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vxlan: keep flags and vni in network byte order
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Prevent repeated conversions from and to network order in the fast path.

To achieve this, define all flag constants in big endian order and store VNI
as __be32. To prevent confusion between the actual VNI value and the VNI
field from the header (which contains additional reserved byte), strictly
distinguish between "vni" and "vni_field".

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Jiri Benc authored and David S. Miller committed Feb 18, 2016
1 parent d4ac05f commit 54bfd87
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Showing 2 changed files with 116 additions and 69 deletions.
115 changes: 57 additions & 58 deletions drivers/net/vxlan.c
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Original file line number Diff line number Diff line change
Expand Up @@ -197,9 +197,9 @@ static int vxlan_nla_put_addr(struct sk_buff *skb, int attr,
#endif

/* Virtual Network hash table head */
static inline struct hlist_head *vni_head(struct vxlan_sock *vs, u32 id)
static inline struct hlist_head *vni_head(struct vxlan_sock *vs, __be32 vni)
{
return &vs->vni_list[hash_32(id, VNI_HASH_BITS)];
return &vs->vni_list[hash_32((__force u32)vni, VNI_HASH_BITS)];
}

/* Socket hash table head */
Expand Down Expand Up @@ -242,20 +242,20 @@ static struct vxlan_sock *vxlan_find_sock(struct net *net, sa_family_t family,
return NULL;
}

static struct vxlan_dev *vxlan_vs_find_vni(struct vxlan_sock *vs, u32 id)
static struct vxlan_dev *vxlan_vs_find_vni(struct vxlan_sock *vs, __be32 vni)
{
struct vxlan_dev *vxlan;

hlist_for_each_entry_rcu(vxlan, vni_head(vs, id), hlist) {
if (vxlan->default_dst.remote_vni == id)
hlist_for_each_entry_rcu(vxlan, vni_head(vs, vni), hlist) {
if (vxlan->default_dst.remote_vni == vni)
return vxlan;
}

return NULL;
}

/* Look up VNI in a per net namespace table */
static struct vxlan_dev *vxlan_find_vni(struct net *net, u32 id,
static struct vxlan_dev *vxlan_find_vni(struct net *net, __be32 vni,
sa_family_t family, __be16 port,
u32 flags)
{
Expand All @@ -265,7 +265,7 @@ static struct vxlan_dev *vxlan_find_vni(struct net *net, u32 id,
if (!vs)
return NULL;

return vxlan_vs_find_vni(vs, id);
return vxlan_vs_find_vni(vs, vni);
}

/* Fill in neighbour message in skbuff. */
Expand Down Expand Up @@ -315,7 +315,7 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
nla_put_be16(skb, NDA_PORT, rdst->remote_port))
goto nla_put_failure;
if (rdst->remote_vni != vxlan->default_dst.remote_vni &&
nla_put_u32(skb, NDA_VNI, rdst->remote_vni))
nla_put_u32(skb, NDA_VNI, be32_to_cpu(rdst->remote_vni)))
goto nla_put_failure;
if (rdst->remote_ifindex &&
nla_put_u32(skb, NDA_IFINDEX, rdst->remote_ifindex))
Expand Down Expand Up @@ -383,7 +383,7 @@ static void vxlan_ip_miss(struct net_device *dev, union vxlan_addr *ipa)
};
struct vxlan_rdst remote = {
.remote_ip = *ipa, /* goes to NDA_DST */
.remote_vni = VXLAN_N_VID,
.remote_vni = cpu_to_be32(VXLAN_N_VID),
};

vxlan_fdb_notify(vxlan, &f, &remote, RTM_GETNEIGH);
Expand Down Expand Up @@ -452,7 +452,7 @@ static struct vxlan_fdb *vxlan_find_mac(struct vxlan_dev *vxlan,
/* caller should hold vxlan->hash_lock */
static struct vxlan_rdst *vxlan_fdb_find_rdst(struct vxlan_fdb *f,
union vxlan_addr *ip, __be16 port,
__u32 vni, __u32 ifindex)
__be32 vni, __u32 ifindex)
{
struct vxlan_rdst *rd;

Expand All @@ -469,7 +469,8 @@ static struct vxlan_rdst *vxlan_fdb_find_rdst(struct vxlan_fdb *f,

/* Replace destination of unicast mac */
static int vxlan_fdb_replace(struct vxlan_fdb *f,
union vxlan_addr *ip, __be16 port, __u32 vni, __u32 ifindex)
union vxlan_addr *ip, __be16 port, __be32 vni,
__u32 ifindex)
{
struct vxlan_rdst *rd;

