Improves compatibility with AddressSanitizers

[src/app-framework-binder.git] / src / afb-api-so.c

diff --git a/src/afb-api-so.c b/src/afb-api-so.c
index 2b71d92..02e986e 100644 (file)
--- a/src/afb-api-so.c
+++ b/src/afb-api-so.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2016, 2017, 2018 "IoT.bzh"
+ * Copyright (C) 2015-2020 "IoT.bzh"
  * Author José Bollo <jose.bollo@iot.bzh>
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -15,9 +15,12 @@
  * limitations under the License.
  */
 
+#if WITH_DYNAMIC_BINDING
+
 #define _GNU_SOURCE
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <dlfcn.h>
 #include <string.h>
 #include <dirent.h>
@@ -25,17 +28,19 @@
 #include <sys/stat.h>
 
 #include "afb-api-so.h"
-#include "afb-api-so-v2.h"
 #include "afb-api-so-v3.h"
 #include "verbose.h"
 #include "sig-monitor.h"
 
-#if defined(WITH_LEGACY_BINDING_V1)
+#if WITH_LEGACY_BINDING_V1
 #   include "afb-api-so-v1.h"
 #endif
-#if defined(WITH_LEGACY_BINDING_VDYN)
+#if WITH_LEGACY_BINDING_VDYN
 #   include "afb-api-so-vdyn.h"
 #endif
+#if WITH_LEGACY_BINDING_V2
+#   include "afb-api-so-v2.h"
+#endif
 
 struct safe_dlopen
 {
@@ -70,10 +75,23 @@ static int load_binding(const char *path, int force, struct afb_apiset *declare_
        int obsolete = 0;
        int rc;
        void *handle;
+       static int dlopen_flags = 0;
+
+       /* compute the dlopen flags */
+       if (dlopen_flags == 0) {
+               /* For ASan mode, export AFB_NO_RTLD_DEEPBIND=1, to disable RTLD_DEEPBIND */
+               char *string = secure_getenv("AFB_NO_RTLD_DEEPBIND");
+               if (string && string[0] == '1' && string[1] == 0)
+                       dlopen_flags = RTLD_NOW | RTLD_LOCAL;
+               else
+                       dlopen_flags = RTLD_NOW | RTLD_LOCAL | RTLD_DEEPBIND;
+       }
 
-       // This is a loadable library let's check if it's a binding
+       /* set default return code rc according to force */
        rc = -!!force;
-       handle = safe_dlopen(path, RTLD_NOW | RTLD_LOCAL | RTLD_DEEPBIND);
+
+       /* try to open the library */
+       handle = safe_dlopen(path, dlopen_flags);
        if (handle == NULL) {
                if (force)
                        ERROR("binding [%s] not loadable: %s", path, dlerror());
@@ -81,6 +99,9 @@ static int load_binding(const char *path, int force, struct afb_apiset *declare_
                        WARNING("binding [%s] not loadable: %s", path, dlerror());
                goto error;
        }
+       /*
+        * This is a loadable library let's check if it's a binding ...
+        */
 
        /* try the version 3 */
        rc = afb_api_so_v3_add(path, handle, declare_set, call_set);
@@ -91,6 +112,7 @@ static int load_binding(const char *path, int force, struct afb_apiset *declare_
        if (rc)
                return 0; /* yes version 3 */
 
+#if WITH_LEGACY_BINDING_V2
        /* try the version 2 */
        rc = afb_api_so_v2_add(path, handle, declare_set, call_set);
        if (rc < 0) {
@@ -99,8 +121,14 @@ static int load_binding(const char *path, int force, struct afb_apiset *declare_
        }
        if (rc)
                return 0; /* yes version 2 */
+#else
+       if (dlsym(handle, "afbBindingV2")) {
+               WARNING("binding [%s]: version 2 not supported", path);
+               obsolete = 1;
+       }
+#endif
 
-#if defined(WITH_LEGACY_BINDING_VDYN)
+#if WITH_LEGACY_BINDING_VDYN
        /* try the version dyn */
        rc = afb_api_so_vdyn_add(path, handle, declare_set, call_set);
        if (rc < 0) {
@@ -116,7 +144,7 @@ static int load_binding(const char *path, int force, struct afb_apiset *declare_
        }
 #endif
 
-#if defined(WITH_LEGACY_BINDING_V1)
+#if WITH_LEGACY_BINDING_V1
        /* try the version 1 */
        rc = afb_api_so_v1_add(path, handle, declare_set, call_set);
        if (rc < 0) {
@@ -152,6 +180,7 @@ static int adddirs(char path[PATH_MAX], size_t end, struct afb_apiset *declare_s
 {
        DIR *dir;
        struct dirent *dent;
+       struct stat st;
        size_t len;
        int rc = 0;
 
@@ -175,12 +204,19 @@ static int adddirs(char path[PATH_MAX], size_t end, struct afb_apiset *declare_s
                        break;
                }
 
+               /* get the name and inspect dereferenced link instead of the directory entry */
                len = strlen(dent->d_name);
                if (len + end >= PATH_MAX) {
-                       ERROR("path too long while scanning bindings for %s", dent->d_name);
+                       ERROR("path too long while scanning bindings for %.*s%s", (int)end, path, dent->d_name);
                        continue;
                }
-               if (dent->d_type == DT_DIR) {
+               memcpy(&path[end], dent->d_name, len+1);
+               rc = stat(path, &st);
+               if (rc < 0) {
+                       ERROR("getting status of %s failed: %m", path);
+                       continue;
+               }
+               else if (S_ISDIR(st.st_mode)) {
                        /* case of directories */
                        if (dent->d_name[0] == '.') {
 /*
@@ -213,7 +249,7 @@ debug file made dlopen crashing.
 See https://sourceware.org/bugzilla/show_bug.cgi?id=22101
  */
 #if !defined(AFB_API_SO_ACCEPT_DOT_PREFIXED_DIRS) /* not defined by default */
-                               continue; /* ignore any directory beginnign with a dot */
+                               continue; /* ignore any directory beginning with a dot */
 #else
                                if (len == 1)
                                        continue; /* . */
@@ -230,13 +266,11 @@ See https://sourceware.org/bugzilla/show_bug.cgi?id=22101
 #endif
 #endif
                        }
-                       memcpy(&path[end], dent->d_name, len+1);
                        rc = adddirs(path, end+len, declare_set, call_set, failstops);
-               } else if (dent->d_type == DT_REG || dent->d_type == DT_LNK) {
+               } else if (S_ISREG(st.st_mode)) {
                        /* case of files */
                        if (memcmp(&dent->d_name[len - 3], ".so", 4))
                                continue;
-                       memcpy(&path[end], dent->d_name, len+1);
                        rc = load_binding(path, 0, declare_set, call_set);
                }
                if (rc < 0 && failstops) {
@@ -307,3 +341,4 @@ int afb_api_so_add_pathset_nofails(const char *pathset, struct afb_apiset *decla
        return afb_api_so_add_pathset(pathset, declare_set, call_set, 0);
 }
 
+#endif