
/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


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


static ngx_uint_t ngx_stream_preread_can_peek(ngx_connection_t *c);
static ngx_int_t ngx_stream_preread_peek(ngx_stream_session_t *s,
    ngx_stream_phase_handler_t *ph);
static ngx_int_t ngx_stream_preread(ngx_stream_session_t *s,
    ngx_stream_phase_handler_t *ph);
static ngx_int_t ngx_stream_core_preconfiguration(ngx_conf_t *cf);
static void *ngx_stream_core_create_main_conf(ngx_conf_t *cf);
static char *ngx_stream_core_init_main_conf(ngx_conf_t *cf, void *conf);
static void *ngx_stream_core_create_srv_conf(ngx_conf_t *cf);
static char *ngx_stream_core_merge_srv_conf(ngx_conf_t *cf, void *parent,
    void *child);
static char *ngx_stream_core_error_log(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_stream_core_server(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_stream_core_listen(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_stream_core_server_name(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_stream_core_resolver(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_command_t  ngx_stream_core_commands[] = {

    { ngx_string("variables_hash_max_size"),
      NGX_STREAM_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_MAIN_CONF_OFFSET,
      offsetof(ngx_stream_core_main_conf_t, variables_hash_max_size),
      NULL },

    { ngx_string("variables_hash_bucket_size"),
      NGX_STREAM_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_MAIN_CONF_OFFSET,
      offsetof(ngx_stream_core_main_conf_t, variables_hash_bucket_size),
      NULL },

    { ngx_string("server_names_hash_max_size"),
      NGX_STREAM_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_MAIN_CONF_OFFSET,
      offsetof(ngx_stream_core_main_conf_t, server_names_hash_max_size),
      NULL },

    { ngx_string("server_names_hash_bucket_size"),
      NGX_STREAM_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_MAIN_CONF_OFFSET,
      offsetof(ngx_stream_core_main_conf_t, server_names_hash_bucket_size),
      NULL },

    { ngx_string("server"),
      NGX_STREAM_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_NOARGS,
      ngx_stream_core_server,
      0,
      0,
      NULL },

    { ngx_string("listen"),
      NGX_STREAM_SRV_CONF|NGX_CONF_1MORE,
      ngx_stream_core_listen,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("server_name"),
      NGX_STREAM_SRV_CONF|NGX_CONF_1MORE,
      ngx_stream_core_server_name,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("error_log"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_1MORE,
      ngx_stream_core_error_log,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("resolver"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_1MORE,
      ngx_stream_core_resolver,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("resolver_timeout"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_core_srv_conf_t, resolver_timeout),
      NULL },

    { ngx_string("proxy_protocol_timeout"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_core_srv_conf_t, proxy_protocol_timeout),
      NULL },

    { ngx_string("tcp_nodelay"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_core_srv_conf_t, tcp_nodelay),
      NULL },

    { ngx_string("preread_buffer_size"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_core_srv_conf_t, preread_buffer_size),
      NULL },

    { ngx_string("preread_timeout"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_core_srv_conf_t, preread_timeout),
      NULL },

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_core_module_ctx = {
    ngx_stream_core_preconfiguration,      /* preconfiguration */
    NULL,                                  /* postconfiguration */

    ngx_stream_core_create_main_conf,      /* create main configuration */
    ngx_stream_core_init_main_conf,        /* init main configuration */

    ngx_stream_core_create_srv_conf,       /* create server configuration */
    ngx_stream_core_merge_srv_conf         /* merge server configuration */
};


ngx_module_t  ngx_stream_core_module = {
    NGX_MODULE_V1,
    &ngx_stream_core_module_ctx,           /* module context */
    ngx_stream_core_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
};


void
ngx_stream_core_run_phases(ngx_stream_session_t *s)
{
    ngx_int_t                     rc;
    ngx_stream_phase_handler_t   *ph;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_get_module_main_conf(s, ngx_stream_core_module);

    ph = cmcf->phase_engine.handlers;

    while (ph[s->phase_handler].checker) {

        rc = ph[s->phase_handler].checker(s, &ph[s->phase_handler]);

        if (rc == NGX_OK) {
            return;
        }
    }
}


ngx_int_t
ngx_stream_core_generic_phase(ngx_stream_session_t *s,
    ngx_stream_phase_handler_t *ph)
{
    ngx_int_t  rc;

    /*
     * generic phase checker,
     * used by all phases, except for preread and content
     */

