cregit-Linux how code gets into the kernel

Release 4.14 net/atm/lec.c

Directory: net/atm
 * lec.c: Lan Emulation driver
 * Marko Kiiskila <>

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

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/capability.h>

/* We are ethernet device */
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <net/sock.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <asm/byteorder.h>
#include <linux/uaccess.h>
#include <net/arp.h>
#include <net/dst.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/seq_file.h>

/* And atm device */
#include <linux/atmdev.h>
#include <linux/atmlec.h>

/* Proxy LEC knows about bridging */
#include "../bridge/br_private.h"

static unsigned char bridge_ula_lec[] = { 0x01, 0x80, 0xc2, 0x00, 0x00 };

/* Modular too */
#include <linux/module.h>
#include <linux/init.h>

#include "lec.h"
#include "lec_arpc.h"
#include "resources.h"

#define DUMP_PACKETS 0		
                                 * 0 = None,
                                 * 1 = 30 first bytes
                                 * 2 = Whole packet

#define LEC_UNRES_QUE_LEN 8	
                                 * number of tx packets to queue for a
                                 * single destination while waiting for SVC

static int lec_open(struct net_device *dev);
static netdev_tx_t lec_start_xmit(struct sk_buff *skb,
				  struct net_device *dev);
static int lec_close(struct net_device *dev);
static struct lec_arp_table *lec_arp_find(struct lec_priv *priv,
					  const unsigned char *mac_addr);
static int lec_arp_remove(struct lec_priv *priv,
			  struct lec_arp_table *to_remove);
/* LANE2 functions */
static void lane2_associate_ind(struct net_device *dev, const u8 *mac_address,
				const u8 *tlvs, u32 sizeoftlvs);
static int lane2_resolve(struct net_device *dev, const u8 *dst_mac, int force,
			 u8 **tlvs, u32 *sizeoftlvs);
static int lane2_associate_req(struct net_device *dev, const u8 *lan_dst,
			       const u8 *tlvs, u32 sizeoftlvs);

static int lec_addr_delete(struct lec_priv *priv, const unsigned char *atm_addr,
			   unsigned long permanent);
static void lec_arp_check_empties(struct lec_priv *priv,
				  struct atm_vcc *vcc, struct sk_buff *skb);
static void lec_arp_destroy(struct lec_priv *priv);
static void lec_arp_init(struct lec_priv *priv);
static struct atm_vcc *lec_arp_resolve(struct lec_priv *priv,
				       const unsigned char *mac_to_find,
				       int is_rdesc,
				       struct lec_arp_table **ret_entry);
static void lec_arp_update(struct lec_priv *priv, const unsigned char *mac_addr,
			   const unsigned char *atm_addr,
			   unsigned long remoteflag,
			   unsigned int targetless_le_arp);
static void lec_flush_complete(struct lec_priv *priv, unsigned long tran_id);
static int lec_mcast_make(struct lec_priv *priv, struct atm_vcc *vcc);
static void lec_set_flush_tran_id(struct lec_priv *priv,
				  const unsigned char *atm_addr,
				  unsigned long tran_id);
static void lec_vcc_added(struct lec_priv *priv,
			  const struct atmlec_ioc *ioc_data,
			  struct atm_vcc *vcc,
			  void (*old_push)(struct atm_vcc *vcc,
					   struct sk_buff *skb));
static void lec_vcc_close(struct lec_priv *priv, struct atm_vcc *vcc);

/* must be done under lec_arp_lock */

static inline void lec_arp_hold(struct lec_arp_table *entry) { refcount_inc(&entry->usage); }


Chas Williams1995.00%150.00%
Elena Reshetova15.00%150.00%

static inline void lec_arp_put(struct lec_arp_table *entry) { if (refcount_dec_and_test(&entry->usage)) kfree(entry); }


