Apply multiarch rules when loading plugins too.

lib/util/multiarch.c

@@ -0,0 +1,103 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2022 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#ifdef __linux__
+# include <sys/utsname.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "sudo_compat.h"
+#include "sudo_util.h"
+
+# if defined(__linux__)
+/* 
+ * On Linux systems that use muti-arch, the actual DSO may be in a
+ * machine-specific subdirectory.  If the specified path contains
+ * /lib/ or /libexec/, insert a multi-arch directory after it.
+ * If sb is non-NULL, stat(2) will be called on the new path, filling in sb.
+ * Returns a dynamically allocated string on success and NULL on failure.
+ */
+char *
+sudo_stat_multiarch_v1(const char *path, struct stat *sb)
+{
+#  if defined(__ILP32__)
+    const char *libdirs[] = { "/libx32/", "/lib/", "/libexec/", NULL };
+#  elif defined(__LP64__)
+    const char *libdirs[] = { "/lib64/", "/lib/", "/libexec/", NULL };
+#  else
+    const char *libdirs[] = { "/lib32/", "/lib/", "/libexec/", NULL };
+#  endif
+    const char **lp, *lib, *slash;
+    struct utsname unamebuf;
+    char *newpath = NULL;
+    int len;
+
+    if (uname(&unamebuf) == -1)
+	return NULL;
+
+    for (lp = libdirs; *lp != NULL; lp++) {
+	/* Replace lib64, lib32, libx32 with lib in new path. */
+	const char *newlib = lp == libdirs ? "/lib/" : *lp;
+
+	/* Search for lib dir in path, find the trailing slash. */
+	lib = strstr(path, *lp);
+	if (lib == NULL)
+	    continue;
+	slash = lib + strlen(*lp) - 1;
+
+	/* Make sure there isn't already a machine-linux-gnu dir. */
+	len = strcspn(slash + 1, "/-");
+	if (strncmp(slash + 1 + len, "-linux-gnu/", 11) == 0) {
+	    /* Multiarch already present. */
+	    break;
+	}
+
+	/* Add machine-linux-gnu dir after /lib/ or /libexec/. */
+	len = asprintf(&newpath, "%.*s%s%s-linux-gnu%s",
+	    (int)(lib - path), path, newlib, unamebuf.machine, slash);
+	if (len == -1) {
+	    newpath = NULL;
+	    break;
+	}
+
+	/* If sb was set, use stat(2) to make sure newpath exists. */
+	if (sb == NULL || stat(newpath, sb) == 0)
+	    break;
+	free(newpath);
+	newpath = NULL;
+    }
+
+    return newpath;
+}
+#else
+char *
+sudo_stat_multiarch_v1(const char *path, struct stat *sb)
+{
+    return NULL;
+}
+#endif /* __linux__ */