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

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 b78cf2414fda
children
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


typedef struct {
    uint32_t                    percent;
    ngx_http_variable_value_t   value;
} ngx_http_split_clients_part_t;


typedef struct {
    ngx_http_complex_value_t    value;
    ngx_array_t                 parts;
} ngx_http_split_clients_ctx_t;


static char *ngx_conf_split_clients_block(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_split_clients(ngx_conf_t *cf, ngx_command_t *dummy,
    void *conf);

static ngx_command_t  ngx_http_split_clients_commands[] = {

    { ngx_string("split_clients"),
      NGX_HTTP_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE2,
      ngx_conf_split_clients_block,
      NGX_HTTP_MAIN_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


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

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

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

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


ngx_module_t  ngx_http_split_clients_module = {
    NGX_MODULE_V1,
    &ngx_http_split_clients_module_ctx,    /* module context */
    ngx_http_split_clients_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_split_clients_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{
    ngx_http_split_clients_ctx_t *ctx = (ngx_http_split_clients_ctx_t *) data;

    uint32_t                        hash;
    ngx_str_t                       val;
    ngx_uint_t                      i;
    ngx_http_split_clients_part_t  *part;

    *v = ngx_http_variable_null_value;

    if (ngx_http_complex_value(r, &ctx->value, &val) != NGX_OK) {
        return NGX_OK;
    }

    hash = ngx_murmur_hash2(val.data, val.len);

    part = ctx->parts.elts;

    for (i = 0; i < ctx->parts.nelts; i++) {

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "http split: %uD %uD", hash, part[i].percent);

        if (hash < part[i].percent || part[i].percent == 0) {
            *v = part[i].value;
            return NGX_OK;
        }
    }

    return NGX_OK;
}


static char *
ngx_conf_split_clients_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char                                *rv;
    uint32_t                             sum, last;
    ngx_str_t                           *value, name;
    ngx_uint_t                           i;
    ngx_conf_t                           save;
    ngx_http_variable_t                 *var;
    ngx_http_split_clients_ctx_t        *ctx;
    ngx_http_split_clients_part_t       *part;
    ngx_http_compile_complex_value_t     ccv;

    ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_split_clients_ctx_t));
    if (ctx == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = &value[1];
    ccv.complex_value = &ctx->value;

    if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    name = value[2];

    if (name.data[0] != '$') {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid variable name \"%V\"", &name);
        return NGX_CONF_ERROR;
    }

    name.len--;
    name.data++;

    var = ngx_http_add_variable(cf, &name, NGX_HTTP_VAR_CHANGEABLE);
    if (var == NULL) {
        return NGX_CONF_ERROR;
    }

    var->get_handler = ngx_http_split_clients_variable;
    var->data = (uintptr_t) ctx;

    if (ngx_array_init(&ctx->parts, cf->pool, 2,
                       sizeof(ngx_http_split_clients_part_t))
        != NGX_OK)
    {
        return NGX_CONF_ERROR;
    }

    save = *cf;
    cf->ctx = ctx;
    cf->handler = ngx_http_split_clients;
    cf->handler_conf = conf;

    rv = ngx_conf_parse(cf, NULL);

    *cf = save;

    if (rv != NGX_CONF_OK) {
        return rv;
    }

    sum = 0;
    last = 0;
    part = ctx->parts.elts;

    for (i = 0; i < ctx->parts.nelts; i++) {
        sum = part[i].percent ? sum + part[i].percent : 10000;
        if (sum > 10000) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "percent total is greater than 100%%");
            return NGX_CONF_ERROR;
        }

        if (part[i].percent) {
            last += part[i].percent * (uint64_t) 0xffffffff / 10000;
            part[i].percent = last;
        }
    }

    return rv;
}


static char *
ngx_http_split_clients(ngx_conf_t *cf, ngx_command_t *dummy, void *conf)
{
    ngx_int_t                       n;
    ngx_str_t                      *value;
    ngx_http_split_clients_ctx_t   *ctx;
    ngx_http_split_clients_part_t  *part;

    ctx = cf->ctx;
    value = cf->args->elts;

    part = ngx_array_push(&ctx->parts);
    if (part == NULL) {
        return NGX_CONF_ERROR;
    }

    if (value[0].len == 1 && value[0].data[0] == '*') {
        part->percent = 0;

    } else {
        if (value[0].len == 0 || value[0].data[value[0].len - 1] != '%') {
            goto invalid;
        }

        n = ngx_atofp(value[0].data, value[0].len - 1, 2);
        if (n == NGX_ERROR || n == 0) {
            goto invalid;
        }

        part->percent = (uint32_t) n;
    }

    part->value.len = value[1].len;
    part->value.valid = 1;
    part->value.no_cacheable = 0;
    part->value.not_found = 0;
    part->value.data = value[1].data;

    return NGX_CONF_OK;

invalid:

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "invalid percent value \"%V\"", &value[0]);
    return NGX_CONF_ERROR;
}