extern "C" void SystemNative_ReadEvents(int32_t sock, NetworkChangeEvent onNetworkChange)
{
char buffer[4096];
iovec iov = {buffer, sizeof(buffer)};
sockaddr_nl sanl;
msghdr msg = { .msg_name = reinterpret_cast<void*>(&sanl), .msg_namelen = sizeof(sockaddr_nl), .msg_iov = &iov, .msg_iovlen = 1 };
ssize_t len;
while (CheckInterrupted(len = recvmsg(sock, &msg, 0)));
if (len == -1)
{
// Probably means the socket has been closed.
return;
}
for (nlmsghdr* hdr = reinterpret_cast<nlmsghdr*>(buffer); NLMSG_OK(hdr, UnsignedCast(len)); NLMSG_NEXT(hdr, len))
{
switch (hdr->nlmsg_type)
{
case NLMSG_DONE:
return; // End of a multi-part message; stop reading.
case NLMSG_ERROR:
return;
case RTM_NEWADDR:
onNetworkChange(sock, NetworkChangeKind::AddressAdded);
break;
case RTM_DELADDR:
onNetworkChange(sock, NetworkChangeKind::AddressRemoved);
break;
case RTM_NEWLINK:
onNetworkChange(sock, ReadNewLinkMessage(hdr));
break;
case RTM_DELLINK:
onNetworkChange(sock, NetworkChangeKind::LinkRemoved);
break;
default:
break;
}
}
}
NetworkChangeKind ReadNewLinkMessage(nlmsghdr* hdr)
{
assert(hdr != nullptr);
ifinfomsg* ifimsg;
ifimsg = reinterpret_cast<ifinfomsg*>(NLMSG_DATA(hdr));
if (ifimsg->ifi_family == AF_INET)
{
if ((ifimsg->ifi_flags & IFF_UP) != 0)
{
return NetworkChangeKind::LinkAdded;
}
}
return NetworkChangeKind::None;
}
extern "C" NetworkChangeKind SystemNative_ReadSingleEvent(int32_t sock)
{
char buffer[4096];
iovec iov = {buffer, sizeof(buffer)};
sockaddr_nl sanl;
msghdr msg = { .msg_name = reinterpret_cast<void*>(&sanl), .msg_namelen = sizeof(sockaddr_nl), .msg_iov = &iov, .msg_iovlen = 1 };
ssize_t len;
while (CheckInterrupted(len = recvmsg(sock, &msg, 0)));
if (len == -1)
{
// Probably means the socket has been closed.
// If so, the managed side will ignore the return value.
return NetworkChangeKind::None;
}
nlmsghdr* hdr = reinterpret_cast<nlmsghdr*>(buffer);
// This channel should only send a single message at a time.
// This means there should be no multi-part messages (NLM_F_MULTI).
assert((hdr->nlmsg_flags & NLM_F_MULTI) == 0);
switch (hdr->nlmsg_type)
{
case NLMSG_DONE:
return NetworkChangeKind::None;
case NLMSG_ERROR:
return NetworkChangeKind::None;
case RTM_NEWADDR:
return NetworkChangeKind::AddressAdded;
case RTM_DELADDR:
return NetworkChangeKind::AddressRemoved;
case RTM_NEWLINK:
return ReadNewLinkMessage(hdr);
case RTM_DELLINK:
return NetworkChangeKind::LinkRemoved;
default:
return NetworkChangeKind::None;
}
}
NetworkChangeKind ReadNewLinkMessage(nlmsghdr* hdr)
{
assert(hdr != nullptr);
ifinfomsg* ifimsg;
ifimsg = reinterpret_cast<ifinfomsg*>(NLMSG_DATA(hdr));
if (ifimsg->ifi_family == AF_INET)
{
if ((ifimsg->ifi_flags & IFF_UP) != 0)
{
return NetworkChangeKind::LinkAdded;
}
}
return NetworkChangeKind::None;
}
extern "C" NetworkChangeKind ReadSingleEvent(int32_t sock)
{
char buffer[4096];
iovec iov = { buffer, sizeof(buffer) };
sockaddr_nl sanl;
msghdr msg = { reinterpret_cast<void*>(&sanl), sizeof(sockaddr_nl), &iov, 1, NULL, 0, 0};
ssize_t len = recvmsg(sock, &msg, 0);
if (len == -1)
{
// Probably means the socket has been closed.
// If so, the managed side will ignore the return value.
return NetworkChangeKind::None;
}
nlmsghdr* hdr = reinterpret_cast<nlmsghdr*>(buffer);
// This channel should only send a single message at a time.
// This means there should be no multi-part messages (NLM_F_MULTI).
assert ((hdr->nlmsg_flags & NLM_F_MULTI) == 0);
switch (hdr->nlmsg_type)
{
case NLMSG_DONE:
return NetworkChangeKind::None;
case NLMSG_ERROR:
return NetworkChangeKind::None;
case RTM_NEWADDR:
return NetworkChangeKind::AddressAdded;
case RTM_DELADDR:
return NetworkChangeKind::AddressRemoved;
case RTM_NEWLINK:
return ReadNewLinkMessage(hdr);
case RTM_DELLINK:
return NetworkChangeKind::LinkRemoved;
default:
return NetworkChangeKind::None;
}
}
