johnsonjh/gfpsgo

// Copyright 2021 Jeffrey H. Johnson <trnsz@pobox.com>
// Copyright 2018 psgo authors
//
// 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 capabilities provides a mapping from common kernel bit masks to
// the alphanumerical representation of kernel capabilities.
// See capabilities(7) for additional information.
package capabilities

var (
    // capabilities are a mapping from a numerical value to the textual
    // representation of a given capability.  A map allows to easily check
    // if a given value is included or not.
    //
    // NOTE: this map must be maintained and kept in sync with the
    //       ./include/uapi/linux/capability.h kernel header.
    capabilities = map[uint]string{
        0:  "CHOWN",
        1:  "DAC_OVERRIDE",
        2:  "DAC_READ_SEARCH",
        3:  "FOWNER",
        4:  "FSETID",
        5:  "KILL",
        6:  "SETGID",
        7:  "SETUID",
        8:  "SETPCAP",
        9:  "LINUX_IMMUTABLE",
        10: "NET_BIND_SERVICE",
        11: "NET_BROADCAST",
        12: "NET_ADMIN",
        13: "NET_RAW",
        14: "IPC_LOCK",
        15: "IPC_OWNER",
        16: "SYS_MODULE",
        17: "SYS_RAWIO",
        18: "SYS_CHROOT",
        19: "SYS_PTRACE",
        20: "SYS_PACCT",
        21: "SYS_ADMIN",
        22: "SYS_BOOT",
        23: "SYS_NICE",
        24: "SYS_RESOURCE",
        25: "SYS_TIME",
        26: "SYS_TTY_CONFIG",
        27: "MKNOD",
        28: "LEASE",
        29: "AUDIT_WRITE",
        30: "AUDIT_CONTROL",
        31: "SETFCAP",
        32: "MAC_OVERRIDE",
        33: "MAC_ADMIN",
        34: "SYSLOG",
        35: "WAKE_ALARM",
        36: "BLOCK_SUSPEND",
        37: "AUDIT_READ",
    }

    // FullCAPs represents a bitmask with a full capability set.
    FullCAPs = uint64(0x3FFFFFFFFF)
)

// TranslateMask iterates over mask and returns a slice of corresponding
// capabilities.  If a bit is out of range of known capabilities, it is set
// as "unknown" to catch potential regressions when new capabilities are
// added to the kernel.
func TranslateMask(mask uint64) []string {
    caps := []string{}
    for i := uint(0); i < 64; i++ {
        if (mask>>i)&0x1 == 1 {
            c, known := capabilities[i]
            if !known {
                c = "unknown"
            }
            caps = append(caps, c)
        }
    }
    return caps
}