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Release 4.8 net/atm/br2684.c

Directory: net/atm
/*
 * Ethernet netdevice using ATM AAL5 as underlying carrier
 * (RFC1483 obsoleted by RFC2684) for Linux
 *
 * Authors: Marcell GAL, 2000, XDSL Ltd, Hungary
 *          Eric Kinzie, 2006-2007, US Naval Research Laboratory
 */


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

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/ip.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <net/arp.h>
#include <linux/atm.h>
#include <linux/atmdev.h>
#include <linux/capability.h>
#include <linux/seq_file.h>

#include <linux/atmbr2684.h>

#include "common.h"


static void skb_debug(const struct sk_buff *skb) { #ifdef SKB_DEBUG #define NUM2PRINT 50 print_hex_dump(KERN_DEBUG, "br2684: skb: ", DUMP_OFFSET, 16, 1, skb->data, min(NUM2PRINT, skb->len), true); #endif }

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#define BR2684_ETHERTYPE_LEN 2 #define BR2684_PAD_LEN 2 #define LLC 0xaa, 0xaa, 0x03 #define SNAP_BRIDGED 0x00, 0x80, 0xc2 #define SNAP_ROUTED 0x00, 0x00, 0x00 #define PID_ETHERNET 0x00, 0x07 #define ETHERTYPE_IPV4 0x08, 0x00 #define ETHERTYPE_IPV6 0x86, 0xdd #define PAD_BRIDGED 0x00, 0x00 static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 }; static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 }; static const unsigned char llc_oui_pid_pad[] = { LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED }; static const unsigned char pad[] = { PAD_BRIDGED }; static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 }; static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 }; enum br2684_encaps { e_vc = BR2684_ENCAPS_VC, e_llc = BR2684_ENCAPS_LLC, }; struct br2684_vcc { struct atm_vcc *atmvcc; struct net_device *device; /* keep old push, pop functions for chaining */ void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb); void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb); void (*old_release_cb)(struct atm_vcc *vcc); struct module *old_owner; enum br2684_encaps encaps; struct list_head brvccs; #ifdef CONFIG_ATM_BR2684_IPFILTER struct br2684_filter filter; #endif /* CONFIG_ATM_BR2684_IPFILTER */ unsigned int copies_needed, copies_failed; atomic_t qspace; }; struct br2684_dev { struct net_device *net_dev; struct list_head br2684_devs; int number; struct list_head brvccs; /* one device <=> one vcc (before xmas) */ int mac_was_set; enum br2684_payload payload; }; /* * This lock should be held for writing any time the list of devices or * their attached vcc's could be altered. It should be held for reading * any time these are being queried. Note that we sometimes need to * do read-locking under interrupt context, so write locking must block * the current CPU's interrupts */ static DEFINE_RWLOCK(devs_lock); static LIST_HEAD(br2684_devs);
static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev) { return netdev_priv(net_dev); }

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static inline struct net_device *list_entry_brdev(const struct list_head *le) { return list_entry(le, struct br2684_dev, br2684_devs)->net_dev; }

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static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc) { return (struct br2684_vcc *)(atmvcc->user_back); }

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static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le) { return list_entry(le, struct br2684_vcc, brvccs); }

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/* Caller should hold read_lock(&devs_lock) */
static struct net_device *br2684_find_dev(const struct br2684_if_spec *s) { struct list_head *lh; struct net_device *net_dev; switch (s->method) { case BR2684_FIND_BYNUM: list_for_each(lh, &br2684_devs) { net_dev = list_entry_brdev(lh); if (BRPRIV(net_dev)->number == s->spec.devnum) return net_dev; } break; case BR2684_FIND_BYIFNAME: list_for_each(lh, &br2684_devs) { net_dev = list_entry_brdev(lh); if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ)) return net_dev; } break; } return NULL; }

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static int atm_dev_event(struct notifier_block *this, unsigned long event, void *arg) { struct atm_dev *atm_dev = arg; struct list_head *lh; struct net_device *net_dev; struct br2684_vcc *brvcc; struct atm_vcc *atm_vcc; unsigned long flags; pr_debug("event=%ld dev=%p\n", event, atm_dev); read_lock_irqsave(&devs_lock, flags); list_for_each(lh, &br2684_devs) { net_dev = list_entry_brdev(lh); list_for_each_entry(brvcc, &BRPRIV(net_dev)->brvccs, brvccs) { atm_vcc = brvcc->atmvcc; if (atm_vcc && brvcc->atmvcc->dev == atm_dev) { if (atm_vcc->dev->signal == ATM_PHY_SIG_LOST) netif_carrier_off(net_dev); else netif_carrier_on(net_dev); } } } read_unlock_irqrestore(&devs_lock, flags); return NOTIFY_DONE; }

