diff options
Diffstat (limited to 'pkg/tcpip/ports')
| -rw-r--r-- | pkg/tcpip/ports/ports.go | 116 |
1 files changed, 79 insertions, 37 deletions
diff --git a/pkg/tcpip/ports/ports.go b/pkg/tcpip/ports/ports.go index b937cb84b..edc29ad27 100644 --- a/pkg/tcpip/ports/ports.go +++ b/pkg/tcpip/ports/ports.go @@ -54,17 +54,27 @@ type Flags struct { LoadBalanced bool } -func (f Flags) bits() reuseFlag { - var rf reuseFlag +// Bits converts the Flags to their bitset form. +func (f Flags) Bits() BitFlags { + var rf BitFlags if f.MostRecent { - rf |= mostRecentFlag + rf |= MostRecentFlag } if f.LoadBalanced { - rf |= loadBalancedFlag + rf |= LoadBalancedFlag } return rf } +// Effective returns the effective behavior of a flag config. +func (f Flags) Effective() Flags { + e := f + if e.LoadBalanced && e.MostRecent { + e.MostRecent = false + } + return e +} + // PortManager manages allocating, reserving and releasing ports. type PortManager struct { mu sync.RWMutex @@ -78,56 +88,88 @@ type PortManager struct { hint uint32 } -type reuseFlag int +// BitFlags is a bitset representation of Flags. +type BitFlags uint32 const ( - mostRecentFlag reuseFlag = 1 << iota - loadBalancedFlag + // MostRecentFlag represents Flags.MostRecent. + MostRecentFlag BitFlags = 1 << iota + + // LoadBalancedFlag represents Flags.LoadBalanced. + LoadBalancedFlag + + // nextFlag is the value that the next added flag will have. + // + // It is used to calculate FlagMask below. It is also the number of + // valid flag states. nextFlag - flagMask = nextFlag - 1 + // FlagMask is a bit mask for BitFlags. + FlagMask = nextFlag - 1 ) -type portNode struct { - // refs stores the count for each possible flag combination. +// ToFlags converts the bitset into a Flags struct. +func (f BitFlags) ToFlags() Flags { + return Flags{ + MostRecent: f&MostRecentFlag != 0, + LoadBalanced: f&LoadBalancedFlag != 0, + } +} + +// FlagCounter counts how many references each flag combination has. +type FlagCounter struct { + // refs stores the count for each possible flag combination, (0 though + // FlagMask). refs [nextFlag]int } -func (p portNode) totalRefs() int { +// AddRef increases the reference count for a specific flag combination. +func (c *FlagCounter) AddRef(flags BitFlags) { + c.refs[flags]++ +} + +// DropRef decreases the reference count for a specific flag combination. +func (c *FlagCounter) DropRef(flags BitFlags) { + c.refs[flags]-- +} + +// TotalRefs calculates the total number of references for all flag +// combinations. +func (c FlagCounter) TotalRefs() int { var total int - for _, r := range p.refs { + for _, r := range c.refs { total += r } return total } -// flagRefs returns the number of references with all specified flags. -func (p portNode) flagRefs(flags reuseFlag) int { +// FlagRefs returns the number of references with all specified flags. +func (c FlagCounter) FlagRefs(flags BitFlags) int { var total int - for i, r := range p.refs { - if reuseFlag(i)&flags == flags { + for i, r := range c.refs { + if BitFlags(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 { +// AllRefsHave returns if all references have all specified flags. +func (c FlagCounter) AllRefsHave(flags BitFlags) bool { + for i, r := range c.refs { + if BitFlags(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 { +// IntersectionRefs returns the set of flags shared by all references. +func (c FlagCounter) IntersectionRefs() BitFlags { + intersection := FlagMask + for i, r := range c.refs { if r > 0 { - intersection &= reuseFlag(i) + intersection &= BitFlags(i) } } return intersection @@ -135,26 +177,26 @@ func (p portNode) intersectionRefs() reuseFlag { // deviceNode is never empty. When it has no elements, it is removed from the // map that references it. -type deviceNode map[tcpip.NICID]portNode +type deviceNode map[tcpip.NICID]FlagCounter // 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 +// device, check against all FlagCounters. If binding to a specific device, check // against the unspecified device and the provided device. // // 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() + flagBits := flags.Bits() if bindToDevice == 0 { // Trying to binding all devices. if flagBits == 0 { // Can't bind because the (addr,port) is already bound. return false } - intersection := flagMask + intersection := FlagMask for _, p := range d { - i := p.intersectionRefs() + i := p.IntersectionRefs() intersection &= i if intersection&flagBits == 0 { // Can't bind because the (addr,port) was @@ -165,17 +207,17 @@ func (d deviceNode) isAvailable(flags Flags, bindToDevice tcpip.NICID) bool { return true } - intersection := flagMask + intersection := FlagMask if p, ok := d[0]; ok { - intersection = p.intersectionRefs() + intersection = p.IntersectionRefs() if intersection&flagBits == 0 { return false } } if p, ok := d[bindToDevice]; ok { - i := p.intersectionRefs() + i := p.IntersectionRefs() intersection &= i if intersection&flagBits == 0 { return false @@ -324,7 +366,7 @@ func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber if !s.isPortAvailableLocked(networks, transport, addr, port, flags, bindToDevice) { return false } - flagBits := flags.bits() + flagBits := flags.Bits() // Reserve port on all network protocols. for _, network := range networks { @@ -340,7 +382,7 @@ func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber m[addr] = d } n := d[bindToDevice] - n.refs[flagBits]++ + n.AddRef(flagBits) d[bindToDevice] = n } @@ -353,7 +395,7 @@ func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transp s.mu.Lock() defer s.mu.Unlock() - flagBits := flags.bits() + flagBits := flags.Bits() for _, network := range networks { desc := portDescriptor{network, transport, port} @@ -368,7 +410,7 @@ func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transp } n.refs[flagBits]-- d[bindToDevice] = n - if n.refs == [nextFlag]int{} { + if n.TotalRefs() == 0 { delete(d, bindToDevice) } if len(d) == 0 { |