core/ngx_connection.c源文件分析
本节我们介绍一下nginx中对socket connection的相关操作.主要包括两个方面的内容：
-
监听socket对象(ngx_listening_t)相关操作
-
连接socket对象(ngx_connection_t)相关操作
1. 函数ngx_create_listening()
/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
ngx_os_io_t ngx_io;
//从reusable_connections_queue队列中释放一些长连接
static void ngx_drain_connections(void);
ngx_listening_t *
ngx_create_listening(ngx_conf_t *cf, void *sockaddr, socklen_t socklen)
{
size_t len;
ngx_listening_t *ls;
struct sockaddr *sa;
u_char text[NGX_SOCKADDR_STRLEN];
ls = ngx_array_push(&cf->cycle->listening);
if (ls == NULL) {
return NULL;
}
ngx_memzero(ls, sizeof(ngx_listening_t));
sa = ngx_palloc(cf->pool, socklen);
if (sa == NULL) {
return NULL;
}
ngx_memcpy(sa, sockaddr, socklen);
ls->sockaddr = sa;
ls->socklen = socklen;
len = ngx_sock_ntop(sa, socklen, text, NGX_SOCKADDR_STRLEN, 1);
ls->addr_text.len = len;
switch (ls->sockaddr->sa_family) {
#if (NGX_HAVE_INET6)
case AF_INET6:
ls->addr_text_max_len = NGX_INET6_ADDRSTRLEN;
break;
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
case AF_UNIX:
ls->addr_text_max_len = NGX_UNIX_ADDRSTRLEN;
len++;
break;
#endif
case AF_INET:
ls->addr_text_max_len = NGX_INET_ADDRSTRLEN;
break;
default:
ls->addr_text_max_len = NGX_SOCKADDR_STRLEN;
break;
}
ls->addr_text.data = ngx_pnalloc(cf->pool, len);
if (ls->addr_text.data == NULL) {
return NULL;
}
ngx_memcpy(ls->addr_text.data, text, len);
ls->fd = (ngx_socket_t) -1;
ls->type = SOCK_STREAM;
ls->backlog = NGX_LISTEN_BACKLOG;
ls->rcvbuf = -1;
ls->sndbuf = -1;
#if (NGX_HAVE_SETFIB)
ls->setfib = -1;
#endif
#if (NGX_HAVE_TCP_FASTOPEN)
ls->fastopen = -1;
#endif
return ls;
}这里主要是根据sockaddr地址构建一个ngx_listening_t结构体对象，存放于cycle->listening数组中。这里并未真正创建socket：
ls->fd = (ngx_socket_t) -1;
ls->type = SOCK_STREAM;
ls->backlog = NGX_LISTEN_BACKLOG;
ls->rcvbuf = -1;
ls->sndbuf = -1;注意这里将二进制形式表示的socket地址sockaddr转换为字符串形式时长度的确定。
2. 函数ngx_clone_listening()
ngx_int_t
ngx_clone_listening(ngx_conf_t *cf, ngx_listening_t *ls)
{
#if (NGX_HAVE_REUSEPORT)
ngx_int_t n;
ngx_core_conf_t *ccf;
ngx_listening_t ols;
if (!ls->reuseport) {
return NGX_OK;
}
ols = *ls;
ccf = (ngx_core_conf_t *) ngx_get_conf(cf->cycle->conf_ctx,
ngx_core_module);
for (n = 1; n < ccf->worker_processes; n++) {
/* create a socket for each worker process */
ls = ngx_array_push(&cf->cycle->listening);
if (ls == NULL) {
return NGX_ERROR;
}
*ls = ols;
ls->worker = n;
}
#endif
return NGX_OK;
}我们在objs/ngx_auto_config.h头文件中有如下定义：
#ifndef NGX_HAVE_REUSEPORT #define NGX_HAVE_REUSEPORT 1 #endif
一般是在worker0创建完成一个监听socket后，通过此函数再复制到其他worker进程。
3. 函数ngx_set_inherited_sockets()
ngx_int_t
ngx_set_inherited_sockets(ngx_cycle_t *cycle)
{
size_t len;
ngx_uint_t i;
ngx_listening_t *ls;
socklen_t olen;
#if (NGX_HAVE_DEFERRED_ACCEPT || NGX_HAVE_TCP_FASTOPEN)
ngx_err_t err;
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
struct accept_filter_arg af;