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static struct notifier_block atm_dev_notifier = { .notifier_call = atm_dev_event, }; /* chained vcc->pop function. Check if we should wake the netif_queue */
static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb) { struct br2684_vcc *brvcc = BR2684_VCC(vcc); pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device); brvcc->old_pop(vcc, skb); /* If the queue space just went up from zero, wake */ if (atomic_inc_return(&brvcc->qspace) == 1) netif_wake_queue(brvcc->device); }

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Total66100.00%3100.00%

/* * Send a packet out a particular vcc. Not to useful right now, but paves * the way for multiple vcc's per itf. Returns true if we can send, * otherwise false */
static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev, struct br2684_vcc *brvcc) { struct br2684_dev *brdev = BRPRIV(dev); struct atm_vcc *atmvcc; int minheadroom = (brvcc->encaps == e_llc) ? ((brdev->payload == p_bridged) ? sizeof(llc_oui_pid_pad) : sizeof(llc_oui_ipv4)) : ((brdev->payload == p_bridged) ? BR2684_PAD_LEN : 0); if (skb_headroom(skb) < minheadroom) { struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom); brvcc->copies_needed++; dev_kfree_skb(skb); if (skb2 == NULL) { brvcc->copies_failed++; return 0; } skb = skb2; } if (brvcc->encaps == e_llc) { if (brdev->payload == p_bridged) { skb_push(skb, sizeof(llc_oui_pid_pad)); skb_copy_to_linear_data(skb, llc_oui_pid_pad, sizeof(llc_oui_pid_pad)); } else if (brdev->payload == p_routed) { unsigned short prot = ntohs(skb->protocol); skb_push(skb, sizeof(llc_oui_ipv4)); switch (prot) { case ETH_P_IP: skb_copy_to_linear_data(skb, llc_oui_ipv4, sizeof(llc_oui_ipv4)); break; case ETH_P_IPV6: skb_copy_to_linear_data(skb, llc_oui_ipv6, sizeof(llc_oui_ipv6)); break; default: dev_kfree_skb(skb); return 0; } } } else { /* e_vc */ if (brdev->payload == p_bridged) { skb_push(skb, 2); memset(skb->data, 0, 2); } } skb_debug(skb); ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc; pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev); atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc); ATM_SKB(skb)->atm_options = atmvcc->atm_options; dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; if (atomic_dec_return(&brvcc->qspace) < 1) { /* No more please! */ netif_stop_queue(brvcc->device); /* We might have raced with br2684_pop() */ if (unlikely(atomic_read(&brvcc->qspace) > 0)) netif_wake_queue(brvcc->device); } /* If this fails immediately, the skb will be freed and br2684_pop() will wake the queue if appropriate. Just return an error so that the stats are updated correctly */ return !atmvcc->send(atmvcc, skb); }

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david woodhousedavid woodhouse296.94%19.09%
karl hiramotokarl hiramoto266.22%19.09%
stephen hemmingerstephen hemminger153.59%218.18%
arnaldo carvalho de meloarnaldo carvalho de melo51.20%327.27%
Total418100.00%11100.00%


static void br2684_release_cb(struct atm_vcc *atmvcc) { struct br2684_vcc *brvcc = BR2684_VCC(atmvcc); if (atomic_read(&brvcc->qspace) > 0) netif_wake_queue(brvcc->device); if (brvcc->old_release_cb) brvcc->old_release_cb(atmvcc); }

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static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb, const struct br2684_dev *brdev) { return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next); /* 1 vcc/dev right now */ }

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static netdev_tx_t br2684_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct br2684_dev *brdev = BRPRIV(dev); struct br2684_vcc *brvcc; struct atm_vcc *atmvcc; netdev_tx_t ret = NETDEV_TX_OK; pr_debug("skb_dst(skb)=%p\n", skb_dst(skb)); read_lock(&devs_lock); brvcc = pick_outgoing_vcc(skb, brdev); if (brvcc == NULL) { pr_debug("no vcc attached to dev %s\n", dev->name); dev->stats.tx_errors++; dev->stats.tx_carrier_errors++; /* netif_stop_queue(dev); */ dev_kfree_skb(skb); goto out_devs; } atmvcc = brvcc->atmvcc; bh_lock_sock(sk_atm(atmvcc)); if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) || test_bit(ATM_VF_CLOSE, &atmvcc->flags) || !test_bit(ATM_VF_READY, &atmvcc->flags)) { dev->stats.tx_dropped++; dev_kfree_skb(skb); goto out; } if (sock_owned_by_user(sk_atm(atmvcc))) { netif_stop_queue(brvcc->device); ret = NETDEV_TX_BUSY; goto out; } if (!br2684_xmit_vcc(skb, dev, brvcc)) { /* * We should probably use netif_*_queue() here, but that * involves added complication. We need to walk before * we can run. * * Don't free here! this pointer might be no longer valid! */ dev->stats.tx_errors++; dev->stats.tx_fifo_errors++; } out: bh_unlock_sock(sk_atm(atmvcc)); out_devs: read_unlock(&devs_lock); return ret; }

