view src/mail/ngx_mail_smtp_module.c @ 8338:0f9e9786b90d quic

Added primitive flow control mechanisms. + MAX_STREAM_DATA frame is sent when recv() is performed on stream The new value is a sum of total bytes received by stream + free space in a buffer; The sending of MAX_STREM_DATA frame in response to STREAM_DATA_BLOCKED frame is adjusted to follow the same logic as above. + MAX_DATA frame is sent when total amount of received data is 2x of current limit. The limit is doubled. + Default values of transport parameters are adjusted to more meaningful values: initial stream limits are set to quic buffer size instead of unrealistically small 255. initial max data is decreased to 16 buffer sizes, in an assumption that this is enough for a relatively short connection, instead of randomly chosen big number. All this allows to initiate a stable flow of streams that does not block on stream/connection limits (tested with FF 77.0a1 and 100K requests)
author Vladimir Homutov <vl@nginx.com>
date Wed, 15 Apr 2020 18:54:03 +0300
parents f18c285c2e59
children dc955d274130
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#include <ngx_mail.h>
#include <ngx_mail_smtp_module.h>


static void *ngx_mail_smtp_create_srv_conf(ngx_conf_t *cf);
static char *ngx_mail_smtp_merge_srv_conf(ngx_conf_t *cf, void *parent,
    void *child);


static ngx_conf_bitmask_t  ngx_mail_smtp_auth_methods[] = {
    { ngx_string("plain"), NGX_MAIL_AUTH_PLAIN_ENABLED },
    { ngx_string("login"), NGX_MAIL_AUTH_LOGIN_ENABLED },
    { ngx_string("cram-md5"), NGX_MAIL_AUTH_CRAM_MD5_ENABLED },
    { ngx_string("external"), NGX_MAIL_AUTH_EXTERNAL_ENABLED },
    { ngx_string("none"), NGX_MAIL_AUTH_NONE_ENABLED },
    { ngx_null_string, 0 }
};


static ngx_str_t  ngx_mail_smtp_auth_methods_names[] = {
    ngx_string("PLAIN"),
    ngx_string("LOGIN"),
    ngx_null_string,  /* APOP */
    ngx_string("CRAM-MD5"),
    ngx_string("EXTERNAL"),
    ngx_null_string   /* NONE */
};


static ngx_mail_protocol_t  ngx_mail_smtp_protocol = {
    ngx_string("smtp"),
    { 25, 465, 587, 0 },
    NGX_MAIL_SMTP_PROTOCOL,

    ngx_mail_smtp_init_session,
    ngx_mail_smtp_init_protocol,
    ngx_mail_smtp_parse_command,
    ngx_mail_smtp_auth_state,

    ngx_string("451 4.3.2 Internal server error" CRLF),
    ngx_string("421 4.7.1 SSL certificate error" CRLF),
    ngx_string("421 4.7.1 No required SSL certificate" CRLF)
};


static ngx_command_t  ngx_mail_smtp_commands[] = {

    { ngx_string("smtp_client_buffer"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_smtp_srv_conf_t, client_buffer_size),
      NULL },

    { ngx_string("smtp_greeting_delay"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_smtp_srv_conf_t, greeting_delay),
      NULL },

    { ngx_string("smtp_capabilities"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
      ngx_mail_capabilities,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_smtp_srv_conf_t, capabilities),
      NULL },

    { ngx_string("smtp_auth"),
      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
      ngx_conf_set_bitmask_slot,
      NGX_MAIL_SRV_CONF_OFFSET,
      offsetof(ngx_mail_smtp_srv_conf_t, auth_methods),
      &ngx_mail_smtp_auth_methods },

      ngx_null_command
};


static ngx_mail_module_t  ngx_mail_smtp_module_ctx = {
    &ngx_mail_smtp_protocol,               /* protocol */

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

    ngx_mail_smtp_create_srv_conf,         /* create server configuration */
    ngx_mail_smtp_merge_srv_conf           /* merge server configuration */
};


ngx_module_t  ngx_mail_smtp_module = {
    NGX_MODULE_V1,
    &ngx_mail_smtp_module_ctx,             /* module context */
    ngx_mail_smtp_commands,                /* module directives */
    NGX_MAIL_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 void *
ngx_mail_smtp_create_srv_conf(ngx_conf_t *cf)
{
    ngx_mail_smtp_srv_conf_t  *sscf;

