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// SPDX-License-Identifier: (Apache-2.0 OR MIT)
// Derived from uBPF <https://github.com/iovisor/ubpf>
// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
// Copyright 2023 Isovalent, Inc. <quentin@isovalent.com>
//! Virtual machine and JIT compiler for eBPF programs.
#![doc(html_logo_url = "https://raw.githubusercontent.com/qmonnet/rbpf/main/misc/rbpf.png",
html_favicon_url = "https://raw.githubusercontent.com/qmonnet/rbpf/main/misc/rbpf.ico")]
// Test examples from README.md as part as doc tests.
#![doc = include_str!("../README.md")]
#![warn(missing_docs)]
// There are unused mut warnings due to unsafe code.
#![allow(unused_mut)]
// Allows old-style clippy
#![allow(renamed_and_removed_lints)]
#![cfg_attr(feature = "cargo-clippy", allow(redundant_field_names, single_match, cast_lossless, doc_markdown, match_same_arms, unreadable_literal))]
extern crate byteorder;
extern crate combine;
extern crate time;
use std::u32;
use std::collections::HashMap;
use std::io::{Error, ErrorKind};
use byteorder::{ByteOrder, LittleEndian};
pub mod assembler;
pub mod disassembler;
pub mod ebpf;
pub mod helpers;
pub mod insn_builder;
mod asm_parser;
mod interpreter;
#[cfg(not(windows))]
mod jit;
mod verifier;
/// eBPF verification function that returns an error if the program does not meet its requirements.
///
/// Some examples of things the verifier may reject the program for:
///
/// - Program does not terminate.
/// - Unknown instructions.
/// - Bad formed instruction.
/// - Unknown eBPF helper index.
pub type Verifier = fn (prog: &[u8]) -> Result<(), Error>;
/// eBPF helper function.
pub type Helper = fn (u64, u64, u64, u64, u64) -> u64;
// A metadata buffer with two offset indications. It can be used in one kind of eBPF VM to simulate
// the use of a metadata buffer each time the program is executed, without the user having to
// actually handle it. The offsets are used to tell the VM where in the buffer the pointers to
// packet data start and end should be stored each time the program is run on a new packet.
struct MetaBuff {
data_offset: usize,
data_end_offset: usize,
buffer: Vec<u8>,
}
/// A virtual machine to run eBPF program. This kind of VM is used for programs expecting to work
/// on a metadata buffer containing pointers to packet data.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, // Load mem from mbuff at offset 8 into R1.
/// 0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // ldhx r1[2], r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
/// ];
///
/// // Just for the example we create our metadata buffer from scratch, and we store the pointers
/// // to packet data start and end in it.
/// let mut mbuff = [0u8; 32];
/// unsafe {
/// let mut data = mbuff.as_ptr().offset(8) as *mut u64;
/// let mut data_end = mbuff.as_ptr().offset(24) as *mut u64;
/// *data = mem.as_ptr() as u64;
/// *data_end = mem.as_ptr() as u64 + mem.len() as u64;
/// }
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
///
/// // Provide both a reference to the packet data, and to the metadata buffer.
/// let res = vm.execute_program(mem, &mut mbuff).unwrap();
/// assert_eq!(res, 0x2211);
/// ```
pub struct EbpfVmMbuff<'a> {
prog: Option<&'a [u8]>,
verifier: Verifier,
#[cfg(not(windows))]
jit: Option<jit::JitMemory<'a>>,
helpers: HashMap<u32, ebpf::Helper>,
}
impl<'a> EbpfVmMbuff<'a> {
/// Create a new virtual machine instance, and load an eBPF program into that instance.
/// When attempting to load the program, it passes through a simple verifier.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, // Load mem from mbuff into R1.
/// 0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // ldhx r1[2], r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
/// ```
pub fn new(prog: Option<&'a [u8]>) -> Result<EbpfVmMbuff<'a>, Error> {
if let Some(prog) = prog {
verifier::check(prog)?;
}
Ok(EbpfVmMbuff {
prog,
verifier: verifier::check,
#[cfg(not(windows))]
jit: None,
helpers: HashMap::new(),
})
}
/// Load a new eBPF program into the virtual machine instance.
///
/// # Examples
///
/// ```
/// let prog1 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let prog2 = &[
/// 0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, // Load mem from mbuff into R1.
/// 0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // ldhx r1[2], r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog1)).unwrap();
/// vm.set_program(prog2).unwrap();
/// ```
pub fn set_program(&mut self, prog: &'a [u8]) -> Result<(), Error> {
(self.verifier)(prog)?;
self.prog = Some(prog);
Ok(())
}
/// Set a new verifier function. The function should return an `Error` if the program should be
/// rejected by the virtual machine. If a program has been loaded to the VM already, the
/// verifier is immediately run.
///
/// # Examples
///
/// ```
/// use std::io::{Error, ErrorKind};
/// use rbpf::ebpf;
///
/// // Define a simple verifier function.