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                   "generic phase: %ui", s->phase_handler);

    rc = ph->handler(s);

    if (rc == NGX_OK) {
        s->phase_handler = ph->next;
        return NGX_AGAIN;
    }

    if (rc == NGX_DECLINED) {
        s->phase_handler++;
        return NGX_AGAIN;
    }

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

    if (rc == NGX_ERROR) {
        rc = NGX_STREAM_INTERNAL_SERVER_ERROR;
    }

    ngx_stream_finalize_session(s, rc);

    return NGX_OK;
}


ngx_int_t
ngx_stream_core_preread_phase(ngx_stream_session_t *s,
    ngx_stream_phase_handler_t *ph)
{
    ngx_int_t                    rc;
    ngx_connection_t            *c;
    ngx_stream_core_srv_conf_t  *cscf;

    c = s->connection;

    c->log->action = "prereading client data";

    cscf = ngx_stream_get_module_srv_conf(s, ngx_stream_core_module);

    if (c->read->timedout) {
        rc = NGX_STREAM_OK;
        goto done;
    }

    if (!c->read->timer_set) {
        rc = ph->handler(s);

        if (rc != NGX_AGAIN) {
            goto done;
        }
    }

    if (c->buffer == NULL) {
        c->buffer = ngx_create_temp_buf(c->pool, cscf->preread_buffer_size);
        if (c->buffer == NULL) {
            rc = NGX_ERROR;
            goto done;
        }
    }

    if (ngx_stream_preread_can_peek(c)) {
        rc = ngx_stream_preread_peek(s, ph);

    } else {
        rc = ngx_stream_preread(s, ph);
    }

done:

    if (rc == NGX_AGAIN) {
        if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
            ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
            return NGX_OK;
        }

        if (!c->read->timer_set) {
            ngx_add_timer(c->read, cscf->preread_timeout);
        }

        c->read->handler = ngx_stream_session_handler;

        return NGX_OK;
    }

    if (c->read->timer_set) {
        ngx_del_timer(c->read);
    }

    if (rc == NGX_OK) {
        s->phase_handler = ph->next;
        return NGX_AGAIN;
    }

    if (rc == NGX_DECLINED) {
        s->phase_handler++;
        return NGX_AGAIN;
    }

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

    if (rc == NGX_ERROR) {
        rc = NGX_STREAM_INTERNAL_SERVER_ERROR;
    }

    ngx_stream_finalize_session(s, rc);

    return NGX_OK;
}


static ngx_uint_t
ngx_stream_preread_can_peek(ngx_connection_t *c)
{
#if (NGX_STREAM_SSL)
    if (c->ssl) {
        return 0;
    }
#endif

    if ((ngx_event_flags & NGX_USE_CLEAR_EVENT) == 0) {
        return 0;
    }

#if (NGX_HAVE_KQUEUE)
    if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
        return 1;
    }
#endif

#if (NGX_HAVE_EPOLLRDHUP)
    if ((ngx_event_flags & NGX_USE_EPOLL_EVENT) && ngx_use_epoll_rdhup) {
        return 1;
    }
#endif

    return 0;
}


static ngx_int_t
ngx_stream_preread_peek(ngx_stream_session_t *s, ngx_stream_phase_handler_t *ph)
{
    ssize_t            n;
    ngx_int_t          rc;
    ngx_err_t          err;
    ngx_connection_t  *c;

    c = s->connection;

    n = recv(c->fd, (char *) c->buffer->last,
             c->buffer->end - c->buffer->last, MSG_PEEK);

    err = ngx_socket_errno;

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream recv(): %z", n);

    if (n == -1) {
        if (err == NGX_EAGAIN) {
            c->read->ready = 0;
            return NGX_AGAIN;
        }

        ngx_connection_error(c, err, "recv() failed");
        return NGX_STREAM_OK;
    }

    if (n == 0) {
        return NGX_STREAM_OK;
    }

    c->buffer->last += n;

    rc = ph->handler(s);

    if (rc != NGX_AGAIN) {
        c->buffer->last = c->buffer->pos;
        return rc;
    }

    if (c->buffer->last == c->buffer->end) {
        ngx_log_error(NGX_LOG_ERR, c->log, 0, "preread buffer full");
        return NGX_STREAM_BAD_REQUEST;
    }

    if (c->read->pending_eof) {
        return NGX_STREAM_OK;
    }

    c->buffer->last = c->buffer->pos;

    return NGX_AGAIN;
}


static ngx_int_t
ngx_stream_preread(ngx_stream_session_t *s, ngx_stream_phase_handler_t *ph)
{
    ssize_t            n;
    ngx_int_t          rc;
    ngx_connection_t  *c;

