utils

Documentation

Index

• Constants
• Variables
• func AddrIsLocal(addr net.Addr) bool
• func AddrIsUnix(addr net.Addr) bool
• func AddrToIP(addr net.Addr) net.IP
• func ArgsToStrings(maxLength int, arguments []string, delim string) []string
• func BitsetCopy(set []uint32, other []uint32)
• func BitsetEmpty(set []uint32) (empty bool)
• func BitsetGet(set []uint32, position uint) bool
• func BitsetSet(set []uint32, position uint, on bool) (changed bool)
• func BitsetSubtract(set []uint32, other []uint32)
• func BitsetUnion(set []uint32, other []uint32)
• func CopyFile(src string, dst string) (err error)
• func FieldsFuncN(s string, f func(rune) bool, n int) []string
• func FieldsN(s string, n int) []string
• func GenerateSecretKey() string
• func GenerateSecretToken() string
• func IPInNets(ip net.IP, nets []net.IPNet) bool
• func IsHostname(name string) bool
• func LookupHostname(addr string) string
• func MungeSecretToken(token string) (result string)
• func NetToNormalizedString(network net.IPNet) string
• func NormalizeIPToNet(addr net.IP) (network net.IPNet)
• func NormalizeNet(network net.IPNet) (result net.IPNet)
• func NormalizedNetFromString(str string) (result net.IPNet, err error)
• func ParseNetList(netList []string) (nets []net.IPNet, err error)
• func SecretTokensMatch(storedToken string, suppliedToken string) bool
• func StringToBool(str string) (result bool, err error)
• func WordWrap(text string, lineWidth int) []string
• type MessagePair
• type Once
  • func (o *Once) Do(f func())
  • func (o *Once) Done() bool
• type Semaphore
  • func (semaphore *Semaphore) Acquire()
  • func (semaphore *Semaphore) AcquireWithContext(ctx context.Context) (acquired bool)
  • func (semaphore *Semaphore) AcquireWithTimeout(timeout time.Duration) (acquired bool)
  • func (semaphore *Semaphore) Initialize(capacity int)
  • func (semaphore *Semaphore) Release()
  • func (semaphore *Semaphore) TryAcquire() (acquired bool)
• type SplitMessage
  • func MakeSplitMessage(original string, origIs512 bool) (result SplitMessage)
• type TokenLineBuilder
  • func (t *TokenLineBuilder) Add(token string)
  • func (t *TokenLineBuilder) Initialize(lineLen int, delim string)
  • func (t *TokenLineBuilder) Lines() (result []string)

Constants

const (
	SecretTokenLength = 26
)

Variables

var (
	// slingamn's own private b32 alphabet, removing 1, l, o, and 0
	B32Encoder = base32.NewEncoding("abcdefghijkmnpqrstuvwxyz23456789").WithPadding(base32.NoPadding)
)

var (
	ErrInvalidParams = errors.New("Invalid parameters")
)

var (
	IPv4LoopbackAddress = net.ParseIP("127.0.0.1").To16()
)

Functions

func AddrIsLocal

func AddrIsLocal(addr net.Addr) bool

AddrIsLocal returns whether the address is from a trusted local connection (loopback or unix).

func AddrIsUnix

func AddrIsUnix(addr net.Addr) bool

AddrIsUnix returns whether the address is a unix domain socket.

func AddrToIP

func AddrToIP(addr net.Addr) net.IP

AddrToIP returns the IP address for a net.Addr; unix domain sockets are treated as IPv4 loopback

func ArgsToStrings

func ArgsToStrings(maxLength int, arguments []string, delim string) []string

ArgsToStrings takes the arguments and splits them into a series of strings, each argument separated by delim and each string bounded by maxLength.

func BitsetCopy

func BitsetCopy(set []uint32, other []uint32)

BitsetCopy copies the contents of `other` over `set`. Similar caveats about race conditions as with `BitsetUnion` apply.

func BitsetEmpty

func BitsetEmpty(set []uint32) (empty bool)

BitsetEmpty returns whether the bitset is empty. This has false positives under concurrent modification (i.e., it can return true even though w.r.t. the sequence of atomic modifications, there was no point at which the bitset was completely empty), but that's not how we're using this method.

func BitsetGet

func BitsetGet(set []uint32, position uint) bool

BitsetGet returns whether a given bit of the bitset is set.

func BitsetSet

func BitsetSet(set []uint32, position uint, on bool) (changed bool)

BitsetSet sets a given bit of the bitset to 0 or 1, returning whether it changed.

func BitsetSubtract

func BitsetSubtract(set []uint32, other []uint32)

BitsetSubtract modifies `set` to subtract the contents of `other`. Similar caveats about race conditions as with `BitsetUnion` apply.

func BitsetUnion

func BitsetUnion(set []uint32, other []uint32)

BitsetUnion modifies `set` to be the union of `set` and `other`. This has race conditions in that we don't necessarily get a single consistent view of `other` across word boundaries.

func CopyFile

func CopyFile(src string, dst string) (err error)

implementation of `cp` (go should really provide this...)

func FieldsFuncN

func FieldsFuncN(s string, f func(rune) bool, n int) []string

FieldsFuncN is like strings.FieldsFunc, but returns at most n fields, and the nth field includes any runes at the end of the string normally excluded by f.

