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-rw-r--r--pkg/tcpip/header/icmpv4.go6
-rw-r--r--pkg/tcpip/header/ipv4.go486
-rw-r--r--pkg/tcpip/network/ipv4/icmp.go99
-rw-r--r--pkg/tcpip/network/ipv4/ipv4.go351
-rw-r--r--pkg/tcpip/stack/nic.go3
-rw-r--r--pkg/tcpip/tcpip.go9
6 files changed, 904 insertions, 50 deletions
diff --git a/pkg/tcpip/header/icmpv4.go b/pkg/tcpip/header/icmpv4.go
index 0f5fb3964..2f13dea6a 100644
--- a/pkg/tcpip/header/icmpv4.go
+++ b/pkg/tcpip/header/icmpv4.go
@@ -127,6 +127,12 @@ func (b ICMPv4) Code() ICMPv4Code { return ICMPv4Code(b[1]) }
// SetCode sets the ICMP code field.
func (b ICMPv4) SetCode(c ICMPv4Code) { b[1] = byte(c) }
+// Pointer returns the pointer field in a Parameter Problem packet.
+func (b ICMPv4) Pointer() byte { return b[icmpv4PointerOffset] }
+
+// SetPointer sets the pointer field in a Parameter Problem packet.
+func (b ICMPv4) SetPointer(c byte) { b[icmpv4PointerOffset] = c }
+
// Checksum is the ICMP checksum field.
func (b ICMPv4) Checksum() uint16 {
return binary.BigEndian.Uint16(b[icmpv4ChecksumOffset:])
diff --git a/pkg/tcpip/header/ipv4.go b/pkg/tcpip/header/ipv4.go
index ee307d163..961b77628 100644
--- a/pkg/tcpip/header/ipv4.go
+++ b/pkg/tcpip/header/ipv4.go
@@ -16,6 +16,7 @@ package header
import (
"encoding/binary"
+ "errors"
"fmt"
"gvisor.dev/gvisor/pkg/tcpip"
@@ -38,7 +39,6 @@ import (
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Options | Padding |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-//
const (
versIHL = 0
tos = 1
@@ -93,7 +93,7 @@ type IPv4Fields struct {
DstAddr tcpip.Address
}
-// IPv4 represents an ipv4 header stored in a byte array.
+// IPv4 is an IPv4 header.
// Most of the methods of IPv4 access to the underlying slice without
// checking the boundaries and could panic because of 'index out of range'.
// Always call IsValid() to validate an instance of IPv4 before using other
@@ -106,10 +106,13 @@ const (
IPv4MinimumSize = 20
// IPv4MaximumHeaderSize is the maximum size of an IPv4 header. Given
- // that there are only 4 bits to represents the header length in 32-bit
- // units, the header cannot exceed 15*4 = 60 bytes.
+ // that there are only 4 bits (max 0xF (15)) to represent the header length
+ // in 32-bit (4 byte) units, the header cannot exceed 15*4 = 60 bytes.
IPv4MaximumHeaderSize = 60
+ // IPv4MaximumOptionsSize is the largest size the IPv4 options can be.
+ IPv4MaximumOptionsSize = IPv4MaximumHeaderSize - IPv4MinimumSize
+
// IPv4MaximumPayloadSize is the maximum size of a valid IPv4 payload.
//
// Linux limits this to 65,515 octets (the max IP datagram size - the IPv4
@@ -130,7 +133,7 @@ const (
// IPv4ProtocolNumber is IPv4's network protocol number.
IPv4ProtocolNumber tcpip.NetworkProtocolNumber = 0x0800
- // IPv4Version is the version of the ipv4 protocol.
+ // IPv4Version is the version of the IPv4 protocol.
IPv4Version = 4
// IPv4AllSystems is the all systems IPv4 multicast address as per
@@ -198,14 +201,13 @@ func IPVersion(b []byte) int {
// Internet Header Length is the length of the internet header in 32
// bit words, and thus points to the beginning of the data. Note that
// the minimum value for a correct header is 5.
-//
const (
ipVersionShift = 4
ipIHLMask = 0x0f
IPv4IHLStride = 4
)
-// HeaderLength returns the value of the "header length" field of the ipv4
+// HeaderLength returns the value of the "header length" field of the IPv4
// header. The length returned is in bytes.
func (b IPv4) HeaderLength() uint8 {
return (b[versIHL] & ipIHLMask) * IPv4IHLStride
@@ -219,17 +221,17 @@ func (b IPv4) SetHeaderLength(hdrLen uint8) {
b[versIHL] = (IPv4Version << ipVersionShift) | ((hdrLen / IPv4IHLStride) & ipIHLMask)
}
-// ID returns the value of the identifier field of the ipv4 header.
+// ID returns the value of the identifier field of the IPv4 header.
func (b IPv4) ID() uint16 {
return binary.BigEndian.Uint16(b[id:])
}
-// Protocol returns the value of the protocol field of the ipv4 header.
+// Protocol returns the value of the protocol field of the IPv4 header.
func (b IPv4) Protocol() uint8 {
return b[protocol]
}
-// Flags returns the "flags" field of the ipv4 header.
+// Flags returns the "flags" field of the IPv4 header.
func (b IPv4) Flags() uint8 {
return uint8(binary.BigEndian.Uint16(b[flagsFO:]) >> 13)
}
@@ -239,41 +241,44 @@ func (b IPv4) More() bool {
return b.Flags()&IPv4FlagMoreFragments != 0
}
-// TTL returns the "TTL" field of the ipv4 header.
+// TTL returns the "TTL" field of the IPv4 header.
func (b IPv4) TTL() uint8 {
return b[ttl]
}
-// FragmentOffset returns the "fragment offset" field of the ipv4 header.
+// FragmentOffset returns the "fragment offset" field of the IPv4 header.
func (b IPv4) FragmentOffset() uint16 {
return binary.BigEndian.Uint16(b[flagsFO:]) << 3
}
-// TotalLength returns the "total length" field of the ipv4 header.
+// TotalLength returns the "total length" field of the IPv4 header.
func (b IPv4) TotalLength() uint16 {
return binary.BigEndian.Uint16(b[IPv4TotalLenOffset:])
}
-// Checksum returns the checksum field of the ipv4 header.
+// Checksum returns the checksum field of the IPv4 header.
func (b IPv4) Checksum() uint16 {
return binary.BigEndian.Uint16(b[checksum:])
}
-// SourceAddress returns the "source address" field of the ipv4 header.
