1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
/*
* Copyright © 2014 Canonical Ltd.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3, as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranties of
* MERCHANTABILITY, SATISFACTORY QUALITY, 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, see <http://www.gnu.org/licenses/>.
*
* Authors:
* Ted Gould <ted.gould@canonical.com>
*/
#define _POSIX_C_SOURCE 200212L
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <signal.h>
void
sigchild_handler (int signal)
{
fprintf(stderr, "XMir has closed unexpectedly\n");
exit(EXIT_FAILURE);
}
struct sigaction sigchild_action = {
.sa_handler = sigchild_handler,
.sa_flags = SA_NOCLDWAIT
};
int
main (int argc, char * argv[])
{
if (argc < 3) {
fprintf(stderr, "xmir-helper needs more arguments: xmir-helper $(appid) $(thing to exec) ... \n");
return EXIT_FAILURE;
}
/* Make nice variables for the things we need */
char * appid = argv[1];
char * xmir = getenv("UBUNTU_APP_LAUNCH_XMIR_PATH");
if (xmir == NULL) {
xmir = "/usr/bin/Xmir";
}
/* Build a socket pair to get the connection back from XMir */
int sockets[2];
if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sockets) != 0) {
fprintf(stderr, "Unable to create socketpair for communicating with XMir\n");
return EXIT_FAILURE;
}
/* Give them nice names, the compiler will optimize out */
int xmirsocket = sockets[0];
int helpersocket = sockets[1];
/* Watch for the child dying */
if (sigaction(SIGCHLD, &sigchild_action, NULL) != 0) {
fprintf(stderr, "Unable to setup child signal handler\n");
return EXIT_FAILURE;
}
/* Start XMir */
if (fork() == 0) {
/* XMir start here */
/* GOAL: XMir -displayfd ${xmirsocket} -mir ${appid} */
char socketbuf[16] = {0};
snprintf(socketbuf, 16, "%d", xmirsocket);
char * xmirexec[6] = {
xmir,
"-displayfd",
socketbuf,
"-mir",
appid,
NULL
};
printf("Executing XMir on PID: %d", getpid());
return execv(xmir, xmirexec);
}
/* Wait to get the display number from XMir */
char readbuf[16] = {0};
if (read(helpersocket, readbuf, 16) == 0) {
fprintf(stderr, "Not reading anything from XMir\n");
return 1;
}
int i;
for (i = 0; i < sizeof(readbuf); i++) {
if (readbuf[i] == '\n') {
readbuf[i] = '\0';
break;
}
}
char displaynumber[16] = {0};
snprintf(displaynumber, 16, ":%s", readbuf);
/* Set up the display variable */
setenv("DISPLAY", displaynumber, 1);
/* Now that we have everything setup, we can execute */
char ** nargv = &argv[2];
int execret = execvp(nargv[0], nargv);
return execret;
}
|