tty/ipwireless/network.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * IPWireless 3G PCMCIA Network Driver
0004  *
0005  * Original code
0006  *   by Stephen Blackheath <stephen@blacksapphire.com>,
0007  *      Ben Martel <benm@symmetric.co.nz>
0008  *
0009  * Copyrighted as follows:
0010  *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
0011  *
0012  * Various driver changes and rewrites, port to new kernels
0013  *   Copyright (C) 2006-2007 Jiri Kosina
0014  *
0015  * Misc code cleanups and updates
0016  *   Copyright (C) 2007 David Sterba
0017  */
0018
0019 #include <linux/interrupt.h>
0020 #include <linux/kernel.h>
0021 #include <linux/mutex.h>
0022 #include <linux/netdevice.h>
0023 #include <linux/ppp_channel.h>
0024 #include <linux/ppp_defs.h>
0025 #include <linux/slab.h>
0026 #include <linux/ppp-ioctl.h>
0027 #include <linux/skbuff.h>
0028
0029 #include "network.h"
0030 #include "hardware.h"
0031 #include "main.h"
0032 #include "tty.h"
0033
0034 #define MAX_ASSOCIATED_TTYS 2
0035
0036 #define SC_RCV_BITS     (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
0037
0038 struct ipw_network {
0039     /* Hardware context, used for calls to hardware layer. */
0040     struct ipw_hardware *hardware;
0041     /* Context for kernel 'generic_ppp' functionality */
0042     struct ppp_channel *ppp_channel;
0043     /* tty context connected with IPW console */
0044     struct ipw_tty *associated_ttys[NO_OF_IPW_CHANNELS][MAX_ASSOCIATED_TTYS];
0045     /* True if ppp needs waking up once we're ready to xmit */
0046     int ppp_blocked;
0047     /* Number of packets queued up in hardware module. */
0048     int outgoing_packets_queued;
0049     /* Spinlock to avoid interrupts during shutdown */
0050     spinlock_t lock;
0051     struct mutex close_lock;
0052
0053     /* PPP ioctl data, not actually used anywere */
0054     unsigned int flags;
0055     unsigned int rbits;
0056     u32 xaccm[8];
0057     u32 raccm;
0058     int mru;
0059
0060     int shutting_down;
0061     unsigned int ras_control_lines;
0062
0063     struct work_struct work_go_online;
0064     struct work_struct work_go_offline;
0065 };
0066
0067 static void notify_packet_sent(void *callback_data, unsigned int packet_length)
0068 {
0069     struct ipw_network *network = callback_data;
0070     unsigned long flags;
0071
0072     spin_lock_irqsave(&network->lock, flags);
0073     network->outgoing_packets_queued--;
0074     if (network->ppp_channel != NULL) {
0075         if (network->ppp_blocked) {
0076             network->ppp_blocked = 0;
0077             spin_unlock_irqrestore(&network->lock, flags);
0078             ppp_output_wakeup(network->ppp_channel);
0079             if (ipwireless_debug)
0080                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
0081                        ": ppp unblocked\n");
0082         } else
0083             spin_unlock_irqrestore(&network->lock, flags);
0084     } else
0085         spin_unlock_irqrestore(&network->lock, flags);
0086 }
0087
0088 /*
0089  * Called by the ppp system when it has a packet to send to the hardware.
0090  */
0091 static int ipwireless_ppp_start_xmit(struct ppp_channel *ppp_channel,
0092                      struct sk_buff *skb)
0093 {
0094     struct ipw_network *network = ppp_channel->private;
0095     unsigned long flags;
0096
0097     spin_lock_irqsave(&network->lock, flags);
0098     if (network->outgoing_packets_queued < ipwireless_out_queue) {
0099         unsigned char *buf;
0100         static unsigned char header[] = {
0101             PPP_ALLSTATIONS, /* 0xff */
0102             PPP_UI,      /* 0x03 */
0103         };
0104         int ret;
0105
0106         network->outgoing_packets_queued++;
0107         spin_unlock_irqrestore(&network->lock, flags);
0108
0109         /*
0110          * If we have the requested amount of headroom in the skb we
0111          * were handed, then we can add the header efficiently.
