xref: /onnv-gate/usr/src/cmd/cmd-inet/sbin/dhcpagent/adopt.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  *
26*0Sstevel@tonic-gate  * ADOPTING state of the client state machine.
27*0Sstevel@tonic-gate  */
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
30*0Sstevel@tonic-gate 
31*0Sstevel@tonic-gate #include <sys/types.h>
32*0Sstevel@tonic-gate #include <string.h>
33*0Sstevel@tonic-gate #include <unistd.h>
34*0Sstevel@tonic-gate #include <stdlib.h>
35*0Sstevel@tonic-gate #include <sys/sockio.h>
36*0Sstevel@tonic-gate #include <sys/socket.h>
37*0Sstevel@tonic-gate #include <netinet/in.h>
38*0Sstevel@tonic-gate #include <sys/systeminfo.h>
39*0Sstevel@tonic-gate #include <netinet/inetutil.h>
40*0Sstevel@tonic-gate #include <netinet/dhcp.h>
41*0Sstevel@tonic-gate #include <dhcpmsg.h>
42*0Sstevel@tonic-gate 
43*0Sstevel@tonic-gate #include "async.h"
44*0Sstevel@tonic-gate #include "util.h"
45*0Sstevel@tonic-gate #include "packet.h"
46*0Sstevel@tonic-gate #include "interface.h"
47*0Sstevel@tonic-gate #include "states.h"
48*0Sstevel@tonic-gate 
49*0Sstevel@tonic-gate 
50*0Sstevel@tonic-gate typedef struct {
51*0Sstevel@tonic-gate 	char		dk_if_name[IFNAMSIZ];
52*0Sstevel@tonic-gate 	char		dk_ack[1];
53*0Sstevel@tonic-gate } dhcp_kcache_t;
54*0Sstevel@tonic-gate 
55*0Sstevel@tonic-gate static int	get_dhcp_kcache(dhcp_kcache_t **, size_t *);
56*0Sstevel@tonic-gate 
57*0Sstevel@tonic-gate /*
58*0Sstevel@tonic-gate  * dhcp_adopt(): adopts the interface managed by the kernel for diskless boot
59*0Sstevel@tonic-gate  *
60*0Sstevel@tonic-gate  *   input: void
61*0Sstevel@tonic-gate  *  output: int: nonzero on success, zero on failure
62*0Sstevel@tonic-gate  */
63*0Sstevel@tonic-gate 
64*0Sstevel@tonic-gate int
65*0Sstevel@tonic-gate dhcp_adopt(void)
66*0Sstevel@tonic-gate {
67*0Sstevel@tonic-gate 	int		retval;
68*0Sstevel@tonic-gate 	dhcp_kcache_t	*kcache = NULL;
69*0Sstevel@tonic-gate 	size_t		kcache_size;
70*0Sstevel@tonic-gate 	PKT_LIST	*plp = NULL;
71*0Sstevel@tonic-gate 	struct ifslist	*ifsp;
72*0Sstevel@tonic-gate 
73*0Sstevel@tonic-gate 	retval = get_dhcp_kcache(&kcache, &kcache_size);
74*0Sstevel@tonic-gate 	if (retval == 0 || kcache_size < sizeof (dhcp_kcache_t)) {
75*0Sstevel@tonic-gate 		dhcpmsg(MSG_CRIT, "dhcp_adopt: cannot fetch kernel cache");
76*0Sstevel@tonic-gate 		goto failure;
77*0Sstevel@tonic-gate 	}
78*0Sstevel@tonic-gate 
79*0Sstevel@tonic-gate 	dhcpmsg(MSG_DEBUG, "dhcp_adopt: fetched %s kcache", kcache->dk_if_name);
80*0Sstevel@tonic-gate 
81*0Sstevel@tonic-gate 	/*
82*0Sstevel@tonic-gate 	 * convert the kernel's ACK into binary
83*0Sstevel@tonic-gate 	 */
84*0Sstevel@tonic-gate 
85*0Sstevel@tonic-gate 	plp = calloc(1, sizeof (PKT_LIST));
86*0Sstevel@tonic-gate 	if (plp == NULL)
87*0Sstevel@tonic-gate 		goto failure;
88*0Sstevel@tonic-gate 
89*0Sstevel@tonic-gate 	plp->len = strlen(kcache->dk_ack) / 2;
90*0Sstevel@tonic-gate 	plp->pkt = malloc(plp->len);
91*0Sstevel@tonic-gate 	if (plp->pkt == NULL)
92*0Sstevel@tonic-gate 		goto failure;
93*0Sstevel@tonic-gate 
94*0Sstevel@tonic-gate 	dhcpmsg(MSG_DEBUG, "dhcp_adopt: allocated ACK of %d bytes", plp->len);
95*0Sstevel@tonic-gate 
96*0Sstevel@tonic-gate 	if (hexascii_to_octet(kcache->dk_ack, plp->len * 2, plp->pkt, &plp->len)
97*0Sstevel@tonic-gate 	    != 0) {
98*0Sstevel@tonic-gate 		dhcpmsg(MSG_CRIT, "dhcp_adopt: cannot convert kernel ACK");
99*0Sstevel@tonic-gate 		goto failure;
100*0Sstevel@tonic-gate 	}
101*0Sstevel@tonic-gate 
102*0Sstevel@tonic-gate 	if (dhcp_options_scan(plp, B_TRUE) != 0) {
103*0Sstevel@tonic-gate 		dhcpmsg(MSG_CRIT, "dhcp_adopt: cannot parse kernel ACK");
104*0Sstevel@tonic-gate 		goto failure;
105*0Sstevel@tonic-gate 	}
106*0Sstevel@tonic-gate 
107*0Sstevel@tonic-gate 	/*
108*0Sstevel@tonic-gate 	 * make an interface to represent the "cached interface" in
109*0Sstevel@tonic-gate 	 * the kernel, hook up the ACK packet we made, and send out
110*0Sstevel@tonic-gate 	 * the extend request (to attempt to renew the lease).
