mod_cgi.c

最新apache的源代码

                            command, argv, r, p, &e_info)) != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                      "couldn't spawn child process: %s", r->filename);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    /* Transfer any put/post args, CERN style...
     * Note that we already ignore SIGPIPE in the core server.
     */
    bb = apr_brigade_create(r->pool, c->bucket_alloc);
    seen_eos = 0;
    child_stopped_reading = 0;
    if (conf->logname) {
        dbuf = apr_palloc(r->pool, conf->bufbytes + 1);
        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;
        }

        APR_BRIGADE_FOREACH(bucket, bb) {
            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 */
            apr_bucket_read(bucket, &data, &len, APR_BLOCK_READ);
            
            if (conf->logname && dbpos < conf->bufbytes) {
                int cursize;

                if ((dbpos + len) > conf->bufbytes) {
                    cursize = conf->bufbytes - dbpos;
                }
                else {
                    cursize = len;
                }
                memcpy(dbuf + 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;
            }
        }
        apr_brigade_cleanup(bb);
    }
    while (!seen_eos);

    if (conf->logname) {
        dbuf[dbpos] = '\0';
    }
    /* Is this flush really needed? */
    apr_file_flush(script_out);
    apr_file_close(script_out);

    AP_DEBUG_ASSERT(script_in != NULL);

    apr_brigade_cleanup(bb);

#if APR_FILES_AS_SOCKETS
    apr_file_pipe_timeout_set(script_in, 0);
    apr_file_pipe_timeout_set(script_err, 0);
    
    b = cgi_bucket_create(r, script_in, script_err, c->bucket_alloc);
#else
    b = apr_bucket_pipe_create(script_in, c->bucket_alloc);
#endif
    APR_BRIGADE_INSERT_TAIL(bb, b);
    b = apr_bucket_eos_create(c->bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(bb, b);

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

        if ((ret = ap_scan_script_header_err_brigade(r, bb, sbuf))) {
            return log_script(r, conf, ret, dbuf, sbuf, bb, script_err);
        }

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

        if (location && location[0] == '/' && r->status == 200) {
            discard_script_output(bb);
            apr_brigade_destroy(bb);
            apr_file_pipe_timeout_set(script_err, r->server->timeout);
            log_script_err(r, script_err);
            /* This redirect needs to be a GET no matter what the original
             * method was.
             */
            r->method = apr_pstrdup(r->pool, "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) {
            /* XX 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 (rv == APR_SUCCESS && !r->connection->aborted) {
        apr_file_pipe_timeout_set(script_err, r->server->timeout);
        log_script_err(r, script_err);
    }
    
    apr_file_close(script_err);

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

/*============================================================================
 *============================================================================
 * This is the beginning of the cgi filter code moved from mod_include. This
 *   is the code required to handle the "exec" SSI directive.
 *============================================================================
 *============================================================================*/
static int include_cgi(char *s, request_rec *r, ap_filter_t *next,
                       apr_bucket *head_ptr, apr_bucket **inserted_head)
{
    request_rec *rr = ap_sub_req_lookup_uri(s, r, next);
    int rr_status;
    apr_bucket  *tmp_buck, *tmp2_buck;

    if (rr->status != HTTP_OK) {
        ap_destroy_sub_req(rr);
        return -1;
    }

    /* No hardwired path info or query allowed */

    if ((rr->path_info && rr->path_info[0]) || rr->args) {
        ap_destroy_sub_req(rr);
        return -1;
    }
    if (rr->finfo.filetype != APR_REG) {
        ap_destroy_sub_req(rr);
        return -1;
    }

    /* Script gets parameters of the *document*, for back compatibility */

    rr->path_info = r->path_info;       /* hard to get right; see mod_cgi.c */
    rr->args = r->args;

    /* Force sub_req to be treated as a CGI request, even if ordinary
     * typing rules would have called it something else.
     */

    ap_set_content_type(rr, CGI_MAGIC_TYPE);

    /* Run it. */

    rr_status = ap_run_sub_req(rr);
    if (ap_is_HTTP_REDIRECT(rr_status)) {
        apr_size_t len_loc;
        const char *location = apr_table_get(rr->headers_out, "Location");
        conn_rec *c = r->connection;

        location = ap_escape_html(rr->pool, location);
        len_loc = strlen(location);

        /* XXX: if most of this stuff is going to get copied anyway,
         * it'd be more efficient to pstrcat it into a single pool buffer
         * and a single pool bucket */

        tmp_buck = apr_bucket_immortal_create("<A HREF=\"",
                                              sizeof("<A HREF=\"") - 1,
                                              c->bucket_alloc);
        APR_BUCKET_INSERT_BEFORE(head_ptr, tmp_buck);
        tmp2_buck = apr_bucket_heap_create(location, len_loc, NULL,
                                           c->bucket_alloc);
        APR_BUCKET_INSERT_BEFORE(head_ptr, tmp2_buck);
        tmp2_buck = apr_bucket_immortal_create("\">", sizeof("\">") - 1,
                                               c->bucket_alloc);
        APR_BUCKET_INSERT_BEFORE(head_ptr, tmp2_buck);
        tmp2_buck = apr_bucket_heap_create(location, len_loc, NULL,
                                           c->bucket_alloc);
        APR_BUCKET_INSERT_BEFORE(head_ptr, tmp2_buck);
        tmp2_buck = apr_bucket_immortal_create("</A>", sizeof("</A>") - 1,
                                               c->bucket_alloc);
        APR_BUCKET_INSERT_BEFORE(head_ptr, tmp2_buck);

        if (*inserted_head == NULL) {
            *inserted_head = tmp_buck;
        }
    }

    ap_destroy_sub_req(rr);

