[qmail] / addrcheck.c

#include "cdb.h"
#include "stralloc.h"
#include "byte.h"
#include "str.h"
#include "addrcheck.h"
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>

/* #define DEBUG */
#ifdef DEBUG
#  define D(x) x
#  include <stdio.h>
#  include <sys/types.h>
#else
#  define D(x)
#endif

#define STRALLOC_INIT { 0 }

/* --- @probe@ --- *
 *
 * Arguments:	@int cdb@ = the CDB file descriptor
 *		@int prefix@ = the prefix character (e.g., @'V'@)
 *		@const char *key, int len@ = the key string and its length
 *		@const char *suffix@ = a suffix to append to the key
 *		@const char **kp@ = where to put the full key string
 *		@uint32 *dlen@ = where to put the answer's length
 *
 * Returns:	Zero if the lookup failed, @+1@ on success, or @-1@ for an
 *		error.
 *
 * Use:		Probes a CDB file.  The key looked up is the character
 *		@prefix@ followed by the first @len@ bytes of @key@, followed
 *		by @suffix@ (if non-null).
 */

static int probe(int cdb, int prefix, const char *key, int len,
		 const char *suffix, const char **kp, uint32 *dlen)
{
  static stralloc k = STRALLOC_INIT;
  char ch = prefix;
  int rc;

  k.len = 0;
  if (!stralloc_append(&k, &ch) ||
      !stralloc_catb(&k, key, len) ||
      (suffix && !stralloc_cats(&k, suffix)) ||
      !stralloc_0(&k))
    return (-1);
  if (kp) *kp = k.s;
  D( fprintf(stderr, "*** `%.*s' -> ", k.len, k.s); )
  rc = cdb_seek(cdb, k.s, k.len - 1, dlen);
  D( if (rc == -1)
       fprintf(stderr, "error: %s\n", strerror(errno));
     else if (rc == 0)
       fprintf(stderr, "not found\n");
     else if (!*dlen)
       fprintf(stderr, "empty\n");
     else {
       int n = *dlen;
       int nn;
       char buf[256];
       off_t pos = lseek(cdb, 0, SEEK_CUR);
       fprintf(stderr, "`");
       while (n) {
	 nn = sizeof(buf); if (nn > n) nn = n;
	 read(cdb, buf, nn);
	 fwrite(buf, 1, nn, stderr);
	 n -= nn;
       }
       fprintf(stderr, "'\n");
       lseek(cdb, pos, SEEK_SET);
     } )
  return (rc);
}

/* --- @localprobe@ --- *
 *
 * Arguments:	@int cdb@ = the CDB file descriptor
 *		@const char *sender@ = the envelope-sender address
 *		@const char *key, int len@ = the (possibly defaulted) mailbox
 *			name to look up
 *		@const char *suffix@ = a suffix to append to the key (e.g.,
 *			@"-default"@)
 *		@const char *tail@ = the tail of the local address matching
 *			any defaulted extension part
 *		@int *rc@ = where to put the answer
 *
 * Returns:	Positive if found, zero if not found, negative on error.
 *
 * Use:		Looks up a local-part in the database.  This may involve
 *		invoking a Userv service for the recipient's owner.
 */

static int localprobe(int cdb, const char *sender,
		      const char *key, int len,
		      const char *suffix, const char *tail, int *rc)
{
  int err;
  uint32 dlen;
  char ch;
  const char *k;
  static stralloc u =  STRALLOC_INIT;
  static stralloc serv = STRALLOC_INIT;
  int kid;
  int n;
  int wstat;
  int p[2];

  if ((err = probe(cdb, 'L', key, len, suffix, &k, &dlen)) < 0)
    return (-1);
  if (!err) { *rc = 0; return (0); }
  if (!dlen) { errno = EINVAL; return (-1); }  
  if (read(cdb, &ch, 1) != 1) { errno = EIO; return (-1); }
  if (ch == '?') {
    u.len = 0;
    if (!stralloc_ready(&u, dlen - 1)) return (-1);
    if (read(cdb, u.s, dlen - 1) != dlen - 1) { errno = EIO; return (-1); }
    u.len = dlen - 1;
    serv.len = 0;
    if (!stralloc_cats(&serv, "addrcheck:") ||
	!stralloc_cats(&serv, k + 1) ||
	!stralloc_0(&serv) ||
	!stralloc_0(&u))
      return (-1);
    D( fprintf(stderr, "asking user:\n\
  user = %s; service = %s\n  tail = %s; sender = %s\n\
  address = %s; key = %s\n",
	       u.s, serv.s, tail, sender, key, k + 1); )
	       
