{"id":124,"date":"2024-12-03T22:50:56","date_gmt":"2024-12-03T14:50:56","guid":{"rendered":"http:\/\/yangnanbei.top\/?p=124"},"modified":"2024-12-26T20:50:43","modified_gmt":"2024-12-26T12:50:43","slug":"socket%e7%bd%91%e7%bb%9c%e7%bc%96%e7%a8%8b","status":"publish","type":"post","link":"http:\/\/yangnanbei.top\/index.php\/2024\/12\/03\/socket%e7%bd%91%e7%bb%9c%e7%bc%96%e7%a8%8b\/","title":{"rendered":"Socket\u7f51\u7edc\u7f16\u7a0b\u7684\u4e00\u5207"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">TCP\uff0cUDP<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">TCP<\/h2>\n\n\n\n<p>\u7279\u70b9\uff1a<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>\u9762\u5411\u8fde\u63a5<\/li>\n\n\n\n<li>\u8d85\u65f6\u91cd\u4f20<\/li>\n\n\n\n<li>\u62e5\u585e\u63a7\u5236<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">TCP\u4e09\u6b21\u63e1\u624b<\/h3>\n\n\n\n<figure class=\"wp-block-image\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=MTFkZDI4NWE0YzNmMDNjODAxZGU4MDI0MGI2ZTQ1NzFfOVI0cGRTNnlwRzQxMHVEMTRYZExiTlNGdDU2cGR0YVJfVG9rZW46QUlwU2Jva3ZCb2Rmd0t4WXJjUmNYSjh5bnNoXzE3MzUyMTc0MjA6MTczNTIyMTAyMF9WNA'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=MTFkZDI4NWE0YzNmMDNjODAxZGU4MDI0MGI2ZTQ1NzFfOVI0cGRTNnlwRzQxMHVEMTRYZExiTlNGdDU2cGR0YVJfVG9rZW46QUlwU2Jva3ZCb2Rmd0t4WXJjUmNYSjh5bnNoXzE3MzUyMTc0MjA6MTczNTIyMTAyMF9WNA\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">TCP\u56db\u6b21\u6325\u624b<\/h3>\n\n\n\n<figure class=\"wp-block-image\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=ZWFmMTMwNTVhOTBlMTgxY2Q1Yjk1MTU2OGVkMWUxYjZfTkZuOWx2V1NyQW01VTZaamNTczdoR0R3c05zNkZxeGNfVG9rZW46UFNSMmJqa2V2bzdhWkl4OHBsVGN4ajNhbmdiXzE3MzUyMTc0MjA6MTczNTIyMTAyMF9WNA'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=ZWFmMTMwNTVhOTBlMTgxY2Q1Yjk1MTU2OGVkMWUxYjZfTkZuOWx2V1NyQW01VTZaamNTczdoR0R3c05zNkZxeGNfVG9rZW46UFNSMmJqa2V2bzdhWkl4OHBsVGN4ajNhbmdiXzE3MzUyMTc0MjA6MTczNTIyMTAyMF9WNA\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">UDP<\/h2>\n\n\n\n<p>\u7279\u70b9\uff1a<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>\u65e0\u8fde\u63a5<\/li>\n\n\n\n<li>\u4e0d\u53ef\u9760<\/li>\n<\/ol>\n\n\n\n<p>\u4f7f\u7528udp\u7684\u670d\u52a1\uff1aDNS\uff0cSNMP\u8fd9\u4e9b\u573a\u666f\u5bf9\u5ef6\u65f6\u3001\u4e22\u5305\u4e0d\u654f\u611f\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Socket<\/h1>\n\n\n\n<p>socket\u662f\u7f51\u7edc\u7f16\u7a0b\u4e2d\u7ed5\u4e0d\u5f00\u7684\u4e00\u4e2a\u8bdd\u9898\uff0c\u6700\u65e9\u7531\u4f2f\u514b\u5229\u5927\u5b66\u7684\u7814\u7a76\u5458\u63d0\u51fa\uff0c\u4e5f\u79f0\u4f2f\u514b\u5229\u5957\u63a5\u5b57\u3002\u5b83\u53ef\u4ee5\u89c6\u4e3a\u4e00\u4e2a\u7528\u4e8e\u5c4f\u853d\u5e95\u5c42\u534f\u8bae\u6808\u7684\u63a5\u53e3\u3002<\/p>\n\n\n\n<p>\u4e0b\u56fe\u662fsocket\u7f51\u7edc\u7f16\u7a0b\u7ecf\u5178\u7684Client\/Server\u6a21\u578b\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">TCP\u6a21\u578b<\/h3>\n\n\n\n<figure class=\"wp-block-image\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=YmVmNTVhZDBmOGUwZWRlYzg4YzhjMzk2NDJiNGU5ODlfaUFQSlFMUTQ1dnRYZUwzTm43V2o2SDh1M0lnV3VxZ3ZfVG9rZW46Q294SWJETG9Vb2lURVp4NnpiQmNxaXlCbnVmXzE3MzUyMTc0MjA6MTczNTIyMTAyMF9WNA'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=YmVmNTVhZDBmOGUwZWRlYzg4YzhjMzk2NDJiNGU5ODlfaUFQSlFMUTQ1dnRYZUwzTm43V2o2SDh1M0lnV3VxZ3ZfVG9rZW46Q294SWJETG9Vb2lURVp4NnpiQmNxaXlCbnVmXzE3MzUyMTc0MjA6MTczNTIyMTAyMF9WNA\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">UDP\u6a21\u578b<\/h3>\n\n\n\n<figure