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
60static int
61llflags_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	}
104out:
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
116int
117cap_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
143static int
144llflags_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
159CREATE_SERVICE("rtsold.llflags", NULL, llflags_command, 0);
160#endif /* WITH_CASPER */
161