{"id":2436,"date":"2024-03-19T02:12:11","date_gmt":"2024-03-18T18:12:11","guid":{"rendered":"http:\/\/www.ccwifi.cc\/blogs\/?p=2436"},"modified":"2024-03-19T02:12:11","modified_gmt":"2024-03-18T18:12:11","slug":"%e6%8f%a1%e6%89%8b%e5%8c%85%e4%b8%8b%e8%bd%bd%e5%be%aa%e5%ba%8f%e6%b8%90%e8%bf%9b%e6%90%9e%e6%87%82tcp%e4%b8%89%e6%ac%a1%e6%8f%a18405","status":"publish","type":"post","link":"https:\/\/www.ccwifi.cc\/blogs\/2024\/03\/19\/%e6%8f%a1%e6%89%8b%e5%8c%85%e4%b8%8b%e8%bd%bd%e5%be%aa%e5%ba%8f%e6%b8%90%e8%bf%9b%e6%90%9e%e6%87%82tcp%e4%b8%89%e6%ac%a1%e6%8f%a18405\/","title":{"rendered":"\u63e1\u624b\u5305\u4e0b\u8f7d \u5faa\u5e8f\u6e10\u8fdb\u641e\u61c2 TCP \u4e09\u6b21\u63e1\u624b\u6838\u5fc3"},"content":{"rendered":"
\n

\u5728\u7ebfwifi\u8dd1\u5305 \u91d1\u521a\u5305\u8dd1\u5305 cap\u8dd1\u5305 hccapx ewsa\u5728\u7ebf \u5c31\u6765 \u63e1\u624b\u5305\u8dd1\u5305<\/a><\/strong><\/p>\n

\u5404\u4f4d\u597d \u53c8\u89c1\u9762\u4e86 \u6211\u662f\u66f9\u64cd \u4eca\u5929\u7ed9\u5927\u5bb6\u5e26\u6765\u4e00\u7bc7\u65b0\u7684\u6559\u7a0b<\/p>\n

\u5e0c\u671b\u5404\u4f4d\u7ec6\u5fc3\u5b66\u4e60 \u4f4e\u8c03\u7528\u7f51<\/p>\n<\/div>\n

\"\u63e1\u624b\u5305\u4e0b\u8f7d\"<\/p>\n

\u5f15\u8a00\uff1a\u672c\u6587\u7684\u76ee\u7684\u662f\u901a\u8fc7\u751f\u52a8\u7684\u4f8b\u5b50\u548c\u5b9e\u9645\u64cd\u4f5c\uff0c\u5c06\u62bd\u8c61\u7684\u3001\u865a\u62df\u7684\u7f51\u7edc\u8f6c\u5316\u4e3a\u5177\u4f53\u7684\u3001\u53ef\u89c6\u5316\u7684\u5f62\u5f0f\u3002\u901a\u8fc7\u9010\u6b65\u638c\u63e1TCP\u4e09\u6b21\u63e1\u624b\u7684\u6838\u5fc3\u77e5\u8bc6\u70b9\uff0c\u4e3a\u6df1\u5165\u5b66\u4e60TCP\u534f\u8bae\u6253\u4e0b\u57fa\u7840\u3002<\/p>\n

\u901a\u4fd7\u7248\uff1a\u5982\u4e0b\u56fe\u6240\u793a\uff0c\u5c0f\u660e\uff08\u5ba2\u6237\u7aef\uff09\u7ed9\u5c0f\u7f8e\uff08\u670d\u52a1\u7aef\uff09\u6253\u7535\u8bdd\uff0c\u5728\u7ecf\u8fc7\u4e92\u76f8\u8be2\u95ee\u548c\u5e94\u7b54\uff0c\u786e\u8ba4\u901a\u4fe1\u7545\u901a\u540e\uff0c\u624d\u5f00\u59cb\u6109\u5feb\u5730\u804a\u5929\u3002\uff08\u8bf7\u6ce8\u610f\uff0c\u8fd9\u4e2a\u4f8b\u5b50\u5e76\u4e0d\u4e00\u5b9a\u662f\u5b8c\u7f8e\u7684\uff0c\u4e3b\u8981\u662f\u4e3a\u4e86\u7406\u89e3\u6982\u5ff5\uff09<\/p>\n

\"\u63e1\u624b\u5305\u4e0b\u8f7d\"\"\u63e1\u624b\u5305\u4e0b\u8f7d\"<\/p>\n

\u7ec6\u8282\u7248\uff1a\u4e00\u4e2aTCP\u62a5\u6587\u6bb5\u5206\u4e3a\u9996\u90e8\u548c\u6570\u636e\u4e24\u90e8\u5206\uff0cTCP\u7684\u6240\u6709\u529f\u80fd\u90fd\u4f53\u73b0\u5728\u9996\u90e8\u7684\u5404\u4e2a\u5b57\u6bb5\u4e2d\u3002<\/p>\n

