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Diffstat (limited to 'pkg/tcpip/ports/ports.go')
-rw-r--r--pkg/tcpip/ports/ports.go150
1 files changed, 119 insertions, 31 deletions
diff --git a/pkg/tcpip/ports/ports.go b/pkg/tcpip/ports/ports.go
index 30cea8996..b937cb84b 100644
--- a/pkg/tcpip/ports/ports.go
+++ b/pkg/tcpip/ports/ports.go
@@ -18,9 +18,9 @@ package ports
import (
"math"
"math/rand"
- "sync"
"sync/atomic"
+ "gvisor.dev/gvisor/pkg/sync"
"gvisor.dev/gvisor/pkg/tcpip"
)
@@ -41,6 +41,30 @@ type portDescriptor struct {
port uint16
}
+// Flags represents the type of port reservation.
+//
+// +stateify savable
+type Flags struct {
+ // MostRecent represents UDP SO_REUSEADDR.
+ MostRecent bool
+
+ // LoadBalanced indicates SO_REUSEPORT.
+ //
+ // LoadBalanced takes precidence over MostRecent.
+ LoadBalanced bool
+}
+
+func (f Flags) bits() reuseFlag {
+ var rf reuseFlag
+ if f.MostRecent {
+ rf |= mostRecentFlag
+ }
+ if f.LoadBalanced {
+ rf |= loadBalancedFlag
+ }
+ return rf
+}
+
// PortManager manages allocating, reserving and releasing ports.
type PortManager struct {
mu sync.RWMutex
@@ -54,9 +78,59 @@ type PortManager struct {
hint uint32
}
+type reuseFlag int
+
+const (
+ mostRecentFlag reuseFlag = 1 << iota
+ loadBalancedFlag
+ nextFlag
+
+ flagMask = nextFlag - 1
+)
+
type portNode struct {
- reuse bool
- refs int
+ // refs stores the count for each possible flag combination.
+ refs [nextFlag]int
+}
+
+func (p portNode) totalRefs() int {
+ var total int
+ for _, r := range p.refs {
+ total += r
+ }
+ return total
+}
+
+// flagRefs returns the number of references with all specified flags.
+func (p portNode) flagRefs(flags reuseFlag) int {
+ var total int
+ for i, r := range p.refs {
+ if reuseFlag(i)&flags == flags {
+ total += r
+ }
+ }
+ return total
+}
+
+// allRefsHave returns if all references have all specified flags.
+func (p portNode) allRefsHave(flags reuseFlag) bool {
+ for i, r := range p.refs {
+ if reuseFlag(i)&flags == flags && r > 0 {
+ return false
+ }
+ }
+ return true
+}
+
+// intersectionRefs returns the set of flags shared by all references.
+func (p portNode) intersectionRefs() reuseFlag {
+ intersection := flagMask
+ for i, r := range p.refs {
+ if r > 0 {
+ intersection &= reuseFlag(i)
+ }
+ }
+ return intersection
}
// deviceNode is never empty. When it has no elements, it is removed from the
@@ -66,30 +140,44 @@ type deviceNode map[tcpip.NICID]portNode
// isAvailable checks whether binding is possible by device. If not binding to a
// device, check against all portNodes. If binding to a specific device, check
// against the unspecified device and the provided device.
-func (d deviceNode) isAvailable(reuse bool, bindToDevice tcpip.NICID) bool {
+//
+// If either of the port reuse flags is enabled on any of the nodes, all nodes
+// sharing a port must share at least one reuse flag. This matches Linux's
+// behavior.
+func (d deviceNode) isAvailable(flags Flags, bindToDevice tcpip.NICID) bool {
+ flagBits := flags.bits()
if bindToDevice == 0 {
// Trying to binding all devices.
- if !reuse {
+ if flagBits == 0 {
// Can't bind because the (addr,port) is already bound.
return false
}
+ intersection := flagMask
for _, p := range d {
- if !p.reuse {
- // Can't bind because the (addr,port) was previously bound without reuse.
+ i := p.intersectionRefs()
+ intersection &= i
+ if intersection&flagBits == 0 {
+ // Can't bind because the (addr,port) was
+ // previously bound without reuse.
return false
}
}
return true
}
+ intersection := flagMask
+
if p, ok := d[0]; ok {
- if !reuse || !p.reuse {
+ intersection = p.intersectionRefs()
+ if intersection&flagBits == 0 {
return false
}
}
if p, ok := d[bindToDevice]; ok {
- if !reuse || !p.reuse {
+ i := p.intersectionRefs()
+ intersection &= i
+ if intersection&flagBits == 0 {
return false
}
}
@@ -103,12 +191,12 @@ type bindAddresses map[tcpip.Address]deviceNode
// isAvailable checks whether an IP address is available to bind to. If the
// address is the "any" address, check all other addresses. Otherwise, just
// check against the "any" address and the provided address.
