aya: Add BPF_PROG_TYPE_CGROUP_SOCK_ADDR

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>

aya/src/bpf.rs

@@ -22,10 +22,10 @@ use crate::{
         MapKind, Object, ParseError, ProgramSection,
     },
     programs::{
-        BtfTracePoint, CgroupSkb, CgroupSkbAttachType, CgroupSysctl, Extension, FEntry, FExit,
-        KProbe, LircMode2, Lsm, PerfEvent, ProbeKind, Program, ProgramData, ProgramError,
-        RawTracePoint, SchedClassifier, SkMsg, SkSkb, SkSkbKind, SockOps, SocketFilter, TracePoint,
-        UProbe, Xdp,
+        BtfTracePoint, CgroupSkb, CgroupSkbAttachType, CgroupSockAddr, CgroupSysctl, Extension,
+        FEntry, FExit, KProbe, LircMode2, Lsm, PerfEvent, ProbeKind, Program, ProgramData,
+        ProgramError, RawTracePoint, SchedClassifier, SkMsg, SkSkb, SkSkbKind, SockOps,
+        SocketFilter, TracePoint, UProbe, Xdp,
     },
     sys::{
         bpf_load_btf, bpf_map_freeze, bpf_map_update_elem_ptr, is_btf_datasec_supported,
@@ -481,6 +481,12 @@ impl<'a> BpfLoader<'a> {
                             data: ProgramData::new(prog_name, obj, btf_fd),
                             expected_attach_type: Some(CgroupSkbAttachType::Egress),
                         }),
+                        ProgramSection::CgroupSockAddr { attach_type, .. } => {
+                            Program::CgroupSockAddr(CgroupSockAddr {
+                                data: ProgramData::new(prog_name, obj, btf_fd),
+                                attach_type: *attach_type,
+                            })
+                        }
                         ProgramSection::LircMode2 { .. } => Program::LircMode2(LircMode2 {
                             data: ProgramData::new(prog_name, obj, btf_fd),
                         }),

aya/src/obj/mod.rs

@@ -21,6 +21,7 @@ use crate::{
     bpf_map_def,
     generated::{bpf_insn, bpf_map_type::BPF_MAP_TYPE_ARRAY, BPF_F_RDONLY_PROG},
     obj::btf::{Btf, BtfError, BtfExt},
+    programs::CgroupSockAddrAttachType,
     BpfError,
 };
 use std::slice::from_raw_parts_mut;
@@ -104,30 +105,82 @@ pub(crate) struct Function {
 
 #[derive(Debug, Clone)]
 pub enum ProgramSection {
-    KRetProbe { name: String },
-    KProbe { name: String },
-    UProbe { name: String },
-    URetProbe { name: String },
-    TracePoint { name: String },
-    SocketFilter { name: String },
-    Xdp { name: String },
-    SkMsg { name: String },
-    SkSkbStreamParser { name: String },
-    SkSkbStreamVerdict { name: String },
-    SockOps { name: String },
-    SchedClassifier { name: String },
-    CgroupSkb { name: String },
-    CgroupSkbIngress { name: String },
-    CgroupSkbEgress { name: String },
-    CgroupSysctl { name: String },
-    LircMode2 { name: String },
-    PerfEvent { name: String },
-    RawTracePoint { name: String },
-    Lsm { name: String },
-    BtfTracePoint { name: String },
-    FEntry { name: String },
-    FExit { name: String },
-    Extension { name: String },
+    KRetProbe {
+        name: String,
+    },
+    KProbe {
+        name: String,
+    },
+    UProbe {
+        name: String,
+    },
+    URetProbe {
+        name: String,
+    },
+    TracePoint {
+        name: String,
+    },
+    SocketFilter {
+        name: String,
+    },
+    Xdp {
+        name: String,
+    },
+    SkMsg {
+        name: String,
+    },
+    SkSkbStreamParser {
+        name: String,
+    },
+    SkSkbStreamVerdict {
+        name: String,
+    },
+    SockOps {
+        name: String,
+    },
+    SchedClassifier {
+        name: String,
+    },
+    CgroupSkb {
+        name: String,
+    },
+    CgroupSkbIngress {
+        name: String,
+    },
+    CgroupSkbEgress {
+        name: String,
+    },
+    CgroupSockAddr {
+        name: String,
+        attach_type: CgroupSockAddrAttachType,
+    },
+    CgroupSysctl {
+        name: String,
+    },
+    LircMode2 {
+        name: String,
+    },
+    PerfEvent {
+        name: String,
+    },
+    RawTracePoint {
+        name: String,
+    },
+    Lsm {
+        name: String,
+    },
+    BtfTracePoint {
+        name: String,
+    },
+    FEntry {
+        name: String,
+    },
+    FExit {
+        name: String,
+    },
+    Extension {
+        name: String,
+    },
 }
 
