网站开发比较流行的框架,微网站是什么,荣成市建设局网站是什么,乡村建设的网站ZoreMQ Transport Protocol是一个传输层协议#xff0c;用于ZMQ的连接的信息交互#xff0c;本文档描述的是3.0协议#xff0c;主要分析基于NULL Security Mechanism 协议语法
ZMTP由三部分组成#xff0c;分别是 greeting、handshake、traffic
部分描述构成greeting描述… ZoreMQ Transport Protocol是一个传输层协议用于ZMQ的连接的信息交互本文档描述的是3.0协议主要分析基于NULL Security Mechanism 协议语法
ZMTP由三部分组成分别是 greeting、handshake、traffic
部分描述构成greeting描述ZMQ版本、安全机制等signature version mechanism as-server fillerhandshake描述端类型如 PUB/SUBREQ/REP一个或多个commandtraffic命令或者消息command
ZMTP Wireshark 抓包
WireShark 默认不提供ZMTP解析插件需要自己配置步骤如下 插件仓库https://github.com/whitequark/zmtp-wireshark 下载插件https://github.com/whitequark/zmtp-wireshark/blob/master/zmtp-dissector.lua
将插件zmtp-dissector.lua放到WireShark安装目录比如我的是C:\Program Files\Wireshark
修改C:\Program Files\Wireshark\init.lua在文件末尾添加
dofile(DATA_DIR..zmtp-dissector.lua)对基于TCP端口通讯ZMQ进行抓包例如端口为7380将该端口Decode As ZMTP 解析接如下 greeting
greeting 固定64个字节大小下面将依次介绍每个部分。
signature
固定10字节大小固定值为ff 00 00 00 00 00 00 00 01 7f;
signature可以用来校验链接是否为ZMQ链接连续读取10个字节判断开头是否为0xff结尾是否为0x7f。
version
固定2字节大小格式为{major_version, minor_version}3.0 协议则为03 00实际编码过程中只会校验major_version;
mechanism
固定20字节大小这里只介绍NULL Security Mechanism也就是不校验其值为NULL,剩余以内容填充0
as-server
固定一个字节大小0x00 或者 0x01 当mechanism为NULL时候as-server必须为0。
filler
填充greeting至64个字节。
抓包示意
由Wireshark解析过后的协议。 Frame
在greeting之后的所有数据格式都为Frame包含command和message。
frame的格式如下: Frame Flag Payload Length Payload 抓包示意如下 Flag Flag 为1字节大小每位代表不同的意思参考抓包解释 低1位表示是否有更多Frame这里用于ZMQ中sendmore属性 低2位表示长度是否为8字节长度否则为1字节长度 低3位表示当前frame是否为Command 其他保留为0 Payload Length 数据长度可以为1字节或者8字节大小根据Flag中的标志位决定 Payload 实际的数据大小为Payload Length。
handshake
此阶段用来交换对端的READY命令以及metadata主要包含对端的类型。handshake本质是Command为Frame的一种。 在NULL Security Mechanism机制中以PUB/SUB模式为例handshake的数据如下 Payload内容如下 [1 byte] Command size [n bytes]Command Name [1 bytes]Metadata Key size [n bytes]Metadata Key [4 bytes]Metadata Value size [n bytes]Metadata Value 使用Socket实现ZMQ SUB方法
代码如下
//
// ZMTP 3.0 debugging subscriber
#define WIN32_LEAN_AND_MEAN
#include Windows.h
#include WinSock2.h
#include ws2tcpip.h#include stdio.h
#include stdlib.h
#include stdbool.h
#include string.h
#include assert.h
#include fcntl.h
#include cstdint
#include iostream#pragma comment(lib, ws2_32.lib)typedef struct
{uint8_t flags; // Must be zerouint8_t size; // Size, 0 to 255 byteuint8_t data[255]; // Message data
} zmtp_msg_t;static void derp(char *s)
{perror(s);exit(1);
}static void tcp_send(int handle, void *buffer, size_t len)
{if (send(handle, (char *) buffer, len, 0) -1)derp((char *) send);
}static void tcp_recv(int handle, void *buffer, size_t len)
{printf( - reading %d bytes: , (int) len);fflush(stdout);size_t len_recd 0;while (len_recd len){size_t bytes recv(handle, (char *) buffer len_recd, len - len_recd, 0);if (bytes 0)break; // Peer has shutdownprintf( [%d], (int) bytes);fflush(stdout);if (bytes -1)derp((char *) recv);len_recd bytes;}printf(\n);fflush(stdout);
}static void zmtp_recv(int handle, zmtp_msg_t *msg)
{tcp_recv(handle, (uint8_t *) msg, 2);tcp_recv(handle, msg-data, msg-size);
}static void zmtp_send(int handle, zmtp_msg_t *msg)
{tcp_send(handle, (uint8_t *) msg, msg-size 2);