Expand All @@ -491,7 +492,7 @@ static int vxlan_fdb_replace(struct vxlan_fdb *f,

/* Add/update destinations for multicast */
static int vxlan_fdb_append(struct vxlan_fdb *f,
union vxlan_addr *ip, __be16 port, __u32 vni,
union vxlan_addr *ip, __be16 port, __be32 vni,
__u32 ifindex, struct vxlan_rdst **rdp)
{
struct vxlan_rdst *rd;
Expand Down Expand Up @@ -523,7 +524,8 @@ static int vxlan_fdb_append(struct vxlan_fdb *f,
static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb,
unsigned int off,
struct vxlanhdr *vh, size_t hdrlen,
u32 data, struct gro_remcsum *grc,
__be32 vni_field,
struct gro_remcsum *grc,
bool nopartial)
{
size_t start, offset;
Expand All @@ -534,10 +536,8 @@ static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb,
if (!NAPI_GRO_CB(skb)->csum_valid)
return NULL;

start = (data & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
offset = start + ((data & VXLAN_RCO_UDP) ?
offsetof(struct udphdr, check) :
offsetof(struct tcphdr, check));
start = vxlan_rco_start(vni_field);
offset = start + vxlan_rco_offset(vni_field);

vh = skb_gro_remcsum_process(skb, (void *)vh, off, hdrlen,
start, offset, grc, nopartial);
Expand All @@ -557,7 +557,7 @@ static struct sk_buff **vxlan_gro_receive(struct sk_buff **head,
int flush = 1;
struct vxlan_sock *vs = container_of(uoff, struct vxlan_sock,
udp_offloads);
u32 flags;
__be32 flags;
struct gro_remcsum grc;

skb_gro_remcsum_init(&grc);
Expand All @@ -573,11 +573,11 @@ static struct sk_buff **vxlan_gro_receive(struct sk_buff **head,

skb_gro_postpull_rcsum(skb, vh, sizeof(struct vxlanhdr));

flags = ntohl(vh->vx_flags);
flags = vh->vx_flags;

if ((flags & VXLAN_HF_RCO) && (vs->flags & VXLAN_F_REMCSUM_RX)) {
vh = vxlan_gro_remcsum(skb, off_vx, vh, sizeof(struct vxlanhdr),
ntohl(vh->vx_vni), &grc,
vh->vx_vni, &grc,
!!(vs->flags &
VXLAN_F_REMCSUM_NOPARTIAL));

Expand Down Expand Up @@ -668,7 +668,7 @@ static void vxlan_notify_del_rx_port(struct vxlan_sock *vs)
static int vxlan_fdb_create(struct vxlan_dev *vxlan,
const u8 *mac, union vxlan_addr *ip,
__u16 state, __u16 flags,
__be16 port, __u32 vni, __u32 ifindex,
__be16 port, __be32 vni, __u32 ifindex,
__u8 ndm_flags)
{
struct vxlan_rdst *rd = NULL;
Expand Down Expand Up @@ -777,7 +777,8 @@ static void vxlan_fdb_destroy(struct vxlan_dev *vxlan, struct vxlan_fdb *f)
}

static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
union vxlan_addr *ip, __be16 *port, u32 *vni, u32 *ifindex)
union vxlan_addr *ip, __be16 *port, __be32 *vni,
u32 *ifindex)
{
struct net *net = dev_net(vxlan->dev);
int err;
Expand Down Expand Up @@ -810,7 +811,7 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
if (tb[NDA_VNI]) {
if (nla_len(tb[NDA_VNI]) != sizeof(u32))
return -EINVAL;
*vni = nla_get_u32(tb[NDA_VNI]);
*vni = cpu_to_be32(nla_get_u32(tb[NDA_VNI]));
} else {
*vni = vxlan->default_dst.remote_vni;
}
Expand Down Expand Up @@ -840,7 +841,8 @@ static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
/* struct net *net = dev_net(vxlan->dev); */
union vxlan_addr ip;
__be16 port;
u32 vni, ifindex;
__be32 vni;
u32 ifindex;
int err;

if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_REACHABLE))) {
Expand Down Expand Up @@ -877,7 +879,8 @@ static int vxlan_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
struct vxlan_rdst *rd = NULL;
union vxlan_addr ip;
__be16 port;
u32 vni, ifindex;
__be32 vni;
u32 ifindex;
int err;

err = vxlan_fdb_parse(tb, vxlan, &ip, &port, &vni, &ifindex);
Expand Down Expand Up @@ -1133,17 +1136,16 @@ static int vxlan_igmp_leave(struct vxlan_dev *vxlan)
}

