view src/core/ngx_conf_file.c @ 8006:32b0ba4855a6

HTTP/2: made it possible to flush response headers (ticket #1743). Response headers can be buffered in the SSL buffer. But stream's fake connection buffered flag did not reflect this, so any attempts to flush the buffer without sending additional data were stopped by the write filter. It does not seem to be possible to reflect this in fc->buffered though, as we never known if main connection's c->buffered corresponds to the particular stream or not. As such, fc->buffered might prevent request finalization due to sending data on some other stream. Fix is to implement handling of flush buffers when the c->need_flush_buf flag is set, similarly to the existing last buffer handling. The same flag is now used for UDP sockets in the stream module instead of explicit checking of c->type.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 03 Feb 2022 01:44:38 +0300
parents 485dba3e2a01
children 3108d4d668e4
line wrap: on
line source


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


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

#define NGX_CONF_BUFFER  4096

static ngx_int_t ngx_conf_add_dump(ngx_conf_t *cf, ngx_str_t *filename);
static ngx_int_t ngx_conf_handler(ngx_conf_t *cf, ngx_int_t last);
static ngx_int_t ngx_conf_read_token(ngx_conf_t *cf);
static void ngx_conf_flush_files(ngx_cycle_t *cycle);


static ngx_command_t  ngx_conf_commands[] = {

    { ngx_string("include"),
      NGX_ANY_CONF|NGX_CONF_TAKE1,
      ngx_conf_include,
      0,
      0,
      NULL },

      ngx_null_command
};


ngx_module_t  ngx_conf_module = {
    NGX_MODULE_V1,
    NULL,                                  /* module context */
    ngx_conf_commands,                     /* module directives */
    NGX_CONF_MODULE,                       /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    ngx_conf_flush_files,                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


/* The eight fixed arguments */

static ngx_uint_t argument_number[] = {
    NGX_CONF_NOARGS,
    NGX_CONF_TAKE1,
    NGX_CONF_TAKE2,
    NGX_CONF_TAKE3,
    NGX_CONF_TAKE4,
    NGX_CONF_TAKE5,
    NGX_CONF_TAKE6,
    NGX_CONF_TAKE7
};


char *
ngx_conf_param(ngx_conf_t *cf)
{
    char             *rv;
    ngx_str_t        *param;
    ngx_buf_t         b;
    ngx_conf_file_t   conf_file;

    param = &cf->cycle->conf_param;

    if (param->len == 0) {
        return NGX_CONF_OK;
    }

    ngx_memzero(&conf_file, sizeof(ngx_conf_file_t));

    ngx_memzero(&b, sizeof(ngx_buf_t));

    b.start = param->data;
    b.pos = param->data;
    b.last = param->data + param->len;
    b.end = b.last;
    b.temporary = 1;

    conf_file.file.fd = NGX_INVALID_FILE;
    conf_file.file.name.data = NULL;
    conf_file.line = 0;

    cf->conf_file = &conf_file;
    cf->conf_file->buffer = &b;

    rv = ngx_conf_parse(cf, NULL);

    cf->conf_file = NULL;

    return rv;
}


static ngx_int_t
ngx_conf_add_dump(ngx_conf_t *cf, ngx_str_t *filename)
{
    off_t             size;
    u_char           *p;
    uint32_t          hash;
    ngx_buf_t        *buf;
    ngx_str_node_t   *sn;
    ngx_conf_dump_t  *cd;

    hash = ngx_crc32_long(filename->data, filename->len);

    sn = ngx_str_rbtree_lookup(&cf->cycle->config_dump_rbtree, filename, hash);

    if (sn) {
        cf->conf_file->dump = NULL;
        return NGX_OK;
    }

    p = ngx_pstrdup(cf->cycle->pool, filename);
    if (p == NULL) {
        return NGX_ERROR;
    }

    cd = ngx_array_push(&cf->cycle->config_dump);
    if (cd == NULL) {
        return NGX_ERROR;
    }