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
int timeout;
#endif
#if (NGX_HAVE_REUSEPORT)
int reuseport;
#endif
ls = cycle->listening.elts;
for (i = 0; i < cycle->listening.nelts; i++) {
ls[i].sockaddr = ngx_palloc(cycle->pool, NGX_SOCKADDRLEN);
if (ls[i].sockaddr == NULL) {
return NGX_ERROR;
}
ls[i].socklen = NGX_SOCKADDRLEN;
if (getsockname(ls[i].fd, ls[i].sockaddr, &ls[i].socklen) == -1) {
ngx_log_error(NGX_LOG_CRIT, cycle->log, ngx_socket_errno,
"getsockname() of the inherited "
"socket #%d failed", ls[i].fd);
ls[i].ignore = 1;
continue;
}
switch (ls[i].sockaddr->sa_family) {
#if (NGX_HAVE_INET6)
case AF_INET6:
ls[i].addr_text_max_len = NGX_INET6_ADDRSTRLEN;
len = NGX_INET6_ADDRSTRLEN + sizeof("[]:65535") - 1;
break;
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
case AF_UNIX:
ls[i].addr_text_max_len = NGX_UNIX_ADDRSTRLEN;
len = NGX_UNIX_ADDRSTRLEN;
break;
#endif
case AF_INET:
ls[i].addr_text_max_len = NGX_INET_ADDRSTRLEN;
len = NGX_INET_ADDRSTRLEN + sizeof(":65535") - 1;
break;
default:
ngx_log_error(NGX_LOG_CRIT, cycle->log, ngx_socket_errno,
"the inherited socket #%d has "
"an unsupported protocol family", ls[i].fd);
ls[i].ignore = 1;
continue;
}
ls[i].addr_text.data = ngx_pnalloc(cycle->pool, len);
if (ls[i].addr_text.data == NULL) {
return NGX_ERROR;
}
len = ngx_sock_ntop(ls[i].sockaddr, ls[i].socklen,
ls[i].addr_text.data, len, 1);
if (len == 0) {
return NGX_ERROR;
}
ls[i].addr_text.len = len;
ls[i].backlog = NGX_LISTEN_BACKLOG;
olen = sizeof(int);
if (getsockopt(ls[i].fd, SOL_SOCKET, SO_TYPE, (void *) &ls[i].type,
&olen)
== -1)
{
ngx_log_error(NGX_LOG_CRIT, cycle->log, ngx_socket_errno,
"getsockopt(SO_TYPE) %V failed", &ls[i].addr_text);
ls[i].ignore = 1;
continue;
}
olen = sizeof(int);
if (getsockopt(ls[i].fd, SOL_SOCKET, SO_RCVBUF, (void *) &ls[i].rcvbuf,
&olen)
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"getsockopt(SO_RCVBUF) %V failed, ignored",
&ls[i].addr_text);
ls[i].rcvbuf = -1;
}
olen = sizeof(int);
if (getsockopt(ls[i].fd, SOL_SOCKET, SO_SNDBUF, (void *) &ls[i].sndbuf,
&olen)
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"getsockopt(SO_SNDBUF) %V failed, ignored",
&ls[i].addr_text);
ls[i].sndbuf = -1;
}
#if 0
/* SO_SETFIB is currently a set only option */
#if (NGX_HAVE_SETFIB)
olen = sizeof(int);
if (getsockopt(ls[i].fd, SOL_SOCKET, SO_SETFIB,
(void *) &ls[i].setfib, &olen)
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"getsockopt(SO_SETFIB) %V failed, ignored",
&ls[i].addr_text);
ls[i].setfib = -1;
}
#endif
#endif
#if (NGX_HAVE_REUSEPORT)
reuseport = 0;
olen = sizeof(int);
if (getsockopt(ls[i].fd, SOL_SOCKET, SO_REUSEPORT,
(void *) &reuseport, &olen)
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"getsockopt(SO_REUSEPORT) %V failed, ignored",
&ls[i].addr_text);
} else {
ls[i].reuseport = reuseport ? 1 : 0;
}
#endif
if (ls[i].type != SOCK_STREAM) {
continue;
}
#if (NGX_HAVE_TCP_FASTOPEN)
olen = sizeof(int);
if (getsockopt(ls[i].fd, IPPROTO_TCP, TCP_FASTOPEN,
(void *) &ls[i].fastopen, &olen)
== -1)
{
err = ngx_socket_errno;
if (err != NGX_EOPNOTSUPP && err != NGX_ENOPROTOOPT) {
ngx_log_error(NGX_LOG_NOTICE, cycle->log, err,
"getsockopt(TCP_FASTOPEN) %V failed, ignored",
&ls[i].addr_text);
}
ls[i].fastopen = -1;
}
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
ngx_memzero(&af, sizeof(struct accept_filter_arg));
olen = sizeof(struct accept_filter_arg);
if (getsockopt(ls[i].fd, SOL_SOCKET, SO_ACCEPTFILTER, &af, &olen)
== -1)
{
err = ngx_socket_errno;
if (err == NGX_EINVAL) {
continue;
}
ngx_log_error(NGX_LOG_NOTICE, cycle->log, err,
"getsockopt(SO_ACCEPTFILTER) for %V failed, ignored",
&ls[i].addr_text);
continue;
}
if (olen < sizeof(struct accept_filter_arg) || af.af_name[0] == '\0') {
continue;
}
ls[i].accept_filter = ngx_palloc(cycle->pool, 16);
if (ls[i].accept_filter == NULL) {
return NGX_ERROR;
}
(void) ngx_cpystrn((u_char *) ls[i].accept_filter,
(u_char *) af.af_name, 16);
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
timeout = 0;
olen = sizeof(int);
if (getsockopt(ls[i].fd, IPPROTO_TCP, TCP_DEFER_ACCEPT, &timeout, &olen)
== -1)
{
err = ngx_socket_errno;
if (err == NGX_EOPNOTSUPP) {
continue;
}
ngx_log_error(NGX_LOG_NOTICE, cycle->log, err,
"getsockopt(TCP_DEFER_ACCEPT) for %V failed, ignored",
&ls[i].addr_text);
continue;
}
if (olen < sizeof(int) || timeout == 0) {
continue;
}
ls[i].deferred_accept = 1;
#endif
}
return NGX_OK;
}本函数主要用于平滑升级时，设置继承而来的socket。在objs/ngx_auto_config.h头文件中我们有如下定义：
#ifndef NGX_HAVE_DEFERRED_ACCEPT #define NGX_HAVE_DEFERRED_ACCEPT 1 #endif #ifndef NGX_HAVE_TCP_FASTOPEN #define NGX_HAVE_TCP_FASTOPEN 1 #endif #ifndef NGX_HAVE_REUSEPORT #define NGX_HAVE_REUSEPORT 1 #endif
并且支持SO_ACCEPTFILTER与TCP_DEFER_ACCEPT。
本函数是受ngx_add_inherited_sockets()函数调用的，并且在该函数中通过继承已经设置了ngx_listening_t对象的fd字段。接下来我们分析一下本函数的实现：
ngx_int_t
ngx_set_inherited_sockets(ngx_cycle_t *cycle)
{
for (i = 0; i < cycle->listening.nelts; i++)
{
//1: 通过fd获得绑定的地址信息： 二进制表示形式以及字符串表示形式
getsockname(fd,&sockaddr,&socklen);
//2: 获得相应socket的设置选项
getsockopt(ls[i].fd, SOL_SOCKET, SO_TYPE, (void *) &ls[i].type,&olen); //获取失败，则忽略当前继承过来的这个listening socket
getsockopt(ls[i].fd, SOL_SOCKET, SO_RCVBUF, (void *) &ls[i].rcvbuf,&olen);
getsockopt(ls[i].fd, SOL_SOCKET, SO_SNDBUF, (void *) &ls[i].sndbuf, &olen);
#if (NGX_HAVE_REUSEPORT)
//是否支持端口复用
getsockopt(ls[i].fd, SOL_SOCKET, SO_REUSEPORT,(void *) &reuseport, &olen);
#endif
//3: 针对TCP的选项设置
if (ls[i].type != SOCK_STREAM) {
continue; //非TCP类型，则continue，不在进行如下的检测
}
#if (NGX_HAVE_TCP_FASTOPEN)
getsockopt(ls[i].fd, IPPROTO_TCP, TCP_FASTOPEN,(void *) &ls[i].fastopen, &olen);
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
getsockopt(ls[i].fd, SOL_SOCKET, SO_ACCEPTFILTER, &af, &olen);
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
getsockopt(ls[i].fd, IPPROTO_TCP, TCP_DEFER_ACCEPT, &timeout, &olen);
#endif
}
}4. 函数ngx_open_listening_sockets()
ngx_int_t
ngx_open_listening_sockets(ngx_cycle_t *cycle)
{
int reuseaddr;
ngx_uint_t i, tries, failed;
ngx_err_t err;
ngx_log_t *log;
ngx_socket_t s;
ngx_listening_t *ls;
reuseaddr = 1;
#if (NGX_SUPPRESS_WARN)
failed = 0;
#endif
log = cycle->log;
/* TODO: configurable try number */
for (tries = 5; tries; tries--) {
failed = 0;
/* for each listening socket */
ls = cycle->listening.elts;
for (i = 0; i < cycle->listening.nelts; i++) {
if (ls[i].ignore) {
continue;
}
#if (NGX_HAVE_REUSEPORT)
if (ls[i].add_reuseport) {
/*
* to allow transition from a socket without SO_REUSEPORT
* to multiple sockets with SO_REUSEPORT, we have to set
* SO_REUSEPORT on the old socket before opening new ones
*/
int reuseport = 1;
if (setsockopt(ls[i].fd, SOL_SOCKET, SO_REUSEPORT,
(const void *) &reuseport, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(SO_REUSEPORT) %V failed, ignored",
&ls[i].addr_text);
}
ls[i].add_reuseport = 0;
}
#endif
if (ls[i].fd != (ngx_socket_t) -1) {
continue;
}
if (ls[i].inherited) {
/* TODO: close on exit */
/* TODO: nonblocking */
/* TODO: deferred accept */
continue;
}
s = ngx_socket(ls[i].sockaddr->sa_family, ls[i].type, 0);
if (s == (ngx_socket_t) -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_socket_n " %V failed", &ls[i].addr_text);
return NGX_ERROR;
}
if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
(const void *) &reuseaddr, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
"setsockopt(SO_REUSEADDR) %V failed",
&ls[i].addr_text);
if (ngx_close_socket(s) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[i].addr_text);
}
return NGX_ERROR;
}
#if (NGX_HAVE_REUSEPORT)
if (ls[i].reuseport) {
int reuseport;
reuseport = 1;
if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
(const void *) &reuseport, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
"setsockopt(SO_REUSEPORT) %V failed, ignored",
&ls[i].addr_text);
if (ngx_close_socket(s) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[i].addr_text);
}
return NGX_ERROR;
}
}
#endif
#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
if (ls[i].sockaddr->sa_family == AF_INET6) {
int ipv6only;
ipv6only = ls[i].ipv6only;
if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
(const void *) &ipv6only, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
"setsockopt(IPV6_V6ONLY) %V failed, ignored",
&ls[i].addr_text);
}
}
#endif
/* TODO: close on exit */
if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) {
if (ngx_nonblocking(s) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_nonblocking_n " %V failed",
&ls[i].addr_text);
if (ngx_close_socket(s) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[i].addr_text);
}
return NGX_ERROR;
