1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Implements the IPX routing routines.
4 * Code moved from af_ipx.c.
5 *
6 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 2003
7 *
8 * See net/ipx/ChangeLog.
9 */
10
11 #include <linux/list.h>
12 #include <linux/route.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15
16 #include <net/ipx.h>
17 #include <net/sock.h>
18
19 LIST_HEAD(ipx_routes);
20 DEFINE_RWLOCK(ipx_routes_lock);
21
22 extern struct ipx_interface *ipx_internal_net;
23
24 extern struct ipx_interface *ipxitf_find_using_net(__be32 net);
25 extern int ipxitf_demux_socket(struct ipx_interface *intrfc,
26 struct sk_buff *skb, int copy);
27 extern int ipxitf_demux_socket(struct ipx_interface *intrfc,
28 struct sk_buff *skb, int copy);
29
ipxrtr_lookup(__be32 net)30 struct ipx_route *ipxrtr_lookup(__be32 net)
31 {
32 struct ipx_route *r;
33
34 read_lock_bh(&ipx_routes_lock);
35 list_for_each_entry(r, &ipx_routes, node)
36 if (r->ir_net == net) {
37 ipxrtr_hold(r);
38 goto unlock;
39 }
40 r = NULL;
41 unlock:
42 read_unlock_bh(&ipx_routes_lock);
43 return r;
44 }
45
46 /*
47 * Caller must hold a reference to intrfc
48 */
ipxrtr_add_route(__be32 network,struct ipx_interface * intrfc,unsigned char * node)49 int ipxrtr_add_route(__be32 network, struct ipx_interface *intrfc,
50 unsigned char *node)
51 {
52 struct ipx_route *rt;
53 int rc;
54
55 /* Get a route structure; either existing or create */
56 rt = ipxrtr_lookup(network);
57 if (!rt) {
58 rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
59 rc = -EAGAIN;
60 if (!rt)
61 goto out;
62
63 refcount_set(&rt->refcnt, 1);
64 ipxrtr_hold(rt);
65 write_lock_bh(&ipx_routes_lock);
66 list_add(&rt->node, &ipx_routes);
67 write_unlock_bh(&ipx_routes_lock);
68 } else {
69 rc = -EEXIST;
70 if (intrfc == ipx_internal_net)
71 goto out_put;
72 }
73
74 rt->ir_net = network;
75 rt->ir_intrfc = intrfc;
76 if (!node) {
77 memset(rt->ir_router_node, '\0', IPX_NODE_LEN);
78 rt->ir_routed = 0;
79 } else {
80 memcpy(rt->ir_router_node, node, IPX_NODE_LEN);
81 rt->ir_routed = 1;
82 }
83
84 rc = 0;
85 out_put:
86 ipxrtr_put(rt);
87 out:
88 return rc;
89 }
90
ipxrtr_del_routes(struct ipx_interface * intrfc)91 void ipxrtr_del_routes(struct ipx_interface *intrfc)
92 {
93 struct ipx_route *r, *tmp;
94
95 write_lock_bh(&ipx_routes_lock);
96 list_for_each_entry_safe(r, tmp, &ipx_routes, node)
97 if (r->ir_intrfc == intrfc) {
98 list_del(&r->node);
99 ipxrtr_put(r);
100 }
101 write_unlock_bh(&ipx_routes_lock);
102 }
103
ipxrtr_create(struct ipx_route_definition * rd)104 static int ipxrtr_create(struct ipx_route_definition *rd)
105 {
106 struct ipx_interface *intrfc;
107 int rc = -ENETUNREACH;
108
109 /* Find the appropriate interface */
110 intrfc = ipxitf_find_using_net(rd->ipx_router_network);
111 if (!intrfc)
112 goto out;
113 rc = ipxrtr_add_route(rd->ipx_network, intrfc, rd->ipx_router_node);
114 ipxitf_put(intrfc);
115 out:
116 return rc;
117 }
118
ipxrtr_delete(__be32 net)119 static int ipxrtr_delete(__be32 net)
120 {
121 struct ipx_route *r, *tmp;
122 int rc;
123
124 write_lock_bh(&ipx_routes_lock);
125 list_for_each_entry_safe(r, tmp, &ipx_routes, node)
126 if (r->ir_net == net) {
127 /* Directly connected; can't lose route */
128 rc = -EPERM;
129 if (!r->ir_routed)
130 goto out;
131 list_del(&r->node);
132 ipxrtr_put(r);
133 rc = 0;
134 goto out;
135 }
136 rc = -ENOENT;
137 out:
138 write_unlock_bh(&ipx_routes_lock);
139 return rc;
140 }
141
142 /*
143 * The skb has to be unshared, we'll end up calling ipxitf_send, that'll
144 * modify the packet
145 */
ipxrtr_route_skb(struct sk_buff * skb)146 int ipxrtr_route_skb(struct sk_buff *skb)
147 {
148 struct ipxhdr *ipx = ipx_hdr(skb);
149 struct ipx_route *r = ipxrtr_lookup(IPX_SKB_CB(skb)->ipx_dest_net);
150
151 if (!r) { /* no known route */
152 kfree_skb(skb);
153 return 0;
154 }
155
156 ipxitf_hold(r->ir_intrfc);
157 ipxitf_send(r->ir_intrfc, skb, r->ir_routed ?
