Fix: utils: avoid strncpy overlap in utils_partial_realpath

[lttng-tools.git] / src / common / utils.c

diff --git a/src/common/utils.c b/src/common/utils.c
index 7006a21581ea91f952c7d7dbe57a1095d467979e..6bf0a10e163a3fb434b9b117b38e912884ddf546 100644 (file)
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -60,16 +60,15 @@
  * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with
  * /test2/test3 then returned. In normal time, realpath(3) fails if the end
  * point directory does not exist.
- * In case resolved_path is NULL, the string returned was allocated in the
- * function and thus need to be freed by the caller. The size argument allows
- * to specify the size of the resolved_path argument if given, or the size to
- * allocate.
+ *
+ * Return a newly-allocated string.
  */
-LTTNG_HIDDEN
-char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
+static
+char *utils_partial_realpath(const char *path)
 {
        char *cut_path = NULL, *try_path = NULL, *try_path_prev = NULL;
        const char *next, *prev, *end;
+       char *resolved_path = NULL;
 
        /* Safety net */
        if (path == NULL) {
@@ -150,13 +149,11 @@ char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
                cut_path = NULL;
        }
 
-       /* Allocate memory for the resolved path if necessary */
+       /* Allocate memory for the resolved path. */
+       resolved_path = zmalloc(LTTNG_PATH_MAX);
        if (resolved_path == NULL) {
-               resolved_path = zmalloc(size);
-               if (resolved_path == NULL) {
-                       PERROR("zmalloc resolved path");
-                       goto error;
-               }
+               PERROR("zmalloc resolved path");
+               goto error;
        }
 
        /*
@@ -180,7 +177,8 @@ char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
                }
 
                /* Concatenate the strings */
-               snprintf(resolved_path, size, "%s%s", try_path_prev, cut_path);
+               snprintf(resolved_path, LTTNG_PATH_MAX, "%s%s",
+                               try_path_prev, cut_path);
 
                /* Free the allocated memory */
                free(cut_path);
@@ -192,7 +190,7 @@ char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
         * return it as is
         */
        } else {
-               strncpy(resolved_path, path, size);
+               strncpy(resolved_path, path, LTTNG_PATH_MAX);
        }
 
        /* Then we return the 'partially' resolved path */
@@ -371,11 +369,13 @@ char *_utils_expand_path(const char *path, bool keep_symlink)
 
        if (keep_symlink) {
                /* Resolve partially our path */
-               absolute_path = utils_partial_realpath(absolute_path,
-                               absolute_path, LTTNG_PATH_MAX);
-               if (!absolute_path) {
+               char *new_absolute_path = utils_partial_realpath(absolute_path);
+               if (!new_absolute_path) {
                        goto error;
                }
+
+               free(absolute_path);
+               absolute_path = new_absolute_path;
        }
 
        ret = expand_double_slashes_dot_and_dotdot(absolute_path);
@@ -679,8 +679,8 @@ int utils_mkdir(const char *path, mode_t mode, int uid, int gid)
        int ret;
        struct lttng_directory_handle *handle;
        const struct lttng_credentials creds = {
-               .uid = (uid_t) uid,
-               .gid = (gid_t) gid,
+               .uid = LTTNG_OPTIONAL_INIT_VALUE(uid),
+               .gid = LTTNG_OPTIONAL_INIT_VALUE(gid),
        };
 
        handle = lttng_directory_handle_create(NULL);
@@ -708,8 +708,8 @@ int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid)
        int ret;
        struct lttng_directory_handle *handle;
        const struct lttng_credentials creds = {
-               .uid = (uid_t) uid,
-               .gid = (gid_t) gid,
+               .uid = LTTNG_OPTIONAL_INIT_VALUE(uid),
+               .gid = LTTNG_OPTIONAL_INIT_VALUE(gid),
        };
 
        handle = lttng_directory_handle_create(NULL);
@@ -1274,8 +1274,14 @@ int utils_get_group_id(const char *name, bool warn, gid_t *gid)
                }
        }
        if (ret) {
-               PERROR("Failed to get group file entry for group name \"%s\"",
-                               name);
+               if (ret == ESRCH) {
+                       DBG("Could not find group file entry for group name '%s'",
+                                       name);
+               } else {
+                       PERROR("Failed to get group file entry for group name '%s'",
+                                       name);
+               }
+
                ret = -1;
                goto error;
        }
@@ -1663,3 +1669,39 @@ end:
        free(buf);
        return ret_val;
 }
+
+LTTNG_HIDDEN
+int utils_parse_unsigned_long_long(const char *str,
+               unsigned long long *value)
+{
+       int ret;
+       char *endptr;
+
+       assert(str);
+       assert(value);
+
+       errno = 0;
+       *value = strtoull(str, &endptr, 10);
+
+       /* Conversion failed. Out of range? */
+       if (errno != 0) {
+               /* Don't print an error; allow the caller to log a better error. */
+               DBG("Failed to parse string as unsigned long long number: string = '%s', errno = %d",
+                               str, errno);
+               ret = -1;
+               goto end;
+       }
+
+       /* Not the end of the string or empty string. */
+       if (*endptr || endptr == str) {
+               DBG("Failed to parse string as unsigned long long number: string = '%s'",
+                               str);
+               ret = -1;
+               goto end;
+       }
+
+       ret = 0;
+
+end:
+       return ret;
+}