[exim.git] / src / src / lookups / mysql.c

/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/* Copyright (c) University of Cambridge 1995 - 2015 */
/* See the file NOTICE for conditions of use and distribution. */

/* Thanks to Paul Kelly for contributing the original code for these
functions. */


#include "../exim.h"
#include "lf_functions.h"

#include <mysql.h>       /* The system header */


/* Structure and anchor for caching connections. */

typedef struct mysql_connection {
  struct mysql_connection *next;
  uschar  *server;
  MYSQL *handle;
} mysql_connection;

static mysql_connection *mysql_connections = NULL;


/*************************************************
*              Open entry point                  *
*************************************************/

/* See local README for interface description. */

static void *
mysql_open(uschar *filename, uschar **errmsg)
{
return (void *)(1);    /* Just return something non-null */
}


/*************************************************
*               Tidy entry point                 *
*************************************************/

/* See local README for interface description. */

static void
mysql_tidy(void)
{
mysql_connection *cn;
while ((cn = mysql_connections) != NULL)
  {
  mysql_connections = cn->next;
  DEBUG(D_lookup) debug_printf("close MYSQL connection: %s\n", cn->server);
  mysql_close(cn->handle);
  }
}


/*************************************************
*        Internal search function                *
*************************************************/

/* This function is called from the find entry point to do the search for a
single server.

Arguments:
  query        the query string
  server       the server string
  resultptr    where to store the result
  errmsg       where to point an error message
  defer_break  TRUE if no more servers are to be tried after DEFER
  do_cache     set false if data is changed

The server string is of the form "host/dbname/user/password". The host can be
host:port. This string is in a nextinlist temporary buffer, so can be
overwritten.

Returns:       OK, FAIL, or DEFER
*/

static int
perform_mysql_search(const uschar *query, uschar *server, uschar **resultptr,
  uschar **errmsg, BOOL *defer_break, BOOL *do_cache)
{
MYSQL *mysql_handle = NULL;        /* Keep compilers happy */
MYSQL_RES *mysql_result = NULL;
MYSQL_ROW mysql_row_data;
MYSQL_FIELD *fields;

int i;
int ssize = 0;
int offset = 0;
int yield = DEFER;
unsigned int num_fields;
uschar *result = NULL;
mysql_connection *cn;
uschar *server_copy = NULL;
uschar *sdata[4];

/* Disaggregate the parameters from the server argument. The order is host,
database, user, password. We can write to the string, since it is in a
nextinlist temporary buffer. The copy of the string that is used for caching
has the password removed. This copy is also used for debugging output. */

for (i = 3; i > 0; i--)
  {
  uschar *pp = Ustrrchr(server, '/');
  if (pp == NULL)
    {
    *errmsg = string_sprintf("incomplete MySQL server data: %s",
      (i == 3)? server : server_copy);
    *defer_break = TRUE;
    return DEFER;
    }
  *pp++ = 0;
  sdata[i] = pp;
  if (i == 3) server_copy = string_copy(server);  /* sans password */
  }
sdata[0] = server;   /* What's left at the start */

/* See if we have a cached connection to the server */

for (cn = mysql_connections; cn != NULL; cn = cn->next)
  {
  if (Ustrcmp(cn->server, server_copy) == 0)
    {
    mysql_handle = cn->handle;
    break;
    }
  }

/* If no cached connection, we must set one up. Mysql allows for a host name
and port to be specified. It also allows the name of a Unix socket to be used.
Unfortunately, this contains slashes, but its use is expected to be rare, so
the rather cumbersome syntax shouldn't inconvenience too many people. We use
this:  host:port(socket)  where all the parts are optional. */

if (cn == NULL)
  {
  uschar *p;
  uschar *socket = NULL;
  int port = 0;

  if ((p = Ustrchr(sdata[0], '(')) != NULL)
    {
    *p++ = 0;
    socket = p;
    while (*p != 0 && *p != ')') p++;
    *p = 0;
    }

  if ((p = Ustrchr(sdata[0], ':')) != NULL)
    {
    *p++ = 0;
    port = Uatoi(p);
    }

  if (Ustrchr(sdata[0], '/') != NULL)
    {
    *errmsg = string_sprintf("unexpected slash in MySQL server hostname: %s",
      sdata[0]);
    *defer_break = TRUE;
    return DEFER;
    }