+// SourceAddress returns the "source address" field of the IPv4 header.
func (b IPv4) SourceAddress() tcpip.Address {
return tcpip.Address(b[srcAddr : srcAddr+IPv4AddressSize])
}
-// DestinationAddress returns the "destination address" field of the ipv4
+// DestinationAddress returns the "destination address" field of the IPv4
// header.
func (b IPv4) DestinationAddress() tcpip.Address {
return tcpip.Address(b[dstAddr : dstAddr+IPv4AddressSize])
}
-// Options returns a a buffer holding the options.
-func (b IPv4) Options() []byte {
+// IPv4Options is a buffer that holds all the raw IP options.
+type IPv4Options []byte
+
+// Options returns a buffer holding the options.
+func (b IPv4) Options() IPv4Options {
hdrLen := b.HeaderLength()
- return b[options:hdrLen:hdrLen]
+ return IPv4Options(b[options:hdrLen:hdrLen])
}
// TransportProtocol implements Network.TransportProtocol.
@@ -286,17 +291,17 @@ func (b IPv4) Payload() []byte {
return b[b.HeaderLength():][:b.PayloadLength()]
}
-// PayloadLength returns the length of the payload portion of the ipv4 packet.
+// PayloadLength returns the length of the payload portion of the IPv4 packet.
func (b IPv4) PayloadLength() uint16 {
return b.TotalLength() - uint16(b.HeaderLength())
}
-// TOS returns the "type of service" field of the ipv4 header.
+// TOS returns the "type of service" field of the IPv4 header.
func (b IPv4) TOS() (uint8, uint32) {
return b[tos], 0
}
-// SetTOS sets the "type of service" field of the ipv4 header.
+// SetTOS sets the "type of service" field of the IPv4 header.
func (b IPv4) SetTOS(v uint8, _ uint32) {
b[tos] = v
}
@@ -306,18 +311,18 @@ func (b IPv4) SetTTL(v byte) {
b[ttl] = v
}
-// SetTotalLength sets the "total length" field of the ipv4 header.
+// SetTotalLength sets the "total length" field of the IPv4 header.
func (b IPv4) SetTotalLength(totalLength uint16) {
binary.BigEndian.PutUint16(b[IPv4TotalLenOffset:], totalLength)
}
-// SetChecksum sets the checksum field of the ipv4 header.
+// SetChecksum sets the checksum field of the IPv4 header.
func (b IPv4) SetChecksum(v uint16) {
binary.BigEndian.PutUint16(b[checksum:], v)
}
// SetFlagsFragmentOffset sets the "flags" and "fragment offset" fields of the
-// ipv4 header.
+// IPv4 header.
func (b IPv4) SetFlagsFragmentOffset(flags uint8, offset uint16) {
v := (uint16(flags) << 13) | (offset >> 3)
binary.BigEndian.PutUint16(b[flagsFO:], v)
@@ -328,23 +333,23 @@ func (b IPv4) SetID(v uint16) {
binary.BigEndian.PutUint16(b[id:], v)
}
-// SetSourceAddress sets the "source address" field of the ipv4 header.
+// SetSourceAddress sets the "source address" field of the IPv4 header.
func (b IPv4) SetSourceAddress(addr tcpip.Address) {
copy(b[srcAddr:srcAddr+IPv4AddressSize], addr)
}
-// SetDestinationAddress sets the "destination address" field of the ipv4
+// SetDestinationAddress sets the "destination address" field of the IPv4
// header.
func (b IPv4) SetDestinationAddress(addr tcpip.Address) {
copy(b[dstAddr:dstAddr+IPv4AddressSize], addr)
}
-// CalculateChecksum calculates the checksum of the ipv4 header.
+// CalculateChecksum calculates the checksum of the IPv4 header.
func (b IPv4) CalculateChecksum() uint16 {
return Checksum(b[:b.HeaderLength()], 0)
}
-// Encode encodes all the fields of the ipv4 header.
+// Encode encodes all the fields of the IPv4 header.
func (b IPv4) Encode(i *IPv4Fields) {
b.SetHeaderLength(i.IHL)
b[tos] = i.TOS
@@ -358,7 +363,7 @@ func (b IPv4) Encode(i *IPv4Fields) {
copy(b[dstAddr:dstAddr+IPv4AddressSize], i.DstAddr)
}
-// EncodePartial updates the total length and checksum fields of ipv4 header,
+// EncodePartial updates the total length and checksum fields of IPv4 header,
// taking in the partial checksum, which is the checksum of the header without
// the total length and checksum fields. It is useful in cases when similar
// packets are produced.
@@ -405,3 +410,424 @@ func IsV4LoopbackAddress(addr tcpip.Address) bool {
}
return addr[0] == 0x7f
}
+
+// ========================= Options ==========================
+
+// An IPv4OptionType can hold the valuse for the Type in an IPv4 option.
+type IPv4OptionType byte
+
+// These constants are needed to identify individual options in the option list.
+// While RFC 791 (page 31) says "Every internet module must be able to act on
+// every option." This has not generally been adhered to and some options have
+// very low rates of support. We do not support options other than those shown
+// below.
+
+const (
+ // IPv4OptionListEndType is the option type for the End Of Option List
+ // option. Anything following is ignored.
+ IPv4OptionListEndType IPv4OptionType = 0
+
+ // IPv4OptionNOPType is the No-Operation option. May appear between other
+ // options and may appear multiple times.
+ IPv4OptionNOPType IPv4OptionType = 1
+
+ // IPv4OptionRecordRouteType is used by each router on the path of the packet
+ // to record its path. It is carried over to an Echo Reply.
+ IPv4OptionRecordRouteType IPv4OptionType = 7
+
+ // IPv4OptionTimestampType is the option type for the Timestamp option.
+ IPv4OptionTimestampType IPv4OptionType = 68
+
+ // ipv4OptionTypeOffset is the offset in an option of its type field.
+ ipv4OptionTypeOffset = 0
+
+ // IPv4OptionLengthOffset is the offset in an option of its length field.
+ IPv4OptionLengthOffset = 1
+)
+
+// Potential errors when parsing generic IP options.
+var (
+ ErrIPv4OptZeroLength = errors.New("zero length IP option")
+ ErrIPv4OptDuplicate = errors.New("duplicate IP option")
+ ErrIPv4OptInvalid = errors.New("invalid IP option")
+ ErrIPv4OptMalformed = errors.New("malformed IP option")
+ ErrIPv4OptionTruncated = errors.New("truncated IP option")
+ ErrIPv4OptionAddress = errors.New("bad IP option address")
+)
+
+// IPv4Option is an interface representing various option types.
+type IPv4Option interface {
+ // Type returns the type identifier of the option.
+ Type() IPv4OptionType
+
+ // Size returns the size of the option in bytes.
+ Size() uint8
+
+ // Contents returns a slice holding the contents of the option.
