Emulate RTLD_DEFAULT and RTLD_SELF w/ shl_findsym() using NULL

and PROG_HANDLE.

diff --git a/compat/dlopen.c b/compat/dlopen.c
index fa7fd71ff4ee0b451754407dfe1cfc5c44f0d931..73c7a9440b657e12b4bab11ba66f4c3c06afcde7 100644 (file)
--- a/compat/dlopen.c
+++ b/compat/dlopen.c
@@ -77,7 +77,13 @@ sudo_dlsym(void *vhandle, const char *symbol)
     shl_t handle = vhandle;
     void *value = NULL;
 
-    (void)shl_findsym(&handle, symbol, TYPE_UNDEFINED, &value);
+    /* RTLD_NEXT is not unsupported with shl_findsym(). */
+    if (vhandle == RTLD_DEFAULT)
+       (void)shl_findsym(NULL, symbol, TYPE_UNDEFINED, &value);
+    else if (vhandle == RTLD_SELF)
+       (void)shl_findsym(PROG_HANDLE, symbol, TYPE_UNDEFINED, &value);
+    else if (vhandle != RTLD_NEXT)
+       (void)shl_findsym(&handle, symbol, TYPE_UNDEFINED, &value);
 
     return value;
 }
@@ -117,9 +123,11 @@ sudo_dlsym(void *handle, const char *symbol)
 {
     struct sudo_preload_table *sym;
 
-    for (sym = sudo_preload_table; sym->name != NULL; sym++) {
-       if (strcmp(symbol, sym->name) == 0)
-           return sym->address;
+    if (symbol != RTLD_NEXT && symbol != RTLD_DEFAULT && symbol != RTLD_SELF) {
+       for (sym = sudo_preload_table; sym->name != NULL; sym++) {
+           if (strcmp(symbol, sym->name) == 0)
+               return sym->address;
+       }
     }
     return NULL;
 }