This patch provides generic Large Receive Offload (LRO) functionality
for IPv4/TCP traffic.
LRO combines received tcp packets to a single larger tcp packet and
passes them then to the network stack in order to increase performance
(throughput). The interface supports two modes: Drivers can either pass
SKBs or fragment lists to the LRO engine.
Signed-off-by: Jan-Bernd Themann <[EMAIL PROTECTED]>
---
include/linux/inet_lro.h | 177 ++++++++++++++
net/ipv4/Kconfig | 8 +
net/ipv4/Makefile | 1 +
net/ipv4/inet_lro.c | 600 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 786 insertions(+), 0 deletions(-)
create mode 100644 include/linux/inet_lro.h
create mode 100644 net/ipv4/inet_lro.c
diff --git a/include/linux/inet_lro.h b/include/linux/inet_lro.h
new file mode 100644
index 0000000..e1fc1d1
--- /dev/null
+++ b/include/linux/inet_lro.h
@@ -0,0 +1,177 @@
+/*
+ * linux/include/linux/inet_lro.h
+ *
+ * Large Receive Offload (ipv4 / tcp)
+ *
+ * (C) Copyright IBM Corp. 2007
+ *
+ * Authors:
+ * Jan-Bernd Themann <[EMAIL PROTECTED]>
+ * Christoph Raisch <[EMAIL PROTECTED]>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __INET_LRO_H_
+#define __INET_LRO_H_
+
+#include <net/ip.h>
+#include <net/tcp.h>
+
+/*
+ * LRO statistics
+ */
+
+struct net_lro_stats {
+ unsigned long aggregated;
+ unsigned long flushed;
+ unsigned long no_desc;
+};
+
+/*
+ * LRO descriptor for a tcp session
+ */
+struct net_lro_desc {
+ struct sk_buff *parent;
+ struct sk_buff *last_skb;
+ struct skb_frag_struct *next_frag;
+ struct iphdr *iph;
+ struct tcphdr *tcph;
+ struct vlan_group *vgrp;
+ __wsum data_csum;
+ u32 tcp_rcv_tsecr;
+ u32 tcp_rcv_tsval;
+ u32 tcp_ack;
+ u32 tcp_next_seq;
+ u32 skb_tot_frags_len;
+ u16 ip_tot_len;
+ u16 tcp_saw_tstamp; /* timestamps enabled */
+ u16 tcp_window;
+ u16 vlan_tag;
+ int pkt_aggr_cnt; /* counts aggregated packets */
+ int vlan_packet;
+ int mss;
+ int active;
+};
+
+/*
+ * Large Receive Offload (LRO) Manager
+ *
+ * Fields must be set by driver
+ */
+
+struct net_lro_mgr {
+ struct net_device *dev;
+ struct net_lro_stats stats;
+
+ /* LRO features */
+ unsigned long features;
+#define LRO_F_NAPI 1 /* Pass packets to stack via NAPI */
+#define LRO_F_EXTRACT_VLAN_ID 2 /* Set flag if VLAN IDs are extracted
+ from received packets and eth protocol
+ is still ETH_P_8021Q */
+
+ u32 ip_summed; /* Set in non generated SKBs in page mode */
+ u32 ip_summed_aggr; /* Set in aggregated SKBs: CHECKSUM_UNNECESSARY
+ * or CHECKSUM_NONE */
+
+ int max_desc; /* Max number of LRO descriptors */
+ int max_aggr; /* Max number of LRO packets to be aggregated */
+
+ struct net_lro_desc *lro_arr; /* Array of LRO descriptors */
+
+ /*
+ * Optimized driver functions
+ *
+ * get_skb_header: returns tcp and ip header for packet in SKB
+ */
+ int (*get_skb_header)(struct sk_buff *skb, void **ip_hdr,
+ void **tcpudp_hdr, u64 *hdr_flags, void *priv);
+
+ /* hdr_flags: */
+#define LRO_IPV4 1 /* ip_hdr is IPv4 header */
+#define LRO_TCP 2 /* tcpudp_hdr is TCP header */
+
+ /*
+ * get_frag_header: returns mac, tcp and ip header for packet in SKB
+ *
+ * @hdr_flags: Indicate what kind of LRO has to be done
+ * (IPv4/IPv6/TCP/UDP)
+ */
+ int (*get_frag_header)(struct skb_frag_struct *frag, void **mac_hdr,
+ void **ip_hdr, void **tcpudp_hdr, u64 *hdr_flags,
+ void *priv);
+};
+
+/*
+ * Processes a SKB
+ *
+ * @lro_mgr: LRO manager to use
+ * @skb: SKB to aggregate
+ * @priv: Private data that may be used by driver functions
+ * (for example get_tcp_ip_hdr)
+ */
+
+void lro_receive_skb(struct net_lro_mgr *lro_mgr,
+ struct sk_buff *skb,
+ void *priv);
+
+/*
+ * Processes a SKB with VLAN HW acceleration support
+ */
+
+void lro_vlan_hwaccel_receive_skb(struct net_lro_mgr *lro_mgr,
+ struct sk_buff *skb,
+ struct vlan_group *vgrp,
+ u16 vlan_tag,
+ void *priv);
+
+/*
+ * Processes a fragment list
+ *
+ * This functions aggregate fragments and generate SKBs do pass
+ * the packets to the stack.
