i3
util.c
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1 /*
2  * vim:ts=4:sw=4:expandtab
3  *
4  * i3 - an improved dynamic tiling window manager
5  * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
6  *
7  * util.c: Utility functions, which can be useful everywhere within i3 (see
8  * also libi3).
9  *
10  */
11 #include "all.h"
12 
13 #include <sys/wait.h>
14 #include <stdarg.h>
15 #if defined(__OpenBSD__)
16 #include <sys/cdefs.h>
17 #endif
18 #include <fcntl.h>
19 #include <pwd.h>
20 #include <yajl/yajl_version.h>
21 #include <libgen.h>
22 
23 #define SN_API_NOT_YET_FROZEN 1
24 #include <libsn/sn-launcher.h>
25 
26 int min(int a, int b) {
27  return (a < b ? a : b);
28 }
29 
30 int max(int a, int b) {
31  return (a > b ? a : b);
32 }
33 
34 bool rect_contains(Rect rect, uint32_t x, uint32_t y) {
35  return (x >= rect.x &&
36  x <= (rect.x + rect.width) &&
37  y >= rect.y &&
38  y <= (rect.y + rect.height));
39 }
40 
42  return (Rect){a.x + b.x,
43  a.y + b.y,
44  a.width + b.width,
45  a.height + b.height};
46 }
47 
48 /*
49  * Updates *destination with new_value and returns true if it was changed or false
50  * if it was the same
51  *
52  */
53 bool update_if_necessary(uint32_t *destination, const uint32_t new_value) {
54  uint32_t old_value = *destination;
55 
56  return ((*destination = new_value) != old_value);
57 }
58 
59 /*
60  * exec()s an i3 utility, for example the config file migration script or
61  * i3-nagbar. This function first searches $PATH for the given utility named,
62  * then falls back to the dirname() of the i3 executable path and then falls
63  * back to the dirname() of the target of /proc/self/exe (on linux).
64  *
65  * This function should be called after fork()ing.
66  *
67  * The first argument of the given argv vector will be overwritten with the
68  * executable name, so pass NULL.
69  *
70  * If the utility cannot be found in any of these locations, it exits with
71  * return code 2.
72  *
73  */
74 void exec_i3_utility(char *name, char *argv[]) {
75  /* start the migration script, search PATH first */
76  char *migratepath = name;
77  argv[0] = migratepath;
78  execvp(migratepath, argv);
79 
80  /* if the script is not in path, maybe the user installed to a strange
81  * location and runs the i3 binary with an absolute path. We use
82  * argv[0]’s dirname */
83  char *pathbuf = strdup(start_argv[0]);
84  char *dir = dirname(pathbuf);
85  sasprintf(&migratepath, "%s/%s", dir, name);
86  argv[0] = migratepath;
87  execvp(migratepath, argv);
88 
89 #if defined(__linux__)
90  /* on linux, we have one more fall-back: dirname(/proc/self/exe) */
91  char buffer[BUFSIZ];
92  if (readlink("/proc/self/exe", buffer, BUFSIZ) == -1) {
93  warn("could not read /proc/self/exe");
94  exit(1);
95  }
96  dir = dirname(buffer);
97  sasprintf(&migratepath, "%s/%s", dir, name);
98  argv[0] = migratepath;
99  execvp(migratepath, argv);
100 #endif
101 
102  warn("Could not start %s", name);
103  exit(2);
104 }
105 
106 /*
107  * Checks a generic cookie for errors and quits with the given message if there
108  * was an error.
109  *
110  */
111 void check_error(xcb_connection_t *conn, xcb_void_cookie_t cookie, char *err_message) {
112  xcb_generic_error_t *error = xcb_request_check(conn, cookie);
113  if (error != NULL) {
114  fprintf(stderr, "ERROR: %s (X error %d)\n", err_message , error->error_code);
115  xcb_disconnect(conn);
116  exit(-1);
117  }
118 }
119 
120 /*
121  * This function resolves ~ in pathnames.
