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view src/http/modules/ngx_http_upstream_keepalive_module.c @ 7355:b64adc956643

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Rewrite: removed r->err_status special handling (ticket #1634). Trying to look into r->err_status in the "return" directive makes it behave differently than real errors generated in other parts of the code, and is an endless source of various problems. This behaviour was introduced in 726:7b71936d5299 (0.4.4) with the comment "fix: "return" always overrode "error_page" response code". It is not clear if there were any real cases this was expected to fix, but there are several cases which are broken due to this change, some previously fixed (4147:7f64de1cc2c0). In ticket #1634, the problem is that when r->err_status is set to a non-special status code, it is not possible to return a response by simply returning r->err_status. If this is the case, the only option is to return script's e->status instead. An example configuration: location / { error_page 404 =200 /err502; return 404; } location = /err502 { return 502; } After the change, such a configuration will properly return standard 502 error, much like it happens when a 502 error is generated by proxy_pass. This also fixes the following configuration to properly close connection as clearly requested by "return 444": location / { error_page 404 /close; return 404; } location = /close { return 444; } Previously, this required "error_page 404 = /close;" to work as intended.
author Maxim Dounin <mdounin@mdounin.ru>
date Fri, 21 Sep 2018 15:59:33 +0300
parents 70c6b08973a0
children 3939483cd1b5
line wrap: on
line source


/*
 * Copyright (C) Maxim Dounin
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>


typedef struct {
    ngx_uint_t                         max_cached;
    ngx_uint_t                         requests;
    ngx_msec_t                         timeout;

    ngx_queue_t                        cache;
    ngx_queue_t                        free;

    ngx_http_upstream_init_pt          original_init_upstream;
    ngx_http_upstream_init_peer_pt     original_init_peer;

} ngx_http_upstream_keepalive_srv_conf_t;


typedef struct {
    ngx_http_upstream_keepalive_srv_conf_t  *conf;

    ngx_queue_t                        queue;
    ngx_connection_t                  *connection;

    socklen_t                          socklen;
    ngx_sockaddr_t                     sockaddr;

} ngx_http_upstream_keepalive_cache_t;


typedef struct {
    ngx_http_upstream_keepalive_srv_conf_t  *conf;

    ngx_http_upstream_t               *upstream;

    void                              *data;

    ngx_event_get_peer_pt              original_get_peer;
    ngx_event_free_peer_pt             original_free_peer;

#if (NGX_HTTP_SSL)
    ngx_event_set_peer_session_pt      original_set_session;
    ngx_event_save_peer_session_pt     original_save_session;
#endif

} ngx_http_upstream_keepalive_peer_data_t;


static ngx_int_t ngx_http_upstream_init_keepalive_peer(ngx_http_request_t *r,
    ngx_http_upstream_srv_conf_t *us);
static ngx_int_t ngx_http_upstream_get_keepalive_peer(ngx_peer_connection_t *pc,
    void *data);
static void ngx_http_upstream_free_keepalive_peer(ngx_peer_connection_t *pc,
    void *data, ngx_uint_t state);

static void ngx_http_upstream_keepalive_dummy_handler(ngx_event_t *ev);
static void ngx_http_upstream_keepalive_close_handler(ngx_event_t *ev);
static void ngx_http_upstream_keepalive_close(ngx_connection_t *c);

#if (NGX_HTTP_SSL)
static ngx_int_t ngx_http_upstream_keepalive_set_session(
    ngx_peer_connection_t *pc, void *data);
static void ngx_http_upstream_keepalive_save_session(ngx_peer_connection_t *pc,
    void *data);
#endif

static void *ngx_http_upstream_keepalive_create_conf(ngx_conf_t *cf);
static char *ngx_http_upstream_keepalive(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_command_t  ngx_http_upstream_keepalive_commands[] = {

