net/ipx/ipx_route.c

   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/spinlock.h>
  13
  14 #include <net/ipx.h>
  15 #include <net/sock.h>
  16
  17 LIST_HEAD(ipx_routes);
  18 DEFINE_RWLOCK(ipx_routes_lock);
  19
  20 extern struct ipx_interface *ipx_internal_net;
  21
  22 extern __be16 ipx_cksum(struct ipxhdr *packet, int length);
  23 extern struct ipx_interface *ipxitf_find_using_net(__be32 net);
  24 extern int ipxitf_demux_socket(struct ipx_interface *intrfc,
  25                                struct sk_buff *skb, int copy);
  26 extern int ipxitf_demux_socket(struct ipx_interface *intrfc,
  27                                struct sk_buff *skb, int copy);
  28 extern int ipxitf_send(struct ipx_interface *intrfc, struct sk_buff *skb,
  29                        char *node);
  30 extern struct ipx_interface *ipxitf_find_using_net(__be32 net);
  31
  32 struct ipx_route *ipxrtr_lookup(__be32 net)
  33 {
  34         struct ipx_route *r;
  35
  36         read_lock_bh(&ipx_routes_lock);
  37         list_for_each_entry(r, &ipx_routes, node)
  38                 if (r->ir_net == net) {
  39                         ipxrtr_hold(r);
  40                         goto unlock;
  41                 }
  42         r = NULL;
  43 unlock:
  44         read_unlock_bh(&ipx_routes_lock);
  45         return r;
  46 }
  47
  48 /*
  49  * Caller must hold a reference to intrfc
  50  */
  51 int ipxrtr_add_route(__be32 network, struct ipx_interface *intrfc,
  52                      unsigned char *node)
  53 {
  54         struct ipx_route *rt;
  55         int rc;
  56
  57         /* Get a route structure; either existing or create */
  58         rt = ipxrtr_lookup(network);
  59         if (!rt) {
  60                 rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
  61                 rc = -EAGAIN;
  62                 if (!rt)
  63                         goto out;
  64
  65                 atomic_set(&rt->refcnt, 1);
  66                 ipxrtr_hold(rt);
  67                 write_lock_bh(&ipx_routes_lock);
  68                 list_add(&rt->node, &ipx_routes);
  69                 write_unlock_bh(&ipx_routes_lock);
  70         } else {
  71                 rc = -EEXIST;
  72                 if (intrfc == ipx_internal_net)
  73                         goto out_put;
  74         }
  75
  76         rt->ir_net      = network;
  77         rt->ir_intrfc   = intrfc;
  78         if (!node) {
  79                 memset(rt->ir_router_node, '\0', IPX_NODE_LEN);
  80                 rt->ir_routed = 0;
  81         } else {
  82                 memcpy(rt->ir_router_node, node, IPX_NODE_LEN);
  83                 rt->ir_routed = 1;
  84         }
  85
  86         rc = 0;
  87 out_put:
  88         ipxrtr_put(rt);
  89 out:
  90         return rc;
  91 }
  92
  93 void ipxrtr_del_routes(struct ipx_interface *intrfc)
  94 {
  95         struct ipx_route *r, *tmp;
  96
  97         write_lock_bh(&ipx_routes_lock);
  98         list_for_each_entry_safe(r, tmp, &ipx_routes, node)
  99                 if (r->ir_intrfc == intrfc) {
 100                         list_del(&r->node);
 101                         ipxrtr_put(r);
 102                 }
 103         write_unlock_bh(&ipx_routes_lock);
 104 }
 105
 106 static int ipxrtr_create(struct ipx_route_definition *rd)
 107 {
 108         struct ipx_interface *intrfc;
 109         int rc = -ENETUNREACH;
 110
 111         /* Find the appropriate interface */
 112         intrfc = ipxitf_find_using_net(rd->ipx_router_network);
 113         if (!intrfc)
 114                 goto out;
 115         rc = ipxrtr_add_route(rd->ipx_network, intrfc, rd->ipx_router_node);
 116         ipxitf_put(intrfc);
 117 out:
 118         return rc;
 119 }
 120
 121 static int ipxrtr_delete(__be32 net)
 122 {
 123         struct ipx_route *r, *tmp;
 124         int rc;
 125
 126         write_lock_bh(&ipx_routes_lock);
 127         list_for_each_entry_safe(r, tmp, &ipx_routes, node)
 128                 if (r->ir_net == net) {
 129                         /* Directly connected; can't lose route */
 130                         rc = -EPERM;
 131                         if (!r->ir_routed)
 132                                 goto out;
 133                         list_del(&r->node);
 134                         ipxrtr_put(r);
 135                         rc = 0;
 136                         goto out;
 137                 }
 138         rc = -ENOENT;
 139 out:
 140         write_unlock_bh(&ipx_routes_lock);
 141         return rc;
 142 }
 143
 144 /*
 145  * The skb has to be unshared, we'll end up calling ipxitf_send, that'll
 146  * modify the packet
 147  */
 148 int ipxrtr_route_skb(struct sk_buff *skb)
 149 {
 150         struct ipxhdr *ipx = ipx_hdr(skb);
 151         struct ipx_route *r = ipxrtr_lookup(IPX_SKB_CB(skb)->ipx_dest_net);
 152
 153         if (!r) {       /* no known route */
 154                 kfree_skb(skb);
 155                 return 0;
 156         }
 157
 158         ipxitf_hold(r->ir_intrfc);
 159         ipxitf_send(r->ir_intrfc, skb, r->ir_routed ?
 160                         r->ir_router_node : ipx->ipx_dest.node);
 161         ipxitf_put(r->ir_intrfc);
 162         ipxrtr_put(r);
 163
 164         return 0;
 165 }
 166
 167 /*
 168  * Route an outgoing frame from a socket.
 169  */
 170 int ipxrtr_route_packet(struct sock *sk, struct sockaddr_ipx *usipx,
 171                         struct iovec *iov, size_t len, int noblock)
 172 {
 173         struct sk_buff *skb;
 174         struct ipx_sock *ipxs = ipx_sk(sk);
 175         struct ipx_interface *intrfc;
 176         struct ipxhdr *ipx;
 177         size_t size;
 178         int ipx_offset;
 179         struct ipx_route *rt = NULL;
 180         int rc;
 181
 182         /* Find the appropriate interface on which to send packet */
 183         if (!usipx->sipx_network && ipx_primary_net) {
 184                 usipx->sipx_network = ipx_primary_net->if_netnum;
 185                 intrfc = ipx_primary_net;
 186         } else {
 187                 rt = ipxrtr_lookup(usipx->sipx_network);
 188                 rc = -ENETUNREACH;
 189                 if (!rt)
 190                         goto out;
 191                 intrfc = rt->ir_intrfc;
 192         }
 193
 194         ipxitf_hold(intrfc);
 195         ipx_offset = intrfc->if_ipx_offset;
 196         size = sizeof(struct ipxhdr) + len + ipx_offset;
 197
 198         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 199         if (!skb)
 200                 goto out_put;
 201
 202         skb_reserve(skb, ipx_offset);
 203         skb->sk = sk;
 204
 205         /* Fill in IPX header */
 206         skb->h.raw = skb->nh.raw = 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_fromiovec(skb_put(skb, len), iov, 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 || 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);
 247 out_put:
 248         ipxitf_put(intrfc);
 249         if (rt)
 250                 ipxrtr_put(rt);
 251 out:
 252         return rc;
 253 }
 254
 255 /*
 256  * We use a normal struct rtentry for route handling
 257  */
 258 int 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
 290 out:
 291         return rc;
 292 }