xref: /titanic_41/usr/src/cmd/cmd-inet/sbin/netstrategy/netstrategy.c (revision 5d863251ca4082a754d77741fb0e6d2bf9c6b3cd)
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 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * This program does the following:
31  *
32  * a) Returns:
33  *	0	- if the program successfully determined the net strategy.
34  *	!0	- if an error occurred.
35  *
36  * b) If the program is successful, it prints three tokens to
37  *    stdout: <root fs type> <interface name> <net config strategy>.
38  *    where:
39  *	<root fs type>		-	"nfs" or "ufs"
40  *	<interface name>	-	"hme0" or "none"
41  *	<net config strategy>	-	"dhcp", "rarp", "bootprops"
42  *					or "none"
43  *
44  *    Eg:
45  *	# /sbin/netstrategy
46  *	ufs hme0 dhcp
47  *
48  *    <root fs type> identifies the system's root file system type.
49  *
50  *    <interface name> is the 16 char name of the root interface, and is only
51  *	set if rarp/dhcp was used to configure the interface.
52  *
53  *    <net config strategy> can be either "rarp", "dhcp", "bootprops", or
54  *	"none" depending on which strategy was used to configure the
55  *	interface. Is "none" if no interface was configured using a
56  *	net-based strategy.
57  *
58  * CAVEATS: what about autoclient systems? XXX
59  *
60  * The logic here must match that in usr/src/uts/common/fs/nfs/nfs_dlinet.c,
61  * in particular that code (which implements diskless boot) imposes an
62  * ordering on possible ways of configuring network interfaces.
63  */
64 
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <unistd.h>
68 #include <string.h>
69 #include <sys/types.h>
70 #include <errno.h>
71 #include <alloca.h>
72 #include <sys/systeminfo.h>
73 #include <sys/socket.h>
74 #include <sys/sockio.h>
75 #include <net/if.h>
76 #include <sys/statvfs.h>
77 #include <libdevinfo.h>
78 
79 static char *program;
80 
81 static char *
82 get_root_fstype()
83 {
84 	static struct statvfs vfs;
85 
86 	/* root location */
87 	if (statvfs("/", &vfs) < 0) {
88 		return ("none");
89 	} else {
90 		if (strncmp(vfs.f_basetype, "nfs", sizeof ("nfs") - 1) == 0)
91 			vfs.f_basetype[sizeof ("nfs") - 1] = '\0';
92 		return (vfs.f_basetype);
93 	}
94 }
95 
96 /*
97  * The following boot properties can be used to configure a network
98  * interface in the case of a diskless boot.
99  *	host-ip, subnet-mask, server-path, server-name, server-ip.
100  *
101  * XXX non-diskless case requires "network-interface"?
102  */
103 static boolean_t
104 boot_properties_present()
105 {
106 	/* XXX should use sys/bootprops.h, but it's not delivered */
107 	const char *required_properties[] = {
108 		"host-ip",
109 		"subnet-mask",
110 		"server-path",
111 		"server-name",
112 		"server-ip",
113 		NULL,
114 	};
115 	const char **prop = required_properties;
116 	char *prop_value;
117 	di_node_t dn;
118 
119 	if ((dn = di_init("/", DINFOPROP)) == DI_NODE_NIL) {
120 		(void) fprintf(stderr, "%s: di_init: %s\n", program,
121 		    strerror(errno));
122 		di_fini(dn);
123 		return (B_FALSE);
124 	}
125 
126 	while (*prop != NULL) {
127 		if (di_prop_lookup_strings(DDI_DEV_T_ANY,
128 		    dn, *prop, &prop_value) != 1) {
129 			di_fini(dn);
130 			return (B_FALSE);
131 		}
132 		prop++;
133 	}
134 	di_fini(dn);
135 
136 	return (B_TRUE);
137 }
138 
139 static char *
140 get_first_interface()
141 {
142 	int fd;
143 	struct lifnum ifnum;
144 	struct lifconf ifconf;
145 	struct lifreq *ifr;
146 	static char interface[IFNAMSIZ];
147 
148 	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
149 		(void) fprintf(stderr, "%s: socket: %s\n", program,
150 		    strerror(errno));
151 		return (NULL);
152 	}
153 
154 	ifnum.lifn_family = AF_UNSPEC;
155 	ifnum.lifn_flags = 0;
156 	ifnum.lifn_count = 0;
157 
158 	if (ioctl(fd, SIOCGLIFNUM, &ifnum) < 0) {
159 		(void) fprintf(stderr, "%s: SIOCGLIFNUM: %s\n", program,
160 		    strerror(errno));
161 		(void) close(fd);
162 		return (NULL);
163 	}
164 
165 	ifconf.lifc_family = AF_UNSPEC;
166 	ifconf.lifc_flags = 0;
167 	ifconf.lifc_len = ifnum.lifn_count * sizeof (struct lifreq);
168 	ifconf.lifc_buf = alloca(ifconf.lifc_len);
169 
170 	if (ioctl(fd, SIOCGLIFCONF, &ifconf) < 0) {
171 		(void) fprintf(stderr, "%s: SIOCGLIFCONF: %s\n", program,
172 		    strerror(errno));
173 		(void) close(fd);
174 		return (NULL);
175 	}
176 
177 	for (ifr = ifconf.lifc_req; ifr < &ifconf.lifc_req[ifconf.lifc_len /
178 	    sizeof (ifconf.lifc_req[0])]; ifr++) {
179 
180 		if (strchr(ifr->lifr_name, ':') != NULL)
181 			continue;	/* skip logical interfaces */
182 
183 		if (ioctl(fd, SIOCGLIFFLAGS, ifr) < 0) {
184 			(void) fprintf(stderr, "%s: SIOCGIFFLAGS: %s\n",
185 			    program, strerror(errno));
186 			continue;
187 		}
188 
189 		if (ifr->lifr_flags & (IFF_VIRTUAL|IFF_POINTOPOINT))
190 			continue;
191 
192 		if (ifr->lifr_flags & IFF_UP) {
193 			/*
194 			 * For the "nfs rarp" and "nfs bootprops"
195 			 * cases, we assume that the first non-virtual
196 			 * IFF_UP interface is the one used.
