Simplify handling scripts: parse all these "no" and '\0' once, and
then keep simpler logic for net_tap_open() and net_init_tap_one(): NULL
means no script to run, otherwise run script.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 net/tap.c | 45 +++++++++++++++++++++++++--------------------
 1 file changed, 25 insertions(+), 20 deletions(-)

diff --git a/net/tap.c b/net/tap.c
index e42c7ca044..084ee4f649 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -88,6 +88,21 @@ static void launch_script(const char *setup_script, const char *ifname,
 static void tap_send(void *opaque);
 static void tap_writable(void *opaque);
 
+static char *tap_parse_script(const char *script_arg, const char *default_path)
+{
+    g_autofree char *res = g_strdup(script_arg);
+
+    if (!res) {
+        res = get_relocated_path(default_path);
+    }
+
+    if (res[0] == '\0' || strcmp(res, "no") == 0) {
+        return NULL;
+    }
+
+    return g_steal_pointer(&res);
+}
+
 static void tap_update_fd_handler(TAPState *s)
 {
     qemu_set_fd_handler(s->fd,
@@ -655,9 +670,7 @@ static int net_tap_open(int *vnet_hdr, bool vnet_hdr_required,
         return -1;
     }
 
-    if (setup_script &&
-        setup_script[0] != '\0' &&
-        strcmp(setup_script, "no") != 0) {
+    if (setup_script) {
         launch_script(setup_script, ifname, fd, &err);
         if (err) {
             error_propagate(errp, err);
@@ -693,9 +706,9 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
         qemu_set_info_str(&s->nc, "helper=%s", tap->helper);
     } else {
         qemu_set_info_str(&s->nc, "ifname=%s,script=%s,downscript=%s", ifname,
-                          script, downscript);
+                          script ?: "no", downscript ?: "no");
 
-        if (strcmp(downscript, "no") != 0) {
+        if (downscript) {
             snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
             snprintf(s->down_script_arg, sizeof(s->down_script_arg),
                      "%s", ifname);
@@ -950,10 +963,10 @@ free_fail:
             return -1;
         }
     } else {
-        const char *script = tap->script;
-        const char *downscript = tap->downscript;
-        g_autofree char *default_script = NULL;
-        g_autofree char *default_downscript = NULL;
+        g_autofree char *script =
+            tap_parse_script(tap->script, DEFAULT_NETWORK_SCRIPT);
+        g_autofree char *downscript =
+            tap_parse_script(tap->script, DEFAULT_NETWORK_DOWN_SCRIPT);
         bool vnet_hdr_required = tap->has_vnet_hdr && tap->vnet_hdr;
 
         if (tap->vhostfds) {
@@ -961,14 +974,6 @@ free_fail:
             return -1;
         }
 
-        if (!script) {
-            script = default_script = get_relocated_path(DEFAULT_NETWORK_SCRIPT);
-        }
-        if (!downscript) {
-            downscript = default_downscript =
-                                 get_relocated_path(DEFAULT_NETWORK_DOWN_SCRIPT);
-        }
-
         if (tap->ifname) {
             pstrcpy(ifname, sizeof ifname, tap->ifname);
         } else {
@@ -978,7 +983,7 @@ free_fail:
         for (i = 0; i < queues; i++) {
             vnet_hdr = tap->has_vnet_hdr ? tap->vnet_hdr : 1;
             fd = net_tap_open(&vnet_hdr, vnet_hdr_required,
-                              i >= 1 ? "no" : script,
+                              i >= 1 ? NULL : script,
                               ifname, sizeof ifname, queues > 1, errp);
             if (fd == -1) {
                 return -1;
@@ -993,8 +998,8 @@ free_fail:
             }
 
             net_init_tap_one(tap, peer, "tap", name, ifname,
-                             i >= 1 ? "no" : script,
-                             i >= 1 ? "no" : downscript,
+                             i >= 1 ? NULL : script,
+                             i >= 1 ? NULL : downscript,
                              vhostfdname, vnet_hdr, fd, &err);
             if (err) {
                 error_propagate(errp, err);
-- 
2.48.1

On 23.09.25 13:00, Vladimir Sementsov-Ogievskiy wrote:
> Simplify handling scripts: parse all these "no" and '\0' once, and
> then keep simpler logic for net_tap_open() and net_init_tap_one(): NULL
> means no script to run, otherwise run script.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
>   net/tap.c | 45 +++++++++++++++++++++++++--------------------
>   1 file changed, 25 insertions(+), 20 deletions(-)
> 

[..]

>                        "%s", ifname);
> @@ -950,10 +963,10 @@ free_fail:
>               return -1;
>           }
>       } else {
> -        const char *script = tap->script;
> -        const char *downscript = tap->downscript;
> -        g_autofree char *default_script = NULL;
> -        g_autofree char *default_downscript = NULL;
> +        g_autofree char *script =
> +            tap_parse_script(tap->script, DEFAULT_NETWORK_SCRIPT);
> +        g_autofree char *downscript =
> +            tap_parse_script(tap->script, DEFAULT_NETWORK_DOWN_SCRIPT);

Ohh, tap->downscript of-course

>           bool vnet_hdr_required = tap->has_vnet_hdr && tap->vnet_hdr;
>   
>           if (tap->vhostfds) {
> @@ -961,14 +974,6 @@ free_fail:
>               return -1;
>           }
>   
-- 
Best regards,
Vladimir