/*
 * netsniff-ng - the packet sniffing beast
 * Copyright 2012 Daniel Borkmann.
 * Subject to the GPL, version 2.
 * Parts derived from iw, subject to ISC license.
 * Copyright 2007, 2008	Johannes Berg
 * Copyright 2007 Andy Lutomirski
 * Copyright 2007 Mike Kershaw
 * Copyright 2008-2009 Luis R. Rodriguez
 */

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <limits.h>
#include <sys/socket.h>
#include <linux/if.h>
#include <linux/nl80211.h>
#include <netlink/genl/genl.h>
#include <netlink/genl/family.h>
#include <netlink/genl/ctrl.h>
#include <netlink/msg.h>
#include <netlink/attr.h>

#include "die.h"
#include "str.h"
#include "dev.h"
#include "mac80211.h"
#include "xmalloc.h"
#include "built_in.h"

struct nl80211_state {
	struct nl_sock *nl_sock;
	struct nl_cache *nl_cache;
	struct genl_family *nl80211;
};

static void get_mac80211_phydev(const char *device, char *phydev_path,
				size_t phydev_len)
{
	int ret;
	char *pathstr;
	ssize_t num;

	ret = asprintf(&pathstr, "/sys/class/net/%s/phy80211", device);
	if (ret < 0)
		panic("Can't generate path name string for /sys/class/net device");

	num = readlink(pathstr, phydev_path, phydev_len);
	if (num < 0) {
		if (errno == ENOENT || errno == EINVAL)
			panic("It's probably not a mac80211 device!\n");
		panic("Can't readlink %s: %s!\n", pathstr, strerror(errno));
	}

	xfree(pathstr);
	phydev_path[min_t(size_t, num, phydev_len - 1)] = 0;
}

static inline struct nl_msg *nl80211_nlmsg_xalloc(void)
{
	struct nl_msg *ret = nlmsg_alloc();
	if (!ret)
		panic("Cannot allocate nlmsg memory!\n");
	return ret;
}

static inline struct nl_sock *nl80211_nl_socket_xalloc(void)
{
	struct nl_sock *ret = nl_socket_alloc();
	if (!ret)
		panic("Cannot allocate nl socket memory!\n");
	return ret;
}

static void nl80211_init(struct nl80211_state *state)
{
	int ret;

	state->nl_sock = nl80211_nl_socket_xalloc();

	ret = genl_connect(state->nl_sock);
	if (ret)
		panic("Cannot connect generic netlink!\n");

	ret = genl_ctrl_alloc_cache(state->nl_sock, &state->nl_cache);
	if (ret < 0)
		panic("Failed to allocate generic netlink cache: %s!",
		      nl_geterror(-ret));

	state->nl80211 = genl_ctrl_search_by_name(state->nl_cache, "nl80211");
	if (!state->nl80211)
		panic("nl80211 not found in netlink cache!\n");
}

static void nl80211_cleanup(struct nl80211_state *state)
{
	genl_family_put(state->nl80211);

	nl_cache_free(state->nl_cache);
	nl_socket_free(state->nl_sock);
}

static int nl80211_wait_handler(struct nl_msg *msg __maybe_unused, void *arg)
{
	int *finished = arg;

	*finished = 1;

	return NL_STOP;
}

static int nl80211_error_handler(struct sockaddr_nl *nla __maybe_unused,
				 struct nlmsgerr *err,
				 void *arg __maybe_unused)
{
	panic("nl80211 returned with error (%d): %s\n", err->error,
	      nl_geterror(err->error));
}

static int nl80211_add_mon_if(struct nl80211_state *state, const char *device,
			      const char *mondevice)
{
	int ifindex, ret;
	struct nl_msg *msg;
	struct nl_cb *cb = NULL;
	int finished = 0;

	ifindex = device_ifindex(device);

	msg = nl80211_nlmsg_xalloc();

	genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
		    0, NL80211_CMD_NEW_INTERFACE, 0);

