rbpf/tests/misc.rs

// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
//
// 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.


// These crates would be needed to load bytecode from a BPF-compiled object file. Since the crates
// are not used anywhere else in the library, it is deactivated: we do not want to load and compile
// them just for the tests. If you want to use them, do not forget to add the following
// dependencies to your Cargo.toml file:
//
// ---
// byteorder = "0.5.3"
// elf = "0.0.10"
// ---
//
// extern crate byteorder;
// extern crate elf;
// use std::path::PathBuf;

extern crate rbpf;
use rbpf::helpers;

// The following two examples have been compiled from C with the following command:
//
// ```bash
//  clang -O2 -emit-llvm -c <file.c> -o - | llc -march=bpf -filetype=obj -o <file.o>
// ```
//
// The C source code was the following:
//
// ```c
// #include <linux/ip.h>
// #include <linux/in.h>
// #include <linux/tcp.h>
// #include <linux/bpf.h>
//
// #define ETH_ALEN 6
// #define ETH_P_IP 0x0008 /* htons(0x0800) */
// #define TCP_HDR_LEN 20
//
// #define BLOCKED_TCP_PORT 0x9999
//
// struct eth_hdr {
//     unsigned char   h_dest[ETH_ALEN];
//     unsigned char   h_source[ETH_ALEN];
//     unsigned short  h_proto;
// };
//
// #define SEC(NAME) __attribute__((section(NAME), used))
// SEC(".classifier")
// int handle_ingress(struct __sk_buff *skb)
// {
//     void *data = (void *)(long)skb->data;
//     void *data_end = (void *)(long)skb->data_end;
//     struct eth_hdr *eth = data;
//     struct iphdr *iph = data + sizeof(*eth);
//     struct tcphdr *tcp = data + sizeof(*eth) + sizeof(*iph);
//
//     /* single length check */
//     if (data + sizeof(*eth) + sizeof(*iph) + sizeof(*tcp) > data_end)
//         return 0;
//     if (eth->h_proto != ETH_P_IP)
//         return 0;
//     if (iph->protocol != IPPROTO_TCP)
//         return 0;
//     if (tcp->source == BLOCKED_TCP_PORT || tcp->dest == BLOCKED_TCP_PORT)
//         return -1;
//     return 0;
// }
// char _license[] SEC(".license") = "GPL";
// ```
//
// This program, once compiled, can be injected into Linux kernel, with tc for instance. Sadly, we
// need to bring some modifications to the generated bytecode in order to run it: the three
// instructions with opcode 0x61 load data from a packet area as 4-byte words, where we need to
// load it as 8-bytes double words (0x79). The kernel does the same kind of translation before
// running the program, but rbpf does not implement this.
//
// In addition, the offset at which the pointer to the packet data is stored must be changed: since
// we use 8 bytes instead of 4 for the start and end addresses of the data packet, we cannot use
// the offsets produced by clang (0x4c and 0x50), the addresses would overlap. Instead we can use,
// for example, 0x40 and 0x50. See comments on the bytecode below to see the modifications.
//
// Once the bytecode has been (manually, in our case) edited, we can load the bytecode directly
// from the ELF object file. This is easy to do, but requires the addition of two crates in the
// Cargo.toml file (see comments above), so here we use just the hardcoded bytecode instructions
// instead.

#[test]
fn test_vm_block_port() {
    // To load the bytecode from an object file instead of using the hardcoded instructions,
    // use the additional crates commented at the beginning of this file (and also add them to your
    // Cargo.toml). See comments above.
    //
    // ---
    // let filename = "my_ebpf_object_file.o";
    //
    // let path = PathBuf::from(filename);
    // let file = match elf::File::open_path(&path) {
    //     Ok(f) => f,
    //     Err(e) => panic!("Error: {:?}", e),
    // };
    //
    // let text_scn = match file.get_section(".classifier") {
    //     Some(s) => s,
    //     None => panic!("Failed to look up .classifier section"),
    // };
    //
    // let ref prog = &text_scn.data;
    // ---

    let prog = vec![
        0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x79, 0x12, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // 0x79 instead of 0x61
        0x79, 0x11, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // 0x79 instead of 0x61, 0x40 i.o. 0x4c
        0xbf, 0x13, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x07, 0x03, 0x00, 0x00, 0x36, 0x00, 0x00, 0x00,
        0x2d, 0x23, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x69, 0x12, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x55, 0x02, 0x10, 0x00, 0x08, 0x00, 0x00, 0x00,
        0x71, 0x12, 0x17, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x55, 0x02, 0x0e, 0x00, 0x06, 0x00, 0x00, 0x00,
        0x18, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x79, 0x11, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00, // 0x79 instead of 0x61
        0xbf, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x57, 0x02, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00,
        0x15, 0x02, 0x08, 0x00, 0x99, 0x99, 0x00, 0x00,
        0x18, 0x02, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x5f, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0xb7, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
        0x18, 0x02, 0x00, 0x00, 0x00, 0x00, 0x99, 0x99,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x1d, 0x21, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
        0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
    ];