/// fn verifier(prog: &[u8]) -> Result<(), Error> {
/// let last_insn = ebpf::get_insn(prog, (prog.len() / ebpf::INSN_SIZE) - 1);
/// if last_insn.opc != ebpf::EXIT {
/// return Err(Error::new(ErrorKind::Other,
/// "[Verifier] Error: program does not end with “EXIT” instruction"));
/// }
/// Ok(())
/// }
///
/// let prog1 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog1)).unwrap();
/// // Change the verifier.
/// vm.set_verifier(verifier).unwrap();
/// ```
pub fn set_verifier(&mut self, verifier: Verifier) -> Result<(), Error> {
if let Some(prog) = self.prog {
verifier(prog)?;
}
self.verifier = verifier;
Ok(())
}
/// Register a built-in or user-defined helper function in order to use it later from within
/// the eBPF program. The helper is registered into a hashmap, so the `key` can be any `u32`.
///
/// If using JIT-compiled eBPF programs, be sure to register all helpers before compiling the
/// program. You should be able to change registered helpers after compiling, but not to add
/// new ones (i.e. with new keys).
///
/// # Examples
///
/// ```
/// use rbpf::helpers;
///
/// // This program was compiled with clang, from a C program containing the following single
/// // instruction: `return bpf_trace_printk("foo %c %c %c\n", 10, 1, 2, 3);`
/// let prog = &[
/// 0x18, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // load 0 as u64 into r1 (That would be
/// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // replaced by tc by the address of
/// // the format string, in the .map
/// // section of the ELF file).
/// 0xb7, 0x02, 0x00, 0x00, 0x0a, 0x00, 0x00, 0x00, // mov r2, 10
/// 0xb7, 0x03, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // mov r3, 1
/// 0xb7, 0x04, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, // mov r4, 2
/// 0xb7, 0x05, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, // mov r5, 3
/// 0x85, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, // call helper with key 6
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
///
/// // Register a helper.
/// // On running the program this helper will print the content of registers r3, r4 and r5 to
/// // standard output.
/// vm.register_helper(6, helpers::bpf_trace_printf).unwrap();
/// ```
pub fn register_helper(&mut self, key: u32, function: Helper) -> Result<(), Error> {
self.helpers.insert(key, function);
Ok(())
}
/// Execute the program loaded, with the given packet data and metadata buffer.
///
/// If the program is made to be compatible with Linux kernel, it is expected to load the
/// address of the beginning and of the end of the memory area used for packet data from the
/// metadata buffer, at some appointed offsets. It is up to the user to ensure that these
/// pointers are correctly stored in the buffer.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, // Load mem from mbuff into R1.
/// 0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // ldhx r1[2], r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
/// ];
///
/// // Just for the example we create our metadata buffer from scratch, and we store the
/// // pointers to packet data start and end in it.
/// let mut mbuff = [0u8; 32];
/// unsafe {
/// let mut data = mbuff.as_ptr().offset(8) as *mut u64;
/// let mut data_end = mbuff.as_ptr().offset(24) as *mut u64;
/// *data = mem.as_ptr() as u64;
/// *data_end = mem.as_ptr() as u64 + mem.len() as u64;
/// }
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
///
/// // Provide both a reference to the packet data, and to the metadata buffer.
/// let res = vm.execute_program(mem, &mut mbuff).unwrap();
/// assert_eq!(res, 0x2211);
/// ```
pub fn execute_program(&self, mem: &[u8], mbuff: &[u8]) -> Result<u64, Error> {
interpreter::execute_program(self.prog, mem, mbuff, &self.helpers)
}
/// JIT-compile the loaded program. No argument required for this.
///
/// If using helper functions, be sure to register them into the VM before calling this
/// function.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, // Load mem from mbuff into R1.
/// 0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // ldhx r1[2], r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
///
/// vm.jit_compile();
/// ```
#[cfg(not(windows))]
pub fn jit_compile(&mut self) -> Result<(), Error> {
let prog = match self.prog {
Some(prog) => prog,
None => Err(Error::new(ErrorKind::Other, "Error: No program set, call prog_set() to load one"))?,
};
self.jit = Some(jit::JitMemory::new(prog, &self.helpers, true, false)?);
Ok(())
}
/// Execute the previously JIT-compiled program, with the given packet data and metadata
/// buffer, in a manner very similar to `execute_program()`.
///
/// If the program is made to be compatible with Linux kernel, it is expected to load the
/// address of the beginning and of the end of the memory area used for packet data from the
/// metadata buffer, at some appointed offsets. It is up to the user to ensure that these
/// pointers are correctly stored in the buffer.
///
/// # Safety
///
/// **WARNING:** JIT-compiled assembly code is not safe, in particular there is no runtime
/// check for memory access; so if the eBPF program attempts erroneous accesses, this may end
/// very bad (program may segfault). It may be wise to check that the program works with the
/// interpreter before running the JIT-compiled version of it.
///
/// For this reason the function should be called from within an `unsafe` bloc.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, // Load mem from mbuff into r1.
/// 0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // ldhx r1[2], r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
/// ];
///
/// // Just for the example we create our metadata buffer from scratch, and we store the
/// // pointers to packet data start and end in it.
