leevis.com
leevis.com copied to clipboard
Published
20 hours ago •
vislee
vislee
nginx stream proxy module 代码分析
概述
stream proxy 模块是stream类型模块的重点。四层代理的主要功能实现模块。 该proxy模块也提供了proxy_pass指令把4层流量转发到上游。
源码
stream类型的模块是通过一个ngx_stream_module的核心模块来管理的。 在stream指令的解析函数ngx_stream_block中，首先会创建一个ngx_stream_conf_ctx_t类型的上下文ctx，该结构体有两个指针数组的成员，用来保存stream类型模块的main和srv级别的配置。
typedef struct {
void **main_conf; // 指针数组指针
void **srv_conf; // 指针数组指针
} ngx_stream_conf_ctx_t;
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_stream_conf_ctx_t));
ctx->main_conf = ngx_pcalloc(cf->pool,
sizeof(void *) * ngx_stream_max_module);
ctx->srv_conf = ngx_pcalloc(cf->pool,
sizeof(void *) * ngx_stream_max_module);
// 调用stream各模块的回调函数创建保存配置的结构体
ctx->main_conf[mi] = module->create_main_conf(cf);
ctx->srv_conf[mi] = module->create_srv_conf(cf);
启动阶段
-
调用ngx_stream_proxy_create_srv_conf函数创建保存proxy_xxx 指令配置的结构体，其类型为：ngx_stream_proxy_srv_conf_t。
-
调用ngx_stream_proxy_commands[]数组中的函数解析配置文件。 指令proxy_pass 的函数对应为ngx_stream_proxy_pass，该函数赋值content阶段一个回调函数ngx_stream_proxy_handler。并根据配置查找或添加一个上游，该部分已经属于upstream模块的范畴。 假如proxy_pass 的 address配置的就是ip地址，然后调用ngx_stream_upstream_add添加一个上游地址，其类型为ngx_stream_upstream_srv_conf_t，并赋值到pscf->upstream。
其他的指令基本就是赋值ngx_stream_proxy_srv_conf_t结构体，就是ngx_stream_proxy_create_srv_conf分配的结构体。
typedef struct {
ngx_msec_t connect_timeout;
ngx_msec_t timeout;
ngx_msec_t next_upstream_timeout;
size_t buffer_size;
size_t upload_rate;
size_t download_rate;
ngx_uint_t responses;
ngx_uint_t next_upstream_tries;
ngx_flag_t next_upstream;
ngx_flag_t proxy_protocol;
ngx_stream_upstream_local_t *local;
#if (NGX_STREAM_SSL)
ngx_flag_t ssl_enable;
ngx_flag_t ssl_session_reuse;
ngx_uint_t ssl_protocols;
ngx_str_t ssl_ciphers;
ngx_stream_complex_value_t *ssl_name;
ngx_flag_t ssl_server_name;
ngx_flag_t ssl_verify;
ngx_uint_t ssl_verify_depth;
ngx_str_t ssl_trusted_certificate;
ngx_str_t ssl_crl;
ngx_str_t ssl_certificate;
ngx_str_t ssl_certificate_key;
ngx_array_t *ssl_passwords;
ngx_ssl_t *ssl;
#endif
ngx_stream_upstream_srv_conf_t *upstream;
ngx_stream_complex_value_t *upstream_value;
} ngx_stream_proxy_srv_conf_t;
执行阶段
执行到NGX_STREAM_CONTENT_PHASE阶段后，会调用对应的checker函数ngx_stream_core_content_phase，该函数会调用cscf->handler，如果该server block配置了proxy_pass则回调函数就是ngx_stream_proxy_handler。
static void
ngx_stream_proxy_handler(ngx_stream_session_t *s)
{
u_char *p;
ngx_str_t *host;
ngx_uint_t i;
ngx_connection_t *c;
ngx_resolver_ctx_t *ctx, temp;
ngx_stream_upstream_t *u;
ngx_stream_core_srv_conf_t *cscf;
ngx_stream_proxy_srv_conf_t *pscf;
ngx_stream_upstream_srv_conf_t *uscf, **uscfp;
ngx_stream_upstream_main_conf_t *umcf;
c = s->connection;
pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
"proxy connection handler");
// 分配一个上游结构体
u = ngx_pcalloc(c->pool, sizeof(ngx_stream_upstream_t));
if (u == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
s->upstream = u;
s->log_handler = ngx_stream_proxy_log_error;
u->peer.log = c->log;
u->peer.log_error = NGX_ERROR_ERR;
// 设置本地bind的ip
if (ngx_stream_proxy_set_local(s, u, pscf->local) != NGX_OK) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
