Adjust the read/write watermarks according to the TCP send buffer.

This fixes sending of large files.  Previously, httpd was reading the
input file too quickly and could run out of memory when filling the
input buffer.

Found by jsg@
OK florian@

diff --git a/usr.sbin/httpd/httpd.h b/usr.sbin/httpd/httpd.h
index 0983ce2..449c10f 100644 (file)
--- a/usr.sbin/httpd/httpd.h
+++ b/usr.sbin/httpd/httpd.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: httpd.h,v 1.47 2014/08/06 02:04:42 jsing Exp $        */
+/*     $OpenBSD: httpd.h,v 1.48 2014/08/06 09:36:31 reyk Exp $ */
 
 /*
  * Copyright (c) 2006 - 2014 Reyk Floeter <reyk@openbsd.org>
@@ -273,6 +273,7 @@ struct client {
        struct evbuffer         *clt_output;
        struct event             clt_ev;
        void                    *clt_desc;
+       int                      clt_sndbufsiz;
 
        int                      clt_fd;
        struct ressl            *clt_ressl_ctx;

diff --git a/usr.sbin/httpd/server.c b/usr.sbin/httpd/server.c
index e3727ae..b9d3c75 100644 (file)
--- a/usr.sbin/httpd/server.c
+++ b/usr.sbin/httpd/server.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: server.c,v 1.31 2014/08/06 04:39:50 jsg Exp $ */
+/*     $OpenBSD: server.c,v 1.32 2014/08/06 09:36:31 reyk Exp $        */
 
 /*
  * Copyright (c) 2006 - 2014 Reyk Floeter <reyk@openbsd.org>
@@ -631,6 +631,7 @@ server_input(struct client *clt)
        struct server_config    *srv_conf = clt->clt_srv_conf;
        evbuffercb               inrd = server_read;
        evbuffercb               inwr = server_write;
+       socklen_t                slen;
 
        if (server_httpdesc_init(clt) == -1) {
                server_close(clt, "failed to allocate http descriptor");
@@ -640,6 +641,13 @@ server_input(struct client *clt)
        clt->clt_toread = TOREAD_HTTP_HEADER;
        inrd = server_read_http;
 
+       slen = sizeof(clt->clt_sndbufsiz);
+       if (getsockopt(clt->clt_s, SOL_SOCKET, SO_SNDBUF,
+           &clt->clt_sndbufsiz, &slen) == -1) {
+               server_close(clt, "failed to get send buffer size");
+               return;
+       }
+
        /*
         * Client <-> Server
         */
@@ -657,6 +665,10 @@ server_input(struct client *clt)
                    server_ssl_writecb, clt->clt_bev);
        }
 
+       /* Adjust write watermark to the socket buffer output size */
+       bufferevent_setwatermark(clt->clt_bev, EV_WRITE,
+           clt->clt_sndbufsiz, 0);
+
        bufferevent_settimeout(clt->clt_bev,
            srv_conf->timeout.tv_sec, srv_conf->timeout.tv_sec);
        bufferevent_enable(clt->clt_bev, EV_READ|EV_WRITE);

diff --git a/usr.sbin/httpd/server_file.c b/usr.sbin/httpd/server_file.c
index 4989f19..5b72aaf 100644 (file)
--- a/usr.sbin/httpd/server_file.c
+++ b/usr.sbin/httpd/server_file.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: server_file.c,v 1.29 2014/08/04 17:43:20 reyk Exp $   */
+/*     $OpenBSD: server_file.c,v 1.30 2014/08/06 09:36:31 reyk Exp $   */
 
 /*
  * Copyright (c) 2006 - 2014 Reyk Floeter <reyk@openbsd.org>
@@ -201,6 +201,10 @@ server_file(struct httpd *env, struct client *clt)
                goto fail;
        }
 
+       /* Adjust read watermark to the socket output buffer size */
+       bufferevent_setwatermark(clt->clt_srvbev, EV_READ, 0,
+           clt->clt_sndbufsiz);
+
        bufferevent_settimeout(clt->clt_srvbev,
            srv_conf->timeout.tv_sec, srv_conf->timeout.tv_sec);
        bufferevent_enable(clt->clt_srvbev, EV_READ);