stub.c revision 706f2543 
1/* Copyright (c) 2008 Apple Inc.
2 *
3 * Permission is hereby granted, free of charge, to any person
4 * obtaining a copy of this software and associated documentation files
5 * (the "Software"), to deal in the Software without restriction,
6 * including without limitation the rights to use, copy, modify, merge,
7 * publish, distribute, sublicense, and/or sell copies of the Software,
8 * and to permit persons to whom the Software is furnished to do so,
9 * subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be
12 * included in all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
17 * NONINFRINGEMENT.  IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT
18 * HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
19 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Except as contained in this notice, the name(s) of the above
24 * copyright holders shall not be used in advertising or otherwise to
25 * promote the sale, use or other dealings in this Software without
26 * prior written authorization.
27 */
28
29#include <CoreServices/CoreServices.h>
30
31#ifdef HAVE_DIX_CONFIG_H
32#include <dix-config.h>
33#endif
34
35#include <string.h>
36#include <stdio.h>
37#include <unistd.h>
38#include <errno.h>
39
40#include <sys/socket.h>
41#include <sys/un.h>
42
43#define kX11AppBundleId LAUNCHD_ID_PREFIX".X11"
44#define kX11AppBundlePath "/Contents/MacOS/X11"
45
46static char *server_bootstrap_name = kX11AppBundleId;
47
48#include <mach/mach.h>
49#include <mach/mach_error.h>
50#include <servers/bootstrap.h>
51#include "mach_startup.h"
52
53#include <signal.h>
54
55#include <AvailabilityMacros.h>
56
57#include "launchd_fd.h"
58
59#ifndef BUILD_DATE
60#define BUILD_DATE "?"
61#endif
62#ifndef XSERVER_VERSION
63#define XSERVER_VERSION "?"
64#endif
65
66#define DEBUG 1
67
68static char x11_path[PATH_MAX + 1];
69
70static pid_t x11app_pid = 0;
71
72static void set_x11_path(void) {
73#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1050
74
75    CFURLRef appURL = NULL;
76    OSStatus osstatus = LSFindApplicationForInfo(kLSUnknownCreator, CFSTR(kX11AppBundleId), nil, nil, &appURL);
77
78    switch (osstatus) {
79        case noErr:
80            if (appURL == NULL) {
81                fprintf(stderr, "Xquartz: Invalid response from LSFindApplicationForInfo(%s)\n",
82                        kX11AppBundleId);
83                exit(1);
84            }
85
86            if (!CFURLGetFileSystemRepresentation(appURL, true, (unsigned char *)x11_path, sizeof(x11_path))) {
87                fprintf(stderr, "Xquartz: Error resolving URL for %s\n", kX11AppBundleId);
88                exit(3);
89            }
90
91            strlcat(x11_path, kX11AppBundlePath, sizeof(x11_path));
92#ifdef DEBUG
93            fprintf(stderr, "Xquartz: X11.app = %s\n", x11_path);
94#endif
95            break;
96        case kLSApplicationNotFoundErr:
97            fprintf(stderr, "Xquartz: Unable to find application for %s\n", kX11AppBundleId);
98            exit(10);
99        default:
100            fprintf(stderr, "Xquartz: Unable to find application for %s, error code = %d\n",
101                    kX11AppBundleId, (int)osstatus);
102            exit(11);
103    }
104#else
105    /* TODO: Make Tiger smarter... but TBH, this should never get called on Tiger... */