class=\"wp-block-image\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=NmZlY2MzMTU2MjFmOTZmZDYzMDExNGExNzViMmE4ZmJfZHk4RXN4VEVYbjUyTUpwQ1ZUNGVlbTNoZFpTYVJVYmxfVG9rZW46RHlyTGJKQW40b202OHB4OENEemNUY2xRbkxjXzE3MzUyMTc0MjA6MTczNTIyMTAyMF9WNA'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=NmZlY2MzMTU2MjFmOTZmZDYzMDExNGExNzViMmE4ZmJfZHk4RXN4VEVYbjUyTUpwQ1ZUNGVlbTNoZFpTYVJVYmxfVG9rZW46RHlyTGJKQW40b202OHB4OENEemNUY2xRbkxjXzE3MzUyMTc0MjA6MTczNTIyMTAyMF9WNA\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u6211\u4eec\u53ef\u4ee5\u5c06\u6574\u4e2asocket\u7f51\u7edc\u7684\u6570\u636e\u4f20\u8f93\u60f3\u8c61\u6210\u6253\u7535\u8bdd\u3002\u6253\u7535\u8bdd\u5c31\u9700\u8981\u6709\u7535\u8bdd\u673a\uff0c\u9700\u8981\u5b89\u88c5\u7535\u8bdd\u7ebf\uff0c\u6709\u4e86\u7535\u8bdd\u673a\u88c5\u597d\u7535\u8bdd\u7ebf\uff0c\u6211\u4eec\u8fd8\u9700\u8981\u8d2d\u4e70\u4e00\u4e2a\u7535\u8bdd\u53f7\u7801\uff0c\u8fd9\u6837\u522b\u4eba\u624d\u77e5\u9053\u600e\u4e48\u80fd\u627e\u5230\u4f60\u3002\u5bf9\u6bd4socket\u7684api\uff0cbind\u5c31\u50cf\u662f\u53bb\u7535\u4fe1\u516c\u53f8\u5f00\u6237\uff0clisten\u5c31\u662f\u542c\u5230\u4e86\u7535\u8bdd\u94c3\u58f0\uff0caccept\u5c31\u662f\u62ff\u8d77\u7535\u8bdd\u5f00\u59cb\u63a5\u542c\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td>socket api<\/td><td>socket\u7f16\u7a0b\u542b\u4e49<\/td><td>\u73b0\u5b9e\u4e16\u754c<\/td><\/tr><tr><td>socket<\/td><td>\u521b\u5efasocket<\/td><td>\u5b89\u88c5\u7535\u8bdd\u673a<\/td><\/tr><tr><td>bind<\/td><td>\u7ed1\u5b9a\u7aef\u53e3<\/td><td>\u5f00\u6237\uff0c\u8bbe\u5b9a\u7535\u8bdd\u53f7\u7801<\/td><\/tr><tr><td>listen<\/td><td>\u76d1\u542c\u63cf\u8ff0\u7b26<\/td><td>\u542c\u5230\u7535\u8bdd\u54cd\u94c3<\/td><\/tr><tr><td>connect<\/td><td>\u5efa\u7acb\u8fde\u63a5<\/td><td>\u6253\u901a\u7535\u8bdd<\/td><\/tr><tr><td>accept<\/td><td>\u63a5\u53d7\u6570\u636e<\/td><td>\u6536\u542c<\/td><\/tr><tr><td>send\/sendto<\/td><td>\u53d1\u9001\u6570\u636e<\/td><td>\u8bf4\u8bdd<\/td><\/tr><tr><td>recv\/recvfrom<\/td><td>\u63a5\u6536\u6570\u636e<\/td><td>\u6536\u542c<\/td><\/tr><tr><td>close\/shutdown<\/td><td>\u5173\u95ed\u63cf\u8ff0\u7b26<\/td><td>\u5173\u95ed\u6587\u4ef6<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Socket API\u6982\u8ff0<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">socket &#8211; \u521b\u5efa\u5957\u63a5\u5b57<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>int socket(int domain, int type, int protocol);<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>domain \u6307\u4ee3<code>PF_INET<\/code>\u3001<code>PF_INET6<\/code> \u4ee5\u53ca <code>PF_LOCAL<\/code> \u7b49\uff0c\u8868\u793a\u8981\u521b\u5efa\u4f55\u79cd\u5957\u63a5\u5b57<\/li>\n\n\n\n<li>type \u7684\u53ef\u7528\u503c\n<ul class=\"wp-block-list\">\n<li><code>SOCK_STREAM<\/code>: \u5b57\u8282\u6d41\uff0c\u5bf9\u5e94 TCP<\/li>\n\n\n\n<li><code>SOCK_DGRAM<\/code>\uff1a\u6570\u636e\u62a5\uff0c\u5bf9\u5e94 UDP<\/li>\n\n\n\n<li><code>SOCK_RAW<\/code>: \u539f\u59cb\u5957\u63a5\u5b57<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Protocol \u901a\u4fe1\u534f\u8bae\uff0cdepreciated\uff0c\u4e00\u822c\u586b\u51990<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">bind &#8211; \u7ed1\u5b9a\u7535\u8bdd\u53f7\u7801<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>int bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen);<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>sockfd\uff1asocket\u521b\u5efa\u51fa\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26<\/li>\n\n\n\n<li>addr\uff1a\u901a\u7528\u5730\u5740\uff0c\u6ce8\u610f\u8fd9\u91cc\u7684\u7c7b\u578b\u672c\u8eab\u5e94\u8be5\u662fvoid*\uff0c\u53ea\u662fsocket\u521b\u5efa\u65f6c\u8fd8\u4e0d\u652f\u6301void*\u7c7b\u578b\u3002<strong>bind \u51fd\u6570\u4f1a\u6839\u636e len \u5b57\u6bb5\u5224\u65ad\u4f20\u5165\u7684\u53c2\u6570 addr \u8be5\u600e\u4e48\u89e3\u6790\uff0clen \u5b57\u6bb5\u8868\u793a\u7684\u5c31\u662f\u4f20\u5165\u7684\u5730\u5740\u957f\u5ea6\uff0c\u5b83\u662f\u4e00\u4e2a\u53ef\u53d8\u503c<\/strong>\u3002<\/li>\n\n\n\n<li>addrlen\uff1a\u5730\u5740\u957f\u5ea6<\/li>\n<\/ul>\n\n\n\n<p>\u5bf9\u4e8e\u4f7f\u7528\u8005\u6765\u8bf4\uff0c\u6bcf\u6b21\u4f20\u53c2\u7684\u65f6\u5019\u6211\u4eec\u90fd\u9700\u8981\u628aipv4\uff0cipv6\u6216\u8005\u672c\u5730\u5957\u63a5\u5b57\u8f6c\u5316\u4e3a\u901a\u7528\u5957\u63a5\u5b57\u7684\u683c\u5f0f\uff0c\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct sockaddr_in addr;\nbind(sock, (struct sockaddr*)&amp;addr, sizeof(addr));<\/code><\/pre>\n\n\n\n<p>\u6545\u800c\u6211\u4eec\u53ef\u4ee5\u628abind\u7684\u53c2\u6570\u7406\u89e3\u6210 <code>void*<\/code>, \u53ea\u662fBSD\u8bbe\u8ba1socket\u7684\u65f6\u5019\uff081982\u5e74\uff09, \u90a3\u65f6C\u8fd8\u6ca1\u6709<code>void*<\/code>\u7684\u652f\u6301\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">listen &#8211; \u63a5\u4e0a\u7535\u8bdd\u7ebf<\/h3>\n\n\n\n<p>bind\u51fd\u6570\u8ba9\u6211\u4eec\u7684\u5957\u63a5\u5b57\u548c\u5730\u5740\u5173\u8054\uff0c\u4f46\u662f\u8981\u8ba9\u522b\u4eba\u6253\u901a\u7535\u8bdd\uff0c\u6211\u4eec\u8fd8\u9700\u8981\u63a5\u4e0a\u7535\u8bdd\u7ebf\uff0c\u8ba9\u670d\u52a1\u5904\u4e8e\u53ef\u63a5\u542c\u7684\u72b6\u6001\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>int listen(int listensockfd, int backlog);<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>sockfd: \u5957\u63a5\u5b57\u63cf\u8ff0\u7b26<\/li>\n\n\n\n<li>backlog: \u8868\u793a\u5df2\u5b8c\u6210(<code>ESTABLISHED<\/code>)\u4e14\u672aaccept\u7684\u961f\u5217\u5927\u5c0f\u3002\n<ul class=\"wp-block-list\">\n<li>\u8fd9\u4e2a\u53c2\u6570\u7684\u5927\u5c0f\u51b3\u5b9a\u4e86\u53ef\u4ee5\u63a5\u6536\u7684\u5e76\u53d1\u6570\u76ee\u3002\u8fd9\u4e2a\u53c2\u6570\u8d8a\u5927\uff0c\u7406\u8bba\u4e0a\u5e76\u53d1\u6570\u76ee\u4e5f\u8d8a\u5927\u3002\u4f46\u662f\u53c2\u6570\u8fc7\u5927 -> \u7cfb\u7edf\u8d44\u6e90\u6d88\u8017\u591a\u3002\u5bf9\u4e8eLinux\u7cfb\u7edf\u6765\u8bf4\uff0c\u4e0d\u5141\u8bb8\u5bf9\u8fd9\u4e2a\u53c2\u6570\u8fdb\u884c\u6539\u53d8\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">accept &#8211; \u7535\u8bdd\u94c3\u54cd<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>int accept(int listensockfd, struct sockaddr *_Nullable restrict addr,\n        socklen_t *_Nullable restrict addrlen);<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>sockfd: listen\u5957\u63a5\u5b57\uff0c\u8fd9\u662f\u901a\u8fc7bind\uff0clisten\u4e00\u7cfb\u5217\u64cd\u4f5c\u5f97\u5230\u7684fd<\/li>\n\n\n\n<li>addr: \u6307\u5411\u5ba2\u6237\u7aef\u5730\u5740\u7684\u6307\u9488<\/li>\n\n\n\n<li>addrlen: \u5730\u5740\u7684\u5927\u5c0f<\/li>\n<\/ul>\n\n\n\n<p>\u8981\u6ce8\u610f\u6709\u4e24\u4e2a\u5957\u63a5\u5b57\uff0c\u7b2c\u4e00\u4e2a\u662f\u76d1\u542c\u5957\u63a5\u5b57listensockfd\uff0c\u5176\u4f5c\u4e3a\u8f93\u5165\u53c2\u6570\u5b58\u5728\uff1b\u7b2c\u4e8c\u4e2a\u662f\u8fd4\u56de\u7684\u5df2\u8fde\u63a5\u5957\u63a5\u5b57\u63cf\u8ff0\u5b57\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">connect &#8211; \u62e8\u6253\u7535\u8bdd<\/h3>\n\n\n\n<p>\u4e0a\u8ff0\u7684api\u4e3a\u670d\u52a1\u5668api\uff0c\u73b0\u5728\u6211\u4eec\u6765\u770b\u770b\u5ba2\u6237\u7aef\u7684api\u3002\u5ba2\u6237\u7aef\u548c\u670d\u52a1\u5668\u7aef\u7684\u94fe\u63a5\u5efa\u7acb\uff0c\u662f\u901a\u8fc7connect\u51fd\u6570\u5b8c\u6210\u7684\u3002\u8fd9\u662fconnect\u7684\u6784\u5efa\u51fd\u6570\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>int connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen);<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>sockfdfd: \u7531socket\u51fd\u6570\u521b\u5efa<\/li>\n\n\n\n<li>addr: \u6307\u5411\u5957\u63a5\u5b57\u5730\u5740\u7684\u7ed3\u6784<\/li>\n\n\n\n<li>addrlen: \u5957\u63a5\u5b57\u5730\u5740\u7ed3\u6784\u5927\u5c0f<\/li>\n<\/ul>\n\n\n\n<p>\u5ba2\u6237\u7aef\u5728\u8c03\u7528\u51fd\u6570connect\u524d\u4e0d\u5fc5\u975e\u5f97\u8c03\u7528bind\uff0c\u82e5\u9700\u8981\u7684\u8bdd\uff0c\u5185\u6838\u4f1a\u786e\u5b9a\u6e90ip\u5730\u5740\uff0c\u5e76\u6309\u7167\u4e00\u5b9a\u7684\u7b97\u6cd5\u9009\u62e9\u4e00\u4e2a\u4e34\u65f6\u7aef\u53e3\u4f5c\u4e3a\u6e90\u7aef\u53e3\u3002<\/p>\n\n\n\n<p>\u82e5\u4e3atcp\u5957\u63a5\u5b57\uff0c\u90a3\u4e48\u8c03\u7528connect\u51fd\u6570\u5c06\u6fc0\u53d1TCP\u4e09\u6b21\u63e1\u624b\u7684\u8fc7\u7a0b\uff0c\u800c\u4e14\u53ea\u5728\u8fde\u63a5\u5efa\u7acb\u6210\u529f\u6216\u8005\u51fa\u9519\u7684\u65f6\u5019\u624d\u8fd4\u56de\u3002\u5176\u4e2d\u51fa\u9519\u8fd4\u56de\u53ef\u80fd\u6709\u4ee5\u4e0b\u51e0\u79cd\u60c5\u51b5\uff1a<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>\u4e09\u6b21\u63e1\u624b\u65e0\u6cd5\u5efa\u7acb\uff0c\u5ba2\u6237\u7aef\u53d1\u51fa\u7684SYN\u5305\u6ca1\u6709\u4efb\u4f55\u54cd\u5e94\uff0c\u4e8e\u662f\u8fd4\u56de<code>TIMEOUT<\/code>\u9519\u8bef\u3002\u6b64\u7c7b\u9519\u8bef\u7684\u5e38\u89c1\u539f\u56e0\u662f\u5bf9\u5e94\u7684\u670d\u52a1\u7aefIP\u5199\u9519\u3002<\/li>\n\n\n\n<li>\u5ba2\u6237\u7aef\u6536\u5230\u4e86<strong><code>RST<\/code><\/strong>\u5e94\u7b54\uff0c\u6b64\u65f6\u5ba2\u6237\u7aef\u4f1a\u7acb\u5373\u8fd4\u56de<strong><code>CONNECTION REFUSED<\/code><\/strong>\u9519\u8bef\u3002\u8fd9\u79cd\u60c5\u51b5\u5e38\u89c1\u4e8e\u5ba2\u6237\u7aef\u53d1\u9001\u8fde\u63a5\u8bf7\u6c42\u65f6\u7aef\u53e3\u5199\u9519\u3002\u56e0\u4e3a RST \u662fTCP\u5728\u53d1\u751f\u9519\u8bef\u65f6\u53d1\u9001\u7684\u4e00\u79cdTCP\u5206\u8282\u3002\n<ol class=\"wp-block-list\">\n<li>\u4ea7\u751f<code>RST<\/code>\u7684 \u4e09\u4e2a\u6761\u4ef6\uff1a\n<ol class=\"wp-block-list\">\n<li>\u76ee\u7684\u5730\u4e3a\u67d0\u7aef\u53e3\u7684SYN\u5230\u8fbe\uff0c\u4f46\u662f\u8be5\u7aef\u53e3\u672a\u88ab\u76d1\u542c<\/li>\n\n\n\n<li>TCP\u60f3\u53d6\u6d88\u4e00\u4e2a\u5df2\u6709\u7684\u8fde\u63a5<\/li>\n\n\n\n<li>TCP\u63a5\u6536\u5230\u4e00\u4e2a\u6839\u672c\u4e0d\u5b58\u5728\u7684\u8fde\u63a5\u4e0a\u7684\u5206\u8282<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n\n\n\n<li>\u5ba2\u6237\u7aef\u53d1\u51fa\u7684SYN\u5305\u5728\u7f51\u7edc\u4e0a\u8fd4\u56de\u4e86<strong><code>destination unreachable<\/code><\/strong>, \u5373\u76ee\u7684\u4e0d\u53ef\u8fbe\u9519\u8bef\u3002\u6b64\u7c7b\u9519\u8bef\u7684\u5e38\u89c1\u539f\u56e0\u662f\u8def\u7531\u4e0d\u901a\u3002<\/li>\n\n\n\n<li>\u6536\u53d1\u7f13\u51b2\u533a<\/li>\n<\/ol>\n\n\n\n<p>\u5ba2\u6237\u7aef\u5728\u53d1\u9001\u6570\u636e\u65f6\u53ef\u9009\u62e9\u5982\u4e0b\u56db\u4e2a\u51fd\u6570\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>ssize_t write(int fd, const void *buf, size_t count);\nssize_t send(int sockfd, const void *buf, size_t len, int flags);\nssize_t sendto(int sockfd, const void *buf, size_t len, int flags,\n                      const struct sockaddr *dest_addr, socklen_t addrlen);\nssize_t sendmsg(int sockfd, const struct msghdr *msg, int