MAC中.DS_store去除和关闭方法

最新推荐文章于 2025-09-11 00:52:44 发布
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本文介绍如何使用命令行工具批量删除Mac系统中产生的.DS_Store隐藏文件，并提供了设置选项来避免再次生成此类文件的方法。

一、删除所有隐藏.DS_store文件

sudo find / -name ".DS_Store" -depth -exec rm {} \;

二、设置不再产生.DS_store文件选项

defaults write com.apple.desktopservices DSDontWriteNetworkStores true

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NSD_DEBUG("[DHCPS]" fmt, ##__VA_ARGS__) #define DHCPS_INFO(fmt, ...) NSD_LOG(LOG_INFO, "[Network][DHCP]" fmt, ##__VA_ARGS__) #define DHCPS_WARN(fmt, ...) NSD_WARN("[DHCPS]" fmt, ##__VA_ARGS__) #endif /* dhcps.c * * udhcp Server * Copyright (C) 1999 Matthew Ramsay <matthewr@moreton.com.au> * Chris Trew <ctrew@moreton.com.au> * * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <netinet/if_ether.h> #include <linux/filter.h> #include <linux/if_packet.h> #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <string.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <unistd.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include "options.h" #include "packet.h" #include "dhcp.h" #include "dhcps.h" #include "libds.h" /* DHCPS模块中各个参数项单位都改为秒 */ #define LEASE_TIME_MAX (48*60*60) /* 租期最长2天 */ #define LEASE_TIME_MIN (1*60) /* 租期最短一分钟 */ #define LEASE_OFFER_TIME (2*60*60) #define DECLINE_TIME (60*60) #define CONFLICT_TIME (60*60) #define DHCP_CHANGE_RECEIVE_PORT 52261 #define DHCP_CHANGE_SEND_PORT 52262 #define DEFAULT_DHCPS_IP "192.168.191.1" #define DEFAULT_DHCPS_MASK "255.255.255.0" #define DEF_DHCPS_IP_BEGIN "192.168.191.120" #define DEF_DHCPS_IP_END "192.168.191.199" #define DHCPS_HOST_NAME_LEN 32 #define DHCPS_OPTION_AUTO "auto" #define DHCPS_OPTION_ENABLE "enable" #define DHCPS_OPTION_POOLSTART "pool_start" #define DHCPS_OPTION_POOLEND "pool_end" #define DHCPS_OPTION_LEASETIME "lease_time" #define DHCPS_OPTION_GATEWAY "gateway" #define DHCPS_OPTION_PRIDNS "pri_dns" #define DHCPS_OPTION_SNDDNS "snd_dns" #define DHCPS_OPTION_IP "ip" #define DHCPS_OPTION_MAC "mac" #define DHCPS_OPTION_EXPIRES "expires" #define DHCPS_OPTION_HOSTNAME "hostname" DHCPS_PARAMS dhcps_params; LOCAL struct dhcp_packet recv_dhcp_packet; LOCAL struct dhcp_packet packet; #define DHCPS_MALLOC(size) malloc(size) #define DHCPS_FREE(addr) free((UINT8*)(addr)) #define ISNOTSAMESUBNET(ip1, ip2, mask) (0 != (((ip1) ^ (ip2)) & (mask))) /* 是否4G IPC - 4G上网模式 */ LOCAL U16 get_lte_enabled(void) { LTE_CAPABILITY lte_cap = {0}; LTE_CONFIG_INFO_DATA lte_config = {0}; if (0 == ds_read(LTE_CAPABILITY_PATH, (U8 *)&lte_cap, sizeof(lte_cap))) { //未定义lte_capability，判断为非4G IPC，未开启4G上网模式 return 0; } if (0 == ds_read(LTE_INFO_DATA_PATH, (U8 *)&lte_config, sizeof(lte_config))) { //4G IPC默认4G上网模式，获取失败时按照4G上网处理 return 1; } return !(lte_cap.internet_wired_support && lte_config.internet_wired_enable); } /* clear every lease out that chaddr OR yiaddr matches and is nonzero */ LOCAL void clear_lease(U8 *mac, U32 ip, DHCPS_LEASE *leases) { S32 i, j, k; for (j = 0; j < CHADDR_LEN && !mac[j]; j++); for (i = 0; i < DHCPS_LEASE_LIST_SIZE; i++) { if ((j != CHADDR_LEN && !memcmp(leases[i].mac, mac, 6)) || (ip && leases[i].ip == ip)) { memset(&(leases[i]), 0, sizeof(leases[i])); for (k = i;(k + 1) < DHCPS_LEASE_LIST_SIZE; k++) { memcpy(&(leases[k]), &(leases[k + 1]), sizeof(leases[k])); memset(&(leases[k + 1]), 0, sizeof(leases[k + 1])); } i--; } } } /* Find the oldest expired lease, NULL if there are no expired leases */ LOCAL S32 oldest_expired_lease(DHCPS_LEASE *leases) { U32 i; for (i = 0; i < DHCPS_LEASE_LIST_SIZE; i++) { if (leases[i].expires == 0) { return i; } } return -1; } /* add a lease into the table, clearing out any old ones */ LOCAL S32 add_lease(U32 state, char *host_name, U8 *mac, U32 ip, U32 time_lease, DHCPS_LEASE *dhcps_lease) { S32 lease_index = -1 ; IP_ADDR ipAddr = {0}; /* clean out any old ones */ clear_lease(mac, ip, dhcps_lease); lease_index = oldest_expired_lease(dhcps_lease); if (lease_index != -1) { dhcps_lease[lease_index].state = state; DHCPS_DEBUG("state = %d", dhcps_lease[lease_index].state); memcpy(dhcps_lease[lease_index].host_name, host_name, 32); /* add by Li Shaozhang, 07Jun07 */ DHCPS_DEBUG("hostname = %s", dhcps_lease[lease_index].host_name); memcpy(dhcps_lease[lease_index].mac, mac, 6); DHCPS_DEBUG("mac = %02x-%02x-%02x-%02x-%02x-%02x", dhcps_lease[lease_index].mac[0],\ dhcps_lease[lease_index].mac[1], dhcps_lease[lease_index].mac[2],\ dhcps_lease[lease_index].mac[3], dhcps_lease[lease_index].mac[4],\ dhcps_lease[lease_index].mac[5]); dhcps_lease[lease_index].ip = ip; ipAddr.ipAddr = ip; DHCPS_DEBUG("ip = %d.%d.%d.%d", ipAddr.ipAddrByteFormat[0], ipAddr.ipAddrByteFormat[1], ipAddr.ipAddrByteFormat[2], ipAddr.ipAddrByteFormat[3]); dhcps_lease[lease_index].expires = time_lease; DHCPS_DEBUG("lease = %d", dhcps_lease[lease_index].expires); } return lease_index; } /* true if a lease has expired */ LOCAL S32 lease_expired(S32 lease_index, DHCPS_LEASE *dhcps_lease) { return (dhcps_lease[lease_index].expires == 0); } /* * Find the first lease that matches chaddr, NULL if no match. * Modified by xcl, if the lease ip is not in the same subnet, deleted it and return null. */ LOCAL S32 find_lease_by_mac(U8 *mac, DHCPS_LEASE *dhcps_lease) { U32 i; for (i = 0; i < DHCPS_LEASE_LIST_SIZE; i++) { if (!memcmp(dhcps_lease[i].mac, mac, 6)) { /* If not in the very subnet, delete this lease. 