diff options
Diffstat (limited to 'net/phonet/af_phonet.c')
| -rw-r--r-- | net/phonet/af_phonet.c | 477 |
1 files changed, 477 insertions, 0 deletions
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c new file mode 100644 index 000000000000..9e9c6fce11aa --- /dev/null +++ b/net/phonet/af_phonet.c @@ -0,0 +1,477 @@ +/* + * File: af_phonet.c + * + * Phonet protocols family + * + * Copyright (C) 2008 Nokia Corporation. + * + * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com> + * Original author: Sakari Ailus <sakari.ailus@nokia.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <asm/unaligned.h> +#include <net/sock.h> + +#include <linux/if_phonet.h> +#include <linux/phonet.h> +#include <net/phonet/phonet.h> +#include <net/phonet/pn_dev.h> + +static struct net_proto_family phonet_proto_family; +static struct phonet_protocol *phonet_proto_get(int protocol); +static inline void phonet_proto_put(struct phonet_protocol *pp); + +/* protocol family functions */ + +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 (net != &init_net) + return -EAFNOSUPPORT; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + 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); +#ifdef CONFIG_KMOD + if (pnp == NULL && + request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0) + pnp = phonet_proto_get(protocol); +#endif + 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 struct net_proto_family phonet_proto_family = { + .family = PF_PHONET, + .create = pn_socket_create, + .owner = THIS_MODULE, +}; + +/* Phonet device header operations */ +static int pn_header_create(struct sk_buff *skb, struct net_device *dev, + unsigned short type, const void *daddr, + const void *saddr, unsigned len) +{ + u8 *media = skb_push(skb, 1); + + if (type != ETH_P_PHONET) + return -1; + + if (!saddr) + saddr = dev->dev_addr; + *media = *(const u8 *)saddr; + return 1; +} + +static int pn_header_parse(const struct sk_buff *skb, unsigned char *haddr) +{ + const u8 *media = skb_mac_header(skb); + *haddr = *media; + return 1; +} + +struct header_ops phonet_header_ops = { + .create = pn_header_create, + .parse = pn_header_parse, +}; +EXPORT_SYMBOL(phonet_header_ops); + +/* + * Prepends an ISI header and sends a datagram. + */ +static int pn_send(struct sk_buff *skb, struct net_device *dev, + u16 dst, u16 src, u8 res, u8 irq) +{ + struct phonethdr *ph; + int err; + + if (skb->len + 2 > 0xffff) { + /* Phonet length field would overflow */ + err = -EMSGSIZE; + goto drop; + } + + skb_reset_transport_header(skb); + WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */ + skb_push(skb, sizeof(struct phonethdr)); + skb_reset_network_header(skb); + ph = pn_hdr(skb); + ph->pn_rdev = pn_dev(dst); + ph->pn_sdev = pn_dev(src); + ph->pn_res = res; + ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph)); + ph->pn_robj = pn_obj(dst); + ph->pn_sobj = pn_obj(src); + + skb->protocol = htons(ETH_P_PHONET); + skb->priority = 0; + skb->dev = dev; + + if (pn_addr(src) == pn_addr(dst)) { + skb_reset_mac_header(skb); + skb->pkt_type = PACKET_LOOPBACK; + skb_orphan(skb); + if (irq) + netif_rx(skb); + else + netif_rx_ni(skb); + err = 0; + } else { + err = dev_hard_header(skb, dev, ntohs(skb->protocol), + NULL, NULL, skb->len); + if (err < 0) { + err = -EHOSTUNREACH; + goto drop; + } + err = dev_queue_xmit(skb); + } + + return err; +drop: + kfree_skb(skb); + return err; +} + +static int