bpf/prog_tests/sockopt_sk.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <test_progs.h>
0003 #include "cgroup_helpers.h"
0004
0005 #include <linux/tcp.h>
0006 #include "sockopt_sk.skel.h"
0007
0008 #ifndef SOL_TCP
0009 #define SOL_TCP IPPROTO_TCP
0010 #endif
0011
0012 #define SOL_CUSTOM          0xdeadbeef
0013
0014 static int getsetsockopt(void)
0015 {
0016     int fd, err;
0017     union {
0018         char u8[4];
0019         __u32 u32;
0020         char cc[16]; /* TCP_CA_NAME_MAX */
0021         struct tcp_zerocopy_receive zc;
0022     } buf = {};
0023     socklen_t optlen;
0024     char *big_buf = NULL;
0025
0026     fd = socket(AF_INET, SOCK_STREAM, 0);
0027     if (fd < 0) {
0028         log_err("Failed to create socket");
0029         return -1;
0030     }
0031
0032     /* IP_TOS - BPF bypass */
0033
0034     optlen = getpagesize() * 2;
0035     big_buf = calloc(1, optlen);
0036     if (!big_buf) {
0037         log_err("Couldn't allocate two pages");
0038         goto err;
0039     }
0040
0041     *(int *)big_buf = 0x08;
0042     err = setsockopt(fd, SOL_IP, IP_TOS, big_buf, optlen);
0043     if (err) {
0044         log_err("Failed to call setsockopt(IP_TOS)");
0045         goto err;
0046     }
0047
0048     memset(big_buf, 0, optlen);
0049     optlen = 1;
0050     err = getsockopt(fd, SOL_IP, IP_TOS, big_buf, &optlen);
0051     if (err) {
0052         log_err("Failed to call getsockopt(IP_TOS)");
0053         goto err;
0054     }
0055
0056     if (*big_buf != 0x08) {
0057         log_err("Unexpected getsockopt(IP_TOS) optval 0x%x != 0x08",
0058             (int)*big_buf);
0059         goto err;
0060     }
0061
0062     /* IP_TTL - EPERM */
0063
0064     buf.u8[0] = 1;
0065     err = setsockopt(fd, SOL_IP, IP_TTL, &buf, 1);
0066     if (!err || errno != EPERM) {
0067         log_err("Unexpected success from setsockopt(IP_TTL)");
0068         goto err;
0069     }
0070
0071     /* SOL_CUSTOM - handled by BPF */
0072
0073     buf.u8[0] = 0x01;
0074     err = setsockopt(fd, SOL_CUSTOM, 0, &buf, 1);
0075     if (err) {
0076         log_err("Failed to call setsockopt");
0077         goto err;
0078     }
0079
0080     buf.u32 = 0x00;
0081     optlen = 4;
0082     err = getsockopt(fd, SOL_CUSTOM, 0, &buf, &optlen);
0083     if (err) {
0084         log_err("Failed to call getsockopt");
0085         goto err;
0086     }
0087
0088     if (optlen != 1) {
0089         log_err("Unexpected optlen %d != 1", optlen);
0090         goto err;
0091     }
0092     if (buf.u8[0] != 0x01) {
0093         log_err("Unexpected buf[0] 0x%02x != 0x01", buf.u8[0]);
0094         goto err;
0095     }
0096
0097     /* IP_FREEBIND - BPF can't access optval past PAGE_SIZE */
0098
0099     optlen = getpagesize() * 2;
0100     memset(big_buf, 0, optlen);
0101
0102     err = setsockopt(fd, SOL_IP, IP_FREEBIND, big_buf, optlen);
0103     if (err != 0) {
0104         log_err("Failed to call setsockopt, ret=%d", err);
0105         goto err;
0106     }
0107
0108     err = getsockopt(fd, SOL_IP, IP_FREEBIND, big_buf, &optlen);
0109     if (err != 0) {
0110         log_err("Failed to call getsockopt, ret=%d", err);
0111         goto err;
0112     }
0113
0114     if (optlen != 1 || *(__u8 *)big_buf != 0x55) {
0115         log_err("Unexpected IP_FREEBIND getsockopt, optlen=%d, optval=0x%x",
0116             optlen, *(__u8 *)big_buf);
0117     }
0118
