xref: /cloud-hypervisor/fuzz/fuzz_targets/net.rs (revision 6fd5b0f696be5a81efd050566eec112a78533468)
1e2e02c8fSBo Chen // Copyright © 2022 Intel Corporation
2e2e02c8fSBo Chen //
3e2e02c8fSBo Chen // SPDX-License-Identifier: Apache-2.0
4e2e02c8fSBo Chen 
5e2e02c8fSBo Chen #![no_main]
6e2e02c8fSBo Chen 
7e2e02c8fSBo Chen use std::fs::File;
8e2e02c8fSBo Chen use std::io::{Read, Write};
9e2e02c8fSBo Chen use std::os::unix::io::{AsRawFd, FromRawFd};
10e2e02c8fSBo Chen use std::sync::Arc;
11f041c940SRob Bradford 
12*6fd5b0f6SWei Liu use libfuzzer_sys::{fuzz_target, Corpus};
13f041c940SRob Bradford use seccompiler::SeccompAction;
14e2e02c8fSBo Chen use virtio_devices::{VirtioDevice, VirtioInterrupt, VirtioInterruptType};
15e2e02c8fSBo Chen use virtio_queue::{Queue, QueueT};
1661e57e1cSRuoqing He use vm_memory::bitmap::AtomicBitmap;
1761e57e1cSRuoqing He use vm_memory::{Bytes, GuestAddress, GuestMemoryAtomic};
18e2e02c8fSBo Chen use vmm::EpollContext;
19e2e02c8fSBo Chen use vmm_sys_util::eventfd::{EventFd, EFD_NONBLOCK};
20e2e02c8fSBo Chen 
21e2e02c8fSBo Chen type GuestMemoryMmap = vm_memory::GuestMemoryMmap<AtomicBitmap>;
22e2e02c8fSBo Chen 
23e2e02c8fSBo Chen macro_rules! align {
24e2e02c8fSBo Chen     ($n:expr, $align:expr) => {{
256164aa08SRuoqing He         $n.div_ceil($align) * $align
26e2e02c8fSBo Chen     }};
27e2e02c8fSBo Chen }
28e2e02c8fSBo Chen 
29e2e02c8fSBo Chen const TAP_INPUT_SIZE: usize = 128;
30e2e02c8fSBo Chen const QUEUE_DATA_SIZE: usize = 4;
31e2e02c8fSBo Chen const MEM_SIZE: usize = 32 * 1024 * 1024;
32e2e02c8fSBo Chen // Guest memory gap
33e2e02c8fSBo Chen const GUEST_MEM_GAP: u64 = 1 * 1024 * 1024;
34e2e02c8fSBo Chen // Guest physical address for the first virt queue
35e2e02c8fSBo Chen const BASE_VIRT_QUEUE_ADDR: u64 = MEM_SIZE as u64 + GUEST_MEM_GAP;
36e2e02c8fSBo Chen // Number of queues
37e2e02c8fSBo Chen const QUEUE_NUM: usize = 2;
38e2e02c8fSBo Chen // Max entries in the queue.
39e2e02c8fSBo Chen const QUEUE_SIZE: u16 = 256;
40e2e02c8fSBo Chen // Descriptor table alignment
41e2e02c8fSBo Chen const DESC_TABLE_ALIGN_SIZE: u64 = 16;
42e2e02c8fSBo Chen // Used ring alignment
43e2e02c8fSBo Chen const USED_RING_ALIGN_SIZE: u64 = 4;
44e2e02c8fSBo Chen // Descriptor table size
45e2e02c8fSBo Chen const DESC_TABLE_SIZE: u64 = 16_u64 * QUEUE_SIZE as u64;
46e2e02c8fSBo Chen // Available ring size
47e2e02c8fSBo Chen const AVAIL_RING_SIZE: u64 = 6_u64 + 2 * QUEUE_SIZE as u64;
48e2e02c8fSBo Chen // Padding size before used ring
49e2e02c8fSBo Chen const PADDING_SIZE: u64 = align!(AVAIL_RING_SIZE, USED_RING_ALIGN_SIZE) - AVAIL_RING_SIZE;
50e2e02c8fSBo Chen // Used ring size
51e2e02c8fSBo Chen const USED_RING_SIZE: u64 = 6_u64 + 8 * QUEUE_SIZE as u64;
52e2e02c8fSBo Chen // Virtio-queue size in bytes
53e2e02c8fSBo Chen const QUEUE_BYTES_SIZE: usize = align!(
54e2e02c8fSBo Chen     DESC_TABLE_SIZE + AVAIL_RING_SIZE + PADDING_SIZE + USED_RING_SIZE,
55e2e02c8fSBo Chen     DESC_TABLE_ALIGN_SIZE
56e2e02c8fSBo Chen ) as usize;
57e2e02c8fSBo Chen 
58*6fd5b0f6SWei Liu fuzz_target!(|bytes: &[u8]| -> Corpus {
