1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-cleanup-sockets.c  dbus-cleanup-sockets utility
3  *
4  * Copyright (C) 2003 Red Hat, Inc.
5  * Copyright (C) 2002 Michael Meeks
6  *
7  * Note that this file is NOT licensed under the Academic Free License,
8  * as it is based on linc-cleanup-sockets which is LGPL.
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
23  *
24  */
25 #include <config.h>
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #include <stdio.h>
29 #include <fcntl.h>
30 #include <unistd.h>
31 #include <dirent.h>
32 #include <sys/socket.h>
33 #include <sys/un.h>
34 #include <errno.h>
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #ifndef TRUE
39 #define TRUE (1)
40 #endif
41 
42 #ifndef FALSE
43 #define FALSE (0)
44 #endif
45 
46 #ifndef NULL
47 #define NULL ((void*) 0)
48 #endif
49 
50 static void*
xmalloc(size_t bytes)51 xmalloc (size_t bytes)
52 {
53   void *mem;
54 
55   if (bytes == 0)
56     return NULL;
57 
58   mem = malloc (bytes);
59 
60   if (mem == NULL)
61     {
62       fprintf (stderr, "Allocation of %d bytes failed\n",
63                (int) bytes);
64       exit (1);
65     }
66 
67   return mem;
68 }
69 
70 static void*
xrealloc(void * old,size_t bytes)71 xrealloc (void *old, size_t bytes)
72 {
73   void *mem;
74 
75   if (bytes == 0)
76     {
77       free (old);
78       return NULL;
79     }
80 
81   mem = realloc (old, bytes);
82 
83   if (mem == NULL)
84     {
85       fprintf (stderr, "Reallocation of %d bytes failed\n",
86                (int) bytes);
87       exit (1);
88     }
89 
90   return mem;
91 }
92 
93 #ifdef AF_UNIX
94 
95 typedef enum
96   {
97     SOCKET_UNKNOWN,
98     SOCKET_FAILED_TO_HANDLE,
99     SOCKET_DEAD,
100     SOCKET_ALIVE,
101     SOCKET_UNLINKED
102   } SocketStatus;
103 
104 static int alive_count = 0;
105 static int cleaned_count = 0;
106 static int unhandled_count = 0;
107 
108 typedef struct
109 {
110   char *name;
111   int   fd;
112   SocketStatus status;
113   int   n_retries;
114 } SocketEntry;
115 
116 static SocketEntry*
socket_entry_new(const char * dir,const char * fname)117 socket_entry_new (const char *dir,
118                   const char *fname)
119 {
120   SocketEntry *se;
121   int len;
122 
123   se = xmalloc (sizeof (SocketEntry));
124 
125   len = strlen (dir) + strlen (fname) + 2; /* 2 = nul and '/' */
126   se->name = xmalloc (len);
127 
128   strcpy (se->name, dir);
129   strcat (se->name, "/");
130   strcat (se->name, fname);
131 
132   se->fd = -1;
133 
134   se->status = SOCKET_UNKNOWN;
135 
136   se->n_retries = 0;
137 
138   return se;
139 }
140 
141 static void
free_socket_entry(SocketEntry * se)142 free_socket_entry (SocketEntry *se)
143 {
144   if (se)
145     {
146       free (se->name);
147       if (se->fd >= 0)
148         close (se->fd);
149       free (se);
150     }
151 }
152 
153 static void
free_socket_entries(SocketEntry ** entries,int n_entries)154 free_socket_entries (SocketEntry** entries,
155                      int           n_entries)
156 {
157   int i;
158 
159   if (entries)
160     {
161       for (i = 0; i < n_entries; ++i)
162         free_socket_entry (entries[i]);
163       free (entries);
164     }
165 }
166 
167 static void
read_sockets(const char * dir,SocketEntry *** entries_p,int * n_entries_p)168 read_sockets (const char    *dir,
169               SocketEntry ***entries_p,
170               int           *n_entries_p)
171 {
172   DIR   *dirh;
173   struct dirent *dent;
174   SocketEntry **entries;
175   int n_entries;
176   int allocated;
177 
178   n_entries = 0;
179   allocated = 2;
