view src/mysql/ngx_http_mysql_test.c @ 4964:2464ccebdb52

Upstream: fixed SIGSEGV with the "if" directive. Configuration like location / { set $true 1; if ($true) { proxy_pass http://backend; } if ($true) { # nothing } } resulted in segmentation fault due to NULL pointer dereference as the upstream configuration wasn't initialized in an implicit location created by the last if(), but the r->content_handler was set due to first if(). Instead of committing a suicide by dereferencing a NULL pointer, return 500 (Internal Server Error) in such cases, i.e. if uscf is NULL. Better fix would be to avoid such cases by fixing the "if" directive handling, but it's out of scope of this patch. Prodded by Piotr Sikora.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 13 Dec 2012 16:05:59 +0000
parents d620f497c50f
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */

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


typedef struct {
    ngx_addr_t  *peers;
    ngx_uint_t   npeers;
} ngx_http_mysql_test_conf_t;


static void ngx_http_mysql_auth(ngx_mysql_t *m);
static void ngx_http_mysql_done(ngx_mysql_t *m);
static void *ngx_http_mysql_test_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_mysql_test(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);

static ngx_command_t  ngx_http_mysql_test_commands[] = {

    { ngx_string("mysql_test"),
      NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_mysql_test,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


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

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

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

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


ngx_module_t  ngx_http_mysql_test_module = {
    NGX_MODULE_V1,
    &ngx_http_mysql_test_module_ctx, /* module context */
    ngx_http_mysql_test_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_str_t  ngx_mysql_login = ngx_string("root");
static ngx_str_t  ngx_mysql_passwd = ngx_string("tp");
static ngx_str_t  ngx_mysql_database = ngx_string("mysql");
static ngx_str_t  ngx_mysql_command_query =
    ngx_string("select * from user");


static ngx_int_t
ngx_http_mysql_test_handler(ngx_http_request_t *r)
{
    ngx_int_t                    rc;
    ngx_mysql_t                 *m;
    ngx_http_mysql_test_conf_t  *mtcf;

    mtcf = ngx_http_get_module_loc_conf(r, ngx_http_mysql_test_module);

    m = ngx_pcalloc(r->pool, sizeof(ngx_mysql_t));

    if (m == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    m->pool = r->pool;
    m->handler = ngx_http_mysql_auth;
    m->data = r;

    m->login = &ngx_mysql_login;
    m->passwd = &ngx_mysql_passwd;
    m->database = &ngx_mysql_database;

    /* STUB */
    m->peer.sockaddr = mtcf->peers[0].sockaddr;
    m->peer.socklen = mtcf->peers[0].socklen;
    m->peer.name = &mtcf->peers[0].name;
    m->peer.tries = mtcf->npeers;
    m->peer.get = ngx_event_get_peer;
    /**/
    m->peer.log = r->connection->log;
    m->peer.log_error = NGX_ERROR_ERR;

    rc = ngx_mysql_connect(m);

    if (rc == NGX_OK || rc == NGX_AGAIN) {
        return NGX_DONE;
    }

    return NGX_HTTP_INTERNAL_SERVER_ERROR;
}


static void
ngx_http_mysql_auth(ngx_mysql_t *m)
{
    ngx_http_request_t  *r;

    r = m->data;

    if (m->state != NGX_OK) {
        ngx_http_finalize_request(r, NGX_HTTP_NO_CONTENT);
        return;
    }

    m->query.len = NGX_MYSQL_CMDPKT_LEN + ngx_mysql_command_query.len;

    m->query.data = ngx_pnalloc(r->pool, m->query.len);
    if (m->query.data == NULL) {
        ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_memcpy(m->query.data + NGX_MYSQL_CMDPKT_LEN,
               ngx_mysql_command_query.data, ngx_mysql_command_query.len);

    m->handler = ngx_http_mysql_done;

    ngx_mysql_query(m);
}


static void
ngx_http_mysql_done(ngx_mysql_t *m)
{
    ngx_http_request_t  *r;

    r = m->data;

    ngx_http_finalize_request(r, NGX_HTTP_NO_CONTENT);
}


static void *
ngx_http_mysql_test_create_loc_conf(ngx_conf_t *cf)
{
    ngx_http_mysql_test_conf_t  *conf;

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

    return conf;
}

static char *
ngx_http_mysql_test(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_mysql_test_conf_t  *mtcf = conf;

    ngx_str_t                 *value;
    ngx_url_t                  u;
    ngx_http_core_loc_conf_t  *clcf;

    clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
    clcf->handler = ngx_http_mysql_test_handler;

    value = cf->args->elts;

    ngx_memzero(&u, sizeof(ngx_url_t));

    u.url = value[1];
    u.default_port = 3306;

    if (ngx_parse_url(cf->pool, &u) != NGX_OK) {
        if (u.err) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "%s in upstream \"%V\"", u.err, &u.url);
        }

        return NGX_CONF_ERROR;
    }

    mtcf->peers = u.addrs;
    mtcf->npeers = u.naddrs;

    return NGX_CONF_OK;
}