Mercurial > hg > nginx
view src/stream/ngx_stream_handler.c @ 8045:aa28c802409f
Resolver: make TCP write timer event cancelable.
Similar to 70e65bf8dfd7, the change is made to ensure that the ability to
cancel resolver tasks is fully controlled by the caller. As mentioned in the
referenced commit, it is safe to make this timer cancelable because resolve
tasks can have their own timeouts that are not cancelable.
The scenario where this may become a problem is a periodic background resolve
task (not tied to a specific request or a client connection), which receives a
response with short TTL, large enough to warrant fallback to a TCP query.
With each event loop wakeup, we either have a previously set write timer
instance or schedule a new one. The non-cancelable write timer can delay or
block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable
flag is set by the API user, and there are no other tasks or connections.
We use the resolver API in this way to maintain the list of upstream server
addresses specified with the 'resolve' parameter, and there could be third-party
modules implementing similar logic.
author | Aleksei Bavshin <a.bavshin@f5.com> |
---|---|
date | Wed, 01 Jun 2022 20:17:23 -0700 |
parents | 3908156a51fa |
children | 893b3313f53c |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_stream.h> static void ngx_stream_log_session(ngx_stream_session_t *s); static void ngx_stream_close_connection(ngx_connection_t *c); static u_char *ngx_stream_log_error(ngx_log_t *log, u_char *buf, size_t len); static void ngx_stream_proxy_protocol_handler(ngx_event_t *rev); void ngx_stream_init_connection(ngx_connection_t *c) { u_char text[NGX_SOCKADDR_STRLEN]; size_t len; ngx_uint_t i; ngx_time_t *tp; ngx_event_t *rev; struct sockaddr *sa; ngx_stream_port_t *port; struct sockaddr_in *sin; ngx_stream_in_addr_t *addr; ngx_stream_session_t *s; ngx_stream_addr_conf_t *addr_conf; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; ngx_stream_in6_addr_t *addr6; #endif ngx_stream_core_srv_conf_t *cscf; ngx_stream_core_main_conf_t *cmcf; /* find the server configuration for the address:port */ port = c->listening->servers; if (port->naddrs > 1) { /* * There are several addresses on this port and one of them * is the "*:port" wildcard so getsockname() is needed to determine * the server address. * * AcceptEx() and recvmsg() already gave this address. */ if (ngx_connection_local_sockaddr(c, NULL, 0) != NGX_OK) { ngx_stream_close_connection(c); return; } sa = c->local_sockaddr; switch (sa->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) sa; addr6 = port->addrs; /* the last address is "*" */ for (i = 0; i < port->naddrs - 1; i++) { if (ngx_memcmp(&addr6[i].addr6, &sin6->sin6_addr, 16) == 0) { break; } } addr_conf = &addr6[i].conf; break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) sa; addr = port->addrs; /* the last address is "*" */ for (i = 0; i < port->naddrs - 1; i++) { if (addr[i].addr == sin->sin_addr.s_addr) { break; } } addr_conf = &addr[i].conf; break; } } else { switch (c->local_sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: addr6 = port->addrs; addr_conf = &addr6[0].conf; break; #endif default: /* AF_INET */ addr = port->addrs; addr_conf = &addr[0].conf; break; } } s = ngx_pcalloc(c->pool, sizeof(ngx_stream_session_t)); if (s == NULL) { ngx_stream_close_connection(c); return; } s->signature = NGX_STREAM_MODULE; s->main_conf = addr_conf->ctx->main_conf; s->srv_conf = addr_conf->ctx->srv_conf; #if (NGX_STREAM_SSL) s->ssl = addr_conf->ssl; #endif if (c->buffer) { s->received += c->buffer->last - c->buffer->pos; } s->connection = c; c->data = s; cscf = ngx_stream_get_module_srv_conf(s, ngx_stream_core_module); ngx_set_connection_log(c, cscf->error_log); len = ngx_sock_ntop(c->sockaddr, c->socklen, text, NGX_SOCKADDR_STRLEN, 1); ngx_log_error(NGX_LOG_INFO, c->log, 0, "*%uA %sclient %*s connected to %V", c->number, c->type == SOCK_DGRAM ? "udp " : "", len, text, &addr_conf->addr_text); c->log->connection = c->number; c->log->handler = ngx_stream_log_error; c->log->data = s; c->log->action = "initializing