view src/core/ngx_conf_file.c @ 7119:fef61d26da39

Fixed buffer overread with unix sockets after accept(). Some OSes (notably macOS, NetBSD, and Solaris) allow unix socket addresses larger than struct sockaddr_un. Moreover, some of them (macOS, Solaris) return socklen of the socket address before it was truncated to fit the buffer provided. As such, on these systems socklen must not be used without additional check that it is within the buffer provided. Appropriate checks added to ngx_event_accept() (after accept()), ngx_event_recvmsg() (after recvmsg()), and ngx_set_inherited_sockets() (after getsockname()). We also obtain socket addresses via getsockname() in ngx_connection_local_sockaddr(), but it does not need any checks as it is only used for INET and INET6 sockets (as there can be no wildcard unix sockets).
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 04 Oct 2017 21:19:33 +0300
parents 577628e6b6a6
children d91a8c4ac6bb
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, 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) {
            if (ch == ' ' || ch == '\t' || ch == CR || ch == LF) {
                continue;
            }

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

            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;

            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 == 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;
}