+ *
+ * @lro_mgr: LRO manager to use
+ * @frags: Fragment to be processed. Must contain entire header in first
+ * element.
+ * @len: Length of received data
+ * @true_size: Actual size of memory the fragment is consuming
+ * @priv: Private data that may be used by driver functions
+ * (for example get_tcp_ip_hdr)
+ */
+
+void lro_receive_frags(struct net_lro_mgr *lro_mgr,
+ struct skb_frag_struct *frags,
+ int len, int true_size, void *priv, __wsum sum);
+
+void lro_vlan_hwaccel_receive_frags(struct net_lro_mgr *lro_mgr,
+ struct skb_frag_struct *frags,
+ int len, int true_size,
+ struct vlan_group *vgrp,
+ u16 vlan_tag,
+ void *priv, __wsum sum);
+
+/*
+ * Forward all aggregated SKBs held by lro_mgr to network stack
+ */
+
+void lro_flush_all(struct net_lro_mgr *lro_mgr);
+
+void lro_flush_pkt(struct net_lro_mgr *lro_mgr,
+ struct iphdr *iph, struct tcphdr *tcph);
+
+#endif
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index fb79097..d894f61 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -394,6 +394,14 @@ config INET_XFRM_MODE_BEET
If unsure, say Y.
+config INET_LRO
+ tristate "Large Receive Offload (ipv4/tcp)"
+
+ ---help---
+ Support for Large Receive Offload (ipv4/tcp).
+
+ If unsure, say Y.
+
config INET_DIAG
tristate "INET: socket monitoring interface"
default y
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index fbf1674..a02c36d 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_INET_ESP) += esp4.o
obj-$(CONFIG_INET_IPCOMP) += ipcomp.o
obj-$(CONFIG_INET_XFRM_TUNNEL) += xfrm4_tunnel.o
obj-$(CONFIG_INET_XFRM_MODE_BEET) += xfrm4_mode_beet.o
+obj-$(CONFIG_INET_LRO) += inet_lro.o
obj-$(CONFIG_INET_TUNNEL) += tunnel4.o
obj-$(CONFIG_INET_XFRM_MODE_TRANSPORT) += xfrm4_mode_transport.o
obj-$(CONFIG_INET_XFRM_MODE_TUNNEL) += xfrm4_mode_tunnel.o
diff --git a/net/ipv4/inet_lro.c b/net/ipv4/inet_lro.c
new file mode 100644
index 0000000..3309adc
--- /dev/null
+++ b/net/ipv4/inet_lro.c
@@ -0,0 +1,600 @@
+/*
+ * linux/net/ipv4/inet_lro.c
+ *
+ * Large Receive Offload (ipv4 / tcp)
+ *
+ * (C) Copyright IBM Corp. 2007
+ *
+ * Authors:
+ * Jan-Bernd Themann <[EMAIL PROTECTED]>
+ * Christoph Raisch <[EMAIL PROTECTED]>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <linux/module.h>
+#include <linux/if_vlan.h>
+#include <linux/inet_lro.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jan-Bernd Themann <[EMAIL PROTECTED]>");
+MODULE_DESCRIPTION("Large Receive Offload (ipv4 / tcp)");
+
+#define TCP_HDR_LEN(tcph) (tcph->doff << 2)
+#define IP_HDR_LEN(iph) (iph->ihl << 2)
+#define TCP_PAYLOAD_LENGTH(iph, tcph) \
+ (ntohs(iph->tot_len) - IP_HDR_LEN(iph) - TCP_HDR_LEN(tcph))
+
+#define IPH_LEN_WO_OPTIONS 5
+#define TCPH_LEN_WO_OPTIONS 5
+#define TCPH_LEN_W_TIMESTAMP 8
+
+#define LRO_MAX_PG_HLEN 64
+
+#define LRO_INC_STATS(lro_mgr, attr) { lro_mgr->stats.attr++; }
