Commit 06852d0f authored by Ruediger Pluem's avatar Ruediger Pluem
Browse files

* If the mod_proxy backend connection broke in the middle of the response, 

  then
  - Do not cache it.
  - Signal the client that something went wrong by closing the connection
    and not sending the last-chunk marker if the response was T-E chunked.

server/core_filters.c         : Close the connection to the client by setting
                                c->keepalive to AP_CONN_CLOSE.
modules/http/chunk_filter.c   : Do not send last-chunk marker in the case
                                the backend broke.
modules/proxy/mod_proxy_http.c: Signal that the backend connection broke.
modules/cache/mod_disk_cache.c: Respect r->no_cache for discarding the response


Submitted by: Roy T. Fielding, Jim Jagielski, Ruediger Pluem
Reviewed by: Roy T. Fielding, Jim Jagielski, Ruediger Pluem


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@357461 13f79535-47bb-0310-9956-ffa450edef68
parent 30fb3270

CHANGES

+2 −1
Original line number Diff line number Diff line
@@ -6,7 +6,8 @@ Changes with Apache 2.3.0 
     connection as errored out.  [Justin Erenkrantz]















  *) mod_proxy: If we get an error reading the upstream response,













     close the connection.  [Brian Akins, Justin Erenkrantz]













     close the connection.













     [Justin Erenkrantz, Roy T. Fielding, Jim Jagielski, Ruediger Pluem]





























  *) mod_ssl: Fix a possible crash during access control checks if a















     non-SSL request is processed for an SSL vhost (such as the

































modules/cache/mod_disk_cache.c



+1
−1






























Original line number
Diff line number
Diff line








@@ -1010,7 +1010,7 @@ static apr_status_t store_body(cache_handle_t *h, request_rec *r,













     * sanity checks.















     */















    if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(bb))) {













        if (r->connection->aborted) {













        if (r->connection->aborted || r->no_cache) {















            ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server,















                         "disk_cache: Discarding body for URL %s "















                         "because connection has been aborted.",

































modules/http/chunk_filter.c



+16
−2






























Original line number
Diff line number
Diff line








@@ -47,6 +47,7 @@ apr_status_t ap_http_chunk_filter(ap_filter_t *f, apr_bucket_brigade *b)













    apr_bucket_brigade *more;















    apr_bucket *e;















    apr_status_t rv;













    int bad_gateway_seen = 0;































    for (more = NULL; b; b = more, more = NULL) {















        apr_off_t bytes = 0;









@@ -67,6 +68,13 @@ apr_status_t ap_http_chunk_filter(ap_filter_t *f, apr_bucket_brigade *b)













                eos = e;















                break;















            }













            if (AP_BUCKET_IS_ERROR(e)













                && (((ap_bucket_error *)(e->data))->status













                    == HTTP_BAD_GATEWAY)) {













                /* We had a broken backend. Memorize this. */













                bad_gateway_seen = 1;













                continue;













            }















            if (APR_BUCKET_IS_FLUSH(e)) {















                flush = e;















                more = apr_brigade_split(b, APR_BUCKET_NEXT(e));










@@ -146,13 +154,19 @@ apr_status_t ap_http_chunk_filter(ap_filter_t *f, apr_bucket_brigade *b)













         *   2) the trailer















         *   3) the end-of-chunked body CRLF















         *













         * If there is no EOS bucket, then do nothing.













         * If there is no EOS bucket, or if we had seen an error bucket with













         * status HTTP_BAD_GATEWAY then do nothing.













         * The error bucket with status HTTP_BAD_GATEWAY indicates that the













         * connection to the backend (mod_proxy) broke in the middle of the













         * response. In order to signal the client that something went wrong













         * we do not create the last-chunk marker and set c->keepalive to













         * AP_CONN_CLOSE in the core output filter.















         *















         * XXX: it would be nice to combine this with the end-of-chunk















         * marker above, but this is a bit more straight-forward for















         * now.















