MXS-955: Put back proper .maxadmin handling

Now MaxScale again supports having 'hostname', 'user', 'port' and 'passwd'
in the .maxadmin file in addition to 'socket'.

Author: jhnwkmn

Documentation/Reference/MaxAdmin.md

@@ -287,13 +287,22 @@ Then simply set this file to have execute permissions and it may be run like any
 
 ## The .maxadmin file
 
-MaxAdmin supports a mechanism to set defaults for all the command line switches via a file in the home directory of the user. If a file named .maxadmin exists it will be read and parameters set according to the lies in this files. The parameter that can be set is: socket. An example of a .maxadmin file that will alter the default password and user name arguments would be
+MaxAdmin supports a mechanism to set defaults for the command line switches via a file in the home directory of the user. If a file named `.maxadmin` exists, it will be read and parameters set according to the entries in that file.
+
+This mechanism can be used to provide defaults to the command line options. If a command line option is provided, it will still override the value in the `.maxadmin` file.
+
+The parameters than can be set are:
+   * `1.4`: _hostname_, _port_, _user_ and _passwd_
+   * `2.0.0` and `2.0.1`: _socket_
+   * `2.0.2` onwards: _socket_, _hostname_, _port_, _user_ and _passwd_ (and as synonym _password_)
+
+An example of a `.maxadmin` file that will alter the default socket path is:
 
     socket=/somepath/maxadmin.socket
 
-This mechanism can be used to provide a means of passwords entry into maxadmin or to override any of the command line option defaults. If a command line option is given that will still override the value in the .maxadmin file.
+Note that if in `2.0.2` or later, a value for _socket_ as well as any of the internet socket related options, such as _hostname_, is provided in `.maxadmin`, then _socket_ takes precedense. In that case, provide at least one internet socket related option on the command line to force MaxAdmin to use an internet socket and thus the internet socket related options from `.maxadmin`.
 
-The .maxadmin file may  be made read only to protect any passwords written to that file.
+The `.maxadmin` file may  be made read only to protect any passwords written to that file.
 
 <a name="help"></a>
 # Getting Help

client/maxadmin.c

@@ -75,7 +75,9 @@ static void DoSource(int so, char *cmd);
 static void DoUsage(const char*);
 static int isquit(char *buf);
 static void PrintVersion(const char *progname);
-static void read_inifile(char **, int*);
+static void read_inifile(char **socket,
+                         char **hostname, char **port, char **user, char **passwd,
+                         int *editor);
 static bool getPassword(char *password, size_t length);
 
 #ifdef HISTORY
@@ -116,10 +118,6 @@ static struct option long_options[] =
 int
 main(int argc, char **argv)
 {
-    const char* vi = "vi";
-    const char* emacs = "emacs";
-
-    int i, num, rv;
 #ifdef HISTORY
     char *buf;
     EditLine *el = NULL;
@@ -133,39 +131,45 @@ main(int argc, char **argv)
     char *port = NULL;
     char *user = NULL;
     char *passwd = NULL;
-    char *conn_socket = NULL;
-    char *default_socket = MAXADMIN_DEFAULT_SOCKET;
+    char *socket_path = NULL;
     int use_emacs = 0;
-    int so;
-    int option_index = 0;
-    char c;
 
-    read_inifile(&conn_socket, &use_emacs);
+    read_inifile(&socket_path, &hostname, &port, &user, &passwd, &use_emacs);
+
+    bool use_inet_socket = false;
+    bool use_unix_socket = false;
 
+    int option_index = 0;
+    char c;
     while ((c = getopt_long(argc, argv, "h:p:P:u:S:v?e",
                             long_options, &option_index)) >= 0)
     {
         switch (c)
         {
             case 'h':
+                use_inet_socket = true;
                 hostname = strdup(optarg);
                 break;
 
             case 'p':
+                use_inet_socket = true;
                 passwd = strdup(optarg);
                 memset(optarg, '\0', strlen(optarg));
                 break;
 
             case 'P':
+                use_inet_socket = true;
                 port = strdup(optarg);
                 break;
 
             case 'u':
+                use_inet_socket = true;
                 user = strdup(optarg);
                 break;
 
             case 'S':
-                conn_socket = strdup(optarg);
+                use_unix_socket = true;
+                socket_path = strdup(optarg);
                 break;
 
             case 'v':
@@ -182,16 +186,20 @@ main(int argc, char **argv)
         }
     }
 
-    if ((hostname || port || user || passwd) && (conn_socket))
+    if (use_inet_socket && use_unix_socket)
     {
-        // Either socket or any parameters related to hostname/port.
+        // Both unix socket path and at least of the internet socket
+        // options have been provided.
         DoUsage(argv[0]);
         exit(EXIT_FAILURE);
     }
 
-    if (hostname || port || user || passwd)
+    if (use_inet_socket || (!socket_path && (hostname || port || user || passwd)))
     {
-        assert(!conn_socket);
+        // If any of the internet socket options have explicitly been provided, or
+        // .maxadmin does not contain "socket" but does contain at least one of
+        // the internet socket options, we use an internet socket. Note that if
+        // -S is provided, then socket_path will be non-NULL.
 
