svn commit: r228089 - head/sys/net
John Baldwin
jhb at FreeBSD.org
Mon Nov 28 19:35:08 UTC 2011
Author: jhb
Date: Mon Nov 28 19:35:08 2011
New Revision: 228089
URL: http://svn.freebsd.org/changeset/base/228089
Log:
Change the if_vlan driver to use if_transmit for forwarding packets to the
parent interface. This avoids the overhead of queueing a packet to an IFQ
only to immediately dequeue it again.
Suggested by: np
Reviewed by: brooks
MFC after: 1 month
Modified:
head/sys/net/if_vlan.c
Modified: head/sys/net/if_vlan.c
==============================================================================
--- head/sys/net/if_vlan.c Mon Nov 28 19:28:29 2011 (r228088)
+++ head/sys/net/if_vlan.c Mon Nov 28 19:35:08 2011 (r228089)
@@ -34,9 +34,8 @@
* we need to pretend to be enough of an Ethernet implementation
* to make arp work. The way we do this is by telling everyone
* that we are an Ethernet, and then catch the packets that
- * ether_output() left on our output queue when it calls
- * if_start(), rewrite them for use by the real outgoing interface,
- * and ask it to send them.
+ * ether_output() sends to us via if_transmit(), rewrite them for
+ * use by the real outgoing interface, and ask it to send them.
*/
#include <sys/cdefs.h>
@@ -183,14 +182,15 @@ static __inline struct ifvlan * vlan_get
#endif
static void trunk_destroy(struct ifvlantrunk *trunk);
-static void vlan_start(struct ifnet *ifp);
static void vlan_init(void *foo);
static void vlan_input(struct ifnet *ifp, struct mbuf *m);
static int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr);
+static void vlan_qflush(struct ifnet *ifp);
static int vlan_setflag(struct ifnet *ifp, int flag, int status,
int (*func)(struct ifnet *, int));
static int vlan_setflags(struct ifnet *ifp, int status);
static int vlan_setmulti(struct ifnet *ifp);
+static int vlan_transmit(struct ifnet *ifp, struct mbuf *m);
static void vlan_unconfig(struct ifnet *ifp);
static void vlan_unconfig_locked(struct ifnet *ifp);
static int vlan_config(struct ifvlan *ifv, struct ifnet *p, uint16_t tag);
@@ -944,9 +944,9 @@ vlan_clone_create(struct if_clone *ifc,
/* NB: mtu is not set here */
ifp->if_init = vlan_init;
- ifp->if_start = vlan_start;
+ ifp->if_transmit = vlan_transmit;
+ ifp->if_qflush = vlan_qflush;
ifp->if_ioctl = vlan_ioctl;
- ifp->if_snd.ifq_maxlen = ifqmaxlen;
ifp->if_flags = VLAN_IFFLAGS;
ether_ifattach(ifp, eaddr);
/* Now undo some of the damage... */
@@ -1005,99 +1005,95 @@ vlan_init(void *foo __unused)
}
/*
- * The if_start method for vlan(4) interface. It doesn't
- * raises the IFF_DRV_OACTIVE flag, since it is called
- * only from IFQ_HANDOFF() macro in ether_output_frame().
- * If the interface queue is full, and vlan_start() is
- * not called, the queue would never get emptied and
- * interface would stall forever.
+ * The if_transmit method for vlan(4) interface.
*/
-static void
-vlan_start(struct ifnet *ifp)
+static int
+vlan_transmit(struct ifnet *ifp, struct mbuf *m)
{
struct ifvlan *ifv;
struct ifnet *p;
- struct mbuf *m;
int error;
ifv = ifp->if_softc;
p = PARENT(ifv);
- for (;;) {
- IF_DEQUEUE(&ifp->if_snd, m);
- if (m == NULL)
- break;
- BPF_MTAP(ifp, m);
+ BPF_MTAP(ifp, m);
- /*
- * Do not run parent's if_start() if the parent is not up,
- * or parent's driver will cause a system crash.
- */
- if (!UP_AND_RUNNING(p)) {
- m_freem(m);
- ifp->if_collisions++;
- continue;
- }
+ /*
+ * Do not run parent's if_transmit() if the parent is not up,
+ * or parent's driver will cause a system crash.
+ */
+ if (!UP_AND_RUNNING(p)) {
+ m_freem(m);
+ ifp->if_collisions++;
+ return (0);
+ }
- /*
- * Pad the frame to the minimum size allowed if told to.
