// Derived from uBPF <https://github.com/iovisor/ubpf>
// Copyright 2015 Big Switch Networks, Inc
// (uBPF: VM architecture, parts of the interpreter, originally in C)
// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
// (Translation to Rust, MetaBuff/multiple classes addition, hashmaps for helpers)
//
// Licensed under the Apache License, Version 2.0 <http://www.apache.org/licenses/LICENSE-2.0> or
// the MIT license <http://opensource.org/licenses/MIT>, at your option. This file may not be
// copied, modified, or distributed except according to those terms.
//! Virtual machine and JIT compiler for eBPF programs.
#![doc(html_logo_url = "https://raw.githubusercontent.com/qmonnet/rbpf/master/misc/rbpf.png",
html_favicon_url = "https://raw.githubusercontent.com/qmonnet/rbpf/master/misc/rbpf.ico")]
#![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;
#[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;
/// eBPF Jit-compiled program.
pub type JitProgram = unsafe fn(*mut u8, usize, *mut u8, usize, usize, usize) -> 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,
jit: Option<JitProgram>,
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: prog,
verifier: verifier::check,
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);
/// ```
#[allow(unknown_lints)]
#[allow(cyclomatic_complexity)]
pub fn execute_program(&self, mem: &[u8], mbuff: &[u8]) -> Result<u64, Error> {
const U32MAX: u64 = u32::MAX as u64;
let prog = match self.prog {
Some(prog) => prog,
None => Err(Error::new(ErrorKind::Other,
"Error: No program set, call prog_set() to load one"))?,
};
let stack = vec![0u8;ebpf::STACK_SIZE];
// R1 points to beginning of memory area, R10 to stack
let mut reg: [u64;11] = [
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, stack.as_ptr() as u64 + stack.len() as u64
];
if !mbuff.is_empty() {
reg[1] = mbuff.as_ptr() as u64;
}
else if !mem.is_empty() {
reg[1] = mem.as_ptr() as u64;
}
let check_mem_load = | addr: u64, len: usize, insn_ptr: usize | {
EbpfVmMbuff::check_mem(addr, len, "load", insn_ptr, mbuff, mem, &stack)
};
let check_mem_store = | addr: u64, len: usize, insn_ptr: usize | {
EbpfVmMbuff::check_mem(addr, len, "store", insn_ptr, mbuff, mem, &stack)
};
// Loop on instructions
let mut insn_ptr:usize = 0;
while insn_ptr * ebpf::INSN_SIZE < prog.len() {
let insn = ebpf::get_insn(prog, insn_ptr);
insn_ptr += 1;
let _dst = insn.dst as usize;
let _src = insn.src as usize;
match insn.opc {
// BPF_LD class
// LD_ABS_* and LD_IND_* are supposed to load pointer to data from metadata buffer.
// Since this pointer is constant, and since we already know it (mem), do not
// bother re-fetching it, just use mem already.
ebpf::LD_ABS_B => reg[0] = unsafe {
let x = (mem.as_ptr() as u64 + (insn.imm as u32) as u64) as *const u8;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
ebpf::LD_ABS_H => reg[0] = unsafe {
let x = (mem.as_ptr() as u64 + (insn.imm as u32) as u64) as *const u16;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
ebpf::LD_ABS_W => reg[0] = unsafe {
let x = (mem.as_ptr() as u64 + (insn.imm as u32) as u64) as *const u32;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
ebpf::LD_ABS_DW => reg[0] = unsafe {
let x = (mem.as_ptr() as u64 + (insn.imm as u32) as u64) as *const u64;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
ebpf::LD_IND_B => reg[0] = unsafe {
let x = (mem.as_ptr() as u64 + reg[_src] + (insn.imm as u32) as u64) as *const u8;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
ebpf::LD_IND_H => reg[0] = unsafe {
let x = (mem.as_ptr() as u64 + reg[_src] + (insn.imm as u32) as u64) as *const u16;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
ebpf::LD_IND_W => reg[0] = unsafe {
let x = (mem.as_ptr() as u64 + reg[_src] + (insn.imm as u32) as u64) as *const u32;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
