diff options
Diffstat (limited to 'resolv/res_send.c')
| -rw-r--r-- | resolv/res_send.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/resolv/res_send.c b/resolv/res_send.c index ea7cf192b2..572e72c32f 100644 --- a/resolv/res_send.c +++ b/resolv/res_send.c @@ -1199,19 +1199,30 @@ send_dg(res_state statp, } /* Check for the correct header layout and a matching - question. */ + question. Some recursive resolvers send REFUSED + without copying back the question section + (producing a response that is only HFIXEDSZ bytes + long). Skip query matching in this case. */ + bool thisansp_error = (anhp->rcode == SERVFAIL || + anhp->rcode == NOTIMP || + anhp->rcode == REFUSED); + bool skip_query_match = (*thisresplenp == HFIXEDSZ + && ntohs (anhp->qdcount) == 0 + && thisansp_error); int matching_query = 0; /* Default to no matching query. */ if (!recvresp1 && anhp->id == hp->id - && __libc_res_queriesmatch (buf, buf + buflen, - *thisansp, - *thisansp + *thisanssizp)) + && (skip_query_match + || __libc_res_queriesmatch (buf, buf + buflen, + *thisansp, + *thisansp + *thisanssizp))) matching_query = 1; if (!recvresp2 && anhp->id == hp2->id - && __libc_res_queriesmatch (buf2, buf2 + buflen2, - *thisansp, - *thisansp + *thisanssizp)) + && (skip_query_match + || __libc_res_queriesmatch (buf2, buf2 + buflen2, + *thisansp, + *thisansp + *thisanssizp))) matching_query = 2; if (matching_query == 0) /* Spurious UDP packet. Drop it and continue @@ -1221,9 +1232,7 @@ send_dg(res_state statp, goto wait; } - if (anhp->rcode == SERVFAIL || - anhp->rcode == NOTIMP || - anhp->rcode == REFUSED) { + if (thisansp_error) { next_ns: if (recvresp1 || (buf2 != NULL && recvresp2)) { *resplen2 = 0; |