mod_cgi.c

apache简化版

/* ====================================================================
 * Copyright (c) 1995-1998 The Apache Group.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 */

/*
 * http_script: keeps all script-related ramblings together.
 * 
 * Compliant to CGI/1.1 spec
 * 
 * Adapted by rst from original NCSA code by Rob McCool
 *
 * Apache adds some new env vars; REDIRECT_URL and REDIRECT_QUERY_STRING for
 * custom error responses, and DOCUMENT_ROOT because we found it useful.
 * It also adds SERVER_ADMIN - useful for scripts to know who to mail when 
 * they fail.
 */

#include "httpd.h"
#include "http_config.h"
#include "http_request.h"
#include "http_core.h"
#include "http_protocol.h"
#include "http_main.h"
#include "http_log.h"
#include "util_script.h"
#include "http_conf_globals.h"

module MODULE_VAR_EXPORT cgi_module;

/* KLUDGE --- for back-combatibility, we don't have to check ExecCGI
 * in ScriptAliased directories, which means we need to know if this
 * request came through ScriptAlias or not... so the Alias module
 * leaves a note for us.
 */

static int is_scriptaliased(request_rec *r)
{
    const char *t = ap_table_get(r->notes, "alias-forced-type");
    return t && (!strcasecmp(t, "cgi-script"));
}

/* Configuration stuff */

#define DEFAULT_LOGBYTES 10385760
#define DEFAULT_BUFBYTES 1024

typedef struct {
    char *logname;
    long logbytes;
    int bufbytes;
} cgi_server_conf;

static void *create_cgi_config(pool *p, server_rec *s)
{
    cgi_server_conf *c =
    (cgi_server_conf *) ap_pcalloc(p, sizeof(cgi_server_conf));

    c->logname = NULL;
    c->logbytes = DEFAULT_LOGBYTES;
    c->bufbytes = DEFAULT_BUFBYTES;

    return c;
}

static void *merge_cgi_config(pool *p, void *basev, void *overridesv)
{
    cgi_server_conf *base = (cgi_server_conf *) basev, *overrides = (cgi_server_conf *) overridesv;

    return overrides->logname ? overrides : base;
}

static const char *set_scriptlog(cmd_parms *cmd, void *dummy, char *arg)
{
    server_rec *s = cmd->server;
    cgi_server_conf *conf =
    (cgi_server_conf *) ap_get_module_config(s->module_config, &cgi_module);

    conf->logname = arg;
    return NULL;
}

static const char *set_scriptlog_length(cmd_parms *cmd, void *dummy, char *arg)
{
    server_rec *s = cmd->server;
    cgi_server_conf *conf =
    (cgi_server_conf *) ap_get_module_config(s->module_config, &cgi_module);

    conf->logbytes = atol(arg);
    return NULL;
}

static const char *set_scriptlog_buffer(cmd_parms *cmd, void *dummy, char *arg)
{
    server_rec *s = cmd->server;
    cgi_server_conf *conf =
    (cgi_server_conf *) ap_get_module_config(s->module_config, &cgi_module);

    conf->bufbytes = atoi(arg);
    return NULL;
}

static const command_rec cgi_cmds[] =
{
    {"ScriptLog", set_scriptlog, NULL, RSRC_CONF, TAKE1,
     "the name of a log for script debugging info"},
    {"ScriptLogLength", set_scriptlog_length, NULL, RSRC_CONF, TAKE1,
     "the maximum length (in bytes) of the script debug log"},
    {"ScriptLogBuffer", set_scriptlog_buffer, NULL, RSRC_CONF, TAKE1,
     "the maximum size (in bytes) to record of a POST request"},
    {NULL}
};

static int log_scripterror(request_rec *r, cgi_server_conf * conf, int ret,
			   int show_errno, char *error)
{
    FILE *f;
    struct stat finfo;

    ap_log_rerror(APLOG_MARK, show_errno|APLOG_ERR, r, 
		"%s: %s", error, r->filename);

    if (!conf->logname ||
	((stat(ap_server_root_relative(r->pool, conf->logname), &finfo) == 0)
	 &&   (finfo.st_size > conf->logbytes)) ||
         ((f = ap_pfopen(r->pool, ap_server_root_relative(r->pool, conf->logname),
		      "a")) == NULL)) {
	return ret;
    }

