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 along
18  * with this program; see the file COPYING; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef _ZEBRA_OSPF_PACKET_H
23 #define _ZEBRA_OSPF_PACKET_H
24 
25 #define OSPF_HEADER_SIZE         24U
26 #define OSPF_AUTH_SIMPLE_SIZE     8U
27 #define OSPF_AUTH_MD5_SIZE       16U
28 
29 #define OSPF_MAX_PACKET_SIZE  65535U   /* includes IP Header size. */
30 #define OSPF_HELLO_MIN_SIZE      20U   /* not including neighbors */
31 #define OSPF_DB_DESC_MIN_SIZE     8U
32 #define OSPF_LS_REQ_MIN_SIZE      0U
33 #define OSPF_LS_UPD_MIN_SIZE      4U
34 #define OSPF_LS_ACK_MIN_SIZE      0U
35 
36 #define OSPF_MSG_HELLO         1  /* OSPF Hello Message. */
37 #define OSPF_MSG_DB_DESC       2  /* OSPF Database Descriptoin Message. */
38 #define OSPF_MSG_LS_REQ        3  /* OSPF Link State Request Message. */
39 #define OSPF_MSG_LS_UPD        4  /* OSPF Link State Update Message. */
40 #define OSPF_MSG_LS_ACK        5  /* OSPF Link State Acknoledgement Message. */
41 
42 #define OSPF_SEND_PACKET_DIRECT         1
43 #define OSPF_SEND_PACKET_INDIRECT       2
44 #define OSPF_SEND_PACKET_LOOP           3
45 
46 #define OSPF_HELLO_REPLY_DELAY          1
47 
48 /* Return values of functions involved in packet verification, see ospf6d. */
49 #define MSG_OK    0
50 #define MSG_NG    1
51 
52 struct ospf_packet {
53 	struct ospf_packet *next;
54 
55 	/* Pointer to data stream. */
56 	struct stream *s;
57 
58 	/* IP destination address. */
59 	struct in_addr dst;
60 
61 	/* OSPF packet length. */
62 	uint16_t length;
63 };
64 
65 /* OSPF packet queue structure. */
66 struct ospf_fifo {
67 	unsigned long count;
68 
69 	struct ospf_packet *head;
70 	struct ospf_packet *tail;
71 };
72 
73 /* OSPF packet header structure. */
74 struct ospf_header {
75 	uint8_t version;	  /* OSPF Version. */
76 	uint8_t type;		  /* Packet Type. */
77 	uint16_t length;	  /* Packet Length. */
78 	struct in_addr router_id; /* Router ID. */
79 	struct in_addr area_id;   /* Area ID. */
80 	uint16_t checksum;	/* Check Sum. */
81 	uint16_t auth_type;       /* Authentication Type. */
82 	/* Authentication Data. */
83 	union {
84 		/* Simple Authentication. */
85 		uint8_t auth_data[OSPF_AUTH_SIMPLE_SIZE];
86 		/* Cryptographic Authentication. */
87 		struct {
88 			uint16_t zero;	 /* Should be 0. */
89 			uint8_t key_id;	/* Key ID. */
90 			uint8_t auth_data_len; /* Auth Data Length. */
91 			uint32_t crypt_seqnum; /* Cryptographic Sequence
92 						   Number. */
93 		} crypt;
94 	} u;
95 };
96 
97 /* OSPF Hello body format. */
98 struct ospf_hello {
99 	struct in_addr network_mask;
100 	uint16_t hello_interval;
101 	uint8_t options;
102 	uint8_t priority;
103 	uint32_t dead_interval;
104 	struct in_addr d_router;
105 	struct in_addr bd_router;
106 	struct in_addr neighbors[1];
107 };
108 
109 /* OSPF Database Description body format. */
110 struct ospf_db_desc {
111 	uint16_t mtu;
112 	uint8_t options;
113 	uint8_t flags;
114 	uint32_t dd_seqnum;
115 };
116 
117 struct ospf_ls_update {
118 	uint32_t num_lsas;
119 };
120 
121 /* Macros. */
122 /* XXX Perhaps obsolete; function in ospf_packet.c */
123 #define OSPF_PACKET_MAX(oi)     ospf_packet_max (oi)
124 
125 #define OSPF_OUTPUT_PNT(S)      ((S)->data + (S)->putp)
126 #define OSPF_OUTPUT_LENGTH(S)   ((S)->endp)
127 
128 #define IS_SET_DD_MS(X)         ((X) & OSPF_DD_FLAG_MS)
129 #define IS_SET_DD_M(X)          ((X) & OSPF_DD_FLAG_M)
130 #define IS_SET_DD_I(X)          ((X) & OSPF_DD_FLAG_I)
131 #define IS_SET_DD_ALL(X)        ((X) & OSPF_DD_FLAG_ALL)
132 
133 /* Prototypes. */
134 extern void ospf_packet_free(struct ospf_packet *);
135 extern struct ospf_fifo *ospf_fifo_new(void);
136 extern void ospf_fifo_push(struct ospf_fifo *, struct ospf_packet *);
137 extern struct ospf_packet *ospf_fifo_pop(struct ospf_fifo *);
138 extern struct ospf_packet *ospf_fifo_head(struct ospf_fifo *);
139 extern void ospf_fifo_flush(struct ospf_fifo *);
140 extern void ospf_fifo_free(struct ospf_fifo *);
141 
142 extern int ospf_read(struct thread *);
143 extern void ospf_hello_send(struct ospf_interface *);
144 extern void ospf_db_desc_send(struct ospf_neighbor *);
145 extern void ospf_db_desc_resend(struct ospf_neighbor *);
146 extern void ospf_ls_req_send(struct ospf_neighbor *);
147 extern void ospf_ls_upd_send_lsa(struct ospf_neighbor *, struct ospf_lsa *,
148 				 int);
149 extern void ospf_ls_upd_send(struct ospf_neighbor *, struct list *, int, int);
150 extern void ospf_ls_ack_send(struct ospf_neighbor *, struct ospf_lsa *);
151 extern void ospf_ls_ack_send_delayed(struct ospf_interface *);
152 extern void ospf_ls_retransmit(struct ospf_interface *, struct ospf_lsa *);
153 extern void ospf_ls_req_event(struct ospf_neighbor *);
154 
155 extern int ospf_ls_upd_timer(struct thread *);
156 extern int ospf_ls_ack_timer(struct thread *);
157 extern int ospf_poll_timer(struct thread *);
158 extern int ospf_hello_reply_timer(struct thread *);
159 
160 extern const struct message ospf_packet_type_str[];
161 extern const size_t ospf_packet_type_str_max;
162 
163 extern void ospf_proactively_arp(struct ospf_neighbor *);
164 
165 #endif /* _ZEBRA_OSPF_PACKET_H */
166