    c = s->connection;

    while (c->read->ready) {

        n = c->recv(c, c->buffer->last, c->buffer->end - c->buffer->last);

        if (n == NGX_AGAIN) {
            return NGX_AGAIN;
        }

        if (n == NGX_ERROR || n == 0) {
            return NGX_STREAM_OK;
        }

        c->buffer->last += n;

        rc = ph->handler(s);

        if (rc != NGX_AGAIN) {
            return rc;
        }

        if (c->buffer->last == c->buffer->end) {
            ngx_log_error(NGX_LOG_ERR, c->log, 0, "preread buffer full");
            return NGX_STREAM_BAD_REQUEST;
        }
    }

    return NGX_AGAIN;
}


ngx_int_t
ngx_stream_core_content_phase(ngx_stream_session_t *s,
    ngx_stream_phase_handler_t *ph)
{
    ngx_connection_t            *c;
    ngx_stream_core_srv_conf_t  *cscf;

    c = s->connection;

    c->log->action = NULL;

    cscf = ngx_stream_get_module_srv_conf(s, ngx_stream_core_module);

    if (c->type == SOCK_STREAM
        && cscf->tcp_nodelay
        && ngx_tcp_nodelay(c) != NGX_OK)
    {
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return NGX_OK;
    }

    if (cscf->handler == NULL) {
        ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                       "no handler for server");
        ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
        return NGX_OK;
    }

    cscf->handler(s);

    return NGX_OK;
}


ngx_int_t
ngx_stream_validate_host(ngx_str_t *host, ngx_pool_t *pool, ngx_uint_t alloc)
{
    u_char     *h, ch;
    size_t      i, dot_pos, host_len;
    ngx_int_t   port;

    enum {
        sw_host_start = 0,
        sw_host,
        sw_host_ip_literal,
        sw_host_end,
        sw_port,
    } state;

    dot_pos = host->len;
    host_len = host->len;
    port = 0;

    h = host->data;

    state = sw_host_start;

    for (i = 0; i < host->len; i++) {
        ch = h[i];

        switch (state) {

        case sw_host_start:

            if (ch == '[') {
                state = sw_host_ip_literal;
                break;
            }

            state = sw_host;

            /* fall through */

        case sw_host:

            if (ch >= 'A' && ch <= 'Z') {
                alloc = 1;
                break;
            }

            if (ch >= 'a' && ch <= 'z') {
                break;
            }

            if (ch >= '0' && ch <= '9') {
                break;
            }

            switch (ch) {
            case ':':
                host_len = i;
                state = sw_port;
                break;
            case '-':
                break;
            case '.':
                if (dot_pos == i - 1) {
                    return NGX_DECLINED;
                }
                dot_pos = i;
                break;
            case '_':
            case '~':
                /* unreserved */
                break;
            case '!':
            case '$':
            case '&':
            case '\'':
            case '(':
            case ')':
            case '*':
            case '+':
            case ',':
            case ';':
            case '=':
                /* sub-delims */
                break;
            case '%':
                /* pct-encoded */
                break;
            default:
                return NGX_DECLINED;
            }
            break;

        case sw_host_ip_literal:

            if (ch >= 'A' && ch <= 'Z') {
                alloc = 1;
                break;
            }

            if (ch >= 'a' && ch <= 'z') {
                break;
            }

            if (ch >= '0' && ch <= '9') {
                break;
            }

            switch (ch) {
            case ':':
                break;
            case ']':
                host_len = i + 1;
                state = sw_host_end;
                break;
            case '-':
                break;
            case '.':
                if (dot_pos == i - 1) {
                    return NGX_DECLINED;
                }
                dot_pos = i;
                break;
            case '_':
            case '~':
                /* unreserved */
                break;
            case '!':
            case '$':
            case '&':
            case '\'':
            case '(':
            case ')':
            case '*':
            case '+':
            case ',':
            case ';':
            case '=':
                /* sub-delims */
                break;
            default:
                return NGX_DECLINED;
            }
            break;

        case sw_host_end:

            if (ch == ':') {
                state = sw_port;
                break;
            }
            return NGX_DECLINED;

        case sw_port:

            if (ch >= '0' && ch <= '9') {
                if (port >= 6553 && (port > 6553 || (ch - '0') > 5)) {
                    return NGX_DECLINED;
                }

                port = port * 10 + (ch - '0');
                break;
            }
            return NGX_DECLINED;
        }
    }

