xref: /freebsd/usr.sbin/rtsold/cap_llflags.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 #include <unistd.h>
48 
49 #include <libcasper.h>
50 #include <libcasper_service.h>
51 
52 #include "rtsold.h"
53 
54 /*
55  * A service to fetch the flags for the link-local IPv6 address on the specified
56  * interface.  This cannot easily be done in capability mode because we need to
57  * use the routing socket sysctl API to find the link-local address of a
58  * particular interface.  The SIOCGIFCONF ioctl is one other option, but as
59  * currently implemented it is less flexible (it cannot report the required
60  * buffer length), and hard-codes a buffer length limit.
61  */
62 
63 static int
64 llflags_get(const char *ifname, int *flagsp)
65 {
66 	struct in6_ifreq ifr6;
67 	struct ifaddrs *ifap, *ifa;
68 	struct sockaddr_in6 *sin6;
69 	int error, s;
70 
71 	s = socket(PF_INET6, SOCK_DGRAM, 0);
72 	if (s < 0)
73 		return (-1);
74 
75 	ifap = NULL;
76 	if (getifaddrs(&ifap) != 0) {
77 		error = errno;
78 		goto out;
79 	}
80 	error = ENOENT;
81 	for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
82 		if (strcmp(ifa->ifa_name, ifname) != 0)
83 			continue;
84 		if (ifa->ifa_addr->sa_family != AF_INET6)
85 			continue;
86 
87 		sin6 = (struct sockaddr_in6 *)(void *)ifa->ifa_addr;
88 		if (!IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
89 			continue;
90 
91 		memset(&ifr6, 0, sizeof(ifr6));
92 		if (strlcpy(ifr6.ifr_name, ifname, sizeof(ifr6.ifr_name)) >=
93 		    sizeof(ifr6.ifr_name)) {
94 			error = errno;
95 			goto out;
96 		}
97 		memcpy(&ifr6.ifr_ifru.ifru_addr, sin6, sin6->sin6_len);
98 		if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
99 			error = errno;
100 			goto out;
101 		}
102 
103 		*flagsp = ifr6.ifr_ifru.ifru_flags6;
104 		error = 0;
105 		break;
106 	}
107 out:
108 	(void)close(s);
109 	if (ifap != NULL)
110 		freeifaddrs(ifap);
111 	if (error != 0) {
112 		errno = error;
113 		return (-1);
114 	} else {
115 		return (0);
116 	}
117 }
118 
119 int
120 cap_llflags_get(cap_channel_t *cap, const char *ifname, int *flagsp)
121 {
122 #ifdef WITH_CASPER
123 	nvlist_t *nvl;
124 	int error;
125 
126 	nvl = nvlist_create(0);
127 	nvlist_add_string(nvl, "cmd", "get");
128 	nvlist_add_string(nvl, "ifname", ifname);
129 	nvl = cap_xfer_nvlist(cap, nvl);
130 	if (nvl == NULL)
131 		return (-1);
132 	error = (int)dnvlist_get_number(nvl, "error", 0);
133 	if (error == 0)
134 		*flagsp = (int)nvlist_get_number(nvl, "flags");
135 	nvlist_destroy(nvl);
136 	if (error != 0)
137 		errno = error;
138 	return (error == 0 ? 0 : -1);
139 #else
140 	(void)cap;
141 	return (llflags_get(ifname, flagsp));
142 #endif
143 }
144 
145 #ifdef WITH_CASPER
146 static int
147 llflags_command(const char *cmd, const nvlist_t *limits __unused,
148     nvlist_t *nvlin, nvlist_t *nvlout)
149 {
150 	const char *ifname;
151 	int flags;
152 
153 	if (strcmp(cmd, "get") != 0)
154 		return (EINVAL);
155 	ifname = nvlist_get_string(nvlin, "ifname");
156 	if (llflags_get(ifname, &flags) != 0)
157 		return (errno);
158 	nvlist_add_number(nvlout, "flags", flags);
159 	return (0);
160 }
161 
162 CREATE_SERVICE("rtsold.llflags", NULL, llflags_command, 0);
163 #endif /* WITH_CASPER */
164