\u5e8f\u5217\u53f7\uff1a\u672c\u62a5\u6587\u6bb5\u6240\u53d1\u9001\u6570\u636e\u7684\u7b2c\u4e00\u4e2a\u5b57\u8282\u7684\u5e8f\u53f7\uff0c\u5728\u5efa\u7acb\u8fde\u63a5\u65f6\u4f1a\u968f\u673a\u751f\u6210\u521d\u59cb\u5e8f\u5217\u53f7ISN\uff08Inital Sequence Number\uff09\u3002<\/p>\n

\u786e\u8ba4\u53f7\uff1a\u4e0b\u4e00\u6b21\u5e94\u8be5\u6536\u5230\u7684\u6570\u636e\u7684\u5e8f\u5217\u53f7\uff0c\u82e5\u786e\u8ba4\u53f7\u4e3aN\uff0c\u5219\u4ee3\u8868\u5230\u5e8f\u5217\u53f7N-1\u4e3a\u6b62\u7684\u6570\u636e\u90fd\u5df2\u7ecf\u6b63\u786e\u6536\u5230\u3002<\/p>\n

\u63a7\u5236\u4f4d\uff1a<\/p>\n

func main() {\n  \/\/ \u76d1\u542c\u7aef\u53e3\n  l, err := net.Listen(\"tcp\", \"0.0.0.0:8080\")\n  if err != nil {\n    panic(err)\n  }\n  defer l.Close()\n  for {\n    \/\/ \u63a5\u53d7\u8fde\u63a5\n    conn, err := l.Accept()\n    if err != nil {\n      log.Printf(\"accept err: %sn\", err)\n      continue\n    }\n    go hello(conn)\n  }\n}\nfunc hello(conn net.Conn) {\n  defer conn.Close()\n  buf := make([]byte, 1024)\n  \/\/ \u8bfb\u6570\u636e\n  if _, err := conn.Read(buf); err != nil {\n    log.Printf(\"conn read err: %sn\", err)\n    return\n  }\n  log.Printf(\"%sn\", string(buf))\n  \/\/ \u5199\u6570\u636e\n  if _, err := conn.Write([]byte(\"hello, xiao ming.n\")); err != nil {\n    log.Printf(\"conn write err: %sn\", err)\n    return\n  }\n}\n<\/code><\/pre>\n
echo -n \"hello, xiao mei.\" | nc 81.68.197.93 8080\n<\/code><\/pre>\n
\u7531\u4e8e\u4e0a\u8ff0\u62a5\u6587\u90fd\u672a\u643a\u5e26\u6570\u636e\uff0c\u5373len=0\uff0c\u6240\u4ee5\u54cd\u5e94\u7684ack\u7b49\u4e8e\u8bf7\u6c42\u7684seq+1\u3002<\/p>\n
\u5b9e\u6218\u7248\uff1a\u4e3a\u4e86\u6355\u83b7\u6bd4\u8f83\u7eaf\u51c0\u7684\u6570\u636e\u5305\uff0c\u6211\u4eec\u5b9e\u73b0\u4e86\u4e00\u4e2a\u7b80\u5355\u7684TCP\u670d\u52a1\u5668\uff0c\u7528\u4e8e\u63a5\u6536\u5ba2\u6237\u7aef\u7684\u8bf7\u6c42\u5e76\u8fdb\u884c\u56de\u590d\u3002<\/p>\n
\u5ba2\u6237\u7aef\u8bf7\u6c42\uff1a<\/p>\n
\"\u63e1\u624b\u5305\u4e0b\u8f7d\"\"\u63e1\u624b\u5305\u4e0b\u8f7d\"<\/p>\n
\u4f7f\u7528Wireshark\u8fdb\u884c\u5206\u6790\uff08\u7edf\u8ba1-\u6d41\u91cf\u56fe\uff09\uff0c\u53ef\u4ee5\u6e05\u695a\u5730\u770b\u5230\u4e09\u6b21\u63e1\u624b\u7684\u8fc7\u7a0b\u3002\u540c\u65f6\u4e5f\u53ef\u4ee5\u770b\u5230\u5e8f\u5217\u53f7\uff08seq\uff09\u548c\u786e\u8ba4\u53f7\uff08ack\uff09\u4e4b\u95f4\u7684\u5173\u7cfb\u3002\u5728\u63e1\u624b\u6210\u529f\u540e\uff0c\u53d1\u9001\u4e86len=16\u7684\u6570\u636e\u5305\uff0c\u7136\u540eack=17\u8868\u793a\u5e8f\u5217\u53f7\u572816\u4e4b\u524d\u7684\u6570\u636e\u90fd\u5df2\u7ecf\u6b63\u786e\u63a5\u6536\u3002<\/p>\n
\u6ce8\u610f\uff1aISN\u662f\u4e00\u4e2a\u968f\u673a\u6570\uff0c\u5e76\u4e0d\u4e3a0\u3002\u4e3a\u4e86\u663e\u793a\u66f4\u53cb\u597d\uff0cWireshark\u4f7f\u7528\u4e86\u76f8\u5bf9\u5e8f\u53f7\u3002\u53d6\u6d88\u76f8\u5bf9\u5e8f\u53f7\u663e\u793a\u540e\uff0c\u53ef\u4ee5\u770b\u5230\u771f\u6b63\u7684\u5e8f\u5217\u53f7\uff0c\u4f8b\u5982Seq=3503481500\u3002<\/p>\n
\"\u63e1\u624b\u5305\u4e0b\u8f7d\"<\/p>\n
# \u4f7f\u7528 netstat \u547d\u4ee4\u67e5\u770b\u5f53\u524d\u7cfb\u7edf\u7684 TCP \u8fde\u63a5\u72b6\u6001\n$ netstat -t\nActive Internet connections (w\/o servers)\nProto Recv-Q Send-Q Local Address           Foreign Address         State\ntcp        0      0 ubuntu:58824            39.156.66.18:http       TIME_WAIT\ntcp        0      0 localhost:20172         localhost:37276         ESTABLISHED<\/code><\/pre>\n
\u63e1\u624b\u5305\u6e90\u6587\u4ef6\u4e0b\u8f7d\u5730\u5740<\/p>\n
\u72b6\u6001\u673a\uff1aTCP\u6240\u8c13\u7684\u9762\u5411\u8fde\u63a5\u672c\u8d28\u4e0a\u662f\u5ba2\u6237\u7aef\u548c\u670d\u52a1\u7aef\u5404\u81ea\u7ef4\u62a4\u7684\u4e00\u4e2a”\u8fde\u63a5\u72b6\u6001”\u3002\u5728\u4e09\u6b21\u63e1\u624b\u671f\u95f4\uff0c\u72b6\u6001\u7684\u53d8\u5316\u5982\u4e0b\uff1a<\/p>\n
LISTEN\uff1a\u670d\u52a1\u7aef\u4e3b\u52a8\u76d1\u542c\u4e00\u4e2a\u7aef\u53e3\uff0c\u7b49\u5f85\u5ba2\u6237\u7aef\u7684\u8fde\u63a5\u8bf7\u6c42<\/p>\n
SYN-SENT\uff1a\u53d1\u9001SYN\u5305\u540e\u7684\u72b6\u6001<\/p>\n
SYN-RECEIVED\uff1a\u6536\u5230SYN\u5305\uff0c\u5e76\u53d1\u9001\u4e86SYN+ACK\u5305\u540e\u7684\u72b6\u6001<\/p>\n
ESTABLISHED\uff1a\u8fde\u63a5\u5efa\u7acb\u6210\u529f<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63e1\u624b\u5305\u4e0b\u8f7d \u5faa\u5e8f\u6e10\u8fdb\u641e\u61c2 TCP \u4e09\u6b21\u63e1\u624b\u6838\u5fc3\u524d\u8a00\u672c\u6587\u65e8\u5728\u901a\u8fc7\u5f62\u8c61\u7684\u4f8b\u5b50\u548c\u5b9e\u64cd\uff0c\u628a\u65e0\u5f62\u7684\u3001\u865a\u62df\u7684\u7f51\u7edc\u8f6c\u4e3a\u5177\u4f53\u7684\u3001\u53ef\u89c6\u5316\u7684\u3002\u5e26\u9886\u7f51\u7edc\u5c0f\u767d\u4e00\u6b65\u6b65\u7684\u638c\u63e1 TCP \u4e09\u6b21\u63e1\u624b\u6838\u5fc3\u77e5\u8bc6\u70b9\uff0c\u4e3a\u540e\u7eed\u6df1\u5165\u5b66\u4e60 TCP \u534f\u8bae\u6253\u57fa\u7840\u3002\u901a\u4fd7\u7248\u5982\u4e0b\u56fe\u6240\u793a<\/p>\n","protected":false},"author":1,"featured_media":2437,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"topic":[],"class_list":["post-2436","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-1"],"_links":{"self":[{"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/posts\/2436","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/comments?post=2436"}],"version-history":[{"count":0,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/posts\/2436\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/media\/2437"}],"wp:attachment":[{"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/media?parent=2436"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/categories?post=2436"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/tags?post=2436"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/topic?post=2436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}