/* 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; }
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