+ Contents() []byte
+}
+
+var _ IPv4Option = (*IPv4OptionGeneric)(nil)
+
+// IPv4OptionGeneric is an IPv4 Option of unknown type.
+type IPv4OptionGeneric []byte
+
+// Type implements IPv4Option.
+func (o *IPv4OptionGeneric) Type() IPv4OptionType {
+ return IPv4OptionType((*o)[ipv4OptionTypeOffset])
+}
+
+// Size implements IPv4Option.
+func (o *IPv4OptionGeneric) Size() uint8 { return uint8(len(*o)) }
+
+// Contents implements IPv4Option.
+func (o *IPv4OptionGeneric) Contents() []byte { return []byte(*o) }
+
+// IPv4OptionIterator is an iterator pointing to a specific IP option
+// at any point of time. It also holds information as to a new options buffer
+// that we are building up to hand back to the caller.
+type IPv4OptionIterator struct {
+ options IPv4Options
+ // ErrCursor is where we are while parsing options. It is exported as any
+ // resulting ICMP packet is supposed to have a pointer to the byte within
+ // the IP packet where the error was detected.
+ ErrCursor uint8
+ nextErrCursor uint8
+ newOptions [IPv4MaximumOptionsSize]byte
+ writePoint int
+}
+
+// MakeIterator sets up and returns an iterator of options. It also sets up the
+// building of a new option set.
+func (o IPv4Options) MakeIterator() IPv4OptionIterator {
+ return IPv4OptionIterator{
+ options: o,
+ nextErrCursor: IPv4MinimumSize,
+ }
+}
+
+// RemainingBuffer returns the remaining (unused) part of the new option buffer,
+// into which a new option may be written.
+func (i *IPv4OptionIterator) RemainingBuffer() IPv4Options {
+ return IPv4Options(i.newOptions[i.writePoint:])
+}
+
+// ConsumeBuffer marks a portion of the new buffer as used.
+func (i *IPv4OptionIterator) ConsumeBuffer(size int) {
+ i.writePoint += size
+}
+
+// PushNOPOrEnd puts one of the single byte options onto the new options.
+// Only values 0 or 1 (ListEnd or NOP) are valid input.
+func (i *IPv4OptionIterator) PushNOPOrEnd(val IPv4OptionType) {
+ if val > IPv4OptionNOPType {
+ panic(fmt.Sprintf("invalid option type %d pushed onto option build buffer", val))
+ }
+ i.newOptions[i.writePoint] = byte(val)
+ i.writePoint++
+}
+
+// Finalize returns the completed replacement options buffer padded
+// as needed.
+func (i *IPv4OptionIterator) Finalize() IPv4Options {
+ // RFC 791 page 31 says:
+ // The options might not end on a 32-bit boundary. The internet header
+ // must be filled out with octets of zeros. The first of these would
+ // be interpreted as the end-of-options option, and the remainder as
+ // internet header padding.
+ // Since the buffer is already zero filled we just need to step the write
+ // pointer up to the next multiple of 4.
+ options := IPv4Options(i.newOptions[:(i.writePoint+0x3) & ^0x3])
+ // Poison the write pointer.
+ i.writePoint = len(i.newOptions)
+ return options
+}
+
+// Next returns the next IP option in the buffer/list of IP options.
+// It returns
+// - A slice of bytes holding the next option or nil if there is error.
+// - A boolean which is true if parsing of all the options is complete.
+// - An error which is non-nil if an error condition was encountered.
+func (i *IPv4OptionIterator) Next() (IPv4Option, bool, error) {
+ // The opts slice gets shorter as we process the options. When we have no
+ // bytes left we are done.
+ if len(i.options) == 0 {
+ return nil, true, nil
+ }
+
+ i.ErrCursor = i.nextErrCursor
+
+ optType := IPv4OptionType(i.options[ipv4OptionTypeOffset])
+
+ if optType == IPv4OptionNOPType || optType == IPv4OptionListEndType {
+ optionBody := i.options[:1]
+ i.options = i.options[1:]
+ i.nextErrCursor = i.ErrCursor + 1
+ retval := IPv4OptionGeneric(optionBody)
+ return &retval, false, nil
+ }
+
+ // There are no more single byte options defined. All the rest have a length
+ // field so we need to sanity check it.
+ if len(i.options) == 1 {
+ return nil, true, ErrIPv4OptMalformed
+ }
+
+ optLen := i.options[IPv4OptionLengthOffset]
+
+ if optLen == 0 {
+ i.ErrCursor++
+ return nil, true, ErrIPv4OptZeroLength
+ }
+
+ if optLen == 1 {
+ i.ErrCursor++
+ return nil, true, ErrIPv4OptMalformed
+ }
+
+ if optLen > uint8(len(i.options)) {
+ i.ErrCursor++
+ return nil, true, ErrIPv4OptionTruncated
+ }
+
+ optionBody := i.options[:optLen]
+ i.nextErrCursor = i.ErrCursor + optLen
+ i.options = i.options[optLen:]
+
+ // Check the length of some option types that we know.
+ switch optType {
+ case IPv4OptionTimestampType:
+ if optLen < IPv4OptionTimestampHdrLength {
+ i.ErrCursor++
+ return nil, true, ErrIPv4OptMalformed
+ }
+ retval := IPv4OptionTimestamp(optionBody)
+ return &retval, false, nil
+
+ case IPv4OptionRecordRouteType:
+ if optLen < IPv4OptionRecordRouteHdrLength {
+ i.ErrCursor++
+ return nil, true, ErrIPv4OptMalformed
+ }
+ retval := IPv4OptionRecordRoute(optionBody)
+ return &retval, false, nil
+ }
+ retval := IPv4OptionGeneric(optionBody)
+ return &retval, false, nil
+}
+
+//
+// IP Timestamp option - RFC 791 page 22.
+// +--------+--------+--------+--------+
+// |01000100| length | pointer|oflw|flg|
+// +--------+--------+--------+--------+
+// | internet address |
+// +--------+--------+--------+--------+
+// | timestamp |
+// +--------+--------+--------+--------+
+// | ... |
+//
+// Type = 68
+//
+// The Option Length is the number of octets in the option counting
+// the type, length, pointer, and overflow/flag octets (maximum
+// length 40).
+//
+// The Pointer is the number of octets from the beginning of this
+// option to the end of timestamps plus one (i.e., it points to the
+// octet beginning the space for next timestamp). The smallest
+// legal value is 5. The timestamp area is full when the pointer
+// is greater than the length.
+//
+// The Overflow (oflw) [4 bits] is the number of IP modules that
+// cannot register timestamps due to lack of space.
