[libc-commits] [libc] [libc] Implement getsockopt and setsockopt on linux (PR #192237)
Pavel Labath via libc-commits
libc-commits at lists.llvm.org
Thu Apr 16 02:59:35 PDT 2026
https://github.com/labath updated https://github.com/llvm/llvm-project/pull/192237
>From 4504a6253d21fd5684431cc89c6136d9d92eaef5 Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavel at labath.sk>
Date: Fri, 10 Apr 2026 09:50:22 +0000
Subject: [PATCH 1/4] [libc] Implement getsockopt and setsockopt on linux
This patch implements getsockopt and setsockopt socket functions on Linux.
It follows the established pattern of wrapping socketcall or using direct syscalls.
I added a basic test setting a couple of options.
I only added the first couple of simple constants (e.g. whose value does
not depend on the architecture). I've left the others for a separate
patch.
---
libc/config/linux/aarch64/entrypoints.txt | 2 +
libc/config/linux/riscv/entrypoints.txt | 2 +
libc/config/linux/x86_64/entrypoints.txt | 2 +
.../linux/sys-socket-macros.h | 18 +++++
.../linux/syscall_wrappers/CMakeLists.txt | 26 +++++++
.../linux/syscall_wrappers/getsockopt.h | 49 +++++++++++++
.../linux/syscall_wrappers/setsockopt.h | 49 +++++++++++++
libc/src/sys/socket/CMakeLists.txt | 14 ++++
libc/src/sys/socket/getsockopt.h | 23 ++++++
libc/src/sys/socket/linux/CMakeLists.txt | 26 +++++++
libc/src/sys/socket/linux/getsockopt.cpp | 31 ++++++++
libc/src/sys/socket/linux/setsockopt.cpp | 31 ++++++++
libc/src/sys/socket/setsockopt.h | 23 ++++++
libc/test/src/sys/socket/linux/CMakeLists.txt | 19 +++++
.../src/sys/socket/linux/socketopt_test.cpp | 70 +++++++++++++++++++
15 files changed, 385 insertions(+)
create mode 100644 libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
create mode 100644 libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
create mode 100644 libc/src/sys/socket/getsockopt.h
create mode 100644 libc/src/sys/socket/linux/getsockopt.cpp
create mode 100644 libc/src/sys/socket/linux/setsockopt.cpp
create mode 100644 libc/src/sys/socket/setsockopt.h
create mode 100644 libc/test/src/sys/socket/linux/socketopt_test.cpp
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 9e9752dcde915..6f7567cf3789f 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -1214,7 +1214,9 @@ if(LLVM_LIBC_FULL_BUILD)
libc.src.sys.socket.accept
libc.src.sys.socket.bind
libc.src.sys.socket.connect
+ libc.src.sys.socket.getsockopt
libc.src.sys.socket.listen
+ libc.src.sys.socket.setsockopt
libc.src.sys.socket.socket
)
endif()
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 0e1e806362dcd..1856d8edba7de 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -1348,7 +1348,9 @@ if(LLVM_LIBC_FULL_BUILD)
libc.src.sys.socket.accept
libc.src.sys.socket.bind
libc.src.sys.socket.connect
+ libc.src.sys.socket.getsockopt
libc.src.sys.socket.listen
+ libc.src.sys.socket.setsockopt
libc.src.sys.socket.socket
libc.src.sys.socket.socketpair
libc.src.sys.socket.send
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 9476ebbad1517..92324118a51c8 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -1419,8 +1419,10 @@ if(LLVM_LIBC_FULL_BUILD)
libc.src.sys.socket.socket
libc.src.sys.socket.bind
libc.src.sys.socket.connect
+ libc.src.sys.socket.getsockopt
libc.src.sys.socket.listen
libc.src.sys.socket.socketpair
+ libc.src.sys.socket.setsockopt
libc.src.sys.socket.send
libc.src.sys.socket.sendto
libc.src.sys.socket.sendmsg
diff --git a/libc/include/llvm-libc-macros/linux/sys-socket-macros.h b/libc/include/llvm-libc-macros/linux/sys-socket-macros.h
index f335200a103bb..5a5cfd578dcbf 100644
--- a/libc/include/llvm-libc-macros/linux/sys-socket-macros.h
+++ b/libc/include/llvm-libc-macros/linux/sys-socket-macros.h
@@ -25,4 +25,22 @@
