Merge pull request #17884 from poettering/test-dlopen

tests: add test that dlopen()s our weak shared library deps once

meson.build

@@ -1117,6 +1117,7 @@ conf.set10('HAVE_LIBIPTC', have)
 want_qrencode = get_option('qrencode')
 if want_qrencode != 'false' and not skip_deps
         libqrencode = dependency('libqrencode',
+                                 version : '>= 4',
                                  required : want_qrencode == 'true')
         have = libqrencode.found()
 else

src/shared/qrcode-util.c

@@ -5,12 +5,45 @@
 #if HAVE_QRENCODE
 #include <qrencode.h>
 
+#include "alloc-util.h"
 #include "dlfcn-util.h"
 #include "locale-util.h"
 #include "terminal-util.h"
 
 #define ANSI_WHITE_ON_BLACK "\033[40;37;1m"
 
+static void *qrcode_dl = NULL;
+
+static QRcode* (*sym_QRcode_encodeString)(const char *string, int version, QRecLevel level, QRencodeMode hint, int casesensitive) = NULL;
+static void (*sym_QRcode_free)(QRcode *qrcode) = NULL;
+
+int dlopen_qrencode(void) {
+        _cleanup_(dlclosep) void *dl = NULL;
+        int r;
+
+        if (qrcode_dl)
+                return 0; /* Already loaded */
+
+        dl = dlopen("libqrencode.so.4", RTLD_LAZY);
+        if (!dl)
+                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
+                                       "libqrcode support is not installed: %s", dlerror());
+
+        r = dlsym_many_and_warn(
+                        dl,
+                        LOG_DEBUG,
+                        DLSYM_ARG(QRcode_encodeString),
+                        DLSYM_ARG(QRcode_free),
+                        NULL);
+        if (r < 0)
+                return r;
+
+        /* Note that we never release the reference here, because there's no real reason to, after all this
+         * was traditionally a regular shared library dependency which lives forever too. */
+        qrcode_dl = TAKE_PTR(dl);
+        return 1;
+}
+
 static void print_border(FILE *output, unsigned width) {
         /* Four rows of border */
         for (unsigned y = 0; y < 4; y += 2) {
@@ -65,9 +98,6 @@ static void write_qrcode(FILE *output, QRcode *qr) {
 }
 
 int print_qrcode(FILE *out, const char *header, const char *string) {
-        QRcode* (*sym_QRcode_encodeString)(const char *string, int version, QRecLevel level, QRencodeMode hint, int casesensitive);
-        void (*sym_QRcode_free)(QRcode *qrcode);
-        _cleanup_(dlclosep) void *dl = NULL;
         QRcode* qr;
         int r;
 
@@ -76,17 +106,7 @@ int print_qrcode(FILE *out, const char *header, const char *string) {
         if (!is_locale_utf8() || !colors_enabled())
                 return -EOPNOTSUPP;
 
-        dl = dlopen("libqrencode.so.4", RTLD_LAZY);
-        if (!dl)
-                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
-                                       "QRCODE support is not installed: %s", dlerror());
-
-        r = dlsym_many_and_warn(
-                        dl,
-                        LOG_DEBUG,
-                        DLSYM_ARG(QRcode_encodeString),
-                        DLSYM_ARG(QRcode_free),
-                        NULL);
+        r = dlopen_qrencode();
         if (r < 0)
                 return r;
 

src/shared/qrcode-util.h

@@ -5,6 +5,8 @@
 #include <errno.h>
 
 #if HAVE_QRENCODE
+int dlopen_qrencode(void);
+
 int print_qrcode(FILE *out, const char *header, const char *string);
 #else
 static inline int print_qrcode(FILE *out, const char *header, const char *string) {

src/test/meson.build

@@ -71,6 +71,10 @@ tests += [
           libshared],
          []],
 
+        [['src/test/test-dlopen-so.c'],
+         [libshared],
+         []],
+
         [['src/test/test-job-type.c'],
          [libcore,
           libshared],

src/test/test-dlopen-so.c

@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <dlfcn.h>
+#include <stdlib.h>
+
+#include "cryptsetup-util.h"
+#include "idn-util.h"
+#include "macro.h"
+#include "main-func.h"
+#include "pwquality-util.h"
+#include "qrcode-util.h"
+#include "tests.h"
+
+static int run(int argc, char **argv) {
+        test_setup_logging(LOG_DEBUG);
+
+        /* Try to load each of our weak library dependencies once. This is supposed to help finding cases
+         * where .so versions change and distributions update, but systemd doesn't have the new so names
+         * around yet. */
+
+#if HAVE_LIBIDN2 || HAVE_LIBIDN
+        assert_se(dlopen_idn() >= 0);
+#endif
+
+#if HAVE_LIBCRYPTSETUP
+        assert_se(dlopen_cryptsetup() >= 0);
+#endif
+
+#if HAVE_PWQUALITY
+        assert_se(dlopen_pwquality() >= 0);
+#endif
+
+#if HAVE_QRENCODE
+        assert_se(dlopen_qrencode() >= 0);
+#endif
+
+        return 0;
+}
+
+DEFINE_MAIN_FUNCTION(run);

test/test-functions

@@ -676,6 +676,19 @@ install_missing_libraries() {
     for i in $initdir{,/usr}/{sbin,bin}/* $initdir{,/usr}/lib/systemd/{,tests/{,manual/,unsafe/}}*; do
         LD_LIBRARY_PATH="${LD_LIBRARY_PATH:+$LD_LIBRARY_PATH:}$(get_ldpath $i):$(get_ldpath $i)/src/udev" inst_libs $i
     done
+
+    # A number of dependencies is now optional via dlopen, so the install
+    # script will not pick them up, since it looks at linkage.
+    for lib in libcryptsetup libidn libidn2 pwquality libqrencode; do
+            if pkg-config --exists ${lib}; then
+                    path=$(pkg-config --variable=libdir ${lib})
+                    if ! [[ ${lib} =~ ^lib ]]; then
+                            lib="lib${lib}"
+                    fi
+                    inst_libs "${path}/${lib}.so"
+                    inst_library "${path}/${lib}.so"
+            fi
+    done
 }
 
 cleanup_loopdev() {