0112          */
0113         if (skb_headroom(skb) >= 2) {
0114             memcpy(skb_push(skb, 2), header, 2);
0115             ret = ipwireless_send_packet(network->hardware,
0116                            IPW_CHANNEL_RAS, skb->data,
0117                            skb->len,
0118                            notify_packet_sent,
0119                            network);
0120             if (ret < 0) {
0121                 skb_pull(skb, 2);
0122                 return 0;
0123             }
0124         } else {
0125             /* Otherwise (rarely) we do it inefficiently. */
0126             buf = kmalloc(skb->len + 2, GFP_ATOMIC);
0127             if (!buf)
0128                 return 0;
0129             memcpy(buf + 2, skb->data, skb->len);
0130             memcpy(buf, header, 2);
0131             ret = ipwireless_send_packet(network->hardware,
0132                            IPW_CHANNEL_RAS, buf,
0133                            skb->len + 2,
0134                            notify_packet_sent,
0135                            network);
0136             kfree(buf);
0137             if (ret < 0)
0138                 return 0;
0139         }
0140         kfree_skb(skb);
0141         return 1;
0142     } else {
0143         /*
0144          * Otherwise reject the packet, and flag that the ppp system
0145          * needs to be unblocked once we are ready to send.
0146          */
0147         network->ppp_blocked = 1;
0148         spin_unlock_irqrestore(&network->lock, flags);
0149         if (ipwireless_debug)
0150             printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": ppp blocked\n");
0151         return 0;
0152     }
0153 }
0154
0155 /* Handle an ioctl call that has come in via ppp. (copy of ppp_async_ioctl() */
0156 static int ipwireless_ppp_ioctl(struct ppp_channel *ppp_channel,
0157                 unsigned int cmd, unsigned long arg)
0158 {
0159     struct ipw_network *network = ppp_channel->private;
0160     int err, val;
0161     u32 accm[8];
0162     int __user *user_arg = (int __user *) arg;
0163
0164     err = -EFAULT;
0165     switch (cmd) {
0166     case PPPIOCGFLAGS:
0167         val = network->flags | network->rbits;
0168         if (put_user(val, user_arg))
0169             break;
0170         err = 0;
0171         break;
0172
0173     case PPPIOCSFLAGS:
0174         if (get_user(val, user_arg))
0175             break;
0176         network->flags = val & ~SC_RCV_BITS;
0177         network->rbits = val & SC_RCV_BITS;
0178         err = 0;
0179         break;
0180
0181     case PPPIOCGASYNCMAP:
0182         if (put_user(network->xaccm[0], user_arg))
0183             break;
0184         err = 0;
0185         break;
0186
0187     case PPPIOCSASYNCMAP:
0188         if (get_user(network->xaccm[0], user_arg))
0189             break;
0190         err = 0;
0191         break;
0192
0193     case PPPIOCGRASYNCMAP:
0194         if (put_user(network->raccm, user_arg))
0195             break;
0196         err = 0;
0197         break;
0198
0199     case PPPIOCSRASYNCMAP:
0200         if (get_user(network->raccm, user_arg))
0201             break;
0202         err = 0;
0203         break;
0204
0205     case PPPIOCGXASYNCMAP:
0206         if (copy_to_user((void __user *) arg, network->xaccm,
0207                     sizeof(network->xaccm)))
0208             break;
0209         err = 0;
0210         break;
0211
0212     case PPPIOCSXASYNCMAP:
0213         if (copy_from_user(accm, (void __user *) arg, sizeof(accm)))
0214             break;
0215         accm[2] &= ~0x40000000U;    /* can't escape 0x5e */
0216         accm[3] |= 0x60000000U; /* must escape 0x7d, 0x7e */
0217         memcpy(network->xaccm, accm, sizeof(network->xaccm));
0218         err = 0;
0219         break;
0220
0221     case PPPIOCGMRU:
0222         if (put_user(network->mru, user_arg))
0223             break;
0224         err = 0;
0225         break;
0226
0227     case PPPIOCSMRU:
0228         if (get_user(val, user_arg))
0229             break;
0230         if (val < PPP_MRU)
0231             val = PPP_MRU;
0232         network->mru = val;
0233         err = 0;
0234         break;
0235
0236     default:
0237         err = -ENOTTY;
0238     }
0239
0240     return err;
0241 }
0242
0243 static const struct ppp_channel_ops ipwireless_ppp_channel_ops = {
0244     .start_xmit = ipwireless_ppp_start_xmit,
0245     .ioctl      = ipwireless_ppp_ioctl
0246 };
0247
0248 static void do_go_online(struct work_struct *work_go_online)
0249 {
0250     struct ipw_network *network =
0251         container_of(work_go_online, struct ipw_network,
0252                 work_go_online);
0253     unsigned long flags;
0254
0255     spin_lock_irqsave(&network->lock, flags);
