1 /*
2  *	BIRD Internet Routing Daemon -- Network Interfaces
3  *
4  *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
5  *
6  *	Can be freely distributed and used under the terms of the GNU GPL.
7  */
8 
9 #ifndef _BIRD_IFACE_H_
10 #define _BIRD_IFACE_H_
11 
12 #include "lib/lists.h"
13 
14 extern list iface_list;
15 
16 struct proto;
17 struct pool;
18 
19 struct ifa {				/* Interface address */
20   node n;
21   struct iface *iface;			/* Interface this address belongs to */
22   ip_addr ip;				/* IP address of this host */
23   ip_addr prefix;			/* Network prefix */
24   unsigned pxlen;			/* Prefix length */
25   ip_addr brd;				/* Broadcast address */
26   ip_addr opposite;			/* Opposite end of a point-to-point link */
27   unsigned scope;			/* Interface address scope */
28   unsigned flags;			/* Analogous to iface->flags */
29 };
30 
31 struct iface {
32   node n;
33   char name[16];
34   unsigned flags;
35   unsigned mtu;
36   unsigned index;			/* OS-dependent interface index */
37   unsigned master_index;		/* Interface index of master iface */
38   list addrs;				/* Addresses assigned to this interface */
39   struct ifa *addr;			/* Primary address */
40 #ifdef IPV6
41   struct ifa *llv6;			/* Selected IPv6 link-local address */
42 #endif
43   struct iface *master;			/* Master iface (e.g. for VRF) */
44   list neighbors;			/* All neighbors on this interface */
45 };
46 
47 #define IF_UP 1				/* IF_ADMIN_UP and IP address known */
48 #define IF_MULTIACCESS 2
49 #define IF_BROADCAST 4
50 #define IF_MULTICAST 8
51 #define IF_SHUTDOWN 0x10		/* Interface disappeared */
52 #define IF_LOOPBACK 0x20
53 #define IF_IGNORE 0x40			/* Not to be used by routing protocols (loopbacks etc.) */
54 #define IF_ADMIN_UP 0x80		/* Administrative up (e.g. IFF_UP in Linux) */
55 #define IF_LINK_UP 0x100		/* Link available (e.g. IFF_LOWER_UP in Linux) */
56 
57 #define IA_PRIMARY 0x10000		/* This address is primary */
58 #define IA_SECONDARY 0x20000		/* This address has been reported as secondary by the kernel */
59 #define IA_PEER 0x40000			/* A peer/ptp address */
60 #define IA_HOST 0x80000			/* A host/loopback address */
61 #define IA_FLAGS 0xff0000
62 
63 /*
64  * There are three kinds of addresses in BIRD:
65  *  - Standard (prefix-based) addresses, these may define ifa.opposite (for /30 or /31).
66  *  - Peer/ptp addresses, without common prefix for ifa.ip and ifa.opposite.
67  *    ifa.opposite is defined and ifa.prefix/pxlen == ifa.opposite/32 (for simplicity).
68  *  - Host addresses, with ifa.prefix/pxlen == ifa.ip/32 (or /128).
69  *    May be considered a special case of standard addresses.
70  *
71  * Peer addresses (AFAIK) do not exist in IPv6. Linux also supports generalized peer
72  * addresses (with pxlen < 32 and ifa.ip outside prefix), we do not support that.
73  */
74 
75 
76 #define IF_JUST_CREATED 0x10000000	/* Send creation event as soon as possible */
77 #define IF_TMP_DOWN 0x20000000		/* Temporary shutdown due to interface reconfiguration */
78 #define IF_UPDATED 0x40000000		/* Touched in last scan */
79 
80 /* Interface change events */
81 
82 #define IF_CHANGE_UP 1
83 #define IF_CHANGE_DOWN 2
84 #define IF_CHANGE_MTU 4
85 #define IF_CHANGE_CREATE 8		/* Seen this interface for the first time */
86 #define IF_CHANGE_LINK 0x10
87 #define IF_CHANGE_TOO_MUCH 0x40000000	/* Used internally */
88 
89 void if_init(void);
90 void if_dump(struct iface *);
91 void if_dump_all(void);
92 void ifa_dump(struct ifa *);
93 void if_show(void);
94 void if_show_summary(void);
95 struct iface *if_update(struct iface *);
96 void if_delete(struct iface *old);
97 struct ifa *ifa_update(struct ifa *);
98 void ifa_delete(struct ifa *);
99 void if_start_update(void);
100 void if_end_partial_update(struct iface *);
101 void if_end_update(void);
102 void if_flush_ifaces(struct proto *p);
103 void if_feed_baby(struct proto *);
104 struct iface *if_find_by_index(unsigned);
105 struct iface *if_find_by_name(char *);
106 struct iface *if_get_by_name(char *);
107 void ifa_recalc_all_primary_addresses(void);
108 
109 static inline struct ifa *
ifa_llv6(struct iface * i UNUSED4)110 ifa_llv6(struct iface *i UNUSED4)
111 {
112 #ifdef IPV6
113   return i->llv6;
114 #else
115   return NULL;
116 #endif
117 }
118 
119 
120 /* The Neighbor Cache */
121 
122 typedef struct neighbor {
123   node n;				/* Node in global neighbor list */
124   node if_n;				/* Node in per-interface neighbor list */
125   ip_addr addr;				/* Address of the neighbor */
126   struct ifa *ifa;			/* Ifa on related iface */
127   struct iface *iface;			/* Interface it's connected to */
128   struct proto *proto;			/* Protocol this belongs to */
129   void *data;				/* Protocol-specific data */
130   unsigned aux;				/* Protocol-specific data */
131   unsigned flags;
132   int scope;				/* Address scope, -1 for unreachable sticky neighbors,
133 					   SCOPE_HOST when it's our own address */
134 } neighbor;
135 
136 #define NEF_STICKY 1
137 #define NEF_ONLINK 2
138 #define NEF_BIND 4			/* Used internally for neighbors bound to an iface */
139 
140 neighbor *neigh_find(struct proto *, ip_addr *, unsigned flags);
141 neighbor *neigh_find2(struct proto *p, ip_addr *a, struct iface *ifa, unsigned flags);
142 
neigh_connected_to(struct proto * p,ip_addr * a,struct iface * i)143 static inline int neigh_connected_to(struct proto *p, ip_addr *a, struct iface *i)
144 {
145   neighbor *n = neigh_find(p, a, 0);
146   return n && n->iface == i;
147 }
148 
149 void neigh_dump(neighbor *);
150 void neigh_dump_all(void);
151 void neigh_prune(void);
152 void neigh_if_up(struct iface *);
153 void neigh_if_down(struct iface *);
154 void neigh_if_link(struct iface *);
155 void neigh_ifa_update(struct ifa *);
156 void neigh_init(struct pool *);
157 
158 /*
159  *	Interface Pattern Lists
160  */
161 
162 struct iface_patt_node {
163   node n;
164   int positive;
165   byte *pattern;
166   ip_addr prefix;
167   int pxlen;
168 };
169 
170 struct iface_patt {
171   node n;
172   list ipn_list;			/* A list of struct iface_patt_node */
173 
174   /* Protocol-specific data follow after this structure */
175 };
176 
177 int iface_patt_match(struct iface_patt *ifp, struct iface *i, struct ifa *a);
178 struct iface_patt *iface_patt_find(list *l, struct iface *i, struct ifa *a);
179 int iface_patts_equal(list *, list *, int (*)(struct iface_patt *, struct iface_patt *));
180 
181 
182 u32 if_choose_router_id(struct iface_patt *mask, u32 old_id);
183 
184 #endif
185