u->peer.type = c->type;
u->start_sec = ngx_time();
// 下游可读可写回调函数
c->write->handler = ngx_stream_proxy_downstream_handler;
c->read->handler = ngx_stream_proxy_downstream_handler;
s->upstream_states = ngx_array_create(c->pool, 1,
sizeof(ngx_stream_upstream_state_t));
if (s->upstream_states == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
if (c->type == SOCK_STREAM) {
p = ngx_pnalloc(c->pool, pscf->buffer_size);
if (p == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
// 下游数据缓存区
u->downstream_buf.start = p;
u->downstream_buf.end = p + pscf->buffer_size;
u->downstream_buf.pos = p;
u->downstream_buf.last = p;
if (c->read->ready) {
ngx_post_event(c->read, &ngx_posted_events);
}
}
if (pscf->upstream_value) {
if (ngx_stream_proxy_eval(s, pscf) != NGX_OK) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
}
if (u->resolved == NULL) {
// 上游服务地址
uscf = pscf->upstream;
} else {
#if (NGX_STREAM_SSL)
u->ssl_name = u->resolved->host;
#endif
host = &u->resolved->host;
umcf = ngx_stream_get_module_main_conf(s, ngx_stream_upstream_module);
uscfp = umcf->upstreams.elts;
for (i = 0; i < umcf->upstreams.nelts; i++) {
uscf = uscfp[i];
if (uscf->host.len == host->len
&& ((uscf->port == 0 && u->resolved->no_port)
|| uscf->port == u->resolved->port)
&& ngx_strncasecmp(uscf->host.data, host->data, host->len) == 0)
{
goto found;
}
}
if (u->resolved->sockaddr) {
if (u->resolved->port == 0
&& u->resolved->sockaddr->sa_family != AF_UNIX)
{
ngx_log_error(NGX_LOG_ERR, c->log, 0,
"no port in upstream \"%V\"", host);
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
if (ngx_stream_upstream_create_round_robin_peer(s, u->resolved)
!= NGX_OK)
{
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
ngx_stream_proxy_connect(s);
return;
}
if (u->resolved->port == 0) {
ngx_log_error(NGX_LOG_ERR, c->log, 0,
"no port in upstream \"%V\"", host);
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
temp.name = *host;
cscf = ngx_stream_get_module_srv_conf(s, ngx_stream_core_module);
ctx = ngx_resolve_start(cscf->resolver, &temp);
if (ctx == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
if (ctx == NGX_NO_RESOLVER) {
ngx_log_error(NGX_LOG_ERR, c->log, 0,
"no resolver defined to resolve %V", host);
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
ctx->name = *host;
ctx->handler = ngx_stream_proxy_resolve_handler;
ctx->data = s;
ctx->timeout = cscf->resolver_timeout;
u->resolved->ctx = ctx;
if (ngx_resolve_name(ctx) != NGX_OK) {
u->resolved->ctx = NULL;
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
return;
}
found:
if (uscf == NULL) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0, "no upstream configuration");
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
u->upstream = uscf;
#if (NGX_STREAM_SSL)
u->ssl_name = uscf->host;
#endif
if (uscf->peer.init(s, uscf) != NGX_OK) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
u->peer.start_time = ngx_current_msec;
if (pscf->next_upstream_tries
&& u->peer.tries > pscf->next_upstream_tries)
{
u->peer.tries = pscf->next_upstream_tries;
}
// 向上游发起连接请求