  /* If the database is the empty string, set it NULL - the query must then
  define it. */

  if (sdata[1][0] == 0) sdata[1] = NULL;

  DEBUG(D_lookup)
    debug_printf("MYSQL new connection: host=%s port=%d socket=%s "
      "database=%s user=%s\n", sdata[0], port, socket, sdata[1], sdata[2]);

  /* Get store for a new handle, initialize it, and connect to the server */

  mysql_handle = store_get(sizeof(MYSQL));
  mysql_init(mysql_handle);
  if (mysql_real_connect(mysql_handle,
      /*  host        user         passwd     database */
      CS sdata[0], CS sdata[2], CS sdata[3], CS sdata[1],
      port, CS socket, CLIENT_MULTI_RESULTS) == NULL)
    {
    *errmsg = string_sprintf("MYSQL connection failed: %s",
      mysql_error(mysql_handle));
    *defer_break = FALSE;
    goto MYSQL_EXIT;
    }

  /* Add the connection to the cache */

  cn = store_get(sizeof(mysql_connection));
  cn->server = server_copy;
  cn->handle = mysql_handle;
  cn->next = mysql_connections;
  mysql_connections = cn;
  }

/* Else use a previously cached connection */

else
  {
  DEBUG(D_lookup)
    debug_printf("MYSQL using cached connection for %s\n", server_copy);
  }

/* Run the query */

if (mysql_query(mysql_handle, CS query) != 0)
  {
  *errmsg = string_sprintf("MYSQL: query failed: %s\n",
    mysql_error(mysql_handle));
  *defer_break = FALSE;
  goto MYSQL_EXIT;
  }

/* Pick up the result. If the query was not of the type that returns data,
namely INSERT, UPDATE, or DELETE, an error occurs here. However, this situation
can be detected by calling mysql_field_count(). If its result is zero, no data
was expected (this is all explained clearly in the MySQL manual). In this case,
we return the number of rows affected by the command. In this event, we do NOT
want to cache the result; also the whole cache for the handle must be cleaned
up. Setting do_cache FALSE requests this. */

if ((mysql_result = mysql_use_result(mysql_handle)) == NULL)
  {
  if ( mysql_field_count(mysql_handle) == 0 )
    {
    DEBUG(D_lookup) debug_printf("MYSQL: query was not one that returns data\n");
    result = string_sprintf("%d", mysql_affected_rows(mysql_handle));
    *do_cache = FALSE;
    goto MYSQL_EXIT;
    }
  *errmsg = string_sprintf("MYSQL: lookup result failed: %s\n",
    mysql_error(mysql_handle));
  *defer_break = FALSE;
  goto MYSQL_EXIT;
  }

/* Find the number of fields returned. If this is one, we don't add field
names to the data. Otherwise we do. */

num_fields = mysql_num_fields(mysql_result);

/* Get the fields and construct the result string. If there is more than one
row, we insert '\n' between them. */

fields = mysql_fetch_fields(mysql_result);

while ((mysql_row_data = mysql_fetch_row(mysql_result)) != NULL)
  {
  unsigned long *lengths = mysql_fetch_lengths(mysql_result);

  if (result != NULL)
      result = string_cat(result, &ssize, &offset, US"\n", 1);

  if (num_fields == 1)
    {
    if (mysql_row_data[0] != NULL)    /* NULL value yields nothing */
      result = string_cat(result, &ssize, &offset, US mysql_row_data[0],
        lengths[0]);
    }

  else for (i = 0; i < num_fields; i++)
    {
    result = lf_quote(US fields[i].name, US mysql_row_data[i], lengths[i],
      result, &ssize, &offset);
    }
  }

/* more results? -1 = no, >0 = error, 0 = yes (keep looping)
   This is needed because of the CLIENT_MULTI_RESULTS on mysql_real_connect(),
   we don't expect any more results. */

while((i = mysql_next_result(mysql_handle)) >= 0) {
   if(i == 0) {   /* Just ignore more results */
     DEBUG(D_lookup) debug_printf("MYSQL: got unexpected more results\n");
     continue;
   }

