ip_tunnel: convert __be16 tunnel flags to bitmaps

Historically, tunnel flags like TUNNEL_CSUM or TUNNEL_ERSPAN_OPT
have been defined as __be16. Now all of those 16 bits are occupied
and there's no more free space for new flags.
It can't be simply switched to a bigger container with no
adjustments to the values, since it's an explicit Endian storage,
and on LE systems (__be16)0x0001 equals to
(__be64)0x0001000000000000.
We could probably define new 64-bit flags depending on the
Endianness, i.e. (__be64)0x0001 on BE and (__be64)0x00010000... on
LE, but that would introduce an Endianness dependency and spawn a
ton of Sparse warnings. To mitigate them, all of those places which
were adjusted with this change would be touched anyway, so why not
define stuff properly if there's no choice.

Define IP_TUNNEL_*_BIT counterparts as a bit number instead of the
value already coded and a fistful of <16 <-> bitmap> converters and
helpers. The two flags which have a different bit position are
SIT_ISATAP_BIT and VTI_ISVTI_BIT, as they were defined not as
__cpu_to_be16(), but as (__force __be16), i.e. had different
positions on LE and BE. Now they both have strongly defined places.
Change all __be16 fields which were used to store those flags, to
IP_TUNNEL_DECLARE_FLAGS() -> DECLARE_BITMAP(__IP_TUNNEL_FLAG_NUM) ->
unsigned long[1] for now, and replace all TUNNEL_* occurrences to
their bitmap counterparts. Use the converters in the places which talk
to the userspace, hardware (NFP) or other hosts (GRE header). The rest
must explicitly use the new flags only. This must be done at once,
otherwise there will be too many conversions throughout the code in
the intermediate commits.
Finally, disable the old __be16 flags for use in the kernel code
(except for the two 'irregular' flags mentioned above), to prevent
any accidental (mis)use of them. For the userspace, nothing is
changed, only additions were made.

Most noticeable bloat-o-meter difference (.text):

vmlinux:	307/-1 (306)
gre.ko:		62/0 (62)
ip_gre.ko:	941/-217 (724)	[*]
ip_tunnel.ko:	390/-900 (-510)	[**]
ip_vti.ko:	138/0 (138)
ip6_gre.ko:	534/-18 (516)	[*]
ip6_tunnel.ko:	118/-10 (108)

[*] gre_flags_to_tnl_flags() grew, but still is inlined
[**] ip_tunnel_find() got uninlined, hence such decrease

The average code size increase in non-extreme case is 100-200 bytes
per module, mostly due to sizeof(long) > sizeof(__be16), as
%__IP_TUNNEL_FLAG_NUM is less than %BITS_PER_LONG and the compilers
are able to expand the majority of bitmap_*() calls here into direct
operations on scalars.

Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 18 deletions

diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c
index 1536f8b16f1b..af7c99845948 100644
--- a/net/sched/act_tunnel_key.c
+++ b/net/sched/act_tunnel_key.c
@@ -230,7 +230,7 @@ static int tunnel_key_copy_opts(const struct nlattr *nla, u8 *dst,
 	nla_for_each_attr(attr, head, len, rem) {
 		switch (nla_type(attr)) {
 		case TCA_TUNNEL_KEY_ENC_OPTS_GENEVE:
-			if (type && type != TUNNEL_GENEVE_OPT) {
+			if (type && type != IP_TUNNEL_GENEVE_OPT_BIT) {
 				NL_SET_ERR_MSG(extack, "Duplicate type for geneve options");
 				return -EINVAL;
 			}
@@ -247,7 +247,7 @@ static int tunnel_key_copy_opts(const struct nlattr *nla, u8 *dst,
 				dst_len -= opt_len;
 				dst += opt_len;
 			}
-			type = TUNNEL_GENEVE_OPT;
+			type = IP_TUNNEL_GENEVE_OPT_BIT;
 			break;
 		case TCA_TUNNEL_KEY_ENC_OPTS_VXLAN:
 			if (type) {
@@ -259,7 +259,7 @@ static int tunnel_key_copy_opts(const struct nlattr *nla, u8 *dst,
 			if (opt_len < 0)
 				return opt_len;
 			opts_len += opt_len;
-			type = TUNNEL_VXLAN_OPT;
+			type = IP_TUNNEL_VXLAN_OPT_BIT;
 			break;
 		case TCA_TUNNEL_KEY_ENC_OPTS_ERSPAN:
 			if (type) {
@@ -271,7 +271,7 @@ static int tunnel_key_copy_opts(const struct nlattr *nla, u8 *dst,
 			if (opt_len < 0)
 				return opt_len;
 			opts_len += opt_len;
-			type = TUNNEL_ERSPAN_OPT;
+			type = IP_TUNNEL_ERSPAN_OPT_BIT;
 			break;
 		}
 	}
@@ -302,7 +302,7 @@ static int tunnel_key_opts_set(struct nlattr *nla, struct ip_tunnel_info *info,
 	switch (nla_type(nla_data(nla))) {
 	case TCA_TUNNEL_KEY_ENC_OPTS_GENEVE:
 #if IS_ENABLED(CONFIG_INET)
-		info->key.tun_flags |= TUNNEL_GENEVE_OPT;
+		__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, info->key.tun_flags);
 		return tunnel_key_copy_opts(nla, ip_tunnel_info_opts(info),
 					    opts_len, extack);
 #else
@@ -310,7 +310,7 @@ static int tunnel_key_opts_set(struct nlattr *nla, struct ip_tunnel_info *info,
 #endif
 	case TCA_TUNNEL_KEY_ENC_OPTS_VXLAN:
 #if IS_ENABLED(CONFIG_INET)
-		info->key.tun_flags |= TUNNEL_VXLAN_OPT;
+		__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags);
 		return tunnel_key_copy_opts(nla, ip_tunnel_info_opts(info),
 					    opts_len, extack);
 #else
@@ -318,7 +318,7 @@ static int tunnel_key_opts_set(struct nlattr *nla, struct ip_tunnel_info *info,
 #endif
 	case TCA_TUNNEL_KEY_ENC_OPTS_ERSPAN:
 #if IS_ENABLED(CONFIG_INET)
-		info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
+		__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, info->key.tun_flags);
 		return tunnel_key_copy_opts(nla, ip_tunnel_info_opts(info),
 					    opts_len, extack);
 #else
@@ -363,6 +363,7 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla,
 	bool bind = act_flags & TCA_ACT_FLAGS_BIND;
 	struct nlattr *tb[TCA_TUNNEL_KEY_MAX + 1];
 	struct tcf_tunnel_key_params *params_new;
+	IP_TUNNEL_DECLARE_FLAGS(flags) = { };
 	struct metadata_dst *metadata = NULL;
 	struct tcf_chain *goto_ch = NULL;
 	struct tc_tunnel_key *parm;
@@ -371,7 +372,6 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla,
 	__be16 dst_port = 0;
 	__be64 key_id = 0;
 	int opts_len = 0;
-	__be16 flags = 0;
 	u8 tos, ttl;
 	int ret = 0;
 	u32 index;
@@ -412,16 +412,16 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla,
 
