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-rw-r--r--container/dispatcher.go14
-rw-r--r--container/dispatcher_test.go3
-rw-r--r--container/init.go7
-rw-r--r--internal/netlink/netlink.go93
-rw-r--r--internal/netlink/rtnl.go11
5 files changed, 96 insertions, 32 deletions
diff --git a/container/dispatcher.go b/container/dispatcher.go
index dce5f023..9f971fa5 100644
--- a/container/dispatcher.go
+++ b/container/dispatcher.go
@@ -1,6 +1,7 @@
package container
import (
+ "context"
"io"
"io/fs"
"net"
@@ -66,7 +67,7 @@ type syscallDispatcher interface {
// ensureFile provides ensureFile.
ensureFile(name string, perm, pperm os.FileMode) error
// mustLoopback provides mustLoopback.
- mustLoopback(msg message.Msg)
+ mustLoopback(ctx context.Context, msg message.Msg)
// seccompLoad provides [seccomp.Load].
seccompLoad(rules []std.NativeRule, flags seccomp.ExportFlag) error
@@ -170,7 +171,7 @@ func (k direct) mountTmpfs(fsname, target string, flags uintptr, size int, perm
func (direct) ensureFile(name string, perm, pperm os.FileMode) error {
return ensureFile(name, perm, pperm)
}
-func (direct) mustLoopback(msg message.Msg) {
+func (direct) mustLoopback(ctx context.Context, msg message.Msg) {
var lo int
if ifi, err := net.InterfaceByName("lo"); err != nil {
msg.GetLogger().Fatalln(err)
@@ -199,11 +200,14 @@ func (direct) mustLoopback(msg message.Msg) {
msg.GetLogger().Fatalf("RTNETLINK answers: %v", err)
default:
- msg.GetLogger().Fatalf("RTNETLINK answers with malformed message")
+ if err == context.DeadlineExceeded || err == context.Canceled {
+ msg.GetLogger().Fatalf("interrupted RTNETLINK operation")
+ }
+ msg.GetLogger().Fatal("RTNETLINK answers with malformed message")
}
}
- must(c.SendNewaddrLo(uint32(lo)))
- must(c.SendIfInfomsg(syscall.RTM_NEWLINK, 0, &syscall.IfInfomsg{
+ must(c.SendNewaddrLo(ctx, uint32(lo)))
+ must(c.SendIfInfomsg(ctx, syscall.RTM_NEWLINK, 0, &syscall.IfInfomsg{
Family: syscall.AF_UNSPEC,
Index: int32(lo),
Flags: syscall.IFF_UP,
diff --git a/container/dispatcher_test.go b/container/dispatcher_test.go
index ee2c3f19..b57c53b9 100644
--- a/container/dispatcher_test.go
+++ b/container/dispatcher_test.go
@@ -2,6 +2,7 @@ package container
import (
"bytes"
+ "context"
"fmt"
"io"
"io/fs"
@@ -468,7 +469,7 @@ func (k *kstub) ensureFile(name string, perm, pperm os.FileMode) error {
stub.CheckArg(k.Stub, "pperm", pperm, 2))
}
-func (*kstub) mustLoopback(message.Msg) { /* noop */ }
+func (*kstub) mustLoopback(context.Context, message.Msg) { /* noop */ }
func (k *kstub) seccompLoad(rules []std.NativeRule, flags seccomp.ExportFlag) error {
k.Helper()
diff --git a/container/init.go b/container/init.go
index 799bb29b..7a561733 100644
--- a/container/init.go
+++ b/container/init.go
@@ -7,6 +7,7 @@ import (
"log"
"os"
"os/exec"
+ "os/signal"
"path"
"slices"
"strconv"
@@ -175,7 +176,11 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
}
if !params.HostNet {
- k.mustLoopback(msg)
+ ctx, cancel := signal.NotifyContext(context.Background(), CancelSignal,
+ os.Interrupt, SIGTERM, SIGQUIT)
+ defer cancel() // for panics
+ k.mustLoopback(ctx, msg)
+ cancel()
}
// write uid/gid map here so parent does not need to set dumpable
diff --git a/internal/netlink/netlink.go b/internal/netlink/netlink.go
index df6af840..406f567b 100644
--- a/internal/netlink/netlink.go
+++ b/internal/netlink/netlink.go
@@ -2,10 +2,12 @@
package netlink
import (
+ "context"
"fmt"
"os"
"sync"
"syscall"
+ "time"
"unsafe"
)
@@ -37,6 +39,10 @@ type conn struct {
pos int
// A page holding incoming and outgoing messages.
