act_api.c

来自「linux 内核源代码」· C语言 代码 · 共 1,075 行 · 第 1/2 页

struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
				  char *name, int ovr, int bind, int *err)
{
	struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
	struct tc_action *head = NULL, *act, *act_prev = NULL;
	int i;

	if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
		*err = -EINVAL;
		return head;
	}

	for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
		act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
		if (act == NULL)
			goto err;
		act->order = i+1;

		if (head == NULL)
			head = act;
		else
			act_prev->next = act;
		act_prev = act;
	}
	return head;

err:
	if (head != NULL)
		tcf_action_destroy(head, bind);
	return NULL;
}

int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
			  int compat_mode)
{
	int err = 0;
	struct gnet_dump d;
	struct tcf_act_hdr *h = a->priv;

	if (h == NULL)
		goto errout;

	/* compat_mode being true specifies a call that is supposed
	 * to add additional backward compatiblity statistic TLVs.
	 */
	if (compat_mode) {
		if (a->type == TCA_OLD_COMPAT)
			err = gnet_stats_start_copy_compat(skb, 0,
				TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
		else
			return 0;
	} else
		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
					    &h->tcf_lock, &d);

	if (err < 0)
		goto errout;

	if (a->ops != NULL && a->ops->get_stats != NULL)
		if (a->ops->get_stats(skb, a) < 0)
			goto errout;

	if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
	    gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
	    gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
		goto errout;

	if (gnet_stats_finish_copy(&d) < 0)
		goto errout;

	return 0;

errout:
	return -1;
}

static int
tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
	     u16 flags, int event, int bind, int ref)
{
	struct tcamsg *t;
	struct nlmsghdr *nlh;
	unsigned char *b = skb_tail_pointer(skb);
	struct rtattr *x;

	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);

	t = NLMSG_DATA(nlh);
	t->tca_family = AF_UNSPEC;
	t->tca__pad1 = 0;
	t->tca__pad2 = 0;

	x = (struct rtattr *)skb_tail_pointer(skb);
	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);

	if (tcf_action_dump(skb, a, bind, ref) < 0)
		goto rtattr_failure;

	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;

	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
	return skb->len;

rtattr_failure:
nlmsg_failure:
	nlmsg_trim(skb, b);
	return -1;
}

static int
act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
{
	struct sk_buff *skb;

	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!skb)
		return -ENOBUFS;
	if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
		kfree_skb(skb);
		return -EINVAL;
	}

	return rtnl_unicast(skb, pid);
}

static struct tc_action *
tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
{
	struct rtattr *tb[TCA_ACT_MAX+1];
	struct tc_action *a;
	int index;

	*err = -EINVAL;
	if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
		return NULL;

	if (tb[TCA_ACT_INDEX - 1] == NULL ||
	    RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
		return NULL;
	index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);

	*err = -ENOMEM;
	a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
	if (a == NULL)
		return NULL;

	*err = -EINVAL;
	a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
	if (a->ops == NULL)
		goto err_free;
	if (a->ops->lookup == NULL)
		goto err_mod;
	*err = -ENOENT;
	if (a->ops->lookup(a, index) == 0)
		goto err_mod;

	module_put(a->ops->owner);
	*err = 0;
	return a;
err_mod:
	module_put(a->ops->owner);
err_free:
	kfree(a);
	return NULL;
}

static void cleanup_a(struct tc_action *act)
{
	struct tc_action *a;

	for (a = act; a; a = act) {
		act = a->next;
		kfree(a);
	}
}

static struct tc_action *create_a(int i)
{
	struct tc_action *act;

	act = kzalloc(sizeof(*act), GFP_KERNEL);
	if (act == NULL) {
		printk("create_a: failed to alloc!\n");
		return NULL;
	}
	act->order = i;
	return act;
}

static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
{
	struct sk_buff *skb;
	unsigned char *b;
	struct nlmsghdr *nlh;
	struct tcamsg *t;
	struct netlink_callback dcb;
	struct rtattr *x;
	struct rtattr *tb[TCA_ACT_MAX+1];
	struct rtattr *kind;
	struct tc_action *a = create_a(0);
	int err = -EINVAL;

	if (a == NULL) {
		printk("tca_action_flush: couldnt create tc_action\n");
		return err;
	}

	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!skb) {
		printk("tca_action_flush: failed skb alloc\n");
		kfree(a);
		return -ENOBUFS;
	}

	b = skb_tail_pointer(skb);

	if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
		goto err_out;

	kind = tb[TCA_ACT_KIND-1];
	a->ops = tc_lookup_action(kind);
	if (a->ops == NULL)
		goto err_out;

	nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
	t = NLMSG_DATA(nlh);
	t->tca_family = AF_UNSPEC;
	t->tca__pad1 = 0;
	t->tca__pad2 = 0;

	x = (struct rtattr *)skb_tail_pointer(skb);
	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);

	err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
	if (err < 0)
		goto rtattr_failure;

	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;

	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
	nlh->nlmsg_flags |= NLM_F_ROOT;
	module_put(a->ops->owner);
	kfree(a);
	err = rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
	if (err > 0)
		return 0;

	return err;

rtattr_failure:
nlmsg_failure:
	module_put(a->ops->owner);
err_out:
	kfree_skb(skb);
	kfree(a);
	return err;
}

static int
tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
{
	int i, ret = 0;
	struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
	struct tc_action *head = NULL, *act, *act_prev = NULL;

	if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
		return -EINVAL;

	if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
		if (tb[0] != NULL && tb[1] == NULL)
			return tca_action_flush(tb[0], n, pid);
	}

	for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
		act = tcf_action_get_1(tb[i], n, pid, &ret);
		if (act == NULL)
			goto err;
		act->order = i+1;

		if (head == NULL)
			head = act;
		else
			act_prev->next = act;
		act_prev = act;
	}

	if (event == RTM_GETACTION)
		ret = act_get_notify(pid, n, head, event);
	else { /* delete */
		struct sk_buff *skb;

		skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
		if (!skb) {
			ret = -ENOBUFS;
			goto err;
		}

		if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
				 0, 1) <= 0) {
			kfree_skb(skb);
			ret = -EINVAL;
			goto err;
		}

