if (err)
goto out_put;
+ set_dp_devs_mtu(dp, dev);
dp_sysfs_add_if(dp->ports[port_no]);
err = __put_user(port_no, &port.port);
#endif
#if defined(CONFIG_XEN) && defined(HAVE_PROTO_DATA_VALID)
-/* This code is copied verbatim from net/dev/core.c in Xen's
- * linux-2.6.18-92.1.10.el5.xs5.0.0.394.644. We can't call those functions
- * directly because they aren't exported. */
+/* This code is based on a skb_checksum_setup from net/dev/core.c from a
+ * combination of Lenny's 2.6.26 Xen kernel and Xen's
+ * linux-2.6.18-92.1.10.el5.xs5.0.0.394.644. We can't call this function
+ * directly because it isn't exported in all versions. */
static int skb_pull_up_to(struct sk_buff *skb, void *ptr)
{
if (ptr < (void *)skb->tail)
int vswitch_skb_checksum_setup(struct sk_buff *skb)
{
- if (skb->proto_csum_blank) {
- if (skb->protocol != htons(ETH_P_IP))
- goto out;
- if (!skb_pull_up_to(skb, skb->nh.iph + 1))
- goto out;
- skb->h.raw = (unsigned char *)skb->nh.iph + 4*skb->nh.iph->ihl;
- switch (skb->nh.iph->protocol) {
- case IPPROTO_TCP:
- skb->csum = offsetof(struct tcphdr, check);
- break;
- case IPPROTO_UDP:
- skb->csum = offsetof(struct udphdr, check);
- break;
- default:
- if (net_ratelimit())
- printk(KERN_ERR "Attempting to checksum a non-"
- "TCP/UDP packet, dropping a protocol"
- " %d packet", skb->nh.iph->protocol);
- goto out;
- }
- if (!skb_pull_up_to(skb, skb->h.raw + skb->csum + 2))
- goto out;
- skb->ip_summed = CHECKSUM_HW;
- skb->proto_csum_blank = 0;
+ struct iphdr *iph;
+ unsigned char *th;
+ int err = -EPROTO;
+ __u16 csum_start, csum_offset;
+
+ if (!skb->proto_csum_blank)
+ return 0;
+
+ if (skb->protocol != htons(ETH_P_IP))
+ goto out;
+
+ if (!skb_pull_up_to(skb, skb_network_header(skb) + 1))
+ goto out;
+
+ iph = ip_hdr(skb);
+ th = skb_network_header(skb) + 4 * iph->ihl;
+
+ csum_start = th - skb->head;
+ switch (iph->protocol) {
+ case IPPROTO_TCP:
+ csum_offset = offsetof(struct tcphdr, check);
+ break;
+ case IPPROTO_UDP:
+ csum_offset = offsetof(struct udphdr, check);
+ break;
+ default:
+ if (net_ratelimit())
+ printk(KERN_ERR "Attempting to checksum a non-"
+ "TCP/UDP packet, dropping a protocol"
+ " %d packet", iph->protocol);
+ goto out;
}
- return 0;
+
+ if (!skb_pull_up_to(skb, th + csum_offset + 2))
+ goto out;
+
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->proto_csum_blank = 0;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
+ skb->csum_start = csum_start;
+ skb->csum_offset = csum_offset;
+#else
+ skb_set_transport_header(skb, csum_start - skb_headroom(skb));
+ skb->csum = csum_offset;
+#endif
+
+ err = 0;
+
out:
- return -EPROTO;
+ return err;
}
#endif /* CONFIG_XEN && HAVE_PROTO_DATA_VALID */
+ /* Types of checksums that we can receive (these all refer to L4 checksums):
+ * 1. CHECKSUM_NONE: Device that did not compute checksum, contains full
+ * (though not verified) checksum in packet but not in skb->csum. Packets
+ * from the bridge local port will also have this type.
+ * 2. CHECKSUM_COMPLETE (CHECKSUM_HW): Good device that computes checksums,
+ * also the GRE module. This is the same as CHECKSUM_NONE, except it has
+ * a valid skb->csum. Importantly, both contain a full checksum (not
+ * verified) in the packet itself. The only difference is that if the
+ * packet gets to L4 processing on this machine (not in DomU) we won't
+ * have to recompute the checksum to verify. Most hardware devices do not
+ * produce packets with this type, even if they support receive checksum
+ * offloading (they produce type #5).
