ngx_http_upstream.c

Nginx是一个高性能的HTTP和反向代理服务器

/*
 * Copyright (C) Igor Sysoev
 */


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


static void ngx_http_upstream_resolve_handler(ngx_resolver_ctx_t *ctx);
static void ngx_http_upstream_rd_check_broken_connection(ngx_http_request_t *r);
static void ngx_http_upstream_wr_check_broken_connection(ngx_http_request_t *r);
static void ngx_http_upstream_check_broken_connection(ngx_http_request_t *r,
    ngx_event_t *ev);
static void ngx_http_upstream_connect(ngx_http_request_t *r,
    ngx_http_upstream_t *u);
static ngx_int_t ngx_http_upstream_reinit(ngx_http_request_t *r,
    ngx_http_upstream_t *u);
static void ngx_http_upstream_send_request(ngx_http_request_t *r,
    ngx_http_upstream_t *u);
static void ngx_http_upstream_send_request_handler(ngx_event_t *wev);
static void ngx_http_upstream_process_header(ngx_event_t *rev);
static ngx_int_t ngx_http_upstream_test_connect(ngx_connection_t *c);
static void ngx_http_upstream_process_body_in_memory(ngx_event_t *rev);
static void ngx_http_upstream_send_response(ngx_http_request_t *r,
    ngx_http_upstream_t *u);
static void
    ngx_http_upstream_process_non_buffered_downstream(ngx_http_request_t *r);
static void ngx_http_upstream_process_non_buffered_body(ngx_event_t *ev);
static ngx_int_t ngx_http_upstream_non_buffered_filter_init(void *data);
static ngx_int_t ngx_http_upstream_non_buffered_filter(void *data,
    ssize_t bytes);
static void ngx_http_upstream_process_downstream(ngx_http_request_t *r);
static void ngx_http_upstream_process_body(ngx_event_t *ev);
static void ngx_http_upstream_store(ngx_http_request_t *r,
    ngx_http_upstream_t *u);
static void ngx_http_upstream_dummy_handler(ngx_event_t *wev);
static void ngx_http_upstream_next(ngx_http_request_t *r,
    ngx_http_upstream_t *u, ngx_uint_t ft_type);
static void ngx_http_upstream_cleanup(void *data);
static void ngx_http_upstream_finalize_request(ngx_http_request_t *r,
    ngx_http_upstream_t *u, ngx_int_t rc);

static ngx_int_t ngx_http_upstream_process_header_line(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t
    ngx_http_upstream_process_multi_header_lines(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_ignore_header_line(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_process_limit_rate(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_process_buffering(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_process_charset(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_copy_header_line(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t
    ngx_http_upstream_copy_multi_header_lines(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_copy_content_type(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_copy_content_length(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_rewrite_location(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_upstream_rewrite_refresh(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
#if (NGX_HTTP_GZIP)
static ngx_int_t ngx_http_upstream_copy_content_encoding(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
#endif

static ngx_int_t ngx_http_upstream_add_variables(ngx_conf_t *cf);
static ngx_int_t ngx_http_upstream_addr_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_upstream_status_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_upstream_response_time_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

static char *ngx_http_upstream(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy);
static char *ngx_http_upstream_server(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);

static void *ngx_http_upstream_create_main_conf(ngx_conf_t *cf);
static char *ngx_http_upstream_init_main_conf(ngx_conf_t *cf, void *conf);

#if (NGX_HTTP_SSL)
static void ngx_http_upstream_ssl_init_connection(ngx_http_request_t *,
    ngx_http_upstream_t *u, ngx_connection_t *c);
static void ngx_http_upstream_ssl_handshake(ngx_connection_t *c);
#endif


ngx_http_upstream_header_t  ngx_http_upstream_headers_in[] = {

    { ngx_string("Status"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, status),
                 ngx_http_upstream_copy_header_line, 0, 0 },

    { ngx_string("Content-Type"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, content_type),
                 ngx_http_upstream_copy_content_type, 0, 1 },

    { ngx_string("Content-Length"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, content_length),
                 ngx_http_upstream_copy_content_length, 0, 0 },

    { ngx_string("Date"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, date),
                 ngx_http_upstream_copy_header_line,
                 offsetof(ngx_http_headers_out_t, date), 0 },

    { ngx_string("Last-Modified"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, last_modified),
                 ngx_http_upstream_copy_header_line,
                 offsetof(ngx_http_headers_out_t, last_modified), 0 },

