From a551add5d8a5bf631cd9859c761e579fdb33ec82 Mon Sep 17 00:00:00 2001 From: Kevin Krakauer Date: Mon, 13 Apr 2020 17:37:21 -0700 Subject: Remove View.First() and View.RemoveFirst() These methods let users eaily break the VectorisedView abstraction, and allowed netstack to slip into pseudo-enforcement of the "all headers are in the first View" invariant. Removing them and replacing with PullUp(n) breaks this reliance and will make it easier to add iptables support and rework network buffer management. The new View.PullUp(n) method is low cost in the common case, when when all the headers fit in the first View. --- pkg/tcpip/link/loopback/loopback.go | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'pkg/tcpip/link/loopback/loopback.go') diff --git a/pkg/tcpip/link/loopback/loopback.go b/pkg/tcpip/link/loopback/loopback.go index 1e2255bfa..073c84ef9 100644 --- a/pkg/tcpip/link/loopback/loopback.go +++ b/pkg/tcpip/link/loopback/loopback.go @@ -98,13 +98,13 @@ func (e *endpoint) WritePackets(*stack.Route, *stack.GSO, stack.PacketBufferList // WriteRawPacket implements stack.LinkEndpoint.WriteRawPacket. func (e *endpoint) WriteRawPacket(vv buffer.VectorisedView) *tcpip.Error { - // Reject the packet if it's shorter than an ethernet header. - if vv.Size() < header.EthernetMinimumSize { + // There should be an ethernet header at the beginning of vv. + hdr, ok := vv.PullUp(header.EthernetMinimumSize) + if !ok { + // Reject the packet if it's shorter than an ethernet header. return tcpip.ErrBadAddress } - - // There should be an ethernet header at the beginning of vv. - linkHeader := header.Ethernet(vv.First()[:header.EthernetMinimumSize]) + linkHeader := header.Ethernet(hdr) vv.TrimFront(len(linkHeader)) e.dispatcher.DeliverNetworkPacket(e, "" /* remote */, "" /* local */, linkHeader.Type(), stack.PacketBuffer{ Data: vv, -- cgit v1.2.3