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 #undef WAIT_FOR_DEMON /* #define this if system calls on SVC sockets 23 should block until the demon runs. 24 Danger: may cause nasty hangs if the demon 25 crashes. */ 26 27 struct atm_vcc *sigd = NULL; 28 #ifdef WAIT_FOR_DEMON 29 static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep); 30 #endif 31 32 static void sigd_put_skb(struct sk_buff *skb) 33 { 34 #ifdef WAIT_FOR_DEMON 35 DECLARE_WAITQUEUE(wait, current); 36 37 add_wait_queue(&sigd_sleep, &wait); 38 while (!sigd) { 39 set_current_state(TASK_UNINTERRUPTIBLE); 40 pr_debug("atmsvc: waiting for signaling daemon...\n"); 41 schedule(); 42 } 43 current->state = TASK_RUNNING; 44 remove_wait_queue(&sigd_sleep, &wait); 45 #else 46 if (!sigd) { 47 pr_debug("atmsvc: no signaling daemon\n"); 48 kfree_skb(skb); 49 return; 50 } 51 #endif 52 atm_force_charge(sigd, skb->truesize); 53 skb_queue_tail(&sk_atm(sigd)->sk_receive_queue, skb); 54 sk_atm(sigd)->sk_data_ready(sk_atm(sigd)); 55 } 56 57 static void modify_qos(struct atm_vcc *vcc, struct atmsvc_msg *msg) 58 { 59 struct sk_buff *skb; 60 61 if (test_bit(ATM_VF_RELEASED, &vcc->flags) || 62 !test_bit(ATM_VF_READY, &vcc->flags)) 63 return; 64 msg->type = as_error; 65 if (!vcc->dev->ops->change_qos) 66 msg->reply = -EOPNOTSUPP; 67 else { 68 /* should lock VCC */ 69 msg->reply = vcc->dev->ops->change_qos(vcc, &msg->qos, 70 msg->reply); 71 if (!msg->reply) 72 msg->type = as_okay; 73 } 74 /* 75 * Should probably just turn around the old skb. But the, the buffer 76 * space accounting needs to follow the change too. Maybe later. 77 */ 78 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL))) 79 schedule(); 80 *(struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)) = *msg; 81 sigd_put_skb(skb); 82 } 83 84 static int sigd_send(struct atm_vcc *vcc, struct sk_buff *skb) 85 { 86 struct atmsvc_msg *msg; 87 struct atm_vcc *session_vcc; 88 struct sock *sk; 89 90 msg = (struct atmsvc_msg *) skb->data; 91 atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc); 92 vcc = *(struct atm_vcc **) &msg->vcc; 93 pr_debug("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc); 94 sk = sk_atm(vcc); 95 96 switch (msg->type) { 97 case as_okay: 98 sk->sk_err = -msg->reply; 99 clear_bit(ATM_VF_WAITING, &vcc->flags); 100 if (!*vcc->local.sas_addr.prv && !*vcc->local.sas_addr.pub) { 101 vcc->local.sas_family = AF_ATMSVC; 102 memcpy(vcc->local.sas_addr.prv, 103 msg->local.sas_addr.prv, ATM_ESA_LEN); 104 memcpy(vcc->local.sas_addr.pub, 105 msg->local.sas_addr.pub, ATM_E164_LEN + 1); 106 } 107 session_vcc = vcc->session ? vcc->session : vcc; 108 if (session_vcc->vpi || session_vcc->vci) 109 break; 110 session_vcc->itf = msg->pvc.sap_addr.itf; 111 session_vcc->vpi = msg->pvc.sap_addr.vpi; 112 session_vcc->vci = msg->pvc.sap_addr.vci; 113 if (session_vcc->vpi || session_vcc->vci) 114 session_vcc->qos = msg->qos; 115 break; 116 case as_error: 117 clear_bit(ATM_VF_REGIS, &vcc->flags); 118 clear_bit(ATM_VF_READY, &vcc->flags); 119 sk->sk_err = -msg->reply; 120 clear_bit(ATM_VF_WAITING, &vcc->flags); 121 break; 122 case as_indicate: 123 vcc = *(struct atm_vcc **)&msg->listen_vcc; 124 sk = sk_atm(vcc); 125 pr_debug("as_indicate!!!