ngx_stream_proxy_connect(s);
}
static void
ngx_stream_proxy_connect(ngx_stream_session_t *s)
{
ngx_int_t rc;
ngx_connection_t *c, *pc;
ngx_stream_upstream_t *u;
ngx_stream_proxy_srv_conf_t *pscf;
c = s->connection;
c->log->action = "connecting to upstream";
pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);
u = s->upstream;
u->connected = 0;
u->proxy_protocol = pscf->proxy_protocol;
if (u->state) {
u->state->response_time = ngx_current_msec - u->state->response_time;
}
u->state = ngx_array_push(s->upstream_states);
if (u->state == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
ngx_memzero(u->state, sizeof(ngx_stream_upstream_state_t));
u->state->connect_time = (ngx_msec_t) -1;
u->state->first_byte_time = (ngx_msec_t) -1;
u->state->response_time = ngx_current_msec;
// 向上游发起连接请求
// 并添加到epoll
rc = ngx_event_connect_peer(&u->peer);
ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "proxy connect: %i", rc);
if (rc == NGX_ERROR) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
u->state->peer = u->peer.name;
if (rc == NGX_BUSY) {
ngx_log_error(NGX_LOG_ERR, c->log, 0, "no live upstreams");
ngx_stream_proxy_finalize(s, NGX_STREAM_BAD_GATEWAY);
return;
}
if (rc == NGX_DECLINED) {
ngx_stream_proxy_next_upstream(s);
return;
}
/* rc == NGX_OK || rc == NGX_AGAIN || rc == NGX_DONE */
pc = u->peer.connection;
pc->data = s;
pc->log = c->log;
pc->pool = c->pool;
pc->read->log = c->log;
pc->write->log = c->log;
if (rc != NGX_AGAIN) {
ngx_stream_proxy_init_upstream(s);
return;
}
// 上游可读可写回调函数
pc->read->handler = ngx_stream_proxy_connect_handler;
pc->write->handler = ngx_stream_proxy_connect_handler;
ngx_add_timer(pc->write, pscf->connect_timeout);
}
// 上游初始化函数
// 已经建立起上游的连接了
static void
ngx_stream_proxy_init_upstream(ngx_stream_session_t *s)
{
u_char *p;
ngx_chain_t *cl;
ngx_connection_t *c, *pc;
ngx_log_handler_pt handler;
ngx_stream_upstream_t *u;
ngx_stream_core_srv_conf_t *cscf;
ngx_stream_proxy_srv_conf_t *pscf;
u = s->upstream;
pc = u->peer.connection;
cscf = ngx_stream_get_module_srv_conf(s, ngx_stream_core_module);
if (pc->type == SOCK_STREAM
&& cscf->tcp_nodelay
&& ngx_tcp_nodelay(pc) != NGX_OK)
{
ngx_stream_proxy_next_upstream(s);
return;
}
pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);
#if (NGX_STREAM_SSL)
if (pc->type == SOCK_STREAM && pscf->ssl) {
if (u->proxy_protocol) {
if (ngx_stream_proxy_send_proxy_protocol(s) != NGX_OK) {
return;
}
u->proxy_protocol = 0;
}
if (pc->ssl == NULL) {
ngx_stream_proxy_ssl_init_connection(s);
return;
}
}
#endif
// 下游的连接
c = s->connection;
if (c->log->log_level >= NGX_LOG_INFO) {
ngx_str_t str;
u_char addr[NGX_SOCKADDR_STRLEN];
str.len = NGX_SOCKADDR_STRLEN;
str.data = addr;
if (ngx_connection_local_sockaddr(pc, &str, 1) == NGX_OK) {
handler = c->log->handler;
c->log->handler = NULL;
ngx_log_error(NGX_LOG_INFO, c->log, 0,
"%sproxy %V connected to %V",
pc->type == SOCK_DGRAM ? "udp " : "",
&str, u->peer.name);
c->log->handler = handler;
}
}
u->state->connect_time = ngx_current_msec - u->state->response_time;
if (u->peer.notify) {
u->peer.notify(&u->peer, u->peer.data,