    if (state == sw_host_ip_literal) {
        return NGX_DECLINED;
    }

    if (dot_pos == host_len - 1) {
        host_len--;
    }

    if (host_len == 0) {
        return NGX_DECLINED;
    }

    if (alloc) {
        host->data = ngx_pnalloc(pool, host_len);
        if (host->data == NULL) {
            return NGX_ERROR;
        }

        ngx_strlow(host->data, h, host_len);
    }

    host->len = host_len;

    return NGX_OK;
}


ngx_int_t
ngx_stream_find_virtual_server(ngx_stream_session_t *s,
    ngx_str_t *host, ngx_stream_core_srv_conf_t **cscfp)
{
    ngx_stream_core_srv_conf_t  *cscf;

    if (s->virtual_names == NULL) {
        return NGX_DECLINED;
    }

    cscf = ngx_hash_find_combined(&s->virtual_names->names,
                                  ngx_hash_key(host->data, host->len),
                                  host->data, host->len);

    if (cscf) {
        *cscfp = cscf;
        return NGX_OK;
    }

#if (NGX_PCRE)

    if (host->len && s->virtual_names->nregex) {
        ngx_int_t                  n;
        ngx_uint_t                 i;
        ngx_stream_server_name_t  *sn;

        sn = s->virtual_names->regex;

        for (i = 0; i < s->virtual_names->nregex; i++) {

            n = ngx_stream_regex_exec(s, sn[i].regex, host);

            if (n == NGX_DECLINED) {
                continue;
            }

            if (n == NGX_OK) {
                *cscfp = sn[i].server;
                return NGX_OK;
            }

            return NGX_ERROR;
        }
    }

#endif /* NGX_PCRE */

    return NGX_DECLINED;
}


static ngx_int_t
ngx_stream_core_preconfiguration(ngx_conf_t *cf)
{
    return ngx_stream_variables_add_core_vars(cf);
}


static void *
ngx_stream_core_create_main_conf(ngx_conf_t *cf)
{
    ngx_stream_core_main_conf_t  *cmcf;

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

    if (ngx_array_init(&cmcf->servers, cf->pool, 4,
                       sizeof(ngx_stream_core_srv_conf_t *))
        != NGX_OK)
    {
        return NULL;
    }

    cmcf->server_names_hash_max_size = NGX_CONF_UNSET_UINT;
    cmcf->server_names_hash_bucket_size = NGX_CONF_UNSET_UINT;

    cmcf->variables_hash_max_size = NGX_CONF_UNSET_UINT;
    cmcf->variables_hash_bucket_size = NGX_CONF_UNSET_UINT;

    return cmcf;
}


static char *
ngx_stream_core_init_main_conf(ngx_conf_t *cf, void *conf)
{
    ngx_stream_core_main_conf_t *cmcf = conf;

    ngx_conf_init_uint_value(cmcf->server_names_hash_max_size, 512);
    ngx_conf_init_uint_value(cmcf->server_names_hash_bucket_size,
                             ngx_cacheline_size);

    cmcf->server_names_hash_bucket_size =
            ngx_align(cmcf->server_names_hash_bucket_size, ngx_cacheline_size);


    ngx_conf_init_uint_value(cmcf->variables_hash_max_size, 1024);
    ngx_conf_init_uint_value(cmcf->variables_hash_bucket_size, 64);

    cmcf->variables_hash_bucket_size =
               ngx_align(cmcf->variables_hash_bucket_size, ngx_cacheline_size);

    if (cmcf->ncaptures) {
        cmcf->ncaptures = (cmcf->ncaptures + 1) * 3;
    }

    return NGX_CONF_OK;
}


static void *
ngx_stream_core_create_srv_conf(ngx_conf_t *cf)
{
    ngx_stream_core_srv_conf_t  *cscf;

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

    /*
     * set by ngx_pcalloc():
     *
     *     cscf->handler = NULL;
     *     cscf->error_log = NULL;
     */

    if (ngx_array_init(&cscf->server_names, cf->temp_pool, 4,
                       sizeof(ngx_stream_server_name_t))
        != NGX_OK)
    {
        return NULL;
    }

    cscf->file_name = cf->conf_file->file.name.data;
    cscf->line = cf->conf_file->line;
    cscf->resolver_timeout = NGX_CONF_UNSET_MSEC;
    cscf->proxy_protocol_timeout = NGX_CONF_UNSET_MSEC;
    cscf->tcp_nodelay = NGX_CONF_UNSET;
    cscf->preread_buffer_size = NGX_CONF_UNSET_SIZE;
    cscf->preread_timeout = NGX_CONF_UNSET_MSEC;

