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+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/* Copyright (c) The Exim Maintainers 2020 - 2022 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+/* Thanks to Petr Cech for contributing the original code for these
+functions. Thanks to Joachim Wieland for the initial patch for the Unix domain
+socket extension. */
+
+#include "../exim.h"
+#include "lf_functions.h"
+
+#include <libpq-fe.h> /* The system header */
+
+/* Structure and anchor for caching connections. */
+
+typedef struct pgsql_connection {
+ struct pgsql_connection *next;
+ uschar *server;
+ PGconn *handle;
+} pgsql_connection;
+
+static pgsql_connection *pgsql_connections = NULL;
+
+
+
+/*************************************************
+* Open entry point *
+*************************************************/
+
+/* See local README for interface description. */
+
+static void *
+pgsql_open(const uschar * filename, uschar ** errmsg)
+{
+return (void *)(1); /* Just return something non-null */
+}
+
+
+
+/*************************************************
+* Tidy entry point *
+*************************************************/
+
+/* See local README for interface description. */
+
+static void
+pgsql_tidy(void)
+{
+pgsql_connection *cn;
+while ((cn = pgsql_connections) != NULL)
+ {
+ pgsql_connections = cn->next;
+ DEBUG(D_lookup) debug_printf_indent("close PGSQL connection: %s\n", cn->server);
+ PQfinish(cn->handle);
+ }
+}
+
+
+/*************************************************
+* Notice processor function for pgsql *
+*************************************************/
+
+/* This function is passed to pgsql below, and called for any PostgreSQL
+"notices". By default they are written to stderr, which is undesirable.
+
+Arguments:
+ arg an opaque user cookie (not used)
+ message the notice
+
+Returns: nothing
+*/
+
+static void
+notice_processor(void *arg, const char *message)
+{
+arg = arg; /* Keep compiler happy */
+DEBUG(D_lookup) debug_printf_indent("PGSQL: %s\n", message);
+}
+
+
+
+/*************************************************
+* Internal search function *
+*************************************************/
+
+/* This function is called from the find entry point to do the search for a
+single server. The server string is of the form "server/dbname/user/password".
+
+PostgreSQL supports connections through Unix domain sockets. This is usually
+faster and costs less cpu time than a TCP/IP connection. However it can only be
+used if the mail server runs on the same machine as the database server. A
+configuration line for PostgreSQL via Unix domain sockets looks like this:
+
+hide pgsql_servers = (/tmp/.s.PGSQL.5432)/db/user/password[:<nextserver>]
+
+We enclose the path name in parentheses so that its slashes aren't visually
+confused with the delimiters for the other pgsql_server settings.
+
+For TCP/IP connections, the server is a host name and optional port (with a
+colon separator).
+
+NOTE:
+ 1) All three '/' must be present.
+ 2) If host is omitted the local unix socket is used.
+
+Arguments:
+ query the query string
+ server the server string; this is in dynamic memory and can be updated
+ resultptr where to store the result
+ errmsg where to point an error message
+ defer_break set TRUE if no more servers are to be tried after DEFER
+ do_cache set FALSE if data is changed
+ opts options list
+
+Returns: OK, FAIL, or DEFER
+*/
+
+static int
+perform_pgsql_search(const uschar *query, uschar *server, uschar **resultptr,
+ uschar **errmsg, BOOL *defer_break, uint *do_cache, const uschar * opts)
+{
+PGconn *pg_conn = NULL;
+PGresult *pg_result = NULL;
+
+gstring * result = NULL;
+int yield = DEFER;
+unsigned int num_fields, num_tuples;
+pgsql_connection *cn;
+rmark reset_point = store_mark();
+uschar *server_copy = NULL;
+uschar *sdata[3];
+
+/* Disaggregate the parameters from the server argument. The order is host or
+path, 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 (int i = 2; i >= 0; i--)
+ {
+ uschar *pp = Ustrrchr(server, '/');
+ if (!pp)
+ {
+ *errmsg = string_sprintf("incomplete pgSQL server data: %s",
+ (i == 2)? server : server_copy);
+ *defer_break = TRUE;
+ return DEFER;
+ }
+ *pp++ = 0;
+ sdata[i] = pp;
+ if (i == 2) server_copy = string_copy(server); /* sans password */
+ }
+
+/* The total server string has now been truncated so that what is left at the