buf []byte
+ // An instant some time after conn was established, but before the first
+ // I/O operation on f through raw. This serves as a cached deadline to
+ // cancel blocking I/O.
+ t time.Time
}
// dial returns the address of a newly connected conn of specified family.
@@ -65,6 +71,7 @@ func dial(family int) (*conn, error) {
c.pos = syscall.NLMSG_HDRLEN
c.buf = make([]byte, os.Getpagesize())
+ c.t = time.Now().UTC()
return &c, nil
}
@@ -79,35 +86,79 @@ func (c *conn) Close() error {
// recvfrom wraps recv(2) with nonblocking behaviour via the runtime network poller.
func (c *conn) recvfrom(
+ ctx context.Context,
p []byte,
flags int,
) (n int, from syscall.Sockaddr, err error) {
- rcErr := c.raw.Read(func(fd uintptr) (done bool) {
- n, from, err = syscall.Recvfrom(int(fd), p, flags)
- return err != syscall.EWOULDBLOCK
- })
- if err != nil {
- err = os.NewSyscallError("recvfrom", err)
- } else {
- err = rcErr
+ if err = c.f.SetReadDeadline(time.Time{}); err != nil {
+ return
+ }
+
+ done := make(chan error, 1)
+ go func() {
+ done <- c.raw.Read(func(fd uintptr) (done bool) {
+ n, from, err = syscall.Recvfrom(int(fd), p, flags)
+ return err != syscall.EWOULDBLOCK
+ })
+ }()
+
+ select {
+ case rcErr := <-done:
+ if err != nil {
+ err = os.NewSyscallError("recvfrom", err)
+ } else {
+ err = rcErr
+ }
+
+ case <-ctx.Done():
+ cancelErr := c.f.SetReadDeadline(c.t)
+ <-done
+ if cancelErr != nil {
+ err = cancelErr
+ } else {
+ err = ctx.Err()
+ }
+ return
}
return
}
// sendto wraps send(2) with nonblocking behaviour via the runtime network poller.
func (c *conn) sendto(
+ ctx context.Context,
p []byte,
flags int,
to syscall.Sockaddr,
) (err error) {
- rcErr := c.raw.Write(func(fd uintptr) (done bool) {
- err = syscall.Sendto(int(fd), p, flags, to)
- return err != syscall.EWOULDBLOCK
- })
- if err != nil {
- err = os.NewSyscallError("sendto", err)
- } else {
- err = rcErr
+ if err = c.f.SetWriteDeadline(time.Time{}); err != nil {
+ return
+ }
+
+ done := make(chan error, 1)
+ go func() {
+ done <- c.raw.Write(func(fd uintptr) (done bool) {
+ err = syscall.Sendto(int(fd), p, flags, to)
+ return err != syscall.EWOULDBLOCK
+ })
+ }()
+
+ select {
+ case rcErr := <-done:
+ if err != nil {
+ err = os.NewSyscallError("sendto", err)
+ } else {
+ err = rcErr
+ }
+
+ case <-ctx.Done():
+ cancelErr := c.f.SetWriteDeadline(c.t)
+ <-done
+ if cancelErr != nil {
+ err = cancelErr
+ } else {
+ err = ctx.Err()
+ }
+ return
}
return
}
@@ -192,10 +243,10 @@ type HandlerFunc func(resp []syscall.NetlinkMessage) error
// receive receives from a socket with specified flags until a non-nil error is
// returned by f. An error of type [Complete] is returned as nil.