   *errmsg = string_sprintf("MYSQL: lookup result error when checking for more results: %s\n",
       mysql_error(mysql_handle));
   goto MYSQL_EXIT;
}

/* If result is NULL then no data has been found and so we return FAIL.
Otherwise, we must terminate the string which has been built; string_cat()
always leaves enough room for a terminating zero. */

if (result == NULL)
  {
  yield = FAIL;
  *errmsg = US"MYSQL: no data found";
  }
else
  {
  result[offset] = 0;
  store_reset(result + offset + 1);
  }

/* Get here by goto from various error checks and from the case where no data
was read (e.g. an update query). */

MYSQL_EXIT:

/* Free mysal store for any result that was got; don't close the connection, as
it is cached. */

if (mysql_result != NULL) mysql_free_result(mysql_result);

/* Non-NULL result indicates a sucessful result */

if (result != NULL)
  {
  *resultptr = result;
  return OK;
  }
else
  {
  DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
  return yield;      /* FAIL or DEFER */
  }
}


/*************************************************
*               Find entry point                 *
*************************************************/

/* See local README for interface description. The handle and filename
arguments are not used. The code to loop through a list of servers while the
query is deferred with a retryable error is now in a separate function that is
shared with other SQL lookups. */

static int
mysql_find(void *handle, uschar *filename, const uschar *query, int length,
  uschar **result, uschar **errmsg, BOOL *do_cache)
{
return lf_sqlperform(US"MySQL", US"mysql_servers", mysql_servers, query,
  result, errmsg, do_cache, perform_mysql_search);
}


/*************************************************
*               Quote entry point                *
*************************************************/

/* The only characters that need to be quoted (with backslash) are newline,
tab, carriage return, backspace, backslash itself, and the quote characters.
Percent, and underscore and not escaped. They are only special in contexts
where they can be wild cards, and this isn't usually the case for data inserted
from messages, since that isn't likely to be treated as a pattern of any kind.
Sadly, MySQL doesn't seem to behave like other programs. If you use something
like "where id="ab\%cd" it does not treat the string as "ab%cd". So you really
can't quote "on spec".

Arguments:
  s          the string to be quoted
  opt        additional option text or NULL if none

Returns:     the processed string or NULL for a bad option
*/

static uschar *
mysql_quote(uschar *s, uschar *opt)
{
register int c;
int count = 0;
uschar *t = s;
uschar *quoted;

if (opt != NULL) return NULL;     /* No options recognized */

while ((c = *t++) != 0)
  if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL) count++;

if (count == 0) return s;
t = quoted = store_get(Ustrlen(s) + count + 1);

while ((c = *s++) != 0)
  {
  if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL)
    {
    *t++ = '\\';
    switch(c)
      {
      case '\n': *t++ = 'n';
      break;
      case '\t': *t++ = 't';
      break;
      case '\r': *t++ = 'r';
      break;
      case '\b': *t++ = 'b';
      break;
      default:   *t++ = c;
      break;
      }
    }
  else *t++ = c;
  }

*t = 0;
return quoted;
}


/*************************************************
*         Version reporting entry point          *
*************************************************/

/* See local README for interface description. */

#include "../version.h"

void
mysql_version_report(FILE *f)
{
fprintf(f, "Library version: MySQL: Compile: %s [%s]\n"
           "                        Runtime: %s\n",
        MYSQL_SERVER_VERSION, MYSQL_COMPILATION_COMMENT,
        mysql_get_client_info());
#ifdef DYNLOOKUP
fprintf(f, "                        Exim version %s\n", EXIM_VERSION_STR);
#endif
}

/* These are the lookup_info blocks for this driver */

static lookup_info mysql_lookup_info = {
  US"mysql",                     /* lookup name */
  lookup_querystyle,             /* query-style lookup */
  mysql_open,                    /* open function */
  NULL,                          /* no check function */
  mysql_find,                    /* find function */
  NULL,                          /* no close function */
  mysql_tidy,                    /* tidy function */
  mysql_quote,                   /* quoting function */
  mysql_version_report           /* version reporting */
};

