用python实现dsr协议

DSR（Dynamic Source Routing）是一种基于跳跃的无线自组织网络路由协议。

以下是使用Python实现DSR协议的基本步骤：

1. 导入必要的模块

import random
import time

2. 定义节点类

class Node:
    def __init__(self, id):
        self.id = id
        self.route_table = {} # 路由表
        self.buffer = [] # 缓存

3. 定义路由表项类

class RouteTableEntry:
    def __init__(self, next_hop, seq_num, hop_count):
        self.next_hop = next_hop # 下一跳节点
        self.seq_num = seq_num # 序列号
        self.hop_count = hop_count # 跳数

4. 定义数据包类

class Packet:
    def __init__(self, src, dst, seq_num, data):
        self.src = src # 源节点
        self.dst = dst # 目的节点
        self.seq_num = seq_num # 序列号
        self.data = data # 数据

5. 定义DSR协议类

class DSR:
    def __init__(self, nodes):
        self.nodes = nodes # 节点列表

    # 发送数据包
    def send_packet(self, src, dst, data):
        seq_num = random.randint(1, 100) # 生成随机序列号
        packet = Packet(src, dst, seq_num, data)
        self.nodes[src].buffer.append(packet) # 将数据包放入源节点的缓存中

    # 处理数据包
    def process_packet(self, node):
        packet = node.buffer.pop(0) # 从缓存中取出数据包
        if packet.dst == node.id: # 如果目的节点是当前节点
            print(f"Node {node.id} received packet: {packet.data}")
        else:
            if packet.seq_num in node.route_table: # 如果已经有路由表项
                next_hop = node.route_table[packet.seq_num].next_hop
                self.nodes[next_hop].buffer.append(packet) # 将数据包转发到下一跳节点
            else:
                for neighbor in self.get_neighbors(node): # 广播请求
                    request_packet = Packet(node.id, neighbor, packet.seq_num, "REQ")
                    self.nodes[neighbor].buffer.append(request_packet)
                time.sleep(1) # 等待响应
                if packet.seq_num in node.route_table: # 如果已经有路由表项
                    next_hop = node.route_table[packet.seq_num].next_hop
                    self.nodes[next_hop].buffer.append(packet) # 将数据包转发到下一跳节点
                else: # 如果仍然没有路由表项，说明无法到达目的节点
                    print(f"Node {node.id} cannot reach node {packet.dst}")

    # 处理请求
    def process_request(self, node):
        packet = node.buffer.pop(0) # 从缓存中取出请求包
        if packet.dst == node.id: # 如果目的节点是当前节点
            seq_num = packet.seq_num
            if seq_num in node.route_table: # 如果已有路由表项
                reply_packet = Packet(node.id, packet.src, seq_num, "REP")
                self.nodes[packet.src].buffer.append(reply_packet) # 发送响应
            else:
                reply_packet = Packet(node.id, packet.src, seq_num, "NREP")
                self.nodes[packet.src].buffer.append(reply_packet) # 发送无法响应
        else: # 转发请求
            for neighbor in self.get_neighbors(node):
                if neighbor != packet.src: # 避免回路
                    self.nodes[neighbor].buffer.append(packet)

    # 处理响应
    def process_reply(self, node):
        packet = node.buffer.pop(0) # 从缓存中取出响应包
        if packet.dst == node.id: # 如果目的节点是当前节点
            seq_num = packet.seq_num
            if seq_num not in node.route_table: # 如果没有路由表项
                node.route_table[seq_num] = RouteTableEntry(packet.src, seq_num, 1) # 添加路由表项
        else: # 转发响应
            for neighbor in self.get_neighbors(node):
                if neighbor != packet.src: # 避免回路
                    self.nodes[neighbor].buffer.append(packet)

    # 获取邻居节点列表
    def get_neighbors(self, node):
        neighbors = []
        for i in range(len(self.nodes)):
            if i != node.id and random.random() < 0.5: # 随机选择50%的节点作为邻居
                neighbors.append(i)
        return neighbors

    # 执行DSR协议
    def run(self, src, dst, data):
        self.send_packet(src, dst, data) # 发送数据包
        while len(self.nodes[src].buffer) > 0: # 处理缓存中的数据包、请求和响应
            packet_type = self.nodes[src].buffer[0].data
            if packet_type == "REQ":
                self.process_request(self.nodes[src])
            elif packet_type == "REP":
                self.process_reply(self.nodes[src])
            else:
                self.process_packet(self.nodes[src])

6. 创建节点，并执行DSR协议

nodes = []
for i in range(5):
    nodes.append(Node(i))

dsr = DSR(nodes)
dsr.run(0, 4, "Hello, world!")

完整代码如下：