/* * Generic PPP layer for Linux. * * Copyright 1999-2000 Paul Mackerras. * * 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. * * The generic PPP layer handles the PPP network interfaces, the * /dev/ppp device, packet and VJ compression, and multilink. * It talks to PPP `channels' via the interface defined in * include/linux/ppp_channel.h. Channels provide the basic means for * sending and receiving PPP frames on some kind of communications * channel. * * Part of the code in this driver was inspired by the old async-only * PPP driver, written by Michael Callahan and Al Longyear, and * subsequently hacked by Paul Mackerras. * * ==FILEVERSION 20000417== */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define PPP_VERSION "2.4.1" /* * Network protocols we support. */ #define NP_IP 0 /* Internet Protocol V4 */ #define NP_IPV6 1 /* Internet Protocol V6 */ #define NP_IPX 2 /* IPX protocol */ #define NP_AT 3 /* Appletalk protocol */ #define NUM_NP 4 /* Number of NPs. */ #define MPHDRLEN 6 /* multilink protocol header length */ #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ #define MIN_FRAG_SIZE 64 /* * An instance of /dev/ppp can be associated with either a ppp * interface unit or a ppp channel. In both cases, file->private_data * points to one of these. */ struct ppp_file { enum { INTERFACE=1, CHANNEL } kind; struct sk_buff_head xq; /* pppd transmit queue */ struct sk_buff_head rq; /* receive queue for pppd */ wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ atomic_t refcnt; /* # refs (incl /dev/ppp attached) */ int hdrlen; /* space to leave for headers */ struct list_head list; /* link in all_* list */ int index; /* interface unit / channel number */ }; #define PF_TO_X(pf, X) ((X *)((char *)(pf)-(unsigned long)(&((X *)0)->file))) #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) #define ROUNDUP(n, x) (((n) + (x) - 1) / (x)) /* * Data structure describing one ppp unit. * A ppp unit corresponds to a ppp network interface device * and represents a multilink bundle. * It can have 0 or more ppp channels connected to it. */ struct ppp { struct ppp_file file; /* stuff for read/write/poll */ struct list_head channels; /* list of attached channels */ int n_channels; /* how many channels are attached */ spinlock_t rlock; /* lock for receive side */ spinlock_t wlock; /* lock for transmit side */ int mru; /* max receive unit */ unsigned int flags; /* control bits */ unsigned int xstate; /* transmit state bits */ unsigned int rstate; /* receive state bits */ int debug; /* debug flags */ struct slcompress *vj; /* state for VJ header compression */ enum NPmode npmode[NUM_NP]; /* what to do with each net proto */ struct sk_buff *xmit_pending; /* a packet ready to go out */ struct compressor *xcomp; /* transmit packet compressor */ void *xc_state; /* its internal state */ struct compressor *rcomp; /* receive decompressor */ void *rc_state; /* its internal state */ unsigned long last_xmit; /* jiffies when last pkt sent */ unsigned long last_recv; /* jiffies when last pkt rcvd */ struct net_device *dev; /* network interface device */ #ifdef CONFIG_PPP_MULTILINK int nxchan; /* next channel to send something on */ u32 nxseq; /* next sequence number to send */ int mrru; /* MP: max reconst. receive unit */ u32 nextseq; /* MP: seq no of next packet */ u32 minseq; /* MP: min of most recent seqnos */ struct sk_buff_head mrq; /* MP: receive reconstruction queue */ #endif /* CONFIG_PPP_MULTILINK */ struct net_device_stats stats; /* statistics */ }; /* * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP. * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. * Bits in xstate: SC_COMP_RUN */ #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ |SC_COMP_TCP|SC_REJ_COMP_TCP) /* * Private data structure for each channel. * This includes the data structure used for multilink. */ struct channel { struct ppp_file file; /* stuff for read/write/poll */ struct ppp_channel *chan; /* public channel data structure */ spinlock_t downl; /* protects `chan', file.xq dequeue */ struct ppp *ppp; /* ppp unit we're connected to */ struct list_head clist; /* link in list of channels per unit */ rwlock_t upl; /* protects `ppp' and `ulist' */ #ifdef CONFIG_PPP_MULTILINK u8 avail; /* flag used in multilink stuff */ u8 had_frag; /* >= 1 fragments have been sent */ u32 lastseq; /* MP: last sequence # received */ #endif /* CONFIG_PPP_MULTILINK */ }; /* * SMP locking issues: * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels * list and the ppp.n_channels field, you need to take both locks * before you modify them. * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> * channel.downl. */ /* * all_ppp_lock protects the all_ppp_units. * It also ensures that finding a ppp unit in the all_ppp_units list * and updating its file.refcnt field is atomic. */ static spinlock_t all_ppp_lock = SPIN_LOCK_UNLOCKED; static LIST_HEAD(all_ppp_units); /* * all_channels_lock protects all_channels and last_channel_index, * and the atomicity of find a channel and updating its file.refcnt * field. */ static spinlock_t all_channels_lock = SPIN_LOCK_UNLOCKED; static LIST_HEAD(all_channels); static int last_channel_index; /* Get the PPP protocol number from a skb */ #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1]) /* We limit the length of ppp->file.rq to this (arbitrary) value */ #define PPP_MAX_RQLEN 32 /* * Maximum number of multilink fragments queued up. * This has to be large enough to cope with the maximum latency of * the slowest channel relative to the others. Strictly it should * depend on the number of channels and their characteristics. */ #define PPP_MP_MAX_QLEN 128 /* Multilink header bits. */ #define B 0x80 /* this fragment begins a packet */ #define E 0x40 /* this fragment ends a