github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/tcpip/stack/icmp_rate_limit.go (about)

     1  // Copyright 2018 The gVisor Authors.
     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 stack
    16  
    17  import (
    18  	"golang.org/x/time/rate"
    19  )
    20  
    21  const (
    22  	// icmpLimit is the default maximum number of ICMP messages permitted by this
    23  	// rate limiter.
    24  	icmpLimit = 1000
    25  
    26  	// icmpBurst is the default number of ICMP messages that can be sent in a single
    27  	// burst.
    28  	icmpBurst = 50
    29  )
    30  
    31  // ICMPRateLimiter is a global rate limiter that controls the generation of
    32  // ICMP messages generated by the stack.
    33  type ICMPRateLimiter struct {
    34  	*rate.Limiter
    35  }
    36  
    37  // NewICMPRateLimiter returns a global rate limiter for controlling the rate
    38  // at which ICMP messages are generated by the stack.
    39  func NewICMPRateLimiter() *ICMPRateLimiter {
    40  	return &ICMPRateLimiter{Limiter: rate.NewLimiter(icmpLimit, icmpBurst)}
    41  }