 			key32 = nla_get_be32(tb[TCA_TUNNEL_KEY_ENC_KEY_ID]);
 			key_id = key32_to_tunnel_id(key32);
-			flags = TUNNEL_KEY;
+			__set_bit(IP_TUNNEL_KEY_BIT, flags);
 		}
 
-		flags |= TUNNEL_CSUM;
+		__set_bit(IP_TUNNEL_CSUM_BIT, flags);
 		if (tb[TCA_TUNNEL_KEY_NO_CSUM] &&
 		    nla_get_u8(tb[TCA_TUNNEL_KEY_NO_CSUM]))
-			flags &= ~TUNNEL_CSUM;
+			__clear_bit(IP_TUNNEL_CSUM_BIT, flags);
 
 		if (nla_get_flag(tb[TCA_TUNNEL_KEY_NO_FRAG]))
-			flags |= TUNNEL_DONT_FRAGMENT;
+			__set_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, flags);
 
 		if (tb[TCA_TUNNEL_KEY_ENC_DST_PORT])
 			dst_port = nla_get_be16(tb[TCA_TUNNEL_KEY_ENC_DST_PORT]);
@@ -663,15 +663,15 @@ static int tunnel_key_opts_dump(struct sk_buff *skb,
 	if (!start)
 		return -EMSGSIZE;
 
-	if (info->key.tun_flags & TUNNEL_GENEVE_OPT) {
+	if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, info->key.tun_flags)) {
 		err = tunnel_key_geneve_opts_dump(skb, info);
 		if (err)
 			goto err_out;
-	} else if (info->key.tun_flags & TUNNEL_VXLAN_OPT) {
+	} else if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags)) {
 		err = tunnel_key_vxlan_opts_dump(skb, info);
 		if (err)
 			goto err_out;
-	} else if (info->key.tun_flags & TUNNEL_ERSPAN_OPT) {
+	} else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, info->key.tun_flags)) {
 		err = tunnel_key_erspan_opts_dump(skb, info);
 		if (err)
 			goto err_out;
@@ -741,7 +741,7 @@ static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
 		struct ip_tunnel_key *key = &info->key;
 		__be32 key_id = tunnel_id_to_key32(key->tun_id);
 
-		if (((key->tun_flags & TUNNEL_KEY) &&
+		if ((test_bit(IP_TUNNEL_KEY_BIT, key->tun_flags) &&
 		     nla_put_be32(skb, TCA_TUNNEL_KEY_ENC_KEY_ID, key_id)) ||
 		    tunnel_key_dump_addresses(skb,
 					      &params->tcft_enc_metadata->u.tun_info) ||
@@ -749,8 +749,8 @@ static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
 		      nla_put_be16(skb, TCA_TUNNEL_KEY_ENC_DST_PORT,
 				   key->tp_dst)) ||
 		    nla_put_u8(skb, TCA_TUNNEL_KEY_NO_CSUM,
-			       !(key->tun_flags & TUNNEL_CSUM)) ||
-		    ((key->tun_flags & TUNNEL_DONT_FRAGMENT) &&
+			       !test_bit(IP_TUNNEL_CSUM_BIT, key->tun_flags)) ||
+		    (test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, key->tun_flags) &&
 		     nla_put_flag(skb, TCA_TUNNEL_KEY_NO_FRAG)) ||
 		    tunnel_key_opts_dump(skb, info))
 			goto nla_put_failure;