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vrouter_mod.c
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vrouter_mod.c
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/*
* vrouter_mod.c -- linux vrouter module
*
* Copyright (c) 2013 Juniper Networks, Inc. All rights reserved.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/smp.h>
#include <linux/netdevice.h>
#include <linux/cpumask.h>
#include <linux/time.h>
#include <linux/highmem.h>
#include <linux/version.h>
#include <linux/if_vlan.h>
#include <linux/icmp.h>
#include "vr_packet.h"
#include "vr_interface.h"
#include "vr_sandesh.h"
#include "vrouter.h"
#include "vr_linux.h"
#include "vr_os.h"
#include "vr_compat.h"
#include "vr_hash.h"
#include "vr_fragment.h"
#include "vr_bridge.h"
#include "vr_packet.h"
#include "vr_flow.h"
unsigned int vr_num_cpus = 1;
extern unsigned int vr_bridge_entries;
extern unsigned int vr_bridge_oentries;
extern unsigned int vr_mpls_labels;
extern unsigned int vr_nexthops;
extern unsigned int vr_vrfs;
extern unsigned int vr_flow_hold_limit;
extern char *ContrailBuildInfo;
int vrouter_dbg;
extern struct vr_packet *linux_get_packet(struct sk_buff *,
struct vr_interface *);
extern int lh_enqueue_to_assembler(struct vrouter *, struct vr_packet *,
struct vr_forwarding_md *);
extern int vr_assembler_init(void);
extern void vr_assembler_exit(void);
struct work_arg {
struct work_struct wa_work;
void (*fn)(void *);
void *wa_arg;
};
struct rcu_cb_data {
struct rcu_head rcd_rcu;
vr_defer_cb rcd_user_cb;
struct vrouter *rcd_router;
unsigned char rcd_user_data[0];
};
extern int vrouter_init(void);
extern void vrouter_exit(bool);
extern int vr_genetlink_init(void);
extern void vr_genetlink_exit(void);
extern int vr_mem_init(void);
extern void vr_mem_exit(void);
extern void vr_malloc_stats(unsigned int, unsigned int);
extern void vr_free_stats(unsigned int);
extern void vhost_exit(void);
extern int lh_gro_process(struct vr_packet *, struct vr_interface *, bool);
static void lh_reset_skb_fields(struct vr_packet *pkt);
static int
lh_printk(const char *format, ...)
{
int printed;
va_list args;
va_start(args, format);
printed = vprintk(format, args);
va_end(args);
return printed;
}
static void *
lh_malloc(unsigned int size, unsigned int object)
{
void *mem = kmalloc(size, GFP_ATOMIC);
if (mem != NULL) {
vr_malloc_stats(size, object);
}
return mem;
}
static void *
lh_zalloc(unsigned int size, unsigned int object)
{
void *mem = kzalloc(size, GFP_ATOMIC);
if (mem != NULL) {
vr_malloc_stats(size, object);
}
return mem;
}
static void
lh_free(void *mem, unsigned int object)
{
if (mem) {
vr_free_stats(object);
kfree(mem);
}
return;
}
static void *
lh_page_alloc(unsigned int size)
{
unsigned int order;
if (size & (PAGE_SIZE - 1)) {
size += PAGE_SIZE;
size &= ~(PAGE_SIZE - 1);
}
order = get_order(size);
return (void *)__get_free_pages(GFP_ATOMIC | __GFP_ZERO | __GFP_COMP, order);
}
static void
