From eddc8d342b6371b55cb8910fc8365ce0a3880f50 Mon Sep 17 00:00:00 2001
From: Alan Somers <asomers@gmail.com>
Date: Tue, 5 Feb 2019 08:00:26 -0700
Subject: [PATCH] Specialize CMSG_NXTHDR for Android and Emscripten

---
 src/unix/notbsd/android/mod.rs | 14 ++++++++++++++
 src/unix/notbsd/emscripten.rs  | 17 +++++++++++++++++
 src/unix/notbsd/linux/mod.rs   | 19 +++++++++++++++++++
 src/unix/notbsd/mod.rs         | 18 ------------------
 4 files changed, 50 insertions(+), 18 deletions(-)

diff --git a/src/unix/notbsd/android/mod.rs b/src/unix/notbsd/android/mod.rs
index 0e2eebf0..f768ce12 100644
--- a/src/unix/notbsd/android/mod.rs
+++ b/src/unix/notbsd/android/mod.rs
@@ -1688,6 +1688,20 @@ pub const MODULE_INIT_IGNORE_VERMAGIC: ::c_uint = 0x0002;
 pub const ENOATTR: ::c_int = ::ENODATA;
 
 f! {
+    pub fn CMSG_NXTHDR(mhdr: *const msghdr,
+                       cmsg: *const cmsghdr) -> *mut cmsghdr {
+        let next = (cmsg as usize
+                    + super::CMSG_ALIGN((*cmsg).cmsg_len as usize))
+            as *mut cmsghdr;
+        let max = (*mhdr).msg_control as usize
+            + (*mhdr).msg_controllen as usize;
+        if (next.offset(1)) as usize > max {
+            0 as *mut cmsghdr
+        } else {
+            next as *mut cmsghdr
+        }
+    }
+
     pub fn CPU_ZERO(cpuset: &mut cpu_set_t) -> () {
         for slot in cpuset.__bits.iter_mut() {
             *slot = 0;
diff --git a/src/unix/notbsd/emscripten.rs b/src/unix/notbsd/emscripten.rs
index 9bf2026b..2685e769 100644
--- a/src/unix/notbsd/emscripten.rs
+++ b/src/unix/notbsd/emscripten.rs
@@ -1515,6 +1515,23 @@ pub const ARPD_FLUSH: ::c_ushort = 0x03;
 pub const ATF_MAGIC: ::c_int = 0x80;
 
 f! {
+    pub fn CMSG_NXTHDR(mhdr: *const msghdr,
+                       cmsg: *const cmsghdr) -> *mut cmsghdr {
+        if ((*cmsg).cmsg_len as usize) < mem::size_of::<cmsghdr>() {
+            return 0 as *mut cmsghdr;
+        };
+        let next = (cmsg as usize +
+                    super::CMSG_ALIGN((*cmsg).cmsg_len as usize))
+            as *mut cmsghdr;
+        let max = (*mhdr).msg_control as usize
+            + (*mhdr).msg_controllen as usize;
+        if (next.offset(1)) as usize > max {
+            0 as *mut cmsghdr
+        } else {
+            next as *mut cmsghdr
+        }
+    }
+
     pub fn CPU_ZERO(cpuset: &mut cpu_set_t) -> () {
         for slot in cpuset.bits.iter_mut() {
             *slot = 0;
diff --git a/src/unix/notbsd/linux/mod.rs b/src/unix/notbsd/linux/mod.rs
index e1a24dcd..034db9bc 100644
--- a/src/unix/notbsd/linux/mod.rs
+++ b/src/unix/notbsd/linux/mod.rs
@@ -1897,6 +1897,25 @@ pub const SOF_TIMESTAMPING_SYS_HARDWARE: ::c_uint = 1 << 5;
 pub const SOF_TIMESTAMPING_RAW_HARDWARE: ::c_uint = 1 << 6;
 
 f! {
+    pub fn CMSG_NXTHDR(mhdr: *const msghdr,
+                       cmsg: *const cmsghdr) -> *mut cmsghdr {
+        if ((*cmsg).cmsg_len as usize) < mem::size_of::<cmsghdr>() {
+            return 0 as *mut cmsghdr;
+        };
+        let next = (cmsg as usize +
+                    super::CMSG_ALIGN((*cmsg).cmsg_len as usize))
+            as *mut cmsghdr;
+        let max = (*mhdr).msg_control as usize
+            + (*mhdr).msg_controllen as usize;
+        if (next.offset(1)) as usize > max ||
+            next as usize + super::CMSG_ALIGN((*next).cmsg_len as usize) > max
+        {
+            0 as *mut cmsghdr
+        } else {
+            next as *mut cmsghdr
+        }
+    }
+
     pub fn CPU_ZERO(cpuset: &mut cpu_set_t) -> () {
         for slot in cpuset.bits.iter_mut() {
             *slot = 0;
diff --git a/src/unix/notbsd/mod.rs b/src/unix/notbsd/mod.rs
index bbb76ac2..3698590a 100644
--- a/src/unix/notbsd/mod.rs
+++ b/src/unix/notbsd/mod.rs
@@ -1127,24 +1127,6 @@ f! {
         }
     }
 
-    pub fn CMSG_NXTHDR(mhdr: *const msghdr,
-                       cmsg: *const cmsghdr) -> *mut cmsghdr {
-        if ((*cmsg).cmsg_len as usize) < mem::size_of::<cmsghdr>() {
-            return 0 as *mut cmsghdr;
-        };
-        let next = (cmsg as usize + CMSG_ALIGN((*cmsg).cmsg_len as usize))
-            as *mut cmsghdr;
-        let max = (*mhdr).msg_control as usize
-            + (*mhdr).msg_controllen as usize;
-        if (next.offset(1)) as usize > max
-            || next as usize + CMSG_ALIGN((*next).cmsg_len as usize) > max
-        {
-            0 as *mut cmsghdr
-        } else {
-            next as *mut cmsghdr
-        }
-    }
-
     pub fn CMSG_DATA(cmsg: *const cmsghdr) -> *mut ::c_uchar {
         cmsg.offset(1) as *mut ::c_uchar
     }