LXR linux/net/ipx/ipx

   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 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);
 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