    { ngx_string("Server"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, server),
                 ngx_http_upstream_copy_header_line,
                 offsetof(ngx_http_headers_out_t, server), 0 },

    { ngx_string("WWW-Authenticate"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, www_authenticate),
                 ngx_http_upstream_copy_header_line, 0, 0 },

    { ngx_string("Location"),
                 ngx_http_upstream_ignore_header_line, 0,
                 ngx_http_upstream_rewrite_location, 0, 0 },

    { ngx_string("Refresh"),
                 ngx_http_upstream_ignore_header_line, 0,
                 ngx_http_upstream_rewrite_refresh, 0, 0 },

    { ngx_string("Set-Cookie"),
                 ngx_http_upstream_ignore_header_line, 0,
                 ngx_http_upstream_copy_header_line, 0, 1 },

    { ngx_string("Content-Disposition"),
                 ngx_http_upstream_ignore_header_line, 0,
                 ngx_http_upstream_copy_header_line, 0, 1 },

    { ngx_string("Cache-Control"),
                 ngx_http_upstream_process_multi_header_lines,
                 offsetof(ngx_http_upstream_headers_in_t, cache_control),
                 ngx_http_upstream_copy_multi_header_lines,
                 offsetof(ngx_http_headers_out_t, cache_control), 1 },

    { ngx_string("Expires"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, expires),
                 ngx_http_upstream_copy_header_line,
                 offsetof(ngx_http_headers_out_t, expires), 1 },

    { ngx_string("Accept-Ranges"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, accept_ranges),
                 ngx_http_upstream_copy_header_line,
                 offsetof(ngx_http_headers_out_t, accept_ranges), 1 },

    { ngx_string("Connection"),
                 ngx_http_upstream_ignore_header_line, 0,
                 ngx_http_upstream_ignore_header_line, 0, 0 },

    { ngx_string("Keep-Alive"),
                 ngx_http_upstream_ignore_header_line, 0,
                 ngx_http_upstream_ignore_header_line, 0, 0 },

    { ngx_string("X-Powered-By"),
                 ngx_http_upstream_ignore_header_line, 0,
                 ngx_http_upstream_copy_header_line, 0, 0 },

    { ngx_string("X-Accel-Expires"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, x_accel_expires),
                 ngx_http_upstream_copy_header_line, 0, 0 },

    { ngx_string("X-Accel-Redirect"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, x_accel_redirect),
                 ngx_http_upstream_ignore_header_line, 0, 0 },

    { ngx_string("X-Accel-Limit-Rate"),
                 ngx_http_upstream_process_limit_rate, 0,
                 ngx_http_upstream_ignore_header_line, 0, 0 },

    { ngx_string("X-Accel-Buffering"),
                 ngx_http_upstream_process_buffering, 0,
                 ngx_http_upstream_ignore_header_line, 0, 0 },

    { ngx_string("X-Accel-Charset"),
                 ngx_http_upstream_process_charset, 0,
                 ngx_http_upstream_ignore_header_line, 0, 0 },

#if (NGX_HTTP_GZIP)
    { ngx_string("Content-Encoding"),
                 ngx_http_upstream_process_header_line,
                 offsetof(ngx_http_upstream_headers_in_t, content_encoding),
                 ngx_http_upstream_copy_content_encoding, 0, 0 },
#endif

    { ngx_null_string, NULL, 0, NULL, 0, 0 }
};


static ngx_command_t  ngx_http_upstream_commands[] = {

    { ngx_string("upstream"),
      NGX_HTTP_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE1,
      ngx_http_upstream,
      0,
      0,
      NULL },

    { ngx_string("server"),
      NGX_HTTP_UPS_CONF|NGX_CONF_1MORE,
      ngx_http_upstream_server,
      NGX_HTTP_SRV_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_upstream_module_ctx = {
    ngx_http_upstream_add_variables,       /* preconfiguration */
    NULL,                                  /* postconfiguration */

    ngx_http_upstream_create_main_conf,    /* create main configuration */
    ngx_http_upstream_init_main_conf,      /* init main configuration */

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

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


ngx_module_t  ngx_http_upstream_module = {
    NGX_MODULE_V1,
    &ngx_http_upstream_module_ctx,         /* module context */
    ngx_http_upstream_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_http_variable_t  ngx_http_upstream_vars[] = {

    { ngx_string("upstream_addr"), NULL,
      ngx_http_upstream_addr_variable, 0, NGX_HTTP_VAR_NOHASH, 0 },