/// let mut mbuff = [0u8; 32];
/// unsafe {
/// let mut data = mbuff.as_ptr().offset(8) as *mut u64;
/// let mut data_end = mbuff.as_ptr().offset(24) as *mut u64;
/// *data = mem.as_ptr() as u64;
/// *data_end = mem.as_ptr() as u64 + mem.len() as u64;
/// }
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
///
/// # #[cfg(not(windows))]
/// vm.jit_compile();
///
/// // Provide both a reference to the packet data, and to the metadata buffer.
/// # #[cfg(not(windows))]
/// unsafe {
/// let res = vm.execute_program_jit(mem, &mut mbuff).unwrap();
/// assert_eq!(res, 0x2211);
/// }
/// ```
#[cfg(not(windows))]
pub unsafe fn execute_program_jit(&self, mem: &mut [u8], mbuff: &'a mut [u8]) -> Result<u64, Error> {
// If packet data is empty, do not send the address of an empty slice; send a null pointer
// as first argument instead, as this is uBPF's behavior (empty packet should not happen
// in the kernel; anyway the verifier would prevent the use of uninitialized registers).
// See `mul_loop` test.
let mem_ptr = match mem.len() {
0 => std::ptr::null_mut(),
_ => mem.as_ptr() as *mut u8
};
// The last two arguments are not used in this function. They would be used if there was a
// need to indicate to the JIT at which offset in the mbuff mem_ptr and mem_ptr + mem.len()
// should be stored; this is what happens with struct EbpfVmFixedMbuff.
match &self.jit {
Some(jit) => Ok(jit.get_prog()(mbuff.as_ptr() as *mut u8, mbuff.len(), mem_ptr, mem.len(), 0, 0)),
None => Err(Error::new(ErrorKind::Other,
"Error: program has not been JIT-compiled")),
}
}
}
/// A virtual machine to run eBPF program. This kind of VM is used for programs expecting to work
/// on a metadata buffer containing pointers to packet data, but it internally handles the buffer
/// so as to save the effort to manually handle the metadata buffer for the user.
///
/// This struct implements a static internal buffer that is passed to the program. The user has to
/// indicate the offset values at which the eBPF program expects to find the start and the end of
/// packet data in the buffer. On calling the `execute_program()` or `execute_program_jit()` functions, the
/// struct automatically updates the addresses in this static buffer, at the appointed offsets, for
/// the start and the end of the packet data the program is called upon.
///
/// # Examples
///
/// This was compiled with clang from the following program, in C:
///
/// ```c
/// #include <linux/bpf.h>
/// #include "path/to/linux/samples/bpf/bpf_helpers.h"
///
/// SEC(".classifier")
/// int classifier(struct __sk_buff *skb)
/// {
/// void *data = (void *)(long)skb->data;
/// void *data_end = (void *)(long)skb->data_end;
///
/// // Check program is long enough.
/// if (data + 5 > data_end)
/// return 0;
///
/// return *((char *)data + 5);
/// }
/// ```
///
/// Some small modifications have been brought to have it work, see comments.
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// // Here opcode 0x61 had to be replace by 0x79 so as to load a 8-bytes long address.
/// // Also, offset 0x4c had to be replace with e.g. 0x40 so as to prevent the two pointers
/// // from overlapping in the buffer.
/// 0x79, 0x12, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // load pointer to mem from r1[0x40] to r2
/// 0x07, 0x02, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, // add r2, 5
/// // Here opcode 0x61 had to be replace by 0x79 so as to load a 8-bytes long address.
/// 0x79, 0x11, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // load ptr to mem_end from r1[0x50] to r1
/// 0x2d, 0x12, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, // if r2 > r1 skip 3 instructions
/// 0x71, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // load r2 (= *(mem + 5)) into r0
/// 0x67, 0x00, 0x00, 0x00, 0x38, 0x00, 0x00, 0x00, // r0 >>= 56
/// 0xc7, 0x00, 0x00, 0x00, 0x38, 0x00, 0x00, 0x00, // r0 <<= 56 (arsh) extend byte sign to u64
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let mem1 = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
/// ];
/// let mem2 = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0x27
/// ];
///
/// // Instantiate a VM. Note that we provide the start and end offsets for mem pointers.
/// let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
///
/// // Provide only a reference to the packet data. We do not manage the metadata buffer.
/// let res = vm.execute_program(mem1).unwrap();
/// assert_eq!(res, 0xffffffffffffffdd);
///
/// let res = vm.execute_program(mem2).unwrap();
/// assert_eq!(res, 0x27);
/// ```
pub struct EbpfVmFixedMbuff<'a> {
parent: EbpfVmMbuff<'a>,
mbuff: MetaBuff,
}
impl<'a> EbpfVmFixedMbuff<'a> {
/// Create a new virtual machine instance, and load an eBPF program into that instance.