+start is the identification of the server (host or path). See if we have a
+cached connection to the server. */
+
+for (cn = pgsql_connections; cn; cn = cn->next)
+ if (Ustrcmp(cn->server, server_copy) == 0)
+ {
+ pg_conn = cn->handle;
+ break;
+ }
+
+/* If there is no cached connection, we must set one up. */
+
+if (!cn)
+ {
+ uschar *port = US"";
+
+ /* For a Unix domain socket connection, the path is in parentheses */
+
+ if (*server == '(')
+ {
+ uschar *last_slash, *last_dot, *p;
+
+ p = ++server;
+ while (*p && *p != ')') p++;
+ *p = 0;
+
+ last_slash = Ustrrchr(server, '/');
+ last_dot = Ustrrchr(server, '.');
+
+ DEBUG(D_lookup) debug_printf_indent("PGSQL new connection: socket=%s "
+ "database=%s user=%s\n", server, sdata[0], sdata[1]);
+
+ /* A valid socket name looks like this: /var/run/postgresql/.s.PGSQL.5432
+ We have to call PQsetdbLogin with '/var/run/postgresql' as the hostname
+ argument and put '5432' into the port variable. */
+
+ if (!last_slash || !last_dot)
+ {
+ *errmsg = string_sprintf("PGSQL invalid filename for socket: %s", server);
+ *defer_break = TRUE;
+ return DEFER;
+ }
+
+ /* Terminate the path name and set up the port: we'll have something like
+ server = "/var/run/postgresql" and port = "5432". */
+
+ *last_slash = 0;
+ port = last_dot + 1;
+ }
+
+ /* Host connection; sort out the port */
+
+ else
+ {
+ uschar *p;
+ if ((p = Ustrchr(server, ':')))
+ {
+ *p++ = 0;
+ port = p;
+ }
+
+ if (Ustrchr(server, '/'))
+ {
+ *errmsg = string_sprintf("unexpected slash in pgSQL server hostname: %s",
+ server);
+ *defer_break = TRUE;
+ return DEFER;
+ }
+
+ DEBUG(D_lookup) debug_printf_indent("PGSQL new connection: host=%s port=%s "
+ "database=%s user=%s\n", server, port, sdata[0], sdata[1]);
+ }
+
+ /* If the database is the empty string, set it NULL - the query must then
+ define it. */
+
+ if (sdata[0][0] == 0) sdata[0] = NULL;
+
+ /* Get store for a new handle, initialize it, and connect to the server */
+
+ pg_conn=PQsetdbLogin(
+ /* host port options tty database user passwd */
+ CS server, CS port, NULL, NULL, CS sdata[0], CS sdata[1], CS sdata[2]);
+
+ if(PQstatus(pg_conn) == CONNECTION_BAD)
+ {
+ reset_point = store_reset(reset_point);
+ *errmsg = string_sprintf("PGSQL connection failed: %s",
+ PQerrorMessage(pg_conn));
+ PQfinish(pg_conn);
+ goto PGSQL_EXIT;
+ }
+
+ /* Set the client encoding to SQL_ASCII, which means that the server will
+ not try to interpret the query as being in any fancy encoding such as UTF-8
+ or other multibyte code that might cause problems with escaping. */
+
+ PQsetClientEncoding(pg_conn, "SQL_ASCII");
+
+ /* Set the notice processor to prevent notices from being written to stderr
+ (which is what the default does). Our function (above) just produces debug
+ output. */
+
+ PQsetNoticeProcessor(pg_conn, notice_processor, NULL);
+
+ /* Add the connection to the cache */
+
+ cn = store_get(sizeof(pgsql_connection), GET_UNTAINTED);
+ cn->server = server_copy;
+ cn->handle = pg_conn;
+ cn->next = pgsql_connections;
+ pgsql_connections = cn;
+ }
+
+/* Else use a previously cached connection */
+
+else
+ {
+ DEBUG(D_lookup) debug_printf_indent("PGSQL using cached connection for %s\n",
+ server_copy);
+ }
+
+/* Run the query */
+
+pg_result = PQexec(pg_conn, CS query);
+switch(PQresultStatus(pg_result))
+ {
+ case PGRES_EMPTY_QUERY:
+ case PGRES_COMMAND_OK:
+ /* The command was successful but did not return any data since it was
+ not SELECT but either an INSERT, UPDATE or DELETE statement. Tell the
+ high level code to not cache this query, and clean the current cache for
+ this handle by setting *do_cache zero. */
+
+ result = string_cat(result, US PQcmdTuples(pg_result));
+ *do_cache = 0;
+ DEBUG(D_lookup) debug_printf_indent("PGSQL: command does not return any data "
+ "but was successful. Rows affected: %s\n", string_from_gstring(result));
+ break;
+
+ case PGRES_TUPLES_OK:
+ break;
+
+ default:
+ /* This was the original code:
+ *errmsg = string_sprintf("PGSQL: query failed: %s\n",
+ PQresultErrorMessage(pg_result));
+ This was suggested by a user:
+ */
+
+ *errmsg = string_sprintf("PGSQL: query failed: %s (%s) (%s)\n",
+ PQresultErrorMessage(pg_result),
+ PQresStatus(PQresultStatus(pg_result)), query);
+ goto PGSQL_EXIT;
+ }
+
+/* Result is in pg_result. Find the number of fields returned. If this is one,
+we don't add field names to the data. Otherwise we do. If the query did not
