From e2d617c0ccf658a55552955f07018ecfa0135210 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Mon, 25 Mar 2013 01:08:17 +0000 Subject: xen-netfront: remove unused variable `extra' This variable is supposed to hold reference to the last extra_info in the loop. However there is only type of extra info here and the loop to process extra info is missing, so this variable is never used and causes confusion. Remove it at the moment. We can add it back when necessary. Signed-off-by: Wei Liu Reviewed-by: David Vrabel Signed-off-by: David S. Miller --- drivers/net/xen-netfront.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'drivers/net/xen-netfront.c') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 7ffa43bd7cf..55276635e69 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -537,7 +537,6 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) struct netfront_info *np = netdev_priv(dev); struct netfront_stats *stats = this_cpu_ptr(np->stats); struct xen_netif_tx_request *tx; - struct xen_netif_extra_info *extra; char *data = skb->data; RING_IDX i; grant_ref_t ref; @@ -581,7 +580,6 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; - extra = NULL; tx->flags = 0; if (skb->ip_summed == CHECKSUM_PARTIAL) @@ -597,10 +595,7 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) gso = (struct xen_netif_extra_info *) RING_GET_REQUEST(&np->tx, ++i); - if (extra) - extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE; - else - tx->flags |= XEN_NETTXF_extra_info; + tx->flags |= XEN_NETTXF_extra_info; gso->u.gso.size = skb_shinfo(skb)->gso_size; gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4; @@ -609,7 +604,6 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) gso->type = XEN_NETIF_EXTRA_TYPE_GSO; gso->flags = 0; - extra = gso; } np->tx.req_prod_pvt = i + 1; -- cgit v1.2.3-70-g09d2 From 7158ff6d0c6aa3724fb51c6c11143d31e166eb1f Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Mon, 25 Mar 2013 01:08:19 +0000 Subject: xen-netfront: frags -> slots in xennet_get_responses This function is in fact counting the ring slots required for responses. Separate the concepts of ring slots and skb frags make the code clearer, as now netfront and netback can have different MAX_SKB_FRAGS, slot and frag are not mapped 1:1 any more. Signed-off-by: Wei Liu Reviewed-by: David Vrabel Signed-off-by: David S. Miller --- drivers/net/xen-netfront.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/net/xen-netfront.c') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 55276635e69..d9097a78696 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -712,7 +712,7 @@ static int xennet_get_responses(struct netfront_info *np, struct sk_buff *skb = xennet_get_rx_skb(np, cons); grant_ref_t ref = xennet_get_rx_ref(np, cons); int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD); - int frags = 1; + int slots = 1; int err = 0; unsigned long ret; @@ -756,27 +756,27 @@ next: if (!(rx->flags & XEN_NETRXF_more_data)) break; - if (cons + frags == rp) { + if (cons + slots == rp) { if (net_ratelimit()) - dev_warn(dev, "Need more frags\n"); + dev_warn(dev, "Need more slots\n"); err = -ENOENT; break; } - rx = RING_GET_RESPONSE(&np->rx, cons + frags); - skb = xennet_get_rx_skb(np, cons + frags); - ref = xennet_get_rx_ref(np, cons + frags); - frags++; + rx = RING_GET_RESPONSE(&np->rx, cons + slots); + skb = xennet_get_rx_skb(np, cons + slots); + ref = xennet_get_rx_ref(np, cons + slots); + slots++; } - if (unlikely(frags > max)) { + if (unlikely(slots > max)) { if (net_ratelimit()) dev_warn(dev, "Too many frags\n"); err = -E2BIG; } if (unlikely(err)) - np->rx.rsp_cons = cons + frags; + np->rx.rsp_cons = cons + slots; return err; } -- cgit v1.2.3-70-g09d2 From 697089dc13c52d668322ac6cb8548520de27ed0e Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Mon, 22 Apr 2013 02:20:40 +0000 Subject: xen-netfront: frags -> slots in log message Also fix a typo in comment. Signed-off-by: Wei Liu Acked-by: Ian Campbell Signed-off-by: David S. Miller --- drivers/net/xen-netfront.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/xen-netfront.c') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index d9097a78696..1bb2e2072a6 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -735,7 +735,7 @@ static int xennet_get_responses(struct netfront_info *np, /* * This definitely indicates a bug, either in this driver or in * the backend driver. In future this should flag the bad - * situation to the system controller to reboot the backed. + * situation to the system controller to reboot the backend. */ if (ref == GRANT_INVALID_REF) { if (net_ratelimit()) @@ -771,7 +771,7 @@ next: if (unlikely(slots > max)) { if (net_ratelimit()) - dev_warn(dev, "Too many frags\n"); + dev_warn(dev, "Too many slots\n"); err = -E2BIG; } -- cgit v1.2.3-70-g09d2 From 9ecd1a75d977e2e8c48139c7d3efed183f898d94 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Mon, 22 Apr 2013 02:20:41 +0000 Subject: xen-netfront: reduce gso_max_size to account for max TCP header The maximum packet including header that can be handled by netfront / netback wire format is 65535. Reduce gso_max_size accordingly. Drop skb and print warning when skb->len > 65535. This can 1) save the effort to send malformed packet to netback, 2) help spotting misconfiguration of netfront in the future. Signed-off-by: Wei Liu Acked-by: Ian Campbell Signed-off-by: David S. Miller --- drivers/net/xen-netfront.c | 17 +++++++++++++++-- include/xen/interface/io/netif.h | 1 + 2 files changed, 16 insertions(+), 2 deletions(-) (limited to 'drivers/net/xen-netfront.c') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 1bb2e2072a6..1db10141506 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -36,7 +36,7 @@ #include #include #include -#include +#include #include #include #include @@ -547,6 +547,16 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) unsigned int len = skb_headlen(skb); unsigned long flags; + /* If skb->len is too big for wire format, drop skb and alert + * user about misconfiguration. + */ + if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { + net_alert_ratelimited( + "xennet: skb->len = %u, too big for wire format\n", + skb->len); + goto drop; + } + slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) + xennet_count_skb_frag_slots(skb); if (unlikely(slots > MAX_SKB_FRAGS + 1)) { @@ -1058,7 +1068,8 @@ err: static int xennet_change_mtu(struct net_device *dev, int mtu) { - int max = xennet_can_sg(dev) ? 65535 - ETH_HLEN : ETH_DATA_LEN; + int max = xennet_can_sg(dev) ? + XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN; if (mtu > max) return -EINVAL; @@ -1362,6 +1373,8 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev) SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops); SET_NETDEV_DEV(netdev, &dev->dev); + netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER); + np->netdev = netdev; netif_carrier_off(netdev); diff --git a/include/xen/interface/io/netif.h b/include/xen/interface/io/netif.h index 9dfc1200098..58fadcac33a 100644 --- a/include/xen/interface/io/netif.h +++ b/include/xen/interface/io/netif.h @@ -47,6 +47,7 @@ #define _XEN_NETTXF_extra_info (3) #define XEN_NETTXF_extra_info (1U<<_XEN_NETTXF_extra_info) +#define XEN_NETIF_MAX_TX_SIZE 0xFFFF struct xen_netif_tx_request { grant_ref_t gref; /* Reference to buffer page */ uint16_t offset; /* Offset within buffer page */ -- cgit v1.2.3-70-g09d2