ebpf::LD_IND_DW => reg[0] = unsafe {
let x = (mem.as_ptr() as u64 + reg[_src] + (insn.imm as u32) as u64) as *const u64;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
ebpf::LD_DW_IMM => {
let next_insn = ebpf::get_insn(prog, insn_ptr);
insn_ptr += 1;
reg[_dst] = ((insn.imm as u32) as u64) + ((next_insn.imm as u64) << 32);
},
// BPF_LDX class
ebpf::LD_B_REG => reg[_dst] = unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_src] as *const u8).offset(insn.off as isize) as *const u8;
check_mem_load(x as u64, 1, insn_ptr)?;
*x as u64
},
ebpf::LD_H_REG => reg[_dst] = unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_src] as *const u8).offset(insn.off as isize) as *const u16;
check_mem_load(x as u64, 2, insn_ptr)?;
*x as u64
},
ebpf::LD_W_REG => reg[_dst] = unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_src] as *const u8).offset(insn.off as isize) as *const u32;
check_mem_load(x as u64, 4, insn_ptr)?;
*x as u64
},
ebpf::LD_DW_REG => reg[_dst] = unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_src] as *const u8).offset(insn.off as isize) as *const u64;
check_mem_load(x as u64, 8, insn_ptr)?;
*x as u64
},
// BPF_ST class
ebpf::ST_B_IMM => unsafe {
let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u8;
check_mem_store(x as u64, 1, insn_ptr)?;
*x = insn.imm as u8;
},
ebpf::ST_H_IMM => unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u16;
check_mem_store(x as u64, 2, insn_ptr)?;
*x = insn.imm as u16;
},
ebpf::ST_W_IMM => unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u32;
check_mem_store(x as u64, 4, insn_ptr)?;
*x = insn.imm as u32;
},
ebpf::ST_DW_IMM => unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u64;
check_mem_store(x as u64, 8, insn_ptr)?;
*x = insn.imm as u64;
},
// BPF_STX class
ebpf::ST_B_REG => unsafe {
let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u8;
check_mem_store(x as u64, 1, insn_ptr)?;
*x = reg[_src] as u8;
},
ebpf::ST_H_REG => unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u16;
check_mem_store(x as u64, 2, insn_ptr)?;
*x = reg[_src] as u16;
},
ebpf::ST_W_REG => unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u32;
check_mem_store(x as u64, 4, insn_ptr)?;
*x = reg[_src] as u32;
},
ebpf::ST_DW_REG => unsafe {
#[allow(cast_ptr_alignment)]
let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u64;
check_mem_store(x as u64, 8, insn_ptr)?;
*x = reg[_src] as u64;
},
ebpf::ST_W_XADD => unimplemented!(),
ebpf::ST_DW_XADD => unimplemented!(),
// BPF_ALU class
// TODO Check how overflow works in kernel. Should we &= U32MAX all src register value
// before we do the operation?
// Cf ((0x11 << 32) - (0x1 << 32)) as u32 VS ((0x11 << 32) as u32 - (0x1 << 32) as u32
ebpf::ADD32_IMM => reg[_dst] = (reg[_dst] as i32).wrapping_add(insn.imm) as u64, //((reg[_dst] & U32MAX) + insn.imm as u64) & U32MAX,
ebpf::ADD32_REG => reg[_dst] = (reg[_dst] as i32).wrapping_add(reg[_src] as i32) as u64, //((reg[_dst] & U32MAX) + (reg[_src] & U32MAX)) & U32MAX,
ebpf::SUB32_IMM => reg[_dst] = (reg[_dst] as i32).wrapping_sub(insn.imm) as u64,
ebpf::SUB32_REG => reg[_dst] = (reg[_dst] as i32).wrapping_sub(reg[_src] as i32) as u64,
ebpf::MUL32_IMM => reg[_dst] = (reg[_dst] as i32).wrapping_mul(insn.imm) as u64,
ebpf::MUL32_REG => reg[_dst] = (reg[_dst] as i32).wrapping_mul(reg[_src] as i32) as u64,
ebpf::DIV32_IMM => reg[_dst] = (reg[_dst] as u32 / insn.imm as u32) as u64,
ebpf::DIV32_REG => {
if reg[_src] == 0 {
Err(Error::new(ErrorKind::Other,"Error: division by 0"))?;
}
reg[_dst] = (reg[_dst] as u32 / reg[_src] as u32) as u64;
},
ebpf::OR32_IMM => reg[_dst] = (reg[_dst] as u32 | insn.imm as u32) as u64,
ebpf::OR32_REG => reg[_dst] = (reg[_dst] as u32 | reg[_src] as u32) as u64,
ebpf::AND32_IMM => reg[_dst] = (reg[_dst] as u32 & insn.imm as u32) as u64,
