From 73df946d56c74384511a194dd01dbe099584fd1a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 15:14:23 +0200 Subject: Adding upstream version 1.16.10. Signed-off-by: Daniel Baumann --- src/plugin/plugin.go | 72 +++++++++++++++++++++ src/plugin/plugin_dlopen.go | 154 ++++++++++++++++++++++++++++++++++++++++++++ src/plugin/plugin_stubs.go | 17 +++++ src/plugin/plugin_test.go | 17 +++++ 4 files changed, 260 insertions(+) create mode 100644 src/plugin/plugin.go create mode 100644 src/plugin/plugin_dlopen.go create mode 100644 src/plugin/plugin_stubs.go create mode 100644 src/plugin/plugin_test.go (limited to 'src/plugin') diff --git a/src/plugin/plugin.go b/src/plugin/plugin.go new file mode 100644 index 0000000..4a524bf --- /dev/null +++ b/src/plugin/plugin.go @@ -0,0 +1,72 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package plugin implements loading and symbol resolution of Go plugins. +// +// A plugin is a Go main package with exported functions and variables that +// has been built with: +// +// go build -buildmode=plugin +// +// When a plugin is first opened, the init functions of all packages not +// already part of the program are called. The main function is not run. +// A plugin is only initialized once, and cannot be closed. +// +// Currently plugins are only supported on Linux, FreeBSD, and macOS. +// Please report any issues. +package plugin + +// Plugin is a loaded Go plugin. +type Plugin struct { + pluginpath string + err string // set if plugin failed to load + loaded chan struct{} // closed when loaded + syms map[string]interface{} +} + +// Open opens a Go plugin. +// If a path has already been opened, then the existing *Plugin is returned. +// It is safe for concurrent use by multiple goroutines. +func Open(path string) (*Plugin, error) { + return open(path) +} + +// Lookup searches for a symbol named symName in plugin p. +// A symbol is any exported variable or function. +// It reports an error if the symbol is not found. +// It is safe for concurrent use by multiple goroutines. +func (p *Plugin) Lookup(symName string) (Symbol, error) { + return lookup(p, symName) +} + +// A Symbol is a pointer to a variable or function. +// +// For example, a plugin defined as +// +// package main +// +// import "fmt" +// +// var V int +// +// func F() { fmt.Printf("Hello, number %d\n", V) } +// +// may be loaded with the Open function and then the exported package +// symbols V and F can be accessed +// +// p, err := plugin.Open("plugin_name.so") +// if err != nil { +// panic(err) +// } +// v, err := p.Lookup("V") +// if err != nil { +// panic(err) +// } +// f, err := p.Lookup("F") +// if err != nil { +// panic(err) +// } +// *v.(*int) = 7 +// f.(func())() // prints "Hello, number 7" +type Symbol interface{} diff --git a/src/plugin/plugin_dlopen.go b/src/plugin/plugin_dlopen.go new file mode 100644 index 0000000..9200fdc --- /dev/null +++ b/src/plugin/plugin_dlopen.go @@ -0,0 +1,154 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build linux,cgo darwin,cgo freebsd,cgo + +package plugin + +/* +#cgo linux LDFLAGS: -ldl +#include +#include +#include +#include + +#include + +static uintptr_t pluginOpen(const char* path, char** err) { + void* h = dlopen(path, RTLD_NOW|RTLD_GLOBAL); + if (h == NULL) { + *err = (char*)dlerror(); + } + return (uintptr_t)h; +} + +static void* pluginLookup(uintptr_t h, const char* name, char** err) { + void* r = dlsym((void*)h, name); + if (r == NULL) { + *err = (char*)dlerror(); + } + return r; +} +*/ +import "C" + +import ( + "errors" + "sync" + "unsafe" +) + +func open(name string) (*Plugin, error) { + cPath := make([]byte, C.PATH_MAX+1) + cRelName := make([]byte, len(name)+1) + copy(cRelName, name) + if C.realpath( + (*C.char)(unsafe.Pointer(&cRelName[0])), + (*C.char)(unsafe.Pointer(&cPath[0]))) == nil { + return nil, errors.New(`plugin.Open("` + name + `"): realpath failed`) + } + + filepath := C.GoString((*C.char)(unsafe.Pointer(&cPath[0]))) + + pluginsMu.Lock() + if