Re: [PATCH net-next v15 14/14] selftests: add ncdevmem, netcat for devmem TCP

On Fri, Jun 28, 2024 at 9:38 AM Mina Almasry almasrymina@google.com wrote:

Hi Mina, Thank you so much for this work!

ncdevmem is a devmem TCP netcat. It works similarly to netcat, but it sends and receives data using the devmem TCP APIs. It uses udmabuf as the dmabuf provider. It is compatible with a regular netcat running on a peer, or a ncdevmem running on a peer.

In addition to normal netcat support, ncdevmem has a validation mode, where it sends a specific pattern and validates this pattern on the receiver side to ensure data integrity.

Suggested-by: Stanislav Fomichev sdf@google.com Signed-off-by: Mina Almasry almasrymina@google.com

---

v15:

• Fix linking against libynl. (Jakub)

v9: https://lore.kernel.org/netdev/20240403002053.2376017-15-almasrymina@google....

• Remove unused nic_pci_addr entry (Cong).

v6:

• Updated to bind 8 queues.
• Added RSS configuration.
• Added some more tests for the netlink API.

Changes in v1:

• Many more general cleanups (Willem).
• Removed driver reset (Jakub).
• Removed hardcoded if index (Paolo).

RFC v2:

• General cleanups (Willem).

---

tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 9 + tools/testing/selftests/net/ncdevmem.c | 542 +++++++++++++++++++++++++ 3 files changed, 552 insertions(+) create mode 100644 tools/testing/selftests/net/ncdevmem.c

diff --git a/tools/testing/selftests/net/.gitignore b/tools/testing/selftests/net/.gitignore index 666ab7d9390b1..fe770903118c5 100644 --- a/tools/testing/selftests/net/.gitignore +++ b/tools/testing/selftests/net/.gitignore @@ -17,6 +17,7 @@ ipv6_flowlabel ipv6_flowlabel_mgr log.txt msg_zerocopy +ncdevmem nettest psock_fanout psock_snd diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index bc3925200637c..39420a6e86b7f 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -95,6 +95,11 @@ TEST_PROGS += fq_band_pktlimit.sh TEST_PROGS += vlan_hw_filter.sh TEST_PROGS += bpf_offload.py

+# YNL files, must be before "include ..lib.mk" +EXTRA_CLEAN += $(OUTPUT)/libynl.a +YNL_GEN_FILES := ncdevmem +TEST_GEN_FILES += $(YNL_GEN_FILES)

TEST_FILES := settings TEST_FILES += in_netns.sh lib.sh net_helper.sh setup_loopback.sh setup_veth.sh

@@ -104,6 +109,10 @@ TEST_INCLUDES := forwarding/lib.sh

include ../lib.mk

+# YNL build +YNL_GENS := netdev +include ynl.mk

$(OUTPUT)/epoll_busy_poll: LDLIBS += -lcap $(OUTPUT)/reuseport_bpf_numa: LDLIBS += -lnuma $(OUTPUT)/tcp_mmap: LDLIBS += -lpthread -lcrypto diff --git a/tools/testing/selftests/net/ncdevmem.c b/tools/testing/selftests/net/ncdevmem.c new file mode 100644 index 0000000000000..e00255e54f77b --- /dev/null +++ b/tools/testing/selftests/net/ncdevmem.c @@ -0,0 +1,542 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#define __EXPORTED_HEADERS__

+#include <linux/uio.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <stdbool.h> +#include <string.h> +#include <errno.h> +#define __iovec_defined +#include <fcntl.h> +#include <malloc.h> +#include <error.h>

+#include <arpa/inet.h> +#include <sys/socket.h> +#include <sys/mman.h> +#include <sys/ioctl.h> +#include <sys/syscall.h>

+#include <linux/memfd.h> +#include <linux/if.h> +#include <linux/dma-buf.h> +#include <linux/udmabuf.h> +#include <libmnl/libmnl.h> +#include <linux/types.h> +#include <linux/netlink.h> +#include <linux/genetlink.h> +#include <linux/netdev.h> +#include <time.h>

+#include "netdev-user.h" +#include <ynl.h>

+#define PAGE_SHIFT 12 +#define TEST_PREFIX "ncdevmem" +#define NUM_PAGES 16000

+#ifndef MSG_SOCK_DEVMEM +#define MSG_SOCK_DEVMEM 0x2000000 +#endif

+/*

• • tcpdevmem netcat. Works similarly to netcat but does device memory TCP
• • instead of regular TCP. Uses udmabuf to mock a dmabuf provider.
• • Usage:
• • On server:
• • ncdevmem -s <server IP> -c <client IP> -f eth1 -d 3 -n 0000:06:00.0 -l \
• • -p 5201 -v 7

The 'n' option disappeared, please remove it.

