Mix/Src/maildir.c

/* Mixmaster version 3.0  --  (C) 1999 - 2006 Anonymizer Inc. and others.

   Mixmaster may be redistributed and modified under certain conditions.
   This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
   ANY KIND, either express or implied. See the file COPYRIGHT for
   details.

   Maildir support routines
   $Id: $ */


/* Maildir support for Mixmaster 3 - see
   http://www.qmail.org/man/man5/maildir.html and
   http://cr.yp.to/proto/maildir.html

   Added by and (C) 2001 Doobee R. Tzeck 
   drt@un.bewaff.net - http://c0re.jp/

   To test it try:
   $ gcc maildir.c -DUNITTEST -o test_maildir
   $ ./test_maildir
   this should print a single line saying "OK"
*/

#include "mix3.h"

#ifdef WIN32
#include <io.h>
#include <direct.h>
#include <process.h>
#define S_IWUSR _S_IWRITE
#define S_IRUSR _S_IREAD
#else /* end of WIN32 */
#include <unistd.h>
#endif /* else not WIN32 */
#include <fcntl.h>
#include <time.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <stdarg.h>
#include <assert.h>

#if defined(S_IFDIR) && !defined(S_ISDIR)
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif /* defined(S_IFDIR) && !defined(S_ISDIR) */

#ifndef SHORTNAMES

static unsigned long namecounter = 0;

int checkDirectory(char *dir, char *append, int create) {
  char tmp[PATHMAX];
  struct stat buf;
  int err;

  tmp[0] = '\0';
  strcatn(tmp, dir, PATHMAX);
  if (append)
    strcatn(tmp, append, PATHMAX);

  err = stat(tmp, &buf);
  if (err == -1) {
    if (create) {
#ifndef POSIX
      err = mkdir(tmp);
#else /* end of not POSIX */
      err = mkdir(tmp, S_IRWXU);
#endif /* else if POSIX */
      if (err == 0)
        errlog(NOTICE, "Creating directory %s.\n", tmp);
    } else
      err = 1;
  } else if (!S_ISDIR(buf.st_mode))
    err = -1;

  return err;
}

/* Write "message" to "maildir", retunr 0 on success, -1 on failure */
#define MAX_BASENAME 113 /* actual length should be smaller than 111 bytes */
#define MAX_SUBNAME 123 /* actual length should be smaller than 115 bytes */
int maildirWrite(char *maildir, BUFFER *message, int create) {
  int fd;
  int count;
  int returnValue;
  char hostname[64];
  struct stat statbuf;
  char basename[MAX_BASENAME];
  char tmpname[MAX_SUBNAME];
  char newname[MAX_SUBNAME];
  int messagesize;
  char olddirectory[PATHMAX] = "";
  char normalizedmaildir[PATHMAX];

  /* Declare a handler for SIGALRM so we can time out. */
  /* set_handler(SIGALRM, alarm_handler);  */
  /* alarm(86400); */

  hostname[0] = '\0';
  gethostname(hostname, 63);
  hostname[63] = '\0';

  mixfile(normalizedmaildir, maildir);
  if ((checkDirectory(normalizedmaildir, NULL, create) != 0) ||
      (checkDirectory(normalizedmaildir, "tmp", create) != 0) ||
      (checkDirectory(normalizedmaildir, "cur", create) != 0) ||
      (checkDirectory(normalizedmaildir, "new", create) != 0)) {
    returnValue = -1;
    goto realend;
  }

  messagesize = message->length;

  /* Step 1: chdir to maildir (and save current dir) */
  if (getcwd(olddirectory, PATHMAX) == NULL) {
    returnValue = -1;
    goto realend;
  }
  olddirectory[PATHMAX-1] = '\0';
  if(chdir(normalizedmaildir) != 0) {
    returnValue = -1;
    goto functionExit;
  }

  /* Step 2:  Stat the temporary file.  Wait for ENOENT as a response. */
  for (count = 0;; count++) {
    tmpname[0] = '\0';
    newname[0] = '\0';
    snprintf(basename, MAX_BASENAME, "%lu.%u_%lu.%s,S=%u",
      time(NULL), getpid(), namecounter++, hostname, messagesize);
    basename[MAX_BASENAME-1] = '\0';
    strcatn(tmpname, "tmp" DIRSEPSTR, MAX_SUBNAME);
    strcatn(tmpname, basename, MAX_SUBNAME);
    strcatn(newname, "new" DIRSEPSTR, MAX_SUBNAME);
    strcatn(newname, basename, MAX_SUBNAME);

    if (stat(tmpname, &statbuf) == 0)
      errno = EEXIST;
    else if (errno == ENOENT) {
      /* Step 4: create the file (at least try) */
      fd = open(tmpname, O_WRONLY|O_CREAT|O_EXCL, S_IWUSR|S_IRUSR);
      if (fd >= 0)
        break; /* we managed to open the file */
    }

    if (count > 5) {
      /* Too many retries - give up */
      errlog(ERRORMSG, "Can't create message in %s\n", maildir);
      returnValue = -1;
      goto functionExit;
    }

    /* Step 3: sleep and retry */
    sleep(2);
  }

  /* Step 5:  write file */
  if(write(fd, message->data, message->length) != message->length) {
    returnValue = -1;
    goto functionExit;
  }

  /* on NFS this could fail */
#ifndef WIN32
  if((fsync(fd) != 0) || (close(fd) != 0)) {
#else /* end of not WIN32 */
  if((_commit(fd) != 0) || (close(fd) != 0)) {
#endif /* else if WIN32 */
    returnValue = -1;
    goto functionExit;
  }

  /* Step 6: move message to 'cur' */
#ifdef POSIX
  for (count = 0;; count++) {
    if(link(tmpname, newname) != 0) {
      if (errno == EXDEV || errno == EPERM) {
        /* We probably are on coda or some other filesystem that does not allow
         * hardlinks. rename() the file instead of link() and unlink()
         * I know, It's evil (PP).
         */
        if (rename(tmpname, newname) != 0) {
          returnValue = -1;
          goto functionExit;
        };
        break;
      } else if (errno != EEXIST) {
        returnValue = -1;
        goto functionExit;
      }
    } else {
      /* We successfully linked the message in new/. Now let's get
       * rid of our tmp/ entry
       */
      if(unlink(tmpname) != 0) {
        /* unlinking failed */
        returnValue = -1;
        goto functionExit;
      }
      break;
    }

    if (count > 5) {
      /* Too many retries - give up */
      errlog(ERRORMSG, "Can't move message to %s/new/\n", maildir);
      returnValue = -1;
      goto functionExit;
    }

    sleep(2);
    newname[0] = '\0';
    snprintf(basename, MAX_BASENAME, "%lu.%u_%lu.%s,S=%u",
      time(NULL), getpid(), namecounter++, hostname, messagesize);
    basename[MAX_BASENAME-1] = '\0';
    strcatn(newname, "new" DIRSEPSTR, MAX_SUBNAME);
    strcatn(newname, basename, MAX_SUBNAME);
  }
#else /* end of POSIX */
  /* On non POSIX systems we simply use rename(). Let's hope DJB
   * never finds out
   */
  if (rename(tmpname, newname) != 0) {
    returnValue = -1;
    goto functionExit;
  };
#endif /* else if not POSIX */

  returnValue = 0;

functionExit:
  /* return to original directory */
  assert(olddirectory[0] != '\0');
  if(chdir(olddirectory) != 0)
    returnValue = -1;

realend:

  return returnValue;
}

#else /* end of SHORTNAMES */
int maildirWrite(char *maildir, BUFFER *message, int create) {
{
  errlog(ERRORMSG, "Maildir delivery does not work with SHORTNAMES.\n");
  return -1;
}
#endif /* else if not SHORTNAMES */


#ifdef UNITTEST

#include <dirent.h>

/* mock-up of errlog for unittest */
void errlog(int type, char *fmt,...)
{
  va_list ap;

  va_start(ap, fmt);
  vfprintf(stderr, fmt, ap);
  va_end(ap);
}

/* main for unittest */
int main()
{
  int i, j, maildirWriteRes, count = 23;
  int fd;
  DIR *d;
  struct dirent *de;
  BUFFER message;
  char text[] = "From: nobody@un.bewaff.net\nTo: hackers@c0re.jp\nSubject: testing\n\nthis is just a test\n";
  char buf[1024];

  /* create buffer with test data */
  message.data = text;
  message.length = strlen(text);

