github.com/elfadel/cilium@v1.6.12/pkg/datapath/linux/utils.go (about)

     1  // Copyright 2019 Authors of Cilium
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package linux
    16  
    17  import (
    18  	"fmt"
    19  	"net"
    20  	"reflect"
    21  
    22  	"github.com/cilium/cilium/pkg/byteorder"
    23  )
    24  
    25  // goArray2C transforms a byte slice into its hexadecimal string representation.
    26  // Example:
    27  // array := []byte{0x12, 0xFF, 0x0, 0x01}
    28  // fmt.Print(GoArray2C(array)) // "{ 0x12, 0xff, 0x0, 0x1 }"
    29  func goArray2C(array []byte) string {
    30  	ret := ""
    31  
    32  	for i, e := range array {
    33  		if i == 0 {
    34  			ret = ret + fmt.Sprintf("%#x", e)
    35  		} else {
    36  			ret = ret + fmt.Sprintf(", %#x", e)
    37  		}
    38  	}
    39  	return ret
    40  }
    41  
    42  // FmtDefineAddress returns the a define string from the given name and addr.
    43  // Example:
    44  // fmt.Print(FmtDefineAddress("foo", []byte{1, 2, 3})) // "#define foo { .addr = { 0x1, 0x2, 0x3 } }\n"
    45  func FmtDefineAddress(name string, addr []byte) string {
    46  	return fmt.Sprintf("#define %s { .addr = { %s } }\n", name, goArray2C(addr))
    47  }
    48  
    49  // defineUint32 writes the C definition for an unsigned 32-bit value.
    50  func defineUint32(name string, value uint32) string {
    51  	return fmt.Sprintf("DEFINE_U32(%s, %#08x);\t/* %d */\n#define %s fetch_u32(%s)\n",
    52  		name, value, value, name, name)
    53  }
    54  
    55  // defineIPv4 writes the C definition for the given IPv4 address.
    56  func defineIPv4(name string, addr []byte) string {
    57  	if len(addr) != net.IPv4len {
    58  		return fmt.Sprintf("/* BUG: bad ip define %s %s */\n", name, goArray2C(addr))
    59  	}
    60  	nboAddr := byteorder.HostSliceToNetwork(addr, reflect.Uint32).(uint32)
    61  	return defineUint32(name, nboAddr)
    62  }
    63  
    64  // defineIPv6 writes the C definition for the given IPv6 address.
    65  func defineIPv6(name string, addr []byte) string {
    66  	if len(addr) != net.IPv6len {
    67  		return fmt.Sprintf("/* BUG: bad ip define %s %s */\n", name, goArray2C(addr))
    68  	}
    69  	return fmt.Sprintf("DEFINE_IPV6(%s, %s);\n", name, goArray2C(addr))
    70  }
    71  
    72  func dumpRaw(name string, addr []byte) string {
    73  	return fmt.Sprintf(" %s%s\n", name, goArray2C(addr))
    74  }
    75  
    76  // defineMAC writes the C definition for the given MAC name and addr.
    77  func defineMAC(name string, addr []byte) string {
    78  	if len(addr) != 6 { /* MAC len */
    79  		return fmt.Sprintf("/* BUG: bad mac define %s %s */\n", name, goArray2C(addr))
    80  	}
    81  	return fmt.Sprintf("DEFINE_MAC(%s, %s);\n#define %s fetch_mac(%s)\n",
    82  		name, goArray2C(addr), name, name)
    83  }