--- zzzz-none-000/linux-2.4.17/drivers/net/hamradio/6pack.c 2001-09-13 23:04:43.000000000 +0000 +++ sangam-fb-322/linux-2.4.17/drivers/net/hamradio/6pack.c 2004-11-24 13:23:31.000000000 +0000 @@ -1,1068 +1,1068 @@ -/* - * 6pack.c This module implements the 6pack protocol for kernel-based - * devices like TTY. It interfaces between a raw TTY and the - * kernel's AX.25 protocol layers. - * - * Version: @(#)6pack.c 0.3.0 04/07/98 - * - * Authors: Andreas Könsgen - * - * Quite a lot of stuff "stolen" by Jörg Reuter from slip.c, written by - * - * Laurence Culhane, - * Fred N. van Kempen, - * - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#define SIXPACK_VERSION "Revision: 0.3.0" - -/* sixpack priority commands */ -#define SIXP_SEOF 0x40 /* start and end of a 6pack frame */ -#define SIXP_TX_URUN 0x48 /* transmit overrun */ -#define SIXP_RX_ORUN 0x50 /* receive overrun */ -#define SIXP_RX_BUF_OVL 0x58 /* receive buffer overflow */ - -#define SIXP_CHKSUM 0xFF /* valid checksum of a 6pack frame */ - -/* masks to get certain bits out of the status bytes sent by the TNC */ - -#define SIXP_CMD_MASK 0xC0 -#define SIXP_CHN_MASK 0x07 -#define SIXP_PRIO_CMD_MASK 0x80 -#define SIXP_STD_CMD_MASK 0x40 -#define SIXP_PRIO_DATA_MASK 0x38 -#define SIXP_TX_MASK 0x20 -#define SIXP_RX_MASK 0x10 -#define SIXP_RX_DCD_MASK 0x18 -#define SIXP_LEDS_ON 0x78 -#define SIXP_LEDS_OFF 0x60 -#define SIXP_CON 0x08 -#define SIXP_STA 0x10 - -#define SIXP_FOUND_TNC 0xe9 -#define SIXP_CON_ON 0x68 -#define SIXP_DCD_MASK 0x08 -#define SIXP_DAMA_OFF 0 - -/* default level 2 parameters */ -#define SIXP_TXDELAY 25 /* in 10 ms */ -#define SIXP_PERSIST 50 /* in 256ths */ -#define SIXP_SLOTTIME 10 /* in 10 ms */ -#define SIXP_INIT_RESYNC_TIMEOUT 150 /* in 10 ms */ -#define SIXP_RESYNC_TIMEOUT 500 /* in 10 ms */ - -/* 6pack configuration. */ -#define SIXP_NRUNIT 31 /* MAX number of 6pack channels */ -#define SIXP_MTU 256 /* Default MTU */ - -enum sixpack_flags { - SIXPF_INUSE, /* Channel in use */ - SIXPF_ERROR, /* Parity, etc. error */ -}; - -struct sixpack { - int magic; - - /* Various fields. */ - struct tty_struct *tty; /* ptr to TTY structure */ - struct net_device *dev; /* easy for intr handling */ - - /* These are pointers to the malloc()ed frame buffers. */ - unsigned char *rbuff; /* receiver buffer */ - int rcount; /* received chars counter */ - unsigned char *xbuff; /* transmitter buffer */ - unsigned char *xhead; /* pointer to next byte to XMIT */ - int xleft; /* bytes left in XMIT queue */ - - unsigned char raw_buf[4]; - unsigned char cooked_buf[400]; - - unsigned int rx_count; - unsigned int rx_count_cooked; - - /* 6pack interface statistics. */ - struct net_device_stats stats; - - int mtu; /* Our mtu (to spot changes!) */ - int buffsize; /* Max buffers sizes */ - - unsigned long flags; /* Flag values/ mode etc */ - unsigned char mode; /* 6pack mode */ - - /* 6pack stuff */ - unsigned char tx_delay; - unsigned char persistance; - unsigned char slottime; - unsigned char duplex; - unsigned char led_state; - unsigned char status; - unsigned char status1; - unsigned char status2; - unsigned char tx_enable; - unsigned char tnc_ok; - - struct timer_list tx_t; - struct timer_list resync_t; -}; - -#define AX25_6PACK_HEADER_LEN 0 -#define SIXPACK_MAGIC 0x5304 - -typedef struct sixpack_ctrl { - struct sixpack ctrl; /* 6pack things */ - struct net_device dev; /* the device */ -} sixpack_ctrl_t; -static sixpack_ctrl_t **sixpack_ctrls; - -int sixpack_maxdev = SIXP_NRUNIT; /* Can be overridden with insmod! */ -MODULE_PARM(sixpack_maxdev, "i"); -MODULE_PARM_DESC(sixpack_maxdev, "number of 6PACK devices"); - -static void sp_start_tx_timer(struct sixpack *); -static void sp_xmit_on_air(unsigned long); -static void resync_tnc(unsigned long); -static void sixpack_decode(struct sixpack *, unsigned char[], int); -static int encode_sixpack(unsigned char *, unsigned char *, int, unsigned char); -static int sixpack_init(struct net_device *dev); - -static void decode_prio_command(unsigned char, struct sixpack *); -static void decode_std_command(unsigned char, struct sixpack *); -static void decode_data(unsigned char, struct sixpack *); - -static int tnc_init(struct sixpack *); - -/* Find a free 6pack channel, and link in this `tty' line. */ -static inline struct sixpack *sp_alloc(void) -{ - sixpack_ctrl_t *spp = NULL; - int i; - - for (i = 0; i < sixpack_maxdev; i++) { - spp = sixpack_ctrls[i]; - - if (spp == NULL) - break; - - if (!test_and_set_bit(SIXPF_INUSE, &spp->ctrl.flags)) - break; - } - - /* Too many devices... */ - if (i >= sixpack_maxdev) - return NULL; - - /* If no channels are available, allocate one */ - if (!spp && - (sixpack_ctrls[i] = (sixpack_ctrl_t *)kmalloc(sizeof(sixpack_ctrl_t), - GFP_KERNEL)) != NULL) { - spp = sixpack_ctrls[i]; - memset(spp, 0, sizeof(sixpack_ctrl_t)); - - /* Initialize channel control data */ - set_bit(SIXPF_INUSE, &spp->ctrl.flags); - spp->ctrl.tty = NULL; - sprintf(spp->dev.name, "sp%d", i); - spp->dev.base_addr = i; - spp->dev.priv = (void *) &spp->ctrl; - spp->dev.next = NULL; - spp->dev.init = sixpack_init; - } - - if (spp != NULL) { - /* register device so that it can be ifconfig'ed */ - /* sixpack_init() will be called as a side-effect */ - /* SIDE-EFFECT WARNING: sixpack_init() CLEARS spp->ctrl ! */ - - if (register_netdev(&spp->dev) == 0) { - set_bit(SIXPF_INUSE, &spp->ctrl.flags); - spp->ctrl.dev = &spp->dev; - spp->dev.priv = (void *) &spp->ctrl; - SET_MODULE_OWNER(&spp->dev); - return &spp->ctrl; - } else { - clear_bit(SIXPF_INUSE, &spp->ctrl.flags); - printk(KERN_WARNING "sp_alloc() - register_netdev() failure.\n"); - } - } - - return NULL; -} - - -/* Free a 6pack channel. */ -static inline void sp_free(struct sixpack *sp) -{ - /* Free all 6pack frame buffers. */ - if (sp->rbuff) - kfree(sp->rbuff); - sp->rbuff = NULL; - if (sp->xbuff) - kfree(sp->xbuff); - sp->xbuff = NULL; - - if (!test_and_clear_bit(SIXPF_INUSE, &sp->flags)) - printk(KERN_WARNING "%s: sp_free for already free unit.\n", sp->dev->name); -} - - -/* Send one completely decapsulated IP datagram to the IP layer. */ - -/* This is the routine that sends the received data to the kernel AX.25. - 'cmd' is the KISS command. For AX.25 data, it is zero. */ - -static void sp_bump(struct sixpack *sp, char cmd) -{ - struct sk_buff *skb; - int count; - unsigned char *ptr; - - count = sp->rcount+1; - - sp->stats.rx_bytes += count; - - if ((skb = dev_alloc_skb(count)) == NULL) { - printk(KERN_DEBUG "%s: memory squeeze, dropping packet.\n", sp->dev->name); - sp->stats.rx_dropped++; - return; - } - - skb->dev = sp->dev; - ptr = skb_put(skb, count); - *ptr++ = cmd; /* KISS command */ - - memcpy(ptr, (sp->cooked_buf)+1, count); - skb->mac.raw = skb->data; - skb->protocol = htons(ETH_P_AX25); - netif_rx(skb); - sp->stats.rx_packets++; -} - - -/* ----------------------------------------------------------------------- */ - -/* Encapsulate one AX.25 frame and stuff into a TTY queue. */ -static void sp_encaps(struct sixpack *sp, unsigned char *icp, int len) -{ - unsigned char *p; - int actual, count; - - if (len > sp->mtu) { /* sp->mtu = AX25_MTU = max. PACLEN = 256 */ - printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n", sp->dev->name); - sp->stats.tx_dropped++; - netif_start_queue(sp->dev); - return; - } - - p = icp; - - if (p[0] > 5) { - printk(KERN_DEBUG "%s: invalid KISS command -- dropped\n", sp->dev->name); - netif_start_queue(sp->dev); - return; - } - - if ((p[0] != 0) && (len > 2)) { - printk(KERN_DEBUG "%s: KISS control packet too long -- dropped\n", sp->dev->name); - netif_start_queue(sp->dev); - return; - } - - if ((p[0] == 0) && (len < 15)) { - printk(KERN_DEBUG "%s: bad AX.25 packet to transmit -- dropped\n", sp->dev->name); - netif_start_queue(sp->dev); - sp->stats.tx_dropped++; - return; - } - - count = encode_sixpack(p, (unsigned char *) sp->xbuff, len, sp->tx_delay); - sp->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP); - - switch (p[0]) { - case 1: sp->tx_delay = p[1]; return; - case 2: sp->persistance = p[1]; return; - case 3: sp->slottime = p[1]; return; - case 4: /* ignored */ return; - case 5: sp->duplex = p[1]; return; - } - - if (p[0] == 0) { - /* in case of fullduplex or DAMA operation, we don't take care - about the state of the DCD or of any timers, as the determination - of the correct time to send is the job of the AX.25 layer. We send - immediately after data has arrived. */ - if (sp->duplex == 1) { - sp->led_state = 0x70; - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - sp->tx_enable = 1; - actual = sp->tty->driver.write(sp->tty, 0, sp->xbuff, count); - sp->xleft = count - actual; - sp->xhead = sp->xbuff + actual; - sp->led_state = 0x60; - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - } else { - sp->xleft = count; - sp->xhead = sp->xbuff; - sp->status2 = count; - if (sp->duplex == 0) - sp_start_tx_timer(sp); - } - } -} - -/* - * Called by the TTY driver when there's room for more data. If we have - * more packets to send, we send them here. - */ -static void sixpack_write_wakeup(struct tty_struct *tty) -{ - int actual; - struct sixpack *sp = (struct sixpack *) tty->disc_data; - - /* First make sure we're connected. */ - if (!sp || sp->magic != SIXPACK_MAGIC || - !netif_running(sp->dev)) - return; - - if (sp->xleft <= 0) { - /* Now serial buffer is almost free & we can start - * transmission of another packet */ - sp->stats.tx_packets++; - tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); - sp->tx_enable = 0; - netif_wake_queue(sp->dev); - return; - } - - if (sp->tx_enable == 1) { - actual = tty->driver.write(tty, 0, sp->xhead, sp->xleft); - sp->xleft -= actual; - sp->xhead += actual; - } -} - -/* ----------------------------------------------------------------------- */ - -/* Encapsulate an IP datagram and kick it into a TTY queue. */ - -static int sp_xmit(struct sk_buff *skb, struct net_device *dev) -{ - struct sixpack *sp = (struct sixpack *) dev->priv; - - /* We were not busy, so we are now... :-) */ - netif_stop_queue(dev); - sp->stats.tx_bytes += skb->len; - sp_encaps(sp, skb->data, skb->len); - dev_kfree_skb(skb); - return 0; -} - - -/* perform the persistence/slottime algorithm for CSMA access. If the persistence - check was successful, write the data to the serial driver. Note that in case - of DAMA operation, the data is not sent here. */ - -static void sp_xmit_on_air(unsigned long channel) -{ - struct sixpack *sp = (struct sixpack *) channel; - int actual; - static unsigned char random; - - random = random * 17 + 41; - - if (((sp->status1 & SIXP_DCD_MASK) == 0) && (random < sp->persistance)) { - sp->led_state = 0x70; - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - sp->tx_enable = 1; - actual = sp->tty->driver.write(sp->tty, 0, sp->xbuff, sp->status2); - sp->xleft -= actual; - sp->xhead += actual; - sp->led_state = 0x60; - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - sp->status2 = 0; - } else - sp_start_tx_timer(sp); -} - - -/* Return the frame type ID */ -static int sp_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, - void *daddr, void *saddr, unsigned len) -{ -#ifdef CONFIG_INET - if (type != htons(ETH_P_AX25)) - return ax25_encapsulate(skb, dev, type, daddr, saddr, len); -#endif - return 0; -} - - -static int sp_rebuild_header(struct sk_buff *skb) -{ -#ifdef CONFIG_INET - return ax25_rebuild_header(skb); -#else - return 0; -#endif -} - - -/* Open the low-level part of the 6pack channel. */ -static int sp_open(struct net_device *dev) -{ - struct sixpack *sp = (struct sixpack *) dev->priv; - unsigned long len; - - if (sp->tty == NULL) - return -ENODEV; - - /* - * Allocate the 6pack frame buffers: - * - * rbuff Receive buffer. - * xbuff Transmit buffer. - */ - - /* !!! length of the buffers. MTU is IP MTU, not PACLEN! - */ - - len = dev->mtu * 2; - - if ((sp->rbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL) - return -ENOMEM; - - if ((sp->xbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL) { - kfree(sp->rbuff); - return -ENOMEM; - } - - sp->mtu = AX25_MTU + 73; - sp->buffsize = len; - sp->rcount = 0; - sp->rx_count = 0; - sp->rx_count_cooked = 0; - sp->xleft = 0; - - sp->flags &= (1 << SIXPF_INUSE); /* Clear ESCAPE & ERROR flags */ - - sp->duplex = 0; - sp->tx_delay = SIXP_TXDELAY; - sp->persistance = SIXP_PERSIST; - sp->slottime = SIXP_SLOTTIME; - sp->led_state = 0x60; - sp->status = 1; - sp->status1 = 1; - sp->status2 = 0; - sp->tnc_ok = 0; - sp->tx_enable = 0; - - netif_start_queue(dev); - - init_timer(&sp->tx_t); - init_timer(&sp->resync_t); - return 0; -} - - -/* Close the low-level part of the 6pack channel. */ -static int sp_close(struct net_device *dev) -{ - struct sixpack *sp = (struct sixpack *) dev->priv; - - if (sp->tty == NULL) - return -EBUSY; - - sp->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); - - netif_stop_queue(dev); - return 0; -} - -static int sixpack_receive_room(struct tty_struct *tty) -{ - return 65536; /* We can handle an infinite amount of data. :-) */ -} - -/* !!! receive state machine */ - -/* - * Handle the 'receiver data ready' interrupt. - * This function is called by the 'tty_io' module in the kernel when - * a block of 6pack data has been received, which can now be decapsulated - * and sent on to some IP layer for further processing. - */ -static void sixpack_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) -{ - unsigned char buf[512]; - unsigned long flags; - int count1; - - struct sixpack *sp = (struct sixpack *) tty->disc_data; - - if (!sp || sp->magic != SIXPACK_MAGIC || - !netif_running(sp->dev) || !count) - return; - - save_flags(flags); - cli(); - memcpy(buf, cp, countflags)) - sp->stats.rx_errors++; - continue; - } - } - sixpack_decode(sp, buf, count1); -} - -/* - * Open the high-level part of the 6pack channel. - * This function is called by the TTY module when the - * 6pack line discipline is called for. Because we are - * sure the tty line exists, we only have to link it to - * a free 6pcack channel... - */ -static int sixpack_open(struct tty_struct *tty) -{ - struct sixpack *sp = (struct sixpack *) tty->disc_data; - int err; - - /* First make sure we're not already connected. */ - - if (sp && sp->magic == SIXPACK_MAGIC) - return -EEXIST; - - /* OK. Find a free 6pack channel to use. */ - if ((sp = sp_alloc()) == NULL) - return -ENFILE; - sp->tty = tty; - tty->disc_data = sp; - if (tty->driver.flush_buffer) - tty->driver.flush_buffer(tty); - - if (tty->ldisc.flush_buffer) - tty->ldisc.flush_buffer(tty); - - /* Restore default settings */ - sp->dev->type = ARPHRD_AX25; - - /* Perform the low-level 6pack initialization. */ - if ((err = sp_open(sp->dev))) - return err; - - /* Done. We have linked the TTY line to a channel. */ - - tnc_init(sp); - - return sp->dev->base_addr; -} - - -/* - * Close down a 6pack channel. - * This means flushing out any pending queues, and then restoring the - * TTY line discipline to what it was before it got hooked to 6pack - * (which usually is TTY again). - */ -static void sixpack_close(struct tty_struct *tty) -{ - struct sixpack *sp = (struct sixpack *) tty->disc_data; - - /* First make sure we're connected. */ - if (!sp || sp->magic != SIXPACK_MAGIC) - return; - - rtnl_lock(); - dev_close(sp->dev); - - del_timer(&sp->tx_t); - del_timer(&sp->resync_t); - - tty->disc_data = 0; - sp->tty = NULL; - - sp_free(sp); - unregister_netdevice(sp->dev); - rtnl_unlock(); -} - - -static struct net_device_stats *sp_get_stats(struct net_device *dev) -{ - struct sixpack *sp = (struct sixpack *) dev->priv; - return &sp->stats; -} - - -static int sp_set_mac_address(struct net_device *dev, void *addr) -{ - return copy_from_user(dev->dev_addr, addr, AX25_ADDR_LEN) ? -EFAULT : 0; -} - -static int sp_set_dev_mac_address(struct net_device *dev, void *addr) -{ - struct sockaddr *sa = addr; - memcpy(dev->dev_addr, sa->sa_data, AX25_ADDR_LEN); - return 0; -} - - -/* Perform I/O control on an active 6pack channel. */ -static int sixpack_ioctl(struct tty_struct *tty, void *file, int cmd, void *arg) -{ - struct sixpack *sp = (struct sixpack *) tty->disc_data; - unsigned int tmp; - - /* First make sure we're connected. */ - if (!sp || sp->magic != SIXPACK_MAGIC) - return -EINVAL; - - switch(cmd) { - case SIOCGIFNAME: - return copy_to_user(arg, sp->dev->name, strlen(sp->dev->name) + 1) ? -EFAULT : 0; - - case SIOCGIFENCAP: - return put_user(0, (int *)arg); - - case SIOCSIFENCAP: - if (get_user(tmp, (int *) arg)) - return -EFAULT; - - sp->mode = tmp; - sp->dev->addr_len = AX25_ADDR_LEN; /* sizeof an AX.25 addr */ - sp->dev->hard_header_len = AX25_KISS_HEADER_LEN + AX25_MAX_HEADER_LEN + 3; - sp->dev->type = ARPHRD_AX25; - - return 0; - - case SIOCSIFHWADDR: - return sp_set_mac_address(sp->dev, arg); - - /* Allow stty to read, but not set, the serial port */ - case TCGETS: - case TCGETA: - return n_tty_ioctl(tty, (struct file *) file, cmd, (unsigned long) arg); - - default: - return -ENOIOCTLCMD; - } -} - -static int sp_open_dev(struct net_device *dev) -{ - struct sixpack *sp = (struct sixpack *) dev->priv; - if (sp->tty == NULL) - return -ENODEV; - return 0; -} - -/* Fill in our line protocol discipline */ -static struct tty_ldisc sp_ldisc = { - magic: TTY_LDISC_MAGIC, - name: "6pack", - open: sixpack_open, - close: sixpack_close, - ioctl: (int (*)(struct tty_struct *, struct file *, - unsigned int, unsigned long)) sixpack_ioctl, - receive_buf: sixpack_receive_buf, - receive_room: sixpack_receive_room, - write_wakeup: sixpack_write_wakeup, -}; - -/* Initialize 6pack control device -- register 6pack line discipline */ - -static char msg_banner[] __initdata = KERN_INFO "AX.25: 6pack driver, " SIXPACK_VERSION " (dynamic channels, max=%d)\n"; -static char msg_invparm[] __initdata = KERN_ERR "6pack: sixpack_maxdev parameter too large.\n"; -static char msg_nomem[] __initdata = KERN_ERR "6pack: can't allocate sixpack_ctrls[] array! No 6pack available.\n"; -static char msg_regfail[] __initdata = KERN_ERR "6pack: can't register line discipline (err = %d)\n"; - -static int __init sixpack_init_driver(void) -{ - int status; - - /* Do sanity checks on maximum device parameter. */ - if (sixpack_maxdev < 4) - sixpack_maxdev = 4; - - printk(msg_banner, sixpack_maxdev); - - sixpack_ctrls = (sixpack_ctrl_t **) kmalloc(sizeof(void*)*sixpack_maxdev, GFP_KERNEL); - if (sixpack_ctrls == NULL) { - printk(msg_nomem); - return -ENOMEM; - } - - /* Clear the pointer array, we allocate devices when we need them */ - memset(sixpack_ctrls, 0, sizeof(void*)*sixpack_maxdev); /* Pointers */ - - /* Register the provided line protocol discipline */ - if ((status = tty_register_ldisc(N_6PACK, &sp_ldisc)) != 0) { - printk(msg_regfail, status); - kfree(sixpack_ctrls); - } - - return status; -} - -static const char msg_unregfail[] __exitdata = KERN_ERR "6pack: can't unregister line discipline (err = %d)\n"; - -static void __exit sixpack_exit_driver(void) -{ - int i; - - if ((i = tty_register_ldisc(N_6PACK, NULL))) - printk(msg_unregfail, i); - - for (i = 0; i < sixpack_maxdev; i++) { - if (sixpack_ctrls[i]) { - /* - * VSV = if dev->start==0, then device - * unregistered while close proc. - */ - if (netif_running(&sixpack_ctrls[i]->dev)) - unregister_netdev(&sixpack_ctrls[i]->dev); - - kfree(sixpack_ctrls[i]); - } - } - kfree(sixpack_ctrls); -} - - -/* Initialize the 6pack driver. Called by DDI. */ -static int sixpack_init(struct net_device *dev) -{ - struct sixpack *sp = (struct sixpack *) dev->priv; - - static char ax25_bcast[AX25_ADDR_LEN] = - {'Q'<<1,'S'<<1,'T'<<1,' '<<1,' '<<1,' '<<1,'0'<<1}; - static char ax25_test[AX25_ADDR_LEN] = - {'L'<<1,'I'<<1,'N'<<1,'U'<<1,'X'<<1,' '<<1,'1'<<1}; - - if (sp == NULL) /* Allocation failed ?? */ - return -ENODEV; - - /* Set up the "6pack Control Block". (And clear statistics) */ - - memset(sp, 0, sizeof (struct sixpack)); - sp->magic = SIXPACK_MAGIC; - sp->dev = dev; - - /* Finish setting up the DEVICE info. */ - dev->mtu = SIXP_MTU; - dev->hard_start_xmit = sp_xmit; - dev->open = sp_open_dev; - dev->stop = sp_close; - dev->hard_header = sp_header; - dev->get_stats = sp_get_stats; - dev->set_mac_address = sp_set_dev_mac_address; - dev->hard_header_len = AX25_MAX_HEADER_LEN; - dev->addr_len = AX25_ADDR_LEN; - dev->type = ARPHRD_AX25; - dev->tx_queue_len = 10; - dev->rebuild_header = sp_rebuild_header; - dev->tx_timeout = NULL; - - memcpy(dev->broadcast, ax25_bcast, AX25_ADDR_LEN); /* Only activated in AX.25 mode */ - memcpy(dev->dev_addr, ax25_test, AX25_ADDR_LEN); /* "" "" "" "" */ - - /* New-style flags. */ - dev->flags = 0; - - return 0; -} - - - - -/* ----> 6pack timer interrupt handler and friends. <---- */ -static void sp_start_tx_timer(struct sixpack *sp) -{ - int when = sp->slottime; - - del_timer(&sp->tx_t); - sp->tx_t.data = (unsigned long) sp; - sp->tx_t.function = sp_xmit_on_air; - sp->tx_t.expires = jiffies + ((when+1)*HZ)/100; - add_timer(&sp->tx_t); -} - - -/* encode an AX.25 packet into 6pack */ - -static int encode_sixpack(unsigned char *tx_buf, unsigned char *tx_buf_raw, int length, unsigned char tx_delay) -{ - int count = 0; - unsigned char checksum = 0, buf[400]; - int raw_count = 0; - - tx_buf_raw[raw_count++] = SIXP_PRIO_CMD_MASK | SIXP_TX_MASK; - tx_buf_raw[raw_count++] = SIXP_SEOF; - - buf[0] = tx_delay; - for (count = 1; count < length; count++) - buf[count] = tx_buf[count]; - - for (count = 0; count < length; count++) - checksum += buf[count]; - buf[length] = (unsigned char) 0xff - checksum; - - for (count = 0; count <= length; count++) { - if ((count % 3) == 0) { - tx_buf_raw[raw_count++] = (buf[count] & 0x3f); - tx_buf_raw[raw_count] = ((buf[count] >> 2) & 0x30); - } else if ((count % 3) == 1) { - tx_buf_raw[raw_count++] |= (buf[count] & 0x0f); - tx_buf_raw[raw_count] = ((buf[count] >> 2) & 0x3c); - } else { - tx_buf_raw[raw_count++] |= (buf[count] & 0x03); - tx_buf_raw[raw_count++] = (buf[count] >> 2); - } - } - if ((length % 3) != 2) - raw_count++; - tx_buf_raw[raw_count++] = SIXP_SEOF; - return raw_count; -} - - -/* decode a 6pack packet */ - -static void -sixpack_decode(struct sixpack *sp, unsigned char pre_rbuff[], int count) -{ - unsigned char inbyte; - int count1; - - for (count1 = 0; count1 < count; count1++) { - inbyte = pre_rbuff[count1]; - if (inbyte == SIXP_FOUND_TNC) { - printk(KERN_INFO "6pack: TNC found.\n"); - sp->tnc_ok = 1; - del_timer(&sp->resync_t); - } - if ((inbyte & SIXP_PRIO_CMD_MASK) != 0) - decode_prio_command(inbyte, sp); - else if ((inbyte & SIXP_STD_CMD_MASK) != 0) - decode_std_command(inbyte, sp); - else if ((sp->status & SIXP_RX_DCD_MASK) == SIXP_RX_DCD_MASK) - decode_data(inbyte, sp); - } -} - -static int tnc_init(struct sixpack *sp) -{ - unsigned char inbyte = 0xe8; - - sp->tty->driver.write(sp->tty, 0, &inbyte, 1); - - del_timer(&sp->resync_t); - sp->resync_t.data = (unsigned long) sp; - sp->resync_t.function = resync_tnc; - sp->resync_t.expires = jiffies + SIXP_RESYNC_TIMEOUT; - add_timer(&sp->resync_t); - - return 0; -} - - -/* identify and execute a 6pack priority command byte */ - -static void decode_prio_command(unsigned char cmd, struct sixpack *sp) -{ - unsigned char channel; - int actual; - - channel = cmd & SIXP_CHN_MASK; - if ((cmd & SIXP_PRIO_DATA_MASK) != 0) { /* idle ? */ - - /* RX and DCD flags can only be set in the same prio command, - if the DCD flag has been set without the RX flag in the previous - prio command. If DCD has not been set before, something in the - transmission has gone wrong. In this case, RX and DCD are - cleared in order to prevent the decode_data routine from - reading further data that might be corrupt. */ - - if (((sp->status & SIXP_DCD_MASK) == 0) && - ((cmd & SIXP_RX_DCD_MASK) == SIXP_RX_DCD_MASK)) { - if (sp->status != 1) - printk(KERN_DEBUG "6pack: protocol violation\n"); - else - sp->status = 0; - cmd &= !SIXP_RX_DCD_MASK; - } - sp->status = cmd & SIXP_PRIO_DATA_MASK; - } - else { /* output watchdog char if idle */ - if ((sp->status2 != 0) && (sp->duplex == 1)) { - sp->led_state = 0x70; - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - sp->tx_enable = 1; - actual = sp->tty->driver.write(sp->tty, 0, sp->xbuff, sp->status2); - sp->xleft -= actual; - sp->xhead += actual; - sp->led_state = 0x60; - sp->status2 = 0; - - } - } - - /* needed to trigger the TNC watchdog */ - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - - /* if the state byte has been received, the TNC is present, - so the resync timer can be reset. */ - - if (sp->tnc_ok == 1) { - del_timer(&sp->resync_t); - sp->resync_t.data = (unsigned long) sp; - sp->resync_t.function = resync_tnc; - sp->resync_t.expires = jiffies + SIXP_INIT_RESYNC_TIMEOUT; - add_timer(&sp->resync_t); - } - - sp->status1 = cmd & SIXP_PRIO_DATA_MASK; -} - -/* try to resync the TNC. Called by the resync timer defined in - decode_prio_command */ - -static void resync_tnc(unsigned long channel) -{ - static char resync_cmd = 0xe8; - struct sixpack *sp = (struct sixpack *) channel; - - printk(KERN_INFO "6pack: resyncing TNC\n"); - - /* clear any data that might have been received */ - - sp->rx_count = 0; - sp->rx_count_cooked = 0; - - /* reset state machine */ - - sp->status = 1; - sp->status1 = 1; - sp->status2 = 0; - sp->tnc_ok = 0; - - /* resync the TNC */ - - sp->led_state = 0x60; - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - sp->tty->driver.write(sp->tty, 0, &resync_cmd, 1); - - - /* Start resync timer again -- the TNC might be still absent */ - - del_timer(&sp->resync_t); - sp->resync_t.data = (unsigned long) sp; - sp->resync_t.function = resync_tnc; - sp->resync_t.expires = jiffies + SIXP_RESYNC_TIMEOUT; - add_timer(&sp->resync_t); -} - - - -/* identify and execute a standard 6pack command byte */ - -static void decode_std_command(unsigned char cmd, struct sixpack *sp) -{ - unsigned char checksum = 0, rest = 0, channel; - short i; - - channel = cmd & SIXP_CHN_MASK; - switch (cmd & SIXP_CMD_MASK) { /* normal command */ - case SIXP_SEOF: - if ((sp->rx_count == 0) && (sp->rx_count_cooked == 0)) { - if ((sp->status & SIXP_RX_DCD_MASK) == - SIXP_RX_DCD_MASK) { - sp->led_state = 0x68; - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - } - } else { - sp->led_state = 0x60; - /* fill trailing bytes with zeroes */ - sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); - rest = sp->rx_count; - if (rest != 0) - for (i = rest; i <= 3; i++) - decode_data(0, sp); - if (rest == 2) - sp->rx_count_cooked -= 2; - else if (rest == 3) - sp->rx_count_cooked -= 1; - for (i = 0; i < sp->rx_count_cooked; i++) - checksum += sp->cooked_buf[i]; - if (checksum != SIXP_CHKSUM) { - printk(KERN_DEBUG "6pack: bad checksum %2.2x\n", checksum); - } else { - sp->rcount = sp->rx_count_cooked-2; - sp_bump(sp, 0); - } - sp->rx_count_cooked = 0; - } - break; - case SIXP_TX_URUN: printk(KERN_DEBUG "6pack: TX underrun\n"); - break; - case SIXP_RX_ORUN: printk(KERN_DEBUG "6pack: RX overrun\n"); - break; - case SIXP_RX_BUF_OVL: - printk(KERN_DEBUG "6pack: RX buffer overflow\n"); - } -} - -/* decode 4 sixpack-encoded bytes into 3 data bytes */ - -static void decode_data(unsigned char inbyte, struct sixpack *sp) -{ - unsigned char *buf; - - if (sp->rx_count != 3) - sp->raw_buf[sp->rx_count++] = inbyte; - else { - buf = sp->raw_buf; - sp->cooked_buf[sp->rx_count_cooked++] = - buf[0] | ((buf[1] << 2) & 0xc0); - sp->cooked_buf[sp->rx_count_cooked++] = - (buf[1] & 0x0f) | ((buf[2] << 2) & 0xf0); - sp->cooked_buf[sp->rx_count_cooked++] = - (buf[2] & 0x03) | (inbyte << 2); - sp->rx_count = 0; - } -} - - -MODULE_AUTHOR("Andreas Könsgen "); -MODULE_DESCRIPTION("6pack driver for AX.25"); - -module_init(sixpack_init_driver); -module_exit(sixpack_exit_driver); +/* + * 6pack.c This module implements the 6pack protocol for kernel-based + * devices like TTY. It interfaces between a raw TTY and the + * kernel's AX.25 protocol layers. + * + * Version: @(#)6pack.c 0.3.0 04/07/98 + * + * Authors: Andreas Könsgen + * + * Quite a lot of stuff "stolen" by Jörg Reuter from slip.c, written by + * + * Laurence Culhane, + * Fred N. van Kempen, + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SIXPACK_VERSION "Revision: 0.3.0" + +/* sixpack priority commands */ +#define SIXP_SEOF 0x40 /* start and end of a 6pack frame */ +#define SIXP_TX_URUN 0x48 /* transmit overrun */ +#define SIXP_RX_ORUN 0x50 /* receive overrun */ +#define SIXP_RX_BUF_OVL 0x58 /* receive buffer overflow */ + +#define SIXP_CHKSUM 0xFF /* valid checksum of a 6pack frame */ + +/* masks to get certain bits out of the status bytes sent by the TNC */ + +#define SIXP_CMD_MASK 0xC0 +#define SIXP_CHN_MASK 0x07 +#define SIXP_PRIO_CMD_MASK 0x80 +#define SIXP_STD_CMD_MASK 0x40 +#define SIXP_PRIO_DATA_MASK 0x38 +#define SIXP_TX_MASK 0x20 +#define SIXP_RX_MASK 0x10 +#define SIXP_RX_DCD_MASK 0x18 +#define SIXP_LEDS_ON 0x78 +#define SIXP_LEDS_OFF 0x60 +#define SIXP_CON 0x08 +#define SIXP_STA 0x10 + +#define SIXP_FOUND_TNC 0xe9 +#define SIXP_CON_ON 0x68 +#define SIXP_DCD_MASK 0x08 +#define SIXP_DAMA_OFF 0 + +/* default level 2 parameters */ +#define SIXP_TXDELAY 25 /* in 10 ms */ +#define SIXP_PERSIST 50 /* in 256ths */ +#define SIXP_SLOTTIME 10 /* in 10 ms */ +#define SIXP_INIT_RESYNC_TIMEOUT 150 /* in 10 ms */ +#define SIXP_RESYNC_TIMEOUT 500 /* in 10 ms */ + +/* 6pack configuration. */ +#define SIXP_NRUNIT 31 /* MAX number of 6pack channels */ +#define SIXP_MTU 256 /* Default MTU */ + +enum sixpack_flags { + SIXPF_INUSE, /* Channel in use */ + SIXPF_ERROR, /* Parity, etc. error */ +}; + +struct sixpack { + int magic; + + /* Various fields. */ + struct tty_struct *tty; /* ptr to TTY structure */ + struct net_device *dev; /* easy for intr handling */ + + /* These are pointers to the malloc()ed frame buffers. */ + unsigned char *rbuff; /* receiver buffer */ + int rcount; /* received chars counter */ + unsigned char *xbuff; /* transmitter buffer */ + unsigned char *xhead; /* pointer to next byte to XMIT */ + int xleft; /* bytes left in XMIT queue */ + + unsigned char raw_buf[4]; + unsigned char cooked_buf[400]; + + unsigned int rx_count; + unsigned int rx_count_cooked; + + /* 6pack interface statistics. */ + struct net_device_stats stats; + + int mtu; /* Our mtu (to spot changes!) */ + int buffsize; /* Max buffers sizes */ + + unsigned long flags; /* Flag values/ mode etc */ + unsigned char mode; /* 6pack mode */ + + /* 6pack stuff */ + unsigned char tx_delay; + unsigned char persistance; + unsigned char slottime; + unsigned char duplex; + unsigned char led_state; + unsigned char status; + unsigned char status1; + unsigned char status2; + unsigned char tx_enable; + unsigned char tnc_ok; + + struct timer_list tx_t; + struct timer_list resync_t; +}; + +#define AX25_6PACK_HEADER_LEN 0 +#define SIXPACK_MAGIC 0x5304 + +typedef struct sixpack_ctrl { + struct sixpack ctrl; /* 6pack things */ + struct net_device dev; /* the device */ +} sixpack_ctrl_t; +static sixpack_ctrl_t **sixpack_ctrls; + +int sixpack_maxdev = SIXP_NRUNIT; /* Can be overridden with insmod! */ +MODULE_PARM(sixpack_maxdev, "i"); +MODULE_PARM_DESC(sixpack_maxdev, "number of 6PACK devices"); + +static void sp_start_tx_timer(struct sixpack *); +static void sp_xmit_on_air(unsigned long); +static void resync_tnc(unsigned long); +static void sixpack_decode(struct sixpack *, unsigned char[], int); +static int encode_sixpack(unsigned char *, unsigned char *, int, unsigned char); +static int sixpack_init(struct net_device *dev); + +static void decode_prio_command(unsigned char, struct sixpack *); +static void decode_std_command(unsigned char, struct sixpack *); +static void decode_data(unsigned char, struct sixpack *); + +static int tnc_init(struct sixpack *); + +/* Find a free 6pack channel, and link in this `tty' line. */ +static inline struct sixpack *sp_alloc(void) +{ + sixpack_ctrl_t *spp = NULL; + int i; + + for (i = 0; i < sixpack_maxdev; i++) { + spp = sixpack_ctrls[i]; + + if (spp == NULL) + break; + + if (!test_and_set_bit(SIXPF_INUSE, &spp->ctrl.flags)) + break; + } + + /* Too many devices... */ + if (i >= sixpack_maxdev) + return NULL; + + /* If no channels are available, allocate one */ + if (!spp && + (sixpack_ctrls[i] = (sixpack_ctrl_t *)kmalloc(sizeof(sixpack_ctrl_t), + GFP_KERNEL)) != NULL) { + spp = sixpack_ctrls[i]; + memset(spp, 0, sizeof(sixpack_ctrl_t)); + + /* Initialize channel control data */ + set_bit(SIXPF_INUSE, &spp->ctrl.flags); + spp->ctrl.tty = NULL; + sprintf(spp->dev.name, "sp%d", i); + spp->dev.base_addr = i; + spp->dev.priv = (void *) &spp->ctrl; + spp->dev.next = NULL; + spp->dev.init = sixpack_init; + } + + if (spp != NULL) { + /* register device so that it can be ifconfig'ed */ + /* sixpack_init() will be called as a side-effect */ + /* SIDE-EFFECT WARNING: sixpack_init() CLEARS spp->ctrl ! */ + + if (register_netdev(&spp->dev) == 0) { + set_bit(SIXPF_INUSE, &spp->ctrl.flags); + spp->ctrl.dev = &spp->dev; + spp->dev.priv = (void *) &spp->ctrl; + SET_MODULE_OWNER(&spp->dev); + return &spp->ctrl; + } else { + clear_bit(SIXPF_INUSE, &spp->ctrl.flags); + printk(KERN_WARNING "sp_alloc() - register_netdev() failure.\n"); + } + } + + return NULL; +} + + +/* Free a 6pack channel. */ +static inline void sp_free(struct sixpack *sp) +{ + /* Free all 6pack frame buffers. */ + if (sp->rbuff) + kfree(sp->rbuff); + sp->rbuff = NULL; + if (sp->xbuff) + kfree(sp->xbuff); + sp->xbuff = NULL; + + if (!test_and_clear_bit(SIXPF_INUSE, &sp->flags)) + printk(KERN_WARNING "%s: sp_free for already free unit.\n", sp->dev->name); +} + + +/* Send one completely decapsulated IP datagram to the IP layer. */ + +/* This is the routine that sends the received data to the kernel AX.25. + 'cmd' is the KISS command. For AX.25 data, it is zero. */ + +static void sp_bump(struct sixpack *sp, char cmd) +{ + struct sk_buff *skb; + int count; + unsigned char *ptr; + + count = sp->rcount+1; + + sp->stats.rx_bytes += count; + + if ((skb = dev_alloc_skb(count)) == NULL) { + printk(KERN_DEBUG "%s: memory squeeze, dropping packet.\n", sp->dev->name); + sp->stats.rx_dropped++; + return; + } + + skb->dev = sp->dev; + ptr = skb_put(skb, count); + *ptr++ = cmd; /* KISS command */ + + memcpy(ptr, (sp->cooked_buf)+1, count); + skb->mac.raw = skb->data; + skb->protocol = htons(ETH_P_AX25); + netif_rx(skb); + sp->stats.rx_packets++; +} + + +/* ----------------------------------------------------------------------- */ + +/* Encapsulate one AX.25 frame and stuff into a TTY queue. */ +static void sp_encaps(struct sixpack *sp, unsigned char *icp, int len) +{ + unsigned char *p; + int actual, count; + + if (len > sp->mtu) { /* sp->mtu = AX25_MTU = max. PACLEN = 256 */ + printk(KERN_DEBUG "%s: truncating oversized transmit packet!\n", sp->dev->name); + sp->stats.tx_dropped++; + netif_start_queue(sp->dev); + return; + } + + p = icp; + + if (p[0] > 5) { + printk(KERN_DEBUG "%s: invalid KISS command -- dropped\n", sp->dev->name); + netif_start_queue(sp->dev); + return; + } + + if ((p[0] != 0) && (len > 2)) { + printk(KERN_DEBUG "%s: KISS control packet too long -- dropped\n", sp->dev->name); + netif_start_queue(sp->dev); + return; + } + + if ((p[0] == 0) && (len < 15)) { + printk(KERN_DEBUG "%s: bad AX.25 packet to transmit -- dropped\n", sp->dev->name); + netif_start_queue(sp->dev); + sp->stats.tx_dropped++; + return; + } + + count = encode_sixpack(p, (unsigned char *) sp->xbuff, len, sp->tx_delay); + sp->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP); + + switch (p[0]) { + case 1: sp->tx_delay = p[1]; return; + case 2: sp->persistance = p[1]; return; + case 3: sp->slottime = p[1]; return; + case 4: /* ignored */ return; + case 5: sp->duplex = p[1]; return; + } + + if (p[0] == 0) { + /* in case of fullduplex or DAMA operation, we don't take care + about the state of the DCD or of any timers, as the determination + of the correct time to send is the job of the AX.25 layer. We send + immediately after data has arrived. */ + if (sp->duplex == 1) { + sp->led_state = 0x70; + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + sp->tx_enable = 1; + actual = sp->tty->driver.write(sp->tty, 0, sp->xbuff, count); + sp->xleft = count - actual; + sp->xhead = sp->xbuff + actual; + sp->led_state = 0x60; + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + } else { + sp->xleft = count; + sp->xhead = sp->xbuff; + sp->status2 = count; + if (sp->duplex == 0) + sp_start_tx_timer(sp); + } + } +} + +/* + * Called by the TTY driver when there's room for more data. If we have + * more packets to send, we send them here. + */ +static void sixpack_write_wakeup(struct tty_struct *tty) +{ + int actual; + struct sixpack *sp = (struct sixpack *) tty->disc_data; + + /* First make sure we're connected. */ + if (!sp || sp->magic != SIXPACK_MAGIC || + !netif_running(sp->dev)) + return; + + if (sp->xleft <= 0) { + /* Now serial buffer is almost free & we can start + * transmission of another packet */ + sp->stats.tx_packets++; + tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); + sp->tx_enable = 0; + netif_wake_queue(sp->dev); + return; + } + + if (sp->tx_enable == 1) { + actual = tty->driver.write(tty, 0, sp->xhead, sp->xleft); + sp->xleft -= actual; + sp->xhead += actual; + } +} + +/* ----------------------------------------------------------------------- */ + +/* Encapsulate an IP datagram and kick it into a TTY queue. */ + +static int sp_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct sixpack *sp = (struct sixpack *) dev->priv; + + /* We were not busy, so we are now... :-) */ + netif_stop_queue(dev); + sp->stats.tx_bytes += skb->len; + sp_encaps(sp, skb->data, skb->len); + dev_kfree_skb(skb); + return 0; +} + + +/* perform the persistence/slottime algorithm for CSMA access. If the persistence + check was successful, write the data to the serial driver. Note that in case + of DAMA operation, the data is not sent here. */ + +static void sp_xmit_on_air(unsigned long channel) +{ + struct sixpack *sp = (struct sixpack *) channel; + int actual; + static unsigned char random; + + random = random * 17 + 41; + + if (((sp->status1 & SIXP_DCD_MASK) == 0) && (random < sp->persistance)) { + sp->led_state = 0x70; + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + sp->tx_enable = 1; + actual = sp->tty->driver.write(sp->tty, 0, sp->xbuff, sp->status2); + sp->xleft -= actual; + sp->xhead += actual; + sp->led_state = 0x60; + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + sp->status2 = 0; + } else + sp_start_tx_timer(sp); +} + + +/* Return the frame type ID */ +static int sp_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, + void *daddr, void *saddr, unsigned len) +{ +#ifdef CONFIG_INET + if (type != htons(ETH_P_AX25)) + return ax25_encapsulate(skb, dev, type, daddr, saddr, len); +#endif + return 0; +} + + +static int sp_rebuild_header(struct sk_buff *skb) +{ +#ifdef CONFIG_INET + return ax25_rebuild_header(skb); +#else + return 0; +#endif +} + + +/* Open the low-level part of the 6pack channel. */ +static int sp_open(struct net_device *dev) +{ + struct sixpack *sp = (struct sixpack *) dev->priv; + unsigned long len; + + if (sp->tty == NULL) + return -ENODEV; + + /* + * Allocate the 6pack frame buffers: + * + * rbuff Receive buffer. + * xbuff Transmit buffer. + */ + + /* !!! length of the buffers. MTU is IP MTU, not PACLEN! + */ + + len = dev->mtu * 2; + + if ((sp->rbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL) + return -ENOMEM; + + if ((sp->xbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL) { + kfree(sp->rbuff); + return -ENOMEM; + } + + sp->mtu = AX25_MTU + 73; + sp->buffsize = len; + sp->rcount = 0; + sp->rx_count = 0; + sp->rx_count_cooked = 0; + sp->xleft = 0; + + sp->flags &= (1 << SIXPF_INUSE); /* Clear ESCAPE & ERROR flags */ + + sp->duplex = 0; + sp->tx_delay = SIXP_TXDELAY; + sp->persistance = SIXP_PERSIST; + sp->slottime = SIXP_SLOTTIME; + sp->led_state = 0x60; + sp->status = 1; + sp->status1 = 1; + sp->status2 = 0; + sp->tnc_ok = 0; + sp->tx_enable = 0; + + netif_start_queue(dev); + + init_timer(&sp->tx_t); + init_timer(&sp->resync_t); + return 0; +} + + +/* Close the low-level part of the 6pack channel. */ +static int sp_close(struct net_device *dev) +{ + struct sixpack *sp = (struct sixpack *) dev->priv; + + if (sp->tty == NULL) + return -EBUSY; + + sp->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP); + + netif_stop_queue(dev); + return 0; +} + +static int sixpack_receive_room(struct tty_struct *tty) +{ + return 65536; /* We can handle an infinite amount of data. :-) */ +} + +/* !!! receive state machine */ + +/* + * Handle the 'receiver data ready' interrupt. + * This function is called by the 'tty_io' module in the kernel when + * a block of 6pack data has been received, which can now be decapsulated + * and sent on to some IP layer for further processing. + */ +static void sixpack_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) +{ + unsigned char buf[512]; + unsigned long flags; + int count1; + + struct sixpack *sp = (struct sixpack *) tty->disc_data; + + if (!sp || sp->magic != SIXPACK_MAGIC || + !netif_running(sp->dev) || !count) + return; + + save_flags(flags); + cli(); + memcpy(buf, cp, countflags)) + sp->stats.rx_errors++; + continue; + } + } + sixpack_decode(sp, buf, count1); +} + +/* + * Open the high-level part of the 6pack channel. + * This function is called by the TTY module when the + * 6pack line