#ifdef DYNLOOKUP
#define mysql_lookup_module_info _lookup_module_info
#endif

static lookup_info *_lookup_list[] = { &mysql_lookup_info };
lookup_module_info mysql_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };

/* End of lookups/mysql.c */
Commit	Line	Data
0756eb3c PH	1	/*************************************************
	2	* Exim - an Internet mail transport agent *
	3	*************************************************/
	4
3386088d	5	/* Copyright (c) University of Cambridge 1995 - 2015 */
0756eb3c PH	6	/* See the file NOTICE for conditions of use and distribution. */
	7
	8	/* Thanks to Paul Kelly for contributing the original code for these
	9	functions. */
	10
	11
	12	#include "../exim.h"
	13	#include "lf_functions.h"
0756eb3c PH	14
	15	#include <mysql.h> /* The system header */
	16
	17
	18	/* Structure and anchor for caching connections. */
	19
	20	typedef struct mysql_connection {
	21	struct mysql_connection *next;
	22	uschar *server;
	23	MYSQL *handle;
	24	} mysql_connection;
	25
	26	static mysql_connection *mysql_connections = NULL;
	27
	28
	29
	30	/*************************************************
	31	* Open entry point *
	32	*************************************************/
	33
	34	/* See local README for interface description. */
	35
e6d225ae	36	static void *
0756eb3c PH	37	mysql_open(uschar filename, uschar *errmsg)
	38	{
	39	return (void )(1); / Just return something non-null */
	40	}
	41
	42
	43
	44	/*************************************************
	45	* Tidy entry point *
	46	*************************************************/
	47
	48	/* See local README for interface description. */
	49
e6d225ae	50	static void
0756eb3c PH	51	mysql_tidy(void)
	52	{
	53	mysql_connection *cn;
	54	while ((cn = mysql_connections) != NULL)
	55	{
	56	mysql_connections = cn->next;
	57	DEBUG(D_lookup) debug_printf("close MYSQL connection: %s\n", cn->server);
	58	mysql_close(cn->handle);
	59	}
	60	}
	61
	62
	63
	64	/*************************************************
	65	* Internal search function *
	66	*************************************************/
	67
	68	/* This function is called from the find entry point to do the search for a
	69	single server.
	70
	71	Arguments:
	72	query the query string
	73	server the server string
	74	resultptr where to store the result
	75	errmsg where to point an error message
	76	defer_break TRUE if no more servers are to be tried after DEFER
	77	do_cache set false if data is changed
	78
	79	The server string is of the form "host/dbname/user/password". The host can be
	80	host:port. This string is in a nextinlist temporary buffer, so can be
	81	overwritten.
	82
	83	Returns: OK, FAIL, or DEFER
	84	*/
	85
	86	static int
55414b25	87	perform_mysql_search(const uschar query, uschar server, uschar **resultptr,
0756eb3c PH	88	uschar *errmsg, BOOL defer_break, BOOL *do_cache)
	89	{
	90	MYSQL mysql_handle = NULL; / Keep compilers happy */
	91	MYSQL_RES *mysql_result = NULL;
	92	MYSQL_ROW mysql_row_data;
	93	MYSQL_FIELD *fields;
	94
	95	int i;
	96	int ssize = 0;
	97	int offset = 0;
	98	int yield = DEFER;
	99	unsigned int num_fields;
	100	uschar *result = NULL;
	101	mysql_connection *cn;
	102	uschar *server_copy = NULL;
	103	uschar *sdata[4];
	104
	105	/* Disaggregate the parameters from the server argument. The order is host,
	106	database, user, password. We can write to the string, since it is in a
	107	nextinlist temporary buffer. The copy of the string that is used for caching
	108	has the password removed. This copy is also used for debugging output. */
	109
	110	for (i = 3; i > 0; i--)
	111	{