NGX_STREAM_UPSTREAM_NOTIFY_CONNECT);
}
c->log->action = "proxying connection";
// 发到上游的缓存区
if (u->upstream_buf.start == NULL) {
p = ngx_pnalloc(c->pool, pscf->buffer_size);
if (p == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
u->upstream_buf.start = p;
u->upstream_buf.end = p + pscf->buffer_size;
u->upstream_buf.pos = p;
u->upstream_buf.last = p;
}
if (c->buffer && c->buffer->pos < c->buffer->last) {
ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0,
"stream proxy add preread buffer: %uz",
c->buffer->last - c->buffer->pos);
cl = ngx_chain_get_free_buf(c->pool, &u->free);
if (cl == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
*cl->buf = *c->buffer;
cl->buf->tag = (ngx_buf_tag_t) &ngx_stream_proxy_module;
cl->buf->flush = 1;
cl->buf->last_buf = (c->type == SOCK_DGRAM);
cl->next = u->upstream_out;
u->upstream_out = cl;
}
if (u->proxy_protocol) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
"stream proxy add PROXY protocol header");
cl = ngx_chain_get_free_buf(c->pool, &u->free);
if (cl == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
p = ngx_pnalloc(c->pool, NGX_PROXY_PROTOCOL_MAX_HEADER);
if (p == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
cl->buf->pos = p;
p = ngx_proxy_protocol_write(c, p, p + NGX_PROXY_PROTOCOL_MAX_HEADER);
if (p == NULL) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
cl->buf->last = p;
cl->buf->temporary = 1;
cl->buf->flush = 0;
cl->buf->last_buf = 0;
cl->buf->tag = (ngx_buf_tag_t) &ngx_stream_proxy_module;
cl->next = u->upstream_out;
u->upstream_out = cl;
u->proxy_protocol = 0;
}
if (c->type == SOCK_DGRAM && pscf->responses == 0) {
pc->read->ready = 0;
pc->read->eof = 1;
}
u->connected = 1;
// 上游可读可写回调函数
pc->read->handler = ngx_stream_proxy_upstream_handler;
pc->write->handler = ngx_stream_proxy_upstream_handler;
if (pc->read->ready || pc->read->eof) {
ngx_post_event(pc->read, &ngx_posted_events);
}
ngx_stream_proxy_process(s, 0, 1);
}
// 下游可读可写回调函数
static void
ngx_stream_proxy_downstream_handler(ngx_event_t *ev)
{
// 下游可读可写事件结构体，可写结构体ev->write=1 可读ev->write=0
ngx_stream_proxy_process_connection(ev, ev->write);
}
// 上游可读可写回调函数
static void
ngx_stream_proxy_upstream_handler(ngx_event_t *ev)
{ // 上游可读可写回调函数，可写结构体ev->write=1 可读ev->write=0
ngx_stream_proxy_process_connection(ev, !ev->write);
}
// 上游下游的可读可写回调函数都调用了该函数
// 下游可写事件，from_ups =1 表示从上游读写到下游
// 下游可读事件，from_ups =0 表示从下游读写到上游
// 上游可写事件，from_ups =0 表示从下游读写到上游
// 上游可读事件，from_ups =1 表示从上游读写到下游
// 这个ev 其实是不一样的。分表代表了上游和下游
static void
ngx_stream_proxy_process_connection(ngx_event_t *ev, ngx_uint_t from_upstream)
{
ngx_connection_t *c, *pc;
ngx_stream_session_t *s;
ngx_stream_upstream_t *u;
ngx_stream_proxy_srv_conf_t *pscf;
c = ev->data;
s = c->data;
u = s->upstream;
if (c->close) {
ngx_log_error(NGX_LOG_INFO, c->log, 0, "shutdown timeout");
ngx_stream_proxy_finalize(s, NGX_STREAM_OK);
return;
}
c = s->connection;
pc = u->peer.connection;
pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);
if (ev->timedout) {
ev->timedout = 0;
if (ev->delayed) {
ev->delayed = 0;
if (!ev->ready) {
if (ngx_handle_read_event(ev, 0) != NGX_OK) {
