netlink_sock_diag.c

/*
 * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
 * Copyright (c) 2017 JingPiao Chen <chenjingpiao@gmail.com>
 * Copyright (c) 2017 The strace developers.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "defs.h"
#include "netlink.h"
#include "netlink_sock_diag.h"

static void
decode_family(struct tcb *const tcp, const uint8_t family,
	      const kernel_ulong_t addr, const unsigned int len)
{
	tprints("{family=");
	printxval(addrfams, family, "AF_???");
	if (len > sizeof(family)) {
		tprints(", ");
		printstr_ex(tcp, addr + sizeof(family),
			    len - sizeof(family), QUOTE_FORCE_HEX);
	}
	tprints("}");
}

typedef DECL_NETLINK_DIAG_DECODER((*netlink_diag_decoder_t));

static const struct {
	const netlink_diag_decoder_t request, response;
} diag_decoders[] = {
	[AF_INET] = { decode_inet_diag_req, decode_inet_diag_msg },
	[AF_INET6] = { decode_inet_diag_req, decode_inet_diag_msg },
	[AF_NETLINK] = { decode_netlink_diag_req, decode_netlink_diag_msg },
	[AF_PACKET] = { decode_packet_diag_req, decode_packet_diag_msg },
#ifdef AF_SMC
	[AF_SMC] = { decode_smc_diag_req, decode_smc_diag_msg },
#endif
	[AF_UNIX] = { decode_unix_diag_req, decode_unix_diag_msg }
};

bool
decode_netlink_sock_diag(struct tcb *const tcp,
			 const struct nlmsghdr *const nlmsghdr,
			 const kernel_ulong_t addr,
			 const unsigned int len)
{
	uint8_t family;

	if (nlmsghdr->nlmsg_type == NLMSG_DONE)
		return false;

	if (!umove_or_printaddr(tcp, addr, &family)) {
		if (family < ARRAY_SIZE(diag_decoders)
		    && len > sizeof(family)) {
			const netlink_diag_decoder_t decoder =
				(nlmsghdr->nlmsg_flags & NLM_F_REQUEST)
				? diag_decoders[family].request
				: diag_decoders[family].response;

			if (decoder) {
				decoder(tcp, nlmsghdr, family, addr, len);
				return true;
			}
		}

		decode_family(tcp, family, addr, len);
	}

	return true;
}