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Commit c3ff8cfe authored by Thomas Graf's avatar Thomas Graf Committed by Jesse Gross
Browse files

openvswitch: Refine Netlink message size calculation and kill FLOW_BUFSIZE 



Kills the FLOW_BUFSIZE constant which needs to be calculated manually
and replaces it with key_attr_size() based on nla_total_size().
Calculates the size of datapath messages instead of relying on
NLMSG_DEFAULT_SIZE and moves the existing message size calculations
into own functions for clarity.

Signed-off-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarJesse Gross <jesse@nicira.com>
parent 32686a9d

net/openvswitch/datapath.c

+52 −24
Original line number Diff line number Diff line
@@ -337,6 +337,35 @@ static int queue_gso_packets(struct net *net, int dp_ifindex, 
	return err;

}



static size_t key_attr_size(void)

{

	return    nla_total_size(4)   /* OVS_KEY_ATTR_PRIORITY */

		+ nla_total_size(4)   /* OVS_KEY_ATTR_IN_PORT */

		+ nla_total_size(4)   /* OVS_KEY_ATTR_SKB_MARK */

		+ nla_total_size(12)  /* OVS_KEY_ATTR_ETHERNET */

		+ nla_total_size(2)   /* OVS_KEY_ATTR_ETHERTYPE */

		+ nla_total_size(4)   /* OVS_KEY_ATTR_8021Q */

		+ nla_total_size(0)   /* OVS_KEY_ATTR_ENCAP */

		+ nla_total_size(2)   /* OVS_KEY_ATTR_ETHERTYPE */

		+ nla_total_size(40)  /* OVS_KEY_ATTR_IPV6 */

		+ nla_total_size(2)   /* OVS_KEY_ATTR_ICMPV6 */

		+ nla_total_size(28); /* OVS_KEY_ATTR_ND */

}



static size_t upcall_msg_size(const struct sk_buff *skb,

			      const struct nlattr *userdata)

{

	size_t size = NLMSG_ALIGN(sizeof(struct ovs_header))

		+ nla_total_size(skb->len) /* OVS_PACKET_ATTR_PACKET */

		+ nla_total_size(key_attr_size()); /* OVS_PACKET_ATTR_KEY */



	/* OVS_PACKET_ATTR_USERDATA */

	if (userdata)

		size += NLA_ALIGN(userdata->nla_len);



	return size;

}



static int queue_userspace_packet(struct net *net, int dp_ifindex,

				  struct sk_buff *skb,

				  const struct dp_upcall_info *upcall_info)
@@ -345,7 +374,6 @@ static int queue_userspace_packet(struct net *net, int dp_ifindex, 
	struct sk_buff *nskb = NULL;

	struct sk_buff *user_skb; /* to be queued to userspace */

	struct nlattr *nla;

	unsigned int len;

	int err;



	if (vlan_tx_tag_present(skb)) {
@@ -366,13 +394,7 @@ static int queue_userspace_packet(struct net *net, int dp_ifindex, 
		goto out;

	}



	len = sizeof(struct ovs_header);

	len += nla_total_size(skb->len);

	len += nla_total_size(FLOW_BUFSIZE);

	if (upcall_info->userdata)

		len += NLA_ALIGN(upcall_info->userdata->nla_len);



	user_skb = genlmsg_new(len, GFP_ATOMIC);

	user_skb = genlmsg_new(upcall_msg_size(skb, upcall_info->userdata), GFP_ATOMIC);

	if (!user_skb) {

		err = -ENOMEM;

		goto out;
@@ -801,6 +823,16 @@ static struct genl_multicast_group ovs_dp_flow_multicast_group = { 
	.name = OVS_FLOW_MCGROUP

};



static size_t ovs_flow_cmd_msg_size(const struct sw_flow_actions *acts)

{

	return NLMSG_ALIGN(sizeof(struct ovs_header))