    if (pipe(p) || (kid = fork()) == -1)
      return (-1);
    if (!kid) {
      close(0); open("/dev/null", O_RDONLY);
      dup2(p[1], 1);
      close(2); open("/dev/null", O_WRONLY);
      close(p[0]); close(p[1]);
      execl("/usr/bin/userv", "/usr/bin/userv",
	    "-f", "stdin=/dev/null",
	    u.s, serv.s,
	    tail, sender, key, k + 1,
	    (char *)0);
      _exit(127);
    }
    close(p[1]);
    n = read(p[0], &ch, 1);
    close(p[0]);
    if (wait_pid(&wstat, kid) < 0) { return (-1); }
    D( fprintf(stderr, "userv exited with status %d\n", wstat); )
    if (n != 1 || wstat) { errno = EAGAIN; return (-1); }
    D( fprintf(stderr, "userv answer was `%c'\n", ch); )
  } else if (dlen != 1) {
    errno = EIO;
    return (-1);
  }
  *rc = ch;
  return (1);
}

/* --- @local@ --- *
 *
 * Arguments:	@int cdb@ = file descriptor for the CDB
 *		@const char *l@ = pointer to local-part to look up
 *		@int len@ = length of the local-part
 *		@const char *sender@ = envelope sender address
 *		@int *rc@ = where to put the answer
 *
 * Returns:	Positive if answered, zero if lookup failed, negative on
 *		error.
 *
 * Use:		Finds out whether @l@ is a valid local-part for a non-virtual
 *		mailbox name.  Handles defaulting of extension addresses and
 *		suchlike.
 */

static int local(int cdb, const char *l, int len,
		 const char *sender, int *rc)
{
  int code;
  int err = 0;
  int dash;

  if ((err = localprobe(cdb, sender, l, len, 0, l + len, &code)) != 0)
    goto done;

  for (;;) {
    dash = byte_rchr(l, len, '-');
    if (dash == len) break;
    if ((err = localprobe(cdb, sender,
			  l, dash, "-default", l + dash + 1, &code)) != 0)
      goto done;
    len = dash;
  }
  *rc = 0;
  return (0);
  
done:
  if (err >= 0) {
    switch (code) {
      case '+': *rc = 1; break;
      case '-': *rc = 0; break;
      default: errno = EINVAL; err = -1; break;
    }
  }
  return (err);
}

/* --- @virt@ --- *
 *
 * Arguments:	@int cdb@ = file descriptor for CDB
 *		@const char *u@ = the local-part of the recipient mailbox
 *		@int ulen@ = length of the local-part
 *		@const char *addr@ = the virtual domain to look up
 *		@int alen@ = length of the virtual domain
 *		@const char *sender@ = the envelope sender address
 *		@int *rc@ = where to put the answer
 *
 * Returns:	Positive if found, zero if not found, negative on error.
 *
 * Use:		Looks up the address as a virtual domain.  If found, the
 *		local-part is appended to the local mailbox handling the
 *		virtual domain and passed to @local@.
 */

static int virt(int cdb, const char *u, int ulen,
		const char *addr, int alen, const char *sender, int *rc)
{
  static stralloc l = STRALLOC_INIT;
  uint32 dlen;
  int err;

  if ((err = probe(cdb, 'V', addr, alen, 0, 0, &dlen)) <= 0)
    return (err);
  if (!stralloc_ready(&l, dlen + 1)) return (-1);
  if (read(cdb, l.s, dlen) != dlen) { errno = EIO; return (-1); }
  l.s[dlen] = '-';
  l.len = dlen + 1;
  if (!stralloc_catb(&l, u, ulen) || !stralloc_0(&l)) return (-1);
  D( printf("*** virtual map -> `%s'\n", l.s); )
  if (local(cdb, l.s, l.len - 1, sender, rc) < 0) return (-1);
  return (1);
}

