Adding upstream version 4.94.2.upstream/4.94.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 510 insertions, 0 deletions

diff --git a/src/lookups/pgsql.c b/src/lookups/pgsql.c
new file mode 100644
index 0000000..a7ea3d5
--- /dev/null
+++ b/src/lookups/pgsql.c
@@ -0,0 +1,510 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
+/* 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), FALSE);
+  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 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
+
+Returns:     the processed string or NULL for a bad option
+*/
+
+static uschar *
+pgsql_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, is_tainted(s));
+
+while ((c = *s++) != 0)
+  {
+  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"
+
+void
+pgsql_version_report(FILE *f)
+{
+#ifdef DYNLOOKUP
+fprintf(f, "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? */
+}
+
+
+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 */