    return cscf;
}


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

    ngx_str_t                  name;
    ngx_stream_server_name_t  *sn;

    ngx_conf_merge_msec_value(conf->resolver_timeout,
                              prev->resolver_timeout, 30000);

    if (conf->resolver == NULL) {

        if (prev->resolver == NULL) {

            /*
             * create dummy resolver in stream {} context
             * to inherit it in all servers
             */

            prev->resolver = ngx_resolver_create(cf, NULL, 0);
            if (prev->resolver == NULL) {
                return NGX_CONF_ERROR;
            }
        }

        conf->resolver = prev->resolver;
    }

    if (conf->error_log == NULL) {
        if (prev->error_log) {
            conf->error_log = prev->error_log;
        } else {
            conf->error_log = &cf->cycle->new_log;
        }
    }

    ngx_conf_merge_msec_value(conf->proxy_protocol_timeout,
                              prev->proxy_protocol_timeout, 30000);

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

    ngx_conf_merge_size_value(conf->preread_buffer_size,
                              prev->preread_buffer_size, 16384);

    ngx_conf_merge_msec_value(conf->preread_timeout,
                              prev->preread_timeout, 30000);

    if (conf->server_names.nelts == 0) {
        /* the array has 4 empty preallocated elements, so push cannot fail */
        sn = ngx_array_push(&conf->server_names);
#if (NGX_PCRE)
        sn->regex = NULL;
#endif
        sn->server = conf;
        ngx_str_set(&sn->name, "");
    }

    sn = conf->server_names.elts;
    name = sn[0].name;

#if (NGX_PCRE)
    if (sn->regex) {
        name.len++;
        name.data--;
    } else
#endif

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

    conf->server_name.len = name.len;
    conf->server_name.data = ngx_pstrdup(cf->pool, &name);
    if (conf->server_name.data == NULL) {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static char *
ngx_stream_core_error_log(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_core_srv_conf_t  *cscf = conf;

    return ngx_log_set_log(cf, &cscf->error_log);
}


static char *
ngx_stream_core_server(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char                         *rv;
    void                         *mconf;
    ngx_uint_t                    m;
    ngx_conf_t                    pcf;
    ngx_stream_module_t          *module;
    ngx_stream_conf_ctx_t        *ctx, *stream_ctx;
    ngx_stream_core_srv_conf_t   *cscf, **cscfp;
    ngx_stream_core_main_conf_t  *cmcf;

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

    stream_ctx = cf->ctx;
    ctx->main_conf = stream_ctx->main_conf;

    /* the server{}'s srv_conf */

    ctx->srv_conf = ngx_pcalloc(cf->pool,
                                sizeof(void *) * ngx_stream_max_module);
    if (ctx->srv_conf == NULL) {
        return NGX_CONF_ERROR;
    }

    for (m = 0; cf->cycle->modules[m]; m++) {
        if (cf->cycle->modules[m]->type != NGX_STREAM_MODULE) {
            continue;
        }

        module = cf->cycle->modules[m]->ctx;

        if (module->create_srv_conf) {
            mconf = module->create_srv_conf(cf);
            if (mconf == NULL) {
                return NGX_CONF_ERROR;
            }

            ctx->srv_conf[cf->cycle->modules[m]->ctx_index] = mconf;
        }
    }

    /* the server configuration context */

    cscf = ctx->srv_conf[ngx_stream_core_module.ctx_index];
    cscf->ctx = ctx;

    cmcf = ctx->main_conf[ngx_stream_core_module.ctx_index];

    cscfp = ngx_array_push(&cmcf->servers);
    if (cscfp == NULL) {
        return NGX_CONF_ERROR;
    }

    *cscfp = cscf;


    /* parse inside server{} */

    pcf = *cf;
    cf->ctx = ctx;
    cf->cmd_type = NGX_STREAM_SRV_CONF;

    rv = ngx_conf_parse(cf, NULL);

    *cf = pcf;

    if (rv == NGX_CONF_OK && !cscf->listen) {
        ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                      "no \"listen\" is defined for server in %s:%ui",
                      cscf->file_name, cscf->line);
        return NGX_CONF_ERROR;
    }

    return rv;
}


static char *
ngx_stream_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_core_srv_conf_t  *cscf = conf;

    ngx_str_t                *value, size;
    ngx_url_t                 u;
    ngx_uint_t                n, i, backlog;
    ngx_stream_listen_opt_t   lsopt;

    cscf->listen = 1;

    value = cf->args->elts;

    ngx_memzero(&u, sizeof(ngx_url_t));

    u.url = value[1];
    u.listen = 1;

