cregit-Linux how code gets into the kernel

Release 4.18 net/appletalk/aarp.c

Directory: net/appletalk
/*
 *      AARP:           An implementation of the AppleTalk AARP protocol for
 *                      Ethernet 'ELAP'.
 *
 *              Alan Cox  <Alan.Cox@linux.org>
 *
 *      This doesn't fit cleanly with the IP arp. Potentially we can use
 *      the generic neighbour discovery code to clean this up.
 *
 *      FIXME:
 *              We ought to handle the retransmits with a single list and a
 *      separate fast timer for when it is needed.
 *              Use neighbour discovery code.
 *              Token Ring Support.
 *
 *              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.
 *
 *
 *      References:
 *              Inside AppleTalk (2nd Ed).
 *      Fixes:
 *              Jaume Grau      -       flush caches on AARP_PROBE
 *              Rob Newberry    -       Added proxy AARP and AARP proc fs,
 *                                      moved probing from DDP module.
 *              Arnaldo C. Melo -       don't mangle rx packets
 *
 */

#include <linux/if_arp.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/datalink.h>
#include <net/psnap.h>
#include <linux/atalk.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/export.h>
#include <linux/etherdevice.h>


int sysctl_aarp_expiry_time = AARP_EXPIRY_TIME;

int sysctl_aarp_tick_time = AARP_TICK_TIME;

int sysctl_aarp_retransmit_limit = AARP_RETRANSMIT_LIMIT;

int sysctl_aarp_resolve_time = AARP_RESOLVE_TIME;

/* Lists of aarp entries */
/**
 *      struct aarp_entry - AARP entry
 *      @last_sent - Last time we xmitted the aarp request
 *      @packet_queue - Queue of frames wait for resolution
 *      @status - Used for proxy AARP
 *      expires_at - Entry expiry time
 *      target_addr - DDP Address
 *      dev - Device to use
 *      hwaddr - Physical i/f address of target/router
 *      xmit_count - When this hits 10 we give up
 *      next - Next entry in chain
 */

struct aarp_entry {
	/* These first two are only used for unresolved entries */
	
unsigned long		last_sent;
	
struct sk_buff_head	packet_queue;
	
int			status;
	
unsigned long		expires_at;
	
struct atalk_addr	target_addr;
	
struct net_device	*dev;
	
char			hwaddr[ETH_ALEN];
	
unsigned short		xmit_count;
	
struct aarp_entry	*next;
};

/* Hashed list of resolved, unresolved and proxy entries */

static struct aarp_entry *resolved[AARP_HASH_SIZE];

static struct aarp_entry *unresolved[AARP_HASH_SIZE];

static struct aarp_entry *proxies[AARP_HASH_SIZE];

static int unresolved_count;

/* One lock protects it all. */
static DEFINE_RWLOCK(aarp_lock);

/* Used to walk the list and purge/kick entries.  */

static struct timer_list aarp_timer;

/*
 *      Delete an aarp queue
 *
 *      Must run under aarp_lock.
 */

static void __aarp_expire(struct aarp_entry *a) { skb_queue_purge(&a->packet_queue); kfree(a); }

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Linus Torvalds (pre-git)2395.83%375.00%
Linus Torvalds14.17%125.00%
Total24100.00%4100.00%

/* * Send an aarp queue entry request * * Must run under aarp_lock. */
static void __aarp_send_query(struct aarp_entry *a) { static unsigned char aarp_eth_multicast[ETH_ALEN] = { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; struct net_device *dev = a->dev; struct elapaarp *eah; int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); struct atalk_addr *sat = atalk_find_dev_addr(dev); if (!skb) return; if (!sat) { kfree_skb(skb); return; } /* Set up the buffer */ skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); skb_reset_network_header(skb); skb_reset_transport_header(skb); skb_put(skb, sizeof(*eah)); skb->protocol = htons(ETH_P_ATALK); skb->dev = dev; eah = aarp_hdr(skb); /* Set up the ARP */ eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); eah->pa_type = htons(ETH_P_ATALK); eah->hw_len = ETH_ALEN; eah->pa_len = AARP_PA_ALEN; eah->function = htons(AARP_REQUEST); ether_addr_copy(eah->hw_src, dev->dev_addr); eah->pa_src_zero = 0; eah->pa_src_net = sat->s_net; eah->pa_src_node = sat->s_node; eth_zero_addr(eah->hw_dst); eah->pa_dst_zero = 0; eah->pa_dst_net = a->target_addr.s_net; eah->pa_dst_node = a->target_addr.s_node; /* Send it */ aarp_dl->request(aarp_dl, skb, aarp_eth_multicast); /* Update the sending count */ a->xmit_count++; a->last_sent = jiffies; }