pn_raw_send(const void *data, int len, struct net_device *dev, + u16 dst, u16 src, u8 res) +{ + struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC); + if (skb == NULL) + return -ENOMEM; + + skb_reserve(skb, MAX_PHONET_HEADER); + __skb_put(skb, len); + skb_copy_to_linear_data(skb, data, len); + return pn_send(skb, dev, dst, src, res, 1); +} + +/* + * Create a Phonet header for the skb and send it out. Returns + * non-zero error code if failed. The skb is freed then. + */ +int pn_skb_send(struct sock *sk, struct sk_buff *skb, + const struct sockaddr_pn *target) +{ + struct net_device *dev; + struct pn_sock *pn = pn_sk(sk); + int err; + u16 src; + u8 daddr = pn_sockaddr_get_addr(target), saddr = PN_NO_ADDR; + + err = -EHOSTUNREACH; + if (sk->sk_bound_dev_if) + dev = dev_get_by_index(sock_net(sk), sk->sk_bound_dev_if); + else + dev = phonet_device_get(sock_net(sk)); + if (!dev || !(dev->flags & IFF_UP)) + goto drop; + + saddr = phonet_address_get(dev, daddr); + if (saddr == PN_NO_ADDR) + goto drop; + + src = pn->sobject; + if (!pn_addr(src)) + src = pn_object(saddr, pn_obj(src)); + + err = pn_send(skb, dev, pn_sockaddr_get_object(target), + src, pn_sockaddr_get_resource(target), 0); + dev_put(dev); + return err; + +drop: + kfree_skb(skb); + if (dev) + dev_put(dev); + return err; +} +EXPORT_SYMBOL(pn_skb_send); + +/* Do not send an error message in response to an error message */ +static inline int can_respond(struct sk_buff *skb) +{ + const struct phonethdr *ph; + const struct phonetmsg *pm; + u8 submsg_id; + + if (!pskb_may_pull(skb, 3)) + return 0; + + ph = pn_hdr(skb); + if (phonet_address_get(skb->dev, ph->pn_rdev) != ph->pn_rdev) + return 0; /* we are not the destination */ + if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5)) + return 0; + + ph = pn_hdr(skb); /* re-acquires the pointer */ + pm = pn_msg(skb); + if (pm->pn_msg_id != PN_COMMON_MESSAGE) + return 1; + submsg_id = (ph->pn_res == PN_PREFIX) + ? pm->pn_e_submsg_id : pm->pn_submsg_id; + if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP && + pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP) + return 1; + return 0; +} + +static int send_obj_unreachable(struct sk_buff *rskb) +{ + const struct phonethdr *oph = pn_hdr(rskb); + const struct phonetmsg *opm = pn_msg(rskb); + struct phonetmsg resp; + + memset(&resp, 0, sizeof(resp)); + resp.pn_trans_id = opm->pn_trans_id; + resp.pn_msg_id = PN_COMMON_MESSAGE; + if (oph->pn_res == PN_PREFIX) { + resp.pn_e_res_id = opm->pn_e_res_id; + resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP; + resp.pn_e_orig_msg_id = opm->pn_msg_id; + resp.pn_e_status = 0; + } else { + resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP; + resp.pn_orig_msg_id = opm->pn_msg_id; + resp.pn_status = 0; + } + return pn_raw_send(&resp, sizeof(resp), rskb->dev, + pn_object(oph->pn_sdev, oph->pn_sobj), + pn_object(oph->pn_rdev, oph->pn_robj), + oph->pn_res); +} + +static int send_reset_indications(struct sk_buff *rskb) +{ + struct phonethdr *oph = pn_hdr(rskb); + static const u8 data[4] = { + 0x00 /* trans ID */, 0x10 /* subscribe msg */, + 0x00 /* subscription count */, 0x00 /* dummy */ + }; + + return pn_raw_send(data, sizeof(data), rskb->dev, + pn_object(oph->pn_sdev, 0x00), + pn_object(oph->pn_rdev, oph->pn_robj), 0x10); +} + + +/* packet type functions */ + +/* + * Stuff received packets to associated sockets. + * On error, returns non-zero