Skip to content

Commit

Permalink
gre6: Cleanup GREv6 transmit path, call common GRE functions
Browse files Browse the repository at this point in the history 
Changes in GREv6 transmit path:
  - Call gre_checksum, remove gre6_checksum
  - Rename ip6gre_xmit2 to __gre6_xmit
  - Call gre_build_header utility function
  - Call ip6_tnl_xmit common function
  - Call ip6_tnl_change_mtu, eliminate ip6gre_tunnel_change_mtu

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
Tom Herbert authored and David S. Miller committed May 2, 2016
1 parent 79ecb90 commit b05229f
Showing 1 changed file with 50 additions and 202 deletions.
252 changes: 50 additions & 202 deletions net/ipv6/ip6_gre.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -488,199 +488,40 @@ struct ipv6_tel_txoption {
__u8 dst_opt[8];
};

static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
static int gre_handle_offloads(struct sk_buff *skb, bool csum)
{
memset(opt, 0, sizeof(struct ipv6_tel_txoption));

opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
opt->dst_opt[3] = 1;
opt->dst_opt[4] = encap_limit;
opt->dst_opt[5] = IPV6_TLV_PADN;
opt->dst_opt[6] = 1;

opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
opt->ops.opt_nflen = 8;
return iptunnel_handle_offloads(skb,
csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
}

static __sum16 gre6_checksum(struct sk_buff *skb)
{
__wsum csum;

if (skb->ip_summed == CHECKSUM_PARTIAL)
csum = lco_csum(skb);
else
csum = skb_checksum(skb, sizeof(struct ipv6hdr),
skb->len - sizeof(struct ipv6hdr), 0);
return csum_fold(csum);
}

static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
struct net_device *dev,
__u8 dsfield,
struct flowi6 *fl6,
int encap_limit,
__u32 *pmtu)
static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
struct net_device *dev, __u8 dsfield,
struct flowi6 *fl6, int encap_limit,
__u32 *pmtu, __be16 proto)
{
struct ip6_tnl *tunnel = netdev_priv(dev);
struct net *net = tunnel->net;
struct net_device *tdev; /* Device to other host */
struct ipv6hdr *ipv6h; /* Our new IP header */
unsigned int min_headroom = 0; /* The extra header space needed */
int gre_hlen;
struct ipv6_tel_txoption opt;
int mtu;
struct dst_entry *dst = NULL, *ndst = NULL;
struct net_device_stats *stats = &tunnel->dev->stats;
int err = -1;
u8 proto;
__be16 protocol;
__be16 protocol = (dev->type == ARPHRD_ETHER) ?
htons(ETH_P_TEB) : proto;

if (dev->type == ARPHRD_ETHER)
IPCB(skb)->flags = 0;

if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
gre_hlen = 0;
ipv6h = (struct ipv6hdr *)skb->data;
fl6->daddr = ipv6h->daddr;
} else {
gre_hlen = tunnel->hlen;
if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
else
fl6->daddr = tunnel->parms.raddr;
}

if (!fl6->flowi6_mark)
dst = dst_cache_get(&tunnel->dst_cache);

if (!dst) {
dst = ip6_route_output(net, NULL, fl6);

if (dst->error)
goto tx_err_link_failure;
dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
if (IS_ERR(dst)) {
err = PTR_ERR(dst);
dst = NULL;
goto tx_err_link_failure;
}
ndst = dst;
}

tdev = dst->dev;

if (tdev == dev) {
stats->collisions++;
net_warn_ratelimited("%s: Local routing loop detected!\n",
tunnel->parms.name);
goto tx_err_dst_release;
}

mtu = dst_mtu(dst) - sizeof(*ipv6h);
if (encap_limit >= 0) {
min_headroom += 8;
mtu -= 8;
}
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
if (skb_dst(skb))
skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
if (skb->len > mtu && !skb_is_gso(skb)) {
*pmtu = mtu;
err = -EMSGSIZE;
goto tx_err_dst_release;
}
if (tunnel->parms.o_flags & TUNNEL_SEQ)
tunnel->o_seqno++;

if (tunnel->err_count > 0) {
if (time_before(jiffies,
tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
tunnel->err_count--;
/* Push GRE header. */
gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));

dst_link_failure(skb);
} else
tunnel->err_count = 0;
}
skb_set_inner_protocol(skb, proto);

skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));

min_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;

if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
int head_delta = SKB_DATA_ALIGN(min_headroom -
skb_headroom(skb) +
16);

err = pskb_expand_head(skb, max_t(int, head_delta, 0),
0, GFP_ATOMIC);
if (min_headroom > dev->needed_headroom)
dev->needed_headroom = min_headroom;
if (unlikely(err))
goto tx_err_dst_release;
}

if (!fl6->flowi6_mark && ndst)
dst_cache_set_ip6(&tunnel->dst_cache, ndst, &fl6->saddr);
skb_dst_set(skb, dst);

proto = NEXTHDR_GRE;
if (encap_limit >= 0) {
init_tel_txopt(&opt, encap_limit);
ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
}

err = iptunnel_handle_offloads(skb,
(tunnel->parms.o_flags & GRE_CSUM) ?
SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
if (err)
goto tx_err_dst_release;

skb_push(skb, gre_hlen);
skb_reset_network_header(skb);
skb_set_transport_header(skb, sizeof(*ipv6h));

