C++ sock_kfree_s函数代码示例

int ipv6_sock_mc_join(struct sock *sk, int ifindex, struct in6_addr *addr)
{
	struct net_device *dev = NULL;
	struct ipv6_mc_socklist *mc_lst;
	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
	int err;

	if (!(ipv6_addr_type(addr) & IPV6_ADDR_MULTICAST))
		return -EINVAL;

	mc_lst = sock_kmalloc(sk, sizeof(struct ipv6_mc_socklist), GFP_KERNEL);

	if (mc_lst == NULL)
		return -ENOMEM;

	mc_lst->next = NULL;
	memcpy(&mc_lst->addr, addr, sizeof(struct in6_addr));
	mc_lst->ifindex = ifindex;

	if (ifindex == 0) {
		struct rt6_info *rt;
		rt = rt6_lookup(addr, NULL, 0, 0);
		if (rt) {
			dev = rt->rt6i_dev;
			dev_hold(dev);
			dst_release(&rt->u.dst);
		}
	} else
		dev = dev_get_by_index(ifindex);

	if (dev == NULL) {
		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
		return -ENODEV;
	}

	/*
	 *	now add/increase the group membership on the device
	 */

	err = ipv6_dev_mc_inc(dev, addr);

	if (err) {
		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
		dev_put(dev);
		return err;
	}

	write_lock_bh(&ipv6_sk_mc_lock);
	mc_lst->next = np->ipv6_mc_list;
	np->ipv6_mc_list = mc_lst;
	write_unlock_bh(&ipv6_sk_mc_lock);

	dev_put(dev);

	return 0;
}

/*
 *	socket leave an anycast group
 */
int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev;
	struct ipv6_ac_socklist *pac, *prev_pac;

	write_lock_bh(&ipv6_sk_ac_lock);
	prev_pac = NULL;
	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
		if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
		     ipv6_addr_equal(&pac->acl_addr, addr))
			break;
		prev_pac = pac;
	}
	if (!pac) {
		write_unlock_bh(&ipv6_sk_ac_lock);
		return -ENOENT;
	}
	if (prev_pac)
		prev_pac->acl_next = pac->acl_next;
	else
		np->ipv6_ac_list = pac->acl_next;

	write_unlock_bh(&ipv6_sk_ac_lock);

	dev = dev_get_by_index(&init_net, pac->acl_ifindex);
	if (dev) {
		ipv6_dev_ac_dec(dev, &pac->acl_addr);
		dev_put(dev);
	}
	sock_kfree_s(sk, pac, sizeof(*pac));
	return 0;
}

static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
{
	struct inet6_request_sock *ireq6 = inet6_rsk(req);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sk_buff *skb;
	struct ipv6_txoptions *opt = NULL;
	struct in6_addr *final_p = NULL, final;
	struct flowi fl;
	int err = -1;
	struct dst_entry *dst;

	memset(&fl, 0, sizeof(fl));
	fl.proto = IPPROTO_DCCP;
	ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
	ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
	fl.fl6_flowlabel = 0;
	fl.oif = ireq6->iif;
	fl.fl_ip_dport = inet_rsk(req)->rmt_port;
	fl.fl_ip_sport = inet_rsk(req)->loc_port;
	security_req_classify_flow(req, &fl);

	opt = np->opt;

	if (opt != NULL && opt->srcrt != NULL) {
		const struct rt0_hdr *rt0 = (struct rt0_hdr *)opt->srcrt;

		ipv6_addr_copy(&final, &fl.fl6_dst);
		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
		final_p = &final;
	}

	err = ip6_dst_lookup(sk, &dst, &fl);
	if (err)
		goto done;

	if (final_p)
		ipv6_addr_copy(&fl.fl6_dst, final_p);

	err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0);
	if (err < 0)
		goto done;

	skb = dccp_make_response(sk, dst, req);
	if (skb != NULL) {
		struct dccp_hdr *dh = dccp_hdr(skb);

		dh->dccph_checksum = dccp_v6_csum_finish(skb,
							 &ireq6->loc_addr,
							 &ireq6->rmt_addr);
		ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
		err = ip6_xmit(sk, skb, &fl, opt, 0);
		err = net_xmit_eval(err);
	}

done:
	if (opt != NULL && opt != np->opt)
		sock_kfree_s(sk, opt, opt->tot_len);
	dst_release(dst);
	return err;
}

