1/*
2 *	Implements the IPX routing routines.
3 *	Code moved from af_ipx.c.
4 *
5 *	Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 2003
6 *
7 *	See net/ipx/ChangeLog.
8 */
9
10#include <linux/list.h>
11#include <linux/route.h>
12#include <linux/slab.h>
13#include <linux/spinlock.h>
14
15#include <net/ipx.h>
16#include <net/sock.h>
17
18LIST_HEAD(ipx_routes);
19DEFINE_RWLOCK(ipx_routes_lock);
20
21extern struct ipx_interface *ipx_internal_net;
22
23extern struct ipx_interface *ipxitf_find_using_net(__be32 net);
24extern int ipxitf_demux_socket(struct ipx_interface *intrfc,
25			       struct sk_buff *skb, int copy);
26extern int ipxitf_demux_socket(struct ipx_interface *intrfc,
27			       struct sk_buff *skb, int copy);
28
29struct ipx_route *ipxrtr_lookup(__be32 net)
30{
31	struct ipx_route *r;
32
33	read_lock_bh(&ipx_routes_lock);
34	list_for_each_entry(r, &ipx_routes, node)
35		if (r->ir_net == net) {
36			ipxrtr_hold(r);
37			goto unlock;
38		}
39	r = NULL;
40unlock:
41	read_unlock_bh(&ipx_routes_lock);
42	return r;
43}
44
45/*
46 * Caller must hold a reference to intrfc
47 */
48int ipxrtr_add_route(__be32 network, struct ipx_interface *intrfc,
49		     unsigned char *node)
50{
51	struct ipx_route *rt;
52	int rc;
53
54	/* Get a route structure; either existing or create */
55	rt = ipxrtr_lookup(network);
56	if (!rt) {
57		rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
58		rc = -EAGAIN;
59		if (!rt)
60			goto out;
61
62		atomic_set(&rt->refcnt, 1);
63		ipxrtr_hold(rt);
64		write_lock_bh(&ipx_routes_lock);
65		list_add(&rt->node, &ipx_routes);
66		write_unlock_bh(&ipx_routes_lock);
67	} else {
68		rc = -EEXIST;
69		if (intrfc == ipx_internal_net)
70			goto out_put;
71	}
72
73	rt->ir_net 	= network;
74	rt->ir_intrfc 	= intrfc;
75	if (!node) {
76		memset(rt->ir_router_node, '\0', IPX_NODE_LEN);
77		rt->ir_routed = 0;
78	} else {
79		memcpy(rt->ir_router_node, node, IPX_NODE_LEN);
80		rt->ir_routed = 1;
81	}
82
83	rc = 0;
84out_put:
85	ipxrtr_put(rt);
86out:
87	return rc;
88}
89
90void ipxrtr_del_routes(struct ipx_interface *intrfc)
91{
92	struct ipx_route *r, *tmp;
93
94	write_lock_bh(&ipx_routes_lock);
95	list_for_each_entry_safe(r, tmp, &ipx_routes, node)
96		if (r->ir_intrfc == intrfc) {
97			list_del(&r->node);
98			ipxrtr_put(r);
99		}
100	write_unlock_bh(&ipx_routes_lock);
101}
102
103static int ipxrtr_create(struct ipx_route_definition *rd)
104{
105	struct ipx_interface *intrfc;
106	int rc = -ENETUNREACH;
107
108	/* Find the appropriate interface */
109	intrfc = ipxitf_find_using_net(rd->ipx_router_network);
110	if (!intrfc)
111		goto out;
112	rc = ipxrtr_add_route(rd->ipx_network, intrfc, rd->ipx_router_node);
113	ipxitf_put(intrfc);
114out:
115	return rc;
116}
117
118static int ipxrtr_delete(__be32 net)
119{
120	struct ipx_route *r, *tmp;
121	int rc;
122
123	write_lock_bh(&ipx_routes_lock);
124	list_for_each_entry_safe(r, tmp, &ipx_routes, node)
125		if (r->ir_net == net) {
126			/* Directly connected; can't lose route */
127			rc = -EPERM;
128			if (!r->ir_routed)
129				goto out;
130			list_del(&r->node);
131			ipxrtr_put(r);
132			rc = 0;
133			goto out;
134		}
135	rc = -ENOENT;
136out:
137	write_unlock_bh(&ipx_routes_lock);
138	return rc;
139}
140
141/*
142 * The skb has to be unshared, we'll end up calling ipxitf_send, that'll
143 * modify the packet
144 */
145int ipxrtr_route_skb(struct sk_buff *skb)
146{
147	struct ipxhdr *ipx = ipx_hdr(skb);
148	struct ipx_route *r = ipxrtr_lookup(IPX_SKB_CB(skb)->ipx_dest_net);
149
150	if (!r) {	/* no known route */
151		kfree_skb(skb);
152		return 0;
153	}
154
155	ipxitf_hold(r->ir_intrfc);
156	ipxitf_send(r->ir_intrfc, skb, r->ir_routed ?
157			r->ir_router_node : ipx->ipx_dest.node);
158	ipxitf_put(r->ir_intrfc);
159	ipxrtr_put(r);
160
161	return 0;
162}
163
164/*
165 * Route an outgoing frame from a socket.