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eric dumazeteric dumazet31.22%112.50%
joe perchesjoe perches10.41%112.50%
Total246100.00%8100.00%

/* * We remember when the MAC gets set, so we don't override it later with * the ESI of the ATM card of the first VC */
static int br2684_mac_addr(struct net_device *dev, void *p) { int err = eth_mac_addr(dev, p); if (!err) BRPRIV(dev)->mac_was_set = 1; return err; }

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#ifdef CONFIG_ATM_BR2684_IPFILTER /* this IOCTL is experimental. */
static int br2684_setfilt(struct atm_vcc *atmvcc, void __user * arg) { struct br2684_vcc *brvcc; struct br2684_filter_set fs; if (copy_from_user(&fs, arg, sizeof fs)) return -EFAULT; if (fs.ifspec.method != BR2684_FIND_BYNOTHING) { /* * This is really a per-vcc thing, but we can also search * by device. */ struct br2684_dev *brdev; read_lock(&devs_lock); brdev = BRPRIV(br2684_find_dev(&fs.ifspec)); if (brdev == NULL || list_empty(&brdev->brvccs) || brdev->brvccs.next != brdev->brvccs.prev) /* >1 VCC */ brvcc = NULL; else brvcc = list_entry_brvcc(brdev->brvccs.next); read_unlock(&devs_lock); if (brvcc == NULL) return -ESRCH; } else brvcc = BR2684_VCC(atmvcc); memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter)); return 0; }

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/* Returns 1 if packet should be dropped */
static inline int packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb) { if (brvcc->filter.netmask == 0) return 0; /* no filter in place */ if (type == htons(ETH_P_IP) && (((struct iphdr *)(skb->data))->daddr & brvcc->filter. netmask) == brvcc->filter.prefix) return 0; if (type == htons(ETH_P_ARP)) return 0; /* * TODO: we should probably filter ARPs too.. don't want to have * them returning values that don't make sense, or is that ok? */ return 1; /* drop */ }

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Total92100.00%4100.00%

#endif /* CONFIG_ATM_BR2684_IPFILTER */
static void br2684_close_vcc(struct br2684_vcc *brvcc) { pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device); write_lock_irq(&devs_lock); list_del(&brvcc->brvccs); write_unlock_irq(&devs_lock); brvcc->atmvcc->user_back = NULL; /* what about vcc->recvq ??? */ brvcc->atmvcc->release_cb = brvcc->old_release_cb; brvcc->old_push(brvcc->atmvcc, NULL); /* pass on the bad news */ module_put(brvcc->old_owner); kfree(brvcc); }

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stephen hemmingerstephen hemminger11.18%120.00%
Total85100.00%5100.00%

