[PATCH v3 4/4] net: convert to use qemu_find_file to locate bridge helper

["Daniel P. Berrangé" <berrange@redhat.com>]

The TAP device code currently uses get_relocate_path to find the bridge
helper, however, this fails when run from the build dir. Adding support
to qemu_find_file for helper binaries, allows it to work from both the
(relocated) install tree and build dir.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 include/net/net.h      | 3 ++-
 include/qemu/datadir.h | 1 +
 net/tap.c              | 5 ++++-
 qemu-options.hx        | 4 ++--
 softmmu/datadir.c      | 9 +++++++++
 softmmu/trace-events   | 2 +-
 6 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/include/net/net.h b/include/net/net.h
index 523136c7ac..6a853512ac 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -228,7 +228,8 @@ NetClientState *net_hub_port_find(int hub_id);
 
 #define DEFAULT_NETWORK_SCRIPT CONFIG_SYSCONFDIR "/qemu-ifup"
 #define DEFAULT_NETWORK_DOWN_SCRIPT CONFIG_SYSCONFDIR "/qemu-ifdown"
-#define DEFAULT_BRIDGE_HELPER CONFIG_QEMU_HELPERDIR "/qemu-bridge-helper"
+#define DEFAULT_BRIDGE_HELPER "qemu-bridge-helper"
+#define DEFAULT_BRIDGE_HELPER_PATH CONFIG_QEMU_HELPERDIR "/qemu-bridge-helper"
 #define DEFAULT_BRIDGE_INTERFACE "br0"
 
 void qdev_set_nic_properties(DeviceState *dev, NICInfo *nd);
diff --git a/include/qemu/datadir.h b/include/qemu/datadir.h
index 427e90787a..a211b6b235 100644
--- a/include/qemu/datadir.h
+++ b/include/qemu/datadir.h
@@ -4,6 +4,7 @@
 #define QEMU_FILE_TYPE_BIOS   0
 #define QEMU_FILE_TYPE_KEYMAP 1
 #define QEMU_FILE_TYPE_ICON   2
+#define QEMU_FILE_TYPE_HELPER 3
 
 /**
  * qemu_find_file:
diff --git a/net/tap.c b/net/tap.c
index b3ddfd4a74..161608e34a 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -42,6 +42,7 @@
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "qemu/sockets.h"
+#include "qemu/datadir.h"
 
 #include "net/tap.h"
 
@@ -507,9 +508,11 @@ static int net_bridge_run_helper(const char *helper, const char *bridge,
     sigprocmask(SIG_BLOCK, &mask, &oldmask);
 
     if (!helper) {
-        helper = default_helper = get_relocated_path(DEFAULT_BRIDGE_HELPER);
+        helper = default_helper = qemu_find_file(QEMU_FILE_TYPE_HELPER,
+                                                 DEFAULT_BRIDGE_HELPER);
     }
 
+    g_printerr("Helper %s\n", helper);
     if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
         error_setg_errno(errp, errno, "socketpair() failed");
         return -1;
diff --git a/qemu-options.hx b/qemu-options.hx
index 377d22fbd8..b5b7e75048 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2665,7 +2665,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
     "                to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
     "                to deconfigure it\n"
     "                use '[down]script=no' to disable script execution\n"
-    "                use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
+    "                use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER_PATH ") to\n"
     "                configure it\n"
     "                use 'fd=h' to connect to an already opened TAP interface\n"
     "                use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
@@ -2684,7 +2684,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
     "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
     "                configure a host TAP network backend with ID 'str' that is\n"
     "                connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
-    "                using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
+    "                using the program 'helper (default=" DEFAULT_BRIDGE_HELPER_PATH ")\n"
 #endif
 #ifdef __linux__
     "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
diff --git a/softmmu/datadir.c b/softmmu/datadir.c
index e5d1fd0116..a68fe7167a 100644
--- a/softmmu/datadir.c
+++ b/softmmu/datadir.c
@@ -36,6 +36,7 @@ static char **extra_firmware_dirs;
 /* Default built-in directories */
 static char *default_data_dir;
 static char *default_icon_dir;
+static char *default_helper_dir;
 
 /* Whether we're known to be executing from a build tree */
 static bool in_build_dir;
@@ -73,6 +74,12 @@ char *qemu_find_file(int type, const char *name)
         default_install_dir = default_icon_dir;
         break;
 
+    case QEMU_FILE_TYPE_HELPER:
+        rel_install_dir = "";
+        rel_build_dir = "";
+        default_install_dir = default_helper_dir;
+        break;
+
     default:
         abort();
     }
@@ -140,9 +147,11 @@ void qemu_add_default_firmwarepath(void)
     /* Add default dirs relative to the executable path */
     default_data_dir = get_relocated_path(CONFIG_QEMU_DATADIR);
     default_icon_dir = get_relocated_path(CONFIG_QEMU_ICONDIR);
+    default_helper_dir = get_relocated_path(CONFIG_QEMU_HELPERDIR);
 
     trace_datadir_init(default_data_dir,
                        default_icon_dir,
+                       default_helper_dir,
                        in_build_dir);
 }
 
diff --git a/softmmu/trace-events b/softmmu/trace-events
index 9c00e9f389..b22d7e7714 100644
--- a/softmmu/trace-events
+++ b/softmmu/trace-events
@@ -6,7 +6,7 @@ balloon_event(void *opaque, unsigned long addr) "opaque %p addr %lu"
 
 # datadir.c
 datadir_load_file(const char *name, const char *path, int err) "name %s location %s errno %d"
-datadir_init(const char *defdatadir, const char *deficondir, bool inbuilddir) "default data dir %s icon dir %s in build dir %d"
+datadir_init(const char *defdatadir, const char *deficondir, const char *defhelperdir, bool inbuilddir) "default data dir %s icon dir %s helper dir %s in build dir %d"
 
 # ioport.c
 cpu_in(unsigned int addr, char size, unsigned int val) "addr 0x%x(%c) value %u"
-- 
2.36.1