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

    sscf->client_buffer_size = NGX_CONF_UNSET_SIZE;
    sscf->greeting_delay = NGX_CONF_UNSET_MSEC;

    if (ngx_array_init(&sscf->capabilities, cf->pool, 4, sizeof(ngx_str_t))
        != NGX_OK)
    {
        return NULL;
    }

    return sscf;
}


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

    u_char                    *p, *auth, *last;
    size_t                     size;
    ngx_str_t                 *c;
    ngx_uint_t                 i, m, auth_enabled;
    ngx_mail_core_srv_conf_t  *cscf;

    ngx_conf_merge_size_value(conf->client_buffer_size,
                              prev->client_buffer_size,
                              (size_t) ngx_pagesize);

    ngx_conf_merge_msec_value(conf->greeting_delay,
                              prev->greeting_delay, 0);

    ngx_conf_merge_bitmask_value(conf->auth_methods,
                              prev->auth_methods,
                              (NGX_CONF_BITMASK_SET
                               |NGX_MAIL_AUTH_PLAIN_ENABLED
                               |NGX_MAIL_AUTH_LOGIN_ENABLED));


    cscf = ngx_mail_conf_get_module_srv_conf(cf, ngx_mail_core_module);

    size = sizeof("220  ESMTP ready" CRLF) - 1 + cscf->server_name.len;

    p = ngx_pnalloc(cf->pool, size);
    if (p == NULL) {
        return NGX_CONF_ERROR;
    }

    conf->greeting.len = size;
    conf->greeting.data = p;

    *p++ = '2'; *p++ = '2'; *p++ = '0'; *p++ = ' ';
    p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len);
    ngx_memcpy(p, " ESMTP ready" CRLF, sizeof(" ESMTP ready" CRLF) - 1);


    size = sizeof("250 " CRLF) - 1 + cscf->server_name.len;

    p = ngx_pnalloc(cf->pool, size);
    if (p == NULL) {
        return NGX_CONF_ERROR;
    }

    conf->server_name.len = size;
    conf->server_name.data = p;

    *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = ' ';
    p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len);
    *p++ = CR; *p = LF;


    if (conf->capabilities.nelts == 0) {
        conf->capabilities = prev->capabilities;
    }

    size = sizeof("250-") - 1 + cscf->server_name.len + sizeof(CRLF) - 1;

    c = conf->capabilities.elts;
    for (i = 0; i < conf->capabilities.nelts; i++) {
        size += sizeof("250 ") - 1 + c[i].len + sizeof(CRLF) - 1;
    }

    auth_enabled = 0;

    for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0;
         m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED;
         m <<= 1, i++)
    {
        if (m & conf->auth_methods) {
            size += 1 + ngx_mail_smtp_auth_methods_names[i].len;
            auth_enabled = 1;
        }
    }

    if (auth_enabled) {
        size += sizeof("250 AUTH") - 1 + sizeof(CRLF) - 1;
    }

    p = ngx_pnalloc(cf->pool, size);
    if (p == NULL) {
        return NGX_CONF_ERROR;
    }

    conf->capability.len = size;
    conf->capability.data = p;

    last = p;

    *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = '-';
    p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len);
    *p++ = CR; *p++ = LF;

    for (i = 0; i < conf->capabilities.nelts; i++) {
        last = p;
        *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = '-';
        p = ngx_cpymem(p, c[i].data, c[i].len);
        *p++ = CR; *p++ = LF;
    }

    auth = p;

    if (auth_enabled) {
        last = p;

        *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = ' ';
        *p++ = 'A'; *p++ = 'U'; *p++ = 'T'; *p++ = 'H';

        for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0;
             m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED;
             m <<= 1, i++)
        {
            if (m & conf->auth_methods) {
                *p++ = ' ';
                p = ngx_cpymem(p, ngx_mail_smtp_auth_methods_names[i].data,
                               ngx_mail_smtp_auth_methods_names[i].len);
            }
        }

        *p++ = CR; *p = LF;

    } else {
        last[3] = ' ';
    }

    size += sizeof("250 STARTTLS" CRLF) - 1;

    p = ngx_pnalloc(cf->pool, size);
    if (p == NULL) {
        return NGX_CONF_ERROR;
    }

    conf->starttls_capability.len = size;
    conf->starttls_capability.data = p;

    p = ngx_cpymem(p, conf->capability.data, conf->capability.len);

    ngx_memcpy(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1);

    p = conf->starttls_capability.data
        + (last - conf->capability.data) + 3;
    *p = '-';

    size = (auth - conf->capability.data)
            + sizeof("250 STARTTLS" CRLF) - 1;

    p = ngx_pnalloc(cf->pool, size);
    if (p == NULL) {
        return NGX_CONF_ERROR;
    }

    conf->starttls_only_capability.len = size;
    conf->starttls_only_capability.data = p;

    p = ngx_cpymem(p, conf->capability.data, auth - conf->capability.data);

    ngx_memcpy(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1);

    if (last < auth) {
        p = conf->starttls_only_capability.data
            + (last - conf->capability.data) + 3;
        *p = '-';
    }

    return NGX_CONF_OK;
}