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author | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
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committer | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
commit | 1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch) | |
tree | 7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/rustix/src/backend/linux_raw/net/msghdr.rs | |
parent | 5ecd8cf2cba827454317368b68571df0d13d7842 (diff) | |
download | fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip |
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/rustix/src/backend/linux_raw/net/msghdr.rs')
-rw-r--r-- | vendor/rustix/src/backend/linux_raw/net/msghdr.rs | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/vendor/rustix/src/backend/linux_raw/net/msghdr.rs b/vendor/rustix/src/backend/linux_raw/net/msghdr.rs new file mode 100644 index 0000000..2b88bfb --- /dev/null +++ b/vendor/rustix/src/backend/linux_raw/net/msghdr.rs @@ -0,0 +1,146 @@ +//! Utilities for dealing with message headers. +//! +//! These take closures rather than returning a `c::msghdr` directly because +//! the message headers may reference stack-local data. + +#![allow(unsafe_code)] + +use crate::backend::c; +use crate::backend::net::write_sockaddr::{encode_sockaddr_v4, encode_sockaddr_v6}; + +use crate::io::{self, IoSlice, IoSliceMut}; +use crate::net::{RecvAncillaryBuffer, SendAncillaryBuffer, SocketAddrV4, SocketAddrV6}; +use crate::utils::as_ptr; + +use core::mem::{size_of, MaybeUninit}; +use core::ptr::null_mut; + +fn msg_iov_len(len: usize) -> c::size_t { + // This cast cannot overflow. + len as c::size_t +} + +pub(crate) fn msg_control_len(len: usize) -> c::size_t { + // Same as above. + len as c::size_t +} + +/// Create a message header intended to receive a datagram. +pub(crate) fn with_recv_msghdr<R>( + name: &mut MaybeUninit<c::sockaddr_storage>, + iov: &mut [IoSliceMut<'_>], + control: &mut RecvAncillaryBuffer<'_>, + f: impl FnOnce(&mut c::msghdr) -> io::Result<R>, +) -> io::Result<R> { + control.clear(); + + let namelen = size_of::<c::sockaddr_storage>() as c::c_int; + let mut msghdr = c::msghdr { + msg_name: name.as_mut_ptr().cast(), + msg_namelen: namelen, + msg_iov: iov.as_mut_ptr().cast(), + msg_iovlen: msg_iov_len(iov.len()), + msg_control: control.as_control_ptr().cast(), + msg_controllen: msg_control_len(control.control_len()), + msg_flags: 0, + }; + + let res = f(&mut msghdr); + + // Reset the control length. + if res.is_ok() { + unsafe { + control.set_control_len(msghdr.msg_controllen.try_into().unwrap_or(usize::MAX)); + } + } + + res +} + +/// Create a message header intended to send without an address. +pub(crate) fn with_noaddr_msghdr<R>( + iov: &[IoSlice<'_>], + control: &mut SendAncillaryBuffer<'_, '_, '_>, + f: impl FnOnce(c::msghdr) -> R, +) -> R { + f(c::msghdr { + msg_name: null_mut(), + msg_namelen: 0, + msg_iov: iov.as_ptr() as _, + msg_iovlen: msg_iov_len(iov.len()), + msg_control: control.as_control_ptr().cast(), + msg_controllen: msg_control_len(control.control_len()), + msg_flags: 0, + }) +} + +/// Create a message header intended to send with an IPv4 address. +pub(crate) fn with_v4_msghdr<R>( + addr: &SocketAddrV4, + iov: &[IoSlice<'_>], + control: &mut SendAncillaryBuffer<'_, '_, '_>, + f: impl FnOnce(c::msghdr) -> R, +) -> R { + let encoded = encode_sockaddr_v4(addr); + + f(c::msghdr { + msg_name: as_ptr(&encoded) as _, + msg_namelen: size_of::<SocketAddrV4>() as _, + msg_iov: iov.as_ptr() as _, + msg_iovlen: msg_iov_len(iov.len()), + msg_control: control.as_control_ptr().cast(), + msg_controllen: msg_control_len(control.control_len()), + msg_flags: 0, + }) +} + +/// Create a message header intended to send with an IPv6 address. +pub(crate) fn with_v6_msghdr<R>( + addr: &SocketAddrV6, + iov: &[IoSlice<'_>], + control: &mut SendAncillaryBuffer<'_, '_, '_>, + f: impl FnOnce(c::msghdr) -> R, +) -> R { + let encoded = encode_sockaddr_v6(addr); + + f(c::msghdr { + msg_name: as_ptr(&encoded) as _, + msg_namelen: size_of::<SocketAddrV6>() as _, + msg_iov: iov.as_ptr() as _, + msg_iovlen: msg_iov_len(iov.len()), + msg_control: control.as_control_ptr().cast(), + msg_controllen: msg_control_len(control.control_len()), + msg_flags: 0, + }) +} + +/// Create a message header intended to send with a Unix address. +pub(crate) fn with_unix_msghdr<R>( + addr: &crate::net::SocketAddrUnix, + iov: &[IoSlice<'_>], + control: &mut SendAncillaryBuffer<'_, '_, '_>, + f: impl FnOnce(c::msghdr) -> R, +) -> R { + f(c::msghdr { + msg_name: as_ptr(&addr.unix) as _, + msg_namelen: addr.addr_len() as _, + msg_iov: iov.as_ptr() as _, + msg_iovlen: msg_iov_len(iov.len()), + msg_control: control.as_control_ptr().cast(), + msg_controllen: msg_control_len(control.control_len()), + msg_flags: 0, + }) +} + +/// Create a zero-initialized message header struct value. +pub(crate) fn zero_msghdr() -> c::msghdr { + c::msghdr { + msg_name: null_mut(), + msg_namelen: 0, + msg_iov: null_mut(), + msg_iovlen: 0, + msg_control: null_mut(), + msg_controllen: 0, + msg_flags: 0, + } +} |