diff options
Diffstat (limited to 'vendor/github.com/vishvananda/netns/netns.go')
-rw-r--r-- | vendor/github.com/vishvananda/netns/netns.go | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/vendor/github.com/vishvananda/netns/netns.go b/vendor/github.com/vishvananda/netns/netns.go new file mode 100644 index 000000000..dd2f21570 --- /dev/null +++ b/vendor/github.com/vishvananda/netns/netns.go @@ -0,0 +1,80 @@ +// Package netns allows ultra-simple network namespace handling. NsHandles +// can be retrieved and set. Note that the current namespace is thread +// local so actions that set and reset namespaces should use LockOSThread +// to make sure the namespace doesn't change due to a goroutine switch. +// It is best to close NsHandles when you are done with them. This can be +// accomplished via a `defer ns.Close()` on the handle. Changing namespaces +// requires elevated privileges, so in most cases this code needs to be run +// as root. +package netns + +import ( + "fmt" + "syscall" +) + +// NsHandle is a handle to a network namespace. It can be cast directly +// to an int and used as a file descriptor. +type NsHandle int + +// Equal determines if two network handles refer to the same network +// namespace. This is done by comparing the device and inode that the +// file descriptors point to. +func (ns NsHandle) Equal(other NsHandle) bool { + if ns == other { + return true + } + var s1, s2 syscall.Stat_t + if err := syscall.Fstat(int(ns), &s1); err != nil { + return false + } + if err := syscall.Fstat(int(other), &s2); err != nil { + return false + } + return (s1.Dev == s2.Dev) && (s1.Ino == s2.Ino) +} + +// String shows the file descriptor number and its dev and inode. +func (ns NsHandle) String() string { + var s syscall.Stat_t + if ns == -1 { + return "NS(None)" + } + if err := syscall.Fstat(int(ns), &s); err != nil { + return fmt.Sprintf("NS(%d: unknown)", ns) + } + return fmt.Sprintf("NS(%d: %d, %d)", ns, s.Dev, s.Ino) +} + +// UniqueId returns a string which uniquely identifies the namespace +// associated with the network handle. +func (ns NsHandle) UniqueId() string { + var s syscall.Stat_t + if ns == -1 { + return "NS(none)" + } + if err := syscall.Fstat(int(ns), &s); err != nil { + return "NS(unknown)" + } + return fmt.Sprintf("NS(%d:%d)", s.Dev, s.Ino) +} + +// IsOpen returns true if Close() has not been called. +func (ns NsHandle) IsOpen() bool { + return ns != -1 +} + +// Close closes the NsHandle and resets its file descriptor to -1. +// It is not safe to use an NsHandle after Close() is called. +func (ns *NsHandle) Close() error { + if err := syscall.Close(int(*ns)); err != nil { + return err + } + (*ns) = -1 + return nil +} + +// None gets an empty (closed) NsHandle. +func None() NsHandle { + return NsHandle(-1) +} |