lh_page_free(void *address, unsigned int size)
{
unsigned int order;
if (size & (PAGE_SIZE - 1)) {
size += PAGE_SIZE;
size &= ~(PAGE_SIZE - 1);
}
order = get_order(size);
free_pages((unsigned long)address, order);
return;
}
uint64_t
lh_vtop(void *address)
{
return (uint64_t)(virt_to_phys(address));
}
struct vr_packet *
lh_palloc(unsigned int size)
{
struct sk_buff *skb;
skb = alloc_skb(size, GFP_ATOMIC);
if (!skb)
return NULL;
return linux_get_packet(skb, NULL);
}
static struct vr_packet *
lh_pexpand_head(struct vr_packet *pkt, unsigned int hspace)
{
struct sk_buff *skb;
skb = vp_os_packet(pkt);
if (!skb)
return NULL;
if (pskb_expand_head(skb, hspace, 0, GFP_ATOMIC))
return NULL;
pkt->vp_head = skb->head;
pkt->vp_data += hspace;
pkt->vp_tail += hspace;
pkt->vp_end = skb_end_pointer(skb) - skb->head;
pkt->vp_network_h += hspace;
pkt->vp_inner_network_h += hspace;
return pkt;
}
static struct vr_packet *
lh_palloc_head(struct vr_packet *pkt, unsigned int size)
{
struct sk_buff *skb, *skb_head;
struct vr_packet *npkt;
skb = vp_os_packet(pkt);
if (!skb)
return NULL;
skb->data = pkt->vp_head + pkt->vp_data;
skb_set_tail_pointer(skb, pkt->vp_len);
skb->len = pkt->vp_len + skb->data_len;
skb_head = alloc_skb(size, GFP_ATOMIC);
if (!skb_head)
return NULL;
npkt = linux_get_packet(skb_head, pkt->vp_if);
if (!npkt)
return npkt;
npkt->vp_ttl = pkt->vp_ttl;
npkt->vp_flags = pkt->vp_flags;
npkt->vp_type = pkt->vp_type;
skb_frag_list_init(skb_head);
skb_frag_add_head(skb_head, skb);
skb_head->len += skb->len;
skb_head->data_len = skb->len;
skb_head->protocol = skb->protocol;
/* Copy the gso fields too */
skb_shinfo(skb_head)->gso_type = skb_shinfo(skb)->gso_type;
skb_shinfo(skb_head)->gso_size = skb_shinfo(skb)->gso_size;
skb_shinfo(skb_head)->gso_segs = skb_shinfo(skb)->gso_segs;
skb_head->ip_summed = skb->ip_summed;
skb_head->csum = skb->csum;
npkt->vp_network_h += pkt->vp_network_h + npkt->vp_end;
npkt->vp_inner_network_h += pkt->vp_inner_network_h + npkt->vp_end;
return npkt;
}
static struct vr_packet *
lh_pclone(struct vr_packet *pkt)
{
struct sk_buff *skb, *skb_c;
struct vr_packet *pkt_clone;
skb = vp_os_packet(pkt);
skb_c = skb_clone(skb, GFP_ATOMIC);
if (!skb_c)
return NULL;
pkt_clone = (struct vr_packet *)skb_c->cb;
pkt_clone->vp_cpu = vr_get_cpu();
return pkt_clone;
}
static void
lh_preset(struct vr_packet *pkt)
{
struct sk_buff *skb;
skb = vp_os_packet(pkt);
pkt->vp_data = skb->data - skb->head;
pkt->vp_tail = skb_tail_pointer(skb) - skb->head;
pkt->vp_len = skb_headlen(skb);
return;
}
static void
lh_pset_data(struct vr_packet *pkt, unsigned short offset)
{
unsigned int skb_head_len;
struct sk_buff *skb;
skb = vp_os_packet(pkt);
skb->data = pkt->vp_head + offset;
skb_head_len = skb_tail_pointer(skb) - skb->data;
skb->len = skb_head_len + skb->data_len;
return;
}
static unsigned int
lh_pgso_size(struct vr_packet *pkt)
{
struct sk_buff *skb = vp_os_packet(pkt);
return skb_shinfo(skb)->gso_size;
}
static void
