TCP connect EADDRNOTAVAIL(99)错误原因分析
转自:http://blog.chinaunix.net/uid-20662820-id-3371081.html
关于TCP connect 返回错误99,可以能大家都会遇到,这里就分析一下这个错误的真正含义:
点击(此处)折叠或打开
- int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
- {
- struct inet_sock *inet = inet_sk(sk);
- struct tcp_sock *tp = tcp_sk(sk);
- struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
- struct rtable *rt;
- __be32 daddr, nexthop;
- int tmp;
- int err;
- if (addr_len < sizeof(struct sockaddr_in))
- return -EINVAL;
- if (usin->sin_family != AF_INET)
- return -EAFNOSUPPORT;
- nexthop = daddr = usin->sin_addr.s_addr;
- if (inet->opt && inet->opt->srr) {
- if (!daddr)
- return -EINVAL;
- nexthop = inet->opt->faddr;
- }
- tmp = ip_route_connect(&rt, nexthop, inet->saddr,
- RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
- IPPROTO_TCP,
- inet->sport, usin->sin_port, sk, 1);
- if (tmp < 0) {
- if (tmp == -ENETUNREACH)
- IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
- return tmp;
- }
- if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
- ip_rt_put(rt);
- return -ENETUNREACH;
- }
- if (!inet->opt || !inet->opt->srr)
- daddr = rt->rt_dst;
- if (!inet->saddr)
- inet->saddr = rt->rt_src;
- inet->rcv_saddr = inet->saddr;
- if (tp->rx_opt.ts_recent_stamp && inet->daddr != daddr) {
- /* Reset inherited state */
- tp->rx_opt.ts_recent = 0;
- tp->rx_opt.ts_recent_stamp = 0;
- tp->write_seq = 0;
- }
- if (tcp_death_row.sysctl_tw_recycle &&
- !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
- struct inet_peer *peer = rt_get_peer(rt);
- /*
- * VJ's idea. We save last timestamp seen from
- * the destination in peer table, when entering state
- * TIME-WAIT * and initialize rx_opt.ts_recent from it,
- * when trying new connection.
- */
- if (peer != NULL &&
- peer->tcp_ts_stamp + TCP_PAWS_MSL >= get_seconds()) {
- tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
- tp->rx_opt.ts_recent = peer->tcp_ts;
- }
- }
- inet->dport = usin->sin_port;
- inet->daddr = daddr;
- inet_csk(sk)->icsk_ext_hdr_len = 0;
- if (inet->opt)
- inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
- tp->rx_opt.mss_clamp = 536;
- /* Socket identity is still unknown (sport may be zero).
- * However we set state to SYN-SENT and not releasing socket
- * lock select source port, enter ourselves into the hash tables and
- * complete initialization after this.
- */
- tcp_set_state(sk, TCP_SYN_SENT);
- err = inet_hash_connect(&tcp_death_row, sk);
- if (err)
- goto failure;
- err = ip_route_newports(&rt, IPPROTO_TCP,
- inet->sport, inet->dport, sk);
- if (err)
- goto failure;
- /* OK, now commit destination to socket. */
- sk->sk_gso_type = SKB_GSO_TCPV4;
- sk_setup_caps(sk, &rt->u.dst);
- if (!tp->write_seq)
- tp->write_seq = secure_tcp_sequence_number(inet->saddr,
- inet->daddr,
- inet->sport,
- usin->sin_port);
- inet->id = tp->write_seq ^ jiffies;
- err = tcp_connect(sk);
- rt = NULL;
- if (err)
- goto failure;
- return 0;
- failure:
- /*
- * This unhashes the socket and releases the local port,
- * if necessary.
