Mercurial > hg > nginx

view src/stream/ngx_stream_map_module.c @ 7054:e02555553d0b

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Range filter: protect from total size overflows. The overflow can be used to circumvent the restriction on total size of ranges introduced in c2a91088b0c0 (1.1.2). Additionally, overflow allows producing ranges with negative start (such ranges can be created by using a suffix, "bytes=-100"; normally this results in 200 due to the total size check). These can result in the following errors in logs: [crit] ... pread() ... failed (22: Invalid argument) [alert] ... sendfile() failed (22: Invalid argument) When using cache, it can be also used to reveal cache file header. It is believed that there are no other negative effects, at least with standard nginx modules. In theory, this can also result in memory disclosure and/or segmentation faults if multiple ranges are allowed, and the response is returned in a single in-memory buffer. This never happens with standard nginx modules though, as well as known 3rd party modules. Fix is to properly protect from possible overflow when incrementing size.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 11 Jul 2017 16:06:23 +0300
parents ec10ce307dc0
children
line wrap: on
line source


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


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


typedef struct {
    ngx_uint_t                    hash_max_size;
    ngx_uint_t                    hash_bucket_size;
} ngx_stream_map_conf_t;


typedef struct {
    ngx_hash_keys_arrays_t        keys;

    ngx_array_t                  *values_hash;
#if (NGX_PCRE)
    ngx_array_t                   regexes;
#endif

    ngx_stream_variable_value_t  *default_value;
    ngx_conf_t                   *cf;
    unsigned                      hostnames:1;
    unsigned                      no_cacheable:1;
} ngx_stream_map_conf_ctx_t;


typedef struct {
    ngx_stream_map_t              map;
    ngx_stream_complex_value_t    value;
    ngx_stream_variable_value_t  *default_value;
    ngx_uint_t                    hostnames;      /* unsigned  hostnames:1 */
} ngx_stream_map_ctx_t;


static int ngx_libc_cdecl ngx_stream_map_cmp_dns_wildcards(const void *one,
    const void *two);
static void *ngx_stream_map_create_conf(ngx_conf_t *cf);
static char *ngx_stream_map_block(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_stream_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf);


static ngx_command_t  ngx_stream_map_commands[] = {

    { ngx_string("map"),
      NGX_STREAM_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE2,
      ngx_stream_map_block,
      NGX_STREAM_MAIN_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("map_hash_max_size"),
      NGX_STREAM_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_MAIN_CONF_OFFSET,
      offsetof(ngx_stream_map_conf_t, hash_max_size),
      NULL },

    { ngx_string("map_hash_bucket_size"),
      NGX_STREAM_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_MAIN_CONF_OFFSET,
      offsetof(ngx_stream_map_conf_t, hash_bucket_size),
      NULL },

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_map_module_ctx = {
    NULL,                                  /* preconfiguration */
    NULL,                                  /* postconfiguration */

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

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


ngx_module_t  ngx_stream_map_module = {
    NGX_MODULE_V1,
    &ngx_stream_map_module_ctx,            /* module context */
    ngx_stream_map_commands,               /* module directives */
    NGX_STREAM_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_stream_map_variable(ngx_stream_session_t *s, ngx_stream_variable_value_t *v,
    uintptr_t data)
{
    ngx_stream_map_ctx_t  *map = (ngx_stream_map_ctx_t *) data;

    ngx_str_t                     val, str;
    ngx_stream_complex_value_t   *cv;
    ngx_stream_variable_value_t  *value;

    ngx_log_debug0(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                   "stream map started");

    if (ngx_stream_complex_value(s, &map->value, &val) != NGX_OK) {
        return NGX_ERROR;
    }

    if (map->hostnames && val.len > 0 && val.data[val.len - 1] == '.') {
        val.len--;
    }

    value = ngx_stream_map_find(s, &map->map, &val);

    if (value == NULL) {
        value = map->default_value;
    }

    if (!value->valid) {
        cv = (ngx_stream_complex_value_t *) value->data;

        if (ngx_stream_complex_value(s, cv, &str) != NGX_OK) {
            return NGX_ERROR;
        }