    size = ngx_file_size(&cf->conf_file->file.info);

    buf = ngx_create_temp_buf(cf->cycle->pool, (size_t) size);
    if (buf == NULL) {
        return NGX_ERROR;
    }

    cd->name.data = p;
    cd->name.len = filename->len;
    cd->buffer = buf;

    cf->conf_file->dump = buf;

    sn = ngx_palloc(cf->temp_pool, sizeof(ngx_str_node_t));
    if (sn == NULL) {
        return NGX_ERROR;
    }

    sn->node.key = hash;
    sn->str = cd->name;

    ngx_rbtree_insert(&cf->cycle->config_dump_rbtree, &sn->node);

    return NGX_OK;
}


char *
ngx_conf_parse(ngx_conf_t *cf, ngx_str_t *filename)
{
    char             *rv;
    ngx_fd_t          fd;
    ngx_int_t         rc;
    ngx_buf_t         buf;
    ngx_conf_file_t  *prev, conf_file;
    enum {
        parse_file = 0,
        parse_block,
        parse_param
    } type;

#if (NGX_SUPPRESS_WARN)
    fd = NGX_INVALID_FILE;
    prev = NULL;
#endif

    if (filename) {

        /* open configuration file */

        fd = ngx_open_file(filename->data, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0);

        if (fd == NGX_INVALID_FILE) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                               ngx_open_file_n " \"%s\" failed",
                               filename->data);
            return NGX_CONF_ERROR;
        }

        prev = cf->conf_file;

        cf->conf_file = &conf_file;

        if (ngx_fd_info(fd, &cf->conf_file->file.info) == NGX_FILE_ERROR) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, ngx_errno,
                          ngx_fd_info_n " \"%s\" failed", filename->data);
        }

        cf->conf_file->buffer = &buf;

        buf.start = ngx_alloc(NGX_CONF_BUFFER, cf->log);
        if (buf.start == NULL) {
            goto failed;
        }

        buf.pos = buf.start;
        buf.last = buf.start;
        buf.end = buf.last + NGX_CONF_BUFFER;
        buf.temporary = 1;

        cf->conf_file->file.fd = fd;
        cf->conf_file->file.name.len = filename->len;
        cf->conf_file->file.name.data = filename->data;
        cf->conf_file->file.offset = 0;
        cf->conf_file->file.log = cf->log;
        cf->conf_file->line = 1;

        type = parse_file;

        if (ngx_dump_config
#if (NGX_DEBUG)
            || 1
#endif
           )
        {
            if (ngx_conf_add_dump(cf, filename) != NGX_OK) {
                goto failed;
            }

        } else {
            cf->conf_file->dump = NULL;
        }

    } else if (cf->conf_file->file.fd != NGX_INVALID_FILE) {

        type = parse_block;

    } else {
        type = parse_param;
    }


    for ( ;; ) {
        rc = ngx_conf_read_token(cf);

        /*
         * ngx_conf_read_token() may return
         *
         *    NGX_ERROR             there is error
         *    NGX_OK                the token terminated by ";" was found
         *    NGX_CONF_BLOCK_START  the token terminated by "{" was found
         *    NGX_CONF_BLOCK_DONE   the "}" was found
         *    NGX_CONF_FILE_DONE    the configuration file is done
         */

        if (rc == NGX_ERROR) {
            goto done;
        }

        if (rc == NGX_CONF_BLOCK_DONE) {

            if (type != parse_block) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unexpected \"}\"");
                goto failed;
            }

            goto done;
        }

        if (rc == NGX_CONF_FILE_DONE) {

            if (type == parse_block) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "unexpected end of file, expecting \"}\"");
                goto failed;
            }

            goto done;
        }

        if (rc == NGX_CONF_BLOCK_START) {

            if (type == parse_param) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "block directives are not supported "
                                   "in -g option");
                goto failed;
            }
        }

        /* rc == NGX_OK || rc == NGX_CONF_BLOCK_START */

        if (cf->handler) {

            /*
             * the custom handler, i.e., that is used in the http's
             * "types { ... }" directive
             */

            if (rc == NGX_CONF_BLOCK_START) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unexpected \"{\"");
                goto failed;
            }

            rv = (*cf->handler)(cf, NULL, cf->handler_conf);
            if (rv == NGX_CONF_OK) {
                continue;
            }

            if (rv == NGX_CONF_ERROR) {
                goto failed;
            }

            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%s", rv);

            goto failed;
        }


        rc = ngx_conf_handler(cf, rc);

        if (rc == NGX_ERROR) {
            goto failed;
        }
    }

failed:

    rc = NGX_ERROR;

done:

    if (filename) {
        if (cf->conf_file->buffer->start) {
            ngx_free(cf->conf_file->buffer->start);
        }

        if (ngx_close_file(fd) == NGX_FILE_ERROR) {
            ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
                          ngx_close_file_n " %s failed",
                          filename->data);
            rc = NGX_ERROR;
        }

        cf->conf_file = prev;
    }

    if (rc == NGX_ERROR) {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static ngx_int_t
ngx_conf_handler(ngx_conf_t *cf, ngx_int_t last)
{
    char           *rv;
    void           *conf, **confp;
    ngx_uint_t      i, found;
    ngx_str_t      *name;
    ngx_command_t  *cmd;

    name = cf->args->elts;

    found = 0;

    for (i = 0; cf->cycle->modules[i]; i++) {

        cmd = cf->cycle->modules[i]->commands;
        if (cmd == NULL) {
            continue;
        }

        for ( /* void */ ; cmd->name.len; cmd++) {

            if (name->len != cmd->name.len) {
                continue;
            }

            if (ngx_strcmp(name->data, cmd->name.data) != 0) {
                continue;
            }

            found = 1;

            if (cf->cycle->modules[i]->type != NGX_CONF_MODULE
                && cf->cycle->modules[i]->type != cf->module_type)
            {
                continue;
            }

            /* is the directive's location right ? */

            if (!(cmd->type & cf->cmd_type)) {
                continue;
            }

            if (!(cmd->type & NGX_CONF_BLOCK) && last != NGX_OK) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                  "directive \"%s\" is not terminated by \";\"",
                                  name->data);
                return NGX_ERROR;
            }

            if ((cmd->type & NGX_CONF_BLOCK) && last != NGX_CONF_BLOCK_START) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "directive \"%s\" has no opening \"{\"",
                                   name->data);
                return NGX_ERROR;
            }

            /* is the directive's argument count right ? */

            if (!(cmd->type & NGX_CONF_ANY)) {

                if (cmd->type & NGX_CONF_FLAG) {

                    if (cf->args->nelts != 2) {
                        goto invalid;
                    }

                } else if (cmd->type & NGX_CONF_1MORE) {

                    if (cf->args->nelts < 2) {
                        goto invalid;
                    }

                } else if (cmd->type & NGX_CONF_2MORE) {

                    if (cf->args->nelts < 3) {
                        goto invalid;
                    }

                } else if (cf->args->nelts > NGX_CONF_MAX_ARGS) {

                    goto invalid;

                } else if (!(cmd->type & argument_number[cf->args->nelts - 1]))
                {
                    goto invalid;
                }
            }

            /* set up the directive's configuration context */

            conf = NULL;

            if (cmd->type & NGX_DIRECT_CONF) {
                conf = ((void **) cf->ctx)[cf->cycle->modules[i]->index];

            } else if (cmd->type & NGX_MAIN_CONF) {
                conf = &(((void **) cf->ctx)[cf->cycle->modules[i]->index]);

            } else if (cf->ctx) {
                confp = *(void **) ((char *) cf->ctx + cmd->conf);

                if (confp) {
                    conf = confp[cf->cycle->modules[i]->ctx_index];
                }
            }

            rv = cmd->set(cf, cmd, conf);