/// When attempting to load the program, it passes through a simple verifier.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x79, 0x12, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem from r1[0x40] to r2
/// 0x07, 0x02, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, // add r2, 5
/// 0x79, 0x11, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem_end from r1[0x50] to r1
/// 0x2d, 0x12, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, // if r2 > r1 skip 3 instructions
/// 0x71, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // load r2 (= *(mem + 5)) into r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM. Note that we provide the start and end offsets for mem pointers.
/// let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
/// ```
pub fn new(prog: Option<&'a [u8]>, data_offset: usize, data_end_offset: usize) -> Result<EbpfVmFixedMbuff<'a>, Error> {
let parent = EbpfVmMbuff::new(prog)?;
let get_buff_len = | x: usize, y: usize | if x >= y { x + 8 } else { y + 8 };
let buffer = vec![0u8; get_buff_len(data_offset, data_end_offset)];
let mbuff = MetaBuff {
data_offset,
data_end_offset,
buffer,
};
Ok(EbpfVmFixedMbuff {
parent,
mbuff,
})
}
/// Load a new eBPF program into the virtual machine instance.
///
/// At the same time, load new offsets for storing pointers to start and end of packet data in
/// the internal metadata buffer.
///
/// # Examples
///
/// ```
/// let prog1 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let prog2 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x79, 0x12, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem from r1[0x40] to r2
/// 0x07, 0x02, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, // add r2, 5
/// 0x79, 0x11, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem_end from r1[0x50] to r1
/// 0x2d, 0x12, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, // if r2 > r1 skip 3 instructions
/// 0x71, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // load r2 (= *(mem + 5)) into r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0x27,
/// ];
///
/// let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog1), 0, 0).unwrap();
/// vm.set_program(prog2, 0x40, 0x50);
///
/// let res = vm.execute_program(mem).unwrap();
/// assert_eq!(res, 0x27);
/// ```
pub fn set_program(&mut self, prog: &'a [u8], data_offset: usize, data_end_offset: usize) -> Result<(), Error> {
let get_buff_len = | x: usize, y: usize | if x >= y { x + 8 } else { y + 8 };
let buffer = vec![0u8; get_buff_len(data_offset, data_end_offset)];
self.mbuff.buffer = buffer;
self.mbuff.data_offset = data_offset;
self.mbuff.data_end_offset = data_end_offset;
self.parent.set_program(prog)?;
Ok(())
}
/// Set a new verifier function. The function should return an `Error` if the program should be
/// rejected by the virtual machine. If a program has been loaded to the VM already, the
/// verifier is immediately run.
///
/// # Examples
///
/// ```
/// use std::io::{Error, ErrorKind};
/// use rbpf::ebpf;
///
/// // Define a simple verifier function.
/// fn verifier(prog: &[u8]) -> Result<(), Error> {
/// let last_insn = ebpf::get_insn(prog, (prog.len() / ebpf::INSN_SIZE) - 1);
/// if last_insn.opc != ebpf::EXIT {
/// return Err(Error::new(ErrorKind::Other,
/// "[Verifier] Error: program does not end with “EXIT” instruction"));
/// }
/// Ok(())
/// }
///
/// let prog1 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog1)).unwrap();
/// // Change the verifier.
/// vm.set_verifier(verifier).unwrap();
/// ```
pub fn set_verifier(&mut self, verifier: Verifier) -> Result<(), Error> {
self.parent.set_verifier(verifier)
}
/// Register a built-in or user-defined helper function in order to use it later from within
/// the eBPF program. The helper is registered into a hashmap, so the `key` can be any `u32`.
///
/// If using JIT-compiled eBPF programs, be sure to register all helpers before compiling the
/// program. You should be able to change registered helpers after compiling, but not to add
/// new ones (i.e. with new keys).
///
/// # Examples
///
/// ```
/// use rbpf::helpers;
///
/// // This program was compiled with clang, from a C program containing the following single
/// // instruction: `return bpf_trace_printk("foo %c %c %c\n", 10, 1, 2, 3);`
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x79, 0x12, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem from r1[0x40] to r2
/// 0x07, 0x02, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, // add r2, 5
/// 0x79, 0x11, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem_end from r1[0x50] to r1
/// 0x2d, 0x12, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, // if r2 > r1 skip 6 instructions
/// 0x71, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // load r2 (= *(mem + 5)) into r1
/// 0xb7, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r2, 0
/// 0xb7, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r3, 0
/// 0xb7, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r4, 0
/// 0xb7, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r5, 0
/// 0x85, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // call helper with key 1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0x09,
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
///
/// // Register a helper. This helper will store the result of the square root of r1 into r0.
/// vm.register_helper(1, helpers::sqrti);
///
/// let res = vm.execute_program(mem).unwrap();
/// assert_eq!(res, 3);
/// ```
pub fn register_helper(&mut self, key: u32, function: fn (u64, u64, u64, u64, u64) -> u64) -> Result<(), Error> {
self.parent.register_helper(key, function)
}
/// Execute the program loaded, with the given packet data.
