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DEFINITIONS
This source file includes following definitions.
- parse_byterange
- use_range_x
- AP_CORE_DECLARE_NONSTD
- ap_set_byterange
/* 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.
*/
/*
* byterange_filter.c --- HTTP byterange filter and friends.
*/
#include "apr.h"
#include "apr_strings.h"
#include "apr_buckets.h"
#include "apr_lib.h"
#include "apr_signal.h"
#define APR_WANT_STDIO /* for sscanf */
#define APR_WANT_STRFUNC
#define APR_WANT_MEMFUNC
#include "apr_want.h"
#define CORE_PRIVATE
#include "util_filter.h"
#include "ap_config.h"
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_protocol.h"
#include "http_main.h"
#include "http_request.h"
#include "http_vhost.h"
#include "http_log.h" /* For errors detected in basic auth common
* support code... */
#include "apr_date.h" /* For apr_date_parse_http and APR_DATE_BAD */
#include "util_charset.h"
#include "util_ebcdic.h"
#include "util_time.h"
#include "mod_core.h"
#if APR_HAVE_STDARG_H
#include <stdarg.h>
#endif
#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif
static int parse_byterange(char *range, apr_off_t clength,
apr_off_t *start, apr_off_t *end)
{
char *dash = strchr(range, '-');
char *errp;
apr_off_t number;
if (!dash) {
return 0;
}
if ((dash == range)) {
/* In the form "-5" */
if (apr_strtoff(&number, dash+1, &errp, 10) || *errp) {
return 0;
}
*start = clength - number;
*end = clength - 1;
}
else {
*dash++ = '\0';
if (apr_strtoff(&number, range, &errp, 10) || *errp) {
return 0;
}
*start = number;
if (*dash) {
if (apr_strtoff(&number, dash, &errp, 10) || *errp) {
return 0;
}
*end = number;
}
else { /* "5-" */
*end = clength - 1;
}
}
if (*start < 0) {
*start = 0;
}
if (*end >= clength) {
*end = clength - 1;
}
if (*start > *end) {
return -1;
}
return (*start > 0 || *end < clength);
}
static int ap_set_byterange(request_rec *r);
typedef struct byterange_ctx {
apr_bucket_brigade *bb;
int num_ranges;
char *boundary;
char *bound_head;
} byterange_ctx;
/*
* Here we try to be compatible with clients that want multipart/x-byteranges
* instead of multipart/byteranges (also see above), as per HTTP/1.1. We
* look for the Request-Range header (e.g. Netscape 2 and 3) as an indication
* that the browser supports an older protocol. We also check User-Agent
* for Microsoft Internet Explorer 3, which needs this as well.
*/
static int use_range_x(request_rec *r)
{
const char *ua;
return (apr_table_get(r->headers_in, "Request-Range")
|| ((ua = apr_table_get(r->headers_in, "User-Agent"))
&& ap_strstr_c(ua, "MSIE 3")));
}
#define BYTERANGE_FMT "%" APR_OFF_T_FMT "-%" APR_OFF_T_FMT "/%" APR_OFF_T_FMT
#define PARTITION_ERR_FMT "apr_brigade_partition() failed " \
"[%" APR_OFF_T_FMT ",%" APR_OFF_T_FMT "]"
AP_CORE_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f,
apr_bucket_brigade *bb)
{
#define MIN_LENGTH(len1, len2) ((len1 > len2) ? len2 : len1)
request_rec *r = f->r;
conn_rec *c = r->connection;
byterange_ctx *ctx;
apr_bucket *e;
apr_bucket_brigade *bsend;
apr_off_t range_start;
apr_off_t range_end;
char *current;
apr_off_t clength = 0;
apr_status_t rv;
int found = 0;
int num_ranges;
/* Iterate through the brigade until reaching EOS or a bucket with
* unknown length. */
for (e = APR_BRIGADE_FIRST(bb);
(e != APR_BRIGADE_SENTINEL(bb) && !APR_BUCKET_IS_EOS(e)
&& e->length != (apr_size_t)-1);
e = APR_BUCKET_NEXT(e)) {
clength += e->length;
}
/* Don't attempt to do byte range work if this brigade doesn't
* contain an EOS, or if any of the buckets has an unknown length;
* this avoids the cases where it is expensive to perform
* byteranging (i.e. may require arbitrary amounts of memory). */
if (!APR_BUCKET_IS_EOS(e) || clength <= 0) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
num_ranges = ap_set_byterange(r);
/* We have nothing to do, get out of the way. */
if (num_ranges == 0) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
ctx = apr_pcalloc(r->pool, sizeof(*ctx));
ctx->num_ranges = num_ranges;
/* create a brigade in case we never call ap_save_brigade() */
ctx->bb = apr_brigade_create(r->pool, c->bucket_alloc);
if (ctx->num_ranges > 1) {
/* Is ap_make_content_type required here? */
const char *orig_ct = ap_make_content_type(r, r->content_type);
ctx->boundary = apr_psprintf(r->pool, "%" APR_UINT64_T_HEX_FMT "%lx",
(apr_uint64_t)r->request_time, (long) getpid());
ap_set_content_type(r, apr_pstrcat(r->pool, "multipart",
use_range_x(r) ? "/x-" : "/",
"byteranges; boundary=",
ctx->boundary, NULL));
if (strcasecmp(orig_ct, NO_CONTENT_TYPE)) {
ctx->bound_head = apr_pstrcat(r->pool,
CRLF "--", ctx->boundary,
CRLF "Content-type: ",
orig_ct,
CRLF "Content-range: bytes ",
NULL);
}
else {
/* if we have no type for the content, do our best */
ctx->bound_head = apr_pstrcat(r->pool,
CRLF "--", ctx->boundary,
CRLF "Content-range: bytes ",
NULL);
}
ap_xlate_proto_to_ascii(ctx->bound_head, strlen(ctx->bound_head));
}
/* this brigade holds what we will be sending */
bsend = apr_brigade_create(r->pool, c->bucket_alloc);
while ((current = ap_getword(r->pool, &r->range, ','))
&& (rv = parse_byterange(current, clength, &range_start,
&range_end))) {
apr_bucket *e2;
apr_bucket *ec;
if (rv == -1) {
continue;
}
/* These calls to apr_brigage_partition should only fail in
* pathological cases, e.g. a file being truncated whilst
* being served. */
if ((rv = apr_brigade_partition(bb, range_start, &ec)) != APR_SUCCESS) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
PARTITION_ERR_FMT, range_start, clength);
continue;
}
if ((rv = apr_brigade_partition(bb, range_end+1, &e2)) != APR_SUCCESS) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
PARTITION_ERR_FMT, range_end+1, clength);
continue;
}
found = 1;
/* For single range requests, we must produce Content-Range header.
