desired. If a process +wants to do this, it simply skips the registration of the UMEM and its +corresponding two rings, sets the XDP_SHARED_UMEM flag in the bind +call and submits the XSK of the process it would like to share UMEM +with as well as its own newly created XSK socket. The new process will +then receive frame id references in its own RX ring that point to this +shared UMEM. Note that since the ring structures are single-consumer / +single-producer (for performance reasons), the new process has to +create its own socket with associated RX and TX rings, since it cannot +share this with the other process. This is also the reason that there +is only one set of FILL and COMPLETION rings per UMEM. It is the +responsibility of a single process to handle the UMEM. + +How is then packets distributed from an XDP program to the XSKs? There +is a BPF map called XSKMAP (or BPF_MAP_TYPE_XSKMAP in full). The +user-space application can place an XSK at an arbitrary place in this +map. The XDP program can then redirect a packet to a specific index in +this map and at this point XDP validates that the XSK in that map was +indeed bound to that device and ring number. If not, the packet is +dropped. If the map is empty at that index, the packet is also +dropped. This also means that it is currently mandatory to have an XDP +program loaded (and one XSK in the XSKMAP) to be able to get any +traffic to user space through the XSK. + +AF_XDP can operate in two different modes: XDP_SKB and XDP_DRV. If the +driver does not have support for XDP, or XDP_SKB is explicitly chosen +when loading the XDP program, XDP_SKB mode is employed that uses SKBs +together with the generic XDP support and copies out the data to user +space. A fallback mode that works for any network device. On the other +hand, if the driver has support for XDP, it will be used by the AF_XDP +code to provide better performance, but there is still a copy of the +data into user space. + +Concepts +======== + +In order to use an AF_XDP socket, a number of associated objects need +to be setup. + +Jonathan Corbet has also written an excellent article on LWN, +"Accelerating networking with AF_XDP". It can be found at +https://lwn.net/Articles/750845/. + +UMEM +---- + +UMEM is a region of virtual contiguous memory, divided into +equal-sized frames. An UMEM is associated to a netdev and a specific +queue id of that netdev. It is created and configured (frame size, +frame headroom, start address and size) by using the XDP_UMEM_REG +setsockopt system call. A UMEM is bound to a netdev and queue id, via +the bind() system call. + +An AF_XDP is socket linked to a single UMEM, but one UMEM can have +multiple AF_XDP sockets. To share an UMEM created via one socket A, +the next socket B can do this by setting the XDP_SHARED_UMEM flag in +struct sockaddr_xdp member sxdp_flags, and passing the file descriptor +of A to struct sockaddr_xdp member sxdp_shared_umem_fd. + +The UMEM has two single-producer/single-consumer rings, that are used +to transfer ownership of UMEM frames between the kernel and the +user-space application. + +Rings +----- + +There are a four different kind of rings: Fill, Completion, RX and +TX. All rings are single-producer/single-consumer, so the user-space +application need explicit synchronization of multiple +processes/threads are reading/writing to them. + +The UMEM uses two rings: Fill and Completion. Each socket associated +with the UMEM must have an RX queue, TX queue or both. Say, that there +is a setup with four sockets (all doing TX and RX). Then there will be +one Fill ring, one Completion ring, four TX rings and four RX rings. + +The rings are head(producer)/tail(consumer) based rings. A producer +writes the data ring at the index pointed out by struct xdp_ring +producer member, and increasing the producer index. A consumer reads +the data ring at the index pointed out by struct xdp_ring consumer +member, and increasing the consumer index. + +The rings are configured and created via the _RING setsockopt system +calls and mmapped to user-space using the appropriate offset to mmap() +(XDP_PGOFF_RX_RING, XDP_PGOFF_TX_RING, XDP_UMEM_PGOFF_FILL_RING and +XDP_UMEM_PGOFF_COMPLETION_RING). + +The size of the rings need to be of size power of two. + +UMEM Fill Ring +~~~~~~~~~~~~~~ + +The Fill ring is used to transfer ownership of UMEM frames from +user-space to kernel-space. The UMEM indicies are passed in the +ring. As an example, if the UMEM is 64k and each frame is 4k, then the +UMEM has 16 frames and can pass indicies between 0 and 15. + +Frames passed to the kernel are used for the ingress path (RX rings). + +The user application produces UMEM indicies to this ring. + +UMEM Completetion Ring +~~~~~~~~~~~~~~~~~~~~~~ + +The Completion Ring is used transfer ownership of UMEM frames from +kernel-space to user-space. Just like the Fill ring, UMEM indicies are +used. + +Frames passed from the kernel to user-space are frames that has been +sent (TX ring) and can be used by user-space again. + +The user application consumes UMEM indicies from this ring. + + +RX Ring +~~~~~~~ + +The RX ring is the receiving side of a socket. Each entry in the ring +is a struct xdp_desc descriptor. The descriptor contains UMEM index +(idx), the length of the data (len), the offset into the frame +(offset). + +If no frames have been passed to kernel via the Fill ring, no +descriptors will (or can) appear on the RX ring. + +The user application consumes struct xdp_desc descriptors from this +ring. + +TX Ring +~~~~~~~ + +The TX ring is used to send frames. The struct xdp_desc descriptor is +filled (index, length and offset) and passed into the ring. + +To start the transfer a sendmsg() system call is required. This might +be relaxed in the future. + +The user application produces struct xdp_desc descriptors to this +ring. + +XSKMAP / BPF_MAP_TYPE_XSKMAP +---------------------------- + +On XDP side there is a BPF map type BPF_MAP_TYPE_XSKMAP (XSKMAP) that +is used in conjunction with bpf_redirect_map() to pass the ingress +frame to a socket. + +The user application inserts the socket into the map, via the bpf() +system call. + +Note that if an XDP program tries to redirect to a socket that does +not match the queue configuration and netdev, the frame will be +dropped. E.g. an AF_XDP socket is bound to netdev eth0 and +queue 17. Only the XDP program executing for eth0 and queue 17 will +successfully pass data to the socket. Please refer to the sample +application (samples/bpf/) in for an example. + +Usage +===== + +In order to use AF_XDP sockets there are two parts needed. The +user-space application and the XDP program. For a complete setup and +usage example, please refer to the sample application. The user-space +side is xdpsock_user.c and the XDP side xdpsock_kern.c. + +Naive ring dequeue and enqueue could look like this:: + + // typedef struct xdp_rxtx_ring RING; + // typedef struct xdp_umem_ring RING; + + // typedef struct xdp_desc RING_TYPE; + // typedef __u32 RING_TYPE; + + int dequeue_one(RING *ring, RING_TYPE *item) + { + __u32 entries = ring->ptrs.producer - ring->ptrs.consumer; + + if (entries == 0) + return -1; + + // read-barrier! + + *item = ring->desc[ring->ptrs.consumer & (RING_SIZE - 1)]; + ring->ptrs.consumer++; + return 0; + } + + int enqueue_one(RING *ring, const RING_TYPE *item) + { + u32 free_entries = RING_SIZE - (ring->ptrs.producer - ring->ptrs.consumer); + + if (free_entries == 0) + return -1; + + ring->desc[ring->ptrs.producer & (RING_SIZE - 1)] = *item; + + // write-barrier! + + ring->ptrs.producer++; + return 0; + } + + +For a more optimized version, please refer to the sample application. + +Sample application +================== + +There is a xdpsock benchmarking/test application included that +demonstrates how to use AF_XDP sockets with both private and shared +UMEMs. Say that you would like your UDP traffic from port 4242 to end +up in queue 16, that we will enable AF_XDP on. Here, we use ethtool +for this:: + + ethtool -N p3p2 rx-flow-hash udp4 fn + ethtool -N p3p2 flow-type udp4 src-port 4242 dst-port 4242 \ + action 16 + +Running the rxdrop benchmark in XDP_DRV mode can then be done +using:: + + samples/bpf/xdpsock -i p3p2 -q 16 -r -N + +For XDP_SKB mode, use the switch "-S" instead of "-N" and all options +can be displayed with "-h", as usual. + +Credits +======= + +- Björn Töpel (AF_XDP core) +- Magnus Karlsson (AF_XDP core) +- Alexander Duyck +- Alexei Starovoitov +- Daniel Borkmann +- Jesper Dangaard Brouer +- John Fastabend +- Jonathan Corbet (LWN coverage) +- Michael S. Tsirkin +- Qi Z Zhang +- Willem de Bruijn + diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst index f204eaff657d..cbd9bdd4a79e 100644 --- a/Documentation/networking/index.rst +++ b/Documentation/networking/index.rst @@ -6,6 +6,7 @@ Contents: .. toctree:: :maxdepth: 2 + af_xdp batman-adv can dpaa2/index diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 5e31770ac087..8e0c7fb6d7cc 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -45,6 +45,7 @@ hostprogs-y += xdp_rxq_info hostprogs-y += syscall_tp hostprogs-y += cpustat hostprogs-y += xdp_adjust_tail +hostprogs-y += xdpsock # Libbpf dependencies LIBBPF := ../../tools/lib/bpf/bpf.o ../../tools/lib/bpf/nlattr.o @@ -98,6 +99,7 @@ xdp_rxq_info-objs := bpf_load.o $(LIBBPF) xdp_rxq_info_user.o syscall_tp-objs := bpf_load.o $(LIBBPF) syscall_tp_user.o cpustat-objs := bpf_load.o $(LIBBPF) cpustat_user.o xdp_adjust_tail-objs := bpf_load.o $(LIBBPF) xdp_adjust_tail_user.o +xdpsock-objs := bpf_load.o $(LIBBPF) xdpsock_user.o # Tell kbuild to always build the programs always := $(hostprogs-y) @@ -151,6 +153,7 @@ always += xdp2skb_meta_kern.o always += syscall_tp_kern.o always += cpustat_kern.o always += xdp_adjust_tail_kern.o +always += xdpsock_kern.o HOSTCFLAGS += -I$(objtree)/usr/include HOSTCFLAGS += -I$(srctree)/tools/lib/ @@ -197,6 +200,7 @@ HOSTLOADLIBES_xdp_rxq_info += -lelf HOSTLOADLIBES_syscall_tp += -lelf HOSTLOADLIBES_cpustat += -lelf HOSTLOADLIBES_xdp_adjust_tail += -lelf +HOSTLOADLIBES_xdpsock += -lelf -pthread # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: # make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang diff --git a/samples/bpf/xdpsock.h b/samples/bpf/xdpsock.h new file mode 100644 index 000000000000..533ab81adfa1 --- /dev/null +++ b/samples/bpf/xdpsock.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef XDPSOCK_H_ +#define XDPSOCK_H_ + +/* Power-of-2 number of sockets */ +#define MAX_SOCKS 4 + +/* Round-robin receive */ +#define RR_LB 0 + +#endif /* XDPSOCK_H_ */ diff --git a/samples/bpf/xdpsock_kern.c b/samples/bpf/xdpsock_kern.c new file mode 100644 index 000000000000..d8806c41362e --- /dev/null +++ b/samples/bpf/xdpsock_kern.