0256     if (!network->ppp_channel) {
0257         struct ppp_channel *channel;
0258
0259         spin_unlock_irqrestore(&network->lock, flags);
0260         channel = kzalloc(sizeof(struct ppp_channel), GFP_KERNEL);
0261         if (!channel) {
0262             printk(KERN_ERR IPWIRELESS_PCCARD_NAME
0263                     ": unable to allocate PPP channel\n");
0264             return;
0265         }
0266         channel->private = network;
0267         channel->mtu = 16384;   /* Wild guess */
0268         channel->hdrlen = 2;
0269         channel->ops = &ipwireless_ppp_channel_ops;
0270
0271         network->flags = 0;
0272         network->rbits = 0;
0273         network->mru = PPP_MRU;
0274         memset(network->xaccm, 0, sizeof(network->xaccm));
0275         network->xaccm[0] = ~0U;
0276         network->xaccm[3] = 0x60000000U;
0277         network->raccm = ~0U;
0278         if (ppp_register_channel(channel) < 0) {
0279             printk(KERN_ERR IPWIRELESS_PCCARD_NAME
0280                     ": unable to register PPP channel\n");
0281             kfree(channel);
0282             return;
0283         }
0284         spin_lock_irqsave(&network->lock, flags);
0285         network->ppp_channel = channel;
0286     }
0287     spin_unlock_irqrestore(&network->lock, flags);
0288 }
0289
0290 static void do_go_offline(struct work_struct *work_go_offline)
0291 {
0292     struct ipw_network *network =
0293         container_of(work_go_offline, struct ipw_network,
0294                 work_go_offline);
0295     unsigned long flags;
0296
0297     mutex_lock(&network->close_lock);
0298     spin_lock_irqsave(&network->lock, flags);
0299     if (network->ppp_channel != NULL) {
0300         struct ppp_channel *channel = network->ppp_channel;
0301
0302         network->ppp_channel = NULL;
0303         spin_unlock_irqrestore(&network->lock, flags);
0304         mutex_unlock(&network->close_lock);
0305         ppp_unregister_channel(channel);
0306     } else {
0307         spin_unlock_irqrestore(&network->lock, flags);
0308         mutex_unlock(&network->close_lock);
0309     }
0310 }
0311
0312 void ipwireless_network_notify_control_line_change(struct ipw_network *network,
0313                            unsigned int channel_idx,
0314                            unsigned int control_lines,
0315                            unsigned int changed_mask)
0316 {
0317     int i;
0318
0319     if (channel_idx == IPW_CHANNEL_RAS)
0320         network->ras_control_lines = control_lines;
0321
0322     for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
0323         struct ipw_tty *tty =
0324             network->associated_ttys[channel_idx][i];
0325
0326         /*
0327          * If it's associated with a tty (other than the RAS channel
0328          * when we're online), then send the data to that tty.  The RAS
0329          * channel's data is handled above - it always goes through
0330          * ppp_generic.
0331          */
0332         if (tty)
0333             ipwireless_tty_notify_control_line_change(tty,
0334                                   channel_idx,
0335                                   control_lines,
0336                                   changed_mask);
0337     }
0338 }
0339
0340 /*
0341  * Some versions of firmware stuff packets with 0xff 0x03 (PPP: ALLSTATIONS, UI)
0342  * bytes, which are required on sent packet, but not always present on received
0343  * packets
0344  */
0345 static struct sk_buff *ipw_packet_received_skb(unsigned char *data,
0346                            unsigned int length)
0347 {
0348     struct sk_buff *skb;
0349
0350     if (length > 2 && data[0] == PPP_ALLSTATIONS && data[1] == PPP_UI) {
0351         length -= 2;
0352         data += 2;
0353     }
0354
0355     skb = dev_alloc_skb(length + 4);
0356     if (skb == NULL)
0357         return NULL;
0358     skb_reserve(skb, 2);
0359     skb_put_data(skb, data, length);
0360
0361     return skb;
0362 }
0363
0364 void ipwireless_network_packet_received(struct ipw_network *network,
0365                     unsigned int channel_idx,
0366                     unsigned char *data,
0367                     unsigned int length)
0368 {
0369     int i;
0370     unsigned long flags;
0371
0372     for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
0373         struct ipw_tty *tty = network->associated_ttys[channel_idx][i];
0374
0375         if (!tty)
0376             continue;
0377
0378         /*
0379          * If it's associated with a tty (other than the RAS channel
0380          * when we're online), then send the data to that tty.  The RAS
0381          * channel's data is handled above - it always goes through
0382          * ppp_generic.