+//
+// The Flag (flg) [4 bits] values are
+//
+// 0 -- time stamps only, stored in consecutive 32-bit words,
+//
+// 1 -- each timestamp is preceded with internet address of the
+// registering entity,
+//
+// 3 -- the internet address fields are prespecified. An IP
+// module only registers its timestamp if it matches its own
+// address with the next specified internet address.
+//
+// Timestamps are defined in RFC 791 page 22 as milliseconds since midnight UTC.
+//
+// The Timestamp is a right-justified, 32-bit timestamp in
+// milliseconds since midnight UT. If the time is not available in
+// milliseconds or cannot be provided with respect to midnight UT
+// then any time may be inserted as a timestamp provided the high
+// order bit of the timestamp field is set to one to indicate the
+// use of a non-standard value.
+
+// IPv4OptTSFlags sefines the values expected in the Timestamp
+// option Flags field.
+type IPv4OptTSFlags uint8
+
+//
+// Timestamp option specific related constants.
+const (
+ // IPv4OptionTimestampHdrLength is the length of the timestamp option header.
+ IPv4OptionTimestampHdrLength = 4
+
+ // IPv4OptionTimestampSize is the size of an IP timestamp.
+ IPv4OptionTimestampSize = 4
+
+ // IPv4OptionTimestampWithAddrSize is the size of an IP timestamp + Address.
+ IPv4OptionTimestampWithAddrSize = IPv4AddressSize + IPv4OptionTimestampSize
+
+ // IPv4OptionTimestampMaxSize is limited by space for options
+ IPv4OptionTimestampMaxSize = IPv4MaximumOptionsSize
+
+ // IPv4OptionTimestampOnlyFlag is a flag indicating that only timestamp
+ // is present.
+ IPv4OptionTimestampOnlyFlag IPv4OptTSFlags = 0
+
+ // IPv4OptionTimestampWithIPFlag is a flag indicating that both timestamps and
+ // IP are present.
+ IPv4OptionTimestampWithIPFlag IPv4OptTSFlags = 1
+
+ // IPv4OptionTimestampWithPredefinedIPFlag is a flag indicating that
+ // predefined IP is present.
+ IPv4OptionTimestampWithPredefinedIPFlag IPv4OptTSFlags = 3
+)
+
+// ipv4TimestampTime provides the current time as specified in RFC 791.
+func ipv4TimestampTime(clock tcpip.Clock) uint32 {
+ const millisecondsPerDay = 24 * 3600 * 1000
+ const nanoPerMilli = 1000000
+ return uint32((clock.NowNanoseconds() / nanoPerMilli) % millisecondsPerDay)
+}
+
+// IP Timestamp option fields.
+const (
+ // IPv4OptTSPointerOffset is the offset of the Timestamp pointer field.
+ IPv4OptTSPointerOffset = 2
+
+ // IPv4OptTSPointerOffset is the offset of the combined Flag and Overflow
+ // fields, (each being 4 bits).
+ IPv4OptTSOFLWAndFLGOffset = 3
+ // These constants define the sub byte fields of the Flag and OverFlow field.
+ ipv4OptionTimestampOverflowshift = 4
+ ipv4OptionTimestampFlagsMask byte = 0x0f
+)
+
+var _ IPv4Option = (*IPv4OptionTimestamp)(nil)
+
+// IPv4OptionTimestamp is a Timestamp option from RFC 791.
+type IPv4OptionTimestamp []byte
+
+// Type implements IPv4Option.Type().
+func (ts *IPv4OptionTimestamp) Type() IPv4OptionType { return IPv4OptionTimestampType }
+
+// Size implements IPv4Option.
+func (ts *IPv4OptionTimestamp) Size() uint8 { return uint8(len(*ts)) }
+
+// Contents implements IPv4Option.
+func (ts *IPv4OptionTimestamp) Contents() []byte { return []byte(*ts) }
+
+// Pointer returns the pointer field in the IP Timestamp option.
+func (ts *IPv4OptionTimestamp) Pointer() uint8 {
+ return (*ts)[IPv4OptTSPointerOffset]
+}
+
+// Flags returns the flags field in the IP Timestamp option.
+func (ts *IPv4OptionTimestamp) Flags() IPv4OptTSFlags {
+ return IPv4OptTSFlags((*ts)[IPv4OptTSOFLWAndFLGOffset] & ipv4OptionTimestampFlagsMask)
+}
+
+// Overflow returns the Overflow field in the IP Timestamp option.
+func (ts *IPv4OptionTimestamp) Overflow() uint8 {
+ return (*ts)[IPv4OptTSOFLWAndFLGOffset] >> ipv4OptionTimestampOverflowshift
+}
+
+// IncOverflow increments the Overflow field in the IP Timestamp option. It
+// returns the incremented value. If the return value is 0 then the field
+// overflowed.
+func (ts *IPv4OptionTimestamp) IncOverflow() uint8 {
+ (*ts)[IPv4OptTSOFLWAndFLGOffset] += 1 << ipv4OptionTimestampOverflowshift
+ return ts.Overflow()
+}
+
+// UpdateTimestamp updates the fields of the next free timestamp slot.
+func (ts *IPv4OptionTimestamp) UpdateTimestamp(addr tcpip.Address, clock tcpip.Clock) {
+ slot := (*ts)[ts.Pointer()-1:]
+
+ switch ts.Flags() {
+ case IPv4OptionTimestampOnlyFlag:
+ binary.BigEndian.PutUint32(slot, ipv4TimestampTime(clock))
+ (*ts)[IPv4OptTSPointerOffset] += IPv4OptionTimestampSize
+ case IPv4OptionTimestampWithIPFlag:
+ if n := copy(slot, addr); n != IPv4AddressSize {
+ panic(fmt.Sprintf("copied %d bytes, expected %d bytes", n, IPv4AddressSize))
+ }
+ binary.BigEndian.PutUint32(slot[IPv4AddressSize:], ipv4TimestampTime(clock))
+ (*ts)[IPv4OptTSPointerOffset] += IPv4OptionTimestampWithAddrSize
+ case IPv4OptionTimestampWithPredefinedIPFlag:
+ if tcpip.Address(slot[:IPv4AddressSize]) == addr {
+ binary.BigEndian.PutUint32(slot[IPv4AddressSize:], ipv4TimestampTime(clock))
+ (*ts)[IPv4OptTSPointerOffset] += IPv4OptionTimestampWithAddrSize
+ }
+ }
+}
+
+// RecordRoute option specific related constants.
+//
+// from RFC 791 page 20:
+// Record Route
+//
+// +--------+--------+--------+---------//--------+
+// |00000111| length | pointer| route data |
+// +--------+--------+--------+---------//--------+
+// Type=7
+//
+// The record route option provides a means to record the route of
+// an internet datagram.