106    strlcpy(x11_path, "/Applications/Utilities/X11.app/Contents/MacOS/X11", sizeof(x11_path));
107#endif
108}
109
110static int connect_to_socket(const char *filename) {
111    struct sockaddr_un servaddr_un;
112    struct sockaddr *servaddr;
113    socklen_t servaddr_len;
114    int ret_fd;
115
116    /* Setup servaddr_un */
117    memset (&servaddr_un, 0, sizeof (struct sockaddr_un));
118    servaddr_un.sun_family = AF_UNIX;
119    strlcpy(servaddr_un.sun_path, filename, sizeof(servaddr_un.sun_path));
120
121    servaddr = (struct sockaddr *) &servaddr_un;
122    servaddr_len = sizeof(struct sockaddr_un) - sizeof(servaddr_un.sun_path) + strlen(filename);
123
124    ret_fd = socket(PF_UNIX, SOCK_STREAM, 0);
125    if(ret_fd == -1) {
126        fprintf(stderr, "Xquartz: Failed to create socket: %s - %s\n", filename, strerror(errno));
127        return -1;
128    }
129
130    if(connect(ret_fd, servaddr, servaddr_len) < 0) {
131        fprintf(stderr, "Xquartz: Failed to connect to socket: %s - %d - %s\n", filename, errno, strerror(errno));
132        close(ret_fd);
133        return -1;
134    }
135
136    return ret_fd;
137}
138
139static void send_fd_handoff(int connected_fd, int launchd_fd) {
140    char databuf[] = "display";
141    struct iovec iov[1];
142
143    union {
144        struct cmsghdr hdr;
145        char bytes[CMSG_SPACE(sizeof(int))];
146    } buf;
147
148    struct msghdr msg;
149    struct cmsghdr *cmsg;
150
151    iov[0].iov_base = databuf;
152    iov[0].iov_len  = sizeof(databuf);
153
154    msg.msg_iov = iov;
155    msg.msg_iovlen = 1;
156    msg.msg_control = buf.bytes;
157    msg.msg_controllen = sizeof(buf);
158    msg.msg_name = 0;
159    msg.msg_namelen = 0;
160    msg.msg_flags = 0;
161
162    cmsg = CMSG_FIRSTHDR (&msg);
163    cmsg->cmsg_level = SOL_SOCKET;
164    cmsg->cmsg_type = SCM_RIGHTS;
165    cmsg->cmsg_len = CMSG_LEN(sizeof(int));
166
167    msg.msg_controllen = cmsg->cmsg_len;
168
169    *((int*)CMSG_DATA(cmsg)) = launchd_fd;
170
171    if(sendmsg(connected_fd, &msg, 0) < 0) {
172        fprintf(stderr, "Xquartz: Error sending $DISPLAY file descriptor over fd %d: %d -- %s\n", connected_fd, errno, strerror(errno));
173        return;
174    }
175
176#ifdef DEBUG
177    fprintf(stderr, "Xquartz: Message sent.  Closing handoff fd.\n");
178#endif
179
180    close(connected_fd);
181}
182
183static void signal_handler(int sig) {
184    if(x11app_pid)
185        kill(x11app_pid, sig);
186    _exit(0);
187}
188
189int main(int argc, char **argv, char **envp) {
190    int envpc;
191    kern_return_t kr;
192    mach_port_t mp;
193    string_array_t newenvp;
194    string_array_t newargv;
195    size_t i;
196    int launchd_fd;
197    string_t handoff_socket_filename;
198    sig_t handler;
199
200    if(argc == 2 && !strcmp(argv[1], "-version")) {
201        fprintf(stderr, "X.org Release 7.5\n");
202        fprintf(stderr, "X.Org X Server %s\n", XSERVER_VERSION);
203        fprintf(stderr, "Build Date: %s\n", BUILD_DATE);
204        return EXIT_SUCCESS;
205    }
206
207    if(getenv("X11_PREFS_DOMAIN"))
208        server_bootstrap_name = getenv("X11_PREFS_DOMAIN");
209
210    /* We don't have a mechanism in place to handle this interrupt driven
211     * server-start notification, so just send the signal now, so xinit doesn't
212     * time out waiting for it and will just poll for the server.
