eBPF defines this as BPF_TUNLEN_MAX and OVS just uses the hard-coded
value inside struct sw_flow_key. Thus, add and use IP_TUNNEL_OPTS_MAX
for this, which makes the code a bit more generic and allows to remove
BPF_TUNLEN_MAX from eBPF code.
Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
---
include/net/ip_tunnels.h | 7 +++++++
net/core/filter.c | 9 ++-------
net/ipv4/ip_tunnel_core.c | 6 ++++++
net/openvswitch/flow.h | 2 +-
4 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 5dc2e45..c35dda9 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -7,6 +7,8 @@
#include <linux/socket.h>
#include <linux/types.h>
#include <linux/u64_stats_sync.h>
+#include <linux/bitops.h>
+
#include <net/dsfield.h>
#include <net/gro_cells.h>
#include <net/inet_ecn.h>
@@ -57,6 +59,11 @@ struct ip_tunnel_key {
#define IP_TUNNEL_INFO_TX 0x01 /* represents tx tunnel parameters */
#define IP_TUNNEL_INFO_IPV6 0x02 /* key contains IPv6 addresses */
+/* Maximum tunnel options length. */
+#define IP_TUNNEL_OPTS_MAX \
+ GENMASK((FIELD_SIZEOF(struct ip_tunnel_info, \
+ options_len) * BITS_PER_BYTE) - 1, 0)
+
struct ip_tunnel_info {
struct ip_tunnel_key key;
#ifdef CONFIG_DST_CACHE
diff --git a/net/core/filter.c b/net/core/filter.c
index 4c35d83..b7177d0 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1904,8 +1904,6 @@ static const struct bpf_func_proto
bpf_skb_set_tunnel_key_proto = {
.arg4_type = ARG_ANYTHING,
};
-#define BPF_TUNLEN_MAX 255
-
static u64 bpf_skb_set_tunnel_opt(u64 r1, u64 r2, u64 size, u64 r4, u64 r5)
{
struct sk_buff *skb = (struct sk_buff *) (long) r1;
@@ -1915,7 +1913,7 @@ static u64 bpf_skb_set_tunnel_opt(u64 r1, u64 r2, u64
size, u64 r4, u64 r5)
if (unlikely(info != &md->u.tun_info || (size & (sizeof(u32) - 1))))
return -EINVAL;
- if (unlikely(size > BPF_TUNLEN_MAX))
+ if (unlikely(size > IP_TUNNEL_OPTS_MAX))
return -ENOMEM;
ip_tunnel_info_opts_set(info, from, size);
@@ -1936,13 +1934,10 @@ static const struct bpf_func_proto *
bpf_get_skb_set_tunnel_proto(enum bpf_func_id which)
{
if (!md_dst) {
- BUILD_BUG_ON(FIELD_SIZEOF(struct ip_tunnel_info,
- options_len) != 1);
-
/* Race is not possible, since it's called from verifier
* that is holding verifier mutex.
*/
- md_dst = metadata_dst_alloc_percpu(BPF_TUNLEN_MAX,
+ md_dst = metadata_dst_alloc_percpu(IP_TUNNEL_OPTS_MAX,
GFP_KERNEL);
if (!md_dst)
return NULL;
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index eaca244..d27276f 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -398,6 +398,12 @@ static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
void __init ip_tunnel_core_init(void)
{
+ /* If you land here, make sure whether increasing ip_tunnel_info's
+ * options_len is a reasonable choice with its usage in front ends
+ * (f.e., it's part of flow keys, etc).
+ */
+ BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255);
+
lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
}
diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h
index 1d055c5..03378e7 100644
--- a/net/openvswitch/flow.h
+++ b/net/openvswitch/flow.h
@@ -55,7 +55,7 @@ struct ovs_tunnel_info {
FIELD_SIZEOF(struct sw_flow_key, recirc_id))
struct sw_flow_key {
- u8 tun_opts[255];
+ u8 tun_opts[IP_TUNNEL_OPTS_MAX];
u8 tun_opts_len;
struct ip_tunnel_key tun_key; /* Encapsulating tunnel key. */
struct {
--
1.9.3
