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/*
* Copyright © 2016 Broadcom
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif
#include <errno.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
static void
kill_server(int server_pid)
{
int ret = kill(server_pid, SIGTERM);
int wstatus;
if (ret) {
fprintf(stderr, "Failed to send kill to the server: %s\n",
strerror(errno));
exit(1);
}
ret = waitpid(server_pid, &wstatus, 0);
if (ret < 0) {
fprintf(stderr, "Failed to wait for X to die: %s\n", strerror(errno));
exit(1);
}
}
static void
usage(int argc, char **argv)
{
fprintf(stderr, "%s <client command> -- <server command>\n", argv[0]);
exit(1);
}
/* Starts the X server, returning its pid. */
static int
start_server(char *const *server_args)
{
int server_pid = fork();
if (server_pid == -1) {
fprintf(stderr, "Fork failed: %s\n", strerror(errno));
exit(1);
} else if (server_pid != 0) {
/* Continue along the main process that will exec the client. */
return server_pid;
}
/* Execute the server. This only returns if an error occurred. */
execvp(server_args[0], server_args);
fprintf(stderr, "Error starting the server: %s\n", strerror(errno));
exit(1);
}
/* Reads the display number out of the started server's display socket. */
static int
get_display(int displayfd)
{
char display_string[10];
ssize_t ret;
ret = read(displayfd, display_string, sizeof(display_string - 1));
if (ret <= 0) {
fprintf(stderr, "Failed reading displayfd: %s\n", strerror(errno));
exit(1);
}
/* We've read in the display number as a string terminated by
* '\n', but not '\0'. Cap it and parse the number.
*/
display_string[ret] = '\0';
return atoi(display_string);
}
static int
start_client(char *const *client_args, int display)
{
char *display_string;
int ret;
int client_pid;
ret = asprintf(&display_string, ":%d", display);
if (ret < 0) {
fprintf(stderr, "asprintf fail\n");
exit(1);
}
ret = setenv("DISPLAY", display_string, true);
if (ret) {
fprintf(stderr, "Failed to set DISPLAY\n");
exit(1);
}
client_pid = fork();
if (client_pid == -1) {
fprintf(stderr, "Fork failed: %s\n", strerror(errno));
exit(1);
} else if (client_pid) {
int wstatus;
ret = waitpid(client_pid, &wstatus, 0);
if (ret < 0) {
fprintf(stderr, "Error waiting for client to start: %s\n",
strerror(errno));
return 1;
}
return WEXITSTATUS(wstatus);
} else {
execvp(client_args[0], client_args);
/* exec only returns if an error occurred. */
fprintf(stderr, "Error starting the client: %s\n", strerror(errno));
exit(1);
}
}
/* Splits the incoming argc/argv into a pair of NULL-terminated arrays
* of args.
*/
static void
parse_args(int argc, char **argv,
char * const **out_client_args,
char * const **out_server_args,
int displayfd)
{
/* We're stripping the -- and the program name, inserting two
* NULLs, and also the -displayfd and fd number.
*/
char **args_storage = calloc(argc + 2, sizeof(char *));
char *const *client_args;
char *const *server_args = NULL;
char **next_arg = args_storage;
bool parsing_client = true;
int i, ret;
char *displayfd_string;
if (!args_storage)
exit(1);
client_args = args_storage;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "--") == 0) {
if (!parsing_client)
usage(argc, argv);
/* Cap the client list */
*next_arg = NULL;
next_arg++;
/* Move to adding into server_args. */
server_args = next_arg;
parsing_client = false;
continue;
}
*next_arg = argv[i];
next_arg++;
}
if (client_args[0] == NULL || !server_args || server_args[0] == NULL)
usage(argc, argv);
/* Give the server -displayfd X */
*next_arg = (char *)"-displayfd";
next_arg++;
ret = asprintf(&displayfd_string, "%d", displayfd);
if (ret < 0) {
fprintf(stderr, "asprintf fail\n");
exit(1);
}
*next_arg = displayfd_string;
next_arg++;
*out_client_args = client_args;
*out_server_args = server_args;
}
int
main(int argc, char **argv)
{
char * const *client_args;
char * const *server_args;
int displayfd_pipe[2];
int display, server_pid;
int ret;
ret = pipe(displayfd_pipe);
if (ret) {
fprintf(stderr, "Pipe creation failure: %s", strerror(errno));
exit(1);
}
parse_args(argc, argv, &client_args, &server_args, displayfd_pipe[1]);
server_pid = start_server(server_args);
display = get_display(displayfd_pipe[0]);
ret = start_client(client_args, display);
kill_server(server_pid);
exit(ret);
}
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