    { ngx_string("keepalive"),
      NGX_HTTP_UPS_CONF|NGX_CONF_TAKE1,
      ngx_http_upstream_keepalive,
      NGX_HTTP_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("keepalive_timeout"),
      NGX_HTTP_UPS_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_upstream_keepalive_srv_conf_t, timeout),
      NULL },

    { ngx_string("keepalive_requests"),
      NGX_HTTP_UPS_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_upstream_keepalive_srv_conf_t, requests),
      NULL },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_upstream_keepalive_module_ctx = {
    NULL,                                  /* preconfiguration */
    NULL,                                  /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    ngx_http_upstream_keepalive_create_conf, /* create server configuration */
    NULL,                                  /* merge server configuration */

    NULL,                                  /* create location configuration */
    NULL                                   /* merge location configuration */
};


ngx_module_t  ngx_http_upstream_keepalive_module = {
    NGX_MODULE_V1,
    &ngx_http_upstream_keepalive_module_ctx, /* module context */
    ngx_http_upstream_keepalive_commands,    /* module directives */
    NGX_HTTP_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_http_upstream_init_keepalive(ngx_conf_t *cf,
    ngx_http_upstream_srv_conf_t *us)
{
    ngx_uint_t                               i;
    ngx_http_upstream_keepalive_srv_conf_t  *kcf;
    ngx_http_upstream_keepalive_cache_t     *cached;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, cf->log, 0,
                   "init keepalive");

    kcf = ngx_http_conf_upstream_srv_conf(us,
                                          ngx_http_upstream_keepalive_module);

    ngx_conf_init_msec_value(kcf->timeout, 60000);
    ngx_conf_init_uint_value(kcf->requests, 100);

    if (kcf->original_init_upstream(cf, us) != NGX_OK) {
        return NGX_ERROR;
    }

    kcf->original_init_peer = us->peer.init;

    us->peer.init = ngx_http_upstream_init_keepalive_peer;

    /* allocate cache items and add to free queue */

    cached = ngx_pcalloc(cf->pool,
                sizeof(ngx_http_upstream_keepalive_cache_t) * kcf->max_cached);
    if (cached == NULL) {
        return NGX_ERROR;
    }

    ngx_queue_init(&kcf->cache);
    ngx_queue_init(&kcf->free);

    for (i = 0; i < kcf->max_cached; i++) {
        ngx_queue_insert_head(&kcf->free, &cached[i].queue);
        cached[i].conf = kcf;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_upstream_init_keepalive_peer(ngx_http_request_t *r,
    ngx_http_upstream_srv_conf_t *us)
{
    ngx_http_upstream_keepalive_peer_data_t  *kp;
    ngx_http_upstream_keepalive_srv_conf_t   *kcf;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "init keepalive peer");

    kcf = ngx_http_conf_upstream_srv_conf(us,
                                          ngx_http_upstream_keepalive_module);

    kp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_keepalive_peer_data_t));
    if (kp == NULL) {
        return NGX_ERROR;
    }

    if (kcf->original_init_peer(r, us) != NGX_OK) {
        return NGX_ERROR;
    }

    kp->conf = kcf;
    kp->upstream = r->upstream;
    kp->data = r->upstream->peer.data;
    kp->original_get_peer = r->upstream->peer.get;
    kp->original_free_peer = r->upstream->peer.free;

    r->upstream->peer.data = kp;
    r->upstream->peer.get = ngx_http_upstream_get_keepalive_peer;
    r->upstream->peer.free = ngx_http_upstream_free_keepalive_peer;

#if (NGX_HTTP_SSL)
    kp->original_set_session = r->upstream->peer.set_session;
    kp->original_save_session = r->upstream->peer.save_session;
    r->upstream->peer.set_session = ngx_http_upstream_keepalive_set_session;
    r->upstream->peer.save_session = ngx_http_upstream_keepalive_save_session;
#endif

    return NGX_OK;
}


static ngx_int_t
ngx_http_upstream_get_keepalive_peer(ngx_peer_connection_t *pc, void *data)
{
    ngx_http_upstream_keepalive_peer_data_t  *kp = data;
    ngx_http_upstream_keepalive_cache_t      *item;

    ngx_int_t          rc;
    ngx_queue_t       *q, *cache;
    ngx_connection_t  *c;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "get keepalive peer");

