Quelle cgi_common.h Sprache: C

/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#include "apr.h"
#include "apr_strings.h"
#include "apr_buckets.h"
#include "apr_lib.h"
#include "apr_poll.h"

#define APR_WANT_STRFUNC
#define APR_WANT_MEMFUNC
#include "apr_want.h"

#include "httpd.h"
#include "util_filter.h"
#include "util_script.h"

static APR_OPTIONAL_FN_TYPE(ap_ssi_get_tag_and_value) *cgi_pfn_gtv;
static APR_OPTIONAL_FN_TYPE(ap_ssi_parse_string) *cgi_pfn_ps;

/* These functions provided by mod_cgi.c/mod_cgid.c still. */
static int log_script(request_rec *r, cgi_server_conf * conf, int ret,
                      char *dbuf, const char *sbuf, apr_bucket_brigade *bb,
                      apr_file_t *script_err);
static apr_status_t include_cgi(include_ctx_t *ctx, ap_filter_t *f,
                                apr_bucket_brigade *bb, char *s);
static apr_status_t include_cmd(include_ctx_t *ctx, ap_filter_t *f,
                                apr_bucket_brigade *bb, const char *command);

/* Read and discard all output from the brigade.  Note that with the
* CGI bucket, the brigade will become empty once the script's stdout
* is closed (or on error/timeout), but the stderr output may not have
* been entirely captured at this point. */
static void discard_script_output(apr_bucket_brigade *bb)
{
    apr_bucket *e;
    const char *buf;
    apr_size_t len;

    for (e = APR_BRIGADE_FIRST(bb);
         e != APR_BRIGADE_SENTINEL(bb) && !APR_BUCKET_IS_EOS(e);
         e = APR_BRIGADE_FIRST(bb))
    {
        if (apr_bucket_read(e, &buf, &len, APR_BLOCK_READ)) {
            break;
        }
        apr_bucket_delete(e);
    }
}

static int log_scripterror(request_rec *r, cgi_server_conf *conf, int ret,
                           apr_status_t rv, const char *logno,
                           const char *error)
{
    apr_file_t *f = NULL;
    apr_finfo_t finfo;
    char time_str[APR_CTIME_LEN];

    /* Intentional no APLOGNO */
    /* Callee provides APLOGNO in error text */
    ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                  "%sstderr from %s: %s", logno ? logno : "", r->filename, error);

    /* XXX Very expensive mainline case! Open, then getfileinfo! */
    if (!conf->logname ||
        ((apr_stat(&finfo, conf->logname,
                   APR_FINFO_SIZE, r->pool) == APR_SUCCESS) &&
         (finfo.size > conf->logbytes)) ||
        (apr_file_open(&f, conf->logname,
                       APR_APPEND|APR_WRITE|APR_CREATE, APR_OS_DEFAULT,
                       r->pool) != APR_SUCCESS)) {
        return ret;
    }

    /* "%% [Wed Jun 19 10:53:21 1996] GET /cgi-bin/printenv HTTP/1.0" */
    apr_ctime(time_str, apr_time_now());
    apr_file_printf(f, "%%%% [%s] %s %s%s%s %s\n", time_str, r->method, r->uri,
                    r->args ? "?" : "", r->args ? r->args : "", r->protocol);
    /* "%% 500 /usr/local/apache/cgi-bin */
    apr_file_printf(f, "%%%% %d %s\n", ret, r->filename);

    apr_file_printf(f, "%%error\n%s\n", error);

    apr_file_close(f);
    return ret;
}

/* Soak up stderr from a script and redirect it to the error log.
*/
static apr_status_t log_script_err(request_rec *r, apr_file_t *script_err)
{
    char argsbuffer[HUGE_STRING_LEN];
    char *newline;
    apr_status_t rv;
    cgi_server_conf *conf = ap_get_module_config(r->server->module_config, &cgi_module);

    while ((rv = apr_file_gets(argsbuffer, HUGE_STRING_LEN,
                               script_err)) == APR_SUCCESS) {

        newline = strchr(argsbuffer, '\n');
        if (newline) {
            char *prev = newline - 1;
            if (prev >= argsbuffer && *prev == '\r') {
                newline = prev;
            }

