// SPDX-License-Identifier: (Apache-2.0 OR MIT) // Derived from uBPF // Copyright 2015 Big Switch Networks, Inc // (uBPF: VM architecture, parts of the interpreter, originally in C) // Copyright 2016 6WIND S.A. // (Translation to Rust, MetaBuff/multiple classes addition, hashmaps for helpers) use std::collections::HashMap; use std::io::{Error, ErrorKind}; use ebpf; fn check_mem(addr: u64, len: usize, access_type: &str, insn_ptr: usize, mbuff: &[u8], mem: &[u8], stack: &[u8]) -> Result<(), Error> { if let Some(addr_end) = addr.checked_add(len as u64) { if mbuff.as_ptr() as u64 <= addr && addr_end <= mbuff.as_ptr() as u64 + mbuff.len() as u64 { return Ok(()) } if mem.as_ptr() as u64 <= addr && addr_end <= mem.as_ptr() as u64 + mem.len() as u64 { return Ok(()) } if stack.as_ptr() as u64 <= addr && addr_end <= 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() ))) } #[allow(unknown_lints)] #[allow(cyclomatic_complexity)] pub fn execute_program(prog_: Option<&[u8]>, mem: &[u8], mbuff: &[u8], helpers: &HashMap) -> Result { const U32MAX: u64 = u32::MAX as u64; let prog = match 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 | { check_mem(addr, len, "load", insn_ptr, mbuff, mem, &stack) }; let check_mem_store = | addr: u64, len: usize, insn_ptr: usize | { 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; let mut do_jump = || { insn_ptr = (insn_ptr as i16 + insn.off) 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.read_unaligned() 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.read_unaligned() 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.read_unaligned() 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.read_unaligned() }, 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.read_unaligned() 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.read_unaligned() 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.read_unaligned() 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.read_unaligned() }, 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(clippy::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.read_unaligned() as u64 }, ebpf::LD_H_REG => reg[_dst] = unsafe { #[allow(clippy::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.read_unaligned() as u64 }, ebpf::LD_W_REG => reg[_dst] = unsafe { #[allow(clippy::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.read_unaligned() as u64 }, ebpf::LD_DW_REG => reg[_dst] = unsafe { #[allow(clippy::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.read_unaligned() }, // 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.write_unaligned(insn.imm as u8); }, ebpf::ST_H_IMM => unsafe { #[allow(clippy::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.write_unaligned(insn.imm as u16); }, ebpf::ST_W_IMM => unsafe { #[allow(clippy::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.write_unaligned(insn.imm as u32); }, ebpf::ST_DW_IMM => unsafe { #[allow(clippy::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.write_unaligned(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.write_unaligned(reg[_src] as u8); }, ebpf::ST_H_REG => unsafe { #[allow(clippy::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.write_unaligned(reg[_src] as u16); }, ebpf::ST_W_REG => unsafe { #[allow(clippy::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.write_unaligned(reg[_src] as u32); }, ebpf::ST_DW_REG => unsafe { #[allow(clippy::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.write_unaligned(reg[_src]); }, 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 if insn.imm as u32 == 0 => reg[_dst] = 0, ebpf::DIV32_IMM => reg[_dst] = (reg[_dst] as u32 / insn.imm as u32) as u64, ebpf::DIV32_REG if reg[_src] as u32 == 0 => reg[_dst] = 0, ebpf::DIV32_REG => 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 if insn.imm as u32 == 0 => (), ebpf::MOD32_IMM => reg[_dst] = (reg[_dst] as