From 1e3e03a47b73966c68a4585b5ecbc7f4efb66b34 Mon Sep 17 00:00:00 2001 From: Evan Brass Date: Tue, 8 Jul 2025 15:14:38 -0700 Subject: [PATCH 1/2] Add a borrowing cmsg api This is mainly to support implementing custom control messages. --- src/sys/socket/mod.rs | 34 +++++++++++++++++++++++++++++----- 1 file changed, 29 insertions(+), 5 deletions(-) diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs index 30c4e0a082..bb60316a17 100644 --- a/src/sys/socket/mod.rs +++ b/src/sys/socket/mod.rs @@ -725,19 +725,43 @@ impl Iterator for CmsgIterator<'_> { type Item = ControlMessageOwned; fn next(&mut self) -> Option { - match self.cmsghdr { + match self.next_raw() { None => None, // No more messages - Some(hdr) => { + Some((hdr, _)) => { // Get the data. // Safe if cmsghdr points to valid data returned by recvmsg(2) - let cm = unsafe { Some(ControlMessageOwned::decode_from(hdr))}; + unsafe { Some(ControlMessageOwned::decode_from(hdr))} + } + } + } +} + +impl CmsgIterator<'_> { + pub fn next_raw(&mut self) -> Option<(&cmsghdr, &[u8])> { + match self.cmsghdr { + None => None, // No more messages + Some(header) => { + // Get the data. + let p = unsafe { CMSG_DATA(header) }; + + // Determine the length of the control message data + // The cast is not unnecessary on all platforms. + #[allow(clippy::unnecessary_cast)] + let len = header as *const _ as usize + header.cmsg_len as usize + - p as usize; + + // Read the value as a slice (This slice is the same one that ControlMessageOwned::Unknown copies) + let value = unsafe { core::slice::from_raw_parts(p, len) }; + // Advance the internal pointer. Safe if mhdr and cmsghdr point // to valid data returned by recvmsg(2) self.cmsghdr = unsafe { - let p = CMSG_NXTHDR(self.mhdr as *const _, hdr as *const _); + let p = CMSG_NXTHDR(self.mhdr as *const _, header as *const _); p.as_ref() }; - cm + + // Return the header and data + Some((header, value)) } } } From 10c04451984d6e6f934d19bda10e30ddbd454d00 Mon Sep 17 00:00:00 2001 From: Evan Brass Date: Wed, 9 Jul 2025 12:14:22 -0700 Subject: [PATCH 2/2] use map --- src/sys/socket/mod.rs | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs index bb60316a17..4af588d770 100644 --- a/src/sys/socket/mod.rs +++ b/src/sys/socket/mod.rs @@ -725,14 +725,8 @@ impl Iterator for CmsgIterator<'_> { type Item = ControlMessageOwned; fn next(&mut self) -> Option { - match self.next_raw() { - None => None, // No more messages - Some((hdr, _)) => { - // Get the data. - // Safe if cmsghdr points to valid data returned by recvmsg(2) - unsafe { Some(ControlMessageOwned::decode_from(hdr))} - } - } + // Safe if cmsghdr points to valid data returned by recvmsg(2) + self.next_raw().map(|(hdr, _)| unsafe { ControlMessageOwned::decode_from(hdr) }) } } pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.

Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy