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_buckets.h"
18
19static apr_status_t pipe_bucket_read(apr_bucket *a, const char **str,
20                                     apr_size_t *len, apr_read_type_e block)
21{
22    apr_file_t *p = a->data;
23    char *buf;
24    apr_status_t rv;
25    apr_interval_time_t timeout;
26
27    if (block == APR_NONBLOCK_READ) {
28        apr_file_pipe_timeout_get(p, &timeout);
29        apr_file_pipe_timeout_set(p, 0);
30    }
31
32    *str = NULL;
33    *len = APR_BUCKET_BUFF_SIZE;
34    buf = apr_bucket_alloc(*len, a->list); /* XXX: check for failure? */
35
36    rv = apr_file_read(p, buf, len);
37
38    if (block == APR_NONBLOCK_READ) {
39        apr_file_pipe_timeout_set(p, timeout);
40    }
41
42    if (rv != APR_SUCCESS && rv != APR_EOF) {
43        apr_bucket_free(buf);
44        return rv;
45    }
46    /*
47     * If there's more to read we have to keep the rest of the pipe
48     * for later.  Otherwise, we'll close the pipe.
49     * XXX: Note that more complicated bucket types that
50     * refer to data not in memory and must therefore have a read()
51     * function similar to this one should be wary of copying this
52     * code because if they have a destroy function they probably
53     * want to migrate the bucket's subordinate structure from the
54     * old bucket to a raw new one and adjust it as appropriate,
55     * rather than destroying the old one and creating a completely
56     * new bucket.
57     */
58    if (*len > 0) {
59        apr_bucket_heap *h;
60        /* Change the current bucket to refer to what we read */
61        a = apr_bucket_heap_make(a, buf, *len, apr_bucket_free);
62        h = a->data;
63        h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */
64        *str = buf;
65        APR_BUCKET_INSERT_AFTER(a, apr_bucket_pipe_create(p, a->list));
66    }
67    else {
68        apr_bucket_free(buf);
69        a = apr_bucket_immortal_make(a, "", 0);
70        *str = a->data;
71        if (rv == APR_EOF) {
72            apr_file_close(p);
73        }
74    }
75    return APR_SUCCESS;
76}
77
78APU_DECLARE(apr_bucket *) apr_bucket_pipe_make(apr_bucket *b, apr_file_t *p)
79{
80    /*
81     * A pipe is closed when the end is reached in pipe_bucket_read().  If
82     * the pipe isn't read to the end (e.g., error path), the pipe will be
83     * closed when its pool goes away.
84     *
85     * Note that typically the pipe is allocated from the request pool
86     * so it will disappear when the request is finished. However the
87     * core filter may decide to set aside the tail end of a CGI
88     * response if the connection is pipelined. This turns out not to
89     * be a problem because the core will have read to the end of the
90     * stream so the bucket(s) that it sets aside will be the heap
91     * buckets created by pipe_bucket_read() above.
92     */
93    b->type        = &apr_bucket_type_pipe;
94    b->length      = (apr_size_t)(-1);
95    b->start       = -1;
96    b->data        = p;
97
98    return b;
99}
100
101APU_DECLARE(apr_bucket *) apr_bucket_pipe_create(apr_file_t *p,
102                                                 apr_bucket_alloc_t *list)
103{
104    apr_bucket *b = apr_bucket_alloc(sizeof(*b), list);
105
106    APR_BUCKET_INIT(b);
107    b->free = apr_bucket_free;
108    b->list = list;
109    return apr_bucket_pipe_make(b, p);
110}
111
112APU_DECLARE_DATA const apr_bucket_type_t apr_bucket_type_pipe = {
113    "PIPE", 5, APR_BUCKET_DATA,
114    apr_bucket_destroy_noop,
115    pipe_bucket_read,
116    apr_bucket_setaside_notimpl,
117    apr_bucket_split_notimpl,
118    apr_bucket_copy_notimpl
119};
120