概述

在w5500基础库中进行封装，通过域名的方式获取实际的ip地址
用于动态获取ntp的ip地址

DNS封装

头文件

/*******************************************************************************Copyright (c) [scl]。保留所有权利。******************************************************************************/
#ifndef F1XX_TEMPLATE_W5500_DNS_H
#define F1XX_TEMPLATE_W5500_DNS_H#include "socket.h"#define TYPE_A 1      /* Host address */
#define TYPE_NS 2      /* Name server */
#define TYPE_MD 3      /* Mail destination (obsolete) */
#define TYPE_MF 4      /* Mail forwarder (obsolete) */
#define TYPE_CNAME 5  /* Canonical name */
#define TYPE_SOA 6      /* Start of Authority */
#define TYPE_MB 7      /* Mailbox name (experimental) */
#define TYPE_MG 8      /* Mail group member (experimental) */
#define TYPE_MR 9      /* Mail rename name (experimental) */
#define TYPE_NULL 10  /* Null (experimental) */
#define TYPE_WKS 11      /* Well-known sockets */
#define TYPE_PTR 12      /* Pointer record */
#define TYPE_HINFO 13 /* Host information */
#define TYPE_MINFO 14 /* Mailbox information (experimental)*/
#define TYPE_MX 15      /* Mail exchanger */
#define TYPE_TXT 16      /* Text strings */
#define TYPE_ANY 255  /* Matches any type */
#define MAX_DNS_BUF_SIZE 256 /* maximum size of DNS buffer. *//*** @memberof delay_ms_cb 毫秒延迟回调* @memberof dns_server_ip: dns 服务ip* @memberof dns_port: dns 端口,默认53*/
struct dns_conf {void (*delay_ms_cb)(uint32_t ms);uint8_t dns_server_ip[4];uint16_t dns_port;
};void dns_config_set(struct dns_conf *cnf);
/**** @param s socket num* @param domain_name 服务域名* @param dst_ip [out] 保存解析的数据* @param wait_ms [in] 发送请求后等待时间* @return*/
bool do_dns(SOCKET s, uint8_t *domain_name, uint8_t *dst_ip, uint32_t wait_ms);#endif //F1XX_TEMPLATE_W5500_DNS_H