}
}
ngx_log_debug2(NGX_LOG_DEBUG_CORE, log, 0,
"bind() %V #%d ", &ls[i].addr_text, s);
if (bind(s, ls[i].sockaddr, ls[i].socklen) == -1) {
err = ngx_socket_errno;
if (err != NGX_EADDRINUSE || !ngx_test_config) {
ngx_log_error(NGX_LOG_EMERG, log, err,
"bind() to %V failed", &ls[i].addr_text);
}
if (ngx_close_socket(s) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[i].addr_text);
}
if (err != NGX_EADDRINUSE) {
return NGX_ERROR;
}
if (!ngx_test_config) {
failed = 1;
}
continue;
}
#if (NGX_HAVE_UNIX_DOMAIN)
if (ls[i].sockaddr->sa_family == AF_UNIX) {
mode_t mode;
u_char *name;
name = ls[i].addr_text.data + sizeof("unix:") - 1;
mode = (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
if (chmod((char *) name, mode) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"chmod() \"%s\" failed", name);
}
if (ngx_test_config) {
if (ngx_delete_file(name) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
ngx_delete_file_n " %s failed", name);
}
}
}
#endif
if (ls[i].type != SOCK_STREAM) {
ls[i].fd = s;
continue;
}
if (listen(s, ls[i].backlog) == -1) {
err = ngx_socket_errno;
/*
* on OpenVZ after suspend/resume EADDRINUSE
* may be returned by listen() instead of bind(), see
* https://bugzilla.openvz.org/show_bug.cgi?id=2470
*/
if (err != NGX_EADDRINUSE || !ngx_test_config) {
ngx_log_error(NGX_LOG_EMERG, log, err,
"listen() to %V, backlog %d failed",
&ls[i].addr_text, ls[i].backlog);
}
if (ngx_close_socket(s) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[i].addr_text);
}
if (err != NGX_EADDRINUSE) {
return NGX_ERROR;
}
if (!ngx_test_config) {
failed = 1;
}
continue;
}
ls[i].listen = 1;
ls[i].fd = s;
}
if (!failed) {
break;
}
/* TODO: delay configurable */
ngx_log_error(NGX_LOG_NOTICE, log, 0,
"try again to bind() after 500ms");
ngx_msleep(500);
}
if (failed) {
ngx_log_error(NGX_LOG_EMERG, log, 0, "still could not bind()");
return NGX_ERROR;
}
return NGX_OK;
}本函数用于打开cycle->listening.elts中符合要求的所有监听sockets。我们在objs/ngx_auto_config.h头文件中有如下定义：
#ifndef NGX_HAVE_REUSEPORT #define NGX_HAVE_REUSEPORT 1 #endif
下面我们来简单分析一下该函数：
ngx_int_t
ngx_open_listening_sockets(ngx_cycle_t *cycle)
{
// 循环检查5次，直到所有都已经打开
for (tries = 5; tries; tries--)
{
for (i = 0; i < cycle->listening.nelts; i++)
{
//1: 对于标记为ignore的ngx_listening_t对象，则直接忽略
//2: 这里主要是为了将一个未被设置为SO_REUSEPORT的socket转化为REUSEPORT类型的socket
#if (NGX_HAVE_REUSEPORT)
if (ls[i].add_reuseport)
{
setsockopt(ls[i].fd, SOL_SOCKET, SO_REUSEPORT,(const void *) &reuseport, sizeof(int));
ls[i].add_reuseport = 0;
}
#endif
//3: 如果fd不为-1，则表示此socket已经处于监听状态，不再继续后续的流程
if (ls[i].fd != (ngx_socket_t) -1) {
continue;
}
//4: 如果是继承而来的socket，也不再继续后面的流程
if (ls[i].inherited) {
continue;
}
//5: 创建socket，并设置相关属性
s = ngx_socket(ls[i].sockaddr->sa_family, ls[i].type, 0);
setsockopt(s, SOL_SOCKET, SO_REUSEADDR,(const void *) &reuseaddr, sizeof(int))
#if (NGX_HAVE_REUSEPORT)