• • On client:
• • yes $(echo -e \x01\x02\x03\x04\x05\x06) | \
• • tr \n \0 | \
• • head -c 5G | \
• • nc <server IP> 5201 -p 5201
• • Note this is compatible with regular netcat. i.e. the sender or receiver can
• • be replaced with regular netcat to test the RX or TX path in isolation.
• */

+static char *server_ip = "192.168.1.4"; +static char *client_ip = "192.168.1.2"; +static char *port = "5201"; +static size_t do_validation; +static int start_queue = 8; +static int num_queues = 8; +static char *ifname = "eth1"; +static unsigned int ifindex = 3; +static unsigned int iterations; +static unsigned int dmabuf_id;

+void print_bytes(void *ptr, size_t size) +{

• unsigned char *p = ptr;
• int i;
• for (i = 0; i < size; i++)
• printf("%02hhX ", p[i]);
• printf("\n");

+}

+void print_nonzero_bytes(void *ptr, size_t size) +{

• unsigned char *p = ptr;
• unsigned int i;
• for (i = 0; i < size; i++)
• putchar(p[i]);
• printf("\n");

+}

+void validate_buffer(void *line, size_t size) +{

• static unsigned char seed = 1;
• unsigned char *ptr = line;
• int errors = 0;
• size_t i;
• for (i = 0; i < size; i++) {
• if (ptr[i] != seed) {
• fprintf(stderr,
• "Failed validation: expected=%u, actual=%u, index=%lu\n",
• seed, ptr[i], i);
• errors++;
• if (errors > 20)
• error(1, 0, "validation failed.");
• }
• seed++;
• if (seed == do_validation)
• seed = 0;
• }
• fprintf(stdout, "Validated buffer\n");

+}

+static void reset_flow_steering(void) +{

• char command[256];
• memset(command, 0, sizeof(command));
• snprintf(command, sizeof(command), "sudo ethtool -K %s ntuple off",
• "eth1");

I think we use ifname instead of "eth1".

• system(command);
• memset(command, 0, sizeof(command));
• snprintf(command, sizeof(command), "sudo ethtool -K %s ntuple on",
• "eth1");

Please use ifname instead of "eth1" too.

• system(command);

+}

+static void configure_rss(void) +{

• char command[256];
• memset(command, 0, sizeof(command));
• snprintf(command, sizeof(command), "sudo ethtool -X %s equal %d",
• ifname, start_queue);
• system(command);

+}

+static void configure_flow_steering(void) +{

• char command[256];
• memset(command, 0, sizeof(command));
• snprintf(command, sizeof(command),
• "sudo ethtool -N %s flow-type tcp4 src-ip %s dst-ip %s src-port %s dst-port %s queue %d",
• ifname, client_ip, server_ip, port, port, start_queue);
• system(command);

+}

+static int bind_rx_queue(unsigned int ifindex, unsigned int dmabuf_fd,

• struct netdev_queue_dmabuf *queues,
• unsigned int n_queue_index, struct ynl_sock **ys)

+{

• struct netdev_bind_rx_req *req = NULL;
• struct netdev_bind_rx_rsp *rsp = NULL;
• struct ynl_error yerr;
• *ys = ynl_sock_create(&ynl_netdev_family, &yerr);
• if (!*ys) {
• fprintf(stderr, "YNL: %s\n", yerr.msg);
• return -1;
• }
• req = netdev_bind_rx_req_alloc();
• netdev_bind_rx_req_set_ifindex(req, ifindex);
• netdev_bind_rx_req_set_dmabuf_fd(req, dmabuf_fd);
• __netdev_bind_rx_req_set_queues(req, queues, n_queue_index);
• rsp = netdev_bind_rx(*ys, req);
• if (!rsp) {
• perror("netdev_bind_rx");
• goto err_close;
• }
• if (!rsp->_present.dmabuf_id) {
• perror("dmabuf_id not present");
• goto err_close;
• }
• printf("got dmabuf id=%d\n", rsp->dmabuf_id);
• dmabuf_id = rsp->dmabuf_id;
• netdev_bind_rx_req_free(req);
• netdev_bind_rx_rsp_free(rsp);
• return 0;