122  * It may resolve wildcards in the first part of the path, but if no match
123  * or multiple matches are found, it just returns a copy of path as given.
124  *
125  */
126 char *resolve_tilde(const char *path) {
127  static glob_t globbuf;
128  char *head, *tail, *result;
129 
130  tail = strchr(path, '/');
131  head = strndup(path, tail ? tail - path : strlen(path));
132 
133  int res = glob(head, GLOB_TILDE, NULL, &globbuf);
134  free(head);
135  /* no match, or many wildcard matches are bad */
136  if (res == GLOB_NOMATCH || globbuf.gl_pathc != 1)
137  result = sstrdup(path);
138  else if (res != 0) {
139  die("glob() failed");
140  } else {
141  head = globbuf.gl_pathv[0];
142  result = scalloc(strlen(head) + (tail ? strlen(tail) : 0) + 1);
143  strncpy(result, head, strlen(head));
144  if (tail)
145  strncat(result, tail, strlen(tail));
146  }
147  globfree(&globbuf);
148 
149  return result;
150 }
151 
152 /*
153  * Checks if the given path exists by calling stat().
154  *
155  */
156 bool path_exists(const char *path) {
157  struct stat buf;
158  return (stat(path, &buf) == 0);
159 }
160 
161 /*
162  * Goes through the list of arguments (for exec()) and checks if the given argument
163  * is present. If not, it copies the arguments (because we cannot realloc it) and
164  * appends the given argument.
165  *
166  */
167 static char **append_argument(char **original, char *argument) {
168  int num_args;
169  for (num_args = 0; original[num_args] != NULL; num_args++) {
170  DLOG("original argument: \"%s\"\n", original[num_args]);
171  /* If the argument is already present we return the original pointer */
172  if (strcmp(original[num_args], argument) == 0)
173  return original;
174  }
175  /* Copy the original array */
176  char **result = smalloc((num_args+2) * sizeof(char*));
177  memcpy(result, original, num_args * sizeof(char*));
178  result[num_args] = argument;
179  result[num_args+1] = NULL;
180 
181  return result;
182 }
183 
184 /*
185  * Returns the name of a temporary file with the specified prefix.
186  *
187  */
188 char *get_process_filename(const char *prefix) {
189  /* dir stores the directory path for this and all subsequent calls so that
190  * we only create a temporary directory once per i3 instance. */
191  static char *dir = NULL;
192  if (dir == NULL) {
193  /* Check if XDG_RUNTIME_DIR is set. If so, we use XDG_RUNTIME_DIR/i3 */
194  if ((dir = getenv("XDG_RUNTIME_DIR"))) {
195  char *tmp;
196  sasprintf(&tmp, "%s/i3", dir);
197  dir = tmp;
198  if (!path_exists(dir)) {
199  if (mkdir(dir, 0700) == -1) {
200  perror("mkdir()");
201  return NULL;
202  }
203  }
204  } else {
205  /* If not, we create a (secure) temp directory using the template
206  * /tmp/i3-<user>.XXXXXX */
207  struct passwd *pw = getpwuid(getuid());
208  const char *username = pw ? pw->pw_name : "unknown";
209  sasprintf(&dir, "/tmp/i3-%s.XXXXXX", username);
210  /* mkdtemp modifies dir */
211  if (mkdtemp(dir) == NULL) {
212  perror("mkdtemp()");
213  return NULL;
214  }
215  }
216  }
217  char *filename;
218  sasprintf(&filename, "%s/%s.%d", dir, prefix, getpid());
219  return filename;
220 }
221 
222 #define y(x, ...) yajl_gen_ ## x (gen, ##__VA_ARGS__)
223 #define ystr(str) yajl_gen_string(gen, (unsigned char*)str, strlen(str))
224 
225 char *store_restart_layout(void) {
226  setlocale(LC_NUMERIC, "C");
227 #if YAJL_MAJOR >= 2
228  yajl_gen gen = yajl_gen_alloc(NULL);
229 #else
230  yajl_gen gen = yajl_gen_alloc(NULL, NULL);
231 #endif
232 
233  dump_node(gen, croot, true);
234 
235  setlocale(LC_NUMERIC, "");
236 