-func (b bindAddresses) isAvailable(addr tcpip.Address, reuse bool, bindToDevice tcpip.NICID) bool {
+func (b bindAddresses) isAvailable(addr tcpip.Address, flags Flags, bindToDevice tcpip.NICID) bool {
if addr == anyIPAddress {
// If binding to the "any" address then check that there are no conflicts
// with all addresses.
for _, d := range b {
- if !d.isAvailable(reuse, bindToDevice) {
+ if !d.isAvailable(flags, bindToDevice) {
return false
}
}
@@ -117,14 +205,14 @@ func (b bindAddresses) isAvailable(addr tcpip.Address, reuse bool, bindToDevice
// Check that there is no conflict with the "any" address.
if d, ok := b[anyIPAddress]; ok {
- if !d.isAvailable(reuse, bindToDevice) {
+ if !d.isAvailable(flags, bindToDevice) {
return false
}
}
// Check that this is no conflict with the provided address.
if d, ok := b[addr]; ok {
- if !d.isAvailable(reuse, bindToDevice) {
+ if !d.isAvailable(flags, bindToDevice) {
return false
}
}
@@ -190,17 +278,17 @@ func (s *PortManager) pickEphemeralPort(offset, count uint32, testPort func(p ui
}
// IsPortAvailable tests if the given port is available on all given protocols.
-func (s *PortManager) IsPortAvailable(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) bool {
+func (s *PortManager) IsPortAvailable(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) bool {
s.mu.Lock()
defer s.mu.Unlock()
- return s.isPortAvailableLocked(networks, transport, addr, port, reuse, bindToDevice)
+ return s.isPortAvailableLocked(networks, transport, addr, port, flags, bindToDevice)
}
-func (s *PortManager) isPortAvailableLocked(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) bool {
+func (s *PortManager) isPortAvailableLocked(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) bool {
for _, network := range networks {
desc := portDescriptor{network, transport, port}
if addrs, ok := s.allocatedPorts[desc]; ok {
- if !addrs.isAvailable(addr, reuse, bindToDevice) {
+ if !addrs.isAvailable(addr, flags, bindToDevice) {
return false
}
}
@@ -212,14 +300,14 @@ func (s *PortManager) isPortAvailableLocked(networks []tcpip.NetworkProtocolNumb
// reserved by another endpoint. If port is zero, ReservePort will search for
// an unreserved ephemeral port and reserve it, returning its value in the
// "port" return value.
-func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) (reservedPort uint16, err *tcpip.Error) {
+func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) (reservedPort uint16, err *tcpip.Error) {
s.mu.Lock()
defer s.mu.Unlock()
// If a port is specified, just try to reserve it for all network
// protocols.
if port != 0 {
- if !s.reserveSpecificPort(networks, transport, addr, port, reuse, bindToDevice) {
+ if !s.reserveSpecificPort(networks, transport, addr, port, flags, bindToDevice) {
return 0, tcpip.ErrPortInUse
}
return port, nil
@@ -227,15 +315,16 @@ func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transp
// A port wasn't specified, so try to find one.
return s.PickEphemeralPort(func(p uint16) (bool, *tcpip.Error) {
- return s.reserveSpecificPort(networks, transport, addr, p, reuse, bindToDevice), nil
+ return s.reserveSpecificPort(networks, transport, addr, p, flags, bindToDevice), nil
})
}
// reserveSpecificPort tries to reserve the given port on all given protocols.
-func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) bool {
- if !s.isPortAvailableLocked(networks, transport, addr, port, reuse, bindToDevice) {
+func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) bool {
+ if !s.isPortAvailableLocked(networks, transport, addr, port, flags, bindToDevice) {
return false
}
+ flagBits := flags.bits()
// Reserve port on all network protocols.
for _, network := range networks {
@@ -250,12 +339,9 @@ func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber
d = make(deviceNode)
m[addr] = d
}
- if n, ok := d[bindToDevice]; ok {
- n.refs++
- d[bindToDevice] = n
- } else {
- d[bindToDevice] = portNode{reuse: reuse, refs: 1}
- }
+ n := d[bindToDevice]
+ n.refs[flagBits]++
+ d[bindToDevice] = n
}
return true
@@ -263,10 +349,12 @@ func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber
// ReleasePort releases the reservation on a port/IP combination so that it can
// be reserved by other endpoints.
-func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, bindToDevice tcpip.NICID) {
+func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) {
s.mu.Lock()
defer s.mu.Unlock()
+ flagBits := flags.bits()
+
for _, network := range networks {
desc := portDescriptor{network, transport, port}
if m, ok := s.allocatedPorts[desc]; ok {
@@ -278,9 +366,9 @@ func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transp
if !ok {
continue
}
- n.refs--
+ n.refs[flagBits]--
d[bindToDevice] = n
- if n.refs == 0 {
+ if n.refs == [nextFlag]int{} {
delete(d, bindToDevice)
}
if len(d) == 0 {
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 07:35:55 +0000