eal: restrict default plugin path to shared lib mode

[dpdk.git] / lib / librte_eal / common / eal_common_options.c

diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index 176a985..34edd8c 100644 (file)
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -15,6 +15,7 @@
 #include <getopt.h>
 #ifndef RTE_EXEC_ENV_WINDOWS
 #include <dlfcn.h>
+#include <libgen.h>
 #endif
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -358,7 +359,14 @@ eal_plugin_add(const char *path)
        return 0;
 }
 
-#ifndef RTE_EXEC_ENV_WINDOWS
+#ifdef RTE_EXEC_ENV_WINDOWS
+int
+eal_plugins_init(void)
+{
+       return 0;
+}
+#else
+
 static int
 eal_plugindir_init(const char *path)
 {
@@ -398,17 +406,93 @@ eal_plugindir_init(const char *path)
        /* XXX this ignores failures from readdir() itself */
        return (dent == NULL) ? 0 : -1;
 }
-#endif
+
+static int
+verify_perms(const char *dirpath)
+{
+       struct stat st;
+
+       /* if not root, check down one level first */
+       if (strcmp(dirpath, "/") != 0) {
+               static __thread char last_dir_checked[PATH_MAX];
+               char copy[PATH_MAX];
+               const char *dir;
+
+               strlcpy(copy, dirpath, PATH_MAX);
+               dir = dirname(copy);
+               if (strncmp(dir, last_dir_checked, PATH_MAX) != 0) {
+                       if (verify_perms(dir) != 0)
+                               return -1;
+                       strlcpy(last_dir_checked, dir, PATH_MAX);
+               }
+       }
+
+       /* call stat to check for permissions and ensure not world writable */
+       if (stat(dirpath, &st) != 0) {
+               RTE_LOG(ERR, EAL, "Error with stat on %s, %s\n",
+                               dirpath, strerror(errno));
+               return -1;
+       }
+       if (st.st_mode & S_IWOTH) {
+               RTE_LOG(ERR, EAL,
+                               "Error, directory path %s is world-writable and insecure\n",
+                               dirpath);
+               return -1;
+       }
+
+       return 0;
+}
+
+static void *
+eal_dlopen(const char *pathname)
+{
+       void *retval = NULL;
+       char *realp = realpath(pathname, NULL);
+
+       if (realp == NULL && errno == ENOENT) {
+               /* not a full or relative path, try a load from system dirs */
+               retval = dlopen(pathname, RTLD_NOW);
+               if (retval == NULL)
+                       RTE_LOG(ERR, EAL, "%s\n", dlerror());
+               return retval;
+       }
+       if (realp == NULL) {
+               RTE_LOG(ERR, EAL, "Error with realpath for %s, %s\n",
+                               pathname, strerror(errno));
+               goto out;
+       }
+       if (strnlen(realp, PATH_MAX) == PATH_MAX) {
+               RTE_LOG(ERR, EAL, "Error, driver path greater than PATH_MAX\n");
+               goto out;
+       }
+
+       /* do permissions checks */
+       if (verify_perms(realp) != 0)
+               goto out;
+
+       retval = dlopen(realp, RTLD_NOW);
+       if (retval == NULL)
+               RTE_LOG(ERR, EAL, "%s\n", dlerror());
+out:
+       free(realp);
+       return retval;
+}
 
 int
 eal_plugins_init(void)
 {
-#ifndef RTE_EXEC_ENV_WINDOWS
        struct shared_driver *solib = NULL;
        struct stat sb;
 
-       if (*default_solib_dir != '\0' && stat(default_solib_dir, &sb) == 0 &&
-                               S_ISDIR(sb.st_mode))
+       /* If we are not statically linked, add default driver loading
+        * path if it exists as a directory.
+        * (Using dlopen with NOLOAD flag on EAL, will return NULL if the EAL
+        * shared library is not already loaded i.e. it's statically linked.)
+        */
+       if (dlopen("librte_eal.so", RTLD_LAZY | RTLD_NOLOAD) != NULL &&
+                       *default_solib_dir != '\0' &&
+                       stat(default_solib_dir, &sb) == 0 &&
+                       S_ISDIR(sb.st_mode))
                eal_plugin_add(default_solib_dir);
 
        TAILQ_FOREACH(solib, &solib_list, next) {
@@ -423,17 +507,15 @@ eal_plugins_init(void)
                } else {
                        RTE_LOG(DEBUG, EAL, "open shared lib %s\n",
                                solib->name);
-                       solib->lib_handle = dlopen(solib->name, RTLD_NOW);
-                       if (solib->lib_handle == NULL) {
-                               RTE_LOG(ERR, EAL, "%s\n", dlerror());
+                       solib->lib_handle = eal_dlopen(solib->name);
+                       if (solib->lib_handle == NULL)
                                return -1;
-                       }
                }
 
        }
-#endif
        return 0;
 }
+#endif
 
 /*
  * Parse the coremask given as argument (hexadecimal string) and fill