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Diffstat (limited to 'vendor/github.com/google/gofuzz/fuzz.go')
-rw-r--r-- | vendor/github.com/google/gofuzz/fuzz.go | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/vendor/github.com/google/gofuzz/fuzz.go b/vendor/github.com/google/gofuzz/fuzz.go new file mode 100644 index 000000000..4f888fbc8 --- /dev/null +++ b/vendor/github.com/google/gofuzz/fuzz.go @@ -0,0 +1,453 @@ +/* +Copyright 2014 Google Inc. All rights reserved. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package fuzz + +import ( + "fmt" + "math/rand" + "reflect" + "time" +) + +// fuzzFuncMap is a map from a type to a fuzzFunc that handles that type. +type fuzzFuncMap map[reflect.Type]reflect.Value + +// Fuzzer knows how to fill any object with random fields. +type Fuzzer struct { + fuzzFuncs fuzzFuncMap + defaultFuzzFuncs fuzzFuncMap + r *rand.Rand + nilChance float64 + minElements int + maxElements int +} + +// New returns a new Fuzzer. Customize your Fuzzer further by calling Funcs, +// RandSource, NilChance, or NumElements in any order. +func New() *Fuzzer { + f := &Fuzzer{ + defaultFuzzFuncs: fuzzFuncMap{ + reflect.TypeOf(&time.Time{}): reflect.ValueOf(fuzzTime), + }, + + fuzzFuncs: fuzzFuncMap{}, + r: rand.New(rand.NewSource(time.Now().UnixNano())), + nilChance: .2, + minElements: 1, + maxElements: 10, + } + return f +} + +// Funcs adds each entry in fuzzFuncs as a custom fuzzing function. +// +// Each entry in fuzzFuncs must be a function taking two parameters. +// The first parameter must be a pointer or map. It is the variable that +// function will fill with random data. The second parameter must be a +// fuzz.Continue, which will provide a source of randomness and a way +// to automatically continue fuzzing smaller pieces of the first parameter. +// +// These functions are called sensibly, e.g., if you wanted custom string +// fuzzing, the function `func(s *string, c fuzz.Continue)` would get +// called and passed the address of strings. Maps and pointers will always +// be made/new'd for you, ignoring the NilChange option. For slices, it +// doesn't make much sense to pre-create them--Fuzzer doesn't know how +// long you want your slice--so take a pointer to a slice, and make it +// yourself. (If you don't want your map/pointer type pre-made, take a +// pointer to it, and make it yourself.) See the examples for a range of +// custom functions. +func (f *Fuzzer) Funcs(fuzzFuncs ...interface{}) *Fuzzer { + for i := range fuzzFuncs { + v := reflect.ValueOf(fuzzFuncs[i]) + if v.Kind() != reflect.Func { + panic("Need only funcs!") + } + t := v.Type() + if t.NumIn() != 2 || t.NumOut() != 0 { + panic("Need 2 in and 0 out params!") + } + argT := t.In(0) + switch argT.Kind() { + case reflect.Ptr, reflect.Map: + default: + panic("fuzzFunc must take pointer or map type") + } + if t.In(1) != reflect.TypeOf(Continue{}) { + panic("fuzzFunc's second parameter must be type fuzz.Continue") + } + f.fuzzFuncs[argT] = v + } + return f +} + +// RandSource causes f to get values from the given source of randomness. +// Use if you want deterministic fuzzing. +func (f *Fuzzer) RandSource(s rand.Source) *Fuzzer { + f.r = rand.New(s) + return f +} + +// NilChance sets the probability of creating a nil pointer, map, or slice to +// 'p'. 'p' should be between 0 (no nils) and 1 (all nils), inclusive. +func (f *Fuzzer) NilChance(p float64) *Fuzzer { + if p < 0 || p > 1 { + panic("p should be between 0 and 1, inclusive.") + } + f.nilChance = p + return f +} + +// NumElements sets the minimum and maximum number of elements that will be +// added to a non-nil map or slice. +func (f *Fuzzer) NumElements(atLeast, atMost int) *Fuzzer { + if atLeast > atMost { + panic("atLeast must be <= atMost") + } + if atLeast < 0 { + panic("atLeast must be >= 0") + } + f.minElements = atLeast + f.maxElements = atMost + return f +} + +func (f *Fuzzer) genElementCount() int { + if f.minElements == f.maxElements { + return f.minElements + } + return f.minElements + f.r.Intn(f.maxElements-f.minElements+1) +} + +func (f *Fuzzer) genShouldFill() bool { + return f.r.Float64() > f.nilChance +} + +// Fuzz recursively fills all of obj's fields with something random. First +// this tries