+err_close:

• fprintf(stderr, "YNL failed: %s\n", (*ys)->err.msg);
• netdev_bind_rx_req_free(req);
• ynl_sock_destroy(*ys);
• return -1;

+}

+static void create_udmabuf(int *devfd, int *memfd, int *buf, size_t dmabuf_size) +{

• struct udmabuf_create create;
• int ret;
• *devfd = open("/dev/udmabuf", O_RDWR);
• if (*devfd < 0) {
• error(70, 0,
• "%s: [skip,no-udmabuf: Unable to access DMA buffer device file]\n",
• TEST_PREFIX);
• }
• *memfd = memfd_create("udmabuf-test", MFD_ALLOW_SEALING);
• if (*memfd < 0)
• error(70, 0, "%s: [skip,no-memfd]\n", TEST_PREFIX);
• /* Required for udmabuf */
• ret = fcntl(*memfd, F_ADD_SEALS, F_SEAL_SHRINK);
• if (ret < 0)
• error(73, 0, "%s: [skip,fcntl-add-seals]\n", TEST_PREFIX);
• ret = ftruncate(*memfd, dmabuf_size);
• if (ret == -1)
• error(74, 0, "%s: [FAIL,memfd-truncate]\n", TEST_PREFIX);
• memset(&create, 0, sizeof(create));
• create.memfd = *memfd;
• create.offset = 0;
• create.size = dmabuf_size;
• *buf = ioctl(*devfd, UDMABUF_CREATE, &create);
• if (*buf < 0)
• error(75, 0, "%s: [FAIL, create udmabuf]\n", TEST_PREFIX);

