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 2009 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 /*
30  * Interface.[ch] encapsulate all of the agent's knowledge of network
31  * interfaces from the DHCP agent's perspective.  See interface.c for
32  * documentation on how to use the exported functions.  Note that there are not
33  * functional interfaces for manipulating all of the fields in a PIF or LIF --
34  * please read the comments in the structure definitions below for the rules on
35  * accessing various fields.
36  */
37 
38 #ifdef	__cplusplus
39 extern "C" {
40 #endif
41 
42 #include <netinet/in.h>
43 #include <net/if.h>			/* IFNAMSIZ */
44 #include <sys/types.h>
45 #include <netinet/dhcp.h>
46 #include <dhcpagent_ipc.h>
47 #include <libinetutil.h>
48 
49 #include "common.h"
50 #include "util.h"
51 
52 #define	V4_PART_OF_V6(v6)	v6._S6_un._S6_u32[3]
53 
54 struct dhcp_pif_s {
55 	dhcp_pif_t	*pif_next;	/* Note: must be first */
56 	dhcp_pif_t	*pif_prev;
57 	dhcp_lif_t	*pif_lifs;	/* pointer to logical interface list */
58 	uint32_t	pif_index;	/* interface index */
59 	uint16_t	pif_max;	/* largest DHCP packet on this if */
60 	uchar_t		*pif_hwaddr;	/* our link-layer address */
61 	uchar_t		pif_hwlen;	/* our link-layer address len */
62 	uchar_t		pif_hwtype;	/* type of link-layer */
63 	boolean_t	pif_isv6;
64 	boolean_t	pif_running;	/* interface is running */
65 	uint_t		pif_hold_count;	/* reference count */
66 	char		pif_name[LIFNAMSIZ];
67 	char		pif_grifname[LIFNAMSIZ];
68 	uint32_t	pif_grindex;	/* interface index for pif_grifname */
69 	boolean_t	pif_under_ipmp;	/* is an ipmp underlying interface */
70 };
71 
72 struct dhcp_lif_s {
73 	dhcp_lif_t	*lif_next;	/* Note: must be first */
74 	dhcp_lif_t	*lif_prev;
75 	dhcp_pif_t	*lif_pif;	/* backpointer to parent physical if */
76 	dhcp_smach_t	*lif_smachs;	/* pointer to list of state machines */
77 	dhcp_lease_t	*lif_lease;	/* backpointer to lease holding LIF */
78 	uint64_t	lif_flags;	/* Interface flags (IFF_*) */
79 	int		lif_sock_ip_fd;	/* Bound to addr.BOOTPC for src addr */
80 	iu_event_id_t	lif_packet_id;	/* event packet id */
81 	uint_t		lif_max;	/* maximum IP message size */
82 	uint_t		lif_hold_count;	/* reference count */
83 	boolean_t	lif_dad_wait;	/* waiting for DAD resolution */
84 	boolean_t	lif_removed;	/* removed from list */
85 	boolean_t	lif_plumbed;	/* interface plumbed by dhcpagent */
86 	boolean_t	lif_expired;	/* lease has evaporated */
87 	const char	*lif_declined;	/* reason to refuse this address */
88 	uint32_t	lif_iaid;	/* unique and stable identifier */
89 	iu_event_id_t	lif_iaid_id;	/* for delayed writes to /etc */
90 
91 	/*
92 	 * While in any states except ADOPTING, INIT, INFORMATION and
93 	 * INFORM_SENT, the following three fields are equal to what we believe
94 	 * the current address, netmask, and broadcast address on the interface
95 	 * to be.  This is so we can detect if the user changes them and
96 	 * abandon the interface.
97 	 */
98 
99 	in6_addr_t	lif_v6addr;	/* our IP address */
100 	in6_addr_t	lif_v6mask;	/* our netmask */
101 	in6_addr_t	lif_v6peer;	/* our broadcast or peer address */
102 
103 	dhcp_timer_t	lif_preferred;	/* lease preferred timer (v6 only) */
104 	dhcp_timer_t	lif_expire;	/* lease expire timer */
105 
106 	char		lif_name[LIFNAMSIZ];
107 };
108 #define	lif_addr	V4_PART_OF_V6(lif_v6addr)
109 #define	lif_netmask	V4_PART_OF_V6(lif_v6mask)
110 #define	lif_peer	V4_PART_OF_V6(lif_v6peer)
111 #define	lif_broadcast	V4_PART_OF_V6(lif_v6peer)
112 
113 /* used by expired_lif_state to express state of DHCP interfaces */
114 typedef enum dhcp_expire_e {
115 	DHCP_EXP_NOLIFS,
116 	DHCP_EXP_NOEXP,
117 	DHCP_EXP_ALLEXP,
118 	DHCP_EXP_SOMEEXP
119 } dhcp_expire_t;
120 
121 /*
122  * A word on memory management and LIFs and PIFs:
123  *
124  * Since LIFs are often passed as context to callback functions, they cannot be
125  * freed when the interface they represent is dropped or released (or when
126  * those callbacks finally go off, they will be hosed).  To handle this
127  * situation, the structures are reference counted.  Here are the rules for
128  * managing these counts:
129  *
130  * A PIF is created through insert_pif().  Along with initializing the PIF,
131  * this puts a hold on the PIF.  A LIF is created through insert_lif().  This
132  * also initializes the LIF and places a hold on it.  The caller's hold on the
133  * underlying PIF is transferred to the LIF.