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +#define KBUILD_MODNAME "foo" +#include <uapi/linux/bpf.h> +#include "bpf_helpers.h" + +#include "xdpsock.h" + +struct bpf_map_def SEC("maps") qidconf_map = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1, +}; + +struct bpf_map_def SEC("maps") xsks_map = { + .type = BPF_MAP_TYPE_XSKMAP, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 4, +}; + +struct bpf_map_def SEC("maps") rr_map = { + .type = BPF_MAP_TYPE_PERCPU_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(unsigned int), + .max_entries = 1, +}; + +SEC("xdp_sock") +int xdp_sock_prog(struct xdp_md *ctx) +{ + int *qidconf, key = 0, idx; + unsigned int *rr; + + qidconf = bpf_map_lookup_elem(&qidconf_map, &key); + if (!qidconf) + return XDP_ABORTED; + + if (*qidconf != ctx->rx_queue_index) + return XDP_PASS; + +#if RR_LB /* NB! RR_LB is configured in xdpsock.h */ + rr = bpf_map_lookup_elem(&rr_map, &key); + if (!rr) + return XDP_ABORTED; + + *rr = (*rr + 1) & (MAX_SOCKS - 1); + idx = *rr; +#else + idx = 0; +#endif + + return bpf_redirect_map(&xsks_map, idx, 0); +} + +char _license[] SEC("license") = "GPL"; diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c new file mode 100644 index 000000000000..4b8a7cf3e63b --- /dev/null +++ b/samples/bpf/xdpsock_user.c @@ -0,0 +1,948 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2017 - 2018 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include <assert.h> +#include <errno.h> +#include <getopt.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 <locale.h> +#include <sys/types.h> +#include <poll.h> + +#include "bpf_load.h" +#include "bpf_util.h" +#include "libbpf.h" + +#include "xdpsock.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_SIZE 2048 +#define NUM_DESCS 1024 +#define BATCH_SIZE 16 + +#define FQ_NUM_DESCS 1024 +#define CQ_NUM_DESCS 1024 + +#define DEBUG_HEXDUMP 0 + +typedef __u32 u32; + +static unsigned long prev_time; + +enum benchmark_type { + BENCH_RXDROP = 0, + BENCH_TXONLY = 1, + BENCH_L2FWD = 2, +}; + +static enum benchmark_type opt_bench = BENCH_RXDROP; +static u32 opt_xdp_flags; +static const char *opt_if = ""; +static int opt_ifindex; +static int opt_queue; +static int opt_poll; +static int opt_shared_packet_buffer; +static int opt_interval = 1; + +struct xdp_umem_uqueue { + u32 cached_prod; + u32 cached_cons; + u32 mask; + u32 size; + struct xdp_umem_ring *ring; +}; + +struct xdp_umem { + char (*frames)[FRAME_SIZE]; + 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; + struct xdp_rxtx_ring *ring; +}; + +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; +}; + +#define MAX_SOCKS 4 +static int num_socks; +struct xdpsock *xsks[MAX_SOCKS]; + +static unsigned long get_nsecs(void) +{ + struct timespec ts; + + clock_gettime(CLOCK_MONOTONIC, &ts); + return ts.tv_sec * 1000000000UL + ts.tv_nsec; +} + +static void dump_stats(void); + +#define lassert(expr) \ + do { \ + if (!(expr)) { \ + fprintf(stderr, "%s:%s:%i: Assertion failed: " \ + #expr ": errno: %d/\"%s\"\n", \ + __FILE__, __func__, __LINE__, \ + errno, strerror(errno)); \ + dump_stats(); \ + exit(EXIT_FAILURE); \ + } \ + } while (0) + +#define barrier() __asm__ __volatile__("": : :"memory") +#define u_smp_rmb() barrier() +#define u_smp_wmb() barrier() +#define likely(x) __builtin_expect(!!(x), 1) +#define unlikely(x) __builtin_expect(!!