include: move qemu_*_exec_dir() to cutils

The function is required by get_relocated_path() (already in cutils),
and used by qemu-ga and may be generally useful.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220525144140.591926-2-marcandre.lureau@redhat.com>

1 files changed, 117 insertions, 0 deletions

diff --git a/util/cutils.c b/util/cutils.c
index b277721..a58bcfd 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -26,6 +26,15 @@
 #include "qemu/host-utils.h"
 #include <math.h>
 
+#ifdef __FreeBSD__
+#include <sys/sysctl.h>
+#include <sys/user.h>
+#endif
+
+#ifdef __NetBSD__
+#include <sys/sysctl.h>
+#endif
+
 #include "qemu/ctype.h"
 #include "qemu/cutils.h"
 #include "qemu/error-report.h"
@@ -931,6 +940,114 @@ static inline const char *next_component(const char *dir, int *p_len)
     return dir;
 }
 
+static const char *exec_dir;
+
+void qemu_init_exec_dir(const char *argv0)
+{
+#ifdef G_OS_WIN32
+    char *p;
+    char buf[MAX_PATH];
+    DWORD len;
+
+    if (exec_dir) {
+        return;
+    }
+
+    len = GetModuleFileName(NULL, buf, sizeof(buf) - 1);
+    if (len == 0) {
+        return;
+    }
+
+    buf[len] = 0;
+    p = buf + len - 1;
+    while (p != buf && *p != '\\') {
+        p--;
+    }
+    *p = 0;
+    if (access(buf, R_OK) == 0) {
+        exec_dir = g_strdup(buf);
+    } else {
+        exec_dir = CONFIG_BINDIR;
+    }
+#else
+    char *p = NULL;
+    char buf[PATH_MAX];
+
+    if (exec_dir) {
+        return;
+    }
+
+#if defined(__linux__)
+    {
+        int len;
+        len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
+        if (len > 0) {
+            buf[len] = 0;
+            p = buf;
+        }
+    }
+#elif defined(__FreeBSD__) \
+      || (defined(__NetBSD__) && defined(KERN_PROC_PATHNAME))
+    {
+#if defined(__FreeBSD__)
+        static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
+#else
+        static int mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
+#endif
+        size_t len = sizeof(buf) - 1;
+
+        *buf = '\0';
+        if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
+            *buf) {
+            buf[sizeof(buf) - 1] = '\0';
+            p = buf;
+        }
+    }
+#elif defined(__APPLE__)
+    {
+        char fpath[PATH_MAX];
+        uint32_t len = sizeof(fpath);
+        if (_NSGetExecutablePath(fpath, &len) == 0) {
+            p = realpath(fpath, buf);
+            if (!p) {
+                return;
+            }
+        }
+    }
+#elif defined(__HAIKU__)
+    {
+        image_info ii;
+        int32_t c = 0;
+
+        *buf = '\0';
+        while (get_next_image_info(0, &c, &ii) == B_OK) {
+            if (ii.type == B_APP_IMAGE) {
+                strncpy(buf, ii.name, sizeof(buf));
+                buf[sizeof(buf) - 1] = 0;
+                p = buf;
+                break;
+            }
+        }
+    }
+#endif
+    /* If we don't have any way of figuring out the actual executable
+       location then try argv[0].  */
+    if (!p && argv0) {
+        p = realpath(argv0, buf);
+    }
+    if (p) {
+        exec_dir = g_path_get_dirname(p);
+    } else {
+        exec_dir = CONFIG_BINDIR;
+    }
+#endif
+}
+
+const char *qemu_get_exec_dir(void)
+{
+    return exec_dir;
+}
+
 char *get_relocated_path(const char *dir)
 {
     size_t prefix_len = strlen(CONFIG_PREFIX);