            *newline = '\0';
        }
        log_scripterror(r, conf, r->status, 0, APLOGNO(01215), argsbuffer);
    }

    return rv;
}

static apr_status_t cgi_handle_exec(include_ctx_t *ctx, ap_filter_t *f,
                                    apr_bucket_brigade *bb)
{
    char *tag = NULL;
    char *tag_val = NULL;
    request_rec *r = f->r;
    char *file = r->filename;
    char parsed_string[MAX_STRING_LEN];

    if (!ctx->argc) {
        ap_log_rerror(APLOG_MARK,
                      (ctx->flags & SSI_FLAG_PRINTING)
                          ? APLOG_ERR : APLOG_WARNING,
                      0, r, APLOGNO(03195)
                      "missing argument for exec element in %s", r->filename);
    }

    if (!(ctx->flags & SSI_FLAG_PRINTING)) {
        return APR_SUCCESS;
    }

    if (!ctx->argc) {
        SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
        return APR_SUCCESS;
    }

    if (ctx->flags & SSI_FLAG_NO_EXEC) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01228) "exec used but not allowed "
                      "in %s", r->filename);
        SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
        return APR_SUCCESS;
    }

    while (1) {
        cgi_pfn_gtv(ctx, &tag, &tag_val, SSI_VALUE_DECODED);
        if (!tag || !tag_val) {
            break;
        }

        if (!strcmp(tag, "cmd")) {
            apr_status_t rv;

            cgi_pfn_ps(ctx, tag_val, parsed_string, sizeof(parsed_string),
                       SSI_EXPAND_LEAVE_NAME);

            rv = include_cmd(ctx, f, bb, parsed_string);
            if (rv != APR_SUCCESS) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01229) "execution failure "
                              "for parameter \"%s\" to tag exec in file %s",
                              tag, r->filename);
                SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
                break;
            }
        }
        else if (!strcmp(tag, "cgi")) {
            apr_status_t rv;

            cgi_pfn_ps(ctx, tag_val, parsed_string, sizeof(parsed_string),
                       SSI_EXPAND_DROP_NAME);

            rv = include_cgi(ctx, f, bb, parsed_string);
            if (rv != APR_SUCCESS) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01230) "invalid CGI ref "
                              "\"%s\" in %s", tag_val, file);
                SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
                break;
            }
        }
        else {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01231) "unknown parameter "
                          "\"%s\" to tag exec in %s", tag, file);
            SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
            break;
        }
    }

    return APR_SUCCESS;
}

/* Hook to register exec= handling with mod_include. */
static void cgi_optfns_retrieve(void)
{
    APR_OPTIONAL_FN_TYPE(ap_register_include_handler) *cgi_pfn_reg_with_ssi;

    cgi_pfn_reg_with_ssi = APR_RETRIEVE_OPTIONAL_FN(ap_register_include_handler);
    cgi_pfn_gtv          = APR_RETRIEVE_OPTIONAL_FN(ap_ssi_get_tag_and_value);
    cgi_pfn_ps           = APR_RETRIEVE_OPTIONAL_FN(ap_ssi_parse_string);

    if (cgi_pfn_reg_with_ssi && cgi_pfn_gtv && cgi_pfn_ps) {
        /* Required by mod_include filter. This is how mod_cgi registers
         *   with mod_include to provide processing of the exec directive.
         */
        cgi_pfn_reg_with_ssi("exec", cgi_handle_exec);
    }
}

#ifdef WANT_CGI_BUCKET
/* A CGI bucket type is needed to catch any output to stderr from the
* script; see PR 22030. */
static const apr_bucket_type_t bucket_type_cgi;

struct cgi_bucket_data {
    apr_pollset_t *pollset;
    request_rec *r;
    apr_interval_time_t timeout;
};

/* Create a CGI bucket using pipes from script stdout 'out'
* and stderr 'err', for request 'r'. */
static apr_bucket *cgi_bucket_create(request_rec *r,
                                     apr_interval_time_t timeout,
                                     apr_file_t *out, apr_file_t *err,
                                     apr_bucket_alloc_t *list)
{
    apr_bucket *b = apr_bucket_alloc(sizeof(*b), list);
    apr_status_t rv;
    apr_pollfd_t fd;
    struct cgi_bucket_data *data = apr_palloc(r->pool, sizeof *data);

    /* Disable APR timeout handling since we'll use poll() entirely. */
    apr_file_pipe_timeout_set(out, 0);
    apr_file_pipe_timeout_set(err, 0);

    APR_BUCKET_INIT(b);
    b->free = apr_bucket_free;
    b->list = list;
    b->type = &bucket_type_cgi;
    b->length = (apr_size_t)(-1);
    b->start = -1;

    /* Create the pollset */
    rv = apr_pollset_create(&data->pollset, 2, r->pool, 0);
    if (rv != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01217)
                     "apr_pollset_create(); check system or user limits");
        return NULL;
    }

    fd.desc_type = APR_POLL_FILE;
    fd.reqevents = APR_POLLIN;
    fd.p = r->pool;
    fd.desc.f = out; /* script's stdout */
    fd.client_data = (void *)1;
    rv = apr_pollset_add(data->pollset, &fd);
    if (rv != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01218)
                     "apr_pollset_add(); check system or user limits");
        return NULL;
    }

    fd.desc.f = err; /* script's stderr */
    fd.client_data = (void *)2;
    rv = apr_pollset_add(data->pollset, &fd);
    if (rv != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01219)
                     "apr_pollset_add(); check system or user limits");
        return NULL;
    }

    data->r = r;
    data->timeout = timeout;
    b->data = data;
    return b;
}

/* Create a duplicate CGI bucket using given bucket data */
static apr_bucket *cgi_bucket_dup(struct cgi_bucket_data *data,
                                  apr_bucket_alloc_t *list)
{
    apr_bucket *b = apr_bucket_alloc(sizeof(*b), list);
    APR_BUCKET_INIT(b);
    b->free = apr_bucket_free;
    b->list = list;
    b->type = &bucket_type_cgi;
    b->length = (apr_size_t)(-1);
    b->start = -1;
    b->data = data;
    return b;
}

/* Handle stdout from CGI child.  Duplicate of logic from the _read
* method of the real APR pipe bucket implementation. */
static apr_status_t cgi_read_stdout(apr_bucket *a, apr_file_t *out,
                                    const char **str, apr_size_t *len)
{
    char *buf;
    apr_status_t rv;

    *str = NULL;
    *len = APR_BUCKET_BUFF_SIZE;
    buf = apr_bucket_alloc(*len, a->list); /* XXX: check for failure? */

    rv = apr_file_read(out, buf, len);

    if (rv != APR_SUCCESS && rv != APR_EOF) {
        apr_bucket_free(buf);
        return rv;
    }

    if (*len > 0) {
        struct cgi_bucket_data *data = a->data;
        apr_bucket_heap *h;

        /* Change the current bucket to refer to what we read */
        a = apr_bucket_heap_make(a, buf, *len, apr_bucket_free);
        h = a->data;
        h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */
        *str = buf;
        APR_BUCKET_INSERT_AFTER(a, cgi_bucket_dup(data, a->list));
    }
    else {
        apr_bucket_free(buf);
        a = apr_bucket_immortal_make(a, "", 0);
        *str = a->data;
    }
    return rv;
}

/* Read method of CGI bucket: polls on stderr and stdout of the child,
* sending any stderr output immediately away to the error log. */
static apr_status_t cgi_bucket_read(apr_bucket *b, const char **str,
                                    apr_size_t *len, apr_read_type_e block)
{
    struct cgi_bucket_data *data = b->data;
    apr_interval_time_t timeout = 0;
    apr_status_t rv;
    int gotdata = 0;

    if (block != APR_NONBLOCK_READ) {
        timeout = data->timeout > 0 ? data->timeout : data->r->server->timeout;
    }

    do {
        const apr_pollfd_t *results;
        apr_int32_t num;

        rv = apr_pollset_poll(data->pollset, timeout, &num, &results);
        if (APR_STATUS_IS_TIMEUP(rv)) {
            if (timeout) {
                ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, data->r, APLOGNO(01220)
                              "Timeout waiting for output from CGI script %s",
                              data->r->filename);
                return rv;
            }
            else {
                return APR_EAGAIN;
            }
        }
        else if (APR_STATUS_IS_EINTR(rv)) {
            continue;
        }
        else if (rv != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, data->r, APLOGNO(01221)
                          "poll failed waiting for CGI child");
            return rv;
        }

