1 /*
2 *
3 * BlueZ - Bluetooth protocol stack for Linux
4 *
5 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
6 * Copyright (C) 2002-2010 Marcel Holtmann <marcel@holtmann.org>
7 *
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 */
24
25 #ifdef HAVE_CONFIG_H
26 #include <config.h>
27 #endif
28
29 #include <stdio.h>
30 #include <errno.h>
31 #include <fcntl.h>
32 #include <unistd.h>
33 #include <stdint.h>
34 #include <stdlib.h>
35 #include <syslog.h>
36 #include <setjmp.h>
37 #include <string.h>
38
39 #include "lib.h"
40 #include "dund.h"
41
42 #define MS_PPP 2
43 #define MS_SUCCESS 1
44 #define MS_FAILED -1
45 #define MS_TIMEOUT -2
46
47 static sigjmp_buf jmp;
48 static int retry;
49 static int timeout;
50
sig_alarm(int sig)51 static void sig_alarm(int sig)
52 {
53 siglongjmp(jmp, MS_TIMEOUT);
54 }
55
w4_str(int fd,char * str)56 static int w4_str(int fd, char *str)
57 {
58 char buf[40];
59 unsigned len = 0;
60 int r;
61
62 while (1) {
63 r = read(fd, buf + len, sizeof(buf) - len - 1);
64 if (r < 0) {
65 if (errno == EINTR || errno == EAGAIN)
66 continue;
67 break;
68 }
69 if (!r)
70 break;
71
72 len += r;
73
74 if (len < strlen(str))
75 continue;
76 buf[len] = 0;
77
78 if (strstr(buf, str))
79 return MS_SUCCESS;
80
81 /* Detect PPP */
82 if (strchr(buf, '~'))
83 return MS_PPP;
84 }
85 return MS_FAILED;
86 }
87
ms_server(int fd)88 static int ms_server(int fd)
89 {
90 switch (w4_str(fd, "CLIENT")) {
91 case MS_SUCCESS:
92 write_n(fd, "CLIENTSERVER", 12);
93 case MS_PPP:
94 return MS_SUCCESS;
95 default:
96 return MS_FAILED;
97 }
98 }
99
ms_client(int fd)100 static int ms_client(int fd)
101 {
102 write_n(fd, "CLIENT", 6);
103 return w4_str(fd, "CLIENTSERVER");
104 }
105
ms_dun(int fd,int server,int timeo)106 int ms_dun(int fd, int server, int timeo)
107 {
108 sig_t osig;
109
110 retry = 4;
111 timeout = timeo;
112
113 if (!server)
114 timeout /= retry;
115
116 osig = signal(SIGALRM, sig_alarm);
117
118 while (1) {
119 int r = sigsetjmp(jmp, 1);
120 if (r) {
121 if (r == MS_TIMEOUT && !server && --retry)
122 continue;
123
124 alarm(0);
125 signal(SIGALRM, osig);
126
127 switch (r) {
128 case MS_SUCCESS:
129 case MS_PPP:
130 errno = 0;
131 return 0;
132
133 case MS_FAILED:
134 errno = EPROTO;
135 break;
136
137 case MS_TIMEOUT:
138 errno = ETIMEDOUT;
139 break;
140 }
141 return -1;
142 }
143
144 alarm(timeout);
145
146 if (server)
147 r = ms_server(fd);
148 else
149 r = ms_client(fd);
150
151 siglongjmp(jmp, r);
152 }
153 }
154