59e2e02c8fSBo Chen     if bytes.len() < TAP_INPUT_SIZE + (QUEUE_DATA_SIZE + QUEUE_BYTES_SIZE) * QUEUE_NUM
60e2e02c8fSBo Chen         || bytes.len()
61e2e02c8fSBo Chen             > TAP_INPUT_SIZE + (QUEUE_DATA_SIZE + QUEUE_BYTES_SIZE) * QUEUE_NUM + MEM_SIZE
62e2e02c8fSBo Chen     {
63*6fd5b0f6SWei Liu         return Corpus::Reject;
64e2e02c8fSBo Chen     }
65e2e02c8fSBo Chen 
66e2e02c8fSBo Chen     let (dummy_tap_frontend, dummy_tap_backend) = create_socketpair().unwrap();
67e2e02c8fSBo Chen     let if_name = "fuzzer_tap_name".as_bytes().to_vec();
68e2e02c8fSBo Chen     let tap = net_util::Tap::new_for_fuzzing(dummy_tap_frontend, if_name);
69e2e02c8fSBo Chen 
70e2e02c8fSBo Chen     let mut net = virtio_devices::Net::new_with_tap(
71e2e02c8fSBo Chen         "fuzzer_net".to_owned(),
72e2e02c8fSBo Chen         vec![tap],
73e2e02c8fSBo Chen         None,  // guest_mac
74e2e02c8fSBo Chen         false, // iommu
75e2e02c8fSBo Chen         QUEUE_NUM,
76e2e02c8fSBo Chen         QUEUE_SIZE,
77e2e02c8fSBo Chen         SeccompAction::Allow,
78e2e02c8fSBo Chen         None,
79e2e02c8fSBo Chen         EventFd::new(EFD_NONBLOCK).unwrap(),
80e2e02c8fSBo Chen         None,
813494080eSYong He         true,
823494080eSYong He         true,
833494080eSYong He         true,
84e2e02c8fSBo Chen     )
85e2e02c8fSBo Chen     .unwrap();
86e2e02c8fSBo Chen 
87e2e02c8fSBo Chen     let tap_input_bytes = &bytes[..TAP_INPUT_SIZE];
88e2e02c8fSBo Chen     let queue_data = &bytes[TAP_INPUT_SIZE..TAP_INPUT_SIZE + QUEUE_DATA_SIZE * QUEUE_NUM];
89e2e02c8fSBo Chen     let queue_bytes = &bytes[TAP_INPUT_SIZE + QUEUE_DATA_SIZE * QUEUE_NUM
90e2e02c8fSBo Chen         ..TAP_INPUT_SIZE + (QUEUE_DATA_SIZE + QUEUE_BYTES_SIZE) * QUEUE_NUM];
91e2e02c8fSBo Chen     let mem_bytes = &bytes[TAP_INPUT_SIZE + (QUEUE_DATA_SIZE + QUEUE_BYTES_SIZE) * QUEUE_NUM..];
92e2e02c8fSBo Chen 
93e2e02c8fSBo Chen     // Setup the virt queues with the input bytes
94e2e02c8fSBo Chen     let mut queues = setup_virt_queues(
95e2e02c8fSBo Chen         &[
96e2e02c8fSBo Chen             &queue_data[..QUEUE_DATA_SIZE].try_into().unwrap(),
97e2e02c8fSBo Chen             &queue_data[QUEUE_DATA_SIZE..QUEUE_DATA_SIZE * 2]
98e2e02c8fSBo Chen                 .try_into()
99e2e02c8fSBo Chen                 .unwrap(),
100e2e02c8fSBo Chen         ],
101e2e02c8fSBo Chen         BASE_VIRT_QUEUE_ADDR,
102e2e02c8fSBo Chen     );
103e2e02c8fSBo Chen 
104e2e02c8fSBo Chen     // Setup the guest memory with the input bytes
105e2e02c8fSBo Chen     let mem = GuestMemoryMmap::from_ranges(&[
106e2e02c8fSBo Chen         (GuestAddress(0), MEM_SIZE),
107e2e02c8fSBo Chen         (GuestAddress(BASE_VIRT_QUEUE_ADDR), queue_bytes.len()),
108e2e02c8fSBo Chen     ])
109e2e02c8fSBo Chen     .unwrap();
110e2e02c8fSBo Chen     if mem
111e2e02c8fSBo Chen         .write_slice(queue_bytes, GuestAddress(BASE_VIRT_QUEUE_ADDR))
112e2e02c8fSBo Chen         .is_err()
113e2e02c8fSBo Chen     {
114*6fd5b0f6SWei Liu         return Corpus::Reject;
115e2e02c8fSBo Chen     }
116e2e02c8fSBo Chen     if mem.write_slice(mem_bytes, GuestAddress(0 as u64)).is_err() {
117*6fd5b0f6SWei Liu         return Corpus::Reject;
118e2e02c8fSBo Chen     }
119e2e02c8fSBo Chen     let guest_memory = GuestMemoryAtomic::new(mem);
120e2e02c8fSBo Chen 
121e2e02c8fSBo Chen     let input_queue = queues.remove(0);
122e2e02c8fSBo Chen     let input_evt = EventFd::new(0).unwrap();
123e2e02c8fSBo Chen     let input_queue_evt = unsafe { EventFd::from_raw_fd(libc::dup(input_evt.as_raw_fd())) };
124e2e02c8fSBo Chen     let output_queue = queues.remove(0);
125e2e02c8fSBo Chen     let output_evt = EventFd::new(0).unwrap();
126e2e02c8fSBo Chen     let output_queue_evt = unsafe { EventFd::from_raw_fd(libc::dup(output_evt.as_raw_fd())) };
127e2e02c8fSBo Chen 
128e2e02c8fSBo Chen     // Start the thread of dummy tap backend to handle the rx and tx from the virtio-net
129e2e02c8fSBo Chen     let exit_evt = EventFd::new(libc::EFD_NONBLOCK).unwrap();
130e2e02c8fSBo Chen     let tap_backend_thread = {
131e2e02c8fSBo Chen         let dummy_tap_backend = dummy_tap_backend.try_clone().unwrap();
132e2e02c8fSBo Chen         let tap_input_bytes: [u8; TAP_INPUT_SIZE] = tap_input_bytes[..].try_into().unwrap();
133e2e02c8fSBo Chen         let exit_evt = exit_evt.try_clone().unwrap();
134e2e02c8fSBo Chen         std::thread::Builder::new()
135e2e02c8fSBo Chen             .name("dummy_tap_backend".to_string())
136e2e02c8fSBo Chen             .spawn(move || {
137e2e02c8fSBo Chen                 tap_backend_stub(dummy_tap_backend, &tap_input_bytes, exit_evt);
138e2e02c8fSBo Chen             })
139e2e02c8fSBo Chen             .unwrap()
140e2e02c8fSBo Chen     };
141e2e02c8fSBo Chen 
142e2e02c8fSBo Chen     // Kick the 'queue' events and endpoint event before activate the net device
143e2e02c8fSBo Chen     input_queue_evt.write(1).unwrap();
144e2e02c8fSBo Chen     output_queue_evt.write(1).unwrap();
145e2e02c8fSBo Chen 
146e2e02c8fSBo Chen     net.activate(
147e2e02c8fSBo Chen         guest_memory,
148e2e02c8fSBo Chen         Arc::new(NoopVirtioInterrupt {}),
149e2e02c8fSBo Chen         vec![(0, input_queue, input_evt), (1, output_queue, output_evt)],
150e2e02c8fSBo Chen     )
151e2e02c8fSBo Chen     .unwrap();
152e2e02c8fSBo Chen 
153e2e02c8fSBo Chen     // Wait for the events to finish and net device worker thread to return
154e2e02c8fSBo Chen     net.wait_for_epoll_threads();
155e2e02c8fSBo Chen     // Terminate the thread for the dummy tap backend
156e2e02c8fSBo Chen     exit_evt.write(1).ok();
157e2e02c8fSBo Chen     tap_backend_thread.join().unwrap();
158*6fd5b0f6SWei Liu 
159*6fd5b0f6SWei Liu     return Corpus::Keep;
160e2e02c8fSBo Chen });
161e2e02c8fSBo Chen 
162e2e02c8fSBo Chen pub struct NoopVirtioInterrupt {}
163e2e02c8fSBo Chen 
164e2e02c8fSBo Chen impl VirtioInterrupt for NoopVirtioInterrupt {
trigger(&self, _int_type: VirtioInterruptType) -> std::result::Result<(), std::io::Error>165e2e02c8fSBo Chen     fn trigger(&self, _int_type: VirtioInterruptType) -> std::result::Result<(), std::io::Error> {
166e2e02c8fSBo Chen         Ok(())
167e2e02c8fSBo Chen     }
168e2e02c8fSBo Chen }
169e2e02c8fSBo Chen 