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Linus Torvalds (pre-git)24985.27%538.46%
Arnaldo Carvalho de Melo3010.27%430.77%
Stephen Hemminger62.05%17.69%
Linus Torvalds51.71%17.69%
Joe Perches20.68%215.38%
Total292100.00%13100.00%

/* This runs under aarp_lock and in softint context, so only atomic memory * allocations can be used. */
static void aarp_send_reply(struct net_device *dev, struct atalk_addr *us, struct atalk_addr *them, unsigned char *sha) { struct elapaarp *eah; int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); if (!skb) return; /* Set up the buffer */ skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); skb_reset_network_header(skb); skb_reset_transport_header(skb); skb_put(skb, sizeof(*eah)); skb->protocol = htons(ETH_P_ATALK); skb->dev = dev; eah = aarp_hdr(skb); /* Set up the ARP */ eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); eah->pa_type = htons(ETH_P_ATALK); eah->hw_len = ETH_ALEN; eah->pa_len = AARP_PA_ALEN; eah->function = htons(AARP_REPLY); ether_addr_copy(eah->hw_src, dev->dev_addr); eah->pa_src_zero = 0; eah->pa_src_net = us->s_net; eah->pa_src_node = us->s_node; if (!sha) eth_zero_addr(eah->hw_dst); else ether_addr_copy(eah->hw_dst, sha); eah->pa_dst_zero = 0; eah->pa_dst_net = them->s_net; eah->pa_dst_node = them->s_node; /* Send it */ aarp_dl->request(aarp_dl, skb, sha); }

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PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)21585.32%436.36%
Arnaldo Carvalho de Melo3011.90%436.36%
Linus Torvalds41.59%19.09%
Joe Perches31.19%218.18%
Total252100.00%11100.00%

/* * Send probe frames. Called from aarp_probe_network and * aarp_proxy_probe_network. */
static void aarp_send_probe(struct net_device *dev, struct atalk_addr *us) { struct elapaarp *eah; int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); static unsigned char aarp_eth_multicast[ETH_ALEN] = { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; if (!skb) return; /* Set up the buffer */ skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); skb_reset_network_header(skb); skb_reset_transport_header(skb); skb_put(skb, sizeof(*eah)); skb->protocol = htons(ETH_P_ATALK); skb->dev = dev; eah = aarp_hdr(skb); /* Set up the ARP */ eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); eah->pa_type = htons(ETH_P_ATALK); eah->hw_len = ETH_ALEN; eah->pa_len = AARP_PA_ALEN; eah->function = htons(AARP_PROBE); ether_addr_copy(eah->hw_src, dev->dev_addr); eah->pa_src_zero = 0; eah->pa_src_net = us->s_net; eah->pa_src_node = us->s_node; eth_zero_addr(eah->hw_dst); eah->pa_dst_zero = 0; eah->pa_dst_net = us->s_net; eah->pa_dst_node = us->s_node; /* Send it */ aarp_dl->request(aarp_dl, skb, aarp_eth_multicast); }

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Linus Torvalds (pre-git)21385.54%433.33%
Arnaldo Carvalho de Melo3012.05%433.33%
Linus Torvalds31.20%18.33%
Joe Perches20.80%216.67%
Adrian Bunk10.40%18.33%
Total249100.00%12100.00%

/* * Handle an aarp timer expire * * Must run under the aarp_lock. */
static void __aarp_expire_timer(struct aarp_entry **n) { struct aarp_entry *t; while (*n) /* Expired ? */ if (time_after(jiffies, (*n)->expires_at)) { t = *n; *n = (*n)->next; __aarp_expire(t); } else n = &((*n)->next); }

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Linus Torvalds (pre-git)72100.00%3100.00%
Total72100.00%3100.00%

/* * Kick all pending requests 5 times a second. * * Must run under the aarp_lock. */
static void __aarp_kick(struct aarp_entry **n) { struct aarp_entry *t; while (*n) /* Expired: if this will be the 11th tx, we delete instead. */ if ((*n)->xmit_count >= sysctl_aarp_retransmit_limit) { t = *n; *n = (*n)->next; __aarp_expire(t); } else { __aarp_send_query(*n); n = &((*n)->next); } }