+//
+// The option begins with the option type code. The second octet
+// is the option length which includes the option type code and the
+// length octet, the pointer octet, and length-3 octets of route
+// data. The third octet is the pointer into the route data
+// indicating the octet which begins the next area to store a route
+// address. The pointer is relative to this option, and the
+// smallest legal value for the pointer is 4.
+const (
+ // IPv4OptionRecordRouteHdrLength is the length of the Record Route option
+ // header.
+ IPv4OptionRecordRouteHdrLength = 3
+
+ // IPv4OptRRPointerOffset is the offset to the pointer field in an RR
+ // option, which points to the next free slot in the list of addresses.
+ IPv4OptRRPointerOffset = 2
+)
+
+var _ IPv4Option = (*IPv4OptionRecordRoute)(nil)
+
+// IPv4OptionRecordRoute is an IPv4 RecordRoute option defined by RFC 791.
+type IPv4OptionRecordRoute []byte
+
+// Pointer returns the pointer field in the IP RecordRoute option.
+func (rr *IPv4OptionRecordRoute) Pointer() uint8 {
+ return (*rr)[IPv4OptRRPointerOffset]
+}
+
+// StoreAddress stores the given IPv4 address into the next free slot.
+func (rr *IPv4OptionRecordRoute) StoreAddress(addr tcpip.Address) {
+ start := rr.Pointer() - 1 // A one based number.
+ // start and room checked by caller.
+ if n := copy((*rr)[start:], addr); n != IPv4AddressSize {
+ panic(fmt.Sprintf("copied %d bytes, expected %d bytes", n, IPv4AddressSize))
+ }
+ (*rr)[IPv4OptRRPointerOffset] += IPv4AddressSize
+}
+
+// Type implements IPv4Option.
+func (rr *IPv4OptionRecordRoute) Type() IPv4OptionType { return IPv4OptionRecordRouteType }
+
+// Size implements IPv4Option.
+func (rr *IPv4OptionRecordRoute) Size() uint8 { return uint8(len(*rr)) }
+
+// Contents implements IPv4Option.
+func (rr *IPv4OptionRecordRoute) Contents() []byte { return []byte(*rr) }
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index 1edb6de6b..cf287446e 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -15,6 +15,7 @@
package ipv4
import (
+ "errors"
"fmt"
"gvisor.dev/gvisor/pkg/tcpip"
@@ -23,10 +24,10 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/stack"
)
-// handleControl handles the case when an ICMP packet contains the headers of
-// the original packet that caused the ICMP one to be sent. This information is
-// used to find out which transport endpoint must be notified about the ICMP
-// packet.
+// handleControl handles the case when an ICMP error packet contains the headers
+// of the original packet that caused the ICMP one to be sent. This information
+// is used to find out which transport endpoint must be notified about the ICMP
+// packet. We only expect the payload, not the enclosing ICMP packet.
func (e *endpoint) handleControl(typ stack.ControlType, extra uint32, pkt *stack.PacketBuffer) {
h, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
if !ok {
@@ -73,20 +74,65 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
}
h := header.ICMPv4(v)
+ // Only do in-stack processing if the checksum is correct.
+ if header.ChecksumVV(pkt.Data, 0 /* initial */) != 0xffff {
+ received.Invalid.Increment()
+ // It's possible that a raw socket expects to receive this regardless
+ // of checksum errors. If it's an echo request we know it's safe because
+ // we are the only handler, however other types do not cope well with
+ // packets with checksum errors.
+ switch h.Type() {
+ case header.ICMPv4Echo:
+ e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, pkt)
+ }
+ return
+ }
+
+ iph := header.IPv4(pkt.NetworkHeader().View())
+ var newOptions header.IPv4Options
+ if len(iph) > header.IPv4MinimumSize {
+ // RFC 1122 section 3.2.2.6 (page 43) (and similar for other round trip
+ // type ICMP packets):
+ // If a Record Route and/or Time Stamp option is received in an
+ // ICMP Echo Request, this option (these options) SHOULD be
+ // updated to include the current host and included in the IP
+ // header of the Echo Reply message, without "truncation".
+ // Thus, the recorded route will be for the entire round trip.
+ //
+ // So we need to let the option processor know how it should handle them.
+ var op optionsUsage
+ if h.Type() == header.ICMPv4Echo {
+ op = &optionUsageEcho{}
+ } else {
+ op = &optionUsageReceive{}
+ }
+ aux, tmp, err := processIPOptions(r, iph.Options(), op)
+ if err != nil {
+ switch {
+ case
+ errors.Is(err, header.ErrIPv4OptDuplicate),
+ errors.Is(err, errIPv4RecordRouteOptInvalidLength),
+ errors.Is(err, errIPv4RecordRouteOptInvalidPointer),
+ errors.Is(err, errIPv4TimestampOptInvalidLength),
+ errors.Is(err, errIPv4TimestampOptInvalidPointer),
+ errors.Is(err, errIPv4TimestampOptOverflow):
+ _ = e.protocol.returnError(r, &icmpReasonParamProblem{pointer: aux}, pkt)
+ e.protocol.stack.Stats().MalformedRcvdPackets.Increment()
+ r.Stats().IP.MalformedPacketsReceived.Increment()
+ }
+ return
+ }
+ newOptions = tmp
+ }
+
// TODO(b/112892170): Meaningfully handle all ICMP types.
switch h.Type() {
case header.ICMPv4Echo:
received.Echo.Increment()
- // Only send a reply if the checksum is valid.
- headerChecksum := h.Checksum()
- h.SetChecksum(0)
- calculatedChecksum := ^header.ChecksumVV(pkt.Data, 0 /* initial */)
- h.SetChecksum(headerChecksum)
- if calculatedChecksum != headerChecksum {
- // It's possible that a raw socket still expects to receive this.
- e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, pkt)
- received.Invalid.Increment()
+ sent := stats.ICMP.V4PacketsSent
+ if !r.Stack().AllowICMPMessage() {
+ sent.RateLimited.Increment()
return
}
@@ -98,9 +144,14 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
// waiting endpoints. Consider moving responsibility for doing the copy to
// DeliverTransportPacket so that is is only done when needed.
replyData := pkt.Data.ToOwnedView()
- replyIPHdr := header.IPv4(append(buffer.View(nil), pkt.NetworkHeader().View()...))
+ // It's possible that a raw socket expects to receive this.
e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, pkt)
+ pkt = nil
+ // Take the base of the incoming request IP header but replace the options.
+ replyHeaderLength := uint8(header.IPv4MinimumSize + len(newOptions))
+ replyIPHdr := header.IPv4(append(iph[:header.IPv4MinimumSize:header.IPv4MinimumSize], newOptions...))
