C++ sk_alloc函数代码示例

static int bnep_sock_create(struct socket *sock, int protocol)
{
	struct sock *sk;

	BT_DBG("sock %p", sock);

	if (sock->type != SOCK_RAW)
		return -ESOCKTNOSUPPORT;

	sk = sk_alloc(PF_BLUETOOTH, GFP_KERNEL, &bnep_proto, 1);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);

	sock->ops = &bnep_sock_ops;

	sock->state = SS_UNCONNECTED;

	sock_reset_flag(sk, SOCK_ZAPPED);

	sk->sk_protocol = protocol;
	sk->sk_state	= BT_OPEN;

	return 0;
}

/**
 * tipc_create - create a TIPC socket
 * @sock: pre-allocated socket structure
 * @protocol: protocol indicator (must be 0)
 *
 * This routine creates and attaches a 'struct sock' to the 'struct socket',
 * then create and attaches a TIPC port to the 'struct sock' part.
 *
 * Returns 0 on success, errno otherwise
 */
static int tipc_create(struct socket *sock, int protocol)
{
	struct tipc_sock *tsock;
	struct tipc_port *port;
	struct sock *sk;
	u32 ref;

	if (unlikely(protocol != 0))
		return -EPROTONOSUPPORT;

	ref = tipc_createport_raw(NULL, &dispatch, &wakeupdispatch, TIPC_LOW_IMPORTANCE);
	if (unlikely(!ref))
		return -ENOMEM;

	sock->state = SS_UNCONNECTED;

	switch (sock->type) {
	case SOCK_STREAM:
		sock->ops = &stream_ops;
		break;
	case SOCK_SEQPACKET:
		sock->ops = &packet_ops;
		break;
	case SOCK_DGRAM:
		tipc_set_portunreliable(ref, 1);
		/* fall through */
	case SOCK_RDM:
		tipc_set_portunreturnable(ref, 1);
		sock->ops = &msg_ops;
		sock->state = SS_READY;
		break;
	default:
		tipc_deleteport(ref);
		return -EPROTOTYPE;
	}

	sk = sk_alloc(AF_TIPC, GFP_KERNEL, &tipc_proto);
	if (!sk) {
		tipc_deleteport(ref);
		return -ENOMEM;
	}

	sock_init_data(sock, sk);
	init_waitqueue_head(sk->sk_sleep);
	sk->sk_rcvtimeo = 8 * HZ;   /* default connect timeout = 8s */

	tsock = tipc_sk(sk);
	port = tipc_get_port(ref);

	tsock->p = port;
	port->usr_handle = tsock;

	init_MUTEX(&tsock->sem);

	dbg("sock_create: %x\n",tsock);

	atomic_inc(&tipc_user_count);

	return 0;
}

static int rawsock_create(struct net *net, struct socket *sock,
				const struct nfc_protocol *nfc_proto)
{
	struct sock *sk;

	nfc_dbg("sock=%p", sock);

	if (sock->type != SOCK_SEQPACKET)
		return -ESOCKTNOSUPPORT;

	sock->ops = &rawsock_ops;

	sk = sk_alloc(net, PF_NFC, GFP_KERNEL, nfc_proto->proto);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);
	sk->sk_protocol = nfc_proto->id;
	sk->sk_destruct = rawsock_destruct;
	sock->state = SS_UNCONNECTED;

	INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
	nfc_rawsock(sk)->tx_work_scheduled = false;

	return 0;
}

static int bnep_sock_create(struct net *net, struct socket *sock, int protocol,
			    int kern)
{
	struct sock *sk;

	BT_DBG("sock %p", sock);

	if (sock->type != SOCK_RAW)
		return -ESOCKTNOSUPPORT;

	sk = sk_alloc(net, PF_BLUETOOTH, GFP_ATOMIC, &bnep_proto, kern);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);

	sock->ops = &bnep_sock_ops;

	sock->state = SS_UNCONNECTED;

	sock_reset_flag(sk, SOCK_ZAPPED);

	sk->sk_protocol = protocol;
	sk->sk_state	= BT_OPEN;

	bt_sock_link(&bnep_sk_list, sk);
	return 0;
}

static int pn_socket_create(struct net *net, struct socket *sock, int protocol)
{
    struct sock *sk;
    struct pn_sock *pn;
    struct phonet_protocol *pnp;
    int err;