packet */ /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ #define seq_before(a, b) ((s32)((a) - (b)) < 0) #define seq_after(a, b) ((s32)((a) - (b)) > 0) /* Prototypes. */ static ssize_t ppp_file_read(struct ppp_file *pf, struct file *file, char *buf, size_t count); static ssize_t ppp_file_write(struct ppp_file *pf, const char *buf, size_t count); static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file, unsigned int cmd, unsigned long arg); static void ppp_xmit_process(struct ppp *ppp); static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); static void ppp_push(struct ppp *ppp); static void ppp_channel_push(struct channel *pch); static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch); static void ppp_receive_error(struct ppp *ppp); static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb); #ifdef CONFIG_PPP_MULTILINK static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch); static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); #endif /* CONFIG_PPP_MULTILINK */ static int ppp_set_compress(struct ppp *ppp, unsigned long arg); static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); static void ppp_ccp_closed(struct ppp *ppp); static struct compressor *find_compressor(int type); static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); static struct ppp *ppp_create_interface(int unit, int *retp); static void init_ppp_file(struct ppp_file *pf, int kind); static void ppp_destroy_interface(struct ppp *ppp); static struct ppp *ppp_find_unit(int unit); static struct channel *ppp_find_channel(int unit); static int ppp_connect_channel(struct channel *pch, int unit); static int ppp_disconnect_channel(struct channel *pch); static void ppp_destroy_channel(struct channel *pch); /* Translates a PPP protocol number to a NP index (NP == network protocol) */ static inline int proto_to_npindex(int proto) { switch (proto) { case PPP_IP: return NP_IP; case PPP_IPV6: return NP_IPV6; case PPP_IPX: return NP_IPX; case PPP_AT: return NP_AT; } return -EINVAL; } /* Translates an NP index into a PPP protocol number */ static const int npindex_to_proto[NUM_NP] = { PPP_IP, PPP_IPV6, PPP_IPX, PPP_AT, }; /* Translates an ethertype into an NP index */ static inline int ethertype_to_npindex(int ethertype) { switch (ethertype) { case ETH_P_IP: return NP_IP; case ETH_P_IPV6: return NP_IPV6; case ETH_P_IPX: return NP_IPX; case ETH_P_PPPTALK: case ETH_P_ATALK: return NP_AT; } return -1; } /* Translates an NP index into an ethertype */ static const int npindex_to_ethertype[NUM_NP] = { ETH_P_IP, ETH_P_IPV6, ETH_P_IPX, ETH_P_PPPTALK, }; /* * Locking shorthand. */ #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ ppp_recv_lock(ppp); } while (0) #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ ppp_xmit_unlock(ppp); } while (0) /* * /dev/ppp device routines. * The /dev/ppp device is used by pppd to control the ppp unit. * It supports the read, write, ioctl and poll functions. * Open instances of /dev/ppp can be in one of three states: * unattached, attached to a ppp unit, or attached to a ppp channel. */ static int ppp_open(struct inode *inode, struct file *file) { /* * This could (should?) be enforced by the permissions on /dev/ppp. */ if (!capable(CAP_NET_ADMIN)) return -EPERM; MOD_INC_USE_COUNT; return 0; } static int ppp_release(struct inode *inode, struct file *file) { struct ppp_file *pf = (struct ppp_file *) file->private_data; if (pf != 0) { file->private_data = 0; if (atomic_dec_and_test(&pf->refcnt)) { switch (pf->kind) { case INTERFACE: ppp_destroy_interface(PF_TO_PPP(pf)); break; case CHANNEL: ppp_destroy_channel(PF_TO_CHANNEL(pf)); break; } } } MOD_DEC_USE_COUNT; return 0; } static ssize_t ppp_read(struct file *file, char *buf, size_t count, loff_t *ppos) { struct ppp_file *pf = (struct ppp_file *) file->private_data; return ppp_file_read(pf, file, buf, count); } static ssize_t ppp_file_read(struct ppp_file *pf, struct file *file, char *buf, size_t count) { DECLARE_WAITQUEUE(wait, current); ssize_t ret; struct sk_buff *skb = 0; ret = -ENXIO; if (pf == 0) goto out; /* not currently attached */ add_wait_queue(&pf->rwait, &wait); current->state = TASK_INTERRUPTIBLE; for (;;) { skb = skb_dequeue(&pf->rq); if (skb) break; ret = 0; if (pf->kind == CHANNEL && PF_TO_CHANNEL(pf)->chan == 0) break; ret = -EAGAIN; if (file->f_flags & O_NONBLOCK) break; ret = -ERESTARTSYS; if (signal_pending(current)) break; schedule(); } current->state = TASK_RUNNING; remove_wait_queue(&pf->rwait, &wait); if (skb == 0) goto out; ret = -EOVERFLOW; if (skb->len > count) goto outf; ret = -EFAULT; if (copy_to_user(buf, skb->data, skb->len)) goto outf; ret = skb->len; outf: kfree_skb(skb); out: return ret; } static ssize_t ppp_write(struct file *file, const char *buf, size_t count, loff_t *ppos) { struct ppp_file *pf = (struct ppp_file *) file->private_data; return ppp_file_write(pf, buf, count); } static ssize_t ppp_file_write(struct ppp_file *pf, const char *buf, size_t count) { struct sk_buff *skb; ssize_t ret; ret = -ENXIO; if (pf == 0) goto out; ret = -ENOMEM; skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); if (skb == 0) goto out; skb_reserve(skb, pf->hdrlen); ret = -EFAULT; if (copy_from_user(skb_put(skb, count), buf, count)) { kfree_skb(skb); goto out; } skb_queue_tail(&pf->xq, skb); switch (pf->kind) { case INTERFACE: ppp_xmit_process(PF_TO_PPP(pf)); break; case CHANNEL: ppp_channel_push(PF_TO_CHANNEL(pf)); break; } ret = count; out: return ret; } /* No kernel lock - fine */ static unsigned int ppp_poll(struct file *file, poll_table *wait) { struct ppp_file *pf = (struct ppp_file *) file->private_data; unsigned int mask; if (pf == 0) return 0; poll_wait(file, &pf->rwait, wait); mask = POLLOUT | POLLWRNORM; if (skb_peek(&pf->rq) != 0) mask |= POLLIN | POLLRDNORM; if (pf->kind == CHANNEL) { struct channel *pch = PF_TO_CHANNEL(pf); if (pch->chan == 0) mask |= POLLHUP; } return mask; } static int ppp_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct ppp_file *pf = (struct ppp_file *) file->private_data; struct ppp *ppp; int err = -EFAULT, val, val2, i; struct ppp_idle idle; struct npioctl npi; int unit; struct slcompress *vj; if (pf == 0) return ppp_unattached_ioctl(pf, file, cmd, arg); if (pf->kind == CHANNEL) { struct channel *pch = PF_TO_CHANNEL(pf); struct ppp_channel *chan; switch (cmd) { case PPPIOCCONNECT: if (get_user(unit, (int *) arg)) break; err = ppp_connect_channel(pch, unit); break; case PPPIOCDISCONN: err = ppp_disconnect_channel(pch); break; case PPPIOCDETACH: file->private_data = 0; if (atomic_dec_and_test(&pf->refcnt)) ppp_destroy_channel(pch); err = 0; break; default: spin_lock_bh(&pch->downl); chan = pch->chan; err = -ENOTTY; if (chan && chan->ops->ioctl) err = chan->ops->ioctl(chan, cmd, arg); spin_unlock_bh(&pch->downl); } return err; } if (pf->kind != INTERFACE) { /* can't happen */ printk(KERN_ERR "PPP: not interface or channel??\n"); return -EINVAL; } ppp = PF_TO_PPP(pf); switch (cmd) { case PPPIOCDETACH: file->private_data = 0; if (atomic_dec_and_test(&pf->refcnt)) ppp_destroy_interface(ppp); err = 0; break; case PPPIOCSMRU: if (get_user(val, (int *) arg)) break; ppp->mru = val; err = 0; break; case PPPIOCSFLAGS: if (get_user(val, (int *) arg)) break; ppp_lock(ppp); if (ppp->flags & ~val & SC_CCP_OPEN) ppp_ccp_closed(ppp); ppp->flags = val & SC_FLAG_BITS; ppp_unlock(ppp); err = 0; break; case PPPIOCGFLAGS: val = ppp->flags | ppp->xstate | ppp->rstate; if (put_user(val, (int *) arg)) break; err = 0; break; case PPPIOCSCOMPRESS: err = ppp_set_compress(ppp, arg); break; case PPPIOCGUNIT: if (put_user(ppp->file.index, (int *) arg)) break; err = 0; break; case PPPIOCSDEBUG: if (get_user(val, (int *) arg)) break; ppp->debug = val; err = 0; break; case PPPIOCGDEBUG: if (put_user(ppp->debug, (int *) arg)) break; err = 0; break; case PPPIOCGIDLE: idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; idle.recv_idle = (jiffies - ppp->last_recv) / HZ; if (copy_to_user((void *) arg, &idle, sizeof(idle))) break; err = 0; break; case PPPIOCSMAXCID: if (get_user(val, (int *) arg)) break; val2 = 15; if ((val >> 16) != 0) { val2 = val >> 16; val &= 0xffff; } vj = slhc_init(val2+1, val+1); if (vj == 0) { printk(KERN_ERR "PPP: no memory (VJ compressor)\n"); err = -ENOMEM; break; } ppp_lock(ppp); if (ppp->vj != 0) slhc_free(ppp->vj); ppp->vj = vj; ppp_unlock(ppp); err = 0; break; case PPPIOCGNPMODE: case PPPIOCSNPMODE: if (copy_from_user(&npi, (void *) arg, sizeof(npi))) break; err = proto_to_npindex(npi.protocol); if (err < 0) break; i = err; if (cmd == PPPIOCGNPMODE) { err = -EFAULT; npi.mode = ppp->npmode[i]; if (copy_to_user((void *) arg, &npi, sizeof(npi))) break; } else { ppp->npmode[i] = npi.mode; /* we may be able to transmit more packets now (??) */ netif_wake_queue(ppp->dev); } err = 0; break; #ifdef CONFIG_PPP_MULTILINK case PPPIOCSMRRU: if (get_user(val, (int *) arg)) break; ppp_recv_lock(ppp); ppp->mrru = val; ppp_recv_unlock(ppp); err = 0; break; #endif /* CONFIG_PPP_MULTILINK */ default: err = -ENOTTY; } return err; } static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file, unsigned int cmd, unsigned long arg) { int unit, err = -EFAULT; struct ppp *ppp; struct channel *chan; switch (cmd) { case PPPIOCNEWUNIT: /* Create a new ppp unit */ if (get_user(unit, (int *) arg)) break; ppp = ppp_create_interface(unit, &err); if (ppp == 0) break; file->private_data = &ppp->file; err = -EFAULT; if (put_user(ppp->file.index, (int *) arg)) break; err = 0; break; case PPPIOCATTACH: /* Attach to an existing ppp unit */ if (get_user(unit, (int *) arg)) break; spin_lock(&all_ppp_lock); ppp = ppp_find_unit(unit); if (ppp != 0) atomic_inc(&ppp->file.refcnt); spin_unlock(&all_ppp_lock); err = -ENXIO; if (ppp == 0) break; file->private_data = &ppp->file; err = 0; break; case PPPIOCATTCHAN: if (get_user(unit, (int *) arg)) break; spin_lock_bh(&all_channels_lock); chan = ppp_find_channel(unit); if (chan != 0) atomic_inc(&chan->file.refcnt); spin_unlock_bh(&all_channels_lock); err = -ENXIO; if (chan == 0) break; file->private_data = &chan->file; err = 0; break; default: err = -ENOTTY; } return err; } static struct file_operations ppp_device_fops = { read: ppp_read, write: ppp_write, poll: ppp_poll, ioctl: ppp_ioctl, open: ppp_open, release: ppp_release }; #define PPP_MAJOR 108 static devfs_handle_t devfs_handle = NULL; /* Called at boot time if ppp is compiled into the kernel, or at module load time (from init_module) if compiled as a module. */ int __init ppp_init(void) { int err; printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n"); err = devfs_register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); if (err) printk(KERN_ERR "failed to register PPP device (%d)\n", err); devfs_handle = devfs_register(NULL, "ppp", 0, DEVFS_FL_NONE, PPP_MAJOR, 0, S_IFCHR | S_IRUSR | S_IWUSR, 0, 0, &ppp_device_fops, NULL); return 0; } /* * Network interface unit routines. */ static int ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct ppp *ppp = (struct ppp *) dev->priv; int npi, proto; unsigned char *pp; npi = ethertype_to_npindex(ntohs(skb->protocol)); if (npi < 0) goto outf; /* Drop, accept or reject the packet */ switch (ppp->npmode[npi]) { case NPMODE_PASS: break; case NPMODE_QUEUE: /* it would be nice to have a way to tell the network system to queue this one up for later. */ goto outf; case NPMODE_DROP: case NPMODE_ERROR: goto outf; } /* Put the 2-byte PPP protocol number on the front, making sure there is room for the address and control fields. */ if (skb_headroom(skb) < PPP_HDRLEN) { struct sk_buff *ns; ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC); if (ns == 0) goto outf; skb_reserve(ns, dev->hard_header_len); memcpy(skb_put(ns, skb->len), skb->data, skb->len); kfree_skb(skb); skb = ns; } pp = skb_push(skb, 2); proto = npindex_to_proto[npi]; pp[0] = proto >> 8; pp[1] = proto; netif_stop_queue(dev); skb_queue_tail(&ppp->file.xq, skb); ppp_xmit_process(ppp); return 0; outf: kfree_skb(skb); ++ppp->stats.tx_dropped; return 0; } static struct net_device_stats * ppp_net_stats(struct net_device *dev) { struct ppp *ppp = (struct ppp *) dev->priv; return &ppp->stats; } static int ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) { struct ppp *ppp = dev->priv; int err = -EFAULT; void *addr = (void *) ifr->ifr_ifru.ifru_data; struct ppp_stats stats; struct ppp_comp_stats cstats; char *vers; switch (cmd) { case SIOCGPPPSTATS: ppp_get_stats(ppp, &stats); if (copy_to_user(addr, &stats, sizeof(stats))) break; err = 0; break; case SIOCGPPPCSTATS: memset(&cstats, 0, sizeof(cstats)); if (ppp->xc_state != 0) ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); if (ppp->rc_state != 0) ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); if (copy_to_user(addr, &cstats, sizeof(cstats))) break; err = 0; break; case SIOCGPPPVER: vers = PPP_VERSION; if (copy_to_user(addr, vers, strlen(vers) + 1)) break; err = 0; break; default: err = -EINVAL; } return err; } int ppp_net_init(struct net_device *dev) { dev->hard_header_len = PPP_HDRLEN; dev->mtu = PPP_MTU; dev->hard_start_xmit = ppp_start_xmit; dev->get_stats = ppp_net_stats; dev->do_ioctl = ppp_net_ioctl; dev->addr_len = 0; dev->tx_queue_len = 3; dev->type = ARPHRD_PPP; dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; dev_init_buffers(dev); return 0; } /* * Transmit-side routines. */ /* * Called to do any work queued up on the transmit side * that can now be done. */ static void ppp_xmit_process(struct ppp *ppp) { struct sk_buff *skb; ppp_xmit_lock(ppp); ppp_push(ppp); while (ppp->xmit_pending == 0 && (skb = skb_dequeue(&ppp->file.xq)) != 0) ppp_send_frame(ppp, skb); /* If there's no work left to do, tell the core net code that we can accept some more. */ if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0 && ppp->dev != 0) netif_wake_queue(ppp->dev); ppp_xmit_unlock(ppp); } /* * Compress and send a frame. * The caller should have locked the xmit path, * and xmit_pending should be 0. */ static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) { int proto = PPP_PROTO(skb); struct sk_buff *new_skb; int len; unsigned char *cp; ++ppp->stats.tx_packets; ppp->stats.tx_bytes += skb->len - 2; switch (proto) { case PPP_IP: if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0) break; /* try to do VJ TCP header compression */ new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, GFP_ATOMIC); if (new_skb == 0) { printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n"); goto drop; } skb_reserve(new_skb, ppp->dev->hard_header_len - 2); cp = skb->data + 2; len = slhc_compress(ppp->vj, cp, skb->len - 2, new_skb->data + 2, &cp, !(ppp->flags & SC_NO_TCP_CCID)); if (cp == skb->data + 2) { /* didn't compress */ kfree_skb(new_skb); } else { if (cp[0] & SL_TYPE_COMPRESSED_TCP) { proto = PPP_VJC_COMP; cp[0] &= ~SL_TYPE_COMPRESSED_TCP; } else { proto = PPP_VJC_UNCOMP; cp[0] = skb->data[2]; } kfree_skb(skb); skb = new_skb; cp = skb_put(skb, len + 2); cp[0] = 0; cp[1] = proto; } break; case PPP_CCP: /* peek at outbound CCP frames */ ppp_ccp_peek(ppp, skb, 0); break; } /* try to do packet compression */ if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0 && proto != PPP_LCP && proto != PPP_CCP) { new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len, GFP_ATOMIC); if (new_skb == 0) { printk(KERN_ERR "PPP: no memory (comp pkt)\n"); goto drop; } if (ppp->dev->hard_header_len > PPP_HDRLEN) skb_reserve(new_skb, ppp->dev->hard_header_len - PPP_HDRLEN); /* compressor still expects A/C bytes in hdr */ len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, new_skb->data, skb->len + 2, ppp->dev->mtu + PPP_HDRLEN); if (len > 0 && (ppp->flags & SC_CCP_UP)) { kfree_skb(skb); skb = new_skb; skb_put(skb, len); skb_pull(skb, 2); /* pull off A/C bytes */ } else { /* didn't compress, or CCP not up yet */ kfree_skb(new_skb); } } /* for data packets, record the time */ if (proto < 0x8000) ppp->last_xmit = jiffies; /* * If we are waiting for traffic (demand dialling), * queue it up for pppd to receive. */ if (ppp->flags & SC_LOOP_TRAFFIC) { if (ppp->file.rq.qlen > PPP_MAX_RQLEN) goto drop; skb_queue_tail(&ppp->file.rq, skb); wake_up_interruptible(&ppp->file.rwait); return; } ppp->xmit_pending = skb; ppp_push(ppp); return; drop: kfree_skb(skb); ++ppp->stats.tx_errors; } /* * Try to send the frame in xmit_pending. * The caller should have the xmit path locked. */ static void ppp_push(struct ppp *ppp) { struct list_head *list; struct channel *pch; struct sk_buff *skb = ppp->xmit_pending; if (skb == 0) return; list = &ppp->channels; if (list_empty(list)) { /* nowhere to send the packet, just drop it */ ppp->xmit_pending = 0; kfree_skb(skb); return; } if ((ppp->flags & SC_MULTILINK) == 0) { /* not doing multilink: send it down the first channel */ list = list->next; pch = list_entry(list, struct channel, clist); spin_lock_bh(&pch->downl); if (pch->chan) { if (pch->chan->ops->start_xmit(pch->chan, skb)) ppp->xmit_pending = 0; } else { /* channel got unregistered */ kfree_skb(skb); ppp->xmit_pending = 0; } spin_unlock_bh(&pch->downl); return; } #ifdef CONFIG_PPP_MULTILINK /* Multilink: fragment the packet over as many links as can take the packet at the moment. */ if (!ppp_mp_explode(ppp, skb)) return; #endif /* CONFIG_PPP_MULTILINK */ ppp->xmit_pending = 0; kfree_skb(skb); } #ifdef CONFIG_PPP_MULTILINK /* * Divide a packet to be transmitted into fragments and * send them out the individual links. */ static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) { int nch, len, fragsize; int i, bits, hdrlen, mtu; int flen, fnb; unsigned char *p, *q; struct list_head *list; struct channel *pch; struct sk_buff *frag; struct ppp_channel *chan; nch = 0; hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; list = &ppp->channels; while ((list = list->next) != &ppp->channels) { pch = list_entry(list, struct channel, clist); nch += pch->avail = (skb_queue_len(&pch->file.xq) == 0); /* * If a channel hasn't had a fragment yet, it has to get * one before we send any fragments on later channels. * If it can't take a fragment now, don't give any * to subsequent channels. */ if (!pch->had_frag && !pch->avail) { while ((list = list->next) != &ppp->channels) { pch = list_entry(list, struct channel, clist); pch->avail = 0; } break; } } if (nch == 0) return 0; /* can't take now, leave it in xmit_pending */ /* Do protocol field compression (XXX this should be optional) */ p = skb->data; len = skb->len; if (*p == 0) { ++p; --len; } /* decide on fragment size */ fragsize = len; if (nch > 1) { int maxch = ROUNDUP(len, MIN_FRAG_SIZE); if (nch > maxch) nch = maxch; fragsize = ROUNDUP(fragsize, nch); } /* skip to the channel after the one we last used and start at that one */ for (i = 0; i < ppp->nxchan; ++i) { list = list->next; if (list == &ppp->channels) { i = 0; break; } } /* create a fragment for each channel */ bits = B; do { list = list->next; if (list == &ppp->channels) { i = 0; continue; } pch = list_entry(list, struct channel, clist); ++i; if (!pch->avail) continue; /* check the channel's mtu and whether it is still attached. */ spin_lock_bh(&pch->downl); if (pch->chan == 0 || (mtu = pch->chan->mtu) < hdrlen) { /* can't use this channel */ spin_unlock_bh(&pch->downl); pch->avail = 0; if (--nch == 0) break; continue; } /* * We have to create multiple fragments for this channel * if fragsize is greater than the channel's mtu. */ if (fragsize > len) fragsize = len; for (flen = fragsize; flen > 0; flen -= fnb) { fnb = flen; if (fnb > mtu + 2 - hdrlen) fnb = mtu + 2 - hdrlen; if (fnb >= len) bits |= E; frag = alloc_skb(fnb + hdrlen, GFP_ATOMIC); if (frag == 0) goto noskb; q = skb_put(frag, fnb + hdrlen); /* make the MP header */ q[0] = PPP_MP >> 8; q[1] = PPP_MP; if (ppp->flags & SC_MP_XSHORTSEQ) { q[2] = bits + ((ppp->nxseq >> 8) & 0xf); q[3] = ppp->nxseq; } else { q[2] = bits; q[3] = ppp->nxseq >> 16; q[4] = ppp->nxseq >> 8; q[5] = ppp->nxseq; } /* copy the data in */ memcpy(q + hdrlen, p, fnb); /* try to send it down the channel */ chan = pch->chan; if (!chan->ops->start_xmit(chan, frag)) skb_queue_tail(&pch->file.xq, frag); pch->had_frag = 1; p += fnb; len -= fnb; ++ppp->nxseq; bits = 0; } spin_unlock_bh(&pch->downl); } while (len > 0); ppp->nxchan = i; return 1; noskb: spin_unlock_bh(&pch->downl); if (ppp->debug & 1) printk(KERN_ERR "PPP: no memory (fragment)\n"); ++ppp->stats.tx_errors; ++ppp->nxseq; return 1; /* abandon the frame */ } #endif /* CONFIG_PPP_MULTILINK */ /* * Try to send data out on a channel. */ static void ppp_channel_push(struct channel *pch) { struct sk_buff *skb; struct ppp *ppp; spin_lock_bh(&pch->downl); if (pch->chan != 0) { while (skb_queue_len(&pch->file.xq) > 0) { skb = skb_dequeue(&pch->file.xq); if (!pch->chan->ops->start_xmit(pch->chan, skb)) { /* put the packet back and try again later */ skb_queue_head(&pch->file.xq, skb); break; } } } else { /* channel got deregistered */ skb_queue_purge(&pch->file.xq); } spin_unlock_bh(&pch->downl); /* see if there is anything from the attached unit to be sent */ if (skb_queue_len(&pch->file.xq) == 0) { read_lock_bh(&pch->upl); ppp = pch->ppp; if (ppp != 0) ppp_xmit_process(ppp); read_unlock_bh(&pch->upl); } } /* * Receive-side routines. */ /* misuse a few fields of the skb for MP reconstruction */ #define sequence priority #define BEbits cb[0] static inline void ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) { ppp_recv_lock(ppp); /* ppp->dev == 0 means interface is closing down */ if (ppp->dev != 0) ppp_receive_frame(ppp, skb, pch); else kfree_skb(skb); ppp_recv_unlock(ppp); } void ppp_input(struct ppp_channel *chan, struct sk_buff *skb) { struct channel *pch = chan->ppp; int proto; if (pch == 0 || skb->len == 0) { kfree_skb(skb); return; } proto = PPP_PROTO(skb); read_lock_bh(&pch->upl); if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) { /* put it on the channel queue */ skb_queue_tail(&pch->file.rq, skb); /* drop old frames if queue too long */ while (pch->file.rq.qlen > PPP_MAX_RQLEN && (skb = skb_dequeue(&pch->file.rq)) != 0) kfree_skb(skb); wake_up_interruptible(&pch->file.rwait); } else { ppp_do_recv(pch->ppp, skb, pch); } read_unlock_bh(&pch->upl); } /* Put a 0-length skb in the receive queue as an error indication */ void ppp_input_error(struct ppp_channel *chan, int code) { struct channel *pch = chan->ppp; struct sk_buff *skb; if (pch == 0) return; read_lock_bh(&pch->upl); if (pch->ppp != 0) { skb = alloc_skb(0, GFP_ATOMIC); if (skb != 0) { skb->len = 0; /* probably unnecessary */ skb->cb[0] = code; ppp_do_recv(pch->ppp, skb, pch); } } read_unlock_bh(&pch->upl); } /* * We come in here to process a received frame. * The receive side of the ppp unit is locked. */ static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) { if (skb->len >= 2) { #ifdef CONFIG_PPP_MULTILINK /* XXX do channel-level decompression here */ if (PPP_PROTO(skb) == PPP_MP) ppp_receive_mp_frame(ppp, skb, pch); else #endif /* CONFIG_PPP_MULTILINK */ ppp_receive_nonmp_frame(ppp, skb); return; } if (skb->len > 0) /* note: a 0-length skb is used as an error indication */ ++ppp->stats.rx_length_errors; kfree_skb(skb); ppp_receive_error(ppp); } static