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Linus Torvalds (pre-git)7698.70%375.00%
Linus Torvalds11.30%125.00%
Total77100.00%4100.00%

/* * A device has gone down. Take all entries referring to the device * and remove them. * * Must run under the aarp_lock. */
static void __aarp_expire_device(struct aarp_entry **n, struct net_device *dev) { struct aarp_entry *t; while (*n) if ((*n)->dev == dev) { t = *n; *n = (*n)->next; __aarp_expire(t); } else n = &((*n)->next); }

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Linus Torvalds (pre-git)73100.00%3100.00%
Total73100.00%3100.00%

/* Handle the timer event */
static void aarp_expire_timeout(struct timer_list *unused) { int ct; write_lock_bh(&aarp_lock); for (ct = 0; ct < AARP_HASH_SIZE; ct++) { __aarp_expire_timer(&resolved[ct]); __aarp_kick(&unresolved[ct]); __aarp_expire_timer(&unresolved[ct]); __aarp_expire_timer(&proxies[ct]); } write_unlock_bh(&aarp_lock); mod_timer(&aarp_timer, jiffies + (unresolved_count ? sysctl_aarp_tick_time : sysctl_aarp_expiry_time)); }

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Linus Torvalds (pre-git)8894.62%675.00%
Kees Cook33.23%112.50%
Arnaldo Carvalho de Melo22.15%112.50%
Total93100.00%8100.00%

/* Network device notifier chain handler. */
static int aarp_device_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); int ct; if (!net_eq(dev_net(dev), &init_net)) return NOTIFY_DONE; if (event == NETDEV_DOWN) { write_lock_bh(&aarp_lock); for (ct = 0; ct < AARP_HASH_SIZE; ct++) { __aarp_expire_device(&resolved[ct], dev); __aarp_expire_device(&unresolved[ct], dev); __aarp_expire_device(&proxies[ct], dev); } write_unlock_bh(&aarp_lock); } return NOTIFY_DONE; }

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PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)8873.33%440.00%
Eric W. Biedermann1915.83%220.00%
Hideaki Yoshifuji / 吉藤英明86.67%220.00%
Jiri Pirko32.50%110.00%
Arnaldo Carvalho de Melo21.67%110.00%
Total120100.00%10100.00%

/* Expire all entries in a hash chain */
static void __aarp_expire_all(struct aarp_entry **n) { struct aarp_entry *t; while (*n) { t = *n; *n = (*n)->next; __aarp_expire(t); } }

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Stephen Hemminger44100.00%1100.00%
Total44100.00%1100.00%

/* Cleanup all hash chains -- module unloading */
static void aarp_purge(void) { int ct; write_lock_bh(&aarp_lock); for (ct = 0; ct < AARP_HASH_SIZE; ct++) { __aarp_expire_all(&resolved[ct]); __aarp_expire_all(&unresolved[ct]); __aarp_expire_all(&proxies[ct]); } write_unlock_bh(&aarp_lock); }

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PersonTokensPropCommitsCommitProp
Stephen Hemminger65100.00%1100.00%
Total65100.00%1100.00%

/* * Create a new aarp entry. This must use GFP_ATOMIC because it * runs while holding spinlocks. */
static struct aarp_entry *aarp_alloc(void) { struct aarp_entry *a = kmalloc(sizeof(*a), GFP_ATOMIC); if (a) skb_queue_head_init(&a->packet_queue); return a; }

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Linus Torvalds (pre-git)3995.12%150.00%
Arnaldo Carvalho de Melo24.88%150.00%
Total41100.00%2100.00%

/* * Find an entry. We might return an expired but not yet purged entry. We * don't care as it will do no harm. * * This must run under the aarp_lock. */
static struct aarp_entry *__aarp_find_entry(struct aarp_entry *list, struct net_device *dev, struct atalk_addr *sat) { while (list) { if (list->target_addr.s_net == sat->s_net && list->target_addr.s_node == sat->s_node && list->dev == dev) break; list = list->next; } return list; }

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Linus Torvalds (pre-git)6698.51%375.00%
Arnaldo Carvalho de Melo11.49%125.00%
Total67100.00%4100.00%

/* Called from the DDP code, and thus must be exported. */
void aarp_proxy_remove(struct net_device *dev, struct atalk_addr *sa) { int hash = sa->s_node % (AARP_HASH_SIZE - 1); struct aarp_entry *a; write_lock_bh(&aarp_lock); a = __aarp_find_entry(proxies[hash], dev, sa); if (a) a->expires_at = jiffies - 1; write_unlock_bh(&aarp_lock); }

