From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/irda/discovery.c | 417 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 417 insertions(+) create mode 100644 net/irda/discovery.c (limited to 'net/irda/discovery.c') diff --git a/net/irda/discovery.c b/net/irda/discovery.c new file mode 100644 index 000000000..364d70aed --- /dev/null +++ b/net/irda/discovery.c @@ -0,0 +1,417 @@ +/********************************************************************* + * + * Filename: discovery.c + * Version: 0.1 + * Description: Routines for handling discoveries at the IrLMP layer + * Status: Experimental. + * Author: Dag Brattli + * Created at: Tue Apr 6 15:33:50 1999 + * Modified at: Sat Oct 9 17:11:31 1999 + * Modified by: Dag Brattli + * Modified at: Fri May 28 3:11 CST 1999 + * Modified by: Horst von Brand + * + * Copyright (c) 1999 Dag Brattli, All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + * + ********************************************************************/ + +#include +#include +#include +#include +#include +#include + +#include +#include + +#include + +#include + +/* + * Function irlmp_add_discovery (cachelog, discovery) + * + * Add a new discovery to the cachelog, and remove any old discoveries + * from the same device + * + * Note : we try to preserve the time this device was *first* discovered + * (as opposed to the time of last discovery used for cleanup). This is + * used by clients waiting for discovery events to tell if the device + * discovered is "new" or just the same old one. They can't rely there + * on a binary flag (new/old), because not all discovery events are + * propagated to them, and they might not always listen, so they would + * miss some new devices popping up... + * Jean II + */ +void irlmp_add_discovery(hashbin_t *cachelog, discovery_t *new) +{ + discovery_t *discovery, *node; + unsigned long flags; + + /* Set time of first discovery if node is new (see below) */ + new->firststamp = new->timestamp; + + spin_lock_irqsave(&cachelog->hb_spinlock, flags); + + /* + * Remove all discoveries of devices that has previously been + * discovered on the same link with the same name (info), or the + * same daddr. We do this since some devices (mostly PDAs) change + * their device address between every discovery. + */ + discovery = (discovery_t *) hashbin_get_first(cachelog); + while (discovery != NULL ) { + node = discovery; + + /* Be sure to stay one item ahead */ + discovery = (discovery_t *) hashbin_get_next(cachelog); + + if ((node->data.saddr == new->data.saddr) && + ((node->data.daddr == new->data.daddr) || + (strcmp(node->data.info, new->data.info) == 0))) + { + /* This discovery is a previous discovery + * from the same device, so just remove it + */ + hashbin_remove_this(cachelog, (irda_queue_t *) node); + /* Check if hints bits are unchanged */ + if (get_unaligned((__u16 *)node->data.hints) == get_unaligned((__u16 *)new->data.hints)) + /* Set time of first discovery for this node */ + new->firststamp = node->firststamp; + kfree(node); + } + } + + /* Insert the new and updated version */ + hashbin_insert(cachelog, (irda_queue_t *) new, new->data.daddr, NULL); + + spin_unlock_irqrestore(&cachelog->hb_spinlock, flags); +} + +/* + * Function irlmp_add_discovery_log (cachelog, log) + * + * Merge a disovery log into the cachelog. + * + */ +void irlmp_add_discovery_log(hashbin_t *cachelog, hashbin_t *log) +{ + discovery_t *discovery; + + /* + * If log is missing this means that IrLAP was unable to perform the + * discovery, so restart discovery again with just the half timeout + * of the normal one. + */ + /* Well... It means that there was nobody out there - Jean II */ + if (log == NULL) { + /* irlmp_start_discovery_timer(irlmp, 150); */ + return; + } + + /* + * Locking : we are the only owner of this discovery log, so + * no need to lock it. + * We just need to lock the global log in irlmp_add_discovery(). + */ + discovery = (discovery_t *) hashbin_remove_first(log); + while (discovery != NULL) { + irlmp_add_discovery(cachelog, discovery); + + discovery = (discovery_t *) hashbin_remove_first(log); + } + + /* Delete the now empty log */ + hashbin_delete(log, (FREE_FUNC) kfree); +} + +/* + * Function irlmp_expire_discoveries (log, saddr, force) + * + * Go through all discoveries and expire all that has stayed too long + * + * Note : this assume that IrLAP won't change its saddr, which + * currently is a valid assumption... + */ +void irlmp_expire_discoveries(hashbin_t *log, __u32 saddr, int force) +{ + discovery_t * discovery; + discovery_t * curr; + unsigned long flags; + discinfo_t * buffer = NULL; + int n; /* Size of the full log */ + int i = 0; /* How many we expired */ + + IRDA_ASSERT(log != NULL, return;); + spin_lock_irqsave(&log->hb_spinlock, flags); + + discovery = (discovery_t *) hashbin_get_first(log); + while (discovery != NULL) { + /* Be sure to be one item ahead */ + curr = discovery; + discovery = (discovery_t *) hashbin_get_next(log); + + /* Test if it's time to expire this discovery */ + if ((curr->data.saddr == saddr) && + (force || + ((jiffies - curr->timestamp) > DISCOVERY_EXPIRE_TIMEOUT))) + { + /* Create buffer as needed. + * As this function get called a lot and most time + * we don't have anything to put in the log (we are + * quite picky), we can save a lot of overhead + * by not calling kmalloc. Jean II */ + if(buffer == NULL) { + /* Create the client specific buffer */ + n = HASHBIN_GET_SIZE(log); + buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); + if (buffer == NULL) { + spin_unlock_irqrestore(&log->hb_spinlock, flags); + return; + } + + } + + /* Copy discovery information */ + memcpy(&(buffer[i]), &(curr->data), + sizeof(discinfo_t)); + i++; + + /* Remove it from the log */ + curr = hashbin_remove_this(log, (irda_queue_t *) curr); + kfree(curr); + } + } + + /* Drop the spinlock before calling the higher layers, as + * we can't guarantee they won't call us back and create a + * deadlock. We will work on our own private data, so we + * don't care to be interrupted. - Jean II */ + spin_unlock_irqrestore(&log->hb_spinlock, flags); + + if(buffer == NULL) + return; + + /* Tell IrLMP and registered clients about it */ + irlmp_discovery_expiry(buffer, i); + + /* Free up our buffer */ + kfree(buffer); +} + +#if 0 +/* + * Function irlmp_dump_discoveries (log) + * + * Print out all discoveries in log + * + */ +void irlmp_dump_discoveries(hashbin_t *log) +{ + discovery_t *discovery; + + IRDA_ASSERT(log != NULL, return;); + + discovery = (discovery_t *) hashbin_get_first(log); + while (discovery != NULL) { + pr_debug("Discovery:\n"); + pr_debug(" daddr=%08x\n", discovery->data.daddr); + pr_debug(" saddr=%08x\n", discovery->data.saddr); + pr_debug(" nickname=%s\n", discovery->data.info); + + discovery = (discovery_t *) hashbin_get_next(log); + } +} +#endif + +/* + * Function irlmp_copy_discoveries (log, pn, mask) + * + * Copy all discoveries in a buffer + * + * This function implement a safe way for lmp clients to access the + * discovery log. The basic problem is that we don't want the log + * to change (add/remove) while the client is reading it. If the + * lmp client manipulate directly the hashbin, he is sure to get + * into troubles... + * The idea is that we copy all the current discovery log in a buffer + * which is specific to the client and pass this copy to him. As we + * do this operation with the spinlock grabbed, we are safe... + * Note : we don't want those clients to grab the spinlock, because + * we have no control on how long they will hold it... + * Note : we choose to copy the log in "struct irda_device_info" to + * save space... + * Note : the client must kfree himself() the log... + * Jean II + */ +struct irda_device_info *irlmp_copy_discoveries(hashbin_t *log, int *pn, + __u16 mask, int old_entries) +{ + discovery_t * discovery; + unsigned long flags; + discinfo_t * buffer = NULL; + int j_timeout = (sysctl_discovery_timeout * HZ); + int n; /* Size of the full log */ + int i = 0; /* How many we picked */ + + IRDA_ASSERT(pn != NULL, return NULL;); + IRDA_ASSERT(log != NULL, return NULL;); + + /* Save spin lock */ + spin_lock_irqsave(&log->hb_spinlock, flags); + + discovery = (discovery_t *) hashbin_get_first(log); + while (discovery != NULL) { + /* Mask out the ones we don't want : + * We want to match the discovery mask, and to get only + * the most recent one (unless we want old ones) */ + if ((get_unaligned((__u16 *)discovery->data.hints) & mask) && + ((old_entries) || + ((jiffies - discovery->firststamp) < j_timeout))) { + /* Create buffer as needed. + * As this function get called a lot and most time + * we don't have anything to put in the log (we are + * quite picky), we can save a lot of overhead + * by not calling kmalloc. Jean II */ + if(buffer == NULL) { + /* Create the client specific buffer */ + n = HASHBIN_GET_SIZE(log); + buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); + if (buffer == NULL) { + spin_unlock_irqrestore(&log->hb_spinlock, flags); + return NULL; + } + + } + + /* Copy discovery information */ + memcpy(&(buffer[i]), &(discovery->data), + sizeof(discinfo_t)); + i++; + } + discovery = (discovery_t *) hashbin_get_next(log); + } + + spin_unlock_irqrestore(&log->hb_spinlock, flags); + + /* Get the actual number of device in the buffer and return */ + *pn = i; + return buffer; +} + +#ifdef CONFIG_PROC_FS +static inline discovery_t *discovery_seq_idx(loff_t pos) + +{ + discovery_t *discovery; + + for (discovery = (discovery_t *) hashbin_get_first(irlmp->cachelog); + discovery != NULL; + discovery = (discovery_t *) hashbin_get_next(irlmp->cachelog)) { + if (pos-- == 0) + break; + } + + return discovery; +} + +static void *discovery_seq_start(struct seq_file *seq, loff_t *pos) +{ + spin_lock_irq(&irlmp->cachelog->hb_spinlock); + return *pos ? discovery_seq_idx(*pos - 1) : SEQ_START_TOKEN; +} + +static void *discovery_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + ++*pos; + return (v == SEQ_START_TOKEN) + ? (void *) hashbin_get_first(irlmp->cachelog) + : (void *) hashbin_get_next(irlmp->cachelog); +} + +static void discovery_seq_stop(struct seq_file *seq, void *v) +{ + spin_unlock_irq(&irlmp->cachelog->hb_spinlock); +} + +static int discovery_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_puts(seq, "IrLMP: Discovery log:\n\n"); + else { + const discovery_t *discovery = v; + + seq_printf(seq, "nickname: %s, hint: 0x%02x%02x", + discovery->data.info, + discovery->data.hints[0], + discovery->data.hints[1]); +#if 0 + if ( discovery->data.hints[0] & HINT_PNP) + seq_puts(seq, "PnP Compatible "); + if ( discovery->data.hints[0] & HINT_PDA) + seq_puts(seq, "PDA/Palmtop "); + if ( discovery->data.hints[0] & HINT_COMPUTER) + seq_puts(seq, "Computer "); + if ( discovery->data.hints[0] & HINT_PRINTER) + seq_puts(seq, "Printer "); + if ( discovery->data.hints[0] & HINT_MODEM) + seq_puts(seq, "Modem "); + if ( discovery->data.hints[0] & HINT_FAX) + seq_puts(seq, "Fax "); + if ( discovery->data.hints[0] & HINT_LAN) + seq_puts(seq, "LAN Access "); + + if ( discovery->data.hints[1] & HINT_TELEPHONY) + seq_puts(seq, "Telephony "); + if ( discovery->data.hints[1] & HINT_FILE_SERVER) + seq_puts(seq, "File Server "); + if ( discovery->data.hints[1] & HINT_COMM) + seq_puts(seq, "IrCOMM "); + if ( discovery->data.hints[1] & HINT_OBEX) + seq_puts(seq, "IrOBEX "); +#endif + seq_printf(seq,", saddr: 0x%08x, daddr: 0x%08x\n\n", + discovery->data.saddr, + discovery->data.daddr); + + seq_putc(seq, '\n'); + } + return 0; +} + +static const struct seq_operations discovery_seq_ops = { + .start = discovery_seq_start, + .next = discovery_seq_next, + .stop = discovery_seq_stop, + .show = discovery_seq_show, +}; + +static int discovery_seq_open(struct inode *inode, struct file *file) +{ + IRDA_ASSERT(irlmp != NULL, return -EINVAL;); + + return seq_open(file, &discovery_seq_ops); +} + +const struct file_operations discovery_seq_fops = { + .owner = THIS_MODULE, + .open = discovery_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; +#endif -- cgit v1.2.3