  /* write <count> messages to maildir */
  for(i = 0; i < count; i++) {
    maildirWriteRes = maildirWrite("Maildir.test_maildir", message, 1);
    assert(maildirWriteRes == 0);
  }

  /* read them back */
  d = opendir("Maildir.test_maildir/new");
  assert(d != NULL);
  for (i = 0; i < count + 2; i++)
    {
      de = readdir(d);
      if(de->d_name[0] != '.')
        {
          buf[0] = '\0';
          strcat(buf, "Maildir.test_maildir/new/");
          strcat(buf, de->d_name);
          fd = open(buf, O_RDONLY);
          j = unlink(buf);
          assert(j == 0);
          j = read(fd, buf, strlen(text));
          assert(j == strlen(text));
          buf[strlen(text)] = '\0';
          /* check if they match the original message */
          assert(strcmp(text, buf) == 0);
          close(fd);
        }
    }

  /* no files left in directory? */
  assert(readdir(d) == NULL);

  /* delete maildir */
  j = rmdir("Maildir.test_maildir/tmp");
  assert(j == 0);
  j = rmdir("Maildir.test_maildir/new");
  assert(j == 0);
  j = rmdir("Maildir.test_maildir/cur");
  assert(j == 0);
  j = rmdir("Maildir.test_maildir");
  assert(j == 0);

  /* check if writing to a non existant maildir yields an error */
  assert(maildirWrite("Maildir.test_maildir", &message, 0) == -1);

