diff options
Diffstat (limited to 'drivers/tty/n_gsm.c')
| -rw-r--r-- | drivers/tty/n_gsm.c | 160 |
1 files changed, 149 insertions, 11 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 348d85c13f91..7aa05ebed8e1 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -318,6 +318,11 @@ struct gsm_mux { struct gsm_control *pending_cmd;/* Our current pending command */ spinlock_t control_lock; /* Protects the pending command */ + /* Keep-alive */ + struct timer_list ka_timer; /* Keep-alive response timer */ + u8 ka_num; /* Keep-alive match pattern */ + signed int ka_retries; /* Keep-alive retry counter, -1 if not yet initialized */ + /* Configuration */ int adaption; /* 1 or 2 supported */ u8 ftype; /* UI or UIH */ @@ -325,6 +330,7 @@ struct gsm_mux { unsigned int t3; /* Power wake-up timer in seconds. */ int n2; /* Retry count */ u8 k; /* Window size */ + u32 keep_alive; /* Control channel keep-alive in 10ms */ /* Statistics (not currently exposed) */ unsigned long bad_fcs; @@ -540,6 +546,11 @@ static u8 gsm_encode_modem(const struct gsm_dlci *dlci) modembits |= MDM_IC; if (dlci->modem_tx & TIOCM_CD || dlci->gsm->initiator) modembits |= MDM_DV; + /* special mappings for passive side to operate as UE */ + if (dlci->modem_tx & TIOCM_OUT1) + modembits |= MDM_IC; + if (dlci->modem_tx & TIOCM_OUT2) + modembits |= MDM_DV; return modembits; } @@ -1531,6 +1542,7 @@ static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, if (brk & 0x01) tty_insert_flip_char(&dlci->port, 0, TTY_BREAK); dlci->modem_rx = mlines; + wake_up_interruptible(&dlci->gsm->event); } /** @@ -1897,11 +1909,13 @@ static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, const u8 *data, int clen) { struct gsm_control *ctrl; + struct gsm_dlci *dlci; unsigned long flags; spin_lock_irqsave(&gsm->control_lock, flags); ctrl = gsm->pending_cmd; + dlci = gsm->dlci[0]; command |= 1; /* Does the reply match our command */ if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) { @@ -1916,6 +1930,53 @@ static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, /* Or did we receive the PN response to our PN command */ } else if (command == CMD_PN) { gsm_control_negotiation(gsm, 0, data, clen); + /* Or did we receive the TEST response to our TEST command */ + } else if (command == CMD_TEST && clen == 1 && *data == gsm->ka_num) { + gsm->ka_retries = -1; /* trigger new keep-alive message */ + if (dlci && !dlci->dead) + mod_timer(&gsm->ka_timer, jiffies + gsm->keep_alive * HZ / 100); + } + spin_unlock_irqrestore(&gsm->control_lock, flags); +} + +/** + * gsm_control_keep_alive - check timeout or start keep-alive + * @t: timer contained in our gsm object + * + * Called off the keep-alive timer expiry signaling that our link + * partner is not responding anymore. Link will be closed. + * This is also called to startup our timer. + */ + +static void gsm_control_keep_alive(struct timer_list *t) +{ + struct gsm_mux *gsm = from_timer(gsm, t, ka_timer); + unsigned long flags; + + spin_lock_irqsave(&gsm->control_lock, flags); + if (gsm->ka_num && gsm->ka_retries == 0) { + /* Keep-alive expired -> close the link */ + if (debug & DBG_ERRORS) + pr_debug("%s keep-alive timed out\n", __func__); + spin_unlock_irqrestore(&gsm->control_lock, flags); + if (gsm->dlci[0]) + gsm_dlci_begin_close(gsm->dlci[0]); + return; + } else if (gsm->keep_alive && gsm->dlci[0] && !gsm->dlci[0]->dead) { + if (gsm->ka_retries > 0) { + /* T2 expired for keep-alive -> resend */ + gsm->ka_retries--; + } else { + /* Start keep-alive timer */ + gsm->ka_num++; + if (!gsm->ka_num) + gsm->ka_num++; + gsm->ka_retries = (signed int)gsm->n2; + } + gsm_control_command(gsm, CMD_TEST, &gsm->ka_num, + sizeof(gsm->ka_num)); + mod_timer(&gsm->ka_timer, + jiffies + gsm->t2 * HZ / 100); } spin_unlock_irqrestore(&gsm->control_lock, flags); } @@ -2059,14 +2120,16 @@ static void gsm_dlci_close(struct gsm_dlci *dlci) tty_port_tty_hangup(&dlci->port, false); gsm_dlci_clear_queues(dlci->gsm, dlci); /* Ensure that gsmtty_open() can return. */ - tty_port_set_initialized(&dlci->port, 0); + tty_port_set_initialized(&dlci->port, false); wake_up_interruptible(&dlci->port.open_wait); - } else + } else { + del_timer(&dlci->gsm->ka_timer); dlci->gsm->dead = true; + } /* A DLCI 0 close is a MUX termination so we need to kick that back to userspace somehow */ gsm_dlci_data_kick(dlci); - wake_up(&dlci->gsm->event); + wake_up_all(&dlci->gsm->event); } /** @@ -2078,6 +2141,8 @@ static void gsm_dlci_close(struct gsm_dlci *dlci) static void gsm_dlci_open(struct gsm_dlci *dlci) { + struct gsm_mux *gsm = dlci->gsm; + /* Note that SABM UA .. SABM UA first UA lost can mean that we go open -> open */ del_timer(&dlci->t1); @@ -2087,8 +2152,15 @@ static void gsm_dlci_open(struct gsm_dlci *dlci) if (debug & DBG_ERRORS) pr_debug("DLCI %d goes open.\n", dlci->addr); /* Send current modem state */ - if (dlci->addr) + if (dlci->addr) { gsm_modem_update(dlci, 0); + } else { + /* Start keep-alive control */ + gsm->ka_num = 0; + gsm->ka_retries = -1; + mod_timer(&gsm->ka_timer, + jiffies + gsm->keep_alive * HZ / 100); + } gsm_dlci_data_kick(dlci); wake_up(&dlci->gsm->event); } @@ -2267,6 +2339,7 @@ static void gsm_dlci_begin_close(struct gsm_dlci *dlci) dlci->state = DLCI_CLOSING; gsm_command(dlci->gsm, dlci->addr, DISC|PF); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); + wake_up_interruptible(&gsm->event); } /** @@ -2840,6 +2913,7 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc) /* Finish outstanding timers, making sure they are done */ del_timer_sync(&gsm->kick_timer); del_timer_sync(&gsm->t2_timer); + del_timer_sync(&gsm->ka_timer); /* Finish writing to ldisc */ flush_work(&gsm->tx_work); @@ -2987,6 +3061,7 @@ static struct gsm_mux *gsm_alloc_mux(void) INIT_LIST_HEAD(&gsm->tx_data_list); timer_setup(&gsm->kick_timer, gsm_kick_timer, 0); timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0); + timer_setup(&gsm->ka_timer, gsm_control_keep_alive, 0); INIT_WORK(&gsm->tx_work, gsmld_write_task); init_waitqueue_head(&gsm->event); spin_lock_init(&gsm->control_lock); @@ -3003,6 +3078,7 @@ static struct gsm_mux *gsm_alloc_mux(void) gsm->mru = 64; /* Default to encoding 1 so these should be 64 */ gsm->mtu = 64; gsm->dead = true; /* Avoid early tty opens */ + gsm->keep_alive = 0; /* Disabled */ /* Store the instance to the mux array or abort if no space is * available. @@ -3138,6 +3214,29 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) return 0; } +static void gsm_copy_config_ext_values(struct gsm_mux *gsm, + struct gsm_config_ext *ce) +{ + memset(ce, 0, sizeof(*ce)); + ce->keep_alive = gsm->keep_alive; +} + +static int gsm_config_ext(struct gsm_mux *gsm, struct gsm_config_ext *ce) +{ + unsigned int i; + + /* + * Check that userspace doesn't put stuff in here to prevent