180   entries = xmalloc (sizeof (SocketEntry*) * allocated);
181 
182   dirh = opendir (dir);
183   if (dirh == NULL)
184     {
185       fprintf (stderr, "Failed to open directory %s: %s\n",
186                dir, strerror (errno));
187       exit (1);
188     }
189 
190   while ((dent = readdir (dirh)))
191     {
192       SocketEntry *se;
193 
194       if (strncmp (dent->d_name, "dbus-", 5) != 0)
195         continue;
196 
197       se = socket_entry_new (dir, dent->d_name);
198 
199       if (n_entries == allocated)
200         {
201           allocated *= 2;
202           entries = xrealloc (entries, sizeof (SocketEntry*) * allocated);
203         }
204 
205       entries[n_entries] = se;
206       n_entries += 1;
207     }
208 
209   closedir (dirh);
210 
211   *entries_p = entries;
212   *n_entries_p = n_entries;
213 }
214 
215 static SocketStatus
open_socket(SocketEntry * se)216 open_socket (SocketEntry *se)
217 {
218   int ret;
219   struct sockaddr_un saddr;
220 
221   if (se->n_retries > 5)
222     {
223       fprintf (stderr, "Warning: giving up on socket %s after several retries; unable to determine socket's status\n",
224                se->name);
225       return SOCKET_FAILED_TO_HANDLE;
226     }
227 
228   se->n_retries += 1;
229 
230   se->fd = socket (AF_UNIX, SOCK_STREAM, 0);
231   if (se->fd < 0)
232     {
233       fprintf (stderr, "Warning: failed to open a socket to use for connecting: %s\n",
234                strerror (errno));
235       return SOCKET_UNKNOWN;
236     }
237 
238   if (fcntl (se->fd, F_SETFL, O_NONBLOCK) < 0)
239     {
240       fprintf (stderr, "Warning: failed set socket %s nonblocking: %s\n",
241                se->name, strerror (errno));
242       return SOCKET_UNKNOWN;
243     }
244 
245 
246   memset (&saddr, '\0', sizeof (saddr)); /* nul-terminates the sun_path */
247 
248   saddr.sun_family = AF_UNIX;
249   strncpy (saddr.sun_path, se->name, sizeof (saddr.sun_path) - 1);
250 
251   do
252     {
253       ret = connect (se->fd, (struct sockaddr*) &saddr, sizeof (saddr));
254     }
255   while (ret < 0 && errno == EINTR);
256 
257   if (ret >= 0)
258     return SOCKET_ALIVE;
259   else
260     {
261       switch (errno)
262         {
263         case EINPROGRESS:
264         case EAGAIN:
265           return SOCKET_UNKNOWN;
266         case ECONNREFUSED:
267           return SOCKET_DEAD;
268         default:
269           fprintf (stderr, "Warning: unexpected error connecting to socket %s: %s\n",
270                    se->name, strerror (errno));
271           return SOCKET_FAILED_TO_HANDLE;
272         }
273     }
274 }
275 
276 static int
handle_sockets(SocketEntry ** entries,int n_entries)277 handle_sockets (SocketEntry **entries,
278                 int           n_entries)
279 {
280   int i;
281   int n_unknown;
282 
283   n_unknown = 0;
284 
285   i = 0;
286   while (i < n_entries)
287     {
288       SocketEntry *se;
289       SocketStatus status;
290 
291       se = entries[i];
292       ++i;
293 
294       if (se->fd >= 0)
295         {
296           fprintf (stderr, "Internal error, socket has fd  kept open while status = %d\n",
297                    se->status);
298           exit (1);
299         }
300 
301       if (se->status != SOCKET_UNKNOWN)
302         continue;
303 
304       status = open_socket (se);
305 
306       switch (status)
307         {
308         case SOCKET_DEAD:
309           cleaned_count += 1;
310           if (unlink (se->name) < 0)
311             {
312               fprintf (stderr, "Warning: Failed to delete %s: %s\n",
313                        se->name, strerror (errno));
314 
