From c3ff8cfe3e7748a93c4815b76e464d54c7efd241 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Fri, 29 Mar 2013 14:46:49 +0100 Subject: [PATCH] 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: Thomas Graf Signed-off-by: Jesse Gross --- net/openvswitch/datapath.c | 76 +++++++++++++++++++++++++++++++--------------- net/openvswitch/flow.h | 21 ------------- 2 files changed, 52 insertions(+), 45 deletions(-) diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index bca63c8..49ee37b 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -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 @@ error: 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); diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h index a7bb60f..0875fde 100644 --- a/net/openvswitch/flow.h +++ b/net/openvswitch/flow.h @@ -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 *); -- 2.7.4