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- //
- // redirect_to_local_http
- //
- // Description:
- //
- //
- // Author: <king@tao.kingstone>, (C) 2009
- //
- // Copyright: See COPYING file that comes with this distribution
- //
- #include <stdio.h>
- #include <arpa/inet.h>
- #include <netinet/in.h>
- #include <netinet/ip.h>
- #include <netinet/tcp.h>
- #include <netinet/udp.h>
- #include <time.h>
- #include <libnet.h>
- #include <glib.h>
- #include <gio/gio.h>
- #include <gmodule.h>
- #include <glib/gi18n.h>
- #include "global.h"
- #include "pcap_hander.h"
- #include "clientmgr.h"
- static void init_thread_libnet();
- static void redirector_host_resove_by_dns(GObject *source_object, GAsyncResult *res,gpointer user_data);
- #define HTTP_PORT 0x5000
- #define DNS_PORT 0x3500
- #define GROUP_NAME "http_redirect"
- static u_int8_t httphead[512];
- static u_int8_t httphead_t[] =
- "HTTP/1.0 302 Found\n"
- "Location: %s\n"
- "Connection:close\n\n"
- "<html>\n\t<head>\n\t\t<meta http-equiv=\"Refresh\"content=\"0 ; "
- "url=%s\">\n\t</head>\n</html>\n";
- static in_addr_t redirector_ip;
- static GList* whiteip;
- static __thread libnet_t * libnet = NULL;
- static u_int8_t blank[128];
- static void http_redirector_init(const gchar * desturl)
- {
- char host[128];
- sscanf(desturl,"http://%128[^/^:]",host);
- redirector_ip = inet_addr(host);
- if (redirector_ip == INADDR_NONE)
- {
- g_debug(_("host in the url is not an ipv4 address, will do async dns lookup"));
- GResolver * dns = g_resolver_get_default();
- g_resolver_lookup_by_name_async(dns,host,NULL,redirector_host_resove_by_dns,dns);
- }
- sprintf((char*) httphead, (char*) httphead_t, desturl, desturl);
- }
- static inline void init_thread_libnet()
- {
- if(!libnet)
- {
- static char buf[LIBNET_ERRBUF_SIZE];
- libnet = libnet_init(LIBNET_RAW4, NULL, buf);
- }
- }
- static gboolean http_redirector( pcap_process_thread_param * param, gpointer user_data)
- {
- /*******************************************************************
- * here we use TCP
- * when we recv a SYN=1,ACK=0 packet, we just send a syn=1,ack=1 packet
- * that contains nothing
- * then we push a packet taht contains
- * HTTP/1.0 302 Found
- * Location: http://192.168.0.1/
- * connection:close
- *
- * please visit http://192.168.0.1
- * and then we reset the connection
- * ****************************************************************/
- struct tcphdr * tcp_head;
- struct udphdr * udp_head;
- if(clientmgr_get_client_is_enable_by_mac(param->packet_linklayer_hdr+6))
- {
- //继续交给后续代码处理
- return FALSE ;
- }
- //非 enable 的客户端，现在要开始这般处理了,重定向到 ... 嘿嘿
- struct iphdr * ip_head = (typeof(ip_head))(param->packet_ip_contents);
- if (ip_head->daddr == redirector_ip)
- {
- return TRUE;
- }
- if (ip_head->saddr == redirector_ip)
- {
- return TRUE;
- }
- //如果是在 white list ....
- if (whiteip && g_list_find(whiteip, GINT_TO_POINTER(ip_head->daddr)))
- return FALSE;
- if (whiteip && g_list_find(whiteip, GINT_TO_POINTER(ip_head->saddr)))
- return FALSE;
- // g_debug(_("thread %p is doing the redirect stuff"),g_thread_self());
- //Retrive the tcp header and udp header
- tcp_head = (struct tcphdr*) ((char*) ip_head + ip_head->ihl * 4);
- udp_head = (struct udphdr*) ((char*) ip_head + ip_head->ihl * 4);
- #ifdef DEBUG_ONLY_HTTP_PORT
- if (tcp_head->dest != HTTP_PORT)
- return TRUE;
- #endif
- //初始化libnet，每个线程一个 libnet ;)
- init_thread_libnet();
- // http 重定向
- if(ip_head->protocol == IPPROTO_TCP && tcp_head->dest == HTTP_PORT)
- {
- u_int8_t tcp_flags = ((struct libnet_tcp_hdr *) tcp_head)->th_flags;
- if(tcp_flags == TH_SYN)
- {
- /********************************
- * 对于这样的一个握手数据包
- * 我们应该要建立连接了
- * 回复一个syn ack 就是了
- *********************************/
- // here we just echo ack and syn.