    /* ask balancer */

    rc = kp->original_get_peer(pc, kp->data);

    if (rc != NGX_OK) {
        return rc;
    }

    /* search cache for suitable connection */

    cache = &kp->conf->cache;

    for (q = ngx_queue_head(cache);
         q != ngx_queue_sentinel(cache);
         q = ngx_queue_next(q))
    {
        item = ngx_queue_data(q, ngx_http_upstream_keepalive_cache_t, queue);
        c = item->connection;

        if (ngx_memn2cmp((u_char *) &item->sockaddr, (u_char *) pc->sockaddr,
                         item->socklen, pc->socklen)
            == 0)
        {
            ngx_queue_remove(q);
            ngx_queue_insert_head(&kp->conf->free, q);

            goto found;
        }
    }

    return NGX_OK;

found:

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "get keepalive peer: using connection %p", c);

    c->idle = 0;
    c->sent = 0;
    c->log = pc->log;
    c->read->log = pc->log;
    c->write->log = pc->log;
    c->pool->log = pc->log;

    if (c->read->timer_set) {
        ngx_del_timer(c->read);
    }

    pc->connection = c;
    pc->cached = 1;

    return NGX_DONE;
}


static void
ngx_http_upstream_free_keepalive_peer(ngx_peer_connection_t *pc, void *data,
    ngx_uint_t state)
{
    ngx_http_upstream_keepalive_peer_data_t  *kp = data;
    ngx_http_upstream_keepalive_cache_t      *item;

    ngx_queue_t          *q;
    ngx_connection_t     *c;
    ngx_http_upstream_t  *u;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "free keepalive peer");

    /* cache valid connections */

    u = kp->upstream;
    c = pc->connection;

    if (state & NGX_PEER_FAILED
        || c == NULL
        || c->read->eof
        || c->read->error
        || c->read->timedout
        || c->write->error
        || c->write->timedout)
    {
        goto invalid;
    }

    if (c->requests >= kp->conf->requests) {
        goto invalid;
    }

    if (!u->keepalive) {
        goto invalid;
    }

    if (!u->request_body_sent) {
        goto invalid;
    }

    if (ngx_terminate || ngx_exiting) {
        goto invalid;
    }

    if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
        goto invalid;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
                   "free keepalive peer: saving connection %p", c);

    if (ngx_queue_empty(&kp->conf->free)) {

        q = ngx_queue_last(&kp->conf->cache);
        ngx_queue_remove(q);

        item = ngx_queue_data(q, ngx_http_upstream_keepalive_cache_t, queue);

        ngx_http_upstream_keepalive_close(item->connection);

    } else {
        q = ngx_queue_head(&kp->conf->free);
        ngx_queue_remove(q);

        item = ngx_queue_data(q, ngx_http_upstream_keepalive_cache_t, queue);
    }

    ngx_queue_insert_head(&kp->conf->cache, q);

    item->connection = c;

    pc->connection = NULL;

    c->read->delayed = 0;
    ngx_add_timer(c->read, kp->conf->timeout);

    if (c->write->timer_set) {
        ngx_del_timer(c->write);
    }

    c->write->handler = ngx_http_upstream_keepalive_dummy_handler;
    c->read->handler = ngx_http_upstream_keepalive_close_handler;

    c->data = item;
    c->idle = 1;
    c->log = ngx_cycle->log;
    c->read->log = ngx_cycle->log;
    c->write->log = ngx_cycle->log;
    c->pool->log = ngx_cycle->log;

    item->socklen = pc->socklen;
    ngx_memcpy(&item->sockaddr, pc->sockaddr, pc->socklen);

