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//! pcap is a packet capture library available on Linux, Windows and Mac. This
//! crate supports creating and configuring capture contexts, sniffing packets,
//! sending packets to interfaces, listing devices, and recording packet captures
//! to pcap-format dump files.
//!
//! # Capturing packets
//! The easiest way to open an active capture handle and begin sniffing is to
//! use `.open()` on a `Device`. You can obtain the "default" device using
//! `Device::lookup()`, or you can obtain the device(s) you need via `Device::list()`.
//!
//! ```no_run
//! use pcap::Device;
//!
//! let mut cap = Device::lookup().unwrap().unwrap().open().unwrap();
//!
//! while let Ok(packet) = cap.next_packet() {
//! println!("received packet! {:?}", packet);
//! }
//!
//! ```
//!
//! `Capture`'s `.next_packet()` will produce a `Packet` which can be dereferenced to access the
//! `&[u8]` packet contents.
//!
//! # Custom configuration
//!
//! You may want to configure the `timeout`, `snaplen` or other parameters for the capture
//! handle. In this case, use `Capture::from_device()` to obtain a `Capture<Inactive>`, and
//! proceed to configure the capture handle. When you're finished, run `.open()` on it to
//! turn it into a `Capture<Active>`.
//!
//! ```no_run
//! use pcap::{Device, Capture};
//!
//! let main_device = Device::lookup().unwrap().unwrap();
//! let mut cap = Capture::from_device(main_device).unwrap()
//! .promisc(true)
//! .snaplen(5000)
//! .open().unwrap();
//!
//! while let Ok(packet) = cap.next_packet() {
//! println!("received packet! {:?}", packet);
//! }
//! ```
//!
//! # Abstracting over different capture types
//!
//! You can abstract over live captures (`Capture<Active>`) and file captures
//! (`Capture<Offline>`) using generics and the [`Activated`] trait, for example:
//!
//! ```
//! use pcap::{Activated, Capture};
//!
//! fn read_packets<T: Activated>(mut capture: Capture<T>) {
//! while let Ok(packet) = capture.next_packet() {
//! println!("received packet! {:?}", packet);
//! }
//! }
//! ```
use bitflags::bitflags;
use std::borrow::Borrow;
use std::convert::TryFrom;
use std::ffi::{self, CStr, CString};
use std::fmt;
use std::marker::PhantomData;
use std::mem;
use std::net::IpAddr;
use std::ops::Deref;
#[cfg(not(windows))]
use std::os::unix::io::{AsRawFd, RawFd};
use std::path::Path;
use std::ptr::{self, NonNull};
use std::slice;
use self::Error::*;
#[cfg(target_os = "windows")]
use windows_sys::Win32::Networking::WinSock::{AF_INET, AF_INET6, SOCKADDR_IN, SOCKADDR_IN6};
#[cfg(target_os = "windows")]
use windows_sys::Win32::Foundation::HANDLE;
mod raw;
#[cfg(windows)]
pub mod sendqueue;
#[cfg(feature = "capture-stream")]
mod stream;
#[cfg(feature = "capture-stream")]
pub use stream::PacketStream;
mod iterator;
pub use iterator::PacketIter;
mod codec;
pub use codec::PacketCodec;
/// An error received from pcap
#[derive(Debug, PartialEq, Eq)]
pub enum Error {
/// The underlying library returned invalid UTF-8
MalformedError(std::str::Utf8Error),
/// The underlying library returned a null string
InvalidString,
/// The unerlying library returned an error
PcapError(String),
/// The linktype was invalid or unknown
InvalidLinktype,
/// The timeout expired while reading from a live capture
TimeoutExpired,
/// No more packets to read from the file
NoMorePackets,
/// Must be in non-blocking mode to function
NonNonBlock,
/// There is not sufficent memory to create a dead capture
InsufficientMemory,
/// An invalid input string (internal null)
InvalidInputString,
/// An IO error occurred
IoError(std::io::ErrorKind),
#[cfg(not(windows))]
/// An invalid raw file descriptor was provided
InvalidRawFd,
/// Errno error
ErrnoError(errno::Errno),
/// Buffer size overflows capacity
BufferOverflow,
}
impl Error {
unsafe fn new(ptr: *const libc::c_char) -> Error {
match cstr_to_string(ptr) {
Err(e) => e as Error,
Ok(string) => PcapError(string.unwrap_or_default()),
}
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
MalformedError(ref e) => write!(f, "libpcap returned invalid UTF-8: {}", e),
InvalidString => write!(f, "libpcap returned a null string"),
PcapError(ref e) => write!(f, "libpcap error: {}", e),
InvalidLinktype => write!(f, "invalid or unknown linktype"),
TimeoutExpired => write!(f, "timeout expired while reading from a live capture"),
NonNonBlock => write!(f, "must be in non-blocking mode to function"),
NoMorePackets => write!(f, "no more packets to read from the file"),
InsufficientMemory => write!(f, "insufficient memory"),
InvalidInputString => write!(f, "invalid input string (internal null)"),
IoError(ref e) => write!(f, "io error occurred: {:?}", e),
#[cfg(not(windows))]
InvalidRawFd => write!(f, "invalid raw file descriptor provided"),
ErrnoError(ref e) => write!(f, "libpcap os errno: {}", e),
BufferOverflow => write!(f, "buffer size too large"),
}
}
}
impl std::error::Error for Error {
fn description(&self) -> &str {
match *self {
MalformedError(..) => "libpcap returned invalid UTF-8",
PcapError(..) => "libpcap FFI error",
InvalidString => "libpcap returned a null string",
InvalidLinktype => "invalid or unknown linktype",
TimeoutExpired => "timeout expired while reading from a live capture",
NonNonBlock => "must be in non-blocking mode to function",
NoMorePackets => "no more packets to read from the file",
InsufficientMemory => "insufficient memory",
InvalidInputString => "invalid input string (internal null)",
IoError(..) => "io error occurred",
#[cfg(not(windows))]
InvalidRawFd => "invalid raw file descriptor provided",
ErrnoError(..) => "internal error, providing errno",
BufferOverflow => "buffer size too large",
}
}
fn cause(&self) -> Option<&dyn std::error::Error> {
match *self {
MalformedError(ref e) => Some(e),
_ => None,
}
}
}
impl From<ffi::NulError> for Error {
fn from(_: ffi::NulError) -> Error {
InvalidInputString
}
}
impl From<std::str::Utf8Error> for Error {
fn from(obj: std::str::Utf8Error) -> Error {
MalformedError(obj)
}
}
impl From<std::io::Error> for Error {
fn from(obj: std::io::Error) -> Error {
IoError(obj.kind())
}
}
impl From<std::io::ErrorKind> for Error {
fn from(obj: std::io::ErrorKind) -> Error {
IoError(obj)
}
}
bitflags! {
/// Network device flags.