Chas Williams2696.30%150.00%
Elena Reshetova13.70%150.00%

static struct lane2_ops lane2_ops = { .resolve = lane2_resolve, /* spec 3.1.3 */ .associate_req = lane2_associate_req, /* spec 3.1.4 */ .associate_indicator = NULL /* spec 3.1.5 */ }; static unsigned char bus_mac[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; /* Device structures */ static struct net_device *dev_lec[MAX_LEC_ITF]; #if IS_ENABLED(CONFIG_BRIDGE)
static void lec_handle_bridge(struct sk_buff *skb, struct net_device *dev) { char *buff; struct lec_priv *priv; /* * Check if this is a BPDU. If so, ask zeppelin to send * LE_TOPOLOGY_REQUEST with the same value of Topology Change bit * as the Config BPDU has */ buff = skb->data + skb->dev->hard_header_len; if (*buff++ == 0x42 && *buff++ == 0x42 && *buff++ == 0x03) { struct sock *sk; struct sk_buff *skb2; struct atmlec_msg *mesg; skb2 = alloc_skb(sizeof(struct atmlec_msg), GFP_ATOMIC); if (skb2 == NULL) return; skb2->len = sizeof(struct atmlec_msg); mesg = (struct atmlec_msg *)skb2->data; mesg->type = l_topology_change; buff += 4; mesg->content.normal.flag = *buff & 0x01; /* 0x01 is topology change */ priv = netdev_priv(dev); atm_force_charge(priv->lecd, skb2->truesize); sk = sk_atm(priv->lecd); skb_queue_tail(&sk->sk_receive_queue, skb2); sk->sk_data_ready(sk); } }


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#endif /* IS_ENABLED(CONFIG_BRIDGE) */ /* * Open/initialize the netdevice. This is called (in the current kernel) * sometime after booting when the 'ifconfig' program is run. * * This routine should set everything up anew at each open, even * registers that "should" only need to be set once at boot, so that * there is non-reboot way to recover if something goes wrong. */
static int lec_open(struct net_device *dev) { netif_start_queue(dev); return 0; }


Linus Torvalds (pre-git)19100.00%2100.00%

static void lec_send(struct atm_vcc *vcc, struct sk_buff *skb) { struct net_device *dev = skb->dev; ATM_SKB(skb)->vcc = vcc; ATM_SKB(skb)->atm_options = vcc->atm_options; refcount_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc); if (vcc->send(vcc, skb) < 0) { dev->stats.tx_dropped++; return; } dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; }


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static void lec_tx_timeout(struct net_device *dev) { pr_info("%s\n", dev->name); netif_trans_update(dev); netif_wake_queue(dev); }


Chas Williams2583.33%250.00%
Florian Westphal310.00%125.00%
Joe Perches26.67%125.00%

