view src/http/v2/ngx_http_v2_module.c @ 8895:457afc332c67

Stream: don't flush empty buffers created for read errors. When we generate the last_buf buffer for an UDP upstream recv error, it does not contain any data from the wire. ngx_stream_write_filter attempts to forward it anyways, which is incorrect (e.g., UDP upstream ECONNREFUSED will be translated to an empty packet). This happens because we mark the buffer as both 'flush' and 'last_buf', and ngx_stream_write_filter has special handling for flush with certain types of connections (see d127837c714f, 32b0ba4855a6). The flags are meant to be mutually exclusive, so the fix is to ensure that flush and last_buf are not set at the same time. Reproduction: stream { upstream unreachable { server 127.0.0.1:8880; } server { listen 127.0.0.1:8998 udp; proxy_pass unreachable; } } 1 0.000000000 127.0.0.1 → 127.0.0.1 UDP 47 45588 → 8998 Len=5 2 0.000166300 127.0.0.1 → 127.0.0.1 UDP 47 51149 → 8880 Len=5 3 0.000172600 127.0.0.1 → 127.0.0.1 ICMP 75 Destination unreachable (Port unreachable) 4 0.000202400 127.0.0.1 → 127.0.0.1 UDP 42 8998 → 45588 Len=0 Fixes d127837c714f.
author Aleksei Bavshin <a.bavshin@f5.com>
date Mon, 23 May 2022 11:29:44 -0700
parents 827202ca1269
children
line wrap: on
line source


/*
 * Copyright (C) Nginx, Inc.
 * Copyright (C) Valentin V. Bartenev
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include <ngx_http_v2_module.h>


static ngx_int_t ngx_http_v2_add_variables(ngx_conf_t *cf);

static ngx_int_t ngx_http_v2_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

static ngx_int_t ngx_http_v2_module_init(ngx_cycle_t *cycle);

static void *ngx_http_v2_create_main_conf(ngx_conf_t *cf);
static char *ngx_http_v2_init_main_conf(ngx_conf_t *cf, void *conf);
static void *ngx_http_v2_create_srv_conf(ngx_conf_t *cf);
static char *ngx_http_v2_merge_srv_conf(ngx_conf_t *cf, void *parent,
    void *child);
static void *ngx_http_v2_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_v2_merge_loc_conf(ngx_conf_t *cf, void *parent,
    void *child);

static char *ngx_http_v2_push(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);

static char *ngx_http_v2_recv_buffer_size(ngx_conf_t *cf, void *post,
    void *data);
static char *ngx_http_v2_pool_size(ngx_conf_t *cf, void *post, void *data);
static char *ngx_http_v2_preread_size(ngx_conf_t *cf, void *post, void *data);
static char *ngx_http_v2_streams_index_mask(ngx_conf_t *cf, void *post,
    void *data);
static char *ngx_http_v2_chunk_size(ngx_conf_t *cf, void *post, void *data);
static char *ngx_http_v2_obsolete(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_conf_deprecated_t  ngx_http_v2_recv_timeout_deprecated = {
    ngx_conf_deprecated, "http2_recv_timeout", "client_header_timeout"
};

static ngx_conf_deprecated_t  ngx_http_v2_idle_timeout_deprecated = {
    ngx_conf_deprecated, "http2_idle_timeout", "keepalive_timeout"
};

static ngx_conf_deprecated_t  ngx_http_v2_max_requests_deprecated = {
    ngx_conf_deprecated, "http2_max_requests", "keepalive_requests"
};

static ngx_conf_deprecated_t  ngx_http_v2_max_field_size_deprecated = {
    ngx_conf_deprecated, "http2_max_field_size", "large_client_header_buffers"
};

static ngx_conf_deprecated_t  ngx_http_v2_max_header_size_deprecated = {
    ngx_conf_deprecated, "http2_max_header_size", "large_client_header_buffers"
};


static ngx_conf_post_t  ngx_http_v2_recv_buffer_size_post =
    { ngx_http_v2_recv_buffer_size };
static ngx_conf_post_t  ngx_http_v2_pool_size_post =
    { ngx_http_v2_pool_size };
static ngx_conf_post_t  ngx_http_v2_preread_size_post =
    { ngx_http_v2_preread_size };
static ngx_conf_post_t  ngx_http_v2_streams_index_mask_post =
    { ngx_http_v2_streams_index_mask };
static ngx_conf_post_t  ngx_http_v2_chunk_size_post =
    { ngx_http_v2_chunk_size };


static ngx_command_t  ngx_http_v2_commands[] = {

    { ngx_string("http2_recv_buffer_size"),
      NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_MAIN_CONF_OFFSET,
      offsetof(ngx_http_v2_main_conf_t, recv_buffer_size),
      &ngx_http_v2_recv_buffer_size_post },

