/* * * BlueZ - Bluetooth protocol stack for Linux * * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com> * Copyright (C) 2002-2010 Marcel Holtmann <marcel@holtmann.org> * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <stdio.h> #include <errno.h> #include <fcntl.h> #include <unistd.h> #include <stdint.h> #include <stdlib.h> #include <syslog.h> #include <setjmp.h> #include <string.h> #include "lib.h" #include "dund.h" #define MS_PPP 2 #define MS_SUCCESS 1 #define MS_FAILED -1 #define MS_TIMEOUT -2 static sigjmp_buf jmp; static int retry; static int timeout; static void sig_alarm(int sig) { siglongjmp(jmp, MS_TIMEOUT); } static int w4_str(int fd, char *str) { char buf[40]; unsigned len = 0; int r; while (1) { r = read(fd, buf + len, sizeof(buf) - len - 1); if (r < 0) { if (errno == EINTR || errno == EAGAIN) continue; break; } if (!r) break; len += r; if (len < strlen(str)) continue; buf[len] = 0; if (strstr(buf, str)) return MS_SUCCESS; /* Detect PPP */ if (strchr(buf, '~')) return MS_PPP; } return MS_FAILED; } static int ms_server(int fd) { switch (w4_str(fd, "CLIENT")) { case MS_SUCCESS: write_n(fd, "CLIENTSERVER", 12); case MS_PPP: return MS_SUCCESS; default: return MS_FAILED; } } static int ms_client(int fd) { write_n(fd, "CLIENT", 6); return w4_str(fd, "CLIENTSERVER"); } int ms_dun(int fd, int server, int timeo) { sig_t osig; retry = 4; timeout = timeo; if (!server) timeout /= retry; osig = signal(SIGALRM, sig_alarm); while (1) { int r = sigsetjmp(jmp, 1); if (r) { if (r == MS_TIMEOUT && !server && --retry) continue; alarm(0); signal(SIGALRM, osig); switch (r) { case MS_SUCCESS: case MS_PPP: errno = 0; return 0; case MS_FAILED: errno = EPROTO; break; case MS_TIMEOUT: errno = ETIMEDOUT; break; } return -1; } alarm(timeout); if (server) r = ms_server(fd); else r = ms_client(fd); siglongjmp(jmp, r); } }