Roopa Prabhu | 499a242 | 2015-07-21 10:43:46 +0200 | [diff] [blame] | 1 | /* |
| 2 | * lwtunnel Infrastructure for light weight tunnels like mpls |
| 3 | * |
| 4 | * Authors: Roopa Prabhu, <roopa@cumulusnetworks.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <linux/capability.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/types.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/uaccess.h> |
| 19 | #include <linux/skbuff.h> |
| 20 | #include <linux/netdevice.h> |
| 21 | #include <linux/lwtunnel.h> |
| 22 | #include <linux/in.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/err.h> |
| 25 | |
| 26 | #include <net/lwtunnel.h> |
| 27 | #include <net/rtnetlink.h> |
| 28 | |
| 29 | struct lwtunnel_state *lwtunnel_state_alloc(int encap_len) |
| 30 | { |
| 31 | struct lwtunnel_state *lws; |
| 32 | |
| 33 | lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC); |
| 34 | |
| 35 | return lws; |
| 36 | } |
| 37 | EXPORT_SYMBOL(lwtunnel_state_alloc); |
| 38 | |
| 39 | const struct lwtunnel_encap_ops __rcu * |
| 40 | lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly; |
| 41 | |
| 42 | int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops, |
| 43 | unsigned int num) |
| 44 | { |
| 45 | if (num > LWTUNNEL_ENCAP_MAX) |
| 46 | return -ERANGE; |
| 47 | |
| 48 | return !cmpxchg((const struct lwtunnel_encap_ops **) |
| 49 | &lwtun_encaps[num], |
| 50 | NULL, ops) ? 0 : -1; |
| 51 | } |
| 52 | EXPORT_SYMBOL(lwtunnel_encap_add_ops); |
| 53 | |
| 54 | int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops, |
| 55 | unsigned int encap_type) |
| 56 | { |
| 57 | int ret; |
| 58 | |
| 59 | if (encap_type == LWTUNNEL_ENCAP_NONE || |
| 60 | encap_type > LWTUNNEL_ENCAP_MAX) |
| 61 | return -ERANGE; |
| 62 | |
| 63 | ret = (cmpxchg((const struct lwtunnel_encap_ops **) |
| 64 | &lwtun_encaps[encap_type], |
| 65 | ops, NULL) == ops) ? 0 : -1; |
| 66 | |
| 67 | synchronize_net(); |
| 68 | |
| 69 | return ret; |
| 70 | } |
| 71 | EXPORT_SYMBOL(lwtunnel_encap_del_ops); |
| 72 | |
| 73 | int lwtunnel_build_state(struct net_device *dev, u16 encap_type, |
| 74 | struct nlattr *encap, struct lwtunnel_state **lws) |
| 75 | { |
| 76 | const struct lwtunnel_encap_ops *ops; |
| 77 | int ret = -EINVAL; |
| 78 | |
| 79 | if (encap_type == LWTUNNEL_ENCAP_NONE || |
| 80 | encap_type > LWTUNNEL_ENCAP_MAX) |
| 81 | return ret; |
| 82 | |
| 83 | ret = -EOPNOTSUPP; |
| 84 | rcu_read_lock(); |
| 85 | ops = rcu_dereference(lwtun_encaps[encap_type]); |
| 86 | if (likely(ops && ops->build_state)) |
| 87 | ret = ops->build_state(dev, encap, lws); |
| 88 | rcu_read_unlock(); |
| 89 | |
| 90 | return ret; |
| 91 | } |
| 92 | EXPORT_SYMBOL(lwtunnel_build_state); |
| 93 | |
| 94 | int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate) |
| 95 | { |
| 96 | const struct lwtunnel_encap_ops *ops; |
| 97 | struct nlattr *nest; |
| 98 | int ret = -EINVAL; |
| 99 | |
| 100 | if (!lwtstate) |
| 101 | return 0; |
| 102 | |
| 103 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || |
| 104 | lwtstate->type > LWTUNNEL_ENCAP_MAX) |
| 105 | return 0; |
| 106 | |
| 107 | ret = -EOPNOTSUPP; |
| 108 | nest = nla_nest_start(skb, RTA_ENCAP); |
| 109 | rcu_read_lock(); |
| 110 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); |
| 111 | if (likely(ops && ops->fill_encap)) |
| 112 | ret = ops->fill_encap(skb, lwtstate); |
| 113 | rcu_read_unlock(); |
| 114 | |
| 115 | if (ret) |
| 116 | goto nla_put_failure; |
| 117 | nla_nest_end(skb, nest); |
| 118 | ret = nla_put_u16(skb, RTA_ENCAP_TYPE, lwtstate->type); |
| 119 | if (ret) |
| 120 | goto nla_put_failure; |
| 121 | |
| 122 | return 0; |
| 123 | |
| 124 | nla_put_failure: |
| 125 | nla_nest_cancel(skb, nest); |
| 126 | |
| 127 | return (ret == -EOPNOTSUPP ? 0 : ret); |
| 128 | } |
| 129 | EXPORT_SYMBOL(lwtunnel_fill_encap); |
| 130 | |
| 131 | int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) |
| 132 | { |
| 133 | const struct lwtunnel_encap_ops *ops; |
| 134 | int ret = 0; |
| 135 | |
| 136 | if (!lwtstate) |
| 137 | return 0; |
| 138 | |
| 139 | if (lwtstate->type == LWTUNNEL_ENCAP_NONE || |
| 140 | lwtstate->type > LWTUNNEL_ENCAP_MAX) |
| 141 | return 0; |
| 142 | |
| 143 | rcu_read_lock(); |
| 144 | ops = rcu_dereference(lwtun_encaps[lwtstate->type]); |
| 145 | if (likely(ops && ops->get_encap_size)) |
| 146 | ret = nla_total_size(ops->get_encap_size(lwtstate)); |
| 147 | rcu_read_unlock(); |
| 148 | |
| 149 | return ret; |
| 150 | } |
| 151 | EXPORT_SYMBOL(lwtunnel_get_encap_size); |
| 152 | |
| 153 | int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b) |
| 154 | { |
| 155 | const struct lwtunnel_encap_ops *ops; |
| 156 | int ret = 0; |
| 157 | |
| 158 | if (!a && !b) |
| 159 | return 0; |
| 160 | |
| 161 | if (!a || !b) |
| 162 | return 1; |
| 163 | |
| 164 | if (a->type != b->type) |
| 165 | return 1; |
| 166 | |
| 167 | if (a->type == LWTUNNEL_ENCAP_NONE || |
| 168 | a->type > LWTUNNEL_ENCAP_MAX) |
| 169 | return 0; |
| 170 | |
| 171 | rcu_read_lock(); |
| 172 | ops = rcu_dereference(lwtun_encaps[a->type]); |
| 173 | if (likely(ops && ops->cmp_encap)) |
| 174 | ret = ops->cmp_encap(a, b); |
| 175 | rcu_read_unlock(); |
| 176 | |
| 177 | return ret; |
| 178 | } |
| 179 | EXPORT_SYMBOL(lwtunnel_cmp_encap); |