/*
 *	socket leave on multicast group
 */
int ipv6_sock_mc_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
{
	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
	struct ipv6_mc_socklist *mc_lst, **lnk;

	write_lock_bh(&ipv6_sk_mc_lock);
	for (lnk = &np->ipv6_mc_list; (mc_lst = *lnk) !=NULL ; lnk = &mc_lst->next) {
		if (mc_lst->ifindex == ifindex &&
		    ipv6_addr_cmp(&mc_lst->addr, addr) == 0) {
			struct net_device *dev;

			*lnk = mc_lst->next;
			write_unlock_bh(&ipv6_sk_mc_lock);

			if ((dev = dev_get_by_index(ifindex)) != NULL) {
				ipv6_dev_mc_dec(dev, &mc_lst->addr);
				dev_put(dev);
			}
			sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
			return 0;
		}
	}
	write_unlock_bh(&ipv6_sk_mc_lock);

	return -ENOENT;
}

int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
{
	struct sk_filter *fp; 
	unsigned int fsize = sizeof(struct sock_filter) * fprog->len;
	int err;

	/* Make sure new filter is there and in the right amounts. */
        if (fprog->filter == NULL || fprog->len > BPF_MAXINSNS)
                return (-EINVAL);

	fp = (struct sk_filter *)sock_kmalloc(sk, fsize+sizeof(*fp), GFP_KERNEL);
	if(fp == NULL)
		return (-ENOMEM);

	if (copy_from_user(fp->insns, fprog->filter, fsize)) {
		sock_kfree_s(sk, fp, fsize+sizeof(*fp)); 
		return -EFAULT;
	}

	atomic_set(&fp->refcnt, 1);
	fp->len = fprog->len;

	if ((err = sk_chk_filter(fp->insns, fp->len))==0) {
		struct sk_filter *old_fp = sk->filter;
		sk->filter = fp;
		synchronize_bh();
		fp = old_fp;
	}

	if (fp)
		sk_filter_release(sk, fp);

	return (err);
}

/**
 *	sk_attach_filter - attach a socket filter
 *	@fprog: the filter program
 *	@sk: the socket to use
 *
 * Attach the user's filter code. We first run some sanity checks on
 * it to make sure it does not explode on us later. If an error
 * occurs or there is insufficient memory for the filter a negative
 * errno code is returned. On success the return is zero.
 */
int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
{
	struct sk_filter *fp, *old_fp;
	unsigned int fsize = sizeof(struct sock_filter) * fprog->len;
	int err;

	/* Make sure new filter is there and in the right amounts. */
	if (fprog->filter == NULL)
		return -EINVAL;

	fp = sock_kmalloc(sk, fsize+sizeof(*fp), GFP_KERNEL);
	if (!fp)
		return -ENOMEM;
	if (copy_from_user(fp->insns, fprog->filter, fsize)) {
		sock_kfree_s(sk, fp, fsize+sizeof(*fp));
		return -EFAULT;
	}

	atomic_set(&fp->refcnt, 1);
	fp->len = fprog->len;

	err = sk_chk_filter(fp->insns, fp->len);
	if (err) {
		sk_filter_uncharge(sk, fp);
		return err;
	}

	old_fp = rcu_dereference_protected(sk->sk_filter,
					   sock_owned_by_user(sk));
	rcu_assign_pointer(sk->sk_filter, fp);

	if (old_fp)
		sk_filter_uncharge(sk, old_fp);
	return 0;
}

static void
MksckPageDescSkDestruct(struct sock *sk)
{
	struct sock *mkSk = NULL;
	struct MksckPageDescInfo *mpdi;
	lock_sock(sk);
	mpdi = sk->sk_protinfo;
	while (mpdi) {
		struct MksckPageDescInfo *next = mpdi->next;
		MksckPageDescManage(mpdi->descs, mpdi->pages,
				    MANAGE_DECREMENT);
		kfree(mpdi);
		mpdi = next;
	}
	if (sk->sk_user_data) {
		mkSk = (struct sock *)sk->sk_user_data;
		sk->sk_user_data = NULL;
	}
	sk->sk_protinfo  = NULL;
	release_sock(sk);

	if (mkSk) {
		lock_sock(mkSk);
		sock_kfree_s(mkSk, mkSk->sk_user_data, sizeof(int));
		mkSk->sk_user_data = NULL;
		release_sock(mkSk);
		sock_put(mkSk); 
	}
}

int inet6_destroy_sock(struct sock *sk)
{
	struct sk_buff *skb;
	struct ipv6_txoptions *opt;