static struct vxlanhdr *vxlan_remcsum(struct sk_buff *skb, struct vxlanhdr *vh,
size_t hdrlen, u32 data, bool nopartial)
size_t hdrlen, __be32 vni_field,
bool nopartial)
{
size_t start, offset, plen;

if (skb->remcsum_offload)
return vh;

start = (data & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;
offset = start + ((data & VXLAN_RCO_UDP) ?
offsetof(struct udphdr, check) :
offsetof(struct tcphdr, check));
start = vxlan_rco_start(vni_field);
offset = start + vxlan_rco_offset(vni_field);

plen = hdrlen + offset + sizeof(u16);

Expand All @@ -1159,7 +1161,7 @@ static struct vxlanhdr *vxlan_remcsum(struct sk_buff *skb, struct vxlanhdr *vh,
}

static void vxlan_rcv(struct vxlan_sock *vs, struct sk_buff *skb,
struct vxlan_metadata *md, u32 vni,
struct vxlan_metadata *md, __be32 vni,
struct metadata_dst *tun_dst)
{
struct iphdr *oip = NULL;
Expand Down Expand Up @@ -1257,16 +1259,16 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
{
struct metadata_dst *tun_dst = NULL;
struct vxlan_sock *vs;
u32 flags, vni;
__be32 flags, vni_field;
struct vxlan_metadata _md;
struct vxlan_metadata *md = &_md;

/* Need Vxlan and inner Ethernet header to be present */
if (!pskb_may_pull(skb, VXLAN_HLEN))
goto error;

flags = ntohl(vxlan_hdr(skb)->vx_flags);
vni = ntohl(vxlan_hdr(skb)->vx_vni);
flags = vxlan_hdr(skb)->vx_flags;
vni_field = vxlan_hdr(skb)->vx_vni;

if (flags & VXLAN_HF_VNI) {
flags &= ~VXLAN_HF_VNI;
Expand All @@ -1283,17 +1285,18 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
goto drop;

if ((flags & VXLAN_HF_RCO) && (vs->flags & VXLAN_F_REMCSUM_RX)) {
if (!vxlan_remcsum(skb, vxlan_hdr(skb), sizeof(struct vxlanhdr), vni,
if (!vxlan_remcsum(skb, vxlan_hdr(skb), sizeof(struct vxlanhdr),
vni_field,
!!(vs->flags & VXLAN_F_REMCSUM_NOPARTIAL)))
goto drop;

flags &= ~VXLAN_HF_RCO;
vni &= VXLAN_VNI_MASK;
vni_field &= VXLAN_VNI_MASK;
}

if (vxlan_collect_metadata(vs)) {
tun_dst = udp_tun_rx_dst(skb, vxlan_get_sk_family(vs), TUNNEL_KEY,
cpu_to_be64(vni >> 8), sizeof(*md));
vxlan_vni(vni_field), sizeof(*md));

if (!tun_dst)
goto drop;
Expand Down Expand Up @@ -1324,7 +1327,7 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
flags &= ~VXLAN_GBP_USED_BITS;
}

if (flags || vni & ~VXLAN_VNI_MASK) {
if (flags || vni_field & ~VXLAN_VNI_MASK) {
/* If there are any unprocessed flags remaining treat
* this as a malformed packet. This behavior diverges from
* VXLAN RFC (RFC7348) which stipulates that bits in reserved
Expand All @@ -1337,7 +1340,7 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
goto bad_flags;
}

vxlan_rcv(vs, skb, md, vni >> 8, tun_dst);
vxlan_rcv(vs, skb, md, vxlan_vni(vni_field), tun_dst);
return 0;

drop:
Expand Down Expand Up @@ -1680,7 +1683,7 @@ static void vxlan_build_gbp_hdr(struct vxlanhdr *vxh, u32 vxflags,
return;

gbp = (struct vxlanhdr_gbp *)vxh;
vxh->vx_flags |= htonl(VXLAN_HF_GBP);
vxh->vx_flags |= VXLAN_HF_GBP;

if (md->gbp & VXLAN_GBP_DONT_LEARN)
gbp->dont_learn = 1;
Expand All @@ -1700,7 +1703,6 @@ static int vxlan_build_skb(struct sk_buff *skb, struct dst_entry *dst,
int min_headroom;
int err;
int type = udp_sum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
u16 hdrlen = sizeof(struct vxlanhdr);