/* --- @addrcheck@ --- *
 *
 * Arguments:	@int cdb@ = file descriptor for CDB to look things up in
 *		@const char *addr@ = the (full) recipient mailbox to look up
 *		@const char *sender@ = the (full) envelope sender address
 *		@int *rc@ = where to put the answer.
 *
 * Returns:	Nonnegative on success, or @-1@ on failure.
 *
 * Use:		Determines whether @addr@ is a valid mailbox on this system,
 *		by examining the given CDB file.  On exit, @*rc@ is set to
 *		@'+'@ if the mailbox is valid, or @'-'@ if not.
 */

int addrcheck(int cdb, const char *addr, const char *sender, int *rc)
{
  int at, len, dot;
  int err = 0;
  uint32 dlen;
  static stralloc l = STRALLOC_INIT;

  len = str_len(addr);
  at = str_rchr(addr, '@');
  if (!addr[at])
    return (local(cdb, addr, len, sender, rc));

  if ((err = virt(cdb, addr, at, addr, len, sender, rc)) != 0)
    return (err);
  dot = at + 1;
  while (addr[dot]) {
    if ((err = virt(cdb, addr, at, addr + dot, len - dot, sender, rc)) != 0)
      return (err);
    dot += byte_chr(addr + dot + 1, len - dot - 1, '.') + 1;
  }

  if ((err = probe(cdb, '@', addr + at + 1, len - at - 1, 0, 0, &dlen)) < 0)
    return (-1);
  if (!err) { *rc = 1; return (0); }
  if (dlen != 0) { errno = EINVAL; return (-1); }
  l.len = 0;
  if (!stralloc_catb(&l, addr, at) ||
      !stralloc_0(&l))
    return (-1);
  return (local(cdb, l.s, l.len - 1, sender, rc));
}

#ifdef TEST

#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
  int fd;
  int rc;
  int i;

  if (argc < 4) {
    fprintf(stderr, "usage: addrcheck CDB SENDER ADDR...\n");
    return (1);
  }
  if ((fd = open(argv[1], O_RDONLY)) < 0) {
    perror(argv[1]);
    return (1);
  }
  for (i = 3; i < argc; i++) {
    if (addrcheck(fd, argv[i], argv[2], &rc) < 0) {
      perror("checking");
      return (1);
    }
    printf("%s: %s\n", argv[i], rc ? "ok" : "bad");
  }
  return (0);
}

#endif
Commit	Line	Data
ca51b51d MW	1	#include "cdb.h"
	2	#include "stralloc.h"
	3	#include "byte.h"
	4	#include "str.h"
	5	#include "addrcheck.h"
	6	#include <errno.h>
0a045fc1	7	#include <unistd.h>
5373b260	8	#include <fcntl.h>
ca51b51d MW	9
	10	/* #define DEBUG */
	11	#ifdef DEBUG
	12	# define D(x) x
	13	# include <stdio.h>
	14	# include <sys/types.h>
ca51b51d MW	15	#else
	16	# define D(x)
	17	#endif
	18
	19	#define STRALLOC_INIT { 0 }
	20
dd1ee021 MW	21	/* --- @probe@ --- *
	22	*
	23	* Arguments: @int cdb@ = the CDB file descriptor
	24	* @int prefix@ = the prefix character (e.g., @'V'@)
	25	* @const char *key, int len@ = the key string and its length
	26	* @const char *suffix@ = a suffix to append to the key
	27	* @const char **kp@ = where to put the full key string
	28	* @uint32 *dlen@ = where to put the answer's length
	29	*
	30	* Returns: Zero if the lookup failed, @+1@ on success, or @-1@ for an
	31	* error.
	32	*
	33	* Use: Probes a CDB file. The key looked up is the character
	34	* @prefix@ followed by the first @len@ bytes of @key@, followed
	35	* by @suffix@ (if non-null).
	36	*/
	37
ca51b51d	38	static int probe(int cdb, int prefix, const char *key, int len,
0a045fc1	39	const char suffix, const char kp, uint32 dlen)
ca51b51d MW	40	{
	41	static stralloc k = STRALLOC_INIT;
	42	char ch = prefix;
	43	int rc;
	44
	45	k.len = 0;
	46	if (!stralloc_append(&k, &ch) \|\|
	47	!stralloc_catb(&k, key, len) \|\|
0a045fc1 MW	48	(suffix && !stralloc_cats(&k, suffix)) \|\|
0a045fc1 MW	49	!stralloc_0(&k))
ca51b51d	50	return (-1);
0a045fc1	51	if (kp) *kp = k.s;
ca51b51d	52	D( fprintf(stderr, "*** `%.*s' -> ", k.len, k.s); )
0a045fc1	53	rc = cdb_seek(cdb, k.s, k.len - 1, dlen);
ca51b51d MW	54	D( if (rc == -1)
	55	fprintf(stderr, "error: %s\n", strerror(errno));
	56	else if (rc == 0)
	57	fprintf(stderr, "not found\n");
	58	else if (!*dlen)
	59	fprintf(stderr, "empty\n");
	60	else {
	61	int n = *dlen;
	62	int nn;
	63	char buf[256];
	64	off_t pos = lseek(cdb, 0, SEEK_CUR);
	65	fprintf(stderr, "`");
	66	while (n) {
	67	nn = sizeof(buf); if (nn > n) nn = n;
	68	read(cdb, buf, nn);
	69	fwrite(buf, 1, nn, stderr);
	70	n -= nn;
	71	}
	72	fprintf(stderr, "'\n");
	73	lseek(cdb, pos, SEEK_SET);
	74	} )
	75	return (rc);
	76	}
	77
dd1ee021 MW	78	/* --- @localprobe@ --- *
	79	*
	80	* Arguments: @int cdb@ = the CDB file descriptor
	81	* @const char *sender@ = the envelope-sender address
	82	* @const char *key, int len@ = the (possibly defaulted) mailbox
	83	* name to look up
	84	* @const char *suffix@ = a suffix to append to the key (e.g.,
	85	* @"-default"@)
	86	* @const char *tail@ = the tail of the local address matching
	87	* any defaulted extension part
	88	* @int *rc@ = where to put the answer
	89	*
	90	* Returns: Positive if found, zero if not found, negative on error.
	91	*
	92	* Use: Looks up a local-part in the database. This may involve
	93	* invoking a Userv service for the recipient's owner.
	94	*/
	95
0a045fc1 MW	96	static int localprobe(int cdb, const char *sender,
	97	const char *key, int len,
	98	const char suffix, const char tail, int *rc)
ca51b51d MW	99	{
	100	int err;
	101	uint32 dlen;
	102	char ch;
0a045fc1 MW	103	const char *k;
	104	static stralloc u = STRALLOC_INIT;
	105	static stralloc serv = STRALLOC_INIT;
	106	int kid;
	107	int n;
	108	int wstat;
	109	int p[2];
	110
	111	if ((err = probe(cdb, 'L', key, len, suffix, &k, &dlen)) < 0)
ca51b51d MW	112	return (-1);