pub struct IfFlags: u32 {
/// Set if the device is a loopback interface
const LOOPBACK = raw::PCAP_IF_LOOPBACK;
/// Set if the device is up
const UP = raw::PCAP_IF_UP;
/// Set if the device is running
const RUNNING = raw::PCAP_IF_RUNNING;
/// Set if the device is a wireless interface; this includes IrDA as well as radio-based
/// networks such as IEEE 802.15.4 and IEEE 802.11, so it doesn't just mean Wi-Fi
const WIRELESS = raw::PCAP_IF_WIRELESS;
}
}
impl From<u32> for IfFlags {
fn from(flags: u32) -> Self {
IfFlags::from_bits_truncate(flags)
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
/// Indication of whether the adapter is connected or not; for wireless interfaces, "connected"
/// means "associated with a network".
pub enum ConnectionStatus {
/// It's unknown whether the adapter is connected or not
Unknown,
/// The adapter is connected
Connected,
/// The adapter is disconnected
Disconnected,
/// The notion of "connected" and "disconnected" don't apply to this interface; for example, it
/// doesn't apply to a loopback device
NotApplicable,
}
impl From<u32> for ConnectionStatus {
fn from(flags: u32) -> Self {
match flags & raw::PCAP_IF_CONNECTION_STATUS {
raw::PCAP_IF_CONNECTION_STATUS_UNKNOWN => ConnectionStatus::Unknown,
raw::PCAP_IF_CONNECTION_STATUS_CONNECTED => ConnectionStatus::Connected,
raw::PCAP_IF_CONNECTION_STATUS_DISCONNECTED => ConnectionStatus::Disconnected,
raw::PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE => ConnectionStatus::NotApplicable,
// DeviceFlags::CONNECTION_STATUS should be a 2-bit mask which means that the four
// values should cover all the possibilities.
_ => unreachable!(),
}
}
}
#[derive(Debug, Clone)]
pub struct DeviceFlags {
pub if_flags: IfFlags,
pub connection_status: ConnectionStatus,
}
impl From<u32> for DeviceFlags {
fn from(flags: u32) -> Self {
DeviceFlags {
if_flags: flags.into(),
connection_status: flags.into(),
}
}
}
impl DeviceFlags {
pub fn empty() -> Self {
DeviceFlags {
if_flags: IfFlags::empty(),
connection_status: ConnectionStatus::Unknown,
}
}
pub fn contains(&self, if_flags: IfFlags) -> bool {
self.if_flags.contains(if_flags)
}
pub fn is_loopback(&self) -> bool {
self.contains(IfFlags::LOOPBACK)
}
pub fn is_up(&self) -> bool {
self.contains(IfFlags::UP)
}
pub fn is_running(&self) -> bool {
self.contains(IfFlags::RUNNING)
}
pub fn is_wireless(&self) -> bool {
self.contains(IfFlags::WIRELESS)
}
}
#[derive(Debug, Clone)]
/// A network device name and pcap's description of it.
pub struct Device {
/// The name of the interface
pub name: String,
/// A textual description of the interface, if available
pub desc: Option<String>,
/// Addresses associated with this interface
pub addresses: Vec<Address>,
/// Interface flags
pub flags: DeviceFlags,
}
impl Device {
fn new(
name: String,
desc: Option<String>,
addresses: Vec<Address>,
flags: DeviceFlags,
) -> Device {
Device {
name,
desc,
addresses,
flags,
}
}
/// Opens a `Capture<Active>` on this device.
pub fn open(self) -> Result<Capture<Active>, Error> {
Capture::from_device(self)?.open()
}
/// Returns the default Device suitable for captures according to pcap_findalldevs,
/// or an error from pcap. Note that there may be no suitable devices.
pub fn lookup() -> Result<Option<Device>, Error> {
unsafe {
Device::with_all_devs(|all_devs| {
let dev = all_devs;
Ok(if !dev.is_null() {
Some(Device::try_from(&*dev)?)
} else {
None
})
})
}
}
/// Returns a vector of `Device`s known by pcap via pcap_findalldevs.
pub fn list() -> Result<Vec<Device>, Error> {
unsafe {
Device::with_all_devs(|all_devs| {
let mut devices = vec![];
let mut dev = all_devs;
while !dev.is_null() {
devices.push(Device::try_from(&*dev)?);
dev = (*dev).next;
}
Ok(devices)
})
}
}
unsafe fn with_all_devs<T, F>(func: F) -> Result<T, Error>
where
F: FnOnce(*mut raw::pcap_if_t) -> Result<T, Error>,
{
let all_devs = with_errbuf(|err| {
let mut all_devs: *mut raw::pcap_if_t = ptr::null_mut();
if raw::pcap_findalldevs(&mut all_devs, err) != 0 {
return Err(Error::new(err));
}
Ok(all_devs)
})?;
let result = func(all_devs);
raw::pcap_freealldevs(all_devs);
result
}
}
impl From<&str> for Device {
fn from(name: &str) -> Self {
Device::new(name.into(), None, Vec::new(), DeviceFlags::empty())
}
}
impl TryFrom<&raw::pcap_if_t> for Device {
type Error = Error;
fn try_from(dev: &raw::pcap_if_t) -> Result<Self, Error> {
Ok(Device::new(
unsafe { cstr_to_string(dev.name)?.ok_or(InvalidString)? },
unsafe { cstr_to_string(dev.description)? },
unsafe { Address::new_vec(dev.addresses) },
DeviceFlags::from(dev.flags),
))
}
}
#[derive(Debug, Clone)]
/// Address information for an interface
pub struct Address {
/// The address
pub addr: IpAddr,
/// Network mask for this address
pub netmask: Option<IpAddr>,
/// Broadcast address for this address
pub broadcast_addr: Option<IpAddr>,
/// P2P destination address for this address
pub dst_addr: Option<IpAddr>,
}
impl Address {
unsafe fn new_vec(mut ptr: *const raw::pcap_addr_t) -> Vec<Address> {
let mut vec = Vec::new();
while !ptr.is_null() {
if let Some(addr) = Address::new(ptr) {
vec.push(addr);
}
ptr = (*ptr).next;
}
vec
}
unsafe fn new(ptr: *const raw::pcap_addr_t) -> Option<Address> {
Self::convert_sockaddr((*ptr).addr).map(|addr| Address {
addr,
netmask: Self::convert_sockaddr((*ptr).netmask),
broadcast_addr: Self::convert_sockaddr((*ptr).broadaddr),
dst_addr: Self::convert_sockaddr((*ptr).dstaddr),
})
}
#[cfg(not(target_os = "windows"))]
unsafe fn convert_sockaddr(ptr: *const libc::sockaddr) -> Option<IpAddr> {
if ptr.is_null() {
return None;
}
match (*ptr).sa_family as i32 {
libc::AF_INET => {
let ptr: *const libc::sockaddr_in = std::mem::transmute(ptr);
Some(IpAddr::V4(u32::from_be((*ptr).sin_addr.s_addr).into()))
}
libc::AF_INET6 => {
let ptr: *const libc::sockaddr_in6 = std::mem::transmute(ptr);
Some(IpAddr::V6((*ptr).sin6_addr.s6_addr.into()))
}
_ => None,
}
}
#[cfg(target_os = "windows")]
unsafe fn convert_sockaddr(ptr: *const libc::sockaddr) -> Option<IpAddr> {
if ptr.is_null() {
return None;
}
match (*ptr).sa_family as u32 {
AF_INET => {
let ptr: *const SOCKADDR_IN = std::mem::transmute(ptr);
let addr: [u8; 4] = ((*ptr).sin_addr.S_un.S_addr).to_ne_bytes();
Some(IpAddr::from(addr))
}
AF_INET6 => {
let ptr: *const SOCKADDR_IN6 = std::mem::transmute(ptr);
let addr = (*ptr).sin6_addr.u.Byte;
Some(IpAddr::from(addr))
}
_ => None,
}
}
}
/// This is a datalink link type.
///
/// As an example, `Linktype(1)` is ethernet. A full list of linktypes is available
/// [here](http://www.tcpdump.org/linktypes.html). The const bellow are not exhaustive.
/// ```rust
/// use pcap::Linktype;
///
/// let lt = Linktype(1);
/// assert_eq!(Linktype::ETHERNET, lt);
/// ```
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub struct Linktype(pub i32);
impl Linktype {
/// Gets the name of the link type, such as EN10MB
pub fn get_name(&self) -> Result<String, Error> {
unsafe { cstr_to_string(raw::pcap_datalink_val_to_name(self.0)) }?.ok_or(InvalidLinktype)
}
/// Gets the description of a link type.
pub fn get_description(&self) -> Result<String, Error> {
unsafe { cstr_to_string(raw::pcap_datalink_val_to_description(self.0)) }?
.ok_or(InvalidLinktype)
}
/// Gets the linktype from a name string
pub fn from_name(name: &str) -> Result<Linktype, Error> {
let name = CString::new(name)?;
let val = unsafe { raw::pcap_datalink_name_to_val(name.as_ptr()) };
if val == -1 {
return Err(InvalidLinktype);
}
Ok(Linktype(val))
}
pub const NULL: Self = Self(0);
pub const ETHERNET: Self = Self(1);
pub const AX25: Self = Self(3);
pub const IEEE802_5: Self = Self(6);
pub const ARCNET_BSD: Self = Self(7);
pub const SLIP: Self = Self(8);
pub const PPP: Self = Self(9);
pub const FDDI: Self = Self(10);
pub const PPP_HDLC: Self = Self(50);
pub const PPP_ETHER: Self = Self(51);
pub const ATM_RFC1483: Self = Self(100);
pub const RAW: Self = Self(101);
pub const C_HDLC: Self = Self(104);
pub const IEEE802_11: Self = Self(105);
pub const FRELAY: Self = Self(107);
pub const LOOP: Self = Self(108);
pub const LINUX_SLL: Self = Self(113);
pub const LTALK: Self = Self(114);
pub const PFLOG: Self = Self(117);
pub const IEEE802_11_PRISM: Self = Self(119);
pub const IP_OVER_FC: Self = Self(122);
pub const SUNATM: Self = Self(123);
pub const IEEE802_11_RADIOTAP: Self = Self(127);
pub const ARCNET_LINUX: Self = Self(129);
pub const APPLE_IP_OVER_IEEE1394: Self = Self(138);
pub const MTP2_WITH_PHDR: Self = Self(139);
pub const MTP2: Self = Self(140);
pub const MTP3: Self = Self(141);
pub const SCCP: Self = Self(142);
pub const DOCSIS: Self = Self(143);
pub const LINUX_IRDA: Self = Self(144);
pub const USER0: Self = Self(147);
pub const USER1: Self = Self(148);
pub const USER2: Self = Self(149);
pub const USER3: Self = Self(150);
pub const USER4: Self = Self(151);
pub const USER5: Self = Self(152);
pub const USER6: Self = Self(153);
pub const USER7: Self = Self(154);
pub const USER8: Self = Self(155);
pub const USER9: Self = Self(156);
pub const USER10: Self = Self(157);
pub const USER11: Self = Self(158);
pub const USER12: Self = Self(159);
pub const USER13: Self = Self(160);
pub const USER14: Self = Self(161);
pub const USER15: Self = Self(162);
pub const IEEE802_11_AVS: Self = Self(163);
pub const BACNET_MS_TP: Self = Self(165);
pub const PPP_PPPD: Self = Self(166);
pub const GPRS_LLC: Self = Self(169);
pub const GPF_T: Self = Self(170);
pub const GPF_F: Self = Self(171);
pub const LINUX_LAPD: Self = Self(177);
pub const MFR: Self = Self(182);
pub const BLUETOOTH_HCI_H4: Self = Self(187);
pub const USB_LINUX: Self = Self(189);
pub const PPI: Self = Self(192);
pub const IEEE802_15_4_WITHFCS: Self = Self(195);
pub const SITA: Self = Self(196);
pub const ERF: Self = Self(197);
pub const BLUETOOTH_HCI_H4_WITH_PHDR: Self = Self(201);
pub const AX25_KISS: Self = Self(202);
pub const LAPD: Self = Self(203);
pub const PPP_WITH_DIR: Self = Self(204);
pub const C_HDLC_WITH_DIR: Self = Self(205);
pub const FRELAY_WITH_DIR: Self = Self(206);
pub const LAPB_WITH_DIR: Self = Self(207);
pub const IPMB_LINUX: Self = Self(209);
pub const IEEE802_15_4_NONASK_PHY: Self = Self(215);
pub const USB_LINUX_MMAPPED: Self = Self(220);
pub const FC_2: Self = Self(224);
pub const FC_2_WITH_FRAME_DELIMS: Self = Self(225);
pub const IPNET: Self = Self(226);
pub const CAN_SOCKETCAN: Self = Self(227);
pub const IPV4: Self = Self(228);
pub const IPV6: Self = Self(229);
pub const IEEE802_15_4_NOFCS: Self = Self(230);
pub const DBUS: Self = Self(231);
pub const DVB_CI: Self = Self(235);
pub const MUX27010: Self = Self(236);
pub const STANAG_5066_D_PDU: Self = Self(237);
pub const NFLOG: Self = Self(239);
pub const NETANALYZER: Self = Self(240);
pub const NETANALYZER_TRANSPARENT: Self = Self(241);
pub const IPOIB: Self = Self(242);
pub const MPEG_2_TS: Self = Self(243);
pub const NG40: Self = Self(244);
pub const NFC_LLCP: Self = Self(245);
pub const INFINIBAND: Self = Self(247);
pub const SCTP: Self = Self(248);
pub const USBPCAP: Self = Self(249);
pub const RTAC_SERIAL: Self = Self(250);
pub const BLUETOOTH_LE_LL: Self = Self(251);
pub const NETLINK: Self = Self(253);
pub const BLUETOOTH_LINUX_MONITOR: Self = Self(254);
pub const BLUETOOTH_BREDR_BB: Self = Self(255);
pub const BLUETOOTH_LE_LL_WITH_PHDR: Self = Self(256);
pub const PROFIBUS_DL: Self = Self(257);
pub const PKTAP: Self = Self(258);
pub const EPON: Self = Self(259);
pub const IPMI_HPM_2: Self = Self(260);
pub const ZWAVE_R1_R2: Self = Self(261);
pub const ZWAVE_R3: Self = Self(262);
pub const WATTSTOPPER_DLM: Self = Self(263);
pub const ISO_14443: Self = Self(264);