if ((vxflags & VXLAN_F_REMCSUM_TX) &&
skb->ip_summed == CHECKSUM_PARTIAL) {
Expand Down Expand Up @@ -1733,18 +1735,15 @@ static int vxlan_build_skb(struct sk_buff *skb, struct dst_entry *dst,
return PTR_ERR(skb);

vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh));
vxh->vx_flags = htonl(VXLAN_HF_VNI);
vxh->vx_vni = vni;
vxh->vx_flags = VXLAN_HF_VNI;
vxh->vx_vni = vxlan_vni_field(vni);

if (type & SKB_GSO_TUNNEL_REMCSUM) {
u32 data = (skb_checksum_start_offset(skb) - hdrlen) >>
VXLAN_RCO_SHIFT;
unsigned int start;

if (skb->csum_offset == offsetof(struct udphdr, check))
data |= VXLAN_RCO_UDP;

vxh->vx_vni |= htonl(data);
vxh->vx_flags |= htonl(VXLAN_HF_RCO);
start = skb_checksum_start_offset(skb) - sizeof(struct vxlanhdr);
vxh->vx_vni |= vxlan_compute_rco(start, skb->csum_offset);
vxh->vx_flags |= VXLAN_HF_RCO;

if (!skb_is_gso(skb)) {
skb->ip_summed = CHECKSUM_NONE;
Expand Down Expand Up @@ -1892,7 +1891,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
struct vxlan_metadata _md;
struct vxlan_metadata *md = &_md;
__be16 src_port = 0, dst_port;
u32 vni;
__be32 vni;
__be16 df = 0;
__u8 tos, ttl;
int err;
Expand All @@ -1914,7 +1913,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
goto drop;
}
dst_port = info->key.tp_dst ? : vxlan->cfg.dst_port;
vni = be64_to_cpu(info->key.tun_id);
vni = vxlan_tun_id_to_vni(info->key.tun_id);
remote_ip.sa.sa_family = ip_tunnel_info_af(info);
if (remote_ip.sa.sa_family == AF_INET)
remote_ip.sin.sin_addr.s_addr = info->key.u.ipv4.dst;
Expand Down Expand Up @@ -2007,7 +2006,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
err = vxlan_build_skb(skb, &rt->dst, sizeof(struct iphdr),
htonl(vni << 8), md, flags, udp_sum);
vni, md, flags, udp_sum);
if (err < 0)
goto xmit_tx_error;

Expand Down Expand Up @@ -2065,7 +2064,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
ttl = ttl ? : ip6_dst_hoplimit(ndst);
skb_scrub_packet(skb, xnet);
err = vxlan_build_skb(skb, ndst, sizeof(struct ipv6hdr),
htonl(vni << 8), md, flags, udp_sum);
vni, md, flags, udp_sum);
if (err < 0) {
dst_release(ndst);
return;
Expand Down Expand Up @@ -2222,7 +2221,7 @@ static void vxlan_cleanup(unsigned long arg)
static void vxlan_vs_add_dev(struct vxlan_sock *vs, struct vxlan_dev *vxlan)
{
struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
__u32 vni = vxlan->default_dst.remote_vni;
__be32 vni = vxlan->default_dst.remote_vni;

spin_lock(&vn->sock_lock);
hlist_add_head_rcu(&vxlan->hlist, vni_head(vs, vni));
Expand Down Expand Up @@ -2837,7 +2836,7 @@ static int vxlan_newlink(struct net *src_net, struct net_device *dev,
memset(&conf, 0, sizeof(conf));

if (data[IFLA_VXLAN_ID])
conf.vni = nla_get_u32(data[IFLA_VXLAN_ID]);
conf.vni = cpu_to_be32(nla_get_u32(data[IFLA_VXLAN_ID]));

if (data[IFLA_VXLAN_GROUP]) {
conf.remote_ip.sin.sin_addr.s_addr = nla_get_in_addr(data[IFLA_VXLAN_GROUP]);
Expand Down Expand Up @@ -2941,7 +2940,7 @@ static int vxlan_newlink(struct net *src_net, struct net_device *dev,
break;

case -EEXIST:
pr_info("duplicate VNI %u\n", conf.vni);
pr_info("duplicate VNI %u\n", be32_to_cpu(conf.vni));
break;
}

Expand Down Expand Up @@ -2999,7 +2998,7 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
.high = htons(vxlan->cfg.port_max),
};

if (nla_put_u32(skb, IFLA_VXLAN_ID, dst->remote_vni))
if (nla_put_u32(skb, IFLA_VXLAN_ID, be32_to_cpu(dst->remote_vni)))
goto nla_put_failure;

if (!vxlan_addr_any(&dst->remote_ip)) {
Expand Down
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