1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef MPLS_INTERNAL_H 3 #define MPLS_INTERNAL_H 4 #include <net/mpls.h> 5 6 /* put a reasonable limit on the number of labels 7 * we will accept from userspace 8 */ 9 #define MAX_NEW_LABELS 30 10 11 struct mpls_entry_decoded { 12 u32 label; 13 u8 ttl; 14 u8 tc; 15 u8 bos; 16 }; 17 18 struct mpls_pcpu_stats { 19 struct mpls_link_stats stats; 20 struct u64_stats_sync syncp; 21 }; 22 23 struct mpls_dev { 24 int input_enabled; 25 struct net_device *dev; 26 struct mpls_pcpu_stats __percpu *stats; 27 28 struct ctl_table_header *sysctl; 29 struct rcu_head rcu; 30 }; 31 32 #if BITS_PER_LONG == 32 33 34 #define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field) \ 35 do { \ 36 __typeof__(*(mdev)->stats) *ptr = \ 37 raw_cpu_ptr((mdev)->stats); \ 38 local_bh_disable(); \ 39 u64_stats_update_begin(&ptr->syncp); \ 40 ptr->stats.pkts_field++; \ 41 ptr->stats.bytes_field += (len); \ 42 u64_stats_update_end(&ptr->syncp); \ 43 local_bh_enable(); \ 44 } while (0) 45 46 #define MPLS_INC_STATS(mdev, field) \ 47 do { \ 48 __typeof__(*(mdev)->stats) *ptr = \ 49 raw_cpu_ptr((mdev)->stats); \ 50 local_bh_disable(); \ 51 u64_stats_update_begin(&ptr->syncp); \ 52 ptr->stats.field++; \ 53 u64_stats_update_end(&ptr->syncp); \ 54 local_bh_enable(); \ 55 } while (0) 56 57 #else 58 59 #define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field) \ 60 do { \ 61 this_cpu_inc((mdev)->stats->stats.pkts_field); \ 62 this_cpu_add((mdev)->stats->stats.bytes_field, (len)); \ 63 } while (0) 64 65 #define MPLS_INC_STATS(mdev, field) \ 66 this_cpu_inc((mdev)->stats->stats.field) 67 68 #endif 69 70 struct sk_buff; 71 72 #define LABEL_NOT_SPECIFIED (1 << 20) 73 74 /* This maximum ha length copied from the definition of struct neighbour */ 75 #define VIA_ALEN_ALIGN sizeof(unsigned long) 76 #define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN)) 77 78 enum mpls_payload_type { 79 MPT_UNSPEC, /* IPv4 or IPv6 */ 80 MPT_IPV4 = 4, 81 MPT_IPV6 = 6, 82 83 /* Other types not implemented: 84 * - Pseudo-wire with or without control word (RFC4385) 85 * - GAL (RFC5586) 86 */ 87 }; 88 89 struct mpls_nh { /* next hop label forwarding entry */ 90 struct net_device __rcu *nh_dev; 91 92 /* nh_flags is accessed under RCU in the packet path; it is 93 * modified handling netdev events with rtnl lock held 94 */ 95 unsigned int nh_flags; 96 u8 nh_labels; 97 u8 nh_via_alen; 98 u8 nh_via_table; 99 u8 nh_reserved1; 100 101 u32 nh_label[0]; 102 }; 103 104 /* offset of via from beginning of mpls_nh */ 105 #define MPLS_NH_VIA_OFF(num_labels) \ 106 ALIGN(sizeof(struct mpls_nh) + (num_labels) * sizeof(u32), \ 107 VIA_ALEN_ALIGN) 108 109 /* all nexthops within a route have the same size based on the 110 * max number of labels and max via length across all nexthops 111 */ 112 #define MPLS_NH_SIZE(num_labels, max_via_alen) \ 113 (MPLS_NH_VIA_OFF((num_labels)) + \ 114 ALIGN((max_via_alen), VIA_ALEN_ALIGN)) 115 116 enum mpls_ttl_propagation { 117 MPLS_TTL_PROP_DEFAULT, 118 MPLS_TTL_PROP_ENABLED, 119 MPLS_TTL_PROP_DISABLED, 120 }; 121 122 /* The route, nexthops and vias are stored together in the same memory 123 * block: 124 * 125 * +----------------------+ 126 * | mpls_route | 127 * +----------------------+ 128 * | mpls_nh 0 | 129 * +----------------------+ 130 * | alignment padding | 4 bytes for odd number of labels 131 * +----------------------+ 132 * | via[rt_max_alen] 0 | 133 * +----------------------+ 134 * | alignment padding | via's aligned on sizeof(unsigned long) 135 * +----------------------+ 136 * | ... | 137 * +----------------------+ 138 * | mpls_nh n-1 | 139 * +----------------------+ 140 * | via[rt_max_alen] n-1 | 141 * +----------------------+ 142 */ 143 struct mpls_route { /* next hop label forwarding entry */ 144 struct rcu_head rt_rcu; 145 u8 rt_protocol; 146 u8 rt_payload_type; 147 u8 rt_max_alen; 148 u8 rt_ttl_propagate; 149 u8 rt_nhn; 150 /* rt_nhn_alive is accessed under RCU in the packet path; it 151 * is modified handling netdev events with rtnl lock held 152 */ 153 u8 rt_nhn_alive; 154 u8 rt_nh_size; 155 u8 rt_via_offset; 156 u8 rt_reserved1; 157 struct mpls_nh rt_nh[0]; 158 }; 159 160 #define for_nexthops(rt) { \ 161 int nhsel; struct mpls_nh *nh; u8 *__nh; \ 162 for (nhsel = 0, nh = (rt)->rt_nh, __nh = (u8 *)((rt)->rt_nh); \ 163 nhsel < (rt)->rt_nhn; \ 164 __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++) 165 166 #define change_nexthops(rt) { \ 167 int nhsel; struct mpls_nh *nh; u8 *__nh; \ 168 for (nhsel = 0, nh = (struct mpls_nh *)((rt)->rt_nh), \ 169 __nh = (u8 *)((rt)->rt_nh); \ 170 nhsel < (rt)->rt_nhn; \ 171 __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++) 172 173 #define endfor_nexthops(rt) } 174 175 static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos) 176 { 177 struct mpls_shim_hdr result; 178 result.label_stack_entry = 179 cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) | 180 (tc << MPLS_LS_TC_SHIFT) | 181 (bos ? (1 << MPLS_LS_S_SHIFT) : 0) | 182 (ttl << MPLS_LS_TTL_SHIFT)); 183 return result; 184 } 185 186 static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr) 187 { 188 struct mpls_entry_decoded result; 189 unsigned entry = be32_to_cpu(hdr->label_stack_entry); 190 191 result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT; 192 result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT; 193 result.tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT; 194 result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT; 195 196 return result; 197 } 198 199 static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev) 200 { 201 return rcu_dereference_rtnl(dev->mpls_ptr); 202 } 203 204 int nla_put_labels(struct sk_buff *skb, int attrtype, u8 labels, 205 const u32 label[]); 206 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels, 207 u32 label[], struct netlink_ext_ack *extack); 208 bool mpls_output_possible(const struct net_device *dev); 209 unsigned int mpls_dev_mtu(const struct net_device *dev); 210 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu); 211 void mpls_stats_inc_outucastpkts(struct net_device *dev, 212 const struct sk_buff *skb); 213 214 #endif /* MPLS_INTERNAL_H */ 215