        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->len = str.len;
        v->data = str.data;

    } else {
        *v = *value;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                   "stream map: \"%V\" \"%v\"", &val, v);

    return NGX_OK;
}


static void *
ngx_stream_map_create_conf(ngx_conf_t *cf)
{
    ngx_stream_map_conf_t  *mcf;

    mcf = ngx_palloc(cf->pool, sizeof(ngx_stream_map_conf_t));
    if (mcf == NULL) {
        return NULL;
    }

    mcf->hash_max_size = NGX_CONF_UNSET_UINT;
    mcf->hash_bucket_size = NGX_CONF_UNSET_UINT;

    return mcf;
}


static char *
ngx_stream_map_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_map_conf_t  *mcf = conf;

    char                                *rv;
    ngx_str_t                           *value, name;
    ngx_conf_t                           save;
    ngx_pool_t                          *pool;
    ngx_hash_init_t                      hash;
    ngx_stream_map_ctx_t                *map;
    ngx_stream_variable_t               *var;
    ngx_stream_map_conf_ctx_t            ctx;
    ngx_stream_compile_complex_value_t   ccv;

    if (mcf->hash_max_size == NGX_CONF_UNSET_UINT) {
        mcf->hash_max_size = 2048;
    }

    if (mcf->hash_bucket_size == NGX_CONF_UNSET_UINT) {
        mcf->hash_bucket_size = ngx_cacheline_size;

    } else {
        mcf->hash_bucket_size = ngx_align(mcf->hash_bucket_size,
                                          ngx_cacheline_size);
    }

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

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));

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

    if (ngx_stream_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_stream_add_variable(cf, &name, NGX_STREAM_VAR_CHANGEABLE);
    if (var == NULL) {
        return NGX_CONF_ERROR;
    }

    var->get_handler = ngx_stream_map_variable;
    var->data = (uintptr_t) map;

    pool = ngx_create_pool(NGX_DEFAULT_POOL_SIZE, cf->log);
    if (pool == NULL) {
        return NGX_CONF_ERROR;
    }

    ctx.keys.pool = cf->pool;
    ctx.keys.temp_pool = pool;

    if (ngx_hash_keys_array_init(&ctx.keys, NGX_HASH_LARGE) != NGX_OK) {
        ngx_destroy_pool(pool);
        return NGX_CONF_ERROR;
    }

    ctx.values_hash = ngx_pcalloc(pool, sizeof(ngx_array_t) * ctx.keys.hsize);
    if (ctx.values_hash == NULL) {
        ngx_destroy_pool(pool);
        return NGX_CONF_ERROR;
    }

#if (NGX_PCRE)
    if (ngx_array_init(&ctx.regexes, cf->pool, 2,
                       sizeof(ngx_stream_map_regex_t))
        != NGX_OK)
    {
        ngx_destroy_pool(pool);
        return NGX_CONF_ERROR;
    }
#endif

    ctx.default_value = NULL;
    ctx.cf = &save;
    ctx.hostnames = 0;
    ctx.no_cacheable = 0;

    save = *cf;
    cf->pool = pool;
    cf->ctx = &ctx;
    cf->handler = ngx_stream_map;
    cf->handler_conf = conf;

    rv = ngx_conf_parse(cf, NULL);

    *cf = save;

