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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/syndtr/gocapability/capability/capability_linux.go | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/syndtr/gocapability/capability/capability_linux.go')
-rw-r--r-- | vendor/github.com/syndtr/gocapability/capability/capability_linux.go | 650 |
1 files changed, 650 insertions, 0 deletions
diff --git a/vendor/github.com/syndtr/gocapability/capability/capability_linux.go b/vendor/github.com/syndtr/gocapability/capability/capability_linux.go new file mode 100644 index 000000000..6d2135ac5 --- /dev/null +++ b/vendor/github.com/syndtr/gocapability/capability/capability_linux.go @@ -0,0 +1,650 @@ +// Copyright (c) 2013, Suryandaru Triandana <syndtr@gmail.com> +// All rights reserved. +// +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +package capability + +import ( + "bufio" + "errors" + "fmt" + "io" + "os" + "strings" + "syscall" +) + +var errUnknownVers = errors.New("unknown capability version") + +const ( + linuxCapVer1 = 0x19980330 + linuxCapVer2 = 0x20071026 + linuxCapVer3 = 0x20080522 +) + +var ( + capVers uint32 + capLastCap Cap +) + +func init() { + var hdr capHeader + capget(&hdr, nil) + capVers = hdr.version + + if initLastCap() == nil { + CAP_LAST_CAP = capLastCap + if capLastCap > 31 { + capUpperMask = (uint32(1) << (uint(capLastCap) - 31)) - 1 + } else { + capUpperMask = 0 + } + } +} + +func initLastCap() error { + if capLastCap != 0 { + return nil + } + + f, err := os.Open("/proc/sys/kernel/cap_last_cap") + if err != nil { + return err + } + defer f.Close() + + var b []byte = make([]byte, 11) + _, err = f.Read(b) + if err != nil { + return err + } + + fmt.Sscanf(string(b), "%d", &capLastCap) + + return nil +} + +func mkStringCap(c Capabilities, which CapType) (ret string) { + for i, first := Cap(0), true; i <= CAP_LAST_CAP; i++ { + if !c.Get(which, i) { + continue + } + if first { + first = false + } else { + ret += ", " + } + ret += i.String() + } + return +} + +func mkString(c Capabilities, max CapType) (ret string) { + ret = "{" + for i := CapType(1); i <= max; i <<= 1 { + ret += " " + i.String() + "=\"" + if c.Empty(i) { + ret += "empty" + } else if c.Full(i) { + ret += "full" + } else { + ret += c.StringCap(i) + } + ret += "\"" + } + ret += " }" + return +} + +func newPid(pid int) (c Capabilities, err error) { + switch capVers { + case linuxCapVer1: + p := new(capsV1) + p.hdr.version = capVers + p.hdr.pid = pid + c = p + case linuxCapVer2, linuxCapVer3: + p := new(capsV3) + p.hdr.version = capVers + p.hdr.pid = pid + c = p + default: + err = errUnknownVers + return + } + err = c.Load() + if err != nil { + c = nil + } + return +} + +type capsV1 struct { + hdr capHeader + data capData +} + +func (c *capsV1) Get(which CapType, what Cap) bool { + if what > 32 { + return false + } + + switch which { + case EFFECTIVE: + return (1<<uint(what))&c.data.effective != 0 + case PERMITTED: + return (1<<uint(what))&c.data.permitted != 0 + case INHERITABLE: + return (1<<uint(what))&c.data.inheritable != 0 + } + + return false +} + +func (c *capsV1) getData(which CapType) (ret uint32) { + switch which { + case EFFECTIVE: + ret = c.data.effective + case PERMITTED: + ret = c.data.permitted + case INHERITABLE: + ret = c.data.inheritable + } + return +} + +func (c *capsV1) Empty(which CapType) bool { + return c.getData(which) == 0 +} + +func (c *capsV1) Full(which CapType) bool { + return (c.getData(which) & 0x7fffffff) == 0x7fffffff +} + +func (c *capsV1) Set(which CapType, caps ...Cap) { + for _, what := range caps { + if what > 32 { + continue + } + + if which&EFFECTIVE != 0 { + c.data.effective |= 1 << uint(what) + } + if which&PERMITTED != 0 { + c.data.permitted |= 1 << uint(what) + } + if which&INHERITABLE != 0 { + c.data.inheritable |= 1 << uint(what) + } + } +} + +func (c *capsV1) Unset(which CapType, caps ...Cap) { + for _, what := range caps { + if what > 32 { + continue + } + + if which&EFFECTIVE != 0 { + c.data.effective &= ^(1 << uint(what)) + } + if which&PERMITTED != 0 { + c.data.permitted &= ^(1 << uint(what)) + } + if which&INHERITABLE != 0 { + c.data.inheritable &= ^(1 << uint(what)) + } + } +} + +func (c *capsV1) Fill(kind CapType) { + if kind&CAPS == CAPS { + c.data.effective = 0x7fffffff + c.data.permitted = 0x7fffffff + c.data.inheritable = 0 + } +} + +func (c *capsV1) Clear(kind CapType) { + if kind&CAPS == CAPS { + c.data.effective = 0 + c.data.permitted = 0 + c.data.inheritable = 0 + } +} + +func (c *capsV1) StringCap(which CapType) (ret string) { + return mkStringCap(c, which) +} + +func (c *capsV1) String() (ret string) { + return mkString(c, BOUNDING) +} + +func (c *capsV1) Load() (err error) { + return capget(&c.hdr, &c.data) +} + +func (c *capsV1) Apply(kind CapType) error { + if kind&CAPS == CAPS { + return capset(&c.hdr, &c.data) + } + return nil +} + +type capsV3 struct { + hdr capHeader + data [2]capData + bounds [2]uint32 + ambient [2]uint32 +} + +func (c *capsV3) Get(which CapType, what Cap) bool { + var i uint + if what > 31 { + i = uint(what) >> 5 + what %= 32 + } + + switch which { + case EFFECTIVE: + return (1<<uint(what))&c.data[i].effective != 0 + case PERMITTED: + return (1<<uint(what))&c.data[i].permitted != 0 + case INHERITABLE: + return (1<<uint(what))&c.data[i].inheritable != 0 + case BOUNDING: + return (1<<uint(what))&c.bounds[i] != 0 + case AMBIENT: + return (1<<uint(what))&c.ambient[i] != 0 + } + + return false +} + +func (c *capsV3) getData(which CapType, dest []uint32) { + switch which { + case EFFECTIVE: + dest[0] = c.data[0].effective + dest[1] = c.data[1].effective + case PERMITTED: + dest[0] = c.data[0].permitted + dest[1] = c.data[1].permitted + case INHERITABLE: + dest[0] = c.data[0].inheritable + dest[1] = c.data[1].inheritable + case BOUNDING: + dest[0] = c.bounds[0] + dest[1] = c.bounds[1] + case AMBIENT: + dest[0] = c.ambient[0] + dest[1] = c.ambient[1] + } +} + +func (c *capsV3) Empty(which CapType) bool { + var data [2]uint32 + c.getData(which, data[:]) + return data[0] == 0 && data[1] == 0 +} + +func (c *capsV3) Full(which CapType) bool { + var data [2]uint32 + c.getData(which, data[:]) + if (data[0] & 0xffffffff) != 0xffffffff { + return false + } + return (data[1] & capUpperMask) == capUpperMask +} + +func (c *capsV3) Set(which CapType, caps ...Cap) { + for _, what := range caps { + var i uint + if what > 31 { + i = uint(what) >> 5 + what %= 32 + } + + if which&EFFECTIVE != 0 { + c.data[i].effective |= 1 << uint(what) + } + if which&PERMITTED != 0 { + c.data[i].permitted |= 1 << uint(what) + } + if which&INHERITABLE != 0 { + c.data[i].inheritable |= 1 << uint(what) + } + if which&BOUNDING != 0 { + c.bounds[i] |= 1 << uint(what) + } + if