  puts("OK");
}
#endif /* UNITTEST */
1	/* Mixmaster version 3.0 -- (C) 1999 - 2006 Anonymizer Inc. and others.
2
3	Mixmaster may be redistributed and modified under certain conditions.
4	This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
5	ANY KIND, either express or implied. See the file COPYRIGHT for
6	details.
7
8	Maildir support routines
9	$Id: $ */
10
11
12	/* Maildir support for Mixmaster 3 - see
13	http://www.qmail.org/man/man5/maildir.html and
14	http://cr.yp.to/proto/maildir.html
15
16	Added by and (C) 2001 Doobee R. Tzeck
17	drt@un.bewaff.net - http://c0re.jp/
18
19	To test it try:
20	$ gcc maildir.c -DUNITTEST -o test_maildir
21	$ ./test_maildir
22	this should print a single line saying "OK"
23	*/
24
25	#include "mix3.h"
26
27	#ifdef WIN32
28	#include <io.h>
29	#include <direct.h>
30	#include <process.h>
31	#define S_IWUSR _S_IWRITE
32	#define S_IRUSR _S_IREAD
33	#else /* end of WIN32 */
34	#include <unistd.h>
35	#endif /* else not WIN32 */
36	#include <fcntl.h>
37	#include <time.h>
38	#include <string.h>
39	#include <sys/stat.h>
40	#include <sys/types.h>
41	#include <errno.h>
42	#include <stdarg.h>
43	#include <assert.h>
44
45	#if defined(S_IFDIR) && !defined(S_ISDIR)
46	#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
47	#endif /* defined(S_IFDIR) && !defined(S_ISDIR) */
48
49	#ifndef SHORTNAMES
50
51	static unsigned long namecounter = 0;
52
53	int checkDirectory(char dir, char append, int create) {
54	char tmp[PATHMAX];
55	struct stat buf;
56	int err;
57
58	tmp[0] = '\0';
59	strcatn(tmp, dir, PATHMAX);
60	if (append)
61	strcatn(tmp, append, PATHMAX);
62
63	err = stat(tmp, &buf);
64	if (err == -1) {
65	if (create) {
66	#ifndef POSIX
67	err = mkdir(tmp);
68	#else /* end of not POSIX */
69	err = mkdir(tmp, S_IRWXU);
70	#endif /* else if POSIX */
71	if (err == 0)
72	errlog(NOTICE, "Creating directory %s.\n", tmp);
73	} else
74	err = 1;
75	} else if (!S_ISDIR(buf.st_mode))
76	err = -1;
77
78	return err;
79	}
80
81	/* Write "message" to "maildir", retunr 0 on success, -1 on failure */
82	#define MAX_BASENAME 113 /* actual length should be smaller than 111 bytes */
83	#define MAX_SUBNAME 123 /* actual length should be smaller than 115 bytes */
84	int maildirWrite(char maildir, BUFFER message, int create) {
85	int fd;
86	int count;
87	int returnValue;
88	char hostname[64];
89	struct stat statbuf;
90	char basename[MAX_BASENAME];
91	char tmpname[MAX_SUBNAME];
92	char newname[MAX_SUBNAME];
93	int messagesize;
94	char olddirectory[PATHMAX] = "";
95	char normalizedmaildir[PATHMAX];
96
97	/* Declare a handler for SIGALRM so we can time out. */
98	/* set_handler(SIGALRM, alarm_handler); */
99	/* alarm(86400); */
100
101	hostname[0] = '\0';
102	gethostname(hostname, 63);
103	hostname[63] = '\0';
104
105	mixfile(normalizedmaildir, maildir);
106	if ((checkDirectory(normalizedmaildir, NULL, create) != 0) \|\|
107	(checkDirectory(normalizedmaildir, "tmp", create) != 0) \|\|
108	(checkDirectory(normalizedmaildir, "cur", create) != 0) \|\|
109	(checkDirectory(normalizedmaildir, "new", create) != 0)) {
110	returnValue = -1;
111	goto realend;
112	}
113
114	messagesize = message->length;
115
116	/* Step 1: chdir to maildir (and save current dir) */
117	if (getcwd(olddirectory, PATHMAX) == NULL) {
118	returnValue = -1;
119	goto realend;
120	}
121	olddirectory[PATHMAX-1] = '\0';
122	if(chdir(normalizedmaildir) != 0) {
123	returnValue = -1;
124	goto functionExit;
125	}
126
127	/* Step 2: Stat the temporary file. Wait for ENOENT as a response. */
128	for (count = 0;; count++) {
129	tmpname[0] = '\0';
130	newname[0] = '\0';
131	snprintf(basename, MAX_BASENAME, "%lu.%u_%lu.%s,S=%u",
132	time(NULL), getpid(), namecounter++, hostname, messagesize);
133	basename[MAX_BASENAME-1] = '\0';
134	strcatn(tmpname, "tmp" DIRSEPSTR, MAX_SUBNAME);
135	strcatn(tmpname, basename, MAX_SUBNAME);
136	strcatn(newname, "new" DIRSEPSTR, MAX_SUBNAME);
137	strcatn(newname, basename, MAX_SUBNAME);
138
139	if (stat(tmpname, &statbuf) == 0)
140	errno = EEXIST;
141	else if (errno == ENOENT) {
142	/* Step 4: create the file (at least try) */
143	fd = open(tmpname, O_WRONLY\|O_CREAT\|O_EXCL, S_IWUSR\|S_IRUSR);
144	if (fd >= 0)
145	break; /* we managed to open the file */
146	}
147
148	if (count > 5) {
149	/* Too many retries - give up */
150	errlog(ERRORMSG, "Can't create message in %s\n", maildir);
151	returnValue = -1;
152	goto functionExit;
153	}
154
