NeoMutt  2022-04-29-145-g9b6a0e
Teaching an old dog new tricks
DOXYGEN
monitor.c
Go to the documentation of this file.
1 
30 #include "config.h"
31 #include <errno.h>
32 #include <limits.h>
33 #include <poll.h>
34 #include <stdbool.h>
35 #include <stdint.h>
36 #include <stdio.h>
37 #include <string.h>
38 #include <sys/inotify.h>
39 #include <sys/stat.h>
40 #include <unistd.h>
41 #include "mutt/lib.h"
42 #include "core/lib.h"
43 #include "gui/lib.h"
44 #include "monitor.h"
45 #include "index/lib.h"
46 #ifndef HAVE_INOTIFY_INIT1
47 #include <fcntl.h>
48 #endif
49 
50 bool MonitorFilesChanged = false;
51 bool MonitorContextChanged = false;
52 
53 static int INotifyFd = -1;
54 static struct Monitor *Monitor = NULL;
55 static size_t PollFdsCount = 0;
56 static size_t PollFdsLen = 0;
57 static struct pollfd *PollFds = NULL;
58 
59 static int MonitorContextDescriptor = -1;
60 
61 #define INOTIFY_MASK_DIR (IN_MOVED_TO | IN_ATTRIB | IN_CLOSE_WRITE | IN_ISDIR)
62 #define INOTIFY_MASK_FILE IN_CLOSE_WRITE
63 
64 #define EVENT_BUFLEN MAX(4096, sizeof(struct inotify_event) + NAME_MAX + 1)
65 
70 {
76 };
77 
81 struct Monitor
82 {
83  struct Monitor *next;
85  dev_t st_dev;
86  ino_t st_ino;
87  enum MailboxType type;
88  int desc;
89 };
90 
95 {
96  enum MailboxType type;
97  bool is_dir;
98  const char *path;
99  dev_t st_dev;
100  ino_t st_ino;
101  struct Monitor *monitor;
102  struct Buffer path_buf;
103 };
104 
110 static void mutt_poll_fd_add(int fd, short events)
111 {
112  int i = 0;
113  for (; (i < PollFdsCount) && (PollFds[i].fd != fd); i++)
114  ; // do nothing
115 
116  if (i == PollFdsCount)
117  {
118  if (PollFdsCount == PollFdsLen)
119  {
120  PollFdsLen += 2;
121  mutt_mem_realloc(&PollFds, PollFdsLen * sizeof(struct pollfd));
122  }
123  PollFdsCount++;
124  PollFds[i].fd = fd;
125  PollFds[i].events = events;
126  }
127  else
128  PollFds[i].events |= events;
129 }
130 
137 static int mutt_poll_fd_remove(int fd)
138 {
139  int i = 0;
140  for (; (i < PollFdsCount) && (PollFds[i].fd != fd); i++)
141  ; // do nothing
142 
143  if (i == PollFdsCount)
144  return -1;
145  int d = PollFdsCount - i - 1;
146  if (d != 0)
147  memmove(&PollFds[i], &PollFds[i + 1], d * sizeof(struct pollfd));
148  PollFdsCount--;
149  return 0;
150 }
151 
157 static int monitor_init(void)
158 {
159  if (INotifyFd != -1)
160  return 0;
161 
162 #ifdef HAVE_INOTIFY_INIT1
163  INotifyFd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
164  if (INotifyFd == -1)
165  {
166  mutt_debug(LL_DEBUG2, "inotify_init1 failed, errno=%d %s\n", errno, strerror(errno));
167  return -1;
168  }
169 #else
170  INotifyFd = inotify_init();
171  if (INotifyFd == -1)
172  {
173  mutt_debug(LL_DEBUG2, "monitor: inotify_init failed, errno=%d %s\n", errno,
174  strerror(errno));
175  return -1;
176  }
177  fcntl(INotifyFd, F_SETFL, O_NONBLOCK);
178  fcntl(INotifyFd, F_SETFD, FD_CLOEXEC);
179 #endif
180  mutt_poll_fd_add(0, POLLIN);
181  mutt_poll_fd_add(INotifyFd, POLLIN);