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

            if (rv == NGX_CONF_ERROR) {
                return NGX_ERROR;
            }

            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "\"%s\" directive %s", name->data, rv);

            return NGX_ERROR;
        }
    }

    if (found) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "\"%s\" directive is not allowed here", name->data);

        return NGX_ERROR;
    }

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "unknown directive \"%s\"", name->data);

    return NGX_ERROR;

invalid:

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "invalid number of arguments in \"%s\" directive",
                       name->data);

    return NGX_ERROR;
}


static ngx_int_t
ngx_conf_read_token(ngx_conf_t *cf)
{
    u_char      *start, ch, *src, *dst;
    off_t        file_size;
    size_t       len;
    ssize_t      n, size;
    ngx_uint_t   found, need_space, last_space, sharp_comment, variable;
    ngx_uint_t   quoted, s_quoted, d_quoted, start_line;
    ngx_str_t   *word;
    ngx_buf_t   *b, *dump;

    found = 0;
    need_space = 0;
    last_space = 1;
    sharp_comment = 0;
    variable = 0;
    quoted = 0;
    s_quoted = 0;
    d_quoted = 0;

    cf->args->nelts = 0;
    b = cf->conf_file->buffer;
    dump = cf->conf_file->dump;
    start = b->pos;
    start_line = cf->conf_file->line;

    file_size = ngx_file_size(&cf->conf_file->file.info);

    for ( ;; ) {

        if (b->pos >= b->last) {

            if (cf->conf_file->file.offset >= file_size) {

                if (cf->args->nelts > 0 || !last_space) {

                    if (cf->conf_file->file.fd == NGX_INVALID_FILE) {
                        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                           "unexpected end of parameter, "
                                           "expecting \";\"");
                        return NGX_ERROR;
                    }

                    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                  "unexpected end of file, "
                                  "expecting \";\" or \"}\"");
                    return NGX_ERROR;
                }

                return NGX_CONF_FILE_DONE;
            }

            len = b->pos - start;

            if (len == NGX_CONF_BUFFER) {
                cf->conf_file->line = start_line;

                if (d_quoted) {
                    ch = '"';

                } else if (s_quoted) {
                    ch = '\'';

                } else {
                    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                       "too long parameter \"%*s...\" started",
                                       10, start);
                    return NGX_ERROR;
                }

                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "too long parameter, probably "
                                   "missing terminating \"%c\" character", ch);
                return NGX_ERROR;
            }

            if (len) {
                ngx_memmove(b->start, start, len);
            }

            size = (ssize_t) (file_size - cf->conf_file->file.offset);

            if (size > b->end - (b->start + len)) {
                size = b->end - (b->start + len);
            }

            n = ngx_read_file(&cf->conf_file->file, b->start + len, size,
                              cf->conf_file->file.offset);

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

            if (n != size) {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   ngx_read_file_n " returned "
                                   "only %z bytes instead of %z",
                                   n, size);
                return NGX_ERROR;
            }

            b->pos = b->start + len;
            b->last = b->pos + n;
            start = b->start;

            if (dump) {
                dump->last = ngx_cpymem(dump->last, b->pos, size);
            }
        }

        ch = *b->pos++;

        if (ch == LF) {
            cf->conf_file->line++;

            if (sharp_comment) {
                sharp_comment = 0;
            }
        }

        if (sharp_comment) {
            continue;
        }

        if (quoted) {
            quoted = 0;
            continue;
        }

        if (need_space) {
            if (ch == ' ' || ch == '\t' || ch == CR || ch == LF) {
                last_space = 1;
                need_space = 0;
                continue;
            }

            if (ch == ';') {
                return NGX_OK;
            }

            if (ch == '{') {
                return NGX_CONF_BLOCK_START;
            }

            if (ch == ')') {
                last_space = 1;
                need_space = 0;

