1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "apr_strings.h"
18#include "ap_config.h"
19#include "httpd.h"
20#include "http_config.h"
21#include "http_protocol.h"
22#include "http_log.h"
23#include "util_script.h"
24#include "http_main.h"
25#include "http_request.h"
26
27#include "mod_core.h"
28
29#define ASIS_MAGIC_TYPE "httpd/send-as-is"
30
31static int asis_handler(request_rec *r)
32{
33    conn_rec *c = r->connection;
34    apr_file_t *f = NULL;
35    apr_status_t rv;
36    const char *location;
37
38    if(strcmp(r->handler,ASIS_MAGIC_TYPE) && strcmp(r->handler,"send-as-is"))
39        return DECLINED;
40
41    r->allowed |= (AP_METHOD_BIT << M_GET);
42    if (r->method_number != M_GET)
43        return DECLINED;
44    if (r->finfo.filetype == 0) {
45        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
46                    "File does not exist: %s", r->filename);
47        return HTTP_NOT_FOUND;
48    }
49
50    if ((rv = apr_file_open(&f, r->filename, APR_READ,
51                APR_OS_DEFAULT, r->pool)) != APR_SUCCESS) {
52        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
53                    "file permissions deny server access: %s", r->filename);
54        return HTTP_FORBIDDEN;
55    }
56
57    ap_scan_script_header_err(r, f, NULL);
58    location = apr_table_get(r->headers_out, "Location");
59
60    if (location && location[0] == '/' &&
61        ((r->status == HTTP_OK) || ap_is_HTTP_REDIRECT(r->status))) {
62
63        apr_file_close(f);
64
65        /* Internal redirect -- fake-up a pseudo-request */
66        r->status = HTTP_OK;
67
68        /* This redirect needs to be a GET no matter what the original
69         * method was.
70         */
71        r->method = apr_pstrdup(r->pool, "GET");
72        r->method_number = M_GET;
73
74        ap_internal_redirect_handler(location, r);
75        return OK;
76    }
77
78    if (!r->header_only) {
79        apr_bucket_brigade *bb;
80        apr_bucket *b;
81        apr_off_t pos = 0;
82
83        rv = apr_file_seek(f, APR_CUR, &pos);
84        if (rv != APR_SUCCESS) {
85            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
86                          "mod_asis: failed to find end-of-headers position "
87                          "for %s", r->filename);
88            apr_file_close(f);
89            return HTTP_INTERNAL_SERVER_ERROR;
90        }
91
92        bb = apr_brigade_create(r->pool, c->bucket_alloc);
93#if APR_HAS_LARGE_FILES
94        if (r->finfo.size - pos > AP_MAX_SENDFILE) {
95            /* APR_HAS_LARGE_FILES issue; must split into mutiple buckets,
96             * no greater than MAX(apr_size_t), and more granular than that
97             * in case the brigade code/filters attempt to read it directly.
98             */
99            apr_off_t fsize = r->finfo.size - pos;
100            b = apr_bucket_file_create(f, pos, AP_MAX_SENDFILE,
101                                       r->pool, c->bucket_alloc);
102            while (fsize > AP_MAX_SENDFILE) {
103                APR_BRIGADE_INSERT_TAIL(bb, b);
104                apr_bucket_copy(b, &b);
105                b->start += AP_MAX_SENDFILE;
106                fsize -= AP_MAX_SENDFILE;
107            }
108            b->length = (apr_size_t)fsize; /* Resize just the last bucket */
109        }
110        else
111#endif
112        b = apr_bucket_file_create(f, pos, (apr_size_t) (r->finfo.size - pos),
113                                   r->pool, c->bucket_alloc);
114        APR_BRIGADE_INSERT_TAIL(bb, b);
115        b = apr_bucket_eos_create(c->bucket_alloc);
116        APR_BRIGADE_INSERT_TAIL(bb, b);
117        rv = ap_pass_brigade(r->output_filters, bb);
118        if (rv != APR_SUCCESS) {
119            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
120                          "mod_asis: ap_pass_brigade failed for file %s", r->filename);
121            return HTTP_INTERNAL_SERVER_ERROR;
122        }
123    }
124    else {
125        apr_file_close(f);
126    }
127
128    return OK;
129}
130
131static void register_hooks(apr_pool_t *p)
132{
133    ap_hook_handler(asis_handler,NULL,NULL,APR_HOOK_MIDDLE);
134}
135
136module AP_MODULE_DECLARE_DATA asis_module =
137{
138    STANDARD20_MODULE_STUFF,
139    NULL,              /* create per-directory config structure */
140    NULL,              /* merge per-directory config structures */
141    NULL,              /* create per-server config structure */
142    NULL,              /* merge per-server config structures */
143    NULL,              /* command apr_table_t */
144    register_hooks     /* register hooks */
145};
146