cregit-Linux how code gets into the kernel

Release 4.11 net/irda/discovery.c

Directory: net/irda
/*********************************************************************
 *
 * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)17379.72%342.86%
Jean Tourrilhes3214.75%228.57%
Graf Yang104.61%114.29%
Hideaki Yoshifuji / 吉藤英明20.92%114.29%
Total217100.00%7100.00%

/* * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)7697.44%150.00%
Jean Tourrilhes22.56%150.00%
Total78100.00%2100.00%

/* * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13753.73%342.86%
Jean Tourrilhes11745.88%342.86%
Robert P. J. Day10.39%114.29%
Total255100.00%7100.00%

#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; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13654.84%120.00%
Jean Tourrilhes10743.15%360.00%
Graf Yang52.02%120.00%
Total248100.00%5100.00%

#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; }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger4473.33%133.33%
Linus Torvalds (pre-git)1321.67%133.33%
Jean Tourrilhes35.00%133.33%
Total60100.00%3100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger3280.00%120.00%
Linus Torvalds (pre-git)512.50%240.00%
Jean Tourrilhes25.00%120.00%
David S. Miller12.50%120.00%
Total40100.00%5100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger4483.02%133.33%
Linus Torvalds (pre-git)916.98%266.67%
Total53100.00%3100.00%


static void discovery_seq_stop(struct seq_file *seq, void *v) { spin_unlock_irq(&irlmp->cachelog->hb_spinlock); }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger2496.00%150.00%
David S. Miller14.00%150.00%
Total25100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger4846.15%120.00%
Linus Torvalds (pre-git)4442.31%240.00%
Jean Tourrilhes1110.58%120.00%
Hideaki Yoshifuji / 吉藤英明10.96%120.00%
Total104100.00%5100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
Stephen Hemminger2578.12%120.00%
Linus Torvalds (pre-git)515.62%240.00%
Jean Tourrilhes13.12%120.00%
David S. Miller13.12%120.00%
Total32100.00%5100.00%

const struct file_operations discovery_seq_fops = { .owner = THIS_MODULE, .open = discovery_seq_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; #endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)61650.53%626.09%
Jean Tourrilhes28223.13%313.04%
Stephen Hemminger28123.05%14.35%
Graf Yang181.48%14.35%
Al Viro30.25%14.35%
Hideaki Yoshifuji / 吉藤英明30.25%14.35%
Tejun Heo30.25%14.35%
Paul Gortmaker30.25%14.35%
David S. Miller30.25%14.35%
Philippe De Muyter10.08%14.35%
Andries E. Brouwer10.08%14.35%
Jeff Kirsher10.08%14.35%
Joe Perches10.08%14.35%
Hirofumi Ogawa10.08%14.35%
Arjan van de Ven10.08%14.35%
Robert P. J. Day10.08%14.35%
Total1219100.00%23100.00%
Directory: net/irda
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