pub const RDS: Self = Self(265);
pub const USB_DARWIN: Self = Self(266);
pub const SDLC: Self = Self(268);
pub const LORATAP: Self = Self(270);
pub const VSOCK: Self = Self(271);
pub const NORDIC_BLE: Self = Self(272);
pub const DOCSIS31_XRA31: Self = Self(273);
pub const ETHERNET_MPACKET: Self = Self(274);
pub const DISPLAYPORT_AUX: Self = Self(275);
pub const LINUX_SLL2: Self = Self(276);
pub const OPENVIZSLA: Self = Self(278);
pub const EBHSCR: Self = Self(279);
pub const VPP_DISPATCH: Self = Self(280);
pub const DSA_TAG_BRCM: Self = Self(281);
pub const DSA_TAG_BRCM_PREPEND: Self = Self(282);
pub const IEEE802_15_4_TAP: Self = Self(283);
pub const DSA_TAG_DSA: Self = Self(284);
pub const DSA_TAG_EDSA: Self = Self(285);
pub const ELEE: Self = Self(286);
pub const Z_WAVE_SERIAL: Self = Self(287);
pub const USB_2_0: Self = Self(288);
pub const ATSC_ALP: Self = Self(289);
}
/// Represents a packet returned from pcap.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Packet<'a> {
/// The packet header provided by pcap, including the timeval, captured length, and packet
/// length
pub header: &'a PacketHeader,
/// The captured packet data
pub data: &'a [u8],
}
impl<'a> Packet<'a> {
#[doc(hidden)]
pub fn new(header: &'a PacketHeader, data: &'a [u8]) -> Packet<'a> {
Packet { header, data }
}
}
impl<'b> Deref for Packet<'b> {
type Target = [u8];
fn deref(&self) -> &[u8] {
self.data
}
}
#[repr(C)]
#[derive(Copy, Clone)]
/// Represents a packet header provided by pcap, including the timeval, caplen and len.
pub struct PacketHeader {
/// The time when the packet was captured
pub ts: libc::timeval,
/// The number of bytes of the packet that are available from the capture
pub caplen: u32,
/// The length of the packet, in bytes (which might be more than the number of bytes available
/// from the capture, if the length of the packet is larger than the maximum number of bytes to
/// capture)
pub len: u32,
}
impl fmt::Debug for PacketHeader {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"PacketHeader {{ ts: {}.{:06}, caplen: {}, len: {} }}",
self.ts.tv_sec, self.ts.tv_usec, self.caplen, self.len
)
}
}
impl PartialEq for PacketHeader {
fn eq(&self, rhs: &PacketHeader) -> bool {
self.ts.tv_sec == rhs.ts.tv_sec
&& self.ts.tv_usec == rhs.ts.tv_usec
&& self.caplen == rhs.caplen
&& self.len == rhs.len
}
}
impl Eq for PacketHeader {}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
/// Packet statistics for a capture
pub struct Stat {
/// Number of packets received
pub received: u32,
/// Number of packets dropped because there was no room in the operating system's buffer when
/// they arrived, because packets weren't being read fast enough
pub dropped: u32,
/// Number of packets dropped by the network interface or its driver
pub if_dropped: u32,
}
impl Stat {
fn new(received: u32, dropped: u32, if_dropped: u32) -> Stat {
Stat {
received,
dropped,
if_dropped,
}
}
}
#[repr(u32)]
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
/// Timestamp resolution types
///
/// Not all systems and interfaces will necessarily support all of these resolutions when doing
/// live captures; all of them can be requested when reading a safefile.
pub enum Precision {
/// Use timestamps with microsecond precision. This is the default.
Micro = 0,
/// Use timestamps with nanosecond precision.
Nano = 1,
}
/// Phantom type representing an inactive capture handle.
pub enum Inactive {}
/// Phantom type representing an active capture handle.
pub enum Active {}
/// Phantom type representing an offline capture handle, from a pcap dump file.
/// Implements `Activated` because it behaves nearly the same as a live handle.
pub enum Offline {}
/// Phantom type representing a dead capture handle. This can be use to create
/// new save files that are not generated from an active capture.
/// Implements `Activated` because it behaves nearly the same as a live handle.
pub enum Dead {}
/// `Capture`s can be in different states at different times, and in these states they
/// may or may not have particular capabilities. This trait is implemented by phantom
/// types which allows us to punt these invariants to the type system to avoid runtime
/// errors.
pub trait Activated: State {}
impl Activated for Active {}
impl Activated for Offline {}
impl Activated for Dead {}
/// `Capture`s can be in different states at different times, and in these states they
/// may or may not have particular capabilities. This trait is implemented by phantom
/// types which allows us to punt these invariants to the type system to avoid runtime
/// errors.
pub trait State {}
impl State for Inactive {}
impl State for Active {}
impl State for Offline {}
impl State for Dead {}
/// This is a pcap capture handle which is an abstraction over the `pcap_t` provided by pcap.
/// There are many ways to instantiate and interact with a pcap handle, so phantom types are
/// used to express these behaviors.
///
/// **`Capture<Inactive>`** is created via `Capture::from_device()`. This handle is inactive,
/// so you cannot (yet) obtain packets from it. However, you can configure things like the
/// buffer size, snaplen, timeout, and promiscuity before you activate it.
