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1// SPDX-License-Identifier: GPL-2.0-only2/* drivers/atm/atmtcp.c - ATM over TCP "device" driver */3 4/* Written 1997-2000 by Werner Almesberger, EPFL LRC/ICA */5 6 7#include <linux/module.h>8#include <linux/wait.h>9#include <linux/atmdev.h>10#include <linux/atm_tcp.h>11#include <linux/bitops.h>12#include <linux/init.h>13#include <linux/slab.h>14#include <linux/uaccess.h>15#include <linux/atomic.h>16 17 18extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */19 20 21#define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))22 23 24struct atmtcp_dev_data {25 struct atm_vcc *vcc; /* control VCC; NULL if detached */26 int persist; /* non-zero if persistent */27};28 29 30#define DEV_LABEL "atmtcp"31 32#define MAX_VPI_BITS 8 /* simplifies life */33#define MAX_VCI_BITS 1634 35 36/*37 * Hairy code ahead: the control VCC may be closed while we're still38 * waiting for an answer, so we need to re-validate out_vcc every once39 * in a while.40 */41 42 43static int atmtcp_send_control(struct atm_vcc *vcc,int type,44 const struct atmtcp_control *msg,int flag)45{46 DECLARE_WAITQUEUE(wait,current);47 struct atm_vcc *out_vcc;48 struct sk_buff *skb;49 struct atmtcp_control *new_msg;50 int old_test;51 int error = 0;52 53 out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;54 if (!out_vcc) return -EUNATCH;55 skb = alloc_skb(sizeof(*msg),GFP_KERNEL);56 if (!skb) return -ENOMEM;57 mb();58 out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;59 if (!out_vcc) {60 dev_kfree_skb(skb);61 return -EUNATCH;62 }63 atm_force_charge(out_vcc,skb->truesize);64 new_msg = skb_put(skb, sizeof(*new_msg));65 *new_msg = *msg;66 new_msg->hdr.length = ATMTCP_HDR_MAGIC;67 new_msg->type = type;68 memset(&new_msg->vcc,0,sizeof(atm_kptr_t));69 *(struct atm_vcc **) &new_msg->vcc = vcc;70 old_test = test_bit(flag,&vcc->flags);71 out_vcc->push(out_vcc,skb);72 add_wait_queue(sk_sleep(sk_atm(vcc)), &wait);73 while (test_bit(flag,&vcc->flags) == old_test) {74 mb();75 out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;76 if (!out_vcc) {77 error = -EUNATCH;78 break;79 }80 set_current_state(TASK_UNINTERRUPTIBLE);81 schedule();82 }83 set_current_state(TASK_RUNNING);84 remove_wait_queue(sk_sleep(sk_atm(vcc)), &wait);85 return error;86}87 88 89static int atmtcp_recv_control(const struct atmtcp_control *msg)90{91 struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;92 93 vcc->vpi = msg->addr.sap_addr.vpi;94 vcc->vci = msg->addr.sap_addr.vci;95 vcc->qos = msg->qos;96 sk_atm(vcc)->sk_err = -msg->result;97 switch (msg->type) {98 case ATMTCP_CTRL_OPEN:99 change_bit(ATM_VF_READY,&vcc->flags);100 break;101 case ATMTCP_CTRL_CLOSE:102 change_bit(ATM_VF_ADDR,&vcc->flags);103 break;104 default:105 printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",106 msg->type);107 return -EINVAL;108 }109 wake_up(sk_sleep(sk_atm(vcc)));110 return 0;111}112 113 114static void atmtcp_v_dev_close(struct atm_dev *dev)115{116 /* Nothing.... Isn't this simple :-) -- REW */117}118 119 120static int atmtcp_v_open(struct atm_vcc *vcc)121{122 struct atmtcp_control msg;123 int error;124 short vpi = vcc->vpi;125 int vci = vcc->vci;126 127 memset(&msg,0,sizeof(msg));128 msg.addr.sap_family = AF_ATMPVC;129 msg.hdr.vpi = htons(vpi);130 msg.addr.sap_addr.vpi = vpi;131 msg.hdr.vci = htons(vci);132 msg.addr.sap_addr.vci = vci;133 if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;134 msg.type = ATMTCP_CTRL_OPEN;135 msg.qos = vcc->qos;136 set_bit(ATM_VF_ADDR,&vcc->flags);137 clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */138 error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);139 if (error) return error;140 return -sk_atm(vcc)->sk_err;141}142 143 144static void atmtcp_v_close(struct atm_vcc *vcc)145{146 struct atmtcp_control msg;147 148 memset(&msg,0,sizeof(msg));149 msg.addr.sap_family = AF_ATMPVC;150 msg.addr.sap_addr.vpi = vcc->vpi;151 msg.addr.sap_addr.vci = vcc->vci;152 clear_bit(ATM_VF_READY,&vcc->flags);153 (void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);154}155 156 157static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)158{159 