111*0Sstevel@tonic-gate 	 *
112*0Sstevel@tonic-gate 	 * we do a send_extend() instead of doing a dhcp_init_reboot()
113*0Sstevel@tonic-gate 	 * because although dhcp_init_reboot() is more correct from a
114*0Sstevel@tonic-gate 	 * protocol perspective, it introduces a window where a
115*0Sstevel@tonic-gate 	 * diskless client has no IP address but may need to page in
116*0Sstevel@tonic-gate 	 * more of this program.  we could mlockall(), but that's
117*0Sstevel@tonic-gate 	 * going to be a mess, especially with handling malloc() and
118*0Sstevel@tonic-gate 	 * stack growth, so it's easier to just renew().  the only
119*0Sstevel@tonic-gate 	 * catch here is that if we are not granted a renewal, we're
120*0Sstevel@tonic-gate 	 * totally hosed and can only bail out.
121*0Sstevel@tonic-gate 	 */
122*0Sstevel@tonic-gate 
123*0Sstevel@tonic-gate 	ifsp = insert_ifs(kcache->dk_if_name, B_TRUE, &retval);
124*0Sstevel@tonic-gate 	if (ifsp == NULL)
125*0Sstevel@tonic-gate 		goto failure;
126*0Sstevel@tonic-gate 
127*0Sstevel@tonic-gate 	ifsp->if_state   = ADOPTING;
128*0Sstevel@tonic-gate 	ifsp->if_dflags |= DHCP_IF_PRIMARY;
129*0Sstevel@tonic-gate 
130*0Sstevel@tonic-gate 	/*
131*0Sstevel@tonic-gate 	 * move to BOUND and use the information in our ACK packet
132*0Sstevel@tonic-gate 	 */
133*0Sstevel@tonic-gate 
134*0Sstevel@tonic-gate 	if (dhcp_bound(ifsp, plp) == 0) {
135*0Sstevel@tonic-gate 		dhcpmsg(MSG_CRIT, "dhcp_adopt: cannot use cached packet");
136*0Sstevel@tonic-gate 		goto failure;
137*0Sstevel@tonic-gate 	}
138*0Sstevel@tonic-gate 
139*0Sstevel@tonic-gate 	if (async_start(ifsp, DHCP_EXTEND, B_FALSE) == 0) {
140*0Sstevel@tonic-gate 		dhcpmsg(MSG_CRIT, "dhcp_adopt: async_start failed");
141*0Sstevel@tonic-gate 		goto failure;
142*0Sstevel@tonic-gate 	}
143*0Sstevel@tonic-gate 
144*0Sstevel@tonic-gate 	if (dhcp_extending(ifsp) == 0) {
145*0Sstevel@tonic-gate 		dhcpmsg(MSG_CRIT, "dhcp_adopt: cannot send renew request");
146*0Sstevel@tonic-gate 		goto failure;
147*0Sstevel@tonic-gate 	}
148*0Sstevel@tonic-gate 
149*0Sstevel@tonic-gate 	free(kcache);
150*0Sstevel@tonic-gate 	return (1);
151*0Sstevel@tonic-gate 
152*0Sstevel@tonic-gate failure:
153*0Sstevel@tonic-gate 	free(kcache);
154*0Sstevel@tonic-gate 	if (plp != NULL)
155*0Sstevel@tonic-gate 		free(plp->pkt);
156*0Sstevel@tonic-gate 	free(plp);
157*0Sstevel@tonic-gate 	return (0);
158*0Sstevel@tonic-gate }
159*0Sstevel@tonic-gate 
160*0Sstevel@tonic-gate /*
161*0Sstevel@tonic-gate  * get_dhcp_kcache(): fetches the DHCP ACK and interface name from the kernel
162*0Sstevel@tonic-gate  *
163*0Sstevel@tonic-gate  *   input: dhcp_kcache_t **: a dynamically-allocated cache packet
164*0Sstevel@tonic-gate  *	    size_t *: the length of that packet (on return)
165*0Sstevel@tonic-gate  *  output: int: nonzero on success, zero on failure
166*0Sstevel@tonic-gate  */
167*0Sstevel@tonic-gate 
168*0Sstevel@tonic-gate static int
169*0Sstevel@tonic-gate get_dhcp_kcache(dhcp_kcache_t **kernel_cachep, size_t *kcache_size)
170*0Sstevel@tonic-gate {
171*0Sstevel@tonic-gate 	char	dummy;
172*0Sstevel@tonic-gate 	long	size;
173*0Sstevel@tonic-gate 
174*0Sstevel@tonic-gate 	size = sysinfo(SI_DHCP_CACHE, &dummy, sizeof (dummy));
175*0Sstevel@tonic-gate 	if (size == -1)
176*0Sstevel@tonic-gate 		return (0);
177*0Sstevel@tonic-gate 
178*0Sstevel@tonic-gate 	*kcache_size   = size;
179*0Sstevel@tonic-gate 	*kernel_cachep = malloc(*kcache_size);
180*0Sstevel@tonic-gate 	if (*kernel_cachep == NULL)
181*0Sstevel@tonic-gate 		return (0);
182*0Sstevel@tonic-gate 
183*0Sstevel@tonic-gate 	(void) sysinfo(SI_DHCP_CACHE, (caddr_t)*kernel_cachep, size);
184*0Sstevel@tonic-gate 	return (1);
185*0Sstevel@tonic-gate }
186