#if !defined (CONFIG_SAMSUNG_PHONE_SVNET) && !defined (CONFIG_SAMSUNG_PHONE_SVNET_MODULE)
    if (!capable(CAP_SYS_ADMIN))
        return -EPERM;
#endif

    if (protocol == 0) {
        /* Default protocol selection */
        switch (sock->type) {
        case SOCK_DGRAM:
            protocol = PN_PROTO_PHONET;
            break;
        case SOCK_SEQPACKET:
            protocol = PN_PROTO_PIPE;
            break;
        default:
            return -EPROTONOSUPPORT;
        }
    }

    pnp = phonet_proto_get(protocol);
    if (pnp == NULL &&
            request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0)
        pnp = phonet_proto_get(protocol);

    if (pnp == NULL)
        return -EPROTONOSUPPORT;
    if (sock->type != pnp->sock_type) {
        err = -EPROTONOSUPPORT;
        goto out;
    }

    sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot);
    if (sk == NULL) {
        err = -ENOMEM;
        goto out;
    }

    sock_init_data(sock, sk);
    sock->state = SS_UNCONNECTED;
    sock->ops = pnp->ops;
    sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
    sk->sk_protocol = protocol;
    pn = pn_sk(sk);
    pn->sobject = 0;
    pn->resource = 0;
    sk->sk_prot->init(sk);
    err = 0;

out:
    phonet_proto_put(pnp);
    return err;
}

static int
MksckCreate(struct net *net,
	    struct socket *sock,
	    int protocol,
	    int kern)
{
	struct sock *sk;
	uid_t currentUid = current_euid();

	if (!(currentUid == 0 ||
	    currentUid == Mvpkm_vmwareUid)) {
		pr_warn("MksckCreate: rejected from process %s " \
			"tgid=%d, pid=%d euid:%d.\n",
			current->comm,
			task_tgid_vnr(current),
			task_pid_vnr(current),
			currentUid);
		return -EPERM;
	}

	if (!sock)
		return -EINVAL;

	if (protocol)
		return -EPROTONOSUPPORT;

	switch (sock->type) {
	case SOCK_DGRAM:
		sock->ops = &mksckDgramOps;
		break;
	default:
		return -ESOCKTNOSUPPORT;
	}

	sock->state = SS_UNCONNECTED;

	sk = sk_alloc(net, mksckFamilyOps.family, GFP_KERNEL, &mksckProto);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);

	sk->sk_type        = SOCK_DGRAM;
	sk->sk_destruct    = MksckSkDestruct;
	sk->sk_backlog_rcv = MksckBacklogRcv;


	sk->sk_protinfo = NULL;
	sock_reset_flag(sk, SOCK_DONE);

	return 0;
}

/*
 * Create a socket. Initialise the socket, blank the addresses
 * set the state.
 */
static int ieee802154_create(struct net *net, struct socket *sock,
			     int protocol, int kern)
{
	struct sock *sk;
	int rc;
	struct proto *proto;
	const struct proto_ops *ops;

	if (net != &init_net)
		return -EAFNOSUPPORT;

	switch (sock->type) {
	case SOCK_RAW:
		proto = &ieee802154_raw_prot;
		ops = &ieee802154_raw_ops;
		break;
	case SOCK_DGRAM:
		proto = &ieee802154_dgram_prot;
		ops = &ieee802154_dgram_ops;
		break;
	default:
		rc = -ESOCKTNOSUPPORT;
		goto out;
	}

	rc = -ENOMEM;
	sk = sk_alloc(net, PF_IEEE802154, GFP_KERNEL, proto);
	if (!sk)
		goto out;
	rc = 0;

	sock->ops = ops;

	sock_init_data(sock, sk);
	/* FIXME: sk->sk_destruct */
	sk->sk_family = PF_IEEE802154;

	/* Checksums on by default */
	sock_set_flag(sk, SOCK_ZAPPED);

	if (sk->sk_prot->hash)
		sk->sk_prot->hash(sk);

	if (sk->sk_prot->init) {
		rc = sk->sk_prot->init(sk);
		if (rc)
			sk_common_release(sk);
	}
out:
	return rc;
}

/*
 * create an RxRPC socket
 */
static int rxrpc_create(struct net *net, struct socket *sock, int protocol,
			int kern)
{
	struct rxrpc_net *rxnet;
	struct rxrpc_sock *rx;
	struct sock *sk;

	_enter("%p,%d", sock, protocol);

