net/atm/signaling.c

   1 /* net/atm/signaling.c - ATM signaling */
   2
   3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   4
   5 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
   6
   7 #include <linux/errno.h>        /* error codes */
   8 #include <linux/kernel.h>       /* printk */
   9 #include <linux/skbuff.h>
  10 #include <linux/wait.h>
  11 #include <linux/sched.h>        /* jiffies and HZ */
  12 #include <linux/atm.h>          /* ATM stuff */
  13 #include <linux/atmsap.h>
  14 #include <linux/atmsvc.h>
  15 #include <linux/atmdev.h>
  16 #include <linux/bitops.h>
  17 #include <linux/slab.h>
  18
  19 #include "resources.h"
  20 #include "signaling.h"
  21
  22 struct atm_vcc *sigd = NULL;
  23
  24 static void sigd_put_skb(struct sk_buff *skb)
  25 {
  26         if (!sigd) {
  27                 pr_debug("atmsvc: no signaling daemon\n");
  28                 kfree_skb(skb);
  29                 return;
  30         }
  31         atm_force_charge(sigd, skb->truesize);
  32         skb_queue_tail(&sk_atm(sigd)->sk_receive_queue, skb);
  33         sk_atm(sigd)->sk_data_ready(sk_atm(sigd));
  34 }
  35
  36 static void modify_qos(struct atm_vcc *vcc, struct atmsvc_msg *msg)
  37 {
  38         struct sk_buff *skb;
  39
  40         if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
  41             !test_bit(ATM_VF_READY, &vcc->flags))
  42                 return;
  43         msg->type = as_error;
  44         if (!vcc->dev->ops->change_qos)
  45                 msg->reply = -EOPNOTSUPP;
  46         else {
  47                 /* should lock VCC */
  48                 msg->reply = vcc->dev->ops->change_qos(vcc, &msg->qos,
  49                                                        msg->reply);
  50                 if (!msg->reply)
  51                         msg->type = as_okay;
  52         }
  53         /*
  54          * Should probably just turn around the old skb. But the, the buffer
  55          * space accounting needs to follow the change too. Maybe later.
  56          */
  57         while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
  58                 schedule();
  59         *(struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)) = *msg;
  60         sigd_put_skb(skb);
  61 }
  62
  63 static int sigd_send(struct atm_vcc *vcc, struct sk_buff *skb)
  64 {
  65         struct atmsvc_msg *msg;
  66         struct atm_vcc *session_vcc;
  67         struct sock *sk;
  68
  69         msg = (struct atmsvc_msg *) skb->data;
  70         WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc));
  71         vcc = *(struct atm_vcc **) &msg->vcc;
  72         pr_debug("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc);
  73         sk = sk_atm(vcc);
  74
  75         switch (msg->type) {
  76         case as_okay:
  77                 sk->sk_err = -msg->reply;
  78                 clear_bit(ATM_VF_WAITING, &vcc->flags);
  79                 if (!*vcc->local.sas_addr.prv && !*vcc->local.sas_addr.pub) {
  80                         vcc->local.sas_family = AF_ATMSVC;
  81                         memcpy(vcc->local.sas_addr.prv,
  82                                msg->local.sas_addr.prv, ATM_ESA_LEN);
  83                         memcpy(vcc->local.sas_addr.pub,
  84                                msg->local.sas_addr.pub, ATM_E164_LEN + 1);
  85                 }
  86                 session_vcc = vcc->session ? vcc->session : vcc;
  87                 if (session_vcc->vpi || session_vcc->vci)
  88                         break;
  89                 session_vcc->itf = msg->pvc.sap_addr.itf;
  90                 session_vcc->vpi = msg->pvc.sap_addr.vpi;
  91                 session_vcc->vci = msg->pvc.sap_addr.vci;
  92                 if (session_vcc->vpi || session_vcc->vci)
  93                         session_vcc->qos = msg->qos;
  94                 break;
  95         case as_error:
  96                 clear_bit(ATM_VF_REGIS, &vcc->flags);
  97                 clear_bit(ATM_VF_READY, &vcc->flags);
  98                 sk->sk_err = -msg->reply;
  99                 clear_bit(ATM_VF_WAITING, &vcc->flags);
 100                 break;
 101         case as_indicate:
 102                 vcc = *(struct atm_vcc **)&msg->listen_vcc;
 103                 sk = sk_atm(vcc);
 104                 pr_debug("as_indicate!!!\n");
 105                 lock_sock(sk);
 106                 if (sk_acceptq_is_full(sk)) {
 107                         sigd_enq(NULL, as_reject, vcc, NULL, NULL);
 108                         dev_kfree_skb(skb);
 109                         goto as_indicate_complete;
 110                 }
 111                 sk->sk_ack_backlog++;
 112                 skb_queue_tail(&sk->sk_receive_queue, skb);
