mirror of
https://github.com/opencontainers/runc.git
synced 2026-07-10 21:53:57 +08:00
Aleksa Sarai
244c9fc426
This implements {createTTY, detach} and all of the combinations and
negations of the two that were previously implemented. There are some
valid questions about out-of-OCI-scope topics like !createTTY and how
things should be handled (why do we dup the current stdio to the
process, and how is that not a security issue). However, these will be
dealt with in a separate patchset.
In order to allow for late console setup, split setupRootfs into the
"preparation" section where all of the mounts are created and the
"finalize" section where we pivot_root and set things as ro. In between
the two we can set up all of the console mountpoints and symlinks we
need.
We use two-stage synchronisation to ensures that when the syscalls are
reordered in a suboptimal way, an out-of-place read() on the parentPipe
will not gobble the ancilliary information.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
89 lines
2.0 KiB
Go
89 lines
2.0 KiB
Go
// +build linux
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package libcontainer
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import (
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"syscall"
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"github.com/vishvananda/netlink/nl"
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)
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// list of known message types we want to send to bootstrap program
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// The number is randomly chosen to not conflict with known netlink types
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const (
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InitMsg uint16 = 62000
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CloneFlagsAttr uint16 = 27281
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NsPathsAttr uint16 = 27282
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UidmapAttr uint16 = 27283
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GidmapAttr uint16 = 27284
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SetgroupAttr uint16 = 27285
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// When syscall.NLA_HDRLEN is in gccgo, take this out.
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syscall_NLA_HDRLEN = (syscall.SizeofNlAttr + syscall.NLA_ALIGNTO - 1) & ^(syscall.NLA_ALIGNTO - 1)
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)
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type Int32msg struct {
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Type uint16
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Value uint32
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}
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// Serialize serializes the message.
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// Int32msg has the following representation
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// | nlattr len | nlattr type |
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// | uint32 value |
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func (msg *Int32msg) Serialize() []byte {
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buf := make([]byte, msg.Len())
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native := nl.NativeEndian()
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native.PutUint16(buf[0:2], uint16(msg.Len()))
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native.PutUint16(buf[2:4], msg.Type)
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native.PutUint32(buf[4:8], msg.Value)
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return buf
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}
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func (msg *Int32msg) Len() int {
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return syscall_NLA_HDRLEN + 4
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}
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// Bytemsg has the following representation
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// | nlattr len | nlattr type |
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// | value | pad |
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type Bytemsg struct {
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Type uint16
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Value []byte
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}
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func (msg *Bytemsg) Serialize() []byte {
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l := msg.Len()
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buf := make([]byte, (l+syscall.NLA_ALIGNTO-1) & ^(syscall.NLA_ALIGNTO-1))
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native := nl.NativeEndian()
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native.PutUint16(buf[0:2], uint16(l))
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native.PutUint16(buf[2:4], msg.Type)
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copy(buf[4:], msg.Value)
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return buf
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}
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func (msg *Bytemsg) Len() int {
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return syscall_NLA_HDRLEN + len(msg.Value) + 1 // null-terminated
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}
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type Boolmsg struct {
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Type uint16
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Value bool
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}
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func (msg *Boolmsg) Serialize() []byte {
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buf := make([]byte, msg.Len())
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native := nl.NativeEndian()
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native.PutUint16(buf[0:2], uint16(msg.Len()))
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native.PutUint16(buf[2:4], msg.Type)
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if msg.Value {
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buf[4] = 1
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} else {
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buf[4] = 0
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}
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return buf
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}
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func (msg *Boolmsg) Len() int {
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return syscall_NLA_HDRLEN + 1
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}
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