breakages + * in the future. + */ + for (i = 0; i < ARRAY_SIZE(ce->reserved); i++) + if (ce->reserved[i]) + return -EINVAL; + + gsm->keep_alive = ce->keep_alive; + return 0; +} + /** * gsmld_output - write to link * @gsm: our mux @@ -3456,6 +3555,7 @@ static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) { struct gsm_config c; + struct gsm_config_ext ce; struct gsm_mux *gsm = tty->disc_data; unsigned int base; @@ -3472,6 +3572,15 @@ static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd, case GSMIOC_GETFIRST: base = mux_num_to_base(gsm); return put_user(base + 1, (__u32 __user *)arg); + case GSMIOC_GETCONF_EXT: + gsm_copy_config_ext_values(gsm, &ce); + if (copy_to_user((void __user *)arg, &ce, sizeof(ce))) + return -EFAULT; + return 0; + case GSMIOC_SETCONF_EXT: + if (copy_from_user(&ce, (void __user *)arg, sizeof(ce))) + return -EFAULT; + return gsm_config_ext(gsm, &ce); default: return n_tty_ioctl_helper(tty, cmd, arg); } @@ -3770,16 +3879,43 @@ static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk) return -EPROTONOSUPPORT; } -static int gsm_carrier_raised(struct tty_port *port) +/** + * gsm_wait_modem_change - wait for modem status line change + * @dlci: channel + * @mask: modem status line bits + * + * The function returns if: + * - any given modem status line bit changed + * - the wait event function got interrupted (e.g. by a signal) + * - the underlying DLCI was closed + * - the underlying ldisc device was removed + */ +static int gsm_wait_modem_change(struct gsm_dlci *dlci, u32 mask) +{ + struct gsm_mux *gsm = dlci->gsm; + u32 old = dlci->modem_rx; + int ret; + + ret = wait_event_interruptible(gsm->event, gsm->dead || + dlci->state != DLCI_OPEN || + (old ^ dlci->modem_rx) & mask); + if (gsm->dead) + return -ENODEV; + if (dlci->state != DLCI_OPEN) + return -EL2NSYNC; + return ret; +} + +static bool gsm_carrier_raised(struct tty_port *port) { struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); struct gsm_mux *gsm = dlci->gsm; /* Not yet open so no carrier info */ if (dlci->state != DLCI_OPEN) - return 0; + return false; if (debug & DBG_CD_ON) - return 1; + return true; /* * Basic mode with control channel in ADM mode may not respond @@ -3787,16 +3923,16 @@ static int gsm_carrier_raised(struct tty_port *port) */ if (gsm->encoding == GSM_BASIC_OPT && gsm->dlci[0]->mode == DLCI_MODE_ADM && !dlci->modem_rx) - return 1; + return true; return dlci->modem_rx & TIOCM_CD; } -static void gsm_dtr_rts(struct tty_port *port, int onoff) +static void gsm_dtr_rts(struct tty_port *port, bool active) { struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); unsigned int modem_tx = dlci->modem_tx; - if (onoff) + if (active) modem_tx |= TIOCM_DTR | TIOCM_RTS; else modem_tx &= ~(TIOCM_DTR | TIOCM_RTS); @@ -3880,7 +4016,7 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp) dlci->modem_rx = 0; /* We could in theory open and close before we wait - eg if we get a DM straight back. This is ok as that will have caused a hangup */ - tty_port_set_initialized(port, 1); + tty_port_set_initialized(port, true); /* Start sending off SABM messages */ if (gsm->initiator) gsm_dlci_begin_open(dlci); @@ -4029,6 +4165,8 @@ static int gsmtty_ioctl(struct tty_struct *tty, gsm_destroy_network(dlci); mutex_unlock(&dlci->mutex); return 0; + case TIOCMIWAIT: + return gsm_wait_modem_change(dlci, (u32)arg); default: return -ENOIOCTLCMD; } |