1 /*
2 ** Copyright 2006, 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 #include <cutils/sockets.h>
18
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <stddef.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25
26 #include <sys/socket.h>
27 #include <sys/select.h>
28 #include <sys/types.h>
29 #include <netinet/in.h>
30 #include <netdb.h>
31
toggle_O_NONBLOCK(int s)32 static int toggle_O_NONBLOCK(int s) {
33 int flags = fcntl(s, F_GETFL);
34 if (flags == -1 || fcntl(s, F_SETFL, flags ^ O_NONBLOCK) == -1) {
35 close(s);
36 return -1;
37 }
38 return s;
39 }
40
41 // Connect to the given host and port.
42 // 'timeout' is in seconds (0 for no timeout).
43 // Returns a file descriptor or -1 on error.
44 // On error, check *getaddrinfo_error (for use with gai_strerror) first;
45 // if that's 0, use errno instead.
socket_network_client_timeout(const char * host,int port,int type,int timeout,int * getaddrinfo_error)46 int socket_network_client_timeout(const char* host, int port, int type, int timeout,
47 int* getaddrinfo_error) {
48 struct addrinfo hints;
49 memset(&hints, 0, sizeof(hints));
50 hints.ai_family = AF_UNSPEC;
51 hints.ai_socktype = type;
52
53 char port_str[16];
54 snprintf(port_str, sizeof(port_str), "%d", port);
55
56 struct addrinfo* addrs;
57 *getaddrinfo_error = getaddrinfo(host, port_str, &hints, &addrs);
58 if (*getaddrinfo_error != 0) {
59 return -1;
60 }
61
62 int result = -1;
63 for (struct addrinfo* addr = addrs; addr != NULL; addr = addr->ai_next) {
64 // The Mac doesn't have SOCK_NONBLOCK.
65 int s = socket(addr->ai_family, type, addr->ai_protocol);
66 if (s == -1 || toggle_O_NONBLOCK(s) == -1) break;
67
68 int rc = connect(s, addr->ai_addr, addr->ai_addrlen);
69 if (rc == 0) {
70 result = toggle_O_NONBLOCK(s);
71 break;
72 } else if (rc == -1 && errno != EINPROGRESS) {
73 close(s);
74 continue;
75 }
76
77 fd_set r_set;
78 FD_ZERO(&r_set);
79 FD_SET(s, &r_set);
80 fd_set w_set = r_set;
81
82 struct timeval ts;
83 ts.tv_sec = timeout;
84 ts.tv_usec = 0;
85 if ((rc = select(s + 1, &r_set, &w_set, NULL, (timeout != 0) ? &ts : NULL)) == -1) {
86 close(s);
87 break;
88 }
89 if (rc == 0) { // we had a timeout
90 errno = ETIMEDOUT;
91 close(s);
92 break;
93 }
94
95 int error = 0;
96 socklen_t len = sizeof(error);
97 if (FD_ISSET(s, &r_set) || FD_ISSET(s, &w_set)) {
98 if (getsockopt(s, SOL_SOCKET, SO_ERROR, &error, &len) < 0) {
99 close(s);
100 break;
101 }
102 } else {
103 close(s);
104 break;
105 }
106
107 if (error) { // check if we had a socket error
108 // TODO: Update the timeout.
109 errno = error;
110 close(s);
111 continue;
112 }
113
114 result = toggle_O_NONBLOCK(s);
115 break;
116 }
117
118 freeaddrinfo(addrs);
119 return result;
120 }
121
socket_network_client(const char * host,int port,int type)122 int socket_network_client(const char* host, int port, int type) {
123 int getaddrinfo_error;
124 return socket_network_client_timeout(host, port, type, 0, &getaddrinfo_error);
125 }
126