- Fix chaos replies to have truncation for short message lengths,

  or long reply strings.

diff --git a/daemon/worker.c b/daemon/worker.c
index 93215a2378c14f4e50c09bfc91b41c60371e08eb..b438700af1f698a4644fe3ca6c390f48a004de62 100644 (file)
--- a/daemon/worker.c
+++ b/daemon/worker.c
@@ -789,6 +789,14 @@ chaos_replystr(sldns_buffer* pkt, char** str, int num, struct edns_data* edns,
        int i;
        unsigned int rd = LDNS_RD_WIRE(sldns_buffer_begin(pkt));
        unsigned int cd = LDNS_CD_WIRE(sldns_buffer_begin(pkt));
+       size_t udpsize = edns->udp_size;
+       edns->edns_version = EDNS_ADVERTISED_VERSION;
+       edns->udp_size = EDNS_ADVERTISED_SIZE;
+       edns->bits &= EDNS_DO;
+       if(!inplace_cb_reply_local_call(&worker->env, NULL, NULL, NULL,
+               LDNS_RCODE_NOERROR, edns, repinfo, worker->scratchpad,
+               worker->env.now_tv))
+                       edns->opt_list = NULL;
        sldns_buffer_clear(pkt);
        sldns_buffer_skip(pkt, (ssize_t)sizeof(uint16_t)); /* skip id */
        sldns_buffer_write_u16(pkt, (uint16_t)(BIT_QR|BIT_RA));
@@ -804,6 +812,12 @@ chaos_replystr(sldns_buffer* pkt, char** str, int num, struct edns_data* edns,
        for(i=0; i<num; i++) {
                size_t len = strlen(str[i]);
                if(len>255) len=255; /* cap size of TXT record */
+               if(sldns_buffer_position(pkt)+2+2+2+4+2+1+len+
+                       calc_edns_field_size(edns) > udpsize) {
+                       sldns_buffer_write_u16_at(pkt, 6, i); /* ANCOUNT */
+                       LDNS_TC_SET(sldns_buffer_begin(pkt));
+                       break;
+               }
                sldns_buffer_write_u16(pkt, 0xc00c); /* compr ptr to query */
                sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_TXT);
                sldns_buffer_write_u16(pkt, LDNS_RR_CLASS_CH);
@@ -813,13 +827,6 @@ chaos_replystr(sldns_buffer* pkt, char** str, int num, struct edns_data* edns,
                sldns_buffer_write(pkt, str[i], len);
        }
        sldns_buffer_flip(pkt);
-       edns->edns_version = EDNS_ADVERTISED_VERSION;
-       edns->udp_size = EDNS_ADVERTISED_SIZE;
-       edns->bits &= EDNS_DO;
-       if(!inplace_cb_reply_local_call(&worker->env, NULL, NULL, NULL,
-               LDNS_RCODE_NOERROR, edns, repinfo, worker->scratchpad,
-               worker->env.now_tv))
-                       edns->opt_list = NULL;
        if(sldns_buffer_capacity(pkt) >=
                sldns_buffer_limit(pkt)+calc_edns_field_size(edns))
                attach_edns_record(pkt, edns);

diff --git a/doc/Changelog b/doc/Changelog
index 9d0651485ed345e094a7adf942ff8b44f1789437..6e7abc812cf7c627ff303a4fd61892713d119049 100644 (file)
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,3 +1,7 @@
+11 October 2021: Wouter
+       - Fix chaos replies to have truncation for short message lengths,
+         or long reply strings.
+
 4 October 2021: Wouter
        - Fix to add example.conf note for outbound-msg-retry.