ngx_stream_proxy_finalize(s,
NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
if (u->connected && !c->read->delayed && !pc->read->delayed) {
ngx_add_timer(c->write, pscf->timeout);
}
return;
}
} else {
if (s->connection->type == SOCK_DGRAM) {
if (pscf->responses == NGX_MAX_INT32_VALUE) {
/*
* successfully terminate timed out UDP session
* with unspecified number of responses
*/
pc->read->ready = 0;
pc->read->eof = 1;
ngx_stream_proxy_process(s, 1, 0);
return;
}
ngx_connection_error(pc, NGX_ETIMEDOUT, "upstream timed out");
if (u->received == 0) {
ngx_stream_proxy_next_upstream(s);
return;
}
} else {
ngx_connection_error(c, NGX_ETIMEDOUT, "connection timed out");
}
ngx_stream_proxy_finalize(s, NGX_STREAM_OK);
return;
}
} else if (ev->delayed) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
"stream connection delayed");
if (ngx_handle_read_event(ev, 0) != NGX_OK) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
}
return;
}
if (from_upstream && !u->connected) {
return;
}
ngx_stream_proxy_process(s, from_upstream, ev->write);
}
// 最终都会调用到这个处理函数
// 无论是上游可读可写事件还是下游可读可写事件都会调用该函数
// from_ups == 1 可能是上游的可读事件（从上游读内容），也可能是下游的可写事件（写的内容来自上游）
static void
ngx_stream_proxy_process(ngx_stream_session_t *s, ngx_uint_t from_upstream,
ngx_uint_t do_write)
{
off_t *received, limit;
size_t size, limit_rate;
ssize_t n;
ngx_buf_t *b;
ngx_int_t rc;
ngx_uint_t flags;
ngx_msec_t delay;
ngx_chain_t *cl, **ll, **out, **busy;
ngx_connection_t *c, *pc, *src, *dst;
ngx_log_handler_pt handler;
ngx_stream_upstream_t *u;
ngx_stream_proxy_srv_conf_t *pscf;
u = s->upstream;
c = s->connection;
pc = u->connected ? u->peer.connection : NULL;
if (c->type == SOCK_DGRAM && (ngx_terminate || ngx_exiting)) {
/* socket is already closed on worker shutdown */
handler = c->log->handler;
c->log->handler = NULL;
ngx_log_error(NGX_LOG_INFO, c->log, 0, "disconnected on shutdown");
c->log->handler = handler;
ngx_stream_proxy_finalize(s, NGX_STREAM_OK);
return;
}
pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);
if (from_upstream) {
// 从上游读 或者 写到下游
src = pc;
dst = c;
b = &u->upstream_buf;
// 下载限速
limit_rate = pscf->download_rate;
// 从上游读取到内容的长度
received = &u->received;
// 写到下游
out = &u->downstream_out;
busy = &u->downstream_busy;
} else {
src = c;
dst = pc;
b = &u->downstream_buf;
limit_rate = pscf->upload_rate;
received = &s->received;
out = &u->upstream_out;
busy = &u->upstream_busy;
}
for ( ;; ) {
if (do_write && dst) {
if (*out || *busy || dst->buffered) {
rc = ngx_stream_top_filter(s, *out, from_upstream);
if (rc == NGX_ERROR) {
if (c->type == SOCK_DGRAM && !from_upstream) {
ngx_stream_proxy_next_upstream(s);
return;
}
ngx_stream_proxy_finalize(s, NGX_STREAM_OK);
return;
}
ngx_chain_update_chains(c->pool, &u->free, busy, out,
(ngx_buf_tag_t) &ngx_stream_proxy_module);
if (*busy == NULL) {
b->pos = b->start;
b->last = b->start;
}
}
}
size = b->end - b->last;
if (size && src->read->ready && !src->read->delayed
&& !src->read->error)
{
if (limit_rate) {
limit = (off_t) limit_rate * (ngx_time() - u->start_sec + 1)
- *received;
if (limit <= 0) {