158 r->ir_router_node : ipx->ipx_dest.node);
159 ipxitf_put(r->ir_intrfc);
160 ipxrtr_put(r);
161
162 return 0;
163 }
164
165 /*
166 * Route an outgoing frame from a socket.
167 */
ipxrtr_route_packet(struct sock * sk,struct sockaddr_ipx * usipx,struct msghdr * msg,size_t len,int noblock)168 int ipxrtr_route_packet(struct sock *sk, struct sockaddr_ipx *usipx,
169 struct msghdr *msg, size_t len, int noblock)
170 {
171 struct sk_buff *skb;
172 struct ipx_sock *ipxs = ipx_sk(sk);
173 struct ipx_interface *intrfc;
174 struct ipxhdr *ipx;
175 size_t size;
176 int ipx_offset;
177 struct ipx_route *rt = NULL;
178 int rc;
179
180 /* Find the appropriate interface on which to send packet */
181 if (!usipx->sipx_network && ipx_primary_net) {
182 usipx->sipx_network = ipx_primary_net->if_netnum;
183 intrfc = ipx_primary_net;
184 } else {
185 rt = ipxrtr_lookup(usipx->sipx_network);
186 rc = -ENETUNREACH;
187 if (!rt)
188 goto out;
189 intrfc = rt->ir_intrfc;
190 }
191
192 ipxitf_hold(intrfc);
193 ipx_offset = intrfc->if_ipx_offset;
194 size = sizeof(struct ipxhdr) + len + ipx_offset;
195
196 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
197 if (!skb)
198 goto out_put;
199
200 skb_reserve(skb, ipx_offset);
201 skb->sk = sk;
202
203 /* Fill in IPX header */
204 skb_reset_network_header(skb);
205 skb_reset_transport_header(skb);
206 skb_put(skb, sizeof(struct ipxhdr));
207 ipx = ipx_hdr(skb);
208 ipx->ipx_pktsize = htons(len + sizeof(struct ipxhdr));
209 IPX_SKB_CB(skb)->ipx_tctrl = 0;
210 ipx->ipx_type = usipx->sipx_type;
211
212 IPX_SKB_CB(skb)->last_hop.index = -1;
213 #ifdef CONFIG_IPX_INTERN
214 IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
215 memcpy(ipx->ipx_source.node, ipxs->node, IPX_NODE_LEN);
216 #else
217 rc = ntohs(ipxs->port);
218 if (rc == 0x453 || rc == 0x452) {
219 /* RIP/SAP special handling for mars_nwe */
220 IPX_SKB_CB(skb)->ipx_source_net = intrfc->if_netnum;
221 memcpy(ipx->ipx_source.node, intrfc->if_node, IPX_NODE_LEN);
222 } else {
223 IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
224 memcpy(ipx->ipx_source.node, ipxs->intrfc->if_node,
225 IPX_NODE_LEN);
226 }
227 #endif /* CONFIG_IPX_INTERN */
228 ipx->ipx_source.sock = ipxs->port;
229 IPX_SKB_CB(skb)->ipx_dest_net = usipx->sipx_network;
230 memcpy(ipx->ipx_dest.node, usipx->sipx_node, IPX_NODE_LEN);
231 ipx->ipx_dest.sock = usipx->sipx_port;
232
233 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
234 if (rc) {
235 kfree_skb(skb);
236 goto out_put;
237 }
238
239 /* Apply checksum. Not allowed on 802.3 links. */
240 if (sk->sk_no_check_tx ||
241 intrfc->if_dlink_type == htons(IPX_FRAME_8023))
242 ipx->ipx_checksum = htons(0xFFFF);
243 else
244 ipx->ipx_checksum = ipx_cksum(ipx, len + sizeof(struct ipxhdr));
245
246 rc = ipxitf_send(intrfc, skb, (rt && rt->ir_routed) ?
247 rt->ir_router_node : ipx->ipx_dest.node);
248 out_put:
249 ipxitf_put(intrfc);
250 if (rt)
251 ipxrtr_put(rt);
252 out:
253 return rc;
254 }
255
256 /*
257 * We use a normal struct rtentry for route handling
258 */
ipxrtr_ioctl(unsigned int cmd,void __user * arg)259 int ipxrtr_ioctl(unsigned int cmd, void __user *arg)
260 {
261 struct rtentry rt; /* Use these to behave like 'other' stacks */
262 struct sockaddr_ipx *sg, *st;
263 int rc = -EFAULT;
264
265 if (copy_from_user(&rt, arg, sizeof(rt)))
266 goto out;
267
268 sg = (struct sockaddr_ipx *)&rt.rt_gateway;
269 st = (struct sockaddr_ipx *)&rt.rt_dst;
270
271 rc = -EINVAL;
272 if (!(rt.rt_flags & RTF_GATEWAY) || /* Direct routes are fixed */
273 sg->sipx_family != AF_IPX ||
274 st->sipx_family != AF_IPX)
275 goto out;
276
277 switch (cmd) {
278 case SIOCDELRT:
279 rc = ipxrtr_delete(st->sipx_network);
280 break;
281 case SIOCADDRT: {
282 struct ipx_route_definition f;
283 f.ipx_network = st->sipx_network;
284 f.ipx_router_network = sg->sipx_network;
285 memcpy(f.ipx_router_node, sg->sipx_node, IPX_NODE_LEN);
286 rc = ipxrtr_create(&f);
287 break;
288 }
289 }
290
291 out:
292 return rc;
293 }
294