diff options
Diffstat (limited to 'pkg/sentry/socket')
| -rw-r--r-- | pkg/sentry/socket/netfilter/netfilter.go | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go index 512ad624a..257cb485b 100644 --- a/pkg/sentry/socket/netfilter/netfilter.go +++ b/pkg/sentry/socket/netfilter/netfilter.go @@ -26,6 +26,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/syserr" "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/tcpip/iptables" "gvisor.dev/gvisor/pkg/tcpip/stack" "gvisor.dev/gvisor/pkg/usermem" @@ -288,6 +289,7 @@ func marshalRedirectTarget() []byte { TargetSize: linux.SizeOfXTRedirectTarget, }, } + copy(target.Target.Name[:], redirectTargetName) ret := make([]byte, 0, linux.SizeOfXTRedirectTarget) return binary.Marshal(ret, usermem.ByteOrder, target) @@ -405,7 +407,7 @@ func SetEntries(stack *stack.Stack, optVal []byte) *syserr.Error { nflog("entry doesn't have enough room for its target (only %d bytes remain)", len(optVal)) return syserr.ErrInvalidArgument } - target, err := parseTarget(optVal[:targetSize]) + target, err := parseTarget(filter, optVal[:targetSize]) if err != nil { nflog("failed to parse target: %v", err) return syserr.ErrInvalidArgument @@ -552,7 +554,7 @@ func parseMatchers(filter iptables.IPHeaderFilter, optVal []byte) ([]iptables.Ma // parseTarget parses a target from optVal. optVal should contain only the // target. -func parseTarget(optVal []byte) (iptables.Target, error) { +func parseTarget(filter iptables.IPHeaderFilter, optVal []byte) (iptables.Target, error) { nflog("set entries: parsing target of size %d", len(optVal)) if len(optVal) < linux.SizeOfXTEntryTarget { return nil, fmt.Errorf("optVal has insufficient size for entry target %d", len(optVal)) @@ -604,6 +606,10 @@ func parseTarget(optVal []byte) (iptables.Target, error) { return nil, fmt.Errorf("netfilter.SetEntries: optVal has insufficient size for redirect target %d", len(optVal)) } + if filter.Protocol != header.TCPProtocolNumber && filter.Protocol != header.UDPProtocolNumber { + return nil, fmt.Errorf("netfilter.SetEntries: invalid argument") + } + var redirectTarget linux.XTRedirectTarget buf = optVal[:linux.SizeOfXTRedirectTarget] binary.Unmarshal(buf, usermem.ByteOrder, &redirectTarget) @@ -612,21 +618,30 @@ func parseTarget(optVal []byte) (iptables.Target, error) { var target iptables.RedirectTarget nfRange := redirectTarget.NfRange - target.RangeSize = nfRange.Rangesize - target.Flags = nfRange.RangeIPV4[0].Flags + // RangeSize should be 1. + if nfRange.RangeSize != 1 { + return nil, fmt.Errorf("netfilter.SetEntries: invalid argument") + } + + // TODO(gvisor.dev/issue/170): Check if the flags are valid. + // Also check if we need to map ports or IP. + // For now, redirect target only supports dest port change. + if nfRange.RangeIPV4.Flags&linux.NF_NAT_RANGE_PROTO_SPECIFIED == 0 { + return nil, fmt.Errorf("netfilter.SetEntries: invalid argument.") + } + target.Flags = nfRange.RangeIPV4.Flags - target.MinIP = tcpip.Address(nfRange.RangeIPV4[0].MinIP[:]) - target.MaxIP = tcpip.Address(nfRange.RangeIPV4[0].MaxIP[:]) + target.MinIP = tcpip.Address(nfRange.RangeIPV4.MinIP[:]) + target.MaxIP = tcpip.Address(nfRange.RangeIPV4.MaxIP[:]) // Convert port from big endian to little endian. port := make([]byte, 2) - binary.BigEndian.PutUint16(port, nfRange.RangeIPV4[0].MinPort) + binary.BigEndian.PutUint16(port, nfRange.RangeIPV4.MinPort) target.MinPort = binary.LittleEndian.Uint16(port) - binary.BigEndian.PutUint16(port, nfRange.RangeIPV4[0].MaxPort) + binary.BigEndian.PutUint16(port, nfRange.RangeIPV4.MaxPort) target.MaxPort = binary.LittleEndian.Uint16(port) return target, nil - } // Unknown target. |