lib: print NULL for NULL nexthops

Instead of crashing, print "NULL" when printfrr callback for
nexthops is called for a NULL nexthop argument.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

diff --git a/lib/nexthop.c b/lib/nexthop.c
index b2fa9456909fe802834a5d1c225bf1ce3385aa33..dd8c1082057667e8acbcaaf94338b02593380de4 100644 (file)
--- a/lib/nexthop.c
+++ b/lib/nexthop.c
@@ -739,6 +739,16 @@ static ssize_t printfrr_nh(char *buf, size_t bsz, const char *fmt,
        const char *s, *v_is = "", *v_via = "", *v_viaif = "via ";
        ssize_t ret = 3;
 
+       /* NULL-check */
+       if (nexthop == NULL) {
+               if (fmt[2] == 'v' && fmt[3] == 'v')
+                       ret++;
+
+               strlcpy(buf, "NULL", bsz);
+
+               return ret;
+       }
+
        switch (fmt[2]) {
        case 'v':
                if (fmt[3] == 'v') {