	112	uschar *pp = Ustrrchr(server, '/');
	113	if (pp == NULL)
	114	{
	115	*errmsg = string_sprintf("incomplete MySQL server data: %s",
	116	(i == 3)? server : server_copy);
	117	*defer_break = TRUE;
	118	return DEFER;
	119	}
	120	*pp++ = 0;
	121	sdata[i] = pp;
	122	if (i == 3) server_copy = string_copy(server); /* sans password */
	123	}
	124	sdata[0] = server; /* What's left at the start */
	125
	126	/* See if we have a cached connection to the server */
	127
	128	for (cn = mysql_connections; cn != NULL; cn = cn->next)
	129	{
	130	if (Ustrcmp(cn->server, server_copy) == 0)
	131	{
	132	mysql_handle = cn->handle;
	133	break;
	134	}
	135	}
	136
	137	/* If no cached connection, we must set one up. Mysql allows for a host name
	138	and port to be specified. It also allows the name of a Unix socket to be used.
	139	Unfortunately, this contains slashes, but its use is expected to be rare, so
	140	the rather cumbersome syntax shouldn't inconvenience too many people. We use
	141	this: host:port(socket) where all the parts are optional. */
	142
	143	if (cn == NULL)
	144	{
	145	uschar *p;
	146	uschar *socket = NULL;
	147	int port = 0;
	148
	149	if ((p = Ustrchr(sdata[0], '(')) != NULL)
	150	{
	151	*p++ = 0;
152	socket = p;
153	while (p != 0 && p != ')') p++;
154	*p = 0;
155	}
156
157	if ((p = Ustrchr(sdata[0], ':')) != NULL)
158	{
159	*p++ = 0;
160	port = Uatoi(p);
161	}
162
163	if (Ustrchr(sdata[0], '/') != NULL)
164	{
165	*errmsg = string_sprintf("unexpected slash in MySQL server hostname: %s",
166	sdata[0]);
167	*defer_break = TRUE;
168	return DEFER;
169	}
170
171	/* If the database is the empty string, set it NULL - the query must then
172	define it. */
173
174	if (sdata[1][0] == 0) sdata[1] = NULL;
175
176	DEBUG(D_lookup)
177	debug_printf("MYSQL new connection: host=%s port=%d socket=%s "
178	"database=%s user=%s\n", sdata[0], port, socket, sdata[1], sdata[2]);
179
180	/* Get store for a new handle, initialize it, and connect to the server */
181
182	mysql_handle = store_get(sizeof(MYSQL));
183	mysql_init(mysql_handle);
184	if (mysql_real_connect(mysql_handle,
185	/* host user passwd database */
186	CS sdata[0], CS sdata[2], CS sdata[3], CS sdata[1],
f6efe9ce	187	port, CS socket, CLIENT_MULTI_RESULTS) == NULL)
0756eb3c PH	188	{
	189	*errmsg = string_sprintf("MYSQL connection failed: %s",
	190	mysql_error(mysql_handle));
	191	*defer_break = FALSE;
	192	goto MYSQL_EXIT;
	193	}
	194
	195	/* Add the connection to the cache */
	196
	197	cn = store_get(sizeof(mysql_connection));
	198	cn->server = server_copy;
	199	cn->handle = mysql_handle;
	200	cn->next = mysql_connections;
	201	mysql_connections = cn;
	202	}
	203
	204	/* Else use a previously cached connection */
	205
	206	else
	207	{
	208	DEBUG(D_lookup)
	209	debug_printf("MYSQL using cached connection for %s\n", server_copy);
	210	}
	211
	212	/* Run the query */
	213
	214	if (mysql_query(mysql_handle, CS query) != 0)
	215	{
	216	*errmsg = string_sprintf("MYSQL: query failed: %s\n",
	217	mysql_error(mysql_handle));
	218	*defer_break = FALSE;
	219	goto MYSQL_EXIT;
	220	}
	221
	222	/* Pick up the result. If the query was not of the type that returns data,
	223	namely INSERT, UPDATE, or DELETE, an error occurs here. However, this situation
	224	can be detected by calling mysql_field_count(). If its result is zero, no data
	225	was expected (this is all explained clearly in the MySQL manual). In this case,
	226	we return the number of rows affected by the command. In this event, we do NOT
	227	want to cache the result; also the whole cache for the handle must be cleaned