/*
* Push down and install the IP header.
*/
ipv6h = ipv6_hdr(skb);
ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
ipv6h->hop_limit = tunnel->parms.hop_limit;
ipv6h->nexthdr = proto;
ipv6h->saddr = fl6->saddr;
ipv6h->daddr = fl6->daddr;

((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
protocol = (dev->type == ARPHRD_ETHER) ?
htons(ETH_P_TEB) : skb->protocol;
((__be16 *)(ipv6h + 1))[1] = protocol;

if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
__be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);

if (tunnel->parms.o_flags&GRE_SEQ) {
++tunnel->o_seqno;
*ptr = htonl(tunnel->o_seqno);
ptr--;
}
if (tunnel->parms.o_flags&GRE_KEY) {
*ptr = tunnel->parms.o_key;
ptr--;
}
if ((tunnel->parms.o_flags & GRE_CSUM) &&
!(skb_shinfo(skb)->gso_type &
(SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {
*ptr = 0;
*(__sum16 *)ptr = gre6_checksum(skb);
}
}

skb_set_inner_protocol(skb, protocol);

ip6tunnel_xmit(NULL, skb, dev);
return 0;
tx_err_link_failure:
stats->tx_carrier_errors++;
dst_link_failure(skb);
tx_err_dst_release:
dst_release(dst);
return err;
return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
NEXTHDR_GRE);
}

static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
Expand All @@ -699,7 +540,6 @@ static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
encap_limit = t->parms.encap_limit;

memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
fl6.flowi6_proto = IPPROTO_GRE;

dsfield = ipv4_get_dsfield(iph);

Expand All @@ -709,7 +549,12 @@ static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
fl6.flowi6_mark = skb->mark;

err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
if (err)
return -1;

err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
skb->protocol);
if (err != 0) {
/* XXX: send ICMP error even if DF is not set. */
if (err == -EMSGSIZE)
Expand Down Expand Up @@ -749,7 +594,6 @@ static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
encap_limit = t->parms.encap_limit;

memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
fl6.flowi6_proto = IPPROTO_GRE;

dsfield = ipv6_get_dsfield(ipv6h);
if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
Expand All @@ -759,7 +603,11 @@ static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
fl6.flowi6_mark = skb->mark;

err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
return -1;

err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
&mtu, skb->protocol);
if (err != 0) {
if (err == -EMSGSIZE)
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
Expand Down Expand Up @@ -803,7 +651,11 @@ static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
fl6.flowi6_proto = skb->protocol;

err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
if (err)
return err;

err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);

return err;
}
Expand Down Expand Up @@ -1080,15 +932,6 @@ static int ip6gre_tunnel_ioctl(struct net_device *dev,
return err;
}

static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
{
if (new_mtu < 68 ||
new_mtu > 0xFFF8 - dev->hard_header_len)
return -EINVAL;
dev->mtu = new_mtu;
return 0;
}

static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type,
const void *daddr, const void *saddr, unsigned int len)
Expand Down Expand Up @@ -1132,7 +975,7 @@ static const struct net_device_ops ip6gre_netdev_ops = {
.ndo_uninit = ip6gre_tunnel_uninit,
.ndo_start_xmit = ip6gre_tunnel_xmit,
.ndo_do_ioctl = ip6gre_tunnel_ioctl,
.ndo_change_mtu = ip6gre_tunnel_change_mtu,
.ndo_change_mtu = ip6_tnl_change_mtu,
.ndo_get_stats64 = ip_tunnel_get_stats64,
.ndo_get_iflink = ip6_tnl_get_iflink,
};
Expand All @@ -1148,17 +991,11 @@ static void ip6gre_dev_free(struct net_device *dev)

static void ip6gre_tunnel_setup(struct net_device *dev)
{
struct ip6_tnl *t;

dev->netdev_ops = &ip6gre_netdev_ops;
dev->destructor = ip6gre_dev_free;

dev->type = ARPHRD_IP6GRE;
dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
t = netdev_priv(dev);
if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
dev->mtu -= 8;

dev->flags |= IFF_NOARP;
dev->addr_len = sizeof(struct in6_addr);
netif_keep_dst(dev);
Expand All @@ -1168,6 +1005,7 @@ static int ip6gre_tunnel_init_common(struct net_device *dev)
{
struct ip6_tnl *tunnel;
int ret;
int t_hlen;

tunnel = netdev_priv(dev);

Expand All @@ -1186,6 +1024,16 @@ static int ip6gre_tunnel_init_common(struct net_device *dev)
return ret;
}

tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);

t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);

dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4;
dev->mtu = ETH_DATA_LEN - t_hlen - 4;

if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
dev->mtu -= 8;

return 0;
}

Expand Down Expand Up @@ -1420,7 +1268,7 @@ static const struct net_device_ops ip6gre_tap_netdev_ops = {
.ndo_start_xmit = ip6gre_tunnel_xmit,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
.ndo_change_mtu = ip6gre_tunnel_change_mtu,
.ndo_change_mtu = ip6_tnl_change_mtu,
.ndo_get_stats64 = ip_tunnel_get_stats64,
.ndo_get_iflink = ip6_tnl_get_iflink,
};
Expand Down

0 comments on commit b05229f

Please sign in to comment.