         if (!hostname)
         {
@@ -210,23 +218,29 @@ main(int argc, char **argv)
     }
     else
     {
-        if (!conn_socket)
+        use_unix_socket = true;
+
+        if (!socket_path)
         {
-            conn_socket = MAXADMIN_DEFAULT_SOCKET;
+            socket_path = MAXADMIN_DEFAULT_SOCKET;
         }
     }
 
-    assert(!((hostname || port) && conn_socket));
+    int so;
 
-    if (conn_socket)
+    if (use_unix_socket)
     {
-        if ((so = connectUsingUnixSocket(conn_socket)) == -1)
+        assert(socket_path);
+
+        if ((so = connectUsingUnixSocket(socket_path)) == -1)
         {
             exit(EXIT_FAILURE);
         }
     }
     else
     {
+        assert(hostname && user && port);
+
         char password[MAX_PASSWORD_LEN];
 
         if (passwd == NULL)
@@ -301,11 +315,11 @@ main(int argc, char **argv)
 
     if (use_emacs)
     {
-        el_set(el, EL_EDITOR, emacs); /** Editor is emacs */
+        el_set(el, EL_EDITOR, "emacs"); /** Editor is emacs */
     }
     else
     {
-        el_set(el, EL_EDITOR, vi); /* Default editor is vi      */
+        el_set(el, EL_EDITOR, "vi"); /* Default editor is vi      */
     }
     el_set(el, EL_SIGNAL, 1); /* Handle signals gracefully  */
     el_set(el, EL_PROMPT, prompt); /* Set the prompt function */
@@ -325,6 +339,7 @@ main(int argc, char **argv)
      */
     el_source(el, NULL);
 
+    int num;
     while ((buf = (char *) el_gets(el, &num)) != NULL && num != 0)
     {
 #else
@@ -333,7 +348,7 @@ main(int argc, char **argv)
         num = strlen(buf);
 #endif
         /* Strip trailing \n\r */
-        for (i = num - 1; buf[i] == '\r' || buf[i] == '\n'; i--)
+        for (int i = num - 1; buf[i] == '\r' || buf[i] == '\n'; i--)
         {
             buf[i] = 0;
         }
@@ -350,6 +365,7 @@ main(int argc, char **argv)
         else if (!strcasecmp(buf, "history"))
         {
 #ifdef HISTORY
+            int rv;
             for (rv = history(hist, &ev, H_LAST); rv != -1;
                  rv = history(hist, &ev, H_PREV))
             {
@@ -394,11 +410,11 @@ main(int argc, char **argv)
 /**
  * Connect to the MaxScale server
  *
- * @param conn_socket The UNIX socket to connect to
+ * @param socket_path The UNIX socket to connect to
  * @return       The connected socket or -1 on error
  */
 static int
-connectUsingUnixSocket(const char *conn_socket)
+connectUsingUnixSocket(const char *socket_path)
 {
     int so = -1;
 
@@ -408,7 +424,7 @@ connectUsingUnixSocket(const char *conn_socket)
 
         memset(&local_addr, 0, sizeof local_addr);
         local_addr.sun_family = AF_UNIX;
-        strncpy(local_addr.sun_path, conn_socket, sizeof(local_addr.sun_path) - 1);
+        strncpy(local_addr.sun_path, socket_path, sizeof(local_addr.sun_path) - 1);
 
         if (connect(so, (struct sockaddr *) &local_addr, sizeof(local_addr)) == 0)
         {
@@ -441,7 +457,7 @@ connectUsingUnixSocket(const char *conn_socket)
         {
             char errbuf[STRERROR_BUFLEN];
             fprintf(stderr, "Unable to connect to MaxScale at %s: %s\n",
-                    conn_socket, strerror_r(errno, errbuf, sizeof(errbuf)));
+                    socket_path, strerror_r(errno, errbuf, sizeof(errbuf)));
             close(so);
             so = -1;
         }
@@ -853,13 +869,16 @@ rtrim(char *str)
  * Read defaults for hostname, port, user and password from
  * the .maxadmin file in the users home directory.
  *
- * @param hostname  Pointer the hostname to be updated
+ * @param socket    Pointer to the socket to be updated.
+ * @param hostname  Pointer to the hostname to be updated
  * @param port      Pointer to the port to be updated
  * @param user      Pointer to the user to be updated
  * @param passwd    Pointer to the password to be updated
  */
 static void
-read_inifile(char **conn_socket, int* editor)
+read_inifile(char **socket,
+             char **hostname, char** port, char **user, char **passwd,
+             int* editor)
 {
     char pathname[400];
     char *home, *brkt;
@@ -893,11 +912,26 @@ read_inifile(char **conn_socket, int* editor)
         {
             if (strcmp(name, "socket") == 0)
             {
-                *conn_socket = strdup(value);
+                *socket = strdup(value);
+            }
+            else if (strcmp(name, "hostname") == 0)
+            {
+                *hostname = strdup(value);
+            }
+            else if (strcmp(name, "port") == 0)
+            {
+                *port = strdup(value);
+            }
+            else if (strcmp(name, "user") == 0)
+            {
+                *user = strdup(value);
+            }
+            else if ((strcmp(name, "passwd") == 0) || (strcmp(name, "password") == 0))
+            {
+                *passwd = strdup(value);
             }
             else if (strcmp(name, "editor") == 0)
             {
-
                 if (strcmp(value, "vi") == 0)
                 {
                     *editor = 0;