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 __be16 ipx_cksum(struct ipxhdr *packet, int length);
  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 extern int ipxitf_send(struct ipx_interface *intrfc, struct sk_buff *skb,
  30                        char *node);
  31 extern struct ipx_interface *ipxitf_find_using_net(__be32 net);
  32
  33 struct ipx_route *ipxrtr_lookup(__be32 net)
  34 {
  35         struct ipx_route *r;
  36
  37         read_lock_bh(&ipx_routes_lock);
  38         list_for_each_entry(r, &ipx_routes, node)
  39                 if (r->ir_net == net) {
  40                         ipxrtr_hold(r);
  41                         goto unlock;
  42                 }
  43         r = NULL;
  44 unlock:
  45         read_unlock_bh(&ipx_routes_lock);
  46         return r;
  47 }
  48
  49 /*
  50  * Caller must hold a reference to intrfc
  51  */
  52 int ipxrtr_add_route(__be32 network, struct ipx_interface *intrfc,
  53                      unsigned char *node)
  54 {
  55         struct ipx_route *rt;
  56         int rc;
  57
  58         /* Get a route structure; either existing or create */
  59         rt = ipxrtr_lookup(network);
  60         if (!rt) {
  61                 rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
  62                 rc = -EAGAIN;
  63                 if (!rt)
  64                         goto out;
  65
  66                 atomic_set(&rt->refcnt, 1);
  67                 ipxrtr_hold(rt);
  68                 write_lock_bh(&ipx_routes_lock);
  69                 list_add(&rt->node, &ipx_routes);
  70                 write_unlock_bh(&ipx_routes_lock);
  71         } else {
  72                 rc = -EEXIST;
  73                 if (intrfc == ipx_internal_net)
  74                         goto out_put;
  75         }
  76
  77         rt->ir_net      = network;
  78         rt->ir_intrfc   = intrfc;
  79         if (!node) {
  80                 memset(rt->ir_router_node, '\0', IPX_NODE_LEN);
  81                 rt->ir_routed = 0;
  82         } else {
  83                 memcpy(rt->ir_router_node, node, IPX_NODE_LEN);
  84                 rt->ir_routed = 1;
  85         }
  86
  87         rc = 0;
  88 out_put:
  89         ipxrtr_put(rt);
  90 out:
  91         return rc;
  92 }
  93
  94 void ipxrtr_del_routes(struct ipx_interface *intrfc)
  95 {
  96         struct ipx_route *r, *tmp;
  97
  98         write_lock_bh(&ipx_routes_lock);
  99         list_for_each_entry_safe(r, tmp, &ipx_routes, node)
 100                 if (r->ir_intrfc == intrfc) {
 101                         list_del(&r->node);
 102                         ipxrtr_put(r);
 103                 }
 104         write_unlock_bh(&ipx_routes_lock);
 105 }
 106
 107 static int ipxrtr_create(struct ipx_route_definition *rd)
 108 {
 109         struct ipx_interface *intrfc;
 110         int rc = -ENETUNREACH;
 111
 112         /* Find the appropriate interface */
 113         intrfc = ipxitf_find_using_net(rd->ipx_router_network);
 114         if (!intrfc)
 115                 goto out;
 116         rc = ipxrtr_add_route(rd->ipx_network, intrfc, rd->ipx_router_node);
 117         ipxitf_put(intrfc);
 118 out:
 119         return rc;
 120 }
 121
 122 static int ipxrtr_delete(__be32 net)
 123 {
 124         struct ipx_route *r, *tmp;
 125         int rc;
 126
 127         write_lock_bh(&ipx_routes_lock);
 128         list_for_each_entry_safe(r, tmp, &ipx_routes, node)
 129                 if (r->ir_net == net) {
 130                         /* Directly connected; can't lose route */
 131                         rc = -EPERM;
 132                         if (!r->ir_routed)
 133                                 goto out;
 134                         list_del(&r->node);
 135                         ipxrtr_put(r);
 136                         rc = 0;
 137                         goto out;
 138                 }
 139         rc = -ENOENT;
 140 out:
 141         write_unlock_bh(&ipx_routes_lock);
 142         return rc;
 143 }
 144
 145 /*
 146  * The skb has to be unshared, we'll end up calling ipxitf_send, that'll
 147  * modify the packet
 148  */
 149 int ipxrtr_route_skb(struct sk_buff *skb)
 150 {
 151         struct ipxhdr *ipx = ipx_hdr(skb);
 152         struct ipx_route *r = ipxrtr_lookup(IPX_SKB_CB(skb)->ipx_dest_net);
 153
 154         if (!r) {       /* no known route */
 155                 kfree_skb(skb);
 156                 return 0;
 157         }
 158
 159         ipxitf_hold(r->ir_intrfc);
 160         ipxitf_send(r->ir_intrfc, skb, r->ir_routed ?
 161                         r->ir_router_node : ipx->ipx_dest.node);
 162         ipxitf_put(r->ir_intrfc);
 163         ipxrtr_put(r);
 164
 165         return 0;
 166 }
 167
 168 /*
 169  * Route an outgoing frame from a socket.