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

        return NGX_CONF_ERROR;
    }

    ngx_memzero(&lsopt, sizeof(ngx_stream_listen_opt_t));

    lsopt.backlog = NGX_LISTEN_BACKLOG;
    lsopt.type = SOCK_STREAM;
    lsopt.rcvbuf = -1;
    lsopt.sndbuf = -1;
#if (NGX_HAVE_SETFIB)
    lsopt.setfib = -1;
#endif
#if (NGX_HAVE_TCP_FASTOPEN)
    lsopt.fastopen = -1;
#endif
#if (NGX_HAVE_INET6)
    lsopt.ipv6only = 1;
#endif

    backlog = 0;

    for (i = 2; i < cf->args->nelts; i++) {

        if (ngx_strcmp(value[i].data, "default_server") == 0) {
            lsopt.default_server = 1;
            continue;
        }

#if !(NGX_WIN32)
        if (ngx_strcmp(value[i].data, "udp") == 0) {
            lsopt.type = SOCK_DGRAM;
            continue;
        }
#endif

        if (ngx_strcmp(value[i].data, "bind") == 0) {
            lsopt.set = 1;
            lsopt.bind = 1;
            continue;
        }

#if (NGX_HAVE_SETFIB)
        if (ngx_strncmp(value[i].data, "setfib=", 7) == 0) {
            lsopt.setfib = ngx_atoi(value[i].data + 7, value[i].len - 7);
            lsopt.set = 1;
            lsopt.bind = 1;

            if (lsopt.setfib == NGX_ERROR) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "invalid setfib \"%V\"", &value[i]);
                return NGX_CONF_ERROR;
            }

            continue;
        }
#endif

#if (NGX_HAVE_TCP_FASTOPEN)
        if (ngx_strncmp(value[i].data, "fastopen=", 9) == 0) {
            lsopt.fastopen = ngx_atoi(value[i].data + 9, value[i].len - 9);
            lsopt.set = 1;
            lsopt.bind = 1;

            if (lsopt.fastopen == NGX_ERROR) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "invalid fastopen \"%V\"", &value[i]);
                return NGX_CONF_ERROR;
            }

            continue;
        }
#endif

        if (ngx_strncmp(value[i].data, "backlog=", 8) == 0) {
            lsopt.backlog = ngx_atoi(value[i].data + 8, value[i].len - 8);
            lsopt.set = 1;
            lsopt.bind = 1;

            if (lsopt.backlog == NGX_ERROR || lsopt.backlog == 0) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "invalid backlog \"%V\"", &value[i]);
                return NGX_CONF_ERROR;
            }

            backlog = 1;

            continue;
        }

        if (ngx_strncmp(value[i].data, "rcvbuf=", 7) == 0) {
            size.len = value[i].len - 7;
            size.data = value[i].data + 7;

            lsopt.rcvbuf = ngx_parse_size(&size);
            lsopt.set = 1;
            lsopt.bind = 1;

            if (lsopt.rcvbuf == NGX_ERROR) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "invalid rcvbuf \"%V\"", &value[i]);
                return NGX_CONF_ERROR;
            }

            continue;
        }

        if (ngx_strncmp(value[i].data, "sndbuf=", 7) == 0) {
            size.len = value[i].len - 7;
            size.data = value[i].data + 7;

            lsopt.sndbuf = ngx_parse_size(&size);
            lsopt.set = 1;
            lsopt.bind = 1;

            if (lsopt.sndbuf == NGX_ERROR) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "invalid sndbuf \"%V\"", &value[i]);
                return NGX_CONF_ERROR;
            }

            continue;
        }

        if (ngx_strncmp(value[i].data, "accept_filter=", 14) == 0) {
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
            lsopt.accept_filter = (char *) &value[i].data[14];
            lsopt.set = 1;
            lsopt.bind = 1;
#else
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "accept filters \"%V\" are not supported "
                               "on this platform, ignored",
                               &value[i]);
#endif
            continue;
        }

        if (ngx_strcmp(value[i].data, "deferred") == 0) {
#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
            lsopt.deferred_accept = 1;
            lsopt.set = 1;
            lsopt.bind = 1;
#else
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "the deferred accept is not supported "
                               "on this platform, ignored");
#endif
            continue;
        }

        if (ngx_strncmp(value[i].data, "ipv6only=o", 10) == 0) {
#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
            if (ngx_strcmp(&value[i].data[10], "n") == 0) {
                lsopt.ipv6only = 1;