-func (c *conn) receive(f HandlerFunc, flags int) error {
+func (c *conn) receive(ctx context.Context, f HandlerFunc, flags int) error {
for {
buf := c.buf
- if n, _, err := c.recvfrom(buf, flags); err != nil {
+ if n, _, err := c.recvfrom(ctx, buf, flags); err != nil {
return err
} else if n < syscall.NLMSG_HDRLEN {
return syscall.EBADE
@@ -224,17 +275,17 @@ func (c *conn) receive(f HandlerFunc, flags int) error {
}
// Roundtrip sends the pending message and handles the reply.
-func (c *conn) Roundtrip(f HandlerFunc) error {
+func (c *conn) Roundtrip(ctx context.Context, f HandlerFunc) error {
if c.buf == nil {
return syscall.EINVAL
}
defer func() { c.seq++ }()
- if err := c.sendto(c.pending(), 0, &syscall.SockaddrNetlink{
+ if err := c.sendto(ctx, c.pending(), 0, &syscall.SockaddrNetlink{
Family: syscall.AF_NETLINK,
}); err != nil {
return err
}
- return c.receive(f, 0)
+ return c.receive(ctx, f, 0)
}
diff --git a/internal/netlink/rtnl.go b/internal/netlink/rtnl.go
index e6585bf8..e824f091 100644
--- a/internal/netlink/rtnl.go
+++ b/internal/netlink/rtnl.go
@@ -1,6 +1,7 @@
package netlink
import (
+ "context"
"syscall"
"unsafe"
)
@@ -72,6 +73,7 @@ func (c *RouteConn) writeIfAddrmsg(
// SendIfAddrmsg sends an ifaddrmsg structure to rtnetlink.
func (c *RouteConn) SendIfAddrmsg(
+ ctx context.Context,
typ, flags uint16,
msg *syscall.IfAddrmsg,
attrs ...RtAttrMsg[InAddr],
@@ -79,7 +81,7 @@ func (c *RouteConn) SendIfAddrmsg(
if !c.writeIfAddrmsg(typ, flags, msg, attrs...) {
return syscall.ENOMEM
}
- return c.Roundtrip(rtnlConsume)
+ return c.Roundtrip(ctx, rtnlConsume)
}
// writeNewaddrLo writes a RTM_NEWADDR message for the loopback address.
@@ -104,11 +106,11 @@ func (c *RouteConn) writeNewaddrLo(lo uint32) bool {
}
// SendNewaddrLo sends a RTM_NEWADDR message for the loopback address to the kernel.
-func (c *RouteConn) SendNewaddrLo(lo uint32) error {
+func (c *RouteConn) SendNewaddrLo(ctx context.Context, lo uint32) error {
if !c.writeNewaddrLo(lo) {
return syscall.ENOMEM
}
- return c.Roundtrip(rtnlConsume)
+ return c.Roundtrip(ctx, rtnlConsume)
}
// writeIfInfomsg writes an ifinfomsg structure to conn.
@@ -122,11 +124,12 @@ func (c *RouteConn) writeIfInfomsg(
// SendIfInfomsg sends an ifinfomsg structure to rtnetlink.
func (c *RouteConn) SendIfInfomsg(
+ ctx context.Context,
typ, flags uint16,
msg *syscall.IfInfomsg,
) error {
if !c.writeIfInfomsg(typ, flags, msg) {
return syscall.ENOMEM
}
- return c.Roundtrip(rtnlConsume)
+ return c.Roundtrip(ctx, rtnlConsume)
}
generated by cgit v1.3.1 (git 2.54.0) at 2026-08-29 23:41:29 +0000