cregit-Linux how code gets into the kernel

Release 4.14 net/atm/clip.c

Directory: net/atm
/* net/atm/clip.c - RFC1577 Classical IP over ATM */

/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#include <linux/string.h>
#include <linux/errno.h>
#include <linux/kernel.h> /* for UINT_MAX */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/wait.h>
#include <linux/timer.h>
#include <linux/if_arp.h> /* for some manifest constants */
#include <linux/notifier.h>
#include <linux/atm.h>
#include <linux/atmdev.h>
#include <linux/atmclip.h>
#include <linux/atmarp.h>
#include <linux/capability.h>
#include <linux/ip.h> /* for net/route.h */
#include <linux/in.h> /* for struct sockaddr_in */
#include <linux/if.h> /* for IFF_UP */
#include <linux/inetdevice.h>
#include <linux/bitops.h>
#include <linux/poison.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <net/route.h> /* for struct rtable and routing */
#include <net/icmp.h> /* icmp_send */
#include <net/arp.h>
#include <linux/param.h> /* for HZ */
#include <linux/uaccess.h>
#include <asm/byteorder.h> /* for htons etc. */
#include <linux/atomic.h>

#include "common.h"
#include "resources.h"
#include <net/atmclip.h>

static struct net_device *clip_devs;

static struct atm_vcc *atmarpd;

static struct timer_list idle_timer;

static const struct neigh_ops clip_neigh_ops;

static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip) { struct sock *sk; struct atmarp_ctrl *ctrl; struct sk_buff *skb; pr_debug("(%d)\n", type); if (!atmarpd) return -EUNATCH; skb = alloc_skb(sizeof(struct atmarp_ctrl), GFP_ATOMIC); if (!skb) return -ENOMEM; ctrl = skb_put(skb, sizeof(struct atmarp_ctrl)); ctrl->type = type; ctrl->itf_num = itf; ctrl->ip = ip; atm_force_charge(atmarpd, skb->truesize); sk = sk_atm(atmarpd); skb_queue_tail(&sk->sk_receive_queue, skb); sk->sk_data_ready(sk); return 0; }


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Al Viro10.74%111.11%

static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry) { pr_debug("%p to entry %p (neigh %p)\n", clip_vcc, entry, entry->neigh); clip_vcc->entry = entry; clip_vcc->xoff = 0; /* @@@ may overrun buffer by one packet */ clip_vcc->next = entry->vccs; entry->vccs = clip_vcc; entry->neigh->used = jiffies; }


Linus Torvalds (pre-git)6296.88%250.00%
Stephen Hemminger11.56%125.00%
Joe Perches11.56%125.00%

static void unlink_clip_vcc(struct clip_vcc *clip_vcc) { struct atmarp_entry *entry = clip_vcc->entry; struct clip_vcc **walk; if (!entry) { pr_crit("!clip_vcc->entry (clip_vcc %p)\n", clip_vcc); return; } netif_tx_lock_bh(entry->neigh->dev); /* block clip_start_xmit() */ entry->neigh->used = jiffies; for (walk = &entry->vccs; *walk; walk = &(*walk)->next) if (*walk == clip_vcc) { int error; *walk = clip_vcc->next; /* atomic */ clip_vcc->entry = NULL; if (clip_vcc->xoff) netif_wake_queue(entry->neigh->dev); if (entry->vccs) goto out; entry->expires = jiffies - 1; /* force resolution or expiration */ error = neigh_update(entry->neigh, NULL, NUD_NONE, NEIGH_UPDATE_F_ADMIN, 0); if (error) pr_crit("neigh_update failed with %d\n", error); goto out; } pr_crit("ATMARP: failed (entry %p, vcc 0x%p)\n", entry, clip_vcc); out: netif_tx_unlock_bh(entry->neigh->dev); }


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Hideaki Yoshifuji / 吉藤英明10.52%114.29%

/* The neighbour entry n->lock is held. */
static int neigh_check_cb(struct neighbour *n) { struct atmarp_entry *entry = neighbour_priv(n); struct clip_vcc *cv; if (n->ops != &clip_neigh_ops) return 0; for (cv = entry->vccs; cv; cv = cv->next) { unsigned long exp = cv->last_use + cv->idle_timeout; if (cv->idle_timeout && time_after(jiffies, exp)) { pr_debug("releasing vcc %p->%p of entry %p\n", cv, cv->vcc, entry); vcc_release_async(cv->vcc, -ETIMEDOUT); } } if (entry->vccs || time_before(jiffies, entry->expires)) return 0; if (refcount_read(&n->refcnt) > 1) { struct sk_buff *skb; pr_debug("destruction postponed with ref %d\n", refcount_read(&n->refcnt)); while ((skb = skb_dequeue(&n->arp_queue)) != NULL) dev_kfree_skb(skb); return 0; } pr_debug("expired neigh %p\n", n); return 1; }


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Stephen Hemminger31.58%114.29%
Elena Reshetova21.05%114.29%
Chas Williams10.53%114.29%

static void idle_timer_check(unsigned long dummy) { write_lock(&arp_tbl.lock); __neigh_for_each_release(&arp_tbl, neigh_check_cb); mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ); write_unlock(&arp_tbl.lock); }


Linus Torvalds (pre-git)2350.00%125.00%
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Chas Williams510.87%125.00%
Eric Dumazet36.52%125.00%

static int clip_arp_rcv(struct sk_buff *skb) { struct atm_vcc *vcc; pr_debug("\n"); vcc = ATM_SKB(skb)->vcc; if (!vcc || !atm_charge(vcc, skb->truesize)) { dev_kfree_skb_any(skb); return 0; } pr_debug("pushing to %p\n", vcc); pr_debug("using %p\n", CLIP_VCC(vcc)->old_push); CLIP_VCC(vcc)->old_push(vcc, skb); return 0; }


Linus Torvalds (pre-git)8595.51%250.00%
Stephen Hemminger33.37%125.00%
Joe Perches11.12%125.00%

static const unsigned char llc_oui[] = { 0xaa, /* DSAP: non-ISO */ 0xaa, /* SSAP: non-ISO */ 0x03, /* Ctrl: Unnumbered Information Command PDU */ 0x00, /* OUI: EtherType */ 0x00, 0x00 };
static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb) { struct clip_vcc *clip_vcc = CLIP_VCC(vcc); pr_debug("\n"); if (!clip_devs) { atm_return(vcc, skb->truesize); kfree_skb(skb); return; } if (!skb) { pr_debug("removing VCC %p\n", clip_vcc); if (clip_vcc->entry) unlink_clip_vcc(clip_vcc); clip_vcc->old_push(vcc, NULL); /* pass on the bad news */ kfree(clip_vcc); return; } atm_return(vcc, skb->truesize); skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs; /* clip_vcc->entry == NULL if we don't have an IP address yet */ if (!skb->dev) { dev_kfree_skb_any(skb); return; } ATM_SKB(skb)->vcc = vcc; skb_reset_mac_header(skb); if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data, llc_oui, sizeof(llc_oui))) skb->protocol = htons(ETH_P_IP); else { skb->protocol = ((__be16 *)skb->data)[3]; skb_pull(skb, RFC1483LLC_LEN); if (skb->protocol == htons(ETH_P_ARP)) { skb->dev->stats.rx_packets++; skb->dev->stats.rx_bytes += skb->len; clip_arp_rcv(skb); return; } } clip_vcc->last_use = jiffies; skb->dev->stats.rx_packets++; skb->dev->stats.rx_bytes += skb->len; memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data)); netif_rx(skb); }


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Stephen Hemminger20.66%110.00%
Al Viro10.33%110.00%
Joe Perches10.33%110.00%

/* * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that * clip_pop is atomic with respect to the critical section in clip_start_xmit. */
static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb) { struct clip_vcc *clip_vcc = CLIP_VCC(vcc); struct net_device *dev = skb->dev; int old; unsigned long flags; pr_debug("(vcc %p)\n", vcc); clip_vcc->old_pop(vcc, skb); /* skb->dev == NULL in outbound ARP packets */ if (!dev) return; spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags); if (atm_may_send(vcc, 0)) { old = xchg(&clip_vcc->xoff, 0); if (old) netif_wake_queue(dev); } spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags); }


Linus Torvalds (pre-git)12198.37%466.67%
Stephen Hemminger10.81%116.67%
Joe Perches10.81%116.67%

static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb) { __be32 *ip = (__be32 *) neigh->primary_key; pr_debug("(neigh %p, skb %p)\n", neigh, skb); to_atmarpd(act_need, PRIV(neigh->dev)->number, *ip); }


Linus Torvalds (pre-git)3972.22%125.00%
David S. Miller1324.07%125.00%
Joe Perches11.85%125.00%
Stephen Hemminger11.85%125.00%

static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb) { #ifndef CONFIG_ATM_CLIP_NO_ICMP icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); #endif kfree_skb(skb); }


Linus Torvalds (pre-git)37100.00%1100.00%

static const struct neigh_ops clip_neigh_ops = { .family = AF_INET, .solicit = clip_neigh_solicit, .error_report = clip_neigh_error, .output = neigh_direct_output, .connected_output = neigh_direct_output, };
static int clip_constructor(struct net_device *dev, struct neighbour *neigh) { struct atmarp_entry *entry = neighbour_priv(neigh); if (neigh->tbl->family != AF_INET) return -EINVAL; if (neigh->type != RTN_UNICAST) return -EINVAL; neigh->nud_state = NUD_NONE; neigh->ops = &clip_neigh_ops; neigh->output = neigh->ops->output; entry->neigh = neigh; entry->vccs = NULL; entry->expires = jiffies - 1; return 0; }


Linus Torvalds (pre-git)7576.53%120.00%
David S. Miller1212.24%240.00%
Herbert Xu66.12%120.00%
Jiri Pirko55.10%120.00%

/* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */ /* * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means * to allocate the neighbour entry but not to ask atmarpd for resolution. Also, * don't increment the usage count. This is used to create entries in * clip_setentry. */
static int clip_encap(struct atm_vcc *vcc, int mode) { if (!CLIP_VCC(vcc)) return -EBADFD; CLIP_VCC(vcc)->encap = mode; return 0; }


Linus Torvalds (pre-git)2565.79%133.33%
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Chas Williams12.63%133.33%

static netdev_tx_t clip_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct clip_priv *clip_priv = PRIV(dev); struct dst_entry *dst = skb_dst(skb); struct atmarp_entry *entry; struct neighbour *n; struct atm_vcc *vcc; struct rtable *rt; __be32 *daddr; int old; unsigned long flags; pr_debug("(skb %p)\n", skb); if (!dst) { pr_err("skb_dst(skb) == NULL\n"); dev_kfree_skb(skb); dev->stats.tx_dropped++; return NETDEV_TX_OK; } rt = (struct rtable *) dst; if (rt->rt_gateway) daddr = &rt->rt_gateway; else daddr = &ip_hdr(skb)->daddr; n = dst_neigh_lookup(dst, daddr); if (!n) { pr_err("NO NEIGHBOUR !\n"); dev_kfree_skb(skb); dev->stats.tx_dropped++; return NETDEV_TX_OK; } entry = neighbour_priv(n); if (!entry->vccs) { if (time_after(jiffies, entry->expires)) { /* should be resolved */ entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ; to_atmarpd(act_need, PRIV(dev)->number, *((__be32 *)n->primary_key)); } if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS) skb_queue_tail(&entry->neigh->arp_queue, skb); else { dev_kfree_skb(skb); dev->stats.tx_dropped++; } goto out_release_neigh; } pr_debug("neigh %p, vccs %p\n", entry, entry->vccs); ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc; pr_debug("using neighbour %p, vcc %p\n", n, vcc); if (entry->vccs->encap) { void *here; here = skb_push(skb, RFC1483LLC_LEN); memcpy(here, llc_oui, sizeof(llc_oui)); ((__be16 *) here)[3] = skb->protocol; } refcount_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc); ATM_SKB(skb)->atm_options = vcc->atm_options; entry->vccs->last_use = jiffies; pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev); old = xchg(&entry->vccs->xoff, 1); /* assume XOFF ... */ if (old) { pr_warn("XOFF->XOFF transition\n"); goto out_release_neigh; } dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; vcc->send(vcc, skb); if (atm_may_send(vcc, 0)) { entry->vccs->xoff = 0; goto out_release_neigh; } spin_lock_irqsave(&clip_priv->xoff_lock, flags); netif_stop_queue(dev); /* XOFF -> throttle immediately */ barrier(); if (!entry->vccs->xoff) netif_start_queue(dev); /* Oh, we just raced with clip_pop. netif_start_queue should be good enough, because nothing should really be asleep because of the brief netif_stop_queue. If this isn't true or if it changes, use netif_wake_queue instead. */ spin_unlock_irqrestore(&clip_priv->xoff_lock, flags); out_release_neigh: neigh_release(n); return NETDEV_TX_OK; }


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Elena Reshetova10.19%14.76%
Chas Williams10.19%14.76%
Al Viro10.19%14.76%

static int clip_mkip(struct atm_vcc *vcc, int timeout) { struct clip_vcc *clip_vcc; if (!vcc->push) return -EBADFD; clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL); if (!clip_vcc) return -ENOMEM; pr_debug("%p vcc %p\n", clip_vcc, vcc); clip_vcc->vcc = vcc; vcc->user_back = clip_vcc; set_bit(ATM_VF_IS_CLIP, &vcc->flags); clip_vcc->entry = NULL; clip_vcc->xoff = 0; clip_vcc->encap = 1; clip_vcc->last_use = jiffies; clip_vcc->idle_timeout = timeout * HZ; clip_vcc->old_push = vcc->push; clip_vcc->old_pop = vcc->pop; vcc->push = clip_push; vcc->pop = clip_pop; /* re-process everything received between connection setup and MKIP */ vcc_process_recv_queue(vcc); return 0; }


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Stephen Hemminger10.66%111.11%
Joe Perches10.66%111.11%

static int clip_setentry(struct atm_vcc *vcc, __be32 ip) { struct neighbour *neigh; struct atmarp_entry *entry; int error; struct clip_vcc *clip_vcc; struct rtable *rt; if (vcc->push != clip_push) { pr_warn("non-CLIP VCC\n"); return -EBADF; } clip_vcc = CLIP_VCC(vcc); if (!ip) { if (!clip_vcc->entry) { pr_err("hiding hidden ATMARP entry\n"); return 0; } pr_debug("remove\n"); unlink_clip_vcc(clip_vcc); return 0; } rt = ip_route_output(&init_net, ip, 0, 1, 0); if (IS_ERR(rt)) return PTR_ERR(rt); neigh = __neigh_lookup(&arp_tbl, &ip, rt->, 1); ip_rt_put(rt); if (!neigh) return -ENOMEM; entry = neighbour_priv(neigh); if (entry != clip_vcc->entry) { if (!clip_vcc->entry) pr_debug("add\n"); else { pr_debug("update\n"); unlink_clip_vcc(clip_vcc); } link_vcc(clip_vcc, entry); } error = neigh_update(neigh, llc_oui, NUD_PERMANENT, NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN, 0); neigh_release(neigh); return error; }


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David S. Miller198.05%430.77%
Joe Perches62.54%215.38%
Stephen Hemminger31.27%17.69%
Hideaki Yoshifuji / 吉藤英明31.27%17.69%
Roopa Prabhu20.85%17.69%
Denis V. Lunev20.85%17.69%
Chas Williams10.42%17.69%
Al Viro10.42%17.69%

static const struct net_device_ops clip_netdev_ops = { .ndo_start_xmit = clip_start_xmit, .ndo_neigh_construct = clip_constructor, };
static void clip_setup(struct net_device *dev) { dev->netdev_ops = &clip_netdev_ops; dev->type = ARPHRD_ATM; dev->neigh_priv_len = sizeof(struct atmarp_entry); dev->hard_header_len = RFC1483LLC_LEN; dev->mtu = RFC1626_MTU; dev->tx_queue_len = 100; /* "normal" queue (packets) */ /* When using a "real" qdisc, the qdisc determines the queue */ /* length. tx_queue_len is only used for the default case, */ /* without any more elaborate queuing. 100 is a reasonable */ /* compromise between decent burst-tolerance and protection */ /* against memory hogs. */ netif_keep_dst(dev); }