flags);<\/code><\/pre>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li><code>write<\/code>\u662f\u5e38\u89c1\u7684\u6587\u4ef6\u5199\u51fd\u6570\uff0c\u5982\u679cfd\u6362\u6210\u5e38\u7528\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u5c31\u662f\u666e\u901a\u7684\u5199\u6587\u4ef6\u51fd\u6570\u3002<\/li>\n\n\n\n<li><code>send<\/code> \u7528\u4e8etcp\u6d41\u53d1\u9001\u6570\u636e\uff0c<code>sendto<\/code>\u7528\u4e8eudp\u53d1\u9001\u6570\u636e\u3002\u53ef\u6307\u5b9a\u9009\u9879\u53d1\u9001\u5e26\u5916\u6570\u636e\u3002<\/li>\n\n\n\n<li><code>sendmsg<\/code> \u6307\u5b9a\u591a\u91cd\u7f13\u51b2\u533a\u4f20\u8f93\u6570\u636e\uff0c\u4ee5\u7ed3\u6784\u4f53msghdr\u7684\u65b9\u5f0f\u53d1\u9001\u6570\u636e\u3002<\/li>\n<\/ol>\n\n\n\n<p>\u4ee5\u4e0a\u51fd\u6570\u7684\u4f7f\u7528\u573a\u666f\u4e0d\u540c\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u7f13\u51b2\u533a\u5927\u5c0f<\/h3>\n\n\n\n<p>\u5f53TCP\u4e09\u6b21\u63e1\u624b\u6210\u529f\uff0cTCP\u8fde\u63a5\u5efa\u7acb\u540e\uff0cos kernel \u4f1a\u4e3a\u6bcf\u4e00\u4e2a\u8fde\u63a5\u521b\u5efa\u914d\u5957\u7684\u8bbe\u7f6e\uff0c\u5982<strong>\u53d1\u9001\u7f13\u51b2\u533a\u3002<\/strong><\/p>\n\n\n\n<p>\u5728linux\u7cfb\u7edf\u4e2d\u53d1\u9001\u7f13\u51b2\u533a\u7684\u5927\u5c0f\u53d7\u4ee5\u4e0b\u9009\u9879\u548c\u884c\u4e3a\u63a7\u5236\uff1a<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>\u7531kernel\u63a7\u5236\uff0c\u7f13\u51b2\u533a\u7684\u6700\u5c0f\u503c\uff0c\u9ed8\u8ba4\u503c\u548c\u6700\u5927\u503c\uff1a<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>cat \/proc\/sys\/net\/ipv4\/tcp_wmem\n4096    16384   4194304<\/code><\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>\u7531kernel\u63a7\u5236\uff0c\u7f13\u51b2\u533a\u7684\u6700\u5927\u503c\uff1a<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>cat  \/proc\/sys\/net\/core\/wmem_max\n212992<\/code><\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li>\u7531kernel\u63a7\u5236\uff0c\u7f13\u51b2\u533a\u7684\u9ed8\u8ba4\u503c<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>cat \/proc\/sys\/net\/core\/wmem_default\n212992<\/code><\/pre>\n\n\n\n<ol start=\"4\" class=\"wp-block-list\">\n<li>\u5728socket\u9009\u9879\u4e2d\uff0c\u53ef\u901a\u8fc7<code>setsockopt<\/code>\u8bbe\u7f6e\u7f13\u51b2\u533a\u5927\u5c0f\u4e3an<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>int send_buf_size = 20 * 1024 * 1024;\nsetsockopt(fd, SOL_SOCKET, SO_SEND_BUF, &amp;set_buf_size, sizeof(int));<\/code><\/pre>\n\n\n\n<p>\u8981\u6ce8\u610f\u7684\u662f\uff1a<\/p>\n\n\n\n<p>\u901a\u8fc7<code>setsockopt<\/code>\u8bbe\u7f6e\u7f13\u51b2\u533a\u5927\u5c0f\u4e3an\uff0c\u4f46\u662f\u6700\u5927\u5927\u5c0f\u53d7<code>\/proc\/sys\/net\/core\/wmem_max<\/code>\u63a7\u5236\u3002\u4e14\u5b9e\u9645\u4e0a\u6211\u4eec\u53d1\u73b0<code>getsockopt<\/code>\u83b7\u53d6\u7684\u7f13\u51b2\u533a\u5927\u5c0f\u4e3a2*n\uff0c\u8fd9\u662f\u57fa\u4e8eoverhead\u89e3\u5305\u7684\u9700\u6c42\uff0c\u4f1a\u591a\u9884\u7559\u7a7a\u95f4\u3002<\/p>\n\n\n\n<p>\u6e90\u7801\u7684\u5904\u7406\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>case so_sendbuf:\nif (val &gt; sysctl_wmem_max)\n        val = stsctl_wmen_max;\nif ((val * 2) &lt; SOCK_MIN_SENDBUF)\n        sk-&gt;sk_sndbuf = SOCK_MIN_SENDBUF;\nelse\n        sk-&gt;sk_sendbuf = val * 2;<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u5199\u5165\u6570\u636e<\/h3>\n\n\n\n<p>\u53d1\u9001\u7f13\u51b2\u533a\u7684\u5927\u5c0f\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0a\u7684\u8bbe\u7f6e\u6539\u53d8\uff0c\u5f53\u6211\u4eec\u7684\u7a0b\u5e8f\u8c03\u7528\u5199\u5165\u51fd\u6570\u65f6\uff0c\u5b9e\u9645\u4e0a\u505a\u7684\u4e8b\u662f\u5c06\u6570\u636e\u4eceuser space\u62f7\u8d1d\u5230os