discipline is called for. Because we are + * sure the tty line exists, we only have to link it to + * a free 6pcack channel... + */ +static int sixpack_open(struct tty_struct *tty) +{ + struct sixpack *sp = (struct sixpack *) tty->disc_data; + int err; + + /* First make sure we're not already connected. */ + + if (sp && sp->magic == SIXPACK_MAGIC) + return -EEXIST; + + /* OK. Find a free 6pack channel to use. */ + if ((sp = sp_alloc()) == NULL) + return -ENFILE; + sp->tty = tty; + tty->disc_data = sp; + if (tty->driver.flush_buffer) + tty->driver.flush_buffer(tty); + + if (tty->ldisc.flush_buffer) + tty->ldisc.flush_buffer(tty); + + /* Restore default settings */ + sp->dev->type = ARPHRD_AX25; + + /* Perform the low-level 6pack initialization. */ + if ((err = sp_open(sp->dev))) + return err; + + /* Done. We have linked the TTY line to a channel. */ + + tnc_init(sp); + + return sp->dev->base_addr; +} + + +/* + * Close down a 6pack channel. + * This means flushing out any pending queues, and then restoring the + * TTY line discipline to what it was before it got hooked to 6pack + * (which usually is TTY again). + */ +static void sixpack_close(struct tty_struct *tty) +{ + struct sixpack *sp = (struct sixpack *) tty->disc_data; + + /* First make sure we're connected. */ + if (!sp || sp->magic != SIXPACK_MAGIC) + return; + + rtnl_lock(); + dev_close(sp->dev); + + del_timer(&sp->tx_t); + del_timer(&sp->resync_t); + + tty->disc_data = 0; + sp->tty = NULL; + + sp_free(sp); + unregister_netdevice(sp->dev); + rtnl_unlock(); +} + + +static struct net_device_stats *sp_get_stats(struct net_device *dev) +{ + struct sixpack *sp = (struct sixpack *) dev->priv; + return &sp->stats; +} + + +static int sp_set_mac_address(struct net_device *dev, void *addr) +{ + return copy_from_user(dev->dev_addr, addr, AX25_ADDR_LEN) ? -EFAULT : 0; +} + +static int sp_set_dev_mac_address(struct net_device *dev, void *addr) +{ + struct sockaddr *sa = addr; + memcpy(dev->dev_addr, sa->sa_data, AX25_ADDR_LEN); + return 0; +} + + +/* Perform I/O control on an active 6pack channel. */ +static int sixpack_ioctl(struct tty_struct *tty, void *file, int cmd, void *arg) +{ + struct sixpack *sp = (struct sixpack *) tty->disc_data; + unsigned int tmp; + + /* First make sure we're connected. */ + if (!sp || sp->magic != SIXPACK_MAGIC) + return -EINVAL; + + switch(cmd) { + case SIOCGIFNAME: + return copy_to_user(arg, sp->dev->name, strlen(sp->dev->name) + 1) ? -EFAULT : 0; + + case SIOCGIFENCAP: + return put_user(0, (int *)arg); + + case SIOCSIFENCAP: + if (get_user(tmp, (int *) arg)) + return -EFAULT; + + sp->mode = tmp; + sp->dev->addr_len = AX25_ADDR_LEN; /* sizeof an AX.25 addr */ + sp->dev->hard_header_len = AX25_KISS_HEADER_LEN + AX25_MAX_HEADER_LEN + 3; + sp->dev->type = ARPHRD_AX25; + + return 0; + + case SIOCSIFHWADDR: + return sp_set_mac_address(sp->dev, arg); + + /* Allow stty to read, but not set, the serial port */ + case TCGETS: + case TCGETA: + return n_tty_ioctl(tty, (struct file *) file, cmd, (unsigned long) arg); + + default: + return -ENOIOCTLCMD; + } +} + +static int sp_open_dev(struct net_device *dev) +{ + struct sixpack *sp = (struct sixpack *) dev->priv; + if (sp->tty == NULL) + return -ENODEV; + return 0; +} + +/* Fill in our line protocol discipline */ +static struct tty_ldisc sp_ldisc = { + magic: TTY_LDISC_MAGIC, + name: "6pack", + open: sixpack_open, + close: sixpack_close, + ioctl: (int (*)(struct tty_struct *, struct file *, + unsigned int, unsigned long)) sixpack_ioctl, + receive_buf: sixpack_receive_buf, + receive_room: sixpack_receive_room, + write_wakeup: sixpack_write_wakeup, +}; + +/* Initialize 6pack control device -- register 6pack line discipline */ + +static char msg_banner[] __initdata = KERN_INFO "AX.25: 6pack driver, " SIXPACK_VERSION " (dynamic channels, max=%d)\n"; +static char msg_invparm[] __initdata = KERN_ERR "6pack: sixpack_maxdev parameter too large.\n"; +static char msg_nomem[] __initdata = KERN_ERR "6pack: can't allocate sixpack_ctrls[] array! No 6pack available.\n"; +static char msg_regfail[] __initdata = KERN_ERR "6pack: can't register line discipline (err = %d)\n"; + +static int __init sixpack_init_driver(void) +{ + int status; + + /* Do sanity checks on maximum device parameter. */ + if (sixpack_maxdev < 4) + sixpack_maxdev = 4; + + printk(msg_banner, sixpack_maxdev); + + sixpack_ctrls = (sixpack_ctrl_t **) kmalloc(sizeof(void*)*sixpack_maxdev, GFP_KERNEL); + if (sixpack_ctrls == NULL) { + printk(msg_nomem); + return -ENOMEM; + } + + /* Clear the pointer array, we allocate devices when we need them */ + memset(sixpack_ctrls, 0, sizeof(void*)*sixpack_maxdev); /* Pointers */ + + /* Register the provided line protocol discipline */ + if ((status = tty_register_ldisc(N_6PACK, &sp_ldisc)) != 0) { + printk(msg_regfail, status); + kfree(sixpack_ctrls); + } + + return status; +} + +static const char msg_unregfail[] __exitdata = KERN_ERR "6pack: can't unregister line discipline (err = %d)\n"; + +static void __exit sixpack_exit_driver(void) +{ + int i; + + if ((i = tty_register_ldisc(N_6PACK, NULL))) + printk(msg_unregfail, i); + + for (i = 0; i < sixpack_maxdev; i++) { + if (sixpack_ctrls[i]) { + /* + * VSV = if dev->start==0, then device + * unregistered while close proc. + */ + if (netif_running(&sixpack_ctrls[i]->dev)) + unregister_netdev(&sixpack_ctrls[i]->dev); + + kfree(sixpack_ctrls[i]); + } + } + kfree(sixpack_ctrls); +} + + +/* Initialize the 6pack driver. Called by DDI. */ +static int sixpack_init(struct net_device *dev) +{ + struct sixpack *sp = (struct sixpack *) dev->priv; + + static char ax25_bcast[AX25_ADDR_LEN] = + {'Q'<<1,'S'<<1,'T'<<1,' '<<1,' '<<1,' '<<1,'0'<<1}; + static char ax25_test[AX25_ADDR_LEN] = + {'L'<<1,'I'<<1,'N'<<1,'U'<<1,'X'<<1,' '<<1,'1'<<1}; + + if (sp == NULL) /* Allocation failed ?? */ + return -ENODEV; + + /* Set up the "6pack Control Block". (And clear statistics) */ + + memset(sp, 0, sizeof (struct sixpack)); + sp->magic = SIXPACK_MAGIC; + sp->dev = dev; + + /* Finish setting up the DEVICE info. */ + dev->mtu = SIXP_MTU; + dev->hard_start_xmit = sp_xmit; + dev->open = sp_open_dev; + dev->stop = sp_close; + dev->hard_header = sp_header; + dev->get_stats = sp_get_stats; + dev->set_mac_address = sp_set_dev_mac_address; + dev->hard_header_len = AX25_MAX_HEADER_LEN; + dev->addr_len = AX25_ADDR_LEN; + dev->type = ARPHRD_AX25; + dev->tx_queue_len = 10; + dev->rebuild_header = sp_rebuild_header; + dev->tx_timeout = NULL; + + memcpy(dev->broadcast, ax25_bcast, AX25_ADDR_LEN); /* Only activated in AX.25 mode */ + memcpy(dev->dev_addr, ax25_test, AX25_ADDR_LEN); /* "" "" "" "" */ + + /* New-style flags. */ + dev->flags = 0; + + return 0; +} + + + + +/* ----> 6pack timer interrupt handler and friends. <---- */ +static void sp_start_tx_timer(struct sixpack *sp) +{ + int when = sp->slottime; + + del_timer(&sp->tx_t); + sp->tx_t.data = (unsigned long) sp; + sp->tx_t.function = sp_xmit_on_air; + sp->tx_t.expires = jiffies + ((when+1)*HZ)/100; + add_timer(&sp->tx_t); +} + + +/* encode an AX.25 packet into 6pack */ + +static int encode_sixpack(unsigned char *tx_buf, unsigned char *tx_buf_raw, int length, unsigned char tx_delay) +{ + int count = 0; + unsigned char checksum = 0, buf[400]; + int raw_count = 0; + + tx_buf_raw[raw_count++] = SIXP_PRIO_CMD_MASK | SIXP_TX_MASK; + tx_buf_raw[raw_count++] = SIXP_SEOF; + + buf[0] = tx_delay; + for (count = 1; count < length; count++) + buf[count] = tx_buf[count]; + + for (count = 0; count < length; count++) + checksum += buf[count]; + buf[length] = (unsigned char) 0xff - checksum; + + for (count = 0; count <= length; count++) { + if ((count % 3) == 0) { + tx_buf_raw[raw_count++] = (buf[count] & 0x3f); + tx_buf_raw[raw_count] = ((buf[count] >> 2) & 0x30); + } else if ((count % 3) == 1) { + tx_buf_raw[raw_count++] |= (buf[count] & 0x0f); + tx_buf_raw[raw_count] = ((buf[count] >> 2) & 0x3c); + } else { + tx_buf_raw[raw_count++] |= (buf[count] & 0x03); + tx_buf_raw[raw_count++] = (buf[count] >> 2); + } + } + if ((length % 3) != 2) + raw_count++; + tx_buf_raw[raw_count++] = SIXP_SEOF; + return raw_count; +} + + +/* decode a 6pack packet */ + +static void +sixpack_decode(struct sixpack *sp, unsigned char pre_rbuff[], int count) +{ + unsigned char inbyte; + int count1; + + for (count1 = 0; count1 < count; count1++) { + inbyte = pre_rbuff[count1]; + if (inbyte == SIXP_FOUND_TNC) { + printk(KERN_INFO "6pack: TNC found.\n"); + sp->tnc_ok = 1; + del_timer(&sp->resync_t); + } + if ((inbyte & SIXP_PRIO_CMD_MASK) != 0) + decode_prio_command(inbyte, sp); + else if ((inbyte & SIXP_STD_CMD_MASK) != 0) + decode_std_command(inbyte, sp); + else if ((sp->status & SIXP_RX_DCD_MASK) == SIXP_RX_DCD_MASK) + decode_data(inbyte, sp); + } +} + +static int tnc_init(struct sixpack *sp) +{ + unsigned char inbyte = 0xe8; + + sp->tty->driver.write(sp->tty, 0, &inbyte, 1); + + del_timer(&sp->resync_t); + sp->resync_t.data = (unsigned long) sp; + sp->resync_t.function = resync_tnc; + sp->resync_t.expires = jiffies + SIXP_RESYNC_TIMEOUT; + add_timer(&sp->resync_t); + + return 0; +} + + +/* identify and execute a 6pack priority command byte */ + +static void decode_prio_command(unsigned char cmd, struct sixpack *sp) +{ + unsigned char channel; + int actual; + + channel = cmd & SIXP_CHN_MASK; + if ((cmd & SIXP_PRIO_DATA_MASK) != 0) { /* idle ? */ + + /* RX and DCD flags can only be set in the same prio command, + if the DCD flag has been set without the RX flag in the previous + prio command. If DCD has not been set before, something in the + transmission has gone wrong. In this case, RX and DCD are + cleared in order to prevent the decode_data routine from + reading further data that might be corrupt. */ + + if (((sp->status & SIXP_DCD_MASK) == 0) && + ((cmd & SIXP_RX_DCD_MASK) == SIXP_RX_DCD_MASK)) { + if (sp->status != 1) + printk(KERN_DEBUG "6pack: protocol violation\n"); + else + sp->status = 0; + cmd &= !SIXP_RX_DCD_MASK; + } + sp->status = cmd & SIXP_PRIO_DATA_MASK; + } + else { /* output watchdog char if idle */ + if ((sp->status2 != 0) && (sp->duplex == 1)) { + sp->led_state = 0x70; + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + sp->tx_enable = 1; + actual = sp->tty->driver.write(sp->tty, 0, sp->xbuff, sp->status2); + sp->xleft -= actual; + sp->xhead += actual; + sp->led_state = 0x60; + sp->status2 = 0; + + } + } + + /* needed to trigger the TNC watchdog */ + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + + /* if the state byte has been received, the TNC is present, + so the resync timer can be reset. */ + + if (sp->tnc_ok == 1) { + del_timer(&sp->resync_t); + sp->resync_t.data = (unsigned long) sp; + sp->resync_t.function = resync_tnc; + sp->resync_t.expires = jiffies + SIXP_INIT_RESYNC_TIMEOUT; + add_timer(&sp->resync_t); + } + + sp->status1 = cmd & SIXP_PRIO_DATA_MASK; +} + +/* try to resync the TNC. Called by the resync timer defined in + decode_prio_command */ + +static void resync_tnc(unsigned long channel) +{ + static char resync_cmd = 0xe8; + struct sixpack *sp = (struct sixpack *) channel; + + printk(KERN_INFO "6pack: resyncing TNC\n"); + + /* clear any data that might have been received */ + + sp->rx_count = 0; + sp->rx_count_cooked = 0; + + /* reset state machine */ + + sp->status = 1; + sp->status1 = 1; + sp->status2 = 0; + sp->tnc_ok = 0; + + /* resync the TNC */ + + sp->led_state = 0x60; + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + sp->tty->driver.write(sp->tty, 0, &resync_cmd, 1); + + + /* Start resync timer again -- the TNC might be still absent */ + + del_timer(&sp->resync_t); + sp->resync_t.data = (unsigned long) sp; + sp->resync_t.function = resync_tnc; + sp->resync_t.expires = jiffies + SIXP_RESYNC_TIMEOUT; + add_timer(&sp->resync_t); +} + + + +/* identify and execute a standard 6pack command byte */ + +static void decode_std_command(unsigned char cmd, struct sixpack *sp) +{ + unsigned char checksum = 0, rest = 0, channel; + short i; + + channel = cmd & SIXP_CHN_MASK; + switch (cmd & SIXP_CMD_MASK) { /* normal command */ + case SIXP_SEOF: + if ((sp->rx_count == 0) && (sp->rx_count_cooked == 0)) { + if ((sp->status & SIXP_RX_DCD_MASK) == + SIXP_RX_DCD_MASK) { + sp->led_state = 0x68; + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + } + } else { + sp->led_state = 0x60; + /* fill trailing bytes with zeroes */ + sp->tty->driver.write(sp->tty, 0, &sp->led_state, 1); + rest = sp->rx_count; + if (rest != 0) + for (i = rest; i <= 3; i++) + decode_data(0, sp); + if (rest == 2) + sp->rx_count_cooked -= 2; + else if (rest == 3) + sp->rx_count_cooked -= 1; + for (i = 0; i < sp->rx_count_cooked; i++) + checksum += sp->cooked_buf[i]; + if (checksum != SIXP_CHKSUM) { + printk(KERN_DEBUG "6pack: bad checksum %2.2x\n", checksum); + } else { + sp->rcount = sp->rx_count_cooked-2; + sp_bump(sp, 0); + } + sp->rx_count_cooked = 0; + } + break; + case SIXP_TX_URUN: printk(KERN_DEBUG "6pack: TX underrun\n"); + break; + case SIXP_RX_ORUN: printk(KERN_DEBUG "6pack: RX overrun\n"); + break; + case SIXP_RX_BUF_OVL: + printk(KERN_DEBUG "6pack: RX buffer overflow\n"); + } +} + +/* decode 4 sixpack-encoded bytes into 3 data bytes */ + +static void decode_data(unsigned char inbyte, struct sixpack *sp) +{ + unsigned char *buf; + + if (sp->rx_count != 3) + sp->raw_buf[sp->rx_count++] = inbyte; + else { + buf = sp->raw_buf; + sp->cooked_buf[sp->rx_count_cooked++] = + buf[0] | ((buf[1] << 2) & 0xc0); + sp->cooked_buf[sp->rx_count_cooked++] = + (buf[1] & 0x0f) | ((buf[2] << 2) & 0xf0); + sp->cooked_buf[sp->rx_count_cooked++] = + (buf[2] & 0x03) | (inbyte << 2); + sp->rx_count = 0; + } +} + + +MODULE_AUTHOR("Andreas Könsgen "); +MODULE_DESCRIPTION("6pack driver for AX.25"); + +module_init(sixpack_init_driver); +module_exit(sixpack_exit_driver);