inet::{new, bind, connect, send}: implement

* implement inet::{new, bind, connect, send}
* remove the in-kernel dhcp client
* remove the dependency of libc in userland applications (ones inside
  `userland/`)
* init: launch the DHCP client (`dhcpd`)

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

Author: Andy-Python-Programmer

bootstrap.yml

@@ -1,5 +1,6 @@
 imports:
   - file: bootstrap/xorg.yml
+  - file: bootstrap/net.yml
 
 general:
   cargo:

bootstrap/net.yml

@@ -0,0 +1,29 @@
+packages:
+  - name: dhcpd
+    source:
+      subdir: 'bundled'
+      git: 'https://github.com/Andy-Python-Programmer/dhcpd'
+      branch: 'main'
+    tools_required:
+      - host-rust
+      - host-gcc
+    sources_required:
+      - rust-patched-libs
+    pkgs_required:
+      - mlibc
+    configure:
+      - args: ['python3', '@SOURCE_ROOT@/tools/cargo-inject-patches.py', '@THIS_SOURCE_DIR@/Cargo.toml']
+    build:
+      - args:
+        - 'cargo'
+        - 'install'
+        - '--locked'
+        - '--target-dir'
+        - '@THIS_BUILD_DIR@'
+        - '--path'
+        - '@THIS_SOURCE_DIR@'
+        - '--root'
+        - '@THIS_COLLECT_DIR@/usr'
+        - '-j@PARALLELISM@'
+        environ:
+          RUSTFLAGS: '-Cforce-frame-pointers=yes -Clink-args=-no-pie'

patches/mlibc/mlibc.patch

@@ -1,6 +1,6 @@
-From f4c7bb3f8556d4f50fe132109de2dfedfccac293 Mon Sep 17 00:00:00 2001
+From a5ec321f99ccfe66889e802626230a792a3d7140 Mon Sep 17 00:00:00 2001
 From: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
-Date: Mon, 20 Feb 2023 18:40:41 +1100
+Date: Sun, 26 Feb 2023 17:20:53 +1100
 Subject: [PATCH] <xxx>
 
 ---
@@ -12,11 +12,11 @@ Subject: [PATCH] <xxx>
  options/rtdl/generic/linker.cpp       |   2 +-
  sysdeps/aero/generic/aero.cpp         |  77 +++++++----
  sysdeps/aero/generic/filesystem.cpp   |  51 ++++++-
- sysdeps/aero/generic/sockets.cpp      |  87 +++++++++++-
+ sysdeps/aero/generic/sockets.cpp      |  96 ++++++++++++-
  sysdeps/aero/generic/time.cpp         |  24 ++++
- sysdeps/aero/include/aero/syscall.h   |  10 ++
+ sysdeps/aero/include/aero/syscall.h   |  11 ++
  sysdeps/aero/meson.build              |   1 +
- 12 files changed, 402 insertions(+), 47 deletions(-)
+ 12 files changed, 412 insertions(+), 47 deletions(-)
  create mode 100644 sysdeps/aero/generic/time.cpp
 
 diff --git a/.gitignore b/.gitignore
@@ -524,17 +524,18 @@ index a3e2aca..8a1e086 100644
 +#endif
  } // namespace mlibc
 diff --git a/sysdeps/aero/generic/sockets.cpp b/sysdeps/aero/generic/sockets.cpp
-index b6b18fe..b4635df 100644
+index b6b18fe..0ee0838 100644
 --- a/sysdeps/aero/generic/sockets.cpp
 +++ b/sysdeps/aero/generic/sockets.cpp
-@@ -1,5 +1,6 @@
+@@ -1,5 +1,7 @@
  #include <mlibc/all-sysdeps.hpp>
  #include <mlibc/thread-entry.hpp>
 +#include <mlibc/debug.hpp>
++#include<abi-bits/in.h>
 
  #include <aero/syscall.h>
  #include <stdint.h>
-@@ -46,8 +47,8 @@ int sys_listen(int fd, int backlog) {
+@@ -46,8 +48,8 @@ int sys_listen(int fd, int backlog) {
      return 0;
  }
 
@@ -545,11 +546,19 @@ index b6b18fe..b4635df 100644
 
      if (result < 0) {
          return -result;
-@@ -56,4 +57,86 @@ int sys_accept(int fd, int *newfd) {
+@@ -56,4 +58,94 @@ int sys_accept(int fd, int *newfd) {
      *newfd = result;
      return 0;
  }
 +
++int sys_msg_send(int fd, const struct msghdr *hdr, int flags, ssize_t *length) {
++	auto result = syscall(SYS_SOCK_SEND, fd, hdr, flags);
++	if (result < 0)
++		return -result;
++
++	*length = result;
++	return 0;
++}
 +
 +int sys_msg_recv(int sockfd, struct msghdr *msg_hdr, int flags, ssize_t *length) {
 +	auto result = syscall(SYS_SOCK_RECV, sockfd, msg_hdr, flags);
@@ -664,10 +673,10 @@ index 0000000..460412d
 +}
 \ No newline at end of file
 diff --git a/sysdeps/aero/include/aero/syscall.h b/sysdeps/aero/include/aero/syscall.h
-index 12f8dc6..78fc99d 100644
+index 12f8dc6..432bad2 100644
 --- a/sysdeps/aero/include/aero/syscall.h
 +++ b/sysdeps/aero/include/aero/syscall.h
-@@ -64,6 +64,16 @@
+@@ -64,6 +64,17 @@
  #define SYS_FUTEX_WAIT 57
  #define SYS_FUTEX_WAKE 58
  #define SYS_LINK 59
@@ -681,6 +690,7 @@ index 12f8dc6..78fc99d 100644
 +#define SYS_SOCKET_PAIR 67
 +#define SYS_RENAME 68
 +#define SYS_MPROTECT 69
++#define SYS_SOCK_SEND 70
 
