xref: /freebsd/usr.sbin/rtsold/cap_llflags.c (revision 0957b409)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2018 The FreeBSD Foundation
5  *
6  * This software was developed by Mark Johnston under sponsorship from
7  * the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions are
11  * met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/types.h>
35 #include <sys/dnv.h>
36 #include <sys/ioctl.h>
37 #include <sys/nv.h>
38 #include <sys/queue.h>
39 
40 #include <net/if.h>
41 #include <netinet/in.h>
42 #include <netinet6/in6_var.h>
43 
44 #include <errno.h>
45 #include <ifaddrs.h>
46 #include <string.h>
47 
48 #include <libcasper.h>
49 #include <libcasper_service.h>
50 
51 #include "rtsold.h"
52 
53 /*
54  * A service to fetch the flags for the link-local IPv6 address on the specified
55  * interface.  This cannot easily be done in capability mode because we need to
56  * use the routing socket sysctl API to find the link-local address of a
57  * particular interface.  The SIOCGIFCONF ioctl is one other option, but as
58  * currently implemented it is less flexible (it cannot report the required
59  * buffer length), and hard-codes a buffer length limit.
60  */
61 
62 static int
63 llflags_get(const char *ifname, int *flagsp)
64 {
65 	struct in6_ifreq ifr6;
66 	struct ifaddrs *ifap, *ifa;
67 	struct sockaddr_in6 *sin6;
68 	int error, s;
69 
70 	s = socket(PF_INET6, SOCK_DGRAM, 0);
71 	if (s < 0)
72 		return (-1);
73 
74 	if (getifaddrs(&ifap) != 0)
75 		return (-1);
76 	error = -1;
77 	for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
78 		if (strcmp(ifa->ifa_name, ifname) != 0)
79 			continue;
80 		if (ifa->ifa_addr->sa_family != AF_INET6)
81 			continue;
82 
83 		sin6 = (struct sockaddr_in6 *)(void *)ifa->ifa_addr;
84 		if (!IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
85 			continue;
86 
87 		memset(&ifr6, 0, sizeof(ifr6));
88 		if (strlcpy(ifr6.ifr_name, ifname, sizeof(ifr6.ifr_name)) >=
89 		    sizeof(ifr6.ifr_name)) {
90 			freeifaddrs(ifap);
91 			errno = EINVAL;
92 			return (-1);
93 		}
94 		memcpy(&ifr6.ifr_ifru.ifru_addr, sin6, sin6->sin6_len);
95 		if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
96 			error = errno;
97 			freeifaddrs(ifap);
98 			errno = error;
99 			return (-1);
100 		}
101 
102 		*flagsp = ifr6.ifr_ifru.ifru_flags6;
103 		error = 0;
104 		break;
105 	}
106 	(void)close(s);
107 	freeifaddrs(ifap);
108 	if (error == -1)
109 		errno = ENOENT;
110 	return (error);
111 }
112 
113 int
114 cap_llflags_get(cap_channel_t *cap, const char *ifname, int *flagsp)
115 {
116 #ifdef WITH_CASPER
117 	nvlist_t *nvl;
118 	int error;
119 
120 	nvl = nvlist_create(0);
121 	nvlist_add_string(nvl, "cmd", "get");
122 	nvlist_add_string(nvl, "ifname", ifname);
123 	nvl = cap_xfer_nvlist(cap, nvl);
124 	if (nvl == NULL)
125 		return (-1);
126 	error = (int)dnvlist_get_number(nvl, "error", 0);
127 	if (error == 0)
128 		*flagsp = (int)nvlist_get_number(nvl, "flags");
129 	nvlist_destroy(nvl);
130 	if (error != 0)
131 		errno = error;
132 	return (error == 0 ? 0 : -1);
133 #else
134 	(void)cap;
135 	return (llflags_get(ifname, flagsp));
136 #endif
137 }
138 
139 #ifdef WITH_CASPER
140 static int
141 llflags_command(const char *cmd, const nvlist_t *limits __unused,
142     nvlist_t *nvlin, nvlist_t *nvlout)
143 {
144 	const char *ifname;
145 	int flags;
146 
147 	if (strcmp(cmd, "get") != 0)
148 		return (EINVAL);
149 	ifname = nvlist_get_string(nvlin, "ifname");
150 	if (llflags_get(ifname, &flags) != 0)
151 		return (errno);
152 	nvlist_add_number(nvlout, "flags", flags);
153 	return (0);
154 }
155 
156 CREATE_SERVICE("rtsold.llflags", NULL, llflags_command, 0);
157 #endif /* WITH_CASPER */
158