static netdev_tx_t lec_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct sk_buff *skb2; struct lec_priv *priv = netdev_priv(dev); struct lecdatahdr_8023 *lec_h; struct atm_vcc *vcc; struct lec_arp_table *entry; unsigned char *dst; int min_frame_size; int is_rdesc; pr_debug("called\n"); if (!priv->lecd) { pr_info("%s:No lecd attached\n", dev->name); dev->stats.tx_errors++; netif_stop_queue(dev); kfree_skb(skb); return NETDEV_TX_OK; } pr_debug("skbuff head:%lx data:%lx tail:%lx end:%lx\n", (long)skb->head, (long)skb->data, (long)skb_tail_pointer(skb), (long)skb_end_pointer(skb)); #if IS_ENABLED(CONFIG_BRIDGE) if (memcmp(skb->data, bridge_ula_lec, sizeof(bridge_ula_lec)) == 0) lec_handle_bridge(skb, dev); #endif /* Make sure we have room for lec_id */ if (skb_headroom(skb) < 2) { pr_debug("reallocating skb\n"); skb2 = skb_realloc_headroom(skb, LEC_HEADER_LEN); if (unlikely(!skb2)) { kfree_skb(skb); return NETDEV_TX_OK; } consume_skb(skb); skb = skb2; } skb_push(skb, 2); /* Put le header to place */ lec_h = (struct lecdatahdr_8023 *)skb->data; lec_h->le_header = htons(priv->lecid); #if DUMP_PACKETS >= 2 #define MAX_DUMP_SKB 99 #elif DUMP_PACKETS >= 1 #define MAX_DUMP_SKB 30 #endif #if DUMP_PACKETS >= 1 printk(KERN_DEBUG "%s: send datalen:%ld lecid:%4.4x\n", dev->name, skb->len, priv->lecid); print_hex_dump(KERN_DEBUG, "", DUMP_OFFSET, 16, 1, skb->data, min(skb->len, MAX_DUMP_SKB), true); #endif /* DUMP_PACKETS >= 1 */ /* Minimum ethernet-frame size */ min_frame_size = LEC_MINIMUM_8023_SIZE; if (skb->len < min_frame_size) { if ((skb->len + skb_tailroom(skb)) < min_frame_size) { skb2 = skb_copy_expand(skb, 0, min_frame_size - skb->truesize, GFP_ATOMIC); dev_kfree_skb(skb); if (skb2 == NULL) { dev->stats.tx_dropped++; return NETDEV_TX_OK; } skb = skb2; } skb_put(skb, min_frame_size - skb->len); } /* Send to right vcc */ is_rdesc = 0; dst = lec_h->h_dest; entry = NULL; vcc = lec_arp_resolve(priv, dst, is_rdesc, &entry); pr_debug("%s:vcc:%p vcc_flags:%lx, entry:%p\n", dev->name, vcc, vcc ? vcc->flags : 0, entry); if (!vcc || !test_bit(ATM_VF_READY, &vcc->flags)) { if (entry && (entry->tx_wait.qlen < LEC_UNRES_QUE_LEN)) { pr_debug("%s:queuing packet, MAC address %pM\n", dev->name, lec_h->h_dest); skb_queue_tail(&entry->tx_wait, skb); } else { pr_debug("%s:tx queue full or no arp entry, dropping, MAC address: %pM\n", dev->name, lec_h->h_dest); dev->stats.tx_dropped++; dev_kfree_skb(skb); } goto out; } #if DUMP_PACKETS > 0 printk(KERN_DEBUG "%s:sending to vpi:%d vci:%d\n", dev->name, vcc->vpi, vcc->vci); #endif /* DUMP_PACKETS > 0 */ while (entry && (skb2 = skb_dequeue(&entry->tx_wait))) { pr_debug("emptying tx queue, MAC address %pM\n", lec_h->h_dest); lec_send(vcc, skb2); } lec_send(vcc, skb); if (!atm_may_send(vcc, 0)) { struct lec_vcc_priv *vpriv = LEC_VCC_PRIV(vcc); vpriv->xoff = 1; netif_stop_queue(dev); /* * vcc->pop() might have occurred in between, making * the vcc usuable again. Since xmit is serialized, * this is the only situation we have to re-test. */ if (atm_may_send(vcc, 0)) netif_wake_queue(dev); } out: if (entry) lec_arp_put(entry); netif_trans_update(dev); return NETDEV_TX_OK; }


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Andrew Morton10.15%13.57%
Paul Gortmaker10.15%13.57%

/* The inverse routine to net_open(). */
static int lec_close(struct net_device *dev) { netif_stop_queue(dev); return 0; }