源文件

/*******************************************************************************Copyright (c) [scl]。保留所有权利。******************************************************************************/
#include "w5500_dns.h"#define DBG_ENABLE
#define DBG_SECTION_NAME "dns"
#define DBG_LEVEL DBG_INFO // DBG_LOG DBG_INFO DBG_WARNING DBG_ERROR#include "sys_dbg.h"/* Header for all domain messages */
struct dhdr {uint16_t id; /* Identification */uint8_t qr;  /* Query/Response */uint8_t opcode;uint8_t aa;     /* Authoratative answer */uint8_t tc;     /* Truncation */uint8_t rd;     /* Recursion desired */uint8_t ra;     /* Recursion available */uint8_t rcode; /* Response code */uint16_t qdcount; /* Question count */uint16_t ancount; /* Answer count */uint16_t nscount; /* Authority (name server) count */uint16_t arcount; /* Additional record count */
};static uint8_t DNS_BUF[MAX_DNS_BUF_SIZE] = {0};
static struct dhdr dhp = {0}; /*定义一个结构体用来包含报文头信息*/
static uint16_t MSG_ID = 0x1122;
struct dns_conf *cnf_ptr = NULL;static int dns_packet_build(uint16_t op, uint8_t *name, uint8_t *buf, uint16_t len);static bool parse_DNS_Response(struct dhdr *pdhdr, uint8_t *pbuf, uint8_t *dst_result_ip);static uint8_t *dns_question(uint8_t *msg, uint8_t *cp);static uint8_t *dns_answer(uint8_t *msg, uint8_t *cp, uint8_t *dst_result_ip);static int16_t parse_name(uint8_t *msg, uint8_t *compressed, uint16_t len);void dns_config_set(struct dns_conf *cnf) {cnf_ptr = cnf;
}/*** dns 解析* @param s* @param domain_name 域名* @return*/
bool do_dns(SOCKET s, uint8_t *domain_name, uint8_t *dst_ip, uint32_t wait_ms) {if (cnf_ptr == NULL) {LOG_E("dns_config_set not set");goto _exit_false;}if (udp_client_init(s, cnf_ptr->dns_port)) {uint16_t len = dns_packet_build(0, domain_name, DNS_BUF, MAX_DNS_BUF_SIZE);sendto(s, DNS_BUF, len, cnf_ptr->dns_server_ip, cnf_ptr->dns_port); /*发送DNS请求报文给DNS服务器*/for (int i = 0; i < wait_ms / 2; ++i) {len = w5500_socket_rx_size_read(s);if (len > 0) break;cnf_ptr->delay_ms_cb(2);}if (len > 0) {if (len > MAX_DNS_BUF_SIZE) len = MAX_DNS_BUF_SIZE;recvfrom_simple(s, DNS_BUF, len);if (parse_DNS_Response(&dhp, DNS_BUF, dst_ip)) {close(s);/*关闭socket*/return true;/*返回DNS解析成功域名信息*/} else {LOG_W("parse_DNS_Response err");}} else {LOG_D("w5500_socket_rx_size_read not rec data");}} else {LOG_W("udp_client_init error");}_exit_false:return false;
}static int dns_packet_build(uint16_t op, uint8_t *name, uint8_t *buf, uint16_t len) {uint8_t *cp = buf;uint8_t *cp1;uint8_t *dname;uint16_t p;uint16_t dlen;MSG_ID++;*(uint16_t *) &cp[0] = htons(MSG_ID);p = (op << 11) | 0x0100;*(uint16_t *) &cp[2] = htons(p);*(uint16_t *) &cp[4] = htons(1);*(uint16_t *) &cp[6] = htons(0);*(uint16_t *) &cp[8] = htons(0);*(uint16_t *) &cp[10] = htons(0);cp += sizeof(uint16_t) * 6;dname = name;dlen = strlen((char *) dname);for (;;) {/* Look for next dot */cp1 = (unsigned char *) strchr((char *) dname, '.');if (cp1) {/* More to come */len = cp1 - dname;} else {len = dlen; /* Last component */}*cp++ = len;   /* Write length of component */if (len == 0) break;strncpy((char *) cp, (char *) dname, len);/* Copy component up to (but not including) dot */cp += len;if (!cp1) {*cp++ = 0;                                                                                                                    /* Last one; write null and finish */break;}dname += len + 1;dlen -= len + 1;}*(uint16_t *) &cp[0] = htons(0x0001);    /* type */*(uint16_t *) &cp[2] = htons(0x0001);    /* class */cp += sizeof(uint16_t) * 2;return ((int) ((uint32_t) (cp) - (uint32_t) (buf)));}static bool