view src/stream/ngx_stream_return_module.c @ 8971:1e2f4e9c8195 quic

QUIC: reworked migration handling. The quic connection now holds active, backup and probe paths instead of sockets. The number of migration paths is now limited and cannot be inflated by a bad client or an attacker. The client id is now associated with path rather than socket. This allows to simplify processing of output and connection ids handling. New migration abandons any previously started migrations. This allows to free consumed client ids and request new for use in future migrations and make progress in case when connection id limit is hit during migration. A path now can be revalidated without losing its state. The patch also fixes various issues with NAT rebinding case handling: - paths are now validated (previously, there was no validation and paths were left in limited state) - attempt to reuse id on different path is now again verified (this was broken in 40445fc7c403) - former path is now validated in case of apparent migration
author Vladimir Homutov <vl@nginx.com>
date Wed, 19 Jan 2022 22:39:24 +0300
parents 56fc55e32f23
children
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/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


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


typedef struct {
    ngx_stream_complex_value_t   text;
} ngx_stream_return_srv_conf_t;


typedef struct {
    ngx_chain_t                 *out;
} ngx_stream_return_ctx_t;


static void ngx_stream_return_handler(ngx_stream_session_t *s);
static void ngx_stream_return_write_handler(ngx_event_t *ev);

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


static ngx_command_t  ngx_stream_return_commands[] = {

    { ngx_string("return"),
      NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_stream_return,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


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

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

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


ngx_module_t  ngx_stream_return_module = {
    NGX_MODULE_V1,
    &ngx_stream_return_module_ctx,         /* module context */
    ngx_stream_return_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 void
ngx_stream_return_handler(ngx_stream_session_t *s)
{
    ngx_str_t                      text;
    ngx_buf_t                     *b;
    ngx_connection_t              *c;
    ngx_stream_return_ctx_t       *ctx;
    ngx_stream_return_srv_conf_t  *rscf;

    c = s->connection;

    c->log->action = "returning text";

    rscf = ngx_stream_get_module_srv_conf(s, ngx_stream_return_module);

    if (ngx_stream_complex_value(s, &rscf->text, &text) != NGX_OK) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0,
                   "stream return text: \"%V\"", &text);

    if (text.len == 0) {
        ngx_stream_finalize_session(s, NGX_STREAM_OK);
        return;
    }

    ctx = ngx_pcalloc(c->pool, sizeof(ngx_stream_return_ctx_t));
    if (ctx == NULL) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_stream_set_ctx(s, ctx, ngx_stream_return_module);

    b = ngx_calloc_buf(c->pool);
    if (b == NULL) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    b->memory = 1;
    b->pos = text.data;
    b->last = text.data + text.len;
    b->last_buf = 1;

    ctx->out = ngx_alloc_chain_link(c->pool);
    if (ctx->out == NULL) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ctx->out->buf = b;
    ctx->out->next = NULL;

    c->write->handler = ngx_stream_return_write_handler;

    ngx_stream_return_write_handler(c->write);
}


static void
ngx_stream_return_write_handler(ngx_event_t *ev)
{
    ngx_connection_t         *c;
    ngx_stream_session_t     *s;
    ngx_stream_return_ctx_t  *ctx;

    c = ev->data;
    s = c->data;

    if (ev->timedout) {
        ngx_connection_error(c, NGX_ETIMEDOUT, "connection timed out");
        ngx_stream_finalize_session(s, NGX_STREAM_OK);
        return;
    }

    ctx = ngx_stream_get_module_ctx(s, ngx_stream_return_module);

    if (ngx_stream_top_filter(s, ctx->out, 1) == NGX_ERROR) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ctx->out = NULL;

    if (!c->buffered) {
        ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                       "stream return done sending");
        ngx_stream_finalize_session(s, NGX_STREAM_OK);
        return;
    }

    if (ngx_handle_write_event(ev, 0) != NGX_OK) {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return;
    }

    ngx_add_timer(ev, 5000);
}


static void *
ngx_stream_return_create_srv_conf(ngx_conf_t *cf)
{
    ngx_stream_return_srv_conf_t  *conf;

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

    return conf;
}


static char *
ngx_stream_return(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_return_srv_conf_t *rscf = conf;

    ngx_str_t                           *value;
    ngx_stream_core_srv_conf_t          *cscf;
    ngx_stream_compile_complex_value_t   ccv;

    if (rscf->text.value.data) {
        return "is duplicate";
    }

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));

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

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

    cscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_core_module);

    cscf->handler = ngx_stream_return_handler;

    return NGX_CONF_OK;
}