    { ngx_string("upstream_status"), NULL,
      ngx_http_upstream_status_variable, 0, NGX_HTTP_VAR_NOHASH, 0 },

    { ngx_string("upstream_response_time"), NULL,
      ngx_http_upstream_response_time_variable, 0, NGX_HTTP_VAR_NOHASH, 0 },

    { ngx_null_string, NULL, NULL, 0, 0, 0 }
};


void
ngx_http_upstream_init(ngx_http_request_t *r)
{
    ngx_str_t                      *host;
    ngx_uint_t                      i;
    ngx_connection_t               *c;
    ngx_resolver_ctx_t             *ctx, temp;
    ngx_http_cleanup_t             *cln;
    ngx_http_upstream_t            *u;
    ngx_http_core_loc_conf_t       *clcf;
    ngx_http_upstream_srv_conf_t   *uscf, **uscfp;
    ngx_http_upstream_main_conf_t  *umcf;

    c = r->connection;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http init upstream, client timer: %d", c->read->timer_set);

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

    u = r->upstream;

    if (!r->post_action && !u->conf->ignore_client_abort) {
        r->read_event_handler = ngx_http_upstream_rd_check_broken_connection;
        r->write_event_handler = ngx_http_upstream_wr_check_broken_connection;
    }

    if (ngx_event_flags & NGX_USE_CLEAR_EVENT) {

        if (!c->write->active) {
            if (ngx_add_event(c->write, NGX_WRITE_EVENT, NGX_CLEAR_EVENT)
                == NGX_ERROR)
            {
                ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                return;
            }
        }
    }

    if (r->request_body) {
        u->request_bufs = r->request_body->bufs;
    }

    if (u->create_request(r) != NGX_OK) {
        ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
    }

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    u->output.pool = r->pool;
    u->output.bufs.num = 1;
    u->output.bufs.size = clcf->client_body_buffer_size;
    u->output.output_filter = ngx_chain_writer;
    u->output.filter_ctx = &u->writer;

    u->writer.pool = r->pool;

    if (r->upstream_states == NULL) {

        r->upstream_states = ngx_array_create(r->pool, 1,
                                            sizeof(ngx_http_upstream_state_t));
        if (r->upstream_states == NULL) {
            ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
            return;
        }

    } else {

        u->state = ngx_array_push(r->upstream_states);
        if (u->state == NULL) {
            ngx_http_upstream_finalize_request(r, u,
                                               NGX_HTTP_INTERNAL_SERVER_ERROR);
            return;
        }

        ngx_memzero(u->state, sizeof(ngx_http_upstream_state_t));
    }

    cln = ngx_http_cleanup_add(r, 0);
    if (cln == NULL) {
        ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
    }

    cln->handler = ngx_http_upstream_cleanup;
    cln->data = r;
    u->cleanup = &cln->handler;

    u->store = (u->conf->store || u->conf->store_lengths);

    if (u->resolved == NULL) {

        uscf = u->conf->upstream;

    } else {

        host = &u->resolved->host;

        umcf = ngx_http_get_module_main_conf(r, ngx_http_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->default_port)
                     || uscf->port == u->resolved->port)
                && ngx_memcmp(uscf->host.data, host->data, host->len) == 0)
            {
                goto found;
            }
        }

        temp.name = *host;

        ctx = ngx_resolve_start(clcf->resolver, &temp);
        if (ctx == NULL) {
            ngx_http_finalize_request(r, NGX_HTTP_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_http_finalize_request(r, NGX_HTTP_BAD_GATEWAY);
            return;
        }

        ctx->name = *host;
        ctx->type = NGX_RESOLVE_A;
        ctx->handler = ngx_http_upstream_resolve_handler;
        ctx->data = r;
        ctx->timeout = clcf->resolver_timeout;

        u->resolved->ctx = ctx;

        if (ngx_resolve_name(ctx) != NGX_OK) {
            u->resolved->ctx = NULL;
            ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
            return;
        }

        return;
    }

found:

    if (uscf->peer.init(r, uscf) != NGX_OK) {
        ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_http_upstream_connect(r, u);
}


static void
ngx_http_upstream_resolve_handler(ngx_resolver_ctx_t *ctx)
{
    ngx_http_request_t            *r;
    ngx_http_upstream_resolved_t  *ur;

    r = ctx->data;

    r->upstream->resolved->ctx = NULL;

    if (ctx->state) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "%V could not be resolved (%i: %s)",
                      &ctx->name, ctx->state,
                      ngx_resolver_strerror(ctx->state));