+
+/*
+ * Basic tcp checks whether packet is suitable for LRO
+ */
+
+static int lro_tcp_ip_check(struct iphdr *iph, struct tcphdr *tcph,
+ int len, struct net_lro_desc *lro_desc)
+{
+ /* check ip header: don't aggregate padded frames */
+ if (ntohs(iph->tot_len) != len)
+ return -1;
+
+ if (TCP_PAYLOAD_LENGTH(iph, tcph) == 0)
+ return -1;
+
+ if (iph->ihl != IPH_LEN_WO_OPTIONS)
+ return -1;
+
+ if (tcph->cwr || tcph->ece || tcph->urg || !tcph->ack
+ || tcph->rst || tcph->syn || tcph->fin)
+ return -1;
+
+ if (INET_ECN_is_ce(ipv4_get_dsfield(iph)))
+ return -1;
+
+ if (tcph->doff != TCPH_LEN_WO_OPTIONS
+ && tcph->doff != TCPH_LEN_W_TIMESTAMP)
+ return -1;
+
+ /* check tcp options (only timestamp allowed) */
+ if (tcph->doff == TCPH_LEN_W_TIMESTAMP) {
+ u32 *topt = (u32 *)(tcph + 1);
+
+ if (*topt != htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16)
+ | (TCPOPT_TIMESTAMP << 8)
+ | TCPOLEN_TIMESTAMP))
+ return -1;
+
+ /* timestamp should be in right order */
+ topt++;
+ if (lro_desc && after(ntohl(lro_desc->tcp_rcv_tsval),
+ ntohl(*topt)))
+ return -1;
+
+ /* timestamp reply should not be zero */
+ topt++;
+ if (*topt == 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+static void lro_update_tcp_ip_header(struct net_lro_desc *lro_desc)
+{
+ struct iphdr *iph = lro_desc->iph;
+ struct tcphdr *tcph = lro_desc->tcph;
+ u32 *p;
+ __wsum tcp_hdr_csum;
+
+ tcph->ack_seq = lro_desc->tcp_ack;
+ tcph->window = lro_desc->tcp_window;
+
+ if (lro_desc->tcp_saw_tstamp) {
+ p = (u32 *)(tcph + 1);
+ *(p+2) = lro_desc->tcp_rcv_tsecr;
+ }
+
+ iph->tot_len = htons(lro_desc->ip_tot_len);
+
+ iph->check = 0;
+ iph->check = ip_fast_csum((u8 *)lro_desc->iph, iph->ihl);
+
+ tcph->check = 0;
+ tcp_hdr_csum = csum_partial((u8 *)tcph, TCP_HDR_LEN(tcph), 0);
+ lro_desc->data_csum = csum_add(lro_desc->data_csum, tcp_hdr_csum);
+ tcph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
+ lro_desc->ip_tot_len -
+ IP_HDR_LEN(iph), IPPROTO_TCP,
+ lro_desc->data_csum);
+}
+
+static __wsum lro_tcp_data_csum(struct iphdr *iph, struct tcphdr *tcph, int
len)
+{
+ __wsum tcp_csum;
+ __wsum tcp_hdr_csum;
+ __wsum tcp_ps_hdr_csum;
+
+ tcp_csum = ~csum_unfold(tcph->check);
+ tcp_hdr_csum = csum_partial((u8 *)tcph, TCP_HDR_LEN(tcph), tcp_csum);
+
+ tcp_ps_hdr_csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
+ len + TCP_HDR_LEN(tcph),
+ IPPROTO_TCP, 0);
+
+ return csum_sub(csum_sub(tcp_csum, tcp_hdr_csum),
+ tcp_ps_hdr_csum);
+}
+
+static void lro_init_desc(struct net_lro_desc *lro_desc, struct sk_buff *skb,
+ struct iphdr *iph, struct tcphdr *tcph,
+ u16 vlan_tag, struct vlan_group *vgrp)
+{
+ int nr_frags;
+ u32 *ptr;
+ u32 tcp_data_len = TCP_PAYLOAD_LENGTH(iph, tcph);
+
+ nr_frags = skb_shinfo(skb)->nr_frags;
+ lro_desc->parent = skb;