///
/// **`Capture<Active>`** is created by calling `.open()` on a `Capture<Inactive>`. This
/// activates the capture handle, allowing you to get packets with `.next_packet()` or apply filters
/// with `.filter()`.
///
/// **`Capture<Offline>`** is created via `Capture::from_file()`. This allows you to read a
/// pcap format dump file as if you were opening an interface -- very useful for testing or
/// analysis.
///
/// **`Capture<Dead>`** is created via `Capture::dead()`. This allows you to create a pcap
/// format dump file without needing an active capture.
///
/// # Example:
///
/// ```no_run
/// # use pcap::{Capture, Device};
/// let mut cap = Capture::from_device(Device::lookup().unwrap().unwrap()) // open the "default" interface
/// .unwrap() // assume the device exists and we are authorized to open it
/// .open() // activate the handle
/// .unwrap(); // assume activation worked
///
/// while let Ok(packet) = cap.next_packet() {
/// println!("received packet! {:?}", packet);
/// }
/// ```
pub struct Capture<T: State + ?Sized> {
nonblock: bool,
handle: NonNull<raw::pcap_t>,
_marker: PhantomData<T>,
}
// A Capture is safe to Send as it encapsulates the entire lifetime of `raw::pcap_t *`, but it is
// not safe to Sync as libpcap does not promise thread-safe access to the same `raw::pcap_t *` from
// multiple threads.
unsafe impl<T: State + ?Sized> Send for Capture<T> {}
impl<T: State + ?Sized> From<NonNull<raw::pcap_t>> for Capture<T> {
fn from(handle: NonNull<raw::pcap_t>) -> Self {
Capture {
nonblock: false,
handle,
_marker: PhantomData,
}
}
}
impl<T: State + ?Sized> Capture<T> {
fn new_raw<F>(path: Option<&str>, func: F) -> Result<Capture<T>, Error>
where
F: FnOnce(*const libc::c_char, *mut libc::c_char) -> *mut raw::pcap_t,
{
with_errbuf(|err| {
let handle = match path {
None => func(ptr::null(), err),
Some(path) => {
let path = CString::new(path)?;
func(path.as_ptr(), err)
}
};
Ok(Capture::from(
NonNull::<raw::pcap_t>::new(handle).ok_or_else(|| unsafe { Error::new(err) })?,
))
})
}
/// Set the minumum amount of data received by the kernel in a single call.
///
/// Note that this value is set to 0 when the capture is set to immediate mode. You should not
/// call `min_to_copy` on captures in immediate mode if you want them to stay in immediate mode.
#[cfg(windows)]
pub fn min_to_copy(self, to: i32) -> Capture<T> {
unsafe {
raw::pcap_setmintocopy(self.handle.as_ptr(), to as _);
}
self
}
/// Get handle to the Capture context's internal Win32 event semaphore.
///
/// # Safety
///
/// The caller must ensure that the `Capture` context outlives the returned `HANDLE` since it is
/// a kernel object owned by the `Capture`'s pcap context.
#[cfg(windows)]
pub unsafe fn get_event(&self) -> HANDLE {
raw::pcap_getevent(self.handle.as_ptr())
}
fn check_err(&self, success: bool) -> Result<(), Error> {
if success {
Ok(())
} else {
Err(unsafe { Error::new(raw::pcap_geterr(self.handle.as_ptr())) })
}
}
}
impl Capture<Offline> {
/// Opens an offline capture handle from a pcap dump file, given a path.
pub fn from_file<P: AsRef<Path>>(path: P) -> Result<Capture<Offline>, Error> {
Capture::new_raw(path.as_ref().to_str(), |path, err| unsafe {
raw::pcap_open_offline(path, err)
})
}
/// Opens an offline capture handle from a pcap dump file, given a path.
/// Takes an additional precision argument specifying the time stamp precision desired.
#[cfg(libpcap_1_5_0)]
pub fn from_file_with_precision<P: AsRef<Path>>(
path: P,
precision: Precision,
) -> Result<Capture<Offline>, Error> {
Capture::new_raw(path.as_ref().to_str(), |path, err| unsafe {
raw::pcap_open_offline_with_tstamp_precision(path, precision as _, err)
})
}
/// Opens an offline capture handle from a pcap dump file, given a file descriptor.
///
/// # Safety
///
/// Unsafe, because the returned Capture assumes it is the sole owner of the file descriptor.
#[cfg(not(windows))]
pub unsafe fn from_raw_fd(fd: RawFd) -> Result<Capture<Offline>, Error> {
open_raw_fd(fd, b'r')
.and_then(|file| Capture::new_raw(None, |_, err| raw::pcap_fopen_offline(file, err)))
}
/// Opens an offline capture handle from a pcap dump file, given a file descriptor. Takes an
/// additional precision argument specifying the time stamp precision desired.
///
/// # Safety
///
/// Unsafe, because the returned Capture assumes it is the sole owner of the file descriptor.
#[cfg(all(not(windows), libpcap_1_5_0))]
pub unsafe fn from_raw_fd_with_precision(
fd: RawFd,
precision: Precision,
) -> Result<Capture<Offline>, Error> {
open_raw_fd(fd, b'r').and_then(|file| {
Capture::new_raw(None, |_, err| {
raw::pcap_fopen_offline_with_tstamp_precision(file, precision as _, err)
})
})
}
/// Get the major version number of the pcap dump file format.
pub fn major_version(&self) -> i32 {
unsafe { raw::pcap_major_version(self.handle.as_ptr()) }
}
/// Get the minor version number of the pcap dump file format.
pub fn minor_version(&self) -> i32 {
unsafe { raw::pcap_minor_version(self.handle.as_ptr()) }
}
/// Get the (major, minor) version number of the pcap dump file format.
pub fn version(&self) -> (i32, i32) {
(self.major_version(), self.minor_version())
}
}
#[repr(i32)]
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
/// Timestamp types
///
/// Not all systems and interfaces will necessarily support all of these.
///
/// Note that time stamps synchronized with the system clock can go backwards, as the system clock
/// can go backwards. If a clock is not in sync with the system clock, that could be because the
/// system clock isn't keeping accurate time, because the other clock isn't keeping accurate time,
/// or both.
///
/// Note that host-provided time stamps generally correspond to the time when the time-stamping
/// code sees the packet; this could be some unknown amount of time after the first or last bit of
/// the packet is received by the network adapter, due to batching of interrupts for packet
/// arrival, queueing delays, etc..
pub enum TimestampType {
/// Timestamps are provided by the host machine, rather than by the capture device.
///
/// The characteristics of the timestamp are unknown.
