From 55f0c3316af8ea2a1fcc16511efc580f307623f6 Mon Sep 17 00:00:00 2001
From: gVisor bot <gvisor-bot@google.com>
Date: Mon, 27 Apr 2020 12:25:10 -0700
Subject: Automated rollback of changelist 308163542

PiperOrigin-RevId: 308674219
---
 pkg/tcpip/network/ipv4/icmp.go | 20 ++++++++------------
 pkg/tcpip/network/ipv4/ipv4.go | 12 ++----------
 2 files changed, 10 insertions(+), 22 deletions(-)

(limited to 'pkg/tcpip/network/ipv4')

diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index 4cbefe5ab..c4bf1ba5c 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -25,11 +25,7 @@ import (
 // used to find out which transport endpoint must be notified about the ICMP
 // packet.
 func (e *endpoint) handleControl(typ stack.ControlType, extra uint32, pkt stack.PacketBuffer) {
-	h, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
-	if !ok {
-		return
-	}
-	hdr := header.IPv4(h)
+	h := header.IPv4(pkt.Data.First())
 
 	// We don't use IsValid() here because ICMP only requires that the IP
 	// header plus 8 bytes of the transport header be included. So it's
@@ -38,12 +34,12 @@ func (e *endpoint) handleControl(typ stack.ControlType, extra uint32, pkt stack.
 	//
 	// Drop packet if it doesn't have the basic IPv4 header or if the
 	// original source address doesn't match the endpoint's address.
-	if hdr.SourceAddress() != e.id.LocalAddress {
+	if len(h) < header.IPv4MinimumSize || h.SourceAddress() != e.id.LocalAddress {
 		return
 	}
 
-	hlen := int(hdr.HeaderLength())
-	if pkt.Data.Size() < hlen || hdr.FragmentOffset() != 0 {
+	hlen := int(h.HeaderLength())
+	if pkt.Data.Size() < hlen || h.FragmentOffset() != 0 {
 		// We won't be able to handle this if it doesn't contain the
 		// full IPv4 header, or if it's a fragment not at offset 0
 		// (because it won't have the transport header).
@@ -52,15 +48,15 @@ func (e *endpoint) handleControl(typ stack.ControlType, extra uint32, pkt stack.
 
 	// Skip the ip header, then deliver control message.
 	pkt.Data.TrimFront(hlen)
-	p := hdr.TransportProtocol()
-	e.dispatcher.DeliverTransportControlPacket(e.id.LocalAddress, hdr.DestinationAddress(), ProtocolNumber, p, typ, extra, pkt)
+	p := h.TransportProtocol()
+	e.dispatcher.DeliverTransportControlPacket(e.id.LocalAddress, h.DestinationAddress(), ProtocolNumber, p, typ, extra, pkt)
 }
 
 func (e *endpoint) handleICMP(r *stack.Route, pkt stack.PacketBuffer) {
 	stats := r.Stats()
 	received := stats.ICMP.V4PacketsReceived
-	v, ok := pkt.Data.PullUp(header.ICMPv4MinimumSize)
-	if !ok {
+	v := pkt.Data.First()
+	if len(v) < header.ICMPv4MinimumSize {
 		received.Invalid.Increment()
 		return
 	}
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 17202cc7a..104aafbed 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -328,11 +328,7 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
 func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt stack.PacketBuffer) *tcpip.Error {
 	// The packet already has an IP header, but there are a few required
 	// checks.
-	h, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
-	if !ok {
-		return tcpip.ErrInvalidOptionValue
-	}
-	ip := header.IPv4(h)
+	ip := header.IPv4(pkt.Data.First())
 	if !ip.IsValid(pkt.Data.Size()) {
 		return tcpip.ErrInvalidOptionValue
 	}
@@ -382,11 +378,7 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt stack.PacketBuf
 // HandlePacket is called by the link layer when new ipv4 packets arrive for
 // this endpoint.
 func (e *endpoint) HandlePacket(r *stack.Route, pkt stack.PacketBuffer) {
-	headerView, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
-	if !ok {
-		r.Stats().IP.MalformedPacketsReceived.Increment()
-		return
-	}
+	headerView := pkt.Data.First()
 	h := header.IPv4(headerView)
 	if !h.IsValid(pkt.Data.Size()) {
 		r.Stats().IP.MalformedPacketsReceived.Increment()
-- 
cgit v1.2.3