	/* we support transport protocol UDP/UDP6 only */
	if (protocol != PF_INET &&
	    IS_ENABLED(CONFIG_AF_RXRPC_IPV6) && protocol != PF_INET6)
		return -EPROTONOSUPPORT;

	if (sock->type != SOCK_DGRAM)
		return -ESOCKTNOSUPPORT;

	sock->ops = &rxrpc_rpc_ops;
	sock->state = SS_UNCONNECTED;

	sk = sk_alloc(net, PF_RXRPC, GFP_KERNEL, &rxrpc_proto, kern);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);
	sock_set_flag(sk, SOCK_RCU_FREE);
	sk->sk_state		= RXRPC_UNBOUND;
	sk->sk_write_space	= rxrpc_write_space;
	sk->sk_max_ack_backlog	= 0;
	sk->sk_destruct		= rxrpc_sock_destructor;

	rx = rxrpc_sk(sk);
	rx->family = protocol;
	rx->calls = RB_ROOT;

	spin_lock_init(&rx->incoming_lock);
	INIT_LIST_HEAD(&rx->sock_calls);
	INIT_LIST_HEAD(&rx->to_be_accepted);
	INIT_LIST_HEAD(&rx->recvmsg_q);
	rwlock_init(&rx->recvmsg_lock);
	rwlock_init(&rx->call_lock);
	memset(&rx->srx, 0, sizeof(rx->srx));

	rxnet = rxrpc_net(sock_net(&rx->sk));
	timer_reduce(&rxnet->peer_keepalive_timer, jiffies + 1);

	_leave(" = 0 [%p]", rx);
	return 0;
}

/**
 *	llc_sk_alloc - Allocates LLC sock
 *	@family: upper layer protocol family
 *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
 *
 *	Allocates a LLC sock and initializes it. Returns the new LLC sock
 *	or %NULL if there's no memory available for one
 */
struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority, struct proto *prot)
{
	struct sock *sk = sk_alloc(net, family, priority, prot);

	if (!sk)
		goto out;
	llc_sk_init(sk);
	sock_init_data(NULL, sk);
#ifdef LLC_REFCNT_DEBUG
	atomic_inc(&llc_sock_nr);
//	printk(KERN_DEBUG "LLC socket %p created in %s, now we have %d alive\n", sk,
;
#endif
out:
	return sk;
}

/*
 * sys_socket -> sock_create -> __sock_create -> this
 */
static int raw_create(struct net *net, struct socket *sock, int protocol, int kern)
{
	struct sock *sk;
	int err;

	/* init sock struct */
	err = -ENOBUFS;
	sk = sk_alloc(net, PF_RAW, GFP_KERNEL, &raw_proto);
	if (sk == NULL)
		goto out;
	sock->ops = &raw_ops;
	sock_init_data(sock, sk);
	sk->sk_family = PF_RAW;
	err = 0;
out:
	return err;
}

static struct sock *nr_alloc_sock(void)
{
	nr_cb *nr;
	struct sock *sk = sk_alloc(PF_NETROM, GFP_ATOMIC, 1, NULL);

	if (!sk)
		goto out;

	nr = sk->sk_protinfo = kmalloc(sizeof(*nr), GFP_ATOMIC);
	if (!nr)
		goto frees;

	memset(nr, 0x00, sizeof(*nr));
	nr->sk = sk;
out:
	return sk;
frees:
	sk_free(sk);
	sk = NULL;
	goto out;
}

int vcc_create(struct socket *sock, int protocol, int family)
{
	struct sock *sk;
	struct atm_vcc *vcc;

	sock->sk = NULL;
	if (sock->type == SOCK_STREAM)
		return -EINVAL;
	sk = sk_alloc(family, GFP_KERNEL, 1, NULL);
	if (!sk)
		return -ENOMEM;
	sock_init_data(sock, sk);
	sk_set_owner(sk, THIS_MODULE);
	sk->sk_state_change = vcc_def_wakeup;
	sk->sk_write_space = vcc_write_space;

	vcc = sk->sk_protinfo = kmalloc(sizeof(*vcc), GFP_KERNEL);
	if (!vcc) {
		sk_free(sk);
		return -ENOMEM;
	}