Host = 0,
/// A timestamp provided by the host machine that is low precision but relatively cheap to
/// fetch.
///
/// This is normally done using the system clock, so it's normally synchornized with times
/// you'd fetch from system calls.
HostLowPrec = 1,
/// A timestamp provided by the host machine that is high precision. It might be more expensive
/// to fetch.
///
/// The timestamp might or might not be synchronized with the system clock, and might have
/// problems with time stamps for packets received on different CPUs, depending on the
/// platform.
HostHighPrec = 2,
/// The timestamp is a high-precision time stamp supplied by the capture device.
///
/// The timestamp is synchronized with the system clock.
Adapter = 3,
/// The timestamp is a high-precision time stamp supplied by the capture device.
///
/// The timestamp is not synchronized with the system clock.
AdapterUnsynced = 4,
}
#[deprecated(note = "Renamed to TimestampType")]
/// An old name for `TimestampType`, kept around for backward-compatibility.
pub type TstampType = TimestampType;
#[repr(u32)]
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
/// The direction of packets to be captured. Use with `Capture::direction`.
pub enum Direction {
/// Capture packets received by or sent by the device. This is the default.
InOut = raw::PCAP_D_INOUT,
/// Only capture packets received by the device.
In = raw::PCAP_D_IN,
/// Only capture packets sent by the device.
Out = raw::PCAP_D_OUT,
}
impl Capture<Inactive> {
/// Opens a capture handle for a device. You can pass a `Device` or an `&str` device
/// name here. The handle is inactive, but can be activated via `.open()`.
///
/// # Example
/// ```
/// use pcap::*;
///
/// // Usage 1: Capture from a single owned device
/// let dev: Device = pcap::Device::lookup()
/// .expect("device lookup failed")
/// .expect("no device available");
/// let cap1 = Capture::from_device(dev);
///
/// // Usage 2: Capture from an element of device list.
/// let list: Vec<Device> = pcap::Device::list().unwrap();
/// let cap2 = Capture::from_device(list[0].clone());
///
/// // Usage 3: Capture from `&str` device name
/// let cap3 = Capture::from_device("eth0");
/// ```
pub fn from_device<D: Into<Device>>(device: D) -> Result<Capture<Inactive>, Error> {
let device: Device = device.into();
Capture::new_raw(Some(&device.name), |name, err| unsafe {
raw::pcap_create(name, err)
})
}
/// Activates an inactive capture created from `Capture::from_device()` or returns
/// an error.
pub fn open(self) -> Result<Capture<Active>, Error> {
unsafe {
self.check_err(raw::pcap_activate(self.handle.as_ptr()) == 0)?;
Ok(mem::transmute(self))
}
}
/// Set the read timeout for the Capture. By default, this is 0, so it will block
/// indefinitely.
pub fn timeout(self, ms: i32) -> Capture<Inactive> {
unsafe { raw::pcap_set_timeout(self.handle.as_ptr(), ms) };
self
}
/// Set the time stamp type to be used by a capture device.
#[cfg(libpcap_1_2_1)]
pub fn tstamp_type(self, tstamp_type: TimestampType) -> Capture<Inactive> {
unsafe { raw::pcap_set_tstamp_type(self.handle.as_ptr(), tstamp_type as _) };
self
}
/// Set promiscuous mode on or off. By default, this is off.
pub fn promisc(self, to: bool) -> Capture<Inactive> {
unsafe { raw::pcap_set_promisc(self.handle.as_ptr(), to as _) };
self
}
/// Set immediate mode on or off. By default, this is off.
///
/// Note that in WinPcap immediate mode is set by passing a 0 argument to `min_to_copy`.
/// Immediate mode will be unset if `min_to_copy` is later called with a non-zero argument.
/// Immediate mode is unset by resetting `min_to_copy` to the WinPcap default possibly changing
/// a previously set value. When using `min_to_copy`, it is best to avoid `immediate_mode`.
#[cfg(any(libpcap_1_5_0, windows))]
pub fn immediate_mode(self, to: bool) -> Capture<Inactive> {
// Prior to 1.5.0 when `pcap_set_immediate_mode` was introduced, the necessary steps to set
// immediate mode were more complicated, depended on the OS, and in some configurations had
// to be set on an active capture. See
// https://www.tcpdump.org/manpages/pcap_set_immediate_mode.3pcap.html. Since we do not
// expect pre-1.5.0 version on unix systems in the wild, we simply ignore those cases.
#[cfg(libpcap_1_5_0)]
unsafe {
raw::pcap_set_immediate_mode(self.handle.as_ptr(), to as _)
};
// In WinPcap we use `pcap_setmintocopy` as it does not have `pcap_set_immediate_mode`.
#[cfg(all(windows, not(libpcap_1_5_0)))]
unsafe {
raw::pcap_setmintocopy(
self.handle.as_ptr(),
if to {
0
} else {
raw::WINPCAP_MINTOCOPY_DEFAULT
},
)
};
self
}
/// Set rfmon mode on or off. The default is maintained by pcap.
#[cfg(not(windows))]
pub fn rfmon(self, to: bool) -> Capture<Inactive> {
unsafe { raw::pcap_set_rfmon(self.handle.as_ptr(), to as _) };
self
}
/// Set the buffer size for incoming packet data.
///
/// The default is 1000000. This should always be larger than the snaplen.
pub fn buffer_size(self, to: i32) -> Capture<Inactive> {
unsafe { raw::pcap_set_buffer_size(self.handle.as_ptr(), to) };
self
}
/// Set the time stamp precision returned in captures.
#[cfg(libpcap_1_5_0)]
pub fn precision(self, precision: Precision) -> Capture<Inactive> {
unsafe { raw::pcap_set_tstamp_precision(self.handle.as_ptr(), precision as _) };
self
}
/// Set the snaplen size (the maximum length of a packet captured into the buffer).
/// Useful if you only want certain headers, but not the entire packet.