	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex);
	NLA_PUT_STRING(msg, NL80211_ATTR_IFNAME, mondevice);
	NLA_PUT_U32(msg, NL80211_ATTR_IFTYPE, NL80211_IFTYPE_MONITOR);

	ret = nl_send_auto_complete(state->nl_sock, msg);
	if (ret < 0) {
		if (ret == -ENFILE) {
			nlmsg_free(msg);
			return -EBUSY;
		}

		panic("Cannot send_auto_complete!\n");
	}

	cb = nl_cb_alloc(NL_CB_CUSTOM);
	if (!cb)
		panic("Cannot alloc nl_cb!\n");

	nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, nl80211_wait_handler, &finished);
	nl_cb_err(cb, NL_CB_CUSTOM, nl80211_error_handler, NULL);

	nl_recvmsgs(state->nl_sock, cb);

	if (!finished) {
		ret = nl_wait_for_ack(state->nl_sock);
		if (ret < 0) {
			if (ret == -ENFILE) {
				nlmsg_free(msg);
				return -EBUSY;
			}

			panic("Waiting for netlink ack failed!\n");
		}
	}

	nl_cb_put(cb);
	nlmsg_free(msg);
	return 0;

nla_put_failure:
	panic("nla put failure!\n");
	return -EIO; /* dummy */
}

static int nl80211_del_mon_if(struct nl80211_state *state,
			      const char *mondevice)
{
	int ifindex, ret;
	struct nl_msg *msg;

	ifindex = device_ifindex(mondevice);

	msg = nl80211_nlmsg_xalloc();

	genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
		    0, NL80211_CMD_DEL_INTERFACE, 0);

	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex);

	ret = nl_send_auto_complete(state->nl_sock, msg);
	if (ret < 0)
		panic("Cannot send_auto_complete!\n");

	ret = nl_wait_for_ack(state->nl_sock);
	if (ret < 0)
		panic("Waiting for netlink ack failed!\n");

	nlmsg_free(msg);
	return 0;

nla_put_failure:
	panic("nla put failure!\n");
	return -EIO; /* dummy */
}

void enter_rfmon_mac80211(const char *device, char **mondev)
{
	int ret;
	short flags;
	uint32_t n;
	char phydev_path[256];
	struct nl80211_state nlstate;

	/* XXX: is this already a monN device? */
	get_mac80211_phydev(device, phydev_path, sizeof(phydev_path));
	nl80211_init(&nlstate);

	for (n = 0; n < UINT_MAX; n++) {
		char mondevice[32];

		slprintf(mondevice, sizeof(mondevice), "mon%u", n);

		if (__device_ifindex(mondevice) > 0)
			continue;

		ret = nl80211_add_mon_if(&nlstate, device, mondevice);
		if (ret == 0) {
			*mondev = xstrdup(mondevice);

			flags = device_get_flags(*mondev);
			flags |= IFF_UP | IFF_RUNNING;
			device_set_flags(*mondev, flags);

			nl80211_cleanup(&nlstate);
			return;
		}
	}

	panic("No free monN interfaces!\n");
}

void leave_rfmon_mac80211(const char *mondev)
{
	short flags;
	struct nl80211_state nlstate;

	flags = device_get_flags(mondev);
	flags &= ~(IFF_UP | IFF_RUNNING);
	device_set_flags(mondev, flags);

	nl80211_init(&nlstate);
	nl80211_del_mon_if(&nlstate, mondev);
	nl80211_cleanup(&nlstate);
}
vers.

When this quirk was added, we checked ctrl-&gt;tagset in order to avoid
quirking in probe time, supposing we would never require such delay
during probe. Well, it was too optimistic; we in fact need this quirk
at probe time in some cases, like after a kexec.

In some experiments, after abnormal shutdown of machine (aka power cord
unplug), we booted into our bootloader in Power, which is a Linux kernel,
and kexec'ed into another distro. If this kexec is too quick, we end up
reaching the probe of NVMe adapter in that distro when adapter is in
bad state (not fully initialized on our bootloader). What happens next
is that nvme_wait_ready() is unable to complete, except if the quirk is
enabled.

So, this patch removes the original ctrl-&gt;tagset verification in order
to enable the quirk even on probe time.

Fixes: 54adc01055b7 ("nvme/quirk: Add a delay before checking for adapter readiness")
Reported-by: Andrew Byrne &lt;byrneadw@ie.ibm.com&gt;
Reported-by: Jaime A. H. Gomez &lt;jahgomez@mx1.ibm.com&gt;
Reported-by: Zachary D. Myers &lt;zdmyers@us.ibm.com&gt;
Signed-off-by: Guilherme G. Piccoli &lt;gpiccoli@linux.vnet.ibm.com&gt;
Acked-by: Jeffrey Lien &lt;Jeff.Lien@wdc.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=b5a10c5f7532b7473776da87e67f8301bbc32693'>Diffstat</a></div><table summary='diffstat' class='diffstat'>