github.com/kaydxh/golang@v0.0.131/go/net/grpc/ip.go (about)

     1  /*
     2   *Copyright (c) 2022, kaydxh
     3   *
     4   *Permission is hereby granted, free of charge, to any person obtaining a copy
     5   *of this software and associated documentation files (the "Software"), to deal
     6   *in the Software without restriction, including without limitation the rights
     7   *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     8   *copies of the Software, and to permit persons to whom the Software is
     9   *furnished to do so, subject to the following conditions:
    10   *
    11   *The above copyright notice and this permission notice shall be included in all
    12   *copies or substantial portions of the Software.
    13   *
    14   *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    15   *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    16   *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    17   *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    18   *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    19   *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    20   *SOFTWARE.
    21   */
    22  package grpc
    23  
    24  import (
    25  	"context"
    26  	"fmt"
    27  	"net"
    28  
    29  	"google.golang.org/grpc/metadata"
    30  	"google.golang.org/grpc/peer"
    31  )
    32  
    33  // returns IP address from grpc context.
    34  // It will lookup IP in  X-Forwarded-For and X-Real-IP headers, if both
    35  // get empty, lookup IP from peer context
    36  func GetIPFromContext(ctx context.Context) (net.IP, error) {
    37  	// FromIncomingContext returns the incoming metadata in ctx if it exists.
    38  	md, ok := metadata.FromIncomingContext(ctx)
    39  	if ok {
    40  		peerAddr := md.Get("x-real-ip")
    41  		if len(peerAddr) > 0 {
    42  			return net.ParseIP(peerAddr[0]), nil
    43  		}
    44  
    45  		peerAddr = md.Get("x-forwarded-for")
    46  		if len(peerAddr) > 0 {
    47  			return net.ParseIP(peerAddr[0]), nil
    48  		}
    49  	}
    50  
    51  	//if use proxy, only return proxy address
    52  	// FromContext returns the peer information in ctx if it exists.
    53  	peerAddr, ok := peer.FromContext(ctx)
    54  	if !ok {
    55  		return nil, fmt.Errorf("unexpected context")
    56  	}
    57  
    58  	if peerAddr.Addr == net.Addr(nil) {
    59  		return nil, fmt.Errorf("unexpected err: peer address is nil")
    60  	}
    61  
    62  	host, _, err := net.SplitHostPort(peerAddr.Addr.String())
    63  	if err != nil {
    64  		return nil, fmt.Errorf("invalid peer host: %v, err: %v", peerAddr.Addr.String(), err)
    65  	}
    66  
    67  	return net.ParseIP(host), nil
    68  }