xref: /titanic_41/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.h (revision 4202ea4b139fb1fab45cd14d9d03a81b86902341)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	INTERFACE_H
27 #define	INTERFACE_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 /*
32  * Interface.[ch] encapsulate all of the agent's knowledge of network
33  * interfaces from the DHCP agent's perspective.  See interface.c for
34  * documentation on how to use the exported functions.  Note that there are not
35  * functional interfaces for manipulating all of the fields in a PIF or LIF --
36  * please read the comments in the structure definitions below for the rules on
37  * accessing various fields.
38  */
39 
40 #ifdef	__cplusplus
41 extern "C" {
42 #endif
43 
44 #include <netinet/in.h>
45 #include <net/if.h>			/* IFNAMSIZ */
46 #include <sys/types.h>
47 #include <netinet/dhcp.h>
48 #include <dhcpagent_ipc.h>
49 #include <libinetutil.h>
50 
51 #include "common.h"
52 #include "util.h"
53 
54 #define	V4_PART_OF_V6(v6)	v6._S6_un._S6_u32[3]
55 
56 struct dhcp_pif_s {
57 	dhcp_pif_t	*pif_next;	/* Note: must be first */
58 	dhcp_pif_t	*pif_prev;
59 	dhcp_lif_t	*pif_lifs;	/* pointer to logical interface list */
60 	uint32_t	pif_index;	/* interface index */
61 	uint16_t	pif_max;	/* largest DHCP packet on this if */
62 	uchar_t		*pif_hwaddr;	/* our link-layer address */
63 	uchar_t		pif_hwlen;	/* our link-layer address len */
64 	uchar_t		pif_hwtype;	/* type of link-layer */
65 	boolean_t	pif_isv6;
66 	boolean_t	pif_running;	/* interface is running */
67 	uint_t		pif_hold_count;	/* reference count */
68 	char		pif_name[LIFNAMSIZ];
69 };
70 
71 struct dhcp_lif_s {
72 	dhcp_lif_t	*lif_next;	/* Note: must be first */
73 	dhcp_lif_t	*lif_prev;
74 	dhcp_pif_t	*lif_pif;	/* backpointer to parent physical if */
75 	dhcp_smach_t	*lif_smachs;	/* pointer to list of state machines */
76 	dhcp_lease_t	*lif_lease;	/* backpointer to lease holding LIF */
77 	uint64_t	lif_flags;	/* Interface flags (IFF_*) */
78 	int		lif_sock_ip_fd;	/* Bound to addr.BOOTPC for src addr */
79 	iu_event_id_t	lif_packet_id;	/* event packet id */
80 	uint_t		lif_max;	/* maximum IP message size */
81 	uint_t		lif_hold_count;	/* reference count */
82 	boolean_t	lif_dad_wait;	/* waiting for DAD resolution */
83 	boolean_t	lif_removed;	/* removed from list */
84 	boolean_t	lif_plumbed;	/* interface plumbed by dhcpagent */
85 	boolean_t	lif_expired;	/* lease has evaporated */
86 	const char	*lif_declined;	/* reason to refuse this address */
87 	uint32_t	lif_iaid;	/* unique and stable identifier */
88 	iu_event_id_t	lif_iaid_id;	/* for delayed writes to /etc */
89 
90 	/*
91 	 * While in any states except ADOPTING, INIT, INFORMATION and
92 	 * INFORM_SENT, the following three fields are equal to what we believe
93 	 * the current address, netmask, and broadcast address on the interface
94 	 * to be.  This is so we can detect if the user changes them and
95 	 * abandon the interface.
96 	 */
97 
98 	in6_addr_t	lif_v6addr;	/* our IP address */
99 	in6_addr_t	lif_v6mask;	/* our netmask */
100 	in6_addr_t	lif_v6peer;	/* our broadcast or peer address */
101 
102 	dhcp_timer_t	lif_preferred;	/* lease preferred timer (v6 only) */
103 	dhcp_timer_t	lif_expire;	/* lease expire timer */
104 
105 	char		lif_name[LIFNAMSIZ];
106 };
107 #define	lif_addr	V4_PART_OF_V6(lif_v6addr)
108 #define	lif_netmask	V4_PART_OF_V6(lif_v6mask)
109 #define	lif_peer	V4_PART_OF_V6(lif_v6peer)
110 #define	lif_broadcast	V4_PART_OF_V6(lif_v6peer)
111 
112 /* used by expired_lif_state to express state of DHCP interfaces */
113 typedef enum dhcp_expire_e {
114 	DHCP_EXP_NOLIFS,
115 	DHCP_EXP_NOEXP,
116 	DHCP_EXP_ALLEXP,
117 	DHCP_EXP_SOMEEXP
118 } dhcp_expire_t;
119 
120 /*
121  * A word on memory management and LIFs and PIFs:
122  *
123  * Since LIFs are often passed as context to callback functions, they cannot be
124  * freed when the interface they represent is dropped or released (or when
125  * those callbacks finally go off, they will be hosed).  To handle this
126  * situation, the structures are reference counted.  Here are the rules for
127  * managing these counts:
128  *
129  * A PIF is created through insert_pif().  Along with initializing the PIF,
130  * this puts a hold on the PIF.  A LIF is created through insert_lif().  This
131  * also initializes the LIF and places a hold on it.  The caller's hold on the
132  * underlying PIF is transferred to the LIF.