            } else {
                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                   "unexpected \"%c\"", ch);
                return NGX_ERROR;
            }
        }

        if (last_space) {

            start = b->pos - 1;
            start_line = cf->conf_file->line;

            if (ch == ' ' || ch == '\t' || ch == CR || ch == LF) {
                continue;
            }

            switch (ch) {

            case ';':
            case '{':
                if (cf->args->nelts == 0) {
                    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                       "unexpected \"%c\"", ch);
                    return NGX_ERROR;
                }

                if (ch == '{') {
                    return NGX_CONF_BLOCK_START;
                }

                return NGX_OK;

            case '}':
                if (cf->args->nelts != 0) {
                    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                       "unexpected \"}\"");
                    return NGX_ERROR;
                }

                return NGX_CONF_BLOCK_DONE;

            case '#':
                sharp_comment = 1;
                continue;

            case '\\':
                quoted = 1;
                last_space = 0;
                continue;

            case '"':
                start++;
                d_quoted = 1;
                last_space = 0;
                continue;

            case '\'':
                start++;
                s_quoted = 1;
                last_space = 0;
                continue;

            case '$':
                variable = 1;
                last_space = 0;
                continue;

            default:
                last_space = 0;
            }

        } else {
            if (ch == '{' && variable) {
                continue;
            }

            variable = 0;

            if (ch == '\\') {
                quoted = 1;
                continue;
            }

            if (ch == '$') {
                variable = 1;
                continue;
            }

            if (d_quoted) {
                if (ch == '"') {
                    d_quoted = 0;
                    need_space = 1;
                    found = 1;
                }

            } else if (s_quoted) {
                if (ch == '\'') {
                    s_quoted = 0;
                    need_space = 1;
                    found = 1;
                }

            } else if (ch == ' ' || ch == '\t' || ch == CR || ch == LF
                       || ch == ';' || ch == '{')
            {
                last_space = 1;
                found = 1;
            }

            if (found) {
                word = ngx_array_push(cf->args);
                if (word == NULL) {
                    return NGX_ERROR;
                }

                word->data = ngx_pnalloc(cf->pool, b->pos - 1 - start + 1);
                if (word->data == NULL) {
                    return NGX_ERROR;
                }

                for (dst = word->data, src = start, len = 0;
                     src < b->pos - 1;
                     len++)
                {
                    if (*src == '\\') {
                        switch (src[1]) {
                        case '"':
                        case '\'':
                        case '\\':
                            src++;
                            break;

                        case 't':
                            *dst++ = '\t';
                            src += 2;
                            continue;

                        case 'r':
                            *dst++ = '\r';
                            src += 2;
                            continue;

                        case 'n':
                            *dst++ = '\n';
                            src += 2;
                            continue;
                        }

                    }
                    *dst++ = *src++;
                }
                *dst = '\0';
                word->len = len;

                if (ch == ';') {
                    return NGX_OK;
                }

                if (ch == '{') {
                    return NGX_CONF_BLOCK_START;
                }

                found = 0;
            }
        }
    }
}


char *
ngx_conf_include(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char        *rv;
    ngx_int_t    n;
    ngx_str_t   *value, file, name;
    ngx_glob_t   gl;

    value = cf->args->elts;
    file = value[1];

    ngx_log_debug1(NGX_LOG_DEBUG_CORE, cf->log, 0, "include %s", file.data);

    if (ngx_conf_full_name(cf->cycle, &file, 1) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    if (strpbrk((char *) file.data, "*?[") == NULL) {

        ngx_log_debug1(NGX_LOG_DEBUG_CORE, cf->log, 0, "include %s", file.data);

        return ngx_conf_parse(cf, &file);
    }

    ngx_memzero(&gl, sizeof(ngx_glob_t));

    gl.pattern = file.data;
    gl.log = cf->log;
    gl.test = 1;

