xref: /titanic_41/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.h (revision 51208d123c034a24326c8a1bfc3b557a63d467e8)
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 2007 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 	int		pif_dlpi_fd;
68 	int		pif_dlpi_count;
69 	iu_event_id_t	pif_dlpi_id;	/* event id for ack/nak/offer */
70 	uint_t		pif_hold_count;	/* reference count */
71 
72 	/*
73 	 * The destination address is the broadcast address of the interface,
74 	 * in DLPI terms (which means it includes both a link-layer broadcast
75 	 * address and a SAP, and the order depends on the requirements of the
76 	 * underlying driver).  We store it as a token like this because it's
77 	 * generally how we need to use it.
78 	 */
79 
80 	uchar_t		*pif_daddr;	/* our destination address */
81 	uchar_t		pif_dlen;	/* our destination address len */
82 
83 	uint_t		pif_saplen;	/* the SAP len */
84 	boolean_t	pif_sap_before;	/* does SAP come before address? */
85 	char		pif_name[LIFNAMSIZ];
86 };
87 
88 struct dhcp_lif_s {
89 	dhcp_lif_t	*lif_next;	/* Note: must be first */
90 	dhcp_lif_t	*lif_prev;
91 	dhcp_pif_t	*lif_pif;	/* backpointer to parent physical if */
92 	dhcp_smach_t	*lif_smachs;	/* pointer to list of state machines */
93 	dhcp_lease_t	*lif_lease;	/* backpointer to lease holding LIF */
94 	uint64_t	lif_flags;	/* Interface flags (IFF_*) */
95 	int		lif_sock_ip_fd;	/* Bound to addr.BOOTPC for src addr */
96 	iu_event_id_t	lif_acknak_id;	/* event acknak id */
97 	uint_t		lif_max;	/* maximum IP message size */
98 	uint_t		lif_hold_count;	/* reference count */
99 	boolean_t	lif_dad_wait;	/* waiting for DAD resolution */
100 	boolean_t	lif_removed;	/* removed from list */
101 	boolean_t	lif_plumbed;	/* interface plumbed by dhcpagent */
102 	boolean_t	lif_expired;	/* lease has evaporated */
103 	const char	*lif_declined;	/* reason to refuse this address */
104 	uint32_t	lif_iaid;	/* unique and stable identifier */
105 	iu_event_id_t	lif_iaid_id;	/* for delayed writes to /etc */
106 
107 	/*
108 	 * While in any states except ADOPTING, INIT, INFORMATION and
109 	 * INFORM_SENT, the following three fields are equal to what we believe
110 	 * the current address, netmask, and broadcast address on the interface
111 	 * to be.  This is so we can detect if the user changes them and
112 	 * abandon the interface.
113 	 */
114 
115 	in6_addr_t	lif_v6addr;	/* our IP address */
116 	in6_addr_t	lif_v6mask;	/* our netmask */
117 	in6_addr_t	lif_v6peer;	/* our broadcast or peer address */
118 
119 	dhcp_timer_t	lif_preferred;	/* lease preferred timer (v6 only) */
120 	dhcp_timer_t	lif_expire;	/* lease expire timer */
121 
122 	char		lif_name[LIFNAMSIZ];
123 };
124 #define	lif_addr	V4_PART_OF_V6(lif_v6addr)
125 #define	lif_netmask	V4_PART_OF_V6(lif_v6mask)
126 #define	lif_peer	V4_PART_OF_V6(lif_v6peer)
127 #define	lif_broadcast	V4_PART_OF_V6(lif_v6peer)
128 
129 /* used by expired_lif_state to express state of DHCP interfaces */
130 typedef enum dhcp_expire_e {
131 	DHCP_EXP_NOLIFS,
132 	DHCP_EXP_NOEXP,
133 	DHCP_EXP_ALLEXP,
134 	DHCP_EXP_SOMEEXP
135 } dhcp_expire_t;
136 
137 /*
138  * A word on memory management and LIFs and PIFs:
139  *
140  * Since LIFs are often passed as context to callback functions, they cannot be
141  * freed when the interface they represent is dropped or released (or when
142  * those callbacks finally go off, they will be hosed).  To handle this
143  * situation, the structures are reference counted.  Here are the rules for
144  * managing these counts:
145  *
146  * A PIF is created through insert_pif().  Along with initializing the PIF,
147  * this puts a hold on the PIF.  A LIF is created through insert_lif().  This
148  * also initializes the LIF and places a hold on it.  The caller's hold on the
149  * underlying PIF is transferred to the LIF.