///
/// If the program is made to be compatible with Linux kernel, it is expected to load the
/// address of the beginning and of the end of the memory area used for packet data from some
/// metadata buffer, which in the case of this VM is handled internally. The offsets at which
/// the addresses should be placed should have be set at the creation of the VM.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x79, 0x12, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem from r1[0x40] to r2
/// 0x07, 0x02, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, // add r2, 5
/// 0x79, 0x11, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem_end from r1[0x50] to r1
/// 0x2d, 0x12, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, // if r2 > r1 skip 3 instructions
/// 0x71, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // load r2 (= *(mem + 5)) into r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
/// ];
///
/// // Instantiate a VM. Note that we provide the start and end offsets for mem pointers.
/// let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
///
/// // Provide only a reference to the packet data. We do not manage the metadata buffer.
/// let res = vm.execute_program(mem).unwrap();
/// assert_eq!(res, 0xdd);
/// ```
pub fn execute_program(&mut self, mem: &'a mut [u8]) -> Result<u64, Error> {
let l = self.mbuff.buffer.len();
// Can this ever happen? Probably not, should be ensured at mbuff creation.
if self.mbuff.data_offset + 8 > l || self.mbuff.data_end_offset + 8 > l {
Err(Error::new(ErrorKind::Other, format!("Error: buffer too small ({:?}), cannot use data_offset {:?} and data_end_offset {:?}",
l, self.mbuff.data_offset, self.mbuff.data_end_offset)))?;
}
LittleEndian::write_u64(&mut self.mbuff.buffer[(self.mbuff.data_offset) .. ], mem.as_ptr() as u64);
LittleEndian::write_u64(&mut self.mbuff.buffer[(self.mbuff.data_end_offset) .. ], mem.as_ptr() as u64 + mem.len() as u64);
self.parent.execute_program(mem, &self.mbuff.buffer)
}
/// JIT-compile the loaded program. No argument required for this.
///
/// If using helper functions, be sure to register them into the VM before calling this
/// function.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x79, 0x12, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem from r1[0x40] to r2
/// 0x07, 0x02, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, // add r2, 5
/// 0x79, 0x11, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem_end from r1[0x50] to r1
/// 0x2d, 0x12, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, // if r2 > r1 skip 3 instructions
/// 0x71, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // load r2 (= *(mem + 5)) into r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM. Note that we provide the start and end offsets for mem pointers.
/// let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
///
/// vm.jit_compile();
/// ```
#[cfg(not(windows))]
pub fn jit_compile(&mut self) -> Result<(), Error> {
let prog = match self.parent.prog {
Some(prog) => prog,
None => Err(Error::new(ErrorKind::Other, "Error: No program set, call prog_set() to load one"))?,
};
self.parent.jit = Some(jit::JitMemory::new(prog, &self.parent.helpers, true, true)?);
Ok(())
}
/// Execute the previously JIT-compiled program, with the given packet data, in a manner very
/// similar to `execute_program()`.
///
/// If the program is made to be compatible with Linux kernel, it is expected to load the
/// address of the beginning and of the end of the memory area used for packet data from some
/// metadata buffer, which in the case of this VM is handled internally. The offsets at which
/// the addresses should be placed should have be set at the creation of the VM.
///
/// # Safety
///
/// **WARNING:** JIT-compiled assembly code is not safe, in particular there is no runtime
/// check for memory access; so if the eBPF program attempts erroneous accesses, this may end
/// very bad (program may segfault). It may be wise to check that the program works with the
/// interpreter before running the JIT-compiled version of it.
///
/// For this reason the function should be called from within an `unsafe` bloc.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x79, 0x12, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem from r1[0x40] to r2
/// 0x07, 0x02, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, // add r2, 5
/// 0x79, 0x11, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // load mem_end from r1[0x50] to r1
/// 0x2d, 0x12, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, // if r2 > r1 skip 3 instructions
/// 0x71, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // load r2 (= *(mem + 5)) into r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
/// ];
///
/// // Instantiate a VM. Note that we provide the start and end offsets for mem pointers.
/// let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
///
/// # #[cfg(not(windows))]
/// vm.jit_compile();
///
/// // Provide only a reference to the packet data. We do not manage the metadata buffer.
/// # #[cfg(not(windows))]
/// unsafe {
/// let res = vm.execute_program_jit(mem).unwrap();
/// assert_eq!(res, 0xdd);
/// }
/// ```
// This struct redefines the `execute_program_jit()` function, in order to pass the offsets
// associated with the fixed mbuff.
#[cfg(not(windows))]
pub unsafe fn execute_program_jit(&mut self, mem: &'a mut [u8]) -> Result<u64, Error> {
// If packet data is empty, do not send the address of an empty slice; send a null pointer
// as first argument instead, as this is uBPF's behavior (empty packet should not happen
// in the kernel; anyway the verifier would prevent the use of uninitialized registers).
