/* Experimental ethernet netdevice using ATM AAL5 as underlying carrier (RFC1483 obsoleted by RFC2684) for Linux 2.4 Author: Marcell GAL, 2000, XDSL Ltd, Hungary */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ipcommon.h" /* * Define this to use a version of the code which interacts with the higher * layers in a more intelligent way, by always reserving enough space for * our header at the begining of the packet. However, there may still be * some problems with programs like tcpdump. In 2.5 we'll sort out what * we need to do to get this perfect. For now we just will copy the packet * if we need space for the header */ /* #define FASTER_VERSION 1 */ /* #define DEBUG 1 #define SKB_DEBUG 1 */ #ifdef DEBUG #define DPRINTK(format, args...) printk(KERN_DEBUG "br2684: " format, ##args) #else #define DPRINTK(format, args...) #endif #ifdef SKB_DEBUG static void skb_debug(const struct sk_buff *skb) { #define NUM2PRINT 50 char buf[NUM2PRINT * 3 + 1]; /* 3 chars per byte */ int i = 0; for (i = 0; i < skb->len && i < NUM2PRINT; i++) { sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]); } printk(KERN_DEBUG "br2684: skb: %s\n", buf); } #else #define skb_debug(skb) do {} while (0) #endif static unsigned char llc_oui_pid_pad[] = { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 }; #define PADLEN (2) enum br2684_encaps { e_vc = BR2684_ENCAPS_VC, e_llc = BR2684_ENCAPS_LLC, }; struct br2684_vcc { struct atm_vcc *atmvcc; struct br2684_dev *brdev; /* 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); */ enum br2684_encaps encaps; struct list_head brvccs; #ifdef CONFIG_ATM_BR2684_IPFILTER struct br2684_filter filter; #endif /* CONFIG_ATM_BR2684_IPFILTER */ #ifndef FASTER_VERSION unsigned copies_needed, copies_failed; #endif /* FASTER_VERSION */ }; 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) */ struct net_device_stats stats; int mac_was_set; }; /* * 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 rwlock_t devs_lock = RW_LOCK_UNLOCKED; static LIST_HEAD(br2684_devs); static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev) { return (struct br2684_dev *) ((char *) (net_dev) - (unsigned long) (&((struct br2684_dev *) 0)->net_dev)); } static inline struct br2684_dev *list_entry_brdev(const struct list_head *le) { return list_entry(le, struct br2684_dev, br2684_devs); } static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc) { return (struct br2684_vcc *) (atmvcc->user_back); } static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le) { return list_entry(le, struct br2684_vcc, brvccs); } /* Caller should hold read_lock(&devs_lock) */ static struct br2684_dev *br2684_find_dev(const struct br2684_if_spec *s) { struct list_head *lh; struct br2684_dev *brdev; switch (s->method) { case BR2684_FIND_BYNUM: list_for_each(lh, &br2684_devs) { brdev = list_entry_brdev(lh); if (brdev->number == s->spec.devnum) return brdev; } break; case BR2684_FIND_BYIFNAME: list_for_each(lh, &br2684_devs) { brdev = list_entry_brdev(lh); if (!strncmp(brdev->net_dev.name, s->spec.ifname, sizeof brdev->net_dev.name)) return brdev; } break; } return NULL; } /* * Send a packet out a particular vcc. Not too 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 br2684_dev *brdev, struct br2684_vcc *brvcc) { struct atm_vcc *atmvcc; #ifdef FASTER_VERSION if (brvcc->encaps == e_llc) memcpy(skb_push(skb, 8), llc_oui_pid_pad, 8); /* last 2 bytes of llc_oui_pid_pad are managed by header routines; yes, you got it: 8 + 2 = sizeof(llc_oui_pid_pad) */ #else int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2; 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; } skb_push(skb, minheadroom); if (brvcc->encaps == e_llc) memcpy(skb->data, llc_oui_pid_pad, 10); else memset(skb->data, 0, 2); #endif /* FASTER_VERSION */ skb_debug(skb); ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc; DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev); ATM_SKB(skb)->iovcnt = 0; ATM_SKB(skb)->atm_options = atmvcc->atm_options; if (!atm_may_send(atmvcc, skb->truesize)) { brdev->stats.tx_dropped++; /* we free this here for now, because we cannot know in a higher layer whether the skb point it supplied wasn't freed yet. now, it always is. */ DPRINTK("atm_vcc (%p) full ! dropping\n",atmvcc); dev_kfree_skb(skb); return 0; } /* atomic_add(skb->truesize, &atmvcc->sk->wmem_alloc); */ atomic_add(skb->truesize,&atmvcc->tx_inuse); brdev->stats.tx_packets++; brdev->stats.tx_bytes += skb->len; atmvcc->send(atmvcc, skb); return 1; } static inline struct br2684_vcc *pick_outgoing_vcc(struct sk_buff *skb, struct br2684_dev *brdev) { return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next); /* 1 vcc/dev right now */ } static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct br2684_dev *brdev = BRPRIV(dev); struct br2684_vcc *brvcc; DPRINTK("br2684_start_xmit, skb->dst=%p\n", skb->dst); read_lock(&devs_lock); brvcc = pick_outgoing_vcc(skb, brdev); if (brvcc == NULL) { DPRINTK("no vcc attached to dev %s\n", dev->name); brdev->stats.tx_errors++; brdev->stats.tx_carrier_errors++; /* netif_stop_queue(dev); */ dev_kfree_skb(skb); read_unlock(&devs_lock); /* Pretend we succeeded so the packet is dropped. */ /* return 0; */ return -EUNATCH; } if (!br2684_xmit_vcc(skb, brdev, brvcc)) { /* * We should probably use netif_*_queue() here, but that * involves added complication. We need to walk before * we can run * * Note: at this point, skb is no longer valid. * br2684_xmit_vcc() might have realloced or freed it. * We don't need to worry about that. */ brdev->stats.tx_errors++; brdev->stats.tx_fifo_errors++; } read_unlock(&devs_lock); return 0; } static struct net_device_stats *br2684_get_stats(struct net_device *dev) { DPRINTK("br2684_get_stats\n"); return &BRPRIV(dev)->stats; } #ifdef FASTER_VERSION /* * These mirror eth_header and eth_header_cache. They are not usually * exported for use in modules, so we grab them from net_device * after ether_setup() is done with it. Bit of a hack. */ static int (*my_eth_header)(struct sk_buff *, struct net_device *, unsigned short, void *, void *, unsigned); static int (*my_eth_header_cache)(struct neighbour *, struct hh_cache *); static int br2684_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned len) { u16 *pad_before_eth; int t = my_eth_header(skb, dev, type, daddr, saddr, len); if (t > 0) { pad_before_eth = (u16 *) skb_push(skb, 2); *pad_before_eth = 0; return dev->hard_header_len; /* or return 16; ? */ } else return t; } static int br2684_header_cache(struct neighbour *neigh, struct hh_cache *hh) { /* hh_data is 16 bytes long. if encaps is ether-llc we need 24, so xmit will add the additional header part in that case */ u16 *pad_before_eth = (u16 *)(hh->hh_data); int t = my_eth_header_cache(neigh, hh); DPRINTK("br2684_header_cache, neigh=%p, hh_cache=%p\n", neigh, hh); if (t < 0) return t; else { *pad_before_eth = 0; hh->hh_len = PADLEN + ETH_HLEN; } return 0; } /* * This is similar to eth_type_trans, which cannot be used because of * our dev->hard_header_len */ static inline unsigned short br_type_trans(struct sk_buff *skb, struct net_device *dev) { struct ethhdr *eth; unsigned char *rawp; eth = skb->mac.ethernet; if (*eth->h_dest & 1) { if (memcmp(eth->h_dest, dev->broadcast, ETH_ALEN) == 0) skb->pkt_type = PACKET_BROADCAST; else skb->pkt_type = PACKET_MULTICAST; } else if (memcmp(eth->h_dest, dev->dev_addr, ETH_ALEN)) skb->pkt_type = PACKET_OTHERHOST; if (ntohs(eth->h_proto) >= 1536) return eth->h_proto; rawp = skb->data; /* * This is a magic hack to spot IPX packets. Older Novell breaks * the protocol design and runs IPX over 802.3 without an 802.2 LLC * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This * won't work for fault tolerant netware