intercept: Add initial test fixes for open source drivers on snapd

This will forcibly perform redirects for "missing" DRI libraries to
help open source drivers actually work. This is as yet untested.

Signed-off-by: Ikey Doherty <ikey@solus-project.com>

src/intercept/intercept.h

@@ -13,6 +13,19 @@
 
 #include <stdbool.h>
 
+/**
+ * Attempt to handle snapd specific DRI path replacements to ensure that
+ * we can always load DRI modules for open source drivers.
+ *
+ * @note This must be run for all processes
+ *
+ * @param name The original search name
+ * @param soname Pointer to store the final soname in
+ *
+ * @returns True if we performed any redirection, to stop further processing.
+ */
+bool lsi_override_snapd_dri(const char *name, const char **soname);
+
 /**
  * Attempt to handle snapd specific paths and perform any necessary redirections
  * for the solus-runtime-gaming based LSI snap package.

src/intercept/main.c

@@ -605,6 +605,9 @@ _nica_public_ char *la_objsearch(const char *name, __lsi_unused__ uintptr_t *coo
         if (lsi_override_snapd_nvidia(name, &out_name)) {
                 return (char *)out_name;
         }
+        if (lsi_override_snapd_dri(name, &out_name)) {
+                return (char *)out_name;
+        }
 #endif
         switch (work_mode) {
         case INTERCEPT_MODE_STEAM:

src/intercept/snapd.c

@@ -153,6 +153,60 @@ bool lsi_override_snapd_nvidia(const char *name, const char **soname)
         return true;
 }
 
+bool lsi_override_snapd_dri(const char *name, const char **soname)
+{
+        const char *lib_dir = NULL;
+        static char path_lookup[PATH_MAX];
+        static char path_copy[PATH_MAX];
+        char *small_name = NULL;
+
+        /* Only mangle when we start looking for paths */
+        if (!strstr(name, "/")) {
+                return false;
+        }
+
+        /* Must be a proper dri lookup */
+        if (!strstr(name, "_dri.so") && !strstr(name, "_drv_video.so")) {
+                return false;
+        }
+
+        /* If this guy exists we don't actually care.. */
+        if (lsi_file_exists(name)) {
+                return false;
+        }
+
+#if UINTPTR_MAX == 0xffffffffffffffff
+        /* 64-bit libdir */
+        lib_dir = "/usr/lib/dri";
+#else
+        /* 32-bit libdir */
+        lib_dir = "/usr/lib32/dri";
+#endif
+
+        /* Grab the link name */
+        if (!strcpy(path_copy, name)) {
+                return false;
+        }
+        small_name = basename(path_copy);
+
+        if (snprintf(path_lookup, sizeof(path_lookup), "%s/%s", lib_dir, small_name) < 0) {
+                return false;
+        }
+
+        /* Sod all we can do here */
+        if (!lsi_file_exists(path_lookup)) {
+                lsi_log_error("Missing DRI file: %s (%s)", name, path_lookup);
+                return false;
+        }
+
+        *soname = path_lookup;
+        lsi_log_debug("Enforcing snapd DRI links: \033[31;1m%s\033[0m -> \033[34;1m%s\033[0m",
+                      name,
+                      path_lookup);
+
+        return true;
+}
+
 bool lsi_override_snapd_gl(const char *name, const char **soname)
 {
         for (size_t i = 0; i < ARRAY_SIZE(libgl_source_table); i++) {