#define SOCK_SEQPACKET 5
#define SOCK_PACKET 10
+#define SOL_SOCKET 1
+
+#define SO_DEBUG 1
+#define SO_REUSEADDR 2
+#define SO_TYPE 3
+#define SO_ERROR 4
+#define SO_DONTROUTE 5
+#define SO_BROADCAST 6
+#define SO_SNDBUF 7
+#define SO_RCVBUF 8
+#define SO_KEEPALIVE 9
+#define SO_OOBINLINE 10
+#define SO_NO_CHECK 11
+#define SO_PRIORITY 12
+#define SO_LINGER 13
+#define SO_BSDCOMPAT 14
+#define SO_REUSEPORT 15
+
#endif // LLVM_LIBC_MACROS_LINUX_SYS_SOCKET_MACROS_H
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt b/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
index 3d5ef62d09e66..f00fa9668afe7 100644
--- a/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
@@ -53,6 +53,19 @@ add_header_library(
libc.include.sys_syscall
)
+add_header_library(
+ getsockopt
+ HDRS
+ getsockopt.h
+ DEPENDS
+ libc.src.__support.common
+ libc.src.__support.error_or
+ libc.src.__support.libc_errno
+ libc.src.__support.macros.config
+ libc.hdr.types.socklen_t
+ libc.include.sys_syscall
+)
+
add_header_library(
listen
HDRS
@@ -78,6 +91,19 @@ add_header_library(
libc.include.sys_syscall
)
+add_header_library(
+ setsockopt
+ HDRS
+ setsockopt.h
+ DEPENDS
+ libc.src.__support.common
+ libc.src.__support.error_or
+ libc.src.__support.libc_errno
+ libc.src.__support.macros.config
+ libc.hdr.types.socklen_t
+ libc.include.sys_syscall
+)
+
add_header_library(
raise
HDRS
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
new file mode 100644
index 0000000000000..7fecaab83c7d1
--- /dev/null
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
@@ -0,0 +1,49 @@
+//===-- Implementation header for getsockopt --------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_GETSOCKOPT_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_GETSOCKOPT_H
+
+#include "src/__support/OSUtil/linux/syscall.h" // syscall_impl
+#include "src/__support/common.h"
+#include "src/__support/error_or.h"
+#include "src/__support/macros/config.h"
+
+#include "hdr/types/socklen_t.h"
+#include <linux/net.h> // For SYS_GETSOCKOPT socketcall number.
+#include <sys/syscall.h> // For syscall numbers
+
+namespace LIBC_NAMESPACE_DECL {
+namespace linux_syscalls {
+
+LIBC_INLINE ErrorOr<int> getsockopt(int sockfd, int level, int optname,
+ void *optval, socklen_t *optlen) {
+#ifdef SYS_getsockopt
+ int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_getsockopt, sockfd, level,
+ optname, optval, optlen);
+#elif defined(SYS_socketcall)
+ unsigned long sockcall_args[5] = {static_cast<unsigned long>(sockfd),
+ static_cast<unsigned long>(level),
+ static_cast<unsigned long>(optname),
+ reinterpret_cast<unsigned long>(optval),
+ reinterpret_cast<unsigned long>(optlen)};
+ int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_socketcall, SYS_GETSOCKOPT,
+ sockcall_args);
+#else
+#error "getsockopt and socketcall syscalls unavailable for this platform."
+#endif
+
+ if (ret < 0)
+ return Error(-static_cast<int>(ret));
+ return ret;
+}
+
+} // namespace linux_syscalls
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_GETSOCKOPT_H
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
new file mode 100644
index 0000000000000..2b24522e77ec5
--- /dev/null
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
@@ -0,0 +1,49 @@
+//===-- Implementation header for setsockopt --------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_SETSOCKOPT_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_SETSOCKOPT_H
+
+#include "src/__support/OSUtil/linux/syscall.h" // syscall_impl
+#include "src/__support/common.h"
+#include "src/__support/error_or.h"
+#include "src/__support/macros/config.h"
+
+#include "hdr/types/socklen_t.h"
+#include <linux/net.h> // For SYS_SETSOCKOPT socketcall number.
