diff options
Diffstat (limited to 'vendor/golang.org/x/sys/unix/pledge_openbsd.go')
-rw-r--r-- | vendor/golang.org/x/sys/unix/pledge_openbsd.go | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/unix/pledge_openbsd.go b/vendor/golang.org/x/sys/unix/pledge_openbsd.go new file mode 100644 index 000000000..eb48294b2 --- /dev/null +++ b/vendor/golang.org/x/sys/unix/pledge_openbsd.go @@ -0,0 +1,163 @@ +// 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 unix + +import ( + "errors" + "fmt" + "strconv" + "syscall" + "unsafe" +) + +// Pledge implements the pledge syscall. +// +// The pledge syscall does not accept execpromises on OpenBSD releases +// before 6.3. +// +// execpromises must be empty when Pledge is called on OpenBSD +// releases predating 6.3, otherwise an error will be returned. +// +// For more information see pledge(2). +func Pledge(promises, execpromises string) error { + maj, min, err := majmin() + if err != nil { + return err + } + + err = pledgeAvailable(maj, min, execpromises) + if err != nil { + return err + } + + pptr, err := syscall.BytePtrFromString(promises) + if err != nil { + return err + } + + // This variable will hold either a nil unsafe.Pointer or + // an unsafe.Pointer to a string (execpromises). + var expr unsafe.Pointer + + // If we're running on OpenBSD > 6.2, pass execpromises to the syscall. + if maj > 6 || (maj == 6 && min > 2) { + exptr, err := syscall.BytePtrFromString(execpromises) + if err != nil { + return err + } + expr = unsafe.Pointer(exptr) + } + + _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0) + if e != 0 { + return e + } + + return nil +} + +// PledgePromises implements the pledge syscall. +// +// This changes the promises and leaves the execpromises untouched. +// +// For more information see pledge(2). +func PledgePromises(promises string) error { + maj, min, err := majmin() + if err != nil { + return err + } + + err = pledgeAvailable(maj, min, "") + if err != nil { + return err + } + + // This variable holds the execpromises and is always nil. + var expr unsafe.Pointer + + pptr, err := syscall.BytePtrFromString(promises) + if err != nil { + return err + } + + _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(unsafe.Pointer(pptr)), uintptr(expr), 0) + if e != 0 { + return e + } + + return nil +} + +// PledgeExecpromises implements the pledge syscall. +// +// This changes the execpromises and leaves the promises untouched. +// +// For more information see pledge(2). +func PledgeExecpromises(execpromises string) error { + maj, min, err := majmin() + if err != nil { + return err + } + + err = pledgeAvailable(maj, min, execpromises) + if err != nil { + return err + } + + // This variable holds the promises and is always nil. + var pptr unsafe.Pointer + + exptr, err := syscall.BytePtrFromString(execpromises) + if err != nil { + return err + } + + _, _, e := syscall.Syscall(SYS_PLEDGE, uintptr(pptr), uintptr(unsafe.Pointer(exptr)), 0) + if e != 0 { + return e + } + + return nil +} + +// majmin returns major and minor version number for an OpenBSD system. +func majmin() (major int, minor int, err error) { + var v Utsname + err = Uname(&v) + if err != nil { + return + } + + major, err = strconv.Atoi(string(v.Release[0])) + if err != nil { + err = errors.New("cannot parse major version number returned by uname") + return + } + + minor, err = strconv.Atoi(string(v.Release[2])) + if err != nil { + err = errors.New("cannot parse minor version number returned by uname") + return + } + + return +} + +// pledgeAvailable checks for availability of the pledge(2) syscall +// based on the running OpenBSD version. +func pledgeAvailable(maj, min int, execpromises string) error { + // If OpenBSD <= 5.9, pledge is not available. + if (maj == 5 && min != 9) || maj < 5 { + return fmt.Errorf("pledge syscall is not available on OpenBSD %d.%d", maj, min) + } + + // If OpenBSD <= 6.2 and execpromises is not empty, + // return an error - execpromises is not available before 6.3 + if (maj < 6 || (maj == 6 && min <= 2)) && execpromises != "" { + return fmt.Errorf("cannot use execpromises on OpenBSD %d.%d", maj, min) + } + + return nil +} |