From bd35961de8f963b06913290356a6cd44a42a41fe Mon Sep 17 00:00:00 2001
From: David Woodhouse <dwmw2@infradead.org>
Date: Tue, 9 Jun 2020 13:18:06 +0100
Subject: [PATCH] uci: truncate hostname at first dot

Oh, and stop at the size of the target buffer too.
---
 src/utils/dawn_uci.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/utils/dawn_uci.c b/src/utils/dawn_uci.c
index ca2566d..8c4b7a3 100644
--- a/src/utils/dawn_uci.c
+++ b/src/utils/dawn_uci.c
@@ -34,7 +34,14 @@ void uci_get_hostname(char* hostname)
 
     if(ptr.flags & UCI_LOOKUP_COMPLETE)
     {
-        strncpy(hostname, ptr.o->v.string, HOST_NAME_MAX);
+        char *dot = strchr(ptr.o->v.string, '.');
+        size_t len = HOST_NAME_MAX - 1;
+
+        if (dot && dot < ptr.o->v.string + len)
+        {
+            len = dot - ptr.o->v.string;
+        }
+        snprintf(hostname, HOST_NAME_MAX, "%.*s", len, ptr.o->v.string);
     }
 
     uci_free_context(c);