+#include <sys/syscall.h> // For syscall numbers
+
+namespace LIBC_NAMESPACE_DECL {
+namespace linux_syscalls {
+
+LIBC_INLINE ErrorOr<int> setsockopt(int sockfd, int level, int optname,
+ const void *optval, socklen_t optlen) {
+#ifdef SYS_setsockopt
+ int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_setsockopt, sockfd, level,
+ optname, optval, optlen);
+#elif defined(SYS_socketcall)
+ unsigned long sockcall_args[5] = {static_cast<unsigned long>(sockfd),
+ static_cast<unsigned long>(level),
+ static_cast<unsigned long>(optname),
+ reinterpret_cast<unsigned long>(optval),
+ static_cast<unsigned long>(optlen)};
+ int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_socketcall, SYS_SETSOCKOPT,
+ sockcall_args);
+#else
+#error "setsockopt and socketcall syscalls unavailable for this platform."
+#endif
+
+ if (ret < 0)
+ return Error(-static_cast<int>(ret));
+ return ret;
+}
+
+} // namespace linux_syscalls
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_SETSOCKOPT_H
diff --git a/libc/src/sys/socket/CMakeLists.txt b/libc/src/sys/socket/CMakeLists.txt
index b16e342dfe490..50558c667c78a 100644
--- a/libc/src/sys/socket/CMakeLists.txt
+++ b/libc/src/sys/socket/CMakeLists.txt
@@ -30,6 +30,13 @@ add_entrypoint_object(
.${LIBC_TARGET_OS}.connect
)
+add_entrypoint_object(
+ getsockopt
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.getsockopt
+)
+
add_entrypoint_object(
listen
ALIAS
@@ -58,6 +65,13 @@ add_entrypoint_object(
.${LIBC_TARGET_OS}.sendto
)
+add_entrypoint_object(
+ setsockopt
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.setsockopt
+)
+
add_entrypoint_object(
sendmsg
ALIAS
diff --git a/libc/src/sys/socket/getsockopt.h b/libc/src/sys/socket/getsockopt.h
new file mode 100644
index 0000000000000..6d71dace9c3c2
--- /dev/null
+++ b/libc/src/sys/socket/getsockopt.h
@@ -0,0 +1,23 @@
+//===-- Implementation header for getsockopt --------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_SOCKET_GETSOCKOPT_H
+#define LLVM_LIBC_SRC_SYS_SOCKET_GETSOCKOPT_H
+
+#include "src/__support/macros/config.h"
+
+#include "hdr/types/socklen_t.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int getsockopt(int sockfd, int level, int optname, void *__restrict optval,
+ socklen_t *__restrict optlen);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_SOCKET_GETSOCKOPT_H
diff --git a/libc/src/sys/socket/linux/CMakeLists.txt b/libc/src/sys/socket/linux/CMakeLists.txt
index 2a79de6081892..d76a6b1ad70fd 100644
--- a/libc/src/sys/socket/linux/CMakeLists.txt
+++ b/libc/src/sys/socket/linux/CMakeLists.txt
@@ -52,6 +52,19 @@ add_entrypoint_object(
libc.src.errno.errno
)
+add_entrypoint_object(
+ getsockopt
+ SRCS
+ getsockopt.cpp
+ HDRS
+ ../getsockopt.h
+ DEPENDS
+ libc.include.sys_socket
+ libc.src.__support.OSUtil.osutil
+ libc.hdr.types.socklen_t
+ libc.src.errno.errno
+)
+
add_entrypoint_object(
listen
SRCS
@@ -106,6 +119,19 @@ add_entrypoint_object(
libc.src.errno.errno
)
+add_entrypoint_object(
+ setsockopt
+ SRCS
+ setsockopt.cpp
+ HDRS
+ ../setsockopt.h
+ DEPENDS
+ libc.include.sys_socket
+ libc.src.__support.OSUtil.osutil
+ libc.hdr.types.socklen_t
+ libc.src.errno.errno
+)
+
add_entrypoint_object(
sendmsg
SRCS
diff --git a/libc/src/sys/socket/linux/getsockopt.cpp b/libc/src/sys/socket/linux/getsockopt.cpp
new file mode 100644
index 0000000000000..b964a667850bc
--- /dev/null
+++ b/libc/src/sys/socket/linux/getsockopt.cpp
@@ -0,0 +1,31 @@
+//===-- Linux implementation of getsockopt --------------------------------===//
+//
+// 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 "src/sys/socket/getsockopt.h"
+
+#include "hdr/types/socklen_t.h"
+#include "src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, getsockopt,
+ (int sockfd, int level, int optname, void *__restrict optval,
+ socklen_t *__restrict optlen)) {
+ auto result =
+ linux_syscalls::getsockopt(sockfd, level, optname, optval, optlen);
+ if (!result.has_value()) {
+ libc_errno = result.error();
+ return -1;
+ }
+
+ return result.value();
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/sys/socket/linux/setsockopt.cpp b/libc/src/sys/socket/linux/setsockopt.cpp
new file mode 100644
index 0000000000000..2ca995b76c340
--- /dev/null
+++ b/libc/src/sys/socket/linux/setsockopt.cpp
@@ -0,0 +1,31 @@
+//===-- Linux implementation of setsockopt --------------------------------===//
+//
+// 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 "src/sys/socket/setsockopt.h"
+
+#include "hdr/types/socklen_t.h"
+#include "src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, setsockopt,
+ (int sockfd, int level, int optname, const void *optval,
+ socklen_t optlen)) {
+ auto result =
+ linux_syscalls::setsockopt(sockfd, level, optname, optval, optlen);
+ if (!result.has_value()) {
+ libc_errno = result.error();
+ return -1;
+ }
+
+ return result.value();
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/sys/socket/setsockopt.h b/libc/src/sys/socket/setsockopt.h
new file mode 100644
index 0000000000000..9fee722f51927
--- /dev/null
+++ b/libc/src/sys/socket/setsockopt.h
@@ -0,0 +1,23 @@
+//===-- Implementation header for setsockopt --------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_SOCKET_SETSOCKOPT_H
+#define LLVM_LIBC_SRC_SYS_SOCKET_SETSOCKOPT_H
+
+#include "src/__support/macros/config.h"
+
+#include "hdr/types/socklen_t.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int setsockopt(int sockfd, int level, int optname, const void *optval,
+ socklen_t optlen);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_SOCKET_SETSOCKOPT_H
diff --git a/libc/test/src/sys/socket/linux/CMakeLists.txt b/libc/test/src/sys/socket/linux/CMakeLists.txt
index 478c2d0b4489b..b4e5d5c462fab 100644
--- a/libc/test/src/sys/socket/linux/CMakeLists.txt
+++ b/libc/test/src/sys/socket/linux/CMakeLists.txt
@@ -79,6 +79,25 @@ add_libc_unittest(
libc.test.UnitTest.ErrnoSetterMatcher
)
+add_libc_unittest(
+ socketopt_test
+ SUITE
+ libc_sys_socket_unittests
+ SRCS
+ socketopt_test.cpp
+ DEPENDS
+ libc.include.sys_socket
+ libc.hdr.sys_socket_macros
+ libc.hdr.types.socklen_t
+ libc.src.errno.errno
+ libc.src.sys.socket.getsockopt
+ libc.src.sys.socket.setsockopt
+ libc.src.sys.socket.socket
+ libc.src.unistd.close
+ libc.test.UnitTest.ErrnoCheckingTest
+ libc.test.UnitTest.ErrnoSetterMatcher
+)
+
add_libc_unittest(
socketpair_test
SUITE
diff --git a/libc/test/src/sys/socket/linux/socketopt_test.cpp b/libc/test/src/sys/socket/linux/socketopt_test.cpp
new file mode 100644
index 0000000000000..2164c8288e739
--- /dev/null
+++ b/libc/test/src/sys/socket/linux/socketopt_test.cpp
@@ -0,0 +1,70 @@
+//===-- Unittests for getsockopt and setsockopt ---------------------------===//
+//
+// 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 "src/sys/socket/getsockopt.h"
+#include "src/sys/socket/setsockopt.h"
+#include "src/sys/socket/socket.h"
+
+#include "src/unistd/close.h"
+
+#include "test/UnitTest/ErrnoCheckingTest.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+#include <sys/socket.h>
+
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+using LlvmLibcSocketOptTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+
+TEST_F(LlvmLibcSocketOptTest, BasicSocketOpt) {
