view src/core/ngx_conf_file.c @ 9203:0de20f43db25

Fixed request termination with AIO and subrequests (ticket #2555). When a request was terminated due to an error via ngx_http_terminate_request() while an AIO operation was running in a subrequest, various issues were observed. This happened because ngx_http_request_finalizer() was only set in the subrequest where ngx_http_terminate_request() was called, but not in the subrequest where the AIO operation was running. After completion of the AIO operation normal processing of the subrequest was resumed, leading to issues. In particular, in case of the upstream module, termination of the request called upstream cleanup, which closed the upstream connection. Attempts to further work with the upstream connection after AIO operation completion resulted in segfaults in ngx_ssl_recv(), "readv() failed (9: Bad file descriptor) while reading upstream" errors, or socket leaks. In ticket #2555, issues were observed with the following configuration with cache background update (with thread writing instrumented to introduce a delay, when a client closes the connection during an update): location = /background-and-aio-write { proxy_pass ... proxy_cache one; proxy_cache_valid 200 1s; proxy_cache_background_update on; proxy_cache_use_stale updating; aio threads; aio_write on; limit_rate 1000; } Similarly, the same issue can be seen with SSI, and can be caused by errors in subrequests, such as in the following configuration (where "/proxy" uses AIO, and "/sleep" returns 444 after some delay, causing request termination): location = /ssi-active-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/proxy" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Or the same with both AIO operation and the error in non-active subrequests (which needs slightly different handling, see below): location = /ssi-non-active-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static" --> <!--#include virtual="/proxy" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Similarly, issues can be observed with just static files. However, with static files potential impact is limited due to timeout safeguards in ngx_http_writer(), and the fact that c->error is set during request termination. In a simple configuration with an AIO operation in the active subrequest, such as in the following configuration, the connection is closed right after completion of the AIO operation anyway, since ngx_http_writer() tries to write to the connection and fails due to c->error set: location = /ssi-active-static-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static-aio" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } In the following configuration, with an AIO operation in a non-active subrequest, the connection is closed only after send_timeout expires: location = /ssi-non-active-static-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static" --> <!--#include virtual="/static-aio" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Fix is to introduce r->main->terminated flag, which is to be checked by AIO event handlers when the r->main->blocked counter is decremented. When the flag is set, handlers are expected to wake up the connection instead of the subrequest (which might be already cleaned up). Additionally, now ngx_http_request_finalizer() is always set in the active subrequest, so waking up the connection properly finalizes the request even if termination happened in a non-active subrequest.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 30 Jan 2024 03:20:05 +0300
parents 3108d4d668e4
children
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;
}