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Eric Dumazet57.94%225.00%
Stephen Hemminger34.76%112.50%
Al Viro23.17%112.50%

static int clip_create(int number) { struct net_device *dev; struct clip_priv *clip_priv; int error; if (number != -1) { for (dev = clip_devs; dev; dev = PRIV(dev)->next) if (PRIV(dev)->number == number) return -EEXIST; } else { number = 0; for (dev = clip_devs; dev; dev = PRIV(dev)->next) if (PRIV(dev)->number >= number) number = PRIV(dev)->number + 1; } dev = alloc_netdev(sizeof(struct clip_priv), "", NET_NAME_UNKNOWN, clip_setup); if (!dev) return -ENOMEM; clip_priv = PRIV(dev); sprintf(dev->name, "atm%d", number); spin_lock_init(&clip_priv->xoff_lock); clip_priv->number = number; error = register_netdev(dev); if (error) { free_netdev(dev); return error; } clip_priv->next = clip_devs; clip_devs = dev; pr_debug("registered (net:%s)\n", dev->name); return number; }


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Al Viro52.38%116.67%
Tom Gundersen20.95%116.67%
Stephen Hemminger10.48%116.67%
Chas Williams10.48%116.67%

static int clip_device_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); if (!net_eq(dev_net(dev), &init_net)) return NOTIFY_DONE; if (event == NETDEV_UNREGISTER) return NOTIFY_DONE; /* ignore non-CLIP devices */ if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops) return NOTIFY_DONE; switch (event) { case NETDEV_UP: pr_debug("NETDEV_UP\n"); to_atmarpd(act_up, PRIV(dev)->number, 0); break; case NETDEV_GOING_DOWN: pr_debug("NETDEV_DOWN\n"); to_atmarpd(act_down, PRIV(dev)->number, 0); break; case NETDEV_CHANGE: case NETDEV_CHANGEMTU: pr_debug("NETDEV_CHANGE*\n"); to_atmarpd(act_change, PRIV(dev)->number, 0); break; } return NOTIFY_DONE; }


Linus Torvalds (pre-git)10970.32%220.00%
Stephen Hemminger2113.55%330.00%
Eric W. Biedermann95.81%110.00%
Hideaki Yoshifuji / 吉藤英明85.16%220.00%
Jiri Pirko53.23%110.00%
Joe Perches31.94%110.00%

static int clip_inet_event(struct notifier_block *this, unsigned long event, void *ifa) { struct in_device *in_dev; struct netdev_notifier_info info; in_dev = ((struct in_ifaddr *)ifa)->ifa_dev; /* * Transitions are of the down-change-up type, so it's sufficient to * handle the change on up. */ if (event != NETDEV_UP) return NOTIFY_DONE; netdev_notifier_info_init(&info, in_dev->dev); return clip_device_event(this, NETDEV_CHANGE, &info); }


Linus Torvalds (pre-git)5677.78%150.00%
Américo Wang1622.22%150.00%

static struct notifier_block clip_dev_notifier = { .notifier_call = clip_device_event, }; static struct notifier_block clip_inet_notifier = { .notifier_call = clip_inet_event, };
static void atmarpd_close(struct atm_vcc *vcc) { pr_debug("\n"); rtnl_lock(); atmarpd = NULL; skb_queue_purge(&sk_atm(vcc)->sk_receive_queue); rtnl_unlock(); pr_debug("(done)\n"); module_put(THIS_MODULE); }


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Stephen Hemminger817.02%222.22%
Chas Williams612.77%222.22%
Arnaldo Carvalho de Melo48.51%222.22%