lh_pfree(struct vr_packet *pkt, unsigned short reason)
{
struct vrouter *router = vrouter_get(0);
struct sk_buff *skb;
skb = vp_os_packet(pkt);
if (!skb)
return;
if (router)
((uint64_t *)(router->vr_pdrop_stats[pkt->vp_cpu]))[reason]++;
kfree_skb(skb);
return;
}
void
lh_pfree_skb(struct sk_buff *skb, unsigned short reason)
{
struct vrouter *router = vrouter_get(0);
unsigned int cpu;
cpu = vr_get_cpu();
if ((cpu < vr_num_cpus) && (router))
((uint64_t *)(router->vr_pdrop_stats[cpu]))[reason]++;
kfree_skb(skb);
return;
}
static int
lh_pcopy(unsigned char *dst, struct vr_packet *p_src,
unsigned int offset, unsigned int len)
{
int ret;
struct sk_buff *src;
src = vp_os_packet(p_src);
ret = skb_copy_bits(src, offset, dst, len);
if (ret)
return ret;
return len;
}
static unsigned short
lh_pfrag_len(struct vr_packet *pkt)
{
struct sk_buff *skb;
skb = vp_os_packet(pkt);
if (!skb)
return 0;
return skb->data_len;
}
static unsigned short
lh_phead_len(struct vr_packet *pkt)
{
struct sk_buff *skb;
skb = vp_os_packet(pkt);
if (!skb)
return 0;
return skb_headlen(skb);
}
static void
lh_get_time(unsigned long *sec, unsigned long *usec)
{
struct timeval t;
do_gettimeofday(&t);
*sec = t.tv_sec;
*usec = t.tv_usec;
return;
}
static unsigned int
lh_get_cpu(void)
{
unsigned int cpu = get_cpu();
put_cpu();
return cpu;
}
static void
lh_get_mono_time(unsigned int *sec, unsigned int *nsec)
{
struct timespec t;
uint64_t jiffies = get_jiffies_64();
jiffies_to_timespec(jiffies, &t);
*sec = t.tv_sec;
*nsec = t.tv_nsec;
return;
}
static void
lh_work(struct work_struct *work)
{
struct work_arg *wa = container_of(work, struct work_arg, wa_work);
rcu_read_lock();
wa->fn(wa->wa_arg);
rcu_read_unlock();
kfree(wa);
return;
}
static int
lh_schedule_work(unsigned int cpu, void (*fn)(void *), void *arg)
{
unsigned int alloc_flag;
struct work_arg *wa;
if (in_softirq()) {
alloc_flag = GFP_ATOMIC;
} else {
alloc_flag = GFP_KERNEL;
}
wa = kzalloc(sizeof(*wa), alloc_flag);
if (!wa)
return -ENOMEM;
wa->fn = fn;
wa->wa_arg = arg;
INIT_WORK(&wa->wa_work, lh_work);
schedule_work_on(cpu, &wa->wa_work);
return 0;
}
static void
lh_delay_op(void)
{
synchronize_net();
return;
}
static void *
lh_inner_network_header(struct vr_packet *pkt)
{
struct sk_buff *skb;
struct sk_buff *frag;
struct vr_packet *frag_pkt;
unsigned short off = pkt->vp_inner_network_h - pkt->vp_end;
skb = vp_os_packet(pkt);
while (skb_shinfo(skb)->frag_list) {
frag = skb_shinfo(skb)->frag_list;
frag_pkt = (struct vr_packet *)frag->cb;
if (off < frag_pkt->vp_end)
return frag_pkt->vp_head + off;
off -= frag_pkt->vp_end;
skb = frag;
}
return NULL;
}
/*
* lh_pheader_pointer - wrapper for skb_header_pointer
*/
static void *
lh_pheader_pointer(struct vr_packet *pkt, unsigned short hdr_len, void *buf)
{
int offset;
struct sk_buff *skb = vp_os_packet(pkt);
/*
* vp_data is the offset from the skb head. skb_header_pointer expects
* the offset from skb->data, so calculate this offset.