to find a custom fuzz function (see Funcs). If there is no +// custom function this tests whether the object implements fuzz.Interface and, +// if so, calls Fuzz on it to fuzz itself. If that fails, this will see if +// there is a default fuzz function provided by this package. If all of that +// fails, this will generate random values for all primitive fields and then +// recurse for all non-primitives. +// +// Not safe for cyclic or tree-like structs! +// +// obj must be a pointer. Only exported (public) fields can be set (thanks, golang :/ ) +// Intended for tests, so will panic on bad input or unimplemented fields. +func (f *Fuzzer) Fuzz(obj interface{}) { + v := reflect.ValueOf(obj) + if v.Kind() != reflect.Ptr { + panic("needed ptr!") + } + v = v.Elem() + f.doFuzz(v, 0) +} + +// FuzzNoCustom is just like Fuzz, except that any custom fuzz function for +// obj's type will not be called and obj will not be tested for fuzz.Interface +// conformance. This applies only to obj and not other instances of obj's +// type. +// Not safe for cyclic or tree-like structs! +// obj must be a pointer. Only exported (public) fields can be set (thanks, golang :/ ) +// Intended for tests, so will panic on bad input or unimplemented fields. +func (f *Fuzzer) FuzzNoCustom(obj interface{}) { + v := reflect.ValueOf(obj) + if v.Kind() != reflect.Ptr { + panic("needed ptr!") + } + v = v.Elem() + f.doFuzz(v, flagNoCustomFuzz) +} + +const ( + // Do not try to find a custom fuzz function. Does not apply recursively. + flagNoCustomFuzz uint64 = 1 << iota +) + +func (f *Fuzzer) doFuzz(v reflect.Value, flags uint64) { + if !v.CanSet() { + return + } + + if flags&flagNoCustomFuzz == 0 { + // Check for both pointer and non-pointer custom functions. + if v.CanAddr() && f.tryCustom(v.Addr()) { + return + } + if f.tryCustom(v) { + return + } + } + + if fn, ok := fillFuncMap[v.Kind()]; ok { + fn(v, f.r) + return + } + switch v.Kind() { + case reflect.Map: + if f.genShouldFill() { + v.Set(reflect.MakeMap(v.Type())) + n := f.genElementCount() + for i := 0; i < n; i++ { + key := reflect.New(v.Type().Key()).Elem() + f.doFuzz(key, 0) + val := reflect.New(v.Type().Elem()).Elem() + f.doFuzz(val, 0) + v.SetMapIndex(key, val) + } + return + } + v.Set(reflect.Zero(v.Type())) + case reflect.Ptr: + if f.genShouldFill() { + v.Set(reflect.New(v.Type().Elem())) + f.doFuzz(v.Elem(), 0) + return + } + v.Set(reflect.Zero(v.Type())) + case reflect.Slice: + if f.genShouldFill() { + n := f.genElementCount() + v.Set(reflect.MakeSlice(v.Type(), n, n)) + for i := 0; i < n; i++ { + f.doFuzz(v.Index(i), 0) + } + return + } + v.Set(reflect.Zero(v.Type())) + case reflect.Array: + if f.genShouldFill() { + n := v.Len() + for i := 0; i < n; i++ { + f.doFuzz(v.Index(i), 0) + } + return + } + v.Set(reflect.Zero(v.Type())) + case reflect.Struct: + for i := 0; i < v.NumField(); i++ { + f.doFuzz(v.Field(i), 0) + } + case reflect.Chan: + fallthrough + case reflect.Func: + fallthrough + case reflect.Interface: + fallthrough + default: + panic(fmt.Sprintf("Can't handle %#v", v.Interface())) + } +} + +// tryCustom searches for custom handlers, and returns true iff it finds a match +// and successfully randomizes v. +func (f *Fuzzer) tryCustom(v reflect.Value) bool { + // First: see if we have a fuzz function for it. + doCustom, ok := f.fuzzFuncs[v.Type()] + if !ok { + // Second: see if it can fuzz itself. + if v.CanInterface() { + intf := v.Interface() + if fuzzable, ok := intf.(Interface); ok { + fuzzable.Fuzz(Continue{f: f, Rand: f.r}) + return true + } + } + // Finally: see if there is a default fuzz function. + doCustom, ok = f.defaultFuzzFuncs[v.Type()] + if !ok { + return false + } + } + + switch v.Kind() { + case reflect.Ptr: + if v.IsNil() { + if !v.CanSet() { + return false + } + v.Set(reflect.New(v.Type().Elem())) + } + case reflect.Map: + if v.IsNil() { + if !v.CanSet() { + return false + } + v.Set(reflect.MakeMap(v.Type())) + } + default: + return false + } + + doCustom.Call([]reflect.Value{v, reflect.ValueOf(Continue{ + f: f, + Rand: f.r, + })}) + return true +} + +// Interface represents an object that knows how to fuzz itself. Any time we +// find a type that implements this interface we will delegate the act of +// fuzzing