Fix and consolidate CMSG_* implementations

libc-test/tests/cmsg.rs

@@ -3,11 +3,9 @@
 
 #[cfg(unix)]
 mod t {
-
     use std::mem;
 
     use libc::{
-        self,
         c_uchar,
         c_uint,
         c_void,
@@ -17,8 +15,6 @@ mod t {
 
     extern "C" {
         pub fn cmsg_firsthdr(msgh: *const msghdr) -> *mut cmsghdr;
-        // see below
-        #[cfg(not(target_arch = "sparc64"))]
         pub fn cmsg_nxthdr(mhdr: *const msghdr, cmsg: *const cmsghdr) -> *mut cmsghdr;
         pub fn cmsg_space(length: c_uint) -> usize;
         pub fn cmsg_len(length: c_uint) -> usize;
@@ -52,15 +48,10 @@ mod t {
     #[test]
     fn test_cmsg_len() {
         for l in 0..128 {
-            unsafe {
-                assert_eq!(libc::CMSG_LEN(l) as usize, cmsg_len(l));
-            }
+            assert_eq!(libc::CMSG_LEN(l) as usize, unsafe { cmsg_len(l) });
         }
     }
 
-    // Skip on sparc64
-    // https://github.com/rust-lang/libc/issues/1239
-    #[cfg(not(target_arch = "sparc64"))]
     #[test]
     fn test_cmsg_nxthdr() {
         // Helps to align the buffer on the stack.
@@ -69,42 +60,48 @@ mod t {
 
         const CAPACITY: usize = 512;
         let mut buffer = Align8([0_u8; CAPACITY]);
+        let pcmsghdr = buffer.0.as_mut_ptr().cast::<cmsghdr>();
+
         let mut mhdr: msghdr = unsafe { mem::zeroed() };
-        for start_ofs in 0..64 {
-            let pcmsghdr = buffer.0.as_mut_ptr().cast::<cmsghdr>();
-            mhdr.msg_control = pcmsghdr.cast::<c_void>();
-            mhdr.msg_controllen = (160 - start_ofs) as _;
-            for cmsg_len in 0..64 {
-                // Address must be a multiple of 0x4 for testing on AIX.
-                if cfg!(target_os = "aix") && cmsg_len % std::mem::size_of::<cmsghdr>() != 0 {
-                    continue;
-                }
-                for next_cmsg_len in 0..32 {
+        mhdr.msg_control = pcmsghdr.cast::<c_void>();
+
+        for trunc in 0..64 {
+            mhdr.msg_controllen = (160 - trunc) as _;
+
+            for cmsg_payload_len in 0..64 {
+                let mut current_cmsghdr_ptr = pcmsghdr;
+                assert!(!current_cmsghdr_ptr.is_null());
+                let mut count = 0;
+
+                while !current_cmsghdr_ptr.is_null() {
                     unsafe {
-                        pcmsghdr.cast::<u8>().write_bytes(0, CAPACITY);
-                        (*pcmsghdr).cmsg_len = cmsg_len as _;
-                        let libc_next = libc::CMSG_NXTHDR(&mhdr, pcmsghdr);
-                        let next = cmsg_nxthdr(&mhdr, pcmsghdr);
-                        assert_eq!(libc_next, next);
-
-                        if !libc_next.is_null() {
-                            (*libc_next).cmsg_len = next_cmsg_len;
-                            let libc_next = libc::CMSG_NXTHDR(&mhdr, pcmsghdr);
-                            let next = cmsg_nxthdr(&mhdr, pcmsghdr);
-                            assert_eq!(libc_next, next);
-                        }
+                        (*current_cmsghdr_ptr).cmsg_len =
+                            libc::CMSG_LEN(cmsg_payload_len as _) as _;
+
+                        let libc_next = libc::CMSG_NXTHDR(&mhdr, current_cmsghdr_ptr);
+                        let system_next = cmsg_nxthdr(&mhdr, current_cmsghdr_ptr);
+                        assert_eq!(
+                            system_next, libc_next,
+                            "msg_crontrollen: {}, payload_len: {}, count: {}",
+                            mhdr.msg_controllen, cmsg_payload_len, count
+                        );
+
+                        current_cmsghdr_ptr = libc_next;
+                        count += 1;
                     }
                 }
+
+                unsafe {
+                    pcmsghdr.cast::<u8>().write_bytes(0, CAPACITY);
+                }
             }
         }
     }
 