Linus Torvalds (pre-git)19100.00%2100.00%

static int lec_atm_send(struct atm_vcc *vcc, struct sk_buff *skb) { unsigned long flags; struct net_device *dev = (struct net_device *)vcc->proto_data; struct lec_priv *priv = netdev_priv(dev); struct atmlec_msg *mesg; struct lec_arp_table *entry; int i; char *tmp; /* FIXME */ WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc)); mesg = (struct atmlec_msg *)skb->data; tmp = skb->data; tmp += sizeof(struct atmlec_msg); pr_debug("%s: msg from zeppelin:%d\n", dev->name, mesg->type); switch (mesg->type) { case l_set_mac_addr: for (i = 0; i < 6; i++) dev->dev_addr[i] = mesg->content.normal.mac_addr[i]; break; case l_del_mac_addr: for (i = 0; i < 6; i++) dev->dev_addr[i] = 0; break; case l_addr_delete: lec_addr_delete(priv, mesg->content.normal.atm_addr, mesg->content.normal.flag); break; case l_topology_change: priv->topology_change = mesg->content.normal.flag; break; case l_flush_complete: lec_flush_complete(priv, mesg->content.normal.flag); break; case l_narp_req: /* LANE2: see 7.1.35 in the lane2 spec */ spin_lock_irqsave(&priv->lec_arp_lock, flags); entry = lec_arp_find(priv, mesg->content.normal.mac_addr); lec_arp_remove(priv, entry); spin_unlock_irqrestore(&priv->lec_arp_lock, flags); if (mesg->content.normal.no_source_le_narp) break; /* FALL THROUGH */ case l_arp_update: lec_arp_update(priv, mesg->content.normal.mac_addr, mesg->content.normal.atm_addr, mesg->content.normal.flag, mesg->content.normal.targetless_le_arp); pr_debug("in l_arp_update\n"); if (mesg->sizeoftlvs != 0) { /* LANE2 3.1.5 */ pr_debug("LANE2 3.1.5, got tlvs, size %d\n", mesg->sizeoftlvs); lane2_associate_ind(dev, mesg->content.normal.mac_addr, tmp, mesg->sizeoftlvs); } break; case l_config: priv->maximum_unknown_frame_count = mesg->content.config.maximum_unknown_frame_count; priv->max_unknown_frame_time = (mesg->content.config.max_unknown_frame_time * HZ); priv->max_retry_count = mesg->content.config.max_retry_count; priv->aging_time = (mesg->content.config.aging_time * HZ); priv->forward_delay_time = (mesg->content.config.forward_delay_time * HZ); priv->arp_response_time = (mesg->content.config.arp_response_time * HZ); priv->flush_timeout = (mesg->content.config.flush_timeout * HZ); priv->path_switching_delay = (mesg->content.config.path_switching_delay * HZ); priv->lane_version = mesg->content.config.lane_version; /* LANE2 */ priv->lane2_ops = NULL; if (priv->lane_version > 1) priv->lane2_ops = &lane2_ops; rtnl_lock(); if (dev_set_mtu(dev, mesg->content.config.mtu)) pr_info("%s: change_mtu to %d failed\n", dev->name, mesg->content.config.mtu); rtnl_unlock(); priv->is_proxy = mesg->content.config.is_proxy; break; case l_flush_tran_id: lec_set_flush_tran_id(priv, mesg->content.normal.atm_addr, mesg->content.normal.flag); break; case l_set_lecid: priv->lecid = (unsigned short)(0xffff & mesg->content.normal.flag); break; case l_should_bridge: #if IS_ENABLED(CONFIG_BRIDGE) { pr_debug("%s: bridge zeppelin asks about %pM\n", dev->name, mesg->content.proxy.mac_addr); if (br_fdb_test_addr_hook == NULL) break; if (br_fdb_test_addr_hook(dev, mesg->content.proxy.mac_addr)) { /* hit from bridge table, send LE_ARP_RESPONSE */ struct sk_buff *skb2; struct sock *sk; pr_debug("%s: entry found, responding to zeppelin\n", dev->name); skb2 = alloc_skb(sizeof(struct atmlec_msg), GFP_ATOMIC); if (skb2 == NULL) break; skb2->len = sizeof(struct atmlec_msg); skb_copy_to_linear_data(skb2, mesg, sizeof(*mesg)); atm_force_charge(priv->lecd, skb2->truesize); sk = sk_atm(priv->lecd); skb_queue_tail(&sk->sk_receive_queue, skb2); sk->sk_data_ready(sk); } } #endif /* IS_ENABLED(CONFIG_BRIDGE) */ break; default: pr_info("%s: Unknown message type %d\n", dev->name, mesg->type); dev_kfree_skb(skb); return -EINVAL; } dev_kfree_skb(skb); return 0; }