 impl ProgramSection {
@@ -145,9 +198,10 @@ impl ProgramSection {
             ProgramSection::SkSkbStreamVerdict { name } => name,
             ProgramSection::SockOps { name } => name,
             ProgramSection::SchedClassifier { name } => name,
-            ProgramSection::CgroupSkb { name } => name,
-            ProgramSection::CgroupSkbIngress { name } => name,
-            ProgramSection::CgroupSkbEgress { name } => name,
+            ProgramSection::CgroupSkb { name, .. } => name,
+            ProgramSection::CgroupSkbIngress { name, .. } => name,
+            ProgramSection::CgroupSkbEgress { name, .. } => name,
+            ProgramSection::CgroupSockAddr { name, .. } => name,
             ProgramSection::CgroupSysctl { name } => name,
             ProgramSection::LircMode2 { name } => name,
             ProgramSection::PerfEvent { name } => name,
@@ -221,11 +275,63 @@ impl FromStr for ProgramSection {
                 "skb" => CgroupSkb { name },
                 "sysctl" => CgroupSysctl { name },
                 _ => {
-                    return Err(ParseError::InvalidProgramSection {
-                        section: section.to_owned(),
-                    })
+                    if let Ok(attach_type) = CgroupSockAddrAttachType::try_from(name.as_str()) {
+                        CgroupSockAddr { name, attach_type }
+                    } else {
+                        return Err(ParseError::InvalidProgramSection {
+                            section: section.to_owned(),
+                        });
+                    }
                 }
             },
+            "cgroup/bind4" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::Bind4,
+            },
+            "cgroup/bind6" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::Bind6,
+            },
+            "cgroup/connect4" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::Connect4,
+            },
+            "cgroup/connect6" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::Connect6,
+            },
+            "cgroup/getpeername4" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::GetPeerName4,
+            },
+            "cgroup/getpeername6" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::GetPeerName6,
+            },
+            "cgroup/getsockname4" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::GetSockName4,
+            },
+            "cgroup/getsockname6" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::GetSockName6,
+            },
+            "cgroup/sendmsg4" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::UDPSendMsg4,
+            },
+            "cgroup/sendmsg6" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::UDPSendMsg6,
+            },
+            "cgroup/recvmsg4" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::UDPRecvMsg4,
+            },
+            "cgroup/recvmsg6" => CgroupSockAddr {
+                name,
+                attach_type: CgroupSockAddrAttachType::UDPRecvMsg6,
+            },
             "lirc_mode2" => LircMode2 { name },
             "perf_event" => PerfEvent { name },
             "raw_tp" | "raw_tracepoint" => RawTracePoint { name },
@@ -1641,6 +1747,54 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_parse_section_sock_addr_named() {
+        let mut obj = fake_obj();
+
+        assert_matches!(
+            obj.parse_section(fake_section(
+                BpfSectionKind::Program,
+                "cgroup/connect4/foo",
+                bytes_of(&fake_ins())
+            )),
+            Ok(())
+        );
+        assert_matches!(
+            obj.programs.get("foo"),
+            Some(Program {
+                section: ProgramSection::CgroupSockAddr {
+                    attach_type: CgroupSockAddrAttachType::Connect4,
+                    ..
+                },
+                ..
+            })
+        );
+    }
+
+    #[test]
+    fn test_parse_section_sock_addr_unnamed() {
+        let mut obj = fake_obj();
+
+        assert_matches!(
+            obj.parse_section(fake_section(
+                BpfSectionKind::Program,
+                "cgroup/connect4",
+                bytes_of(&fake_ins())
+            )),
+            Ok(())
+        );
+        assert_matches!(
+            obj.programs.get("connect4"),
+            Some(Program {
+                section: ProgramSection::CgroupSockAddr {
+                    attach_type: CgroupSockAddrAttachType::Connect4,
+                    ..
+                },
+                ..
+            })
+        );
+    }
+
     #[test]
     fn test_patch_map_data() {
         let mut obj = fake_obj();