     #[test]
     fn test_cmsg_space() {
-        unsafe {
-            for l in 0..128 {
-                assert_eq!(libc::CMSG_SPACE(l) as usize, cmsg_space(l));
-            }
+        for l in 0..128 {
+            assert_eq!(libc::CMSG_SPACE(l) as usize, unsafe { cmsg_space(l) });
         }
     }
 }

src/fuchsia/mod.rs

@@ -3000,6 +3000,8 @@ pub const O_NOFOLLOW: c_int = 0x00000080;
 pub const HUGETLB_FLAG_ENCODE_SHIFT: u32 = 26;
 pub const MAP_HUGE_SHIFT: u32 = 26;
 
+// END_PUB_CONST
+
 // intentionally not public, only used for fd_set
 cfg_if! {
     if #[cfg(target_pointer_width = "32")] {
@@ -3011,8 +3013,6 @@ cfg_if! {
     }
 }
 
-// END_PUB_CONST
-
 f! {
     pub fn FD_CLR(fd: c_int, set: *mut fd_set) -> () {
         let fd = fd as usize;
@@ -3069,40 +3069,6 @@ f! {
     pub fn CPU_EQUAL(set1: &cpu_set_t, set2: &cpu_set_t) -> bool {
         set1.bits == set2.bits
     }
-
-    pub fn CMSG_DATA(cmsg: *const cmsghdr) -> *mut c_uchar {
-        cmsg.offset(1) as *mut c_uchar
-    }
-
-    pub fn CMSG_NXTHDR(mhdr: *const msghdr, cmsg: *const cmsghdr) -> *mut cmsghdr {
-        if ((*cmsg).cmsg_len as size_t) < size_of::<cmsghdr>() {
-            core::ptr::null_mut::<cmsghdr>()
-        } else if __CMSG_NEXT(cmsg).add(size_of::<cmsghdr>()) >= __MHDR_END(mhdr) {
-            core::ptr::null_mut::<cmsghdr>()
-        } else {
-            __CMSG_NEXT(cmsg).cast()
-        }
-    }
-
-    pub fn CMSG_FIRSTHDR(mhdr: *const msghdr) -> *mut cmsghdr {
-        if (*mhdr).msg_controllen as size_t >= size_of::<cmsghdr>() {
-            (*mhdr).msg_control.cast()
-        } else {
-            core::ptr::null_mut::<cmsghdr>()
-        }
-    }
-
-    pub const fn CMSG_ALIGN(len: size_t) -> size_t {
-        (len + size_of::<size_t>() - 1) & !(size_of::<size_t>() - 1)
-    }
-
-    pub const fn CMSG_SPACE(len: c_uint) -> c_uint {
-        (CMSG_ALIGN(len as size_t) + CMSG_ALIGN(size_of::<cmsghdr>())) as c_uint
-    }
-
-    pub const fn CMSG_LEN(len: c_uint) -> c_uint {
-        (CMSG_ALIGN(size_of::<cmsghdr>()) + len as size_t) as c_uint
-    }
 }
 
 safe_f! {
@@ -3168,19 +3134,6 @@ safe_f! {
     }
 }
 
-fn __CMSG_LEN(cmsg: *const cmsghdr) -> ssize_t {
-    ((unsafe { (*cmsg).cmsg_len as size_t } + size_of::<c_long>() - 1) & !(size_of::<c_long>() - 1))
-        as ssize_t
-}
-
-fn __CMSG_NEXT(cmsg: *const cmsghdr) -> *mut c_uchar {
-    (unsafe { cmsg.offset(__CMSG_LEN(cmsg)) }) as *mut c_uchar
-}
-
-fn __MHDR_END(mhdr: *const msghdr) -> *mut c_uchar {
-    unsafe { (*mhdr).msg_control.offset((*mhdr).msg_controllen as isize) }.cast()
-}
-
 // EXTERN_FN
 
 #[link(name = "c")]

src/new/aix/mod.rs

@@ -3,4 +3,5 @@
 //! * Headers are not public
 //! * Manual pages: <https://www.ibm.com/docs/en/aix> (under "Technical reference" for that version)
 