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

    if (ctx.no_cacheable) {
        var->flags |= NGX_STREAM_VAR_NOCACHEABLE;
    }

    map->default_value = ctx.default_value ? ctx.default_value:
                                             &ngx_stream_variable_null_value;

    map->hostnames = ctx.hostnames;

    hash.key = ngx_hash_key_lc;
    hash.max_size = mcf->hash_max_size;
    hash.bucket_size = mcf->hash_bucket_size;
    hash.name = "map_hash";
    hash.pool = cf->pool;

    if (ctx.keys.keys.nelts) {
        hash.hash = &map->map.hash.hash;
        hash.temp_pool = NULL;

        if (ngx_hash_init(&hash, ctx.keys.keys.elts, ctx.keys.keys.nelts)
            != NGX_OK)
        {
            ngx_destroy_pool(pool);
            return NGX_CONF_ERROR;
        }
    }

    if (ctx.keys.dns_wc_head.nelts) {

        ngx_qsort(ctx.keys.dns_wc_head.elts,
                  (size_t) ctx.keys.dns_wc_head.nelts,
                  sizeof(ngx_hash_key_t), ngx_stream_map_cmp_dns_wildcards);

        hash.hash = NULL;
        hash.temp_pool = pool;

        if (ngx_hash_wildcard_init(&hash, ctx.keys.dns_wc_head.elts,
                                   ctx.keys.dns_wc_head.nelts)
            != NGX_OK)
        {
            ngx_destroy_pool(pool);
            return NGX_CONF_ERROR;
        }

        map->map.hash.wc_head = (ngx_hash_wildcard_t *) hash.hash;
    }

    if (ctx.keys.dns_wc_tail.nelts) {

        ngx_qsort(ctx.keys.dns_wc_tail.elts,
                  (size_t) ctx.keys.dns_wc_tail.nelts,
                  sizeof(ngx_hash_key_t), ngx_stream_map_cmp_dns_wildcards);

        hash.hash = NULL;
        hash.temp_pool = pool;

        if (ngx_hash_wildcard_init(&hash, ctx.keys.dns_wc_tail.elts,
                                   ctx.keys.dns_wc_tail.nelts)
            != NGX_OK)
        {
            ngx_destroy_pool(pool);
            return NGX_CONF_ERROR;
        }

        map->map.hash.wc_tail = (ngx_hash_wildcard_t *) hash.hash;
    }

#if (NGX_PCRE)

    if (ctx.regexes.nelts) {
        map->map.regex = ctx.regexes.elts;
        map->map.nregex = ctx.regexes.nelts;
    }

#endif

    ngx_destroy_pool(pool);

    return rv;
}


static int ngx_libc_cdecl
ngx_stream_map_cmp_dns_wildcards(const void *one, const void *two)
{
    ngx_hash_key_t  *first, *second;

    first = (ngx_hash_key_t *) one;
    second = (ngx_hash_key_t *) two;

    return ngx_dns_strcmp(first->key.data, second->key.data);
}


static char *
ngx_stream_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf)
{
    u_char                              *data;
    size_t                               len;
    ngx_int_t                            rv;
    ngx_str_t                           *value, v;
    ngx_uint_t                           i, key;
    ngx_stream_map_conf_ctx_t           *ctx;
    ngx_stream_complex_value_t           cv, *cvp;
    ngx_stream_variable_value_t         *var, **vp;
    ngx_stream_compile_complex_value_t   ccv;

    ctx = cf->ctx;

    value = cf->args->elts;

    if (cf->args->nelts == 1
        && ngx_strcmp(value[0].data, "hostnames") == 0)
    {
        ctx->hostnames = 1;
        return NGX_CONF_OK;
    }

    if (cf->args->nelts == 1
        && ngx_strcmp(value[0].data, "volatile") == 0)
    {
        ctx->no_cacheable = 1;
        return NGX_CONF_OK;
    }

    if (cf->args->nelts != 2) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid number of the map parameters");
        return NGX_CONF_ERROR;
    }

    if (ngx_strcmp(value[0].data, "include") == 0) {
        return ngx_conf_include(cf, dummy, conf);
    }

    key = 0;

    for (i = 0; i < value[1].len; i++) {
        key = ngx_hash(key, value[1].data[i]);
    }

    key %= ctx->keys.hsize;

    vp = ctx->values_hash[key].elts;

    if (vp) {
        for (i = 0; i < ctx->values_hash[key].nelts; i++) {

            if (vp[i]->valid) {
                data = vp[i]->data;
                len = vp[i]->len;

