#include <linux/netdev_features.h>
#include <net/flow_keys.h>
+/* A. Checksumming of received packets by device.
+ *
+ * CHECKSUM_NONE:
+ *
+ * Device failed to checksum this packet e.g. due to lack of capabilities.
+ * The packet contains full (though not verified) checksum in packet but
+ * not in skb->csum. Thus, skb->csum is undefined in this case.
+ *
+ * CHECKSUM_UNNECESSARY:
+ *
+ * The hardware you're dealing with doesn't calculate the full checksum
+ * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
+ * for specific protocols e.g. TCP/UDP/SCTP, then, for such packets it will
+ * set CHECKSUM_UNNECESSARY if their checksums are okay. skb->csum is still
+ * undefined in this case though. It is a bad option, but, unfortunately,
+ * nowadays most vendors do this. Apparently with the secret goal to sell
+ * you new devices, when you will add new protocol to your host, f.e. IPv6 8)
+ *
+ * CHECKSUM_COMPLETE:
+ *
+ * This is the most generic way. The device supplied checksum of the _whole_
+ * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
+ * hardware doesn't need to parse L3/L4 headers to implement this.
+ *
+ * Note: Even if device supports only some protocols, but is able to produce
+ * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
+ *
+ * CHECKSUM_PARTIAL:
+ *
+ * This is identical to the case for output below. This may occur on a packet
+ * received directly from another Linux OS, e.g., a virtualized Linux kernel
+ * on the same host. The packet can be treated in the same way as
+ * CHECKSUM_UNNECESSARY, except that on output (i.e., forwarding) the
+ * checksum must be filled in by the OS or the hardware.
+ *
+ * B. Checksumming on output.
+ *
+ * CHECKSUM_NONE:
+ *
+ * The skb was already checksummed by the protocol, or a checksum is not
+ * required.
+ *
+ * CHECKSUM_PARTIAL:
+ *
+ * The device is required to checksum the packet as seen by hard_start_xmit()
+ * from skb->csum_start up to the end, and to record/write the checksum at
+ * offset skb->csum_start + skb->csum_offset.
+ *
+ * The device must show its capabilities in dev->features, set up at device
+ * setup time, e.g. netdev_features.h:
+ *
+ * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything.
+ * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over
+ * IPv4. Sigh. Vendors like this way for an unknown reason.
+ * Though, see comment above about CHECKSUM_UNNECESSARY. 8)
+ * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead.
+ * NETIF_F_... - Well, you get the picture.
+ *
+ * CHECKSUM_UNNECESSARY:
+ *
+ * Normally, the device will do per protocol specific checksumming. Protocol
+ * implementations that do not want the NIC to perform the checksum
+ * calculation should use this flag in their outgoing skbs.
+ *
+ * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC
+ * offload. Correspondingly, the FCoE protocol driver
+ * stack should use CHECKSUM_UNNECESSARY.
+ *
+ * Any questions? No questions, good. --ANK
+ */
+
/* Don't change this without changing skb_csum_unnecessary! */
-#define CHECKSUM_NONE 0
-#define CHECKSUM_UNNECESSARY 1
-#define CHECKSUM_COMPLETE 2
-#define CHECKSUM_PARTIAL 3
+#define CHECKSUM_NONE 0
+#define CHECKSUM_UNNECESSARY 1
+#define CHECKSUM_COMPLETE 2
+#define CHECKSUM_PARTIAL 3
#define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
~(SMP_CACHE_BYTES - 1))
SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
-/* A. Checksumming of received packets by device.
- *
- * NONE: device failed to checksum this packet.
- * skb->csum is undefined.
- *
- * UNNECESSARY: device parsed packet and wouldbe verified checksum.
- * skb->csum is undefined.
- * It is bad option, but, unfortunately, many of vendors do this.
- * Apparently with secret goal to sell you new device, when you
- * will add new protocol to your host. F.e. IPv6. 8)
- *
- * COMPLETE: the most generic way. Device supplied checksum of _all_
- * the packet as seen by netif_rx in skb->csum.
- * NOTE: Even if device supports only some protocols, but
- * is able to produce some skb->csum, it MUST use COMPLETE,
- * not UNNECESSARY.
- *
- * PARTIAL: identical to the case for output below. This may occur
- * on a packet received directly from another Linux OS, e.g.,
- * a virtualised Linux kernel on the same host. The packet can
- * be treated in the same way as UNNECESSARY except that on
- * output (i.e., forwarding) the checksum must be filled in
- * by the OS or the hardware.
- *
- * B. Checksumming on output.
- *
- * NONE: skb is checksummed by protocol or csum is not required.
- *
- * PARTIAL: device is required to csum packet as seen by hard_start_xmit
- * from skb->csum_start to the end and to record the checksum
- * at skb->csum_start + skb->csum_offset.
- *
- * Device must show its capabilities in dev->features, set
- * at device setup time.
- * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
- * everything.
- * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
- * TCP/UDP over IPv4. Sigh. Vendors like this
- * way by an unknown reason. Though, see comment above
- * about CHECKSUM_UNNECESSARY. 8)
- * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
- *
- * UNNECESSARY: device will do per protocol specific csum. Protocol drivers
- * that do not want net to perform the checksum calculation should use
- * this flag in their outgoing skbs.