setsockopt(s, SOL_SOCKET, SO_REUSEPORT,(const void *) &reuseport, sizeof(int));
#endif
#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,(const void *) &ipv6only, sizeof(int))
#endif
ngx_nonblocking(); //如果采用的事件模型不是IOCP模型，则这里设置为非阻塞
bind(s, ls[i].sockaddr, ls[i].socklen)； //绑定
//6: unix domain socket的处理
// 对于unix domain socket，会在本地创建出一个unix域文件，这里更改相应的权限设置
//7: 对于非TCP类型socket，则不再需要后续操作
if (ls[i].type != SOCK_STREAM) {
ls[i].fd = s;
continue;
}
//8: 监听
listen(s, ls[i].backlog);
ls[i].listen = 1;
ls[i].fd = s;
}
}
}5. 函数ngx_configure_listening_sockets()
void
ngx_configure_listening_sockets(ngx_cycle_t *cycle)
{
int value;
ngx_uint_t i;
ngx_listening_t *ls;
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
struct accept_filter_arg af;
#endif
ls = cycle->listening.elts;
for (i = 0; i < cycle->listening.nelts; i++) {
ls[i].log = *ls[i].logp;
if (ls[i].rcvbuf != -1) {
if (setsockopt(ls[i].fd, SOL_SOCKET, SO_RCVBUF,
(const void *) &ls[i].rcvbuf, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(SO_RCVBUF, %d) %V failed, ignored",
ls[i].rcvbuf, &ls[i].addr_text);
}
}
if (ls[i].sndbuf != -1) {
if (setsockopt(ls[i].fd, SOL_SOCKET, SO_SNDBUF,
(const void *) &ls[i].sndbuf, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(SO_SNDBUF, %d) %V failed, ignored",
ls[i].sndbuf, &ls[i].addr_text);
}
}
if (ls[i].keepalive) {
value = (ls[i].keepalive == 1) ? 1 : 0;
if (setsockopt(ls[i].fd, SOL_SOCKET, SO_KEEPALIVE,
(const void *) &value, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(SO_KEEPALIVE, %d) %V failed, ignored",
value, &ls[i].addr_text);
}
}
#if (NGX_HAVE_KEEPALIVE_TUNABLE)
if (ls[i].keepidle) {
value = ls[i].keepidle;
#if (NGX_KEEPALIVE_FACTOR)
value *= NGX_KEEPALIVE_FACTOR;
#endif
if (setsockopt(ls[i].fd, IPPROTO_TCP, TCP_KEEPIDLE,
(const void *) &value, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(TCP_KEEPIDLE, %d) %V failed, ignored",
value, &ls[i].addr_text);
}
}
if (ls[i].keepintvl) {
value = ls[i].keepintvl;
#if (NGX_KEEPALIVE_FACTOR)
value *= NGX_KEEPALIVE_FACTOR;
#endif
if (setsockopt(ls[i].fd, IPPROTO_TCP, TCP_KEEPINTVL,
(const void *) &value, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(TCP_KEEPINTVL, %d) %V failed, ignored",
value, &ls[i].addr_text);
}
}
if (ls[i].keepcnt) {
if (setsockopt(ls[i].fd, IPPROTO_TCP, TCP_KEEPCNT,
(const void *) &ls[i].keepcnt, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(TCP_KEEPCNT, %d) %V failed, ignored",
ls[i].keepcnt, &ls[i].addr_text);
}
}
#endif
#if (NGX_HAVE_SETFIB)
if (ls[i].setfib != -1) {
if (setsockopt(ls[i].fd, SOL_SOCKET, SO_SETFIB,
(const void *) &ls[i].setfib, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(SO_SETFIB, %d) %V failed, ignored",
ls[i].setfib, &ls[i].addr_text);
}
}
#endif
#if (NGX_HAVE_TCP_FASTOPEN)
if (ls[i].fastopen != -1) {
if (setsockopt(ls[i].fd, IPPROTO_TCP, TCP_FASTOPEN,