            } else {
                cvp = (ngx_stream_complex_value_t *) vp[i]->data;
                data = cvp->value.data;
                len = cvp->value.len;
            }

            if (value[1].len != len) {
                continue;
            }

            if (ngx_strncmp(value[1].data, data, len) == 0) {
                var = vp[i];
                goto found;
            }
        }

    } else {
        if (ngx_array_init(&ctx->values_hash[key], cf->pool, 4,
                           sizeof(ngx_stream_variable_value_t *))
            != NGX_OK)
        {
            return NGX_CONF_ERROR;
        }
    }

    var = ngx_palloc(ctx->keys.pool, sizeof(ngx_stream_variable_value_t));
    if (var == NULL) {
        return NGX_CONF_ERROR;
    }

    v.len = value[1].len;
    v.data = ngx_pstrdup(ctx->keys.pool, &value[1]);
    if (v.data == NULL) {
        return NGX_CONF_ERROR;
    }

    ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));

    ccv.cf = ctx->cf;
    ccv.value = &v;
    ccv.complex_value = &cv;

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

    if (cv.lengths != NULL) {
        cvp = ngx_palloc(ctx->keys.pool, sizeof(ngx_stream_complex_value_t));
        if (cvp == NULL) {
            return NGX_CONF_ERROR;
        }

        *cvp = cv;

        var->len = 0;
        var->data = (u_char *) cvp;
        var->valid = 0;

    } else {
        var->len = v.len;
        var->data = v.data;
        var->valid = 1;
    }

    var->no_cacheable = 0;
    var->not_found = 0;

    vp = ngx_array_push(&ctx->values_hash[key]);
    if (vp == NULL) {
        return NGX_CONF_ERROR;
    }

    *vp = var;

found:

    if (ngx_strcmp(value[0].data, "default") == 0) {

        if (ctx->default_value) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "duplicate default map parameter");
            return NGX_CONF_ERROR;
        }

        ctx->default_value = var;

        return NGX_CONF_OK;
    }

#if (NGX_PCRE)

    if (value[0].len && value[0].data[0] == '~') {
        ngx_regex_compile_t      rc;
        ngx_stream_map_regex_t  *regex;
        u_char                   errstr[NGX_MAX_CONF_ERRSTR];

        regex = ngx_array_push(&ctx->regexes);
        if (regex == NULL) {
            return NGX_CONF_ERROR;
        }

        value[0].len--;
        value[0].data++;

        ngx_memzero(&rc, sizeof(ngx_regex_compile_t));

        if (value[0].data[0] == '*') {
            value[0].len--;
            value[0].data++;
            rc.options = NGX_REGEX_CASELESS;
        }

        rc.pattern = value[0];
        rc.err.len = NGX_MAX_CONF_ERRSTR;
        rc.err.data = errstr;

        regex->regex = ngx_stream_regex_compile(ctx->cf, &rc);
        if (regex->regex == NULL) {
            return NGX_CONF_ERROR;
        }

        regex->value = var;

        return NGX_CONF_OK;
    }

#endif

    if (value[0].len && value[0].data[0] == '\\') {
        value[0].len--;
        value[0].data++;
    }

    rv = ngx_hash_add_key(&ctx->keys, &value[0], var,
                          (ctx->hostnames) ? NGX_HASH_WILDCARD_KEY : 0);

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

    if (rv == NGX_DECLINED) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid hostname or wildcard \"%V\"", &value[0]);
    }

    if (rv == NGX_BUSY) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "conflicting parameter \"%V\"", &value[0]);
    }

    return NGX_CONF_ERROR;
}