        for (; num; num--, results++) {
            if (results[0].client_data == (void *)1) {
                /* stdout */
                rv = cgi_read_stdout(b, results[0].desc.f, str, len);
                if (APR_STATUS_IS_EOF(rv)) {
                    rv = APR_SUCCESS;
                }
                gotdata = 1;
            } else {
                /* stderr */
                apr_status_t rv2 = log_script_err(data->r, results[0].desc.f);
                if (APR_STATUS_IS_EOF(rv2)) {
                    apr_pollset_remove(data->pollset, &results[0]);
                }
            }
        }

    } while (!gotdata);

    return rv;
}

static const apr_bucket_type_t bucket_type_cgi = {
    "CGI", 5, APR_BUCKET_DATA,
    apr_bucket_destroy_noop,
    cgi_bucket_read,
    apr_bucket_setaside_notimpl,
    apr_bucket_split_notimpl,
    apr_bucket_copy_notimpl
};

#endif /* WANT_CGI_BUCKET */

/* Handle the CGI response output, having set up the brigade with the
* CGI or PIPE bucket as appropriate. */
static int cgi_handle_response(request_rec *r, int nph, apr_bucket_brigade *bb,
                               apr_interval_time_t timeout, cgi_server_conf *conf,
                               char *logdata, apr_file_t *script_err)
{
    apr_status_t rv;

    /* Handle script return... */
    if (!nph) {
        const char *location;
        char sbuf[MAX_STRING_LEN];
        int ret;

        ret = ap_scan_script_header_err_brigade_ex(r, bb, sbuf,
                                                   APLOG_MODULE_INDEX);

        /* xCGI has its own body framing mechanism which we don't
         * match against any provided Content-Length, so let the
         * core determine C-L vs T-E based on what's actually sent.
         */
        if (!apr_table_get(r->subprocess_env, AP_TRUST_CGILIKE_CL_ENVVAR))
            apr_table_unset(r->headers_out, "Content-Length");
        apr_table_unset(r->headers_out, "Transfer-Encoding");

        if (ret != OK) {
            /* In the case of a timeout reading script output, clear
             * the brigade to avoid a second attempt to read the
             * output. */
            if (ret == HTTP_GATEWAY_TIME_OUT) {
                apr_brigade_cleanup(bb);
            }

            ret = log_script(r, conf, ret, logdata, sbuf, bb, script_err);

            /*
             * ret could be HTTP_NOT_MODIFIED in the case that the CGI script
             * does not set an explicit status and ap_meets_conditions, which
             * is called by ap_scan_script_header_err_brigade, detects that
             * the conditions of the requests are met and the response is
             * not modified.
             * In this case set r->status and return OK in order to prevent
             * running through the error processing stack as this would
             * break with mod_cache, if the conditions had been set by
             * mod_cache itself to validate a stale entity.
             * BTW: We circumvent the error processing stack anyway if the
             * CGI script set an explicit status code (whatever it is) and
             * the only possible values for ret here are:
             *
             * HTTP_NOT_MODIFIED          (set by ap_meets_conditions)
             * HTTP_PRECONDITION_FAILED   (set by ap_meets_conditions)
             * HTTP_INTERNAL_SERVER_ERROR (if something went wrong during the
             * processing of the response of the CGI script, e.g broken headers
             * or a crashed CGI process).
             */
            if (ret == HTTP_NOT_MODIFIED) {
                r->status = ret;
                return OK;
            }

            return ret;
        }

        location = apr_table_get(r->headers_out, "Location");

        if (location && r->status == 200) {
            /* For a redirect whether internal or not, discard any
             * remaining stdout from the script, and log any remaining
             * stderr output, as normal. */
            discard_script_output(bb);
            apr_brigade_destroy(bb);

            if (script_err) {
                apr_file_pipe_timeout_set(script_err, timeout);
                log_script_err(r, script_err);
            }
        }

        if (location && location[0] == '/' && r->status == 200) {
            /* This redirect needs to be a GET no matter what the original
             * method was.
             */
            r->method = "GET";
            r->method_number = M_GET;