(const void *) &ls[i].fastopen, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(TCP_FASTOPEN, %d) %V failed, ignored",
ls[i].fastopen, &ls[i].addr_text);
}
}
#endif
#if 0
if (1) {
int tcp_nodelay = 1;
if (setsockopt(ls[i].fd, IPPROTO_TCP, TCP_NODELAY,
(const void *) &tcp_nodelay, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(TCP_NODELAY) %V failed, ignored",
&ls[i].addr_text);
}
}
#endif
if (ls[i].listen) {
/* change backlog via listen() */
if (listen(ls[i].fd, ls[i].backlog) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"listen() to %V, backlog %d failed, ignored",
&ls[i].addr_text, ls[i].backlog);
}
}
/*
* setting deferred mode should be last operation on socket,
* because code may prematurely continue cycle on failure
*/
#if (NGX_HAVE_DEFERRED_ACCEPT)
#ifdef SO_ACCEPTFILTER
if (ls[i].delete_deferred) {
if (setsockopt(ls[i].fd, SOL_SOCKET, SO_ACCEPTFILTER, NULL, 0)
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(SO_ACCEPTFILTER, NULL) "
"for %V failed, ignored",
&ls[i].addr_text);
if (ls[i].accept_filter) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"could not change the accept filter "
"to \"%s\" for %V, ignored",
ls[i].accept_filter, &ls[i].addr_text);
}
continue;
}
ls[i].deferred_accept = 0;
}
if (ls[i].add_deferred) {
ngx_memzero(&af, sizeof(struct accept_filter_arg));
(void) ngx_cpystrn((u_char *) af.af_name,
(u_char *) ls[i].accept_filter, 16);
if (setsockopt(ls[i].fd, SOL_SOCKET, SO_ACCEPTFILTER,
&af, sizeof(struct accept_filter_arg))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(SO_ACCEPTFILTER, \"%s\") "
"for %V failed, ignored",
ls[i].accept_filter, &ls[i].addr_text);
continue;
}
ls[i].deferred_accept = 1;
}
#endif
#ifdef TCP_DEFER_ACCEPT
if (ls[i].add_deferred || ls[i].delete_deferred) {
if (ls[i].add_deferred) {
/*
* There is no way to find out how long a connection was
* in queue (and a connection may bypass deferred queue at all
* if syncookies were used), hence we use 1 second timeout
* here.
*/
value = 1;
} else {
value = 0;
}
if (setsockopt(ls[i].fd, IPPROTO_TCP, TCP_DEFER_ACCEPT,
&value, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(TCP_DEFER_ACCEPT, %d) for %V failed, "
"ignored",
value, &ls[i].addr_text);
continue;
}
}
if (ls[i].add_deferred) {
ls[i].deferred_accept = 1;
}
#endif
#endif /* NGX_HAVE_DEFERRED_ACCEPT */
#if (NGX_HAVE_IP_RECVDSTADDR)
if (ls[i].wildcard
&& ls[i].type == SOCK_DGRAM
&& ls[i].sockaddr->sa_family == AF_INET)
{
value = 1;
if (setsockopt(ls[i].fd, IPPROTO_IP, IP_RECVDSTADDR,
(const void *) &value, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(IP_RECVDSTADDR) "
"for %V failed, ignored",
&ls[i].addr_text);
}
}
#elif (NGX_HAVE_IP_PKTINFO)
if (ls[i].wildcard
&& ls[i].type == SOCK_DGRAM
&& ls[i].sockaddr->sa_family == AF_INET)
{
value = 1;
if (setsockopt(ls[i].fd, IPPROTO_IP, IP_PKTINFO,
(const void *) &value, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(IP_PKTINFO) "