	/*
	 *	Release destination entry
	 */

	sk_dst_reset(sk);

	/* Release rx options */

	if ((skb = xchg(&sk->net_pinfo.af_inet6.pktoptions, NULL)) != NULL)
		kfree_skb(skb);

	/* Free flowlabels */
	fl6_free_socklist(sk);

	/* Free tx options */

	if ((opt = xchg(&sk->net_pinfo.af_inet6.opt, NULL)) != NULL)
		sock_kfree_s(sk, opt, opt->tot_len);

	return 0;
}

void ipv6_sock_ac_close(struct sock *sk)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev = NULL;
	struct ipv6_ac_socklist *pac;
	int	prev_index;

	write_lock_bh(&ipv6_sk_ac_lock);
	pac = np->ipv6_ac_list;
	np->ipv6_ac_list = NULL;
	write_unlock_bh(&ipv6_sk_ac_lock);

	prev_index = 0;
	while (pac) {
		struct ipv6_ac_socklist *next = pac->acl_next;

		if (pac->acl_ifindex != prev_index) {
			if (dev)
				dev_put(dev);
			dev = dev_get_by_index(&init_net, pac->acl_ifindex);
			prev_index = pac->acl_ifindex;
		}
		if (dev)
			ipv6_dev_ac_dec(dev, &pac->acl_addr);
		sock_kfree_s(sk, pac, sizeof(*pac));
		pac = next;
	}
	if (dev)
		dev_put(dev);
}

void ipv6_sock_ac_close(struct sock *sk)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev = NULL;
	struct ipv6_ac_socklist *pac;
	struct net *net = sock_net(sk);
	int	prev_index;

	if (!np->ipv6_ac_list)
		return;

	rtnl_lock();
	pac = np->ipv6_ac_list;
	np->ipv6_ac_list = NULL;

	prev_index = 0;
	while (pac) {
		struct ipv6_ac_socklist *next = pac->acl_next;

		if (pac->acl_ifindex != prev_index) {
			dev = __dev_get_by_index(net, pac->acl_ifindex);
			prev_index = pac->acl_ifindex;
		}
		if (dev)
			ipv6_dev_ac_dec(dev, &pac->acl_addr);
		sock_kfree_s(sk, pac, sizeof(*pac));
		pac = next;
	}
	rtnl_unlock();
}

/*
 *	socket leave an anycast group
 */
int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net_device *dev;
	struct ipv6_ac_socklist *pac, *prev_pac;
	struct net *net = sock_net(sk);

	ASSERT_RTNL();

	prev_pac = NULL;
	for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
		if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
		     ipv6_addr_equal(&pac->acl_addr, addr))
			break;
		prev_pac = pac;
	}
	if (!pac)
		return -ENOENT;
	if (prev_pac)
		prev_pac->acl_next = pac->acl_next;
	else
		np->ipv6_ac_list = pac->acl_next;

	dev = __dev_get_by_index(net, pac->acl_ifindex);
	if (dev)
		ipv6_dev_ac_dec(dev, &pac->acl_addr);

	sock_kfree_s(sk, pac, sizeof(*pac));
	return 0;
}

int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
{
    struct ip_mc_socklist *iml, **imlp;

    rtnl_lock();
    for (imlp=&sk->protinfo.af_inet.mc_list; (iml=*imlp)!=NULL; imlp=&iml->next) {
        if (iml->multi.imr_multiaddr.s_addr==imr->imr_multiaddr.s_addr &&
                iml->multi.imr_address.s_addr==imr->imr_address.s_addr &&
                (!imr->imr_ifindex || iml->multi.imr_ifindex==imr->imr_ifindex)) {
            struct in_device *in_dev;
            if (--iml->count) {
                rtnl_unlock();
                return 0;
            }