parse_DNS_Response(struct dhdr *pdhdr, uint8_t *pbuf, uint8_t *dst_result_ip) {uint16_t tmp = 0, i = 0;uint8_t *msg = NULL, *cp = NULL;msg = pbuf;memset(pdhdr, 0, sizeof(struct dhdr));pdhdr->id = ntohs(*((uint16_t *) &msg[0]));tmp = ntohs(*((uint16_t *) &msg[2]));if (tmp & 0x8000)pdhdr->qr = 1;pdhdr->opcode = (tmp >> 11) & 0xf;if (tmp & 0x0400)pdhdr->aa = 1;if (tmp & 0x0200)pdhdr->tc = 1;if (tmp & 0x0100)pdhdr->rd = 1;if (tmp & 0x0080)pdhdr->ra = 1;pdhdr->rcode = tmp & 0xf;pdhdr->qdcount = ntohs(*((uint16_t *) &msg[4]));pdhdr->ancount = ntohs(*((uint16_t *) &msg[6]));pdhdr->nscount = ntohs(*((uint16_t *) &msg[8]));pdhdr->arcount = ntohs(*((uint16_t *) &msg[10]));/* Now parse the variable length sections */cp = &msg[12];/* Question section */for (i = 0; i < pdhdr->qdcount; i++) {cp = dns_question(msg, cp);}/* Answer section */for (i = 0; i < pdhdr->ancount; i++) {cp = dns_answer(msg, cp, dst_result_ip);}/* Name server (authority) section */for (i = 0; i < pdhdr->nscount; i++) { ;}/* Additional section */for (i = 0; i < pdhdr->arcount; i++) { ;}if (pdhdr->rcode == 0)return 1;elsereturn 0;
}/**
*@brief		 解析回复消息的问询记录
*@param		 msg - 指向回复信息的指针cp  - 指向问询记录的指针
*@return	 返回下一个记录指针
*/
uint8_t *dns_question(uint8_t *msg, uint8_t *cp) {int16_t len = parse_name(msg, cp, MAX_DNS_BUF_SIZE);if (len == -1)return 0;cp += len;cp += 2; /* type */cp += 2; /* class */return cp;
}static uint8_t *dns_answer(uint8_t *msg, uint8_t *cp, uint8_t *dst_result_ip) {int16_t len, type;len = parse_name(msg, cp, /*name,*/ MAX_DNS_BUF_SIZE);if (len == -1)return 0;cp += len;type = ntohs(*((uint16_t *) &cp[0]));cp += 2; /* type */cp += 2; /* class */cp += 4; /* ttl */cp += 2; /* len */switch (type) {case TYPE_A:dst_result_ip[0] = *cp++;dst_result_ip[1] = *cp++;dst_result_ip[2] = *cp++;dst_result_ip[3] = *cp++;break;case TYPE_CNAME:case TYPE_MB:case TYPE_MG:case TYPE_MR:case TYPE_NS:case TYPE_PTR:/* These types all consist of a single domain name *//* convert it to ascii format */len = parse_name(msg, cp, MAX_DNS_BUF_SIZE);if (len == -1)return 0;cp += len;break;case TYPE_HINFO:len = *cp++;cp += len;len = *cp++;cp += len;break;case TYPE_MX:cp += 2;/* Get domain name of exchanger */len = parse_name(msg, cp, MAX_DNS_BUF_SIZE);if (len == -1)return 0;cp += len;break;case TYPE_SOA:/* Get domain name of name server */len = parse_name(msg, cp, MAX_DNS_BUF_SIZE);if (len == -1)return 0;cp += len;/* Get domain name of responsible person */len = parse_name(msg, cp, MAX_DNS_BUF_SIZE);if (len == -1)return 0;cp += len;cp += 4;cp += 4;cp += 4;cp += 4;cp += 4;break;case TYPE_TXT:/* Just stash */break;default:/* Ignore */break;}return cp;
}static int16_t parse_name(uint8_t *msg, uint8_t *compressed, uint16_t len) {static int8_t name[MAX_DNS_BUF_SIZE];uint16_t slen = 0; /* Length of current segment */uint8_t *cp = NULL;int16_t clen = 0;     /* Total length of compressed name */int16_t indirect = 0; /* Set if indirection encountered */int16_t nseg = 0;     /* Total number of segments in name */int8_t *buf = NULL;buf = name;cp = compressed;for (;;) {slen = *cp++; /* Length of this segment */if (!indirect)clen++;if ((slen & 0xc0) == 0xc0) {if (!indirect)clen++;indirect = 1;/* Follow indirection */cp = &msg[((slen & 0x3f) << 8) + *cp];slen = *cp++;}if (slen == 0) /* zero length == all done */break;len -= slen + 1;if (len <= 0)return -1;if (!indirect)clen += slen;while (slen-- != 0)*buf++ = (int8_t) *cp++;*buf++ = '.';nseg++;}if (nseg == 0) /* Root name; represent as single dot */{*buf++ = '.';len--;}*buf++ = '\0';len--;return clen; /* Length of compressed message */
}

