[Qemu-devel] [PATCH] tap: Add optional parameters to up/down script

[Sasha Levin <levinsasha928@gmail.com>]

This allows the user to add custom parameters to the up or down
scripts.

Cc: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
---
 net.c     |    8 ++++++++
 net/tap.c |   37 ++++++++++++++++++++++++++++++-------
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/net.c b/net.c
index d05930c..bb27598 100644
--- a/net.c
+++ b/net.c
@@ -952,10 +952,18 @@ static const struct {
                 .type = QEMU_OPT_STRING,
                 .help = "script to initialize the interface",
             }, {
+                .name = "scriptparams",
+                .type = QEMU_OPT_STRING,
+                .help = "parameters for the initialization script",
+            }, {
                 .name = "downscript",
                 .type = QEMU_OPT_STRING,
                 .help = "script to shut down the interface",
             }, {
+                .name = "downscriptparams",
+                .type = QEMU_OPT_STRING,
+                .help = "parameters for the deinitialization script",
+            }, {
                 .name = "sndbuf",
                 .type = QEMU_OPT_SIZE,
                 .help = "send buffer limit"
diff --git a/net/tap.c b/net/tap.c
index 1f26dc9..5a9141e 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -52,7 +52,7 @@ typedef struct TAPState {
     VLANClientState nc;
     int fd;
     char down_script[1024];
-    char down_script_arg[128];
+    char down_script_arg[1024];
     uint8_t buf[TAP_BUFSIZE];
     unsigned int read_poll : 1;
     unsigned int write_poll : 1;
@@ -392,7 +392,8 @@ static int net_tap_init(QemuOpts *opts, int *vnet_hdr)
 {
     int fd, vnet_hdr_required;
     char ifname[128] = {0,};
-    const char *setup_script;
+    const char *setup_script, *setup_script_params;
+    char setup_script_formatted[1024];
 
     if (qemu_opt_get(opts, "ifname")) {
         pstrcpy(ifname, sizeof(ifname), qemu_opt_get(opts, "ifname"));
@@ -411,10 +412,16 @@ static int net_tap_init(QemuOpts *opts, int *vnet_hdr)
     }
 
     setup_script = qemu_opt_get(opts, "script");
+    setup_script_params = qemu_opt_get(opts, "scriptparams");
+    if (setup_script_params == NULL)
+        setup_script_params = "";
+
+    snprintf(setup_script_formatted, sizeof(setup_script_formatted),
+             "%s %s", ifname, setup_script_params);
     if (setup_script &&
         setup_script[0] != '\0' &&
         strcmp(setup_script, "no") != 0 &&
-        launch_script(setup_script, ifname, fd)) {
+        launch_script(setup_script, setup_script_formatted, fd)) {
         close(fd);
         return -1;
     }
@@ -432,9 +439,12 @@ int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan
     if (qemu_opt_get(opts, "fd")) {
         if (qemu_opt_get(opts, "ifname") ||
             qemu_opt_get(opts, "script") ||
+            qemu_opt_get(opts, "scriptparams") ||
             qemu_opt_get(opts, "downscript") ||
+            qemu_opt_get(opts, "downscriptparams") ||
             qemu_opt_get(opts, "vnet_hdr")) {
-            error_report("ifname=, script=, downscript= and vnet_hdr= is invalid with fd=");
+            error_report("ifname=, script=, downscript=, scriptparams=, "
+                         "downscriptparams= and vnet_hdr= is invalid with fd=");
             return -1;
         }
 
@@ -455,6 +465,14 @@ int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan
             qemu_opt_set(opts, "downscript", DEFAULT_NETWORK_DOWN_SCRIPT);
         }
 
+        if (!qemu_opt_get(opts, "scriptparams")) {
+            qemu_opt_set(opts, "scriptparams", "");
+        }
+
+        if (!qemu_opt_get(opts, "downscriptparams")) {
+            qemu_opt_set(opts, "downscriptparams", "");
+        }
+
         fd = net_tap_init(opts, &vnet_hdr);
         if (fd == -1) {
             return -1;
@@ -475,18 +493,23 @@ int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan
         snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
     } else {
         const char *ifname, *script, *downscript;
+	const char *scriptparams, *downscriptparams;
 
         ifname     = qemu_opt_get(opts, "ifname");
         script     = qemu_opt_get(opts, "script");
         downscript = qemu_opt_get(opts, "downscript");
+        scriptparams = qemu_opt_get(opts, "scriptparams");
+        downscriptparams = qemu_opt_get(opts, "downscriptparams");
 
         snprintf(s->nc.info_str, sizeof(s->nc.info_str),
-                 "ifname=%s,script=%s,downscript=%s",
-                 ifname, script, downscript);
+                 "ifname=%s,script=%s,scriptparams=%s,downscript=%s,"
+                 "downscriptparams=%s", ifname, script, scriptparams,
+                 downscript, downscriptparams);
 
         if (strcmp(downscript, "no") != 0) {
             snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
-            snprintf(s->down_script_arg, sizeof(s->down_script_arg), "%s", ifname);
+            snprintf(s->down_script_arg, sizeof(s->down_script_arg), "%s %s", ifname,
+                     downscriptparams);
         }
     }
 
-- 
1.7.6.1