*/
offset = pkt->vp_data - (skb->data - skb->head);
return skb_header_pointer(skb, offset, hdr_len, buf);
}
static void
rcu_cb(struct rcu_head *rh)
{
struct rcu_cb_data *cb_data = (struct rcu_cb_data *)rh;
/* Call the user call back */
cb_data->rcd_user_cb(cb_data->rcd_router, cb_data->rcd_user_data);
lh_free(cb_data, VR_DEFER_OBJECT);
return;
}
static void
lh_defer(struct vrouter *router, vr_defer_cb user_cb, void *data)
{
struct rcu_cb_data *cb_data;
cb_data = container_of(data, struct rcu_cb_data, rcd_user_data);
cb_data->rcd_user_cb = user_cb;
cb_data->rcd_router = router;
call_rcu(&cb_data->rcd_rcu, rcu_cb);
return;
}
static void *
lh_get_defer_data(unsigned int len)
{
struct rcu_cb_data *cb_data;
if (!len)
return NULL;
cb_data = lh_malloc(sizeof(*cb_data) + len, VR_DEFER_OBJECT);
if (!cb_data) {
return NULL;
}
return cb_data->rcd_user_data;
}
static void
lh_put_defer_data(void *data)
{
struct rcu_cb_data *cb_data;
if (!data)
return;
cb_data = container_of(data, struct rcu_cb_data, rcd_user_data);
lh_free(cb_data, VR_DEFER_OBJECT);
return;
}
static int
lh_pcow(struct vr_packet **pktp, unsigned short head_room)
{
unsigned int old_off, new_off;
int data_off = 0;
struct vr_packet *pkt = *pktp;
struct sk_buff *skb = vp_os_packet(pkt);
data_off = pkt->vp_data - (skb->data - skb->head);
#ifdef NET_SKBUFF_DATA_USES_OFFSET
old_off = skb->network_header;
#else
old_off = skb->network_header - skb->head;
#endif
if (skb_cow(skb, head_room))
return -ENOMEM;
/* Now manipulate the offsets as data pointers are modified */
pkt->vp_head = skb->head;
pkt->vp_tail = skb_tail_pointer(skb) - skb->head;
/* The data_off, can be negative here */
pkt->vp_data = skb->data - skb->head + data_off;
pkt->vp_end = skb_end_pointer(skb) - skb->head;
/*
* pkt->vp_len is untouched, as it is going to be same
* before and after cow
*/
#ifdef NET_SKBUFF_DATA_USES_OFFSET
new_off = skb->network_header;
#else
new_off = skb->network_header - skb->head;
#endif
pkt->vp_network_h += new_off - old_off;
pkt->vp_inner_network_h += new_off - old_off;
return 0;
}
/*
* lh_get_udp_src_port - return a source port for the outer UDP header.
* The source port is based on a hash of the inner IP source/dest addresses,
* vrf (and inner TCP/UDP ports in the future). The label from fmd
* will be used in the future to detect whether it is a L2/L3 packet.
* Returns 0 on error, valid source port otherwise.
*/
static __u16
lh_get_udp_src_port(struct vr_packet *pkt, struct vr_forwarding_md *fmd,
unsigned short vrf)
{
struct sk_buff *skb = vp_os_packet(pkt);
int pull_len, hdr_len, hash_len;
__u32 hashval, port_range;
struct vr_ip *iph = NULL;
struct vr_ip6 *ip6h = NULL;
__u16 port;
__u16 sport = 0, dport = 0;
struct vr_fragment *frag;
struct vrouter *router = vrouter_get(0);
__u32 hash_key[10];
__u16 *l4_hdr;
struct vr_flow_entry *fentry;
if (hashrnd_inited == 0) {
get_random_bytes(&vr_hashrnd, sizeof(vr_hashrnd));
hashrnd_inited = 1;
}
if (pkt->vp_type == VP_TYPE_IP || pkt->vp_type == VP_TYPE_IP6) {
/*
* pull_len can be negative in the following calculation. This behavior
* will be true in case of mirroring. In mirroring, we do preset first
* which makes vp_data = skb->data, and then we push mirroring headers,
* which makes pull_len < 0 and thats why pull_len is an integer.
*/
if (pkt->vp_type == VP_TYPE_IP)
hdr_len = sizeof(struct iphdr);
else
hdr_len = sizeof(struct ipv6hdr);
pull_len = hdr_len;
pull_len += pkt_get_network_header_off(pkt);
pull_len -= skb_headroom(skb);
/* Lets pull only if ip hdr is beyond this skb */
if ((pkt_get_network_header_off(pkt) + hdr_len) >
pkt->vp_tail) {
/* We dont handle if tails are different */
#ifdef NET_SKBUFF_DATA_USES_OFFSET
if (pkt->vp_tail != skb->tail)
#else
if (pkt->vp_tail != (skb->tail - skb->head))
goto error;
#endif
/*
* pull_len has to be +ve here and hence additional check is not
* needed
*/
if (!pskb_may_pull(skb, (unsigned int)pull_len))
goto error;
}
iph = (struct vr_ip *)(skb->head + pkt_get_network_header_off(pkt));
if (pkt->vp_type == VP_TYPE_IP6) {
ip6h = (struct vr_ip6 *)iph;
if ((ip6h->ip6_nxt == VR_IP_PROTO_TCP) ||
(ip6h->ip6_nxt == VR_IP_PROTO_UDP)) {
/* Pull in L4 ports */
pull_len += 4;
if ((pull_len > 0) &&
!pskb_may_pull(skb,(unsigned int)pull_len)) {
goto error;
}
ip6h = (struct vr_ip6 *)(skb->head +
pkt_get_network_header_off(pkt));
l4_hdr = (__u16 *) (((char *) ip6h) + sizeof(struct vr_ip6));
sport = *l4_hdr;
dport = *(l4_hdr + 1);
}
} else if (vr_ip_transport_header_valid(iph)) {
if ((iph->ip_proto == VR_IP_PROTO_TCP) ||
(iph->ip_proto == VR_IP_PROTO_UDP)) {
pull_len += ((iph->ip_hl * 4) - sizeof(struct vr_ip) + 4);
if ((pull_len > 0) &&
!pskb_may_pull(skb,(unsigned int)pull_len)) {
goto error;
}
iph = (struct vr_ip *)(skb->head +
pkt_get_network_header_off(pkt));
l4_hdr = (__u16 *) (((char *) iph) + (iph->ip_hl * 4));
sport = *l4_hdr;
dport = *(l4_hdr + 1);
}
} else {
/*
* If this fragment required flow lookup, get the source and
* dst port from the frag entry. Otherwise, use 0 as the source
* dst port (which could result in fragments getting a different
* outer UDP source port than non-fragments in the same flow).
*/
frag = vr_fragment_get(router, vrf, iph);
if (frag) {
sport = frag->f_sport;
dport = frag->f_dport;
}
}
if (fmd && fmd->fmd_flow_index >= 0) {
fentry = vr_get_flow_entry(router, fmd->fmd_flow_index);
if (fentry) {
lh_reset_skb_fields(pkt);
return fentry->fe_udp_src_port;
}
}
hash_key[0] = vrf;
hash_key[1] = (sport << 16) | dport;
if (pkt->vp_type == VP_TYPE_IP)
memcpy(&hash_key[2], (char*)&iph->ip_saddr, 2 * VR_IP_ADDRESS_LEN);
else
memcpy(&hash_key[2], (char*)&ip6h->ip6_src, 2 * VR_IP6_ADDRESS_LEN);
hash_len = VR_FLOW_HASH_SIZE(pkt->vp_type);
hashval = jhash(hash_key, hash_len, vr_hashrnd);
lh_reset_skb_fields(pkt);
} else {
/* We treat all non-ip packets as L2 here. For V6 we can extract
* the required fieleds explicity and manipulate the src port
*/
if (pkt_head_len(pkt) < ETH_HLEN)
goto error;
hashval = vr_hash(pkt_data(pkt), ETH_HLEN, vr_hashrnd);
/* Include the VRF to calculate the hash */
hashval = vr_hash_2words(hashval, vrf, vr_hashrnd);
}
/*
* Convert the hash value to a value in the port range that we want
* for dynamic UDP ports
*/
port_range = VR_MUDP_PORT_RANGE_END - VR_MUDP_PORT_RANGE_START;
port = (__u16) (((u64) hashval * port_range) >> 32);
if (port > port_range) {
/*
* Shouldn't happen...