166 */
167int ipxrtr_route_packet(struct sock *sk, struct sockaddr_ipx *usipx,
168			struct iovec *iov, size_t len, int noblock)
169{
170	struct sk_buff *skb;
171	struct ipx_sock *ipxs = ipx_sk(sk);
172	struct ipx_interface *intrfc;
173	struct ipxhdr *ipx;
174	size_t size;
175	int ipx_offset;
176	struct ipx_route *rt = NULL;
177	int rc;
178
179	/* Find the appropriate interface on which to send packet */
180	if (!usipx->sipx_network && ipx_primary_net) {
181		usipx->sipx_network = ipx_primary_net->if_netnum;
182		intrfc = ipx_primary_net;
183	} else {
184		rt = ipxrtr_lookup(usipx->sipx_network);
185		rc = -ENETUNREACH;
186		if (!rt)
187			goto out;
188		intrfc = rt->ir_intrfc;
189	}
190
191	ipxitf_hold(intrfc);
192	ipx_offset = intrfc->if_ipx_offset;
193	size = sizeof(struct ipxhdr) + len + ipx_offset;
194
195	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
196	if (!skb)
197		goto out_put;
198
199	skb_reserve(skb, ipx_offset);
200	skb->sk = sk;
201
202	/* Fill in IPX header */
203	skb_reset_network_header(skb);
204	skb_reset_transport_header(skb);
205	skb_put(skb, sizeof(struct ipxhdr));
206	ipx = ipx_hdr(skb);
207	ipx->ipx_pktsize = htons(len + sizeof(struct ipxhdr));
208	IPX_SKB_CB(skb)->ipx_tctrl = 0;
209	ipx->ipx_type 	 = usipx->sipx_type;
210
211	IPX_SKB_CB(skb)->last_hop.index = -1;
212#ifdef CONFIG_IPX_INTERN
213	IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
214	memcpy(ipx->ipx_source.node, ipxs->node, IPX_NODE_LEN);
215#else
216	rc = ntohs(ipxs->port);
217	if (rc == 0x453 || rc == 0x452) {
218		/* RIP/SAP special handling for mars_nwe */
219		IPX_SKB_CB(skb)->ipx_source_net = intrfc->if_netnum;
220		memcpy(ipx->ipx_source.node, intrfc->if_node, IPX_NODE_LEN);
221	} else {
222		IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
223		memcpy(ipx->ipx_source.node, ipxs->intrfc->if_node,
224			IPX_NODE_LEN);
225	}
226#endif	/* CONFIG_IPX_INTERN */
227	ipx->ipx_source.sock		= ipxs->port;
228	IPX_SKB_CB(skb)->ipx_dest_net	= usipx->sipx_network;
229	memcpy(ipx->ipx_dest.node, usipx->sipx_node, IPX_NODE_LEN);
230	ipx->ipx_dest.sock		= usipx->sipx_port;
231
232	rc = memcpy_fromiovec(skb_put(skb, len), iov, len);
233	if (rc) {
234		kfree_skb(skb);
235		goto out_put;
236	}
237
238	/* Apply checksum. Not allowed on 802.3 links. */
239	if (sk->sk_no_check_tx ||
240	    intrfc->if_dlink_type == htons(IPX_FRAME_8023))
241		ipx->ipx_checksum = htons(0xFFFF);
242	else
243		ipx->ipx_checksum = ipx_cksum(ipx, len + sizeof(struct ipxhdr));
244
245	rc = ipxitf_send(intrfc, skb, (rt && rt->ir_routed) ?
246			 rt->ir_router_node : ipx->ipx_dest.node);
247out_put:
248	ipxitf_put(intrfc);
249	if (rt)
250		ipxrtr_put(rt);
251out:
252	return rc;
253}
254
255/*
256 * We use a normal struct rtentry for route handling
257 */
258int ipxrtr_ioctl(unsigned int cmd, void __user *arg)
259{
260	struct rtentry rt;	/* Use these to behave like 'other' stacks */
261	struct sockaddr_ipx *sg, *st;
262	int rc = -EFAULT;
263
264	if (copy_from_user(&rt, arg, sizeof(rt)))
265		goto out;
266
267	sg = (struct sockaddr_ipx *)&rt.rt_gateway;
268	st = (struct sockaddr_ipx *)&rt.rt_dst;
269
270	rc = -EINVAL;
271	if (!(rt.rt_flags & RTF_GATEWAY) || /* Direct routes are fixed */
272	    sg->sipx_family != AF_IPX ||
273	    st->sipx_family != AF_IPX)
274		goto out;
275
276	switch (cmd) {
277	case SIOCDELRT:
278		rc = ipxrtr_delete(st->sipx_network);
279		break;
280	case SIOCADDRT: {
281		struct ipx_route_definition f;
282		f.ipx_network		= st->sipx_network;
283		f.ipx_router_network	= sg->sipx_network;
284		memcpy(f.ipx_router_node, sg->sipx_node, IPX_NODE_LEN);
285		rc = ipxrtr_create(&f);
286		break;
287	}
288	}
289
290out:
291	return rc;
292}
293