182 
183  return 0;
184 }
185 
189 static void monitor_check_free(void)
190 {
191  if (!Monitor && (INotifyFd != -1))
192  {
194  close(INotifyFd);
195  INotifyFd = -1;
196  MonitorFilesChanged = false;
197  }
198 }
199 
206 static struct Monitor *monitor_new(struct MonitorInfo *info, int descriptor)
207 {
208  struct Monitor *monitor = mutt_mem_calloc(1, sizeof(struct Monitor));
209  monitor->type = info->type;
210  monitor->st_dev = info->st_dev;
211  monitor->st_ino = info->st_ino;
212  monitor->desc = descriptor;
213  monitor->next = Monitor;
214  if (info->type == MUTT_MH)
215  monitor->mh_backup_path = mutt_str_dup(info->path);
216 
217  Monitor = monitor;
218 
219  return monitor;
220 }
221 
226 static void monitor_info_init(struct MonitorInfo *info)
227 {
228  memset(info, 0, sizeof(*info));
229 }
230 
235 static void monitor_info_free(struct MonitorInfo *info)
236 {
238 }
239 
244 static void monitor_delete(struct Monitor *monitor)
245 {
246  if (!monitor)
247  return;
248 
249  struct Monitor **ptr = &Monitor;
250 
251  while (true)
252  {
253  if (!*ptr)
254  return;
255  if (*ptr == monitor)
256  break;
257  ptr = &(*ptr)->next;
258  }
259 
260  FREE(&monitor->mh_backup_path);
261  monitor = monitor->next;
262  FREE(ptr);
263  *ptr = monitor;
264 }
265 
273 {
274  int new_desc = -1;
275  struct Monitor *iter = Monitor;
276  struct stat st = { 0 };
277 
278  while (iter && (iter->desc != desc))
279  iter = iter->next;
280 
281  if (iter)
282  {
283  if ((iter->type == MUTT_MH) && (stat(iter->mh_backup_path, &st) == 0))
284  {
285  new_desc = inotify_add_watch(INotifyFd, iter->mh_backup_path, INOTIFY_MASK_FILE);
286  if (new_desc == -1)
287  {
288  mutt_debug(LL_DEBUG2, "inotify_add_watch failed for '%s', errno=%d %s\n",
289  iter->mh_backup_path, errno, strerror(errno));
290  }
291  else
292  {
293  mutt_debug(LL_DEBUG3, "inotify_add_watch descriptor=%d for '%s'\n",
294  desc, iter->mh_backup_path);
295  iter->st_dev = st.st_dev;
296  iter->st_ino = st.st_ino;
297  iter->desc = new_desc;
298  }
299  }
300  else
301  {
302  mutt_debug(LL_DEBUG3, "cleanup watch (implicitly removed) - descriptor=%d\n", desc);
303  }
304 
305  if (MonitorContextDescriptor == desc)
306  MonitorContextDescriptor = new_desc;
307 
308  if (new_desc == -1)
309  {
310  monitor_delete(iter);
312  }
313  }
314 
315  return new_desc;
316 }
317 
330 static enum ResolveResult monitor_resolve(struct MonitorInfo *info, struct Mailbox *m)
331 {
332  char *fmt = NULL;
333  struct stat st = { 0 };
334 
335  struct Mailbox *m_cur = get_current_mailbox();
336  if (m)
337  {
338  info->type = m->type;
339  info->path = m->realpath;
340  }
341  else if (m_cur)
342  {
343  info->type = m_cur->type;
344  info->path = m_cur->realpath;
345  }
346  else
347  {
349  }
350 
351  if (info->type == MUTT_UNKNOWN)
352  {
354  }
355  else if (info->type == MUTT_MAILDIR)
356  {
357  info->is_dir = true;
358  fmt = "%s/new";
359  }
