87 lines
2.8 KiB
C
87 lines
2.8 KiB
C
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/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of The Linux Foundation nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE DISCLAIMED. IN NO
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* EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <unistd.h>
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#include <syslog.h>
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#include <string.h>
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#include <signal.h>
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#define COMMAND_SIZE 27
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int main(int argc, char **argv) {
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/* Our process ID and Session ID */
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pid_t pid, sid;
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char command[30];
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if (argc < 5) {
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exit(EXIT_FAILURE);
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}
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/* E.g. "usb_composition 9060 n n y" to switch to composition 9060*/
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snprintf(command, COMMAND_SIZE, "usb_composition %s %s %s", argv[1], argv[2], argv[3]);
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pid = fork();
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if (pid < 0) {
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exit(EXIT_FAILURE);
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}
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/* Let parent process exit after disabling USB */
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if (pid > 0) {
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system(command);
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exit(EXIT_SUCCESS);
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}
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if (pid == 0) {
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umask(0);
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sid = setsid();
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if (sid < 0) {
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exit(EXIT_FAILURE);
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}
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if ((chdir("/")) < 0) {
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exit(EXIT_FAILURE);
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}
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close(STDIN_FILENO);
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close(STDOUT_FILENO);
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close(STDERR_FILENO);
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/* Let child process execute remaining usb_composition switch */
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system(command);
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exit(EXIT_SUCCESS);
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}
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}
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