ca51b51d MW	113	if (!err) { *rc = 0; return (0); }
0a045fc1	114	if (!dlen) { errno = EINVAL; return (-1); }
ca51b51d	115	if (read(cdb, &ch, 1) != 1) { errno = EIO; return (-1); }
0a045fc1 MW	116	if (ch == '?') {
	117	u.len = 0;
	118	if (!stralloc_ready(&u, dlen - 1)) return (-1);
	119	if (read(cdb, u.s, dlen - 1) != dlen - 1) { errno = EIO; return (-1); }
	120	u.len = dlen - 1;
	121	serv.len = 0;
	122	if (!stralloc_cats(&serv, "addrcheck:") \|\|
	123	!stralloc_cats(&serv, k + 1) \|\|
	124	!stralloc_0(&serv) \|\|
	125	!stralloc_0(&u))
	126	return (-1);
	127	D( fprintf(stderr, "asking user:\n\
	128	user = %s; service = %s\n tail = %s; sender = %s\n\
	129	address = %s; key = %s\n",
	130	u.s, serv.s, tail, sender, key, k + 1); )
	131
	132	if (pipe(p) \|\| (kid = fork()) == -1)
	133	return (-1);
	134	if (!kid) {
5373b260	135	close(0); open("/dev/null", O_RDONLY);
0a045fc1	136	dup2(p[1], 1);
5373b260 MW	137	close(2); open("/dev/null", O_WRONLY);
5373b260 MW	138	close(p[0]); close(p[1]);
0a045fc1 MW	139	execl("/usr/bin/userv", "/usr/bin/userv",
	140	"-f", "stdin=/dev/null",
	141	u.s, serv.s,
	142	tail, sender, key, k + 1,
	143	(char *)0);
	144	_exit(127);
	145	}
	146	close(p[1]);
	147	n = read(p[0], &ch, 1);
	148	close(p[0]);
	149	if (wait_pid(&wstat, kid) < 0) { return (-1); }
	150	D( fprintf(stderr, "userv exited with status %d\n", wstat); )
	151	if (n != 1 \|\| wstat) { errno = EAGAIN; return (-1); }
	152	D( fprintf(stderr, "userv answer was `%c'\n", ch); )
	153	} else if (dlen != 1) {
	154	errno = EIO;
	155	return (-1);
	156	}
ca51b51d MW	157	*rc = ch;
	158	return (1);
	159	}
	160
dd1ee021 MW	161	/* --- @local@ --- *
	162	*
	163	* Arguments: @int cdb@ = file descriptor for the CDB
	164	* @const char *l@ = pointer to local-part to look up
	165	* @int len@ = length of the local-part
	166	* @const char *sender@ = envelope sender address
	167	* @int *rc@ = where to put the answer
	168	*
	169	* Returns: Positive if answered, zero if lookup failed, negative on
	170	* error.
	171	*
	172	* Use: Finds out whether @l@ is a valid local-part for a non-virtual
	173	* mailbox name. Handles defaulting of extension addresses and
	174	* suchlike.
	175	*/
	176
0a045fc1 MW	177	static int local(int cdb, const char *l, int len,
0a045fc1 MW	178	const char sender, int rc)
ca51b51d MW	179	{
	180	int code;
	181	int err = 0;
	182	int dash;
	183
0a045fc1 MW	184	if ((err = localprobe(cdb, sender, l, len, 0, l + len, &code)) != 0)
0a045fc1 MW	185	goto done;
ca51b51d MW	186
	187	for (;;) {
	188	dash = byte_rchr(l, len, '-');
	189	if (dash == len) break;
0a045fc1 MW	190	if ((err = localprobe(cdb, sender,
	191	l, dash, "-default", l + dash + 1, &code)) != 0)
	192	goto done;
ca51b51d MW	193	len = dash;
	194	}
	195	*rc = 0;
	196	return (0);
	197
	198	done:
	199	if (err >= 0) {
	200	switch (code) {
	201	case '+': *rc = 1; break;
	202	case '-': *rc = 0; break;
	203	default: errno = EINVAL; err = -1; break;
	204	}
	205	}
	206	return (err);
	207	}
	208
dd1ee021 MW	209	/* --- @virt@ --- *
	210	*
	211	* Arguments: @int cdb@ = file descriptor for CDB
	212	* @const char *u@ = the local-part of the recipient mailbox
	213	* @int ulen@ = length of the local-part
	214	* @const char *addr@ = the virtual domain to look up
	215	* @int alen@ = length of the virtual domain
	216	* @const char *sender@ = the envelope sender address
	217	* @int *rc@ = where to put the answer
	218	*
	219	* Returns: Positive if found, zero if not found, negative on error.