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

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

    ap_pfclose(r->pool, f);
    return ret;
}

static int log_script(request_rec *r, cgi_server_conf * conf, int ret,
		  char *dbuf, const char *sbuf, BUFF *script_in, BUFF *script_err)
{
    array_header *hdrs_arr = ap_table_elts(r->headers_in);
    table_entry *hdrs = (table_entry *) hdrs_arr->elts;
    char argsbuffer[HUGE_STRING_LEN];
    FILE *f;
    int i;
    struct stat finfo;

    if (!conf->logname ||
	((stat(ap_server_root_relative(r->pool, conf->logname), &finfo) == 0)
	 &&   (finfo.st_size > conf->logbytes)) ||
         ((f = ap_pfopen(r->pool, ap_server_root_relative(r->pool, conf->logname),
		      "a")) == NULL)) {
	/* Soak up script output */
	while (ap_bgets(argsbuffer, HUGE_STRING_LEN, script_in) > 0)
	    continue;
	while (ap_bgets(argsbuffer, HUGE_STRING_LEN, script_err) > 0)
	    continue;
	return ret;
    }

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

    fputs("%request\n", f);
    for (i = 0; i < hdrs_arr->nelts; ++i) {
	if (!hdrs[i].key)
	    continue;
	fprintf(f, "%s: %s\n", hdrs[i].key, hdrs[i].val);
    }
    if ((r->method_number == M_POST || r->method_number == M_PUT)
	&& *dbuf) {
	fprintf(f, "\n%s\n", dbuf);
    }

    fputs("%response\n", f);
    hdrs_arr = ap_table_elts(r->err_headers_out);
    hdrs = (table_entry *) hdrs_arr->elts;

    for (i = 0; i < hdrs_arr->nelts; ++i) {
	if (!hdrs[i].key)
	    continue;
	fprintf(f, "%s: %s\n", hdrs[i].key, hdrs[i].val);
    }

    if (sbuf && *sbuf)
	fprintf(f, "%s\n", sbuf);

    if (ap_bgets(argsbuffer, HUGE_STRING_LEN, script_in) > 0) {
	fputs("%stdout\n", f);
	fputs(argsbuffer, f);
	while (ap_bgets(argsbuffer, HUGE_STRING_LEN, script_in) > 0)
	    fputs(argsbuffer, f);
	fputs("\n", f);
    }

    if (ap_bgets(argsbuffer, HUGE_STRING_LEN, script_err) > 0) {
	fputs("%stderr\n", f);
	fputs(argsbuffer, f);
	while (ap_bgets(argsbuffer, HUGE_STRING_LEN, script_err) > 0)
	    fputs(argsbuffer, f);
	fputs("\n", f);
    }

    ap_bclose(script_in);
    ap_bclose(script_err);

    ap_pfclose(r->pool, f);
    return ret;
}

/****************************************************************
 *
 * Actual CGI handling...
 */


struct cgi_child_stuff {
    request_rec *r;
    int nph;
    int debug;
    char *argv0;
};

static int cgi_child(void *child_stuff, child_info *pinfo)
{
    struct cgi_child_stuff *cld = (struct cgi_child_stuff *) child_stuff;
    request_rec *r = cld->r;
    char *argv0 = cld->argv0;
    int child_pid;

#ifdef DEBUG_CGI
#ifdef OS2
    /* Under OS/2 need to use device con. */
    FILE *dbg = fopen("con", "w");
#else
    FILE *dbg = fopen("/dev/tty", "w");
#endif