|
 |
0c2424 |
commit 6b61ba29c78e26109426429c6d6b354f6e4443cd
|
|
|
0c2424 |
Author: David Mirabito via Linuxptp-devel <linuxptp-devel@lists.sourceforge.net>
|
|
|
0c2424 |
Date: Tue Mar 19 13:42:48 2019 +1100
|
|
|
0c2424 |
|
|
|
0c2424 |
Avoid fault when receiving zero length packets
|
|
|
0c2424 |
|
|
|
0c2424 |
The manpage for recvmsg says -1 will be returned on error, Zero indicates an
|
|
|
0c2424 |
"orderly shutdown", presumably only in case of stream sockets.
|
|
|
0c2424 |
Further, UNIX Network Programming, Vol 1 says ".. a return value of 0 from
|
|
|
0c2424 |
recvfrom is acceptable for a datagram protocol"
|
|
|
0c2424 |
|
|
|
0c2424 |
Such packets have been observed in the wild, aimed at PTP's multicast
|
|
|
0c2424 |
address and port, possibly related to malformed management queries.
|
|
|
0c2424 |
|
|
|
0c2424 |
Patch to properly check return from recvmesg and not trigger the fault
|
|
|
0c2424 |
codepath. Instead, such packets are treated as "Bad Message" the same as
|
|
|
0c2424 |
non-zero but still too-short UDP payloads.
|
|
|
0c2424 |
|
|
|
0c2424 |
Signed-off-by: David Mirabito <davidjm@arista.com>
|
|
|
0c2424 |
|
|
|
0c2424 |
diff --git a/port.c b/port.c
|
|
|
0c2424 |
index ad9554f..9264211 100644
|
|
|
0c2424 |
--- a/port.c
|
|
|
0c2424 |
+++ b/port.c
|
|
|
0c2424 |
@@ -2563,7 +2563,7 @@ static enum fsm_event bc_event(struct port *p, int fd_index)
|
|
|
0c2424 |
msg->hwts.type = p->timestamping;
|
|
|
0c2424 |
|
|
|
0c2424 |
cnt = transport_recv(p->trp, fd, msg);
|
|
|
0c2424 |
- if (cnt <= 0) {
|
|
|
0c2424 |
+ if (cnt < 0) {
|
|
|
0c2424 |
pr_err("port %hu: recv message failed", portnum(p));
|
|
|
0c2424 |
msg_put(msg);
|
|
|
0c2424 |
return EV_FAULT_DETECTED;
|
|
|
0c2424 |
diff --git a/sk.c b/sk.c
|
|
|
0c2424 |
index 30162eb..93ba77a 100644
|
|
|
0c2424 |
--- a/sk.c
|
|
|
0c2424 |
+++ b/sk.c
|
|
|
0c2424 |
@@ -359,7 +359,7 @@ int sk_receive(int fd, void *buf, int buflen,
|
|
|
0c2424 |
}
|
|
|
0c2424 |
|
|
|
0c2424 |
cnt = recvmsg(fd, &msg, flags);
|
|
|
0c2424 |
- if (cnt < 1)
|
|
|
0c2424 |
+ if (cnt < 0)
|
|
|
0c2424 |
pr_err("recvmsg%sfailed: %m",
|
|
|
0c2424 |
flags == MSG_ERRQUEUE ? " tx timestamp " : " ");
|
|
|
0c2424 |
|