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ciaddr = payload->ciaddr; chaddr = payload->chaddr; } else { ciaddr = payload->yiaddr; chaddr = payload->chaddr; } return make_and_send_dhcp_frame(payload, dhcps_params.server, SERVER_PORT, ciaddr, CLIENT_PORT, chaddr, dhcps_params.dev); } LOCAL void init_packet(struct dhcp_packet *packet, struct dhcp_packet *old_packet, char type) { init_header(packet, type); packet->xid = old_packet->xid; memcpy(packet->chaddr, old_packet->chaddr, CHADDR_LEN); packet->flags = old_packet->flags; packet->giaddr = old_packet->giaddr; packet->ciaddr = old_packet->ciaddr; add_simple_option(packet->options, DHCP_SERVER_ID, dhcps_params.server); } /* add in the bootp options */ LOCAL void add_bootp_options(struct dhcp_packet *packet) { packet->siaddr = dhcps_params.siaddr; if (dhcps_params.sname) { strncpy((char *)packet->sname, dhcps_params.sname, sizeof(packet->sname) - 1); } if (dhcps_params.boot_file) { strncpy((char *)packet->file, dhcps_params.boot_file, sizeof(packet->file) - 1); } } LOCAL S32 get_host_name_len(char* name, S32 len) { S32 index = 0; S32 language_flag = 0; if (len < 32) { return len; } for (index=0; index < 31; index++) { /* GB2312编码每个汉字及符号以两个字节来表示，高位字节使用了0xA1-0xF7，低位字节使用了0xA1-0xFE。*/ /* 为保障存储汉字不出现乱码，出现奇数个大于0xA1的字节时，去掉最后一个。这种方法只能解决采用 */ /* GB2312编码的乱码问题 */ if (*(UINT8*)(name + index) >= 0xA1) { language_flag ^= 1; } } if (language_flag == 0) { return 31; } return 30; } /* send a DHCP OFFER to a DHCP DISCOVER */ LOCAL S32 send_offer(struct dhcp_packet *old_packet, DHCPS_LEASE *dhcps_lease) { S32 lease_index = -1; U32 req_align, lease_time_align = dhcps_params.lease_time; U8 *req, *lease_time; char blank_hostname[] = /*"Unknown"*/""; S32 copy_host_name_len; IP_ADDR ip_addr = {0}; char host_name[DHCPS_HOST_NAME_LEN]; char *host_name_start, *host_name_len; U32 lease_ip; DHCPS_DEBUG("before init_packet."); init_packet(&packet, old_packet, DHCPOFFER); /* the client has a requested ip */ if ((req = get_option(old_packet, DHCP_REQUESTED_IP)) && memcpy(&req_align, req, 4) && ip_in_srv_pool(req_align) && (((-1 == (lease_index = find_lease_by_ip(req_align, dhcps_lease))) || lease_expired(lease_index, dhcps_lease)))) { lease_ip = req_align; if (TRUE == check_ip(lease_ip, dhcps_lease)) { goto choose_dynamic_lease_ip; } packet.yiaddr = lease_ip; goto send_offer; } choose_dynamic_lease_ip: lease_index = find_lease_by_mac(old_packet->chaddr, dhcps_lease); if (-1 != lease_index) { /* lease的时间到期或者ip已经不在地址池中。 */ if ((FALSE == ip_in_srv_pool(dhcps_lease[lease_index].ip)) || lease_expired(lease_index, dhcps_lease)) { memset(&(dhcps_lease[lease_index]), 0, sizeof(dhcps_lease[lease_index])); lease_index = -1; goto choose_pool_ip; } lease_time_align = dhcps_lease[lease_index].expires; packet.yiaddr = dhcps_lease[lease_index].ip; goto send_offer; } choose_pool_ip: packet.yiaddr = find_address(0, dhcps_lease); if (0 == packet.yiaddr) { packet.yiaddr = find_address(1, dhcps_lease); } if(0 == packet.yiaddr) { DHCPS_WARN("No ip addresses to give, OFFER abandoned."); return -1; } send_offer: if (0xFFFFFFFF != lease_time_align) /* 非静态条目。 */ { if (!(host_name_start = (char *)get_option(old_packet, DHCP_HOST_NAME))) { DHCPS_WARN("Lease host name not found."); /* host_name_start = blank_hostname;*/ memset(host_name, 0, DHCPS_HOST_NAME_LEN); memcpy(host_name, blank_hostname, strlen(blank_hostname)); } else { host_name_len = host_name_start - OPT_LEN; memset(host_name, 0, DHCPS_HOST_NAME_LEN); /* fix host name length bug by tiger 20091208 */ copy_host_name_len = get_host_name_len(host_name_start, *host_name_len); memcpy(host_name, host_name_start, copy_host_name_len); } if (-1 == add_lease(DHCPOFFER, host_name, packet.chaddr, packet.yiaddr, dhcps_params.offer_time, dhcps_lease)) { DHCPS_WARN("Lease pool is full, OFFER abandoned."); return -1; } if ((lease_time = get_option(old_packet, DHCP_LEASE_TIME))) { memcpy(&lease_time_align, lease_time, 4); DHCPS_DEBUG("lease time = %d ", lease_time); lease_time_align = ntohl(lease_time_align); if (lease_time_align > (dhcps_params.lease_time*60)) { lease_time_align = (dhcps_params.lease_time*60); } } /* Make sure we aren't just using the lease time from the previous offer */ if (lease_time_align < dhcps_params.min_lease) { lease_time_align = dhcps_params.lease_time; } } DHCPS_DEBUG("OFFER lease time = %d; configed dhcp lease = %d\n", lease_time_align, dhcps_params.lease_time); add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_align)); add_option_string(packet.options, dhcps_params.options.dns); add_option_string(packet.options, dhcps_params.options.subnet); add_option_string(packet.options, dhcps_params.options.router); if(dhcps_params.is_lte) { DHCPS_DEBUG("OFFER: lte enabled\n"); add_option_string(packet.options, dhcps_params.options.router4g); } /*addVendorSpecInfo(oldpacket, packet.options);*/ add_bootp_options(&packet); ip_addr.ipAddr = packet.yiaddr; DHCPS_INFO("Send OFFER with ip %d.%d.%d.%d.", ip_addr.ipAddrByteFormat[0], ip_addr.ipAddrByteFormat[1], ip_addr.ipAddrByteFormat[2], ip_addr.ipAddrByteFormat[3]); return send_packet(&packet, 0); } LOCAL S32 send_NAK(struct dhcp_packet *old_packet) { init_packet(&packet, old_packet, DHCPNAK); return send_packet(&packet, 1); } LOCAL S32 send_ACK(struct dhcp_packet *old_packet, U32 ip, DHCPS_LEASE *dhcps_lease) { U8 *lease_time; U32 lease_time_align = dhcps_params.lease_time; char blank_hostname[] = /*"Unknown"*/""; IP_ADDR ipAddr = {0}; U8 host_name[DHCPS_HOST_NAME_LEN]; U8 *host_name_start = NULL; U8 *host_name_len = NULL; S32 copy_host_name_len = 0; init_packet(&packet, old_packet, DHCPACK); packet.yiaddr = ip; if ((lease_time = get_option(old_packet, DHCP_LEASE_TIME))) { memcpy(&lease_time_align, lease_time, 4); lease_time_align = ntohl(lease_time_align); if ((lease_time_align < dhcps_params.min_lease) || (lease_time_align > dhcps_params.lease_time)) { lease_time_align = dhcps_params.lease_time; } } DHCPS_DEBUG("ACK lease time = %d\n", lease_time_align); add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_align)); add_option_string(packet.options, dhcps_params.options.dns); add_option_string(packet.options, dhcps_params.options.subnet); add_option_string(packet.options, dhcps_params.options.router); if(dhcps_params.is_lte) { DHCPS_DEBUG("ACK: lte enabled\n"); add_option_string(packet.options, dhcps_params.options.router4g); } /*addVendorSpecInfo(oldpacket, packet.options);*/ add_bootp_options(&packet); ipAddr.ipAddr = packet.yiaddr; DHCPS_DEBUG("Send ACK to %d.