and releases the skb. + */ +static int phonet_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pkttype, + struct net_device *orig_dev) +{ + struct phonethdr *ph; + struct sock *sk; + struct sockaddr_pn sa; + u16 len; + + if (dev_net(dev) != &init_net) + goto out; + + /* check we have at least a full Phonet header */ + if (!pskb_pull(skb, sizeof(struct phonethdr))) + goto out; + + /* check that the advertised length is correct */ + ph = pn_hdr(skb); + len = get_unaligned_be16(&ph->pn_length); + if (len < 2) + goto out; + len -= 2; + if ((len > skb->len) || pskb_trim(skb, len)) + goto out; + skb_reset_transport_header(skb); + + pn_skb_get_dst_sockaddr(skb, &sa); + if (pn_sockaddr_get_addr(&sa) == 0) + goto out; /* currently, we cannot be device 0 */ + + sk = pn_find_sock_by_sa(&sa); + if (sk == NULL) { + if (can_respond(skb)) { + send_obj_unreachable(skb); + send_reset_indications(skb); + } + goto out; + } + + /* Push data to the socket (or other sockets connected to it). */ + return sk_receive_skb(sk, skb, 0); + +out: + kfree_skb(skb); + return NET_RX_DROP; +} + +static struct packet_type phonet_packet_type = { + .type = __constant_htons(ETH_P_PHONET), + .dev = NULL, + .func = phonet_rcv, +}; + +/* Transport protocol registration */ +static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly; +static DEFINE_SPINLOCK(proto_tab_lock); + +int __init_or_module phonet_proto_register(int protocol, + struct phonet_protocol *pp) +{ + int err = 0; + + if (protocol >= PHONET_NPROTO) + return -EINVAL; + + err = proto_register(pp->prot, 1); + if (err) + return err; + + spin_lock(&proto_tab_lock); + if (proto_tab[protocol]) + err = -EBUSY; + else + proto_tab[protocol] = pp; + spin_unlock(&proto_tab_lock); + + return err; +} +EXPORT_SYMBOL(phonet_proto_register); + +void phonet_proto_unregister(int protocol, struct phonet_protocol *pp) +{ + spin_lock(&proto_tab_lock); + BUG_ON(proto_tab[protocol] != pp); + proto_tab[protocol] = NULL; + spin_unlock(&proto_tab_lock); + proto_unregister(pp->prot); +} +EXPORT_SYMBOL(phonet_proto_unregister); + +static struct phonet_protocol *phonet_proto_get(int protocol) +{ + struct phonet_protocol *pp; + + if (protocol >= PHONET_NPROTO) + return NULL; + + spin_lock(&proto_tab_lock); + pp = proto_tab[protocol]; + if (pp && !try_module_get(pp->prot->owner)) + pp = NULL; + spin_unlock(&proto_tab_lock); + + return pp; +} + +static inline void phonet_proto_put(struct phonet_protocol *pp) +{ + module_put(pp->prot->owner); +} + +/* Module registration */ +static int __init phonet_init(void) +{ + int err; + + err = sock_register(&phonet_proto_family); + if (err) { + printk(KERN_ALERT + "phonet protocol family initialization failed\n"); + return err; + } + + phonet_device_init(); + dev_add_pack(&phonet_packet_type); + phonet_netlink_register(); + phonet_sysctl_init(); + + err = isi_register(); + if (err) + goto err; + return 0; + +err: + phonet_sysctl_exit(); + sock_unregister(PF_PHONET); + dev_remove_pack(&phonet_packet_type); + phonet_device_exit(); + return err; +} + +static void __exit phonet_exit(void) +{ + isi_unregister(); + phonet_sysctl_exit(); + sock_unregister(PF_PHONET); + dev_remove_pack(&phonet_packet_type); + phonet_device_exit(); +} + +module_init(phonet_init); +module_exit(phonet_exit); +MODULE_DESCRIPTION("Phonet protocol stack for Linux"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NETPROTO(PF_PHONET); |