kernel\u4e2d\u7684\u53d1\u9001\u7f13\u51b2\u533a\u4e2d\uff0c\u800c\u975e\u5c06\u6570\u636e\u901a\u8fc7socket\u4f20\u51fa\u53bb\u3002\u540e\u7eed\u7684\u90e8\u5206\u7531\u5185\u6838\u534f\u8bae\u6808\u5b8c\u6210\u3002<\/p>\n\n\n\n<p>\u5728\u5199\u5165\u7f13\u51b2\u533a\u7684\u65f6\u5019\u6709\u4e24\u79cd\u60c5\u51b5<strong>\uff08\u975e\u963b\u585e\u60c5\u51b5\u4e0b\uff09<\/strong>\uff1a<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>\u5185\u6838\u7f13\u51b2\u533a\u8db3\u591f\u5927\uff0c\u8db3\u4ee5\u5bb9\u7eb3\u6240\u8981\u53d1\u9001\u7684\u6570\u636e\uff0c\u90a3\u4e48\u81ea\u7136\u8fd4\u56de\u6210\u529f\u3002<\/li>\n\n\n\n<li>\u8981\u53d1\u9001\u7684\u6570\u636e\u957f\u5ea6\u8d85\u8fc7\u4e86\u5f53\u4e0b\u5185\u6838\u7f13\u51b2\u533a\u7684\u7a7a\u95f2\u5927\u5c0f\uff0c\u90a3\u4e48\u8fd9\u4e2a\u65f6\u5019<code>send<\/code>\u51fd\u6570\u4f1a\u8fd4\u56de\u5df2\u6210\u529f\u62f7\u8d1d\u5230\u7f13\u51b2\u533a\u4e2d\u7684\u5b57\u8282\u6570\u3002\u540c\u65f6errno\u4f1a\u88ab\u7f6e\u4e3a<code>EAGAIN<\/code>or<code>EWOULDBLOCK<\/code>\u3002<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">\u8bfb\u53d6\u6570\u636e<\/h3>\n\n\n\n<p>\u8ba9\u6211\u4eec\u4ece\u6700\u7b80\u5355\u7684read\u51fd\u6570\u5f00\u59cb<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>ssize_t read(int fd, void *buffer, size_t size);<\/code><\/pre>\n\n\n\n<p>read\u51fd\u6570\u8981\u6c42os kernel\u4ece\u5957\u63a5\u5b57fd\u8bfb\u53d6\u6700\u591a<code>size<\/code>\u4e2a\u5b57\u8282\uff0c\u5e76\u5c06\u7ed3\u679c\u50a8\u5b58\u5230buffer\u4e2d\u3002\u8fd4\u56de\u503c\u544a\u8bc9\u6211\u4eec\u5b9e\u9645\u8bfb\u53d6\u7684\u5b57\u8282\u6570\u76ee\u3002<\/p>\n\n\n\n<p>\u7279\u6b8a\u60c5\u51b5\uff1a<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>ret == 0; \u8868\u793aEOF(end of file), \u8fd9\u5728\u7f51\u7edc\u4e2d\u8868\u793a\u5bf9\u7aef\u53d1\u9001\u4e86FIN\u5305\uff0c\u8981\u5904\u7406\u65ad\u8fde\u7684\u60c5\u51b5<\/li>\n\n\n\n<li>ret == -1; \u8868\u793a\u51fa\u9519\u3002<\/li>\n<\/ol>\n\n\n\n<h1 class=\"wp-block-heading\">\u76f8\u5173\u95ee\u9898<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">socket\u90e8\u5206<\/h2>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>socket\u9ed8\u8ba4\u4e3a\u963b\u585e\u8c03\u7528\uff0c\u65e2\u7136\u6709\u963b\u585e\u8c03\u7528\uff0c\u90a3\u4e48\u5c31\u6709\u975e\u963b\u585e\u8c03\u7528\u3002\u90a3\u4e48\u5982\u4f55\u4f7f\u7528\u975e\u963b\u585e\u8c03\u7528\u5462\uff1f\u4f7f\u7528\u7684\u573a\u666f\u5728\u54ea\u91cc\u5462\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a\u975e\u963b\u585e\u7684\u573a\u666f\uff1a<strong>\u9ad8\u6027\u80fd\u670d\u52a1\u5668\u7f16\u7a0b<\/strong>\u3002\u6240\u6709\u7684\u8c03\u7528\u90fd\u4e0d\u9700\u8981\u7b49\u5f85\u5bf9\u65b9\u51c6\u5907\u597d\u4e86\u518d\u8fd4\u56de\uff0c\u800c\u662f\u7acb\u5373\u8fd4\u56de\u3002\u90a3\u4e48\u600e\u4e48\u77e5\u9053\u662f\u5426\u51c6\u5907\u597d\u4e86\uff1f<\/p>\n\n\n\n<p>\u5c31\u662f\u5c06fd\u6ce8\u518c\u5230\u7c7b\u4f3cselect\u6216\u8005epoll\u8fd9\u6837\u7684io\u591a\u8def\u590d\u7528\u673a\u5236\u4e2d\uff0c<strong>\u53d8\u591a\u4e2afd\u963b\u585e\u4e3a\u4e00\u4e2afd\u963b\u585e<\/strong>\u3002\u90a3\u4e48\u53ea\u8981\u6709\u4efb\u4f55\u4e00\u4e2afd\u51c6\u5907\u597d\u4e86\uff0cselect\u6216\u8005epoll\u90fd\u4f1a\u8fd4\u56de\u3002\u6211\u4eec\u518d\u4ece\u4e2d\u53d6\u51fafd\u505a\u5bf9\u5e94\u7684\u64cd\u4f5c\u5373\u53ef\u3002<\/p>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>\u5ba2\u6237\u7aef\u5728\u53d1\u8d77connect\u8c03\u7528\u4e4b\u524d\uff0c\u53ef\u4ee5\u8c03\u7528bind\u51fd\u6570\u5417\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a\u5ba2\u6237\u7aef\u53ef\u4ee5bind\u6307\u5b9a\u56fa\u5b9a\u7aef\u53e3\u6765\u5efa\u7acb\u8fde\u63a5\u3002<\/p>\n\n\n\n<p>\u82e5\u6ca1\u6709bind\u5219\u4f1a\u4ea7\u751f\u4e00\u4e2a\u968f\u673a\u7684\u7aef\u53e3\u6765\u5b8c\u6210\u8fde\u63a5\u8bf7\u6c42\u3002<\/p>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li>udp\u662f\u5426\u53ef\u4ee5\u4f7f\u7528connect? udp\u4f7f\u7528connect\u548ctcp\u6709\u4f55\u4e0d\u540c\