xref: /freebsd/usr.sbin/rtsold/cap_llflags.c (revision d2033021a73db7b8d910c1ffc52f4d1d0def7162)
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/types.h>
32 #include <sys/dnv.h>
33 #include <sys/ioctl.h>
34 #include <sys/nv.h>
35 #include <sys/queue.h>
36 
37 #include <net/if.h>
38 #include <netinet/in.h>
39 #include <netinet6/in6_var.h>
40 
41 #include <errno.h>
42 #include <ifaddrs.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 #include <libcasper.h>
47 #include <libcasper_service.h>
48 
49 #include "rtsold.h"
50 
51 /*
52  * A service to fetch the flags for the link-local IPv6 address on the specified
53  * interface.  This cannot easily be done in capability mode because we need to
54  * use the routing socket sysctl API to find the link-local address of a
55  * particular interface.  The SIOCGIFCONF ioctl is one other option, but as
56  * currently implemented it is less flexible (it cannot report the required
57  * buffer length), and hard-codes a buffer length limit.
58  */
59 
60 static int
61 llflags_get(const char *ifname, int *flagsp)
62 {
63 	struct in6_ifreq ifr6;
64 	struct ifaddrs *ifap, *ifa;
65 	struct sockaddr_in6 *sin6;
66 	int error, s;
67 
68 	s = socket(PF_INET6, SOCK_DGRAM, 0);
69 	if (s < 0)
70 		return (-1);
71 
72 	ifap = NULL;
73 	if (getifaddrs(&ifap) != 0) {
74 		error = errno;
75 		goto out;
76 	}
77 	error = ENOENT;
78 	for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
79 		if (strcmp(ifa->ifa_name, ifname) != 0)
80 			continue;
81 		if (ifa->ifa_addr->sa_family != AF_INET6)
82 			continue;
83 
84 		sin6 = (struct sockaddr_in6 *)(void *)ifa->ifa_addr;
85 		if (!IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
86 			continue;
87 
88 		memset(&ifr6, 0, sizeof(ifr6));
89 		if (strlcpy(ifr6.ifr_name, ifname, sizeof(ifr6.ifr_name)) >=
90 		    sizeof(ifr6.ifr_name)) {
91 			error = EINVAL;
92 			goto out;
93 		}
94 		memcpy(&ifr6.ifr_ifru.ifru_addr, sin6, sin6->sin6_len);
95 		if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
96 			error = errno;
97 			goto out;
98 		}
99 
100 		*flagsp = ifr6.ifr_ifru.ifru_flags6;
101 		error = 0;
102 		break;
103 	}
104 out:
105 	(void)close(s);
106 	if (ifap != NULL)
107 		freeifaddrs(ifap);
108 	if (error != 0) {
109 		errno = error;
110 		return (-1);
111 	} else {
112 		return (0);
113 	}
114 }
115 
116 int
117 cap_llflags_get(cap_channel_t *cap, const char *ifname, int *flagsp)
118 {
119 #ifdef WITH_CASPER
120 	nvlist_t *nvl;
121 	int error;
122 
123 	nvl = nvlist_create(0);
124 	nvlist_add_string(nvl, "cmd", "get");
125 	nvlist_add_string(nvl, "ifname", ifname);
126 	nvl = cap_xfer_nvlist(cap, nvl);
127 	if (nvl == NULL)
128 		return (-1);
129 	error = (int)dnvlist_get_number(nvl, "error", 0);
130 	if (error == 0)
131 		*flagsp = (int)nvlist_get_number(nvl, "flags");
132 	nvlist_destroy(nvl);
133 	if (error != 0)
134 		errno = error;
135 	return (error == 0 ? 0 : -1);
136 #else
137 	(void)cap;
138 	return (llflags_get(ifname, flagsp));
139 #endif
140 }
141 
142 #ifdef WITH_CASPER
143 static int
144 llflags_command(const char *cmd, const nvlist_t *limits __unused,
145     nvlist_t *nvlin, nvlist_t *nvlout)
146 {
147 	const char *ifname;
148 	int flags;
149 
150 	if (strcmp(cmd, "get") != 0)
151 		return (EINVAL);
152 	ifname = nvlist_get_string(nvlin, "ifname");
153 	if (llflags_get(ifname, &flags) != 0)
154 		return (errno);
155 	nvlist_add_number(nvlout, "flags", flags);
156 	return (0);
157 }
158 
159 CREATE_SERVICE("rtsold.llflags", NULL, llflags_command, 0);
160 #endif /* WITH_CASPER */
161