 113                 pr_debug("waking sk_sleep(sk) 0x%p\n", sk_sleep(sk));
 114                 sk->sk_state_change(sk);
 115 as_indicate_complete:
 116                 release_sock(sk);
 117                 return 0;
 118         case as_close:
 119                 set_bit(ATM_VF_RELEASED, &vcc->flags);
 120                 vcc_release_async(vcc, msg->reply);
 121                 goto out;
 122         case as_modify:
 123                 modify_qos(vcc, msg);
 124                 break;
 125         case as_addparty:
 126         case as_dropparty:
 127                 sk->sk_err_soft = -msg->reply;
 128                                         /* < 0 failure, otherwise ep_ref */
 129                 clear_bit(ATM_VF_WAITING, &vcc->flags);
 130                 break;
 131         default:
 132                 pr_alert("bad message type %d\n", (int)msg->type);
 133                 return -EINVAL;
 134         }
 135         sk->sk_state_change(sk);
 136 out:
 137         dev_kfree_skb(skb);
 138         return 0;
 139 }
 140
 141 void sigd_enq2(struct atm_vcc *vcc, enum atmsvc_msg_type type,
 142                struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc,
 143                const struct sockaddr_atmsvc *svc, const struct atm_qos *qos,
 144                int reply)
 145 {
 146         struct sk_buff *skb;
 147         struct atmsvc_msg *msg;
 148         static unsigned int session = 0;
 149
 150         pr_debug("%d (0x%p)\n", (int)type, vcc);
 151         while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
 152                 schedule();
 153         msg = skb_put_zero(skb, sizeof(struct atmsvc_msg));
 154         msg->type = type;
 155         *(struct atm_vcc **) &msg->vcc = vcc;
 156         *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
 157         msg->reply = reply;
 158         if (qos)
 159                 msg->qos = *qos;
 160         if (vcc)
 161                 msg->sap = vcc->sap;
 162         if (svc)
 163                 msg->svc = *svc;
 164         if (vcc)
 165                 msg->local = vcc->local;
 166         if (pvc)
 167                 msg->pvc = *pvc;
 168         if (vcc) {
 169                 if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
 170                         msg->session = ++session;
 171                         /* every new pmp connect gets the next session number */
 172         }
 173         sigd_put_skb(skb);
 174         if (vcc)
 175                 set_bit(ATM_VF_REGIS, &vcc->flags);
 176 }
 177
 178 void sigd_enq(struct atm_vcc *vcc, enum atmsvc_msg_type type,
 179               struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc,
 180               const struct sockaddr_atmsvc *svc)
 181 {
 182         sigd_enq2(vcc, type, listen_vcc, pvc, svc, vcc ? &vcc->qos : NULL, 0);
 183         /* other ISP applications may use "reply" */
 184 }
 185
 186 static void purge_vcc(struct atm_vcc *vcc)
 187 {
 188         if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
 189             !test_bit(ATM_VF_META, &vcc->flags)) {
 190                 set_bit(ATM_VF_RELEASED, &vcc->flags);
 191                 clear_bit(ATM_VF_REGIS, &vcc->flags);
 192                 vcc_release_async(vcc, -EUNATCH);
 193         }
 194 }
 195
 196 static void sigd_close(struct atm_vcc *vcc)
 197 {
 198         struct sock *s;
 199         int i;
 200
 201         pr_debug("\n");
 202         sigd = NULL;
 203         if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
 204                 pr_err("closing with requests pending\n");
 205         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 206
 207         read_lock(&vcc_sklist_lock);
 208         for (i = 0; i < VCC_HTABLE_SIZE; ++i) {
 209                 struct hlist_head *head = &vcc_hash[i];
 210
 211                 sk_for_each(s, head) {
 212                         vcc = atm_sk(s);
 213
 214                         purge_vcc(vcc);
 215                 }
 216         }
 217         read_unlock(&vcc_sklist_lock);
 218 }
 219
 220 static struct atmdev_ops sigd_dev_ops = {
 221         .close = sigd_close,
 222         .send = sigd_send
 223 };
 224
 225 static struct atm_dev sigd_dev = {
 226         .ops =          &sigd_dev_ops,
 227         .type =         "sig",
 228         .number =       999,
 229         .lock =         __SPIN_LOCK_UNLOCKED(sigd_dev.lock)
 230 };
 231
 232 int sigd_attach(struct atm_vcc *vcc)
 233 {
 234         if (sigd)
 235                 return -EADDRINUSE;
 236         pr_debug("\n");
 237         sigd = vcc;
 238         vcc->dev = &sigd_dev;
 239         vcc_insert_socket(sk_atm(vcc));
 240         set_bit(ATM_VF_META, &vcc->flags);
 241         set_bit(ATM_VF_READY, &vcc->flags);
 242         return 0;
 243 }