360  else
361  {
362  info->is_dir = false;
363  if (info->type == MUTT_MH)
364  fmt = "%s/.mh_sequences";
365  }
366  if (fmt)
367  {
368  mutt_buffer_printf(&info->path_buf, fmt, info->path);
369  info->path = mutt_buffer_string(&info->path_buf);
370  }
371  if (stat(info->path, &st) != 0)
372  return RESOLVE_RES_FAIL_STAT;
373 
374  struct Monitor *iter = Monitor;
375  while (iter && ((iter->st_ino != st.st_ino) || (iter->st_dev != st.st_dev)))
376  iter = iter->next;
377 
378  info->st_dev = st.st_dev;
379  info->st_ino = st.st_ino;
380  info->monitor = iter;
381 
383 }
384 
400 {
401  int rc = 0;
402  char buf[EVENT_BUFLEN] __attribute__((aligned(__alignof__(struct inotify_event))));
403 
404  MonitorFilesChanged = false;
405 
406  if (INotifyFd != -1)
407  {
408  int fds = poll(PollFds, PollFdsCount, MuttGetchTimeout);
409 
410  if (fds == -1)
411  {
412  rc = -1;
413  if (errno != EINTR)
414  {
415  mutt_debug(LL_DEBUG2, "poll() failed, errno=%d %s\n", errno, strerror(errno));
416  }
417  }
418  else
419  {
420  bool input_ready = false;
421  for (int i = 0; fds && (i < PollFdsCount); i++)
422  {
423  if (PollFds[i].revents)
424  {
425  fds--;
426  if (PollFds[i].fd == 0)
427  {
428  input_ready = true;
429  }
430  else if (PollFds[i].fd == INotifyFd)
431  {
432  MonitorFilesChanged = true;
433  mutt_debug(LL_DEBUG3, "file change(s) detected\n");
434  char *ptr = buf;
435  const struct inotify_event *event = NULL;
436 
437  while (true)
438  {
439  int len = read(INotifyFd, buf, sizeof(buf));
440  if (len == -1)
441  {
442  if (errno != EAGAIN)
443  {
444  mutt_debug(LL_DEBUG2, "read inotify events failed, errno=%d %s\n",
445  errno, strerror(errno));
446  }
447  break;
448  }
449 
450  while (ptr < (buf + len))
451  {
452  event = (const struct inotify_event *) ptr;
453  mutt_debug(LL_DEBUG3, "+ detail: descriptor=%d mask=0x%x\n",
454  event->wd, event->mask);
455  if (event->mask & IN_IGNORED)
456  monitor_handle_ignore(event->wd);
457  else if (event->wd == MonitorContextDescriptor)
458  MonitorContextChanged = true;
459  ptr += sizeof(struct inotify_event) + event->len;
460  }
461  }
462  }
463  }
464  }
465  if (!input_ready)
466  rc = MonitorFilesChanged ? -2 : -3;
467  }
468  }
469 
470  return rc;
471 }
472 
481 int mutt_monitor_add(struct Mailbox *m)
482 {
483  struct MonitorInfo info;
484  monitor_info_init(&info);
485 
486  int rc = 0;
487  enum ResolveResult desc = monitor_resolve(&info, m);
488  if (desc != RESOLVE_RES_OK_NOTEXISTING)
489  {
490  if (!m && (desc == RESOLVE_RES_OK_EXISTING))
492  rc = (desc == RESOLVE_RES_OK_EXISTING) ? 0 : -1;
493  goto cleanup;
494  }
495 
496  uint32_t mask = info.is_dir ? INOTIFY_MASK_DIR : INOTIFY_MASK_FILE;
497  if (((INotifyFd == -1) && (monitor_init() == -1)) ||
498  ((desc = inotify_add_watch(INotifyFd, info.path, mask)) == -1))
499  {
500  mutt_debug(LL_DEBUG2, "inotify_add_watch failed for '%s', errno=%d %s\n",
501  info.path, errno, strerror(errno));
