slirp: Rework monitor commands for host forwarding

Improve the monitor interface for adding and removing host forwarding
rules by splitting it up in two commands and rename them to hostfwd_add
and hostfwd_remove. Also split up the paths taken for legacy -redir
support and the monitor add command as the latter will be extended later
on.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

net.c

@@ -871,7 +871,7 @@ static int net_slirp_init(Monitor *mon, VLANState *vlan, const char *model,
     return 0;
 }
 
-static void net_slirp_hostfwd_remove(Monitor *mon, const char *port_str)
+void net_slirp_hostfwd_remove(Monitor *mon, const char *port_str)
 {
     int host_port;
     char buf[256] = "";
@@ -879,8 +879,10 @@ static void net_slirp_hostfwd_remove(Monitor *mon, const char *port_str)
     int is_udp = 0;
     int n;
 
-    if (!mon)
+    if (!slirp_inited) {
+        monitor_printf(mon, "user mode network stack not in use\n");
         return;
+    }
 
     if (!port_str || !port_str[0])
         goto fail_syntax;
@@ -958,31 +960,32 @@ static void slirp_hostfwd(Monitor *mon, const char *redir_str)
     config_error(mon, "invalid host forwarding rule '%s'\n", redir_str);
 }
 
-void net_slirp_redir(Monitor *mon, const char *redir_str, const char *redir_opt2)
+void net_slirp_hostfwd_add(Monitor *mon, const char *redir_str)
 {
-    struct slirp_config_str *config;
-
     if (!slirp_inited) {
-        if (mon) {
+        monitor_printf(mon, "user mode network stack not in use\n");
-            monitor_printf(mon, "user mode network stack not in use\n");
-        } else {
-            config = qemu_malloc(sizeof(*config));
-            pstrcpy(config->str, sizeof(config->str), redir_str);
-            config->flags = SLIRP_CFG_HOSTFWD;
-            config->next = slirp_configs;
-            slirp_configs = config;
-        }
-        return;
-    }
-
-    if (!strcmp(redir_str, "remove")) {
-        net_slirp_hostfwd_remove(mon, redir_opt2);
         return;
     }
 
     slirp_hostfwd(mon, redir_str);
 }
 
+void net_slirp_redir(const char *redir_str)
+{
+    struct slirp_config_str *config;
+
+    if (!slirp_inited) {
+        config = qemu_malloc(sizeof(*config));
+        pstrcpy(config->str, sizeof(config->str), redir_str);
+        config->flags = SLIRP_CFG_HOSTFWD;
+        config->next = slirp_configs;
+        slirp_configs = config;
+        return;
+    }
+
+    slirp_hostfwd(NULL, redir_str);
+}
+
 #ifndef _WIN32
 
 static char smb_dir[1024];

net.h

@@ -132,7 +132,9 @@ int net_client_init(Monitor *mon, const char *device, const char *p);
 void net_client_uninit(NICInfo *nd);
 int net_client_parse(const char *str);
 void net_slirp_smb(const char *exported_dir);
-void net_slirp_redir(Monitor *mon, const char *redir_str, const char *redir_opt2);
+void net_slirp_hostfwd_add(Monitor *mon, const char *redir_str);
+void net_slirp_hostfwd_remove(Monitor *mon, const char *port_str);
+void net_slirp_redir(const char *redir_str);
 void net_cleanup(void);
 int slirp_is_inited(void);
 void net_client_check(void);

qemu-monitor.hx

@@ -536,9 +536,11 @@ Remove host VLAN client.
 ETEXI
 
 #ifdef CONFIG_SLIRP
-    { "host_net_redir", "ss?", net_slirp_redir,
+    { "hostfwd_add", "s", net_slirp_hostfwd_add,
-      "[tcp|udp]:host-port:[guest-host]:guest-port", "redirect TCP or UDP connections from host to guest (requires -net user)\n"
+      "[tcp|udp]:hostport:[guestaddr]:guestport",
-      "host_net_redir remove [tcp:|udp:]host-port -- remove redirection" },
+      "redirect TCP or UDP connections from host to guest (requires -net user)" },
+    { "hostfwd_remove", "s", net_slirp_hostfwd_remove,
+      "[tcp|udp]:hostport", "remove host-to-guest TCP or UDP redirection" },
 #endif
 STEXI
 @item host_net_redir

vl.c

@@ -5319,7 +5319,7 @@ int main(int argc, char **argv, char **envp)
                 break;
 #endif
             case QEMU_OPTION_redir:
-                net_slirp_redir(NULL, optarg, NULL);
+                net_slirp_redir(optarg);
                 break;
 #endif
             case QEMU_OPTION_bt: