Net: Add a basic sys$shutdown() implementation

Calling shutdown prevents further reads and/or writes on a socket.
We should do a few more things based on the type of socket, but this
initial implementation just puts the basic mechanism in place.

Work towards #428.

1 files changed, 13 insertions, 0 deletions

diff --git a/Kernel/Net/Socket.cpp b/Kernel/Net/Socket.cpp
index 48acfe334a..6e66db59c7 100644
--- a/Kernel/Net/Socket.cpp
+++ b/Kernel/Net/Socket.cpp
@@ -149,10 +149,23 @@ KResult Socket::getsockopt(FileDescription&, int level, int option, void* value,
 
 ssize_t Socket::read(FileDescription& description, u8* buffer, ssize_t size)
 {
+    if (is_shut_down_for_reading())
+        return 0;
     return recvfrom(description, buffer, size, 0, nullptr, 0);
 }
 
 ssize_t Socket::write(FileDescription& description, const u8* data, ssize_t size)
 {
+    if (is_shut_down_for_writing())
+        return -EPIPE;
     return sendto(description, data, size, 0, nullptr, 0);
 }
+
+KResult Socket::shutdown(int how)
+{
+    if (type() == SOCK_STREAM && !is_connected())
+        return KResult(-ENOTCONN);
+    m_shut_down_for_reading |= how & SHUT_RD;
+    m_shut_down_for_writing |= how & SHUT_WR;
+    return KSuccess;
+}