linux/net/atm/signaling.c
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   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
  22struct atm_vcc *sigd = NULL;
  23
  24static 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
  36static 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
  63static 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        atomic_sub(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);
 115as_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);
 136out:
 137        dev_kfree_skb(skb);
 138        return 0;
 139}
 140
 141void 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 = (struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg));
 154        memset(msg, 0, sizeof(*msg));
 155        msg->type = type;
 156        *(struct atm_vcc **) &msg->vcc = vcc;
 157        *(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
 158        msg->reply = reply;
 159        if (qos)
 160                msg->qos = *qos;
 161        if (vcc)
 162                msg->sap = vcc->sap;
 163        if (svc)
 164                msg->svc = *svc;
 165        if (vcc)
 166                msg->local = vcc->local;
 167        if (pvc)
 168                msg->pvc = *pvc;
 169        if (vcc) {
 170                if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
 171                        msg->session = ++session;
 172                        /* every new pmp connect gets the next session number */
 173        }
 174        sigd_put_skb(skb);
 175        if (vcc)
 176                set_bit(ATM_VF_REGIS, &vcc->flags);
 177}
 178
 179void sigd_enq(struct atm_vcc *vcc, enum atmsvc_msg_type type,
 180              struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc,
 181              const struct sockaddr_atmsvc *svc)
 182{
 183        sigd_enq2(vcc, type, listen_vcc, pvc, svc, vcc ? &vcc->qos : NULL, 0);
 184        /* other ISP applications may use "reply" */
 185}
 186
 187static void purge_vcc(struct atm_vcc *vcc)
 188{
 189        if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
 190            !test_bit(ATM_VF_META, &vcc->flags)) {
 191                set_bit(ATM_VF_RELEASED, &vcc->flags);
 192                clear_bit(ATM_VF_REGIS, &vcc->flags);
 193                vcc_release_async(vcc, -EUNATCH);
 194        }
 195}
 196
 197static void sigd_close(struct atm_vcc *vcc)
 198{
 199        struct sock *s;
 200        int i;
 201
 202        pr_debug("\n");
 203        sigd = NULL;
 204        if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
 205                pr_err("closing with requests pending\n");
 206        skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 207
 208        read_lock(&vcc_sklist_lock);
 209        for (i = 0; i < VCC_HTABLE_SIZE; ++i) {
 210                struct hlist_head *head = &vcc_hash[i];
 211
 212                sk_for_each(s, head) {
 213                        vcc = atm_sk(s);
 214
 215                        purge_vcc(vcc);
 216                }
 217        }
 218        read_unlock(&vcc_sklist_lock);
 219}
 220
 221static struct atmdev_ops sigd_dev_ops = {
 222        .close = sigd_close,
 223        .send = sigd_send
 224};
 225
 226static struct atm_dev sigd_dev = {
 227        .ops =          &sigd_dev_ops,
 228        .type =         "sig",
 229        .number =       999,
 230        .lock =         __SPIN_LOCK_UNLOCKED(sigd_dev.lock)
 231};
 232
 233int sigd_attach(struct atm_vcc *vcc)
 234{
 235        if (sigd)
 236                return -EADDRINUSE;
 237        pr_debug("\n");
 238        sigd = vcc;
 239        vcc->dev = &sigd_dev;
 240        vcc_insert_socket(sk_atm(vcc));
 241        set_bit(ATM_VF_META, &vcc->flags);
 242        set_bit(ATM_VF_READY, &vcc->flags);
 243        return 0;
 244}
 245
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