	228	up. Setting do_cache FALSE requests this. */
	229
	230	if ((mysql_result = mysql_use_result(mysql_handle)) == NULL)
	231	{
	232	if ( mysql_field_count(mysql_handle) == 0 )
	233	{
	234	DEBUG(D_lookup) debug_printf("MYSQL: query was not one that returns data\n");
	235	result = string_sprintf("%d", mysql_affected_rows(mysql_handle));
	236	*do_cache = FALSE;
	237	goto MYSQL_EXIT;
	238	}
	239	*errmsg = string_sprintf("MYSQL: lookup result failed: %s\n",
	240	mysql_error(mysql_handle));
	241	*defer_break = FALSE;
	242	goto MYSQL_EXIT;
	243	}
	244
	245	/* Find the number of fields returned. If this is one, we don't add field
	246	names to the data. Otherwise we do. */
	247
	248	num_fields = mysql_num_fields(mysql_result);
	249
	250	/* Get the fields and construct the result string. If there is more than one
	251	row, we insert '\n' between them. */
252
253	fields = mysql_fetch_fields(mysql_result);
254
255	while ((mysql_row_data = mysql_fetch_row(mysql_result)) != NULL)
256	{
257	unsigned long *lengths = mysql_fetch_lengths(mysql_result);
258
259	if (result != NULL)
260	result = string_cat(result, &ssize, &offset, US"\n", 1);
261
262	if (num_fields == 1)
263	{
264	if (mysql_row_data[0] != NULL) /* NULL value yields nothing */
265	result = string_cat(result, &ssize, &offset, US mysql_row_data[0],
266	lengths[0]);
267	}
268
269	else for (i = 0; i < num_fields; i++)
270	{
271	result = lf_quote(US fields[i].name, US mysql_row_data[i], lengths[i],
272	result, &ssize, &offset);
273	}
274	}
275
f6efe9ce NM	276	/* more results? -1 = no, >0 = error, 0 = yes (keep looping)
	277	This is needed because of the CLIENT_MULTI_RESULTS on mysql_real_connect(),
	278	we don't expect any more results. */
	279
	280	while((i = mysql_next_result(mysql_handle)) >= 0) {
	281	if(i == 0) { /* Just ignore more results */
	282	DEBUG(D_lookup) debug_printf("MYSQL: got unexpected more results\n");
	283	continue;
	284	}
	285
	286	*errmsg = string_sprintf("MYSQL: lookup result error when checking for more results: %s\n",
	287	mysql_error(mysql_handle));
	288	goto MYSQL_EXIT;
	289	}
	290
0756eb3c PH	291	/* If result is NULL then no data has been found and so we return FAIL.
	292	Otherwise, we must terminate the string which has been built; string_cat()
	293	always leaves enough room for a terminating zero. */
	294
	295	if (result == NULL)
	296	{
	297	yield = FAIL;
	298	*errmsg = US"MYSQL: no data found";
	299	}
	300	else
	301	{
	302	result[offset] = 0;
	303	store_reset(result + offset + 1);
	304	}
	305
	306	/* Get here by goto from various error checks and from the case where no data
	307	was read (e.g. an update query). */
	308
	309	MYSQL_EXIT:
	310
	311	/* Free mysal store for any result that was got; don't close the connection, as
	312	it is cached. */
	313
	314	if (mysql_result != NULL) mysql_free_result(mysql_result);
	315
	316	/* Non-NULL result indicates a sucessful result */
	317
	318	if (result != NULL)
	319	{
	320	*resultptr = result;
	321	return OK;
	322	}
	323	else
	324	{
	325	DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
	326	return yield; /* FAIL or DEFER */
	327	}
	328	}
	329
	330
	331
	332
	333	/*************************************************
	334	* Find entry point *
	335	*************************************************/
	336
	337	/* See local README for interface description. The handle and filename
b7670459 PH	338	arguments are not used. The code to loop through a list of servers while the
	339	query is deferred with a retryable error is now in a separate function that is
	340	shared with other SQL lookups. */
0756eb3c	341
e6d225ae	342	static int
