feat: remove libseccomp rust dependency

Replace `libseccomp` with in house binding.
This way we don't need to add another dependency
and allows us to have access the `seccomp_export_bpf_mem`
method, not exposed in the `libseccomp` crate.
This creates another issue though: the `seccomp_export_bpf_mem`
function needs to be exposed by the libseccomp library. This
is not an issue when `seccompiler` is build in the docker environment
because we build it from source. But version provided by
linux distribution might have this function not exposed.

Signed-off-by: Egor Lazarchuk <[email protected]>

Author: ShadowCurse

Cargo.lock

@@ -20,7 +20,6 @@ bincode = "1.2.1"
 clap = { version = "4.5.21", features = ["derive", "string"] }
 displaydoc = "0.2.5"
 libc = "0.2.167"
-libseccomp = "0.3.0"
 serde = { version = "1.0.215", features = ["derive"] }
 serde_json = "1.0.133"
 thiserror = "2.0.3"

src/seccompiler/Cargo.toml

@@ -2,5 +2,6 @@
 // SPDX-License-Identifier: Apache-2.0
 
 fn main() {
+    println!("cargo::rustc-link-search=/usr/local/lib");
     println!("cargo::rustc-link-lib=seccomp");
 }

src/seccompiler/build.rs

@@ -0,0 +1,174 @@
+// Copyright 2024 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+
+//! Raw FFI bindings for libseccomp library
+
+use std::os::raw::*;
+
+pub const MINUS_EEXIST: i32 = -libc::EEXIST;
+
+/// Filter context/handle (`*mut`)
+pub type scmp_filter_ctx = *mut c_void;
+/// Filter context/handle (`*const`)
+pub type const_scmp_filter_ctx = *const c_void;
+
+/// Comparison operators
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[repr(C)]
+pub enum scmp_compare {
+    _SCMP_CMP_MIN = 0,
+    /// not equal
+    SCMP_CMP_NE = 1,
+    /// less than
+    SCMP_CMP_LT = 2,
+    /// less than or equal
+    SCMP_CMP_LE = 3,
+    /// equal
+    SCMP_CMP_EQ = 4,
+    /// greater than or equal
+    SCMP_CMP_GE = 5,
+    /// greater than
+    SCMP_CMP_GT = 6,
+    /// masked equality
+    SCMP_CMP_MASKED_EQ = 7,
+    _SCMP_CMP_MAX,
+}
+
+/// Argument datum
+pub type scmp_datum_t = u64;
+
+/// Argument / Value comparison definition
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[repr(C)]
+pub struct scmp_arg_cmp {
+    /// argument number, starting at 0
+    pub arg: c_uint,
+    /// the comparison op, e.g. `SCMP_CMP_*`
+    pub op: scmp_compare,
+    pub datum_a: scmp_datum_t,
+    pub datum_b: scmp_datum_t,
+}
+
+pub const SCMP_ARCH_X86_64: u32 = 0xc000003e;
+pub const SCMP_ARCH_AARCH64: u32 = 0xc00000b7;
+/// Kill the process
+pub const SCMP_ACT_KILL_PROCESS: u32 = 0x80000000;
+/// Kill the thread
+pub const SCMP_ACT_KILL_THREAD: u32 = 0x00000000;
+/// Throw a `SIGSYS` signal
+pub const SCMP_ACT_TRAP: u32 = 0x00030000;
+/// Notifies userspace
+pub const SCMP_ACT_ERRNO_MASK: u32 = 0x00050000;
+/// Return the specified error code
+#[must_use]
+pub const fn SCMP_ACT_ERRNO(x: u16) -> u32 {
+    SCMP_ACT_ERRNO_MASK | x as u32
+}
+pub const SCMP_ACT_TRACE_MASK: u32 = 0x7ff00000;
+/// Notify a tracing process with the specified value
+#[must_use]
+pub const fn SCMP_ACT_TRACE(x: u16) -> u32 {
+    SCMP_ACT_TRACE_MASK | x as u32
+}
+/// Allow the syscall to be executed after the action has been logged
+pub const SCMP_ACT_LOG: u32 = 0x7ffc0000;
+/// Allow the syscall to be executed
+pub const SCMP_ACT_ALLOW: u32 = 0x7fff0000;
+
+#[link(name = "seccomp")]
+extern "C" {
+    /// Initialize the filter state
+    ///
+    /// - `def_action`: the default filter action
+    ///
+    /// This function initializes the internal seccomp filter state and should
+    /// be called before any other functions in this library to ensure the filter
+    /// state is initialized.  Returns a filter context on success, `ptr::null()` on failure.
+    pub fn seccomp_init(def_action: u32) -> scmp_filter_ctx;