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static void lec_atm_close(struct atm_vcc *vcc) { struct sk_buff *skb; struct net_device *dev = (struct net_device *)vcc->proto_data; struct lec_priv *priv = netdev_priv(dev); priv->lecd = NULL; /* Do something needful? */ netif_stop_queue(dev); lec_arp_destroy(priv); if (skb_peek(&sk_atm(vcc)->sk_receive_queue)) pr_info("%s closing with messages pending\n", dev->name); while ((skb = skb_dequeue(&sk_atm(vcc)->sk_receive_queue))) { atm_return(vcc, skb->truesize); dev_kfree_skb(skb); } pr_info("%s: Shut down!\n", dev->name); module_put(THIS_MODULE); }


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static const struct atmdev_ops lecdev_ops = { .close = lec_atm_close, .send = lec_atm_send }; static struct atm_dev lecatm_dev = { .ops = &lecdev_ops, .type = "lec", .number = 999, /* dummy device number */ .lock = __SPIN_LOCK_UNLOCKED(lecatm_dev.lock) }; /* * LANE2: new argument struct sk_buff *data contains * the LE_ARP based TLVs introduced in the LANE2 spec */
static int send_to_lecd(struct lec_priv *priv, atmlec_msg_type type, const unsigned char *mac_addr, const unsigned char *atm_addr, struct sk_buff *data) { struct sock *sk; struct sk_buff *skb; struct atmlec_msg *mesg; if (!priv || !priv->lecd) return -1; skb = alloc_skb(sizeof(struct atmlec_msg), GFP_ATOMIC); if (!skb) return -1; skb->len = sizeof(struct atmlec_msg); mesg = (struct atmlec_msg *)skb->data; memset(mesg, 0, sizeof(struct atmlec_msg)); mesg->type = type; if (data != NULL) mesg->sizeoftlvs = data->len; if (mac_addr) ether_addr_copy(mesg->content.normal.mac_addr, mac_addr); else mesg->content.normal.targetless_le_arp = 1; if (atm_addr) memcpy(&mesg->content.normal.atm_addr, atm_addr, ATM_ESA_LEN); atm_force_charge(priv->lecd, skb->truesize); sk = sk_atm(priv->lecd); skb_queue_tail(&sk->sk_receive_queue, skb); sk->sk_data_ready(sk); if (data != NULL) { pr_debug("about to send %d bytes of data\n", data->len); atm_force_charge(priv->lecd, data->truesize); skb_queue_tail(&sk->sk_receive_queue, data); sk->sk_data_ready(sk); } return 0; }


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Stephen Hemminger10.37%19.09%

static void lec_set_multicast_list(struct net_device *dev) { /* * by default, all multicast frames arrive over the bus. * eventually support selective multicast service */ }


Chas Williams12100.00%2100.00%

static const struct net_device_ops lec_netdev_ops = { .ndo_open = lec_open, .ndo_stop = lec_close, .ndo_start_xmit = lec_start_xmit, .ndo_tx_timeout = lec_tx_timeout, .ndo_set_rx_mode = lec_set_multicast_list, }; static const unsigned char lec_ctrl_magic[] = { 0xff, 0x00, 0x01, 0x01 }; #define LEC_DATA_DIRECT_8023 2 #define LEC_DATA_DIRECT_8025 3
static int lec_is_data_direct(struct atm_vcc *vcc) { return ((vcc->sap.blli[0].l3.tr9577.snap[4] == LEC_DATA_DIRECT_8023) || (vcc->sap.blli[0].l3.tr9577.snap[4] == LEC_DATA_DIRECT_8025)); }


Scott Talbert58100.00%1100.00%

static void lec_push(struct atm_vcc *vcc, struct sk_buff *skb) { unsigned long flags; struct net_device *dev = (struct net_device *)vcc->proto_data; struct lec_priv *priv = netdev_priv(dev); #if DUMP_PACKETS > 0 printk(KERN_DEBUG "%s: vcc vpi:%d vci:%d\n", dev->name, vcc->vpi, vcc->vci); #endif if (!skb)