[net-next,2/2] net-backports: selftest: add test for TCP_INQ

From: Soheil Hassas Yeganeh <soheil@google.com>

Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
---
 tools/testing/selftests/net/Makefile  |   3 +-
 tools/testing/selftests/net/tcp_inq.c | 189 ++++++++++++++++++++++++++
 2 files changed, 191 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/net/tcp_inq.c

On Fri, Apr 27, 2018 at 2:50 PM, Soheil Hassas Yeganeh
<soheil.kdev@gmail.com> wrote:
> From: Soheil Hassas Yeganeh <soheil@google.com>
>
> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
> Signed-off-by: Yuchung Cheng <ycheng@google.com>
> Signed-off-by: Willem de Bruijn <willemb@google.com>
> Reviewed-by: Eric Dumazet <edumazet@google.com>
> Reviewed-by: Neal Cardwell <ncardwell@google.com>

Really sorry about the wrong patch subject. I'll send a V2 with the
corrected subject momentarily.

> ---
>  tools/testing/selftests/net/Makefile  |   3 +-
>  tools/testing/selftests/net/tcp_inq.c | 189 ++++++++++++++++++++++++++
>  2 files changed, 191 insertions(+), 1 deletion(-)
>  create mode 100644 tools/testing/selftests/net/tcp_inq.c
>
> diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
> index df9102ec7b7af..0a1821f8dfb18 100644
> --- a/tools/testing/selftests/net/Makefile
> +++ b/tools/testing/selftests/net/Makefile
> @@ -9,7 +9,7 @@ TEST_PROGS += fib_tests.sh fib-onlink-tests.sh in_netns.sh pmtu.sh udpgso.sh
>  TEST_PROGS += udpgso_bench.sh
>  TEST_GEN_FILES =  socket
>  TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy
> -TEST_GEN_FILES += tcp_mmap
> +TEST_GEN_FILES += tcp_mmap tcp_inq
>  TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa
>  TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict
>  TEST_GEN_PROGS += udpgso udpgso_bench_tx udpgso_bench_rx
> @@ -18,3 +18,4 @@ include ../lib.mk
>
>  $(OUTPUT)/reuseport_bpf_numa: LDFLAGS += -lnuma
>  $(OUTPUT)/tcp_mmap: LDFLAGS += -lpthread
> +$(OUTPUT)/tcp_inq: LDFLAGS += -lpthread
> diff --git a/tools/testing/selftests/net/tcp_inq.c b/tools/testing/selftests/net/tcp_inq.c
> new file mode 100644
> index 0000000000000..3f6a27efbe5cf
> --- /dev/null
> +++ b/tools/testing/selftests/net/tcp_inq.c
> @@ -0,0 +1,189 @@
> +/*
> + * Copyright 2018 Google Inc.
> + * Author: Soheil Hassas Yeganeh (soheil@google.com)
> + *
> + * Simple example on how to use TCP_INQ and TCP_CM_INQ.
> + *
> + * License (GPLv2):
> + *
> + * 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.
> + */
> +#define _GNU_SOURCE
> +
> +#include <error.h>
> +#include <netinet/in.h>
> +#include <netinet/tcp.h>
> +#include <pthread.h>
> +#include <stdio.h>
> +#include <errno.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <sys/socket.h>
> +#include <unistd.h>
> +
> +#ifndef TCP_INQ
> +#define TCP_INQ 35
> +#endif
> +
> +#ifndef TCP_CM_INQ
> +#define TCP_CM_INQ TCP_INQ
> +#endif
> +
> +#define BUF_SIZE 8192
> +#define CMSG_SIZE 32
> +
> +static int family = AF_INET6;
> +static socklen_t addr_len = sizeof(struct sockaddr_in6);
> +static int port = 4974;
> +
> +static void setup_loopback_addr(int family, struct sockaddr_storage *sockaddr)
> +{
> +       struct sockaddr_in6 *addr6 = (void *) sockaddr;
> +       struct sockaddr_in *addr4 = (void *) sockaddr;
> +
> +       switch (family) {
> +       case PF_INET:
> +               memset(addr4, 0, sizeof(*addr4));
> +               addr4->sin_family = AF_INET;
> +               addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
> +               addr4->sin_port = htons(port);
> +               break;
> +       case PF_INET6:
> +               memset(addr6, 0, sizeof(*addr6));
> +               addr6->sin6_family = AF_INET6;
> +               addr6->sin6_addr = in6addr_loopback;
> +               addr6->sin6_port = htons(port);
> +               break;
> +       default:
> +               error(1, 0, "illegal family");
> +       }
> +}
> +
> +void *start_server(void *arg)
> +{
> +       int server_fd = (int)(unsigned long)arg;
> +       struct sockaddr_in addr;
> +       socklen_t addrlen = sizeof(addr);
> +       char *buf;
> +       int fd;
> +       int r;
> +
> +       buf = malloc(BUF_SIZE);