+ replyIPHdr.SetHeaderLength(replyHeaderLength)
// As per RFC 1122 section 3.2.1.3, when a host sends any datagram, the IP
// source address MUST be one of its own IP addresses (but not a broadcast
@@ -139,7 +190,8 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
// The fields we need to alter.
//
// We need to produce the entire packet in the data segment in order to
- // use WriteHeaderIncludedPacket().
+ // use WriteHeaderIncludedPacket(). WriteHeaderIncludedPacket sets the
+ // total length and the header checksum so we don't need to set those here.
replyIPHdr.SetSourceAddress(r.LocalAddress)
replyIPHdr.SetDestinationAddress(r.RemoteAddress)
replyIPHdr.SetTTL(r.DefaultTTL())
@@ -157,8 +209,6 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
})
replyPkt.TransportProtocolNumber = header.ICMPv4ProtocolNumber
- // The checksum will be calculated so we don't need to do it here.
- sent := stats.ICMP.V4PacketsSent
if err := r.WriteHeaderIncludedPacket(replyPkt); err != nil {
sent.Dropped.Increment()
return
@@ -244,6 +294,14 @@ type icmpReasonReassemblyTimeout struct{}
func (*icmpReasonReassemblyTimeout) isICMPReason() {}
+// icmpReasonParamProblem is an error to use to request a Parameter Problem
+// message to be sent.
+type icmpReasonParamProblem struct {
+ pointer byte
+}
+
+func (*icmpReasonParamProblem) isICMPReason() {}
+
// returnError takes an error descriptor and generates the appropriate ICMP
// error packet for IPv4 and sends it back to the remote device that sent
// the problematic packet. It incorporates as much of that packet as
@@ -385,7 +443,7 @@ func (p *protocol) returnError(r *stack.Route, reason icmpReason, pkt *stack.Pac
icmpHdr := header.ICMPv4(icmpPkt.TransportHeader().Push(header.ICMPv4MinimumSize))
var counter *tcpip.StatCounter
- switch reason.(type) {
+ switch reason := reason.(type) {
case *icmpReasonPortUnreachable:
icmpHdr.SetType(header.ICMPv4DstUnreachable)
icmpHdr.SetCode(header.ICMPv4PortUnreachable)
@@ -398,6 +456,11 @@ func (p *protocol) returnError(r *stack.Route, reason icmpReason, pkt *stack.Pac
icmpHdr.SetType(header.ICMPv4TimeExceeded)
icmpHdr.SetCode(header.ICMPv4ReassemblyTimeout)
counter = sent.TimeExceeded
+ case *icmpReasonParamProblem:
+ icmpHdr.SetType(header.ICMPv4ParamProblem)
+ icmpHdr.SetCode(header.ICMPv4UnusedCode)
+ icmpHdr.SetPointer(reason.pointer)
+ counter = sent.ParamProblem
default:
panic(fmt.Sprintf("unsupported ICMP type %T", reason))
}
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index e6b842d61..4592984a5 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -16,7 +16,9 @@
package ipv4
import (
+ "errors"
"fmt"
+ "math"
"sync/atomic"
"time"
@@ -31,6 +33,8 @@ import (
)
const (
+ // ReassembleTimeout is the time a packet stays in the reassembly
+ // system before being evicted.
// As per RFC 791 section 3.2:
// The current recommendation for the initial timer setting is 15 seconds.
// This may be changed as experience with this protocol accumulates.
@@ -569,9 +573,14 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
if !ready {
return
}
- }
+ // The reassembler doesn't take care of fixing up the header, so we need
+ // to do it here.
+ h.SetTotalLength(uint16(pkt.Data.Size() + len((h))))
+ h.SetFlagsFragmentOffset(0, 0)
+ }
r.Stats().IP.PacketsDelivered.Increment()
+
p := h.TransportProtocol()
if p == header.ICMPv4ProtocolNumber {
// TODO(gvisor.dev/issues/3810): when we sort out ICMP and transport
@@ -581,6 +590,27 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
e.handleICMP(r, pkt)
return
}
+ if len(h.Options()) != 0 {
+ // TODO(gvisor.dev/issue/4586):
+ // When we add forwarding support we should use the verified options
+ // rather than just throwing them away.
+ aux, _, err := processIPOptions(r, h.Options(), &optionUsageReceive{})
+ if err != nil {
+ switch {
+ case
+ errors.Is(err, header.ErrIPv4OptDuplicate),
+ errors.Is(err, errIPv4RecordRouteOptInvalidPointer),
+ errors.Is(err, errIPv4RecordRouteOptInvalidLength),
+ errors.Is(err, errIPv4TimestampOptInvalidLength),
+ errors.Is(err, errIPv4TimestampOptInvalidPointer),
+ errors.Is(err, errIPv4TimestampOptOverflow):
+ _ = e.protocol.returnError(r, &icmpReasonParamProblem{pointer: aux}, pkt)
+ e.protocol.stack.Stats().MalformedRcvdPackets.Increment()
+ r.Stats().IP.MalformedPacketsReceived.Increment()
+ }
+ return
+ }
+ }
switch res := e.dispatcher.DeliverTransportPacket(r, p, pkt); res {
case stack.TransportPacketHandled:
@@ -905,3 +935,322 @@ func buildNextFragment(pf *fragmentation.PacketFragmenter, originalIPHeader head
return fragPkt, more
}
+
+// optionAction describes possible actions that may be taken on an option
+// while processing it.
+type optionAction uint8
+
+const (
+ // optionRemove says that the option should not be in the output option set.
+ optionRemove optionAction = iota
+
+ // optionProcess says that the option should be fully processed.
+ optionProcess
+
+ // optionVerify says the option should be checked and passed unchanged.
+ optionVerify
+
+ // optionPass says to pass the output set without checking.
+ optionPass
+)
+
+// optionActions list what to do for each option in a given scenario.
+type optionActions struct {
+ // timestamp controls what to do with a Timestamp option.
+ timestamp optionAction
+
+ // recordroute controls what to do with a Record Route option.
+ recordRoute optionAction
+
+ // unknown controls what to do with an unknown option.
+ unknown optionAction
+}
+
+// optionsUsage specifies the ways options may be operated upon for a given
+// scenario during packet processing.
+type optionsUsage interface {
+ actions() optionActions
+}
+
+// optionUsageReceive implements optionsUsage for received packets.
+type optionUsageReceive struct{}
+
+// actions implements optionsUsage.