- * NETIF_F_FCOE_CRC this indicates the device can do FCoE FC CRC
- * offload. Correspondingly, the FCoE protocol driver
- * stack should use CHECKSUM_UNNECESSARY.
- *
- * Any questions? No questions, good. --ANK
- */
-
struct net_device;
struct scatterlist;
struct pipe_inode_info;
unsigned int to, struct ts_config *config,
struct ts_state *state);
-void __skb_get_rxhash(struct sk_buff *skb);
-static inline __u32 skb_get_rxhash(struct sk_buff *skb)
+/*
+ * Packet hash types specify the type of hash in skb_set_hash.
+ *
+ * Hash types refer to the protocol layer addresses which are used to
+ * construct a packet's hash. The hashes are used to differentiate or identify
+ * flows of the protocol layer for the hash type. Hash types are either
+ * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
+ *
+ * Properties of hashes:
+ *
+ * 1) Two packets in different flows have different hash values
+ * 2) Two packets in the same flow should have the same hash value
+ *
+ * A hash at a higher layer is considered to be more specific. A driver should
+ * set the most specific hash possible.
+ *
+ * A driver cannot indicate a more specific hash than the layer at which a hash
+ * was computed. For instance an L3 hash cannot be set as an L4 hash.
+ *
+ * A driver may indicate a hash level which is less specific than the
+ * actual layer the hash was computed on. For instance, a hash computed
+ * at L4 may be considered an L3 hash. This should only be done if the
+ * driver can't unambiguously determine that the HW computed the hash at
+ * the higher layer. Note that the "should" in the second property above
+ * permits this.
+ */
+enum pkt_hash_types {
+ PKT_HASH_TYPE_NONE, /* Undefined type */
+ PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
+ PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
+ PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
+};
+
+static inline void
+skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
+{
+ skb->l4_rxhash = (type == PKT_HASH_TYPE_L4);
+ skb->rxhash = hash;
+}
+
+void __skb_get_hash(struct sk_buff *skb);
+static inline __u32 skb_get_hash(struct sk_buff *skb)
{
if (!skb->l4_rxhash)
- __skb_get_rxhash(skb);
+ __skb_get_hash(skb);
return skb->rxhash;
}
+static inline void skb_clear_hash(struct sk_buff *skb)
+{
+ skb->rxhash = 0;
+ skb->l4_rxhash = 0;
+}
+
+static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
+{
+ if (!skb->l4_rxhash)
+ skb_clear_hash(skb);
+}
+
+static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
+{
+ to->rxhash = from->rxhash;
+ to->l4_rxhash = from->l4_rxhash;
+};
+
#ifdef NET_SKBUFF_DATA_USES_OFFSET
static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
{
skb->mac_header += offset;
}
+static inline void skb_pop_mac_header(struct sk_buff *skb)
+{
+ skb->mac_header = skb->network_header;
+}
+
static inline void skb_probe_transport_header(struct sk_buff *skb,
const int offset_hint)
{
unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
+/**
+ * pskb_trim_rcsum - trim received skb and update checksum
+ * @skb: buffer to trim
+ * @len: new length
+ *
+ * This is exactly the same as pskb_trim except that it ensures the
+ * checksum of received packets are still valid after the operation.
+ */
+
+static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
+{
+ if (likely(len >= skb->len))
+ return 0;
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ skb->ip_summed = CHECKSUM_NONE;
+ return __pskb_trim(skb, len);
+}
+
#define skb_queue_walk(queue, skb) \
for (skb = (queue)->next; \
skb != (struct sk_buff *)(queue); \
__wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
__wsum csum);
-/**
- * pskb_trim_rcsum - trim received skb and update checksum
- * @skb: buffer to trim
- * @len: new length
- *
- * This is exactly the same as pskb_trim except that it ensures the
- * checksum of received packets are still valid after the operation.
- */
-
-static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
-{
- if (likely(len >= skb->len))
- return 0;
- if (skb->ip_summed == CHECKSUM_COMPLETE) {
- __wsum adj = skb_checksum(skb, len, skb->len - len, 0);
-
- skb->csum = csum_sub(skb->csum, adj);
- }
- return __pskb_trim(skb, len);
-}
-
static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
int len, void *buffer)
{
return buffer;
}
+/**
+ * skb_needs_linearize - check if we need to linearize a given skb
+ * depending on the given device features.
+ * @skb: socket buffer to check
+ * @features: net device features
+ *
+ * Returns true if either:
+ * 1. skb has frag_list and the device doesn't support FRAGLIST, or
+ * 2. skb is fragmented and the device does not support SG.
+ */
+static inline bool skb_needs_linearize(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ return skb_is_nonlinear(skb) &&
+ ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
+ (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
+}
+
static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
void *to,
const unsigned int len)
* Ethernet MAC Drivers should call this function in their hard_xmit()
* function immediately before giving the sk_buff to the MAC hardware.
*
+ * Specifically, one should make absolutely sure that this function is
+ * called before TX completion of this packet can trigger. Otherwise
+ * the packet could potentially already be freed.
+ *
* @skb: A socket buffer.
*/
static inline void skb_tx_timestamp(struct sk_buff *skb)
projects / ~andy / linux / blobdiff