    if (ngx_open_glob(&gl) != NGX_OK) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                           ngx_open_glob_n " \"%s\" failed", file.data);
        return NGX_CONF_ERROR;
    }

    rv = NGX_CONF_OK;

    for ( ;; ) {
        n = ngx_read_glob(&gl, &name);

        if (n != NGX_OK) {
            break;
        }

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

        ngx_log_debug1(NGX_LOG_DEBUG_CORE, cf->log, 0, "include %s", file.data);

        rv = ngx_conf_parse(cf, &file);

        if (rv != NGX_CONF_OK) {
            break;
        }
    }

    ngx_close_glob(&gl);

    return rv;
}


ngx_int_t
ngx_conf_full_name(ngx_cycle_t *cycle, ngx_str_t *name, ngx_uint_t conf_prefix)
{
    ngx_str_t  *prefix;

    prefix = conf_prefix ? &cycle->conf_prefix : &cycle->prefix;

    return ngx_get_full_name(cycle->pool, prefix, name);
}


ngx_open_file_t *
ngx_conf_open_file(ngx_cycle_t *cycle, ngx_str_t *name)
{
    ngx_str_t         full;
    ngx_uint_t        i;
    ngx_list_part_t  *part;
    ngx_open_file_t  *file;

#if (NGX_SUPPRESS_WARN)
    ngx_str_null(&full);
#endif

    if (name->len) {
        full = *name;

        if (ngx_conf_full_name(cycle, &full, 0) != NGX_OK) {
            return NULL;
        }

        part = &cycle->open_files.part;
        file = part->elts;

        for (i = 0; /* void */ ; i++) {

            if (i >= part->nelts) {
                if (part->next == NULL) {
                    break;
                }
                part = part->next;
                file = part->elts;
                i = 0;
            }

            if (full.len != file[i].name.len) {
                continue;
            }

            if (ngx_strcmp(full.data, file[i].name.data) == 0) {
                return &file[i];
            }
        }
    }

    file = ngx_list_push(&cycle->open_files);
    if (file == NULL) {
        return NULL;
    }

    if (name->len) {
        file->fd = NGX_INVALID_FILE;
        file->name = full;

    } else {
        file->fd = ngx_stderr;
        file->name = *name;
    }

    file->flush = NULL;
    file->data = NULL;

    return file;
}


static void
ngx_conf_flush_files(ngx_cycle_t *cycle)
{
    ngx_uint_t        i;
    ngx_list_part_t  *part;
    ngx_open_file_t  *file;

    ngx_log_debug0(NGX_LOG_DEBUG_CORE, cycle->log, 0, "flush files");

    part = &cycle->open_files.part;
    file = part->elts;

    for (i = 0; /* void */ ; i++) {

        if (i >= part->nelts) {
            if (part->next == NULL) {
                break;
            }
            part = part->next;
            file = part->elts;
            i = 0;
        }

        if (file[i].flush) {
            file[i].flush(&file[i], cycle->log);
        }
    }
}


void ngx_cdecl
ngx_conf_log_error(ngx_uint_t level, ngx_conf_t *cf, ngx_err_t err,
    const char *fmt, ...)
{
    u_char   errstr[NGX_MAX_CONF_ERRSTR], *p, *last;
    va_list  args;

    last = errstr + NGX_MAX_CONF_ERRSTR;

    va_start(args, fmt);
    p = ngx_vslprintf(errstr, last, fmt, args);
    va_end(args);

    if (err) {
        p = ngx_log_errno(p, last, err);
    }

    if (cf->conf_file == NULL) {
        ngx_log_error(level, cf->log, 0, "%*s", p - errstr, errstr);
        return;
    }

    if (cf->conf_file->file.fd == NGX_INVALID_FILE) {
        ngx_log_error(level, cf->log, 0, "%*s in command line",
                      p - errstr, errstr);
        return;
    }

    ngx_log_error(level, cf->log, 0, "%*s in %s:%ui",
                  p - errstr, errstr,
                  cf->conf_file->file.name.data, cf->conf_file->line);
}


char *
ngx_conf_set_flag_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_str_t        *value;
    ngx_flag_t       *fp;
    ngx_conf_post_t  *post;

    fp = (ngx_flag_t *) (p + cmd->offset);

    if (*fp != NGX_CONF_UNSET) {
        return "is duplicate";
    }

    value = cf->args->elts;

    if (ngx_strcasecmp(value[1].data, (u_char *) "on") == 0) {
        *fp = 1;