213     */
214    handler = signal(SIGUSR1, SIG_IGN);
215    if(handler == SIG_IGN)
216        kill(getppid(), SIGUSR1);
217    signal(SIGUSR1, handler);
218
219    /* Pass on SIGs to X11.app */
220    signal(SIGINT, signal_handler);
221    signal(SIGTERM, signal_handler);
222
223    /* Get the $DISPLAY FD */
224    launchd_fd = launchd_display_fd();
225
226    kr = bootstrap_look_up(bootstrap_port, server_bootstrap_name, &mp);
227    if(kr != KERN_SUCCESS) {
228        pid_t child;
229
230        fprintf(stderr, "Xquartz: Unable to locate waiting server: %s\n", server_bootstrap_name);
231        set_x11_path();
232
233        /* This forking is ugly and will be cleaned up later */
234        child = fork();
235        if(child == -1) {
236            fprintf(stderr, "Xquartz: Could not fork: %s\n", strerror(errno));
237            return EXIT_FAILURE;
238        }
239
240        if(child == 0) {
241            char *_argv[3];
242            _argv[0] = x11_path;
243            _argv[1] = "--listenonly";
244            _argv[2] = NULL;
245            fprintf(stderr, "Xquartz: Starting X server: %s --listenonly\n", x11_path);
246            return execvp(x11_path, _argv);
247        }
248
249        /* Try connecting for 10 seconds */
250        for(i=0; i < 80; i++) {
251            usleep(250000);
252            kr = bootstrap_look_up(bootstrap_port, server_bootstrap_name, &mp);
253            if(kr == KERN_SUCCESS)
254                break;
255        }
256
257        if(kr != KERN_SUCCESS) {
258#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1050
259            fprintf(stderr, "Xquartz: bootstrap_look_up(): %s\n", bootstrap_strerror(kr));
260#else
261            fprintf(stderr, "Xquartz: bootstrap_look_up(): %ul\n", (unsigned long)kr);
262#endif
263            return EXIT_FAILURE;
264        }
265    }
266
267    /* Get X11.app's pid */
268    request_pid(mp, &x11app_pid);
269
270    /* Handoff the $DISPLAY FD */
271    if(launchd_fd != -1) {
272        size_t try, try_max;
273        int handoff_fd = -1;
274
275        for(try=0, try_max=5; try < try_max; try++) {
276            if(request_fd_handoff_socket(mp, handoff_socket_filename) != KERN_SUCCESS) {
277                fprintf(stderr, "Xquartz: Failed to request a socket from the server to send the $DISPLAY fd over (try %d of %d)\n", (int)try+1, (int)try_max);
278                continue;
279            }
280
281            handoff_fd = connect_to_socket(handoff_socket_filename);
282            if(handoff_fd == -1) {
283                fprintf(stderr, "Xquartz: Failed to connect to socket (try %d of %d)\n", (int)try+1, (int)try_max);
284                continue;
285            }
286
287#ifdef DEBUG
288            fprintf(stderr, "Xquartz: Handoff connection established (try %d of %d) on fd %d, \"%s\".  Sending message.\n", (int)try+1, (int)try_max, handoff_fd, handoff_socket_filename);
289#endif
290
291            send_fd_handoff(handoff_fd, launchd_fd);
292            close(handoff_fd);
293            break;
294        }
295    }
296
297    /* Count envp */
298    for(envpc=0; envp[envpc]; envpc++);
299
300    /* We have fixed-size string lengths due to limitations in IPC,
301     * so we need to copy our argv and envp.
302     */
303    newargv = (string_array_t)malloc(argc * sizeof(string_t));
304    newenvp = (string_array_t)malloc(envpc * sizeof(string_t));
305
306    if(!newargv || !newenvp) {
307        fprintf(stderr, "Xquartz: Memory allocation failure\n");
308        return EXIT_FAILURE;
309    }
310
311    for(i=0; i < argc; i++) {
312        strlcpy(newargv[i], argv[i], STRING_T_SIZE);
313    }
314    for(i=0; i < envpc; i++) {
315        strlcpy(newenvp[i], envp[i], STRING_T_SIZE);
316    }
317
318    kr = start_x11_server(mp, newargv, argc, newenvp, envpc);
319
320    free(newargv);
321    free(newenvp);
322
323    if (kr != KERN_SUCCESS) {
324        fprintf(stderr, "Xquartz: start_x11_server: %s\n", mach_error_string(kr));
325        return EXIT_FAILURE;
326    }
327    return EXIT_SUCCESS;
328}
329