Add static assertions for the size of the src address control buffer

diff --git a/pdns/misc.cc b/pdns/misc.cc
index 2686b0fc46c640f890ee0acc3595ea55bb03c706..662670277142877eefa2b6de563fb5f38466bf57 100644 (file)
--- a/pdns/misc.cc
+++ b/pdns/misc.cc
@@ -893,6 +893,7 @@ void addCMsgSrcAddr(struct msghdr* msgh, cmsgbuf_aligned* cmsgbuf, const ComboAd
     struct in6_pktinfo *pkt;
 
     msgh->msg_control = cmsgbuf;
+    static_assert(CMSG_SPACE(sizeof(*pkt)) <= sizeof(*cmsgbuf), "Buffer is too small for in6_pktinfo");
     msgh->msg_controllen = CMSG_SPACE(sizeof(*pkt));
 
     cmsg = CMSG_FIRSTHDR(msgh);
@@ -910,6 +911,7 @@ void addCMsgSrcAddr(struct msghdr* msgh, cmsgbuf_aligned* cmsgbuf, const ComboAd
     struct in_pktinfo *pkt;
 
     msgh->msg_control = cmsgbuf;
+    static_assert(CMSG_SPACE(sizeof(*pkt)) <= sizeof(*cmsgbuf), "Buffer is too small for in_pktinfo");
     msgh->msg_controllen = CMSG_SPACE(sizeof(*pkt));
 
     cmsg = CMSG_FIRSTHDR(msgh);
@@ -925,6 +927,7 @@ void addCMsgSrcAddr(struct msghdr* msgh, cmsgbuf_aligned* cmsgbuf, const ComboAd
     struct in_addr *in;
 
     msgh->msg_control = cmsgbuf;
+    static_assert(CMSG_SPACE(sizeof(*in)) <= sizeof(*cmsgbuf), "Buffer is too small for in_addr");
     msgh->msg_controllen = CMSG_SPACE(sizeof(*in));
 
     cmsg = CMSG_FIRSTHDR(msgh);