*/
port = 0;
}
return (port + VR_MUDP_PORT_RANGE_START);
error:
lh_reset_skb_fields(pkt);
return 0;
}
/*
* lh_adjust_tcp_mss - adjust the TCP MSS in the given packet based on
* vrouter physical interface MTU. Returns 0 on success, non-zero
* otherwise.
*/
static void
lh_adjust_tcp_mss(struct tcphdr *tcph, struct sk_buff *skb, unsigned short overlay_len, unsigned short hlen)
{
int opt_off = sizeof(struct tcphdr);
u8 *opt_ptr = (u8 *) tcph;
u16 pkt_mss, max_mss;
struct net_device *dev;
struct vrouter *router = vrouter_get(0);
if ((tcph == NULL) || (!tcph->syn) || (router == NULL)) {
return;
}
if (router->vr_eth_if == NULL) {
return;
}
while (opt_off < (tcph->doff*4)) {
switch (opt_ptr[opt_off]) {
case TCPOPT_EOL:
return;
case TCPOPT_NOP:
opt_off++;
continue;
case TCPOPT_MSS:
if ((opt_off + TCPOLEN_MSS) > (tcph->doff*4)) {
return;
}
if (opt_ptr[opt_off+1] != TCPOLEN_MSS) {
return;
}
pkt_mss = (opt_ptr[opt_off+2] << 8) | opt_ptr[opt_off+3];
dev = (struct net_device *) router->vr_eth_if->vif_os;
if (dev == NULL) {
return;
}
max_mss = dev->mtu -
(overlay_len + hlen + sizeof(struct tcphdr));
if (pkt_mss > max_mss) {
opt_ptr[opt_off+2] = (max_mss & 0xff00) >> 8;
opt_ptr[opt_off+3] = max_mss & 0xff;
inet_proto_csum_replace2(&tcph->check, skb,
htons(pkt_mss),
htons(max_mss), 0);
}
return;
default:
if ((opt_off + 1) == (tcph->doff*4)) {
return;
}
if (opt_ptr[opt_off+1]) {
opt_off += opt_ptr[opt_off+1];
} else {
opt_off++;
}
continue;
} /* switch */
} /* while */
return;
}
/*
* lh_pkt_from_vm_tcp_mss_adj - perform TCP MSS adjust, if required, for packets
* that are sent by a VM. Returns 0 on success, non-zero otherwise.
*/
static int
lh_pkt_from_vm_tcp_mss_adj(struct vr_packet *pkt, unsigned short overlay_len)
{
struct sk_buff *skb = vp_os_packet(pkt);
int hlen, pull_len, proto, opt_len = 0;
struct vr_ip *iph;
struct vr_ip6 *ip6h;
struct tcphdr *tcph;
/*
* Pull enough of the header into the linear part of the skb to be
* able to inspect/modify the TCP header MSS value.