150  *
151  * Whenever a lease is released or dropped (implicitly or explicitly),
152  * remove_lif() is called, which sets the lif_removed flag and removes the
153  * interface from the internal list of managed interfaces.  Lastly,
154  * remove_lif() calls release_lif() to remove the hold acquired in
155  * insert_lif().  If this decrements the hold count on the interface to zero,
156  * then free() is called and the hold on the PIF is dropped.  If there are
157  * holds other than the hold acquired in insert_lif(), the hold count will
158  * still be > 0, and the interface will remain allocated (though dormant).
159  *
160  * Whenever a callback is scheduled against a LIF, another hold must be put on
161  * the ifslist through hold_lif().
162  *
163  * Whenever a callback is called back against a LIF, release_lif() must be
164  * called to decrement the hold count, which may end up freeing the LIF if the
165  * hold count becomes zero.
166  *
167  * Since some callbacks may take a long time to get called back (such as
168  * timeout callbacks for lease expiration, etc), it is sometimes more
169  * appropriate to cancel the callbacks and call release_lif() if the
170  * cancellation succeeds.  This is done in remove_lif() for the lease preferred
171  * and expire callbacks.
172  *
173  * In general, a callback may also call verify_lif() when it gets called back
174  * in addition to release_lif(), to make sure that the interface is still in
175  * fact under the dhcpagent's control.  To make coding simpler, there is a
176  * third function, verify_smach(), which performs both the release_lif() and
177  * the verify_lif() on all LIFs controlled by a state machine.
178  */
179 
180 extern dhcp_pif_t *v4root;
181 extern dhcp_pif_t *v6root;
182 
183 dhcp_pif_t	*insert_pif(const char *, boolean_t, int *);
184 void		hold_pif(dhcp_pif_t *);
185 void		release_pif(dhcp_pif_t *);
186 dhcp_pif_t	*lookup_pif_by_index(uint_t, boolean_t);
187 dhcp_pif_t	*lookup_pif_by_uindex(uint16_t, dhcp_pif_t *, boolean_t);
188 dhcp_pif_t	*lookup_pif_by_name(const char *, boolean_t);
189 boolean_t	open_dlpi_pif(dhcp_pif_t *);
190 void		close_dlpi_pif(dhcp_pif_t *);
191 void		pif_status(dhcp_pif_t *, boolean_t);
192 
193 dhcp_lif_t	*insert_lif(dhcp_pif_t *, const char *, int *);
194 void		hold_lif(dhcp_lif_t *);
195 void		release_lif(dhcp_lif_t *);
196 void		remove_lif(dhcp_lif_t *);
197 dhcp_lif_t	*lookup_lif_by_name(const char *, const dhcp_pif_t *);
198 boolean_t	verify_lif(const dhcp_lif_t *);
199 dhcp_lif_t	*plumb_lif(dhcp_pif_t *, const in6_addr_t *);
200 void		unplumb_lif(dhcp_lif_t *);
201 dhcp_lif_t	*attach_lif(const char *, boolean_t, int *);
202 int		set_lif_dhcp(dhcp_lif_t *, boolean_t);
203 void		set_lif_deprecated(dhcp_lif_t *);
204 boolean_t	clear_lif_deprecated(dhcp_lif_t *);
205 boolean_t	open_ip_lif(dhcp_lif_t *);
206 void		close_ip_lif(dhcp_lif_t *);
207 void		lif_mark_decline(dhcp_lif_t *, const char *);
208 boolean_t	schedule_lif_timer(dhcp_lif_t *, dhcp_timer_t *,
209 		    iu_tq_callback_t *);
210 void		cancel_lif_timers(dhcp_lif_t *);
211 dhcp_expire_t	expired_lif_state(dhcp_smach_t *);
212 dhcp_lif_t	*find_expired_lif(dhcp_smach_t *);
213 
214 uint_t		get_max_mtu(boolean_t);
215 void		remove_v6_strays(void);
216 
217 #ifdef	__cplusplus
218 }
219 #endif
220 
221 #endif	/* INTERFACE_H */
222