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
63static int
64llflags_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	if (getifaddrs(&ifap) != 0)
76		return (-1);
77	error = -1;
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			freeifaddrs(ifap);
92			errno = EINVAL;
93			return (-1);
94		}
95		memcpy(&ifr6.ifr_ifru.ifru_addr, sin6, sin6->sin6_len);
96		if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
97			error = errno;
98			freeifaddrs(ifap);
99			errno = error;
100			return (-1);
101		}
102
103		*flagsp = ifr6.ifr_ifru.ifru_flags6;
104		error = 0;
105		break;
106	}
107	(void)close(s);
108	freeifaddrs(ifap);
109	if (error == -1)
110		errno = ENOENT;
111	return (error);
112}
113
114int
115cap_llflags_get(cap_channel_t *cap, const char *ifname, int *flagsp)
116{
117#ifdef WITH_CASPER
118	nvlist_t *nvl;
119	int error;
120
121	nvl = nvlist_create(0);
122	nvlist_add_string(nvl, "cmd", "get");
123	nvlist_add_string(nvl, "ifname", ifname);
124	nvl = cap_xfer_nvlist(cap, nvl);
125	if (nvl == NULL)
126		return (-1);
127	error = (int)dnvlist_get_number(nvl, "error", 0);
128	if (error == 0)
129		*flagsp = (int)nvlist_get_number(nvl, "flags");
130	nvlist_destroy(nvl);
131	if (error != 0)
132		errno = error;
133	return (error == 0 ? 0 : -1);
134#else
135	(void)cap;
136	return (llflags_get(ifname, flagsp));
137#endif
138}
139
140#ifdef WITH_CASPER
141static int
142llflags_command(const char *cmd, const nvlist_t *limits __unused,
143    nvlist_t *nvlin, nvlist_t *nvlout)
144{
145	const char *ifname;
146	int flags;
147
148	if (strcmp(cmd, "get") != 0)
149		return (EINVAL);
150	ifname = nvlist_get_string(nvlin, "ifname");
151	if (llflags_get(ifname, &flags) != 0)
152		return (errno);
153	nvlist_add_number(nvlout, "flags", flags);
154	return (0);
155}
156
157CREATE_SERVICE("rtsold.llflags", NULL, llflags_command, 0);
158#endif /* WITH_CASPER */
159