syscall::net: add listen syscall

Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>

Author: Andy-Python-Programmer

patches/mlibc/mlibc.patch

@@ -1,4 +1,4 @@
-From f76727cfa3db5f15b030a3cdc4535ea1eea31ac4 Mon Sep 17 00:00:00 2001
+From 5d484b1a17191d7ce795a2d773e4a72d8fc7490e Mon Sep 17 00:00:00 2001
 From: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
 Date: Thu, 10 Feb 2022 19:12:25 +1100
 Subject: [PATCH] yes
@@ -10,9 +10,9 @@ Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
  sysdeps/aero/generic/aero.cpp       | 12 ++++-
  sysdeps/aero/generic/filesystem.cpp | 79 ++++++++++++++++++++++++++---
  sysdeps/aero/generic/signals.cpp    |  8 ++-
- sysdeps/aero/generic/sockets.cpp    | 38 ++++++++++++++
+ sysdeps/aero/generic/sockets.cpp    | 48 ++++++++++++++++++
  sysdeps/aero/include/aero/syscall.h | 12 +++++
- 7 files changed, 141 insertions(+), 13 deletions(-)
+ 7 files changed, 151 insertions(+), 13 deletions(-)
 
 diff --git a/.gitignore b/.gitignore
 index dbb35e8b..20c8d4c3 100644
@@ -210,10 +210,10 @@ index 3527370c..a6f69fff 100644
  } // namespace mlibc
 \ No newline at end of file
 diff --git a/sysdeps/aero/generic/sockets.cpp b/sysdeps/aero/generic/sockets.cpp
-index e69de29b..c1375859 100644
+index e69de29b..4e6bd608 100644
 --- a/sysdeps/aero/generic/sockets.cpp
 +++ b/sysdeps/aero/generic/sockets.cpp
-@@ -0,0 +1,38 @@
+@@ -0,0 +1,48 @@
 +#include <mlibc/all-sysdeps.hpp>
 +#include <mlibc/thread-entry.hpp>
 +
@@ -251,6 +251,16 @@ index e69de29b..c1375859 100644
 +
 +    return 0;
 +}
++
++int sys_listen(int fd, int backlog) {
++    auto result = syscall(SYS_LISTEN, fd, backlog);
++
++    if (result < 0) {
++        return -result;
++    }
++
++    return 0;
++}
 +} // namespace mlibc
 diff --git a/sysdeps/aero/include/aero/syscall.h b/sysdeps/aero/include/aero/syscall.h
 index 07b1b51b..ef797e40 100644

src/aero_kernel/src/fs/inode.rs

@@ -145,14 +145,18 @@ pub trait INodeInterface: Send + Sync + Downcastable {
         Err(FileSystemError::NotSupported)
     }
 
-    // Socket operations
+    // Socket operations:
     fn bind(&self, _address: SocketAddr, _length: usize) -> Result<()> {
         Err(FileSystemError::NotSocket)
     }
 
     fn connect(&self, _address: SocketAddr, _length: usize) -> Result<()> {
         Err(FileSystemError::NotSocket)
     }
+
+    fn listen(&self, _backlog: usize) -> Result<()> {
+        Err(FileSystemError::NotSocket)
+    }
 }
 
 /// Structure representing the curcial, characteristics of an inode. The metadata

src/aero_kernel/src/socket/unix.rs

@@ -89,6 +89,12 @@ impl INodeInterface for UnixSocket {
     }
 
     fn connect(&self, _address: SocketAddr, _length: usize) -> Result<()> {
-        todo!("{_address:?}")
+        log::error!("UnixSocket::connect() is not implemented");
+        Ok(())
+    }
+
+    fn listen(&self, _backlog: usize) -> Result<()> {
+        log::error!("UnixSocket::listen() not implemented");
+        Ok(())
     }
 }

src/aero_kernel/src/syscall/mod.rs

@@ -211,6 +211,7 @@ pub fn generic_do_syscall(
         SYS_SOCKET => net::socket(b, c, d),
         SYS_BIND => net::bind(b, c, d),
         SYS_CONNECT => net::connect(b, c, d),
+        SYS_LISTEN => net::listen(b, c),
 
         SYS_GETTIME => time::gettime(b, c),
         SYS_SLEEP => time::sleep(b),

src/aero_kernel/src/syscall/net.rs

@@ -19,7 +19,7 @@ fn socket_addr_from_addr<'sys>(address: VirtAddr) -> Result<SocketAddr<'sys>, Ae
     Ok(SocketAddr::from_family(address, family).ok_or(AeroSyscallError::EINVAL)?)
 }
 
-/// Connects the socket referred to by the file descriptor, to the specified address.
+/// Connects the socket to the specified address.
 #[aero_proc::syscall]
 pub fn connect(fd: usize, address: usize, length: usize) -> Result<usize, AeroSyscallError> {
     let address = socket_addr_from_addr(VirtAddr::new(address as u64))?;
@@ -33,6 +33,20 @@ pub fn connect(fd: usize, address: usize, length: usize) -> Result<usize, AeroSy
     Ok(0)
 }
 
+/// Marks the socket as a passive socket (i.e. as a socket that will be used to accept incoming
+/// connection requests).
+#[aero_proc::syscall]
+pub fn listen(fd: usize, backlog: usize) -> Result<usize, AeroSyscallError> {
+    let file = scheduler::get_scheduler()
+        .current_task()
+        .file_table
+        .get_handle(fd)
+        .ok_or(AeroSyscallError::EINVAL)?;
+
+    file.inode().listen(backlog)?;
+    Ok(0)
+}
+
 #[aero_proc::syscall]
 pub fn socket(
     domain: usize,