--- /dev/null
+/*********************************************************************
+ *
+ * Filename: discovery.c
+ * Version: 0.1
+ * Description: Routines for handling discoveries at the IrLMP layer
+ * Status: Experimental.
+ * Author: Dag Brattli <dagb@cs.uit.no>
+ * Created at: Tue Apr 6 15:33:50 1999
+ * Modified at: Sat Oct 9 17:11:31 1999
+ * Modified by: Dag Brattli <dagb@cs.uit.no>
+ * Modified at: Fri May 28 3:11 CST 1999
+ * Modified by: Horst von Brand <vonbrand@sleipnir.valparaiso.cl>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ *
+ ********************************************************************/
+
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+#include <net/irda/irda.h>
+#include <net/irda/irlmp.h>
+
+#include <net/irda/discovery.h>
+
+#include <asm/unaligned.h>
+
+/*
+ * 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
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