Fix authentication so that it doesn't record an extra 'Password

authentication failed' and a 'send() failed: Broken pipe' message
on every connection from psql in password auth mode.  Problem is
that psql doesn't ask user for a password until it sees a password
challenge failure, and libpq just closes the connection unceremoniously
if it's challenged for a password when it hasn't got one to send.
Accordingly, EOF from the client after asking for a password is
normal behavior and should not result in postmaster log entries.

diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index 78bff87..b6d1e61 100644 (file)
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/libpq/auth.c,v 1.68 2001/09/26 19:54:12 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/libpq/auth.c,v 1.69 2001/10/18 22:44:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -37,7 +37,7 @@ static void sendAuthRequest(Port *port, AuthRequest areq);
 static int     checkPassword(Port *port, char *user, char *password);
 static int     old_be_recvauth(Port *port);
 static int     map_old_to_new(Port *port, UserAuth old, int status);
-static void auth_failed(Port *port);
+static void auth_failed(Port *port, int status);
 static int     recv_and_check_password_packet(Port *port);
 static int     recv_and_check_passwordv0(Port *port);
 
@@ -341,17 +341,23 @@ recv_and_check_passwordv0(Port *port)
                           *password,
                           *cp,
                           *start;
+       int                     status;
 
-       pq_getint(&len, 4);
+       if (pq_getint(&len, 4) == EOF)
+               return STATUS_EOF;
        len -= 4;
        buf = palloc(len);
-       pq_getbytes(buf, len);
+       if (pq_getbytes(buf, len) == EOF)
+       {
+               pfree(buf);
+               return STATUS_EOF;
+       }
 
        pp = (PasswordPacketV0 *) buf;
 
        /*
         * The packet is supposed to comprise the user name and the password
-        * as C strings.  Be careful the check that this is the case.
+        * as C strings.  Be careful to check that this is the case.
         */
        user = password = NULL;
 
@@ -379,13 +385,10 @@ recv_and_check_passwordv0(Port *port)
                                 "pg_password_recvauth: badly formed password packet.\n");
                fputs(PQerrormsg, stderr);
                pqdebug("%s", PQerrormsg);
-
-               pfree(buf);
-               auth_failed(port);
+               status = STATUS_ERROR;
        }
        else
        {
-               int                     status;
                UserAuth        saved;
 
                /* Check the password. */
@@ -395,15 +398,16 @@ recv_and_check_passwordv0(Port *port)
 
                status = checkPassword(port, user, password);
 
-               pfree(buf);
                port->auth_method = saved;
 
                /* Adjust the result if necessary. */
                if (map_old_to_new(port, uaPassword, status) != STATUS_OK)
-                       auth_failed(port);
+                       status = STATUS_ERROR;
        }
 
-       return STATUS_OK;
+       pfree(buf);
+
+       return status;
 }
 
 
@@ -420,10 +424,23 @@ recv_and_check_passwordv0(Port *port)
  * postmaster log, which we hope is only readable by good guys.
  */
 static void
-auth_failed(Port *port)
+auth_failed(Port *port, int status)
 {
        const char *authmethod = "Unknown auth method:";
 
+       /*
+        * If we failed due to EOF from client, just quit; there's no point
+        * in trying to send a message to the client, and not much point in
+        * logging the failure in the postmaster log.  (Logging the failure
+        * might be desirable, were it not for the fact that libpq closes the
+        * connection unceremoniously if challenged for a password when it
+        * hasn't got one to send.  We'll get a useless log entry for
+        * every psql connection under password auth, even if it's perfectly
+        * successful, if we log STATUS_EOF events.)
+        */
+       if (status == STATUS_EOF)
+               proc_exit(0);
+
        switch (port->auth_method)
        {
                case uaReject:
@@ -455,6 +472,7 @@ auth_failed(Port *port)
 
        elog(FATAL, "%s authentication failed for user \"%s\"",
                 authmethod, port->user);
+       /* doesn't return */
 }
 
 
@@ -477,10 +495,11 @@ ClientAuthentication(Port *port)
                elog(FATAL, "Missing or erroneous pg_hba.conf file, see postmaster log for details");
 
