openvswitch: Allow for any level of nesting in flow attributes

nlattr_set() is currently hardcoded to two levels of nesting. This change
introduces struct ovs_len_tbl to define minimal length requirements plus
next level nesting tables to traverse the key attributes to arbitrary depth.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 56 insertions, 50 deletions

diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 2e8a9cd10802..518941c5bdf1 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -50,6 +50,13 @@
 
 #include "flow_netlink.h"
 
+struct ovs_len_tbl {
+        int len;
+        const struct ovs_len_tbl *next;
+};
+
+#define OVS_ATTR_NESTED -1
+
 static void update_range(struct sw_flow_match *match,
                          size_t offset, size_t size, bool is_mask)
 {
@@ -289,29 +296,44 @@ size_t ovs_key_attr_size(void)
                 + nla_total_size(28); /* OVS_KEY_ATTR_ND */
 }
 
+static const struct ovs_len_tbl ovs_tunnel_key_lens[OVS_TUNNEL_KEY_ATTR_MAX + 1] = {
+        [OVS_TUNNEL_KEY_ATTR_ID]            = { .len = sizeof(u64) },
+        [OVS_TUNNEL_KEY_ATTR_IPV4_SRC]      = { .len = sizeof(u32) },
+        [OVS_TUNNEL_KEY_ATTR_IPV4_DST]      = { .len = sizeof(u32) },
+        [OVS_TUNNEL_KEY_ATTR_TOS]           = { .len = 1 },
+        [OVS_TUNNEL_KEY_ATTR_TTL]           = { .len = 1 },
+        [OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT] = { .len = 0 },
+        [OVS_TUNNEL_KEY_ATTR_CSUM]          = { .len = 0 },
+        [OVS_TUNNEL_KEY_ATTR_TP_SRC]        = { .len = sizeof(u16) },
+        [OVS_TUNNEL_KEY_ATTR_TP_DST]        = { .len = sizeof(u16) },
+        [OVS_TUNNEL_KEY_ATTR_OAM]           = { .len = 0 },
+        [OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS]   = { .len = OVS_ATTR_NESTED },
+};
+
 /* The size of the argument for each %OVS_KEY_ATTR_* Netlink attribute.  */
-static const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
-        [OVS_KEY_ATTR_ENCAP] = -1,
-        [OVS_KEY_ATTR_PRIORITY] = sizeof(u32),
-        [OVS_KEY_ATTR_IN_PORT] = sizeof(u32),
-        [OVS_KEY_ATTR_SKB_MARK] = sizeof(u32),
-        [OVS_KEY_ATTR_ETHERNET] = sizeof(struct ovs_key_ethernet),
-        [OVS_KEY_ATTR_VLAN] = sizeof(__be16),
-        [OVS_KEY_ATTR_ETHERTYPE] = sizeof(__be16),
-        [OVS_KEY_ATTR_IPV4] = sizeof(struct ovs_key_ipv4),
-        [OVS_KEY_ATTR_IPV6] = sizeof(struct ovs_key_ipv6),
-        [OVS_KEY_ATTR_TCP] = sizeof(struct ovs_key_tcp),
-        [OVS_KEY_ATTR_TCP_FLAGS] = sizeof(__be16),
-        [OVS_KEY_ATTR_UDP] = sizeof(struct ovs_key_udp),
-        [OVS_KEY_ATTR_SCTP] = sizeof(struct ovs_key_sctp),
-        [OVS_KEY_ATTR_ICMP] = sizeof(struct ovs_key_icmp),
-        [OVS_KEY_ATTR_ICMPV6] = sizeof(struct ovs_key_icmpv6),
-        [OVS_KEY_ATTR_ARP] = sizeof(struct ovs_key_arp),
-        [OVS_KEY_ATTR_ND] = sizeof(struct ovs_key_nd),
-        [OVS_KEY_ATTR_RECIRC_ID] = sizeof(u32),
-        [OVS_KEY_ATTR_DP_HASH] = sizeof(u32),
-        [OVS_KEY_ATTR_TUNNEL] = -1,
-        [OVS_KEY_ATTR_MPLS] = sizeof(struct ovs_key_mpls),
+static const struct ovs_len_tbl ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
+        [OVS_KEY_ATTR_ENCAP]     = { .len = OVS_ATTR_NESTED },
+        [OVS_KEY_ATTR_PRIORITY]  = { .len = sizeof(u32) },
+        [OVS_KEY_ATTR_IN_PORT]   = { .len = sizeof(u32) },
+        [OVS_KEY_ATTR_SKB_MARK]  = { .len = sizeof(u32) },
+        [OVS_KEY_ATTR_ETHERNET]  = { .len = sizeof(struct ovs_key_ethernet) },
+        [OVS_KEY_ATTR_VLAN]      = { .len = sizeof(__be16) },
+        [OVS_KEY_ATTR_ETHERTYPE] = { .len = sizeof(__be16) },
+        [OVS_KEY_ATTR_IPV4]      = { .len = sizeof(struct ovs_key_ipv4) },
+        [OVS_KEY_ATTR_IPV6]      = { .len = sizeof(struct ovs_key_ipv6) },
+        [OVS_KEY_ATTR_TCP]       = { .len = sizeof(struct ovs_key_tcp) },
+        [OVS_KEY_ATTR_TCP_FLAGS] = { .len = sizeof(__be16) },
+        [OVS_KEY_ATTR_UDP]       = { .len = sizeof(struct ovs_key_udp) },
+        [OVS_KEY_ATTR_SCTP]      = { .len = sizeof(struct ovs_key_sctp) },
+        [OVS_KEY_ATTR_ICMP]      = { .len = sizeof(struct ovs_key_icmp) },
+        [OVS_KEY_ATTR_ICMPV6]    = { .len = sizeof(struct ovs_key_icmpv6) },
+        [OVS_KEY_ATTR_ARP]       = { .len = sizeof(struct ovs_key_arp) },
+        [OVS_KEY_ATTR_ND]        = { .len = sizeof(struct ovs_key_nd) },
+        [OVS_KEY_ATTR_RECIRC_ID] = { .len = sizeof(u32) },
+        [OVS_KEY_ATTR_DP_HASH]   = { .len = sizeof(u32) },
+        [OVS_KEY_ATTR_TUNNEL]    = { .len = OVS_ATTR_NESTED,
+                                     .next = ovs_tunnel_key_lens, },
+        [OVS_KEY_ATTR_MPLS]      = { .len = sizeof(struct ovs_key_mpls) },
 };
 