134  *
135  * Whenever a lease is released or dropped (implicitly or explicitly),
136  * remove_lif() is called, which sets the lif_removed flag and removes the
137  * interface from the internal list of managed interfaces.  Lastly,
138  * remove_lif() calls release_lif() to remove the hold acquired in
139  * insert_lif().  If this decrements the hold count on the interface to zero,
140  * then free() is called and the hold on the PIF is dropped.  If there are
141  * holds other than the hold acquired in insert_lif(), the hold count will
142  * still be > 0, and the interface will remain allocated (though dormant).
143  *
144  * Whenever a callback is scheduled against a LIF, another hold must be put on
145  * the ifslist through hold_lif().
146  *
147  * Whenever a callback is called back against a LIF, release_lif() must be
148  * called to decrement the hold count, which may end up freeing the LIF if the
149  * hold count becomes zero.
150  *
151  * Since some callbacks may take a long time to get called back (such as
152  * timeout callbacks for lease expiration, etc), it is sometimes more
153  * appropriate to cancel the callbacks and call release_lif() if the
154  * cancellation succeeds.  This is done in remove_lif() for the lease preferred
155  * and expire callbacks.
156  *
157  * In general, a callback may also call verify_lif() when it gets called back
158  * in addition to release_lif(), to make sure that the interface is still in
159  * fact under the dhcpagent's control.  To make coding simpler, there is a
160  * third function, verify_smach(), which performs both the release_lif() and
161  * the verify_lif() on all LIFs controlled by a state machine.
162  */
163 
164 extern dhcp_pif_t *v4root;
165 extern dhcp_pif_t *v6root;
166 
167 dhcp_pif_t	*insert_pif(const char *, boolean_t, int *);
168 void		hold_pif(dhcp_pif_t *);
169 void		release_pif(dhcp_pif_t *);
170 dhcp_pif_t	*lookup_pif_by_uindex(uint16_t, dhcp_pif_t *, boolean_t);
171 dhcp_pif_t	*lookup_pif_by_name(const char *, boolean_t);
172 void		pif_status(dhcp_pif_t *, boolean_t);
173 
174 dhcp_lif_t	*insert_lif(dhcp_pif_t *, const char *, int *);
175 void		hold_lif(dhcp_lif_t *);
176 void		release_lif(dhcp_lif_t *);
177 void		remove_lif(dhcp_lif_t *);
178 dhcp_lif_t	*lookup_lif_by_name(const char *, const dhcp_pif_t *);
179 boolean_t	verify_lif(const dhcp_lif_t *);
180 dhcp_lif_t	*plumb_lif(dhcp_pif_t *, const in6_addr_t *);
181 void		unplumb_lif(dhcp_lif_t *);
182 dhcp_lif_t	*attach_lif(const char *, boolean_t, int *);
183 int		set_lif_dhcp(dhcp_lif_t *);
184 void		set_lif_deprecated(dhcp_lif_t *);
185 boolean_t	clear_lif_deprecated(dhcp_lif_t *);
186 boolean_t	open_ip_lif(dhcp_lif_t *, in_addr_t, boolean_t);
187 void		close_ip_lif(dhcp_lif_t *);
188 void		lif_mark_decline(dhcp_lif_t *, const char *);
189 boolean_t	schedule_lif_timer(dhcp_lif_t *, dhcp_timer_t *,
190 		    iu_tq_callback_t *);
191 void		cancel_lif_timers(dhcp_lif_t *);
192 dhcp_expire_t	expired_lif_state(dhcp_smach_t *);
193 dhcp_lif_t	*find_expired_lif(dhcp_smach_t *);
194 
195 uint_t		get_max_mtu(boolean_t);
196 void		remove_v6_strays(void);
197 
198 #ifdef	__cplusplus
199 }
200 #endif
201 
202 #endif	/* INTERFACE_H */
203