linux/tools/testing/selftests/bpf/prog_tests/bpf_iter_setsockopt.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright (c) 2021 Facebook */
   3#define _GNU_SOURCE
   4#include <sched.h>
   5#include <test_progs.h>
   6#include "network_helpers.h"
   7#include "bpf_dctcp.skel.h"
   8#include "bpf_cubic.skel.h"
   9#include "bpf_iter_setsockopt.skel.h"
  10
  11static int create_netns(void)
  12{
  13        if (!ASSERT_OK(unshare(CLONE_NEWNET), "create netns"))
  14                return -1;
  15
  16        if (!ASSERT_OK(system("ip link set dev lo up"), "bring up lo"))
  17                return -1;
  18
  19        return 0;
  20}
  21
  22static unsigned int set_bpf_cubic(int *fds, unsigned int nr_fds)
  23{
  24        unsigned int i;
  25
  26        for (i = 0; i < nr_fds; i++) {
  27                if (setsockopt(fds[i], SOL_TCP, TCP_CONGESTION, "bpf_cubic",
  28                               sizeof("bpf_cubic")))
  29                        return i;
  30        }
  31
  32        return nr_fds;
  33}
  34
  35static unsigned int check_bpf_dctcp(int *fds, unsigned int nr_fds)
  36{
  37        char tcp_cc[16];
  38        socklen_t optlen = sizeof(tcp_cc);
  39        unsigned int i;
  40
  41        for (i = 0; i < nr_fds; i++) {
  42                if (getsockopt(fds[i], SOL_TCP, TCP_CONGESTION,
  43                               tcp_cc, &optlen) ||
  44                    strcmp(tcp_cc, "bpf_dctcp"))
  45                        return i;
  46        }
  47
  48        return nr_fds;
  49}
  50
  51static int *make_established(int listen_fd, unsigned int nr_est,
  52                             int **paccepted_fds)
  53{
  54        int *est_fds, *accepted_fds;
  55        unsigned int i;
  56
  57        est_fds = malloc(sizeof(*est_fds) * nr_est);
  58        if (!est_fds)
  59                return NULL;
  60
  61        accepted_fds = malloc(sizeof(*accepted_fds) * nr_est);
  62        if (!accepted_fds) {
  63                free(est_fds);
  64                return NULL;
  65        }
  66
  67        for (i = 0; i < nr_est; i++) {
  68                est_fds[i] = connect_to_fd(listen_fd, 0);
  69                if (est_fds[i] == -1)
  70                        break;
  71                if (set_bpf_cubic(&est_fds[i], 1) != 1) {
  72                        close(est_fds[i]);
  73                        break;
  74                }
  75
  76                accepted_fds[i] = accept(listen_fd, NULL, 0);
  77                if (accepted_fds[i] == -1) {
  78                        close(est_fds[i]);
  79                        break;
  80                }
  81        }
  82
  83        if (!ASSERT_EQ(i, nr_est, "create established fds")) {
  84                free_fds(accepted_fds, i);
  85                free_fds(est_fds, i);
  86                return NULL;
  87        }
  88
  89        *paccepted_fds = accepted_fds;
  90        return est_fds;
  91}
  92
  93static unsigned short get_local_port(int fd)
  94{
  95        struct sockaddr_in6 addr;
  96        socklen_t addrlen = sizeof(addr);
  97
  98        if (!getsockname(fd, &addr, &addrlen))
  99                return ntohs(addr.sin6_port);
 100
 101        return 0;
 102}
 103
 104static void do_bpf_iter_setsockopt(struct bpf_iter_setsockopt *iter_skel,
 105                                   bool random_retry)
 106{
 107        int *reuse_listen_fds = NULL, *accepted_fds = NULL, *est_fds = NULL;
 108        unsigned int nr_reuse_listens = 256, nr_est = 256;
 109        int err, iter_fd = -1, listen_fd = -1;
 110        char buf;
 111
 112        /* Prepare non-reuseport listen_fd */
 113        listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
 114        if (!ASSERT_GE(listen_fd, 0, "start_server"))
 115                return;
 116        if (!ASSERT_EQ(set_bpf_cubic(&listen_fd, 1), 1,
 117                       "set listen_fd to cubic"))
 118                goto done;
 119        iter_skel->bss->listen_hport = get_local_port(listen_fd);
 120        if (!ASSERT_NEQ(iter_skel->bss->listen_hport, 0,
 121                        "get_local_port(listen_fd)"))
 122                goto done;
 123
 124        /* Connect to non-reuseport listen_fd */
 125        est_fds = make_established(listen_fd, nr_est, &accepted_fds);