setup_virt_queues(bytes: &[&[u8; QUEUE_DATA_SIZE]], base_addr: u64) -> Vec<Queue>170e2e02c8fSBo Chen fn setup_virt_queues(bytes: &[&[u8; QUEUE_DATA_SIZE]], base_addr: u64) -> Vec<Queue> {
171e2e02c8fSBo Chen     let mut queues = Vec::new();
172e2e02c8fSBo Chen     for (i, b) in bytes.iter().enumerate() {
173e2e02c8fSBo Chen         let mut q = Queue::new(QUEUE_SIZE).unwrap();
174e2e02c8fSBo Chen 
175e2e02c8fSBo Chen         let desc_table_addr = base_addr + (QUEUE_BYTES_SIZE * i) as u64;
176e2e02c8fSBo Chen         let avail_ring_addr = desc_table_addr + DESC_TABLE_SIZE;
177e2e02c8fSBo Chen         let used_ring_addr = avail_ring_addr + PADDING_SIZE + AVAIL_RING_SIZE;
178e2e02c8fSBo Chen         q.try_set_desc_table_address(GuestAddress(desc_table_addr))
179e2e02c8fSBo Chen             .unwrap();
180e2e02c8fSBo Chen         q.try_set_avail_ring_address(GuestAddress(avail_ring_addr))
181e2e02c8fSBo Chen             .unwrap();
182e2e02c8fSBo Chen         q.try_set_used_ring_address(GuestAddress(used_ring_addr))
183e2e02c8fSBo Chen             .unwrap();
184e2e02c8fSBo Chen 
185e2e02c8fSBo Chen         q.set_next_avail(b[0] as u16); // 'u8' is enough given the 'QUEUE_SIZE' is small
186e2e02c8fSBo Chen         q.set_next_used(b[1] as u16);
187e2e02c8fSBo Chen         q.set_event_idx(b[2] % 2 != 0);
188e2e02c8fSBo Chen         q.set_size(b[3] as u16 % QUEUE_SIZE);
189e2e02c8fSBo Chen 
190e2e02c8fSBo Chen         q.set_ready(true);
191e2e02c8fSBo Chen         queues.push(q);
192e2e02c8fSBo Chen     }
193e2e02c8fSBo Chen 
194e2e02c8fSBo Chen     queues
195e2e02c8fSBo Chen }
196e2e02c8fSBo Chen 
create_socketpair() -> Result<(File, File), std::io::Error>197e2e02c8fSBo Chen fn create_socketpair() -> Result<(File, File), std::io::Error> {
198e2e02c8fSBo Chen     let mut fds = [-1, -1];
199e2e02c8fSBo Chen     unsafe {
200e2e02c8fSBo Chen         let ret = libc::socketpair(
201e2e02c8fSBo Chen             libc::AF_UNIX,
202e2e02c8fSBo Chen             libc::SOCK_STREAM | libc::SOCK_NONBLOCK,
203e2e02c8fSBo Chen             0,
204e2e02c8fSBo Chen             fds.as_mut_ptr(),
205e2e02c8fSBo Chen         );
206e2e02c8fSBo Chen         if ret == -1 {
207e2e02c8fSBo Chen             return Err(std::io::Error::last_os_error());
208e2e02c8fSBo Chen         }
209e2e02c8fSBo Chen     }
210e2e02c8fSBo Chen 
211e2e02c8fSBo Chen     let socket1 = unsafe { File::from_raw_fd(fds[0]) };
212e2e02c8fSBo Chen     let socket2 = unsafe { File::from_raw_fd(fds[1]) };
213e2e02c8fSBo Chen     Ok((socket1, socket2))
214e2e02c8fSBo Chen }
215e2e02c8fSBo Chen 
216e2e02c8fSBo Chen enum EpollEvent {
217e2e02c8fSBo Chen     Exit = 0,
218e2e02c8fSBo Chen     Rx = 1,
219e2e02c8fSBo Chen     Tx = 2,
220e2e02c8fSBo Chen     Unknown,
221e2e02c8fSBo Chen }
222e2e02c8fSBo Chen 
223e2e02c8fSBo Chen impl From<u64> for EpollEvent {
from(v: u64) -> Self224e2e02c8fSBo Chen     fn from(v: u64) -> Self {
225e2e02c8fSBo Chen         use EpollEvent::*;
226e2e02c8fSBo Chen         match v {
227e2e02c8fSBo Chen             0 => Exit,
228e2e02c8fSBo Chen             1 => Rx,
229e2e02c8fSBo Chen             2 => Tx,
230e2e02c8fSBo Chen             _ => Unknown,
231e2e02c8fSBo Chen         }