    if (c->read->ready) {
        ngx_http_upstream_keepalive_close_handler(c->read);
    }

invalid:

    kp->original_free_peer(pc, kp->data, state);
}


static void
ngx_http_upstream_keepalive_dummy_handler(ngx_event_t *ev)
{
    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ev->log, 0,
                   "keepalive dummy handler");
}


static void
ngx_http_upstream_keepalive_close_handler(ngx_event_t *ev)
{
    ngx_http_upstream_keepalive_srv_conf_t  *conf;
    ngx_http_upstream_keepalive_cache_t     *item;

    int                n;
    char               buf[1];
    ngx_connection_t  *c;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ev->log, 0,
                   "keepalive close handler");

    c = ev->data;

    if (c->close || c->read->timedout) {
        goto close;
    }

    n = recv(c->fd, buf, 1, MSG_PEEK);

    if (n == -1 && ngx_socket_errno == NGX_EAGAIN) {
        ev->ready = 0;

        if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
            goto close;
        }

        return;
    }

close:

    item = c->data;
    conf = item->conf;

    ngx_http_upstream_keepalive_close(c);

    ngx_queue_remove(&item->queue);
    ngx_queue_insert_head(&conf->free, &item->queue);
}


static void
ngx_http_upstream_keepalive_close(ngx_connection_t *c)
{

#if (NGX_HTTP_SSL)

    if (c->ssl) {
        c->ssl->no_wait_shutdown = 1;
        c->ssl->no_send_shutdown = 1;

        if (ngx_ssl_shutdown(c) == NGX_AGAIN) {
            c->ssl->handler = ngx_http_upstream_keepalive_close;
            return;
        }
    }

#endif

    ngx_destroy_pool(c->pool);
    ngx_close_connection(c);
}


#if (NGX_HTTP_SSL)

static ngx_int_t
ngx_http_upstream_keepalive_set_session(ngx_peer_connection_t *pc, void *data)
{
    ngx_http_upstream_keepalive_peer_data_t  *kp = data;

    return kp->original_set_session(pc, kp->data);
}


static void
ngx_http_upstream_keepalive_save_session(ngx_peer_connection_t *pc, void *data)
{
    ngx_http_upstream_keepalive_peer_data_t  *kp = data;

    kp->original_save_session(pc, kp->data);
    return;
}

#endif


static void *
ngx_http_upstream_keepalive_create_conf(ngx_conf_t *cf)
{
    ngx_http_upstream_keepalive_srv_conf_t  *conf;

    conf = ngx_pcalloc(cf->pool,
                       sizeof(ngx_http_upstream_keepalive_srv_conf_t));
    if (conf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc():
     *
     *     conf->original_init_upstream = NULL;
     *     conf->original_init_peer = NULL;
     *     conf->max_cached = 0;
     */

    conf->timeout = NGX_CONF_UNSET_MSEC;
    conf->requests = NGX_CONF_UNSET_UINT;

    return conf;
}


static char *
ngx_http_upstream_keepalive(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_upstream_srv_conf_t            *uscf;
    ngx_http_upstream_keepalive_srv_conf_t  *kcf = conf;

    ngx_int_t    n;
    ngx_str_t   *value;

    if (kcf->max_cached) {
        return "is duplicate";
    }

    /* read options */

    value = cf->args->elts;

    n = ngx_atoi(value[1].data, value[1].len);

    if (n == NGX_ERROR || n == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid value \"%V\" in \"%V\" directive",
                           &value[1], &cmd->name);
        return NGX_CONF_ERROR;
    }

    kcf->max_cached = n;

    /* init upstream handler */

    uscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_upstream_module);

    kcf->original_init_upstream = uscf->peer.init_upstream
                                  ? uscf->peer.init_upstream
                                  : ngx_http_upstream_init_round_robin;

    uscf->peer.init_upstream = ngx_http_upstream_init_keepalive;

    return NGX_CONF_OK;
}