Apparently some DHCP servers return NULL strings, Gentoo #222381.

diff --git a/dhcp.c b/dhcp.c
index c277a6410facc2fc98c57864010890c2ab852178..c8abd0fbfcf0ca0fd160a5d291add521c79be1fb 100644 (file)
--- a/dhcp.c
+++ b/dhcp.c
@@ -589,7 +589,7 @@ get_option_string(const struct dhcp_message *dhcp, uint8_t option)
        char *s;
 
        p = get_option(dhcp, option, &len, &type);
-       if (!p)
+       if (!p || *p == '\0')
                return NULL;
 
        if (type & RFC3397) {
@@ -1034,8 +1034,12 @@ print_option(char *s, ssize_t len, int type, int dl, const uint8_t *data)
        if (type & RFC3442)
                return decode_rfc3442(s, len, dl, data);
 
-       if (!type || type & STRING)
+       if (type & STRING) {
+               /* Some DHCP servers return NULL strings */
+               if (*data == '\0')
+                       return 0;
                return print_string(s, len, dl, data);
+       }
 
        if (!s) {
                if (type & UINT8)
@@ -1190,7 +1194,8 @@ configure_env(char **env, const char *prefix, const struct dhcp_message *dhcp,
                e = strlen(prefix) + strlen(opt->var) + len + 4;
                v = val = *ep++ = xmalloc(e);
                v += snprintf(val, e, "%s_%s=", prefix, opt->var);
-               print_option(v, len, opt->type, pl, p);
+               if (len != 0)
+                       print_option(v, len, opt->type, pl, p);
        }
 
        return ep - env;