which&AMBIENT != 0 { + c.ambient[i] |= 1 << uint(what) + } + } +} + +func (c *capsV3) Unset(which CapType, caps ...Cap) { + for _, what := range caps { + var i uint + if what > 31 { + i = uint(what) >> 5 + what %= 32 + } + + if which&EFFECTIVE != 0 { + c.data[i].effective &= ^(1 << uint(what)) + } + if which&PERMITTED != 0 { + c.data[i].permitted &= ^(1 << uint(what)) + } + if which&INHERITABLE != 0 { + c.data[i].inheritable &= ^(1 << uint(what)) + } + if which&BOUNDING != 0 { + c.bounds[i] &= ^(1 << uint(what)) + } + if which&AMBIENT != 0 { + c.ambient[i] &= ^(1 << uint(what)) + } + } +} + +func (c *capsV3) Fill(kind CapType) { + if kind&CAPS == CAPS { + c.data[0].effective = 0xffffffff + c.data[0].permitted = 0xffffffff + c.data[0].inheritable = 0 + c.data[1].effective = 0xffffffff + c.data[1].permitted = 0xffffffff + c.data[1].inheritable = 0 + } + + if kind&BOUNDS == BOUNDS { + c.bounds[0] = 0xffffffff + c.bounds[1] = 0xffffffff + } + if kind&AMBS == AMBS { + c.ambient[0] = 0xffffffff + c.ambient[1] = 0xffffffff + } +} + +func (c *capsV3) Clear(kind CapType) { + if kind&CAPS == CAPS { + c.data[0].effective = 0 + c.data[0].permitted = 0 + c.data[0].inheritable = 0 + c.data[1].effective = 0 + c.data[1].permitted = 0 + c.data[1].inheritable = 0 + } + + if kind&BOUNDS == BOUNDS { + c.bounds[0] = 0 + c.bounds[1] = 0 + } + if kind&AMBS == AMBS { + c.ambient[0] = 0 + c.ambient[1] = 0 + } +} + +func (c *capsV3) StringCap(which CapType) (ret string) { + return mkStringCap(c, which) +} + +func (c *capsV3) String() (ret string) { + return mkString(c, BOUNDING) +} + +func (c *capsV3) Load() (err error) { + err = capget(&c.hdr, &c.data[0]) + if err != nil { + return + } + + var status_path string + + if c.hdr.pid == 0 { + status_path = fmt.Sprintf("/proc/self/status") + } else { + status_path = fmt.Sprintf("/proc/%d/status", c.hdr.pid) + } + + f, err := os.Open(status_path) + if err != nil { + return + } + b := bufio.NewReader(f) + for { + line, e := b.ReadString('\n') + if e != nil { + if e != io.EOF { + err = e + } + break + } + if strings.HasPrefix(line, "CapB") { + fmt.Sscanf(line[4:], "nd: %08x%08x", &c.bounds[1], &c.bounds[0]) + break + } + if strings.HasPrefix(line, "CapA") { + fmt.Sscanf(line[4:], "mb: %08x%08x", &c.ambient[1], &c.ambient[0]) + break + } + } + f.Close() + + return +} + +func (c *capsV3) Apply(kind CapType) (err error) { + if kind&BOUNDS == BOUNDS { + var data [2]capData + err = capget(&c.hdr, &data[0]) + if err != nil { + return + } + if (1<<uint(CAP_SETPCAP))&data[0].effective != 0 { + for i := Cap(0); i <= CAP_LAST_CAP; i++ { + if c.Get(BOUNDING, i) { + continue + } + err = prctl(syscall.PR_CAPBSET_DROP, uintptr(i), 0, 0, 0) + if err != nil { + // Ignore EINVAL since the capability may not be supported in this system. + if errno, ok := err.(syscall.Errno); ok && errno == syscall.EINVAL { + err = nil + continue + } + return + } + } + } + } + + if kind&CAPS == CAPS { + err = capset(&c.hdr, &c.data[0]) + if err != nil { + return + } + } + + if kind&AMBS == AMBS { + for i := Cap(0); i <= CAP_LAST_CAP; i++ { + action := pr_CAP_AMBIENT_LOWER + if c.Get(AMBIENT, i) { + action = pr_CAP_AMBIENT_RAISE + } + err := prctl(pr_CAP_AMBIENT, action, uintptr(i), 0, 0) + // Ignore EINVAL as not supported on kernels before 4.3 + if errno, ok := err.