- libnet_build_tcp(ntohs(tcp_head->dest), ntohs(tcp_head->source), tcp_head->seq, ntohl(
- tcp_head->seq) + 1, TH_ACK | TH_SYN, 4096, 0, 0, 20, 0, 0,
- libnet, 0);
- libnet_build_ipv4(40, 0, 0, 0x4000, 63/*ttl*/, IPPROTO_TCP, 0,
- ip_head->daddr, ip_head->saddr, 0, 0, libnet, 0);
- libnet_write(libnet);
- libnet_clear_packet(libnet);
- libnet_build_tcp(ntohs(tcp_head->dest), ntohs(tcp_head->source), tcp_head->seq, ntohl(
- tcp_head->seq) + 1, TH_ACK | TH_SYN, 4096, 0, 0, 20, 0, 0,
- libnet, 0);
- libnet_build_ipv4(40, 0, 0, 0x4000, 63/*ttl*/, IPPROTO_TCP, 0,
- ip_head->daddr, ip_head->saddr, 0, 0, libnet, 0);
- }else if (tcp_flags & (TH_ACK|TH_SYN) )
- {
- /*********************************************
- *现在是发送页面的时候啦！
- *********************************************/
- int SIZEHTTPHEAD = strlen((const char*) httphead);
- libnet_build_tcp(ntohs(tcp_head->dest), ntohs(tcp_head->source), ntohl(tcp_head->ack_seq),
- ntohl(tcp_head->seq) + ntohs(ip_head->tot_len) - 40, TH_ACK
- | TH_PUSH | TH_FIN, 4096, 0, 0, 20 + SIZEHTTPHEAD,
- httphead, SIZEHTTPHEAD, libnet, 0);
- libnet_build_ipv4(40 + SIZEHTTPHEAD, 0, 0, 0x4000, 63/*ttl*/,
- IPPROTO_TCP, 0, ip_head->daddr, ip_head->saddr, 0, 0, libnet, 0);
- }
- else if (tcp_flags & (TH_FIN|TH_RST))
- {
- /*********************************************************
- *好，现在结束连接！
- ********************************************************/
- libnet_build_tcp(ntohs(tcp_head->dest), ntohs(tcp_head->source), ntohl(tcp_head->ack_seq),
- ntohl(tcp_head->seq) + 1, TH_ACK|TH_RST, 4096, 0, 0, 20, 0, 0, libnet,
- 0);
- libnet_build_ipv4(40, 0, 0, 0x4000, 63/*ttl*/, IPPROTO_TCP, 0,
- ip_head->daddr, ip_head->saddr, 0, 0, libnet, 0);
- printf("------------------------------------------------------------------------link disconnect\n");
- }else{
- return FALSE;
- }
- }//其他 TCP 直接 RST
- else if( ip_head->protocol == IPPROTO_TCP)
- {
- libnet_build_tcp(ntohs(tcp_head->dest), ntohs(tcp_head->source), ntohl(tcp_head->ack_seq),
- ntohl(tcp_head->seq) + 1, TH_ACK|TH_RST, 4096, 0, 0, 20, 0, 0, libnet,
- 0);
- libnet_build_ipv4(40, 0, 0, 0x4000, 63/*ttl*/, IPPROTO_TCP, 0,
- ip_head->daddr, ip_head->saddr, 0, 0, libnet, 0);
- }else if(ip_head->protocol == IPPROTO_UDP && udp_head->dest != DNS_PORT)
- {
- //现在是 UDP 的时代了
- libnet_build_udp(ntohs(udp_head->dest),ntohs(udp_head->source),
- sizeof(blank)+sizeof(struct udphdr),0,blank,sizeof(blank),libnet,0);
- libnet_build_ipv4(40, 0, 0, 0x4000, 63/*ttl*/, IPPROTO_UDP, 0,
- ip_head->daddr, ip_head->saddr, 0, 0, libnet, 0);
- }else
- return FALSE;
- // if(param->linklayer_len == 14)
- // libnet_build_ethernet(
- // ((struct libnet_ethernet_hdr *) param->packet_linklayer_hdr)->ether_shost,
- // /((struct libnet_ethernet_hdr *) param->packet_linklayer_hdr)->ether_dhost,
- // ETHERTYPE_IP, 0, 0, libnet, 0);
- libnet_autobuild_ethernet(
- ((struct libnet_ethernet_hdr *) param->packet_linklayer_hdr)->ether_shost,