+ lro_desc->next_frag = &(skb_shinfo(skb)->frags[nr_frags]);
+ lro_desc->iph = iph;
+ lro_desc->tcph = tcph;
+ lro_desc->tcp_next_seq = ntohl(tcph->seq) + tcp_data_len;
+ lro_desc->tcp_ack = ntohl(tcph->ack_seq);
+ lro_desc->tcp_window = tcph->window;
+
+ lro_desc->pkt_aggr_cnt = 1;
+ lro_desc->ip_tot_len = ntohs(iph->tot_len);
+
+ if (tcph->doff == 8) {
+ ptr = (u32 *)(tcph+1);
+ lro_desc->tcp_saw_tstamp = 1;
+ lro_desc->tcp_rcv_tsval = *(ptr+1);
+ lro_desc->tcp_rcv_tsecr = *(ptr+2);
+ }
+
+ lro_desc->mss = tcp_data_len;
+ lro_desc->vgrp = vgrp;
+ lro_desc->vlan_tag = vlan_tag;
+ lro_desc->active = 1;
+
+ lro_desc->data_csum = lro_tcp_data_csum(iph, tcph,
+ tcp_data_len);
+}
+
+static inline void lro_clear_desc(struct net_lro_desc *lro_desc)
+{
+ memset(lro_desc, 0, sizeof(struct net_lro_desc));
+}
+
+static void lro_add_common(struct net_lro_desc *lro_desc, struct iphdr *iph,
+ struct tcphdr *tcph, int tcp_data_len)
+{
+ struct sk_buff *parent = lro_desc->parent;
+ u32 *topt;
+
+ lro_desc->pkt_aggr_cnt++;
+ lro_desc->ip_tot_len += tcp_data_len;
+ lro_desc->tcp_next_seq += tcp_data_len;
+ lro_desc->tcp_window = tcph->window;
+ lro_desc->tcp_ack = tcph->ack_seq;
+
+ /* don't update tcp_rcv_tsval, would not work with PAWS */
+ if (lro_desc->tcp_saw_tstamp) {
+ topt = (u32 *) (tcph + 1);
+ lro_desc->tcp_rcv_tsecr = *(topt + 2);
+ }
+
+ lro_desc->data_csum = csum_block_add(lro_desc->data_csum,
+ lro_tcp_data_csum(iph, tcph,
+ tcp_data_len),
+ parent->len);
+
+ parent->len += tcp_data_len;
+ parent->data_len += tcp_data_len;
+ if (tcp_data_len > lro_desc->mss)
+ lro_desc->mss = tcp_data_len;
+}
+
+static void lro_add_packet(struct net_lro_desc *lro_desc, struct sk_buff *skb,
+ struct iphdr *iph, struct tcphdr *tcph)
+{
+ struct sk_buff *parent = lro_desc->parent;
+ int tcp_data_len = TCP_PAYLOAD_LENGTH(iph, tcph);
+
+ lro_add_common(lro_desc, iph, tcph, tcp_data_len);
+
+ skb_pull(skb, (skb->len - tcp_data_len));
+ parent->truesize += skb->truesize;
+
+ if (lro_desc->last_skb)
+ lro_desc->last_skb->next = skb;
+ else
+ skb_shinfo(parent)->frag_list = skb;
+
+ lro_desc->last_skb = skb;
+}
+
+static void lro_add_frags(struct net_lro_desc *lro_desc,
+ int len, int hlen, int truesize,
+ struct skb_frag_struct *skb_frags,
+ struct iphdr *iph, struct tcphdr *tcph)
+{
+ struct sk_buff *skb = lro_desc->parent;
+ int tcp_data_len = TCP_PAYLOAD_LENGTH(iph, tcph);
+
+ lro_add_common(lro_desc, iph, tcph, tcp_data_len);
+
+ skb->truesize += truesize;
+
+ skb_frags[0].page_offset += hlen;
+ skb_frags[0].size -= hlen;
+
+ while (tcp_data_len > 0) {
+ *(lro_desc->next_frag) = *skb_frags;
+ tcp_data_len -= skb_frags->size;
+ lro_desc->next_frag++;
+ skb_frags++;
+ skb_shinfo(skb)->nr_frags++;
+ }
+}
+
+static int lro_check_tcp_conn(struct net_lro_desc *lro_desc,