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1audp<strong>\u53ef\u4ee5\u4f7f\u7528connect<\/strong>\u3002tcp\u534f\u8bae\u4f7f\u7528connect\u662f\u4e3a\u4e86\u8fdb\u884c\u4e09\u6b21\u63e1\u624b\uff0c\u800cudp\u534f\u8bae\u4f7f\u7528connect\u5b9e\u9645\u4e0a\u4e0d\u4f1a\u5411\u5bf9\u7aef\u53d1\u9001\u4efb\u4f55\u62a5\u6587\uff0c\u800c\u53ea\u662f\u5728\u672c\u673a\u5efa\u7acb\u8d77\u56db\u5143\u7ec4\u7684\u4e0a\u4e0b\u6587\u3002udp\u5728\u4f7f\u7528connect\u540e\u53ef\u4ee5\u4f7f\u7528send\u6765\u4ee3\u66ffsendto\uff0c\u8fd9\u662f\u56e0\u4e3a\u56db\u5143\u7ec4\u662f\u4e0a\u4e0b\u6587\u5df2\u7ecf\u5efa\u7acb\uff0c\u82e5\u672a\u4f7f\u7528connect\uff0c\u5219\u9700\u8981\u4f7f\u7528sendto\u663e\u5f0f\u6307\u5b9a\u5bf9\u7aef\u7684ip\u548cport\u3002<\/p>\n\n\n\n<ol start=\"4\" class=\"wp-block-list\">\n<li>write\u51fd\u6570\u4f20\u5165\u666e\u901a\u6587\u4ef6\u63cf\u8ff0\u7b26\u548c\u5957\u63a5\u5b57\u63cf\u8ff0\u7b26\u6709\u4ec0\u4e48\u533a\u522b\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a1\uff09\u5bf9\u4e8e\u666e\u901a\u6587\u4ef6\u63cf\u8ff0\u7b26\u800c\u8a00\uff0c\u4e00\u4e2afd\u4ee3\u8868\u4e00\u4e2a\u6253\u5f00\u4e86\u7684\u6587\u4ef6\u53e5\u67c4\u3002\u901a\u8fc7\u8c03\u7528write\u51fd\u6570\uff0cos kernel\u5e2e\u6211\u4eec\u5f80\u6587\u4ef6\u7cfb\u7edf\u4e2d\u4e0d\u65ad\u5730\u5199\u5165\u5b57\u8282\u6d41\u3002\u901a\u5e38\u800c\u8a00\uff0c\u5199\u5165\u7684\u5b57\u8282\u6d41\u5927\u5c0f\u548c\u8f93\u5165\u53c2\u6570size\u7684\u503c\u662f\u76f8\u7b49\u7684\uff0c\u5426\u5219\u8868\u793a\u51fa\u9519\u3002<\/p>\n\n\n\n<p>2\uff09\u800c\u5bf9\u4e8e\u5957\u63a5\u5b57fd\u6765\u8bf4\uff0c\u5b83\u4ee3\u8868\u4e00\u4e2a\u53cc\u5411\u7684\u8fde\u63a5\uff0c\u5728\u5957\u63a5\u5b57fd\u4e0a\u8c03\u7528write\u5199\u5165\u7684\u5b57\u8282\u6570\u6709\u53ef\u80fd\u6bd4\u6211\u4eec\u7533\u8bf7\u7684\u8981\u5c11\uff08\u5728<strong>\u7f13\u51b2\u533a\u6ee1<\/strong>\u7684\u60c5\u51b5\u4e0b\uff09\u3002<\/p>\n\n\n\n<ol start=\"5\" class=\"wp-block-list\">\n<li>udp\u5355\u6b21\u4f20\u8f93\u7684\u6700\u5927\u6570\u636e\u91cf\u662f\u591a\u5c11\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a\u6211\u4eec\u77e5\u9053ip\u5c01\u5305\u7684\u603b\u957f\u5ea6\u4e3a\u4e24\u5b57\u8282\uff0c\u5373\u4e00\u4e2aip\u5305\u6700\u5927\u957f\u5ea6\u4e3a65535\uff0c\u90a3\u4e48\u51cf\u53bb\u4e00\u4e2aip\u5934\uff0820\u5b57\u8282\uff09\uff0c\u51cf\u53bb\u4e00\u4e2audp\u5934\uff088\u5b57\u8282\uff09= <strong>65507<\/strong>\u5b57\u8282\u3002<\/p>\n\n\n\n<ol start=\"6\" class=\"wp-block-list\">\n<li>\u5728\u5199\u5165\u53d1\u9001\u7f13\u51b2\u533a\u65f6\u82e5\u7f13\u51b2\u533a\u82e5\u6570\u636e\u4e3a\u5168\u90e8\u62f7\u8d1d\uff0c\u5982\u4f55\u89e3\u51b3\u53d1\u9001\u6570\u636e\u4e0d\u5b8c\u6574\u7684\u95ee\u9898\uff1f\uff08\u5373\u6240\u8c13\u534a\u5305\u95ee\u9898\uff09<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a\u7531\u4e8e\u6211\u4eec\u5df2\u77e5\u6210\u529f\u62f7\u8d1d\u5230\u7f13\u51b2\u533a\u7684\u5b57\u8282\u6570\uff0c\u4e00\u4e2a\u8f83\u597d\u7684\u5904\u7406\u65b9\u5f0f\u662f\u5c06\u5269\u4f59\u672a\u62f7\u8d1d\u7684\u6570\u636e\u4fdd\u5b58\u4e0b\u6765\uff0c\u7136\u540e\u76d1\u63a7\u8be5fd\u76f4\u5230\u4e0b\u6b21\u53ef\u5199\u72b6\u6001\u5230\u6765\u3002\u518d\u5c06\u5176\u5199\u5165\u7f13\u51b2\u533a\u3002<\/p>\n\n\n\n<ol