(x), 0) + +static const char pkt_data[] = + "\x3c\xfd\xfe\x9e\x7f\x71\xec\xb1\xd7\x98\x3a\xc0\x08\x00\x45\x00" + "\x00\x2e\x00\x00\x00\x00\x40\x11\x88\x97\x05\x08\x07\x08\xc8\x14" + "\x1e\x04\x10\x92\x10\x92\x00\x1a\x6d\xa3\x34\x33\x1f\x69\x40\x6b" + "\x54\x59\xb6\x14\x2d\x11\x44\xbf\xaf\xd9\xbe\xaa"; + +static inline u32 umem_nb_free(struct xdp_umem_uqueue *q, u32 nb) +{ + u32 free_entries = q->size - (q->cached_prod - q->cached_cons); + + if (free_entries >= nb) + return free_entries; + + /* Refresh the local tail pointer */ + q->cached_cons = q->ring->ptrs.consumer; + + return q->size - (q->cached_prod - q->cached_cons); +} + +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->ring->ptrs.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->ring->ptrs.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->ring->ptrs.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->desc[idx] = d[i].idx; + } + + u_smp_wmb(); + + fq->ring->ptrs.producer = fq->cached_prod; + + return 0; +} + +static inline int umem_fill_to_kernel(struct xdp_umem_uqueue *fq, u32 *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->desc[idx] = d[i]; + } + + u_smp_wmb(); + + fq->ring->ptrs.producer = fq->cached_prod; + + return 0; +} + +static inline size_t umem_complete_from_kernel(struct xdp_umem_uqueue *cq, + u32 *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->desc[idx]; + } + + if (entries > 0) { + u_smp_wmb(); + + cq->ring->ptrs.consumer = cq->cached_cons; + } + + return entries; +} + +static inline void *xq_get_data(struct xdpsock *xsk, __u32 idx, __u32 off) +{ + lassert(idx < NUM_FRAMES); + return &xsk->umem->frames[idx][off]; +} + +static inline int xq_enq(struct xdp_uqueue *uq, + const struct xdp_desc *descs, + unsigned int ndescs) +{ + struct xdp_rxtx_ring *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->desc[idx].idx = descs[i].idx; + r->desc[idx].len = descs[i].len; + r->desc[idx].offset = descs[i].offset; + } + + u_smp_wmb(); + + r->ptrs.producer = uq->cached_prod; + return 0; +} + +static inline int xq_enq_tx_only(struct xdp_uqueue *uq, + __u32 idx, unsigned int ndescs) +{ + struct xdp_rxtx_ring *q = 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; + + q->desc[idx].idx = idx + i; + q->desc[idx].len = sizeof(pkt_data) - 1; + q->desc[idx].offset = 0; + } + + u_smp_wmb(); + + q->ptrs.producer = uq->cached_prod; + return 0; +} + +static inline int xq_deq(struct xdp_uqueue *uq, + struct xdp_desc *descs, + int ndescs) +{ + struct xdp_rxtx_ring *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->desc[idx]; + } + + if (entries > 0) { + u_smp_wmb(); + + r->ptrs.consumer = uq->cached_cons; + } + + return entries; +} + +static void swap_mac_addresses(void *data) +{ + struct ether_header *eth = (struct ether_header *)data; + struct ether_addr *src_addr = (struct ether_addr *)ð->ether_shost; + struct ether_addr *dst_addr = (struct ether_addr *)ð->ether_dhost; + struct ether_addr tmp; + + tmp = *src_addr; + *src_addr = *dst_addr; + *dst_addr = tmp; +} + +#if DEBUG_HEXDUMP +static void hex_dump(void *pkt, size_t length, const char *prefix) +{ + int i = 0; + const unsigned char *address = (unsigned char *)pkt; + const unsigned char *line = address; + size_t line_size = 32; + unsigned char c; + + printf("length = %zu\n", length); + printf("%s | ", prefix); + 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 | ", prefix); + } + } + printf("\n"); +} +#endif + +static size_t gen_eth_frame(char *frame) +{ + memcpy(frame, pkt_data, sizeof(pkt_data) - 1); + return sizeof(pkt_data) - 1; +} + +static struct xdp_umem *xdp_umem_configure(int