        /* Handle old style authentication. */
-       else if (PG_PROTOCOL_MAJOR(port->proto) == 0)
+       if (PG_PROTOCOL_MAJOR(port->proto) == 0)
        {
-               if (old_be_recvauth(port) != STATUS_OK)
-                       auth_failed(port);
+               status = old_be_recvauth(port);
+               if (status != STATUS_OK)
+                       auth_failed(port, status);
                return;
        }
 
@@ -505,9 +524,8 @@ ClientAuthentication(Port *port)
                        elog(FATAL,
                                 "No pg_hba.conf entry for host %s, user %s, database %s",
                                 hostinfo, port->user, port->database);
-                       return;
+                       break;
                }
-               break;
 
                case uaKrb4:
                        sendAuthRequest(port, AUTH_REQ_KRB4);
@@ -533,11 +551,8 @@ ClientAuthentication(Port *port)
                        {
                                int on = 1;
                                if (setsockopt(port->sock, 0, LOCAL_CREDS, &on, sizeof(on)) < 0)
-                               {
                                        elog(FATAL,
                                                 "pg_local_sendauth: can't do setsockopt: %s\n", strerror(errno));
-                                       return;
-                               }
                        }
 #endif
                        if (port->raddr.sa.sa_family == AF_UNIX)
@@ -551,15 +566,16 @@ ClientAuthentication(Port *port)
                        status = recv_and_check_password_packet(port);
                        break;
 
-                case uaCrypt:
-                        sendAuthRequest(port, AUTH_REQ_CRYPT);
-                        status = recv_and_check_password_packet(port);
-                        break;  
+               case uaCrypt:
+                       sendAuthRequest(port, AUTH_REQ_CRYPT);
+                       status = recv_and_check_password_packet(port);
+                       break;  
                                  
-                case uaPassword:
-                        sendAuthRequest(port, AUTH_REQ_PASSWORD);
-                        status = recv_and_check_password_packet(port);
-                        break;
+               case uaPassword:
+                       sendAuthRequest(port, AUTH_REQ_PASSWORD);
+                       status = recv_and_check_password_packet(port);
+                       break;
+
 #ifdef USE_PAM
                case uaPAM:
                        pam_port_cludge = port;
@@ -575,7 +591,7 @@ ClientAuthentication(Port *port)
        if (status == STATUS_OK)
                sendAuthRequest(port, AUTH_REQ_OK);
        else
-               auth_failed(port);
+               auth_failed(port, status);
 }
 
 
@@ -654,7 +670,7 @@ pam_passwd_conv_proc (int num_msg, const struct pam_message **msg, struct pam_re
 
                initStringInfo(&buf);
                pq_getstr(&buf);
-               if (DebugLvl)
+               if (DebugLvl > 5)
                        fprintf(stderr, "received PAM packet with len=%d, pw=%s\n",
                                len, buf.data);
 
@@ -786,10 +802,9 @@ CheckPAMAuth(Port *port, char *user, char *password)
        }
 }
 
-
-
 #endif /* USE_PAM */
 
+
 /*
  * Called when we have received the password packet.
  */
@@ -801,11 +816,16 @@ recv_and_check_password_packet(Port *port)
        int                     result;
 
        if (pq_eof() == EOF || pq_getint(&len, 4) == EOF)
-               return STATUS_ERROR;    /* client didn't want to send password */
+               return STATUS_EOF;              /* client didn't want to send password */
+
        initStringInfo(&buf);
-       pq_getstr(&buf);                /* receive password */
+       if (pq_getstr(&buf) == EOF)     /* receive password */
+       {
+               pfree(buf.data);
+               return STATUS_EOF;
+       }
 
-       if (DebugLvl)
+       if (DebugLvl > 5)                       /* this is probably a BAD idea... */
                fprintf(stderr, "received password packet with len=%d, pw=%s\n",
                                len, buf.data);
 
@@ -861,7 +881,7 @@ old_be_recvauth(Port *port)
                default:
                        fprintf(stderr, "Invalid startup message type: %u\n", msgtype);
 
-                       return STATUS_OK;
+                       return STATUS_ERROR;
        }
 
        return status;
@@ -914,4 +934,3 @@ map_old_to_new(Port *port, UserAuth old, int status)
 
        return status;
 }
-