237  const unsigned char *payload;
238 #if YAJL_MAJOR >= 2
239  size_t length;
240 #else
241  unsigned int length;
242 #endif
243  y(get_buf, &payload, &length);
244 
245  /* create a temporary file if one hasn't been specified, or just
246  * resolve the tildes in the specified path */
247  char *filename;
248  if (config.restart_state_path == NULL) {
249  filename = get_process_filename("restart-state");
250  if (!filename)
251  return NULL;
252  } else {
254  }
255 
256  int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
257  if (fd == -1) {
258  perror("open()");
259  free(filename);
260  return NULL;
261  }
262 
263  int written = 0;
264  while (written < length) {
265  int n = write(fd, payload + written, length - written);
266  /* TODO: correct error-handling */
267  if (n == -1) {
268  perror("write()");
269  free(filename);
270  close(fd);
271  return NULL;
272  }
273  if (n == 0) {
274  printf("write == 0?\n");
275  free(filename);
276  close(fd);
277  return NULL;
278  }
279  written += n;
280 #if YAJL_MAJOR >= 2
281  printf("written: %d of %zd\n", written, length);
282 #else
283  printf("written: %d of %d\n", written, length);
284 #endif
285  }
286  close(fd);
287 
288  if (length > 0) {
289  printf("layout: %.*s\n", (int)length, payload);
290  }
291 
292  y(free);
293 
294  return filename;
295 }
296 
297 /*
298  * Restart i3 in-place
299  * appends -a to argument list to disable autostart
300  *
301  */
302 void i3_restart(bool forget_layout) {
303  char *restart_filename = forget_layout ? NULL : store_restart_layout();
304 
306 
308 
309  ipc_shutdown();
310 
311  LOG("restarting \"%s\"...\n", start_argv[0]);
312  /* make sure -a is in the argument list or append it */
314 
315  /* replace -r <file> so that the layout is restored */
316  if (restart_filename != NULL) {
317  /* create the new argv */
318  int num_args;
319  for (num_args = 0; start_argv[num_args] != NULL; num_args++);
320  char **new_argv = scalloc((num_args + 3) * sizeof(char*));
321 
322  /* copy the arguments, but skip the ones we'll replace */
323  int write_index = 0;
324  bool skip_next = false;
325  for (int i = 0; i < num_args; ++i) {
326  if (skip_next)
327  skip_next = false;
328  else if (!strcmp(start_argv[i], "-r") ||
329  !strcmp(start_argv[i], "--restart"))
330  skip_next = true;
331  else
332  new_argv[write_index++] = start_argv[i];
333  }
334 
335  /* add the arguments we'll replace */
336  new_argv[write_index++] = "--restart";
337  new_argv[write_index] = restart_filename;
338 
339  /* swap the argvs */
340  start_argv = new_argv;
341  }
342 
343  execvp(start_argv[0], start_argv);
344  /* not reached */
345 }
346 
347 #if defined(__OpenBSD__) || defined(__APPLE__)
348 
349 /*
350  * Taken from FreeBSD
351  * Find the first occurrence of the byte string s in byte string l.
352  *
353  */
354 void *memmem(const void *l, size_t l_len, const void *s, size_t s_len) {
355  register char *cur, *last;
356  const char *cl = (const char *)l;
357  const char *cs = (const char *)s;
358 
359  /* we need something to compare */
360  if (l_len == 0 || s_len == 0)
361  return NULL;
362 
363  /* "s" must be smaller or equal to "l" */
364  if (l_len < s_len)
365  return NULL;
366 
367  /* special case where s_len == 1 */
368  if (s_len == 1)
369  return memchr(l, (int)*cs, l_len);
370 
371  /* the last position where its possible to find "s" in "l" */
372  last = (char *)cl + l_len - s_len;
373 
374  for (cur = (char *)cl; cur <= last; cur++)
375  if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0)
376  return cur;
377 
378  return NULL;
379 }
380 
381 #endif