+ int sock = LIBC_NAMESPACE::socket(AF_UNIX, SOCK_STREAM, 0);
+ ASSERT_GE(sock, 0);
+
+ int optval = 0;
+ socklen_t optlen = sizeof(optval);
+
+ // Test a boolean-like option
+ optval = 1;
+ ASSERT_THAT(LIBC_NAMESPACE::setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
+ &optval, optlen),
+ Succeeds(0));
+
+ optval = 0;
+ ASSERT_THAT(LIBC_NAMESPACE::getsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
+ &optval, &optlen),
+ Succeeds(0));
+ ASSERT_EQ(optval, 1);
+ ASSERT_EQ(optlen, sizeof(optval));
+
+ // Test SO_TYPE (read-only)
+ ASSERT_THAT(
+ LIBC_NAMESPACE::getsockopt(sock, SOL_SOCKET, SO_TYPE, &optval, &optlen),
+ Succeeds(0));
+ ASSERT_EQ(optval, SOCK_STREAM);
+ ASSERT_EQ(optlen, sizeof(optval));
+
+ optval = SOCK_DGRAM;
+ ASSERT_THAT(
+ LIBC_NAMESPACE::setsockopt(sock, SOL_SOCKET, SO_TYPE, &optval, optlen),
+ Fails(ENOPROTOOPT));
+
+ ASSERT_THAT(LIBC_NAMESPACE::close(sock), Succeeds(0));
+}
+
+TEST_F(LlvmLibcSocketOptTest, InvalidSocket) {
+ int optval = 1;
+ socklen_t optlen = sizeof(optval);
+ ASSERT_THAT(
+ LIBC_NAMESPACE::setsockopt(-1, SOL_SOCKET, SO_KEEPALIVE, &optval, optlen),
+ Fails(EBADF));
+
+ ASSERT_THAT(LIBC_NAMESPACE::getsockopt(-1, SOL_SOCKET, SO_KEEPALIVE, &optval,
+ &optlen),
+ Fails(EBADF));
+}
>From 02b9202f1b7d3589e0e4167104f054d93cae3a1c Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavel at labath.sk>
Date: Wed, 15 Apr 2026 13:32:36 +0000
Subject: [PATCH 2/4] add yaml, remove namespaces, add deps
---
libc/include/sys/socket.yaml | 20 +++++++++++++++++++
.../linux/syscall_wrappers/getsockopt.h | 4 ++--
.../linux/syscall_wrappers/setsockopt.h | 4 ++--
libc/src/sys/socket/linux/CMakeLists.txt | 2 ++
4 files changed, 26 insertions(+), 4 deletions(-)
diff --git a/libc/include/sys/socket.yaml b/libc/include/sys/socket.yaml
index bb850de158468..934a5ed400eeb 100644
--- a/libc/include/sys/socket.yaml
+++ b/libc/include/sys/socket.yaml
@@ -39,6 +39,16 @@ functions:
- type: int
- type: const struct sockaddr *
- type: socklen_t
+ - name: getsockopt
+ standards:
+ - POSIX
+ return_type: int
+ arguments:
+ - type: int
+ - type: int
+ - type: int
+ - type: void *__restrict
+ - type: socklen_t *__restrict
- name: listen
standards:
- POSIX
@@ -102,6 +112,16 @@ functions:
- type: int
- type: const struct sockaddr *
- type: socklen_t
+ - name: setsockopt
+ standards:
+ - POSIX
+ return_type: int
+ arguments:
+ - type: int
+ - type: int
+ - type: int
+ - type: const void *
+ - type: socklen_t
- name: socket
standards:
- POSIX
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
index 7fecaab83c7d1..6af11e6b2e7ee 100644
--- a/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
@@ -24,7 +24,7 @@ namespace linux_syscalls {
LIBC_INLINE ErrorOr<int> getsockopt(int sockfd, int level, int optname,
void *optval, socklen_t *optlen) {
#ifdef SYS_getsockopt
- int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_getsockopt, sockfd, level,
+ int ret = syscall_impl<int>(SYS_getsockopt, sockfd, level,
optname, optval, optlen);
#elif defined(SYS_socketcall)
unsigned long sockcall_args[5] = {static_cast<unsigned long>(sockfd),
@@ -32,7 +32,7 @@ LIBC_INLINE ErrorOr<int> getsockopt(int sockfd, int level, int optname,
static_cast<unsigned long>(optname),
reinterpret_cast<unsigned long>(optval),
reinterpret_cast<unsigned long>(optlen)};
- int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_socketcall, SYS_GETSOCKOPT,
+ int ret = syscall_impl<int>(SYS_socketcall, SYS_GETSOCKOPT,
sockcall_args);
#else
#error "getsockopt and socketcall syscalls unavailable for this platform."