/* when AAL5 PDU comes in: */
static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb) { struct br2684_vcc *brvcc = BR2684_VCC(atmvcc); struct net_device *net_dev = brvcc->device; struct br2684_dev *brdev = BRPRIV(net_dev); pr_debug("\n"); if (unlikely(skb == NULL)) { /* skb==NULL means VCC is being destroyed */ br2684_close_vcc(brvcc); if (list_empty(&brdev->brvccs)) { write_lock_irq(&devs_lock); list_del(&brdev->br2684_devs); write_unlock_irq(&devs_lock); unregister_netdev(net_dev); free_netdev(net_dev); } return; } skb_debug(skb); atm_return(atmvcc, skb->truesize); pr_debug("skb from brdev %p\n", brdev); if (brvcc->encaps == e_llc) { if (skb->len > 7 && skb->data[7] == 0x01) __skb_trim(skb, skb->len - 4); /* accept packets that have "ipv[46]" in the snap header */ if ((skb->len >= (sizeof(llc_oui_ipv4))) && (memcmp(skb->data, llc_oui_ipv4, sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) { if (memcmp(skb->data + 6, ethertype_ipv6, sizeof(ethertype_ipv6)) == 0) skb->protocol = htons(ETH_P_IPV6); else if (memcmp(skb->data + 6, ethertype_ipv4, sizeof(ethertype_ipv4)) == 0) skb->protocol = htons(ETH_P_IP); else goto error; skb_pull(skb, sizeof(llc_oui_ipv4)); skb_reset_network_header(skb); skb->pkt_type = PACKET_HOST; /* * Let us waste some time for checking the encapsulation. * Note, that only 7 char is checked so frames with a valid FCS * are also accepted (but FCS is not checked of course). */ } else if ((skb->len >= sizeof(llc_oui_pid_pad)) && (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) { skb_pull(skb, sizeof(llc_oui_pid_pad)); skb->protocol = eth_type_trans(skb, net_dev); } else goto error; } else { /* e_vc */ if (brdev->payload == p_routed) { struct iphdr *iph; skb_reset_network_header(skb); iph = ip_hdr(skb); if (iph->version == 4) skb->protocol = htons(ETH_P_IP); else if (iph->version == 6) skb->protocol = htons(ETH_P_IPV6); else goto error; skb->pkt_type = PACKET_HOST; } else { /* p_bridged */ /* first 2 chars should be 0 */ if (memcmp(skb->data, pad, BR2684_PAD_LEN) != 0) goto error; skb_pull(skb, BR2684_PAD_LEN); skb->protocol = eth_type_trans(skb, net_dev); } } #ifdef CONFIG_ATM_BR2684_IPFILTER if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb))) goto dropped; #endif /* CONFIG_ATM_BR2684_IPFILTER */ skb->dev = net_dev; ATM_SKB(skb)->vcc = atmvcc; /* needed ? */ pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol)); skb_debug(skb); /* sigh, interface is down? */ if (unlikely(!(net_dev->flags & IFF_UP))) goto dropped; net_dev->stats.rx_packets++; net_dev->stats.rx_bytes += skb->len; memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data)); netif_rx(skb); return; dropped: net_dev->stats.rx_dropped++; goto free_skb; error: net_dev->stats.rx_errors++; free_skb: dev_kfree_skb(skb); }

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eric kinzieeric kinzie29348.19%214.29%
chas williamschas williams28847.37%428.57%
stephen hemmingerstephen hemminger71.15%214.29%
pascal hambourgpascal hambourg71.15%17.14%
david s. millerdavid s. miller50.82%17.14%
arnaldo carvalho de meloarnaldo carvalho de melo40.66%17.14%
joe perchesjoe perches20.33%214.29%
pavel emelianovpavel emelianov20.33%17.14%
Total608100.00%14100.00%

/* * Assign a vcc to a dev * Note: we do not have explicit unassign, but look at _push() */
static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg) { struct br2684_vcc *brvcc; struct br2684_dev *brdev; struct net_device *net_dev; struct atm_backend_br2684 be; int err; if (copy_from_user(&be, arg, sizeof be)) return -EFAULT; brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL); if (!brvcc) return -ENOMEM; /* * Allow two packets in the ATM queue. One actually being sent, and one * for the ATM 'TX done' handler to send. It shouldn't take long to get * the next one from the netdev queue, when we need it. More than that * would be bufferbloat. */ atomic_set(&brvcc->qspace, 2); write_lock_irq(&devs_lock); net_dev = br2684_find_dev(&be.ifspec); if (net_dev == NULL) { pr_err("tried to attach to non-existent device\n"); err = -ENXIO; goto error; } brdev = BRPRIV(net_dev); if (atmvcc->push == NULL) { err = -EBADFD; goto error; } if (!list_empty(&brdev->brvccs)) { /* Only 1 VCC/dev right now */ err = -EEXIST; goto error; } if (be.fcs_in != BR2684_FCSIN_NO || be.fcs_out != BR2684_FCSOUT_NO || be.fcs_auto || be.has_vpiid || be.send_padding || (be.encaps != BR2684_ENCAPS_VC && be.encaps != BR2684_ENCAPS_LLC) || be.min_size != 0) { err = -EINVAL; goto error; } pr_debug("vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps, brvcc); if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) { unsigned char *esi = atmvcc->dev->esi; if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5]) memcpy(net_dev->dev_addr, esi, net_dev->addr_len); else net_dev->dev_addr[2] = 1; } list_add(&brvcc->brvccs, &brdev->brvccs); write_unlock_irq(&devs_lock); brvcc->device = net_dev; brvcc