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 18 #include "resources.h" 19 #include "signaling.h" 20 21 #undef WAIT_FOR_DEMON /* #define this if system calls on SVC sockets 22 should block until the demon runs. 23 Danger: may cause nasty hangs if the demon 24 crashes. */ 25 26 struct atm_vcc *sigd = NULL; 27 #ifdef WAIT_FOR_DEMON 28 static DECLARE_WAIT_QUEUE_HEAD(sigd_sleep); 29 #endif 30 31 static void sigd_put_skb(struct sk_buff *skb) 32 { 33 #ifdef WAIT_FOR_DEMON 34 DECLARE_WAITQUEUE(wait, current); 35 36 add_wait_queue(&sigd_sleep, &wait); 37 while (!sigd) { 38 set_current_state(TASK_UNINTERRUPTIBLE); 39 pr_debug("atmsvc: waiting for signaling daemon...\n"); 40 schedule(); 41 } 42 current->state = TASK_RUNNING; 43 remove_wait_queue(&sigd_sleep, &wait); 44 #else 45 if (!sigd) { 46 pr_debug("atmsvc: no signaling daemon\n"); 47 kfree_skb(skb); 48 return; 49 } 50 #endif 51 atm_force_charge(sigd, skb->truesize); 52 skb_queue_tail(&sk_atm(sigd)->sk_receive_queue, skb); 53 sk_atm(sigd)->sk_data_ready(sk_atm(sigd), skb->len); 54 } 55 56 static void modify_qos(struct atm_vcc *vcc, struct atmsvc_msg *msg) 57 { 58 struct sk_buff *skb; 59 60 if (test_bit(ATM_VF_RELEASED, &vcc->flags) || 61 !test_bit(ATM_VF_READY, &vcc->flags)) 62 return; 63 msg->type = as_error; 64 if (!vcc->dev->ops->change_qos) 65 msg->reply = -EOPNOTSUPP; 66 else { 67 /* should lock VCC */ 68 msg->reply = vcc->dev->ops->change_qos(vcc, &msg->qos, 69 msg->reply); 70 if (!msg->reply) 71 msg->type = as_okay; 72 } 73 /* 74 * Should probably just turn around the old skb. But the, the buffer 75 * space accounting needs to follow the change too. Maybe later. 76 */ 77 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL))) 78 schedule(); 79 *(struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)) = *msg; 80 sigd_put_skb(skb); 81 } 82 83 static int sigd_send(struct atm_vcc *vcc, struct sk_buff *skb) 84 { 85 struct atmsvc_msg *msg; 86 struct atm_vcc *session_vcc; 87 struct sock *sk; 88 89 msg = (struct atmsvc_msg *) skb->data; 90 atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc); 91 vcc = *(struct atm_vcc **) &msg->vcc; 92 pr_debug("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc); 93 sk = sk_atm(vcc); 94 95 switch (msg->type) { 96 case as_okay: 97 sk->sk_err = -msg->reply; 98 clear_bit(ATM_VF_WAITING, &vcc->flags); 99 if (!*vcc->local.sas_addr.prv && !*vcc->local.sas_addr.pub) { 100 vcc->local.sas_family = AF_ATMSVC; 101 memcpy(vcc->local.sas_addr.prv, 102 msg->local.sas_addr.prv, ATM_ESA_LEN); 103 memcpy(vcc->local.sas_addr.pub, 104 msg->local.sas_addr.pub, ATM_E164_LEN + 1); 105 } 106 session_vcc = vcc->session ? vcc->session : vcc; 107 if (session_vcc->vpi || session_vcc->vci) 108 break; 109 session_vcc->itf = msg->pvc.sap_addr.itf; 110 session_vcc->vpi = msg->pvc.sap_addr.vpi; 111 session_vcc->vci = msg->pvc.sap_addr.vci; 112 if (session_vcc->vpi || session_vcc->vci) 113 session_vcc->qos = msg->qos; 114 break; 115 case as_error: 116 clear_bit(ATM_VF_REGIS, &vcc->flags); 117 clear_bit(ATM_VF_READY, &vcc->flags); 118 sk->sk_err = -msg->reply; 119 clear_bit(ATM_VF_WAITING, &vcc->flags); 120 break; 121 case as_indicate: 122 vcc = *(struct atm_vcc **)&msg->listen_vcc; 123 sk = sk_atm(vcc); 124 pr_debug("as_indicate!!!