ebpf::AND32_REG => reg[_dst] = (reg[_dst] as u32 & reg[_src] as u32) as u64,
ebpf::LSH32_IMM => reg[_dst] = (reg[_dst] as u32).wrapping_shl(insn.imm as u32) as u64,
ebpf::LSH32_REG => reg[_dst] = (reg[_dst] as u32).wrapping_shl(reg[_src] as u32) as u64,
ebpf::RSH32_IMM => reg[_dst] = (reg[_dst] as u32).wrapping_shr(insn.imm as u32) as u64,
ebpf::RSH32_REG => reg[_dst] = (reg[_dst] as u32).wrapping_shr(reg[_src] as u32) as u64,
ebpf::NEG32 => { reg[_dst] = (reg[_dst] as i32).wrapping_neg() as u64; reg[_dst] &= U32MAX; },
ebpf::MOD32_IMM => reg[_dst] = (reg[_dst] as u32 % insn.imm as u32) as u64,
ebpf::MOD32_REG => {
if reg[_src] == 0 {
Err(Error::new(ErrorKind::Other,"Error: division by 0"))?;
}
reg[_dst] = (reg[_dst] as u32 % reg[_src] as u32) as u64;
},
ebpf::XOR32_IMM => reg[_dst] = (reg[_dst] as u32 ^ insn.imm as u32) as u64,
ebpf::XOR32_REG => reg[_dst] = (reg[_dst] as u32 ^ reg[_src] as u32) as u64,
ebpf::MOV32_IMM => reg[_dst] = insn.imm as u64,
ebpf::MOV32_REG => reg[_dst] = (reg[_src] as u32) as u64,
ebpf::ARSH32_IMM => { reg[_dst] = (reg[_dst] as i32).wrapping_shr(insn.imm as u32) as u64; reg[_dst] &= U32MAX; },
ebpf::ARSH32_REG => { reg[_dst] = (reg[_dst] as i32).wrapping_shr(reg[_src] as u32) as u64; reg[_dst] &= U32MAX; },
ebpf::LE => {
reg[_dst] = match insn.imm {
16 => (reg[_dst] as u16).to_le() as u64,
32 => (reg[_dst] as u32).to_le() as u64,
64 => reg[_dst].to_le(),
_ => unreachable!(),
};
},
ebpf::BE => {
reg[_dst] = match insn.imm {
16 => (reg[_dst] as u16).to_be() as u64,
32 => (reg[_dst] as u32).to_be() as u64,
64 => reg[_dst].to_be(),
_ => unreachable!(),
};
},
// BPF_ALU64 class
ebpf::ADD64_IMM => reg[_dst] = reg[_dst].wrapping_add(insn.imm as u64),
ebpf::ADD64_REG => reg[_dst] = reg[_dst].wrapping_add(reg[_src]),
ebpf::SUB64_IMM => reg[_dst] = reg[_dst].wrapping_sub(insn.imm as u64),
ebpf::SUB64_REG => reg[_dst] = reg[_dst].wrapping_sub(reg[_src]),
ebpf::MUL64_IMM => reg[_dst] = reg[_dst].wrapping_mul(insn.imm as u64),
ebpf::MUL64_REG => reg[_dst] = reg[_dst].wrapping_mul(reg[_src]),
ebpf::DIV64_IMM => reg[_dst] /= insn.imm as u64,
ebpf::DIV64_REG => {
if reg[_src] == 0 {
Err(Error::new(ErrorKind::Other,"Error: division by 0"))?;
}
reg[_dst] /= reg[_src];
},
ebpf::OR64_IMM => reg[_dst] |= insn.imm as u64,
ebpf::OR64_REG => reg[_dst] |= reg[_src],
ebpf::AND64_IMM => reg[_dst] &= insn.imm as u64,
ebpf::AND64_REG => reg[_dst] &= reg[_src],
ebpf::LSH64_IMM => reg[_dst] <<= insn.imm as u64,
ebpf::LSH64_REG => reg[_dst] <<= reg[_src],
ebpf::RSH64_IMM => reg[_dst] >>= insn.imm as u64,
ebpf::RSH64_REG => reg[_dst] >>= reg[_src],
ebpf::NEG64 => reg[_dst] = -(reg[_dst] as i64) as u64,
ebpf::MOD64_IMM => reg[_dst] %= insn.imm as u64,
ebpf::MOD64_REG => {
if reg[_src] == 0 {
Err(Error::new(ErrorKind::Other,"Error: division by 0"))?;
}
reg[_dst] %= reg[_src];
},
ebpf::XOR64_IMM => reg[_dst] ^= insn.imm as u64,
ebpf::XOR64_REG => reg[_dst] ^= reg[_src],
ebpf::MOV64_IMM => reg[_dst] = insn.imm as u64,
ebpf::MOV64_REG => reg[_dst] = reg[_src],
ebpf::ARSH64_IMM => reg[_dst] = (reg[_dst] as i64 >> insn.imm) as u64,
ebpf::ARSH64_REG => reg[_dst] = (reg[_dst] as i64 >> reg[_src]) as u64,
// BPF_JMP class
// TODO: check this actually works as expected for signed / unsigned ops
ebpf::JA => insn_ptr = (insn_ptr as i16 + insn.off) as usize,