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
index 2b24522e77ec5..18b2d47b11246 100644
--- a/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
@@ -24,7 +24,7 @@ namespace linux_syscalls {
LIBC_INLINE ErrorOr<int> setsockopt(int sockfd, int level, int optname,
const void *optval, socklen_t optlen) {
#ifdef SYS_setsockopt
- int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_setsockopt, sockfd, level,
+ int ret = syscall_impl<int>(SYS_setsockopt, sockfd, level,
optname, optval, optlen);
#elif defined(SYS_socketcall)
unsigned long sockcall_args[5] = {static_cast<unsigned long>(sockfd),
@@ -32,7 +32,7 @@ LIBC_INLINE ErrorOr<int> setsockopt(int sockfd, int level, int optname,
static_cast<unsigned long>(optname),
reinterpret_cast<unsigned long>(optval),
static_cast<unsigned long>(optlen)};
- int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_socketcall, SYS_SETSOCKOPT,
+ int ret = syscall_impl<int>(SYS_socketcall, SYS_SETSOCKOPT,
sockcall_args);
#else
#error "setsockopt and socketcall syscalls unavailable for this platform."
diff --git a/libc/src/sys/socket/linux/CMakeLists.txt b/libc/src/sys/socket/linux/CMakeLists.txt
index d76a6b1ad70fd..c63a8e1fafe19 100644
--- a/libc/src/sys/socket/linux/CMakeLists.txt
+++ b/libc/src/sys/socket/linux/CMakeLists.txt
@@ -62,6 +62,7 @@ add_entrypoint_object(
libc.include.sys_socket
libc.src.__support.OSUtil.osutil
libc.hdr.types.socklen_t
+ libc.src.__support.OSUtil.linux.syscall_wrappers.getsockopt
libc.src.errno.errno
)
@@ -129,6 +130,7 @@ add_entrypoint_object(
libc.include.sys_socket
libc.src.__support.OSUtil.osutil
libc.hdr.types.socklen_t
+ libc.src.__support.OSUtil.linux.syscall_wrappers.setsockopt
libc.src.errno.errno
)
>From 1065b07355fe2c07eb356c6790a33bb717a718ba Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavel at labath.sk>
Date: Wed, 15 Apr 2026 13:47:42 +0000
Subject: [PATCH 3/4] format
---
.../__support/OSUtil/linux/syscall_wrappers/getsockopt.h | 7 +++----
.../__support/OSUtil/linux/syscall_wrappers/setsockopt.h | 7 +++----
2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
index 6af11e6b2e7ee..623ba58ebb2ed 100644
--- a/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/getsockopt.h
@@ -24,16 +24,15 @@ namespace linux_syscalls {
LIBC_INLINE ErrorOr<int> getsockopt(int sockfd, int level, int optname,
void *optval, socklen_t *optlen) {
#ifdef SYS_getsockopt
- int ret = syscall_impl<int>(SYS_getsockopt, sockfd, level,
- optname, optval, optlen);
+ int ret =
+ syscall_impl<int>(SYS_getsockopt, sockfd, level, optname, optval, optlen);
#elif defined(SYS_socketcall)
unsigned long sockcall_args[5] = {static_cast<unsigned long>(sockfd),
static_cast<unsigned long>(level),
static_cast<unsigned long>(optname),
reinterpret_cast<unsigned long>(optval),
reinterpret_cast<unsigned long>(optlen)};
- int ret = syscall_impl<int>(SYS_socketcall, SYS_GETSOCKOPT,
- sockcall_args);
+ int ret = syscall_impl<int>(SYS_socketcall, SYS_GETSOCKOPT, sockcall_args);
#else
#error "getsockopt and socketcall syscalls unavailable for this platform."