*/
iph = (struct vr_ip *) (skb->head + pkt->vp_data);
pull_len = pkt->vp_data - (skb_headroom(skb));
/* Pull in ipv4 header-length */
pull_len += sizeof(struct vr_ip);
if (!pskb_may_pull(skb, pull_len)) {
return VP_DROP_PULL;
}
iph = (struct vr_ip *) (skb->head + pkt->vp_data);
if (vr_ip_is_ip6(iph)) {
pull_len += (sizeof(struct vr_ip6) - sizeof(struct vr_ip));
if (!pskb_may_pull(skb, pull_len)) {
return VP_DROP_PULL;
}
ip6h = (struct vr_ip6 *) (skb->head + pkt->vp_data);
proto = ip6h->ip6_nxt;
hlen = sizeof(struct vr_ip6);
} else if (vr_ip_is_ip4(iph)) {
/*
* If this is a fragment and not the first one, it can be ignored
*/
if (iph->ip_frag_off & htons(IP_OFFSET)) {
goto out;
}
proto = iph->ip_proto;
hlen = iph->ip_hl * 4;
opt_len = hlen - sizeof(struct vr_ip);
} else {
goto out;
}
if (proto != VR_IP_PROTO_TCP) {
goto out;
}
pull_len += sizeof(struct tcphdr) + opt_len;
if (!pskb_may_pull(skb, pull_len)) {
return VP_DROP_PULL;
}
tcph = (struct tcphdr *) ((char *) iph + hlen);
if ((tcph->doff << 2) <= (sizeof(struct tcphdr))) {
/*
* Nothing to do if there are no TCP options
*/
goto out;
}
pull_len += ((tcph->doff << 2) - (sizeof(struct tcphdr)));
if (!pskb_may_pull(skb, pull_len)) {
return VP_DROP_PULL;
}
iph = (struct vr_ip *) (skb->head + pkt->vp_data);
tcph = (struct tcphdr *) ((char *) iph + hlen);
lh_adjust_tcp_mss(tcph, skb, overlay_len, hlen);
out:
lh_reset_skb_fields(pkt);
return 0;
}
/*
* lh_reset_skb_fields - if the skb changes, possibley due to pskb_may_pull,
* reset fields of the pkt structure that point at the skb fields.
*/
static void
lh_reset_skb_fields(struct vr_packet *pkt)
{
struct sk_buff *skb = vp_os_packet(pkt);
pkt->vp_head = skb->head;
pkt->vp_tail = skb_tail_pointer(skb) - skb->head;
pkt->vp_end = skb_end_pointer(skb) - skb->head;
pkt->vp_len = pkt->vp_tail - pkt->vp_data;
return;
}
/*
* lh_csum_verify_fast - faster version of skb_checksum which avoids a call
* to kmap_atomic/kunmap_atomic as we already have a pointer obtained
* from an earlier call to kmap_atomic. This function can only be used if
* the skb has a TCP/UDP segment contained entirely in a single frag. Returns 0
* if checksum is ok, non-zero otherwise.
*/
static int
lh_csum_verify_fast(struct vr_ip *iph, void *transport_hdr, unsigned
char proto, unsigned int size)
{
__wsum csum;
csum = csum_tcpudp_nofold(iph->ip_saddr, iph->ip_daddr,
size, proto, 0);
if (csum_fold(csum_partial(transport_hdr, size, csum))) {
return -1;
}
return 0;
}
/*
* lh_csum_verify - verifies checksum of skb containing a TCP segment. Returns
* 0 if checksum is ok, non-zero otherwise.
*/
static int
lh_csum_verify(struct sk_buff *skb, struct vr_ip *iph)
{
skb->csum = csum_tcpudp_nofold(iph->ip_saddr, iph->ip_daddr,
ntohs(iph->ip_len) - (iph->ip_hl * 4),
iph->ip_proto, 0);
if (__skb_checksum_complete(skb)) {
return -1;
}
return 0;
}
/*
* lh_handle_checksum_complete_skb - if the skb has CHECKSUM_COMPLETE set,
* set it to CHECKSUM_NONE.
*/
static void
lh_handle_checksum_complete_skb(struct sk_buff *skb)
{
if (skb->ip_summed == CHECKSUM_COMPLETE) {
skb->csum = 0;
skb->ip_summed = CHECKSUM_NONE;
}
}
/*
* lh_csum_verify_udp - verifies checksum of skb containing a UDP datagram.
* Returns 0 if checksum is ok, non-zero otherwise.
*/
static int
lh_csum_verify_udp(struct sk_buff *skb, struct vr_ip *iph)
{
if (skb->ip_summed == CHECKSUM_COMPLETE) {
if (!csum_tcpudp_magic(iph->ip_saddr, iph->ip_daddr,
skb->len, IPPROTO_UDP, skb->csum)) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
return 0;
}
}
skb->csum = csum_tcpudp_nofold(iph->ip_saddr, iph->ip_daddr,
skb->len, IPPROTO_UDP, 0);
if (__skb_checksum_complete(skb)) {
return -1;