502  rc = -1;
503  goto cleanup;
504  }
505 
506  mutt_debug(LL_DEBUG3, "inotify_add_watch descriptor=%d for '%s'\n", desc, info.path);
507  if (!m)
509 
510  monitor_new(&info, desc);
511 
512 cleanup:
513  monitor_info_free(&info);
514  return rc;
515 }
516 
527 {
528  struct MonitorInfo info, info2;
529  int rc = 0;
530 
531  monitor_info_init(&info);
532  monitor_info_init(&info2);
533 
534  if (!m)
535  {
537  MonitorContextChanged = false;
538  }
539 
540  if (monitor_resolve(&info, m) != RESOLVE_RES_OK_EXISTING)
541  {
542  rc = 2;
543  goto cleanup;
544  }
545 
546  struct Mailbox *m_cur = get_current_mailbox();
547  if (m_cur)
548  {
549  if (m)
550  {
551  if ((monitor_resolve(&info2, NULL) == RESOLVE_RES_OK_EXISTING) &&
552  (info.st_ino == info2.st_ino) && (info.st_dev == info2.st_dev))
553  {
554  rc = 1;
555  goto cleanup;
556  }
557  }
558  else
559  {
560  if (mailbox_find(m_cur->realpath))
561  {
562  rc = 1;
563  goto cleanup;
564  }
565  }
566  }
567 
568  inotify_rm_watch(info.monitor->desc, INotifyFd);
569  mutt_debug(LL_DEBUG3, "inotify_rm_watch for '%s' descriptor=%d\n", info.path,
570  info.monitor->desc);
571 
572  monitor_delete(info.monitor);
574 
575 cleanup:
576  monitor_info_free(&info);
577  monitor_info_free(&info2);
578  return rc;
579 }
void mutt_buffer_dealloc(struct Buffer *buf)
Release the memory allocated by a buffer.
Definition: buffer.c:292
int mutt_buffer_printf(struct Buffer *buf, const char *fmt,...)
Format a string overwriting a Buffer.
Definition: buffer.c:158
static const char * mutt_buffer_string(const struct Buffer *buf)
Convert a buffer to a const char * "string".
Definition: buffer.h:77
Convenience wrapper for the core headers.
int MuttGetchTimeout
Timeout in ms for mutt_getch()
Definition: curs_lib.c:124
#define mutt_debug(LEVEL,...)
Definition: logging.h:84
Convenience wrapper for the gui headers.
GUI manage the main index (list of emails)
struct Mailbox * get_current_mailbox(void)
Get the current Mailbox.
Definition: index.c:606
@ LL_DEBUG3
Log at debug level 3.
Definition: logging.h:42
@ LL_DEBUG2
Log at debug level 2.
Definition: logging.h:41
struct Mailbox * mailbox_find(const char *path)
Find the mailbox with a given path.
Definition: mailbox.c:139
MailboxType
Supported mailbox formats.
Definition: mailbox.h:41
@ MUTT_MH
'MH' Mailbox type
Definition: mailbox.h:47
@ MUTT_UNKNOWN
Mailbox wasn't recognised.
Definition: mailbox.h:44
@ MUTT_MAILDIR
'Maildir' Mailbox type
Definition: mailbox.h:48
void * mutt_mem_calloc(size_t nmemb, size_t size)
Allocate zeroed memory on the heap.
Definition: memory.c:50
void mutt_mem_realloc(void *ptr, size_t size)
Resize a block of memory on the heap.
Definition: memory.c:114
#define FREE(x)
Definition: memory.h:43
#define INOTIFY_MASK_DIR
Definition: monitor.c:61
int mutt_monitor_add(struct Mailbox *m)
Add a watch for a mailbox.
Definition: monitor.c:481
static void monitor_delete(struct Monitor *monitor)
Free a file monitor.