but does for the rest. */ if (*(unsigned short *) rawp == 0xFFFF) return htons(ETH_P_802_3); /* * Real 802.2 LLC */ return htons(ETH_P_802_2); } #endif /* FASTER_VERSION */ /* * 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 (*my_eth_mac_addr)(struct net_device *, void *); static int br2684_mac_addr(struct net_device *dev, void *p) { int err = my_eth_mac_addr(dev, p); if (!err) BRPRIV(dev)->mac_was_set = 1; return err; } #ifdef CONFIG_ATM_BR2684_IPFILTER /* this IOCTL is experimental. */ static int br2684_setfilt(struct atm_vcc *atmvcc, unsigned long arg) { struct br2684_vcc *brvcc; struct br2684_filter_set fs; if (copy_from_user(&fs, (void *) 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 = 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; } /* Returns 1 if packet should be dropped */ static inline int packet_fails_filter(u16 type, struct br2684_vcc *brvcc, struct sk_buff *skb) { if (brvcc->filter.netmask == 0) return 0; /* no filter in place */ if (type == __constant_htons(ETH_P_IP) && (((struct iphdr *) (skb->data))->daddr & brvcc->filter. netmask) == brvcc->filter.prefix) return 0; if (type == __constant_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 */ } #endif /* CONFIG_ATM_BR2684_IPFILTER */ static void br2684_close_vcc(struct br2684_vcc *brvcc) { DPRINTK("removing VCC %p from dev %p\n", brvcc, brvcc->brdev); write_lock_irq(&devs_lock); list_del(&brvcc->brvccs); write_unlock_irq(&devs_lock); brvcc->atmvcc->user_back = NULL; /* what about vcc->recvq ??? */ brvcc->old_push(brvcc->atmvcc, NULL); /* pass on the bad news */ kfree(brvcc); MOD_DEC_USE_COUNT; } /* when AAL5 PDU comes in: */ /* We receive packets */ static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb) { struct br2684_vcc *brvcc = BR2684_VCC(atmvcc); struct br2684_dev *brdev = brvcc->brdev; int plen = sizeof(llc_oui_pid_pad) + ETH_HLEN; DPRINTK("br2684_push\n"); if (skb == NULL) { /* skb==NULL means VCC is being destroyed */ br2684_close_vcc(brvcc); if (list_empty(&brdev->brvccs)) { read_lock(&devs_lock); list_del(&brdev->br2684_devs); read_unlock(&devs_lock); unregister_netdev(&brdev->net_dev); kfree(brdev); } return; } skb_debug(skb); atm_return(atmvcc, skb->truesize); DPRINTK("skb from brdev %p\n", brdev); if (brvcc->encaps == e_llc) { /* 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) */ if (memcmp(skb->data, llc_oui_pid_pad, 7)) { brdev->stats.rx_errors++; DPRINTK("Invalid encapsulation from brdev %p\n", brdev); dev_kfree_skb(skb); return; } } else { plen = PADLEN + ETH_HLEN; /* pad, dstmac,srcmac, ethtype */ /* first 2 chars should be 0 */ if (*((u16 *) (skb->data)) != 0) { brdev->stats.rx_errors++; dev_kfree_skb(skb); return; } } if (skb->len < plen) { brdev->stats.rx_errors++; dev_kfree_skb(skb); /* dev_ not needed? */ return; } #ifdef FASTER_VERSION /* FIXME: tcpdump shows that pointer to mac header is 2 bytes earlier, than should be. What else should I set? */ skb_pull(skb, plen); skb->mac.raw = ((char *) (skb->data)) - ETH_HLEN; skb->pkt_type = PACKET_HOST; #ifdef CONFIG_BR2684_FAST_TRANS skb->protocol = ((u16 *) skb->data)[-1]; #else /* some protocols might require this: */ skb->protocol = br_type_trans(skb, &brdev->net_dev); #endif /* CONFIG_BR2684_FAST_TRANS */ #else skb_pull(skb, plen - ETH_HLEN); skb->protocol = eth_type_trans(skb, &brdev->net_dev); #endif /* FASTER_VERSION */ #ifdef CONFIG_ATM_BR2684_IPFILTER if (packet_fails_filter(skb->protocol, brvcc, skb)) { brdev->stats.rx_dropped++; dev_kfree_skb(skb); return; } #endif /* CONFIG_ATM_BR2684_IPFILTER */ skb->dev = &brdev->net_dev; ATM_SKB(skb)->vcc = atmvcc; /* needed ? */ DPRINTK("received packet's protocol: %x\n", ntohs(skb->protocol)); skb_debug(skb); if (!