* Otherwise, we need to produce the multipart boundaries.
*/
if (ctx->num_ranges == 1) {
apr_table_setn(r->headers_out, "Content-Range",
apr_psprintf(r->pool, "bytes " BYTERANGE_FMT,
range_start, range_end, clength));
}
else {
char *ts;
e = apr_bucket_pool_create(ctx->bound_head, strlen(ctx->bound_head),
r->pool, c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bsend, e);
ts = apr_psprintf(r->pool, BYTERANGE_FMT CRLF CRLF,
range_start, range_end, clength);
ap_xlate_proto_to_ascii(ts, strlen(ts));
e = apr_bucket_pool_create(ts, strlen(ts), r->pool,
c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bsend, e);
}
do {
apr_bucket *foo;
const char *str;
apr_size_t len;
if (apr_bucket_copy(ec, &foo) != APR_SUCCESS) {
/* As above; this should not fail since the bucket has
* a known length, but just to be sure, this takes
* care of uncopyable buckets that do somehow manage
* to slip through. */
/* XXX: check for failure? */
apr_bucket_read(ec, &str, &len, APR_BLOCK_READ);
apr_bucket_copy(ec, &foo);
}
APR_BRIGADE_INSERT_TAIL(bsend, foo);
ec = APR_BUCKET_NEXT(ec);
} while (ec != e2);
}
if (found == 0) {
ap_remove_output_filter(f);
r->status = HTTP_OK;
/* bsend is assumed to be empty if we get here. */
e = ap_bucket_error_create(HTTP_RANGE_NOT_SATISFIABLE, NULL,
r->pool, c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bsend, e);
e = apr_bucket_eos_create(c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bsend, e);
return ap_pass_brigade(f->next, bsend);
}
if (ctx->num_ranges > 1) {
char *end;
/* add the final boundary */
end = apr_pstrcat(r->pool, CRLF "--", ctx->boundary, "--" CRLF, NULL);
ap_xlate_proto_to_ascii(end, strlen(end));
e = apr_bucket_pool_create(end, strlen(end), r->pool, c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bsend, e);
}
e = apr_bucket_eos_create(c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bsend, e);
/* we're done with the original content - all of our data is in bsend. */
apr_brigade_destroy(bb);
/* send our multipart output */
return ap_pass_brigade(f->next, bsend);
}
static int ap_set_byterange(request_rec *r)
{
const char *range;
const char *if_range;
const char *match;
const char *ct;
int num_ranges;
if (r->assbackwards) {
return 0;
}
/* Check for Range request-header (HTTP/1.1) or Request-Range for
* backwards-compatibility with second-draft Luotonen/Franks
* byte-ranges (e.g. Netscape Navigator 2-3).
*
* We support this form, with Request-Range, and (farther down) we
* send multipart/x-byteranges instead of multipart/byteranges for
* Request-Range based requests to work around a bug in Netscape
* Navigator 2-3 and MSIE 3.
*/
if (!(range = apr_table_get(r->headers_in, "Range"))) {
range = apr_table_get(r->headers_in, "Request-Range");
}
if (!range || strncasecmp(range, "bytes=", 6) || r->status != HTTP_OK) {
return 0;
}
/* is content already a single range? */
if (apr_table_get(r->headers_out, "Content-Range")) {
return 0;
}
/* is content already a multiple range? */
if ((ct = apr_table_get(r->headers_out, "Content-Type"))
&& (!strncasecmp(ct, "multipart/byteranges", 20)
|| !strncasecmp(ct, "multipart/x-byteranges", 22))) {
return 0;
}
/* Check the If-Range header for Etag or Date.
* Note that this check will return false (as required) if either
* of the two etags are weak.
*/
if ((if_range = apr_table_get(r->headers_in, "If-Range"))) {
if (if_range[0] == '"') {
if (!(match = apr_table_get(r->headers_out, "Etag"))
|| (strcmp(if_range, match) != 0)) {
return 0;
}
}
else if (!(match = apr_table_get(r->headers_out, "Last-Modified"))
|| (strcmp(if_range, match) != 0)) {
return 0;
}
}
if (!ap_strchr_c(range, ',')) {
/* a single range */
num_ranges = 1;
}
else {
/* a multiple range */
num_ranges = 2;
}
r->status = HTTP_PARTIAL_CONTENT;
r->range = range + 6;
return num_ranges;
}