aya/src/programs/cgroup_sock_addr.rs

@@ -0,0 +1,233 @@
+use thiserror::Error;
+
+use crate::generated::bpf_attach_type;
+use std::{
+    hash::Hash,
+    os::unix::prelude::{AsRawFd, RawFd},
+};
+
+use crate::{
+    generated::bpf_prog_type::BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+    programs::{
+        define_link_wrapper, load_program, FdLink, Link, OwnedLink, ProgAttachLink, ProgramData,
+        ProgramError,
+    },
+    sys::{bpf_link_create, bpf_prog_attach, kernel_version},
+};
+
+/// A program that can be used to inspect or modify socket addresses (`struct sockaddr`).
+///
+/// [`SockAddr`] programs can be used to inspect or modify socket addresses passed to
+/// various syscalls within a [cgroup]. They can be attached to a number of different
+/// places as described in [`SockAddrAttachType`].
+///
+/// [cgroup]: https://man7.org/linux/man-pages/man7/cgroups.7.html
+///
+/// # Minimum kernel version
+///
+/// The minimum kernel version required to use this feature is 4.17.
+///
+/// # Examples
+///
+/// ```no_run
+/// # #[derive(thiserror::Error, Debug)]
+/// # enum Error {
+/// #     #[error(transparent)]
+/// #     IO(#[from] std::io::Error),
+/// #     #[error(transparent)]
+/// #     Map(#[from] aya::maps::MapError),
+/// #     #[error(transparent)]
+/// #     Program(#[from] aya::programs::ProgramError),
+/// #     #[error(transparent)]
+/// #     Bpf(#[from] aya::BpfError)
+/// # }
+/// # let mut bpf = aya::Bpf::load(&[])?;
+/// use std::fs::File;
+/// use std::convert::TryInto;
+/// use aya::programs::{CgroupSockAddr, CgroupSockAddrAttachType};
+///
+/// let file = File::open("/sys/fs/cgroup/unified")?;
+/// let egress: &mut CgroupSockAddr = bpf.program_mut("connect4").unwrap().try_into()?;
+/// egress.load()?;
+/// egress.attach(file)?;
+/// # Ok::<(), Error>(())
+/// ```
+#[derive(Debug)]
+#[doc(alias = "BPF_PROG_TYPE_CGROUP_SOCK_ADDR")]
+pub struct CgroupSockAddr {
+    pub(crate) data: ProgramData<CgroupSockAddrLink>,
+    pub(crate) attach_type: CgroupSockAddrAttachType,
+}
+
+impl CgroupSockAddr {
+    /// Loads the program inside the kernel.
+    pub fn load(&mut self) -> Result<(), ProgramError> {
+        self.data.expected_attach_type = Some(self.attach_type.into());
+        load_program(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, &mut self.data)
+    }
+
+    /// Attaches the program to the given cgroup.
+    ///
+    /// The returned value can be used to detach, see [SockAddr::detach].
+    pub fn attach<T: AsRawFd>(&mut self, cgroup: T) -> Result<CgroupSockAddrLinkId, ProgramError> {
+        let prog_fd = self.data.fd_or_err()?;
+        let cgroup_fd = cgroup.as_raw_fd();
+        let attach_type = self.data.expected_attach_type.unwrap();
+        let k_ver = kernel_version().unwrap();
+        if k_ver >= (5, 7, 0) {
+            let link_fd = bpf_link_create(prog_fd, cgroup_fd, attach_type, None, 0).map_err(
+                |(_, io_error)| ProgramError::SyscallError {
+                    call: "bpf_link_create".to_owned(),
+                    io_error,
+                },
+            )? as RawFd;
+            self.data
+                .links
+                .insert(CgroupSockAddrLink(CgroupSockAddrLinkInner::Fd(
+                    FdLink::new(link_fd),
+                )))
+        } else {
+            bpf_prog_attach(prog_fd, cgroup_fd, attach_type).map_err(|(_, io_error)| {
+                ProgramError::SyscallError {
+                    call: "bpf_prog_attach".to_owned(),
+                    io_error,
+                }
+            })?;
+
+            self.data
+                .links
+                .insert(CgroupSockAddrLink(CgroupSockAddrLinkInner::ProgAttach(
+                    ProgAttachLink::new(prog_fd, cgroup_fd, attach_type),
+                )))
+        }
+    }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: CgroupSockAddrLinkId,
+    ) -> Result<OwnedLink<CgroupSockAddrLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
+
+    /// Detaches the program.
+    ///
+    /// See [SockAddr::attach].
+    pub fn detach(&mut self, link_id: CgroupSockAddrLinkId) -> Result<(), ProgramError> {
+        self.data.links.remove(link_id)
+    }
+}
+
+#[derive(Debug, Hash, Eq, PartialEq)]
+enum CgroupSockAddrLinkIdInner {
+    Fd(<FdLink as Link>::Id),
+    ProgAttach(<ProgAttachLink as Link>::Id),