+pub(crate) mod sys;
 pub(crate) mod unistd;

src/new/aix/sys/mod.rs

@@ -0,0 +1,3 @@
+//! Directory: `sys/`
+
+pub(crate) mod socket;

src/new/aix/sys/socket.rs

@@ -0,0 +1,9 @@
+//! Header: `sys/socket.h`
+
+pub use crate::new::common::posix::sys::socket::{
+    CMSG_DATA,
+    CMSG_FIRSTHDR,
+    CMSG_LEN,
+    CMSG_NXTHDR,
+    CMSG_SPACE,
+};

src/new/apple/libc/mod.rs

@@ -0,0 +1,7 @@
+//! Entrypoint for Apple headers, usually found as part of the Xcode SDK.
+//!
+//! <https://github.com/apple-oss-distributions/Libc/tree/main/include>
+
+pub(crate) mod signal;
+pub(crate) mod sys;
+pub(crate) mod unistd;

src/new/apple/libc/sys/mod.rs

@@ -0,0 +1,3 @@
+//! Directory: `sys/`
+
+pub(crate) mod socket;

src/new/apple/libc/sys/socket.rs

@@ -0,0 +1,20 @@
+//! Header: `sys/socket.h`
+//!
+//! <https://github.com/freebsd/freebsd-src/blob/main/sys/sys/socket.h>
+
+pub(crate) type __ALIGN_BOUNDARY = c_long;
+
+pub use crate::new::common::posix::sys::socket::{
+    CMSG_DATA,
+    CMSG_FIRSTHDR,
+    CMSG_LEN,
+    CMSG_SPACE,
+};
+
+pub unsafe fn CMSG_NXTHDR(mhdr: *const msghdr, cmsg: *const crate::cmsghdr) -> *mut crate::cmsghdr {
+    if cmsg.is_null() {
+        return CMSG_FIRSTHDR(mhdr);
+    }
+
+    crate::new::common::posix::sys::socket::CMSG_NXTHDR(mhdr, cmsg)
+}

src/new/apple/xnu/sys/mod.rs

@@ -3,6 +3,7 @@
 //! <https://github.com/apple-oss-distributions/xnu/tree/main/bsd/sys>
 
 pub(crate) mod signal;
+pub(crate) mod socket;
 
 /// Directory: `sys/_types`
 ///

src/new/apple/xnu/sys/socket.rs

@@ -0,0 +1,11 @@
+//! Header: `sys/socket.h`
+//!
+//! <https://github.com/apple-oss-distributions/xnu/blob/main/bsd/sys/socket.h>
+
+pub use crate::new::common::bsd::sys::socket::CMSG_NXTHDR;
+pub use crate::new::common::posix::sys::socket::{
+    CMSG_DATA,
+    CMSG_FIRSTHDR,
+    CMSG_LEN,
+    CMSG_SPACE,
+};

src/new/bionic_libc/sys/socket.rs

@@ -1,4 +1,6 @@
 //! Header: `sys/socket.h`
+//!
+//! <https://android.googlesource.com/platform/bionic/+/refs/heads/main/libc/include/sys/socket.h>
 
 use crate::prelude::*;
 
@@ -26,6 +28,15 @@ s! {
     }
 }
 
+pub use crate::new::common::posix::sys::socket::{
+    CMSG_ALIGN,
+    CMSG_DATA,
+    CMSG_FIRSTHDR,
+    CMSG_LEN,
+    CMSG_NXTHDR,
+    CMSG_SPACE,
+};
+
 extern "C" {
     pub fn recvmmsg(
         sockfd: c_int,

src/new/common/bsd.rs

@@ -1 +1,17 @@
 //! Interfaces common across the BSD family.
+
+pub(crate) mod sys {
+    pub(crate) mod socket {
+        #[cfg(not(target_os = "dragonfly"))]
+        pub unsafe fn CMSG_NXTHDR(
+            mhdr: *const crate::msghdr,
+            cmsg: *const crate::cmsghdr,
+        ) -> *mut crate::cmsghdr {
+            if cmsg.is_null() {
+                return crate::CMSG_FIRSTHDR(mhdr);
+            }
+
+            crate::new::common::posix::sys::socket::CMSG_NXTHDR(mhdr, cmsg)
+        }
+    }
+}

src/new/common/posix/mod.rs

@@ -13,3 +13,5 @@
 ))]
 pub(crate) mod pthread;
 pub(crate) mod unistd;
+
+pub(crate) mod sys;

src/new/common/posix/sys/mod.rs

@@ -0,0 +1,3 @@
+//! Directory: `sys/`
+
+pub(crate) mod socket;