232e2e02c8fSBo Chen     }
233e2e02c8fSBo Chen }
234e2e02c8fSBo Chen 
235e2e02c8fSBo Chen // Handle the rx and tx requests from the virtio-net device
tap_backend_stub( mut dummy_tap: File, tap_input_bytes: &[u8; TAP_INPUT_SIZE], exit_evt: EventFd, )236e2e02c8fSBo Chen fn tap_backend_stub(
237e2e02c8fSBo Chen     mut dummy_tap: File,
238e2e02c8fSBo Chen     tap_input_bytes: &[u8; TAP_INPUT_SIZE],
239e2e02c8fSBo Chen     exit_evt: EventFd,
240e2e02c8fSBo Chen ) {
241e2e02c8fSBo Chen     let mut epoll = EpollContext::new().unwrap();
242e2e02c8fSBo Chen     epoll
243e2e02c8fSBo Chen         .add_event_custom(&exit_evt, EpollEvent::Exit as u64, epoll::Events::EPOLLIN)
244e2e02c8fSBo Chen         .unwrap();
245e2e02c8fSBo Chen     let dummy_tap_write = dummy_tap.try_clone().unwrap();
246e2e02c8fSBo Chen     epoll
247e2e02c8fSBo Chen         .add_event_custom(
248e2e02c8fSBo Chen             &dummy_tap_write,
249e2e02c8fSBo Chen             EpollEvent::Rx as u64,
250e2e02c8fSBo Chen             epoll::Events::EPOLLOUT,
251e2e02c8fSBo Chen         )
252e2e02c8fSBo Chen         .unwrap();
253e2e02c8fSBo Chen     epoll
254e2e02c8fSBo Chen         .add_event_custom(&dummy_tap, EpollEvent::Tx as u64, epoll::Events::EPOLLIN)
255e2e02c8fSBo Chen         .unwrap();
256e2e02c8fSBo Chen 
257e2e02c8fSBo Chen     let epoll_fd = epoll.as_raw_fd();
258e2e02c8fSBo Chen     let mut events = vec![epoll::Event::new(epoll::Events::empty(), 0); 3];
259e2e02c8fSBo Chen     loop {
260e2e02c8fSBo Chen         let num_events = match epoll::wait(epoll_fd, -1, &mut events[..]) {
261e2e02c8fSBo Chen             Ok(num_events) => num_events,
262e2e02c8fSBo Chen             Err(e) => match e.raw_os_error() {
263e2e02c8fSBo Chen                 Some(libc::EAGAIN) | Some(libc::EINTR) => continue,
264e2e02c8fSBo Chen                 _ => panic!("Unexpected epoll::wait error!"),
265e2e02c8fSBo Chen             },
266e2e02c8fSBo Chen         };
267e2e02c8fSBo Chen 
268e2e02c8fSBo Chen         for event in events.iter().take(num_events) {
269e2e02c8fSBo Chen             let dispatch_event: EpollEvent = event.data.into();
270e2e02c8fSBo Chen             match dispatch_event {
271e2e02c8fSBo Chen                 EpollEvent::Exit => {
272e2e02c8fSBo Chen                     return;
273e2e02c8fSBo Chen                 }
274e2e02c8fSBo Chen                 EpollEvent::Rx => {
275e2e02c8fSBo Chen                     dummy_tap.write_all(tap_input_bytes).unwrap();
276e2e02c8fSBo Chen                     break;
277e2e02c8fSBo Chen                 }
278e2e02c8fSBo Chen                 EpollEvent::Tx => {
279e2e02c8fSBo Chen                     let mut buffer = Vec::new();
280e2e02c8fSBo Chen                     dummy_tap.read_to_end(&mut buffer).ok();
281e2e02c8fSBo Chen                     break;
282e2e02c8fSBo Chen                 }
283e2e02c8fSBo Chen                 _ => {
284e2e02c8fSBo Chen                     panic!("Unexpected Epoll event");
285e2e02c8fSBo Chen                 }
286e2e02c8fSBo Chen             }
287e2e02c8fSBo Chen         }
288e2e02c8fSBo Chen     }
289e2e02c8fSBo Chen }
290