[VPP-1089] VCL-LDPRELOAD: setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, ...) does nothing, therefore, getsockopt(...) does not confirm an expected change

[vvalderrv]

• VPP version: v18.01-rc0~442-ga3611a7

• Stack backtraces:

For setsockopt:

#0  vppcom_session_attr (session_index=1, op=6, buffer=0x0, buflen=0x0) at /home/palmar/dev/vpp/build-data/../src/vcl/vppcom.c:3860
#1  0x00007ffff7985e75 in vcom_session_setsockopt (__sid=1, __level=1, __optname=2, __optval=0x7fffffffd244, __optlen=4) at /home/palmar/dev/vpp/build-data/../src/vcl/vcom_socket.c:2154
#2  0x00007ffff7986183 in vcom_socket_setsockopt (__fd=8, __level=1, __optname=2, __optval=0x7fffffffd244, __optlen=4) at /home/palmar/dev/vpp/build-data/../src/vcl/vcom_socket.c:2244
#3  0x00007ffff797d403 in vcom_setsockopt (__fd=8, __level=1, __optname=2, __optval=0x7fffffffd244, __optlen=4) at /home/palmar/dev/vpp/build-data/../src/vcl/vcom.c:2483
#4  0x00007ffff797d475 in setsockopt (__fd=8, __level=1, __optname=2, __optval=0x7fffffffd244, __optlen=4) at /home/palmar/dev/vpp/build-data/../src/vcl/vcom.c:2496
(...)

For getsockopt:

#0  vcom_socket_getsockopt (__fd=8, __level=1, __optname=2, __optval=0x7fffffffd248, __optlen=0x7fffffffd24c) at /home/palmar/dev/vpp/build-data/../src/vcl/vcom_socket.c:2080
#1  0x00007ffff797d2eb in vcom_getsockopt (__fd=8, __level=1, __optname=2, __optval=0x7fffffffd248, __optlen=0x7fffffffd24c) at /home/palmar/dev/vpp/build-data/../src/vcl/vcom.c:2439
#2  0x00007ffff797d35a in getsockopt (__fd=8, __level=1, __optname=2, __optval=0x7fffffffd248, __optlen=0x7fffffffd24c) at /home/palmar/dev/vpp/build-data/../src/vcl/vcom.c:2452
(...)

• For completeness' sake: Our test case call the setsockopt and getsockopt from the following C++ gRPC code:

grpc/src/core/lib/iomgr/socket_utils_common_posix.cc:

grpc_error* grpc_set_socket_reuse_addr(int fd, int reuse) {
  int val = (reuse != 0);
  int newval;
  socklen_t intlen = sizeof(newval);
  if (0 != setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val))) {
    return GRPC_OS_ERROR(errno, "setsockopt(SO_REUSEADDR)");
  }
  if (0 != getsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &newval, &intlen)) {
    return GRPC_OS_ERROR(errno, "getsockopt(SO_REUSEADDR)");
  }
  if ((newval != 0) != val) {
    return GRPC_ERROR_CREATE_FROM_STATIC_STRING("Failed to set SO_REUSEADDR");
  }

  return GRPC_ERROR_NONE;
}