	220	*
	221	* Use: Looks up the address as a virtual domain. If found, the
	222	* local-part is appended to the local mailbox handling the
	223	* virtual domain and passed to @local@.
	224	*/
	225
ca51b51d	226	static int virt(int cdb, const char *u, int ulen,
0a045fc1	227	const char addr, int alen, const char sender, int *rc)
ca51b51d MW	228	{
	229	static stralloc l = STRALLOC_INIT;
	230	uint32 dlen;
	231	int err;
	232
0a045fc1	233	if ((err = probe(cdb, 'V', addr, alen, 0, 0, &dlen)) <= 0)
ca51b51d MW	234	return (err);
	235	if (!stralloc_ready(&l, dlen + 1)) return (-1);
	236	if (read(cdb, l.s, dlen) != dlen) { errno = EIO; return (-1); }
	237	l.s[dlen] = '-';
	238	l.len = dlen + 1;
0a045fc1 MW	239	if (!stralloc_catb(&l, u, ulen) \|\| !stralloc_0(&l)) return (-1);
	240	D( printf("*** virtual map -> `%s'\n", l.s); )
	241	if (local(cdb, l.s, l.len - 1, sender, rc) < 0) return (-1);
ca51b51d MW	242	return (1);
	243	}
	244
dd1ee021 MW	245	/* --- @addrcheck@ --- *
	246	*
	247	* Arguments: @int cdb@ = file descriptor for CDB to look things up in
	248	* @const char *addr@ = the (full) recipient mailbox to look up
	249	* @const char *sender@ = the (full) envelope sender address
	250	* @int *rc@ = where to put the answer.
	251	*
	252	* Returns: Nonnegative on success, or @-1@ on failure.
	253	*
	254	* Use: Determines whether @addr@ is a valid mailbox on this system,
	255	* by examining the given CDB file. On exit, @*rc@ is set to
	256	* @'+'@ if the mailbox is valid, or @'-'@ if not.
	257	*/
	258
0a045fc1	259	int addrcheck(int cdb, const char addr, const char sender, int *rc)
ca51b51d MW	260	{
	261	int at, len, dot;
	262	int err = 0;
	263	uint32 dlen;
c9d7c47d	264	static stralloc l = STRALLOC_INIT;
ca51b51d MW	265
ca51b51d MW	266	len = str_len(addr);
6646fe46	267	at = str_rchr(addr, '@');
ca51b51d	268	if (!addr[at])
0a045fc1	269	return (local(cdb, addr, len, sender, rc));
ca51b51d	270
0a045fc1	271	if ((err = virt(cdb, addr, at, addr, len, sender, rc)) != 0)
ca51b51d MW	272	return (err);
	273	dot = at + 1;
	274	while (addr[dot]) {
0a045fc1	275	if ((err = virt(cdb, addr, at, addr + dot, len - dot, sender, rc)) != 0)
ca51b51d MW	276	return (err);
	277	dot += byte_chr(addr + dot + 1, len - dot - 1, '.') + 1;
	278	}
	279
0a045fc1	280	if ((err = probe(cdb, '@', addr + at + 1, len - at - 1, 0, 0, &dlen)) < 0)
ca51b51d MW	281	return (-1);
	282	if (!err) { *rc = 1; return (0); }
	283	if (dlen != 0) { errno = EINVAL; return (-1); }
c9d7c47d MW	284	l.len = 0;
	285	if (!stralloc_catb(&l, addr, at) \|\|
	286	!stralloc_0(&l))
	287	return (-1);
	288	return (local(cdb, l.s, l.len - 1, sender, rc));
ca51b51d MW	289	}
	290
	291	#ifdef TEST
0a045fc1	292
ca51b51d MW	293	#include <sys/types.h>
	294	#include <unistd.h>
	295	#include <fcntl.h>
	296	#include <stdio.h>
	297	#include <errno.h>
	298	#include <unistd.h>
	299
	300	int main(int argc, char *argv[])
	301	{
	302	int fd;
	303	int rc;
	304	int i;
	305
0a045fc1 MW	306	if (argc < 4) {
0a045fc1 MW	307	fprintf(stderr, "usage: addrcheck CDB SENDER ADDR...\n");
ca51b51d MW	308	return (1);
	309	}
	310	if ((fd = open(argv[1], O_RDONLY)) < 0) {
	311	perror(argv[1]);
	312	return (1);
	313	}
0a045fc1 MW	314	for (i = 3; i < argc; i++) {
0a045fc1 MW	315	if (addrcheck(fd, argv[i], argv[2], &rc) < 0) {
ca51b51d MW	316	perror("checking");
	317	return (1);
	318	}
	319	printf("%s: %s\n", argv[i], rc ? "ok" : "bad");
	320	}
	321	return (0);
	322	}
	323
	324	#endif