// See `mul_loop` test.
let mem_ptr = match mem.len() {
0 => std::ptr::null_mut(),
_ => mem.as_ptr() as *mut u8
};
match &self.parent.jit {
Some(jit) => Ok(jit.get_prog()(self.mbuff.buffer.as_ptr() as *mut u8,
self.mbuff.buffer.len(),
mem_ptr,
mem.len(),
self.mbuff.data_offset,
self.mbuff.data_end_offset)),
None => Err(Error::new(ErrorKind::Other,
"Error: program has not been JIT-compiled"))
}
}
}
/// A virtual machine to run eBPF program. This kind of VM is used for programs expecting to work
/// directly on the memory area representing packet data.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x71, 0x11, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, // ldxb r1[0x04], r1
/// 0x07, 0x01, 0x00, 0x00, 0x00, 0x22, 0x00, 0x00, // add r1, 0x22
/// 0xbf, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, r1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
/// ];
///
/// // Instantiate a VM.
/// let vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
///
/// // Provide only a reference to the packet data.
/// let res = vm.execute_program(mem).unwrap();
/// assert_eq!(res, 0x22cc);
/// ```
pub struct EbpfVmRaw<'a> {
parent: EbpfVmMbuff<'a>,
}
impl<'a> EbpfVmRaw<'a> {
/// Create a new virtual machine instance, and load an eBPF program into that instance.
/// When attempting to load the program, it passes through a simple verifier.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x71, 0x11, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, // ldxb r1[0x04], r1
/// 0x07, 0x01, 0x00, 0x00, 0x00, 0x22, 0x00, 0x00, // add r1, 0x22
/// 0xbf, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, r1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
/// ```
pub fn new(prog: Option<&'a [u8]>) -> Result<EbpfVmRaw<'a>, Error> {
let parent = EbpfVmMbuff::new(prog)?;
Ok(EbpfVmRaw {
parent,
})
}
/// Load a new eBPF program into the virtual machine instance.
///
/// # Examples
///
/// ```
/// let prog1 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let prog2 = &[
/// 0x71, 0x11, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, // ldxb r1[0x04], r1
/// 0x07, 0x01, 0x00, 0x00, 0x00, 0x22, 0x00, 0x00, // add r1, 0x22
/// 0xbf, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, r1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0x27,
/// ];
///
/// let mut vm = rbpf::EbpfVmRaw::new(Some(prog1)).unwrap();
/// vm.set_program(prog2);
///
/// let res = vm.execute_program(mem).unwrap();
/// assert_eq!(res, 0x22cc);
/// ```
pub fn set_program(&mut self, prog: &'a [u8]) -> Result<(), Error> {
self.parent.set_program(prog)?;
Ok(())
}
/// Set a new verifier function. The function should return an `Error` if the program should be
/// rejected by the virtual machine. If a program has been loaded to the VM already, the
/// verifier is immediately run.
///
/// # Examples
///
/// ```
/// use std::io::{Error, ErrorKind};
/// use rbpf::ebpf;
///
/// // Define a simple verifier function.
/// fn verifier(prog: &[u8]) -> Result<(), Error> {
/// let last_insn = ebpf::get_insn(prog, (prog.len() / ebpf::INSN_SIZE) - 1);
/// if last_insn.opc != ebpf::EXIT {
/// return Err(Error::new(ErrorKind::Other,
/// "[Verifier] Error: program does not end with “EXIT” instruction"));
/// }
/// Ok(())
/// }
///
/// let prog1 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog1)).unwrap();
/// // Change the verifier.
/// vm.set_verifier(verifier).unwrap();
/// ```
pub fn set_verifier(&mut self, verifier: Verifier) -> Result<(), Error> {
self.parent.set_verifier(verifier)
}
/// Register a built-in or user-defined helper function in order to use it later from within
/// the eBPF program. The helper is registered into a hashmap, so the `key` can be any `u32`.
///
/// If using JIT-compiled eBPF programs, be sure to register all helpers before compiling the
/// program. You should be able to change registered helpers after compiling, but not to add
/// new ones (i.e. with new keys).
///
/// # Examples
///
/// ```
/// use rbpf::helpers;
///
/// let prog = &[
/// 0x79, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // ldxdw r1, r1[0x00]
/// 0xb7, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r2, 0
/// 0xb7, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r3, 0
/// 0xb7, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r4, 0
/// 0xb7, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r5, 0
/// 0x85, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // call helper with key 1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mem = &mut [
/// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
///
/// // Register a helper. This helper will store the result of the square root of r1 into r0.
/// vm.register_helper(1, helpers::sqrti);
///
/// let res = vm.execute_program(mem).unwrap();
/// assert_eq!(res, 0x10000000);
/// ```
pub fn register_helper(&mut self, key: u32, function: fn (u64, u64, u64, u64, u64) -> u64) -> Result<(), Error> {
self.parent.register_helper(key, function)
}
/// Execute the program loaded, with the given packet data.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x71, 0x11, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, // ldxb r1[0x04], r1
/// 0x07, 0x01, 0x00, 0x00, 0x00, 0x22, 0x00, 0x00, // add r1, 0x22
/// 0xbf, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, r1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0x27
/// ];
///
/// let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
///
/// let res = vm.execute_program(mem).unwrap();
/// assert_eq!(res, 0x22cc);
/// ```
pub fn execute_program(&self, mem: &'a mut [u8]) -> Result<u64, Error> {
self.parent.execute_program(mem, &[])
}
/// JIT-compile the loaded program. No argument required for this.
