svn commit: r342395 - stable/11/sys/dev/netmap

[Vincenzo Maffione]

Author: vmaffione
Date: Mon Dec 24 15:08:19 2018
New Revision: 342395
URL: https://svnweb.freebsd.org/changeset/base/342395

Log:
  MFC r342300
  
  netmap: move buf_size validation code to its own function
  
  This code validates the netmap buf_size against the interface MTU
  and maximum descriptor size, to make sure the values are consistent.
  Moving this functionality to its own function is needed because this
  function is also called by Linux-specific code.

Modified:
  stable/11/sys/dev/netmap/netmap.c
  stable/11/sys/dev/netmap/netmap_kern.h
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/dev/netmap/netmap.c
==============================================================================
--- stable/11/sys/dev/netmap/netmap.c	Mon Dec 24 15:07:36 2018	(r342394)
+++ stable/11/sys/dev/netmap/netmap.c	Mon Dec 24 15:08:19 2018	(r342395)
@@ -447,7 +447,7 @@ ports attached to the switch)
 #include <machine/bus.h>	/* bus_dmamap_* */
 #include <sys/endian.h>
 #include <sys/refcount.h>
-#include <net/ethernet.h>      /* ETHER_BPF_MTAP */
+#include <net/ethernet.h>	/* ETHER_BPF_MTAP */
 
 
 #elif defined(linux)
@@ -2118,6 +2118,53 @@ netmap_csb_validate(struct netmap_priv_d *priv, struct
 	return 0;
 }
 
+/* Ensure that the netmap adapter can support the given MTU.
+ * @return EINVAL if the na cannot be set to mtu, 0 otherwise.
+ */
+int
+netmap_buf_size_validate(const struct netmap_adapter *na, unsigned mtu) {
+	unsigned nbs = NETMAP_BUF_SIZE(na);
+
+	if (mtu <= na->rx_buf_maxsize) {
+		/* The MTU fits a single NIC slot. We only
+		 * Need to check that netmap buffers are
+		 * large enough to hold an MTU. NS_MOREFRAG
+		 * cannot be used in this case. */
+		if (nbs < mtu) {
+			nm_prerr("error: netmap buf size (%u) "
+				 "< device MTU (%u)", nbs, mtu);
+			return EINVAL;
+		}
+	} else {
+		/* More NIC slots may be needed to receive
+		 * or transmit a single packet. Check that
+		 * the adapter supports NS_MOREFRAG and that
+		 * netmap buffers are large enough to hold
+		 * the maximum per-slot size. */
+		if (!(na->na_flags & NAF_MOREFRAG)) {
+			nm_prerr("error: large MTU (%d) needed "
+				 "but %s does not support "
+				 "NS_MOREFRAG", mtu,
+				 na->ifp->if_xname);
+			return EINVAL;
+		} else if (nbs < na->rx_buf_maxsize) {
+			nm_prerr("error: using NS_MOREFRAG on "
+				 "%s requires netmap buf size "
+				 ">= %u", na->ifp->if_xname,
+				 na->rx_buf_maxsize);
+			return EINVAL;
+		} else {
+			nm_prinf("info: netmap application on "
+				 "%s needs to support "
+				 "NS_MOREFRAG "
+				 "(MTU=%u,netmap_buf_size=%u)",
+				 na->ifp->if_xname, mtu, nbs);
+		}
+	}
+	return 0;
+}
+
+
 /*
  * possibly move the interface to netmap-mode.
  * If success it returns a pointer to netmap_if, otherwise NULL.
@@ -2227,11 +2274,10 @@ netmap_do_regif(struct netmap_priv_d *priv, struct net
 		 */
 		if (na->ifp && nm_priv_rx_enabled(priv)) {
 			/* This netmap adapter is attached to an ifnet. */
-			unsigned nbs = NETMAP_BUF_SIZE(na);
 			unsigned mtu = nm_os_ifnet_mtu(na->ifp);
 
 			ND("%s: mtu %d rx_buf_maxsize %d netmap_buf_size %d",
-					na->name, mtu, na->rx_buf_maxsize, nbs);
+				na->name, mtu, na->rx_buf_maxsize, NETMAP_BUF_SIZE(na));
 
 			if (na->rx_buf_maxsize == 0) {
 				nm_prerr("%s: error: rx_buf_maxsize == 0", na->name);
@@ -2239,45 +2285,9 @@ netmap_do_regif(struct netmap_priv_d *priv, struct net
 				goto err_drop_mem;
 			}
 
-			if (mtu <= na->rx_buf_maxsize) {
-				/* The MTU fits a single NIC slot. We only
-				 * Need to check that netmap buffers are
-				 * large enough to hold an MTU. NS_MOREFRAG
-				 * cannot be used in this case. */
-				if (nbs < mtu) {
-					nm_prerr("error: netmap buf size (%u) "
-						"< device MTU (%u)", nbs, mtu);
-					error = EINVAL;
-					goto err_drop_mem;
-				}
-			} else {
-				/* More NIC slots may be needed to receive
-				 * or transmit a single packet. Check that
-				 * the adapter supports NS_MOREFRAG and that
-				 * netmap buffers are large enough to hold
-				 * the maximum per-slot size. */
-				if (!(na->na_flags & NAF_MOREFRAG)) {
-					nm_prerr("error: large MTU (%d) needed "
-						"but %s does not support "
-						"NS_MOREFRAG", mtu,
-						na->ifp->if_xname);
-					error = EINVAL;
-					goto err_drop_mem;
-				} else if (nbs < na->rx_buf_maxsize) {
-					nm_prerr("error: using NS_MOREFRAG on "
-						"%s requires netmap buf size "
-						">= %u", na->ifp->if_xname,
-						na->rx_buf_maxsize);
-					error = EINVAL;
-					goto err_drop_mem;
-				} else {
-					nm_prinf("info: netmap application on "
-						"%s needs to support "
-						"NS_MOREFRAG "
-						"(MTU=%u,netmap_buf_size=%u)",
-						na->ifp->if_xname, mtu, nbs);
-				}
-			}
+			error = netmap_buf_size_validate(na, mtu);
+			if (error)
+				goto err_drop_mem;
 		}
 
 		/*

Modified: stable/11/sys/dev/netmap/netmap_kern.h
==============================================================================
--- stable/11/sys/dev/netmap/netmap_kern.h	Mon Dec 24 15:07:36 2018	(r342394)
+++ stable/11/sys/dev/netmap/netmap_kern.h	Mon Dec 24 15:08:19 2018	(r342395)
@@ -1452,6 +1452,7 @@ void netmap_set_all_rings(struct netmap_adapter *, int
 void netmap_disable_all_rings(struct ifnet *);
 void netmap_enable_all_rings(struct ifnet *);
 
+int netmap_buf_size_validate(const struct netmap_adapter *na, unsigned mtu);
 int netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
 		uint32_t nr_mode, uint16_t nr_ringid, uint64_t nr_flags);
 void netmap_do_unregif(struct netmap_priv_d *priv);