            *imlp = iml->next;

            in_dev = inetdev_by_index(iml->multi.imr_ifindex);
            if (in_dev) {
                ip_mc_dec_group(in_dev, imr->imr_multiaddr.s_addr);
                in_dev_put(in_dev);
            }
            rtnl_unlock();
            sock_kfree_s(sk, iml, sizeof(*iml));
            return 0;
        }
    }
    rtnl_unlock();
    return -EADDRNOTAVAIL;
}

int ip_mc_join_group(struct sock *sk , struct ip_mreqn *imr)
{
    int err;
    u32 addr = imr->imr_multiaddr.s_addr;
    struct ip_mc_socklist *iml, *i;
    struct in_device *in_dev;
    int count = 0;

    if (!MULTICAST(addr))
        return -EINVAL;

    rtnl_shlock();

    if (!imr->imr_ifindex)
        in_dev = ip_mc_find_dev(imr);
    else {
        in_dev = inetdev_by_index(imr->imr_ifindex);
        if (in_dev)
            __in_dev_put(in_dev);
    }

    if (!in_dev) {
        iml = NULL;
        err = -ENODEV;
        goto done;
    }

    iml = (struct ip_mc_socklist *)sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);

    err = -EADDRINUSE;
    for (i=sk->protinfo.af_inet.mc_list; i; i=i->next) {
        if (memcmp(&i->multi, imr, sizeof(*imr)) == 0) {
            /* New style additions are reference counted */
            if (imr->imr_address.s_addr == 0) {
                i->count++;
                err = 0;
            }
            goto done;
        }
        count++;
    }
    err = -ENOBUFS;
    if (iml == NULL || count >= sysctl_igmp_max_memberships)
        goto done;
    memcpy(&iml->multi, imr, sizeof(*imr));
    iml->next = sk->protinfo.af_inet.mc_list;
    iml->count = 1;
    sk->protinfo.af_inet.mc_list = iml;
    ip_mc_inc_group(in_dev, addr);
    iml = NULL;
    err = 0;

done:
    rtnl_shunlock();
    if (iml)
        sock_kfree_s(sk, iml, sizeof(*iml));
    return err;
}

void ip_mc_drop_socket(struct sock *sk)
{
	struct ip_mc_socklist *iml;

	while ((iml=sk->ip_mc_list) != NULL) {
		struct in_device *in_dev;
		sk->ip_mc_list = iml->next;
		if ((in_dev = inetdev_by_index(iml->multi.imr_ifindex)) != NULL)
			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
		sock_kfree_s(sk, iml, sizeof(*iml));
	}
}

static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
			      struct request_values *rvp)
{
	struct inet6_request_sock *treq = inet6_rsk(req);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sk_buff * skb;
	struct ipv6_txoptions *opt = NULL;
	struct in6_addr * final_p, final;
	struct flowi6 fl6;
	struct dst_entry *dst;
	int err;

	memset(&fl6, 0, sizeof(fl6));
	fl6.flowi6_proto = IPPROTO_TCP;
	fl6.daddr = treq->rmt_addr;
	fl6.saddr = treq->loc_addr;
	fl6.flowlabel = 0;
	fl6.flowi6_oif = treq->iif;
	fl6.flowi6_mark = inet_rsk(req)->ir_mark;
	fl6.fl6_dport = inet_rsk(req)->rmt_port;
	fl6.fl6_sport = inet_rsk(req)->loc_port;
	fl6.flowi6_uid = sock_i_uid(sk);
	security_req_classify_flow(req, flowi6_to_flowi(&fl6));

	opt = np->opt;
	final_p = fl6_update_dst(&fl6, opt, &final);

	dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
	if (IS_ERR(dst)) {
		err = PTR_ERR(dst);
		dst = NULL;
		goto done;
	}
	skb = tcp_make_synack(sk, dst, req, rvp);
	err = -ENOMEM;
	if (skb) {
		__tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);

		fl6.daddr = treq->rmt_addr;
		err = ip6_xmit(sk, skb, &fl6, opt, np->tclass);
		err = net_xmit_eval(err);
	}

done:
	if (opt && opt != np->opt)
		sock_kfree_s(sk, opt, opt->tot_len);
	dst_release(dst);
	return err;
}