refactor: split platform.

crates/wasi/src/nat/linux.rs

@@ -0,0 +1,184 @@
+#![allow(non_snake_case)]
+#![allow(non_camel_case_types)]
+use std::{ffi::c_char, mem::MaybeUninit};
+use std::{
+    fs, io::Write, process::{Command, Stdio}
+};
+use std::mem;
+
+use super::NatError;
+
+
+const ETHTOOL_FWVERS_LEN: usize = 32; 
+const ETHTOOL_BUSINFO_LEN: usize = 32; 
+const ETHTOOL_EROMVERS_LEN: usize = 32; 
+const SIOCETHTOOL: usize = 0x8946;
+const ETHTOOL_GDRVINFO: usize = 0x00000003;
+const ETH_GSTRING_LEN: usize = 32;
+const ETHTOOL_GSTRINGS: usize = 32;
+const ETH_SS_STATS: usize = 32;
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+struct ethtool_gstrings {
+    cmd: u32,
+    string_set: u32,
+    len: u32,
+}
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+struct ethtool_drvinfo {
+    cmd: u32,
+    driver: [c_char; 32],
+    version: [c_char; 32],
+    fw_version: [c_char; ETHTOOL_FWVERS_LEN],
+    bus_info: [c_char; ETHTOOL_BUSINFO_LEN],
+    erom_version: [c_char; ETHTOOL_EROMVERS_LEN],
+    reserved2: [c_char; 12],
+    n_priv_flags: u32,
+    n_stats: u32,
+    testinfo_len: u32,
+    eedump_len: u32,
+    regdump_len: u32,
+}
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct ifreq {
+    pub ifr_ifrn: ifreq_ifrn,
+    pub ifr_ifru: ifreq_ifru,
+}
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub union ifreq_ifrn {
+    pub ifrn_name: [i8; 16usize],
+    align: [u8; 16usize],
+}
+
+type sockaddr = libc::sockaddr;
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub union ifreq_ifru {
+    pub ifru_addr: sockaddr,
+    pub ifru_dstaddr: sockaddr,
+    pub ifru_broadaddr: sockaddr,
+    pub ifru_netmask: sockaddr,
+    pub ifru_hwaddr: sockaddr,
+    pub ifru_flags: ::std::os::raw::c_short,
+    pub ifru_uflags: ::std::os::raw::c_ushort,
+    pub ifru_ivalue: ::std::os::raw::c_int,
+    pub ifru_mtu: ::std::os::raw::c_int,
+    pub ifru_bool: ::std::os::raw::c_uchar,
+    pub ifru_map: ifmap,
+    pub ifru_slave: [::std::os::raw::c_char; 16usize],
+    pub ifru_newname: [::std::os::raw::c_char; 16usize],
+    pub ifru_data: *mut ::std::os::raw::c_char,
+    align: [u64; 3usize],
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct ifmap {
+    pub mem_start: ::std::os::raw::c_ulong,
+    pub mem_end: ::std::os::raw::c_ulong,
+    pub base_addr: ::std::os::raw::c_ushort,
+    pub irq: ::std::os::raw::c_uchar,
+    pub dma: ::std::os::raw::c_uchar,
+    pub port: ::std::os::raw::c_uchar,
+}
+
+pub(crate)fn forward(enable: bool) -> Result<(), NatError> {
+    let mut ip_fwf = io_wrap!(fs::OpenOptions::new()
+        .write(true)
+        .open("/proc/sys/net/ipv4/ip_forward"));
+    let enable = if enable { b"1" } else { b"0" };
+    io_wrap!(ip_fwf.write(enable));
+    Ok(())
+}
+
+fn eth_info(devn: &str) -> Result<(), NatError> {
+    let sock: i32 = syscall!(libc::socket(libc::AF_INET, libc::SOCK_DGRAM, 0)) as _;
+    let mut ifreq = MaybeUninit::<ifreq>::zeroed();
+    let mut drv_info = MaybeUninit::<ethtool_drvinfo>::zeroed();
+    unsafe {
+        drv_info.assume_init_mut().cmd = ETHTOOL_GDRVINFO as _;
+        let req = ifreq.assume_init_mut();
+        req.ifr_ifru.ifru_data = drv_info.as_mut_ptr() as _;
+        req.ifr_ifrn.ifrn_name.as_mut_ptr().copy_from(devn.as_ptr() as _, devn.len());
+    }
+    syscall!(libc::ioctl(sock, SIOCETHTOOL as _, ifreq.as_mut_ptr()));
+    let n_stats = unsafe {
+         drv_info.assume_init_ref().n_stats
+    };
+    if n_stats <= 0 {
+        return Err(NatError::NoStatError)
+    }
+    let size: usize = mem::size_of::<ethtool_gstrings>() + n_stats as usize* ETH_GSTRING_LEN;
+    let mut gstrings_data = vec![0u8; size] ;
+
+    unsafe {
+        let gstr = &mut *(gstrings_data.as_mut_ptr() as *mut ethtool_gstrings);
+        gstr.cmd = ETHTOOL_GSTRINGS as _;
+        gstr.string_set = ETH_SS_STATS as _;
+        gstr.len = n_stats as _;
+        let ifreq = ifreq.assume_init_mut();
+        ifreq.ifr_ifru.ifru_data = gstrings_data.as_mut_ptr() as _;
+    }
+    syscall!(libc::ioctl(sock, SIOCETHTOOL as _, ifreq.as_mut_ptr()));
+    let data = gstrings_data.as_ptr();
+    Ok(())
+}
+
+pub(crate)fn iptable() -> Result<(), NatError> {
+    let active_if = find_active_eth()?;
+    let mut command = Command::new("iptables");
+    command.args(&["-t", "nat", "-A", "POSTROUTING", "-j", "MASQUERADE", "-o", &active_if]);
+    command.stdout(Stdio::piped());
+    command.stderr(Stdio::piped());
+    let child = io_wrap!(command.spawn());
+    let output = io_wrap!(child.wait_with_output());
+    if output.status.success() {
+        Ok(())
+    } else {
+        Err(NatError::CommandError)
+    }
+}
+
+fn find_active_eth() -> Result<String, NatError> {
+    let net_path = std::path::Path::new("/sys/class/net");
+    let read_dir = io_wrap!(fs::read_dir(&net_path));
+    for entry in read_dir {
+        let entry = io_wrap!(entry);
+        let path = entry.path();
+        if path.is_symlink() {
+            let path = io_wrap!(fs::read_link(&path));
+            let path_str = path.to_str();
+            if let Some(s) = path_str {
+                if s.contains("virtual") {
+                    continue;
+                }
+                let split = s.split("/");
+                if let Some(s) = split.last() {
+                    return Ok(s.into());
+                }
+            }
+        }
+    }
+    Err(NatError::NoInterfaceFound)
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_eth_info() {
+        if let Ok(s) = find_active_eth() {
+            let rs = eth_info(&s);
+            assert!(rs.is_ok());
+        }
+    }
+}