         */













        if (eos != NULL) {













        if (eos && !bad_gateway_seen) {















            /* XXX: (2) trailers ... does not yet exist */















            e = apr_bucket_immortal_create(ASCII_ZERO ASCII_CRLF















                                           /* <trailers> */

































modules/proxy/mod_proxy_http.c



+9
−3






























Original line number
Diff line number
Diff line








@@ -1481,12 +1481,18 @@ apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r,













                    }















                    else if (rv != APR_SUCCESS) {















                        /* In this case, we are in real trouble because













                         * our backend bailed on us, so abort our













                         * connection to our user too.













                         * our backend bailed on us.















                         */















                        ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, c,















                                      "proxy: error reading response");













                        c->aborted = 1;













                        r->no_cache = 1;













                        e = ap_bucket_error_create(HTTP_BAD_GATEWAY,  NULL,













                                                   c->pool, c->bucket_alloc);













                        APR_BRIGADE_INSERT_TAIL(bb, e);













                        e = apr_bucket_eos_create(c->bucket_alloc);













                        APR_BRIGADE_INSERT_TAIL(bb, e);













                        ap_pass_brigade(r->output_filters, bb);













                        backend->close = 1;















                        break;















                    }















                    /* next time try a non-blocking read */

































server/core_filters.c



+18
−5






























Original line number
Diff line number
Diff line








@@ -315,7 +315,9 @@ static apr_status_t send_brigade_nonblocking(apr_socket_t *s,













                                             apr_size_t *bytes_written,















                                             conn_rec *c);





























static void remove_empty_buckets(apr_bucket_brigade *bb);













static void detect_error_bucket(apr_bucket *bucket, conn_rec *c);



























static void remove_empty_buckets(apr_bucket_brigade *bb, conn_rec *c);































static apr_status_t send_brigade_blocking(apr_socket_t *s,















                                          apr_bucket_brigade *bb,










@@ -487,7 +489,7 @@ static void setaside_remaining_output(ap_filter_t *f,













    if (bb == NULL) {















        return;















    }













    remove_empty_buckets(bb);













    remove_empty_buckets(bb, c);















    if (!APR_BRIGADE_EMPTY(bb)) {















        c->data_in_output_filters = 1;















        if (make_a_copy) {










@@ -526,7 +528,7 @@ static apr_status_t send_brigade_nonblocking(apr_socket_t *s,













    struct iovec vec[MAX_IOVEC_TO_WRITE];















    apr_size_t nvec = 0;





























    remove_empty_buckets(bb);













    remove_empty_buckets(bb, c);































    for (bucket = APR_BRIGADE_FIRST(bb);















         bucket != APR_BRIGADE_SENTINEL(bb);










@@ -596,16 +598,26 @@ static apr_status_t send_brigade_nonblocking(apr_socket_t *s,













        }















    }





























    remove_empty_buckets(bb);













    remove_empty_buckets(bb, c);































    return APR_SUCCESS;















}





























static void remove_empty_buckets(apr_bucket_brigade *bb)













static void detect_error_bucket(apr_bucket *bucket, conn_rec *c)













{













    if (AP_BUCKET_IS_ERROR(bucket)













        && (((ap_bucket_error *)(bucket->data))->status == HTTP_BAD_GATEWAY)) {













        /* stream aborted and we have not ended it yet */













        c->keepalive = AP_CONN_CLOSE;













    }













}



























static void remove_empty_buckets(apr_bucket_brigade *bb, conn_rec *c)















{















    apr_bucket *bucket;















    while (((bucket = APR_BRIGADE_FIRST(bb)) != APR_BRIGADE_SENTINEL(bb)) &&















           (APR_BUCKET_IS_METADATA(bucket) || (bucket->length == 0))) {













        detect_error_bucket(bucket, c);















        APR_BUCKET_REMOVE(bucket);















        apr_bucket_destroy(bucket);















    }










@@ -678,6 +690,7 @@ static apr_status_t writev_nonblocking(apr_socket_t *s,













            for (i = offset; i < nvec; ) {















                apr_bucket *bucket = APR_BRIGADE_FIRST(bb);















                if (APR_BUCKET_IS_METADATA(bucket)) {













                    detect_error_bucket(bucket, c);















                    APR_BUCKET_REMOVE(bucket);















                    apr_bucket_destroy(bucket);















                }