 170  */
 171 int ipxrtr_route_packet(struct sock *sk, struct sockaddr_ipx *usipx,
 172                         struct iovec *iov, size_t len, int noblock)
 173 {
 174         struct sk_buff *skb;
 175         struct ipx_sock *ipxs = ipx_sk(sk);
 176         struct ipx_interface *intrfc;
 177         struct ipxhdr *ipx;
 178         size_t size;
 179         int ipx_offset;
 180         struct ipx_route *rt = NULL;
 181         int rc;
 182
 183         /* Find the appropriate interface on which to send packet */
 184         if (!usipx->sipx_network && ipx_primary_net) {
 185                 usipx->sipx_network = ipx_primary_net->if_netnum;
 186                 intrfc = ipx_primary_net;
 187         } else {
 188                 rt = ipxrtr_lookup(usipx->sipx_network);
 189                 rc = -ENETUNREACH;
 190                 if (!rt)
 191                         goto out;
 192                 intrfc = rt->ir_intrfc;
 193         }
 194
 195         ipxitf_hold(intrfc);
 196         ipx_offset = intrfc->if_ipx_offset;
 197         size = sizeof(struct ipxhdr) + len + ipx_offset;
 198
 199         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 200         if (!skb)
 201                 goto out_put;
 202
 203         skb_reserve(skb, ipx_offset);
 204         skb->sk = sk;
 205
 206         /* Fill in IPX header */
 207         skb_reset_network_header(skb);
 208         skb_reset_transport_header(skb);
 209         skb_put(skb, sizeof(struct ipxhdr));
 210         ipx = ipx_hdr(skb);
 211         ipx->ipx_pktsize = htons(len + sizeof(struct ipxhdr));
 212         IPX_SKB_CB(skb)->ipx_tctrl = 0;
 213         ipx->ipx_type    = usipx->sipx_type;
 214
 215         IPX_SKB_CB(skb)->last_hop.index = -1;
 216 #ifdef CONFIG_IPX_INTERN
 217         IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
 218         memcpy(ipx->ipx_source.node, ipxs->node, IPX_NODE_LEN);
 219 #else
 220         rc = ntohs(ipxs->port);
 221         if (rc == 0x453 || rc == 0x452) {
 222                 /* RIP/SAP special handling for mars_nwe */
 223                 IPX_SKB_CB(skb)->ipx_source_net = intrfc->if_netnum;
 224                 memcpy(ipx->ipx_source.node, intrfc->if_node, IPX_NODE_LEN);
 225         } else {
 226                 IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
 227                 memcpy(ipx->ipx_source.node, ipxs->intrfc->if_node,
 228                         IPX_NODE_LEN);
 229         }
 230 #endif  /* CONFIG_IPX_INTERN */
 231         ipx->ipx_source.sock            = ipxs->port;
 232         IPX_SKB_CB(skb)->ipx_dest_net   = usipx->sipx_network;
 233         memcpy(ipx->ipx_dest.node, usipx->sipx_node, IPX_NODE_LEN);
 234         ipx->ipx_dest.sock              = usipx->sipx_port;
 235
 236         rc = memcpy_fromiovec(skb_put(skb, len), iov, len);
 237         if (rc) {
 238                 kfree_skb(skb);
 239                 goto out_put;
 240         }
 241
 242         /* Apply checksum. Not allowed on 802.3 links. */
 243         if (sk->sk_no_check || intrfc->if_dlink_type == htons(IPX_FRAME_8023))
 244                 ipx->ipx_checksum = htons(0xFFFF);
 245         else
 246                 ipx->ipx_checksum = ipx_cksum(ipx, len + sizeof(struct ipxhdr));
 247
 248         rc = ipxitf_send(intrfc, skb, (rt && rt->ir_routed) ?
 249                          rt->ir_router_node : ipx->ipx_dest.node);
 250 out_put:
 251         ipxitf_put(intrfc);
 252         if (rt)
 253                 ipxrtr_put(rt);
 254 out:
 255         return rc;
 256 }
 257
 258 /*
 259  * We use a normal struct rtentry for route handling
 260  */
 261 int ipxrtr_ioctl(unsigned int cmd, void __user *arg)
 262 {
 263         struct rtentry rt;      /* Use these to behave like 'other' stacks */
 264         struct sockaddr_ipx *sg, *st;
 265         int rc = -EFAULT;
 266
 267         if (copy_from_user(&rt, arg, sizeof(rt)))
 268                 goto out;
 269
 270         sg = (struct sockaddr_ipx *)&rt.rt_gateway;
 271         st = (struct sockaddr_ipx *)&rt.rt_dst;
 272
 273         rc = -EINVAL;
 274         if (!(rt.rt_flags & RTF_GATEWAY) || /* Direct routes are fixed */
 275             sg->sipx_family != AF_IPX ||
 276             st->sipx_family != AF_IPX)
 277                 goto out;
 278
 279         switch (cmd) {
 280         case SIOCDELRT:
 281                 rc = ipxrtr_delete(st->sipx_network);
 282                 break;
 283         case SIOCADDRT: {
 284                 struct ipx_route_definition f;
 285                 f.ipx_network           = st->sipx_network;
 286                 f.ipx_router_network    = sg->sipx_network;
 287                 memcpy(f.ipx_router_node, sg->sipx_node, IPX_NODE_LEN);
 288                 rc = ipxrtr_create(&f);
 289                 break;
 290         }
 291         }
 292
 293 out:
 294         return rc;
 295 }