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If we have to do an m_pullup() when setting up offload parameters,

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make sure that the pullup was done into trailing space at the end of
the existing first-mbuf-in-chain.  If not, log an error and drop the
packet, because the mbuf chain no longer corresponds to the DMA map,
and we are already committed to transmitting the packet.
This commit is contained in:
thorpej 2004-11-23 23:05:33 +00:00
parent cc4d390c49
commit 978214ebe8
1 changed files with 44 additions and 12 deletions
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56
sys/dev/pci/if_wm.c
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@ -1,4 +1,4 @@
/* $NetBSD: if_wm.c,v 1.85 2004/11/23 21:36:38 thorpej Exp $ */
/* $NetBSD: if_wm.c,v 1.86 2004/11/23 23:05:33 thorpej Exp $ */
/*
* Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@ -47,7 +47,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.85 2004/11/23 21:36:38 thorpej Exp $");
__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.86 2004/11/23 23:05:33 thorpej Exp $");
#include "bpfilter.h"
#include "rnd.h"
@ -277,6 +277,13 @@ struct wm_softc {
struct evcnt sc_ev_txipsum; /* IP checksums comp. out-bound */
struct evcnt sc_ev_txtusum; /* TCP/UDP cksums comp. out-bound */
/* m_pullup() needed for Tx offload */
struct evcnt sc_ev_txpullup_needed;
/* ...failed due to no memory */
struct evcnt sc_ev_txpullup_nomem;
/* ...failed due to lack of space in first mbuf */
struct evcnt sc_ev_txpullup_fail;
struct evcnt sc_ev_txctx_init; /* Tx cksum context cache initialized */
struct evcnt sc_ev_txctx_hit; /* Tx cksum context cache hit */
struct evcnt sc_ev_txctx_miss; /* Tx cksum context cache miss */
@ -1243,6 +1250,13 @@ wm_attach(struct device *parent, struct device *self, void *aux)
evcnt_attach_dynamic(&sc->sc_ev_txtusum, EVCNT_TYPE_MISC,
NULL, sc->sc_dev.dv_xname, "txtusum");
evcnt_attach_dynamic(&sc->sc_ev_txpullup_needed, EVCNT_TYPE_MISC,
NULL, sc->sc_dev.dv_xname, "txpullup needed");
evcnt_attach_dynamic(&sc->sc_ev_txpullup_nomem, EVCNT_TYPE_MISC,
NULL, sc->sc_dev.dv_xname, "txpullup nomem");
evcnt_attach_dynamic(&sc->sc_ev_txpullup_fail, EVCNT_TYPE_MISC,
NULL, sc->sc_dev.dv_xname, "txpullup fail");
evcnt_attach_dynamic(&sc->sc_ev_txctx_init, EVCNT_TYPE_MISC,
NULL, sc->sc_dev.dv_xname, "txctx init");
evcnt_attach_dynamic(&sc->sc_ev_txctx_hit, EVCNT_TYPE_MISC,
@ -1325,13 +1339,13 @@ wm_shutdown(void *arg)
}
/*
* wm_tx_cksum:
* wm_tx_offload:
*
* Set up TCP/IP checksumming parameters for the
* specified packet.
*/
static int
wm_tx_cksum(struct wm_softc *sc, struct wm_txsoft *txs, uint32_t *cmdp,
wm_tx_offload(struct wm_softc *sc, struct wm_txsoft *txs, uint32_t *cmdp,
uint8_t *fieldsp)
{
struct mbuf *m0 = txs->txs_mbuf;
@ -1369,12 +1383,33 @@ wm_tx_cksum(struct wm_softc *sc, struct wm_txsoft *txs, uint32_t *cmdp,
}
if (m0->m_len < (offset + iphl)) {
/*
* Packet headers aren't in the first mbuf. Let's hope
* there is space at the end if it for them.
*/
WM_EVCNT_INCR(&sc->sc_ev_txpullup_needed);
if ((txs->txs_mbuf = m_pullup(m0, offset + iphl)) == NULL) {
log(LOG_ERR, "%s: wm_tx_cksum: mbuf allocation failed, "
WM_EVCNT_INCR(&sc->sc_ev_txpullup_nomem);
log(LOG_ERR,
"%s: wm_tx_offload: mbuf allocation failed, "
"packet dropped\n", sc->sc_dev.dv_xname);
return (ENOMEM);
} else if (m0 != txs->txs_mbuf) {
/*
* The DMA map has already been loaded, so we
* would have to unload and reload it. But then
* if that were to fail, we are already committed
* to transmitting the packet (can't put it back
* on the queue), so we have to drop the packet.
*/
WM_EVCNT_INCR(&sc->sc_ev_txpullup_fail);
log(LOG_ERR, "%s: wm_tx_offload: packet headers did "
"not fit in first mbuf, packet dropped\n",
sc->sc_dev.dv_xname);
m_freem(txs->txs_mbuf);
txs->txs_mbuf = NULL;
return (EINVAL);
}
m0 = txs->txs_mbuf;
}
ip = (struct ip *) (mtod(m0, caddr_t) + offset);
@ -1717,14 +1752,11 @@ wm_start(struct ifnet *ifp)
txs->txs_firstdesc = sc->sc_txnext;
txs->txs_ndesc = segs_needed;
/*
* Set up checksum offload parameters for
* this packet.
*/
/* Set up offload parameters for this packet. */
if (m0->m_pkthdr.csum_flags &
(M_CSUM_IPv4|M_CSUM_TCPv4|M_CSUM_UDPv4)) {
if (wm_tx_cksum(sc, txs, &cksumcmd,
&cksumfields) != 0) {
if (wm_tx_offload(sc, txs, &cksumcmd,
&cksumfields) != 0) {
/* Error message already displayed. */
bus_dmamap_unload(sc->sc_dmat, dmamap);
continue;