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Linus Torvalds (pre-git)6185.92%666.67%
Linus Torvalds79.86%111.11%
Arnaldo Carvalho de Melo34.23%222.22%
Total71100.00%9100.00%

/* This must run under aarp_lock. */
static struct atalk_addr *__aarp_proxy_find(struct net_device *dev, struct atalk_addr *sa) { int hash = sa->s_node % (AARP_HASH_SIZE - 1); struct aarp_entry *a = __aarp_find_entry(proxies[hash], dev, sa); return a ? sa : NULL; }

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PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4276.36%466.67%
Linus Torvalds1120.00%116.67%
Arnaldo Carvalho de Melo23.64%116.67%
Total55100.00%6100.00%

/* * Probe a Phase 1 device or a device that requires its Net:Node to * be set via an ioctl. */
static void aarp_send_probe_phase1(struct atalk_iface *iface) { struct ifreq atreq; struct sockaddr_at *sa = (struct sockaddr_at *)&atreq.ifr_addr; const struct net_device_ops *ops = iface->dev->netdev_ops; sa->sat_addr.s_node = iface->address.s_node; sa->sat_addr.s_net = ntohs(iface->address.s_net); /* We pass the Net:Node to the drivers/cards by a Device ioctl. */ if (!(ops->ndo_do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) { ops->ndo_do_ioctl(iface->dev, &atreq, SIOCGIFADDR); if (iface->address.s_net != htons(sa->sat_addr.s_net) || iface->address.s_node != sa->sat_addr.s_node) iface->status |= ATIF_PROBE_FAIL; iface->address.s_net = htons(sa->sat_addr.s_net); iface->address.s_node = sa->sat_addr.s_node; } }

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Linus Torvalds (pre-git)15089.82%466.67%
Stephen Hemminger169.58%116.67%
Adrian Bunk10.60%116.67%
Total167100.00%6100.00%


void aarp_probe_network(struct atalk_iface *atif) { if (atif->dev->type == ARPHRD_LOCALTLK || atif->dev->type == ARPHRD_PPP) aarp_send_probe_phase1(atif); else { unsigned int count; for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) { aarp_send_probe(atif->dev, &atif->address); /* Defer 1/10th */ msleep(100); if (atif->status & ATIF_PROBE_FAIL) break; } } }

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Linus Torvalds (pre-git)7996.34%466.67%
Nishanth Aravamudan22.44%116.67%
Linus Torvalds11.22%116.67%
Total82100.00%6100.00%


int aarp_proxy_probe_network(struct atalk_iface *atif, struct atalk_addr *sa) { int hash, retval = -EPROTONOSUPPORT; struct aarp_entry *entry; unsigned int count; /* * we don't currently support LocalTalk or PPP for proxy AARP; * if someone wants to try and add it, have fun */ if (atif->dev->type == ARPHRD_LOCALTLK || atif->dev->type == ARPHRD_PPP) goto out; /* * create a new AARP entry with the flags set to be published -- * we need this one to hang around even if it's in use */ entry = aarp_alloc(); retval = -ENOMEM; if (!entry) goto out; entry->expires_at = -1; entry->status = ATIF_PROBE; entry->target_addr.s_node = sa->s_node; entry->target_addr.s_net = sa->s_net; entry->dev = atif->dev; write_lock_bh(&aarp_lock); hash = sa->s_node % (AARP_HASH_SIZE - 1); entry->next = proxies[hash]; proxies[hash] = entry; for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) { aarp_send_probe(atif->dev, sa); /* Defer 1/10th */ write_unlock_bh(&aarp_lock); msleep(100); write_lock_bh(&aarp_lock); if (entry->status & ATIF_PROBE_FAIL) break; } if (entry->status & ATIF_PROBE_FAIL) { entry->expires_at = jiffies - 1; /* free the entry */ retval = -EADDRINUSE; /* return network full */ } else { /* clear the probing flag */ entry->status &= ~ATIF_PROBE; retval = 1; } write_unlock_bh(&aarp_lock); out: return retval; }

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PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)21084.00%444.44%
Arnaldo Carvalho de Melo2811.20%333.33%
Linus Torvalds104.00%111.11%
Nishanth Aravamudan20.80%111.11%
Total250100.00%9100.00%