133  *
134  * Whenever a lease is released or dropped (implicitly or explicitly),
135  * remove_lif() is called, which sets the lif_removed flag and removes the
136  * interface from the internal list of managed interfaces.  Lastly,
137  * remove_lif() calls release_lif() to remove the hold acquired in
138  * insert_lif().  If this decrements the hold count on the interface to zero,
139  * then free() is called and the hold on the PIF is dropped.  If there are
140  * holds other than the hold acquired in insert_lif(), the hold count will
141  * still be > 0, and the interface will remain allocated (though dormant).
142  *
143  * Whenever a callback is scheduled against a LIF, another hold must be put on
144  * the ifslist through hold_lif().
145  *
146  * Whenever a callback is called back against a LIF, release_lif() must be
147  * called to decrement the hold count, which may end up freeing the LIF if the
148  * hold count becomes zero.
149  *
150  * Since some callbacks may take a long time to get called back (such as
151  * timeout callbacks for lease expiration, etc), it is sometimes more
152  * appropriate to cancel the callbacks and call release_lif() if the
153  * cancellation succeeds.  This is done in remove_lif() for the lease preferred
154  * and expire callbacks.
155  *
156  * In general, a callback may also call verify_lif() when it gets called back
157  * in addition to release_lif(), to make sure that the interface is still in
158  * fact under the dhcpagent's control.  To make coding simpler, there is a
159  * third function, verify_smach(), which performs both the release_lif() and
160  * the verify_lif() on all LIFs controlled by a state machine.
161  */
162 
163 extern dhcp_pif_t *v4root;
164 extern dhcp_pif_t *v6root;
165 
166 dhcp_pif_t	*insert_pif(const char *, boolean_t, int *);
167 void		hold_pif(dhcp_pif_t *);
168 void		release_pif(dhcp_pif_t *);
169 dhcp_pif_t	*lookup_pif_by_uindex(uint16_t, dhcp_pif_t *, boolean_t);
170 dhcp_pif_t	*lookup_pif_by_name(const char *, boolean_t);
171 void		pif_status(dhcp_pif_t *, boolean_t);
172 
173 dhcp_lif_t	*insert_lif(dhcp_pif_t *, const char *, int *);
174 void		hold_lif(dhcp_lif_t *);
175 void		release_lif(dhcp_lif_t *);
176 void		remove_lif(dhcp_lif_t *);
177 dhcp_lif_t	*lookup_lif_by_name(const char *, const dhcp_pif_t *);
178 boolean_t	verify_lif(const dhcp_lif_t *);
179 dhcp_lif_t	*plumb_lif(dhcp_pif_t *, const in6_addr_t *);
180 void		unplumb_lif(dhcp_lif_t *);
181 dhcp_lif_t	*attach_lif(const char *, boolean_t, int *);
182 int		set_lif_dhcp(dhcp_lif_t *, boolean_t);
183 void		set_lif_deprecated(dhcp_lif_t *);
184 boolean_t	clear_lif_deprecated(dhcp_lif_t *);
185 boolean_t	open_ip_lif(dhcp_lif_t *, in_addr_t);
186 void		close_ip_lif(dhcp_lif_t *);
187 void		lif_mark_decline(dhcp_lif_t *, const char *);
188 boolean_t	schedule_lif_timer(dhcp_lif_t *, dhcp_timer_t *,
189 		    iu_tq_callback_t *);
190 void		cancel_lif_timers(dhcp_lif_t *);
191 dhcp_expire_t	expired_lif_state(dhcp_smach_t *);
192 dhcp_lif_t	*find_expired_lif(dhcp_smach_t *);
193 
194 uint_t		get_max_mtu(boolean_t);
195 void		remove_v6_strays(void);
196 
197 #ifdef	__cplusplus
198 }
199 #endif
200 
201 #endif	/* INTERFACE_H */
202