struct atm_cirange ci;160 struct atm_vcc *vcc;161 struct sock *s;162 int i;163 164 if (cmd != ATM_SETCIRANGE) return -ENOIOCTLCMD;165 if (copy_from_user(&ci, arg,sizeof(ci))) return -EFAULT;166 if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;167 if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;168 if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||169 ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;170 read_lock(&vcc_sklist_lock);171 for(i = 0; i < VCC_HTABLE_SIZE; ++i) {172 struct hlist_head *head = &vcc_hash[i];173 174 sk_for_each(s, head) {175 vcc = atm_sk(s);176 if (vcc->dev != dev)177 continue;178 if ((vcc->vpi >> ci.vpi_bits) ||179 (vcc->vci >> ci.vci_bits)) {180 read_unlock(&vcc_sklist_lock);181 return -EBUSY;182 }183 }184 }185 read_unlock(&vcc_sklist_lock);186 dev->ci_range = ci;187 return 0;188}189 190 191static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)192{193 struct atmtcp_dev_data *dev_data;194 struct atm_vcc *out_vcc=NULL; /* Initializer quietens GCC warning */195 struct sk_buff *new_skb;196 struct atmtcp_hdr *hdr;197 int size;198 199 if (vcc->qos.txtp.traffic_class == ATM_NONE) {200 if (vcc->pop) vcc->pop(vcc,skb);201 else dev_kfree_skb(skb);202 return -EINVAL;203 }204 dev_data = PRIV(vcc->dev);205 if (dev_data) out_vcc = dev_data->vcc;206 if (!dev_data || !out_vcc) {207 if (vcc->pop) vcc->pop(vcc,skb);208 else dev_kfree_skb(skb);209 if (dev_data) return 0;210 atomic_inc(&vcc->stats->tx_err);211 return -ENOLINK;212 }213 size = skb->len+sizeof(struct atmtcp_hdr);214 new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);215 if (!new_skb) {216 if (vcc->pop) vcc->pop(vcc,skb);217 else dev_kfree_skb(skb);218 atomic_inc(&vcc->stats->tx_err);219 return -ENOBUFS;220 }221 hdr = skb_put(new_skb, sizeof(struct atmtcp_hdr));222 hdr->vpi = htons(vcc->vpi);223 hdr->vci = htons(vcc->vci);224 hdr->length = htonl(skb->len);225 skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);226 if (vcc->pop) vcc->pop(vcc,skb);227 else dev_kfree_skb(skb);228 out_vcc->push(out_vcc,new_skb);229 atomic_inc(&vcc->stats->tx);230 atomic_inc(&out_vcc->stats->rx);231 return 0;232}233 234 235static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)236{237 struct atmtcp_dev_data *dev_data = PRIV(dev);238 239 if (*pos) return 0;240 if (!dev_data->persist) return sprintf(page,"ephemeral\n");241 return sprintf(page,"persistent, %sconnected\n",242 dev_data->vcc ? "" : "dis");243}244 245 246static void atmtcp_c_close(struct atm_vcc *vcc)247{248 struct atm_dev *atmtcp_dev;249 struct atmtcp_dev_data *dev_data;250 251 atmtcp_dev = (struct atm_dev *) vcc->dev_data;252 dev_data = PRIV(atmtcp_dev);253 dev_data->vcc = NULL;254 if (dev_data->persist) return;255 atmtcp_dev->dev_data = NULL;256 kfree(dev_data);257 atm_dev_deregister(atmtcp_dev);258 vcc->dev_data = NULL;259 module_put(THIS_MODULE);260}261 262 263static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)264{265 struct hlist_head *head;266 struct atm_vcc *vcc;267 struct sock *s;268 269 head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];270 271 sk_for_each(s, head) {272 vcc = atm_sk(s);273 if (vcc->dev == dev &&274 vcc->vci == vci && vcc->vpi == vpi &&275 vcc->qos.rxtp.traffic_class != ATM_NONE) {276 return vcc;277 }278 }279 return NULL;280}281 282 283static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)284{285 struct atm_dev *dev;286 struct atmtcp_hdr *hdr;287 struct atm_vcc *out_vcc;288 struct sk_buff *new_skb;289 int result = 0;290 291 if (!skb->len) return 0;292 dev = vcc->dev_data;293 hdr = (struct atmtcp_hdr *) skb->data;294 if (hdr->length == ATMTCP_HDR_MAGIC) {295 result = atmtcp_recv_control(296 (struct atmtcp_control *) skb->data);297 goto done;298 }299 read_lock(&vcc_sklist_lock);300 out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));301 read_unlock(&vcc_sklist_lock);302 if (!out_vcc) {303 result = -EUNATCH;304 atomic_inc(&vcc->stats->tx_err);305 goto done;306 }307 skb_pull(skb,sizeof(struct atmtcp_hdr));308 new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);309 if (!new_skb) {310 result = -ENOBUFS;311 goto done;312 }313 __net_timestamp(new_skb);314 skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);315 out_vcc->push(out_vcc,new_skb);316 atomic_inc(&vcc->stats->tx);317 atomic_inc(&out_vcc->stats->rx);318done:319 if (vcc->pop) vcc->pop(vcc,skb);320 else dev_kfree_skb(skb);321 return result;322}323 324 325/*326 * Device operations for the virtual ATM devices created by ATMTCP.327 */328 329 330static const struct atmdev_ops atmtcp_v_dev_ops = {331 .dev_close = atmtcp_v_dev_close,332 .open = atmtcp_v_open,333 .close = atmtcp_v_close,334 .ioctl = atmtcp_v_ioctl,335 .send = atmtcp_v_send,336 .proc_read = atmtcp_v_proc,337 .owner = THIS_MODULE338};339 340 341/*342 * Device operations for the ATMTCP control device.343 */344 345 346static const struct atmdev_ops atmtcp_c_dev_ops = {347 .close = atmtcp_c_close,348 .send = atmtcp_c_send349};350 351 352static struct atm_dev atmtcp_control_dev = {353 .ops = &atmtcp_c_dev_ops,354 .type = "atmtcp",355 .number = 999,356 .lock = __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)357};358 359 360static int atmtcp_create(int itf,int persist,struct atm_dev **result)361{362 struct atmtcp_dev_data *dev_data;363 struct atm_dev *dev;364 365 dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);366 if (!dev_data)367 return -ENOMEM;368 369 dev = atm_dev_register(DEV_LABEL,NULL,&atmtcp_v_dev_ops,itf,NULL);370 if (!dev) {371 kfree(dev_data);372 return itf == -1 ? -ENOMEM : -EBUSY;373 }374 dev->ci_range.vpi_bits = MAX_VPI_BITS;375 dev->ci_range.vci_bits = MAX_VCI_BITS;376 dev->dev_data = dev_data;377 PRIV(dev)->vcc = NULL;378 PRIV(dev)->persist = persist;379 if (result) *result = dev;380 return 0;381}382 383 384static int atmtcp_attach(struct atm_vcc *vcc,int itf)385{386 struct atm_dev *dev;387 388 dev = NULL;389 if (itf != -1) dev = atm_dev_lookup(itf);390 if (dev) {391 if (dev->ops != &atmtcp_v_dev_ops) {392 atm_dev_put(dev);393 return -EMEDIUMTYPE;394 }395 if (PRIV(dev)->vcc) {396 atm_dev_put(dev);397 return -EBUSY;398 }399 }400 else {401 int error;402 403 error = atmtcp_create(itf,0,&dev);404 if (error) return error;405 }406 PRIV(dev)->vcc = vcc;407 vcc->dev = &atmtcp_control_dev;408 vcc_insert_socket(sk_atm(vcc));409 set_bit(ATM_VF_META,&vcc->flags);410 set_bit(ATM_VF_READY,&vcc->flags);411 vcc->dev_data = dev;412 (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */413 vcc->stats = &atmtcp_control_dev.stats.aal5;414 return dev->number;415}416 417 418static int atmtcp_create_persistent(int itf)419{420 return atmtcp_create(itf,1,NULL);421}422 423 424static int atmtcp_remove_persistent(int itf)425{426 struct atm_dev *dev;427 struct atmtcp_dev_data *dev_data;428 429 dev = atm_dev_lookup(itf);430 if (!dev) return -ENODEV;431 if (dev->ops != &atmtcp_v_dev_ops) {432 atm_dev_put(dev);433 return -EMEDIUMTYPE;434 }435 dev_data = PRIV(dev);436 if (!dev_data->persist) {437 atm_dev_put(dev);438 return 0;439 }440 dev_data->persist = 0;441 if (PRIV(dev)->vcc) {442 atm_dev_put(dev);443 return 0;444 }445 kfree(dev_data);446 atm_dev_put(dev);447 atm_dev_deregister(dev);448 return 0;449}450 451static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)452{453 int err = 0;454 struct atm_vcc *vcc = ATM_SD(sock);455 456 if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)457 return -ENOIOCTLCMD;458 459 if (!capable(CAP_NET_ADMIN))460 return -EPERM;461 462 switch (cmd) {463 case SIOCSIFATMTCP:464 err = atmtcp_attach(vcc, (int) arg);465 if (err >= 0) {466 sock->state = SS_CONNECTED;467 __module_get(THIS_MODULE);468 }469 break;470 case ATMTCP_CREATE:471 err = atmtcp_create_persistent((int) arg);472 break;473 case ATMTCP_REMOVE:474 err = atmtcp_remove_persistent((int) arg);475 break;476 }477 return err;478}479 480static struct atm_ioctl atmtcp_ioctl_ops = {481 .owner = THIS_MODULE,482 .ioctl = atmtcp_ioctl,483};484 485static __init int atmtcp_init(void)486{487 register_atm_ioctl(&atmtcp_ioctl_ops);488 return 0;489}490 491 492static void __exit atmtcp_exit(void)493{494 deregister_atm_ioctl(&atmtcp_ioctl_ops);495}496 497MODULE_DESCRIPTION("ATM over TCP");498MODULE_LICENSE("GPL");499module_init(atmtcp_init);500module_exit(atmtcp_exit);501