    } else if (ngx_strcasecmp(value[1].data, (u_char *) "off") == 0) {
        *fp = 0;

    } else {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                     "invalid value \"%s\" in \"%s\" directive, "
                     "it must be \"on\" or \"off\"",
                     value[1].data, cmd->name.data);
        return NGX_CONF_ERROR;
    }

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, fp);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_str_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_str_t        *field, *value;
    ngx_conf_post_t  *post;

    field = (ngx_str_t *) (p + cmd->offset);

    if (field->data) {
        return "is duplicate";
    }

    value = cf->args->elts;

    *field = value[1];

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, field);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_str_array_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_str_t         *value, *s;
    ngx_array_t      **a;
    ngx_conf_post_t   *post;

    a = (ngx_array_t **) (p + cmd->offset);

    if (*a == NGX_CONF_UNSET_PTR) {
        *a = ngx_array_create(cf->pool, 4, sizeof(ngx_str_t));
        if (*a == NULL) {
            return NGX_CONF_ERROR;
        }
    }

    s = ngx_array_push(*a);
    if (s == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;

    *s = value[1];

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, s);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_keyval_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_str_t         *value;
    ngx_array_t      **a;
    ngx_keyval_t      *kv;
    ngx_conf_post_t   *post;

    a = (ngx_array_t **) (p + cmd->offset);

    if (*a == NGX_CONF_UNSET_PTR || *a == NULL) {
        *a = ngx_array_create(cf->pool, 4, sizeof(ngx_keyval_t));
        if (*a == NULL) {
            return NGX_CONF_ERROR;
        }
    }

    kv = ngx_array_push(*a);
    if (kv == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;

    kv->key = value[1];
    kv->value = value[2];

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, kv);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_num_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_int_t        *np;
    ngx_str_t        *value;
    ngx_conf_post_t  *post;


    np = (ngx_int_t *) (p + cmd->offset);

    if (*np != NGX_CONF_UNSET) {
        return "is duplicate";
    }

    value = cf->args->elts;
    *np = ngx_atoi(value[1].data, value[1].len);
    if (*np == NGX_ERROR) {
        return "invalid number";
    }

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, np);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_size_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    size_t           *sp;
    ngx_str_t        *value;
    ngx_conf_post_t  *post;


    sp = (size_t *) (p + cmd->offset);
    if (*sp != NGX_CONF_UNSET_SIZE) {
        return "is duplicate";
    }

    value = cf->args->elts;

    *sp = ngx_parse_size(&value[1]);
    if (*sp == (size_t) NGX_ERROR) {
        return "invalid value";
    }

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, sp);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_off_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    off_t            *op;
    ngx_str_t        *value;
    ngx_conf_post_t  *post;


    op = (off_t *) (p + cmd->offset);
    if (*op != NGX_CONF_UNSET) {
        return "is duplicate";
    }

    value = cf->args->elts;

    *op = ngx_parse_offset(&value[1]);
    if (*op == (off_t) NGX_ERROR) {
        return "invalid value";
    }

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, op);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_msec_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_msec_t       *msp;
    ngx_str_t        *value;
    ngx_conf_post_t  *post;


    msp = (ngx_msec_t *) (p + cmd->offset);
    if (*msp != NGX_CONF_UNSET_MSEC) {
        return "is duplicate";
    }

    value = cf->args->elts;