sfd) +{ + int fq_size = FQ_NUM_DESCS, cq_size = CQ_NUM_DESCS; + struct xdp_umem_reg mr; + struct xdp_umem *umem; + 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.frame_size = FRAME_SIZE; + mr.frame_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); + + umem->fq.ring = mmap(0, sizeof(struct xdp_umem_ring) + + FQ_NUM_DESCS * sizeof(u32), + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, sfd, + XDP_UMEM_PGOFF_FILL_RING); + lassert(umem->fq.ring != MAP_FAILED); + + umem->fq.mask = FQ_NUM_DESCS - 1; + umem->fq.size = FQ_NUM_DESCS; + + umem->cq.ring = mmap(0, sizeof(struct xdp_umem_ring) + + CQ_NUM_DESCS * sizeof(u32), + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, sfd, + XDP_UMEM_PGOFF_COMPLETION_RING); + lassert(umem->cq.ring != MAP_FAILED); + + umem->cq.mask = CQ_NUM_DESCS - 1; + umem->cq.size = CQ_NUM_DESCS; + + umem->frames = (char (*)[FRAME_SIZE])bufs; + umem->fd = sfd; + + if (opt_bench == BENCH_TXONLY) { + int i; + + for (i = 0; i < NUM_FRAMES; i++) + (void)gen_eth_frame(&umem->frames[i][0]); + } + + return umem; +} + +static struct xdpsock *xsk_configure(struct xdp_umem *umem) +{ + struct sockaddr_xdp sxdp = {}; + int sfd, ndescs = NUM_DESCS; + struct xdpsock *xsk; + bool shared = true; + u32 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); + + /* Rx */ + xsk->rx.ring = mmap(NULL, + sizeof(struct xdp_ring) + + NUM_DESCS * sizeof(struct xdp_desc), + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, sfd, + XDP_PGOFF_RX_RING); + lassert(xsk->rx.ring != MAP_FAILED); + + if (!shared) { + for (i = 0; i < NUM_DESCS / 2; i++) + lassert(umem_fill_to_kernel(&xsk->umem->fq, &i, 1) + == 0); + } + + /* Tx */ + xsk->tx.ring = mmap(NULL, + sizeof(struct xdp_ring) + + NUM_DESCS * sizeof(struct xdp_desc), + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, sfd, + XDP_PGOFF_TX_RING); + lassert(xsk->tx.ring != MAP_FAILED); + + xsk->rx.mask = NUM_DESCS - 1; + xsk->rx.size = NUM_DESCS; + + xsk->tx.mask = NUM_DESCS - 1; + xsk->tx.size = 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; + } + + lassert(bind(sfd, (struct sockaddr *)&sxdp, sizeof(sxdp)) == 0); + + return xsk; +} + +static void print_benchmark(bool running) +{ + const char *bench_str = "INVALID"; + + if (opt_bench == BENCH_RXDROP) + bench_str = "rxdrop"; + else if (opt_bench == BENCH_TXONLY) + bench_str = "txonly"; + else if (opt_bench == BENCH_L2FWD) + bench_str = "l2fwd"; + + printf("%s:%d %s ", opt_if, opt_queue, bench_str); + if (opt_xdp_flags & XDP_FLAGS_SKB_MODE) + printf("xdp-skb "); + else if (opt_xdp_flags & XDP_FLAGS_DRV_MODE) + printf("xdp-drv "); + else + printf(" "); + + if (opt_poll) + printf("poll() "); + + if (running) { + printf("running..."); + fflush(stdout); + } +} + +static void dump_stats(void) +{ + unsigned long now = get_nsecs(); + long dt = now - prev_time; + int i; + + prev_time = now; + + for (i = 0; i < num_socks; i++) { + char *fmt = "%-15s %'-11.0f %'-11lu\n"; + double rx_pps, tx_pps; + + rx_pps = (xsks[i]->rx_npkts - xsks[i]->prev_rx_npkts) * + 1000000000. / dt; + tx_pps = (xsks[i]->tx_npkts - xsks[i]->prev_tx_npkts) * + 1000000000. / dt; + + printf("\n sock%d@", i); + print_benchmark(false); + printf("\n"); + + printf("%-15s %-11s %-11s %-11.2f\n", "", "pps", "pkts", + dt / 1000000000.); + printf(fmt, "rx", rx_pps, xsks[i]->rx_npkts); + printf(fmt, "tx", tx_pps, xsks[i]->tx_npkts); + + xsks[i]->prev_rx_npkts = xsks[i]->rx_npkts; + xsks[i]->prev_tx_npkts = xsks[i]->tx_npkts; + } +} + +static void *poller(void *arg) +{ + (void)arg; + for (;;) { + sleep(opt_interval); + dump_stats(); + } + + return NULL; +} + +static void int_exit(int sig) +{ + (void)sig; + dump_stats(); + bpf_set_link_xdp_fd(opt_ifindex, -1, opt_xdp_flags); + exit(EXIT_SUCCESS); +} + +static struct option long_options[] = { + {"rxdrop", no_argument, 0, 'r'}, + {"txonly", no_argument, 0, 't'}, + {"l2fwd", no_argument, 0, 'l'}, + {"interface", required_argument, 0, 'i'}, + {"queue", required_argument, 0, 'q'}, + {"poll", no_argument, 0, 'p'}, + {"shared-buffer", no_argument, 0, 's'}, + {"xdp-skb", no_argument, 0, 'S'}, + {"xdp-native", no_argument, 0, 'N'}, + {"interval", required_argument, 0, 'n'}, + {0, 0, 0, 0} +}; + +static void usage(const char *prog) +{ + const char *str = + " Usage: %s [OPTIONS]\n" + " Options:\n" + " -r, --rxdrop Discard all incoming packets (default)\n" + " -t, --txonly Only send packets\n" + " -l, --l2fwd MAC swap L2 forwarding\n" + " -i, --interface=n Run on interface n\n" + " -q, --queue=n Use queue n (default 0)\n" + " -p, --poll Use poll syscall\n" + " -s, --shared-buffer Use shared packet buffer\n" + " -S, --xdp-skb=n Use XDP skb-mod\n" + " -N, --xdp-native=n Enfore XDP native mode\n" + " -n, --interval=n Specify statistics update interval (default 1 sec).\n" + "\n"; + fprintf(stderr, str, prog); + exit(EXIT_FAILURE); +} + +static void parse_command_line(int argc, char **argv) +{ + int option_index, c; + + opterr = 0; + + for (;;) { + c = getopt_long(argc, argv, "rtli:q:psSNn:", long_options, + &option_index); + if (c == -1) + break; + + switch (c) { + case 'r': + opt_bench = BENCH_RXDROP; + break; + case 't': + opt_bench = BENCH_TXONLY; + break; + case 'l': + opt_bench = BENCH_L2FWD; + break; + case 'i': + opt_if = optarg; + break; + case 'q': + opt_queue = atoi(optarg); + break; + case 's': + opt_shared_packet_buffer = 1; + break; + case 'p': + opt_poll = 1; + break; + case 'S': + opt_xdp_flags |= XDP_FLAGS_SKB_MODE; + break; + case 'N': + opt_xdp_flags |= XDP_FLAGS_DRV_MODE; + break; + case 'n': + opt_interval = atoi(optarg); + break; + default: + usage(basename(argv[0])); + } + } + + opt_ifindex = if_nametoindex(opt_if); + if (!opt_ifindex) { + fprintf(stderr, "ERROR: interface \"%s\" does not exist\n", + opt_if); + usage(basename(argv[0])); + } +} + +static void kick_tx(int fd) +{ + int ret; + + ret = sendto(fd, NULL, 0, MSG_DONTWAIT, NULL, 0); + if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN) + return; + lassert(0); +} + +static inline void complete_tx_l2fwd(struct xdpsock *xsk) +{ + u32 descs[BATCH_SIZE]; + unsigned int rcvd; + size_t ndescs; + + if (!xsk->outstanding_tx) + return; + + kick_tx(xsk->sfd); + ndescs = (xsk->outstanding_tx > BATCH_SIZE) ? BATCH_SIZE : + xsk->outstanding_tx; + + /* re-add completed Tx buffers */ + rcvd = umem_complete_from_kernel(&xsk->umem->cq, descs, ndescs); + if (rcvd > 0) { + umem_fill_to_kernel(&xsk->umem->fq, descs, rcvd); + xsk->outstanding_tx -= rcvd; + xsk->tx_npkts += rcvd; + } +} + +static inline void complete_tx_only(struct xdpsock *xsk) +{ + u32 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 void rx_drop(struct xdpsock *xsk) +{ + struct xdp_desc descs[BATCH_SIZE]; + unsigned int rcvd, i; + + rcvd = xq_deq(&xsk->rx, descs, BATCH_SIZE); + if (!rcvd) + return; + + for (i = 0; i < rcvd; i++) { + u32 idx = descs[i].idx; + + lassert(idx < NUM_FRAMES); +#if DEBUG_HEXDUMP + char *pkt; + char buf[32]; + + pkt = xq_get_data(xsk, idx, descs[i].offset); + sprintf(buf, "idx=%d", idx); + hex_dump(pkt, descs[i].len, buf); +#endif + } + + xsk->rx_npkts += rcvd; + + umem_fill_to_kernel_ex(&xsk->umem->fq, descs, rcvd); +} + +static void rx_drop_all(void) +{ + struct pollfd fds[MAX_SOCKS + 1]; + int i, ret, timeout, nfds = 1; + + memset(fds, 0, sizeof(fds)); + + for (i = 0; i < num_socks; i++) { + fds[i].fd = xsks[i]->sfd; + fds[i].events = POLLIN; + timeout = 1000; /* 1sn */ + } + + for (;;) { + if (opt_poll) { + ret = poll(fds, nfds, timeout); + if (ret <= 0) + continue; + } + + for (i = 0; i < num_socks; i++) + rx_drop(xsks[i]); + } +} + +static void tx_only(struct xdpsock *xsk) +{ + int timeout, ret, nfds = 1; + struct pollfd fds[nfds + 1]; + unsigned int idx = 0; + + memset(fds, 0, sizeof(fds)); + fds[0].fd = xsk->sfd; + fds[0].events = POLLOUT; + timeout = 1000; /* 1sn */ + + for (;;) { + if (opt_poll) { + ret = poll(fds, nfds, timeout); + if (ret <= 0) + continue; + + if (fds[0].fd != xsk->sfd || + !(fds[0].revents & POLLOUT)) + continue; + } + + if (xq_nb_free(&xsk->tx, BATCH_SIZE) >= BATCH_SIZE) { + lassert(xq_enq_tx_only(&xsk->tx, idx, BATCH_SIZE) == 0); + + xsk->outstanding_tx += BATCH_SIZE; + idx += BATCH_SIZE; + idx %= NUM_FRAMES; + } + + complete_tx_only(xsk); + } +} + +static void l2fwd(struct xdpsock *xsk) +{ + for (;;) { + struct xdp_desc descs[BATCH_SIZE]; + unsigned int rcvd, i; + int ret; + + for (;;) { + complete_tx_l2fwd(xsk); + + rcvd = xq_deq(&xsk->rx, descs, BATCH_SIZE); + if (rcvd > 0) + break; + } + + for (i = 0; i < rcvd; i++) { + char *pkt = xq_get_data(xsk, descs[i].idx, + descs[i].offset); + + swap_mac_addresses(pkt); +#if DEBUG_HEXDUMP + char buf[32]; + u32 idx = descs[i].idx; + + sprintf(buf, "idx=%d", idx); + hex_dump(pkt, descs[i].len, buf); +#endif + } + + xsk->rx_npkts += rcvd; + + ret = xq_enq(&xsk->tx, descs, rcvd); + lassert(ret == 0); + xsk->outstanding_tx += rcvd; + } +} + +int main(int argc, char **argv) +{ + struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + char xdp_filename[256]; + int i, ret, key = 0; + pthread_t pt; + + parse_command_line(argc, argv); + + if (setrlimit(RLIMIT_MEMLOCK, &r)) { + fprintf(stderr, "ERROR: setrlimit(RLIMIT_MEMLOCK) \"%s\"\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + snprintf(xdp_filename, sizeof(xdp_filename), "%s_kern.o", argv[0]); + + if (load_bpf_file(xdp_filename)) { + fprintf(stderr, "ERROR: load_bpf_file %s\n", bpf_log_buf); + exit(EXIT_FAILURE); + } + + if (!prog_fd[0]) { + fprintf(stderr, "ERROR: load_bpf_file: \"%s\"\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + if (bpf_set_link_xdp_fd(opt_ifindex, prog_fd[0], opt_xdp_flags) < 0) { + fprintf(stderr, "ERROR: link set xdp fd failed\n"); + exit(EXIT_FAILURE); + } + + ret = bpf_map_update_elem(map_fd[0], &key, &opt_queue, 0); + if (ret) { + fprintf(stderr, "ERROR: bpf_map_update_elem qidconf\n"); + exit(EXIT_FAILURE); + } + + /* Create sockets... */ + xsks[num_socks++] = xsk_configure(NULL); + +#if RR_LB + for (i = 0; i < MAX_SOCKS - 1; i++) + xsks[num_socks++] = xsk_configure(xsks[0]->umem); +#endif + + /* ...and insert them into the map. */ + for (i = 0; i < num_socks; i++) { + key = i; + ret = bpf_map_update_elem(map_fd[1], &key, &xsks[i]->sfd, 0); + if (ret) { + fprintf(stderr, "ERROR: bpf_map_update_elem %d\n", i); + exit(EXIT_FAILURE); + } + } + + signal(SIGINT, int_exit); + signal(SIGTERM, int_exit); + signal(SIGABRT, int_exit); + + setlocale(LC_ALL, ""); + + ret = pthread_create(&pt, NULL, poller, NULL); + lassert(ret == 0); + + prev_time = get_nsecs(); + + if (opt_bench == BENCH_RXDROP) + rx_drop_all(); + else if (opt_bench == BENCH_TXONLY) + tx_only(xsks[0]); + else + l2fwd(xsks[0]); + + return 0; +} |