(syscall.Errno); ok && errno == syscall.EINVAL { + err = nil + continue + } + } + } + + return +} + +func newFile(path string) (c Capabilities, err error) { + c = &capsFile{path: path} + err = c.Load() + if err != nil { + c = nil + } + return +} + +type capsFile struct { + path string + data vfscapData +} + +func (c *capsFile) Get(which CapType, what Cap) bool { + var i uint + if what > 31 { + if c.data.version == 1 { + return false + } + i = uint(what) >> 5 + what %= 32 + } + + switch which { + case EFFECTIVE: + return (1<<uint(what))&c.data.effective[i] != 0 + case PERMITTED: + return (1<<uint(what))&c.data.data[i].permitted != 0 + case INHERITABLE: + return (1<<uint(what))&c.data.data[i].inheritable != 0 + } + + return false +} + +func (c *capsFile) getData(which CapType, dest []uint32) { + switch which { + case EFFECTIVE: + dest[0] = c.data.effective[0] + dest[1] = c.data.effective[1] + case PERMITTED: + dest[0] = c.data.data[0].permitted + dest[1] = c.data.data[1].permitted + case INHERITABLE: + dest[0] = c.data.data[0].inheritable + dest[1] = c.data.data[1].inheritable + } +} + +func (c *capsFile) Empty(which CapType) bool { + var data [2]uint32 + c.getData(which, data[:]) + return data[0] == 0 && data[1] == 0 +} + +func (c *capsFile) Full(which CapType) bool { + var data [2]uint32 + c.getData(which, data[:]) + if c.data.version == 0 { + return (data[0] & 0x7fffffff) == 0x7fffffff + } + if (data[0] & 0xffffffff) != 0xffffffff { + return false + } + return (data[1] & capUpperMask) == capUpperMask +} + +func (c *capsFile) Set(which CapType, caps ...Cap) { + for _, what := range caps { + var i uint + if what > 31 { + if c.data.version == 1 { + continue + } + i = uint(what) >> 5 + what %= 32 + } + + if which&EFFECTIVE != 0 { + c.data.effective[i] |= 1 << uint(what) + } + if which&PERMITTED != 0 { + c.data.data[i].permitted |= 1 << uint(what) + } + if which&INHERITABLE != 0 { + c.data.data[i].inheritable |= 1 << uint(what) + } + } +} + +func (c *capsFile) Unset(which CapType, caps ...Cap) { + for _, what := range caps { + var i uint + if what > 31 { + if c.data.version == 1 { + continue + } + i = uint(what) >> 5 + what %= 32 + } + + if which&EFFECTIVE != 0 { + c.data.effective[i] &= ^(1 << uint(what)) + } + if which&PERMITTED != 0 { + c.data.data[i].permitted &= ^(1 << uint(what)) + } + if which&INHERITABLE != 0 { + c.data.data[i].inheritable &= ^(1 << uint(what)) + } + } +} + +func (c *capsFile) Fill(kind CapType) { + if kind&CAPS == CAPS { + c.data.effective[0] = 0xffffffff + c.data.data[0].permitted = 0xffffffff + c.data.data[0].inheritable = 0 + if c.data.version == 2 { + c.data.effective[1] = 0xffffffff + c.data.data[1].permitted = 0xffffffff + c.data.data[1].inheritable = 0 + } + } +} + +func (c *capsFile) Clear(kind CapType) { + if kind&CAPS == CAPS { + c.data.effective[0] = 0 + c.data.data[0].permitted = 0 + c.data.data[0].inheritable = 0 + if c.data.version == 2 { + c.data.effective[1] = 0 + c.data.data[1].permitted = 0 + c.data.data[1].inheritable = 0 + } + } +} + +func (c *capsFile) StringCap(which CapType) (ret string) { + return mkStringCap(c, which) +} + +func (c *capsFile) String() (ret string) { + return mkString(c, INHERITABLE) +} + +func (c *capsFile) Load() (err error) { + return getVfsCap(c.path, &c.data) +} + +func (c *capsFile) Apply(kind CapType) (err error) { + if kind&CAPS == CAPS { + return setVfsCap(c.path, &c.data) + } + return +} |