55414b25	343	mysql_find(void handle, uschar filename, const uschar *query, int length,
0756eb3c PH	344	uschar result, uschar errmsg, BOOL *do_cache)
0756eb3c PH	345	{
b7670459 PH	346	return lf_sqlperform(US"MySQL", US"mysql_servers", mysql_servers, query,
b7670459 PH	347	result, errmsg, do_cache, perform_mysql_search);
0756eb3c PH	348	}
	349
	350
	351
	352	/*************************************************
	353	* Quote entry point *
	354	*************************************************/
	355
	356	/* The only characters that need to be quoted (with backslash) are newline,
	357	tab, carriage return, backspace, backslash itself, and the quote characters.
	358	Percent, and underscore and not escaped. They are only special in contexts
	359	where they can be wild cards, and this isn't usually the case for data inserted
	360	from messages, since that isn't likely to be treated as a pattern of any kind.
	361	Sadly, MySQL doesn't seem to behave like other programs. If you use something
	362	like "where id="ab\%cd" it does not treat the string as "ab%cd". So you really
	363	can't quote "on spec".
	364
	365	Arguments:
	366	s the string to be quoted
	367	opt additional option text or NULL if none
	368
	369	Returns: the processed string or NULL for a bad option
	370	*/
	371
e6d225ae	372	static uschar *
0756eb3c PH	373	mysql_quote(uschar s, uschar opt)
	374	{
	375	register int c;
	376	int count = 0;
	377	uschar *t = s;
	378	uschar *quoted;
	379
	380	if (opt != NULL) return NULL; /* No options recognized */
	381
	382	while ((c = *t++) != 0)
	383	if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL) count++;
	384
	385	if (count == 0) return s;
	386	t = quoted = store_get(Ustrlen(s) + count + 1);
	387
	388	while ((c = *s++) != 0)
	389	{
	390	if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL)
	391	{
	392	*t++ = '\\';
	393	switch(c)
	394	{
	395	case '\n': *t++ = 'n';
	396	break;
	397	case '\t': *t++ = 't';
	398	break;
	399	case '\r': *t++ = 'r';
	400	break;
	401	case '\b': *t++ = 'b';
	402	break;
	403	default: *t++ = c;
	404	break;
	405	}
	406	}
	407	else *t++ = c;
	408	}
	409
	410	*t = 0;
	411	return quoted;
	412	}
	413
6545de78 PP	414
	415	/*************************************************
	416	* Version reporting entry point *
	417	*************************************************/
	418
	419	/* See local README for interface description. */
	420
	421	#include "../version.h"
	422
	423	void
	424	mysql_version_report(FILE *f)
	425	{
	426	fprintf(f, "Library version: MySQL: Compile: %s [%s]\n"
	427	" Runtime: %s\n",
	428	MYSQL_SERVER_VERSION, MYSQL_COMPILATION_COMMENT,
	429	mysql_get_client_info());
	430	#ifdef DYNLOOKUP
	431	fprintf(f, " Exim version %s\n", EXIM_VERSION_STR);
	432	#endif
	433	}
	434
e6d225ae DW	435	/* These are the lookup_info blocks for this driver */
	436
	437	static lookup_info mysql_lookup_info = {
	438	US"mysql", /* lookup name */
	439	lookup_querystyle, /* query-style lookup */
	440	mysql_open, /* open function */
	441	NULL, /* no check function */
	442	mysql_find, /* find function */
	443	NULL, /* no close function */
	444	mysql_tidy, /* tidy function */
6545de78 PP	445	mysql_quote, /* quoting function */
6545de78 PP	446	mysql_version_report /* version reporting */
e6d225ae DW	447	};
	448
	449	#ifdef DYNLOOKUP
	450	#define mysql_lookup_module_info _lookup_module_info
	451	#endif
	452
	453	static lookup_info *_lookup_list[] = { &mysql_lookup_info };
	454	lookup_module_info mysql_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
0756eb3c PH	455
0756eb3c PH	456	/* End of lookups/mysql.c */