#endif
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
index 18b2d47b11246..d16c397bba6ac 100644
--- a/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/setsockopt.h
@@ -24,16 +24,15 @@ namespace linux_syscalls {
LIBC_INLINE ErrorOr<int> setsockopt(int sockfd, int level, int optname,
const void *optval, socklen_t optlen) {
#ifdef SYS_setsockopt
- int ret = syscall_impl<int>(SYS_setsockopt, sockfd, level,
- optname, optval, optlen);
+ int ret =
+ syscall_impl<int>(SYS_setsockopt, sockfd, level, optname, optval, optlen);
#elif defined(SYS_socketcall)
unsigned long sockcall_args[5] = {static_cast<unsigned long>(sockfd),
static_cast<unsigned long>(level),
static_cast<unsigned long>(optname),
reinterpret_cast<unsigned long>(optval),
static_cast<unsigned long>(optlen)};
- int ret = syscall_impl<int>(SYS_socketcall, SYS_SETSOCKOPT,
- sockcall_args);
+ int ret = syscall_impl<int>(SYS_socketcall, SYS_SETSOCKOPT, sockcall_args);
#else
#error "setsockopt and socketcall syscalls unavailable for this platform."
#endif
>From e0902337e0a24a9e632c9f74088a3149b93b53fd Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavel at labath.sk>
Date: Thu, 16 Apr 2026 09:59:13 +0000
Subject: [PATCH 4/4] notasock
---
libc/test/src/sys/socket/linux/CMakeLists.txt | 1 +
.../src/sys/socket/linux/socketopt_test.cpp | 18 ++++++++++++++++++
2 files changed, 19 insertions(+)
diff --git a/libc/test/src/sys/socket/linux/CMakeLists.txt b/libc/test/src/sys/socket/linux/CMakeLists.txt
index b4e5d5c462fab..c8a08b0557ce9 100644
--- a/libc/test/src/sys/socket/linux/CMakeLists.txt
+++ b/libc/test/src/sys/socket/linux/CMakeLists.txt
@@ -94,6 +94,7 @@ add_libc_unittest(
libc.src.sys.socket.setsockopt
libc.src.sys.socket.socket
libc.src.unistd.close
+ libc.src.unistd.pipe
libc.test.UnitTest.ErrnoCheckingTest
libc.test.UnitTest.ErrnoSetterMatcher
)
diff --git a/libc/test/src/sys/socket/linux/socketopt_test.cpp b/libc/test/src/sys/socket/linux/socketopt_test.cpp
index 2164c8288e739..c3eac1d1b4ead 100644
--- a/libc/test/src/sys/socket/linux/socketopt_test.cpp
+++ b/libc/test/src/sys/socket/linux/socketopt_test.cpp
@@ -12,6 +12,7 @@
#include "src/sys/socket/socket.h"
#include "src/unistd/close.h"
+#include "src/unistd/pipe.h"
#include "test/UnitTest/ErrnoCheckingTest.h"
#include "test/UnitTest/ErrnoSetterMatcher.h"
@@ -57,6 +58,23 @@ TEST_F(LlvmLibcSocketOptTest, BasicSocketOpt) {
ASSERT_THAT(LIBC_NAMESPACE::close(sock), Succeeds(0));
}
+TEST_F(LlvmLibcSocketOptTest, NotASocket) {
+ int fds[2];
+ ASSERT_THAT(LIBC_NAMESPACE::pipe(fds), Succeeds(0));
+ ASSERT_THAT(LIBC_NAMESPACE::close(fds[1]), Succeeds(0));
+
+ int optval = 1;
+ socklen_t optlen = sizeof(optval);
+ ASSERT_THAT(
+ LIBC_NAMESPACE::setsockopt(fds[0], SOL_SOCKET, SO_KEEPALIVE, &optval, optlen),
+ Fails(ENOTSOCK));
+
+ ASSERT_THAT(LIBC_NAMESPACE::getsockopt(fds[0], SOL_SOCKET, SO_KEEPALIVE, &optval,
+ &optlen),
+ Fails(ENOTSOCK));
+ ASSERT_THAT(LIBC_NAMESPACE::close(fds[0]), Succeeds(0));
+}
+
TEST_F(LlvmLibcSocketOptTest, InvalidSocket) {
int optval = 1;
socklen_t optlen = sizeof(optval);
More information about the libc-commits
mailing list