    return 0;
}


static int include_cmd(include_ctx_t *ctx, apr_bucket_brigade **bb,
                       const char *command, request_rec *r, ap_filter_t *f)
{
    cgi_exec_info_t  e_info;
    const char   **argv;
    apr_file_t    *script_out = NULL, *script_in = NULL, *script_err = NULL;
    apr_bucket_brigade *bcgi;
    apr_bucket *b;
    apr_status_t rv;

    add_ssi_vars(r);

    e_info.process_cgi = 0;
    e_info.cmd_type    = APR_SHELLCMD;
    e_info.detached    = 0;
    e_info.in_pipe     = APR_NO_PIPE;
    e_info.out_pipe    = APR_FULL_BLOCK;
    e_info.err_pipe    = APR_NO_PIPE;
    e_info.prog_type   = RUN_AS_SSI;
    e_info.bb          = bb;
    e_info.ctx         = ctx;
    e_info.next        = f->next;

    if ((rv = cgi_build_command(&command, &argv, r, r->pool, &e_info)) != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                      "don't know how to spawn cmd child process: %s", 
                      r->filename);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    /* run the script in its own process */
    if ((rv = run_cgi_child(&script_out, &script_in, &script_err,
                            command, argv, r, r->pool,
                            &e_info)) != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                      "couldn't spawn child process: %s", r->filename);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    bcgi = apr_brigade_create(r->pool, f->c->bucket_alloc);
    b = apr_bucket_pipe_create(script_in, f->c->bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(bcgi, b);
    ap_pass_brigade(f->next, bcgi);

    /* We can't close the pipe here, because we may return before the
     * full CGI has been sent to the network.  That's okay though,
     * because we can rely on the pool to close the pipe for us.
     */

    return 0;
}

static int handle_exec(include_ctx_t *ctx, apr_bucket_brigade **bb,
                       request_rec *r, ap_filter_t *f, apr_bucket *head_ptr,
                       apr_bucket **inserted_head)
{
    char *tag     = NULL;
    char *tag_val = NULL;
    char *file = r->filename;
    apr_bucket  *tmp_buck;
    char parsed_string[MAX_STRING_LEN];

    *inserted_head = NULL;
    if (ctx->flags & FLAG_PRINTING) {
        if (ctx->flags & FLAG_NO_EXEC) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                          "exec used but not allowed in %s", r->filename);
            CREATE_ERROR_BUCKET(ctx, tmp_buck, head_ptr, *inserted_head);
        }
        else {
            while (1) {
                cgi_pfn_gtv(ctx, &tag, &tag_val, 1);
                if (tag_val == NULL) {
                    if (tag == NULL) {
                        return 0;
                    }
                    else {
                        return 1;
                    }
                }
                if (!strcmp(tag, "cmd")) {
                    cgi_pfn_ps(r, ctx, tag_val, parsed_string,
                               sizeof(parsed_string), 1);
                    if (include_cmd(ctx, bb, parsed_string, r, f) == -1) {
                        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                                    "execution failure for parameter \"%s\" "
                                    "to tag exec in file %s", tag, r->filename);
                        CREATE_ERROR_BUCKET(ctx, tmp_buck, head_ptr,
                                            *inserted_head);
                    }
                }
                else if (!strcmp(tag, "cgi")) {
                    apr_status_t retval = APR_SUCCESS;

                    cgi_pfn_ps(r, ctx, tag_val, parsed_string,
                               sizeof(parsed_string), 0);

                    SPLIT_AND_PASS_PRETAG_BUCKETS(*bb, ctx, f->next, retval);
                    if (retval != APR_SUCCESS) {
                        return retval;
                    }

                    if (include_cgi(parsed_string, r, f->next, head_ptr,
                                    inserted_head) == -1) {
                        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                                      "invalid CGI ref \"%s\" in %s",
                                      tag_val, file);
                        CREATE_ERROR_BUCKET(ctx, tmp_buck, head_ptr,
                                            *inserted_head);
                    }
                }
                else {
                    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                                  "unknown parameter \"%s\" to tag exec in %s",
                                  tag, file);
                    CREATE_ERROR_BUCKET(ctx, tmp_buck, head_ptr,
                                        *inserted_head);
                }
            }
        }
    }
    return 0;
}


/*============================================================================
 *============================================================================
 * This is the end of the cgi filter code moved from mod_include.
 *============================================================================
 *============================================================================*/


static int cgi_post_config(apr_pool_t *p, apr_pool_t *plog,
                                apr_pool_t *ptemp, server_rec *s)
{
    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", handle_exec);
    }

    /* This is the means by which unusual (non-unix) os's may find alternate
     * means to run a given command (e.g. shebang/registry parsing on Win32)
     */
    cgi_build_command    = APR_RETRIEVE_OPTIONAL_FN(ap_cgi_build_command);
    if (!cgi_build_command) {
        cgi_build_command = default_build_command;
    }
    return OK;
}

static void register_hooks(apr_pool_t *p)
{
    static const char * const aszPre[] = { "mod_include.c", NULL };
    ap_hook_handler(cgi_handler, NULL, NULL, APR_HOOK_MIDDLE);
    ap_hook_post_config(cgi_post_config, aszPre, NULL, APR_HOOK_REALLY_FIRST);
}

module AP_MODULE_DECLARE_DATA cgi_module =
{
    STANDARD20_MODULE_STUFF,
    NULL,                        /* dir config creater */
    NULL,                        /* dir merger --- default is to override */
    create_cgi_config,           /* server config */
    merge_cgi_config,            /* merge server config */
    cgi_cmds,                    /* command apr_table_t */
    register_hooks               /* register hooks */
};