            } else if (ngx_strcmp(&value[i].data[10], "ff") == 0) {
                lsopt.ipv6only = 0;

            } else {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "invalid ipv6only flags \"%s\"",
                                   &value[i].data[9]);
                return NGX_CONF_ERROR;
            }

            lsopt.set = 1;
            lsopt.bind = 1;

            continue;
#else
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "ipv6only is not supported "
                               "on this platform");
            return NGX_CONF_ERROR;
#endif
        }

        if (ngx_strcmp(value[i].data, "reuseport") == 0) {
#if (NGX_HAVE_REUSEPORT)
            lsopt.reuseport = 1;
            lsopt.set = 1;
            lsopt.bind = 1;
#else
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "reuseport is not supported "
                               "on this platform, ignored");
#endif
            continue;
        }

        if (ngx_strcmp(value[i].data, "multipath") == 0) {
#ifdef IPPROTO_MPTCP
            lsopt.protocol = IPPROTO_MPTCP;
            lsopt.set = 1;
            lsopt.bind = 1;
#else
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "multipath is not supported "
                               "on this platform, ignored");
#endif
            continue;
        }

        if (ngx_strcmp(value[i].data, "ssl") == 0) {
#if (NGX_STREAM_SSL)
            lsopt.ssl = 1;
            continue;
#else
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "the \"ssl\" parameter requires "
                               "ngx_stream_ssl_module");
            return NGX_CONF_ERROR;
#endif
        }

        if (ngx_strncmp(value[i].data, "so_keepalive=", 13) == 0) {

            if (ngx_strcmp(&value[i].data[13], "on") == 0) {
                lsopt.so_keepalive = 1;

            } else if (ngx_strcmp(&value[i].data[13], "off") == 0) {
                lsopt.so_keepalive = 2;

            } else {

#if (NGX_HAVE_KEEPALIVE_TUNABLE)
                u_char     *p, *end;
                ngx_str_t   s;

                end = value[i].data + value[i].len;
                s.data = value[i].data + 13;

                p = ngx_strlchr(s.data, end, ':');
                if (p == NULL) {
                    p = end;
                }

                if (p > s.data) {
                    s.len = p - s.data;

                    lsopt.tcp_keepidle = ngx_parse_time(&s, 1);
                    if (lsopt.tcp_keepidle == (time_t) NGX_ERROR) {
                        goto invalid_so_keepalive;
                    }
                }

                s.data = (p < end) ? (p + 1) : end;

                p = ngx_strlchr(s.data, end, ':');
                if (p == NULL) {
                    p = end;
                }

                if (p > s.data) {
                    s.len = p - s.data;

                    lsopt.tcp_keepintvl = ngx_parse_time(&s, 1);
                    if (lsopt.tcp_keepintvl == (time_t) NGX_ERROR) {
                        goto invalid_so_keepalive;
                    }
                }

                s.data = (p < end) ? (p + 1) : end;

                if (s.data < end) {
                    s.len = end - s.data;

                    lsopt.tcp_keepcnt = ngx_atoi(s.data, s.len);
                    if (lsopt.tcp_keepcnt == NGX_ERROR) {
                        goto invalid_so_keepalive;
                    }
                }

                if (lsopt.tcp_keepidle == 0 && lsopt.tcp_keepintvl == 0
                    && lsopt.tcp_keepcnt == 0)
                {
                    goto invalid_so_keepalive;
                }

                lsopt.so_keepalive = 1;

#else

                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "the \"so_keepalive\" parameter accepts "
                                   "only \"on\" or \"off\" on this platform");
                return NGX_CONF_ERROR;

#endif
            }

            lsopt.set = 1;
            lsopt.bind = 1;

            continue;

#if (NGX_HAVE_KEEPALIVE_TUNABLE)
        invalid_so_keepalive:

            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid so_keepalive value: \"%s\"",
                               &value[i].data[13]);
            return NGX_CONF_ERROR;
#endif
        }

        if (ngx_strcmp(value[i].data, "proxy_protocol") == 0) {
            lsopt.proxy_protocol = 1;
            continue;
        }

        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid parameter \"%V\"", &value[i]);
        return NGX_CONF_ERROR;
    }

    if (lsopt.type == SOCK_DGRAM) {
#if (NGX_HAVE_TCP_FASTOPEN)
        if (lsopt.fastopen != -1) {
            return "\"fastopen\" parameter is incompatible with \"udp\"";
        }
#endif

        if (backlog) {
            return "\"backlog\" parameter is incompatible with \"udp\"";
        }

