From ed58146d3aeecdb9920fdc017f85c18b5b10f2db Mon Sep 17 00:00:00 2001 From: Nate Karstens Date: Thu, 10 Aug 2017 08:27:32 -0500 Subject: [PATCH 8/8] Handle errors from socket calls Adds handling for socket() or read() returning a negative value (indicating an error has occurred). Upstream-Status: Submitted [dts@apple.com] Signed-off-by: Nate Karstens Signed-off-by: Alex Kiernan --- mDNSPosix/mDNSPosix.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/mDNSPosix/mDNSPosix.c +++ b/mDNSPosix/mDNSPosix.c @@ -1677,7 +1677,7 @@ mDNSlocal void ProcessRoutingNo // Read through the messages on sd and if any indicate that any interface records should // be torn down and rebuilt, return affected indices as a bitmask. Otherwise return 0. { - ssize_t readCount; + ssize_t readVal, readCount; char buff[4096]; struct nlmsghdr *pNLMsg = (struct nlmsghdr*) buff; @@ -1686,7 +1686,10 @@ mDNSlocal void ProcessRoutingNo // enough to hold all pending data and so avoid message fragmentation. // (Note that FIONREAD is not supported on AF_NETLINK.) - readCount = read(sd, buff, sizeof buff); + readVal = read(sd, buff, sizeof buff); + if (readVal < 0) return; + readCount = readVal; + while (1) { // Make sure we've got an entire nlmsghdr in the buffer, and payload, too. @@ -1702,7 +1705,9 @@ mDNSlocal void ProcessRoutingNo pNLMsg = (struct nlmsghdr*) buff; // read more data - readCount += read(sd, buff + readCount, sizeof buff - readCount); + readVal = read(sd, buff + readCount, sizeof buff - readCount); + if (readVal < 0) return; + readCount += readVal; continue; // spin around and revalidate with new readCount } else @@ -1851,6 +1856,7 @@ mDNSlocal mDNSBool mDNSPlatformInit_CanR int err; int s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); struct sockaddr_in s5353; + if (s < 0) return mDNSfalse; s5353.sin_family = AF_INET; s5353.sin_port = MulticastDNSPort.NotAnInteger; s5353.sin_addr.s_addr = 0;