    { ngx_string("http2_pool_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, pool_size),
      &ngx_http_v2_pool_size_post },

    { ngx_string("http2_max_concurrent_streams"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, concurrent_streams),
      NULL },

    { ngx_string("http2_max_concurrent_pushes"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, concurrent_pushes),
      NULL },

    { ngx_string("http2_max_requests"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_obsolete,
      0,
      0,
      &ngx_http_v2_max_requests_deprecated },

    { ngx_string("http2_max_field_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_obsolete,
      0,
      0,
      &ngx_http_v2_max_field_size_deprecated },

    { ngx_string("http2_max_header_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_obsolete,
      0,
      0,
      &ngx_http_v2_max_header_size_deprecated },

    { ngx_string("http2_body_preread_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, preread_size),
      &ngx_http_v2_preread_size_post },

    { ngx_string("http2_streams_index_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, streams_index_mask),
      &ngx_http_v2_streams_index_mask_post },

    { ngx_string("http2_recv_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_obsolete,
      0,
      0,
      &ngx_http_v2_recv_timeout_deprecated },

    { ngx_string("http2_idle_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_obsolete,
      0,
      0,
      &ngx_http_v2_idle_timeout_deprecated },

    { ngx_string("http2_chunk_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_v2_loc_conf_t, chunk_size),
      &ngx_http_v2_chunk_size_post },

    { ngx_string("http2_push_preload"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_v2_loc_conf_t, push_preload),
      NULL },

    { ngx_string("http2_push"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_push,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_v2_module_ctx = {
    ngx_http_v2_add_variables,             /* preconfiguration */
    NULL,                                  /* postconfiguration */

    ngx_http_v2_create_main_conf,          /* create main configuration */
    ngx_http_v2_init_main_conf,            /* init main configuration */

    ngx_http_v2_create_srv_conf,           /* create server configuration */
    ngx_http_v2_merge_srv_conf,            /* merge server configuration */

    ngx_http_v2_create_loc_conf,           /* create location configuration */
    ngx_http_v2_merge_loc_conf             /* merge location configuration */
};


ngx_module_t  ngx_http_v2_module = {
    NGX_MODULE_V1,
    &ngx_http_v2_module_ctx,               /* module context */
    ngx_http_v2_commands,                  /* module directives */
    NGX_HTTP_MODULE,                       /* module type */
    NULL,                                  /* init master */
    ngx_http_v2_module_init,               /* 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_v2_vars[] = {

    { ngx_string("http2"), NULL,
      ngx_http_v2_variable, 0, 0, 0 },

      ngx_http_null_variable
};


static ngx_int_t
ngx_http_v2_add_variables(ngx_conf_t *cf)
{
    ngx_http_variable_t  *var, *v;

    for (v = ngx_http_v2_vars; v->name.len; v++) {
        var = ngx_http_add_variable(cf, &v->name, v->flags);
        if (var == NULL) {
            return NGX_ERROR;
        }

        var->get_handler = v->get_handler;
        var->data = v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_v2_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{

    if (r->stream) {
#if (NGX_HTTP_SSL)

        if (r->connection->ssl) {
            v->len = sizeof("h2") - 1;
            v->valid = 1;
            v->no_cacheable = 0;
            v->not_found = 0;
            v->data = (u_char *) "h2";

            return NGX_OK;
        }

#endif
        v->len = sizeof("h2c") - 1;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = (u_char *) "h2c";

        return NGX_OK;
    }

    *v = ngx_http_variable_null_value;

    return NGX_OK;
}


static ngx_int_t
ngx_http_v2_module_init(ngx_cycle_t *cycle)
{
    return NGX_OK;
}


static void *
ngx_http_v2_create_main_conf(ngx_conf_t *cf)
{
    ngx_http_v2_main_conf_t  *h2mcf;

    h2mcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_v2_main_conf_t));
    if (h2mcf == NULL) {
        return NULL;
    }

    h2mcf->recv_buffer_size = NGX_CONF_UNSET_SIZE;

    return h2mcf;
}


static char *
ngx_http_v2_init_main_conf(ngx_conf_t *cf, void *conf)
{
    ngx_http_v2_main_conf_t *h2mcf = conf;

    ngx_conf_init_size_value(h2mcf->recv_buffer_size, 256 * 1024);

    return NGX_CONF_OK;
}


static void *
ngx_http_v2_create_srv_conf(ngx_conf_t *cf)
{
    ngx_http_v2_srv_conf_t  *h2scf;

    h2scf = ngx_pcalloc(cf->pool, sizeof(ngx_http_v2_srv_conf_t));
    if (h2scf == NULL) {
        return NULL;
    }

    h2scf->pool_size = NGX_CONF_UNSET_SIZE;