+
+    /// Adds an architecture to the filter
+    ///
+    /// - `ctx`: the filter context
+    /// - `arch_token`: the architecture token, e.g. `SCMP_ARCH_*`
+    ///
+    /// This function adds a new architecture to the given seccomp filter context.
+    /// Any new rules added after this function successfully returns will be added
+    /// to this architecture but existing rules will not be added to this
+    /// architecture.  If the architecture token is [`SCMP_ARCH_NATIVE`] then the native
+    /// architecture will be assumed.  Returns zero on success, `-libc::EEXIST` if
+    /// specified architecture is already present, other negative values on failure.
+    pub fn seccomp_arch_add(ctx: scmp_filter_ctx, arch_token: u32) -> c_int;
+
+    /// Resolve a syscall name to a number
+    ///
+    /// - `name`: the syscall name
+    ///
+    /// Resolve the given syscall name to the syscall number.  Returns the syscall
+    /// number on success, including negative pseudo syscall numbers (e.g. `__PNR_*`);
+    /// returns [`__NR_SCMP_ERROR`] on failure.
+    pub fn seccomp_syscall_resolve_name(name: *const c_char) -> c_int;
+
+    /// Add a new rule to the filter
+    ///
+    /// - `ctx`: the filter context
+    /// - `action`: the filter action
+    /// - `syscall`: the syscall number
+    /// - `arg_cnt`: the number of argument filters in the argument filter chain
+    /// - `...`: [`scmp_arg_cmp`] structs
+    ///
+    /// This function adds a series of new argument/value checks to the seccomp
+    /// filter for the given syscall; multiple argument/value checks can be
+    /// specified and they will be chained together (AND'd together) in the filter.
+    /// If the specified rule needs to be adjusted due to architecture specifics it
+    /// will be adjusted without notification.  Returns zero on success, negative
+    /// values on failure.
+    pub fn seccomp_rule_add(
+        ctx: scmp_filter_ctx,
+        action: u32,
+        syscall: c_int,
+        arg_cnt: c_uint,
+        ...
+    ) -> c_int;
+
+    /// Add a new rule to the filter
+    ///
+    /// - `ctx`: the filter context
+    /// - `action`: the filter action
+    /// - `syscall`: the syscall number
+    /// - `arg_cnt`: the number of elements in the arg_array parameter
+    /// - `arg_array`: array of [`scmp_arg_cmp`] structs
+    ///
+    /// This function adds a series of new argument/value checks to the seccomp
+    /// filter for the given syscall; multiple argument/value checks can be
+    /// specified and they will be chained together (AND'd together) in the filter.
+    /// If the specified rule needs to be adjusted due to architecture specifics it
+    /// will be adjusted without notification.  Returns zero on success, negative
+    /// values on failure.
+    pub fn seccomp_rule_add_array(
+        ctx: scmp_filter_ctx,
+        action: u32,
+        syscall: c_int,
+        arg_cnt: c_uint,
+        arg_array: *const scmp_arg_cmp,
+    ) -> c_int;
+
+    /// Generate seccomp Berkeley Packet Filter (BPF) code and export it to a buffer
+    ///
+    /// - `ctx`: the filter context
+    /// - `buf`: the destination buffer
+    /// - `len`: on input the length of the buffer, on output the number of bytes in the program
+    ///
+    /// This function generates seccomp Berkeley Packer Filter (BPF) code and writes
+    /// it to the given buffer.  Returns zero on success, negative values on failure.
+    pub fn seccomp_export_bpf_mem(
+        ctx: const_scmp_filter_ctx,
+        buf: *mut c_void,
+        len: *mut usize,
+    ) -> c_int;
+}
+
+/// Negative pseudo syscall number returned by some functions in case of an error
+pub const __NR_SCMP_ERROR: c_int = -1;