- ETHERTYPE_IP,libnet
- );
- libnet_write(libnet);
- libnet_clear_packet(libnet);
- return TRUE;
- }
- G_MODULE_EXPORT gchar * g_module_check_init(GModule *module)
- {
- gboolean enable;
- GError * err=NULL;
- gchar * url;
- enable = g_key_file_get_boolean(gkeyfile,GROUP_NAME,"enable",&err);
- if(err)
- {
- enable = TRUE;
- g_error_free(err);
- g_message("%s","[http_redirect]:[enable] not specified, default to enable");
- err = NULL;
- }
- if (!enable)
- {
- return "[http_redirect]:[enable=false], user disabled me";
- }
- url = g_key_file_get_string(gkeyfile, GROUP_NAME, "url", NULL);
- if(!url)
- {
- return "[http_redirect]:[url] not defined, please define one";
- }
- http_redirector_init(url);
- gchar * ips = g_key_file_get_string(gkeyfile,GROUP_NAME,"whitelist",&err);
- if(err)
- {
- g_error_free(err);
- }else
- {
- GResolver * dns = g_resolver_get_default();
- void resove_host_by_dns(GObject *source_object, GAsyncResult *res,gpointer user_data)
- {
- GList * hosts = g_resolver_lookup_by_name_finish(G_RESOLVER(source_object),res,NULL);
- if(hosts)
- {
- GList * it = g_list_first(hosts);
- do
- {
- GInetAddress * addr = (GInetAddress*)(it->data);
- if(g_inet_address_get_native_size(addr)==4)
- {
- in_addr_t ip;
- memcpy(&ip,g_inet_address_to_bytes(addr),4);
- whiteip = g_list_prepend(whiteip,GUINT_TO_POINTER(ip));
- g_message(_("%s's DNS result : %s"),(char*)user_data,g_inet_address_to_string(addr));
- }
- }while(( it = g_list_next(it)));
- g_resolver_free_addresses(hosts);
- }
- g_object_unref(source_object);
- g_free(user_data);
- }
- gchar *ptr;
- gchar * one_host =strtok_r(ips," \t",&ptr);
- while( one_host )
- {
- in_addr_t ip = inet_addr(one_host);
- if (ip == INADDR_NONE)
- {
- g_object_ref(dns);
- g_debug(_("host %s is not an ipv4 address, will do async dns lookup"),one_host);
- g_resolver_lookup_by_name_async(dns,one_host,NULL,resove_host_by_dns,g_strdup(one_host));
- }else
- {
- whiteip = g_list_prepend(whiteip,GUINT_TO_POINTER(ip));
- }
- one_host = strtok_r(NULL," \t",&ptr);
- }
- g_object_unref(dns);
- }
- g_module_make_resident(module);
- pcap_hander_register_prepend(http_redirector, 0, IPPROTO_TCP, libnet);
- return NULL;
- }
- void redirector_host_resove_by_dns(GObject *source_object, GAsyncResult *res,gpointer user_data)
- {
- GList * hosts = g_resolver_lookup_by_name_finish(G_RESOLVER(source_object),res,NULL);
- if(hosts)
- {
- GList * it = g_list_first(hosts);
- do
- {
- GInetAddress * addr = (GInetAddress*)(it->data);
- if(g_inet_address_get_native_size(addr)==4)
- {
- memcpy(&redirector_ip,g_inet_address_to_bytes(addr),4);
- g_message(_("DNS result : %s"),g_inet_address_to_string(addr));
- break;
- }
- }while(( it = g_list_next(it)));
- g_resolver_free_addresses(hosts);
- }
- g_object_unref(source_object);
- }
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发表于 2013-04-09 11:38
发表于 2013-04-09 12:11