///
/// If using helper functions, be sure to register them into the VM before calling this
/// function.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x71, 0x11, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, // ldxb r1[0x04], r1
/// 0x07, 0x01, 0x00, 0x00, 0x00, 0x22, 0x00, 0x00, // add r1, 0x22
/// 0xbf, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, r1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
///
/// vm.jit_compile();
/// ```
#[cfg(not(windows))]
pub fn jit_compile(&mut self) -> Result<(), Error> {
let prog = match self.parent.prog {
Some(prog) => prog,
None => Err(Error::new(ErrorKind::Other,
"Error: No program set, call prog_set() to load one"))?,
};
self.parent.jit = Some(jit::JitMemory::new(prog, &self.parent.helpers, false, false)?);
Ok(())
}
/// Execute the previously JIT-compiled program, with the given packet data, in a manner very
/// similar to `execute_program()`.
///
/// # Safety
///
/// **WARNING:** JIT-compiled assembly code is not safe, in particular there is no runtime
/// check for memory access; so if the eBPF program attempts erroneous accesses, this may end
/// very bad (program may segfault). It may be wise to check that the program works with the
/// interpreter before running the JIT-compiled version of it.
///
/// For this reason the function should be called from within an `unsafe` bloc.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0x71, 0x11, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, // ldxb r1[0x04], r1
/// 0x07, 0x01, 0x00, 0x00, 0x00, 0x22, 0x00, 0x00, // add r1, 0x22
/// 0xbf, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, r1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mem = &mut [
/// 0xaa, 0xbb, 0x11, 0x22, 0xcc, 0x27
/// ];
///
/// let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
///
/// # #[cfg(not(windows))]
/// vm.jit_compile();
///
/// # #[cfg(not(windows))]
/// unsafe {
/// let res = vm.execute_program_jit(mem).unwrap();
/// assert_eq!(res, 0x22cc);
/// }
/// ```
#[cfg(not(windows))]
pub unsafe fn execute_program_jit(&self, mem: &'a mut [u8]) -> Result<u64, Error> {
let mut mbuff = vec![];
self.parent.execute_program_jit(mem, &mut mbuff)
}
}
/// A virtual machine to run eBPF program. This kind of VM is used for programs that do not work
/// with any memory area—no metadata buffer, no packet data either.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0xb7, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // mov r1, 1
/// 0xb7, 0x02, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, // mov r2, 2
/// 0xb7, 0x03, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, // mov r3, 3
/// 0xb7, 0x04, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, // mov r4, 4
/// 0xb7, 0x05, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, // mov r5, 5
/// 0xb7, 0x06, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, // mov r6, 6
/// 0xb7, 0x07, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00, // mov r7, 7
/// 0xb7, 0x08, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, // mov r8, 8
/// 0x4f, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // or r0, r5
/// 0x47, 0x00, 0x00, 0x00, 0xa0, 0x00, 0x00, 0x00, // or r0, 0xa0
/// 0x57, 0x00, 0x00, 0x00, 0xa3, 0x00, 0x00, 0x00, // and r0, 0xa3
/// 0xb7, 0x09, 0x00, 0x00, 0x91, 0x00, 0x00, 0x00, // mov r9, 0x91
/// 0x5f, 0x90, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // and r0, r9
/// 0x67, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, // lsh r0, 32
/// 0x67, 0x00, 0x00, 0x00, 0x16, 0x00, 0x00, 0x00, // lsh r0, 22
/// 0x6f, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // lsh r0, r8
/// 0x77, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, // rsh r0, 32
/// 0x77, 0x00, 0x00, 0x00, 0x13, 0x00, 0x00, 0x00, // rsh r0, 19
/// 0x7f, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // rsh r0, r7
/// 0xa7, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, // xor r0, 0x03
/// 0xaf, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // xor r0, r2
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
///
/// // Provide only a reference to the packet data.
/// let res = vm.execute_program().unwrap();
/// assert_eq!(res, 0x11);
/// ```
pub struct EbpfVmNoData<'a> {
parent: EbpfVmRaw<'a>,
}
impl<'a> EbpfVmNoData<'a> {
/// Create a new virtual machine instance, and load an eBPF program into that instance.
/// When attempting to load the program, it passes through a simple verifier.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x11, 0x22, 0x00, 0x00, // mov r0, 0x2211
/// 0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, // be16 r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let vm = rbpf::EbpfVmNoData::new(Some(prog));
/// ```
pub fn new(prog: Option<&'a [u8]>) -> Result<EbpfVmNoData<'a>, Error> {
let parent = EbpfVmRaw::new(prog)?;
Ok(EbpfVmNoData {
parent,
})
}
/// Load a new eBPF program into the virtual machine instance.