(brdev->net_dev.flags & IFF_UP)) { /* sigh, interface is down */ brdev->stats.rx_dropped++; dev_kfree_skb(skb); return; } brdev->stats.rx_packets++; brdev->stats.rx_bytes += skb->len; netif_rx(skb); } static int br2684_regvcc(struct atm_vcc *atmvcc, unsigned long arg) { /* assign a vcc to a dev Note: we do not have explicit unassign, but look at _push() */ int err; struct br2684_vcc *brvcc; struct sk_buff_head copy; struct sk_buff *skb; struct br2684_dev *brdev; struct atm_backend_br2684 be; MOD_INC_USE_COUNT; if (copy_from_user(&be, (void *) arg, sizeof be)) { MOD_DEC_USE_COUNT; return -EFAULT; } write_lock_irq(&devs_lock); brdev = br2684_find_dev(&be.ifspec); if (brdev == NULL) { printk(KERN_ERR "br2684: tried to attach to non-existant device\n"); err = -ENXIO; goto error; } 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; } brvcc = kmalloc(sizeof(struct br2684_vcc), GFP_KERNEL); if (!brvcc) { err = -ENOMEM; goto error; } memset(brvcc, 0, sizeof(struct br2684_vcc)); DPRINTK("br2684_regvcc 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(brdev->net_dev.dev_addr, esi, brdev->net_dev.addr_len); else brdev->net_dev.dev_addr[2] = 1; } list_add(&brvcc->brvccs, &brdev->brvccs); write_unlock_irq(&devs_lock); brvcc->brdev = brdev; brvcc->atmvcc = atmvcc; atmvcc->user_back = brvcc; brvcc->encaps = (enum br2684_encaps) be.encaps; brvcc->old_push = atmvcc->push; barrier(); atmvcc->push = br2684_push; skb_queue_head_init(©); skb_migrate(&atmvcc->sk->receive_queue, ©); while ((skb = skb_dequeue(©))) { #if 0 /* Commented out because old_push does not set skb->dev */ BRPRIV(skb->dev)->stats.rx_bytes -= skb->len; BRPRIV(skb->dev)->stats.rx_packets--; #endif br2684_push(atmvcc, skb); } return 0; error: write_unlock_irq(&devs_lock); MOD_DEC_USE_COUNT; return err; } static int br2684_create(unsigned long arg) { int err; struct br2684_dev *brdev; struct atm_newif_br2684 ni; DPRINTK("br2684_create\n"); /* * We track module use by vcc's NOT the devices they're on. We're * protected here against module death by the kernel_lock, but if * we need to sleep we should make sure that the module doesn't * disappear under us. */ MOD_INC_USE_COUNT; if (copy_from_user(&ni, (void *) arg, sizeof ni)) { MOD_DEC_USE_COUNT; return -EFAULT; } if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) { MOD_DEC_USE_COUNT; return -EINVAL; } if ((brdev = kmalloc(sizeof(struct br2684_dev), GFP_KERNEL)) == NULL) { MOD_DEC_USE_COUNT; return -ENOMEM; } memset(brdev, 0, sizeof(struct br2684_dev)); INIT_LIST_HEAD(&brdev->brvccs); write_lock_irq(&devs_lock); brdev->number = list_empty(&br2684_devs) ? 1 : list_entry_brdev(br2684_devs.prev)->number + 1; list_add_tail(&brdev->br2684_devs, &br2684_devs); write_unlock_irq(&devs_lock); if (ni.ifname[0] != '\0') { memcpy(brdev->net_dev.name, ni.ifname, sizeof(brdev->net_dev.name)); brdev->net_dev.name[sizeof(brdev->net_dev.name) - 1] = '\0'; } else sprintf(brdev->net_dev.name, "nas%d", brdev->number); DPRINTK("registered netdev %s\n", brdev->net_dev.name); ether_setup(&brdev->net_dev); brdev->mac_was_set = 0; #ifdef FASTER_VERSION my_eth_header = brdev->net_dev.hard_header; brdev->net_dev.hard_header = br2684_header; my_eth_header_cache = brdev->net_dev.hard_header_cache; brdev->net_dev.hard_header_cache = br2684_header_cache; brdev->net_dev.hard_header_len = sizeof(llc_oui_pid_pad) + ETH_HLEN; /* 10 + 14 */ #endif my_eth_mac_addr = brdev->net_dev.set_mac_address; brdev->net_dev.set_mac_address = br2684_mac_addr; brdev->net_dev.hard_start_xmit = br2684_start_xmit; brdev->net_dev.get_stats = br2684_get_stats; /* open, stop, do_ioctl ? */ err = register_netdev(&brdev->net_dev); MOD_DEC_USE_COUNT; if (err < 0) { printk(KERN_ERR "br2684_create: register_netdev failed\n"); write_lock_irq(&devs_lock); list_del(&brdev->br2684_devs); write_unlock_irq(&devs_lock); kfree(brdev); return err; } return 0; } /* * This handles ioctls actually performed on our vcc - we must return * -ENOIOCTLCMD for any unrecognized ioctl */ static int br2684_ioctl(struct