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authorRemi Denis-Courmont <remi.denis-courmont@nokia.com>2008-09-22 23:09:13 -0400
committerDavid S. Miller <davem@davemloft.net>2008-09-22 23:09:13 -0400
commitbe0c52bfed7f7828494fa00060efd5d758e92580 (patch)
tree1261d101dee4c1d440d1d90c974c62339a556843 /net/phonet/af_phonet.c
parent87ab4e20b445c6d2d2727ab4f96fa17f7259511e (diff)
Phonet: emit errors when a packet cannot be delivered locally
When there is no listener socket for a received packet, send an error back to the sender. Signed-off-by: Remi Denis-Courmont <remi.denis-courmont@nokia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/phonet/af_phonet.c')
-rw-r--r--net/phonet/af_phonet.c96
1 files changed, 92 insertions, 4 deletions
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c
index 50dc258d5aa2..1d8df6b7e3df 100644
--- a/net/phonet/af_phonet.c
+++ b/net/phonet/af_phonet.c
@@ -132,7 +132,7 @@ EXPORT_SYMBOL(phonet_header_ops);
132 * Prepends an ISI header and sends a datagram. 132 * Prepends an ISI header and sends a datagram.
133 */ 133 */
134static int pn_send(struct sk_buff *skb, struct net_device *dev, 134static int pn_send(struct sk_buff *skb, struct net_device *dev,
135 u16 dst, u16 src, u8 res) 135 u16 dst, u16 src, u8 res, u8 irq)
136{ 136{
137 struct phonethdr *ph; 137 struct phonethdr *ph;
138 int err; 138 int err;
@@ -163,7 +163,10 @@ static int pn_send(struct sk_buff *skb, struct net_device *dev,
163 skb_reset_mac_header(skb); 163 skb_reset_mac_header(skb);
164 skb->pkt_type = PACKET_LOOPBACK; 164 skb->pkt_type = PACKET_LOOPBACK;
165 skb_orphan(skb); 165 skb_orphan(skb);
166 netif_rx_ni(skb); 166 if (irq)
167 netif_rx(skb);
168 else
169 netif_rx_ni(skb);
167 err = 0; 170 err = 0;
168 } else { 171 } else {
169 err = dev_hard_header(skb, dev, ntohs(skb->protocol), 172 err = dev_hard_header(skb, dev, ntohs(skb->protocol),
@@ -181,6 +184,19 @@ drop:
181 return err; 184 return err;
182} 185}
183 186
187static int pn_raw_send(const void *data, int len, struct net_device *dev,
188 u16 dst, u16 src, u8 res)
189{
190 struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC);
191 if (skb == NULL)
192 return -ENOMEM;
193
194 skb_reserve(skb, MAX_PHONET_HEADER);
195 __skb_put(skb, len);
196 skb_copy_to_linear_data(skb, data, len);
197 return pn_send(skb, dev, dst, src, res, 1);
198}
199
184/* 200/*
185 * Create a Phonet header for the skb and send it out. Returns 201 * Create a Phonet header for the skb and send it out. Returns
186 * non-zero error code if failed. The skb is freed then. 202 * 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,
211 src = pn_object(saddr, pn_obj(src)); 227 src = pn_object(saddr, pn_obj(src));
212 228
213 err = pn_send(skb, dev, pn_sockaddr_get_object(target), 229 err = pn_send(skb, dev, pn_sockaddr_get_object(target),
214 src, pn_sockaddr_get_resource(target)); 230 src, pn_sockaddr_get_resource(target), 0);
215 dev_put(dev); 231 dev_put(dev);
216 return err; 232 return err;
217 233
@@ -223,6 +239,73 @@ drop:
223} 239}
224EXPORT_SYMBOL(pn_skb_send); 240EXPORT_SYMBOL(pn_skb_send);
225 241
242/* Do not send an error message in response to an error message */
243static inline int can_respond(struct sk_buff *skb)
244{
245 const struct phonethdr *ph;
246 const struct phonetmsg *pm;
247 u8 submsg_id;
248
249 if (!pskb_may_pull(skb, 3))
250 return 0;
251
252 ph = pn_hdr(skb);
253 if (phonet_address_get(skb->dev, ph->pn_rdev) != ph->pn_rdev)
254 return 0; /* we are not the destination */
255 if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
256 return 0;
257
258 ph = pn_hdr(skb); /* re-acquires the pointer */
259 pm = pn_msg(skb);
260 if (pm->pn_msg_id != PN_COMMON_MESSAGE)
261 return 1;
262 submsg_id = (ph->pn_res == PN_PREFIX)
263 ? pm->pn_e_submsg_id : pm->pn_submsg_id;
264 if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
265 pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
266 return 1;
267 return 0;
268}
269
270static int send_obj_unreachable(struct sk_buff *rskb)
271{
272 const struct phonethdr *oph = pn_hdr(rskb);
273 const struct phonetmsg *opm = pn_msg(rskb);
274 struct phonetmsg resp;
275
276 memset(&resp, 0, sizeof(resp));
277 resp.pn_trans_id = opm->pn_trans_id;
278 resp.pn_msg_id = PN_COMMON_MESSAGE;
279 if (oph->pn_res == PN_PREFIX) {
280 resp.pn_e_res_id = opm->pn_e_res_id;
281 resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
282 resp.pn_e_orig_msg_id = opm->pn_msg_id;
283 resp.pn_e_status = 0;
284 } else {
285 resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
286 resp.pn_orig_msg_id = opm->pn_msg_id;
287 resp.pn_status = 0;
288 }
289 return pn_raw_send(&resp, sizeof(resp), rskb->dev,
290 pn_object(oph->pn_sdev, oph->pn_sobj),
291 pn_object(oph->pn_rdev, oph->pn_robj),
292 oph->pn_res);
293}
294
295static int send_reset_indications(struct sk_buff *rskb)
296{
297 struct phonethdr *oph = pn_hdr(rskb);
298 static const u8 data[4] = {
299 0x00 /* trans ID */, 0x10 /* subscribe msg */,
300 0x00 /* subscription count */, 0x00 /* dummy */
301 };
302
303 return pn_raw_send(data, sizeof(data), rskb->dev,
304 pn_object(oph->pn_sdev, 0x00),
305 pn_object(oph->pn_rdev, oph->pn_robj), 0x10);
306}
307
308
226/* packet type functions */ 309/* packet type functions */
227 310
228/* 311/*
@@ -260,8 +343,13 @@ static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
260 goto out; /* currently, we cannot be device 0 */ 343 goto out; /* currently, we cannot be device 0 */
261 344
262 sk = pn_find_sock_by_sa(&sa); 345 sk = pn_find_sock_by_sa(&sa);
263 if (sk == NULL) 346 if (sk == NULL) {
347 if (can_respond(skb)) {
348 send_obj_unreachable(skb);
349 send_reset_indications(skb);
350 }
264 goto out; 351 goto out;
352 }
265 353
266 /* Push data to the socket (or other sockets connected to it). */ 354 /* Push data to the socket (or other sockets connected to it). */
267 return sk_receive_skb(sk, skb, 0); 355 return sk_receive_skb(sk, skb, 0);