Mercurial > hg > nginx
view src/event/modules/ngx_eventport_module.c @ 6806:75dbab4ea930
Events: improved error event handling for UDP sockets.
Normally, the epoll module calls the read and write handlers depending
on whether EPOLLIN and EPOLLOUT are reported by epoll_wait(). No error
processing is done in the module, the handlers are expected to get an
error when doing I/O.
If an error event is reported without EPOLLIN and EPOLLOUT, the module
set both EPOLLIN and EPOLLOUT to ensure the error event is handled at
least in one active handler.
This works well unless the error is delivered along with only one of
EPOLLIN or EPOLLOUT, and the corresponding handler does not do any I/O.
For example, it happened when getting EPOLLERR|EPOLLOUT from
epoll_wait() upon receiving "ICMP port unreachable" while proxying UDP.
As the write handler had nothing to send it was not able to detect and
log an error, and did not switch to the next upstream.
The fix is to unconditionally set EPOLLIN and EPOLLOUT in case of an
error event. In the aforementioned case, this causes the read handler
to be called which does recv() and detects an error.
In addition to the epoll module, analogous changes were made in
devpoll/eventport/poll.
author | Dmitry Volyntsev <xeioex@nginx.com> |
---|---|
date | Mon, 21 Nov 2016 16:03:42 +0300 |
parents | dc92298b1852 |
children | a72886067bbb |
line wrap: on
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #if (NGX_TEST_BUILD_EVENTPORT) #define ushort_t u_short #define uint_t u_int #ifndef CLOCK_REALTIME #define CLOCK_REALTIME 0 typedef int clockid_t; typedef void * timer_t; #endif /* Solaris declarations */ #define PORT_SOURCE_AIO 1 #define PORT_SOURCE_TIMER 2 #define PORT_SOURCE_USER 3 #define PORT_SOURCE_FD 4 #define PORT_SOURCE_ALERT 5 #define PORT_SOURCE_MQ 6 #ifndef ETIME #define ETIME 64 #endif #define SIGEV_PORT 4 typedef struct { int portev_events; /* event data is source specific */ ushort_t portev_source; /* event source */ ushort_t portev_pad; /* port internal use */ uintptr_t portev_object; /* source specific object */ void *portev_user; /* user cookie */ } port_event_t; typedef struct port_notify { int portnfy_port; /* bind request(s) to port */ void *portnfy_user; /* user defined */ } port_notify_t; #if (__FreeBSD__ && __FreeBSD_version < 700005) || (NGX_DARWIN) typedef struct itimerspec { /* definition per POSIX.4 */ struct timespec it_interval;/* timer period */ struct timespec it_value; /* timer expiration */ } itimerspec_t; #endif int port_create(void); int port_create(void) { return -1; } int port_associate(int port, int source, uintptr_t object, int events, void *user); int port_associate(int port, int source, uintptr_t object, int events, void *user) { return -1; } int port_dissociate(int port, int source, uintptr_t object); int port_dissociate(int port, int source, uintptr_t object) { return -1; } int port_getn(int port, port_event_t list[], uint_t max, uint_t *nget, struct timespec *timeout); int port_getn(int port, port_event_t list[], uint_t max, uint_t *nget, struct timespec *timeout) { return -1; } int port_send(int port, int events, void *user); int port_send(int port, int events, void *user) { return -1; } int timer_create(clockid_t clock_id, struct sigevent *evp, timer_t *timerid); int timer_create(clockid_t clock_id, struct sigevent *evp, timer_t *timerid) { return -1; } int timer_settime(timer_t timerid, int flags, const struct itimerspec *value, struct itimerspec *ovalue); int timer_settime(timer_t timerid, int flags, const struct itimerspec *value, struct itimerspec *ovalue) { return -1; } int timer_delete(timer_t timerid); int timer_delete(timer_t timerid) { return -1; } #endif typedef struct { ngx_uint_t events; } ngx_eventport_conf_t; static ngx_int_t ngx_eventport_init(ngx_cycle_t *cycle, ngx_msec_t timer); static void ngx_eventport_done(ngx_cycle_t *cycle); static ngx_int_t ngx_eventport_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags); static ngx_int_t ngx_eventport_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags); static ngx_int_t ngx_eventport_notify(ngx_event_handler_pt handler); static ngx_int_t ngx_eventport_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags); static void *ngx_eventport_create_conf(ngx_cycle_t *cycle); static char *ngx_eventport_init_conf(ngx_cycle_t *cycle, void *conf); static int ep = -1; static port_event_t *event_list; static ngx_uint_t nevents; static timer_t event_timer = (timer_t) -1; static ngx_event_t notify_event; static ngx_str_t