Definition: monitor.c:244
static int MonitorContextDescriptor
Definition: monitor.c:59
static int mutt_poll_fd_remove(int fd)
Remove a file from the watch list.
Definition: monitor.c:137
static int INotifyFd
Definition: monitor.c:53
static int monitor_handle_ignore(int desc)
Listen for when a backup file is closed.
Definition: monitor.c:272
static enum ResolveResult monitor_resolve(struct MonitorInfo *info, struct Mailbox *m)
Get the monitor for a mailbox.
Definition: monitor.c:330
int mutt_monitor_poll(void)
Check for filesystem changes.
Definition: monitor.c:399
static size_t PollFdsCount
Definition: monitor.c:55
static void mutt_poll_fd_add(int fd, short events)
Add a file to the watch list.
Definition: monitor.c:110
ResolveResult
Results for the Monitor functions.
Definition: monitor.c:70
@ RESOLVE_RES_FAIL_NOTYPE
Can't identify Mailbox type.
Definition: monitor.c:72
@ RESOLVE_RES_FAIL_STAT
Can't stat() the Mailbox file.
Definition: monitor.c:73
@ RESOLVE_RES_OK_NOTEXISTING
File exists, no monitor is attached.
Definition: monitor.c:74
@ RESOLVE_RES_FAIL_NOMAILBOX
No Mailbox to work on.
Definition: monitor.c:71
@ RESOLVE_RES_OK_EXISTING
File exists, monitor is already attached.
Definition: monitor.c:75
bool MonitorFilesChanged
true after a monitored file has changed
Definition: monitor.c:50
static void monitor_check_free(void)
Close down file monitoring.
Definition: monitor.c:189
static int monitor_init(void)
Set up file monitoring.
Definition: monitor.c:157
static struct Monitor * Monitor
Definition: monitor.c:54
bool MonitorContextChanged
true after the current mailbox has changed
Definition: monitor.c:51
static void monitor_info_init(struct MonitorInfo *info)
Set up a file monitor.
Definition: monitor.c:226
static struct Monitor * monitor_new(struct MonitorInfo *info, int descriptor)
Create a new file monitor.
Definition: monitor.c:206
#define INOTIFY_MASK_FILE
Definition: monitor.c:62
#define EVENT_BUFLEN
Definition: monitor.c:64
static void monitor_info_free(struct MonitorInfo *info)
Shutdown a file monitor.
Definition: monitor.c:235
int mutt_monitor_remove(struct Mailbox *m)
Remove a watch for a mailbox.
Definition: monitor.c:526
static size_t PollFdsLen
Definition: monitor.c:56
static struct pollfd * PollFds
Definition: monitor.c:57
Monitor files for changes.
Convenience wrapper for the library headers.
char * mutt_str_dup(const char *str)
Copy a string, safely.
Definition: string.c:250
String manipulation buffer.
Definition: buffer.h:34
A mailbox.
Definition: mailbox.h:79
char * realpath
Used for duplicate detection, context comparison, and the sidebar.
Definition: mailbox.h:81
enum MailboxType type
Mailbox type.
Definition: mailbox.h:102
Information about a monitored file.
Definition: monitor.c:95
dev_t st_dev
Definition: monitor.c:99
enum MailboxType type
Definition: monitor.c:96
struct Monitor * monitor
Definition: monitor.c:101
bool is_dir
Definition: monitor.c:97
ino_t st_ino
Definition: monitor.c:100
const char * path
Definition: monitor.c:98
struct Buffer path_buf
access via path only (maybe not initialized)
Definition: monitor.c:102
A watch on a file.
Definition: monitor.c:82
struct Monitor * next
Linked list.
Definition: monitor.c:83
ino_t st_ino
Definition: monitor.c:86
dev_t st_dev
Definition: monitor.c:85
int desc
Definition: monitor.c:88
enum MailboxType type
Definition: monitor.c:87
char * mh_backup_path
Definition: monitor.c:84