 static bool is_all_zero(const u8 *fp, size_t size)
@@ -352,8 +374,8 @@ static int __parse_flow_nlattrs(const struct nlattr *attr,
                         return -EINVAL;
                 }
 
-                expected_len = ovs_key_lens[type];
-                if (nla_len(nla) != expected_len && expected_len != -1) {
+                expected_len = ovs_key_lens[type].len;
+                if (nla_len(nla) != expected_len && expected_len != OVS_ATTR_NESTED) {
                         OVS_NLERR(log, "Key %d has unexpected len %d expected %d",
                                   type, nla_len(nla), expected_len);
                         return -EINVAL;
@@ -451,30 +473,16 @@ static int ipv4_tun_from_nlattr(const struct nlattr *attr,
                 int type = nla_type(a);
                 int err;
 
-                static const u32 ovs_tunnel_key_lens[OVS_TUNNEL_KEY_ATTR_MAX + 1] = {
-                        [OVS_TUNNEL_KEY_ATTR_ID] = sizeof(u64),
-                        [OVS_TUNNEL_KEY_ATTR_IPV4_SRC] = sizeof(u32),
-                        [OVS_TUNNEL_KEY_ATTR_IPV4_DST] = sizeof(u32),
-                        [OVS_TUNNEL_KEY_ATTR_TOS] = 1,
-                        [OVS_TUNNEL_KEY_ATTR_TTL] = 1,
-                        [OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT] = 0,
-                        [OVS_TUNNEL_KEY_ATTR_CSUM] = 0,
-                        [OVS_TUNNEL_KEY_ATTR_TP_SRC] = sizeof(u16),
-                        [OVS_TUNNEL_KEY_ATTR_TP_DST] = sizeof(u16),
-                        [OVS_TUNNEL_KEY_ATTR_OAM] = 0,
-                        [OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS] = -1,
-                };
-
                 if (type > OVS_TUNNEL_KEY_ATTR_MAX) {
                         OVS_NLERR(log, "Tunnel attr %d out of range max %d",
                                   type, OVS_TUNNEL_KEY_ATTR_MAX);
                         return -EINVAL;
                 }
 
-                if (ovs_tunnel_key_lens[type] != nla_len(a) &&
-                    ovs_tunnel_key_lens[type] != -1) {
+                if (ovs_tunnel_key_lens[type].len != nla_len(a) &&
+                    ovs_tunnel_key_lens[type].len != OVS_ATTR_NESTED) {
                         OVS_NLERR(log, "Tunnel attr %d has unexpected len %d expected %d",
-                                  type, nla_len(a), ovs_tunnel_key_lens[type]);
+                                  type, nla_len(a), ovs_tunnel_key_lens[type].len);
                         return -EINVAL;
                 }
 
@@ -912,18 +920,16 @@ static int ovs_key_from_nlattrs(struct sw_flow_match *match, u64 attrs,
         return 0;
 }
 
-static void nlattr_set(struct nlattr *attr, u8 val, bool is_attr_mask_key)
+static void nlattr_set(struct nlattr *attr, u8 val,
+                       const struct ovs_len_tbl *tbl)
 {
         struct nlattr *nla;
         int rem;
 
         /* The nlattr stream should already have been validated */
         nla_for_each_nested(nla, attr, rem) {
-                /* We assume that ovs_key_lens[type] == -1 means that type is a
-                 * nested attribute
-                 */
-                if (is_attr_mask_key && ovs_key_lens[nla_type(nla)] == -1)
-                        nlattr_set(nla, val, false);
+                if (tbl && tbl[nla_type(nla)].len == OVS_ATTR_NESTED)
+                        nlattr_set(nla, val, tbl[nla_type(nla)].next);
                 else
                         memset(nla_data(nla), val, nla_len(nla));
         }
@@ -931,7 +937,7 @@ static void nlattr_set(struct nlattr *attr, u8 val, bool is_attr_mask_key)
 
 static void mask_set_nlattr(struct nlattr *attr, u8 val)
 {
-        nlattr_set(attr, val, true);
+        nlattr_set(attr, val, ovs_key_lens);
 }
 
 /**
@@ -1628,8 +1634,8 @@ static int validate_set(const struct nlattr *a,
                 return -EINVAL;
 
         if (key_type > OVS_KEY_ATTR_MAX ||
-            (ovs_key_lens[key_type] != nla_len(ovs_key) &&
-             ovs_key_lens[key_type] != -1))
+            (ovs_key_lens[key_type].len != nla_len(ovs_key) &&
+             ovs_key_lens[key_type].len != OVS_ATTR_NESTED))
                 return -EINVAL;
 
         switch (key_type) {