\n"); 126 lock_sock(sk); 127 if (sk_acceptq_is_full(sk)) { 128 sigd_enq(NULL, as_reject, vcc, NULL, NULL); 129 dev_kfree_skb(skb); 130 goto as_indicate_complete; 131 } 132 sk->sk_ack_backlog++; 133 skb_queue_tail(&sk->sk_receive_queue, skb); 134 pr_debug("waking sk_sleep(sk) 0x%p\n", sk_sleep(sk)); 135 sk->sk_state_change(sk); 136 as_indicate_complete: 137 release_sock(sk); 138 return 0; 139 case as_close: 140 set_bit(ATM_VF_RELEASED, &vcc->flags); 141 vcc_release_async(vcc, msg->reply); 142 goto out; 143 case as_modify: 144 modify_qos(vcc, msg); 145 break; 146 case as_addparty: 147 case as_dropparty: 148 sk->sk_err_soft = msg->reply; 149 /* < 0 failure, otherwise ep_ref */ 150 clear_bit(ATM_VF_WAITING, &vcc->flags); 151 break; 152 default: 153 pr_alert("bad message type %d\n", (int)msg->type); 154 return -EINVAL; 155 } 156 sk->sk_state_change(sk); 157 out: 158 dev_kfree_skb(skb); 159 return 0; 160 } 161 162 void sigd_enq2(struct atm_vcc *vcc, enum atmsvc_msg_type type, 163 struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc, 164 const struct sockaddr_atmsvc *svc, const struct atm_qos *qos, 165 int reply) 166 { 167 struct sk_buff *skb; 168 struct atmsvc_msg *msg; 169 static unsigned int session = 0; 170 171 pr_debug("%d (0x%p)\n", (int)type, vcc); 172 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL))) 173 schedule(); 174 msg = (struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)); 175 memset(msg, 0, sizeof(*msg)); 176 msg->type = type; 177 *(struct atm_vcc **) &msg->vcc = vcc; 178 *(struct atm_vcc **) &msg->listen_vcc = listen_vcc; 179 msg->reply = reply; 180 if (qos) 181 msg->qos = *qos; 182 if (vcc) 183 msg->sap = vcc->sap; 184 if (svc) 185 msg->svc = *svc; 186 if (vcc) 187 msg->local = vcc->local; 188 if (pvc) 189 msg->pvc = *pvc; 190 if (vcc) { 191 if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags)) 192 msg->session = ++session; 193 /* every new pmp connect gets the next session number */ 194 } 195 sigd_put_skb(skb); 196 if (vcc) 197 set_bit(ATM_VF_REGIS, &vcc->flags); 198 } 199 200 void sigd_enq(struct atm_vcc *vcc, enum atmsvc_msg_type type, 201 struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc, 202 const struct sockaddr_atmsvc *svc) 203 { 204 sigd_enq2(vcc, type, listen_vcc, pvc, svc, vcc ? &vcc->qos : NULL, 0); 205 /* other ISP applications may use "reply" */ 206 } 207 208 static void purge_vcc(struct atm_vcc *vcc) 209 { 210 if (sk_atm(vcc)->sk_family == PF_ATMSVC && 211 !test_bit(ATM_VF_META, &vcc->flags)) { 212 set_bit(ATM_VF_RELEASED, &vcc->flags); 213 clear_bit(ATM_VF_REGIS, &vcc->flags); 214 vcc_release_async(vcc, -EUNATCH); 215 } 216 } 217 218 static void sigd_close(struct atm_vcc *vcc) 219 { 220 struct sock *s; 221 int i; 222 223 pr_debug("\n"); 224 sigd = NULL; 225 if (skb_peek(&sk_atm(vcc)->sk_receive_queue)) 226 pr_err("closing with requests pending\n"); 227 skb_queue_purge(&sk_atm(vcc)->sk_receive_queue); 228 229 read_lock(&vcc_sklist_lock); 230 for (i = 0; i < VCC_HTABLE_SIZE; ++i) { 231 struct hlist_head *head = &vcc_hash[i]; 232 233 sk_for_each(s, head) { 234 vcc = atm_sk(s); 235 236 purge_vcc(vcc); 237 } 238 } 239 read_unlock(&vcc_sklist_lock); 240 } 241 242 static struct atmdev_ops sigd_dev_ops = { 243 .close = sigd_close, 244 .send = sigd_send 245 }; 246 247 static struct atm_dev sigd_dev = { 248 .ops = &sigd_dev_ops, 249 .type = "sig", 250 .number = 999, 251 .lock = __SPIN_LOCK_UNLOCKED(sigd_dev.lock) 252 }; 253 254 int sigd_attach(struct atm_vcc *vcc) 255 { 256 if (sigd) 257 return -EADDRINUSE; 258 pr_debug("\n"); 259 sigd = vcc; 260 vcc->dev = &sigd_dev; 261 vcc_insert_socket(sk_atm(vcc)); 262 set_bit(ATM_VF_META, &vcc->flags); 263 set_bit(ATM_VF_READY, &vcc->flags); 264 #ifdef WAIT_FOR_DEMON 265 wake_up(&sigd_sleep); 266 #endif 267 return 0; 268 } 269