lib/posix-socket: Socket events

[skuenzer]

Base target

• Architecture(s): [N/A]
• Platform(s): [N/A]
• Application(s): [N/A]

Additional configuration

• CONFIG_LIBPOSIX_SOCKET=y
• CONFIG_LIBPOSIX_SOCKET_EVENTS=y

Description of changes

POSIX-Socket events are events that can be used to track socket connections. As part of the provided information, also the endpoint addresses (local and remote) are reported. Because the implementation is purely integrated to lib/posix-socket, it is independent of the target address family or underlying network stack or implementation.
An event is emitted in the following situations:

• LISTEN: The host listens on a given address for incoming connections
• ACCEPT: An incoming connection is accepted
• CONNECT: A connection to a remote endpoint is established
• CLOSE: A connection or listener is closed

The following snippet is a short example that demonstrates the integration and receiving of event messages: example.c:

#include <sys/socket.h>
#include <uk/socket_event.h>
#include <uk/print.h>
#include <uk/hexdump.h>

static const char *evname(enum uk_socket_event_type event)
{
	switch (event) {
	case UK_SOCKET_EVENT_LISTEN:
		return "listen";
	case UK_SOCKET_EVENT_ACCEPT:
		return "accept";
	case UK_SOCKET_EVENT_CONNECT:
		return "connect";
	case UK_SOCKET_EVENT_CLOSE:
		return "close";
	default:
	}

	return "<undef>";
}

static const char *afname(int family)
{
	switch (family) {
	case AF_UNIX:
		return "unix";
	case AF_INET:
		return "inet";
	case AF_INET6:
		return "inet6";
	default:
	}

	return "<unknown>";
}

static const char *stname(int sockettype)
{
	sockettype &= ~ SOCK_NONBLOCK;
	sockettype &= ~ SOCK_CLOEXEC;

	switch (sockettype) {
	case SOCK_STREAM:
		return "stream";
	case SOCK_DGRAM:
		return "dgram";
	case SOCK_RAW:
		return "raw";
	case SOCK_SEQPACKET:
		return "seqpacket";
	case SOCK_RDM:
		return "rdm";
	default:
	}

	return "<unknown>";
}

static void socket_event(const struct uk_socket_event *e)
{
	uk_pr_crit("- SOCKET EVENT ------------\n");
	uk_pr_crit("socket id: 0x%"__PRIx64"\n", (__u64)e->id);
	uk_pr_crit("event:     %s\n", evname(e->event));
	uk_pr_crit("family:    %s (%u)\n", afname(e->family), e->family);
	uk_pr_crit("type:      %s (%u)\n", stname(e->type), e->type);
	uk_pr_crit("protocol:  %u\n", e->protocol);
	uk_pr_crit("laddr_len: %u\n", e->laddr_len);
	uk_hexdumpk(KLVL_CRIT, e->laddr, e->laddr_len, UK_HXDF_GRPQWORD, 2);
	uk_pr_crit("raddr_len: %u\n", e->raddr_len);
	uk_hexdumpk(KLVL_CRIT, e->raddr, e->raddr_len, UK_HXDF_GRPQWORD, 2);
	uk_pr_crit("===========================\n");
}

UK_SOCKET_EVENT_RECEIVER(AF_INET, socket_event);

[razvand]

Reviewed-by: Razvan Deaconescu razvand@unikraft.io
Approved-by: Razvan Deaconescu razvand@unikraft.io