itself. +type Interface interface { + Fuzz(c Continue) +} + +// Continue can be passed to custom fuzzing functions to allow them to use +// the correct source of randomness and to continue fuzzing their members. +type Continue struct { + f *Fuzzer + + // For convenience, Continue implements rand.Rand via embedding. + // Use this for generating any randomness if you want your fuzzing + // to be repeatable for a given seed. + *rand.Rand +} + +// Fuzz continues fuzzing obj. obj must be a pointer. +func (c Continue) Fuzz(obj interface{}) { + v := reflect.ValueOf(obj) + if v.Kind() != reflect.Ptr { + panic("needed ptr!") + } + v = v.Elem() + c.f.doFuzz(v, 0) +} + +// FuzzNoCustom continues fuzzing obj, except that any custom fuzz function for +// obj's type will not be called and obj will not be tested for fuzz.Interface +// conformance. This applies only to obj and not other instances of obj's +// type. +func (c Continue) FuzzNoCustom(obj interface{}) { + v := reflect.ValueOf(obj) + if v.Kind() != reflect.Ptr { + panic("needed ptr!") + } + v = v.Elem() + c.f.doFuzz(v, flagNoCustomFuzz) +} + +// RandString makes a random string up to 20 characters long. The returned string +// may include a variety of (valid) UTF-8 encodings. +func (c Continue) RandString() string { + return randString(c.Rand) +} + +// RandUint64 makes random 64 bit numbers. +// Weirdly, rand doesn't have a function that gives you 64 random bits. +func (c Continue) RandUint64() uint64 { + return randUint64(c.Rand) +} + +// RandBool returns true or false randomly. +func (c Continue) RandBool() bool { + return randBool(c.Rand) +} + +func fuzzInt(v reflect.Value, r *rand.Rand) { + v.SetInt(int64(randUint64(r))) +} + +func fuzzUint(v reflect.Value, r *rand.Rand) { + v.SetUint(randUint64(r)) +} + +func fuzzTime(t *time.Time, c Continue) { + var sec, nsec int64 + // Allow for about 1000 years of random time values, which keeps things + // like JSON parsing reasonably happy. + sec = c.Rand.Int63n(1000 * 365 * 24 * 60 * 60) + c.Fuzz(&nsec) + *t = time.Unix(sec, nsec) +} + +var fillFuncMap = map[reflect.Kind]func(reflect.Value, *rand.Rand){ + reflect.Bool: func(v reflect.Value, r *rand.Rand) { + v.SetBool(randBool(r)) + }, + reflect.Int: fuzzInt, + reflect.Int8: fuzzInt, + reflect.Int16: fuzzInt, + reflect.Int32: fuzzInt, + reflect.Int64: fuzzInt, + reflect.Uint: fuzzUint, + reflect.Uint8: fuzzUint, + reflect.Uint16: fuzzUint, + reflect.Uint32: fuzzUint, + reflect.Uint64: fuzzUint, + reflect.Uintptr: fuzzUint, + reflect.Float32: func(v reflect.Value, r *rand.Rand) { + v.SetFloat(float64(r.Float32())) + }, + reflect.Float64: func(v reflect.Value, r *rand.Rand) { + v.SetFloat(r.Float64()) + }, + reflect.Complex64: func(v reflect.Value, r *rand.Rand) { + panic("unimplemented") + }, + reflect.Complex128: func(v reflect.Value, r *rand.Rand) { + panic("unimplemented") + }, + reflect.String: func(v reflect.Value, r *rand.Rand) { + v.SetString(randString(r)) + }, + reflect.UnsafePointer: func(v reflect.Value, r *rand.Rand) { + panic("unimplemented") + }, +} + +// randBool returns true or false randomly. +func randBool(r *rand.Rand) bool { + if r.Int()&1 == 1 { + return true + } + return false +} + +type charRange struct { + first, last rune +} + +// choose returns a random unicode character from the given range, using the +// given randomness source. +func (r *charRange) choose(rand *rand.Rand) rune { + count := int64(r.last - r.first) + return r.first + rune(rand.Int63n(count)) +} + +var unicodeRanges = []charRange{ + {' ', '~'}, // ASCII characters + {'\u00a0', '\u02af'}, // Multi-byte encoded characters + {'\u4e00', '\u9fff'}, // Common CJK (even longer encodings) +} + +// randString makes a random string up to 20 characters long. The returned string +// may include a variety of (valid) UTF-8 encodings. +func randString(r *rand.Rand) string { + n := r.Intn(20) + runes := make([]rune, n) + for i := range runes { + runes[i] = unicodeRanges[r.Intn(len(unicodeRanges))].choose(r) + } + return string(runes) +} + +// randUint64 makes random 64 bit numbers. +// Weirdly, rand doesn't have a function that gives you 64 random bits. +func randUint64(r *rand.Rand) uint64 { + return uint64(r.Uint32())<<32 | uint64(r.Uint32()) +} |