{"id":1873,"date":"2019-01-23T13:55:32","date_gmt":"2019-01-23T05:55:32","guid":{"rendered":"https:\/\/www.yusian.com\/blog\/?p=1873"},"modified":"2020-12-02T14:06:14","modified_gmt":"2020-12-02T06:06:14","slug":"tcp%e7%8a%b6%e6%80%81%e8%bd%ac%e6%8d%a2%e9%80%bb%e8%be%91","status":"publish","type":"post","link":"https:\/\/www.yusian.com\/blog\/cpp\/2019\/01\/23\/1355321873.html","title":{"rendered":"TCP\u72b6\u6001\u8f6c\u6362\u903b\u8f91"},"content":{"rendered":"<h3>1\u3001\u5ba2\u6237\u7aef\uff08\u4e3b\u52a8\uff09<\/h3>\n<ul>\n<li>close \u2014> syn_sent \u2014> established \u2014> fin_wait1 \u2014> fin_wait2 \u2014> time_wait \u2014> 2(msl)<\/li>\n<li>close \u2014> syn_sent \u2014> established \u2014> fin_wait1 \u2014> closing \u2014> time_wait \u2014> 2(msl)<\/li>\n<li>close \u2014> syn_sent \u2014> established \u2014> fin_wait1 \u2014> time_wait \u2014> 2(msl)\n<ul>\n<li>msl\uff1amaximum segment lifetime<br \/>\n<!--more--><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>2\u3001\u670d\u52a1\u7aef\uff08\u88ab\u52a8\uff09<\/h3>\n<ul>\n<li>close \u2014> listen \u2014> syn_rcvd \u2014> established \u2014> close_wait \u2014> last_ack \u2014> close<\/li>\n<li>close \u2014> listen \u2014> syn_rcvd &#8212;(RST)&#8212;> listen<br \/>\n<img decoding=\"async\" src=\"https:\/\/www.yusian.com\/blog\/wp-content\/uploads\/2020\/12\/E2574117-2A56-4725-89A7-1D224D20B25D.png\" style=\"zoom:80%\"\/><br \/>\n<img decoding=\"async\" src=\"https:\/\/www.yusian.com\/blog\/wp-content\/uploads\/2020\/12\/7343543D-13F8-44F8-A511-B5B76FB41ED1.png\" style=\"zoom:50%\"\/><\/li>\n<li>CLOSED\uff1a\u8868\u793a\u521d\u59cb\u72b6\u6001\u3002<\/li>\n<li>LISTEN\uff1a\u8be5\u72b6\u6001\u8868\u793a\u670d\u52a1\u5668\u7aef\u7684\u67d0\u4e2aSOCKET\u5904\u4e8e\u76d1\u542c\u72b6\u6001\uff0c\u53ef\u4ee5\u63a5\u53d7\u8fde\u63a5\u3002<\/li>\n<li>SYN_SENT\uff1a\u8fd9\u4e2a\u72b6\u6001\u4e0eSYN_RCVD\u9065\u76f8\u547c\u5e94\uff0c\u5f53\u5ba2\u6237\u7aefSOCKET\u6267\u884cCONNECT\u8fde\u63a5\u65f6\uff0c\u5b83\u9996\u5148\u53d1\u9001SYN\u62a5\u6587\uff0c\u968f\u5373\u8fdb\u5165\u5230\u4e86SYN_SENT\u72b6\u6001\uff0c\u5e76\u7b49\u5f85\u670d\u52a1\u7aef\u7684\u53d1\u9001\u4e09\u6b21\u63e1\u624b\u4e2d\u7684\u7b2c2\u4e2a\u62a5\u6587\u3002SYN_SENT\u72b6\u6001\u8868\u793a\u5ba2\u6237\u7aef\u5df2\u53d1\u9001SYN\u62a5\u6587\u3002<\/li>\n<li>SYN_RCVD: \u8be5\u72b6\u6001\u8868\u793a\u63a5\u6536\u5230SYN\u62a5\u6587\uff0c\u5728\u6b63\u5e38\u60c5\u51b5\u4e0b\uff0c\u8fd9\u4e2a\u72b6\u6001\u662f\u670d\u52a1\u5668\u7aef\u7684SOCKET\u5728\u5efa\u7acbTCP\u8fde\u63a5\u65f6\u7684\u4e09\u6b21\u63e1\u624b\u4f1a\u8bdd\u8fc7\u7a0b\u4e2d\u7684\u4e00\u4e2a\u4e2d\u95f4\u72b6\u6001\uff0c\u5f88\u77ed\u6682\u3002\u6b64\u79cd\u72b6\u6001\u65f6\uff0c\u5f53\u6536\u5230\u5ba2\u6237\u7aef\u7684ACK\u62a5\u6587\u540e\uff0c\u4f1a\u8fdb\u5165\u5230ESTABLISHED\u72b6\u6001\u3002<\/li>\n<li>ESTABLISHED\uff1a\u8868\u793a\u8fde\u63a5\u5df2\u7ecf\u5efa\u7acb\u3002<\/li>\n<li>FIN_WAIT_1:  