1 /*
2  * OSPF Sending and Receiving OSPF Packets.
3  * Copyright (C) 1999 Toshiaki Takada
4  *
5  * This file is part of GNU Zebra.
6  *
7  * GNU Zebra is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the
9  * Free Software Foundation; either version 2, or (at your option) any
10  * later version.
11  *
12  * GNU Zebra is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
20  * 02111-1307, USA.
21  */
22 
23 #ifndef _ZEBRA_OSPF_PACKET_H
24 #define _ZEBRA_OSPF_PACKET_H
25 
26 #define OSPF_HEADER_SIZE         24U
27 #define OSPF_AUTH_SIMPLE_SIZE     8U
28 #define OSPF_AUTH_MD5_SIZE       16U
29 
30 #define OSPF_MAX_PACKET_SIZE  65535U   /* includes IP Header size. */
31 #define OSPF_HELLO_MIN_SIZE      20U   /* not including neighbors */
32 #define OSPF_DB_DESC_MIN_SIZE     8U
33 #define OSPF_LS_REQ_MIN_SIZE      0U
34 #define OSPF_LS_UPD_MIN_SIZE      4U
35 #define OSPF_LS_ACK_MIN_SIZE      0U
36 
37 #define OSPF_MSG_HELLO         1  /* OSPF Hello Message. */
38 #define OSPF_MSG_DB_DESC       2  /* OSPF Database Descriptoin Message. */
39 #define OSPF_MSG_LS_REQ        3  /* OSPF Link State Request Message. */
40 #define OSPF_MSG_LS_UPD        4  /* OSPF Link State Update Message. */
41 #define OSPF_MSG_LS_ACK        5  /* OSPF Link State Acknoledgement Message. */
42 
43 #define OSPF_SEND_PACKET_DIRECT         1
44 #define OSPF_SEND_PACKET_INDIRECT       2
45 #define OSPF_SEND_PACKET_LOOP           3
46 
47 #define OSPF_HELLO_REPLY_DELAY          1
48 
49 /* Return values of functions involved in packet verification, see ospf6d. */
50 #define MSG_OK    0
51 #define MSG_NG    1
52 
53 struct ospf_packet
54 {
55   struct ospf_packet *next;
56 
57   /* Pointer to data stream. */
58   struct stream *s;
59 
60   /* IP destination address. */
61   struct in_addr dst;
62 
63   /* OSPF packet length. */
64   u_int16_t length;
65 };
66 
67 /* OSPF packet queue structure. */
68 struct ospf_fifo
69 {
70   unsigned long count;
71 
72   struct ospf_packet *head;
73   struct ospf_packet *tail;
74 };
75 
76 /* OSPF packet header structure. */
77 struct ospf_header
78 {
79   u_char version;                       /* OSPF Version. */
80   u_char type;                          /* Packet Type. */
81   u_int16_t length;                     /* Packet Length. */
82   struct in_addr router_id;             /* Router ID. */
83   struct in_addr area_id;               /* Area ID. */
84   u_int16_t checksum;                   /* Check Sum. */
85   u_int16_t auth_type;                  /* Authentication Type. */
86   /* Authentication Data. */
87   union
88   {
89     /* Simple Authentication. */
90     u_char auth_data [OSPF_AUTH_SIMPLE_SIZE];
91     /* Cryptographic Authentication. */
92     struct
93     {
94       u_int16_t zero;                   /* Should be 0. */
95       u_char key_id;                    /* Key ID. */
96       u_char auth_data_len;             /* Auth Data Length. */
97       u_int32_t crypt_seqnum;           /* Cryptographic Sequence Number. */
98     } crypt;
99   } u;
100 };
101 
102 /* OSPF Hello body format. */
103 struct ospf_hello
104 {
105   struct in_addr network_mask;
106   u_int16_t hello_interval;
107   u_char options;
108   u_char priority;
109   u_int32_t dead_interval;
110   struct in_addr d_router;
111   struct in_addr bd_router;
112   struct in_addr neighbors[1];
113 };
114 
115 /* OSPF Database Description body format. */
116 struct ospf_db_desc
117 {
118   u_int16_t mtu;
119   u_char options;
120   u_char flags;
121   u_int32_t dd_seqnum;
122 };
123 
124 struct ospf_ls_update
125 {
126   u_int32_t num_lsas;
127 };
128 
129 /* Macros. */
130 /* XXX Perhaps obsolete; function in ospf_packet.c */
131 #define OSPF_PACKET_MAX(oi)     ospf_packet_max (oi)
132 
133 #define OSPF_OUTPUT_PNT(S)      ((S)->data + (S)->putp)
134 #define OSPF_OUTPUT_LENGTH(S)   ((S)->endp)
135 
136 #define IS_SET_DD_MS(X)         ((X) & OSPF_DD_FLAG_MS)
137 #define IS_SET_DD_M(X)          ((X) & OSPF_DD_FLAG_M)
138 #define IS_SET_DD_I(X)          ((X) & OSPF_DD_FLAG_I)
139 #define IS_SET_DD_ALL(X)        ((X) & OSPF_DD_FLAG_ALL)
140 
141 /* Prototypes. */
142 extern void ospf_output_forward (struct stream *, int);
143 extern struct ospf_packet *ospf_packet_new (size_t);
144 extern void ospf_packet_free (struct ospf_packet *);
145 extern struct ospf_fifo *ospf_fifo_new (void);
146 extern void ospf_fifo_push (struct ospf_fifo *, struct ospf_packet *);
147 extern struct ospf_packet *ospf_fifo_pop (struct ospf_fifo *);
148 extern struct ospf_packet *ospf_fifo_head (struct ospf_fifo *);
149 extern void ospf_fifo_flush (struct ospf_fifo *);
150 extern void ospf_fifo_free (struct ospf_fifo *);
151 extern void ospf_packet_add (struct ospf_interface *, struct ospf_packet *);
152 extern void ospf_packet_delete (struct ospf_interface *);
153 extern struct stream *ospf_stream_dup (struct stream *);
154 extern struct ospf_packet *ospf_packet_dup (struct ospf_packet *);
155 
156 extern int ospf_read (struct thread *);
157 extern void ospf_hello_send (struct ospf_interface *);
158 extern void ospf_db_desc_send (struct ospf_neighbor *);
159 extern void ospf_db_desc_resend (struct ospf_neighbor *);
160 extern void ospf_ls_req_send (struct ospf_neighbor *);
161 extern void ospf_ls_upd_send_lsa (struct ospf_neighbor *, struct ospf_lsa *,
162 				  int);
163 extern void ospf_ls_upd_send (struct ospf_neighbor *, struct list *, int);
164 extern void ospf_ls_ack_send (struct ospf_neighbor *, struct ospf_lsa *);
165 extern void ospf_ls_ack_send_delayed (struct ospf_interface *);
166 extern void ospf_ls_retransmit (struct ospf_interface *, struct ospf_lsa *);
167 extern void ospf_ls_req_event (struct ospf_neighbor *);
168 
169 extern int ospf_ls_upd_timer (struct thread *);
170 extern int ospf_ls_ack_timer (struct thread *);
171 extern int ospf_poll_timer (struct thread *);
172 extern int ospf_hello_reply_timer (struct thread *);
173 
174 extern const struct message ospf_packet_type_str[];
175 extern const size_t ospf_packet_type_str_max;
176 
177 #endif /* _ZEBRA_OSPF_PACKET_H */
178