atm_vcc *atmvcc, unsigned int cmd, unsigned long arg) { int err; switch(cmd) { case ATM_SETBACKEND: case ATM_NEWBACKENDIF: { atm_backend_t b; MOD_INC_USE_COUNT; err = get_user(b, (atm_backend_t *) arg); MOD_DEC_USE_COUNT; if (err) return -EFAULT; if (b != ATM_BACKEND_BR2684) return -ENOIOCTLCMD; if (!capable(CAP_NET_ADMIN)) return -EPERM; if (cmd == ATM_SETBACKEND) return br2684_regvcc(atmvcc, arg); else return br2684_create(arg); } #ifdef CONFIG_ATM_BR2684_IPFILTER case BR2684_SETFILT: if (atmvcc->push != br2684_push) return -ENOIOCTLCMD; if (!capable(CAP_NET_ADMIN)) return -EPERM; MOD_INC_USE_COUNT; err = br2684_setfilt(atmvcc, arg); MOD_DEC_USE_COUNT; return err; #endif /* CONFIG_ATM_BR2684_IPFILTER */ } return -ENOIOCTLCMD; } /* Never put more than 256 bytes in at once */ static int br2684_proc_engine(loff_t pos, char *buf) { struct list_head *lhd, *lhc; struct br2684_dev *brdev; struct br2684_vcc *brvcc; list_for_each(lhd, &br2684_devs) { brdev = list_entry_brdev(lhd); if (pos-- == 0) return sprintf(buf, "dev %.16s: num=%d, mac=%02X:%02X:" "%02X:%02X:%02X:%02X (%s)\n", brdev->net_dev.name, brdev->number, brdev->net_dev.dev_addr[0], brdev->net_dev.dev_addr[1], brdev->net_dev.dev_addr[2], brdev->net_dev.dev_addr[3], brdev->net_dev.dev_addr[4], brdev->net_dev.dev_addr[5], brdev->mac_was_set ? "set" : "auto"); list_for_each(lhc, &brdev->brvccs) { brvcc = list_entry_brvcc(lhc); if (pos-- == 0) return sprintf(buf, " vcc %d.%d.%d: encaps=%s" #ifndef FASTER_VERSION ", failed copies %u/%u" #endif /* FASTER_VERSION */ "\n", brvcc->atmvcc->dev->number, brvcc->atmvcc->vpi, brvcc->atmvcc->vci, (brvcc->encaps == e_llc) ? "LLC" : "VC" #ifndef FASTER_VERSION , brvcc->copies_failed , brvcc->copies_needed #endif /* FASTER_VERSION */ ); #ifdef CONFIG_ATM_BR2684_IPFILTER #define b1(var, byte) ((u8 *) &brvcc->filter.var)[byte] #define bs(var) b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3) if (brvcc->filter.netmask != 0 && pos-- == 0) return sprintf(buf, " filter=%d.%d.%d.%d/" "%d.%d.%d.%d\n", bs(prefix), bs(netmask)); #undef bs #undef b1 #endif /* CONFIG_ATM_BR2684_IPFILTER */ } } return 0; } static ssize_t br2684_proc_read(struct file *file, char *buf, size_t count, loff_t *pos) { unsigned long page; int len = 0, x, left; page = get_free_page(GFP_KERNEL); if (!page) return -ENOMEM; left = PAGE_SIZE - 256; if (count < left) left = count; read_lock(&devs_lock); for (;;) { x = br2684_proc_engine(*pos, &((char *) page)[len]); if (x == 0) break; if (x > left) /* * This should only happen if the user passed in * a "count" too small for even one line */ x = -EINVAL; if (x < 0) { len = x; break; } len += x; left -= x; (*pos)++; if (left < 256) break; } read_unlock(&devs_lock); if (len > 0 && copy_to_user(buf, (char *) page, len)) len = -EFAULT; free_page(page); return len; } static struct file_operations br2684_proc_operations = { read: br2684_proc_read, }; extern struct proc_dir_entry *atm_proc_root; /* from proc.c */ extern int (*br2684_ioctl_hook)(struct atm_vcc *, unsigned int, unsigned long); /* the following avoids some spurious warnings from the compiler */ #define UNUSED __attribute__((unused)) static int __init UNUSED br2684_init(void) { struct proc_dir_entry *p; if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL) return -ENOMEM; p->proc_fops = &br2684_proc_operations; br2684_ioctl_hook = br2684_ioctl; return 0; } static void __exit UNUSED br2684_exit(void) { struct br2684_dev *brdev; br2684_ioctl_hook = NULL; remove_proc_entry("br2684", atm_proc_root); while (!list_empty(&br2684_devs)) { brdev = list_entry_brdev(br2684_devs.next); unregister_netdev(&brdev->net_dev); list_del(&brdev->br2684_devs); kfree(brdev); } } module_init(br2684_init); module_exit(br2684_exit); MODULE_AUTHOR("Marcell GAL"); MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5"); MODULE_LICENSE("GPL");