+ struct iphdr *iph,
+ struct tcphdr *tcph)
+{
+ if ((lro_desc->iph->saddr != iph->saddr)
+ || (lro_desc->iph->daddr != iph->daddr)
+ || (lro_desc->tcph->source != tcph->source)
+ || (lro_desc->tcph->dest != tcph->dest))
+ return -1;
+ return 0;
+}
+
+static struct net_lro_desc *lro_get_desc(struct net_lro_mgr *lro_mgr,
+ struct net_lro_desc *lro_arr,
+ struct iphdr *iph,
+ struct tcphdr *tcph)
+{
+ struct net_lro_desc *lro_desc = NULL;
+ struct net_lro_desc *tmp;
+ int max_desc = lro_mgr->max_desc;
+ int i;
+
+ for (i = 0; i < max_desc; i++) {
+ tmp = &lro_arr[i];
+ if (tmp->active)
+ if (!lro_check_tcp_conn(tmp, iph, tcph)) {
+ lro_desc = tmp;
+ goto out;
+ }
+ }
+
+ for (i = 0; i < max_desc; i++) {
+ if (!lro_arr[i].active) {
+ lro_desc = &lro_arr[i];
+ goto out;
+ }
+ }
+
+ LRO_INC_STATS(lro_mgr, no_desc);
+out:
+ return lro_desc;
+}
+
+static void lro_flush(struct net_lro_mgr *lro_mgr,
+ struct net_lro_desc *lro_desc)
+{
+ if (lro_desc->pkt_aggr_cnt > 1)
+ lro_update_tcp_ip_header(lro_desc);
+
+ skb_shinfo(lro_desc->parent)->gso_size = lro_desc->mss;
+
+ if (lro_desc->vgrp) {
+ if (test_bit(LRO_F_NAPI, &lro_mgr->features))
+ vlan_hwaccel_receive_skb(lro_desc->parent,
+ lro_desc->vgrp,
+ lro_desc->vlan_tag);
+ else
+ vlan_hwaccel_rx(lro_desc->parent,
+ lro_desc->vgrp,
+ lro_desc->vlan_tag);
+
+ } else {
+ if (test_bit(LRO_F_NAPI, &lro_mgr->features))
+ netif_receive_skb(lro_desc->parent);
+ else
+ netif_rx(lro_desc->parent);
+ }
+
+ LRO_INC_STATS(lro_mgr, flushed);
+ lro_clear_desc(lro_desc);
+}
+
+static int __lro_proc_skb(struct net_lro_mgr *lro_mgr, struct sk_buff *skb,
+ struct vlan_group *vgrp, u16 vlan_tag, void *priv)
+{
+ struct net_lro_desc *lro_desc;
+ struct iphdr *iph;
+ struct tcphdr *tcph;
+ u64 flags;
+ int vlan_hdr_len = 0;
+
+ if (!lro_mgr->get_skb_header
+ || lro_mgr->get_skb_header(skb, (void *)&iph, (void *)&tcph,
+ &flags, priv))
+ goto out;
+
+ if (!(flags & LRO_IPV4) || !(flags & LRO_TCP))
+ goto out;
+
+ lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
+ if (!lro_desc)
+ goto out;
+
+ if ((skb->protocol == htons(ETH_P_8021Q))
+ && !test_bit(LRO_F_EXTRACT_VLAN_ID, &lro_mgr->features))
+ vlan_hdr_len = VLAN_HLEN;
+
+ if (!lro_desc->active) { /* start new lro session */
+ if (lro_tcp_ip_check(iph, tcph, skb->len - vlan_hdr_len, NULL))
+ goto out;
+
+ skb->ip_summed = lro_mgr->ip_summed_aggr;
+ lro_init_desc(lro_desc, skb, iph, tcph, vlan_tag, vgrp);
+ LRO_INC_STATS(lro_mgr, aggregated);
+ return 0;
+ }
+
+ if (lro_desc->tcp_next_seq != ntohl(tcph->seq))
+ goto out2;
+
+ if (lro_tcp_ip_check(iph, tcph, skb->len, lro_desc))
+ goto out2;
+
+ lro_add_packet(lro_desc, skb, iph, tcph);
+ LRO_INC_STATS(lro_mgr, aggregated);
+
+ if ((lro_desc->pkt_aggr_cnt >= lro_mgr->max_aggr) ||
+ lro_desc->parent->len > (0xFFFF - lro_mgr->dev->mtu))