+ * 3. CHECKSUM_PARTIAL (CHECKSUM_HW): Packet without full checksum and needs to
+ * be computed if it is sent off box. Unfortunately on earlier kernels,
+ * this case is impossible to distinguish from #2, despite having opposite
+ * meanings. Xen adds an extra field on earlier kernels (see #4) in order
+ * to distinguish the different states. The only real user of this type
+ * with bridging is Xen (on later kernels).
+ * 4. CHECKSUM_UNNECESSARY (with proto_csum_blank true): This packet was
+ * generated locally by a Xen DomU and has a partial checksum. If it is
+ * handled on this machine (Dom0 or DomU), then the checksum will not be
+ * computed. If it goes off box, the checksum in the packet needs to
+ * completed. Calling skb_checksum_setup converts this to CHECKSUM_HW
+ * (CHECKSUM_PARTIAL) so that the checksum can be completed. In later
+ * kernels, this combination is replaced with CHECKSUM_PARTIAL.
+ * 5. CHECKSUM_UNNECESSARY (with proto_csum_blank false): Packet with a correct
+ * full checksum or using a protocol without a checksum. skb->csum is
+ * undefined. This is common from devices with receive checksum
+ * offloading. This is somewhat similar to CHECKSUM_NONE, except that
+ * nobody will try to verify the checksum with CHECKSUM_UNNECESSARY.
+ *
+ * Note that on earlier kernels, CHECKSUM_COMPLETE and CHECKSUM_PARTIAL are
+ * both defined as CHECKSUM_HW. Normally the meaning of CHECKSUM_HW is clear
+ * based on whether it is on the transmit or receive path. After the datapath
+ * it will be intepreted as CHECKSUM_PARTIAL. If the packet already has a
+ * checksum, we will panic. Since we can receive packets with checksums, we
+ * assume that all CHECKSUM_HW packets have checksums and map them to
+ * CHECKSUM_NONE, which has a similar meaning (the it is only different if the
+ * packet is processed by the local IP stack, in which case it will need to
+ * be reverified). If we receive a packet with CHECKSUM_HW that really means
+ * CHECKSUM_PARTIAL, it will be sent with the wrong checksum. However, there
+ * shouldn't be any devices that do this with bridging.
+ *
+ * The bridge has similar behavior and this function closely resembles
+ * skb_forward_csum(). It is slightly different because we are only concerned
+ * with bridging and not other types of forwarding and can get away with
+ * slightly more optimal behavior.*/
+void
+forward_ip_summed(struct sk_buff *skb)
+{
+#ifdef CHECKSUM_HW
+ if (skb->ip_summed == CHECKSUM_HW)
+ skb->ip_summed = CHECKSUM_NONE;
+#endif
+}
+
/* Append each packet in 'skb' list to 'queue'. There will be only one packet
* unless we broke up a GSO packet. */
static int
if (skb_queue_len(queue) >= DP_MAX_QUEUE_LEN)
goto err_kfree_skb;
+ forward_ip_summed(skb);
+
/* Break apart GSO packets into their component pieces. Otherwise
* userspace may try to stuff a 64kB packet into a 1500-byte MTU. */
if (skb_is_gso(skb)) {
return mtu ? mtu : ETH_DATA_LEN;
}
+/* Sets the MTU of all datapath devices to the minimum of the ports. 'dev'
+ * is the device whose MTU may have changed. Must be called with RTNL lock
+ * and dp_mutex. */
+void set_dp_devs_mtu(const struct datapath *dp, struct net_device *dev)
+{
+ struct net_bridge_port *p;
+ int mtu;
+
+ ASSERT_RTNL();
+
+ if (is_dp_dev(dev))
+ return;
+
+ mtu = dp_min_mtu(dp);
+
+ list_for_each_entry_rcu (p, &dp->port_list, node) {
+ struct net_device *br_dev = p->dev;
+
+ if (is_dp_dev(br_dev))
+ dev_set_mtu(br_dev, mtu);
+ }
+}
+
static int
put_port(const struct net_bridge_port *p, struct odp_port __user *uop)
{
git://git.onelab.eu / sliver-openvswitch.git / blobdiff