%d.%d.%d.", ipAddr.ipAddrByteFormat[0], ipAddr.ipAddrByteFormat[1], ipAddr.ipAddrByteFormat[2], ipAddr.ipAddrByteFormat[3]); /* TODO:只在请求OFFER时输出信息 */ if (send_packet(&packet, 0) < 0) { return -1; } if (!(host_name_start = get_option(old_packet, DHCP_HOST_NAME))) { DHCPS_DEBUG("Lease host name not found."); /* TODO:只在请求OFFER时输出信息 */ memset(host_name, 0, DHCPS_HOST_NAME_LEN); memcpy(host_name, blank_hostname, strlen(blank_hostname)); } else { /* fix host name length bug by tiger 20091208 */ host_name_len = host_name_start - OPT_LEN; copy_host_name_len = get_host_name_len((char *)host_name_start, (int)*host_name_len); if(copy_host_name_len > DHCPS_HOST_NAME_LEN) { return -1; } memset(host_name, 0, DHCPS_HOST_NAME_LEN); memcpy(host_name, host_name_start, copy_host_name_len); } add_lease(DHCPACK, (char *)host_name, packet.chaddr, packet.yiaddr, lease_time_align, dhcps_lease); return OK; } LOCAL S32 send_inform(struct dhcp_packet *old_packet) { init_packet(&packet, old_packet, DHCPACK); add_option_string(packet.options, dhcps_params.options.dns); add_option_string(packet.options, dhcps_params.options.subnet); add_option_string(packet.options, dhcps_params.options.router); if(dhcps_params.is_lte) { DHCPS_DEBUG("INFORM: lte enabled\n"); add_option_string(packet.options, dhcps_params.options.router4g); } add_bootp_options(&packet); return send_packet(&packet, 0); } LOCAL S32 check_and_ack(struct dhcp_packet* packet, UINT32 ip, DHCPS_LEASE *dhcps_lease) { IP_ADDR ip_addr1 = {0}; ip_addr1.ipAddr = ip; /* if some one reserve it */ if (ip != packet->ciaddr && check_ip(ip, dhcps_lease)) { DHCPS_INFO("REQUEST ip %d.%d.%d.%d already reserved by someone", ip_addr1.ipAddrByteFormat[0], ip_addr1.ipAddrByteFormat[1], ip_addr1.ipAddrByteFormat[2] ,ip_addr1.ipAddrByteFormat[3]); return send_NAK(packet); } if (!ip_in_srv_pool(ip)) { DHCPS_INFO("REQUEST ip %d.%d.%d.%d is not in the address pool", ip_addr1.ipAddrByteFormat[0], ip_addr1.ipAddrByteFormat[1], ip_addr1.ipAddrByteFormat[2] ,ip_addr1.ipAddrByteFormat[3]); return send_NAK(packet); } return send_ACK(packet, ip, dhcps_lease); } LOCAL void destroy_sock(S32 sock) { if (-1 != sock) { close(sock); } } LOCAL S32 create_sock() { struct sockaddr_in sock_addr; S32 option = 1; S32 sock = -1; /* 因为MAX_GROUP_NUM为1，而且这里也只有1份DHCP服务器配置，这里就暂不考虑为多网段提供DHCP服务了。 */ if (ERROR == (sock = socket(AF_INET, SOCK_DGRAM, 0))) { DHCPS_WARN("server socket call failed: %m"); goto error_exit; } if (ERROR == setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&option, sizeof(option))) { DHCPS_WARN("server socket set reuseaddr option failed: %m"); goto error_exit; } if (ERROR == setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char *) &option, sizeof(option))) { DHCPS_WARN("server socket set broadcast option failed: %m"); goto error_exit; } memset(&sock_addr, 0, sizeof(sock_addr)); sock_addr.sin_family = AF_INET; sock_addr.sin_port = htons(SERVER_PORT); sock_addr.sin_addr.s_addr = INADDR_ANY; /* 这里只是针对单个网段提供服务，可以这样做，但如果考虑多网段，多接口，则必须绑定接口的实际地址。 */ if (ERROR == bind(sock, (struct sockaddr *)&sock_addr, sizeof(sock_addr))) { DHCPS_WARN("server socket set broadcast option failed: %m"); goto error_exit; } return sock; error_exit: destroy_sock(sock); return -1; } LOCAL void dhcps_check_timer() { U32 index = 0; U32 move_index = 0; DHCPS_LEASE *dhcps_lease = NULL; dhcps_lease = dhcps_params.lease; for (index = 0; index < DHCPS_LEASE_LIST_SIZE; index++) { if (dhcps_lease[index].ip == 0 || dhcps_lease[index].expires == 0xFFFFFFFF) { continue; } if (dhcps_lease[index].expires > 0) { dhcps_lease[index].expires -= 1; continue; } for (move_index = index; (move_index + 1) < DHCPS_LEASE_LIST_SIZE; move_index++) { memcpy(&(dhcps_lease[move_index]), &(dhcps_lease[move_index + 1]), sizeof(dhcps_lease[move_index])); memset(&(dhcps_lease[move_index + 1]), 0, sizeof(dhcps_lease[move_index + 1])); } index--; } } LOCAL void dhcps_handle(S32 sock) { U8 *server_id, *requested; U32 server_id_align, requested_align; S32 bytes = 0; U8 *state = NULL; S32 lease_index = -1; DHCPS_LEASE *dhcps_lease = NULL; U32 move_index = 0; IP_ADDR ip_addr1 = {0}; IP_ADDR ip_addr2 = {0}; dhcps_lease = dhcps_params.lease; if ((bytes = get_packet(&recv_dhcp_packet, dhcps_params.sock)) < 0) { DHCPS_WARN("Error on read, %m, reopening socket."); return; } if ((state = get_option(&recv_dhcp_packet, DHCP_MESSAGE_TYPE)) == NULL) { DHCPS_WARN("Couldn't get option from packet, ignoring."); return; } lease_index = find_lease_by_mac(recv_dhcp_packet.chaddr, dhcps_lease); if (-1 != lease_index) { /* 如果租约过期需要老化，或者租约与地址段不匹配，需要强制老化。 */ if ((lease_expired(lease_index, dhcps_lease)) || !ip_in_srv_pool(dhcps_lease[lease_index].ip)) { memset(&(dhcps_lease[lease_index]), 0, sizeof(dhcps_lease[lease_index])); lease_index = -1; } } switch (state[0]) { case DHCPDISCOVER: DHCPS_DEBUG("Recv DISCOVER from %02X:%02X:%02X:%02X:%02X:%02X.", recv_dhcp_packet.chaddr[0], recv_dhcp_packet.chaddr[1], recv_dhcp_packet.chaddr[2], recv_dhcp_packet.chaddr[3], recv_dhcp_packet.chaddr[4], recv_dhcp_packet.chaddr[5]); /* 防止被攻击时持续刷log */ if (send_offer(&recv_dhcp_packet, dhcps_lease) < 0) { DHCPS_WARN("Send OFFER failed."); } break; case DHCPREQUEST: DHCPS_DEBUG("Recv REQUEST from %02X:%02X:%02X:%02X:%02X:%02X.", recv_dhcp_packet.chaddr[0], recv_dhcp_packet.chaddr[1], recv_dhcp_packet.chaddr[2], recv_dhcp_packet.chaddr[3], recv_dhcp_packet.chaddr[4], recv_dhcp_packet.chaddr[5]); requested = get_option(&recv_dhcp_packet, DHCP_REQUESTED_IP); server_id = get_option(&recv_dhcp_packet, DHCP_SERVER_ID); if (NULL != requested) { memcpy(&requested_align, requested, 4); } if (NULL != server_id) { memcpy(&server_id_align, server_id, 4); } if (-1 != lease_index) { /* SELECTING State */ if ((NULL != server_id) && (server_id_align == dhcps_params.server) && (NULL != requested) && (requested_align == dhcps_lease[lease_index].ip)) { send_ACK(&recv_dhcp_packet, dhcps_lease[lease_index].ip, dhcps_lease); } /* INIT-REBOOT State */ else if ((NULL == server_id) && (NULL != requested) && (dhcps_lease[lease_index].ip == requested_align)) { send_ACK(&recv_dhcp_packet, dhcps_lease[lease_index].ip, dhcps_lease); } /* RENEWING or REBINDING State */ else if ((NULL == server_id) && (NULL == requested) && (dhcps_lease[lease_index].ip == recv_dhcp_packet.ciaddr)) { send_ACK(&recv_dhcp_packet, dhcps_lease[lease_index].ip, dhcps_lease); } else { /* todo: 显示有效的requested_align */ ip_addr1.ipAddr = recv_dhcp_packet.ciaddr; ip_addr2.ipAddr = dhcps_lease[lease_index].ip; DHCPS_INFO("Send NAK to %d.%d.%d.%d, lease ip %d.%d.%d.%d.", ip_addr1.ipAddrByteFormat[0], ip_addr1.ipAddrByteFormat[1], ip_addr1.ipAddrByteFormat[2] ,ip_addr1.ipAddrByteFormat[3], ip_addr2.ipAddrByteFormat[0], ip_addr2.ipAddrByteFormat[1],ip_addr2.ipAddrByteFormat[2], ip_addr2.ipAddrByteFormat[3]); send_NAK(&recv_dhcp_packet); } } else if (NULL != requested) { /* INIT-REBOOT State */ if (-1 != (lease_index = find_lease_by_ip(requested_align, dhcps_lease))) { /* Requested IP already reserved by other one */ if (lease_expired(lease_index, dhcps_lease)) { /* probably best if we drop this lease */ memset(&(dhcps_lease[lease_index]), 0, sizeof(dhcps_lease[lease_index])); lease_index = -1; check_and_ack(&recv_dhcp_packet, requested_align, dhcps_lease); /* make some contention for this address */ } else /* still reserved by someone */ { ip_addr1.ipAddr = requested_align; DHCPS_INFO("REQUEST ip %d.%d.%d.%d already reserved by %02X:%02X:%02X:%02X:%02X:%02X", ip_addr1.ipAddrByteFormat[0], ip_addr1.ipAddrByteFormat[1], ip_addr1.ipAddrByteFormat[2], ip_addr1.ipAddrByteFormat[3], dhcps_lease[lease_index].mac[0], dhcps_lease[lease_index].mac[1], dhcps_lease[lease_index].mac[2], dhcps_lease[lease_index].mac[3], dhcps_lease[lease_index].mac[4], dhcps_lease[lease_index].mac[5]); send_NAK(&recv_dhcp_packet); } } else { check_and_ack(&recv_dhcp_packet, requested_align, dhcps_lease); } } else { ip_addr1.ipAddr = recv_dhcp_packet.ciaddr; DHCPS_INFO("Send NAK to %d.%d.%d.%d.", ip_addr1.ipAddrByteFormat[0], ip_addr1.ipAddrByteFormat[1], ip_addr1.ipAddrByteFormat[2], ip_addr1.ipAddrByteFormat[3]); send_NAK(&recv_dhcp_packet); } /* otherwise on reply. */ break; case DHCPDECLINE: DHCPS_INFO("Recv DECLINE from %02X:%02X:%02X:%02X:%02X:%02X.", recv_dhcp_packet.chaddr[0], recv_dhcp_packet.chaddr[1], recv_dhcp_packet.chaddr[2], recv_dhcp_packet.chaddr[3], recv_dhcp_packet.chaddr[4], recv_dhcp_packet.chaddr[5]); if (lease_index != -1) { memset(dhcps_lease[lease_index].mac, 0, 6); dhcps_lease[lease_index].expires = dhcps_params.decline_time; dhcps_lease[lease_index].state = 0; } break; case DHCPRELEASE: DHCPS_INFO("Recv RELEASE from %02X:%02X:%02X:%02X:%02X:%02X.", recv_dhcp_packet.chaddr[0], recv_dhcp_packet.chaddr[1], recv_dhcp_packet.chaddr[2], recv_dhcp_packet.chaddr[3], recv_dhcp_packet.chaddr[4], recv_dhcp_packet.chaddr[5]); if (lease_index != -1) { /* Delete the lease, lsz 080221 */ memset(&(dhcps_lease[lease_index]), 0, sizeof(dhcps_lease[lease_index])); for (move_index = lease_index; (move_index + 1) < DHCPS_LEASE_LIST_SIZE; move_index++) { memcpy(&(dhcps_lease[move_index]), &(dhcps_lease[move_index + 1]), sizeof(dhcps_lease[move_index])); memset(&(dhcps_lease[move_index + 1]), 0, sizeof(dhcps_lease[move_index + 1])); } } break; case DHCPINFORM: DHCPS_DEBUG("Recv INFORM from %02X:%02X:%02X:%02X:%02X:%02X.", recv_dhcp_packet.chaddr[0], recv_dhcp_packet.chaddr[1], recv_dhcp_packet.chaddr[2], recv_dhcp_packet.chaddr[3], recv_dhcp_packet.chaddr[4], recv_dhcp_packet.chaddr[5]); send_inform(&recv_dhcp_packet); break; default: DHCPS_WARN("Unsupported DHCP message (%02x) -- ignoring.", state[0]); } return; } LOCAL S32 dhcps_start_cb(dms_handler_t *handler, U8 *mbuf, U32 mlen, U32 sender_dms_id) { DHCPS_MSG *dhcps_msg = (DHCPS_MSG *)mbuf; U32 temp_ip = 0; IP_ADDR ipaddr; if ((NULL == dhcps_msg) || (mlen != sizeof(DHCPS_MSG))) { return ERROR; } strcpy(dhcps_params.dev_name, dhcps_msg->dev_name); if (0 > read_interface_info(dhcps_params.dev_name, &dhcps_params.dev, dhcps_params.mac)) { DHCPS_DEBUG("Read interface info error"); return ERROR; } if (ntohl(dhcps_msg->pool_start) > ntohl(dhcps_msg->pool_end)) { temp_ip = dhcps_msg->pool_start; dhcps_msg->pool_start = dhcps_msg->pool_end; dhcps_msg->pool_end = temp_ip; } if ((dhcps_msg->pool_start != dhcps_params.start) || (dhcps_msg->pool_end != dhcps_params.end)) { dhcps_params.start= dhcps_msg->pool_start; dhcps_params.end = dhcps_msg->pool_end; memset(dhcps_params.lease, 0, sizeof(DHCPS_LEASE)*DHCPS_LEASE_LIST_SIZE); } dhcps_params.gateway = dhcps_msg->gateway; dhcps_params.lease_time = dhcps_msg->lease_time; dhcps_params.dns_server[0] = dhcps_msg->pri_dns; dhcps_params.dns_server[1] = dhcps_msg->snd_dns; dhcps_params.server = dhcps_msg->gateway; dhcps_params.netmask = dhcps_msg->netmask; /* 是否4G路由 */ dhcps_params.is_lte = get_lte_enabled(); memset(&dhcps_params.options, 0, sizeof(DHCP_OPTION_STATIC)); dhcps_params.options.lease[0] = DHCP_LEASE_TIME; dhcps_params.options.lease[1] = 4; memcpy(&(dhcps_params.options.lease[2]), &(dhcps_params.lease_time), 4); temp_ip = dhcps_params.netmask; dhcps_params.options.subnet[0] = DHCP_SUBNET; dhcps_params.options.subnet[1] = 4; memcpy(&(dhcps_params.options.subnet[2]), (char *)&temp_ip, 4); dhcps_params.options.router[0] = DHCP_ROUTER; dhcps_params.options.router[1] = 4; memcpy(&(dhcps_params.options.router[2]), (char *)&dhcps_params.gateway, 4); dhcps_params.options.dns[0] = DHCP_DNS_SERVER; dhcps_params.options.dns[1] = 4; memcpy(&(dhcps_params.options.dns[2]), (char *)&dhcps_params.dns_server[0], 4); dhcps_params.options.router4g[0] = DHCP_4G_ROUTER; dhcps_params.options.router4g[1] = DHCP_4G_ROUTER_LEN; memcpy(&(dhcps_params.options.router4g[2]), DHCP_4G_ROUTER_STR, DHCP_4G_ROUTER_LEN); if (-1 == dhcps_params.sock) { dhcps_params.sock = create_sock(); if (-1 == dhcps_params.sock) { DHCPS_DEBUG("create socket error"); return ERROR; } } if (-1 == dhcps_params.inet_iendx) { dhcps_params.inet_iendx = inet_add_socket(dhcps_params.sock, (void*)dhcps_handle, NULL, NULL); if (ERROR == dhcps_params.inet_iendx) { destroy_sock(dhcps_params.sock); dhcps_params.sock = -1; DHCPS_DEBUG("Listen socket error"); return ERROR; } } if (-1 == dhcps_params.timer_index) { dhcps_params.timer_index = inet_add_timer((void*)dhcps_check_timer, 0, 1, EXECUTE_FOREVER); if (ERROR == dhcps_params.timer_index) { inet_del_socket(dhcps_params.inet_iendx); dhcps_params.inet_iendx = -1; destroy_sock(dhcps_params.sock); dhcps_params.sock = -1; DHCPS_DEBUG("Add timer error"); return ERROR; } } DHCPS_INFO("Start DHCP server"); ipaddr.ipAddr = dhcps_params.server; DHCPS_DEBUG("Server = %d.%d.%d.%d", ipaddr.ipAddrByteFormat[0], ipaddr.ipAddrByteFormat[1], ipaddr.ipAddrByteFormat[2], ipaddr.ipAddrByteFormat[3]); ipaddr.ipAddr = dhcps_params.netmask; DHCPS_DEBUG("Netmask = %d.%d.%d.%d", ipaddr.ipAddrByteFormat[0], ipaddr.ipAddrByteFormat[1], ipaddr.ipAddrByteFormat[2], ipaddr.ipAddrByteFormat[3]); ipaddr.ipAddr = dhcps_params.dns_server[0]; DHCPS_DEBUG("DNS1 = %d.%d.%d.%d", ipaddr.ipAddrByteFormat[0], ipaddr.ipAddrByteFormat[1], ipaddr.ipAddrByteFormat[2], ipaddr.ipAddrByteFormat[3]); ipaddr.ipAddr = dhcps_params.dns_server[1]; DHCPS_DEBUG("DNS2 = %d.%d.%d.%d", ipaddr.ipAddrByteFormat[0], ipaddr.ipAddrByteFormat[1], ipaddr.ipAddrByteFormat[2], ipaddr.ipAddrByteFormat[3]); ipaddr.ipAddr = dhcps_params.start; DHCPS_DEBUG("Pool Start = %d.%d.%d.%d", ipaddr.ipAddrByteFormat[0], ipaddr.ipAddrByteFormat[1], ipaddr.ipAddrByteFormat[2], ipaddr.ipAddrByteFormat[3]); ipaddr.ipAddr = dhcps_params.end; DHCPS_DEBUG("Pool End = %d.%d.%d.%d", ipaddr.ipAddrByteFormat[0], ipaddr.ipAddrByteFormat[1], ipaddr.ipAddrByteFormat[2], ipaddr.ipAddrByteFormat[3]); DHCPS_DEBUG("Lease Time = %d", dhcps_params.lease_time); return OK; } LOCAL S32 dhcps_stop_cb(dms_handler_t *handler, U8 *mbuf, U32 mlen, U32 sender_dms_id) { if (-1 != dhcps_params.inet_iendx) { inet_del_socket(dhcps_params.inet_iendx); dhcps_params.inet_iendx = -1; } if (-1 != dhcps_params.sock) { destroy_sock(dhcps_params.sock); dhcps_params.sock = -1; } if (-1 != dhcps_params.timer_index) { inet_del_timer(dhcps_params.timer_index); dhcps_params.timer_index = -1; } return OK; } LOCAL int dhcps_init() { memset(&recv_dhcp_packet, 0, sizeof(recv_dhcp_packet)); memset(&dhcps_params, 0, sizeof(DHCPS_PARAMS)); dhcps_params.inet_iendx = -1; dhcps_params.timer_index = -1; dhcps_params.sock = -1; dhcps_params.decline_time = DECLINE_TIME; dhcps_params.conflict_time = CONFLICT_TIME; dhcps_params.offer_time = LEASE_OFFER_TIME; dhcps_params.min_lease = LEASE_TIME_MIN; msg_attach_handler(DHCPS_START_MSG, dhcps_start_cb); msg_attach_handler(DHCPS_STOP_MSG, dhcps_stop_cb); return OK; } LOCAL S32 dhcps_reload(DS_MSG *msg) { /* 4G上网模式变化 */ if (ds_path_id_exist(msg->id, msg->num, LTE_INFO_DATA_PATH)) { dhcps_params.is_lte = get_lte_enabled(); } return OK; } LOCAL void dhcps_main() { DS_DAT_MON_DESC dhcps_monitor[] = { DS_DAT_MON(LTE_INFO_DATA_PATH, DATA_ATTRI_NOTIFY), }; DS_MOD_DESC dhcps_module = DS_STRUCT_MOD("dhcps", dhcps_init, NULL, dhcps_reload, NULL, NULL, NULL, dhcps_monitor); MODULE *module_node = ds_register_module("dhcps", &dhcps_module); NSD_ASSERT(NULL != module_node); } NSD_INIT(dhcps_main);
最新发布
11-21
<think> 我们有一个DHCPS模块的代码，大约1000行。现在，我将为这个模块添加注释。由于代码较长，我会分段进行注释，并解释关键部分的功能。 首先，我们来看头文件`dhcps.h`： ```c /* dhcps.h */ #ifndef _DHCPS_H #define _DHCPS_H #include "dhcp.h" #define MAX_FILE_NAME_LEN 256 #define MAX_BOOTP_SRV_NAME_LEN 16 #define DHCPS_DOMAIN_NAME_LENGTH 32 #define DHCP_4G_ROUTER_STR "4g router" #define DHCP_4G_ROUTER_LEN 9 /***************************************************************************************** **********************DHCPS SERVER CLASS************************************************** *****************************************************************************************/ #define DHCPS_LEASE_LIST_SIZE 128 // 定义DHCP租约结构，用于存储客户端租约信息 typedef struct _DHCPS_LEASE { U8 host_name[32]; // 客户端主机名 U8 mac[6]; // 客户端MAC地址 U32 state; // 租约状态 U32 ip; // 分配给客户端的IP地址（网络字节序） U32 expires; // 租约到期时间（秒） } DHCPS_LEASE; // 静态DHCP选项结构，用于配置DHCP服务器提供的选项 typedef struct _DHCP_OPTION_STATIC { UINT8 lease[6]; // 租期选项（类型+长度+值） UINT8 subnet[6]; // 子网掩码选项 UINT8 router[6]; // 路由器（默认网关）选项 UINT8 dns[10]; // DNS服务器选项（最多两个DNS服务器） char domain[34]; // 域名 UINT8 router4g[DHCP_4G_ROUTER_LEN+2]; // 4G路由选项（类型+长度+字符串） } DHCP_OPTION_STATIC; /* Struct to store public server config.*/ // DHCP服务器全局参数配置结构 typedef struct _DHCPS_PARAMS { S32 sock; // 套接字描述符 S32 inet_iendx; // 网络接口索引（用于事件处理） S32 timer_index; // 定时器索引 char dev_name[32]; // 网络接口名称 S32 dev; // 网络接口索引（设备号） UINT8 mac[6]; // 服务器MAC地址 U32 decline_time; // 拒绝地址保留时间（秒） U32 conflict_time; // 地址冲突保留时间（秒） U32 offer_time; // OFFER保留时间（秒） U32 min_lease; // 最小租期（秒） U32 server; // 服务器IP地址（网络字节序） U32 netmask; // 子网掩码（网络字节序） U32 gateway; // 网关地址（网络字节序） U32 dns_server[2]; // DNS服务器地址（网络字节序） char host_name[DHCPS_DOMAIN_NAME_LENGTH]; // 服务器主机名 DHCP_OPTION_STATIC options; // DHCP选项配置 U32 start; // 地址池起始地址（网络字节序） U32 end; // 地址池结束地址（网络字节序） U32 lease_time; // 默认租期（秒） U32 siaddr; // 下一个服务器地址（bootp） char sname[MAX_BOOTP_SRV_NAME_LEN]; // 服务器名称（bootp） char boot_file[MAX_FILE_NAME_LEN]; // 启动文件名（bootp） DHCPS_LEASE lease[DHCPS_LEASE_LIST_SIZE]; // 租约列表 U16 is_lte; // 是否4G上网模式 } DHCPS_PARAMS; // 日志宏定义 #define DHCPS_DEBUG(fmt, ...) NSD_DEBUG("[DHCPS]" fmt, ##__VA_ARGS__) #define DHCPS_INFO(fmt, ...) NSD_LOG(LOG_INFO, "[Network][DHCP]" fmt, ##__VA_ARGS__) #define DHCPS_WARN(fmt, ...) NSD_WARN("[DHCPS]" fmt, ##__VA_ARGS__) #endif ``` 接下来是`dhcps.c`的注释： ```c /* dhcps.c * udhcp Server * ... 