eventport_name = ngx_string("eventport"); static ngx_command_t ngx_eventport_commands[] = { { ngx_string("eventport_events"), NGX_EVENT_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, 0, offsetof(ngx_eventport_conf_t, events), NULL }, ngx_null_command }; ngx_event_module_t ngx_eventport_module_ctx = { &eventport_name, ngx_eventport_create_conf, /* create configuration */ ngx_eventport_init_conf, /* init configuration */ { ngx_eventport_add_event, /* add an event */ ngx_eventport_del_event, /* delete an event */ ngx_eventport_add_event, /* enable an event */ ngx_eventport_del_event, /* disable an event */ NULL, /* add an connection */ NULL, /* delete an connection */ ngx_eventport_notify, /* trigger a notify */ ngx_eventport_process_events, /* process the events */ ngx_eventport_init, /* init the events */ ngx_eventport_done, /* done the events */ } }; ngx_module_t ngx_eventport_module = { NGX_MODULE_V1, &ngx_eventport_module_ctx, /* module context */ ngx_eventport_commands, /* module directives */ NGX_EVENT_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_eventport_init(ngx_cycle_t *cycle, ngx_msec_t timer) { port_notify_t pn; struct itimerspec its; struct sigevent sev; ngx_eventport_conf_t *epcf; epcf = ngx_event_get_conf(cycle->conf_ctx, ngx_eventport_module); if (ep == -1) { ep = port_create(); if (ep == -1) { ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, "port_create() failed"); return NGX_ERROR; } notify_event.active = 1; notify_event.log = cycle->log; } if (nevents < epcf->events) { if (event_list) { ngx_free(event_list); } event_list = ngx_alloc(sizeof(port_event_t) * epcf->events, cycle->log); if (event_list == NULL) { return NGX_ERROR; } } ngx_event_flags = NGX_USE_EVENTPORT_EVENT; if (timer) { ngx_memzero(&pn, sizeof(port_notify_t)); pn.portnfy_port = ep; ngx_memzero(&sev, sizeof(struct sigevent)); sev.sigev_notify = SIGEV_PORT; #if !(NGX_TEST_BUILD_EVENTPORT) sev.sigev_value.sival_ptr = &pn; #endif if (timer_create(CLOCK_REALTIME, &sev, &event_timer) == -1) { ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, "timer_create() failed"); return NGX_ERROR; } its.it_interval.tv_sec = timer / 1000; its.it_interval.tv_nsec = (timer % 1000) * 1000000; its.it_value.tv_sec = timer / 1000; its.it_value.tv_nsec = (timer % 1000) * 1000000; if (timer_settime(event_timer, 0, &its, NULL) == -1) { ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, "timer_settime() failed"); return NGX_ERROR; } ngx_event_flags |= NGX_USE_TIMER_EVENT; } nevents = epcf->events; ngx_io = ngx_os_io; ngx_event_actions = ngx_eventport_module_ctx.actions; return NGX_OK; } static void ngx_eventport_done(ngx_cycle_t *cycle) { if (event_timer != (timer_t) -1) { if (timer_delete(event_timer) == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "timer_delete() failed"); } event_timer = (timer_t) -1; } if (close(ep) == -1) { ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, "close() event port failed"); } ep = -1; ngx_free(event_list); event_list = NULL; nevents = 0; } static ngx_int_t ngx_eventport_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags) { ngx_int_t events, prev; ngx_event_t *e; ngx_connection_t *c; c = ev->data; events = event; if (event == NGX_READ_EVENT) { e = c->write; prev = POLLOUT; #if (NGX_READ_EVENT != POLLIN) events = POLLIN; #endif } else { e = c->read; prev = POLLIN; #if (NGX_WRITE_EVENT != POLLOUT) events = POLLOUT; #endif } if (e->oneshot) { events |= prev; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "eventport add event: fd:%d ev:%04Xi", c->fd, events); if (port_associate(ep, PORT_SOURCE_FD, c->fd, events, (void *) ((uintptr_t) ev | ev->instance)) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno, "port_associate() failed"); return NGX_ERROR; } ev->active = 1; ev->oneshot = 1; return NGX_OK; } static ngx_int_t ngx_eventport_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags) { ngx_event_t *e; ngx_connection_t *c; /* * when the file descriptor is closed, the event port automatically * dissociates it from the port, so we do not need to dissociate explicitly * the event before the closing the file descriptor */ if (flags & NGX_CLOSE_EVENT) { ev->active = 0; ev->oneshot = 0; return NGX_OK; } c = ev->data; if (event == NGX_READ_EVENT) { e = c->write; event = POLLOUT; } else { e = c->read; event = POLLIN; } if (e->oneshot) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "eventport change event: fd:%d ev:%04Xi", c->fd, event); if (port_associate(ep, PORT_SOURCE_FD, c->fd, event, (void *) ((uintptr_t) ev | ev->instance)) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno, "port_associate() failed"); return NGX_ERROR; } } else { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0, "eventport del event: fd:%d", c->fd); if (port_dissociate(ep, PORT_SOURCE_FD, c->fd) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno, "port_dissociate() failed"); return NGX_ERROR; } } ev->active = 0; ev->oneshot = 0; return NGX_OK; } static ngx_int_t ngx_eventport_notify(ngx_event_handler_pt handler) { notify_event.handler = handler; if (port_send(ep, 0, ¬ify_event) != 0) { ngx_log_error(NGX_LOG_ALERT, notify_event.log, ngx_errno, "port_send() failed"); return NGX_ERROR; } return NGX_OK; } ngx_int_t ngx_eventport_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags) { int n, revents; u_int events; ngx_err_t err; ngx_int_t instance; ngx_uint_t i, level; ngx_event_t *ev, *rev, *wev; ngx_queue_t *queue; ngx_connection_t *c; struct timespec ts, *tp; if (timer == NGX_TIMER_INFINITE) { tp = NULL; } else { ts.tv_sec = timer / 1000; ts.tv_nsec = (timer % 1000) * 1000000; tp = &ts; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "eventport timer: %M", timer); events = 1; n = port_getn(ep, event_list, (u_int) nevents, &events, tp); err = ngx_errno; if (flags & NGX_UPDATE_TIME) { ngx_time_update(); } if (n == -1) { if (err == ETIME) { if (timer != NGX_TIMER_INFINITE) { return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "port_getn() returned no events without timeout"); return NGX_ERROR; } level = (err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT; ngx_log_error(level, cycle->log, err, "port_getn() failed"); return NGX_ERROR; } if (events == 0) { if (timer != NGX_TIMER_INFINITE) { return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "port_getn() returned no events without timeout"); return NGX_ERROR; } for (i = 0; i < events; i++) { if (event_list[i].portev_source == PORT_SOURCE_TIMER) { ngx_time_update(); continue; } ev = event_list[i].portev_user; switch (event_list[i].portev_source) { case PORT_SOURCE_FD: instance = (uintptr_t) ev & 1; ev = (ngx_event_t *) ((uintptr_t) ev & (uintptr_t) ~1); if (ev->closed || ev->instance != instance) { /* * the stale event from a file descriptor * that was just closed in this iteration */ ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "eventport: stale event %p", ev); continue; } revents = event_list[i].portev_events; ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "eventport: fd:%d, ev:%04Xd", (int) event_list[i].portev_object, revents); if (revents & (POLLERR|POLLHUP|POLLNVAL)) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "port_getn() error fd:%d ev:%04Xd", (int) event_list[i].portev_object, revents); } if (revents & ~(POLLIN|POLLOUT|POLLERR|POLLHUP|POLLNVAL)) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "strange port_getn() events fd:%d ev:%04Xd", (int) event_list[i].portev_object, revents); } if (revents & (POLLERR|POLLHUP|POLLNVAL)) { /* * if the error events were returned, add POLLIN and POLLOUT * to handle the events at least in one active handler */ revents |= POLLIN|POLLOUT; } c = ev->data; rev = c->read; wev = c->write; rev->active = 0; wev->active = 0; if (revents & POLLIN) { rev->ready = 1; if (flags & NGX_POST_EVENTS) { queue = rev->accept ? &ngx_posted_accept_events : &ngx_posted_events; ngx_post_event(rev, queue); } else { rev->handler(rev); if (ev->closed || ev->instance != instance) { continue; } } if (rev->accept) { if (ngx_use_accept_mutex) { ngx_accept_events = 1; continue; } if (port_associate(ep, PORT_SOURCE_FD, c->fd, POLLIN, (void *) ((uintptr_t) ev | ev->instance)) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno, "port_associate() failed"); return NGX_ERROR; } } } if (revents & POLLOUT) { wev->ready = 1; if (flags & NGX_POST_EVENTS) { ngx_post_event(wev, &ngx_posted_events); } else { wev->handler(wev); } } continue; case PORT_SOURCE_USER: ev->handler(ev); continue; default: ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "unexpected eventport object %d", (int) event_list[i].portev_object); continue; } } return NGX_OK; } static void * ngx_eventport_create_conf(ngx_cycle_t *cycle) { ngx_eventport_conf_t *epcf; epcf = ngx_palloc(cycle->pool, sizeof(ngx_eventport_conf_t)); if (epcf == NULL) { return NULL; } epcf->events = NGX_CONF_UNSET; return epcf; } static char * ngx_eventport_init_conf(ngx_cycle_t *cycle, void *conf) { ngx_eventport_conf_t *epcf = conf; ngx_conf_init_uint_value(epcf->events, 32); return NGX_CONF_OK; }