0383          */
0384         if (channel_idx == IPW_CHANNEL_RAS
0385                 && (network->ras_control_lines &
0386                     IPW_CONTROL_LINE_DCD) != 0
0387                 && ipwireless_tty_is_modem(tty)) {
0388             /*
0389              * If data came in on the RAS channel and this tty is
0390              * the modem tty, and we are online, then we send it to
0391              * the PPP layer.
0392              */
0393             mutex_lock(&network->close_lock);
0394             spin_lock_irqsave(&network->lock, flags);
0395             if (network->ppp_channel != NULL) {
0396                 struct sk_buff *skb;
0397
0398                 spin_unlock_irqrestore(&network->lock,
0399                         flags);
0400
0401                 /* Send the data to the ppp_generic module. */
0402                 skb = ipw_packet_received_skb(data, length);
0403                 if (skb)
0404                     ppp_input(network->ppp_channel, skb);
0405             } else
0406                 spin_unlock_irqrestore(&network->lock,
0407                         flags);
0408             mutex_unlock(&network->close_lock);
0409         }
0410         /* Otherwise we send it out the tty. */
0411         else
0412             ipwireless_tty_received(tty, data, length);
0413     }
0414 }
0415
0416 struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw)
0417 {
0418     struct ipw_network *network =
0419         kzalloc(sizeof(struct ipw_network), GFP_KERNEL);
0420
0421     if (!network)
0422         return NULL;
0423
0424     spin_lock_init(&network->lock);
0425     mutex_init(&network->close_lock);
0426
0427     network->hardware = hw;
0428
0429     INIT_WORK(&network->work_go_online, do_go_online);
0430     INIT_WORK(&network->work_go_offline, do_go_offline);
0431
0432     ipwireless_associate_network(hw, network);
0433
0434     return network;
0435 }
0436
0437 void ipwireless_network_free(struct ipw_network *network)
0438 {
0439     network->shutting_down = 1;
0440
0441     ipwireless_ppp_close(network);
0442     flush_work(&network->work_go_online);
0443     flush_work(&network->work_go_offline);
0444
0445     ipwireless_stop_interrupts(network->hardware);
0446     ipwireless_associate_network(network->hardware, NULL);
0447
0448     kfree(network);
0449 }
0450
0451 void ipwireless_associate_network_tty(struct ipw_network *network,
0452                       unsigned int channel_idx,
0453                       struct ipw_tty *tty)
0454 {
0455     int i;
0456
0457     for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
0458         if (network->associated_ttys[channel_idx][i] == NULL) {
0459             network->associated_ttys[channel_idx][i] = tty;
0460             break;
0461         }
0462 }
0463
0464 void ipwireless_disassociate_network_ttys(struct ipw_network *network,
0465                       unsigned int channel_idx)
0466 {
0467     int i;
0468
0469     for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
0470         network->associated_ttys[channel_idx][i] = NULL;
0471 }
0472
0473 void ipwireless_ppp_open(struct ipw_network *network)
0474 {
0475     if (ipwireless_debug)
0476         printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": online\n");
0477     schedule_work(&network->work_go_online);
0478 }
0479
0480 void ipwireless_ppp_close(struct ipw_network *network)
0481 {
0482     /* Disconnect from the wireless network. */
0483     if (ipwireless_debug)
0484         printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": offline\n");
0485     schedule_work(&network->work_go_offline);
0486 }
0487
0488 int ipwireless_ppp_channel_index(struct ipw_network *network)
0489 {
0490     int ret = -1;
0491     unsigned long flags;
0492
0493     spin_lock_irqsave(&network->lock, flags);
0494     if (network->ppp_channel != NULL)
0495         ret = ppp_channel_index(network->ppp_channel);
0496     spin_unlock_irqrestore(&network->lock, flags);
0497
0498     return ret;
0499 }
0500
0501 int ipwireless_ppp_unit_number(struct ipw_network *network)
0502 {
0503     int ret = -1;
0504     unsigned long flags;
0505
0506     spin_lock_irqsave(&network->lock, flags);
0507     if (network->ppp_channel != NULL)
0508         ret = ppp_unit_number(network->ppp_channel);
0509     spin_unlock_irqrestore(&network->lock, flags);
0510
0511     return ret;
0512 }
0513
0514 int ipwireless_ppp_mru(const struct ipw_network *network)
0515 {
0516     return network->mru;
0517 }