- * This option is in accord with IEEE Std 802.1Q, 2003 Ed.,
- * paragraph C.4.4.3.b. It can help to work around buggy
- * bridges that violate paragraph C.4.4.3.a from the same
- * document, i.e., fail to pad short frames after untagging.
- * E.g., a tagged frame 66 bytes long (incl. FCS) is OK, but
- * untagging it will produce a 62-byte frame, which is a runt
- * and requires padding. There are VLAN-enabled network
- * devices that just discard such runts instead or mishandle
- * them somehow.
- */
- if (soft_pad && p->if_type == IFT_ETHER) {
- static char pad[8]; /* just zeros */
- int n;
-
- for (n = ETHERMIN + ETHER_HDR_LEN - m->m_pkthdr.len;
- n > 0; n -= sizeof(pad))
- if (!m_append(m, min(n, sizeof(pad)), pad))
- break;
-
- if (n > 0) {
- if_printf(ifp, "cannot pad short frame\n");
- ifp->if_oerrors++;
- m_freem(m);
- continue;
- }
- }
+ /*
+ * Pad the frame to the minimum size allowed if told to.
+ * This option is in accord with IEEE Std 802.1Q, 2003 Ed.,
+ * paragraph C.4.4.3.b. It can help to work around buggy
+ * bridges that violate paragraph C.4.4.3.a from the same
+ * document, i.e., fail to pad short frames after untagging.
+ * E.g., a tagged frame 66 bytes long (incl. FCS) is OK, but
+ * untagging it will produce a 62-byte frame, which is a runt
+ * and requires padding. There are VLAN-enabled network
+ * devices that just discard such runts instead or mishandle
+ * them somehow.
+ */
+ if (soft_pad && p->if_type == IFT_ETHER) {
+ static char pad[8]; /* just zeros */
+ int n;
+
+ for (n = ETHERMIN + ETHER_HDR_LEN - m->m_pkthdr.len;
+ n > 0; n -= sizeof(pad))
+ if (!m_append(m, min(n, sizeof(pad)), pad))
+ break;
- /*
- * If underlying interface can do VLAN tag insertion itself,
- * just pass the packet along. However, we need some way to
- * tell the interface where the packet came from so that it
- * knows how to find the VLAN tag to use, so we attach a
- * packet tag that holds it.
- */
- if (p->if_capenable & IFCAP_VLAN_HWTAGGING) {
- m->m_pkthdr.ether_vtag = ifv->ifv_tag;
- m->m_flags |= M_VLANTAG;
- } else {
- m = ether_vlanencap(m, ifv->ifv_tag);
- if (m == NULL) {
- if_printf(ifp,
- "unable to prepend VLAN header\n");
- ifp->if_oerrors++;
- continue;
- }
+ if (n > 0) {
+ if_printf(ifp, "cannot pad short frame\n");
+ ifp->if_oerrors++;
+ m_freem(m);
+ return (0);
}
+ }
- /*
- * Send it, precisely as ether_output() would have.
- * We are already running at splimp.
- */
- error = (p->if_transmit)(p, m);
- if (!error)
- ifp->if_opackets++;
- else
+ /*
+ * If underlying interface can do VLAN tag insertion itself,
+ * just pass the packet along. However, we need some way to
+ * tell the interface where the packet came from so that it
+ * knows how to find the VLAN tag to use, so we attach a
+ * packet tag that holds it.
+ */
+ if (p->if_capenable & IFCAP_VLAN_HWTAGGING) {
+ m->m_pkthdr.ether_vtag = ifv->ifv_tag;
+ m->m_flags |= M_VLANTAG;
+ } else {
+ m = ether_vlanencap(m, ifv->ifv_tag);
+ if (m == NULL) {
+ if_printf(ifp, "unable to prepend VLAN header\n");
ifp->if_oerrors++;
+ return (0);
+ }
}
+
+ /*
+ * Send it, precisely as ether_output() would have.
+ */
+ error = (p->if_transmit)(p, m);
+ if (!error)
+ ifp->if_opackets++;
+ else
+ ifp->if_oerrors++;
+ return (error);
+}
+
+/*
+ * The ifp->if_qflush entry point for vlan(4) is a no-op.
+ */
+static void
+vlan_qflush(struct ifnet *ifp __unused)
+{
}
static void
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