  // Invalid syscall used to trigger a log error in the kernel (as a hint)
  // so, that we can implement the syscall in the kernel.

src/Cargo.lock

@@ -42,10 +42,22 @@ static_assertions = "1.1.0"
 lru = "0.8.0"
 bytemuck = "1.12.1"
 # the crate is not mainted but who cares it works (tm)!
-simple_endian = { git = "https://github.com/michalfita/simple-endian-rs", branch = "bugfix/4/fix-no_std-support-right-way", default_features = false, features = ["bitwise", "comparisons", "format", "math_ops", "neg_ops", "shift_ops", "both_endian", "float_impls", "integer_impls", "byte_impls"] }
-byteorder = { version = "*", default-features=false}
+simple_endian = { git = "https://github.com/michalfita/simple-endian-rs", branch = "bugfix/4/fix-no_std-support-right-way", default_features = false, features = [
+    "bitwise",
+    "comparisons",
+    "format",
+    "math_ops",
+    "neg_ops",
+    "shift_ops",
+    "both_endian",
+    "float_impls",
+    "integer_impls",
+    "byte_impls",
+] }
+byteorder = { version = "*", default-features = false }
 limine = { git = "https://github.com/limine-bootloader/limine-rs" }
 cfg-if = "1.0"
+num-traits = { version = "0.2", default-features = false }
 
 # X86_64 specific dependencies:
 [target.'cfg(target_arch = "x86_64")'.dependencies]

src/aero_kernel/Cargo.toml

@@ -549,6 +549,14 @@ impl INodeInterface for INode {
         return Err(FileSystemError::NotSupported);
     }
 
+    fn send(&self, message_header: &mut MessageHeader) -> super::Result<usize> {
+        if let Some(proxy) = self.proxy.as_ref() {
+            return proxy.send(message_header);
+        }
+
+        return Err(FileSystemError::NotSupported);
+    }
+
     fn recv(&self, message_header: &mut MessageHeader, non_block: bool) -> super::Result<usize> {
         if let Some(proxy) = self.proxy.as_ref() {
             return proxy.recv(message_header, non_block);

src/aero_kernel/src/fs/ext2/mod.rs

@@ -244,6 +244,10 @@ pub trait INodeInterface: Send + Sync {
         Err(FileSystemError::NotSocket)
     }
 
+    fn send(&self, _message_hdr: &mut MessageHeader) -> Result<usize> {
+        Err(FileSystemError::NotSupported)
+    }
+
     fn recv(&self, _message_header: &mut MessageHeader, _non_block: bool) -> Result<usize> {
         Err(FileSystemError::NotSocket)
     }

src/aero_kernel/src/fs/inode.rs

@@ -0,0 +1,76 @@
+use simple_endian::BigEndian;
+
+use super::ip::{self, Ipv4Addr};
+
+#[repr(C, packed)]
+pub struct PseudoHeader {
+    src_ip: Ipv4Addr,
+    dst_ip: Ipv4Addr,
+    reserved: u8,
+    ty: ip::Type,
+    size: BigEndian<u16>,
+}
+
+impl PseudoHeader {
+    pub fn new(ip_hdr: &ip::Header) -> PseudoHeader {
+        let len = ip_hdr.length;
+        PseudoHeader {
+            src_ip: ip_hdr.src_ip,
+            dst_ip: ip_hdr.dest_ip,
+            reserved: 0,
+            ty: ip_hdr.protocol,
+            size: BigEndian::from(len.to_native() - core::mem::size_of::<ip::Header>() as u16),
+        }
+    }
+}
+
+/// Compute the 32-bit internet checksum for `data`.
+fn calculate_checksum(data: &[u8]) -> u32 {
+    let bytes = unsafe {
+        core::slice::from_raw_parts(
+            data.as_ptr() as *const BigEndian<u16>,
+            data.len() / core::mem::size_of::<u16>(),
+        )
+    };
+
+    let mut sum = 0;
+
+    for i in 0..(data.len() / 2) {
+        sum += bytes[i].to_native() as u32
+    }
+
+    // Add left-over byte, if any.
+    if data.len() % 2 == 1 {
+        sum += ((*data.last().unwrap()) as u32) << 8;
+    }
+
+    sum
+}
+
+/// Folds the 32-bit sum (`sum`) to 16 bits in the network byte order.
+pub fn make(mut sum: u32) -> BigEndian<u16> {
+    while (sum >> 16) != 0 {
+        sum = (sum & 0xffff) + (sum >> 16);
+    }
+
+    BigEndian::from(!(sum as u16))
+}
+
+/// Combine several RFC 1071 compliant checksums.
+pub fn make_combine(a: &[u32]) -> BigEndian<u16> {
+    make(a.iter().sum())
+}
+
+/// Compute the internet checksum for `value`.
+pub fn calculate<T: Sized>(value: &T) -> u32 {
+    let bytes = unsafe {
+        core::slice::from_raw_parts(value as *const _ as *const u8, core::mem::size_of::<T>())
+    };
+    calculate_checksum(bytes)
+}
+
+/// Compute the internet checksum for `value` of `size`.
+pub fn calculate_with_len<T: ?Sized>(value: &T, size: usize) -> u32 {
+    let bytes = unsafe { core::slice::from_raw_parts(value as *const _ as *const u8, size) };
+    calculate_checksum(bytes)
+}