- */
- tcp_set_state(sk, TCP_CLOSE);
- ip_rt_put(rt);
- sk->sk_route_caps = 0;
- inet->dport = 0;
- return err;
- }
这里进入第84行代码的函数inet_hash_connect 查找一个本地可用端口与服务器建立连接
点击(此处)折叠或打开
- int inet_hash_connect(struct inet_timewait_death_row *death_row,
- struct sock *sk)
- {
- return __inet_hash_connect(death_row, sk, inet_sk_port_offset(sk),
- __inet_check_established, __inet_hash_nolisten);
- }
该函数实际上调用_inet_hash_connect
点击(此处)折叠或打开
- int __inet_hash_connect(struct inet_timewait_death_row *death_row,
- struct sock *sk, u32 port_offset,
- int (*check_established)(struct inet_timewait_death_row *,
- struct sock *, __u16, struct inet_timewait_sock **),
- void (*hash)(struct sock *sk))
- {
- struct inet_hashinfo *hinfo = death_row->hashinfo;
- const unsigned short snum = inet_sk(sk)->num;
- struct inet_bind_hashbucket *head;
- struct inet_bind_bucket *tb;
- int ret;
- struct net *net = sock_net(sk);
- if (!snum) {
- int i, remaining, low, high, port;
- static u32 hint;
- u32 offset = hint + port_offset;
- struct hlist_node *node;
- struct inet_timewait_sock *tw = NULL;
- inet_get_local_port_range(&low, &high);
- remaining = (high - low) + 1;
- local_bh_disable();
- for (i = 1; i <= remaining; i++) {
- port = low + (i + offset) % remaining;
- head = &hinfo->bhash[inet_bhashfn(net, port,
- hinfo->bhash_size)];
- spin_lock(&head->lock);
- /* Does not bother with rcv_saddr checks,
- * because the established check is already
- * unique enough.
- */
- inet_bind_bucket_for_each(tb, node, &head->chain) {
- if (ib_net(tb) == net && tb->port == port) {
- if (tb->fastreuse >= 0)
- goto next_port;
- WARN_ON(hlist_empty(&tb->owners));
- if (!check_established(death_row, sk,
- port, &tw))
- goto ok;
- goto next_port;
- }
- }
- tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
- net, head, port);
- if (!tb) {
- spin_unlock(&head->lock);
- break;
- }
- tb->fastreuse = -1;
- goto ok;
- next_port:
- spin_unlock(&head->lock);
- }
- local_bh_enable();
- return -EADDRNOTAVAIL;
- ok:
- hint += i;
- /* Head lock still held and bh's disabled */
- inet_bind_hash(sk, tb, port);
- if (sk_unhashed(sk)) {
- inet_sk(sk)->sport = htons(port);
- hash(sk);
- }
- spin_unlock(&head->lock);
- if (tw) {
- inet_twsk_deschedule(tw, death_row);
- inet_twsk_put(tw);
- }
- ret = 0;
- goto out;
- }
- head = &hinfo->bhash[inet_bhashfn(net, snum, hinfo->bhash_size)];
- tb = inet_csk(sk)->icsk_bind_hash;
- spin_lock_bh(&head->lock);
- if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
- hash(sk);
- spin_unlock_bh(&head->lock);
- return 0;
- } else {
- spin_unlock(&head->lock);
- /* No definite answer... Walk to established hash table */
- ret = check_established(death_row, sk, snum, NULL);
- out:
- local_bh_enable();
- return ret;
- }
- }
注意第61行代码,这里返回了EADDRNOTAVAIL错误。
点击(此处)折叠或打开
- void inet_get_local_port_range(int *low, int *high)
- {
- unsigned seq;
- do {
- seq = read_seqbegin(&sysctl_local_ports.lock);
- *low = sysctl_local_ports.range[0];
- *high = sysctl_local_ports.range[1];
- } while (read_seqretry(&sysctl_local_ports.lock, seq));
- }
然后内核在这个范围内选择一个可用的端口作为本地端口去connect服务器,如果没有可用的端口可用,比如这个范围内的端口都处于如下状态中的一种:
TCP connect EADDRNOTAVAIL(99)错误原因分析的更多相关文章
- loadFileSystems error & ExceptionUtils错误原因分析
loadFileSystems error & ExceptionUtils错误原因分析 一见 2014/5/7 C/C++程序通过hdfs.h访问HDFS,运行时遇到如下错误,会是什么原因了 ...
- “undefined reference to JNI_GetCreatedJavaVM”和“File format not recognized”错误原因分析
"undefined reference to JNI_GetCreatedJavaVM"和"File format not recognized"错误原因分析 ...
