diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h index dbe0cbe4f1b7..dfabacee6903 100644 --- a/include/uapi/linux/openvswitch.h +++ b/include/uapi/linux/openvswitch.h @@ -798,6 +798,44 @@ struct ovs_action_push_eth { struct ovs_key_ethernet addresses; }; +/* + * enum ovs_check_pkt_len_attr - Attributes for %OVS_ACTION_ATTR_CHECK_PKT_LEN. + * + * @OVS_CHECK_PKT_LEN_ATTR_PKT_LEN: u16 Packet length to check for. + * @OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER: Nested OVS_ACTION_ATTR_* + * actions to apply if the packer length is greater than the specified + * length in the attr - OVS_CHECK_PKT_LEN_ATTR_PKT_LEN. + * @OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL - Nested OVS_ACTION_ATTR_* + * actions to apply if the packer length is lesser or equal to the specified + * length in the attr - OVS_CHECK_PKT_LEN_ATTR_PKT_LEN. + */ +enum ovs_check_pkt_len_attr { + OVS_CHECK_PKT_LEN_ATTR_UNSPEC, + OVS_CHECK_PKT_LEN_ATTR_PKT_LEN, + OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER, + OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL, + __OVS_CHECK_PKT_LEN_ATTR_MAX, + +#ifdef __KERNEL__ + OVS_CHECK_PKT_LEN_ATTR_ARG /* struct check_pkt_len_arg */ +#endif +}; + +#define OVS_CHECK_PKT_LEN_ATTR_MAX (__OVS_CHECK_PKT_LEN_ATTR_MAX - 1) + +#ifdef __KERNEL__ +struct check_pkt_len_arg { + u16 pkt_len; /* Same value as OVS_CHECK_PKT_LEN_ATTR_PKT_LEN'. */ + bool exec_for_greater; /* When true, actions in IF_GREATER will + * not change flow keys. False otherwise. + */ + bool exec_for_lesser_equal; /* When true, actions in IF_LESS_EQUAL + * will not change flow keys. False + * otherwise. + */ +}; +#endif + /** * enum ovs_action_attr - Action types. * @@ -842,6 +880,9 @@ struct ovs_action_push_eth { * packet, or modify the packet (e.g., change the DSCP field). * @OVS_ACTION_ATTR_CLONE: make a copy of the packet and execute a list of * actions without affecting the original packet and key. + * @OVS_ACTION_ATTR_CHECK_PKT_LEN: Check the packet length and execute a set + * of actions if greater than the specified packet length, else execute + * another set of actions. * * Only a single header can be set with a single %OVS_ACTION_ATTR_SET. Not all * fields within a header are modifiable, e.g. the IPv4 protocol and fragment @@ -876,6 +917,7 @@ enum ovs_action_attr { OVS_ACTION_ATTR_POP_NSH, /* No argument. */ OVS_ACTION_ATTR_METER, /* u32 meter ID. */ OVS_ACTION_ATTR_CLONE, /* Nested OVS_CLONE_ATTR_*. */ + OVS_ACTION_ATTR_CHECK_PKT_LEN, /* Nested OVS_CHECK_PKT_LEN_ATTR_*. */ __OVS_ACTION_ATTR_MAX, /* Nothing past this will be accepted * from userspace. */ diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c index e47ebbbe71b8..2c151bb322c1 100644 --- a/net/openvswitch/actions.c +++ b/net/openvswitch/actions.c @@ -169,6 +169,10 @@ static int clone_execute(struct datapath *dp, struct sk_buff *skb, const struct nlattr *actions, int len, bool last, bool clone_flow_key); +static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, + struct sw_flow_key *key, + const struct nlattr *attr, int len); + static void update_ethertype(struct sk_buff *skb, struct ethhdr *hdr, __be16 ethertype) { @@ -1213,6 +1217,40 @@ static int execute_recirc(struct datapath *dp, struct sk_buff *skb, return clone_execute(dp, skb, key, recirc_id, NULL, 0, last, true); } +static int execute_check_pkt_len(struct datapath *dp, struct sk_buff *skb, + struct sw_flow_key *key, + const struct nlattr *attr, bool last) +{ + const struct nlattr *actions, *cpl_arg; + const struct check_pkt_len_arg *arg; + int rem = nla_len(attr); + bool clone_flow_key; + + /* The first netlink attribute in 'attr' is always + * 'OVS_CHECK_PKT_LEN_ATTR_ARG'. + */ + cpl_arg = nla_data(attr); + arg = nla_data(cpl_arg); + + if (skb->len <= arg->pkt_len) { + /* Second netlink attribute in 'attr' is always + * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'. + */ + actions = nla_next(cpl_arg, &rem); + clone_flow_key = !arg->exec_for_lesser_equal; + } else { + /* Third netlink attribute in 'attr' is always + * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER'. + */ + actions = nla_next(cpl_arg, &rem); + actions = nla_next(actions, &rem); + clone_flow_key = !arg->exec_for_greater; + } + + return clone_execute(dp, skb, key, 0, nla_data(actions), + nla_len(actions), last, clone_flow_key); +} + /* Execute a list of actions against 'skb'. */ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, @@ -1374,6 +1412,16 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, break; } + + case OVS_ACTION_ATTR_CHECK_PKT_LEN: { + bool last = nla_is_last(a, rem); + + err = execute_check_pkt_len(dp, skb, key, a, last); + if (last) + return err; + + break; + } } if (unlikely(err)) { diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c index 691da853bef5..b7543700db87 100644 --- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -91,6 +91,7 @@ static bool actions_may_change_flow(const struct nlattr *actions) case OVS_ACTION_ATTR_SET: case OVS_ACTION_ATTR_SET_MASKED: case OVS_ACTION_ATTR_METER: + case OVS_ACTION_ATTR_CHECK_PKT_LEN: default: return true; } @@ -2838,6 +2839,87 @@ static int validate_userspace(const struct nlattr *attr) return 0; } +static const struct nla_policy cpl_policy[OVS_CHECK_PKT_LEN_ATTR_MAX + 1] = { + [OVS_CHECK_PKT_LEN_ATTR_PKT_LEN] = {.type = NLA_U16 }, + [OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER] = {.type = NLA_NESTED }, + [OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL] = {.type = NLA_NESTED }, +}; + +static int validate_and_copy_check_pkt_len(struct net *net, + const struct nlattr *attr, + const struct sw_flow_key *key, + struct sw_flow_actions **sfa, + __be16 eth_type, __be16 vlan_tci, + bool log, bool last) +{ + const struct nlattr *acts_if_greater, *acts_if_lesser_eq; + struct nlattr *a[OVS_CHECK_PKT_LEN_ATTR_MAX + 1]; + struct check_pkt_len_arg arg; + int nested_acts_start; + int start, err; + + err = nla_parse_strict(a, OVS_CHECK_PKT_LEN_ATTR_MAX, nla_data(attr), + nla_len(attr), cpl_policy, NULL); + if (err) + return err; + + if (!a[OVS_CHECK_PKT_LEN_ATTR_PKT_LEN] || + !nla_get_u16(a[OVS_CHECK_PKT_LEN_ATTR_PKT_LEN])) + return -EINVAL; + + acts_if_lesser_eq = a[OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL]; + acts_if_greater = a[OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER]; + + /* Both the nested action should be present. */ + if (!acts_if_greater || !acts_if_lesser_eq) + return -EINVAL; + + /* validation done, copy the nested actions. */ + start = add_nested_action_start(sfa, OVS_ACTION_ATTR_CHECK_PKT_LEN, + log); + if (start < 0) + return start; + + arg.pkt_len = nla_get_u16(a[OVS_CHECK_PKT_LEN_ATTR_PKT_LEN]); + arg.exec_for_lesser_equal = + last || !actions_may_change_flow(acts_if_lesser_eq); + arg.exec_for_greater = + last || !actions_may_change_flow(acts_if_greater); + + err = ovs_nla_add_action(sfa, OVS_CHECK_PKT_LEN_ATTR_ARG, &arg, + sizeof(arg), log); + if (err) + return err; + + nested_acts_start = add_nested_action_start(sfa, + OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL, log); + if (nested_acts_start < 0) + return nested_acts_start; + + err = __ovs_nla_copy_actions(net, acts_if_lesser_eq, key, sfa, + eth_type, vlan_tci, log); + + if (err) + return err; + + add_nested_action_end(*sfa, nested_acts_start); + + nested_acts_start = add_nested_action_start(sfa, + OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER, log); + if (nested_acts_start < 0) + return nested_acts_start; + + err = __ovs_nla_copy_actions(net, acts_if_greater, key, sfa, + eth_type, vlan_tci, log); + + if (err) + return err; + + add_nested_action_end(*sfa, nested_acts_start); + add_nested_action_end(*sfa, start); + return 0; +} + static int copy_action(const struct nlattr *from, struct sw_flow_actions **sfa, bool log) { @@ -2884,6 +2966,7 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr, [OVS_ACTION_ATTR_POP_NSH] = 0, [OVS_ACTION_ATTR_METER] = sizeof(u32), [OVS_ACTION_ATTR_CLONE] = (u32)-1, + [OVS_ACTION_ATTR_CHECK_PKT_LEN] = (u32)-1, }; const struct ovs_action_push_vlan *vlan; int type = nla_type(a); @@ -3085,6 +3168,19 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr, break; } + case OVS_ACTION_ATTR_CHECK_PKT_LEN: { + bool last = nla_is_last(a, rem); + + err = validate_and_copy_check_pkt_len(net, a, key, sfa, + eth_type, + vlan_tci, log, + last); + if (err) + return err; + skip_copy = true; + break; + } + default: OVS_NLERR(log, "Unknown Action type %d", type); return -EINVAL; @@ -3183,6 +3279,75 @@ static int clone_action_to_attr(const struct nlattr *attr, return err; } +static int check_pkt_len_action_to_attr(const struct nlattr *attr, + struct sk_buff *skb) +{ + struct nlattr *start, *ac_start = NULL; + const struct check_pkt_len_arg *arg; + const struct nlattr *a, *cpl_arg; + int err = 0, rem = nla_len(attr); + + start = nla_nest_start(skb, OVS_ACTION_ATTR_CHECK_PKT_LEN); + if (!start) + return -EMSGSIZE; + + /* The first nested attribute in 'attr' is always + * 'OVS_CHECK_PKT_LEN_ATTR_ARG'. + */ + cpl_arg = nla_data(attr); + arg = nla_data(cpl_arg); + + if (nla_put_u16(skb, OVS_CHECK_PKT_LEN_ATTR_PKT_LEN, arg->pkt_len)) { + err = -EMSGSIZE; + goto out; + } + + /* Second nested attribute in 'attr' is always + * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'. + */ + a = nla_next(cpl_arg, &rem); + ac_start = nla_nest_start(skb, + OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL); + if (!ac_start) { + err = -EMSGSIZE; + goto out; + } + + err = ovs_nla_put_actions(nla_data(a), nla_len(a), skb); + if (err) { + nla_nest_cancel(skb, ac_start); + goto out; + } else { + nla_nest_end(skb, ac_start); + } + + /* Third nested attribute in 'attr' is always + * OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER. + */ + a = nla_next(a, &rem); + ac_start = nla_nest_start(skb, + OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER); + if (!ac_start) { + err = -EMSGSIZE; + goto out; + } + + err = ovs_nla_put_actions(nla_data(a), nla_len(a), skb); + if (err) { + nla_nest_cancel(skb, ac_start); + goto out; + } else { + nla_nest_end(skb, ac_start); + } + + nla_nest_end(skb, start); + return 0; + +out: + nla_nest_cancel(skb, start); + return err; +} + static int set_action_to_attr(const struct nlattr *a, struct sk_buff *skb) { const struct nlattr *ovs_key = nla_data(a); @@ -3277,6 +3442,12 @@ int ovs_nla_put_actions(const struct nlattr *attr, int len, struct sk_buff *skb) return err; break; + case OVS_ACTION_ATTR_CHECK_PKT_LEN: + err = check_pkt_len_action_to_attr(a, skb); + if (err) + return err; + break; + default: if (nla_put(skb, type, nla_len(a), nla_data(a))) return -EMSGSIZE;