func FieldsN

func FieldsN(s string, n int) []string

FieldsN is like strings.Fields, but returns at most n fields, and the nth field includes any whitespace at the end of the string.

func GenerateSecretKey

func GenerateSecretKey() string

generate a 256-bit secret key that can be written into a config file

func GenerateSecretToken

func GenerateSecretToken() string

generate a secret token that cannot be brute-forced via online attacks

func IPInNets

func IPInNets(ip net.IP, nets []net.IPNet) bool

Convenience to test whether `ip` is contained in any of `nets`.

func IsHostname

func IsHostname(name string) bool

IsHostname returns whether we consider `name` a valid hostname.

func LookupHostname

func LookupHostname(addr string) string

LookupHostname returns the hostname for `addr` if it has one. Otherwise, just returns `addr`.

func MungeSecretToken

func MungeSecretToken(token string) (result string)

"munge" a secret token to a new value. requirements: 1. MUST be roughly as unlikely to collide with `GenerateSecretToken` outputs as those outputs are with each other 2. SHOULD be deterministic (motivation: if a JOIN line has msgid x, create a deterministic msgid y for the fake HistServ PRIVMSG that "replays" it) 3. SHOULD be in the same "namespace" as `GenerateSecretToken` outputs (same length and character set)

func NetToNormalizedString

func NetToNormalizedString(network net.IPNet) string

Given a network, produce a human-readable string (i.e., CIDR if it's actually a network, IPv6 address if it's a v6 /128, dotted quad if it's a v4 /32).

func NormalizeIPToNet

func NormalizeIPToNet(addr net.IP) (network net.IPNet)

NormalizeIPToNet represents an address (v4 or v6) as the v6 /128 CIDR containing only it.

func NormalizeNet

func NormalizeNet(network net.IPNet) (result net.IPNet)

NormalizeNet normalizes an IPNet to a v6 CIDR, using the 4-in-6 prefix. (this is like IP.To16(), but for IPNet instead of IP)

func NormalizedNetFromString

func NormalizedNetFromString(str string) (result net.IPNet, err error)

Parse a human-readable description (an address or CIDR, either v4 or v6) into a normalized v6 net.IPNet.

func ParseNetList

func ParseNetList(netList []string) (nets []net.IPNet, err error)

Parse a list of IPs and nets as they would appear in one of our config files, e.g., proxy-allowed-from or a throttling exemption list.

func SecretTokensMatch

func SecretTokensMatch(storedToken string, suppliedToken string) bool

securely check if a supplied token matches a stored token

func StringToBool

func StringToBool(str string) (result bool, err error)

func WordWrap

func WordWrap(text string, lineWidth int) []string

WordWrap wraps the given text into a series of lines that don't exceed lineWidth characters.

Types

type MessagePair

type MessagePair struct {
	Message string
	Msgid   string
}

type Once

type Once struct {
	// contains filtered or unexported fields
}

Once is a fork of sync.Once to expose a Done() method.

func (*Once) Do

func (o *Once) Do(f func())

func (*Once) Done

func (o *Once) Done() bool

type Semaphore

type Semaphore (chan e)

Semaphore is a counting semaphore. A semaphore of capacity 1 can be used as a trylock.

func (*Semaphore) Acquire

func (semaphore *Semaphore) Acquire()

Acquire acquires a semaphore, blocking if necessary.

func (*Semaphore) AcquireWithContext

func (semaphore *Semaphore) AcquireWithContext(ctx context.Context) (acquired bool)

AcquireWithContext tries to acquire a semaphore, blocking at most until the context expires. It returns whether the acquire was successful. Note that if the context is already expired, the acquire may succeed anyway.

func (*Semaphore) AcquireWithTimeout

func (semaphore *Semaphore) AcquireWithTimeout(timeout time.Duration) (acquired bool)

AcquireWithTimeout tries to acquire a semaphore, blocking for a maximum of approximately `d` while waiting for it. It returns whether the acquire was successful.

func (*Semaphore) Initialize

func (semaphore *Semaphore) Initialize(capacity int)

Initialize initializes a semaphore to a given capacity.

func (*Semaphore) Release

func (semaphore *Semaphore) Release()

Release releases a semaphore. It never blocks. (This is not a license to program spurious releases.)

func (*Semaphore) TryAcquire

func (semaphore *Semaphore) TryAcquire() (acquired bool)

TryAcquire tries to acquire a semaphore, returning whether the acquire was successful. It never blocks.

type SplitMessage

type SplitMessage struct {
	MessagePair
	Wrapped []MessagePair // if this is nil, `Message` didn't need wrapping and can be sent to anyone
	Time    time.Time
}

SplitMessage represents a message that's been split for sending.

func MakeSplitMessage

func MakeSplitMessage(original string, origIs512 bool) (result SplitMessage)

type TokenLineBuilder

type TokenLineBuilder struct {
	// contains filtered or unexported fields
}

TokenLineBuilder is a helper for building IRC lines composed of delimited tokens, with a maximum line length.

func (*TokenLineBuilder) Add

func (t *TokenLineBuilder) Add(token string)

Add adds a token to the line, creating a new line if necessary.

func (*TokenLineBuilder) Initialize

func (t *TokenLineBuilder) Initialize(lineLen int, delim string)

func (*TokenLineBuilder) Lines

func (t *TokenLineBuilder) Lines() (result []string)

Lines terminates the line-building and returns all the lines.