- SQL Server 磁盘请求超时的833错误原因分析以及解决
本文出处:http://www.cnblogs.com/wy123/p/6984885.html 最近遇到一个SQL Server服务器响应极度缓慢,并且出现客户端请求报错的情况,在数据库中的erro ...
- 微信的redirect_uri参数错误原因分析
我们可以根据微信的开发者文档 http://mp.weixin.qq.com/wiki/17/c0f37d5704f0b64713d5d2c37b468d75.html 网页授权获取用户验证这一章来 ...
- Entity Framework 数据并发访问错误原因分析与系统架构优化
博客地址 http://blog.csdn.net/foxdave 本文主要记录近两天针对项目发生的数据访问问题的分析研究过程与系统架构优化,我喜欢说通俗的白话,高手轻拍 1. 发现问题 系统新模块上 ...
- 启动Hadoop HDFS时的“Incompatible clusterIDs”错误原因分析
"Incompatible clusterIDs"的错误原因是在执行"hdfs namenode -format"之前,没有清空DataNode节点的data目 ...
- Apache ab压力测试时出现大量的错误原因分析
最近有一个测试任务,是测试nginx的并发请求到底能够达到多少的, 于是就用ab工具对其进行压力测试. 这压力测试一执行,问题就来了:发起10000次请求,并发100,错误的情况能达到30%--50% ...
- FTP上传文件提示550错误原因分析。
今天测试FTP上传文件功能,同样的代码从自己的Demo移到正式的代码中,不能实现功能,并报 Stream rs = ftp.GetRequestStream()提示远程服务器返回错误: (550) 文 ...
- golang学习遭遇错误原因分析续
7. error: reference to field ‘Printf’ in object which has no fields or methods f.Printf("%v&quo ...
随机推荐
- 不是技术牛人,如何拿到国内IT巨头的Offer【转】
转:http://blog.csdn.net/lsldd/article/details/13506263 不久前,byvoid面阿里星计划的面试结果截图泄漏,引起无数IT屌丝的羡慕敬仰.看看这些牛人 ...
- SuperMap iClient
SuperMap iClient 7C——网络客户端GIS开发平台 产品新特性 SuperMap iClient 7C是空间信息和服务的可视化交互开发平台,是SuperMap服务器系列产品的统一客 ...
- 如何安装ArchLinux
如何安装ArchLinux 本文基于ArchLinux(https://www.archlinux.org/)Current Release: 2013.08.01的ISO写的安装教程! ISO下 ...
- ios学习笔记(一)之Object-C
一:Objective-C语言基础 二:Objective-C类与继承和协议 一:Objective-C语言基础: 1.1)#import 包含头文件 与#include 作用相同 1.2)Obje ...
- Windbg是windows平台上强大的调试器
基础调试命令 - .dump/.dumpcap/.writemem/!runaway Windbg是windows平台上强大的调试器,它相对于其他常见的IDE集成的调试器有几个重要的优势, Windb ...
- offsetWidth, offsetHeight, offsetLeft, offsetTop,clientWidth, clientHeight,clientX,pageX,screenX
offsetWidth: 元素在水平方向上占用的空间大小.包括元素的宽度,内边距,(可见的)垂直滚动条的宽度,左右边框的宽度. offsetHeight:元素在垂直方向上占用的空间大小,包括元素的高度 ...
- Arduino 各种模块篇 震动模块 vibrator
vibrator is a good thing. it has multi-funtionality . :) Now the vibrator we choose is the one whic ...
- android自定义View---生成虚线的View
1.在res/values/目录下 新建文件 attrs.xml <? xml version = "1.0" encoding = "utf-8&q ...
- 《Head First Python》学习笔记 01
Python 3提供了70多个内建函数,这是Python“功能齐全”的观点:Python已经包含足够多的内置功能,使你能完成大多数工作,而不必依赖第三方代码. Python 列表: Python列表是 ...
- [ios2]Emoji表情符号兼容方案 【转】
Emoji表情符号兼容方案 一 什么是Emoji emoji就是表情符号:词义来自日语(えもじ,e-moji,moji在日语中的含义是字符) 表情符号现已普遍应用于手机短信和网络聊天软件. emoji ...