197 			 *
198 			 * Since the order of the interfaces retrieved
199 			 * via SIOCGLIFCONF is not deterministic, this
200 			 * is largely silliness, but (a) "it's always
201 			 * been this way", (b) machines booted this
202 			 * way typically only have one interface, and
203 			 * (c) no one consumes the interface name in
204 			 * the RARP case anyway.
205 			 */
206 			(void) strncpy(interface, ifr->lifr_name, IFNAMSIZ);
207 			(void) close(fd);
208 			return (interface);
209 		}
210 	}
211 
212 	(void) close(fd);
213 
214 	return (NULL);
215 }
216 
217 /*
218  * Is DHCP running on the specified interface?
219  */
220 static boolean_t
221 check_dhcp_running(char *interface)
222 {
223 	int fd;
224 	struct ifreq ifr;
225 
226 	if (interface == NULL)
227 		return (B_FALSE);
228 
229 	(void) strncpy(ifr.ifr_name, interface, IFNAMSIZ);
230 
231 	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
232 		(void) fprintf(stderr, "%s: socket: %s\n", program,
233 		    strerror(errno));
234 		return (B_FALSE);
235 	}
236 
237 	if (ioctl(fd, SIOCGIFFLAGS, &ifr) < 0) {
238 		(void) fprintf(stderr, "%s: SIOCGIFFLAGS: %s\n",
239 		    program, strerror(errno));
240 		return (B_FALSE);
241 	}
242 
243 	if (ifr.ifr_flags & IFF_DHCPRUNNING)
244 		return (B_TRUE);
245 
246 	return (B_FALSE);
247 }
248 
249 /* ARGSUSED */
250 int
251 main(int argc, char *argv[])
252 {
253 	char *root, *interface, *strategy, dummy;
254 	long len;
255 
256 	root = interface = strategy = NULL;
257 	program = argv[0];
258 
259 	root = get_root_fstype();
260 
261 	/*
262 	 * If diskless, perhaps boot properties were used to configure
263 	 * the interface.
264 	 */
265 	if ((strcmp(root, "nfs") == 0) && boot_properties_present()) {
266 		strategy = "bootprops";
267 
268 		interface = get_first_interface();
269 		if (interface == NULL) {
270 			(void) fprintf(stderr,
271 			    "%s: cannot identify root interface.\n", program);
272 			return (2);
273 		}
274 
275 		(void) printf("%s %s %s\n", root, interface, strategy);
276 		return (0);
277 	}
278 
279 	/*
280 	 * Handle the simple case where diskless dhcp tells us everything
281 	 * we need to know.
282 	 */
283 	if ((len = sysinfo(SI_DHCP_CACHE, &dummy, sizeof (dummy))) > 1) {
284 		/* interface is first thing in cache. */
285 		strategy = "dhcp";
286 		interface = alloca(len);
287 		(void) sysinfo(SI_DHCP_CACHE, interface, len);
288 		(void) printf("%s %s %s\n", root, interface, strategy);
289 		return (0);
290 	}
291 
292 	/*
293 	 * We're not "nfs dhcp", "nfs none" is impossible, and we don't handle
294 	 * "ufs rarp" (consumers are coded to deal with this reality), so
295 	 * there are three possible situations:
296 	 *
297 	 *	1. We're "ufs dhcp" if there are any interfaces which have
298 	 *	   obtained their addresses through DHCP.  That is, if there
299 	 *	   are any IFF_UP and non-IFF_VIRTUAL interfaces also have
300 	 *	   IFF_DHCPRUNNING set.
301 	 *
302 	 *	2. We're "ufs none" if our filesystem is local and there
303 	 *	   are no interfaces which have obtained their addresses
304 	 *	   through DHCP.
305 	 *
306 	 *	3. We're "nfs rarp" if our filesystem is remote and there's
307 	 *	   at least IFF_UP non-IFF_VIRTUAL interface (which there
308 	 *	   *must* be, since we're running over NFS somehow), then
309 	 *	   it must be RARP since SI_DHCP_CACHE call above failed.
310 	 *	   It's too bad there isn't an IFF_RARPRUNNING flag.
311 	 */
312 
313 	interface = get_first_interface();
314 
315 	if (check_dhcp_running(interface))
316 		strategy = "dhcp";
317 
318 	if (strcmp(root, "nfs") == 0 || strcmp(root, "cachefs") == 0) {
319 		if (interface == NULL) {
320 			(void) fprintf(stderr,
321 			    "%s: cannot identify root interface.\n", program);
322 			return (2);
323 		}
324 		if (strategy == NULL)
325 			strategy = "rarp";	/*  must be rarp/bootparams */
326 	} else {
327 		if (interface == NULL || strategy == NULL)
328 			interface = strategy = "none";
329 	}
330 
331 	(void) printf("%s %s %s\n", root, interface, strategy);
332 	return (0);
333 }
334