Phonet: emit errors when a packet cannot be delivered locally (be0c52bf) · Commits · EulixOS / Software / Kernel

include/linux/phonet.h

+32 −0

Original line number	Diff line number	Diff line
		@@ -45,6 +45,38 @@ struct phonethdr {
		__u8 pn_sobj;
		} __attribute__((packed));

		/* Common Phonet payload header */
		struct phonetmsg {
		__u8 pn_trans_id; /* transaction ID */
		__u8 pn_msg_id; /* message type */
		union {
		struct {
		__u8 pn_submsg_id; /* message subtype */
		__u8 pn_data[5];
		} base;
		struct {
		__u16 pn_e_res_id; /* extended resource ID */
		__u8 pn_e_submsg_id; /* message subtype */
		__u8 pn_e_data[3];
		} ext;
		} pn_msg_u;
		};
		#define PN_COMMON_MESSAGE 0xF0
		#define PN_PREFIX 0xE0 /* resource for extended messages */
		#define pn_submsg_id pn_msg_u.base.pn_submsg_id
		#define pn_e_submsg_id pn_msg_u.ext.pn_e_submsg_id
		#define pn_e_res_id pn_msg_u.ext.pn_e_res_id
		#define pn_data pn_msg_u.base.pn_data
		#define pn_e_data pn_msg_u.ext.pn_e_data

		/* data for unreachable errors */
		#define PN_COMM_SERVICE_NOT_IDENTIFIED_RESP 0x01
		#define PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP 0x14
		#define pn_orig_msg_id pn_data[0]
		#define pn_status pn_data[1]
		#define pn_e_orig_msg_id pn_e_data[0]
		#define pn_e_status pn_e_data[1]

		/* Phonet socket address structure */
		struct sockaddr_pn {
		sa_family_t spn_family;

include/net/phonet/phonet.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -60,6 +60,11 @@ static inline struct phonethdr pn_hdr(struct sk_buff skb)
		return (struct phonethdr *)skb_network_header(skb);
		}

		static inline struct phonetmsg pn_msg(struct sk_buff skb)
		{
		return (struct phonetmsg *)skb_transport_header(skb);
		}

		/*
		* Get the other party's sockaddr from received skb. The skb begins
		* with a Phonet header.

net/phonet/af_phonet.c

+92 −4

Original line number	Diff line number	Diff line
		@@ -132,7 +132,7 @@ 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)
		u16 dst, u16 src, u8 res, u8 irq)
		{
		struct phonethdr *ph;
		int err;
		@@ -163,6 +163,9 @@ static int pn_send(struct sk_buff skb, struct net_device dev,
		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 {
		@@ -181,6 +184,19 @@ static int pn_send(struct sk_buff skb, struct net_device dev,
		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.
		@@ -211,7 +227,7 @@ int pn_skb_send(struct sock sk, struct sk_buff skb,
		src = pn_object(saddr, pn_obj(src));

		err = pn_send(skb, dev, pn_sockaddr_get_object(target),
		src, pn_sockaddr_get_resource(target));
		src, pn_sockaddr_get_resource(target), 0);
		dev_put(dev);
		return err;

		@@ -223,6 +239,73 @@ int pn_skb_send(struct sock sk, struct sk_buff skb,
		}
		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 */

		/*
		@@ -260,8 +343,13 @@ static int phonet_rcv(struct sk_buff skb, struct net_device dev,
		goto out; /* currently, we cannot be device 0 */

		sk = pn_find_sock_by_sa(&sa);
		if (sk == NULL)
		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);