+ lro_flush(lro_mgr, lro_desc);
+
+ return 0;
+
+out2: /* send aggregated SKBs to stack */
+ lro_flush(lro_mgr, lro_desc);
+
+out: /* Original SKB has to be posted to stack */
+ skb->ip_summed = lro_mgr->ip_summed;
+ return 1;
+}
+
+
+static struct sk_buff *lro_gen_skb(struct net_lro_mgr *lro_mgr,
+ struct skb_frag_struct *frags,
+ int len, int true_size,
+ void *mac_hdr,
+ int hlen, __wsum sum,
+ u32 ip_summed)
+{
+ struct sk_buff *skb;
+ struct skb_frag_struct *skb_frags;
+ int data_len = len;
+ int hdr_len = min(len, hlen);
+
+ skb = netdev_alloc_skb(lro_mgr->dev, hlen);
+ if (!skb)
+ return NULL;
+
+ skb->len = len;
+ skb->data_len = len - hdr_len;
+ skb->truesize += true_size;
+ skb->tail += hdr_len;
+
+ memcpy(skb->data, mac_hdr, hdr_len);
+
+ skb_frags = skb_shinfo(skb)->frags;
+ while (data_len > 0) {
+ *skb_frags = *frags;
+ data_len -= frags->size;
+ skb_frags++;
+ frags++;
+ skb_shinfo(skb)->nr_frags++;
+ }
+
+ skb_shinfo(skb)->frags[0].page_offset += hdr_len;
+ skb_shinfo(skb)->frags[0].size -= hdr_len;
+
+ skb->ip_summed = ip_summed;
+ skb->csum = sum;
+ skb->protocol = eth_type_trans(skb, lro_mgr->dev);
+ return skb;
+}
+
+static struct sk_buff *__lro_proc_segment(struct net_lro_mgr *lro_mgr,
+ struct skb_frag_struct *frags,
+ int len, int true_size,
+ struct vlan_group *vgrp,
+ u16 vlan_tag, void *priv, __wsum sum)
+{
+ struct net_lro_desc *lro_desc;
+ struct iphdr *iph;
+ struct tcphdr *tcph;
+ struct sk_buff *skb;
+ u64 flags;
+ void *mac_hdr;
+ int mac_hdr_len;
+ int hdr_len = LRO_MAX_PG_HLEN;
+ int vlan_hdr_len = 0;
+
+ if (!lro_mgr->get_frag_header
+ || lro_mgr->get_frag_header(frags, (void *)&mac_hdr, (void *)&iph,
+ (void *)&tcph, &flags, priv)) {
+ mac_hdr = page_address(frags->page) + frags->page_offset;
+ goto out1;
+ }
+
+ if (!(flags & LRO_IPV4) || !(flags & LRO_TCP))
+ goto out1;
+
+ hdr_len = (int)((void *)(tcph) + TCP_HDR_LEN(tcph) - mac_hdr);
+ mac_hdr_len = (int)((void *)(iph) - mac_hdr);
+
+ lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
+ if (!lro_desc)
+ goto out1;
+
+ if (!lro_desc->active) { /* start new lro session */
+ if (lro_tcp_ip_check(iph, tcph, len - mac_hdr_len, NULL))
+ goto out1;
+
+ skb = lro_gen_skb(lro_mgr, frags, len, true_size, mac_hdr,
+ hdr_len, 0, lro_mgr->ip_summed_aggr);
+ if (!skb)
+ goto out;
+
+ if ((skb->protocol == htons(ETH_P_8021Q))
+ && !test_bit(LRO_F_EXTRACT_VLAN_ID, &lro_mgr->features))
+ vlan_hdr_len = VLAN_HLEN;
+
+ iph = (void *)(skb->data + vlan_hdr_len);
+ tcph = (void *)((u8 *)skb->data + vlan_hdr_len
+ + IP_HDR_LEN(iph));
+
+ lro_init_desc(lro_desc, skb, iph, tcph, 0, NULL);
+ LRO_INC_STATS(lro_mgr, aggregated);
+ return 0;
+ }
+
+ if (lro_desc->tcp_next_seq != ntohl(tcph->seq))
+ goto out2;
+
+ if (lro_tcp_ip_check(iph, tcph, len - mac_hdr_len, lro_desc))