u32 % insn.imm as u32) as u64, ebpf::MOD32_REG if reg[_src] as u32 == 0 => (), ebpf::MOD32_REG => 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 u32 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 if insn.imm == 0 => reg[_dst] = 0, ebpf::DIV64_IMM => reg[_dst] /= insn.imm as u64, ebpf::DIV64_REG if reg[_src] == 0 => reg[_dst] = 0, ebpf::DIV64_REG => 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 if insn.imm == 0 => (), ebpf::MOD64_IMM => reg[_dst] %= insn.imm as u64, ebpf::MOD64_REG if reg[_src] == 0 => (), ebpf::MOD64_REG => 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 => do_jump(), ebpf::JEQ_IMM => if reg[_dst] == insn.imm as u64 { do_jump(); }, ebpf::JEQ_REG => if reg[_dst] == reg[_src] { do_jump(); }, ebpf::JGT_IMM => if reg[_dst] > insn.imm as u64 { do_jump(); }, ebpf::JGT_REG => if reg[_dst] > reg[_src] { do_jump(); }, ebpf::JGE_IMM => if reg[_dst] >= insn.imm as u64 { do_jump(); }, ebpf::JGE_REG => if reg[_dst] >= reg[_src] { do_jump(); }, ebpf::JLT_IMM => if reg[_dst] < insn.imm as u64 { do_jump(); }, ebpf::JLT_REG => if reg[_dst] < reg[_src] { do_jump(); }, ebpf::JLE_IMM => if reg[_dst] <= insn.imm as u64 { do_jump(); }, ebpf::JLE_REG => if reg[_dst] <= reg[_src] { do_jump(); }, ebpf::JSET_IMM => if reg[_dst] & insn.imm as u64 != 0 { do_jump(); }, ebpf::JSET_REG => if reg[_dst] & reg[_src] != 0 { do_jump(); }, ebpf::JNE_IMM => if reg[_dst] != insn.imm as u64 { do_jump(); }, ebpf::JNE_REG => if reg[_dst] != reg[_src] { do_jump(); }, ebpf::JSGT_IMM => if reg[_dst] as i64 > insn.imm as i64 { do_jump(); }, ebpf::JSGT_REG => if reg[_dst] as i64 > reg[_src] as i64 { do_jump(); }, ebpf::JSGE_IMM => if reg[_dst] as i64 >= insn.imm as i64 { do_jump(); }, ebpf::JSGE_REG => if reg[_dst] as i64 >= reg[_src] as i64 { do_jump(); }, ebpf::JSLT_IMM => if (reg[_dst] as i64) < insn.imm as i64 { do_jump(); }, ebpf::JSLT_REG => if (reg[_dst] as i64) < reg[_src] as i64 { do_jump(); }, ebpf::JSLE_IMM => if reg[_dst] as i64 <= insn.imm as i64 { do_jump(); }, ebpf::JSLE_REG => if reg[_dst] as i64 <= reg[_src] as i64 { do_jump(); }, // BPF_JMP32 class ebpf::JEQ_IMM32 => if reg[_dst] as u32 == insn.imm as u32 { do_jump(); }, ebpf::JEQ_REG32 => if reg[_dst] as u32 == reg[_src] as u32 { do_jump(); }, ebpf::JGT_IMM32 => if reg[_dst] as u32 > insn.imm as u32 { do_jump(); }, ebpf::JGT_REG32 => if reg[_dst] as u32 > reg[_src] as u32 { do_jump(); }, ebpf::JGE_IMM32 => if reg[_dst] as u32 >= insn.imm as u32 { do_jump(); }, ebpf::JGE_REG32 => if reg[_dst] as u32 >= reg[_src] as u32 { do_jump(); }, ebpf::JLT_IMM32 => if (reg[_dst] as u32) < insn.imm as u32 { do_jump(); }, ebpf::JLT_REG32 => if (reg[_dst] as u32) < reg[_src] as u32 { do_jump(); }, ebpf::JLE_IMM32 => if reg[_dst] as u32 <= insn.imm as u32 { do_jump(); }, ebpf::JLE_REG32 => if reg[_dst] as u32 <= reg[_src] as u32 { do_jump(); }, ebpf::JSET_IMM32 => if reg[_dst] as u32 & insn.imm as u32 != 0 { do_jump(); }, ebpf::JSET_REG32 => if reg[_dst] as u32 & reg[_src] as u32 != 0 { do_jump(); }, ebpf::JNE_IMM32 => if reg[_dst] as u32 != insn.imm as u32 { do_jump(); }, ebpf::JNE_REG32 => if reg[_dst] as u32 != reg[_src] as u32 { do_jump(); }, ebpf::JSGT_IMM32 => if reg[_dst] as i32 > insn.imm { do_jump(); }, ebpf::JSGT_REG32 => if reg[_dst] as i32 > reg[_src] as i32 { do_jump(); }, ebpf::JSGE_IMM32 => if reg[_dst] as i32 >= insn.imm { do_jump(); }, ebpf::JSGE_REG32 => if reg[_dst] as i32 >= reg[_src] as i32 { do_jump(); }, ebpf::JSLT_IMM32 => if (reg[_dst] as i32) < insn.imm { do_jump(); }, ebpf::JSLT_REG32 => if (reg[_dst] as i32) < reg[_src] as i32 { do_jump(); }, ebpf::JSLE_IMM32 => if reg[_dst] as i32 <= insn.imm { do_jump(); }, ebpf::JSLE_REG32 => if reg[_dst] as i32 <= reg[_src] as i32 { do_jump(); }, // 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) = 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!() }