src->read->delayed = 1;
delay = (ngx_msec_t) (- limit * 1000 / limit_rate + 1);
ngx_add_timer(src->read, delay);
break;
}
if ((off_t) size > limit) {
size = (size_t) limit;
}
}
n = src->recv(src, b->last, size);
if (n == NGX_AGAIN) {
break;
}
if (n == NGX_ERROR) {
if (c->type == SOCK_DGRAM && u->received == 0) {
ngx_stream_proxy_next_upstream(s);
return;
}
src->read->eof = 1;
n = 0;
}
if (n >= 0) {
if (limit_rate) {
delay = (ngx_msec_t) (n * 1000 / limit_rate);
if (delay > 0) {
src->read->delayed = 1;
ngx_add_timer(src->read, delay);
}
}
if (from_upstream) {
if (u->state->first_byte_time == (ngx_msec_t) -1) {
u->state->first_byte_time = ngx_current_msec
- u->state->response_time;
}
}
if (c->type == SOCK_DGRAM && ++u->responses == pscf->responses)
{
src->read->ready = 0;
src->read->eof = 1;
}
for (ll = out; *ll; ll = &(*ll)->next) { /* void */ }
cl = ngx_chain_get_free_buf(c->pool, &u->free);
if (cl == NULL) {
ngx_stream_proxy_finalize(s,
NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
*ll = cl;
cl->buf->pos = b->last;
cl->buf->last = b->last + n;
cl->buf->tag = (ngx_buf_tag_t) &ngx_stream_proxy_module;
cl->buf->temporary = (n ? 1 : 0);
cl->buf->last_buf = src->read->eof;
cl->buf->flush = 1;
*received += n;
b->last += n;
do_write = 1;
continue;
}
}
break;
}
if (src->read->eof && dst && (dst->read->eof || !dst->buffered)) {
handler = c->log->handler;
c->log->handler = NULL;
ngx_log_error(NGX_LOG_INFO, c->log, 0,
"%s%s disconnected"
", bytes from/to client:%O/%O"
", bytes from/to upstream:%O/%O",
src->type == SOCK_DGRAM ? "udp " : "",
from_upstream ? "upstream" : "client",
s->received, c->sent, u->received, pc ? pc->sent : 0);
c->log->handler = handler;
ngx_stream_proxy_finalize(s, NGX_STREAM_OK);
return;
}
flags = src->read->eof ? NGX_CLOSE_EVENT : 0;
if (!src->shared && ngx_handle_read_event(src->read, flags) != NGX_OK) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
if (dst) {
if (!dst->shared && ngx_handle_write_event(dst->write, 0) != NGX_OK) {
ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
return;
}
if (!c->read->delayed && !pc->read->delayed) {
ngx_add_timer(c->write, pscf->timeout);
} else if (c->write->timer_set) {
ngx_del_timer(c->write);
}
}
}
ngx_stream_write_filter.c 把buf chain的内容调用write函数写入套接字缓存区
static ngx_int_t
ngx_stream_write_filter(ngx_stream_session_t *s, ngx_chain_t *in,
ngx_uint_t from_upstream)
{
off_t size;
ngx_uint_t last, flush, sync;
ngx_chain_t *cl, *ln, **ll, **out, *chain;
ngx_connection_t *c;
ngx_stream_write_filter_ctx_t *ctx;
// 写过滤模块上下文
ctx = ngx_stream_get_module_ctx(s, ngx_stream_write_filter_module);
if (ctx == NULL) {
ctx = ngx_pcalloc(s->connection->pool,
sizeof(ngx_stream_write_filter_ctx_t));
if (ctx == NULL) {
return NGX_ERROR;
}
ngx_stream_set_ctx(s, ctx, ngx_stream_write_filter_module);
}
// 内容来源上游，写到下游
if (from_upstream) {
c = s->connection;
out = &ctx->from_upstream;
} else {
c = s->upstream->peer.connection;
out = &ctx->from_downstream;
}
if (c->error) {
return NGX_ERROR;
}
size = 0;
flush = 0;
sync = 0;
last = 0;
ll = out;
/* find the size, the flush point and the last link of the saved chain */