ebpf::JEQ_IMM => if reg[_dst] == insn.imm as u64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JEQ_REG => if reg[_dst] == reg[_src] { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JGT_IMM => if reg[_dst] > insn.imm as u64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JGT_REG => if reg[_dst] > reg[_src] { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JGE_IMM => if reg[_dst] >= insn.imm as u64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JGE_REG => if reg[_dst] >= reg[_src] { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JLT_IMM => if reg[_dst] < insn.imm as u64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JLT_REG => if reg[_dst] < reg[_src] { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JLE_IMM => if reg[_dst] <= insn.imm as u64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JLE_REG => if reg[_dst] <= reg[_src] { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSET_IMM => if reg[_dst] & insn.imm as u64 != 0 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSET_REG => if reg[_dst] & reg[_src] != 0 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JNE_IMM => if reg[_dst] != insn.imm as u64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JNE_REG => if reg[_dst] != reg[_src] { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSGT_IMM => if reg[_dst] as i64 > insn.imm as i64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSGT_REG => if reg[_dst] as i64 > reg[_src] as i64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSGE_IMM => if reg[_dst] as i64 >= insn.imm as i64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSGE_REG => if reg[_dst] as i64 >= reg[_src] as i64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSLT_IMM => if (reg[_dst] as i64) < insn.imm as i64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSLT_REG => if (reg[_dst] as i64) < reg[_src] as i64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSLE_IMM => if (reg[_dst] as i64) <= insn.imm as i64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
ebpf::JSLE_REG => if (reg[_dst] as i64) <= reg[_src] as i64 { insn_ptr = (insn_ptr as i16 + insn.off) as usize; },
// Do not delegate the check to the verifier, since registered functions can be
// changed after the program has been verified.
ebpf::CALL => if let Some(function) = self.helpers.get(&(insn.imm as u32)) {
reg[0] = function(reg[1], reg[2], reg[3], reg[4], reg[5]);
} else {
Err(Error::new(ErrorKind::Other, format!("Error: unknown helper function (id: {:#x})", insn.imm as u32)))?;
},
ebpf::TAIL_CALL => unimplemented!(),
ebpf::EXIT => return Ok(reg[0]),
_ => unreachable!()
}
}
unreachable!()
}
fn check_mem(addr: u64, len: usize, access_type: &str, insn_ptr: usize,
mbuff: &[u8], mem: &[u8], stack: &[u8]) -> Result<(), Error> {
if mbuff.as_ptr() as u64 <= addr && addr + len as u64 <= mbuff.as_ptr() as u64 + mbuff.len() as u64 {
return Ok(())
}
if mem.as_ptr() as u64 <= addr && addr + len as u64 <= mem.as_ptr() as u64 + mem.len() as u64 {
return Ok(())
}
if stack.as_ptr() as u64 <= addr && addr + len as u64 <= stack.as_ptr() as u64 + stack.len() as u64 {
return Ok(())
}
Err(Error::new(ErrorKind::Other, format!(
"Error: out of bounds memory {} (insn #{:?}), addr {:#x}, size {:?}\nmbuff: {:#x}/{:#x}, mem: {:#x}/{:#x}, stack: {:#x}/{:#x}",
access_type, insn_ptr, addr, len,
mbuff.as_ptr() as u64, mbuff.len(),
mem.as_ptr() as u64, mem.len(),
stack.as_ptr() as u64, stack.len()
)))
}
/// 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::compile(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);
/// }
/// ```
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(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_offset,
data_end_offset: data_end_offset,
buffer: buffer,
};
Ok(EbpfVmFixedMbuff {
parent: parent,
mbuff: 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::compile(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.
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(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: 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::compile(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);
/// }
/// ```
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: 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);
/// }
/// ```
pub unsafe fn execute_program_jit(&self) -> Result<(u64), Error> {
self.parent.execute_program_jit(&mut [])
}
}