+}

+int do_server(void) +{

• char ctrl_data[sizeof(int) * 20000];
• struct netdev_queue_dmabuf *queues;
• size_t non_page_aligned_frags = 0;
• struct sockaddr_in client_addr;
• struct sockaddr_in server_sin;
• size_t page_aligned_frags = 0;
• int devfd, memfd, buf, ret;
• size_t total_received = 0;
• socklen_t client_addr_len;
• bool is_devmem = false;
• char *buf_mem = NULL;
• struct ynl_sock *ys;
• size_t dmabuf_size;
• char iobuf[819200];
• char buffer[256];
• int socket_fd;
• int client_fd;
• size_t i = 0;
• int opt = 1;
• dmabuf_size = getpagesize() * NUM_PAGES;
• create_udmabuf(&devfd, &memfd, &buf, dmabuf_size);
• reset_flow_steering();
• /* Configure RSS to divert all traffic from our devmem queues */
• configure_rss();
• /* Flow steer our devmem flows to start_queue */
• configure_flow_steering();
• sleep(1);
• queues = malloc(sizeof(*queues) * num_queues);
• for (i = 0; i < num_queues; i++) {
• queues[i]._present.type = 1;
• queues[i]._present.idx = 1;
• queues[i].type = NETDEV_QUEUE_TYPE_RX;
• queues[i].idx = start_queue + i;
• }
• if (bind_rx_queue(ifindex, buf, queues, num_queues, &ys))
• error(1, 0, "Failed to bind\n");
• buf_mem = mmap(NULL, dmabuf_size, PROT_READ | PROT_WRITE, MAP_SHARED,
• buf, 0);
• if (buf_mem == MAP_FAILED)
• error(1, 0, "mmap()");
• server_sin.sin_family = AF_INET;
• server_sin.sin_port = htons(atoi(port));
• ret = inet_pton(server_sin.sin_family, server_ip, &server_sin.sin_addr);
• if (socket < 0)
• error(79, 0, "%s: [FAIL, create socket]\n", TEST_PREFIX);
• socket_fd = socket(server_sin.sin_family, SOCK_STREAM, 0);
• if (socket < 0)
• error(errno, errno, "%s: [FAIL, create socket]\n", TEST_PREFIX);
• ret = setsockopt(socket_fd, SOL_SOCKET, SO_REUSEPORT, &opt,
• sizeof(opt));
• if (ret)
• error(errno, errno, "%s: [FAIL, set sock opt]\n", TEST_PREFIX);
• ret = setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt,
• sizeof(opt));
• if (ret)
• error(errno, errno, "%s: [FAIL, set sock opt]\n", TEST_PREFIX);
• printf("binding to address %s:%d\n", server_ip,
• ntohs(server_sin.sin_port));
• ret = bind(socket_fd, &server_sin, sizeof(server_sin));
• if (ret)
• error(errno, errno, "%s: [FAIL, bind]\n", TEST_PREFIX);
• ret = listen(socket_fd, 1);
• if (ret)
• error(errno, errno, "%s: [FAIL, listen]\n", TEST_PREFIX);
• client_addr_len = sizeof(client_addr);
• inet_ntop(server_sin.sin_family, &server_sin.sin_addr, buffer,
• sizeof(buffer));
• printf("Waiting or connection on %s:%d\n", buffer,
• ntohs(server_sin.sin_port));
• client_fd = accept(socket_fd, &client_addr, &client_addr_len);
• inet_ntop(client_addr.sin_family, &client_addr.sin_addr, buffer,
• sizeof(buffer));
• printf("Got connection from %s:%d\n", buffer,
• ntohs(client_addr.sin_port));
• while (1) {
• struct iovec iov = { .iov_base = iobuf,
• .iov_len = sizeof(iobuf) };
• struct dmabuf_cmsg *dmabuf_cmsg = NULL;
• struct dma_buf_sync sync = { 0 };
• struct cmsghdr *cm = NULL;
• struct msghdr msg = { 0 };
• struct dmabuf_token token;
• ssize_t ret;
• is_devmem = false;
• printf("\n\n");
• msg.msg_iov = &iov;
• msg.msg_iovlen = 1;
• msg.msg_control = ctrl_data;
• msg.msg_controllen = sizeof(ctrl_data);
• ret = recvmsg(client_fd, &msg, MSG_SOCK_DEVMEM);
• printf("recvmsg ret=%ld\n", ret);
• if (ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK))
• continue;
• if (ret < 0) {
• perror("recvmsg");
• continue;
• }
• if (ret == 0) {
• printf("client exited\n");
• goto cleanup;
• }
• i++;
• for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm)) {
• if (cm->cmsg_level != SOL_SOCKET ||
• (cm->cmsg_type != SCM_DEVMEM_DMABUF &&
• cm->cmsg_type != SCM_DEVMEM_LINEAR)) {
• fprintf(stdout, "skipping non-devmem cmsg\n");
• continue;
• }
• dmabuf_cmsg = (struct dmabuf_cmsg *)CMSG_DATA(cm);
• is_devmem = true;
• if (cm->cmsg_type == SCM_DEVMEM_LINEAR) {
• /* TODO: process data copied from skb's linear
• • buffer.
• */
• fprintf(stdout,
• "SCM_DEVMEM_LINEAR. dmabuf_cmsg->frag_size=%u\n",
• dmabuf_cmsg->frag_size);
• continue;
• }
• token.token_start = dmabuf_cmsg->frag_token;
• token.token_count = 1;
• total_received += dmabuf_cmsg->frag_size;
• printf("received frag_page=%llu, in_page_offset=%llu, frag_offset=%llu, frag_size=%u, token=%u, total_received=%lu, dmabuf_id=%u\n",
• dmabuf_cmsg->frag_offset >> PAGE_SHIFT,
• dmabuf_cmsg->frag_offset % getpagesize(),
• dmabuf_cmsg->frag_offset, dmabuf_cmsg->frag_size,
• dmabuf_cmsg->frag_token, total_received,
• dmabuf_cmsg->dmabuf_id);
• if (dmabuf_cmsg->dmabuf_id != dmabuf_id)
• error(1, 0,
• "received on wrong dmabuf_id: flow steering error\n");
• if (dmabuf_cmsg->frag_size % getpagesize())
• non_page_aligned_frags++;
• else
• page_aligned_frags++;
• sync.flags = DMA_BUF_SYNC_READ | DMA_BUF_SYNC_START;
• ioctl(buf, DMA_BUF_IOCTL_SYNC, &sync);
• if (do_validation)
• validate_buffer(
• ((unsigned char *)buf_mem) +
• dmabuf_cmsg->frag_offset,
• dmabuf_cmsg->frag_size);
• else
• print_nonzero_bytes(
• ((unsigned char *)buf_mem) +
• dmabuf_cmsg->frag_offset,
• dmabuf_cmsg->frag_size);
• sync.flags = DMA_BUF_SYNC_READ | DMA_BUF_SYNC_END;
• ioctl(buf, DMA_BUF_IOCTL_SYNC, &sync);
• ret = setsockopt(client_fd, SOL_SOCKET,
• SO_DEVMEM_DONTNEED, &token,
• sizeof(token));
• if (ret != 1)
• error(1, 0,
• "SO_DEVMEM_DONTNEED not enough tokens");
• }
• if (!is_devmem)
• error(1, 0, "flow steering error\n");
• printf("total_received=%lu\n", total_received);
• }
• fprintf(stdout, "%s: ok\n", TEST_PREFIX);
• fprintf(stdout, "page_aligned_frags=%lu, non_page_aligned_frags=%lu\n",
• page_aligned_frags, non_page_aligned_frags);
• fprintf(stdout, "page_aligned_frags=%lu, non_page_aligned_frags=%lu\n",
• page_aligned_frags, non_page_aligned_frags);

