1 /*
2 *
3 * BlueZ - Bluetooth protocol stack for Linux
4 *
5 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
6 * Copyright (C) 2002-2008 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
41 #define MS_PPP 2
42 #define MS_SUCCESS 1
43 #define MS_FAILED -1
44 #define MS_TIMEOUT -2
45
46 static sigjmp_buf jmp;
47 static int retry;
48 static int timeout;
49
sig_alarm(int sig)50 static void sig_alarm(int sig)
51 {
52 siglongjmp(jmp, MS_TIMEOUT);
53 }
54
w4_str(int fd,char * str)55 static int w4_str(int fd, char *str)
56 {
57 char buf[40];
58 int r, len = 0;
59
60 while (1) {
61 r = read(fd, buf + len, sizeof(buf) - len - 1);
62 if (r < 0) {
63 if (errno == EINTR || errno == EAGAIN)
64 continue;
65 break;
66 }
67 if (!r)
68 break;
69
70 len += r;
71
72 if (len < strlen(str))
73 continue;
74 buf[len] = 0;
75
76 if (strstr(buf, str))
77 return MS_SUCCESS;
78
79 /* Detect PPP */
80 if (strchr(buf, '~'))
81 return MS_PPP;
82 }
83 return MS_FAILED;
84 }
85
ms_server(int fd)86 static int ms_server(int fd)
87 {
88 switch (w4_str(fd, "CLIENT")) {
89 case MS_SUCCESS:
90 write_n(fd, "CLIENTSERVER", 12);
91 case MS_PPP:
92 return MS_SUCCESS;
93 default:
94 return MS_FAILED;
95 }
96 }
97
ms_client(int fd)98 static int ms_client(int fd)
99 {
100 write_n(fd, "CLIENT", 6);
101 return w4_str(fd, "CLIENTSERVER");
102 }
103
ms_dun(int fd,int server,int timeo)104 int ms_dun(int fd, int server, int timeo)
105 {
106 sig_t osig;
107
108 retry = 4;
109 timeout = timeo;
110
111 if (!server)
112 timeout /= retry;
113
114 osig = signal(SIGALRM, sig_alarm);
115
116 while (1) {
117 int r = sigsetjmp(jmp, 1);
118 if (r) {
119 if (r == MS_TIMEOUT && !server && --retry)
120 continue;
121
122 alarm(0);
123 signal(SIGALRM, osig);
124
125 switch (r) {
126 case MS_SUCCESS:
127 case MS_PPP:
128 errno = 0;
129 return 0;
130
131 case MS_FAILED:
132 errno = EPROTO;
133 break;
134
135 case MS_TIMEOUT:
136 errno = ETIMEDOUT;
137 break;
138 }
139 return -1;
140 }
141
142 alarm(timeout);
143
144 if (server)
145 r = ms_server(fd);
146 else
147 r = ms_client(fd);
148
149 siglongjmp(jmp, r);
150 }
151 }
152