\n"); 125 lock_sock(sk); 126 if (sk_acceptq_is_full(sk)) { 127 sigd_enq(NULL, as_reject, vcc, NULL, NULL); 128 dev_kfree_skb(skb); 129 goto as_indicate_complete; 130 } 131 sk->sk_ack_backlog++; 132 skb_queue_tail(&sk->sk_receive_queue, skb); 133 pr_debug("waking sk->sk_sleep 0x%p\n", sk->sk_sleep); 134 sk->sk_state_change(sk); 135 as_indicate_complete: 136 release_sock(sk); 137 return 0; 138 case as_close: 139 set_bit(ATM_VF_RELEASED, &vcc->flags); 140 vcc_release_async(vcc, msg->reply); 141 goto out; 142 case as_modify: 143 modify_qos(vcc, msg); 144 break; 145 case as_addparty: 146 case as_dropparty: 147 sk->sk_err_soft = msg->reply; 148 /* < 0 failure, otherwise ep_ref */ 149 clear_bit(ATM_VF_WAITING, &vcc->flags); 150 break; 151 default: 152 pr_alert("bad message type %d\n", (int)msg->type); 153 return -EINVAL; 154 } 155 sk->sk_state_change(sk); 156 out: 157 dev_kfree_skb(skb); 158 return 0; 159 } 160 161 void sigd_enq2(struct atm_vcc *vcc, enum atmsvc_msg_type type, 162 struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc, 163 const struct sockaddr_atmsvc *svc, const struct atm_qos *qos, 164 int reply) 165 { 166 struct sk_buff *skb; 167 struct atmsvc_msg *msg; 168 static unsigned session = 0; 169 170 pr_debug("%d (0x%p)\n", (int)type, vcc); 171 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL))) 172 schedule(); 173 msg = (struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)); 174 memset(msg, 0, sizeof(*msg)); 175 msg->type = type; 176 *(struct atm_vcc **) &msg->vcc = vcc; 177 *(struct atm_vcc **) &msg->listen_vcc = listen_vcc; 178 msg->reply = reply; 179 if (qos) 180 msg->qos = *qos; 181 if (vcc) 182 msg->sap = vcc->sap; 183 if (svc) 184 msg->svc = *svc; 185 if (vcc) 186 msg->local = vcc->local; 187 if (pvc) 188 msg->pvc = *pvc; 189 if (vcc) { 190 if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags)) 191 msg->session = ++session; 192 /* every new pmp connect gets the next session number */ 193 } 194 sigd_put_skb(skb); 195 if (vcc) 196 set_bit(ATM_VF_REGIS, &vcc->flags); 197 } 198 199 void sigd_enq(struct atm_vcc *vcc, enum atmsvc_msg_type type, 200 struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc, 201 const struct sockaddr_atmsvc *svc) 202 { 203 sigd_enq2(vcc, type, listen_vcc, pvc, svc, vcc ? &vcc->qos : NULL, 0); 204 /* other ISP applications may use "reply" */ 205 } 206 207 static void purge_vcc(struct atm_vcc *vcc) 208 { 209 if (sk_atm(vcc)->sk_family == PF_ATMSVC && 210 !test_bit(ATM_VF_META, &vcc->flags)) { 211 set_bit(ATM_VF_RELEASED, &vcc->flags); 212 clear_bit(ATM_VF_REGIS, &vcc->flags); 213 vcc_release_async(vcc, -EUNATCH); 214 } 215 } 216 217 static void sigd_close(struct atm_vcc *vcc) 218 { 219 struct hlist_node *node; 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, node, 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