155	/* Step 3: sleep and retry */
156	sleep(2);
157	}
158
159	/* Step 5: write file */
160	if(write(fd, message->data, message->length) != message->length) {
161	returnValue = -1;
162	goto functionExit;
163	}
164
165	/* on NFS this could fail */
166	#ifndef WIN32
167	if((fsync(fd) != 0) \|\| (close(fd) != 0)) {
168	#else /* end of not WIN32 */
169	if((_commit(fd) != 0) \|\| (close(fd) != 0)) {
170	#endif /* else if WIN32 */
171	returnValue = -1;
172	goto functionExit;
173	}
174
175	/* Step 6: move message to 'cur' */
176	#ifdef POSIX
177	for (count = 0;; count++) {
178	if(link(tmpname, newname) != 0) {
179	if (errno == EXDEV \|\| errno == EPERM) {
180	/* We probably are on coda or some other filesystem that does not allow
181	* hardlinks. rename() the file instead of link() and unlink()
182	* I know, It's evil (PP).
183	*/
184	if (rename(tmpname, newname) != 0) {
185	returnValue = -1;
186	goto functionExit;
187	};
188	break;
189	} else if (errno != EEXIST) {
190	returnValue = -1;
191	goto functionExit;
192	}
193	} else {
194	/* We successfully linked the message in new/. Now let's get
195	* rid of our tmp/ entry
196	*/
197	if(unlink(tmpname) != 0) {
198	/* unlinking failed */
199	returnValue = -1;
200	goto functionExit;
201	}
202	break;
203	}
204
205	if (count > 5) {
206	/* Too many retries - give up */
207	errlog(ERRORMSG, "Can't move message to %s/new/\n", maildir);
208	returnValue = -1;
209	goto functionExit;
210	}
211
212	sleep(2);
213	newname[0] = '\0';
214	snprintf(basename, MAX_BASENAME, "%lu.%u_%lu.%s,S=%u",
215	time(NULL), getpid(), namecounter++, hostname, messagesize);
216	basename[MAX_BASENAME-1] = '\0';
217	strcatn(newname, "new" DIRSEPSTR, MAX_SUBNAME);
218	strcatn(newname, basename, MAX_SUBNAME);
219	}
220	#else /* end of POSIX */
221	/* On non POSIX systems we simply use rename(). Let's hope DJB
222	* never finds out
223	*/
224	if (rename(tmpname, newname) != 0) {
225	returnValue = -1;
226	goto functionExit;
227	};
228	#endif /* else if not POSIX */
229
230	returnValue = 0;
231
232	functionExit:
233	/* return to original directory */
234	assert(olddirectory[0] != '\0');
235	if(chdir(olddirectory) != 0)
236	returnValue = -1;
237
238	realend:
239
240	return returnValue;
241	}
242
243	#else /* end of SHORTNAMES */
244	int maildirWrite(char maildir, BUFFER message, int create) {
245	{
246	errlog(ERRORMSG, "Maildir delivery does not work with SHORTNAMES.\n");
247	return -1;
248	}
249	#endif /* else if not SHORTNAMES */
250
251
252	#ifdef UNITTEST
253
254	#include <dirent.h>
255
256	/* mock-up of errlog for unittest */
257	void errlog(int type, char *fmt,...)
258	{
259	va_list ap;
260
261	va_start(ap, fmt);
262	vfprintf(stderr, fmt, ap);
263	va_end(ap);
264	}
265
266	/* main for unittest */
267	int main()
268	{
269	int i, j, maildirWriteRes, count = 23;
270	int fd;
271	DIR *d;
272	struct dirent *de;
273	BUFFER message;
274	char text[] = "From: nobody@un.bewaff.net\nTo: hackers@c0re.jp\nSubject: testing\n\nthis is just a test\n";
275	char buf[1024];
276
277	/* create buffer with test data */
278	message.data = text;
279	message.length = strlen(text);
280
281	/* write <count> messages to maildir */
282	for(i = 0; i < count; i++) {
283	maildirWriteRes = maildirWrite("Maildir.test_maildir", message, 1);
284	assert(maildirWriteRes == 0);
285	}
286
287	/* read them back */
288	d = opendir("Maildir.test_maildir/new");
289	assert(d != NULL);
290	for (i = 0; i < count + 2; i++)
291	{
292	de = readdir(d);
293	if(de->d_name[0] != '.')
294	{
295	buf[0] = '\0';
296	strcat(buf, "Maildir.test_maildir/new/");
297	strcat(buf, de->d_name);
298	fd = open(buf, O_RDONLY);
299	j = unlink(buf);
300	assert(j == 0);
301	j = read(fd, buf, strlen(text));
302	assert(j == strlen(text));
303	buf[strlen(text)] = '\0';
304	/* check if they match the original message */
305	assert(strcmp(text, buf) == 0);
306	close(fd);
307	}
308	}
309
310	/* no files left in directory? */
311	assert(readdir(d) == NULL);
312
313	/* delete maildir */
314	j = rmdir("Maildir.test_maildir/tmp");
315	assert(j == 0);
316	j = rmdir("Maildir.test_maildir/new");
317	assert(j == 0);
318	j = rmdir("Maildir.test_maildir/cur");
319	assert(j == 0);
320	j = rmdir("Maildir.test_maildir");
321	assert(j == 0);
322
323	/* check if writing to a non existant maildir yields an error */
324	assert(maildirWrite("Maildir.test_maildir", &message, 0) == -1);
325
326	puts("OK");
327	}
328	#endif /* UNITTEST */