Re: [Libguestfs] [PATCH nbdkit v2] server: public: Add nbdkit_parse_* functions for safely parsing integers.

> else if (strcmp (key, "timeout") == 0) { > - if (sscanf (value, "%ld", &timeout) != 1) { > - nbdkit_error ("cannot parse timeout: %s", value); > + if (nbdkit_parse_uint32_t ("timeout", value, &timeout) == -1) > + return -1; > + /* Because we have to cast it to long before calling the libssh API. */ > + if (timeout > LONG_MAX) { > + nbdkit_error ("timeout too large"); C17 5.2.4.2.1 requires 'long' to be at least 32 bits. Ergo, (uint32_t) timeout > LONG_MAX is always false. You could assert() rather than trying to use nbdkit_error().