/* * File: af_phonet.c * * Phonet protocols family * * Copyright (C) 2008 Nokia Corporation. * * Authors: Sakari Ailus <sakari.ailus@nokia.com> * RĂ©mi Denis-Courmont * * 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 <linux/slab.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> /* Transport protocol registration */ static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly; static struct phonet_protocol *phonet_proto_get(unsigned int protocol) { struct phonet_protocol *pp; if (protocol >= PHONET_NPROTO) return NULL; rcu_read_lock(); pp = rcu_dereference(proto_tab[protocol]); if (pp && !try_module_get(pp->prot->owner)) pp = NULL; rcu_read_unlock(); return pp; } static inline void phonet_proto_put(struct phonet_protocol *pp) { module_put(pp->prot->owner); } /* protocol family functions */ static int pn_socket_create(struct net *net, struct socket *sock, int protocol, int kern) { struct sock *sk; struct pn_sock *pn; struct phonet_protocol *pnp; int err; 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); 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, kern); 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->dobject = 0; pn->resource = 0; sk->sk_prot->init(sk); err = 0; out: phonet_proto_put(pnp); return err; } static const 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 int 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 limit */ || skb->len + sizeof(struct phonethdr) > dev->mtu) { err = -EMSGSIZE; goto drop; } /* Broadcast sending is not implemented */ if (pn_addr(dst) == PNADDR_BROADCAST) { err = -EOPNOTSUPP; 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 (skb->pkt_type == PACKET_LOOPBACK) { skb_reset_mac_header(skb); skb_orphan(skb); err = (irq ? netif_rx(skb) : netif_rx_ni(skb)) ? -ENOBUFS : 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); if (unlikely(err > 0)) err = net_xmit_errno(err); } 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; if (phonet_address_lookup(dev_net(dev), pn_addr(dst)) == 0) skb->pkt_type = PACKET_LOOPBACK; 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 *net = sock_net(sk); struct net_device *dev; struct pn_sock *pn = pn_sk(sk); int err; u16 src, dst; u8 daddr, saddr, res; src = pn->sobject; if (target != NULL) { dst = pn_sockaddr_get_object(target); res = pn_sockaddr_get_resource(target); } else { dst = pn->dobject; res = pn->resource; } daddr = pn_addr(dst); err = -EHOSTUNREACH; if (sk->sk_bound_dev_if) dev = dev_get_by_index(net, sk->sk_bound_dev_if); else if (phonet_address_lookup(net, daddr) == 0) { dev = phonet_device_get(net); skb->pkt_type = PACKET_LOOPBACK; } else if (dst == 0) { /* Resource routing (small race until phonet_rcv()) */ struct sock *sk = pn_find_sock_by_res(net, res); if (sk) { sock_put(sk); dev = phonet_device_get(net); skb->pkt_type = PACKET_LOOPBACK; } else dev = phonet_route_output(net, daddr); } else dev = phonet_route_output(net, daddr); if (!dev || !(dev->flags & IFF_UP)) goto drop; saddr = phonet_address_get(dev, daddr); if (saddr == PN_NO_ADDR) goto drop; if (!pn_addr(src)) src = pn_object(saddr, pn_obj(src)); err = pn_send(skb, dev, dst, src, res, 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 (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5)) return 0; if (ph->pn_res == PN_COMMGR) /* indications */ 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), PN_COMMGR); } /* 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 net *net = dev_net(dev); struct phonethdr *ph; struct sockaddr_pn sa; u16 len; skb = skb_share_check(skb, GFP_ATOMIC); if (!skb) return NET_RX_DROP; /* 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); /* check if this is broadcasted */ if (pn_sockaddr_get_addr(&sa) == PNADDR_BROADCAST) { pn_deliver_sock_broadcast(net, skb); goto out; } /* resource routing */ if (pn_sockaddr_get_object(&sa) == 0) { struct sock *sk = pn_find_sock_by_res(net, sa.spn_resource); if (sk) return sk_receive_skb(sk, skb, 0); } /* check if we are the destination */ if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) { /* Phonet packet input */ struct sock *sk = pn_find_sock_by_sa(net, &sa); if (sk) return sk_receive_skb(sk, skb, 0); if (can_respond(skb)) { send_obj_unreachable(skb); send_reset_indications(skb); } } else if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) goto out; /* Race between address deletion and loopback */ else { /* Phonet packet routing */ struct net_device *out_dev; out_dev = phonet_route_output(net, pn_sockaddr_get_addr(&sa)); if (!out_dev) { net_dbg_ratelimited("No Phonet route to %02X\n", pn_sockaddr_get_addr(&sa)); goto out; } __skb_push(skb, sizeof(struct phonethdr)); skb->dev = out_dev; if (out_dev == dev) { net_dbg_ratelimited("Phonet loop to %02X on %s\n", pn_sockaddr_get_addr(&sa), dev->name); goto out_dev; } /* Some drivers (e.g. TUN) do not allocate HW header space */ if (skb_cow_head(skb, out_dev->hard_header_len)) goto out_dev; if (dev_hard_header(skb, out_dev, ETH_P_PHONET, NULL, NULL, skb->len) < 0) goto out_dev; dev_queue_xmit(skb); dev_put(out_dev); return NET_RX_SUCCESS; out_dev: dev_put(out_dev); } out: kfree_skb(skb); return NET_RX_DROP; } static struct packet_type phonet_packet_type __read_mostly = { .type = cpu_to_be16(ETH_P_PHONET), .func = phonet_rcv, }; static DEFINE_MUTEX(proto_tab_lock); int __init_or_module phonet_proto_register(unsigned 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; mutex_lock(&proto_tab_lock); if (proto_tab[protocol]) err = -EBUSY; else rcu_assign_pointer(proto_tab[protocol], pp); mutex_unlock(&proto_tab_lock); return err; } EXPORT_SYMBOL(phonet_proto_register); void phonet_proto_unregister(unsigned int protocol, struct phonet_protocol *pp) { mutex_lock(&proto_tab_lock); BUG_ON(proto_tab[protocol] != pp); RCU_INIT_POINTER(proto_tab[protocol], NULL); mutex_unlock(&proto_tab_lock); synchronize_rcu(); proto_unregister(pp->prot); } EXPORT_SYMBOL(phonet_proto_unregister); /* Module registration */ static int __init phonet_init(void) { int err; err = phonet_device_init(); if (err) return err; pn_sock_init(); err = sock_register(&phonet_proto_family); if (err) { printk(KERN_ALERT "phonet protocol family initialization failed\n"); goto err_sock; } dev_add_pack(&phonet_packet_type); 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); err_sock: 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);