Make Nix builds work

1 files changed, 195 insertions, 0 deletions

diff --git a/vendor/golang.org/x/sys/unix/cap_freebsd.go b/vendor/golang.org/x/sys/unix/cap_freebsd.go
new file mode 100644
index 0000000..a086578
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/cap_freebsd.go
@@ -0,0 +1,195 @@
+// Copyright 2017 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.
+
+//go:build freebsd
+
+package unix
+
+import (
+        "errors"
+        "fmt"
+)
+
+// Go implementation of C mostly found in /usr/src/sys/kern/subr_capability.c
+
+const (
+        // This is the version of CapRights this package understands. See C implementation for parallels.
+        capRightsGoVersion = CAP_RIGHTS_VERSION_00
+        capArSizeMin       = CAP_RIGHTS_VERSION_00 + 2
+        capArSizeMax       = capRightsGoVersion + 2
+)
+
+var (
+        bit2idx = []int{
+                -1, 0, 1, -1, 2, -1, -1, -1, 3, -1, -1, -1, -1, -1, -1, -1,
+                4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+        }
+)
+
+func capidxbit(right uint64) int {
+        return int((right >> 57) & 0x1f)
+}
+
+func rightToIndex(right uint64) (int, error) {
+        idx := capidxbit(right)
+        if idx < 0 || idx >= len(bit2idx) {
+                return -2, fmt.Errorf("index for right 0x%x out of range", right)
+        }
+        return bit2idx[idx], nil
+}
+
+func caprver(right uint64) int {
+        return int(right >> 62)
+}
+
+func capver(rights *CapRights) int {
+        return caprver(rights.Rights[0])
+}
+
+func caparsize(rights *CapRights) int {
+        return capver(rights) + 2
+}
+
+// CapRightsSet sets the permissions in setrights in rights.
+func CapRightsSet(rights *CapRights, setrights []uint64) error {
+        // This is essentially a copy of cap_rights_vset()
+        if capver(rights) != CAP_RIGHTS_VERSION_00 {
+                return fmt.Errorf("bad rights version %d", capver(rights))
+        }
+
+        n := caparsize(rights)
+        if n < capArSizeMin || n > capArSizeMax {
+                return errors.New("bad rights size")
+        }
+
+        for _, right := range setrights {
+                if caprver(right) != CAP_RIGHTS_VERSION_00 {
+                        return errors.New("bad right version")
+                }
+                i, err := rightToIndex(right)
+                if err != nil {
+                        return err
+                }
+                if i >= n {
+                        return errors.New("index overflow")
+                }
+                if capidxbit(rights.Rights[i]) != capidxbit(right) {
+                        return errors.New("index mismatch")
+                }
+                rights.Rights[i] |= right
+                if capidxbit(rights.Rights[i]) != capidxbit(right) {
+                        return errors.New("index mismatch (after assign)")
+                }
+        }
+
+        return nil
+}
+
+// CapRightsClear clears the permissions in clearrights from rights.
+func CapRightsClear(rights *CapRights, clearrights []uint64) error {
+        // This is essentially a copy of cap_rights_vclear()
+        if capver(rights) != CAP_RIGHTS_VERSION_00 {
+                return fmt.Errorf("bad rights version %d", capver(rights))
+        }
+
+        n := caparsize(rights)
+        if n < capArSizeMin || n > capArSizeMax {
+                return errors.New("bad rights size")
+        }
+
+        for _, right := range clearrights {
+                if caprver(right) != CAP_RIGHTS_VERSION_00 {
+                        return errors.New("bad right version")
+                }
+                i, err := rightToIndex(right)
+                if err != nil {
+                        return err
+                }
+                if i >= n {
+                        return errors.New("index overflow")
+                }
+                if capidxbit(rights.Rights[i]) != capidxbit(right) {
+                        return errors.New("index mismatch")
+                }
+                rights.Rights[i] &= ^(right & 0x01FFFFFFFFFFFFFF)
+                if capidxbit(rights.Rights[i]) != capidxbit(right) {
+                        return errors.New("index mismatch (after assign)")
+                }
+        }
+
+        return nil
+}
+
+// CapRightsIsSet checks whether all the permissions in setrights are present in rights.
+func CapRightsIsSet(rights *CapRights, setrights []uint64) (bool, error) {
+        // This is essentially a copy of cap_rights_is_vset()
+        if capver(rights) != CAP_RIGHTS_VERSION_00 {
+                return false, fmt.Errorf("bad rights version %d", capver(rights))
+        }
+
+        n := caparsize(rights)
+        if n < capArSizeMin || n > capArSizeMax {
+                return false, errors.New("bad rights size")
+        }
+
+        for _, right := range setrights {
+                if caprver(right) != CAP_RIGHTS_VERSION_00 {
+                        return false, errors.New("bad right version")
+                }
+                i, err := rightToIndex(right)
+                if err != nil {
+                        return false, err
+                }
+                if i >= n {
+                        return false, errors.New("index overflow")
+                }
+                if capidxbit(rights.Rights[i]) != capidxbit(right) {
+                        return false, errors.New("index mismatch")
+                }
+                if (rights.Rights[i] & right) != right {
+                        return false, nil
+                }
+        }
+
+        return true, nil
+}
+
+func capright(idx uint64, bit uint64) uint64 {
+        return ((1 << (57 + idx)) | bit)
+}
+
+// CapRightsInit returns a pointer to an initialised CapRights structure filled with rights.
+// See man cap_rights_init(3) and rights(4).
+func CapRightsInit(rights []uint64) (*CapRights, error) {
+        var r CapRights
+        r.Rights[0] = (capRightsGoVersion << 62) | capright(0, 0)
+        r.Rights[1] = capright(1, 0)
+
+        err := CapRightsSet(&r, rights)
+        if err != nil {
+                return nil, err
+        }
+        return &r, nil
+}
+
+// CapRightsLimit reduces the operations permitted on fd to at most those contained in rights.
+// The capability rights on fd can never be increased by CapRightsLimit.
+// See man cap_rights_limit(2) and rights(4).
+func CapRightsLimit(fd uintptr, rights *CapRights) error {
+        return capRightsLimit(int(fd), rights)
+}
+
+// CapRightsGet returns a CapRights structure containing the operations permitted on fd.
+// See man cap_rights_get(3) and rights(4).
+func CapRightsGet(fd uintptr) (*CapRights, error) {
+        r, err := CapRightsInit(nil)
+        if err != nil {
+                return nil, err
+        }
+        err = capRightsGet(capRightsGoVersion, int(fd), r)
+        if err != nil {
+                return nil, err
+        }
+        return r, nil
+}