start=\"7\" class=\"wp-block-list\">\n<li>\u80fd\u5426\u628a\u5185\u6838\u53d1\u9001\u7f13\u51b2\u533a\u7684\u5927\u5c0f\u65e0\u9650\u8c03\u5927\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a\u4e0d\u884c\u3002<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>\u7f51\u5361\u4e00\u6b21\u53d1\u51fa\u53bb\u7684\u6570\u636e\u8868\u80af\u5b9a\u4e5f\u6709\u4e00\u4e2a\u6700\u5927\u957f\u5ea6\uff0c\u6240\u4ee5\u65e0\u8bba\u7d2f\u8ba1\u518d\u591a\u6570\u636e\u6700\u540e\u90fd\u662f\u8981\u5206\u7247\u53d1\u9001\u7684\u3002<\/li>\n\n\n\n<li>\u6570\u636e\u4f20\u8f93\u6709\u65f6\u5ef6\u8981\u6c42\uff0c\u7f13\u51b2\u533a\u91cc\u5982\u679c\u6709\u6570\u636e\u7684\u8bdd\u4e5f\u4f1a\u6301\u7eed\u8fdb\u884c\u6d88\u8d39\uff0c\u5c06\u7f13\u51b2\u533a\u8bbe\u7f6e\u7684\u592a\u5927\u53cd\u800c\u6d6a\u8d39\u7cfb\u7edf\u8d44\u6e90\u3002<\/li>\n<\/ol>\n\n\n\n<ol start=\"8\" class=\"wp-block-list\">\n<li>\u4e00\u6bb5\u6570\u636e\u6d41\u4ece\u5e94\u7528\u7a0b\u5e8f\u53d1\u9001\u7aef\uff0c\u4e00\u76f4\u5230\u5e94\u7528\u7a0b\u5e8f\u63a5\u6536\u7aef\uff0c\u603b\u5171\u7ecf\u8fc7\u591a\u5c11\u6b21\u62f7\u8d1d\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a8\u6b21\u3002\u4e3b\u8981\u4f53\u4f1atcp\/ip\u5206\u5c42\u7684\u601d\u60f3\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=Y2MxMTYyZDBlMzM5MzE4NWVjMjU2YmVhNTEyNDNiODhfTVpJa2FQNDBRTGVHSVBjcnB2YnJudU9IM1J1dVdlWWtfVG9rZW46RTB4emIzWjhGb2wwcW14VHViMGNBWm55bjJoXzE3MzUyMTc0MjE6MTczNTIyMTAyMV9WNA'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/syfdjmqori.feishu.cn\/space\/api\/box\/stream\/download\/asynccode\/?code=Y2MxMTYyZDBlMzM5MzE4NWVjMjU2YmVhNTEyNDNiODhfTVpJa2FQNDBRTGVHSVBjcnB2YnJudU9IM1J1dVdlWWtfVG9rZW46RTB4emIzWjhGb2wwcW14VHViMGNBWm55bjJoXzE3MzUyMTc0MjE6MTczNTIyMTAyMV9WNA\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">TCP\u534f\u8bae\u90e8\u5206<\/h2>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>\u7b80\u5355\u8bf4\u8bf4\uff0c\u4e3a\u4ec0\u4e48tcp\u8fde\u63a5\u9700\u8981\u4e09\u6b21\u63e1\u624b\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a\u672c\u8d28\u4e0a\u662f\u56e0\u4e3atcp\u8fde\u63a5\u7684\u53cc\u65b9\u90fd\u8981\u786e\u8ba4<strong>\u5404\u81ea\u6536\u53d1\u6d88\u606f\u7684\u80fd\u529b\u662f\u6b63\u5e38\u7684<\/strong>\u3002<\/p>\n\n\n\n<p><code>Client -- syn --&gt; Server<\/code>: \u8fd9\u662f\u5ba2\u6237\u7aef\u7b2c\u4e00\u6b21\u53d1\u9001syn\u6d88\u606f\u5230\u670d\u52a1\u7aef\uff0c\u6b64\u65f6client\u53ef\u4ee5\u786e\u8ba4\u81ea\u5df1\u6709\u53d1\u6d88\u606f\u7684\u80fd\u529b\u3002<\/p>\n\n\n\n<p><code>Clinet &lt;-- syn, ack -- Server<\/code>: \u670d\u52a1\u5668\u53d1\u9001sync\u548cack\u5230\uff0c\u6b64\u65f6server\u786e\u8ba4\u81ea\u5df1\u6709\u6536\uff0c\u53d1\u6d88\u606f\u7684\u80fd\u529b\uff0c\u8fd8\u9700\u786e\u8ba4client\u6709\u6536\u6d88\u606f\u7684\u80fd\u529b\u3002<\/p>\n\n\n\n<p><code>Clinet -- ack --&gt; Server<\/code>: \u5ba2\u6237\u7aef\u786e\u8ba4\u81ea\u5df1\u6709\u63a5\u6536\u7684\u80fd\u529b\u3002<\/p>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>\u5982\u679c\u63e1\u624b\u8fc7\u7a0b\u4e2d\u5ba2\u6237\u7aef\u7684\u7b2c\u4e09\u6b21\u5e94\u7b54\uff0c\u670d\u52a1\u5668\u6ca1\u6709\u6536\u5230\uff0c\u7136\u540e\u5ba2\u6237\u7aef\u5f00\u59cb\u53d1\u6d88\u606f\u7ed9\u670d\u52a1\u5668\uff0c\u8fd9\u65f6\u5019\u670d\u52a1\u5668\u548c\u5ba2\u6237\u7aef\u7684\u8868\u73b0\u662f\u4ec0\u4e48\uff1f\u5ba2\u6237\u7aef\u4f1a\u6536\u5230\u4ec0\u4e48\u8fd4\u56de\uff1f<\/li>\n<\/ol>\n\n\n\n<p>\u7b54\uff1a\u5982\u679c\u4e09\u6b21\u5e94\u7b54\u670d\u52a1\u5668\u6ca1\u6709\u6536\u5230\uff0c\u670d\u52a1\u7aef\u8fde\u63a5\u6ca1\u6709\u5efa\u7acb\uff0c\u5ba2\u6237\u7aef\u8fde\u63a5\u5efa\u7acb\u4e86\uff0c\u53d1\u9001\u7684\u62a5\u6587\u4f1a\u88ab\u8bbe\u7f6e\u4e3a<strong>\u8fde\u63a5RST<\/strong>\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>TCP\uff0cUDP TCP \u7279\u70b9\uff1a TCP\u4e09\u6b21\u63e1\u624b TCP\u56db\u6b21\u6325\u624b UDP \u7279\u70b9\uff1a \u4f7f\u7528udp\u7684\u670d\u52a1\uff1aDNS\uff0cSN 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