    *msp = ngx_parse_time(&value[1], 0);
    if (*msp == (ngx_msec_t) NGX_ERROR) {
        return "invalid value";
    }

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, msp);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_sec_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    time_t           *sp;
    ngx_str_t        *value;
    ngx_conf_post_t  *post;


    sp = (time_t *) (p + cmd->offset);
    if (*sp != NGX_CONF_UNSET) {
        return "is duplicate";
    }

    value = cf->args->elts;

    *sp = ngx_parse_time(&value[1], 1);
    if (*sp == (time_t) NGX_ERROR) {
        return "invalid value";
    }

    if (cmd->post) {
        post = cmd->post;
        return post->post_handler(cf, post, sp);
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_bufs_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char *p = conf;

    ngx_str_t   *value;
    ngx_bufs_t  *bufs;


    bufs = (ngx_bufs_t *) (p + cmd->offset);
    if (bufs->num) {
        return "is duplicate";
    }

    value = cf->args->elts;

    bufs->num = ngx_atoi(value[1].data, value[1].len);
    if (bufs->num == NGX_ERROR || bufs->num == 0) {
        return "invalid value";
    }

    bufs->size = ngx_parse_size(&value[2]);
    if (bufs->size == (size_t) NGX_ERROR || bufs->size == 0) {
        return "invalid value";
    }

    return NGX_CONF_OK;
}


char *
ngx_conf_set_enum_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_uint_t       *np, i;
    ngx_str_t        *value;
    ngx_conf_enum_t  *e;

    np = (ngx_uint_t *) (p + cmd->offset);

    if (*np != NGX_CONF_UNSET_UINT) {
        return "is duplicate";
    }

    value = cf->args->elts;
    e = cmd->post;

    for (i = 0; e[i].name.len != 0; i++) {
        if (e[i].name.len != value[1].len
            || ngx_strcasecmp(e[i].name.data, value[1].data) != 0)
        {
            continue;
        }

        *np = e[i].value;

        return NGX_CONF_OK;
    }

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "invalid value \"%s\"", value[1].data);

    return NGX_CONF_ERROR;
}


char *
ngx_conf_set_bitmask_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_uint_t          *np, i, m;
    ngx_str_t           *value;
    ngx_conf_bitmask_t  *mask;


    np = (ngx_uint_t *) (p + cmd->offset);
    value = cf->args->elts;
    mask = cmd->post;

    for (i = 1; i < cf->args->nelts; i++) {
        for (m = 0; mask[m].name.len != 0; m++) {

            if (mask[m].name.len != value[i].len
                || ngx_strcasecmp(mask[m].name.data, value[i].data) != 0)
            {
                continue;
            }

            if (*np & mask[m].mask) {
                ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                                   "duplicate value \"%s\"", value[i].data);

            } else {
                *np |= mask[m].mask;
            }

            break;
        }

        if (mask[m].name.len == 0) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid value \"%s\"", value[i].data);

            return NGX_CONF_ERROR;
        }
    }

    return NGX_CONF_OK;
}


#if 0

char *
ngx_conf_unsupported(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    return "unsupported on this platform";
}

#endif


char *
ngx_conf_deprecated(ngx_conf_t *cf, void *post, void *data)
{
    ngx_conf_deprecated_t  *d = post;

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

    return NGX_CONF_OK;
}


char *
ngx_conf_check_num_bounds(ngx_conf_t *cf, void *post, void *data)
{
    ngx_conf_num_bounds_t  *bounds = post;
    ngx_int_t  *np = data;

    if (bounds->high == -1) {
        if (*np >= bounds->low) {
            return NGX_CONF_OK;
        }

        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "value must be equal to or greater than %i",
                           bounds->low);

        return NGX_CONF_ERROR;
    }

    if (*np >= bounds->low && *np <= bounds->high) {
        return NGX_CONF_OK;
    }

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "value must be between %i and %i",
                       bounds->low, bounds->high);

    return NGX_CONF_ERROR;
}