///
/// The default is 65535.
pub fn snaplen(self, to: i32) -> Capture<Inactive> {
unsafe { raw::pcap_set_snaplen(self.handle.as_ptr(), to) };
self
}
}
///# Activated captures include `Capture<Active>` and `Capture<Offline>`.
impl<T: Activated + ?Sized> Capture<T> {
/// List the datalink types that this captured device supports.
pub fn list_datalinks(&self) -> Result<Vec<Linktype>, Error> {
unsafe {
let mut links: *mut i32 = ptr::null_mut();
let num = raw::pcap_list_datalinks(self.handle.as_ptr(), &mut links);
let mut vec = vec![];
if num > 0 {
vec.extend(
slice::from_raw_parts(links, num as _)
.iter()
.cloned()
.map(Linktype),
)
}
raw::pcap_free_datalinks(links);
self.check_err(num > 0).and(Ok(vec))
}
}
/// Set the datalink type for the current capture handle.
pub fn set_datalink(&mut self, linktype: Linktype) -> Result<(), Error> {
self.check_err(unsafe { raw::pcap_set_datalink(self.handle.as_ptr(), linktype.0) == 0 })
}
/// Get the current datalink type for this capture handle.
pub fn get_datalink(&self) -> Linktype {
unsafe { Linktype(raw::pcap_datalink(self.handle.as_ptr())) }
}
/// Create a `Savefile` context for recording captured packets using this `Capture`'s
/// configurations.
pub fn savefile<P: AsRef<Path>>(&self, path: P) -> Result<Savefile, Error> {
let name = CString::new(path.as_ref().to_str().unwrap())?;
let handle_opt = NonNull::<raw::pcap_dumper_t>::new(unsafe {
raw::pcap_dump_open(self.handle.as_ptr(), name.as_ptr())
});
let handle = self
.check_err(handle_opt.is_some())
.map(|_| handle_opt.unwrap())?;
Ok(Savefile::from(handle))
}
/// Create a `Savefile` context for recording captured packets using this `Capture`'s
/// configurations. The output is written to a raw file descriptor which is opened in `"w"`
/// mode.
///
/// # Safety
///
/// Unsafe, because the returned Savefile assumes it is the sole owner of the file descriptor.
#[cfg(not(windows))]
pub unsafe fn savefile_raw_fd(&self, fd: RawFd) -> Result<Savefile, Error> {
open_raw_fd(fd, b'w').and_then(|file| {
let handle_opt = NonNull::<raw::pcap_dumper_t>::new(raw::pcap_dump_fopen(
self.handle.as_ptr(),
file,
));
let handle = self
.check_err(handle_opt.is_some())
.map(|_| handle_opt.unwrap())?;
Ok(Savefile::from(handle))
})
}
/// Reopen a `Savefile` context for recording captured packets using this `Capture`'s
/// configurations. This is similar to `savefile()` but does not create the file if it
/// does not exist and, if it does already exist, and is a pcap file with the same
/// byte order as the host opening the file, and has the same time stamp precision,
/// link-layer header type, and snapshot length as p, it will write new packets
/// at the end of the file.
#[cfg(libpcap_1_7_2)]
pub fn savefile_append<P: AsRef<Path>>(&self, path: P) -> Result<Savefile, Error> {
let name = CString::new(path.as_ref().to_str().unwrap())?;
let handle_opt = NonNull::<raw::pcap_dumper_t>::new(unsafe {
raw::pcap_dump_open_append(self.handle.as_ptr(), name.as_ptr())
});
let handle = self
.check_err(handle_opt.is_some())
.map(|_| handle_opt.unwrap())?;
Ok(Savefile::from(handle))
}
/// Set the direction of the capture
pub fn direction(&self, direction: Direction) -> Result<(), Error> {
self.check_err(unsafe {
raw::pcap_setdirection(self.handle.as_ptr(), direction as u32 as _) == 0
})
}
/// Blocks until a packet is returned from the capture handle or an error occurs.
///
/// pcap captures packets and places them into a buffer which this function reads
/// from.
///
/// # Warning
///
/// This buffer has a finite length, so if the buffer fills completely new
/// packets will be discarded temporarily. This means that in realtime situations,
/// you probably want to minimize the time between calls to next_packet() method.
pub fn next_packet(&mut self) -> Result<Packet<'_>, Error> {
unsafe {
let mut header: *mut raw::pcap_pkthdr = ptr::null_mut();
let mut packet: *const libc::c_uchar = ptr::null();
let retcode = raw::pcap_next_ex(self.handle.as_ptr(), &mut header, &mut packet);
self.check_err(retcode != -1)?; // -1 => an error occured while reading the packet
match retcode {
i if i >= 1 => {
// packet was read without issue
Ok(Packet::new(
&*(&*header as *const raw::pcap_pkthdr as *const PacketHeader),
slice::from_raw_parts(packet, (*header).caplen as _),
))
}
0 => {
// packets are being read from a live capture and the
// timeout expired
Err(TimeoutExpired)
}
-2 => {
// packets are being read from a "savefile" and there are no
// more packets to read
Err(NoMorePackets)
}
_ => {
// libpcap only defines codes >=1, 0, -1, and -2
unreachable!()
}
}
}
}
/// Return an iterator that call [`Self::next_packet()`] forever. Require a [`PacketCodec`]
pub fn iter<C: PacketCodec>(self, codec: C) -> PacketIter<T, C> {
PacketIter::new(self, codec)
}
/// Returns this capture as a [`futures::Stream`] of packets.
///
/// # Errors
///
/// If this capture is set to be blocking, or if the network device
/// does not support `select()`, an error will be returned.
#[cfg(feature = "capture-stream")]
pub fn stream<C: PacketCodec>(self, codec: C) -> Result<PacketStream<T, C>, Error> {
if !self.nonblock {
return Err(NonNonBlock);
}
PacketStream::new(self, codec)
}
/// Sets the filter on the capture using the given BPF program string. Internally this is
/// compiled using `pcap_compile()`. `optimize` controls whether optimization on the resulting
/// code is performed
///
/// See <http://biot.com/capstats/bpf.html> for more information about this syntax.
pub fn filter(&mut self, program: &str, optimize: bool) -> Result<(), Error> {
let program = CString::new(program)?;
unsafe {
let mut bpf_program: raw::bpf_program = mem::zeroed();
let ret = raw::pcap_compile(
self.handle.as_ptr(),
&mut bpf_program,
program.as_ptr(),
optimize as libc::c_int,
0,
);
self.check_err(ret != -1)?;
let ret = raw::pcap_setfilter(self.handle.as_ptr(), &mut bpf_program);
raw::pcap_freecode(&mut bpf_program);
self.check_err(ret != -1)
}
}
/// Get capture statistics about this capture. The values represent packet statistics from the
/// start of the run to the time of the call.
///
/// See <https://www.tcpdump.org/manpages/pcap_stats.3pcap.html> for per-platform caveats about
/// how packet statistics are calculated.
pub fn stats(&mut self) -> Result<Stat, Error> {
unsafe {
let mut stats: raw::pcap_stat = mem::zeroed();
self.check_err(raw::pcap_stats(self.handle.as_ptr(), &mut stats) != -1)
.map(|_| Stat::new(stats.ps_recv, stats.ps_drop, stats.ps_ifdrop))
}
}
}
impl Capture<Active> {
/// Sends a packet over this capture handle's interface.
pub fn sendpacket<B: Borrow<[u8]>>(&mut self, buf: B) -> Result<(), Error> {
let buf = buf.borrow();
self.check_err(unsafe {
raw::pcap_sendpacket(self.handle.as_ptr(), buf.as_ptr() as _, buf.len() as _) == 0
})
}
/// Set the capture to be non-blocking. When this is set, [`Self::next_packet()`] may return an error indicating
/// that there is no packet available to be read.
pub fn setnonblock(mut self) -> Result<Capture<Active>, Error> {
with_errbuf(|err| unsafe {
if raw::pcap_setnonblock(self.handle.as_ptr(), 1, err) != 0 {
return Err(Error::new(err));
}
self.nonblock = true;
Ok(self)
})
}
}
impl Capture<Dead> {
/// Creates a "fake" capture handle for the given link type.
pub fn dead(linktype: Linktype) -> Result<Capture<Dead>, Error> {
let handle = unsafe { raw::pcap_open_dead(linktype.0, 65535) };
Ok(Capture::from(
NonNull::<raw::pcap_t>::new(handle).ok_or(InsufficientMemory)?,
))
}
/// Creates a "fake" capture handle for the given link type and timestamp precision.
#[cfg(libpcap_1_5_0)]
pub fn dead_with_precision(
linktype: Linktype,
precision: Precision,
) -> Result<Capture<Dead>, Error> {
let handle = unsafe {
raw::pcap_open_dead_with_tstamp_precision(linktype.0, 65535, precision as u32)
};
Ok(Capture::from(
NonNull::<raw::pcap_t>::new(handle).ok_or(InsufficientMemory)?,
))
}
/// Compiles the string into a filter program using `pcap_compile`.
pub fn compile(&self, program: &str, optimize: bool) -> Result<BpfProgram, Error> {
let program = CString::new(program).unwrap();
unsafe {
let mut bpf_program: raw::bpf_program = mem::zeroed();
if -1
== raw::pcap_compile(
self.handle.as_ptr(),
&mut bpf_program,
program.as_ptr(),
optimize as libc::c_int,
0,
)
{
return Err(Error::new(raw::pcap_geterr(self.handle.as_ptr())));
}
Ok(BpfProgram(bpf_program))
}
}
}
#[cfg(not(windows))]
impl AsRawFd for Capture<Active> {
/// Returns the file descriptor for a live capture.
fn as_raw_fd(&self) -> RawFd {
let fd = unsafe { raw::pcap_fileno(self.handle.as_ptr()) };
assert!(fd != -1, "Unable to get file descriptor for live capture");
fd
}
}
impl<T: State + ?Sized> Drop for Capture<T> {
fn drop(&mut self) {
unsafe { raw::pcap_close(self.handle.as_ptr()) }
}
}
impl<T: Activated> From<Capture<T>> for Capture<dyn Activated> {
fn from(cap: Capture<T>) -> Capture<dyn Activated> {
unsafe { mem::transmute(cap) }
}
}
/// Abstraction for writing pcap savefiles, which can be read afterwards via `Capture::from_file()`.
pub struct Savefile {
handle: NonNull<raw::pcap_dumper_t>,
}
// Just like a Capture, a Savefile is safe to Send as it encapsulates the entire lifetime of
// `raw::pcap_dumper_t *`, but it is not safe to Sync as libpcap does not promise thread-safe access
// to the same `raw::pcap_dumper_t *` from multiple threads.
unsafe impl Send for Savefile {}
impl Savefile {
/// Write a packet to a capture file
pub fn write(&mut self, packet: &Packet<'_>) {
unsafe {
raw::pcap_dump(
self.handle.as_ptr() as _,
&*(packet.header as *const PacketHeader as *const raw::pcap_pkthdr),
packet.data.as_ptr(),
);
}
}
/// Flushes all the packets that haven't been written to the savefile
pub fn flush(&mut self) -> Result<(), Error> {
if unsafe { raw::pcap_dump_flush(self.handle.as_ptr() as _) } != 0 {
return Err(Error::ErrnoError(errno::errno()));
}
Ok(())
}
}
impl From<NonNull<raw::pcap_dumper_t>> for Savefile {
fn from(handle: NonNull<raw::pcap_dumper_t>) -> Self {
Savefile { handle }
}
}
impl Drop for Savefile {
fn drop(&mut self) {
unsafe { raw::pcap_dump_close(self.handle.as_ptr()) }
}
}
#[cfg(not(windows))]
/// Open a raw file descriptor.
///
/// # Safety
///
/// Unsafe, because the returned FILE assumes it is the sole owner of the file descriptor.
pub unsafe fn open_raw_fd(fd: RawFd, mode: u8) -> Result<*mut libc::FILE, Error> {
let mode = [mode, 0];
libc::fdopen(fd, mode.as_ptr() as _)
.as_mut()
.map(|f| f as _)
.ok_or(InvalidRawFd)
}
unsafe fn cstr_to_string(ptr: *const libc::c_char) -> Result<Option<String>, Error> {
let string = if ptr.is_null() {
None
} else {
Some(CStr::from_ptr(ptr as _).to_str()?.to_owned())
};
Ok(string)
}
fn with_errbuf<T, F>(func: F) -> Result<T, Error>
where
F: FnOnce(*mut libc::c_char) -> Result<T, Error>,
{
let mut errbuf = [0i8; 256];
func(errbuf.as_mut_ptr() as _)
}
#[test]
fn test_struct_size() {
use std::mem::size_of;
assert_eq!(size_of::<PacketHeader>(), size_of::<raw::pcap_pkthdr>());
}
#[repr(transparent)]
pub struct BpfInstruction(raw::bpf_insn);
#[repr(transparent)]
pub struct BpfProgram(raw::bpf_program);
impl BpfProgram {
/// checks whether a filter matches a packet
pub fn filter(&self, buf: &[u8]) -> bool {
let header: raw::pcap_pkthdr = raw::pcap_pkthdr {
ts: libc::timeval {
tv_sec: 0,
tv_usec: 0,
},
caplen: buf.len() as u32,
len: buf.len() as u32,
};
unsafe { raw::pcap_offline_filter(&self.0, &header, buf.as_ptr()) > 0 }
}
pub fn get_instructions(&self) -> &[BpfInstruction] {
unsafe {
slice::from_raw_parts(
self.0.bf_insns as *const BpfInstruction,
self.0.bf_len as usize,
)
}
}
}
impl Drop for BpfProgram {
fn drop(&mut self) {
unsafe { raw::pcap_freecode(&mut self.0) }
}
}
impl fmt::Display for BpfInstruction {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"{} {} {} {}",
self.0.code, self.0.jt, self.0.jf, self.0.k
)
}
}
unsafe impl Send for BpfProgram {}