+func (*optionUsageReceive) actions() optionActions {
+ return optionActions{
+ timestamp: optionVerify,
+ recordRoute: optionVerify,
+ unknown: optionPass,
+ }
+}
+
+// TODO(gvisor.dev/issue/4586): Add an entry here for forwarding when it
+// is enabled (Process, Process, Pass) and for fragmenting (Process, Process,
+// Pass for frag1, but Remove,Remove,Remove for all other frags).
+
+// optionUsageEcho implements optionsUsage for echo packet processing.
+type optionUsageEcho struct{}
+
+// actions implements optionsUsage.
+func (*optionUsageEcho) actions() optionActions {
+ return optionActions{
+ timestamp: optionProcess,
+ recordRoute: optionProcess,
+ unknown: optionRemove,
+ }
+}
+
+var (
+ errIPv4TimestampOptInvalidLength = errors.New("invalid Timestamp length")
+ errIPv4TimestampOptInvalidPointer = errors.New("invalid Timestamp pointer")
+ errIPv4TimestampOptOverflow = errors.New("overflow in Timestamp")
+ errIPv4TimestampOptInvalidFlags = errors.New("invalid Timestamp flags")
+)
+
+// handleTimestamp does any required processing on a Timestamp option
+// in place.
+func handleTimestamp(tsOpt header.IPv4OptionTimestamp, localAddress tcpip.Address, clock tcpip.Clock, usage optionsUsage) (uint8, error) {
+ flags := tsOpt.Flags()
+ var entrySize uint8
+ switch flags {
+ case header.IPv4OptionTimestampOnlyFlag:
+ entrySize = header.IPv4OptionTimestampSize
+ case
+ header.IPv4OptionTimestampWithIPFlag,
+ header.IPv4OptionTimestampWithPredefinedIPFlag:
+ entrySize = header.IPv4OptionTimestampWithAddrSize
+ default:
+ return header.IPv4OptTSOFLWAndFLGOffset, errIPv4TimestampOptInvalidFlags
+ }
+
+ pointer := tsOpt.Pointer()
+ // To simplify processing below, base further work on the array of timestamps
+ // beyond the header, rather than on the whole option. Also to aid
+ // calculations set 'nextSlot' to be 0 based as in the packet it is 1 based.
+ nextSlot := pointer - (header.IPv4OptionTimestampHdrLength + 1)
+ optLen := tsOpt.Size()
+ dataLength := optLen - header.IPv4OptionTimestampHdrLength
+
+ // In the section below, we verify the pointer, length and overflow counter
+ // fields of the option. The distinction is in which byte you return as being
+ // in error in the ICMP packet. Offsets 1 (length), 2 pointer)
+ // or 3 (overflowed counter).
+ //
+ // The following RFC sections cover this section:
+ //
+ // RFC 791 (page 22):
+ // If there is some room but not enough room for a full timestamp
+ // to be inserted, or the overflow count itself overflows, the
+ // original datagram is considered to be in error and is discarded.
+ // In either case an ICMP parameter problem message may be sent to
+ // the source host [3].
+ //
+ // You can get this situation in two ways. Firstly if the data area is not
+ // a multiple of the entry size or secondly, if the pointer is not at a
+ // multiple of the entry size. The wording of the RFC suggests that
+ // this is not an error until you actually run out of space.
+ if pointer > optLen {
+ // RFC 791 (page 22) says we should switch to using the overflow count.
+ // If the timestamp data area is already full (the pointer exceeds
+ // the length) the datagram is forwarded without inserting the
+ // timestamp, but the overflow count is incremented by one.
+ if flags == header.IPv4OptionTimestampWithPredefinedIPFlag {
+ // By definition we have nothing to do.
+ return 0, nil
+ }
+
+ if tsOpt.IncOverflow() != 0 {
+ return 0, nil
+ }
+ // The overflow count is also full.
+ return header.IPv4OptTSOFLWAndFLGOffset, errIPv4TimestampOptOverflow
+ }
+ if nextSlot+entrySize > dataLength {
+ // The data area isn't full but there isn't room for a new entry.
+ // Either Length or Pointer could be bad.
+ if false {
+ // We must select Pointer for Linux compatibility, even if
+ // only the length is bad.
+ // The Linux code is at (in October 2020)
+ // https://github.com/torvalds/linux/blob/bbf5c979011a099af5dc76498918ed7df445635b/net/ipv4/ip_options.c#L367-L370
+ // if (optptr[2]+3 > optlen) {
+ // pp_ptr = optptr + 2;
+ // goto error;
+ // }
+ // which doesn't distinguish between which of optptr[2] or optlen
+ // is wrong, but just arbitrarily decides on optptr+2.
+ if dataLength%entrySize != 0 {
+ // The Data section size should be a multiple of the expected
+ // timestamp entry size.
+ return header.IPv4OptionLengthOffset, errIPv4TimestampOptInvalidLength
+ }
+ // If the size is OK, the pointer must be corrupted.
+ }
+ return header.IPv4OptTSPointerOffset, errIPv4TimestampOptInvalidPointer
+ }
+
+ if usage.actions().timestamp == optionProcess {
+ tsOpt.UpdateTimestamp(localAddress, clock)
+ }
+ return 0, nil
+}
+
+var (
+ errIPv4RecordRouteOptInvalidLength = errors.New("invalid length in Record Route")
+ errIPv4RecordRouteOptInvalidPointer = errors.New("invalid pointer in Record Route")
+)
+
+// handleRecordRoute checks and processes a Record route option. It is much
+// like the timestamp type 1 option, but without timestamps. The passed in
+// address is stored in the option in the correct spot if possible.
+func handleRecordRoute(rrOpt header.IPv4OptionRecordRoute, localAddress tcpip.Address, usage optionsUsage) (uint8, error) {
+ optlen := rrOpt.Size()
+
+ if optlen < header.IPv4AddressSize+header.IPv4OptionRecordRouteHdrLength {
+ return header.IPv4OptionLengthOffset, errIPv4RecordRouteOptInvalidLength
+ }
+
+ nextSlot := rrOpt.Pointer() - 1 // Pointer is 1 based.
+
+ // RFC 791 page 21 says
+ // If the route data area is already full (the pointer exceeds the
+ // length) the datagram is forwarded without inserting the address
+ // into the recorded route. If there is some room but not enough
+ // room for a full address to be inserted, the original datagram is
+ // considered to be in error and is discarded. In either case an
+ // ICMP parameter problem message may be sent to the source
+ // host.
+ // The use of the words "In either case" suggests that a 'full' RR option
+ // could generate an ICMP at every hop after it fills up. We chose to not
+ // do this (as do most implementations). It is probable that the inclusion
+ // of these words is a copy/paste error from the timestamp option where
+ // there are two failure reasons given.
