xref: /freebsd/sbin/ifconfig/af_link.c (revision ea825d02749f382c3f7e17f28247f20a48733eab)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 static const char rcsid[] =
32   "$FreeBSD$";
33 #endif /* not lint */
34 
35 #include <sys/types.h>
36 #include <sys/ioctl.h>
37 #include <sys/socket.h>
38 #include <net/if.h>
39 
40 #include <err.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <ifaddrs.h>
45 #include <unistd.h>
46 
47 #include <net/if_dl.h>
48 #include <net/if_types.h>
49 #include <net/ethernet.h>
50 
51 #include "ifconfig.h"
52 
53 static struct ifreq link_ridreq;
54 
55 extern char *f_ether;
56 
57 static void
58 link_status(int s __unused, const struct ifaddrs *ifa)
59 {
60 	/* XXX no const 'cuz LLADDR is defined wrong */
61 	struct sockaddr_dl *sdl = (struct sockaddr_dl *) ifa->ifa_addr;
62 	char *ether_format, *format_char;
63 
64 	if (sdl != NULL && sdl->sdl_alen > 0) {
65 		if ((sdl->sdl_type == IFT_ETHER ||
66 		    sdl->sdl_type == IFT_L2VLAN ||
67 		    sdl->sdl_type == IFT_BRIDGE) &&
68 		    sdl->sdl_alen == ETHER_ADDR_LEN) {
69 			ether_format = ether_ntoa((struct ether_addr *)LLADDR(sdl));
70 			if (f_ether != NULL && strcmp(f_ether, "dash") == 0) {
71 				for (format_char = strchr(ether_format, ':');
72 				    format_char != NULL;
73 				    format_char = strchr(ether_format, ':'))
74 					*format_char = '-';
75 			}
76 			printf("\tether %s\n", ether_format);
77 		} else {
78 			int n = sdl->sdl_nlen > 0 ? sdl->sdl_nlen + 1 : 0;
79 
80 			printf("\tlladdr %s\n", link_ntoa(sdl) + n);
81 		}
82 		/* Best-effort (i.e. failures are silent) to get original
83 		 * hardware address, as read by NIC driver at attach time. Only
84 		 * applies to Ethernet NICs (IFT_ETHER). However, laggX
85 		 * interfaces claim to be IFT_ETHER, and re-type their component
86 		 * Ethernet NICs as IFT_IEEE8023ADLAG. So, check for both. If
87 		 * the MAC is zeroed, then it's actually a lagg.
88 		 */
89 		if ((sdl->sdl_type == IFT_ETHER ||
90 		    sdl->sdl_type == IFT_IEEE8023ADLAG) &&
91 		    sdl->sdl_alen == ETHER_ADDR_LEN) {
92 			struct ifreq ifr;
93 			int sock_hw;
94 			int rc;
95 			static const u_char laggaddr[6] = {0};
96 
97 			strncpy(ifr.ifr_name, ifa->ifa_name,
98 			    sizeof(ifr.ifr_name));
99 			memcpy(&ifr.ifr_addr, ifa->ifa_addr,
100 			    sizeof(ifa->ifa_addr->sa_len));
101 			ifr.ifr_addr.sa_family = AF_LOCAL;
102 			if ((sock_hw = socket(AF_LOCAL, SOCK_DGRAM, 0)) < 0) {
103 				warn("socket(AF_LOCAL,SOCK_DGRAM)");
104 				return;
105 			}
106 			rc = ioctl(sock_hw, SIOCGHWADDR, &ifr);
107 			close(sock_hw);
108 			if (rc != 0) {
109 				return;
110 			}
111 
112 			/*
113 			 * If this is definitely a lagg device or the hwaddr
114 			 * matches the link addr, don't bother.
115 			 */
116 			if (memcmp(ifr.ifr_addr.sa_data, laggaddr,
117 			    sdl->sdl_alen) == 0 ||
118 			    memcmp(ifr.ifr_addr.sa_data, LLADDR(sdl),
119 			    sdl->sdl_alen) == 0) {
120 				return;
121 			}
122 			ether_format = ether_ntoa((const struct ether_addr *)
123 			    &ifr.ifr_addr.sa_data);
124 			if (f_ether != NULL && strcmp(f_ether, "dash") == 0) {
125 				for (format_char = strchr(ether_format, ':');
126 				    format_char != NULL;
127 				    format_char = strchr(ether_format, ':'))
128 					*format_char = '-';
129 			}
130 			printf("\thwaddr %s\n", ether_format);
131 		}
132 	}
133 }
134 
135 static void
136 link_getaddr(const char *addr, int which)
137 {
138 	char *temp;
139 	struct sockaddr_dl sdl;
140 	struct sockaddr *sa = &link_ridreq.ifr_addr;
141 
142 	if (which != ADDR)
143 		errx(1, "can't set link-level netmask or broadcast");
144 	if (!strcmp(addr, "random")) {
145 		sdl.sdl_len = sizeof(sdl);
146 		sdl.sdl_alen = ETHER_ADDR_LEN;
147 		sdl.sdl_nlen = 0;
148 		sdl.sdl_family = AF_LINK;
149 		arc4random_buf(&sdl.sdl_data, ETHER_ADDR_LEN);
150 		/* Non-multicast and claim it is locally administered. */
151 		sdl.sdl_data[0] &= 0xfc;
152 		sdl.sdl_data[0] |= 0x02;
153 	} else {
154 		if ((temp = malloc(strlen(addr) + 2)) == NULL)
155 			errx(1, "malloc failed");
156 		temp[0] = ':';
157 		strcpy(temp + 1, addr);
158 		sdl.sdl_len = sizeof(sdl);
159 		link_addr(temp, &sdl);
160 		free(temp);
161 	}
162 	if (sdl.sdl_alen > sizeof(sa->sa_data))
163 		errx(1, "malformed link-level address");
164 	sa->sa_family = AF_LINK;
165 	sa->sa_len = sdl.sdl_alen;
166 	bcopy(LLADDR(&sdl), sa->sa_data, sdl.sdl_alen);
167 }
168 
169 static struct afswtch af_link = {
170 	.af_name	= "link",
171 	.af_af		= AF_LINK,
172 	.af_status	= link_status,
173 	.af_getaddr	= link_getaddr,
174 	.af_aifaddr	= SIOCSIFLLADDR,
175 	.af_addreq	= &link_ridreq,
176 };
177 static struct afswtch af_ether = {
178 	.af_name	= "ether",
179 	.af_af		= AF_LINK,
180 	.af_status	= link_status,
181 	.af_getaddr	= link_getaddr,
182 	.af_aifaddr	= SIOCSIFLLADDR,
183 	.af_addreq	= &link_ridreq,
184 };
185 static struct afswtch af_lladdr = {
186 	.af_name	= "lladdr",
187 	.af_af		= AF_LINK,
188 	.af_status	= link_status,
189 	.af_getaddr	= link_getaddr,
190 	.af_aifaddr	= SIOCSIFLLADDR,
191 	.af_addreq	= &link_ridreq,
192 };
193 
194 static __constructor void
195 link_ctor(void)
196 {
197 	af_register(&af_link);
198 	af_register(&af_ether);
199 	af_register(&af_lladdr);
200 }
201