session"; c->log_error = NGX_ERROR_INFO; s->ctx = ngx_pcalloc(c->pool, sizeof(void *) * ngx_stream_max_module); if (s->ctx == NULL) { ngx_stream_close_connection(c); return; } cmcf = ngx_stream_get_module_main_conf(s, ngx_stream_core_module); s->variables = ngx_pcalloc(s->connection->pool, cmcf->variables.nelts * sizeof(ngx_stream_variable_value_t)); if (s->variables == NULL) { ngx_stream_close_connection(c); return; } tp = ngx_timeofday(); s->start_sec = tp->sec; s->start_msec = tp->msec; rev = c->read; rev->handler = ngx_stream_session_handler; if (addr_conf->proxy_protocol) { c->log->action = "reading PROXY protocol"; rev->handler = ngx_stream_proxy_protocol_handler; if (!rev->ready) { ngx_add_timer(rev, cscf->proxy_protocol_timeout); if (ngx_handle_read_event(rev, 0) != NGX_OK) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); } return; } } if (ngx_use_accept_mutex) { ngx_post_event(rev, &ngx_posted_events); return; } rev->handler(rev); } static void ngx_stream_proxy_protocol_handler(ngx_event_t *rev) { u_char *p, buf[NGX_PROXY_PROTOCOL_MAX_HEADER]; size_t size; ssize_t n; ngx_err_t err; ngx_connection_t *c; ngx_stream_session_t *s; ngx_stream_core_srv_conf_t *cscf; c = rev->data; s = c->data; ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream PROXY protocol handler"); if (rev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out"); ngx_stream_finalize_session(s, NGX_STREAM_OK); return; } n = recv(c->fd, (char *) buf, sizeof(buf), MSG_PEEK); err = ngx_socket_errno; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "recv(): %z", n); if (n == -1) { if (err == NGX_EAGAIN) { rev->ready = 0; if (!rev->timer_set) { cscf = ngx_stream_get_module_srv_conf(s, ngx_stream_core_module); ngx_add_timer(rev, cscf->proxy_protocol_timeout); } if (ngx_handle_read_event(rev, 0) != NGX_OK) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); } return; } ngx_connection_error(c, err, "recv() failed"); ngx_stream_finalize_session(s, NGX_STREAM_OK); return; } if (rev->timer_set) { ngx_del_timer(rev); } p = ngx_proxy_protocol_read(c, buf, buf + n); if (p == NULL) { ngx_stream_finalize_session(s, NGX_STREAM_BAD_REQUEST); return; } size = p - buf; if (c->recv(c, buf, size) != (ssize_t) size) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); return; } c->log->action = "initializing session"; ngx_stream_session_handler(rev); } void ngx_stream_session_handler(ngx_event_t *rev) { ngx_connection_t *c; ngx_stream_session_t *s; c = rev->data; s = c->data; ngx_stream_core_run_phases(s); } void ngx_stream_finalize_session(ngx_stream_session_t *s, ngx_uint_t rc) { ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0, "finalize stream session: %i", rc); s->status = rc; ngx_stream_log_session(s); ngx_stream_close_connection(s->connection); } static void ngx_stream_log_session(ngx_stream_session_t *s) { ngx_uint_t i, n; ngx_stream_handler_pt *log_handler; ngx_stream_core_main_conf_t *cmcf; cmcf = ngx_stream_get_module_main_conf(s, ngx_stream_core_module); log_handler = cmcf->phases[NGX_STREAM_LOG_PHASE].handlers.elts; n = cmcf->phases[NGX_STREAM_LOG_PHASE].handlers.nelts; for (i = 0; i < n; i++) { log_handler[i](s); } } static void ngx_stream_close_connection(ngx_connection_t *c) { ngx_pool_t *pool; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "close stream connection: %d", c->fd); #if (NGX_STREAM_SSL) if (c->ssl) { if (ngx_ssl_shutdown(c) == NGX_AGAIN) { c->ssl->handler = ngx_stream_close_connection; return; } } #endif #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, -1); #endif pool = c->pool; ngx_close_connection(c); ngx_destroy_pool(pool); } static u_char * ngx_stream_log_error(ngx_log_t *log, u_char *buf, size_t len) { u_char *p; ngx_stream_session_t *s; if (log->action) { p = ngx_snprintf(buf, len, " while %s", log->action); len -= p - buf; buf = p; } s = log->data; p = ngx_snprintf(buf, len, ", %sclient: %V, server: %V", s->connection->type == SOCK_DGRAM ? "udp " : "", &s->connection->addr_text, &s->connection->listening->addr_text); len -= p - buf; buf = p; if (s->log_handler) { p = s->log_handler(log, buf, len); } return p; }