Is it possible to create a multiclient pipe? With one server and multiple clients? From the official documentation I have read that " A pipe server could use a single pipe instance to connect with multiple pipe clients by connecting to and disconnecting from each client in sequence, but performance would be poor" ( https://msdn.microsoft.com/en-us/library/windows/desktop/aa365594(v=vs.85).aspx ). Is this behaviour standard (can be done using some flags or something like that) or I have to implement this behaviour by myself? I have written a test with multiply clients, but when I trying to connect by the second client, I got error STATUS_PIPE_NOT_AVAILABLE.
There is my code, it quite big, but functions test_multiple_client and test_multiple_client2 is the same
void test_mutiple_client( PVOID arg )
{
OBJECT_ATTRIBUTES oa;
UNICODE_STRING us;
IO_STATUS_BLOCK iosb;
HANDLE thread = 0, event = 0, client = 0;
NTSTATUS r;
CLIENT_ID id;
LARGE_INTEGER timeout;
ULONG i;
us.Buffer = pipename;
us.Length = sizeof pipename - 2;
us.MaximumLength = us.Length;
oa.Length = sizeof oa;
oa.RootDirectory = 0;
oa.ObjectName = &us;
oa.Attributes = OBJ_CASE_INSENSITIVE;
oa.SecurityDescriptor = 0;
oa.SecurityQualityOfService = 0;
r = NtCreateEvent( &event, EVENT_ALL_ACCESS, NULL, NotificationEvent, 0 );
ok(r == STATUS_SUCCESS, "return wrong (%08lx)\n", r);
r = NtOpenFile( &client, GENERIC_READ | GENERIC_WRITE, &oa, &iosb, FILE_SHARE_READ|FILE_SHARE_WRITE, 0 );
ok(r == STATUS_SUCCESS, "return wrong %08lx\n", r);
dprintf("mc: client1 pipe created\n");
int thread_id = __sync_add_and_fetch(&g__clientsCounter, 1);
while (g__clientsCounter != 2);
dprintf("thread %d stated\n", thread_id);
r = NtReadFile( client, event, 0, 0, &iosb, &i, sizeof i, 0, 0 );
if (r == STATUS_PENDING)
r = NtWaitForSingleObject( event, TRUE, 0 );
ok (r == STATUS_SUCCESS, "read %ld returned %08lx\n", i, r);
ok (i == 13, "lol?????");
r = NtClose( client );
ok( r == STATUS_SUCCESS, "return wrong %08lx\n", r);
}
void test_mutiple_client2( PVOID arg )
{
OBJECT_ATTRIBUTES oa;
UNICODE_STRING us;
IO_STATUS_BLOCK iosb;
HANDLE thread = 0, event = 0, client = 0;
NTSTATUS r;
CLIENT_ID id;
LARGE_INTEGER timeout;
ULONG i;
us.Buffer = pipename;
us.Length = sizeof pipename - 2;
us.MaximumLength = us.Length;
oa.Length = sizeof oa;
oa.RootDirectory = 0;
oa.ObjectName = &us;
oa.Attributes = OBJ_CASE_INSENSITIVE;
oa.SecurityDescriptor = 0;
oa.SecurityQualityOfService = 0;
r = NtCreateEvent( &event, EVENT_ALL_ACCESS, NULL, NotificationEvent, 0 );
ok(r == STATUS_SUCCESS, "return wrong (%08lx)\n", r);
r = NtOpenFile( &client, GENERIC_READ | GENERIC_WRITE, &oa, &iosb, FILE_SHARE_READ|FILE_SHARE_WRITE, 0 );
ok(r == STATUS_SUCCESS, "return wrong %08lx\n", r);
dprintf("mc: client1 pipe created\n");
int thread_id = __sync_add_and_fetch(&g__clientsCounter, 1);
while (g__clientsCounter != 2);
dprintf("thread %d stated\n", thread_id);
r = NtReadFile( client, event, 0, 0, &iosb, &i, sizeof i, 0, 0 );
if (r == STATUS_PENDING)
r = NtWaitForSingleObject( event, TRUE, 0 );
ok (r == STATUS_SUCCESS, "read %ld returned %08lx\n", i, r);
ok (i == 13, "lol?????");
r = NtClose( client );
ok( r == STATUS_SUCCESS, "return wrong %08lx\n", r);
}
void test_multiple_connections( )
{
OBJECT_ATTRIBUTES oa;
UNICODE_STRING us;
IO_STATUS_BLOCK iosb;
HANDLE pipe = 0, thread = 0, event = 0;
NTSTATUS r;
CLIENT_ID id;
LARGE_INTEGER timeout;
ULONG i;
us.Buffer = pipename;
us.Length = sizeof pipename - 2;
us.MaximumLength = us.Length;
oa.Length = sizeof oa;
oa.RootDirectory = 0;
oa.ObjectName = &us;
oa.Attributes = OBJ_CASE_INSENSITIVE;
oa.SecurityDescriptor = 0;
oa.SecurityQualityOfService = 0;
timeout.QuadPart = -10000LL;
r = NtCreateNamedPipeFile( &pipe, GENERIC_READ|GENERIC_WRITE|SYNCHRONIZE,
&oa, &iosb, FILE_SHARE_READ|FILE_SHARE_WRITE, FILE_OPEN_IF, 0, TRUE,
TRUE, FALSE, /*Unlimited*/ -1, 0, 0, &timeout );
ok( r == STATUS_SUCCESS, "return wrong %08lx\n", r);
dprintf("mc: server pipe created\n");
r = RtlCreateUserThread( NtCurrentProcess(), NULL, FALSE,
NULL, 0, 0, &test_mutiple_client, NULL, &thread, &id );
ok( r == STATUS_SUCCESS, "failed to create thread\n" );
r = RtlCreateUserThread( NtCurrentProcess(), NULL, FALSE,
NULL, 0, 0, &test_mutiple_client2, NULL, &thread, &id );
ok( r == STATUS_SUCCESS, "failed to create thread\n" );
r = NtCreateEvent( &event, EVENT_ALL_ACCESS, NULL, NotificationEvent, 0 );
ok(r == STATUS_SUCCESS, "return wrong (%08lx)\n", r);
r = NtFsControlFile( pipe, event, 0, 0, &iosb, FSCTL_PIPE_LISTEN, 0, 0, 0, 0 );
if (r == STATUS_PENDING) {
dprintf("mc: pending\n");
r = NtWaitForSingleObject( event, TRUE, 0 );
}
ok( r == STATUS_SUCCESS, "failed to listen %08lx\n", r );
dprintf("mc: server pipe listen\n");
i = 13;
while (g__clientsCounter != 2);
dprintf("server started\n");
r = NtWriteFile( pipe, event, 0, 0, &iosb, &i, sizeof i, 0, 0 );
if (r == STATUS_PENDING)
r = NtWaitForSingleObject( event, TRUE, 0 );
ok (r == STATUS_SUCCESS, "write %ld returned %08lx\n", i, r);
dprintf("server write data\n");
r = NtClose( pipe );
ok( r == STATUS_SUCCESS, "return wrong %08lx\n", r);
}
The output is
mc: server pipe created
mc: pending
mc: server pipe listen
mc: client1 pipe created
478: return wrong c00000ac
mc: client1 pipe created
thread 2 stated
488: read 2013057864 returned c0000008
489: lol?????492: return wrong c0000008
server started
thread 1 stated
server write data
4 failed, 38 passed
I also have seen an answer of stack ( Number of Clients that can connect to a Named Pipe ) where mentioned that windows pipes can hold up to 256 clients