    h2scf->concurrent_streams = NGX_CONF_UNSET_UINT;
    h2scf->concurrent_pushes = NGX_CONF_UNSET_UINT;

    h2scf->preread_size = NGX_CONF_UNSET_SIZE;

    h2scf->streams_index_mask = NGX_CONF_UNSET_UINT;

    return h2scf;
}


static char *
ngx_http_v2_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_http_v2_srv_conf_t *prev = parent;
    ngx_http_v2_srv_conf_t *conf = child;

    ngx_conf_merge_size_value(conf->pool_size, prev->pool_size, 4096);

    ngx_conf_merge_uint_value(conf->concurrent_streams,
                              prev->concurrent_streams, 128);
    ngx_conf_merge_uint_value(conf->concurrent_pushes,
                              prev->concurrent_pushes, 10);

    ngx_conf_merge_size_value(conf->preread_size, prev->preread_size, 65536);

    ngx_conf_merge_uint_value(conf->streams_index_mask,
                              prev->streams_index_mask, 32 - 1);

    return NGX_CONF_OK;
}


static void *
ngx_http_v2_create_loc_conf(ngx_conf_t *cf)
{
    ngx_http_v2_loc_conf_t  *h2lcf;

    h2lcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_v2_loc_conf_t));
    if (h2lcf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc():
     *
     *     h2lcf->pushes = NULL;
     */

    h2lcf->chunk_size = NGX_CONF_UNSET_SIZE;

    h2lcf->push_preload = NGX_CONF_UNSET;
    h2lcf->push = NGX_CONF_UNSET;

    return h2lcf;
}


static char *
ngx_http_v2_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_http_v2_loc_conf_t *prev = parent;
    ngx_http_v2_loc_conf_t *conf = child;

    ngx_conf_merge_size_value(conf->chunk_size, prev->chunk_size, 8 * 1024);

    ngx_conf_merge_value(conf->push, prev->push, 1);

    if (conf->push && conf->pushes == NULL) {
        conf->pushes = prev->pushes;
    }

    ngx_conf_merge_value(conf->push_preload, prev->push_preload, 0);

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_push(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_v2_loc_conf_t *h2lcf = conf;

    ngx_str_t                         *value;
    ngx_http_complex_value_t          *cv;
    ngx_http_compile_complex_value_t   ccv;

    value = cf->args->elts;

    if (ngx_strcmp(value[1].data, "off") == 0) {

        if (h2lcf->pushes) {
            return "\"off\" parameter cannot be used with URI";
        }

        if (h2lcf->push == 0) {
            return "is duplicate";
        }

        h2lcf->push = 0;
        return NGX_CONF_OK;
    }

    if (h2lcf->push == 0) {
        return "URI cannot be used with \"off\" parameter";
    }

    h2lcf->push = 1;

    if (h2lcf->pushes == NULL) {
        h2lcf->pushes = ngx_array_create(cf->pool, 1,
                                         sizeof(ngx_http_complex_value_t));
        if (h2lcf->pushes == NULL) {
            return NGX_CONF_ERROR;
        }
    }

    cv = ngx_array_push(h2lcf->pushes);
    if (cv == NULL) {
        return NGX_CONF_ERROR;
    }

    ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = &value[1];
    ccv.complex_value = cv;

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

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_recv_buffer_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp <= 2 * NGX_HTTP_V2_STATE_BUFFER_SIZE) {
        return "value is too small";
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_pool_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp < NGX_MIN_POOL_SIZE) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "the pool size must be no less than %uz",
                           NGX_MIN_POOL_SIZE);

        return NGX_CONF_ERROR;
    }

    if (*sp % NGX_POOL_ALIGNMENT) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "the pool size must be a multiple of %uz",
                           NGX_POOL_ALIGNMENT);

        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_preread_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp > NGX_HTTP_V2_MAX_WINDOW) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "the maximum body preread buffer size is %uz",
                           NGX_HTTP_V2_MAX_WINDOW);

        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_streams_index_mask(ngx_conf_t *cf, void *post, void *data)
{
    ngx_uint_t *np = data;

    ngx_uint_t  mask;

    mask = *np - 1;

    if (*np == 0 || (*np & mask)) {
        return "must be a power of two";
    }

    *np = mask;

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_chunk_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "the http2 chunk size cannot be zero");

        return NGX_CONF_ERROR;
    }

    if (*sp > NGX_HTTP_V2_MAX_FRAME_SIZE) {
        *sp = NGX_HTTP_V2_MAX_FRAME_SIZE;
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_obsolete(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_conf_deprecated_t  *d = cmd->post;

    ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                       "the \"%s\" directive is obsolete, "
                       "use the \"%s\" directive instead",
                       d->old_name, d->new_name);

    return NGX_CONF_OK;
}