+ goto out2;
+
+ lro_add_frags(lro_desc, len, hdr_len, true_size, frags, iph, tcph);
+ LRO_INC_STATS(lro_mgr, aggregated);
+
+ if ((skb_shinfo(lro_desc->parent)->nr_frags >= lro_mgr->max_aggr) ||
+ lro_desc->parent->len > (0xFFFF - lro_mgr->dev->mtu))
+ lro_flush(lro_mgr, lro_desc);
+
+ return NULL;
+
+out2: /* send aggregated packets to the stack */
+ lro_flush(lro_mgr, lro_desc);
+
+out1: /* Original packet has to be posted to the stack */
+ skb = lro_gen_skb(lro_mgr, frags, len, true_size, mac_hdr,
+ hdr_len, sum, lro_mgr->ip_summed);
+out:
+ return skb;
+}
+
+void lro_receive_skb(struct net_lro_mgr *lro_mgr,
+ struct sk_buff *skb,
+ void *priv)
+{
+ if (__lro_proc_skb(lro_mgr, skb, NULL, 0, priv)) {
+ if (test_bit(LRO_F_NAPI, &lro_mgr->features))
+ netif_receive_skb(skb);
+ else
+ netif_rx(skb);
+ }
+}
+EXPORT_SYMBOL(lro_receive_skb);
+
+void lro_vlan_hwaccel_receive_skb(struct net_lro_mgr *lro_mgr,
+ struct sk_buff *skb,
+ struct vlan_group *vgrp,
+ u16 vlan_tag,
+ void *priv)
+{
+ if (__lro_proc_skb(lro_mgr, skb, vgrp, vlan_tag, priv)) {
+ if (test_bit(LRO_F_NAPI, &lro_mgr->features))
+ vlan_hwaccel_receive_skb(skb, vgrp, vlan_tag);
+ else
+ vlan_hwaccel_rx(skb, vgrp, vlan_tag);
+ }
+}
+EXPORT_SYMBOL(lro_vlan_hwaccel_receive_skb);
+
+void lro_receive_frags(struct net_lro_mgr *lro_mgr,
+ struct skb_frag_struct *frags,
+ int len, int true_size, void *priv, __wsum sum)
+{
+ struct sk_buff *skb;
+
+ skb = __lro_proc_segment(lro_mgr, frags, len, true_size, NULL, 0,
+ priv, sum);
+ if (!skb)
+ return;
+
+ if (test_bit(LRO_F_NAPI, &lro_mgr->features))
+ netif_receive_skb(skb);
+ else
+ netif_rx(skb);
+}
+EXPORT_SYMBOL(lro_receive_frags);
+
+void lro_vlan_hwaccel_receive_frags(struct net_lro_mgr *lro_mgr,
+ struct skb_frag_struct *frags,
+ int len, int true_size,
+ struct vlan_group *vgrp,
+ u16 vlan_tag, void *priv, __wsum sum)
+{
+ struct sk_buff *skb;
+
+ skb = __lro_proc_segment(lro_mgr, frags, len, true_size, vgrp,
+ vlan_tag, priv, sum);
+ if (!skb)
+ return;
+
+ if (test_bit(LRO_F_NAPI, &lro_mgr->features))
+ vlan_hwaccel_receive_skb(skb, vgrp, vlan_tag);
+ else
+ vlan_hwaccel_rx(skb, vgrp, vlan_tag);
+}
+EXPORT_SYMBOL(lro_vlan_hwaccel_receive_frags);
+
+void lro_flush_all(struct net_lro_mgr *lro_mgr)
+{
+ int i;
+ struct net_lro_desc *lro_desc = lro_mgr->lro_arr;
+
+ for (i = 0; i < lro_mgr->max_desc; i++) {
+ if (lro_desc[i].active)
+ lro_flush(lro_mgr, &lro_desc[i]);
+ }
+}
+EXPORT_SYMBOL(lro_flush_all);
+
+void lro_flush_pkt(struct net_lro_mgr *lro_mgr,
+ struct iphdr *iph, struct tcphdr *tcph)
+{
+ struct net_lro_desc *lro_desc;
+
+ lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
+ if (lro_desc->active)
+ lro_flush(lro_mgr, lro_desc);
+}
+EXPORT_SYMBOL(lro_flush_pkt);
--
1.5.2
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