测试

配置文件

/********************************************************************************  Copyright (c) [scl]。保留所有权利。*     本文仅供个人学习和研究使用，禁止用于商业用途。******************************************************************************/#include "app_conf.h"
#include "w5500_config.h"#if APP_CONFIG_W5500
#define DBG_ENABLE
#define DBG_SECTION_NAME "w5500"
#define DBG_LEVEL W5500_DBG_LEVEL#include "sys_dbg.h"
#include "w5500_dns.h"
#include "w5500_ntp.h"#define W5500_CS stm_port_define(B,12)
#define W5500_RST stm_port_define(C,7)extern struct net_date_time gb_app_time;static SPI_HandleTypeDef *w5500_spi = NULL;static void send_and_rec_bytes(uint8_t *in_dat, uint8_t *out_data, uint16_t len) {while (HAL_SPI_GetState(w5500_spi) != HAL_SPI_STATE_READY);HAL_SPI_TransmitReceive(w5500_spi, in_dat, out_data, len, 1000);while (HAL_SPI_GetState(w5500_spi) != HAL_SPI_STATE_READY);
}static void send_only(uint8_t *in_data, uint16_t len) {HAL_SPI_Transmit(w5500_spi, in_data, len, 1000);
}static void W5500_RST_HIGH(void) { stm_pin_high(W5500_RST); }static void W5500_RST_LOW(void) { stm_pin_low(W5500_RST); }static void W5500_CS_LOW(void) { stm_pin_low(W5500_CS); }static void W5500_CS_HIGH(void) { stm_pin_high(W5500_CS); }static void W5500_Driver_MspInit(void) {stm32_pin_mode(W5500_CS, pin_mode_output);  /*CS*/stm32_pin_mode(W5500_RST, pin_mode_output); /*RST*/stm_pin_low(W5500_RST);stm_pin_low(W5500_CS);/*初始化SPI外设*//*W5500 支持 SPI 模式 0 及模式 3..MOSI 和 MISO 信号无论是接收或发送，均遵从从最高标志位（MSB）到最低标志位（LSB）的传输序列。*/bsp_SpiHandleInit(w5500_spi, SPI_BAUDRATEPRESCALER_2, spi_mode_3);
}module_w5500_t w5500_conf = {.base_conf={.socket_num = 4,.rx_size={4, 4, 4, 4},.tx_size={4, 4, 4, 4},},.net_conf={.ip={192, 168, 199, 12},.gw={192, 168, 199, 1},.sub={255, 255, 255, 0},},.driver={.cs_high = W5500_CS_HIGH,.cs_low = W5500_CS_LOW,.rst_high= W5500_RST_HIGH,.rst_low=W5500_RST_LOW,.delay = HAL_Delay,.send_and_rec_bytes = send_and_rec_bytes,.send_only =send_only},.api = {.msp_init=W5500_Driver_MspInit,}
};
uint8_t ntp_domain[] = {"ntp.ntsc.ac.cn"}; /*ntp域名*/
static struct dns_conf net_dns_cnf = { /*dns服务配置*/.dns_server_ip={114, 114, 114, 114},.dns_port = 53,.delay_ms_cb = HAL_Delay
};
static struct ntp_conf net_ntp_conf = {
//        .ntp_server={114, 118, 7, 163},.ntp_port = 123,.delay_ms_cb = HAL_Delay
};static void w5500_pre_init(void) {/*一般做数据加载，此时系统时钟使用的是内部时钟，如需要使用系统时钟的外设不在此进行初始化*/w5500_spi = conv_spi_handle_ptr(handle_get_by_id(spi2_id));/*初始化资源*/module_w5500_init(&w5500_conf);uint32_t uid0 = HAL_GetUIDw0();uint32_t uid1 = HAL_GetUIDw1();uint32_t uid2 = HAL_GetUIDw2();uint8_t mac[6] = {0, uid0 >> 8, uid1, uid1 >> 8, uid2, uid2 >> 8};memcpy(w5500_conf.net_conf.mac, mac, sizeof(mac));}static void w5500_init(void) {w5500_conf.api.msp_init();/*初始化*/w5500_conf.net_conf_init();uint8_t ip[4];w5500_reg_ip_read(ip);LOG_D("w5500_reg_ip_read:%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);w5500_reg_gw_read(ip);LOG_D("w5500_reg_gw_read:%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);
}static void w5500_after_init(void) {uint8_t try_cnt = 3;// 尝试次数SOCKET sn = 1;/*使用的socket*/
#if APP_CONFIG_W5500_DNS // 启用dnsfor (int i = 0; i < try_cnt; ++i) {dns_config_set(&net_dns_cnf);if (do_dns(sn, ntp_domain, net_ntp_conf.ntp_server, 500)) {LOG_D("dns parse result ip:%d.%d.%d.%d",net_ntp_conf.ntp_server[0], net_ntp_conf.ntp_server[1],net_ntp_conf.ntp_server[2], net_ntp_conf.ntp_server[3]);goto next_step; /*解析成功跳转下一步*/}}LOG_D("do dns try cnt over");return;next_step:#endif#if APP_CONFIG_W5500_NTP // 启用ntpntp_config_set(&net_ntp_conf);for (int i = 0; i < try_cnt; ++i) {if (ntp_date_time_get(sn, 500, &gb_app_time)) {HAL_TIM_Base_Start_IT(handle_get_by_id(tim6_id));goto exit_ok;}}LOG_W("ntp_date_time_get time out");return;exit_ok:LOG_D("NTP TIME：%d-%02d-%02d %02d:%02d:%02d",gb_app_time.year, gb_app_time.month, gb_app_time.day,gb_app_time.hour, gb_app_time.min, gb_app_time.sec);
#elsereturn;
#endif
}app_init_export(w5500_net_conf, w5500_pre_init, w5500_init, w5500_after_init);
#endif