+}
+
+#[derive(Debug)]
+enum CgroupSockAddrLinkInner {
+    Fd(FdLink),
+    ProgAttach(ProgAttachLink),
+}
+
+impl Link for CgroupSockAddrLinkInner {
+    type Id = CgroupSockAddrLinkIdInner;
+
+    fn id(&self) -> Self::Id {
+        match self {
+            CgroupSockAddrLinkInner::Fd(fd) => CgroupSockAddrLinkIdInner::Fd(fd.id()),
+            CgroupSockAddrLinkInner::ProgAttach(p) => CgroupSockAddrLinkIdInner::ProgAttach(p.id()),
+        }
+    }
+
+    fn detach(self) -> Result<(), ProgramError> {
+        match self {
+            CgroupSockAddrLinkInner::Fd(fd) => fd.detach(),
+            CgroupSockAddrLinkInner::ProgAttach(p) => p.detach(),
+        }
+    }
+}
+
+define_link_wrapper!(
+    /// The link used by [SockAddr] programs.
+    CgroupSockAddrLink,
+    /// The type returned by [SockAddr::attach]. Can be passed to [SockAddr::detach].
+    CgroupSockAddrLinkId,
+    CgroupSockAddrLinkInner,
+    CgroupSockAddrLinkIdInner
+);
+
+/// Defines where to attach a [`SockAddr`] program.
+#[derive(Copy, Clone, Debug)]
+pub enum CgroupSockAddrAttachType {
+    /// Attach to IPv4 bind events.
+    Bind4,
+    /// Attach to IPv6 bind events.
+    Bind6,
+    /// Attach to IPv4 connect events.
+    Connect4,
+    /// Attach to IPv6 connect events.
+    Connect6,
+    /// Attach to IPv4 getpeername events.
+    GetPeerName4,
+    /// Attach to IPv6 getpeername events.
+    GetPeerName6,
+    /// Attach to IPv4 getsockname events.
+    GetSockName4,
+    /// Attach to IPv6 getsockname events.
+    GetSockName6,
+    /// Attach to IPv4 udp_sendmsg events.
+    UDPSendMsg4,
+    /// Attach to IPv6 udp_sendmsg events.
+    UDPSendMsg6,
+    /// Attach to IPv4 udp_recvmsg events.
+    UDPRecvMsg4,
+    /// Attach to IPv6 udp_recvmsg events.
+    UDPRecvMsg6,
+}
+
+impl From<CgroupSockAddrAttachType> for bpf_attach_type {
+    fn from(s: CgroupSockAddrAttachType) -> bpf_attach_type {
+        match s {
+            CgroupSockAddrAttachType::Bind4 => bpf_attach_type::BPF_CGROUP_INET4_BIND,
+            CgroupSockAddrAttachType::Bind6 => bpf_attach_type::BPF_CGROUP_INET6_BIND,
+            CgroupSockAddrAttachType::Connect4 => bpf_attach_type::BPF_CGROUP_INET4_CONNECT,
+            CgroupSockAddrAttachType::Connect6 => bpf_attach_type::BPF_CGROUP_INET6_CONNECT,
+            CgroupSockAddrAttachType::GetPeerName4 => bpf_attach_type::BPF_CGROUP_INET4_GETPEERNAME,
+            CgroupSockAddrAttachType::GetPeerName6 => bpf_attach_type::BPF_CGROUP_INET6_GETPEERNAME,
+            CgroupSockAddrAttachType::GetSockName4 => bpf_attach_type::BPF_CGROUP_INET4_GETSOCKNAME,
+            CgroupSockAddrAttachType::GetSockName6 => bpf_attach_type::BPF_CGROUP_INET6_GETSOCKNAME,
+            CgroupSockAddrAttachType::UDPSendMsg4 => bpf_attach_type::BPF_CGROUP_UDP4_SENDMSG,
+            CgroupSockAddrAttachType::UDPSendMsg6 => bpf_attach_type::BPF_CGROUP_UDP6_SENDMSG,
+            CgroupSockAddrAttachType::UDPRecvMsg4 => bpf_attach_type::BPF_CGROUP_UDP4_RECVMSG,
+            CgroupSockAddrAttachType::UDPRecvMsg6 => bpf_attach_type::BPF_CGROUP_UDP6_RECVMSG,
+        }
+    }
+}
+
+#[derive(Debug, Error)]
+#[error("{0} is not a valid attach type for a CGROUP_SOCK_ADDR program")]
+pub(crate) struct InvalidAttachType(String);
+
+impl CgroupSockAddrAttachType {
+    pub(crate) fn try_from(value: &str) -> Result<CgroupSockAddrAttachType, InvalidAttachType> {
+        match value {
+            "bind4" => Ok(CgroupSockAddrAttachType::Bind4),
+            "bind6" => Ok(CgroupSockAddrAttachType::Bind6),
+            "connect4" => Ok(CgroupSockAddrAttachType::Connect4),
+            "connect6" => Ok(CgroupSockAddrAttachType::Connect6),
+            "getpeername4" => Ok(CgroupSockAddrAttachType::GetPeerName4),
+            "getpeername6" => Ok(CgroupSockAddrAttachType::GetPeerName6),
+            "getsockname4" => Ok(CgroupSockAddrAttachType::GetSockName4),
+            "getsockname6" => Ok(CgroupSockAddrAttachType::GetSockName6),
+            "sendmsg4" => Ok(CgroupSockAddrAttachType::UDPSendMsg4),
+            "sendmsg6" => Ok(CgroupSockAddrAttachType::UDPSendMsg6),
+            "recvmsg4" => Ok(CgroupSockAddrAttachType::UDPRecvMsg4),
+            "recvmsg6" => Ok(CgroupSockAddrAttachType::UDPRecvMsg6),
+            _ => Err(InvalidAttachType(value.to_owned())),
+        }
+    }
+}