    let mut packet = vec![
        0x01, 0x23, 0x45, 0x67, 0x89, 0xab,
        0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54,
        0x08, 0x00, // ethertype
        0x45, 0x00, 0x00, 0x3b, // start ip_hdr
        0xa6, 0xab, 0x40, 0x00,
        0x40, 0x06, 0x96, 0x0f,
        0x7f, 0x00, 0x00, 0x01,
        0x7f, 0x00, 0x00, 0x01,
        // Program matches the next two bytes: 0x9999 returns 0xffffffff, else return 0.
        0x99, 0x99, 0xc6, 0xcc, // start tcp_hdr
        0xd1, 0xe5, 0xc4, 0x9d,
        0xd4, 0x30, 0xb5, 0xd2,
        0x80, 0x18, 0x01, 0x56,
        0xfe, 0x2f, 0x00, 0x00,
        0x01, 0x01, 0x08, 0x0a, // start data
        0x00, 0x23, 0x75, 0x89,
        0x00, 0x23, 0x63, 0x2d,
        0x71, 0x64, 0x66, 0x73,
        0x64, 0x66, 0x0au8
    ];

    let mut vm = rbpf::EbpfVmFixedMbuff::new(&prog, 0x40, 0x50);
    vm.register_helper(helpers::BPF_TRACE_PRINTF_IDX, helpers::bpf_trace_printf);

    let res = vm.prog_exec(&mut packet);
    println!("Program returned: {:?} ({:#x})", res, res);
    assert_eq!(res, 0xffffffff);
}

#[test]
fn test_jit_block_port() {
    // To load the bytecode from an object file instead of using the hardcoded instructions,
    // use the additional crates commented at the beginning of this file (and also add them to your
    // Cargo.toml). See comments above.
    //
    // ---
    // let filename = "my_ebpf_object_file.o";
    //
    // let path = PathBuf::from(filename);
    // let file = match elf::File::open_path(&path) {
    //     Ok(f) => f,
    //     Err(e) => panic!("Error: {:?}", e),
    // };
    //
    // let text_scn = match file.get_section(".classifier") {
    //     Some(s) => s,
    //     None => panic!("Failed to look up .classifier section"),
    // };
    //
    // let ref prog = &text_scn.data;
    // ---

    let prog = vec![
        0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x79, 0x12, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, // 0x79 instead of 0x61
        0x79, 0x11, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, // 0x79 instead of 0x61, 0x40 i.o. 0x4c
        0xbf, 0x13, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x07, 0x03, 0x00, 0x00, 0x36, 0x00, 0x00, 0x00,
        0x2d, 0x23, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x69, 0x12, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x55, 0x02, 0x10, 0x00, 0x08, 0x00, 0x00, 0x00,
        0x71, 0x12, 0x17, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x55, 0x02, 0x0e, 0x00, 0x06, 0x00, 0x00, 0x00,
        0x18, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x79, 0x11, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00, // 0x79 instead of 0x61
        0xbf, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x57, 0x02, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00,
        0x15, 0x02, 0x08, 0x00, 0x99, 0x99, 0x00, 0x00,
        0x18, 0x02, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x5f, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0xb7, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
        0x18, 0x02, 0x00, 0x00, 0x00, 0x00, 0x99, 0x99,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x1d, 0x21, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
        0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
    ];

    let mut packet = vec![
        0x01, 0x23, 0x45, 0x67, 0x89, 0xab,
        0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54,
        0x08, 0x00, // ethertype
        0x45, 0x00, 0x00, 0x3b, // start ip_hdr
        0xa6, 0xab, 0x40, 0x00,
        0x40, 0x06, 0x96, 0x0f,
        0x7f, 0x00, 0x00, 0x01,
        0x7f, 0x00, 0x00, 0x01,
        // Program matches the next two bytes: 0x9999 returns 0xffffffff, else return 0.
        0x99, 0x99, 0xc6, 0xcc, // start tcp_hdr
        0xd1, 0xe5, 0xc4, 0x9d,
        0xd4, 0x30, 0xb5, 0xd2,
        0x80, 0x18, 0x01, 0x56,
        0xfe, 0x2f, 0x00, 0x00,
        0x01, 0x01, 0x08, 0x0a, // start data
        0x00, 0x23, 0x75, 0x89,
        0x00, 0x23, 0x63, 0x2d,
        0x71, 0x64, 0x66, 0x73,
        0x64, 0x66, 0x0au8
    ];

    let mut vm = rbpf::EbpfVmFixedMbuff::new(&prog, 0x40, 0x50);
    vm.register_helper(helpers::BPF_TRACE_PRINTF_IDX, helpers::bpf_trace_printf);
    vm.jit_compile();

    let res = vm.prog_exec_jit(&mut packet);
    println!("Program returned: {:?} ({:#x})", res, res);
    assert_eq!(res, 0xffffffff);
}

// Program and memory come from uBPF test ldxh.
#[test]
fn test_vm_mbuff() {
    let prog = vec![
        // Load mem from mbuff into R1
        0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
        // ldhx r1[2], r0
        0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
    ];
    let mut mem = vec![
        0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
    ];

    let mbuff = vec![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;
    }

    let vm = rbpf::EbpfVmMbuff::new(&prog);
    assert_eq!(vm.prog_exec(&mut mem, mbuff), 0x2211);
}

// Program and memory come from uBPF test ldxh.
#[test]
fn test_jit_mbuff() {
    let prog = vec![
        // Load mem from mbuff into R1
        0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
        // ldhx r1[2], r0
        0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
    ];
    let mut mem = vec![
        0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
    ];

    let mbuff = vec![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;
    }

    let mut vm = rbpf::EbpfVmMbuff::new(&prog);
    vm.jit_compile();
    assert_eq!(vm.prog_exec_jit(&mut mem, mbuff), 0x2211);
}