xref: /illumos-gate/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.h (revision dc2bdd7936687cc418a497a3d31be5c8fcc0adab)
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  * Copyright 2019 Joshua M. Clulow <josh@sysmgr.org>
25  */
26 
27 #ifndef	INTERFACE_H
28 #define	INTERFACE_H
29 
30 /*
31  * Interface.[ch] encapsulate all of the agent's knowledge of network
32  * interfaces from the DHCP agent's perspective.  See interface.c for
33  * documentation on how to use the exported functions.  Note that there are not
34  * functional interfaces for manipulating all of the fields in a PIF or LIF --
35  * please read the comments in the structure definitions below for the rules on
36  * accessing various fields.
37  */
38 
39 #ifdef	__cplusplus
40 extern "C" {
41 #endif
42 
43 #include <netinet/in.h>
44 #include <net/if.h>			/* IFNAMSIZ */
45 #include <sys/types.h>
46 #include <netinet/dhcp.h>
47 #include <dhcpagent_ipc.h>
48 #include <libinetutil.h>
49 
50 #include "common.h"
51 #include "util.h"
52 
53 #define	V4_PART_OF_V6(v6)	v6._S6_un._S6_u32[3]
54 
55 struct dhcp_pif_s {
56 	dhcp_pif_t	*pif_next;	/* Note: must be first */
57 	dhcp_pif_t	*pif_prev;
58 	dhcp_lif_t	*pif_lifs;	/* pointer to logical interface list */
59 	uint32_t	pif_index;	/* interface index */
60 	uint_t		pif_mtu_orig;	/* Original interface MTU */
61 	uint_t		pif_mtu;	/* Current interface MTU */
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 	char		pif_grifname[LIFNAMSIZ];
70 	uint32_t	pif_grindex;	/* interface index for pif_grifname */
71 	boolean_t	pif_under_ipmp;	/* is an ipmp underlying interface */
72 };
73 
74 struct dhcp_lif_s {
75 	dhcp_lif_t	*lif_next;	/* Note: must be first */
76 	dhcp_lif_t	*lif_prev;
77 	dhcp_pif_t	*lif_pif;	/* backpointer to parent physical if */
78 	dhcp_smach_t	*lif_smachs;	/* pointer to list of state machines */
79 	dhcp_lease_t	*lif_lease;	/* backpointer to lease holding LIF */
80 	uint64_t	lif_flags;	/* Interface flags (IFF_*) */
81 	int		lif_sock_ip_fd;	/* Bound to addr.BOOTPC for src addr */
82 	iu_event_id_t	lif_packet_id;	/* event packet id */
83 	uint_t		lif_mtu;	/* Requested interface MTU */
84 	uint_t		lif_hold_count;	/* reference count */
85 	boolean_t	lif_dad_wait;	/* waiting for DAD resolution */
86 	boolean_t	lif_removed;	/* removed from list */
87 	boolean_t	lif_plumbed;	/* interface plumbed by dhcpagent */
88 	boolean_t	lif_expired;	/* lease has evaporated */
89 	const char	*lif_declined;	/* reason to refuse this address */
90 	uint32_t	lif_iaid;	/* unique and stable identifier */
91 	iu_event_id_t	lif_iaid_id;	/* for delayed writes to /etc */
92 
93 	/*
94 	 * While in any states except ADOPTING, INIT, INFORMATION and
95 	 * INFORM_SENT, the following three fields are equal to what we believe
96 	 * the current address, netmask, and broadcast address on the interface
97 	 * to be.  This is so we can detect if the user changes them and
98 	 * abandon the interface.
99 	 */
100 
101 	in6_addr_t	lif_v6addr;	/* our IP address */
102 	in6_addr_t	lif_v6mask;	/* our netmask */
103 	in6_addr_t	lif_v6peer;	/* our broadcast or peer address */
104 
105 	dhcp_timer_t	lif_preferred;	/* lease preferred timer (v6 only) */
106 	dhcp_timer_t	lif_expire;	/* lease expire timer */
107 
108 	char		lif_name[LIFNAMSIZ];
109 };
110 #define	lif_addr	V4_PART_OF_V6(lif_v6addr)
111 #define	lif_netmask	V4_PART_OF_V6(lif_v6mask)
112 #define	lif_peer	V4_PART_OF_V6(lif_v6peer)
113 #define	lif_broadcast	V4_PART_OF_V6(lif_v6peer)
114 
115 /* used by expired_lif_state to express state of DHCP interfaces */
116 typedef enum dhcp_expire_e {
117 	DHCP_EXP_NOLIFS,
118 	DHCP_EXP_NOEXP,
119 	DHCP_EXP_ALLEXP,
120 	DHCP_EXP_SOMEEXP
121 } dhcp_expire_t;
122 
123 /*
124  * A word on memory management and LIFs and PIFs:
125  *
126  * Since LIFs are often passed as context to callback functions, they cannot be
127  * freed when the interface they represent is dropped or released (or when
128  * those callbacks finally go off, they will be hosed).  To handle this
129  * situation, the structures are reference counted.  Here are the rules for
130  * managing these counts:
131  *
132  * A PIF is created through insert_pif().  Along with initializing the PIF,
133  * this puts a hold on the PIF.  A LIF is created through insert_lif().  This
134  * also initializes the LIF and places a hold on it.  The caller's hold on the
135  * underlying PIF is transferred to the LIF.
136  *
137  * Whenever a lease is released or dropped (implicitly or explicitly),
138  * remove_lif() is called, which sets the lif_removed flag and removes the
139  * interface from the internal list of managed interfaces.  Lastly,
140  * remove_lif() calls release_lif() to remove the hold acquired in
141  * insert_lif().  If this decrements the hold count on the interface to zero,
142  * then free() is called and the hold on the PIF is dropped.  If there are
143  * holds other than the hold acquired in insert_lif(), the hold count will
144  * still be > 0, and the interface will remain allocated (though dormant).
145  *
146  * Whenever a callback is scheduled against a LIF, another hold must be put on
147  * the ifslist through hold_lif().
148  *
149  * Whenever a callback is called back against a LIF, release_lif() must be
150  * called to decrement the hold count, which may end up freeing the LIF if the
151  * hold count becomes zero.
152  *
153  * Since some callbacks may take a long time to get called back (such as
154  * timeout callbacks for lease expiration, etc), it is sometimes more
155  * appropriate to cancel the callbacks and call release_lif() if the
156  * cancellation succeeds.  This is done in remove_lif() for the lease preferred
157  * and expire callbacks.
158  *
159  * In general, a callback may also call verify_lif() when it gets called back
160  * in addition to release_lif(), to make sure that the interface is still in
161  * fact under the dhcpagent's control.  To make coding simpler, there is a
162  * third function, verify_smach(), which performs both the release_lif() and
163  * the verify_lif() on all LIFs controlled by a state machine.
164  */
165 
166 extern dhcp_pif_t *v4root;
167 extern dhcp_pif_t *v6root;
168 
169 dhcp_pif_t	*insert_pif(const char *, boolean_t, int *);
170 void		hold_pif(dhcp_pif_t *);
171 void		release_pif(dhcp_pif_t *);
172 dhcp_pif_t	*lookup_pif_by_uindex(uint16_t, dhcp_pif_t *, boolean_t);
173 dhcp_pif_t	*lookup_pif_by_name(const char *, boolean_t);
174 void		pif_status(dhcp_pif_t *, boolean_t);
175 
176 dhcp_lif_t	*insert_lif(dhcp_pif_t *, const char *, int *);
177 void		hold_lif(dhcp_lif_t *);
178 void		release_lif(dhcp_lif_t *);
179 void		remove_lif(dhcp_lif_t *);
180 dhcp_lif_t	*lookup_lif_by_name(const char *, const dhcp_pif_t *);
181 boolean_t	verify_lif(const dhcp_lif_t *);
182 dhcp_lif_t	*plumb_lif(dhcp_pif_t *, const in6_addr_t *);
183 void		unplumb_lif(dhcp_lif_t *);
184 dhcp_lif_t	*attach_lif(const char *, boolean_t, int *);
185 int		set_lif_dhcp(dhcp_lif_t *);
186 void		set_lif_deprecated(dhcp_lif_t *);
187 boolean_t	clear_lif_deprecated(dhcp_lif_t *);
188 void		set_lif_mtu(dhcp_lif_t *, uint_t);
189 void		clear_lif_mtu(dhcp_lif_t *);
190 boolean_t	open_ip_lif(dhcp_lif_t *, in_addr_t, boolean_t);
191 void		close_ip_lif(dhcp_lif_t *);
192 void		lif_mark_decline(dhcp_lif_t *, const char *);
193 boolean_t	schedule_lif_timer(dhcp_lif_t *, dhcp_timer_t *,
194 		    iu_tq_callback_t *);
195 void		cancel_lif_timers(dhcp_lif_t *);
196 dhcp_expire_t	expired_lif_state(dhcp_smach_t *);
197 dhcp_lif_t	*find_expired_lif(dhcp_smach_t *);
198 
199 uint_t		get_max_mtu(boolean_t);
200 void		remove_v6_strays(void);
201 
202 #ifdef	__cplusplus
203 }
204 #endif
205 
206 #endif	/* INTERFACE_H */
207