qga: Add initial FreeBSD support

- Fix device path.
- Fix virtio-serial channel initialization.
- Make the code buildable in FreeBSD.

Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>

meson.build

@@ -75,7 +75,7 @@ have_tools = get_option('tools') \
   .allowed()
 have_ga = get_option('guest_agent') \
   .disable_auto_if(not have_system and not have_tools) \
-  .require(targetos in ['sunos', 'linux', 'windows'],
+  .require(targetos in ['sunos', 'linux', 'windows', 'freebsd'],
            error_message: 'unsupported OS for QEMU guest agent') \
   .allowed()
 have_block = have_system or have_tools

qga/channel-posix.c

@@ -149,6 +149,25 @@ static gboolean ga_channel_open(GAChannel *c, const gchar *path,
             return false;
         }
 #endif
+#ifdef __FreeBSD__
+        /*
+         * In the default state channel sends echo of every command to a
+         * client. The client programm doesn't expect this and raises an
+         * error. Suppress echo by resetting ECHO terminal flag.
+         */
+        struct termios tio;
+        if (tcgetattr(fd, &tio) < 0) {
+            error_setg_errno(errp, errno, "error getting channel termios attrs");
+            close(fd);
+            return false;
+        }
+        tio.c_lflag &= ~ECHO;
+        if (tcsetattr(fd, TCSAFLUSH, &tio) < 0) {
+            error_setg_errno(errp, errno, "error setting channel termios attrs");
+            close(fd);
+            return false;
+        }
+#endif /* __FreeBSD__ */
         ret = ga_channel_client_add(c, fd);
         if (ret) {
             error_setg(errp, "error adding channel to main loop");

qga/commands-posix.c

@@ -51,6 +51,14 @@
 #endif
 #endif
 
+#ifdef __FreeBSD__
+/*
+ * The code under HAVE_GETIFADDRS condition can't be compiled in FreeBSD.
+ * Fix it in one of the following patches.
+ */
+#undef HAVE_GETIFADDRS
+#endif
+
 #ifdef HAVE_GETIFADDRS
 #include <arpa/inet.h>
 #include <sys/socket.h>

qga/main.c

@@ -45,9 +45,13 @@
 #endif
 
 #ifndef _WIN32
+#ifdef __FreeBSD__
+#define QGA_VIRTIO_PATH_DEFAULT "/dev/vtcon/org.qemu.guest_agent.0"
+#else /* __FreeBSD__ */
 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
-#define QGA_STATE_RELATIVE_DIR  "run"
+#endif /* __FreeBSD__ */
 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
+#define QGA_STATE_RELATIVE_DIR  "run"
 #else
 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
 #define QGA_STATE_RELATIVE_DIR  "qemu-ga"