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/spinlock.h>
  13
  14#include <net/ipx.h>
  15#include <net/sock.h>
  16
  17LIST_HEAD(ipx_routes);
  18DEFINE_RWLOCK(ipx_routes_lock);
  19
  20extern struct ipx_interface *ipx_internal_net;
  21
  22extern __be16 ipx_cksum(struct ipxhdr *packet, int length);
  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);
  28extern int ipxitf_send(struct ipx_interface *intrfc, struct sk_buff *skb,
  29                       char *node);
  30extern struct ipx_interface *ipxitf_find_using_net(__be32 net);
  31
  32struct 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;
  43unlock:
  44        read_unlock_bh(&ipx_routes_lock);
  45        return r;
  46}
  47
  48/*
  49 * Caller must hold a reference to intrfc
  50 */
  51int 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;
  87out_put:
  88        ipxrtr_put(rt);
  89out:
  90        return rc;
  91}
  92
  93void 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
 106static 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);
 117out:
 118        return rc;
 119}
 120
 121static 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;
 139out:
 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 */
 148int 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 */
 170int 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_reset_network_header(skb);
 207        skb_reset_transport_header(skb);
 208        skb_put(skb, sizeof(struct ipxhdr));
 209        ipx = ipx_hdr(skb);
 210        ipx->ipx_pktsize = htons(len + sizeof(struct ipxhdr));
 211        IPX_SKB_CB(skb)->ipx_tctrl = 0;
 212        ipx->ipx_type    = usipx->sipx_type;
 213
 214        IPX_SKB_CB(skb)->last_hop.index = -1;
 215#ifdef CONFIG_IPX_INTERN
 216        IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
 217        memcpy(ipx->ipx_source.node, ipxs->node, IPX_NODE_LEN);
 218#else
 219        rc = ntohs(ipxs->port);
 220        if (rc == 0x453 || rc == 0x452) {
 221                /* RIP/SAP special handling for mars_nwe */
 222                IPX_SKB_CB(skb)->ipx_source_net = intrfc->if_netnum;
 223                memcpy(ipx->ipx_source.node, intrfc->if_node, IPX_NODE_LEN);
 224        } else {
 225                IPX_SKB_CB(skb)->ipx_source_net = ipxs->intrfc->if_netnum;
 226                memcpy(ipx->ipx_source.node, ipxs->intrfc->if_node,
 227                        IPX_NODE_LEN);
 228        }
 229#endif  /* CONFIG_IPX_INTERN */
 230        ipx->ipx_source.sock            = ipxs->port;
 231        IPX_SKB_CB(skb)->ipx_dest_net   = usipx->sipx_network;
 232        memcpy(ipx->ipx_dest.node, usipx->sipx_node, IPX_NODE_LEN);
 233        ipx->ipx_dest.sock              = usipx->sipx_port;
 234
 235        rc = memcpy_fromiovec(skb_put(skb, len), iov, len);
 236        if (rc) {
 237                kfree_skb(skb);
 238                goto out_put;
 239        }
 240
 241        /* Apply checksum. Not allowed on 802.3 links. */
 242        if (sk->sk_no_check || intrfc->if_dlink_type == htons(IPX_FRAME_8023))
 243                ipx->ipx_checksum = htons(0xFFFF);
 244        else
 245                ipx->ipx_checksum = ipx_cksum(ipx, len + sizeof(struct ipxhdr));
 246
 247        rc = ipxitf_send(intrfc, skb, (rt && rt->ir_routed) ?
 248                         rt->ir_router_node : ipx->ipx_dest.node);
 249out_put:
 250        ipxitf_put(intrfc);
 251        if (rt)
 252                ipxrtr_put(rt);
 253out:
 254        return rc;
 255}
 256
 257/*
 258 * We use a normal struct rtentry for route handling
 259 */
 260int ipxrtr_ioctl(unsigned int cmd, void __user *arg)
 261{
 262        struct rtentry rt;      /* Use these to behave like 'other' stacks */
 263        struct sockaddr_ipx *sg, *st;
 264        int rc = -EFAULT;
 265
 266        if (copy_from_user(&rt, arg, sizeof(rt)))
 267                goto out;
 268
 269        sg = (struct sockaddr_ipx *)&rt.rt_gateway;
 270        st = (struct sockaddr_ipx *)&rt.rt_dst;
 271
 272        rc = -EINVAL;
 273        if (!(rt.rt_flags & RTF_GATEWAY) || /* Direct routes are fixed */
 274            sg->sipx_family != AF_IPX ||
 275            st->sipx_family != AF_IPX)
 276                goto out;
 277
 278        switch (cmd) {
 279        case SIOCDELRT:
 280                rc = ipxrtr_delete(st->sipx_network);
 281                break;
 282        case SIOCADDRT: {
 283                struct ipx_route_definition f;
 284                f.ipx_network           = st->sipx_network;
 285                f.ipx_router_network    = sg->sipx_network;
 286                memcpy(f.ipx_router_node, sg->sipx_node, IPX_NODE_LEN);
 287                rc = ipxrtr_create(&f);
 288                break;
 289        }
 290        }
 291
 292out:
 293        return rc;
 294}
 295