1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 
18 #include <android/multinetwork.h>
19 #include <errno.h>
20 #include <NetdClient.h>    // the functions that communicate with netd
21 #include <resolv_netid.h>  // android_getaddrinfofornet()
22 #include <stdlib.h>
23 #include <sys/limits.h>
24 
25 
getnetidfromhandle(net_handle_t handle,unsigned * netid)26 static int getnetidfromhandle(net_handle_t handle, unsigned *netid) {
27     static const uint32_t k32BitMask = 0xffffffff;
28     // This value MUST be kept in sync with the corresponding value in
29     // the android.net.Network#getNetworkHandle() implementation.
30     static const uint32_t kHandleMagic = 0xcafed00d;
31 
32     // Check for minimum acceptable version of the API in the low bits.
33     if (handle != NETWORK_UNSPECIFIED &&
34         (handle & k32BitMask) != kHandleMagic) {
35         return 0;
36     }
37 
38     if (netid != NULL) {
39         *netid = ((handle >> (CHAR_BIT * sizeof(k32BitMask))) & k32BitMask);
40     }
41     return 1;
42 }
43 
44 
android_setsocknetwork(net_handle_t network,int fd)45 int android_setsocknetwork(net_handle_t network, int fd) {
46     unsigned netid;
47     if (!getnetidfromhandle(network, &netid)) {
48         errno = EINVAL;
49         return -1;
50     }
51 
52     int rval = setNetworkForSocket(netid, fd);
53     if (rval < 0) {
54         errno = -rval;
55         rval = -1;
56     }
57     return rval;
58 }
59 
android_setprocnetwork(net_handle_t network)60 int android_setprocnetwork(net_handle_t network) {
61     unsigned netid;
62     if (!getnetidfromhandle(network, &netid)) {
63         errno = EINVAL;
64         return -1;
65     }
66 
67     int rval = setNetworkForProcess(netid);
68     if (rval < 0) {
69         errno = -rval;
70         rval = -1;
71     }
72     return rval;
73 }
74 
android_getaddrinfofornetwork(net_handle_t network,const char * node,const char * service,const struct addrinfo * hints,struct addrinfo ** res)75 int android_getaddrinfofornetwork(net_handle_t network,
76         const char *node, const char *service,
77         const struct addrinfo *hints, struct addrinfo **res) {
78     unsigned netid;
79     if (!getnetidfromhandle(network, &netid)) {
80         errno = EINVAL;
81         return EAI_SYSTEM;
82     }
83 
84     return android_getaddrinfofornet(node, service, hints, netid, 0, res);
85 }
86 
android_res_nquery(net_handle_t network,const char * dname,int ns_class,int ns_type,enum ResNsendFlags flags)87 int android_res_nquery(net_handle_t network, const char *dname,
88         int ns_class, int ns_type, enum ResNsendFlags flags) {
89     unsigned netid;
90     if (!getnetidfromhandle(network, &netid)) {
91         return -ENONET;
92     }
93 
94     return resNetworkQuery(netid, dname, ns_class, ns_type, flags);
95 }
96 
android_res_nresult(int fd,int * rcode,uint8_t * answer,size_t anslen)97 int android_res_nresult(int fd, int *rcode, uint8_t *answer, size_t anslen) {
98     return resNetworkResult(fd, rcode, answer, anslen);
99 }
100 
android_res_nsend(net_handle_t network,const uint8_t * msg,size_t msglen,enum ResNsendFlags flags)101 int android_res_nsend(net_handle_t network, const uint8_t *msg, size_t msglen,
102         enum ResNsendFlags flags) {
103     unsigned netid;
104     if (!getnetidfromhandle(network, &netid)) {
105         return -ENONET;
106     }
107 
108     return resNetworkSend(netid, msg, msglen, flags);
109 }
110 
android_res_cancel(int nsend_fd)111 void android_res_cancel(int nsend_fd) {
112     resNetworkCancel(nsend_fd);
113 }
114