> +
> +       for (;;) {
> +               fd = accept(server_fd, (struct sockaddr *)&addr, &addrlen);
> +               if (fd == -1) {
> +                       perror("accept");
> +                       break;
> +               }
> +               do {
> +                       r = send(fd, buf, BUF_SIZE, 0);
> +               } while (r < 0 && errno == EINTR);
> +               if (r < 0)
> +                       perror("send");
> +               if (r != BUF_SIZE)
> +                       fprintf(stderr, "can only send %d bytes\n", r);
> +               /* TCP_INQ can overestimate in-queue by one byte if we send
> +                * the FIN packet. Sleep for 1 second, so that the client
> +                * likely invoked recvmsg().
> +                */
> +               sleep(1);
> +               close(fd);
> +       }
> +
> +       free(buf);
> +       close(server_fd);
> +       pthread_exit(0);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +       struct sockaddr_storage listen_addr, addr;
> +       int c, one = 1, inq = -1;
> +       pthread_t server_thread;
> +       char cmsgbuf[CMSG_SIZE];
> +       struct iovec iov[1];
> +       struct cmsghdr *cm;
> +       struct msghdr msg;
> +       int server_fd, fd;
> +       char *buf;
> +
> +       while ((c = getopt(argc, argv, "46p:")) != -1) {
> +               switch (c) {
> +               case '4':
> +                       family = PF_INET;
> +                       addr_len = sizeof(struct sockaddr_in);
> +                       break;
> +               case '6':
> +                       family = PF_INET6;
> +                       addr_len = sizeof(struct sockaddr_in6);
> +                       break;
> +               case 'p':
> +                       port = atoi(optarg);
> +                       break;
> +               }
> +       }
> +
> +       server_fd = socket(family, SOCK_STREAM, 0);
> +       if (server_fd < 0)
> +               error(1, errno, "server socket");
> +       setup_loopback_addr(family, &listen_addr);
> +       if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR,
> +                      &one, sizeof(one)) != 0)
> +               error(1, errno, "setsockopt(SO_REUSEADDR)");
> +       if (bind(server_fd, (const struct sockaddr *)&listen_addr,
> +                addr_len) == -1)
> +               error(1, errno, "bind");
> +       if (listen(server_fd, 128) == -1)
> +               error(1, errno, "listen");
> +       if (pthread_create(&server_thread, NULL, start_server,
> +                          (void *)(unsigned long)server_fd) != 0)
> +               error(1, errno, "pthread_create");
> +
> +       fd = socket(family, SOCK_STREAM, 0);
> +       if (fd < 0)
> +               error(1, errno, "client socket");
> +       setup_loopback_addr(family, &addr);
> +       if (connect(fd, (const struct sockaddr *)&addr, addr_len) == -1)
> +               error(1, errno, "connect");
> +       if (setsockopt(fd, SOL_TCP, TCP_INQ, &one, sizeof(one)) != 0)
> +               error(1, errno, "setsockopt(TCP_INQ)");
> +
> +       msg.msg_name = NULL;
> +       msg.msg_namelen = 0;
> +       msg.msg_iov = iov;
> +       msg.msg_iovlen = 1;
> +       msg.msg_control = cmsgbuf;
> +       msg.msg_controllen = sizeof(cmsgbuf);
> +       msg.msg_flags = 0;
> +
> +       buf = malloc(BUF_SIZE);
> +       iov[0].iov_base = buf;
> +       iov[0].iov_len = BUF_SIZE / 2;
> +
> +       if (recvmsg(fd, &msg, 0) != iov[0].iov_len)
> +               error(1, errno, "recvmsg");
> +       if (msg.msg_flags & MSG_CTRUNC)
> +               error(1, 0, "control message is truncated");
> +
> +       for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm))
> +               if (cm->cmsg_level == SOL_TCP && cm->cmsg_type == TCP_CM_INQ)
> +                       inq = *((int *) CMSG_DATA(cm));
> +
> +       if (inq != BUF_SIZE - iov[0].iov_len) {
> +               fprintf(stderr, "unexpected inq: %d\n", inq);
> +               exit(1);
> +       }
> +
> +       printf("PASSED\n");
> +       free(buf);
> +       close(fd);
> +       return 0;
> +}
> --
> 2.17.0.441.gb46fe60e1d-goog
>