diff options
Diffstat (limited to 'mDNSResponder/mDNSCore/uDNS.c')
| -rwxr-xr-x | mDNSResponder/mDNSCore/uDNS.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/mDNSResponder/mDNSCore/uDNS.c b/mDNSResponder/mDNSCore/uDNS.c index be7a5a32..8c7c3300 100755 --- a/mDNSResponder/mDNSCore/uDNS.c +++ b/mDNSResponder/mDNSCore/uDNS.c @@ -1329,7 +1329,8 @@ mDNSlocal void tcpCallback(TCPSocket *sock, void *context, mDNSBool ConnectionEs else { long n; - if (tcpInfo->nread < 2) // First read the two-byte length preceeding the DNS message + const mDNSBool Read_replylen = (tcpInfo->nread < 2); // Do we need to read the replylen field first? + if (Read_replylen) // First read the two-byte length preceeding the DNS message { mDNSu8 *lenptr = (mDNSu8 *)&tcpInfo->replylen; n = mDNSPlatformReadTCP(sock, lenptr + tcpInfo->nread, 2 - tcpInfo->nread, &closed); @@ -1377,8 +1378,13 @@ mDNSlocal void tcpCallback(TCPSocket *sock, void *context, mDNSBool ConnectionEs if (n < 0) { - LogMsg("ERROR: tcpCallback - read returned %d", n); - err = mStatus_ConnFailed; + // If this is our only read for this invokation, and it fails, then that's bad. + // But if we did successfully read some or all of the replylen field this time through, + // and this is now our second read from the socket, then it's expected that sometimes + // there may be no more data present, and that's perfectly okay. + // Assuming failure of the second read is a problem is what caused this bug: + // <rdar://problem/15043194> mDNSResponder fails to read DNS over TCP packet correctly + if (!Read_replylen) { LogMsg("ERROR: tcpCallback - read returned %d", n); err = mStatus_ConnFailed; } goto exit; } else if (closed) |