0119     /* SO_SNDBUF is overwritten */
0120
0121     buf.u32 = 0x01010101;
0122     err = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buf, 4);
0123     if (err) {
0124         log_err("Failed to call setsockopt(SO_SNDBUF)");
0125         goto err;
0126     }
0127
0128     buf.u32 = 0x00;
0129     optlen = 4;
0130     err = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buf, &optlen);
0131     if (err) {
0132         log_err("Failed to call getsockopt(SO_SNDBUF)");
0133         goto err;
0134     }
0135
0136     if (buf.u32 != 0x55AA*2) {
0137         log_err("Unexpected getsockopt(SO_SNDBUF) 0x%x != 0x55AA*2",
0138             buf.u32);
0139         goto err;
0140     }
0141
0142     /* TCP_CONGESTION can extend the string */
0143
0144     strcpy(buf.cc, "nv");
0145     err = setsockopt(fd, SOL_TCP, TCP_CONGESTION, &buf, strlen("nv"));
0146     if (err) {
0147         log_err("Failed to call setsockopt(TCP_CONGESTION)");
0148         goto err;
0149     }
0150
0151
0152     optlen = sizeof(buf.cc);
0153     err = getsockopt(fd, SOL_TCP, TCP_CONGESTION, &buf, &optlen);
0154     if (err) {
0155         log_err("Failed to call getsockopt(TCP_CONGESTION)");
0156         goto err;
0157     }
0158
0159     if (strcmp(buf.cc, "cubic") != 0) {
0160         log_err("Unexpected getsockopt(TCP_CONGESTION) %s != %s",
0161             buf.cc, "cubic");
0162         goto err;
0163     }
0164
0165     /* TCP_ZEROCOPY_RECEIVE triggers */
0166     memset(&buf, 0, sizeof(buf));
0167     optlen = sizeof(buf.zc);
0168     err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen);
0169     if (err) {
0170         log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d",
0171             err, errno);
0172         goto err;
0173     }
0174
0175     memset(&buf, 0, sizeof(buf));
0176     buf.zc.address = 12345; /* Not page aligned. Rejected by tcp_zerocopy_receive() */
0177     optlen = sizeof(buf.zc);
0178     errno = 0;
0179     err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen);
0180     if (errno != EINVAL) {
0181         log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d",
0182             err, errno);
0183         goto err;
0184     }
0185
0186     free(big_buf);
0187     close(fd);
0188     return 0;
0189 err:
0190     free(big_buf);
0191     close(fd);
0192     return -1;
0193 }
0194
0195 static void run_test(int cgroup_fd)
0196 {
0197     struct sockopt_sk *skel;
0198
0199     skel = sockopt_sk__open_and_load();
0200     if (!ASSERT_OK_PTR(skel, "skel_load"))
0201         goto cleanup;
0202
0203     skel->bss->page_size = getpagesize();
0204
0205     skel->links._setsockopt =
0206         bpf_program__attach_cgroup(skel->progs._setsockopt, cgroup_fd);
0207     if (!ASSERT_OK_PTR(skel->links._setsockopt, "setsockopt_link"))
0208         goto cleanup;
0209
0210     skel->links._getsockopt =
0211         bpf_program__attach_cgroup(skel->progs._getsockopt, cgroup_fd);
0212     if (!ASSERT_OK_PTR(skel->links._getsockopt, "getsockopt_link"))
0213         goto cleanup;
0214
0215     ASSERT_OK(getsetsockopt(), "getsetsockopt");
0216
0217 cleanup:
0218     sockopt_sk__destroy(skel);
0219 }
0220
0221 void test_sockopt_sk(void)
0222 {
0223     int cgroup_fd;
0224
0225     cgroup_fd = test__join_cgroup("/sockopt_sk");
0226     if (CHECK_FAIL(cgroup_fd < 0))
0227         return;
0228
0229     run_test(cgroup_fd);
0230     close(cgroup_fd);
0231 }