版权信息 ... */ #include <netinet/if_ether.h> #include <linux/filter.h> #include <linux/if_packet.h> #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <string.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <unistd.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include "options.h" #include "packet.h" #include "dhcp.h" #include "dhcps.h" #include "libds.h" /* DHCPS模块中各个参数项单位都改为秒 */ #define LEASE_TIME_MAX (48*60*60) /* 租期最长2天 */ #define LEASE_TIME_MIN (1*60) /* 租期最短一分钟 */ #define LEASE_OFFER_TIME (2*60*60) // OFFER保留时间（2小时） #define DECLINE_TIME (60*60) // 拒绝地址保留时间（1小时） #define CONFLICT_TIME (60*60) // 冲突地址保留时间（1小时） #define DHCP_CHANGE_RECEIVE_PORT 52261 // 用于接收配置更改消息的端口 #define DHCP_CHANGE_SEND_PORT 52262 // 用于发送配置更改消息的端口 // 默认配置 #define DEFAULT_DHCPS_IP "192.168.191.1" #define DEFAULT_DHCPS_MASK "255.255.255.0" #define DEF_DHCPS_IP_BEGIN "192.168.191.120" #define DEF_DHCPS_IP_END "192.168.191.199" #define DHCPS_HOST_NAME_LEN 32 // 配置项关键字 #define DHCPS_OPTION_AUTO "auto" #define DHCPS_OPTION_ENABLE "enable" #define DHCPS_OPTION_POOLSTART "pool_start" #define DHCPS_OPTION_POOLEND "pool_end" #define DHCPS_OPTION_LEASETIME "lease_time" #define DHCPS_OPTION_GATEWAY "gateway" #define DHCPS_OPTION_PRIDNS "pri_dns" #define DHCPS_OPTION_SNDDNS "snd_dns" #define DHCPS_OPTION_IP "ip" #define DHCPS_OPTION_MAC "mac" #define DHCPS_OPTION_EXPIRES "expires" #define DHCPS_OPTION_HOSTNAME "hostname" // 全局变量 DHCPS_PARAMS dhcps_params; // 服务器参数 LOCAL struct dhcp_packet recv_dhcp_packet; // 接收到的DHCP包 LOCAL struct dhcp_packet packet; // 用于发送的DHCP包 // 内存分配和释放宏 #define DHCPS_MALLOC(size) malloc(size) #define DHCPS_FREE(addr) free((UINT8*)(addr)) // 判断两个IP是否在同一子网 #define ISNOTSAMESUBNET(ip1, ip2, mask) (0 != (((ip1) ^ (ip2)) & (mask))) /* 是否4G IPC - 4G上网模式 */ LOCAL U16 get_lte_enabled(void) { LTE_CAPABILITY lte_cap = {0}; LTE_CONFIG_INFO_DATA lte_config = {0}; if (0 == ds_read(LTE_CAPABILITY_PATH, (U8 *)&lte_cap, sizeof(lte_cap))) { //未定义lte_capability，判断为非4G IPC，未开启4G上网模式 return 0; } if (0 == ds_read(LTE_INFO_DATA_PATH, (U8 *)&lte_config, sizeof(lte_config))) { //4G IPC默认4G上网模式，获取失败时按照4G上网处理 return 1; } return !(lte_cap.internet_wired_support && lte_config.internet_wired_enable); } /* 清除与给定MAC或IP匹配的租约 */ LOCAL void clear_lease(U8 *mac, U32 ip, DHCPS_LEASE *leases) { S32 i, j, k; // 如果MAC全0，则跳过MAC匹配 for (j = 0; j < CHADDR_LEN && !mac[j]; j++); for (i = 0; i < DHCPS_LEASE_LIST_SIZE; i++) { if ((j != CHADDR_LEN && !memcmp(leases[i].mac, mac, 6)) || (ip && leases[i].ip == ip)) { // 清除匹配的租约，并将后续租约前移 memset(&(leases[i]), 0, sizeof(leases[i])); for (k = i;(k + 1) < DHCPS_LEASE_LIST_SIZE; k++) { memcpy(&(leases[k]), &(leases[k + 1]), sizeof(leases[k])); memset(&(leases[k + 1]), 0, sizeof(leases[k + 1])); } i--; // 因为前移了，所以需要回退索引 } } } /* 查找最早过期的租约，返回索引，如果没有则返回-1 */ LOCAL S32 oldest_expired_lease(DHCPS_LEASE *leases) { U32 i; for (i = 0; i < DHCPS_LEASE_LIST_SIZE; i++) { if (leases[i].expires == 0) // 租约到期时间为0表示空闲 { return i; } } return -1; } /* 添加租约 */ LOCAL S32 add_lease(U32 state, char *host_name, U8 *mac, U32 ip, U32 time_lease, DHCPS_LEASE *dhcps_lease) { S32 lease_index = -1 ; IP_ADDR ipAddr = {0}; // 清理旧的租约 clear_lease(mac, ip, dhcps_lease); // 获取一个空闲的租约位置 lease_index = oldest_expired_lease(dhcps_lease); if (lease_index != -1) { // 填充租约信息 dhcps_lease[lease_index].state = state; DHCPS_DEBUG("state = %d", dhcps_lease[lease_index].state); memcpy(dhcps_lease[lease_index].host_name, host_name, 32); /* add by Li Shaozhang, 07Jun07 */ DHCPS_DEBUG("hostname = %s", dhcps_lease[lease_index].host_name); memcpy(dhcps_lease[lease_index].mac, mac, 6); DHCPS_DEBUG("mac = %02x-%02x-%02x-%02x-%02x-%02x", dhcps_lease[lease_index].mac[0],\ dhcps_lease[lease_index].mac[1], dhcps_lease[lease_index].mac[2],\ dhcps_lease[lease_index].mac[3], dhcps_lease[lease_index].mac[4],\ dhcps_lease[lease_index].mac[5]); dhcps_lease[lease_index].ip = ip; ipAddr.ipAddr = ip; DHCPS_DEBUG("ip = %d.%d.%d.%d", ipAddr.ipAddrByteFormat[0], ipAddr.ipAddrByteFormat[1], ipAddr.ipAddrByteFormat[2], ipAddr.ipAddrByteFormat[3]); dhcps_lease[lease_index].expires = time_lease; DHCPS_DEBUG("lease = %d", dhcps_lease[lease_index].expires); } return lease_index; } /* 检查租约是否过期 */ LOCAL S32 lease_expired(S32 lease_index, DHCPS_LEASE *dhcps_lease) { return (dhcps_lease[lease_index].expires == 0); } /* 通过MAC查找租约，返回索引 */ LOCAL S32 find_lease_by_mac(U8 *mac, DHCPS_LEASE *dhcps_lease) { U32 i; for (i = 0; i < DHCPS_LEASE_LIST_SIZE; i++) { if (!memcmp(dhcps_lease[i].mac, mac, 6)) { /* 如果租约IP与服务器不在同一子网，则删除该租约 */ if (0 == ((dhcps_lease[i].ip ^ dhcps_params.server) & dhcps_params.netmask)) { return i; } memset(&(dhcps_lease[i]), 0, sizeof(dhcps_lease[i])); } } return -1; } /* 通过IP查找租约，返回索引 */ LOCAL S32 find_lease_by_ip(U32 ip, DHCPS_LEASE *dhcps_lease) { U32 i; for (i = 0; i < DHCPS_LEASE_LIST_SIZE; i++) { if (dhcps_lease[i].ip == ip) { return i; } } return -1; } /* 检查IP是否已被占用，如果已被占用则添加到租约表（冲突状态） */ LOCAL S32 check_ip(U32 addr, DHCPS_LEASE *dhcps_lease) { char strIp[18] = {0}; // 如果地址是服务器自身地址，则冲突 if (addr == dhcps_params.server) { DHCPS_WARN("The IP distributed equals to server ip, ignore!!!"); return 1; } // 发送ARP请求检查IP是否已被占用 if (0 == arpping(addr, recv_dhcp_packet.chaddr, dhcps_params.server, dhcps_params.mac, dhcps_params.dev_name, 500)) { DHCPS_WARN("%s belongs to someone, reserving it for %ld seconds.", strIp, dhcps_params.conflict_time); return 1; } return 0; } /* 检查IP是否在服务器地址池内 */ LOCAL S32 ip_in_srv_pool(U32 ip) { IP_ADDR ipAddr = {0}; ipAddr.ipAddr = ip; ip = ntohl(ip); // 转为主机序比较 if ((ip >= ntohl(dhcps_params.start)) && (ip <= ntohl(dhcps_params.end)) && (ip != ntohl(dhcps_params.server))) { return 1; } DHCPS_WARN("IP(%d.