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authorDaniel J Walsh <dwalsh@redhat.com>2022-02-03 18:33:22 -0500
committerDaniel J Walsh <dwalsh@redhat.com>2022-02-03 18:33:22 -0500
commit1d1b2b1509646e07ab4a984c7622fa002a0fcdb7 (patch)
treefd4078e58bc9ab0b6c2ef1938017ce5844f97744 /vendor/github.com/docker/go-connections/sockets/unix_socket.go
parent608b6142edb7a4e179ce6d2ae69707be28f29359 (diff)
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Update containers/buildah v1.24.1
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Diffstat (limited to 'vendor/github.com/docker/go-connections/sockets/unix_socket.go')
-rw-r--r--vendor/github.com/docker/go-connections/sockets/unix_socket.go116
1 files changed, 105 insertions, 11 deletions
diff --git a/vendor/github.com/docker/go-connections/sockets/unix_socket.go b/vendor/github.com/docker/go-connections/sockets/unix_socket.go
index a8b5dbb6f..e7591e6ed 100644
--- a/vendor/github.com/docker/go-connections/sockets/unix_socket.go
+++ b/vendor/github.com/docker/go-connections/sockets/unix_socket.go
@@ -1,5 +1,51 @@
// +build !windows
+/*
+Package sockets is a simple unix domain socket wrapper.
+
+Usage
+
+For example:
+
+ import(
+ "fmt"
+ "net"
+ "os"
+ "github.com/docker/go-connections/sockets"
+ )
+
+ func main() {
+ l, err := sockets.NewUnixSocketWithOpts("/path/to/sockets",
+ sockets.WithChown(0,0),sockets.WithChmod(0660))
+ if err != nil {
+ panic(err)
+ }
+ echoStr := "hello"
+
+ go func() {
+ for {
+ conn, err := l.Accept()
+ if err != nil {
+ return
+ }
+ conn.Write([]byte(echoStr))
+ conn.Close()
+ }
+ }()
+
+ conn, err := net.Dial("unix", path)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ buf := make([]byte, 5)
+ if _, err := conn.Read(buf); err != nil {
+ panic(err)
+ } else if string(buf) != echoStr {
+ panic(fmt.Errorf("Msg may lost"))
+ }
+ }
+*/
package sockets
import (
@@ -8,25 +54,73 @@ import (
"syscall"
)
-// NewUnixSocket creates a unix socket with the specified path and group.
-func NewUnixSocket(path string, gid int) (net.Listener, error) {
+// SockOption sets up socket file's creating option
+type SockOption func(string) error
+
+// WithChown modifies the socket file's uid and gid
+func WithChown(uid, gid int) SockOption {
+ return func(path string) error {
+ if err := os.Chown(path, uid, gid); err != nil {
+ return err
+ }
+ return nil
+ }
+}
+
+// WithChmod modifies socket file's access mode.
+func WithChmod(mask os.FileMode) SockOption {
+ return func(path string) error {
+ if err := os.Chmod(path, mask); err != nil {
+ return err
+ }
+ return nil
+ }
+}
+
+// NewUnixSocketWithOpts creates a unix socket with the specified options.
+// By default, socket permissions are 0000 (i.e.: no access for anyone); pass
+// WithChmod() and WithChown() to set the desired ownership and permissions.
+//
+// This function temporarily changes the system's "umask" to 0777 to work around
+// a race condition between creating the socket and setting its permissions. While
+// this should only be for a short duration, it may affect other processes that
+// create files/directories during that period.
+func NewUnixSocketWithOpts(path string, opts ...SockOption) (net.Listener, error) {
if err := syscall.Unlink(path); err != nil && !os.IsNotExist(err) {
return nil, err
}
- mask := syscall.Umask(0777)
- defer syscall.Umask(mask)
+ // net.Listen does not allow for permissions to be set. As a result, when
+ // specifying custom permissions ("WithChmod()"), there is a short time
+ // between creating the socket and applying the permissions, during which
+ // the socket permissions are Less restrictive than desired.
+ //
+ // To work around this limitation of net.Listen(), we temporarily set the
+ // umask to 0777, which forces the socket to be created with 000 permissions
+ // (i.e.: no access for anyone). After that, WithChmod() must be used to set
+ // the desired permissions.
+ //
+ // We don't use "defer" here, to reset the umask to its original value as soon
+ // as possible. Ideally we'd be able to detect if WithChmod() was passed as
+ // an option, and skip changing umask if default permissions are used.
+ origUmask := syscall.Umask(0777)
l, err := net.Listen("unix", path)
+ syscall.Umask(origUmask)
if err != nil {
return nil, err
}
- if err := os.Chown(path, 0, gid); err != nil {
- l.Close()
- return nil, err
- }
- if err := os.Chmod(path, 0660); err != nil {
- l.Close()
- return nil, err
+
+ for _, op := range opts {
+ if err := op(path); err != nil {
+ _ = l.Close()
+ return nil, err
+ }
}
+
return l, nil
}
+
+// NewUnixSocket creates a unix socket with the specified path and group.
+func NewUnixSocket(path string, gid int) (net.Listener, error) {
+ return NewUnixSocketWithOpts(path, WithChown(0, gid), WithChmod(0660))
+}