		/* now do the delete */
		tcf_action_destroy(head, 0);
		ret = rtnetlink_send(skb, pid, RTNLGRP_TC,
				     n->nlmsg_flags&NLM_F_ECHO);
		if (ret > 0)
			return 0;
		return ret;
	}
err:
	cleanup_a(head);
	return ret;
}

static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
			  u16 flags)
{
	struct tcamsg *t;
	struct nlmsghdr *nlh;
	struct sk_buff *skb;
	struct rtattr *x;
	unsigned char *b;
	int err = 0;

	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!skb)
		return -ENOBUFS;

	b = skb_tail_pointer(skb);

	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
	t = NLMSG_DATA(nlh);
	t->tca_family = AF_UNSPEC;
	t->tca__pad1 = 0;
	t->tca__pad2 = 0;

	x = (struct rtattr *)skb_tail_pointer(skb);
	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);

	if (tcf_action_dump(skb, a, 0, 0) < 0)
		goto rtattr_failure;

	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;

	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
	NETLINK_CB(skb).dst_group = RTNLGRP_TC;

	err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
	if (err > 0)
		err = 0;
	return err;

rtattr_failure:
nlmsg_failure:
	kfree_skb(skb);
	return -1;
}


static int
tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
{
	int ret = 0;
	struct tc_action *act;
	struct tc_action *a;
	u32 seq = n->nlmsg_seq;

	act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
	if (act == NULL)
		goto done;

	/* dump then free all the actions after update; inserted policy
	 * stays intact
	 * */
	ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
	for (a = act; a; a = act) {
		act = a->next;
		kfree(a);
	}
done:
	return ret;
}

static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
{
	struct rtattr **tca = arg;
	u32 pid = skb ? NETLINK_CB(skb).pid : 0;
	int ret = 0, ovr = 0;

	if (tca[TCA_ACT_TAB-1] == NULL) {
		printk("tc_ctl_action: received NO action attribs\n");
		return -EINVAL;
	}

	/* n->nlmsg_flags&NLM_F_CREATE
	 * */
	switch (n->nlmsg_type) {
	case RTM_NEWACTION:
		/* we are going to assume all other flags
		 * imply create only if it doesnt exist
		 * Note that CREATE | EXCL implies that
		 * but since we want avoid ambiguity (eg when flags
		 * is zero) then just set this
		 */
		if (n->nlmsg_flags&NLM_F_REPLACE)
			ovr = 1;
replay:
		ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
		if (ret == -EAGAIN)
			goto replay;
		break;
	case RTM_DELACTION:
		ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
		break;
	case RTM_GETACTION:
		ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
		break;
	default:
		BUG();
	}

	return ret;
}

static struct rtattr *
find_dump_kind(struct nlmsghdr *n)
{
	struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
	struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
	struct rtattr *rta[TCAA_MAX + 1];
	struct rtattr *kind;
	int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
	int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
	struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);

	if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
		return NULL;
	tb1 = rta[TCA_ACT_TAB - 1];
	if (tb1 == NULL)
		return NULL;

	if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
			 NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
		return NULL;
	if (tb[0] == NULL)
		return NULL;

	if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
			 RTA_PAYLOAD(tb[0])) < 0)
		return NULL;
	kind = tb2[TCA_ACT_KIND-1];

	return kind;
}

static int
tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct nlmsghdr *nlh;
	unsigned char *b = skb_tail_pointer(skb);
	struct rtattr *x;
	struct tc_action_ops *a_o;
	struct tc_action a;
	int ret = 0;
	struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
	struct rtattr *kind = find_dump_kind(cb->nlh);

	if (kind == NULL) {
		printk("tc_dump_action: action bad kind\n");
		return 0;
	}

	a_o = tc_lookup_action(kind);
	if (a_o == NULL) {
		return 0;
	}

	memset(&a, 0, sizeof(struct tc_action));
	a.ops = a_o;

	if (a_o->walk == NULL) {
		printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
		goto rtattr_failure;
	}

	nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
			cb->nlh->nlmsg_type, sizeof(*t));
	t = NLMSG_DATA(nlh);
	t->tca_family = AF_UNSPEC;
	t->tca__pad1 = 0;
	t->tca__pad2 = 0;

	x = (struct rtattr *)skb_tail_pointer(skb);
	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);

	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
	if (ret < 0)
		goto rtattr_failure;

	if (ret > 0) {
		x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
		ret = skb->len;
	} else
		nlmsg_trim(skb, x);

	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
	if (NETLINK_CB(cb->skb).pid && ret)
		nlh->nlmsg_flags |= NLM_F_MULTI;
	module_put(a_o->owner);
	return skb->len;

rtattr_failure:
nlmsg_failure:
	module_put(a_o->owner);
	nlmsg_trim(skb, b);
	return skb->len;
}

static int __init tc_action_init(void)
{
	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);

	return 0;
}

subsys_initcall(tc_action_init);

EXPORT_SYMBOL(tcf_register_action);
EXPORT_SYMBOL(tcf_unregister_action);
EXPORT_SYMBOL(tcf_action_exec);
EXPORT_SYMBOL(tcf_action_dump_1);