%d.%d.%d) not in dhcp pool or equal to server ip, ignore!!!", ipAddr.ipAddrByteFormat[0], ipAddr.ipAddrByteFormat[1], ipAddr.ipAddrByteFormat[2], ipAddr.ipAddrByteFormat[3]); return 0; } /* 在地址池中查找一个可分配的地址 */ LOCAL U32 find_address(S32 check_expired, DHCPS_LEASE *dhcps_lease) { U32 addrStart, addrEnd; // 主机序的地址池起止 U32 ret; // 网络序的地址 S32 lease_index = -1; U32 mask = 0; mask = ntohl(dhcps_params.netmask); addrStart = ntohl(dhcps_params.start); addrEnd = ntohl(dhcps_params.end); for (; addrStart <= addrEnd; addrStart++) { ret = htonl(addrStart); // 跳过网络地址（主机号全0） if (!(ret & (~mask))) { continue; } // 跳过广播地址（主机号全1） if ((ret & (~mask)) == (~mask)) { continue; } // 检查该IP是否已被分配 if (-1 != (lease_index = find_lease_by_ip(ret, dhcps_lease))) { // 如果要求检查过期租约，并且该租约已过期，则返回该地址 if (check_expired && lease_expired(lease_index, dhcps_lease)) { return ret; } continue; } // 检查该IP是否已被其他主机静态使用 if (TRUE == check_ip(ret, dhcps_lease)) { continue; } return ret; } return 0; } /* 发送DHCP包，如果force_broadcast为真，则广播 */ LOCAL S32 send_packet(struct dhcp_packet *payload, S32 force_broadcast) { U8 *chaddr = NULL; U32 ciaddr = 0; if (force_broadcast) { DHCPS_DEBUG("Broadcasting packet to client (NAK)."); ciaddr = INADDR_BROADCAST; chaddr = MAC_BCAST_ADDR; } else if (ntohs(payload->flags) & BROADCAST_FLAG) { DHCPS_DEBUG("Broadcasting packet to client (requested)."); ciaddr = INADDR_BROADCAST; chaddr = MAC_BCAST_ADDR; } else if ((0 == payload->yiaddr) && (payload->ciaddr)) { DHCPS_DEBUG("Unicasting packet to client ciaddr."); ciaddr = payload->ciaddr; chaddr = payload->chaddr; } else { ciaddr = payload->yiaddr; chaddr = payload->chaddr; } return make_and_send_dhcp_frame(payload, dhcps_params.server, SERVER_PORT, ciaddr, CLIENT_PORT, chaddr, dhcps_params.dev); } /* 初始化DHCP包 */ LOCAL void init_packet(struct dhcp_packet *packet, struct dhcp_packet *old_packet, char type) { init_header(packet, type); // 设置基本头 packet->xid = old_packet->xid; // 事务ID memcpy(packet->chaddr, old_packet->chaddr, CHADDR_LEN); // 客户端MAC packet->flags = old_packet->flags; // 标志位 packet->giaddr = old_packet->giaddr; // 网关IP packet->ciaddr = old_packet->ciaddr; // 客户端当前IP add_simple_option(packet->options, DHCP_SERVER_ID, dhcps_params.server); // 添加服务器标识选项 } /* 添加BOOTP选项 */ LOCAL void add_bootp_options(struct dhcp_packet *packet) { packet->siaddr = dhcps_params.siaddr; // 下一个服务器地址 if (dhcps_params.sname) { strncpy((char *)packet->sname, dhcps_params.sname, sizeof(packet->sname) - 1); // 服务器名称 } if (dhcps_params.boot_file) { strncpy((char *)packet->file, dhcps_params.boot_file, sizeof(packet->file) - 1); // 启动文件 } } /* 获取主机名长度（考虑中文字符） */ LOCAL S32 get_host_name_len(char* name, S32 len) { S32 index = 0; S32 language_flag = 0; if (len < 32) { return len; } for (index=0; index < 31; index++) { /* 处理中文字符：GB2312编码，每个汉字两个字节，且高位在0xA1-0xF7 */ if (*(UINT8*)(name + index) >= 0xA1) { language_flag ^= 1; // 标记当前字节是否为汉字的一部分 } } // 如果最后是半个汉字，则去掉最后一个字节 if (language_flag == 0) { return 31; } return 30; } /* 发送OFFER包 */ LOCAL S32 send_offer(struct dhcp_packet *old_packet, DHCPS_LEASE *dhcps_lease) { S32 lease_index = -1; U32 req_align, lease_time_align = dhcps_params.lease_time; U8 *req, *lease_time; char blank_hostname[] = /*"Unknown"*/""; // 默认主机名 S32 copy_host_name_len; IP_ADDR ip_addr = {0}; char host_name[DHCPS_HOST_NAME_LEN]; char *host_name_start, *host_name_len; U32 lease_ip; DHCPS_DEBUG("before init_packet."); init_packet(&packet, old_packet, DHCPOFFER); /* 如果客户端有请求IP，并且该IP在地址池中，且未被分配或已过期，则使用该IP */ if ((req = get_option(old_packet, DHCP_REQUESTED_IP)) && memcpy(&req_align, req, 4) && ip_in_srv_pool(req_align) && (((-1 == (lease_index = find_lease_by_ip(req_align, dhcps_lease))) || lease_expired(lease_index, dhcps_lease)))) { lease_ip = req_align; // 检查该IP是否已被占用（ARP检测） if (TRUE == check_ip(lease_ip, dhcps_lease)) { goto choose_dynamic_lease_ip; } packet.yiaddr = lease_ip; goto send_offer; } choose_dynamic_lease_ip: // 尝试通过MAC查找租约 lease_index = find_lease_by_mac(old_packet->chaddr, dhcps_lease); if (-1 != lease_index) { /* 如果租约过期或IP不在地址池中，则清除 */ if ((FALSE == ip_in_srv_pool(dhcps_lease[lease_index].ip)) || lease_expired(lease_index, dhcps_lease)) { memset(&(dhcps_lease[lease_index]), 0, sizeof(dhcps_lease[lease_index])); lease_index = -1; goto choose_pool_ip; } lease_time_align = dhcps_lease[lease_index].expires; packet.yiaddr = dhcps_lease[lease_index].ip; goto send_offer; } choose_pool_ip: // 在地址池中查找可用地址（先查未过期的，再查过期的） packet.yiaddr = find_address(0, dhcps_lease); if (0 == packet.yiaddr) { packet.yiaddr = find_address(1, dhcps_lease); } if(0 == packet.yiaddr) { DHCPS_WARN("No ip addresses to give, OFFER abandoned."); return -1; } send_offer: // 如果租期不是无限长（静态分配），则添加租约 if (0xFFFFFFFF != lease_time_align) { // 获取客户端主机名 if (!(host_name_start = (char *)get_option(old_packet, DHCP_HOST_NAME))) { DHCPS_WARN("Lease host name not found."); memset(host_name, 0, DHCPS_HOST_NAME_LEN); memcpy(host_name, blank_hostname, strlen(blank_hostname)); } else { host_name_len = host_name_start - OPT_LEN; // 选项长度 memset(host_name, 0, DHCPS_HOST_NAME_LEN); // 复制主机名，考虑中文字符 copy_host_name_len = get_host_name_len(host_name_start, *host_name_len); memcpy(host_name, host_name_start, copy_host_name_len); } // 添加租约（状态为OFFER，租期暂时为OFFER保留时间） if (-1 == add_lease(DHCPOFFER, host_name, packet.chaddr, packet.yiaddr, dhcps_params.offer_time, dhcps_lease)) { DHCPS_WARN("Lease pool is full, OFFER abandoned."); return -1; } // 如果客户端请求了租期，则使用请求的租期（但不能超过配置的最大租期） if ((lease_time = get_option(old_packet, DHCP_LEASE_TIME))) { memcpy(&lease_time_align, lease_time, 4); DHCPS_DEBUG("lease time = %d ", lease_time); lease_time_align = ntohl(lease_time_align); if (lease_time_align > (dhcps_params.lease_time*60)) { lease_time_align = (dhcps_params.lease_time*60); } } // 确保租期不小于最小租期 if (lease_time_align < dhcps_params.min_lease) { lease_time_align = dhcps_params.lease_time; } } DHCPS_DEBUG("OFFER lease time = %d; configed dhcp lease = %d\n", lease_time_align, dhcps_params.lease_time); // 添加租期选项 add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_align)); // 添加DNS、子网掩码、路由器选项 add_option_string(packet.options, dhcps_params.options.dns); add_option_string(packet.options, dhcps_params.options.subnet); add_option_string(packet.options, dhcps_params.options.router); // 如果是4G路由，添加4G路由选项 if(dhcps_params.is_lte) { DHCPS_DEBUG("OFFER: lte enabled\n"); add_option_string(packet.options, dhcps_params.options.router4g); } /*addVendorSpecInfo(oldpacket, packet.options);*/ add_bootp_options(&packet); ip_addr.ipAddr = packet.yiaddr; DHCPS_INFO("Send OFFER with ip %d.%d.%d.%d.", ip_addr.ipAddrByteFormat[0], ip_addr.ipAddrByteFormat[1], ip_addr.ipAddrByteFormat[2], ip_addr.ipAddrByteFormat[3]); return send_packet(&packet, 0); } // 由于篇幅原因，以下函数省略详细注释，只说明功能 // send_NAK: 发送NAK包 // send_ACK: 发送ACK包，并添加租约 // send_inform: 发送INFORM响应包 // check_and_ack: 检查请求的IP是否合法，然后发送ACK或NAK // create_sock: 创建并配置服务器套接字 // destroy_sock: 关闭套接字 // dhcps_check_timer: 定时检查租约过期 // dhcps_handle: 处理收到的DHCP包 // dhcps_start_cb: 启动DHCP服务的回调函数（配置参数并启动服务） // dhcps_stop_cb: 停止DHCP服务的回调函数 // dhcps_init: 初始化DHCP服务 // dhcps_reload: 重新加载配置（如4G模式变化） // dhcps_main: 主函数，注册模块 // 最后，模块初始化 NSD_INIT(dhcps_main); ``` 由于代码量很大，这里只对关键函数和结构进行了注释。对于未详细注释的函数，其功能在注释中已简要说明。在实际开发中，建议结合具体的业务逻辑和协议规范进行深入理解。 </think>### DHCP 服务器模块代码注释解析 以下是针对 IPC 设备 DHCP 服务器模块（约 1000 行）的详细注释说明： --- ### 关键结构体解析 #### 1. `DHCPS_LEASE` - DHCP 租约条目 ```c typedef struct _DHCPS_LEASE { U8 host_name[32]; // 客户端主机名 U8 mac[6]; // 客户端 MAC 地址 U32 state; // 租约状态 (OFFER/ACK 等) U32 ip; // 分配的 IP 地址 (网络字节序) U32 expires; // 租约过期时间 (秒) } DHCPS_LEASE; ``` #### 2. `DHCP_OPTION_STATIC` - DHCP 静态选项 ```c typedef struct _DHCP_OPTION_STATIC { UINT8 lease[6]; // 租期选项 (类型+长度+值) UINT8 subnet[6]; // 子网掩码选项 UINT8 router[6]; // 路由器 (网关) 选项 UINT8 dns[10]; // DNS 服务器选项 char domain[34]; // 域名 UINT8 router4g[DHCP_4G_ROUTER_LEN+2]; // 4G 路由特殊选项 } DHCP_OPTION_STATIC; ``` #### 3. `DHCPS_PARAMS` - 服务器核心参数 ```c typedef struct _DHCPS_PARAMS { // 网络层参数 S32 sock; // Socket 描述符 UINT8 mac[6]; // 服务器 MAC U32 server; // 服务器 IP (网络字节序) U32 netmask; // 子网掩码 U32 gateway; // 网关地址 // 地址池配置 U32 start; // 地址池起始 IP U32 end; // 地址池结束 IP U32 lease_time; // 默认租期 (秒) // 租约管理 DHCPS_LEASE lease[DHCPS_LEASE_LIST_SIZE]; // 租约列表 (128条) // 协议选项 DHCP_OPTION_STATIC options; // DHCP 选项集合 U16 is_lte; // 是否 4G 路由模式 (1:是, 0:否) } DHCPS_PARAMS; ``` --- ### 核心功能函数解析 #### 1. 地址分配逻辑 (`find_address`) ```c LOCAL U32 find_address(S32 check_expired, DHCPS_LEASE *dhcps_lease) { U32 addrStart = ntohl(dhcps_params.start); // 地址池起始(主机序) U32 addrEnd = ntohl(dhcps_params.end); // 地址池结束(主机序) for (; addrStart <= addrEnd; addrStart++) { U32 ip = htonl(addrStart); // 转为网络序 // 跳过网络地址(192.168.1.0)和广播地址(192.168.1.255) if ((ip & ~mask) == 0 || (ip & ~mask) == ~mask) continue; // 检查 IP 是否可用 if (lease_index = find_lease_by_ip(ip) >= 0) { if (check_expired && lease_expired(lease_index)) return ip; } else if (!check_ip(ip)) { // ARP 检测冲突 return ip; // 找到可用 IP } } return 0; // 无可用地址 } ``` #### 2. DHCP OFFER 响应 (`send_offer`) ```c LOCAL S32 send_offer(struct dhcp_packet *old_packet, DHCPS_LEASE *leases) { init_packet(&packet, old_packet, DHCPOFFER); // 初始化 DHCP 包 // 1. 优先使用客户端请求的 IP (若在池中且可用) if (requested_ip = get_option(old_packet, DHCP_REQUESTED_IP)) { if (ip_in_srv_pool(requested_ip) && !check_ip(requested_ip)) { packet.yiaddr = requested_ip; goto build_options; } } // 2. 检查现有租约 if ((lease_index = find_lease_by_mac(old_packet->chaddr)) >= 0) { packet.yiaddr = leases[lease_index].ip; lease_time = leases[lease_index].expires; goto build_options; } // 3. 从地址池分配新 IP if (!(packet.yiaddr = find_address(1, leases))) return -1; build_options: // 添加 DHCP 选项 add_simple_option(packet.options, DHCP_LEASE_TIME, lease_time); add_option_string(packet.options, dhcps_params.options.dns); // DNS add_option_string(packet.options, dhcps_params.options.router); // 网关 // 4G 路由特殊处理 if (dhcps_params.is_lte) { add_option_string(packet.options, dhcps_params.options.router4g); } return send_packet(&packet, 0); // 发送 OFFER 包 } ``` #### 3. 租约老化定时任务 (`dhcps_check_timer`) ```c LOCAL void dhcps_check_timer() { for (U32 i = 0; i < DHCPS_LEASE_LIST_SIZE; i++) { if (leases[i].expires == 0 || leases[i].expires == 0xFFFFFFFF) continue; // 租约减秒 (1秒触发1次) if (--leases[i].expires == 0) { // 移除过期租约并前移后续条目 for (U32 j = i; j < DHCPS_LEASE_LIST_SIZE-1; j++) { memcpy(&leases[j], &leases[j+1], sizeof(DHCPS_LEASE)); } memset(&leases[DHCPS_LEASE_LIST_SIZE-1], 0, sizeof(DHCPS_LEASE)); i--; // 重查当前位置 } } } ``` --- ### 网络通信关键点 #### 1. 原始套接字创建 (`create_sock`) ```c LOCAL S32 create_sock() { int sock = socket(AF_INET, SOCK_DGRAM, 0); // 创建 UDP socket setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &opt, sizeof(opt)); // 允许广播 struct sockaddr_in addr; addr.sin_family = AF_INET; addr.sin_port = htons(SERVER_PORT); // DHCP 服务端端口 67 addr.sin_addr.s_addr = INADDR_ANY; // 监听所有接口 bind(sock, (struct sockaddr*)&addr, sizeof(addr)); // 绑定端口 return sock; } ``` #### 2. DHCP 包接收处理 (`dhcps_handle`) ```c LOCAL void dhcps_handle(S32 sock) { struct dhcp_packet packet; int bytes = recvfrom(sock, &packet, sizeof(packet), 0, NULL, NULL); // 根据消息类型处理 switch (get_option(&packet, DHCP_MESSAGE_TYPE)[0]) { case DHCPDISCOVER: // 客户端发现请求 send_offer(&packet); break; case DHCPREQUEST: // 客户端地址请求 process_request(&packet); break;
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