///
/// # Examples
///
/// ```
/// let prog1 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x11, 0x22, 0x00, 0x00, // mov r0, 0x2211
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
/// let prog2 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x11, 0x22, 0x00, 0x00, // mov r0, 0x2211
/// 0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, // be16 r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mut vm = rbpf::EbpfVmNoData::new(Some(prog1)).unwrap();
///
/// let res = vm.execute_program().unwrap();
/// assert_eq!(res, 0x2211);
///
/// vm.set_program(prog2);
///
/// let res = vm.execute_program().unwrap();
/// assert_eq!(res, 0x1122);
/// ```
pub fn set_program(&mut self, prog: &'a [u8]) -> Result<(), Error> {
self.parent.set_program(prog)?;
Ok(())
}
/// Set a new verifier function. The function should return an `Error` if the program should be
/// rejected by the virtual machine. If a program has been loaded to the VM already, the
/// verifier is immediately run.
///
/// # Examples
///
/// ```
/// use std::io::{Error, ErrorKind};
/// use rbpf::ebpf;
///
/// // Define a simple verifier function.
/// fn verifier(prog: &[u8]) -> Result<(), Error> {
/// let last_insn = ebpf::get_insn(prog, (prog.len() / ebpf::INSN_SIZE) - 1);
/// if last_insn.opc != ebpf::EXIT {
/// return Err(Error::new(ErrorKind::Other,
/// "[Verifier] Error: program does not end with “EXIT” instruction"));
/// }
/// Ok(())
/// }
///
/// let prog1 = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r0, 0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// // Instantiate a VM.
/// let mut vm = rbpf::EbpfVmMbuff::new(Some(prog1)).unwrap();
/// // Change the verifier.
/// vm.set_verifier(verifier).unwrap();
/// ```
pub fn set_verifier(&mut self, verifier: Verifier) -> Result<(), Error> {
self.parent.set_verifier(verifier)
}
/// Register a built-in or user-defined helper function in order to use it later from within
/// the eBPF program. The helper is registered into a hashmap, so the `key` can be any `u32`.
///
/// If using JIT-compiled eBPF programs, be sure to register all helpers before compiling the
/// program. You should be able to change registered helpers after compiling, but not to add
/// new ones (i.e. with new keys).
///
/// # Examples
///
/// ```
/// use rbpf::helpers;
///
/// let prog = &[
/// 0xb7, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, // mov r1, 0x010000000
/// 0xb7, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r2, 0
/// 0xb7, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r3, 0
/// 0xb7, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r4, 0
/// 0xb7, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov r5, 0
/// 0x85, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // call helper with key 1
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mut vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
///
/// // Register a helper. This helper will store the result of the square root of r1 into r0.
/// vm.register_helper(1, helpers::sqrti).unwrap();
///
/// let res = vm.execute_program().unwrap();
/// assert_eq!(res, 0x1000);
/// ```
pub fn register_helper(&mut self, key: u32, function: fn (u64, u64, u64, u64, u64) -> u64) -> Result<(), Error> {
self.parent.register_helper(key, function)
}
/// JIT-compile the loaded program. No argument required for this.
///
/// If using helper functions, be sure to register them into the VM before calling this
/// function.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x11, 0x22, 0x00, 0x00, // mov r0, 0x2211
/// 0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, // be16 r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mut vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
///
///
/// vm.jit_compile();
/// ```
#[cfg(not(windows))]
pub fn jit_compile(&mut self) -> Result<(), Error> {
self.parent.jit_compile()
}
/// Execute the program loaded, without providing pointers to any memory area whatsoever.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x11, 0x22, 0x00, 0x00, // mov r0, 0x2211
/// 0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, // be16 r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
///
/// // For this kind of VM, the `execute_program()` function needs no argument.
/// let res = vm.execute_program().unwrap();
/// assert_eq!(res, 0x1122);
/// ```
pub fn execute_program(&self) -> Result<u64, Error> {
self.parent.execute_program(&mut [])
}
/// Execute the previously JIT-compiled program, without providing pointers to any memory area
/// whatsoever, in a manner very similar to `execute_program()`.
///
/// # Safety
///
/// **WARNING:** JIT-compiled assembly code is not safe, in particular there is no runtime
/// check for memory access; so if the eBPF program attempts erroneous accesses, this may end
/// very bad (program may segfault). It may be wise to check that the program works with the
/// interpreter before running the JIT-compiled version of it.
///
/// For this reason the function should be called from within an `unsafe` bloc.
///
/// # Examples
///
/// ```
/// let prog = &[
/// 0xb7, 0x00, 0x00, 0x00, 0x11, 0x22, 0x00, 0x00, // mov r0, 0x2211
/// 0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, // be16 r0
/// 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // exit
/// ];
///
/// let mut vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
///
/// # #[cfg(not(windows))]
/// vm.jit_compile();
///
/// # #[cfg(not(windows))]
/// unsafe {
/// let res = vm.execute_program_jit().unwrap();
/// assert_eq!(res, 0x1122);
/// }
/// ```
#[cfg(not(windows))]
pub unsafe fn execute_program_jit(&self) -> Result<u64, Error> {
self.parent.execute_program_jit(&mut [])
}
}