Pass all parameters to -net tap,... as env vars to if script

qemu_ifup and qemu_ifdown now get in environment variables the values
of all of the settings specified on the command line.  Each parameter
<foo> actually specified appears in an environment variable
QEMU_IF_<foo>.  (NB this variable typically has some lowercase
letters.)

Currently only parameters actually specified appear in the
environment; settings which take their default values are not provided
to the scripts.

diff --git a/vl.c b/vl.c
index f740ac3d047cd3a9719465a9344e536605375b09..33aa28b8b6cd84906292f0d3f377e724f94722f0 100644 (file)
--- a/vl.c
+++ b/vl.c
@@ -4016,7 +4016,7 @@ typedef struct TAPState {
     VLANClientState *vc;
     int fd;
     char down_script[1024];
-    char script_arg[1024];
+    char net_args[2048];
 } TAPState;
 
 static void tap_receive(void *opaque, const uint8_t *buf, int size)
@@ -4261,12 +4261,19 @@ static int tap_open(char *ifname, int ifname_size)
 }
 #endif
 
+static const char *get_opt_name(char *buf, int buf_size, const char *p);
+static const char *get_opt_value(char *buf, int buf_size, const char *p);
+
 static int launch_script(const char *setup_script, const char *ifname,
-                        const char *script_arg, int fd)
+                        const char *net_args, int fd)
 {
-    int pid, status;
-    char *args[4];
+    static const char option_env_prefix[] = "QEMU_IF_";
+#define OPTION_ENV_PREFIX_LEN (sizeof(option_env_prefix)-1)
+    int pid, status, ret;
+    char *args[3];
     char **parg;
+    const char *p;
+    char envvar[128 + OPTION_ENV_PREFIX_LEN], value[1024];
 
         /* try to launch network script */
         pid = fork();
@@ -4280,11 +4287,29 @@ static int launch_script(const char *setup_script, const char *ifname,
                         i != fd)
                         close(i);
 
+                p = net_args;
+                memcpy(envvar, option_env_prefix, OPTION_ENV_PREFIX_LEN);
+                for (;;) {
+                    p = get_opt_name(envvar + OPTION_ENV_PREFIX_LEN,
+                                    sizeof(envvar) - OPTION_ENV_PREFIX_LEN,
+                                    p);
+                    if (*p != '=')
+                        break;
+                    p++;
+                    p = get_opt_value(value, sizeof(value), p);
+                    ret = setenv(envvar, value, 1);
+                    if (ret != 0) {
+                        perror("cannot set option env var");
+                        _exit(-1);
+                    }
+                    if (*p != ',')
+                        break;
+                    p++;
+                }
+
                 parg = args;
                 *parg++ = (char *)setup_script;
                 *parg++ = (char *)ifname;
-                if (script_arg && script_arg[0])
-                    *parg++ = (char *)script_arg;
                 *parg++ = NULL;
                 execv(setup_script, args);
                 _exit(1);
@@ -4302,7 +4327,7 @@ static int launch_script(const char *setup_script, const char *ifname,
 
 static int net_tap_init(VLANState *vlan, const char *ifname1,
                         const char *setup_script, const char *down_script,
-                        const char *script_arg)
+                        const char *net_args)
 {
     TAPState *s;
     int fd;
@@ -4321,7 +4346,7 @@ static int net_tap_init(VLANState *vlan, const char *ifname1,
     if (!setup_script || !strcmp(setup_script, "no"))
         setup_script = "";
     if (setup_script[0] != '\0') {
-       if (launch_script(setup_script, ifname, script_arg, fd))
+       if (launch_script(setup_script, ifname, net_args, fd))
            return -1;
     }
     s = net_tap_fd_init(vlan, fd);
@@ -4331,8 +4356,7 @@ static int net_tap_init(VLANState *vlan, const char *ifname1,
              "tap: ifname=%s setup_script=%s", ifname, setup_script);
     if (down_script && strcmp(down_script, "no"))
         snprintf(s->down_script, sizeof(s->down_script), "%s", down_script);
-    if (script_arg && script_arg[0])
-        snprintf(s->script_arg, sizeof(s->script_arg), "%s", script_arg);
+    snprintf(s->net_args, sizeof(s->net_args), "%s", net_args);
     return 0;
 }
 
@@ -4925,7 +4949,7 @@ static int net_client_init(const char *str)
 #else
     if (!strcmp(device, "tap")) {
         char ifname[64];
-        char setup_script[1024], down_script[1024], script_arg[1024];
+        char setup_script[1024], down_script[1024];
         int fd;
 
        memset(ifname, 0, sizeof(ifname));
@@ -4948,10 +4972,7 @@ static int net_client_init(const char *str)
             if (get_param_value(down_script, sizeof(down_script), "downscript", p) == 0) {
                 pstrcpy(down_script, sizeof(down_script), DEFAULT_NETWORK_DOWN_SCRIPT);
             }
-            if (get_param_value(script_arg, sizeof(script_arg), "scriptarg", p) == 0) {
-                pstrcpy(script_arg, sizeof(script_arg), "");
-            }
-            ret = net_tap_init(vlan, ifname, setup_script, down_script, script_arg);
+            ret = net_tap_init(vlan, ifname, setup_script, down_script, p);
         }
     } else
 #endif
@@ -7290,12 +7311,12 @@ static void help(int exitcode)
            "-net tap[,vlan=n],ifname=name\n"
            "                connect the host TAP network interface to VLAN 'n'\n"
 #else
-           "-net tap[,vlan=n][,fd=h][,ifname=name][,script=file][,downscript=dfile][,scriptarg=extraargument]\n"
+           "-net tap[,vlan=n][,fd=h][,ifname=name][,script=file][,downscript=dfile]\n"
            "                connect the host TAP network interface to VLAN 'n' and use the\n"
            "                network scripts 'file' (default=%s)\n"
            "                and 'dfile' (default=%s);\n"
            "                use '[down]script=no' to disable script execution;\n"
-           "                use 'scriptarg=...' to pass an additional (nonempty) argument;\n"
+           "                script will have QEMU_IF_vlan=... and so on in its environment;\ n"
            "                use 'fd=h' to connect to an already opened TAP interface\n"
 #endif
            "-net socket[,vlan=n][,fd=h][,listen=[host]:port][,connect=host:port]\n"
@@ -8817,7 +8838,7 @@ int main(int argc, char **argv)
 
                 if (sscanf(vc->info_str, "tap: ifname=%63s ", ifname) == 1 &&
                     s->down_script[0])
-                    launch_script(s->down_script, ifname, s->script_arg, s->fd);
+                    launch_script(s->down_script, ifname, s->net_args, s->fd);
             }
         }
     }