FIN_WAIT_1\u548cFIN_WAIT_2\u72b6\u6001\u7684\u771f\u6b63\u542b\u4e49\u90fd\u662f\u8868\u793a\u7b49\u5f85\u5bf9\u65b9\u7684FIN\u62a5\u6587\u3002\u533a\u522b\u662f\uff1a\n<ul>\n<li>FIN_WAIT_1\u72b6\u6001\u662f\u5f53socket\u5728ESTABLISHED\u72b6\u6001\u65f6\uff0c\u60f3\u4e3b\u52a8\u5173\u95ed\u8fde\u63a5\uff0c\u5411\u5bf9\u65b9\u53d1\u9001\u4e86FIN\u62a5\u6587\uff0c\u6b64\u65f6\u8be5socket\u8fdb\u5165\u5230FIN_WAIT_1\u72b6\u6001\u3002<\/li>\n<li>FIN_WAIT_2\u72b6\u6001\u662f\u5f53\u5bf9\u65b9\u56de\u5e94ACK\u540e\uff0c\u8be5socket\u8fdb\u5165\u5230FIN_WAIT_2\u72b6\u6001\uff0c\u6b63\u5e38\u60c5\u51b5\u4e0b\uff0c\u5bf9\u65b9\u5e94\u9a6c\u4e0a\u56de\u5e94ACK\u62a5\u6587\uff0c\u6240\u4ee5FIN_WAIT_1\u72b6\u6001\u4e00\u822c\u8f83\u96be\u89c1\u5230\uff0c\u800cFIN_WAIT_2\u72b6\u6001\u53ef\u7528netstat\u770b\u5230\u3002<\/li>\n<\/ul>\n<\/li>\n<li>FIN_WAIT_2\uff1a\u4e3b\u52a8\u5173\u95ed\u94fe\u63a5\u7684\u4e00\u65b9\uff0c\u53d1\u51faFIN\u6536\u5230ACK\u4ee5\u540e\u8fdb\u5165\u8be5\u72b6\u6001\u3002\u79f0\u4e4b\u4e3a\u534a\u8fde\u63a5\u6216\u534a\u5173\u95ed\u72b6\u6001\u3002\u8be5\u72b6\u6001\u4e0b\u7684socket\u53ea\u80fd\u63a5\u6536\u6570\u636e\uff0c\u4e0d\u80fd\u53d1\u3002<\/li>\n<li>TIME_WAIT: \u8868\u793a\u6536\u5230\u4e86\u5bf9\u65b9\u7684FIN\u62a5\u6587\uff0c\u5e76\u53d1\u9001\u51fa\u4e86ACK\u62a5\u6587\uff0c\u7b492MSL\u540e\u5373\u53ef\u56de\u5230CLOSED\u53ef\u7528\u72b6\u6001\u3002\u5982\u679cFIN_WAIT_1\u72b6\u6001\u4e0b\uff0c\u6536\u5230\u5bf9\u65b9\u540c\u65f6\u5e26 FIN\u6807\u5fd7\u548cACK\u6807\u5fd7\u7684\u62a5\u6587\u65f6\uff0c\u53ef\u4ee5\u76f4\u63a5\u8fdb\u5165\u5230TIME_WAIT\u72b6\u6001\uff0c\u800c\u65e0\u987b\u7ecf\u8fc7FIN_WAIT_2\u72b6\u6001\u3002<\/li>\n<li>CLOSING: \u8fd9\u79cd\u72b6\u6001\u8f83\u7279\u6b8a\uff0c\u5c5e\u4e8e\u4e00\u79cd\u8f83\u7f55\u89c1\u7684\u72b6\u6001\u3002\u6b63\u5e38\u60c5\u51b5\u4e0b\uff0c\u5f53\u4f60\u53d1\u9001FIN\u62a5\u6587\u540e\uff0c\u6309\u7406\u6765\u8bf4\u662f\u5e94\u8be5\u5148\u6536\u5230\uff08\u6216\u540c\u65f6\u6536\u5230\uff09\u5bf9\u65b9\u7684 ACK\u62a5\u6587\uff0c\u518d\u6536\u5230\u5bf9\u65b9\u7684FIN\u62a5\u6587\u3002\u4f46\u662fCLOSING\u72b6\u6001\u8868\u793a\u4f60\u53d1\u9001FIN\u62a5\u6587\u540e\uff0c\u5e76\u6ca1\u6709\u6536\u5230\u5bf9\u65b9\u7684ACK\u62a5\u6587\uff0c\u53cd\u800c\u5374\u4e5f\u6536\u5230\u4e86\u5bf9\u65b9\u7684FIN\u62a5\u6587\u3002\u4ec0\u4e48\u60c5\u51b5\u4e0b\u4f1a\u51fa\u73b0\u6b64\u79cd\u60c5\u51b5\u5462\uff1f\u5982\u679c\u53cc\u65b9\u51e0\u4e4e\u5728\u540c\u65f6close\u4e00\u4e2aSOCKET\u7684\u8bdd\uff0c\u90a3\u4e48\u5c31\u51fa\u73b0\u4e86\u53cc\u65b9\u540c\u65f6\u53d1\u9001FIN\u62a5\u6587\u7684\u60c5\u51b5\uff0c\u4e5f\u5373\u4f1a\u51fa\u73b0CLOSING\u72b6\u6001\uff0c\u8868\u793a\u53cc\u65b9\u90fd\u6b63\u5728\u5173\u95edSOCKET\u8fde\u63a5\u3002<\/li>\n<li>CLOSE_WAIT: \u6b64\u79cd\u72b6\u6001\u8868\u793a\u5728\u7b49\u5f85\u5173\u95ed\u3002\u5f53\u5bf9\u65b9\u5173\u95ed\u4e00\u4e2aSOCKET\u540e\u53d1\u9001FIN\u62a5\u6587\u7ed9\u81ea\u5df1\uff0c\u7cfb\u7edf\u4f1a\u56de\u5e94\u4e00\u4e2aACK\u62a5\u6587\u7ed9\u5bf9\u65b9\uff0c\u6b64\u65f6\u5219\u8fdb\u5165\u5230CLOSE_WAIT\u72b6\u6001\u3002\u63a5\u4e0b\u6765\u5462\uff0c\u5bdf\u770b\u662f\u5426\u8fd8\u6709\u6570\u636e\u53d1\u9001\u7ed9\u5bf9\u65b9\uff0c\u5982\u679c\u6ca1\u6709\u53ef\u4ee5 close\u8fd9\u4e2aSOCKET\uff0c\u53d1\u9001FIN\u62a5\u6587\u7ed9\u5bf9\u65b9\uff0c\u5373\u5173\u95ed\u8fde\u63a5\u3002\u6240\u4ee5\u5728CLOSE_WAIT\u72b6\u6001\u4e0b\uff0c\u9700\u8981\u5173\u95ed\u8fde\u63a5\u3002<\/li>\n<li>LAST_ACK: \u8be5\u72b6\u6001\u662f\u88ab\u52a8\u5173\u95ed\u4e00\u65b9\u5728\u53d1\u9001FIN\u62a5\u6587\u540e\uff0c\u6700\u540e\u7b49\u5f85\u5bf9\u65b9\u7684ACK\u62a5\u6587\u3002\u5f53\u6536\u5230ACK\u62a5\u6587\u540e\uff0c\u5373\u53ef\u4ee5\u8fdb\u5165\u5230CLOSED\u53ef\u7528\u72b6\u6001\u3002<\/li>\n<\/ul>\n<h3>3\u3001\u5728Server&#8212;->Client\u901a\u8baf\u73af\u5883\u4e2d\uff0c\u7ed3\u675fClient\u8fdb\u7a0b<\/h3>\n<p><img decoding=\"async\" src=\"https:\/\/www.yusian.com\/blog\/wp-content\/uploads\/2020\/12\/DB510012-5D90-4226-9046-1EBF6C0A805D.png\" style=\"zoom:40%\" \/><\/p>\n<ul>\n<li>FIN_WAIT1\u72b6\u6001\u65f6\u95f4\u5f88\u77ed\uff0c\u540e\u7eed\u63a5\u6536\u62a5\u6587\u4e0d\u540c\uff0c\u72b6\u6001\u8f6c\u53d8\u4e5f\u4e0d\u4e00\u6837\n<ul>\n<li>FIN_WAIT1 &#8212;(ACK)&#8211;> FIN_WAIT2 &#8212;(FIN)&#8211;> TIME_WAIT &#8212;(ACK)&#8211;>2(MSL)<\/li>\n<li>FIN_WAIT1 &#8212;(FIN)&#8211;> CLOSING   &#8212;(ACK)&#8211;> TIME-WAIT &#8212;(ACK)&#8211;>2(MSL)<\/li>\n<li>FIN_WAIT1 &#8212;(ACK+FIN)&#8211;> TIME_WAITGG &#8212;(ACK)&#8211;>2(MSL)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>4\u3001\u5728Server&#8212;->Client\u901a\u8baf\u73af\u5883\u4e2d\uff0c\u7ed3\u675fServer\u8fdb\u7a0b<\/h3>\n<p><img decoding=\"async\" src=\"https:\/\/www.yusian.com\/blog\/wp-content\/uploads\/2020\/12\/A38EC63D-5ABF-497E-AD6A-5CA2667BFF01.png\" style=\"zoom:40%\" \/><\/p>\n<ul>\n<li>Server\u8fdb\u7a0b\u7ed3\u675f\u524d\u53d1\u9001FIN\u62a5\u6587\uff0c\u901a\u8baf\u72b6\u6001\u7531ESTABLISHED \u2014\u2014> FIN_WAIT1<\/li>\n<li>Client\u6536\u5230FIN\u62a5\u6587\u540e\uff0c\u72b6\u6001\u7531ESTABLISHED \u2014\u2014> CLOSE_WAIT\uff0c\u56de\u590dACK\u62a5\u6587<\/li>\n<li>Server\u6536\u5230ACK\u62a5\u6587\u540e\uff0c\u72b6\u6001\u7531FIN_WAIT1 \u2014\u2014> FIN_WAIT2<\/li>\n<\/ul>\n<h3>5\u3001shutdown\u51fd\u6570<\/h3>\n<ul>\n<li>\u76f8\u6bd4close\u51fd\u6570\n<ul>\n<li>\u53ef\u4ee5\u53ea\u5173\u95ed\u8bfb(SHUT_RD)\u3001\u5199(SHUT_WR)\u6216\u8bfb\u5199(SHUT_RDWR)\u7684\u64cd\u4f5c\uff1b<\/li>\n<li>\u4e0d\u8003\u8651\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u5f15\u7528\u8ba1\u6570\uff0c\u76f4\u63a5\u5173\u95ed\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<pre><code class=\"language-c line-numbers\">#include &lt;sys\/socket.h&gt;\n\nint shutdown(int sockfd, int how);\n\nDESCRIPTION\n       The  shutdown()  call causes all or part of a full-duplex connection on the socket associated with sockfd to be shut down.  If how is SHUT_RD, further receptions will be disallowed.  If how is SHUT_WR, further transmissions will be disallowed.  If how  is  SHUT_RDWR,  further  receptions  and transmissions will be disallowed.\n\nRETURN VALUE\n       On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.\n<\/code><\/pre>\n<h3>6\u3001setsockopt\u51fd\u6570<\/h3>\n<ul>\n<li>\u4e3a\u89e3\u51b3\u7aef\u53e3\u590d\u7528\u7684\u95ee\u9898\uff0c\u53ef\u4ee5\u4f7f\u7528setsockopt\u51fd\u6570<\/li>\n<\/ul>\n<pre><code class=\"language-c line-numbers\">#include &lt;sys\/types.h&gt;          \/* See NOTES *\/\n#include &lt;sys\/socket.h&gt;\n\nint getsockopt(int sockfd, int level, int optname, void *optval, socklen_t *optlen);\n\nint setsockopt(int sockfd, int level, int optname, const void *optval, socklen_t optlen);\n<\/code><\/pre>\n<p>e.g<\/p>\n<pre><code class=\"language-c line-numbers\">int optval = 1;\nsetsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &amp;optval, sizeof(optval));\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>1\u3001\u5ba2\u6237\u7aef\uff08\u4e3b\u52a8\uff09 close \u2014> syn_sent \u2014> established \u2014> fin_wait1 \u2014> fin_wait2 \u2014> time_wait \u2014> 2(msl) close \u2014> syn_sent \u2014> established \u2014> fin_wait1 \u2014> closing \u2014> time_wait \u2014> 2(msl) close \u2014> syn_sent \u2014> established \u2014> fin_wait1 \u2014> time_wait \u2014> 2(msl) msl\uff1amaximum segment lifetime<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[88],"tags":[310,265,324,321],"class_list":["post-1873","post","type-post","status-publish","format-standard","hentry","category-cpp","tag-linux","tag-socket","tag-tcp","tag-321"],"_links":{"self":[{"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/posts\/1873","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/comments?post=1873"}],"version-history":[{"count":0,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/posts\/1873\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/media?parent=1873"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/categories?post=1873"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/tags?post=1873"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}