		+ nla_total_size(key_attr_size()) /* OVS_FLOW_ATTR_KEY */

		+ nla_total_size(sizeof(struct ovs_flow_stats)) /* OVS_FLOW_ATTR_STATS */

		+ nla_total_size(1) /* OVS_FLOW_ATTR_TCP_FLAGS */

		+ nla_total_size(8) /* OVS_FLOW_ATTR_USED */

		+ nla_total_size(acts->actions_len); /* OVS_FLOW_ATTR_ACTIONS */

}



/* Called with genl_lock. */

static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,

				  struct sk_buff *skb, u32 portid,
@@ -879,25 +911,11 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp, 
static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow)

{

	const struct sw_flow_actions *sf_acts;

	int len;



	sf_acts = rcu_dereference_protected(flow->sf_acts,

					    lockdep_genl_is_held());



	/* OVS_FLOW_ATTR_KEY */

	len = nla_total_size(FLOW_BUFSIZE);

	/* OVS_FLOW_ATTR_ACTIONS */

	len += nla_total_size(sf_acts->actions_len);

	/* OVS_FLOW_ATTR_STATS */

	len += nla_total_size(sizeof(struct ovs_flow_stats));

	/* OVS_FLOW_ATTR_TCP_FLAGS */

	len += nla_total_size(1);

	/* OVS_FLOW_ATTR_USED */

	len += nla_total_size(8);



	len += NLMSG_ALIGN(sizeof(struct ovs_header));



	return genlmsg_new(len, GFP_KERNEL);

	return genlmsg_new(ovs_flow_cmd_msg_size(sf_acts), GFP_KERNEL);

}



static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
@@ -1213,6 +1231,16 @@ static struct genl_multicast_group ovs_dp_datapath_multicast_group = { 
	.name = OVS_DATAPATH_MCGROUP

};



static size_t ovs_dp_cmd_msg_size(void)

{

	size_t msgsize = NLMSG_ALIGN(sizeof(struct ovs_header));



	msgsize += nla_total_size(IFNAMSIZ);

	msgsize += nla_total_size(sizeof(struct ovs_dp_stats));



	return msgsize;

}



static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,

				u32 portid, u32 seq, u32 flags, u8 cmd)

{
@@ -1251,7 +1279,7 @@ static struct sk_buff *ovs_dp_cmd_build_info(struct datapath *dp, u32 portid, 
	struct sk_buff *skb;

	int retval;



	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	skb = genlmsg_new(ovs_dp_cmd_msg_size(), GFP_KERNEL);

	if (!skb)

		return ERR_PTR(-ENOMEM);

net/openvswitch/flow.h

+0 −21
Original line number Diff line number Diff line
@@ -138,27 +138,6 @@ int ovs_flow_extract(struct sk_buff *, u16 in_port, struct sw_flow_key *, 
void ovs_flow_used(struct sw_flow *, struct sk_buff *);

u64 ovs_flow_used_time(unsigned long flow_jiffies);



/* Upper bound on the length of a nlattr-formatted flow key.  The longest

 * nlattr-formatted flow key would be:

 *

 *                         struct  pad  nl hdr  total

 *                         ------  ---  ------  -----

 *  OVS_KEY_ATTR_PRIORITY      4    --     4      8

 *  OVS_KEY_ATTR_IN_PORT       4    --     4      8

 *  OVS_KEY_ATTR_SKB_MARK      4    --     4      8

 *  OVS_KEY_ATTR_ETHERNET     12    --     4     16

 *  OVS_KEY_ATTR_ETHERTYPE     2     2     4      8  (outer VLAN ethertype)

 *  OVS_KEY_ATTR_8021Q         4    --     4      8

 *  OVS_KEY_ATTR_ENCAP         0    --     4      4  (VLAN encapsulation)

 *  OVS_KEY_ATTR_ETHERTYPE     2     2     4      8  (inner VLAN ethertype)

 *  OVS_KEY_ATTR_IPV6         40    --     4     44

 *  OVS_KEY_ATTR_ICMPV6        2     2     4      8

 *  OVS_KEY_ATTR_ND           28    --     4     32

 *  -------------------------------------------------

 *  total                                       152

 */

#define FLOW_BUFSIZE 152



int ovs_flow_to_nlattrs(const struct sw_flow_key *, struct sk_buff *);

int ovs_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_lenp,

		      const struct nlattr *);