github.com/osrg/gobgp/v3@v3.30.0/pkg/server/util.go (about)

     1  // Copyright (C) 2016 Nippon Telegraph and Telephone Corporation.
     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
    12  // implied.
    13  // See the License for the specific language governing permissions and
    14  // limitations under the License.
    15  //go:build !windows
    16  // +build !windows
    17  
    18  package server
    19  
    20  import (
    21  	"net"
    22  	"strings"
    23  	"syscall"
    24  
    25  	"github.com/eapache/channels"
    26  
    27  	"github.com/osrg/gobgp/v3/pkg/packet/bgp"
    28  )
    29  
    30  func cleanInfiniteChannel(ch *channels.InfiniteChannel) {
    31  	ch.Close()
    32  	// drain all remaining items
    33  	for range ch.Out() {
    34  	}
    35  }
    36  
    37  // Returns the binary formatted Administrative Shutdown Communication from the
    38  // given string value.
    39  func newAdministrativeCommunication(communication string) (data []byte) {
    40  	if communication == "" {
    41  		return nil
    42  	}
    43  	com := []byte(communication)
    44  	if len(com) > bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX {
    45  		data = []byte{bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX}
    46  		data = append(data, com[:bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX]...)
    47  	} else {
    48  		data = []byte{byte(len(com))}
    49  		data = append(data, com...)
    50  	}
    51  	return data
    52  }
    53  
    54  // Parses the given NOTIFICATION message data as a binary value and returns
    55  // the Administrative Shutdown Communication in string and the rest binary.
    56  func decodeAdministrativeCommunication(data []byte) (string, []byte) {
    57  	if len(data) == 0 {
    58  		return "", data
    59  	}
    60  	communicationLen := int(data[0])
    61  	if communicationLen > bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX {
    62  		communicationLen = bgp.BGP_ERROR_ADMINISTRATIVE_COMMUNICATION_MAX
    63  	}
    64  	if communicationLen > len(data)-1 {
    65  		communicationLen = len(data) - 1
    66  	}
    67  	return string(data[1 : communicationLen+1]), data[communicationLen+1:]
    68  }
    69  
    70  func extractFamilyFromTCPConn(conn *net.TCPConn) int {
    71  	family := syscall.AF_INET
    72  	if strings.Contains(conn.RemoteAddr().String(), "[") {
    73  		family = syscall.AF_INET6
    74  	}
    75  	return family
    76  }
    77  
    78  func setsockOptString(sc syscall.RawConn, level int, opt int, str string) error {
    79  	var opterr error
    80  	fn := func(s uintptr) {
    81  		opterr = syscall.SetsockoptString(int(s), level, opt, str)
    82  	}
    83  	err := sc.Control(fn)
    84  	if opterr == nil {
    85  		return err
    86  	}
    87  	return opterr
    88  }
    89  
    90  func setsockOptInt(sc syscall.RawConn, level, name, value int) error {
    91  	var opterr error
    92  	fn := func(s uintptr) {
    93  		opterr = syscall.SetsockoptInt(int(s), level, name, value)
    94  	}
    95  	err := sc.Control(fn)
    96  	if opterr == nil {
    97  		return err
    98  	}
    99  	return opterr
   100  }
   101  
   102  func setsockoptIpTtl(sc syscall.RawConn, family int, value int) error {
   103  	level := syscall.IPPROTO_IP
   104  	name := syscall.IP_TTL
   105  	if family == syscall.AF_INET6 {
   106  		level = syscall.IPPROTO_IPV6
   107  		name = syscall.IPV6_UNICAST_HOPS
   108  	}
   109  	return setsockOptInt(sc, level, name, value)
   110  }
   111  
   112  func setsockoptTcpMss(sc syscall.RawConn, family int, value uint16) error {
   113  	level := syscall.IPPROTO_TCP
   114  	name := syscall.TCP_MAXSEG
   115  	return setsockOptInt(sc, level, name, int(value))
   116  }