 126        if (!ASSERT_OK_PTR(est_fds, "create established"))
 127                goto done;
 128
 129        /* Prepare reuseport listen fds */
 130        reuse_listen_fds = start_reuseport_server(AF_INET6, SOCK_STREAM,
 131                                                  "::1", 0, 0,
 132                                                  nr_reuse_listens);
 133        if (!ASSERT_OK_PTR(reuse_listen_fds, "start_reuseport_server"))
 134                goto done;
 135        if (!ASSERT_EQ(set_bpf_cubic(reuse_listen_fds, nr_reuse_listens),
 136                       nr_reuse_listens, "set reuse_listen_fds to cubic"))
 137                goto done;
 138        iter_skel->bss->reuse_listen_hport = get_local_port(reuse_listen_fds[0]);
 139        if (!ASSERT_NEQ(iter_skel->bss->reuse_listen_hport, 0,
 140                        "get_local_port(reuse_listen_fds[0])"))
 141                goto done;
 142
 143        /* Run bpf tcp iter to switch from bpf_cubic to bpf_dctcp */
 144        iter_skel->bss->random_retry = random_retry;
 145        iter_fd = bpf_iter_create(bpf_link__fd(iter_skel->links.change_tcp_cc));
 146        if (!ASSERT_GE(iter_fd, 0, "create iter_fd"))
 147                goto done;
 148
 149        while ((err = read(iter_fd, &buf, sizeof(buf))) == -1 &&
 150               errno == EAGAIN)
 151                ;
 152        if (!ASSERT_OK(err, "read iter error"))
 153                goto done;
 154
 155        /* Check reuseport listen fds for dctcp */
 156        ASSERT_EQ(check_bpf_dctcp(reuse_listen_fds, nr_reuse_listens),
 157                  nr_reuse_listens,
 158                  "check reuse_listen_fds dctcp");
 159
 160        /* Check non reuseport listen fd for dctcp */
 161        ASSERT_EQ(check_bpf_dctcp(&listen_fd, 1), 1,
 162                  "check listen_fd dctcp");
 163
 164        /* Check established fds for dctcp */
 165        ASSERT_EQ(check_bpf_dctcp(est_fds, nr_est), nr_est,
 166                  "check est_fds dctcp");
 167
 168        /* Check accepted fds for dctcp */
 169        ASSERT_EQ(check_bpf_dctcp(accepted_fds, nr_est), nr_est,
 170                  "check accepted_fds dctcp");
 171
 172done:
 173        if (iter_fd != -1)
 174                close(iter_fd);
 175        if (listen_fd != -1)
 176                close(listen_fd);
 177        free_fds(reuse_listen_fds, nr_reuse_listens);
 178        free_fds(accepted_fds, nr_est);
 179        free_fds(est_fds, nr_est);
 180}
 181
 182void test_bpf_iter_setsockopt(void)
 183{
 184        struct bpf_iter_setsockopt *iter_skel = NULL;
 185        struct bpf_cubic *cubic_skel = NULL;
 186        struct bpf_dctcp *dctcp_skel = NULL;
 187        struct bpf_link *cubic_link = NULL;
 188        struct bpf_link *dctcp_link = NULL;
 189
 190        if (create_netns())
 191                return;
 192
 193        /* Load iter_skel */
 194        iter_skel = bpf_iter_setsockopt__open_and_load();
 195        if (!ASSERT_OK_PTR(iter_skel, "iter_skel"))
 196                return;
 197        iter_skel->links.change_tcp_cc = bpf_program__attach_iter(iter_skel->progs.change_tcp_cc, NULL);
 198        if (!ASSERT_OK_PTR(iter_skel->links.change_tcp_cc, "attach iter"))
 199                goto done;
 200
 201        /* Load bpf_cubic */
 202        cubic_skel = bpf_cubic__open_and_load();
 203        if (!ASSERT_OK_PTR(cubic_skel, "cubic_skel"))
 204                goto done;
 205        cubic_link = bpf_map__attach_struct_ops(cubic_skel->maps.cubic);
 206        if (!ASSERT_OK_PTR(cubic_link, "cubic_link"))
 207                goto done;
 208
 209        /* Load bpf_dctcp */
 210        dctcp_skel = bpf_dctcp__open_and_load();
 211        if (!ASSERT_OK_PTR(dctcp_skel, "dctcp_skel"))
 212                goto done;
 213        dctcp_link = bpf_map__attach_struct_ops(dctcp_skel->maps.dctcp);
 214        if (!ASSERT_OK_PTR(dctcp_link, "dctcp_link"))
 215                goto done;
 216
 217        do_bpf_iter_setsockopt(iter_skel, true);
 218        do_bpf_iter_setsockopt(iter_skel, false);
 219
 220done:
 221        bpf_link__destroy(cubic_link);
 222        bpf_link__destroy(dctcp_link);
 223        bpf_cubic__destroy(cubic_skel);
 224        bpf_dctcp__destroy(dctcp_skel);
 225        bpf_iter_setsockopt__destroy(iter_skel);
 226}
 227