315               se->status = SOCKET_FAILED_TO_HANDLE;
316             }
317           else
318             se->status = SOCKET_UNLINKED;
319           break;
320 
321         case SOCKET_ALIVE:
322           alive_count += 1;
323           /* FALL THRU */
324 
325         case SOCKET_FAILED_TO_HANDLE:
326         case SOCKET_UNKNOWN:
327           se->status = status;
328           break;
329 
330         case SOCKET_UNLINKED:
331           fprintf (stderr, "Bad status from open_socket(), should not happen\n");
332           exit (1);
333           break;
334         }
335 
336       if (se->fd >= 0)
337         {
338           close (se->fd);
339           se->fd = -1;
340         }
341 
342       if (se->status == SOCKET_UNKNOWN)
343         n_unknown += 1;
344     }
345 
346   return n_unknown == 0;
347 }
348 
349 static void
clean_dir(const char * dir)350 clean_dir (const char *dir)
351 {
352   SocketEntry **entries;
353   int n_entries;
354 
355   read_sockets (dir, &entries, &n_entries);
356 
357   /* open_socket() will fail conclusively after
358    * several retries, so this loop is guaranteed
359    * to terminate eventually
360    */
361   while (!handle_sockets (entries, n_entries))
362     {
363       fprintf (stderr, "Unable to determine state of some sockets, retrying in 2 seconds\n");
364       sleep (2);
365     }
366 
367   unhandled_count += (n_entries - alive_count - cleaned_count);
368 
369   free_socket_entries (entries, n_entries);
370 }
371 
372 #endif /* AF_UNIX */
373 
374 static void
usage(int ecode)375 usage (int ecode)
376 {
377   fprintf (stderr, "dbus-cleanup-sockets [--version] [--help] <socketdir>\n");
378   exit (ecode);
379 }
380 
381 static void
version(void)382 version (void)
383 {
384   printf ("D-Bus Socket Cleanup Utility %s\n"
385           "Copyright (C) 2003 Red Hat, Inc.\n"
386           "Copyright (C) 2002 Michael Meeks\n"
387           "This is free software; see the source for copying conditions.\n"
388           "There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n",
389           VERSION);
390   exit (0);
391 }
392 
393 int
main(int argc,char ** argv)394 main (int argc, char **argv)
395 {
396   int i;
397   int saw_doubledash;
398   const char *dirname;
399 
400   saw_doubledash = FALSE;
401   dirname = NULL;
402   i = 1;
403   while (i < argc)
404     {
405       const char *arg = argv[i];
406 
407       if (strcmp (arg, "--help") == 0 ||
408           strcmp (arg, "-h") == 0 ||
409           strcmp (arg, "-?") == 0)
410         usage (0);
411       else if (strcmp (arg, "--version") == 0)
412         version ();
413       else if (!saw_doubledash)
414 	{
415           if (strcmp (arg, "--") == 0)
416             saw_doubledash = TRUE;
417           else if (*arg == '-')
418             usage (1);
419 	}
420       else
421         {
422           if (dirname != NULL)
423             {
424               fprintf (stderr, "dbus-cleanup-sockets only supports a single directory name\n");
425               exit (1);
426             }
427 
428           dirname = arg;
429         }
430 
431       ++i;
432     }
433 
434   /* Default to session socket dir, usually /tmp */
435   if (dirname == NULL)
436     dirname = DBUS_SESSION_SOCKET_DIR;
437 
438 #ifdef AF_UNIX
439   clean_dir (dirname);
440 
441   printf ("Cleaned up %d sockets in %s; %d sockets are still in use; %d in unknown state\n",
442           cleaned_count, dirname, alive_count, unhandled_count);
443 #else
444   printf ("This system does not support UNIX domain sockets, so dbus-cleanup-sockets does nothing\n");
445 #endif
446 
447   return 0;
448 }
449