From e89e9cf539a28df7d0eb1d0a545368e9920b34ac Mon Sep 17 00:00:00 2001 From: Ananda Raju Date: Tue, 18 Oct 2005 15:46:41 -0700 Subject: [IPv4/IPv6]: UFO Scatter-gather approach Attached is kernel patch for UDP Fragmentation Offload (UFO) feature. 1. This patch incorporate the review comments by Jeff Garzik. 2. Renamed USO as UFO (UDP Fragmentation Offload) 3. udp sendfile support with UFO This patches uses scatter-gather feature of skb to generate large UDP datagram. Below is a "how-to" on changes required in network device driver to use the UFO interface. UDP Fragmentation Offload (UFO) Interface: ------------------------------------------- UFO is a feature wherein the Linux kernel network stack will offload the IP fragmentation functionality of large UDP datagram to hardware. This will reduce the overhead of stack in fragmenting the large UDP datagram to MTU sized packets 1) Drivers indicate their capability of UFO using dev->features |= NETIF_F_UFO | NETIF_F_HW_CSUM | NETIF_F_SG NETIF_F_HW_CSUM is required for UFO over ipv6. 2) UFO packet will be submitted for transmission using driver xmit routine. UFO packet will have a non-zero value for "skb_shinfo(skb)->ufo_size" skb_shinfo(skb)->ufo_size will indicate the length of data part in each IP fragment going out of the adapter after IP fragmentation by hardware. skb->data will contain MAC/IP/UDP header and skb_shinfo(skb)->frags[] contains the data payload. The skb->ip_summed will be set to CHECKSUM_HW indicating that hardware has to do checksum calculation. Hardware should compute the UDP checksum of complete datagram and also ip header checksum of each fragmented IP packet. For IPV6 the UFO provides the fragment identification-id in skb_shinfo(skb)->ip6_frag_id. The adapter should use this ID for generating IPv6 fragments. Signed-off-by: Ananda Raju Signed-off-by: Rusty Russell (forwarded) Signed-off-by: Arnaldo Carvalho de Melo --- include/linux/ethtool.h | 8 ++++++++ include/linux/netdevice.h | 1 + include/linux/skbuff.h | 7 +++++++ 3 files changed, 16 insertions(+) (limited to 'include') diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index ed1440ea4c9..d2c390eff1b 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -269,6 +269,8 @@ u32 ethtool_op_get_tso(struct net_device *dev); int ethtool_op_set_tso(struct net_device *dev, u32 data); int ethtool_op_get_perm_addr(struct net_device *dev, struct ethtool_perm_addr *addr, u8 *data); +u32 ethtool_op_get_ufo(struct net_device *dev); +int ethtool_op_set_ufo(struct net_device *dev, u32 data); /** * ðtool_ops - Alter and report network device settings @@ -298,6 +300,8 @@ int ethtool_op_get_perm_addr(struct net_device *dev, * set_sg: Turn scatter-gather on or off * get_tso: Report whether TCP segmentation offload is enabled * set_tso: Turn TCP segmentation offload on or off + * get_ufo: Report whether UDP fragmentation offload is enabled + * set_ufo: Turn UDP fragmentation offload on or off * self_test: Run specified self-tests * get_strings: Return a set of strings that describe the requested objects * phys_id: Identify the device @@ -364,6 +368,8 @@ struct ethtool_ops { int (*get_perm_addr)(struct net_device *, struct ethtool_perm_addr *, u8 *); int (*begin)(struct net_device *); void (*complete)(struct net_device *); + u32 (*get_ufo)(struct net_device *); + int (*set_ufo)(struct net_device *, u32); }; /* CMDs currently supported */ @@ -400,6 +406,8 @@ struct ethtool_ops { #define ETHTOOL_GTSO 0x0000001e /* Get TSO enable (ethtool_value) */ #define ETHTOOL_STSO 0x0000001f /* Set TSO enable (ethtool_value) */ #define ETHTOOL_GPERMADDR 0x00000020 /* Get permanent hardware address */ +#define ETHTOOL_GUFO 0x00000021 /* Get UFO enable (ethtool_value) */ +#define ETHTOOL_SUFO 0x00000022 /* Set UFO enable (ethtool_value) */ /* compatibility with older code */ #define SPARC_ETH_GSET ETHTOOL_GSET diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index a9281b24c40..c6efce4a04a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -308,6 +308,7 @@ struct net_device #define NETIF_F_VLAN_CHALLENGED 1024 /* Device cannot handle VLAN packets */ #define NETIF_F_TSO 2048 /* Can offload TCP/IP segmentation */ #define NETIF_F_LLTX 4096 /* LockLess TX */ +#define NETIF_F_UFO 8192 /* Can offload UDP Large Send*/ struct net_device *next_sched; diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index b756935da9c..4286d832166 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -137,6 +137,8 @@ struct skb_shared_info { unsigned int nr_frags; unsigned short tso_size; unsigned short tso_segs; + unsigned short ufo_size; + unsigned int ip6_frag_id; struct sk_buff *frag_list; skb_frag_t frags[MAX_SKB_FRAGS]; }; @@ -341,6 +343,11 @@ extern void skb_over_panic(struct sk_buff *skb, int len, extern void skb_under_panic(struct sk_buff *skb, int len, void *here); +extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, + int getfrag(void *from, char *to, int offset, + int len,int odd, struct sk_buff *skb), + void *from, int length); + struct skb_seq_state { __u32 lower_offset; -- cgit v1.2.3