Manually bind static MyProcPort and struct Port

pgrx-pg-sys/src/lib.rs

@@ -20,6 +20,8 @@ mod cstr;
 mod include;
 mod node;
 mod port;
+
+pub mod libpq;
 pub mod submodules;
 
 #[cfg(feature = "cshim")]

pgrx-pg-sys/src/libpq.rs

@@ -0,0 +1,110 @@
+/** Manually-constructed bindings to libpq
+
+Because pgrx is for extensions which run in the Postgres server, it rarely needs access to libpq.
+However, some server-side extensions need to interact with the reality that clients exist.
+Unfortunately, doing that means acknowledging that clients need authentication and authorization,
+areas of concern that are far beyond what pgrx wants to involve itself with or be responsible for.
+
+We define some types and signatures here to allow a minimal amount of usage of items from libpq,
+while largely rejecting the notion that we should involve ourselves in security-laden concerns.
+
+*/
+
+pub mod be {
+
+    unsafe extern "C" {
+        pub static mut MyProcPort: *mut Port;
+    }
+
+    /// #define SCRAM_MAX_KEY_LEN          PG_SHA256_DIGEST_LENGTH
+    /// #define PG_SHA256_DIGEST_LENGTH    32
+    const SCRAM_MAX_KEY_LEN: usize = 32;
+
+    #[repr(C)]
+    pub struct Port {
+        pub sock: crate::pgsocket,
+        pub noblock: bool,
+        pub proto: crate::ProtocolVersion,
+        pub laddr: crate::SockAddr,
+        pub raddr: crate::SockAddr,
+        pub remote_host: *mut core::ffi::c_char,
+        pub remote_hostname: *mut core::ffi::c_char,
+        pub remote_hostname_resolv: core::ffi::c_int,
+        pub remote_hostname_errcode: core::ffi::c_int,
+        pub remote_port: *mut core::ffi::c_char,
+        #[cfg(any(feature = "pg13", feature = "pg14", feature = "pg15", feature = "pg16"))]
+        pub canAcceptConnections: core::ffi::c_uint,
+        #[cfg(feature = "pg18")]
+        pub local_host: [core::ffi::c_char; 64],
+        pub database_name: *mut core::ffi::c_char,
+        pub user_name: *mut core::ffi::c_char,
+        pub cmdline_options: *mut core::ffi::c_char,
+        pub guc_options: *mut crate::List,
+        pub application_name: *mut core::ffi::c_char,
+
+        // The remainder is for completeness, so Rust sees Port's layout as correctly as possible.
+        // Ideally we would use `extern type` so the remainder of this was seen as of unknown size.
+        // An alternative is to simply treat them as private fields, so we do.
+
+        // This should be `*mut crate::HbaLine` if we ever bind that
+        hba: *mut core::ffi::c_void,
+
+        #[cfg(any(feature = "pg14", feature = "pg15"))]
+        authn_id: *const core::ffi::c_char,
+
+        default_keepalives_idle: core::ffi::c_int,
+        default_keepalives_interval: core::ffi::c_int,
+        default_keepalives_count: core::ffi::c_int,
+        default_tcp_user_timeout: core::ffi::c_int,
+        keepalives_idle: core::ffi::c_int,
+        keepalives_interval: core::ffi::c_int,
+        keepalives_count: core::ffi::c_int,
+        tcp_user_timeout: core::ffi::c_int,
+
+        #[cfg(feature = "pg18")]
+        scram_ClientKey: [u8; SCRAM_MAX_KEY_LEN],
+        #[cfg(feature = "pg18")]
+        scram_ServerKey: [u8; SCRAM_MAX_KEY_LEN],
+        #[cfg(feature = "pg18")]
+        has_scram_keys: bool,
+
+        // as if ENABLE_GSS == false && ENABLE_SSPI == false
+        gss: *mut core::ffi::c_void,
+
+        ssl_in_use: bool,
+        peer_cn: *mut core::ffi::c_char,
+        #[cfg(any(
+            feature = "pg14",
+            feature = "pg15",
+            feature = "pg16",
+            feature = "pg17",
+            feature = "pg18"
+        ))]
+        peer_dn: *mut core::ffi::c_char,
+        peer_cert_valid: bool,
+
+        #[cfg(any(feature = "pg17", feature = "pg18"))]
+        alpn_used: bool,
+        #[cfg(feature = "pg18")]
+        last_read_was_eof: bool,
+
+        // NOTE: 5 fields remain on PG17, but two are `#ifdef USE_OPENSSL` in PG17, so treat all
+        // as conditioned on PG18, even if that is not strictly accurate for PG17
+
+        // as if USE_OPENSSL == false
+        #[cfg(feature = "pg18")]
+        ssl: *mut core::ffi::c_void,
+        #[cfg(feature = "pg18")]
+        peer: *mut core::ffi::c_void,
+
+        #[cfg(any(feature = "pg17", feature = "pg18"))]
+        #[cfg_attr(feature = "pg17", deprecated(since = "0.17.0", note = "may be unsound to access on Postgres 17 depending on build `#define`s")]
+        raw_buf: *mut core::ffi::c_char,
+        #[cfg(any(feature = "pg17", feature = "pg18"))]
+        #[cfg_attr(feature = "pg17", deprecated(since = "0.17.0", note = "may be unsound to access on Postgres 17 depending on build `#define`s")]
+        raw_buf_consumed: isize,
+        #[cfg(any(feature = "pg17", feature = "pg18"))]
+        #[cfg_attr(feature = "pg17", deprecated(since = "0.17.0", note = "may be unsound to access on Postgres 17 depending on build `#define`s")]
+        raw_buf_remaining: isize,
+    }
+}