}// This is the 3.0 greeting (64 bytes)
typedef struct
{uint8_t signature[10];uint8_t version[2];uint8_t mechanism[20];uint8_t as_server[1];uint8_t filler[31];
} zmtp_greeting_t;int main(void)
{puts(I: starting subscriber);WSADATA wsData;if (WSAStartup(MAKEWORD(2, 2), wsData) ! 0){std::cerr 无法初始化Winsock std::endl;return 1;}// Create TCP socketint peer;if ((peer socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) -1)derp((char *) socket);const char *serverIP 127.0.0.1;const int serverPort 5559;sockaddr_in serverAddress {};serverAddress.sin_family AF_INET;serverAddress.sin_port htons(serverPort);if (inet_pton(AF_INET, serverIP, (serverAddress.sin_addr)) 0){std::cerr 无效的服务器IP地址 std::endl;closesocket(peer);WSACleanup();return 1;}// Keep trying to connect until we succeedputs(I: waiting for connection);while (connect(peer, reinterpret_castsockaddr *(serverAddress), sizeof(serverAddress)) -1)Sleep(1);puts(I: connected OK);// This is our greeting (64 octets)zmtp_greeting_t outgoing {{0xFF, 0, 0, 0, 0, 0, 0, 0, 1, 0x7F},{3, 0},{N, U, L, L, 0},{0},{0}};// Do full backwards version detection following RFC23// Send first ten bytes of greeting to peertcp_send(peer, outgoing, 10);// Read first byte from peerzmtp_greeting_t incoming;tcp_recv(peer, incoming, 1);uint8_t length incoming.signature[0];if (length ! 0xFF){puts(E: signature not valid (1));closesocket(peer);exit(0);}// Looks like 2.0, read 9 more bytes to be suretcp_recv(peer, (uint8_t *) incoming 1, 9);if ((incoming.signature[9] 1) ! 1){puts(E: signature not valid (2));closesocket(peer);exit(0);}// Exchange major version numbersputs(I: signature valid, exchanging major versions);tcp_send(peer, (uint8_t *) outgoing 10, 1);tcp_recv(peer, (uint8_t *) incoming 10, 1);if (incoming.version[0] 3){// If version 3, the peer is using ZMTP 3.0, so send// rest of the greeting and continue with ZMTP 3.0.puts(I: peer is talking ZMTP 3.0);puts(I: sending rest of greeting...);tcp_send(peer, (uint8_t *) outgoing 11, 53);// Get remainder of greeting from peerputs(I: waiting for greeting from peer...);tcp_recv(peer, (uint8_t *) incoming 11, 53);// Do NULL handshake - send READY command// For now, empty dictionaryputs(I: have full greeting from peer);zmtp_msg_t ready {0x04, 0x19};std::string data;data.push_back(0x05);data.append(READY);data.push_back(0x0b);data.append(Socket-Type);int netByteOrderSize htonl(3);const char *valueBytes reinterpret_castconst char *(netByteOrderSize);data.append(valueBytes, sizeof(netByteOrderSize));data.append(SUB);memcpy(ready.data, data.c_str(), data.size());puts(I: sending READY);zmtp_send(peer, ready);// Now wait for peers READY commandputs(I: expecting READY from peer);zmtp_recv(peer, ready);//assert(memcmp(ready.data, READY , 8) 0);puts(I: OK! NULL security handshake completed);puts(I: send sub command);zmtp_msg_t subCmd {0x00, 0x01};subCmd.data[0] 0x01;zmtp_send(peer, subCmd);}else{puts(E: major version not valid);closesocket(peer);exit(0);}puts(I: READY, printing messages);while (true){zmtp_msg_t msg;zmtp_recv(peer, msg);msg.data[msg.size] 0;puts((char *) msg.data);}closesocket(peer);return 0;
}