aya/src/programs/mod.rs

@@ -37,6 +37,7 @@
 //! [`Bpf::program_mut`]: crate::Bpf::program_mut
 //! [`maps`]: crate::maps
 mod cgroup_skb;
+mod cgroup_sock_addr;
 mod cgroup_sysctl;
 mod extension;
 mod fentry;
@@ -71,6 +72,7 @@ use std::{
 use thiserror::Error;
 
 pub use cgroup_skb::{CgroupSkb, CgroupSkbAttachType};
+pub use cgroup_sock_addr::{CgroupSockAddr, CgroupSockAddrAttachType};
 pub use cgroup_sysctl::CgroupSysctl;
 pub use extension::{Extension, ExtensionError};
 pub use fentry::FEntry;
@@ -229,6 +231,8 @@ pub enum Program {
     SkMsg(SkMsg),
     /// A [`SkSkb`] program
     SkSkb(SkSkb),
+    /// A [`CgroupSockAddr`] program
+    CgroupSockAddr(CgroupSockAddr),
     /// A [`SockOps`] program
     SockOps(SockOps),
     /// A [`SchedClassifier`] program
@@ -279,6 +283,7 @@ impl Program {
             Program::FEntry(_) => BPF_PROG_TYPE_TRACING,
             Program::FExit(_) => BPF_PROG_TYPE_TRACING,
             Program::Extension(_) => BPF_PROG_TYPE_EXT,
+            Program::CgroupSockAddr(_) => BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
         }
     }
 
@@ -304,6 +309,7 @@ impl Program {
             Program::FEntry(p) => p.data.pin(path),
             Program::FExit(p) => p.data.pin(path),
             Program::Extension(p) => p.data.pin(path),
+            Program::CgroupSockAddr(p) => p.data.pin(path),
         }
     }
 }
@@ -509,6 +515,7 @@ impl ProgramFd for Program {
             Program::FEntry(p) => p.data.fd,
             Program::FExit(p) => p.data.fd,
             Program::Extension(p) => p.data.fd,
+            Program::CgroupSockAddr(p) => p.data.fd,
         }
     }
 }
@@ -556,6 +563,7 @@ impl_program_fd!(
     FEntry,
     FExit,
     Extension,
+    CgroupSockAddr,
 );
 
 macro_rules! impl_try_from_program {
@@ -606,6 +614,7 @@ impl_try_from_program!(
     FEntry,
     FExit,
     Extension,
+    CgroupSockAddr,
 );
 
 /// Provides information about a loaded program, like name, id and statistics