+return anything we skip the for loop; this also applies to the case
+PGRES_COMMAND_OK. */
+
+num_fields = PQnfields(pg_result);
+num_tuples = PQntuples(pg_result);
+
+/* Get the fields and construct the result string. If there is more than one
+row, we insert '\n' between them. */
+
+for (int i = 0; i < num_tuples; i++)
+ {
+ if (result)
+ result = string_catn(result, US"\n", 1);
+
+ if (num_fields == 1)
+ result = string_catn(result,
+ US PQgetvalue(pg_result, i, 0), PQgetlength(pg_result, i, 0));
+ else
+ for (int j = 0; j < num_fields; j++)
+ {
+ uschar *tmp = US PQgetvalue(pg_result, i, j);
+ result = lf_quote(US PQfname(pg_result, j), tmp, Ustrlen(tmp), result);
+ }
+ if (!result) result = string_get(1);
+ }
+
+/* If result is NULL then no data has been found and so we return FAIL. */
+
+if (!result)
+ {
+ yield = FAIL;
+ *errmsg = US"PGSQL: no data found";
+ }
+
+/* Get here by goto from various error checks. */
+
+PGSQL_EXIT:
+
+/* Free store for any result that was got; don't close the connection, as
+it is cached. */
+
+if (pg_result) PQclear(pg_result);
+
+/* Non-NULL result indicates a successful result */
+
+if (result)
+ {
+ gstring_release_unused(result);
+ *resultptr = string_from_gstring(result);
+ return OK;
+ }
+else
+ {
+ DEBUG(D_lookup) debug_printf_indent("%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
+pgsql_find(void * handle, const uschar * filename, const uschar * query,
+ int length, uschar ** result, uschar ** errmsg, uint * do_cache,
+ const uschar * opts)
+{
+return lf_sqlperform(US"PostgreSQL", US"pgsql_servers", pgsql_servers, query,
+ result, errmsg, do_cache, opts, perform_pgsql_search);
+}
+
+
+
+/*************************************************
+* Quote entry point *
+*************************************************/
+
+/* The characters that always need to be quoted (with backslash) are newline,
+tab, carriage return, backspace, backslash itself, and the quote characters.
+
+The original code quoted single quotes as \' which is documented as valid in
+the O'Reilly book "Practical PostgreSQL" (first edition) as an alternative to
+the SQL standard '' way of representing a single quote as data. However, in
+June 2006 there was some security issue with using \' and so this has been
+changed.
+
+[Note: There is a function called PQescapeStringConn() that quotes strings.
+This cannot be used because it needs a PGconn argument (the connection handle).
+Why, I don't know. Seems odd for just string escaping...]
+
+Arguments:
+ s the string to be quoted
+ opt additional option text or NULL if none
+ idx lookup type index
+
+Returns: the processed string or NULL for a bad option
+*/
+
+static uschar *
+pgsql_quote(uschar * s, uschar * opt, unsigned idx)
+{
+int count = 0, c;
+uschar * t = s, * quoted;
+
+if (opt) return NULL; /* No options recognized */
+
+while ((c = *t++))
+ if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL) count++;
+
+t = quoted = store_get_quoted(Ustrlen(s) + count + 1, s, idx);
+
+while ((c = *s++))
+ {
+ if (c == '\'')
+ {
+ *t++ = '\'';
+ *t++ = '\'';
+ }
+ else 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"
+
+gstring *
+pgsql_version_report(gstring * g)
+{
+#ifdef DYNLOOKUP
+g = string_fmt_append(g, "Library version: PostgreSQL: Exim version %s\n", EXIM_VERSION_STR);
+#endif
+
+/* Version reporting: there appears to be no available information about
+the client library in libpq-fe.h; once you have a connection object, you
+can access the server version and the chosen protocol version, but those
+aren't really what we want. It might make sense to debug_printf those
+when the connection is established though? */
+
+return g;
+}
+
+
+static lookup_info _lookup_info = {
+ .name = US"pgsql", /* lookup name */
+ .type = lookup_querystyle, /* query-style lookup */
+ .open = pgsql_open, /* open function */
+ .check = NULL, /* no check function */
+ .find = pgsql_find, /* find function */
+ .close = NULL, /* no close function */
+ .tidy = pgsql_tidy, /* tidy function */
+ .quote = pgsql_quote, /* quoting function */
+ .version_report = pgsql_version_report /* version reporting */
+};
+
+#ifdef DYNLOOKUP
+#define pgsql_lookup_module_info _lookup_module_info
+#endif
+
+static lookup_info *_lookup_list[] = { &_lookup_info };
+lookup_module_info pgsql_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
+
+/* End of lookups/pgsql.c */
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-03 09:59:34 +0000