+ if nextSlot >= optlen {
+ return 0, nil
+ }
+
+ // The data area isn't full but there isn't room for a new entry.
+ // Either Length or Pointer could be bad. We must select Pointer for Linux
+ // compatibility, even if only the length is bad.
+ if nextSlot+header.IPv4AddressSize > optlen {
+ if false {
+ // This is what we would do if we were not being Linux compatible.
+ // Check for bad pointer or length value. Must be a multiple of 4 after
+ // accounting for the 3 byte header and not within that header.
+ // RFC 791, page 20 says:
+ // The pointer is relative to this option, and the
+ // smallest legal value for the pointer is 4.
+ //
+ // A recorded route is composed of a series of internet addresses.
+ // Each internet address is 32 bits or 4 octets.
+ // Linux skips this test so we must too. See Linux code at:
+ // https://github.com/torvalds/linux/blob/bbf5c979011a099af5dc76498918ed7df445635b/net/ipv4/ip_options.c#L338-L341
+ // if (optptr[2]+3 > optlen) {
+ // pp_ptr = optptr + 2;
+ // goto error;
+ // }
+ if (optlen-header.IPv4OptionRecordRouteHdrLength)%header.IPv4AddressSize != 0 {
+ // Length is bad, not on integral number of slots.
+ return header.IPv4OptionLengthOffset, errIPv4RecordRouteOptInvalidLength
+ }
+ // If not length, the fault must be with the pointer.
+ }
+ return header.IPv4OptRRPointerOffset, errIPv4RecordRouteOptInvalidPointer
+ }
+ if usage.actions().recordRoute == optionVerify {
+ return 0, nil
+ }
+ rrOpt.StoreAddress(localAddress)
+ return 0, nil
+}
+
+// processIPOptions parses the IPv4 options and produces a new set of options
+// suitable for use in the next step of packet processing as informed by usage.
+// The original will not be touched.
+//
+// Returns
+// - The location of an error if there was one (or 0 if no error)
+// - If there is an error, information as to what it was was.
+// - The replacement option set.
+func processIPOptions(r *stack.Route, orig header.IPv4Options, usage optionsUsage) (uint8, header.IPv4Options, error) {
+
+ opts := header.IPv4Options(orig)
+ optIter := opts.MakeIterator()
+
+ // Each option other than NOP must only appear (RFC 791 section 3.1, at the
+ // definition of every type). Keep track of each of the possible types in
+ // the 8 bit 'type' field.
+ var seenOptions [math.MaxUint8 + 1]bool
+
+ // TODO(gvisor.dev/issue/4586):
+ // This will need tweaking when we start really forwarding packets
+ // as we may need to get two addresses, for rx and tx interfaces.
+ // We will also have to take usage into account.
+ prefixedAddress, err := r.Stack().GetMainNICAddress(r.NICID(), ProtocolNumber)
+ localAddress := prefixedAddress.Address
+ if err != nil {
+ if r.IsInboundBroadcast() || header.IsV4MulticastAddress(r.LocalAddress) {
+ return 0 /* errCursor */, nil, header.ErrIPv4OptionAddress
+ }
+ localAddress = r.LocalAddress
+ }
+
+ for {
+ option, done, err := optIter.Next()
+ if done || err != nil {
+ return optIter.ErrCursor, optIter.Finalize(), err
+ }
+ optType := option.Type()
+ if optType == header.IPv4OptionNOPType {
+ optIter.PushNOPOrEnd(optType)
+ continue
+ }
+ if optType == header.IPv4OptionListEndType {
+ optIter.PushNOPOrEnd(optType)
+ return 0 /* errCursor */, optIter.Finalize(), nil /* err */
+ }
+
+ // check for repeating options (multiple NOPs are OK)
+ if seenOptions[optType] {
+ return optIter.ErrCursor, nil, header.ErrIPv4OptDuplicate
+ }
+ seenOptions[optType] = true
+
+ optLen := int(option.Size())
+ switch option := option.(type) {
+ case *header.IPv4OptionTimestamp:
+ r.Stats().IP.OptionTSReceived.Increment()
+ if usage.actions().timestamp != optionRemove {
+ clock := r.Stack().Clock()
+ newBuffer := optIter.RemainingBuffer()[:len(*option)]
+ _ = copy(newBuffer, option.Contents())
+ offset, err := handleTimestamp(header.IPv4OptionTimestamp(newBuffer), localAddress, clock, usage)
+ if err != nil {
+ return optIter.ErrCursor + offset, nil, err
+ }
+ optIter.ConsumeBuffer(optLen)
+ }
+
+ case *header.IPv4OptionRecordRoute:
+ r.Stats().IP.OptionRRReceived.Increment()
+ if usage.actions().recordRoute != optionRemove {
+ newBuffer := optIter.RemainingBuffer()[:len(*option)]
+ _ = copy(newBuffer, option.Contents())
+ offset, err := handleRecordRoute(header.IPv4OptionRecordRoute(newBuffer), localAddress, usage)
+ if err != nil {
+ return optIter.ErrCursor + offset, nil, err
+ }
+ optIter.ConsumeBuffer(optLen)
+ }
+
+ default:
+ r.Stats().IP.OptionUnknownReceived.Increment()
+ if usage.actions().unknown == optionPass {
+ newBuffer := optIter.RemainingBuffer()[:optLen]
+ // Arguments already heavily checked.. ignore result.
+ _ = copy(newBuffer, option.Contents())
+ optIter.ConsumeBuffer(optLen)
+ }
+ }
+ }
+}
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index b97f4380a..17f2e6b46 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -687,7 +687,8 @@ func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp
// n doesn't have a destination endpoint.
// Send the packet out of n.
- // TODO(gvisor.dev/issue/1085): According to the RFC, we must decrease the TTL field for ipv4/ipv6.
+ // TODO(gvisor.dev/issue/1085): According to the RFC, we must decrease
+ // the TTL field for ipv4/ipv6.
// pkt may have set its header and may not have enough headroom for
// link-layer header for the other link to prepend. Here we create a new
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index ac4d39d3e..3ab2b7654 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -1505,6 +1505,15 @@ type IPStats struct {
// IPTablesOutputDropped is the total number of IP packets dropped in
// the Output chain.
IPTablesOutputDropped *StatCounter
+
+ // OptionTSReceived is the number of Timestamp options seen.
+ OptionTSReceived *StatCounter
+
+ // OptionRRReceived is the number of Record Route options seen.
+ OptionRRReceived *StatCounter
+
+ // OptionUnknownReceived is the number of unknown IP options seen.
+ OptionUnknownReceived *StatCounter
}
// TCPStats collects TCP-specific stats.
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 13:42:51 +0000