#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
        if (lsopt.accept_filter) {
            return "\"accept_filter\" parameter is incompatible with \"udp\"";
        }
#endif

#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
        if (lsopt.deferred_accept) {
            return "\"deferred\" parameter is incompatible with \"udp\"";
        }
#endif

#ifdef IPPROTO_MPTCP
        if (lsopt.protocol == IPPROTO_MPTCP) {
            return "\"multipath\" parameter is incompatible with \"udp\"";
        }
#endif

#if (NGX_STREAM_SSL)
        if (lsopt.ssl) {
            return "\"ssl\" parameter is incompatible with \"udp\"";
        }
#endif

        if (lsopt.so_keepalive) {
            return "\"so_keepalive\" parameter is incompatible with \"udp\"";
        }

        if (lsopt.proxy_protocol) {
            return "\"proxy_protocol\" parameter is incompatible with \"udp\"";
        }
    }

    for (n = 0; n < u.naddrs; n++) {

        for (i = 0; i < n; i++) {
            if (ngx_cmp_sockaddr(u.addrs[n].sockaddr, u.addrs[n].socklen,
                                 u.addrs[i].sockaddr, u.addrs[i].socklen, 1)
                == NGX_OK)
            {
                goto next;
            }
        }

        lsopt.sockaddr = u.addrs[n].sockaddr;
        lsopt.socklen = u.addrs[n].socklen;
        lsopt.addr_text = u.addrs[n].name;
        lsopt.wildcard = ngx_inet_wildcard(lsopt.sockaddr);

        if (ngx_stream_add_listen(cf, cscf, &lsopt) != NGX_OK) {
            return NGX_CONF_ERROR;
        }

    next:
        continue;
    }

    return NGX_CONF_OK;
}


static char *
ngx_stream_core_server_name(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_core_srv_conf_t *cscf = conf;

    u_char                     ch;
    ngx_str_t                 *value;
    ngx_uint_t                 i;
    ngx_stream_server_name_t  *sn;

    value = cf->args->elts;

    for (i = 1; i < cf->args->nelts; i++) {

        ch = value[i].data[0];

        if ((ch == '*' && (value[i].len < 3 || value[i].data[1] != '.'))
            || (ch == '.' && value[i].len < 2))
        {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "server name \"%V\" is invalid", &value[i]);
            return NGX_CONF_ERROR;
        }

        if (ngx_strchr(value[i].data, '/')) {
            ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                               "server name \"%V\" has suspicious symbols",
                               &value[i]);
        }

        sn = ngx_array_push(&cscf->server_names);
        if (sn == NULL) {
            return NGX_CONF_ERROR;
        }

#if (NGX_PCRE)
        sn->regex = NULL;
#endif
        sn->server = cscf;

        if (ngx_strcasecmp(value[i].data, (u_char *) "$hostname") == 0) {
            sn->name = cf->cycle->hostname;

        } else {
            sn->name = value[i];
        }

        if (value[i].data[0] != '~') {
            ngx_strlow(sn->name.data, sn->name.data, sn->name.len);
            continue;
        }

#if (NGX_PCRE)
        {
        u_char               *p;
        ngx_regex_compile_t   rc;
        u_char                errstr[NGX_MAX_CONF_ERRSTR];

        if (value[i].len == 1) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "empty regex in server name \"%V\"", &value[i]);
            return NGX_CONF_ERROR;
        }

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

        ngx_memzero(&rc, sizeof(ngx_regex_compile_t));

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

        for (p = value[i].data; p < value[i].data + value[i].len; p++) {
            if (*p >= 'A' && *p <= 'Z') {
                rc.options = NGX_REGEX_CASELESS;
                break;
            }
        }

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

        sn->name = value[i];
        cscf->captures = (rc.captures > 0);
        }
#else
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "using regex \"%V\" "
                           "requires PCRE library", &value[i]);

        return NGX_CONF_ERROR;
#endif
    }

    return NGX_CONF_OK;
}


static char *
ngx_stream_core_resolver(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_core_srv_conf_t  *cscf = conf;

    ngx_str_t  *value;

    if (cscf->resolver) {
        return "is duplicate";
    }

    value = cf->args->elts;

    cscf->resolver = ngx_resolver_create(cf, &value[1], cf->args->nelts - 1);
    if (cscf->resolver == NULL) {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}
