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/slab.h>
  13 #include <linux/spinlock.h>
  14
  15 #include <net/ipx.h>
  16 #include <net/sock.h>
  17
  18 LIST_HEAD(ipx_routes);
  19 DEFINE_RWLOCK(ipx_routes_lock);
  20
  21 extern struct ipx_interface *ipx_internal_net;
  22
  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
  29 struct 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;
  40 unlock:
  41         read_unlock_bh(&ipx_routes_lock);
  42         return r;
  43 }
  44
  45 /*
  46  * Caller must hold a reference to intrfc
  47  */
  48 int 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;
  84 out_put:
  85         ipxrtr_put(rt);
  86 out:
  87         return rc;
  88 }
  89
  90 void 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
 103 static 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);
 114 out:
 115         return rc;
 116 }
 117
 118 static 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;
 136 out:
 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  */
 145 int 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  */
 167 int ipxrtr_route_packet(struct sock *sk, struct sockaddr_ipx *usipx,
 168                         struct msghdr *msg, 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_from_msg(skb_put(skb, len), msg, 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);
 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 }