1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28#ifndef _RESOLV_NETID_H
29#define _RESOLV_NETID_H
30
31/* This header contains declarations related to per-network DNS
32 * server selection. They are used by system/netd/ and should not be
33 * exposed by the C library's public NDK headers.
34 */
35#include <sys/cdefs.h>
36#include <netinet/in.h>
37#include <stdio.h>
38
39/*
40 * Passing NETID_UNSET as the netId causes system/netd/server/DnsProxyListener.cpp to
41 * fill in the appropriate default netId for the query.
42 */
43#define NETID_UNSET 0u
44
45/*
46 * MARK_UNSET represents the default (i.e. unset) value for a socket mark.
47 */
48#define MARK_UNSET 0u
49
50__BEGIN_DECLS
51
52struct __res_params;
53struct addrinfo;
54
55#define __used_in_netd __attribute__((visibility ("default")))
56
57/*
58 * A struct to capture context relevant to network operations.
59 *
60 * Application and DNS netids/marks can differ from one another under certain
61 * circumstances, notably when a VPN applies to the given uid's traffic but the
62 * VPN network does not have its own DNS servers explicitly provisioned.
63 *
64 * The introduction of per-UID routing means the uid is also an essential part
65 * of the evaluation context. Its proper uninitialized value is
66 * NET_CONTEXT_INVALID_UID.
67 */
68struct android_net_context {
69    unsigned app_netid;
70    unsigned app_mark;
71    unsigned dns_netid;
72    unsigned dns_mark;
73    uid_t uid;
74} __attribute__((packed));
75
76#define NET_CONTEXT_INVALID_UID ((uid_t)-1)
77
78struct hostent *android_gethostbyaddrfornet(const void *, socklen_t, int, unsigned, unsigned) __used_in_netd;
79struct hostent *android_gethostbynamefornet(const char *, int, unsigned, unsigned) __used_in_netd;
80int android_getaddrinfofornet(const char *, const char *, const struct addrinfo *, unsigned,
81    unsigned, struct addrinfo **) __used_in_netd;
82/*
83 * TODO: consider refactoring android_getaddrinfo_proxy() to serve as an
84 * explore_fqdn() dispatch table method, with the below function only making DNS calls.
85 */
86int android_getaddrinfofornetcontext(const char *, const char *, const struct addrinfo *,
87    const struct android_net_context *, struct addrinfo **) __used_in_netd;
88
89/* set name servers for a network */
90extern int _resolv_set_nameservers_for_net(unsigned netid, const char** servers,
91        unsigned numservers, const char *domains, const struct __res_params* params) __used_in_netd;
92
93/* flush the cache associated with a certain network */
94extern void _resolv_flush_cache_for_net(unsigned netid) __used_in_netd;
95
96/* delete the cache associated with a certain network */
97extern void _resolv_delete_cache_for_net(unsigned netid) __used_in_netd;
98
99/* Internal use only. */
100struct hostent *android_gethostbyaddrfornet_proxy(const void *, socklen_t, int , unsigned, unsigned) __LIBC_HIDDEN__;
101int android_getnameinfofornet(const struct sockaddr *, socklen_t, char *, size_t, char *, size_t, int, unsigned, unsigned) __LIBC_HIDDEN__;
102FILE* android_open_proxy(void) __LIBC_HIDDEN__;
103
104/* delete the cache associated with a certain network */
105extern void _resolv_delete_cache_for_net(unsigned netid);
106
107__END_DECLS
108
109#endif /* _RESOLV_NETID_H */
110