/* Send a DDP frame */
int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb, struct atalk_addr *sa, void *hwaddr) { static char ddp_eth_multicast[ETH_ALEN] = { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; int hash; struct aarp_entry *a; skb_reset_network_header(skb); /* Check for LocalTalk first */ if (dev->type == ARPHRD_LOCALTLK) { struct atalk_addr *at = atalk_find_dev_addr(dev); struct ddpehdr *ddp = (struct ddpehdr *)skb->data; int ft = 2; /* * Compressible ? * * IFF: src_net == dest_net == device_net * (zero matches anything) */ if ((!ddp->deh_snet || at->s_net == ddp->deh_snet) && (!ddp->deh_dnet || at->s_net == ddp->deh_dnet)) { skb_pull(skb, sizeof(*ddp) - 4); /* * The upper two remaining bytes are the port * numbers we just happen to need. Now put the * length in the lower two. */ *((__be16 *)skb->data) = htons(skb->len); ft = 1; } /* * Nice and easy. No AARP type protocols occur here so we can * just shovel it out with a 3 byte LLAP header */ skb_push(skb, 3); skb->data[0] = sa->s_node; skb->data[1] = at->s_node; skb->data[2] = ft; skb->dev = dev; goto sendit; } /* On a PPP link we neither compress nor aarp. */ if (dev->type == ARPHRD_PPP) { skb->protocol = htons(ETH_P_PPPTALK); skb->dev = dev; goto sendit; } /* Non ELAP we cannot do. */ if (dev->type != ARPHRD_ETHER) goto free_it; skb->dev = dev; skb->protocol = htons(ETH_P_ATALK); hash = sa->s_node % (AARP_HASH_SIZE - 1); /* Do we have a resolved entry? */ if (sa->s_node == ATADDR_BCAST) { /* Send it */ ddp_dl->request(ddp_dl, skb, ddp_eth_multicast); goto sent; } write_lock_bh(&aarp_lock); a = __aarp_find_entry(resolved[hash], dev, sa); if (a) { /* Return 1 and fill in the address */ a->expires_at = jiffies + (sysctl_aarp_expiry_time * 10); ddp_dl->request(ddp_dl, skb, a->hwaddr); write_unlock_bh(&aarp_lock); goto sent; } /* Do we have an unresolved entry: This is the less common path */ a = __aarp_find_entry(unresolved[hash], dev, sa); if (a) { /* Queue onto the unresolved queue */ skb_queue_tail(&a->packet_queue, skb); goto out_unlock; } /* Allocate a new entry */ a = aarp_alloc(); if (!a) { /* Whoops slipped... good job it's an unreliable protocol 8) */ write_unlock_bh(&aarp_lock); goto free_it; } /* Set up the queue */ skb_queue_tail(&a->packet_queue, skb); a->expires_at = jiffies + sysctl_aarp_resolve_time; a->dev = dev; a->next = unresolved[hash]; a->target_addr = *sa; a->xmit_count = 0; unresolved[hash] = a; unresolved_count++; /* Send an initial request for the address */ __aarp_send_query(a); /* * Switch to fast timer if needed (That is if this is the first * unresolved entry to get added) */ if (unresolved_count == 1) mod_timer(&aarp_timer, jiffies + sysctl_aarp_tick_time); /* Now finally, it is safe to drop the lock. */ out_unlock: write_unlock_bh(&aarp_lock); /* Tell the ddp layer we have taken over for this frame. */ goto sent; sendit: if (skb->sk) skb->priority = skb->sk->sk_priority; if (dev_queue_xmit(skb)) goto drop; sent: return NET_XMIT_SUCCESS; free_it: kfree_skb(skb); drop: return NET_XMIT_DROP; }

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Linus Torvalds (pre-git)46281.34%430.77%
Arnaldo Carvalho de Melo569.86%753.85%
Linus Torvalds498.63%17.69%
Alexey Dobriyan10.18%17.69%
Total568100.00%13100.00%

EXPORT_SYMBOL(aarp_send_ddp); /* * An entry in the aarp unresolved queue has become resolved. Send * all the frames queued under it. * * Must run under aarp_lock. */
static void __aarp_resolved(struct aarp_entry **list, struct aarp_entry *a, int hash) { struct sk_buff *skb; while (*list) if (*list == a) { unresolved_count--; *list = a->next; /* Move into the resolved list */ a->next = resolved[hash]; resolved[hash] = a; /* Kick frames off */ while ((skb = skb_dequeue(&a->