	memset(vcc, 0, sizeof(*vcc));
	vcc->sk = sk;
	vcc->dev = NULL;
	memset(&vcc->local,0,sizeof(struct sockaddr_atmsvc));
	memset(&vcc->remote,0,sizeof(struct sockaddr_atmsvc));
	vcc->qos.txtp.max_sdu = 1 << 16; /* for meta VCs */
	atomic_set(&vcc->sk->sk_wmem_alloc, 0);
	atomic_set(&vcc->sk->sk_rmem_alloc, 0);
	vcc->push = NULL;
	vcc->pop = NULL;
	vcc->push_oam = NULL;
	vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
	vcc->atm_options = vcc->aal_options = 0;
	sk->sk_destruct = vcc_sock_destruct;
	sock->sk = sk;
	return 0;
}

static struct sock *rose_alloc_sock(void)
{
	struct sock *sk;
	rose_cb *rose;

	if ((sk = sk_alloc(PF_ROSE, GFP_ATOMIC, 1)) == NULL)
		return NULL;

	if ((rose = kmalloc(sizeof(*rose), GFP_ATOMIC)) == NULL) {
		sk_free(sk);
		return NULL;
	}

	MOD_INC_USE_COUNT;

	memset(rose, 0x00, sizeof(*rose));

	sk->protinfo.rose = rose;
	rose->sk          = sk;

	return sk;
}

struct sock *alloc_atm_vcc_sk(int family)
{
	struct sock *sk;
	struct atm_vcc *vcc;

	sk = sk_alloc(family, GFP_KERNEL, 1);
	if (!sk) return NULL;
	vcc = sk->protinfo.af_atm = kmalloc(sizeof(*vcc),GFP_KERNEL);
	if (!vcc) {
		sk_free(sk);
		return NULL;
	}
	sock_init_data(NULL,sk);
	sk->destruct = atm_free_sock;
	memset(vcc,0,sizeof(*vcc));
	vcc->sk = sk;
	if (nodev_vccs) nodev_vccs->prev = vcc;
	vcc->prev = NULL;
	vcc->next = nodev_vccs;
	nodev_vccs = vcc;
	return sk;
}

struct sock *sk_clone(struct sock *sk, const gfp_t priority)
{
	struct sock *newsk = sk_alloc(sk->sk_family, priority, sk->sk_prot, 0);

	if (newsk != NULL) {
		struct sk_filter *filter;

		memcpy(newsk, sk, sk->sk_prot->obj_size);

		/* SANITY */
		sk_node_init(&newsk->sk_node);
		sock_lock_init(newsk);
		bh_lock_sock(newsk);

		atomic_set(&newsk->sk_rmem_alloc, 0);
		atomic_set(&newsk->sk_wmem_alloc, 0);
		atomic_set(&newsk->sk_omem_alloc, 0);
		skb_queue_head_init(&newsk->sk_receive_queue);
		skb_queue_head_init(&newsk->sk_write_queue);

		rwlock_init(&newsk->sk_dst_lock);
		rwlock_init(&newsk->sk_callback_lock);

		newsk->sk_dst_cache	= NULL;
		newsk->sk_wmem_queued	= 0;
		newsk->sk_forward_alloc = 0;
		newsk->sk_send_head	= NULL;
		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;

		sock_reset_flag(newsk, SOCK_DONE);
		skb_queue_head_init(&newsk->sk_error_queue);

		filter = newsk->sk_filter;
		if (filter != NULL)
			sk_filter_charge(newsk, filter);

		if (sk->sk_create_child)
			sk->sk_create_child(sk, newsk);

		if (unlikely(xfrm_sk_clone_policy(newsk))) {
			/* It is still raw copy of parent, so invalidate
			 * destructor and make plain sk_free() */
			newsk->sk_destruct = NULL;
			sk_free(newsk);
			newsk = NULL;
			goto out;
		}

		newsk->sk_err	   = 0;
		newsk->sk_priority = 0;
		atomic_set(&newsk->sk_refcnt, 2);

		/*
		 * Increment the counter in the same struct proto as the master
		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
		 * is the same as sk->sk_prot->socks, as this field was copied
		 * with memcpy).
		 *
		 * This _changes_ the previous behaviour, where
		 * tcp_create_openreq_child always was incrementing the
		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
		 * to be taken into account in all callers. -acme
		 */
		sk_refcnt_debug_inc(newsk);
		newsk->sk_socket = NULL;
		newsk->sk_sleep	 = NULL;

		if (newsk->sk_prot->sockets_allocated)
			atomic_inc(newsk->sk_prot->sockets_allocated);
	}
out:
	return newsk;
}