p := plugins[filepath]; p != nil { + pluginsMu.Unlock() + if p.err != "" { + return nil, errors.New(`plugin.Open("` + name + `"): ` + p.err + ` (previous failure)`) + } + <-p.loaded + return p, nil + } + var cErr *C.char + h := C.pluginOpen((*C.char)(unsafe.Pointer(&cPath[0])), &cErr) + if h == 0 { + pluginsMu.Unlock() + return nil, errors.New(`plugin.Open("` + name + `"): ` + C.GoString(cErr)) + } + // TODO(crawshaw): look for plugin note, confirm it is a Go plugin + // and it was built with the correct toolchain. + if len(name) > 3 && name[len(name)-3:] == ".so" { + name = name[:len(name)-3] + } + if plugins == nil { + plugins = make(map[string]*Plugin) + } + pluginpath, syms, errstr := lastmoduleinit() + if errstr != "" { + plugins[filepath] = &Plugin{ + pluginpath: pluginpath, + err: errstr, + } + pluginsMu.Unlock() + return nil, errors.New(`plugin.Open("` + name + `"): ` + errstr) + } + // This function can be called from the init function of a plugin. + // Drop a placeholder in the map so subsequent opens can wait on it. + p := &Plugin{ + pluginpath: pluginpath, + loaded: make(chan struct{}), + } + plugins[filepath] = p + pluginsMu.Unlock() + + initStr := make([]byte, len(pluginpath)+len("..inittask")+1) // +1 for terminating NUL + copy(initStr, pluginpath) + copy(initStr[len(pluginpath):], "..inittask") + + initTask := C.pluginLookup(h, (*C.char)(unsafe.Pointer(&initStr[0])), &cErr) + if initTask != nil { + doInit(initTask) + } + + // Fill out the value of each plugin symbol. + updatedSyms := map[string]interface{}{} + for symName, sym := range syms { + isFunc := symName[0] == '.' + if isFunc { + delete(syms, symName) + symName = symName[1:] + } + + fullName := pluginpath + "." + symName + cname := make([]byte, len(fullName)+1) + copy(cname, fullName) + + p := C.pluginLookup(h, (*C.char)(unsafe.Pointer(&cname[0])), &cErr) + if p == nil { + return nil, errors.New(`plugin.Open("` + name + `"): could not find symbol ` + symName + `: ` + C.GoString(cErr)) + } + valp := (*[2]unsafe.Pointer)(unsafe.Pointer(&sym)) + if isFunc { + (*valp)[1] = unsafe.Pointer(&p) + } else { + (*valp)[1] = p + } + // we can't add to syms during iteration as we'll end up processing + // some symbols twice with the inability to tell if the symbol is a function + updatedSyms[symName] = sym + } + p.syms = updatedSyms + + close(p.loaded) + return p, nil +} + +func lookup(p *Plugin, symName string) (Symbol, error) { + if s := p.syms[symName]; s != nil { + return s, nil + } + return nil, errors.New("plugin: symbol " + symName + " not found in plugin " + p.pluginpath) +} + +var ( + pluginsMu sync.Mutex + plugins map[string]*Plugin +) + +// lastmoduleinit is defined in package runtime +func lastmoduleinit() (pluginpath string, syms map[string]interface{}, errstr string) + +// doInit is defined in package runtime +//go:linkname doInit runtime.doInit +func doInit(t unsafe.Pointer) // t should be a *runtime.initTask diff --git a/src/plugin/plugin_stubs.go b/src/plugin/plugin_stubs.go new file mode 100644 index 0000000..1893203 --- /dev/null +++ b/src/plugin/plugin_stubs.go @@ -0,0 +1,17 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !linux,!freebsd,!darwin !cgo + +package plugin + +import "errors" + +func lookup(p *Plugin, symName string) (Symbol, error) { + return nil, errors.New("plugin: not implemented") +} + +func open(name string) (*Plugin, error) { + return nil, errors.New("plugin: not implemented") +} diff --git a/src/plugin/plugin_test.go b/src/plugin/plugin_test.go new file mode 100644 index 0000000..30b79ed --- /dev/null +++ b/src/plugin/plugin_test.go @@ -0,0 +1,17 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !linux linux,!arm64 + +package plugin_test + +import ( + _ "plugin" + "testing" +) + +func TestPlugin(t *testing.T) { + // This test makes sure that executable that imports plugin + // package can actually run. See issue #28789 for details. +} -- cgit v1.2.3