+cleanup:

• munmap(buf_mem, dmabuf_size);
• close(client_fd);
• close(socket_fd);
• close(buf);
• close(memfd);
• close(devfd);
• ynl_sock_destroy(ys);
• return 0;

+}

+void run_devmem_tests(void) +{

• struct netdev_queue_dmabuf *queues;
• int devfd, memfd, buf;
• struct ynl_sock *ys;
• size_t dmabuf_size;
• size_t i = 0;
• dmabuf_size = getpagesize() * NUM_PAGES;
• create_udmabuf(&devfd, &memfd, &buf, dmabuf_size);
• /* Configure RSS to divert all traffic from our devmem queues */
• configure_rss();
• sleep(1);
• queues = malloc(sizeof(*queues) * num_queues);
• for (i = 0; i < num_queues; i++) {
• queues[i]._present.type = 1;
• queues[i]._present.idx = 1;
• queues[i].type = NETDEV_QUEUE_TYPE_RX;
• queues[i].idx = start_queue + i;
• }
• if (bind_rx_queue(ifindex, buf, queues, num_queues, &ys))
• error(1, 0, "Failed to bind\n");
• /* Closing the netlink socket does an implicit unbind */
• ynl_sock_destroy(ys);

+}

+int main(int argc, char *argv[]) +{

• int is_server = 0, opt;
• while ((opt = getopt(argc, argv, "ls:c:p:v:q:f:n:i:d:")) != -1) {

I think 't' option should be added here.

• switch (opt) {
• case 'l':
• is_server = 1;
• break;
• case 's':
• server_ip = optarg;
• break;
• case 'c':
• client_ip = optarg;
• break;
• case 'p':
• port = optarg;
• break;
• case 'v':
• do_validation = atoll(optarg);
• break;
• case 'q':
• num_queues = atoi(optarg);
• break;
• case 't':
• start_queue = atoi(optarg);
• break;
• case 'f':
• ifname = optarg;
• break;
• case 'd':
• ifindex = atoi(optarg);

How about using if_nametoindex() instead of 'd' option?

• break;
• case 'i':
• iterations = atoll(optarg);

I couldn't find a use of this variable.

• break;
• case '?':
• printf("unknown option: %c\n", optopt);
• break;
• }
• }
• for (; optind < argc; optind++)
• printf("extra arguments: %s\n", argv[optind]);
• run_devmem_tests();
• if (is_server)
• return do_server();
• return 0;

+}

2.45.2.803.g4e1b14247a-goog

Thanks a lot! Taehee Yoo