PATCH/RFC use recvfrom with MSG_TRUNC as flag

Hi Harald, Dieter, what do you think of using MSG_TRUNC and checking if we have truncated our packets in a recv call? Dieter do you know if cygwin will silently ignore the MSG_TRUNC flag or if you will have a problem on Window? diff --git a/openbsc/src/gprs/gprs_ns.c b/openbsc/src/gprs/gprs_ns.c index 3db1d67..ab2d937 100644 --- a/openbsc/src/gprs/gprs_ns.c +++ b/openbsc/src/gprs/gprs_ns.c @@ -867,7 +867,7 @@ static struct msgb *read_nsip_msg(struct bsc_fd *bfd, int *error, return NULL; } - ret = recvfrom(bfd->fd, msg->data, NS_ALLOC_SIZE - NS_ALLOC_HEADROOM, 0, + ret = recvfrom(bfd->fd, msg->data, NS_ALLOC_SIZE - NS_ALLOC_HEADROOM, MSG_TRUNC, (struct sockaddr *)saddr, &saddr_len); if (ret < 0) { LOGP(DNS, LOGL_ERROR, "recv error %s during NSIP recv\n", @@ -879,6 +879,11 @@ static struct msgb *read_nsip_msg(struct bsc_fd *bfd, int *error, msgb_free(msg); *error = ret; return NULL; + } else if (ret > NS_ALLOC_SIZE - NS_ALLOC_HEADROOM) { + LOGP(DNS, LOGL_ERROR, "truncated msg. real size is: %d\n", ret); + msgb_free(msg); + *error = -ENOSPC; + return NULL; } msg->l2h = msg->data;