1 // SPDX-License-Identifier: GPL-2.0 2 /* net/atm/signaling.c - ATM signaling */ 3 4 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */ 5 6 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__ 7 8 #include <linux/errno.h> /* error codes */ 9 #include <linux/kernel.h> /* printk */ 10 #include <linux/skbuff.h> 11 #include <linux/wait.h> 12 #include <linux/sched.h> /* jiffies and HZ */ 13 #include <linux/atm.h> /* ATM stuff */ 14 #include <linux/atmsap.h> 15 #include <linux/atmsvc.h> 16 #include <linux/atmdev.h> 17 #include <linux/bitops.h> 18 #include <linux/slab.h> 19 20 #include "resources.h" 21 #include "signaling.h" 22 23 struct atm_vcc *sigd = NULL; 24 25 static void sigd_put_skb(struct sk_buff *skb) 26 { 27 if (!sigd) { 28 pr_debug("atmsvc: no signaling daemon\n"); 29 kfree_skb(skb); 30 return; 31 } 32 atm_force_charge(sigd, skb->truesize); 33 skb_queue_tail(&sk_atm(sigd)->sk_receive_queue, skb); 34 sk_atm(sigd)->sk_data_ready(sk_atm(sigd)); 35 } 36 37 static void modify_qos(struct atm_vcc *vcc, struct atmsvc_msg *msg) 38 { 39 struct sk_buff *skb; 40 41 if (test_bit(ATM_VF_RELEASED, &vcc->flags) || 42 !test_bit(ATM_VF_READY, &vcc->flags)) 43 return; 44 msg->type = as_error; 45 if (!vcc->dev->ops->change_qos) 46 msg->reply = -EOPNOTSUPP; 47 else { 48 /* should lock VCC */ 49 msg->reply = vcc->dev->ops->change_qos(vcc, &msg->qos, 50 msg->reply); 51 if (!msg->reply) 52 msg->type = as_okay; 53 } 54 /* 55 * Should probably just turn around the old skb. But then, the buffer 56 * space accounting needs to follow the change too. Maybe later. 57 */ 58 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL))) 59 schedule(); 60 *(struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)) = *msg; 61 sigd_put_skb(skb); 62 } 63 64 static int sigd_send(struct atm_vcc *vcc, struct sk_buff *skb) 65 { 66 struct atmsvc_msg *msg; 67 struct atm_vcc *session_vcc; 68 struct sock *sk; 69 70 msg = (struct atmsvc_msg *) skb->data; 71 WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc)); 72 vcc = *(struct atm_vcc **) &msg->vcc; 73 pr_debug("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc); 74 sk = sk_atm(vcc); 75 76 switch (msg->type) { 77 case as_okay: 78 sk->sk_err = -msg->reply; 79 clear_bit(ATM_VF_WAITING, &vcc->flags); 80 if (!*vcc->local.sas_addr.prv && !*vcc->local.sas_addr.pub) { 81 vcc->local.sas_family = AF_ATMSVC; 82 memcpy(vcc->local.sas_addr.prv, 83 msg->local.sas_addr.prv, ATM_ESA_LEN); 84 memcpy(vcc->local.sas_addr.pub, 85 msg->local.sas_addr.pub, ATM_E164_LEN + 1); 86 } 87 session_vcc = vcc->session ? vcc->session : vcc; 88 if (session_vcc->vpi || session_vcc->vci) 89 break; 90 session_vcc->itf = msg->pvc.sap_addr.itf; 91 session_vcc->vpi = msg->pvc.sap_addr.vpi; 92 session_vcc->vci = msg->pvc.sap_addr.vci; 93 if (session_vcc->vpi || session_vcc->vci) 94 session_vcc->qos = msg->qos; 95 break; 96 case as_error: 97 clear_bit(ATM_VF_REGIS, &vcc->flags); 98 clear_bit(ATM_VF_READY, &vcc->flags); 99 sk->sk_err = -msg->reply; 100 clear_bit(ATM_VF_WAITING, &vcc->flags); 101 break; 102 case as_indicate: 103 vcc = *(struct atm_vcc **)&msg->listen_vcc; 104 sk = sk_atm(vcc); 105 pr_debug("as_indicate!!!\n"); 106 lock_sock(sk); 107 if (sk_acceptq_is_full(sk)) { 108 sigd_enq(NULL, as_reject, vcc, NULL, NULL); 109 dev_kfree_skb(skb); 110 goto as_indicate_complete; 111 } 112 sk_acceptq_added(sk); 113 skb_queue_tail(&sk->sk_receive_queue, skb); 114 pr_debug("waking sk_sleep(sk) 0x%p\n", sk_sleep(sk)); 115 sk->sk_state_change(sk); 116 as_indicate_complete: 117 release_sock(sk); 118 return 0; 119 case as_close: 120 set_bit(ATM_VF_RELEASED, &vcc->flags); 121 vcc_release_async(vcc, msg->reply); 122 goto out; 123 case as_modify: 124 modify_qos(vcc, msg); 125 break; 126 case as_addparty: 127 case as_dropparty: 128 WRITE_ONCE(sk->sk_err_soft, -msg->reply); 129 /* < 0 failure, otherwise ep_ref */ 130 clear_bit(ATM_VF_WAITING, &vcc->flags); 131 break; 132 default: 133 pr_alert("bad message type %d\n", (int)msg->type); 134 return -EINVAL; 135 } 136 sk->sk_state_change(sk); 137 out: 138 dev_kfree_skb(skb); 139 return 0; 140 } 141 142 void sigd_enq2(struct atm_vcc *vcc, enum atmsvc_msg_type type, 143 struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc, 144 const struct sockaddr_atmsvc *svc, const struct atm_qos *qos, 145 int reply) 146 { 147 struct sk_buff *skb; 148 struct atmsvc_msg *msg; 149 static unsigned int session = 0; 150 151 pr_debug("%d (0x%p)\n", (int)type, vcc); 152 while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL))) 153 schedule(); 154 msg = skb_put_zero(skb, sizeof(struct atmsvc_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 } 178 179 void 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 } 186 187 static 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 } 196 197 static 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 } 220 221 static const struct atmdev_ops sigd_dev_ops = { 222 .close = sigd_close, 223 .send = sigd_send 224 }; 225 226 static 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 }; 232 233 int 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