[libc-commits] [libc] [libc] Implement connect(2) on linux (PR #189668)

[Pavel Labath via libc-commits]

================
@@ -0,0 +1,68 @@
+//===-- Unittests for connect ---------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "hdr/sys_socket_macros.h"
+#include "hdr/types/struct_sockaddr_un.h"
+#include "src/sys/socket/bind.h"
+#include "src/sys/socket/connect.h"
+#include "src/sys/socket/socket.h"
+
+#include "src/stdio/remove.h"
+#include "src/unistd/close.h"
+
+#include "test/UnitTest/ErrnoCheckingTest.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+using LlvmLibcConnectTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+
+TEST_F(LlvmLibcConnectTest, ConnectLocalSocket) {
+
+  const char *FILENAME = "connect_file.test";
+  auto SOCK_PATH = libc_make_test_file_path(FILENAME);
+
+  int sock1 = LIBC_NAMESPACE::socket(AF_UNIX, SOCK_STREAM, 0);
+  ASSERT_GE(sock1, 0);
+  ASSERT_ERRNO_SUCCESS();
+
+  struct sockaddr_un my_addr;
+
+  my_addr.sun_family = AF_UNIX;
+  unsigned int i = 0;
+  for (;
+       SOCK_PATH[i] != '\0' && (i < sizeof(sockaddr_un) - sizeof(sa_family_t));
+       ++i)
+    my_addr.sun_path[i] = SOCK_PATH[i];
+
+  // It's important that the path fits in the struct, if it doesn't then we
+  // can't try to bind to the file.
+  ASSERT_LT(
+      i, static_cast<unsigned int>(sizeof(sockaddr_un) - sizeof(sa_family_t)));
+  my_addr.sun_path[i] = '\0';
+
+  ASSERT_THAT(
+      LIBC_NAMESPACE::bind(sock1, reinterpret_cast<struct sockaddr *>(&my_addr),
+                           sizeof(struct sockaddr_un)),
+      Succeeds(0));
+
+  int sock2 = LIBC_NAMESPACE::socket(AF_UNIX, SOCK_STREAM, 0);
+  ASSERT_GE(sock2, 0);
+  ASSERT_ERRNO_SUCCESS();
+
+  ASSERT_THAT(
+      LIBC_NAMESPACE::connect(sock2,
+                              reinterpret_cast<struct sockaddr *>(&my_addr),
+                              sizeof(struct sockaddr_un)),
+      Fails(ECONNREFUSED)); // Because the other side is not listen()ing.
+
+  ASSERT_THAT(LIBC_NAMESPACE::close(sock1), Succeeds(0));
+  ASSERT_THAT(LIBC_NAMESPACE::close(sock2), Succeeds(0));
+  ASSERT_THAT(LIBC_NAMESPACE::remove(SOCK_PATH), Succeeds(0));
----------------
labath wrote:

I took this pattern from the bind test, but it has the unfortunate effect of leaving the socket file lying around on the disk if the test fails (which then causes the next run of the test to fail). Maybe there's room for a `scope_exit` in the support library?

https://github.com/llvm/llvm-project/pull/189668