"for %V failed, ignored",
&ls[i].addr_text);
}
}
#endif
#if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO)
if (ls[i].wildcard
&& ls[i].type == SOCK_DGRAM
&& ls[i].sockaddr->sa_family == AF_INET6)
{
value = 1;
if (setsockopt(ls[i].fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
(const void *) &value, sizeof(int))
== -1)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
"setsockopt(IPV6_RECVPKTINFO) "
"for %V failed, ignored",
&ls[i].addr_text);
}
}
#endif
}
return;
}本函数用于配置监听sockets。在objs/ngx_auto_config.h头文件中我们有如下宏定义：
#ifndef NGX_HAVE_DEFERRED_ACCEPT #define NGX_HAVE_DEFERRED_ACCEPT 1 #endif #ifndef NGX_HAVE_KEEPALIVE_TUNABLE #define NGX_HAVE_KEEPALIVE_TUNABLE 1 #endif #ifndef NGX_HAVE_TCP_FASTOPEN #define NGX_HAVE_TCP_FASTOPEN 1 #endif #ifndef NGX_HAVE_IP_PKTINFO #define NGX_HAVE_IP_PKTINFO 1 #endif
接下来我们来简要分析一下该函数：
void
ngx_configure_listening_sockets(ngx_cycle_t *cycle)
{
for (i = 0; i < cycle->listening.nelts; i++)
{
//1: 根据ls[i].rcvbuf条件，设置接收缓冲区
setsockopt(ls[i].fd, SOL_SOCKET, SO_RCVBUF,(const void *) &ls[i].rcvbuf, sizeof(int))
//2: 根据ls[i].sndbuf条件，设置发送缓冲区
setsockopt(ls[i].fd, SOL_SOCKET, SO_SNDBUF,(const void *) &ls[i].sndbuf, sizeof(int))
//3: 根据ls[i].keepalive条件，设置socket的keepalive属性
setsockopt(ls[i].fd, SOL_SOCKET, SO_KEEPALIVE,(const void *) &value, sizeof(int))
#if (NGX_HAVE_KEEPALIVE_TUNABLE)
setsockopt(ls[i].fd, IPPROTO_TCP, TCP_KEEPIDLE,(const void *) &value, sizeof(int))
setsockopt(ls[i].fd, IPPROTO_TCP, TCP_KEEPINTVL,(const void *) &value, sizeof(int))
setsockopt(ls[i].fd, IPPROTO_TCP, TCP_KEEPCNT,(const void *) &ls[i].keepcnt, sizeof(int))
#endif
//4: 当前并不支持setfib: 设置该socket的关联路由表
#if (NGX_HAVE_SETFIB)
setsockopt(ls[i].fd, SOL_SOCKET, SO_SETFIB,(const void *) &ls[i].setfib, sizeof(int))
#endif
//5: 根据ls[i].fastopen条件，设置socket快速打开
#if (NGX_HAVE_TCP_FASTOPEN)
setsockopt(ls[i].fd, IPPROTO_TCP, TCP_FASTOPEN,(const void *) &ls[i].fastopen, sizeof(int))
#endif
//6: 根据ls[i].listen条件，更改listen的backlog队列
listen(ls[i].fd, ls[i].backlog)
//7: 设置延迟接收,设置失败则continue，跳过本次循环
#if (NGX_HAVE_DEFERRED_ACCEPT)
if (ls[i].delete_deferred) {
setsockopt(ls[i].fd, SOL_SOCKET, SO_ACCEPTFILTER, NULL, 0)
}
if (ls[i].add_deferred) {
setsockopt(ls[i].fd, SOL_SOCKET, SO_ACCEPTFILTER,&af, sizeof(struct accept_filter_arg))
}
setsockopt(ls[i].fd, IPPROTO_TCP, TCP_DEFER_ACCEPT,&value, sizeof(int))
#endif
//8: 获得路由目的地址选项设置
#if (NGX_HAVE_IP_RECVDSTADDR)
setsockopt(ls[i].fd, IPPROTO_IP, IP_RECVDSTADDR,(const void *) &value, sizeof(int))
#elif (NGX_HAVE_IP_PKTINFO)
setsockopt(ls[i].fd, IPPROTO_IP, IP_PKTINFO,(const void *) &value, sizeof(int))
#endif
#if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO) //当前并未定义NGX_HAVE_INET6宏定义，
setsockopt(ls[i].fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, (const void *) &value, sizeof(int))
#endif
}
}
[参看]:
