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-rw-r--r--src/parser.rs280
1 files changed, 7 insertions, 273 deletions
diff --git a/src/parser.rs b/src/parser.rs
index c402dae..6ea34c1 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,167 +1,21 @@
use std::{
- convert::TryFrom,
fmt::{Debug, DebugStruct},
mem::{size_of, transmute},
- string::FromUtf8Error,
};
-use thiserror::Error;
-
use crate::{
- nlmsg::{AttributeDecoder, NetlinkType, NfNetlinkAttribute, NfNetlinkDeserializable},
+ error::DecodeError,
+ nlmsg::{
+ get_operation_from_nlmsghdr_type, get_subsystem_from_nlmsghdr_type, pad_netlink_object,
+ pad_netlink_object_with_variable_size, AttributeDecoder, NetlinkType, NfNetlinkAttribute,
+ },
sys::{
nfgenmsg, nlattr, nlmsgerr, nlmsghdr, NFNETLINK_V0, NFNL_MSG_BATCH_BEGIN,
- NFNL_MSG_BATCH_END, NFNL_SUBSYS_NFTABLES, NLA_F_NESTED, NLA_TYPE_MASK, NLMSG_ALIGNTO,
- NLMSG_DONE, NLMSG_ERROR, NLMSG_MIN_TYPE, NLMSG_NOOP, NLM_F_DUMP_INTR,
+ NFNL_MSG_BATCH_END, NFNL_SUBSYS_NFTABLES, NLA_F_NESTED, NLA_TYPE_MASK, NLMSG_DONE,
+ NLMSG_ERROR, NLMSG_MIN_TYPE, NLMSG_NOOP, NLM_F_DUMP_INTR,
},
- ProtocolFamily,
};
-#[derive(Error, Debug)]
-pub enum DecodeError {
- #[error("The buffer is too small to hold a valid message")]
- BufTooSmall,
-
- #[error("The message is too small")]
- NlMsgTooSmall,
-
- #[error("The message holds unexpected data")]
- InvalidDataSize,
-
- #[error("Missing information in the chain to create a rule")]
- MissingChainInformationError,
-
- #[error("The length of the arguments are not compatible with each other")]
- IncompatibleLength,
-
- #[error("Invalid subsystem, expected NFTABLES")]
- InvalidSubsystem(u8),
-
- #[error("Invalid version, expected NFNETLINK_V0")]
- InvalidVersion(u8),
-
- #[error("Invalid port ID")]
- InvalidPortId(u32),
-
- #[error("Invalid sequence number")]
- InvalidSeq(u32),
-
- #[error("The generation number was bumped in the kernel while the operation was running, interrupting it")]
- ConcurrentGenerationUpdate,
-
- #[error("Unsupported message type")]
- UnsupportedType(u16),
-
- #[error("Invalid attribute type")]
- InvalidAttributeType,
-
- #[error("Invalid type for a chain")]
- UnknownChainType,
-
- #[error("Invalid policy for a chain")]
- UnknownChainPolicy,
-
- #[error("Unknown type for a Meta expression")]
- UnknownMetaType(u32),
-
- #[error("Unsupported value for an icmp reject type")]
- UnknownRejectType(u32),
-
- #[error("Unsupported value for an icmp code in a reject expression")]
- UnknownIcmpCode(u8),
-
- #[error("Invalid value for a register")]
- UnknownRegister(u32),
-
- #[error("Invalid type for a verdict expression")]
- UnknownVerdictType(i32),
-
- #[error("Invalid type for a nat expression")]
- UnknownNatType(i32),
-
- #[error("Invalid type for a payload expression")]
- UnknownPayloadType(u32),
-
- #[error("Invalid type for a compare expression")]
- UnknownCmpOp(u32),
-
- #[error("Invalid type for a conntrack key")]
- UnknownConntrackKey(u32),
-
- #[error("Unsupported value for a link layer header field")]
- UnknownLinkLayerHeaderField(u32, u32),
-
- #[error("Unsupported value for an IPv4 header field")]
- UnknownIPv4HeaderField(u32, u32),
-
- #[error("Unsupported value for an IPv6 header field")]
- UnknownIPv6HeaderField(u32, u32),
-
- #[error("Unsupported value for a TCP header field")]
- UnknownTCPHeaderField(u32, u32),
-
- #[error("Unsupported value for an UDP header field")]
- UnknownUDPHeaderField(u32, u32),
-
- #[error("Unsupported value for an ICMPv6 header field")]
- UnknownICMPv6HeaderField(u32, u32),
-
- #[error("Missing the 'base' attribute to deserialize the payload object")]
- PayloadMissingBase,
-
- #[error("Missing the 'offset' attribute to deserialize the payload object")]
- PayloadMissingOffset,
-
- #[error("Missing the 'len' attribute to deserialize the payload object")]
- PayloadMissingLen,
-
- #[error("The object does not contain a name for the expression being parsed")]
- MissingExpressionName,
-
- #[error("Unsupported attribute type")]
- UnsupportedAttributeType(u16),
-
- #[error("Unexpected message type")]
- UnexpectedType(u16),
-
- #[error("The decoded String is not UTF8 compliant")]
- StringDecodeFailure(#[from] FromUtf8Error),
-
- #[error("Invalid value for a protocol family")]
- InvalidProtocolFamily(i32),
-
- #[error("A custom error occured")]
- Custom(Box<dyn std::error::Error + 'static>),
-}
-
-/// The largest nf_tables netlink message is the set element message, which contains the
-/// NFTA_SET_ELEM_LIST_ELEMENTS attribute. This attribute is a nest that describes the set
-/// elements. Given that the netlink attribute length (nla_len) is 16 bits, the largest message is
-/// a bit larger than 64 KBytes.
-pub fn nft_nlmsg_maxsize() -> u32 {
- u32::from(::std::u16::MAX) + unsafe { libc::sysconf(libc::_SC_PAGESIZE) } as u32
-}
-
-#[inline]
-pub const fn pad_netlink_object_with_variable_size(size: usize) -> usize {
- // align on a 4 bytes boundary
- (size + (NLMSG_ALIGNTO as usize - 1)) & !(NLMSG_ALIGNTO as usize - 1)
-}
-
-#[inline]
-pub const fn pad_netlink_object<T>() -> usize {
- let size = size_of::<T>();
- pad_netlink_object_with_variable_size(size)
-}
-
-pub fn get_subsystem_from_nlmsghdr_type(x: u16) -> u8 {
- ((x & 0xff00) >> 8) as u8
-}
-
-pub fn get_operation_from_nlmsghdr_type(x: u16) -> u8 {
- (x & 0x00ff) as u8
-}
-
pub fn get_nlmsghdr(buf: &[u8]) -> Result<nlmsghdr, DecodeError> {
let size_of_hdr = size_of::<nlmsghdr>();
@@ -272,126 +126,6 @@ pub unsafe fn write_attribute<'a>(
obj.write_payload(buf);
}
-impl NfNetlinkAttribute for u8 {
- unsafe fn write_payload(&self, addr: *mut u8) {
- *addr = *self;
- }
-}
-
-impl NfNetlinkDeserializable for u8 {
- fn deserialize(buf: &[u8]) -> Result<(Self, &[u8]), DecodeError> {
- Ok((buf[0], &buf[1..]))
- }
-}
-
-impl NfNetlinkAttribute for u16 {
- unsafe fn write_payload(&self, addr: *mut u8) {
- *(addr as *mut Self) = self.to_be();
- }
-}
-
-impl NfNetlinkDeserializable for u16 {
- fn deserialize(buf: &[u8]) -> Result<(Self, &[u8]), DecodeError> {
- Ok((u16::from_be_bytes([buf[0], buf[1]]), &buf[2..]))
- }
-}
-
-impl NfNetlinkAttribute for i32 {
- unsafe fn write_payload(&self, addr: *mut u8) {
- *(addr as *mut Self) = self.to_be();
- }
-}
-
-impl NfNetlinkDeserializable for i32 {
- fn deserialize(buf: &[u8]) -> Result<(Self, &[u8]), DecodeError> {
- Ok((
- i32::from_be_bytes([buf[0], buf[1], buf[2], buf[3]]),
- &buf[4..],
- ))
- }
-}
-
-impl NfNetlinkAttribute for u32 {
- unsafe fn write_payload(&self, addr: *mut u8) {
- *(addr as *mut Self) = self.to_be();
- }
-}
-
-impl NfNetlinkDeserializable for u32 {
- fn deserialize(buf: &[u8]) -> Result<(Self, &[u8]), DecodeError> {
- Ok((
- u32::from_be_bytes([buf[0], buf[1], buf[2], buf[3]]),
- &buf[4..],
- ))
- }
-}
-
-impl NfNetlinkAttribute for u64 {
- unsafe fn write_payload(&self, addr: *mut u8) {
- *(addr as *mut Self) = self.to_be();
- }
-}
-
-impl NfNetlinkDeserializable for u64 {
- fn deserialize(buf: &[u8]) -> Result<(Self, &[u8]), DecodeError> {
- Ok((
- u64::from_be_bytes([
- buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7],
- ]),
- &buf[8..],
- ))
- }
-}
-
-impl NfNetlinkAttribute for String {
- fn get_size(&self) -> usize {
- self.len()
- }
-
- unsafe fn write_payload(&self, addr: *mut u8) {
- std::ptr::copy_nonoverlapping(self.as_bytes().as_ptr(), addr, self.len());
- }
-}
-
-impl NfNetlinkDeserializable for String {
- fn deserialize(mut buf: &[u8]) -> Result<(Self, &[u8]), DecodeError> {
- // ignore the NULL byte terminator, if any
- if buf.len() > 0 && buf[buf.len() - 1] == 0 {
- buf = &buf[..buf.len() - 1];
- }
- Ok((String::from_utf8(buf.to_vec())?, &[]))
- }
-}
-
-impl NfNetlinkAttribute for Vec<u8> {
- fn get_size(&self) -> usize {
- self.len()
- }
-
- unsafe fn write_payload(&self, addr: *mut u8) {
- std::ptr::copy_nonoverlapping(self.as_ptr(), addr, self.len());
- }
-}
-
-impl NfNetlinkDeserializable for Vec<u8> {
- fn deserialize(buf: &[u8]) -> Result<(Self, &[u8]), DecodeError> {
- Ok((buf.to_vec(), &[]))
- }
-}
-
-impl NfNetlinkAttribute for ProtocolFamily {
- unsafe fn write_payload(&self, addr: *mut u8) {
- (*self as i32).write_payload(addr);
- }
-}
-
-impl NfNetlinkDeserializable for ProtocolFamily {
- fn deserialize(buf: &[u8]) -> Result<(Self, &[u8]), DecodeError> {
- let (v, remaining_data) = i32::deserialize(buf)?;
- Ok((Self::try_from(v)?, remaining_data))
- }
-}
-
pub(crate) fn read_attributes<T: AttributeDecoder + Default>(buf: &[u8]) -> Result<T, DecodeError> {
debug!(
"Calling <{} as NfNetlinkDeserialize>::deserialize()",
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-10 07:52:49 +0000