+/* 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);
+}
+
+