crates/wasi/src/nat/macos.rs

@@ -0,0 +1,46 @@
+use std::{
+    fs::OpenOptions, io::Write, process::{Command, Stdio}
+};
+
+fn sysctl(enable: bool) -> Result<(), NatError> {
+    let mut command = Command::new("sysctl");
+    let enable = if enable { 1 } else { 0 };
+    command.args(&["-w", &format!("net.inet.ip.forwarding={enable}")]);
+    command.stdout(Stdio::piped());
+    command.stderr(Stdio::piped());
+    let mut child = io_wrap!(command.spawn());
+    let exit_code = io_wrap!(child.wait());
+    if exit_code.success() {
+        Ok(())
+    } else {
+        Err(NatError::CommandError)
+    }
+}
+
+fn pfctl() -> Result<(), NatError> {
+    let mut command = Command::new("pfctl");
+    let child = io_wrap!(command.args(&["-f", "/etc/pf.anchors/bls-vm-nat", "-e" ])
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn());
+    let output = io_wrap!(child.wait_with_output());
+    if output.status.success() {
+        return Ok(());
+    } else {
+        let out_string = String::from_utf8(output.stderr).map_err(|_| NatError::Utf8CodeError)?;
+        if let Some(_) = out_string.find("pf already enabled") {
+            return Ok(());
+        }
+    }
+    Err(NatError::CommandError)
+}
+
+/// write the archors file
+fn write_anchors(name: &str) {
+    let mut pfctl = OpenOptions::new()
+        .write(true)
+        .create(true)
+        .open("/etc/pf.anchors/bls-vm-nat")?;
+    let cmd = format!("nat on en0 from {name}:network to any -> (en0)\n");
+    pfctl.write_all(cmd.as_bytes())?;
+}

crates/wasi/src/nat/macros.rs

@@ -0,0 +1,19 @@
+
+macro_rules! io_wrap {
+    ($io_op:expr) => {
+        $io_op.map_err(|e| NatError::IoError(e))?
+    };
+}
+
+#[cfg(any(target_os="linux", target_os="macos"))]
+macro_rules! syscall {
+    ($ep: expr) => {
+        unsafe {
+            let n = $ep as i64;
+            if n < 0 {
+                return Err(NatError::IoError(std::io::Error::last_os_error()));
+            }
+            n
+        }    
+    };
+}