            /* We already read the message body (if any), so don't allow
             * the redirected request to think it has one.  We can ignore
             * Transfer-Encoding, since we used REQUEST_CHUNKED_ERROR.
             */
            apr_table_unset(r->headers_in, "Content-Length");

            ap_internal_redirect_handler(location, r);
            return OK;
        }
        else if (location && r->status == 200) {
            /* XXX: Note that if a script wants to produce its own Redirect
             * body, it now has to explicitly *say* "Status: 302"
             */
            discard_script_output(bb);
            apr_brigade_destroy(bb);
            return HTTP_MOVED_TEMPORARILY;
        }

        rv = ap_pass_brigade(r->output_filters, bb);
    }
    else /* nph */ {
        struct ap_filter_t *cur;

        /* get rid of all filters up through protocol...  since we
         * haven't parsed off the headers, there is no way they can
         * work
         */

        cur = r->proto_output_filters;
        while (cur && cur->frec->ftype < AP_FTYPE_CONNECTION) {
            cur = cur->next;
        }
        r->output_filters = r->proto_output_filters = cur;

        rv = ap_pass_brigade(r->output_filters, bb);
    }

    /* don't soak up script output if errors occurred writing it
     * out...  otherwise, we prolong the life of the script when the
     * connection drops or we stopped sending output for some other
     * reason */
    if (script_err && rv == APR_SUCCESS && !r->connection->aborted) {
        apr_file_pipe_timeout_set(script_err, timeout);
        log_script_err(r, script_err);
    }

    if (script_err) apr_file_close(script_err);

    return OK;                      /* NOT r->status, even if it has changed. */
}

/* Read the request body and write it to fd 'script_out', using 'bb'
* as temporary bucket brigade.  If 'logbuf' is non-NULL, the first
* logbufbytes of stdout are stored in logbuf. */
static apr_status_t cgi_handle_request(request_rec *r, apr_file_t *script_out,
                                       apr_bucket_brigade *bb,
                                       char *logbuf, apr_size_t logbufbytes)
{
    int seen_eos = 0;
    int child_stopped_reading = 0;
    apr_status_t rv;
    int dbpos = 0;

    do {
        apr_bucket *bucket;

        rv = ap_get_brigade(r->input_filters, bb, AP_MODE_READBYTES,
                            APR_BLOCK_READ, HUGE_STRING_LEN);

        if (rv != APR_SUCCESS) {
            return rv;
        }

        for (bucket = APR_BRIGADE_FIRST(bb);
             bucket != APR_BRIGADE_SENTINEL(bb);
             bucket = APR_BUCKET_NEXT(bucket))
        {
            const char *data;
            apr_size_t len;

            if (APR_BUCKET_IS_EOS(bucket)) {
                seen_eos = 1;
                break;
            }

            /* We can't do much with this. */
            if (APR_BUCKET_IS_FLUSH(bucket)) {
                continue;
            }

            /* If the child stopped, we still must read to EOS. */
            if (child_stopped_reading) {
                continue;
            }

            /* read */
            rv = apr_bucket_read(bucket, &data, &len, APR_BLOCK_READ);
            if (rv) {
                return rv;
            }

            if (logbufbytes && dbpos < logbufbytes) {
                int cursize;

                if ((dbpos + len) > logbufbytes) {
                    cursize = logbufbytes - dbpos;
                }
                else {
                    cursize = len;
                }
                memcpy(logbuf + dbpos, data, cursize);
                dbpos += cursize;
            }

            /* Keep writing data to the child until done or too much time
             * elapses with no progress or an error occurs.
             */
            rv = apr_file_write_full(script_out, data, len, NULL);

            if (rv != APR_SUCCESS) {
                /* silly script stopped reading, soak up remaining message */
                child_stopped_reading = 1;
                ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(02651)
                              "Error writing request body to script %s",
                              r->filename);
            }
        }
        apr_brigade_cleanup(bb);
    }
    while (!seen_eos);

    if (logbuf) {
        logbuf[dbpos] = '\0';
    }

    return APR_SUCCESS;
}

quality90%

¤ Dauer der Verarbeitung: 0.3 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.