for (cl = *out; cl; cl = cl->next) {
ll = &cl->next;
ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0,
"write old buf t:%d f:%d %p, pos %p, size: %z "
"file: %O, size: %O",
cl->buf->temporary, cl->buf->in_file,
cl->buf->start, cl->buf->pos,
cl->buf->last - cl->buf->pos,
cl->buf->file_pos,
cl->buf->file_last - cl->buf->file_pos);
#if 1
if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"zero size buf in writer "
"t:%d r:%d f:%d %p %p-%p %p %O-%O",
cl->buf->temporary,
cl->buf->recycled,
cl->buf->in_file,
cl->buf->start,
cl->buf->pos,
cl->buf->last,
cl->buf->file,
cl->buf->file_pos,
cl->buf->file_last);
ngx_debug_point();
return NGX_ERROR;
}
#endif
size += ngx_buf_size(cl->buf);
if (cl->buf->flush || cl->buf->recycled) {
flush = 1;
}
if (cl->buf->sync) {
sync = 1;
}
if (cl->buf->last_buf) {
last = 1;
}
}
/* add the new chain to the existent one */
for (ln = in; ln; ln = ln->next) {
cl = ngx_alloc_chain_link(c->pool);
if (cl == NULL) {
return NGX_ERROR;
}
cl->buf = ln->buf;
*ll = cl;
ll = &cl->next;
ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0,
"write new buf t:%d f:%d %p, pos %p, size: %z "
"file: %O, size: %O",
cl->buf->temporary, cl->buf->in_file,
cl->buf->start, cl->buf->pos,
cl->buf->last - cl->buf->pos,
cl->buf->file_pos,
cl->buf->file_last - cl->buf->file_pos);
#if 1
if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"zero size buf in writer "
"t:%d r:%d f:%d %p %p-%p %p %O-%O",
cl->buf->temporary,
cl->buf->recycled,
cl->buf->in_file,
cl->buf->start,
cl->buf->pos,
cl->buf->last,
cl->buf->file,
cl->buf->file_pos,
cl->buf->file_last);
ngx_debug_point();
return NGX_ERROR;
}
#endif
size += ngx_buf_size(cl->buf);
if (cl->buf->flush || cl->buf->recycled) {
flush = 1;
}
if (cl->buf->sync) {
sync = 1;
}
if (cl->buf->last_buf) {
last = 1;
}
}
*ll = NULL;
ngx_log_debug3(NGX_LOG_DEBUG_STREAM, c->log, 0,
"stream write filter: l:%ui f:%ui s:%O", last, flush, size);
if (size == 0
&& !(c->buffered & NGX_LOWLEVEL_BUFFERED)
&& !(last && c->need_last_buf))
{
if (last || flush || sync) {
for (cl = *out; cl; /* void */) {
ln = cl;
cl = cl->next;
ngx_free_chain(c->pool, ln);
}
*out = NULL;
c->buffered &= ~NGX_STREAM_WRITE_BUFFERED;
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"the stream output chain is empty");
ngx_debug_point();
return NGX_ERROR;
}
// out 这个buf chain的内容写到socket发送缓存区
// 返回的是下一次调用将要写的chain，也就是说该chain之前的内容都已经写入了缓存区
// out这个chain的内容都写入了缓存区，则返回NULL。
chain = c->send_chain(c, *out, 0);
ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0,
"stream write filter %p", chain);
if (chain == NGX_CHAIN_ERROR) {
c->error = 1;
return NGX_ERROR;
}
for (cl = *out; cl && cl != chain; /* void */) {
ln = cl;
cl = cl->next;
ngx_free_chain(c->pool, ln);
}
*out = chain;
if (chain) {
if (c->shared) {
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
"shared connection is busy");
return NGX_ERROR;
}
c->buffered |= NGX_STREAM_WRITE_BUFFERED;
return NGX_AGAIN;
}
c->buffered &= ~NGX_STREAM_WRITE_BUFFERED;
if (c->buffered & NGX_LOWLEVEL_BUFFERED) {
return NGX_AGAIN;
}
return NGX_OK;
}