void ppp_receive_error(struct ppp *ppp) { ++ppp->stats.rx_errors; if (ppp->vj != 0) slhc_toss(ppp->vj); } static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) { struct sk_buff *ns; int proto, len, npi; /* * Decompress the frame, if compressed. * Note that some decompressors need to see uncompressed frames * that come in as well as compressed frames. */ if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN) && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) skb = ppp_decompress_frame(ppp, skb); proto = PPP_PROTO(skb); switch (proto) { case PPP_VJC_COMP: /* decompress VJ compressed packets */ if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP)) goto err; if (skb_tailroom(skb) < 124) { /* copy to a new sk_buff with more tailroom */ ns = dev_alloc_skb(skb->len + 128); if (ns == 0) { printk(KERN_ERR"PPP: no memory (VJ decomp)\n"); goto err; } skb_reserve(ns, 2); memcpy(skb_put(ns, skb->len), skb->data, skb->len); kfree_skb(skb); skb = ns; } len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); if (len <= 0) { printk(KERN_DEBUG "PPP: VJ decompression error\n"); goto err; } len += 2; if (len > skb->len) skb_put(skb, len - skb->len); else if (len < skb->len) skb_trim(skb, len); proto = PPP_IP; break; case PPP_VJC_UNCOMP: if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP)) goto err; if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { printk(KERN_ERR "PPP: VJ uncompressed error\n"); goto err; } proto = PPP_IP; break; case PPP_CCP: ppp_ccp_peek(ppp, skb, 1); break; } ++ppp->stats.rx_packets; ppp->stats.rx_bytes += skb->len - 2; npi = proto_to_npindex(proto); if (npi < 0) { /* control or unknown frame - pass it to pppd */ skb_queue_tail(&ppp->file.rq, skb); /* limit queue length by dropping old frames */ while (ppp->file.rq.qlen > PPP_MAX_RQLEN && (skb = skb_dequeue(&ppp->file.rq)) != 0) kfree_skb(skb); /* wake up any process polling or blocking on read */ wake_up_interruptible(&ppp->file.rwait); } else { /* network protocol frame - give it to the kernel */ ppp->last_recv = jiffies; if ((ppp->dev->flags & IFF_UP) == 0 || ppp->npmode[npi] != NPMODE_PASS) { kfree_skb(skb); } else { skb_pull(skb, 2); /* chop off protocol */ skb->dev = ppp->dev; skb->protocol = htons(npindex_to_ethertype[npi]); skb->mac.raw = skb->data; netif_rx(skb); } } return; err: kfree_skb(skb); ppp_receive_error(ppp); } static struct sk_buff * ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) { int proto = PPP_PROTO(skb); struct sk_buff *ns; int len; if (proto == PPP_COMP) { ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN); if (ns == 0) { printk(KERN_ERR "ppp_decompress_frame: no memory\n"); goto err; } /* the decompressor still expects the A/C bytes in the hdr */ len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN); if (len < 0) { /* Pass the compressed frame to pppd as an error indication. */ if (len == DECOMP_FATALERROR) ppp->rstate |= SC_DC_FERROR; goto err; } kfree_skb(skb); skb = ns; skb_put(skb, len); skb_pull(skb, 2); /* pull off the A/C bytes */ } else { /* Uncompressed frame - pass to decompressor so it can update its dictionary if necessary. */ if (ppp->rcomp->incomp) ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, skb->len + 2); } return skb; err: ppp->rstate |= SC_DC_ERROR; ppp_receive_error(ppp); return skb; } #ifdef CONFIG_PPP_MULTILINK /* * Receive a multilink frame. * We put it on the reconstruction queue and then pull off * as many completed frames as we can. */ static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) { u32 mask, seq; struct list_head *l; int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; if (skb->len < mphdrlen + 1 || ppp->mrru == 0) goto err; /* no good, throw it away */ /* Decode sequence number and begin/end bits */ if (ppp->flags & SC_MP_SHORTSEQ) { seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; mask = 0xfff; } else { seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; mask = 0xffffff; } skb->BEbits = skb->data[2]; skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ /* * Do protocol ID decompression on the first fragment of each packet. */ if ((skb->BEbits & B) && (skb->data[0] & 1)) *skb_push(skb, 1) = 0; /* * Expand sequence number to 32 bits, making it as close * as possible to ppp->minseq. */ seq |= ppp->minseq & ~mask; if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) seq += mask + 1; else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) seq -= mask + 1; /* should never happen */ skb->sequence = seq; pch->lastseq = seq; /* * If this packet comes before the next one we were expecting, * drop it. */ if (seq_before(seq, ppp->nextseq)) { kfree_skb(skb); ++ppp->stats.rx_dropped; ppp_receive_error(ppp); return; } /* * Reevaluate minseq, the minimum over all channels of the * last sequence number received on each channel. Because of * the increasing sequence number rule, we know that any fragment * before `minseq' which hasn't arrived is never going to arrive. * The list of channels can't change because we have the receive * side of the ppp unit locked. */ for (l = ppp->channels.next; l != &ppp->channels; l = l->next) { struct channel *ch = list_entry(l, struct channel, clist); if (seq_before(ch->lastseq, seq)) seq = ch->lastseq; } if (seq_before(ppp->minseq, seq)) ppp->minseq = seq; /* Put the fragment on the reconstruction queue */ ppp_mp_insert(ppp, skb); /* If the queue is getting long, don't wait any longer for packets before the start of the queue. */ if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN && seq_before(ppp->minseq, ppp->mrq.next->sequence)) ppp->minseq = ppp->mrq.next->sequence; /* Pull completed packets off the queue and receive them. */ while ((skb = ppp_mp_reconstruct(ppp)) != 0) ppp_receive_nonmp_frame(ppp, skb); return; err: kfree_skb(skb); ppp_receive_error(ppp); } /* * Insert a fragment on the MP reconstruction queue. * The queue is ordered by increasing sequence number. */ static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) { struct sk_buff *p; struct sk_buff_head *list = &ppp->mrq; u32 seq = skb->sequence; /* N.B. we don't need to lock the list lock because we have the ppp unit receive-side lock. */ for (p = list->next; p != (struct sk_buff *)list; p = p->next) if (seq_before(seq, p->sequence)) break; __skb_insert(skb, p->prev, p, list); } /* * Reconstruct a packet from the MP fragment queue. * We go through increasing sequence numbers until we find a * complete packet, or we get to the sequence number for a fragment * which hasn't arrived but might still do so. */ struct sk_buff * ppp_mp_reconstruct(struct ppp *ppp) { u32 seq = ppp->nextseq; u32 minseq = ppp->minseq; struct sk_buff_head *list = &ppp->mrq; struct sk_buff *p, *next; struct sk_buff *head, *tail; struct sk_buff *skb = NULL; int lost = 0, len = 0; if (ppp->mrru == 0) /* do nothing until mrru is set */ return NULL; head = list->next; tail = NULL; for (p = head; p != (struct sk_buff *) list; p = next) { next = p->next; if (seq_before(p->sequence, seq)) { /* this can't happen, anyway ignore the skb */ printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n", p->sequence, seq); head = next; continue; } if (p->sequence != seq) { /* Fragment `seq' is missing. If it is after minseq, it might arrive later, so stop here. */ if (seq_after(seq, minseq)) break; /* Fragment `seq' is lost, keep going. */ lost = 1; seq = seq_before(minseq, p->sequence)? minseq + 1: p->sequence; next = p; continue; } /* * At this point we know that all the fragments from * ppp->nextseq to seq are either present or lost. * Also, there are no complete packets in the queue * that have no missing fragments and end before this * fragment. */ /* B bit set indicates this fragment starts a packet */ if (p->BEbits & B) { head = p; lost = 0; len = 0; } len += p->len; /* Got a complete packet yet? */ if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) { if (len > ppp->mrru + 2) { ++ppp->stats.rx_length_errors; printk(KERN_DEBUG "PPP: reconstructed packet" " is too long (%d)\n", len); } else if (p == head) { /* fragment is complete packet - reuse skb */ tail = p; skb = skb_get(p); break; } else if ((skb = dev_alloc_skb(len)) == NULL) { ++ppp->stats.rx_missed_errors; printk(KERN_DEBUG "PPP: no memory for " "reconstructed packet"); } else { tail = p; break; } ppp->nextseq = seq + 1; } /* * If this is the ending fragment of a packet, * and we haven't found a complete valid packet yet, * we can discard up to and including this fragment. */ if (p->BEbits & E) head = next; ++seq; } /* If we have a complete packet, copy it all into one skb. */ if (tail != NULL) { /* If we have discarded any fragments, signal a receive error. */ if (head->sequence != ppp->nextseq) { if (ppp->debug & 1) printk(KERN_DEBUG " missed pkts %u..%u\n", ppp->nextseq, head->sequence-1); ++ppp->stats.rx_dropped; ppp_receive_error(ppp); } if (head != tail) /* copy to a single skb */ for (p = head; p != tail->next; p = p->next) memcpy(skb_put(skb, p->len), p->data, p->len); ppp->nextseq = tail->sequence + 1; head = tail->next; } /* Discard all the skbuffs that we have copied the data out of or that we can't use. */ while ((p = list->next) != head) { __skb_unlink(p, list); kfree_skb(p); } return skb; } #endif /* CONFIG_PPP_MULTILINK */ /* * Channel interface. */ /* * Create a new, unattached ppp channel. */ int ppp_register_channel(struct ppp_channel *chan) { struct channel *pch; pch = kmalloc(sizeof(struct channel), GFP_ATOMIC); if (pch == 0) return -ENOMEM; memset(pch, 0, sizeof(struct channel)); pch->ppp = NULL; pch->chan = chan; chan->ppp = pch; init_ppp_file(&pch->file, CHANNEL); pch->file.hdrlen = chan->hdrlen; #ifdef CONFIG_PPP_MULTILINK pch->lastseq = -1; #endif /* CONFIG_PPP_MULTILINK */ spin_lock_init(&pch->downl); pch->upl = RW_LOCK_UNLOCKED; spin_lock_bh(&all_channels_lock); pch->file.index = ++last_channel_index; list_add(&pch->file.list, &all_channels); spin_unlock_bh(&all_channels_lock); MOD_INC_USE_COUNT; return 0; } /* * Return the index of a channel. */ int ppp_channel_index(struct ppp_channel *chan) { struct channel *pch = chan->ppp; return pch->file.index; } /* * Return the PPP unit number to which a channel is connected. */ int ppp_unit_number(struct ppp_channel *chan) { struct channel *pch = chan->ppp; int unit = -1; if (pch != 0) { read_lock_bh(&pch->upl); if (pch->ppp != 0) unit = pch->ppp->file.index; read_unlock_bh(&pch->upl); } return unit; } /* * Disconnect a channel from the generic layer. * This can be called from mainline or BH/softirq level. */ void ppp_unregister_channel(struct ppp_channel *chan) { struct channel *pch = chan->ppp; if (pch == 0) return; /* should never happen */ chan->ppp = 0; /* * This ensures that we have returned from any calls into the * the channel's start_xmit or ioctl routine before we proceed. */ spin_lock_bh(&pch->downl); pch->chan = 0; spin_unlock_bh(&pch->downl); ppp_disconnect_channel(pch); wake_up_interruptible(&pch->file.rwait); spin_lock_bh(&all_channels_lock); list_del(&pch->file.list); spin_unlock_bh(&all_channels_lock); if (atomic_dec_and_test(&pch->file.refcnt)) ppp_destroy_channel(pch); MOD_DEC_USE_COUNT; } /* * Callback from a channel when it can accept more to transmit. * This should be called at BH/softirq level, not interrupt level. */ void ppp_output_wakeup(struct ppp_channel *chan) { struct channel *pch = chan->ppp; if (pch == 0) return; ppp_channel_push(pch); } /* * This is basically temporary compatibility stuff. */ ssize_t ppp_channel_read(struct ppp_channel *chan, struct file *file, char *buf, size_t count) { struct channel *pch = chan->ppp; if (pch == 0) return -ENXIO; return ppp_file_read(&pch->file, file, buf, count); } ssize_t ppp_channel_write(struct ppp_channel *chan, const char *buf, size_t count) { struct channel *pch = chan->ppp; if (pch == 0) return -ENXIO; return ppp_file_write(&pch->file, buf, count); } /* No kernel lock - fine */ unsigned int ppp_channel_poll(struct ppp_channel *chan, struct file *file, poll_table *wait) { unsigned int mask; struct channel *pch = chan->ppp; mask = POLLOUT | POLLWRNORM; if (pch != 0) { poll_wait(file, &pch->file.rwait, wait); if (skb_peek(&pch->file.rq) != 0) mask |= POLLIN | POLLRDNORM; } return mask; } int ppp_channel_ioctl(struct ppp_channel *chan, unsigned int cmd, unsigned long arg) { struct channel *pch = chan->ppp; int err = -ENOTTY; int unit; if (!capable(CAP_NET_ADMIN)) return -EPERM; if (pch == 0) return -EINVAL; switch (cmd) { case PPPIOCATTACH: if (get_user(unit, (int *) arg)) break; err = ppp_connect_channel(pch, unit); break; case PPPIOCDETACH: err = ppp_disconnect_channel(pch); break; } return err; } /* * Compression control. */ /* Process the PPPIOCSCOMPRESS ioctl. */ static int ppp_set_compress(struct ppp *ppp, unsigned long arg) { int err; struct compressor *cp; struct ppp_option_data data; void *state; unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; #ifdef CONFIG_KMOD char modname[32]; #endif err = -EFAULT; if (copy_from_user(&data, (void *) arg, sizeof(data)) || (data.length <= CCP_MAX_OPTION_LENGTH && copy_from_user(ccp_option, data.ptr, data.length))) goto out; err = -EINVAL; if (data.length > CCP_MAX_OPTION_LENGTH || ccp_option[1] < 2 || ccp_option[1] > data.length) goto out; cp = find_compressor(ccp_option[0]); #ifdef CONFIG_KMOD if (cp == 0) { sprintf(modname, "ppp-compress-%d", ccp_option[0]); request_module(modname); cp = find_compressor(ccp_option[0]); } #endif /* CONFIG_KMOD */ if (cp == 0) goto out; err = -ENOBUFS; if (data.transmit) { ppp_xmit_lock(ppp); ppp->xstate &= ~SC_COMP_RUN; if (ppp->xc_state != 0) { ppp->xcomp->comp_free(ppp->xc_state); ppp->xc_state = 0; } ppp_xmit_unlock(ppp); state = cp->comp_alloc(ccp_option, data.length); if (state != 0) { ppp_xmit_lock(ppp); ppp->xcomp = cp; ppp->xc_state = state; ppp_xmit_unlock(ppp); err = 0; } } else { ppp_recv_lock(ppp); ppp->rstate &= ~SC_DECOMP_RUN; if (ppp->rc_state != 0) { ppp->rcomp->decomp_free(ppp->rc_state); ppp->rc_state = 0; } ppp_recv_unlock(ppp); state = cp->decomp_alloc(ccp_option, data.length); if (state != 0) { ppp_recv_lock(ppp); ppp->rcomp = cp; ppp->rc_state = state; ppp_recv_unlock(ppp); err = 0; } } out: return err; } /* * Look at a CCP packet and update our state accordingly. * We assume the caller has the xmit or recv path locked. */ static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) { unsigned char *dp = skb->data + 2; int len; if (skb->len < CCP_HDRLEN + 2 || skb->len < (len = CCP_LENGTH(dp)) + 2) return; /* too short */ switch (CCP_CODE(dp)) { case CCP_CONFREQ: case CCP_TERMREQ: case CCP_TERMACK: /* * CCP is going down - disable compression. */ if (inbound) ppp->rstate &= ~SC_DECOMP_RUN; else ppp->xstate &= ~SC_COMP_RUN; break; case CCP_CONFACK: if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) break; dp += CCP_HDRLEN; len -= CCP_HDRLEN; if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) break; if (inbound) { /* we will start receiving compressed packets */ if (ppp->rc_state == 0) break; if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, ppp->file.index, 0, ppp->mru, ppp->debug)) { ppp->rstate |= SC_DECOMP_RUN; ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); } } else { /* we will soon start sending compressed packets */ if (ppp->xc_state == 0) break; if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, ppp->file.index, 0, ppp->debug)) ppp->xstate |= SC_COMP_RUN; } break; case CCP_RESETACK: /* reset the [de]compressor */ if ((ppp->flags & SC_CCP_UP) == 0) break; if (inbound) { if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { ppp->rcomp->decomp_reset(ppp->rc_state); ppp->rstate &= ~SC_DC_ERROR; } } else { if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) ppp->xcomp->comp_reset(ppp->xc_state); } break; } } /* Free up compression resources. */ static void ppp_ccp_closed(struct ppp *ppp) { ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); ppp->xstate &= ~SC_COMP_RUN; if (ppp->xc_state) { ppp->xcomp->comp_free(ppp->xc_state); ppp->xc_state = 0; } ppp->xstate &= ~SC_DECOMP_RUN; if (ppp->rc_state) { ppp->rcomp->decomp_free(ppp->rc_state); ppp->rc_state = 0; } } /* List of compressors. */ static LIST_HEAD(compressor_list); static spinlock_t compressor_list_lock = SPIN_LOCK_UNLOCKED; struct compressor_entry { struct list_head list; struct compressor *comp; }; static struct compressor_entry * find_comp_entry(int proto) { struct compressor_entry *ce; struct list_head *list = &compressor_list; while ((list = list->next) != &compressor_list) { ce = list_entry(list, struct compressor_entry, list); if (ce->comp->compress_proto == proto) return ce; } return 0; } /* Register a compressor */ int ppp_register_compressor(struct compressor *cp) { struct compressor_entry *ce; int ret; spin_lock(&compressor_list_lock); ret = -EEXIST; if (find_comp_entry(cp->compress_proto) != 0) goto out; ret = -ENOMEM; ce = kmalloc(sizeof(struct compressor_entry), GFP_KERNEL); if (ce == 0) goto out; ret = 0; ce->comp = cp; list_add(&ce->list, &compressor_list); out: spin_unlock(&compressor_list_lock); return ret; } /* Unregister a compressor */ void ppp_unregister_compressor(struct compressor *cp) { struct compressor_entry *ce; spin_lock(&compressor_list_lock); ce = find_comp_entry(cp->compress_proto); if (ce != 0 && ce->comp == cp) { list_del(&ce->list); kfree(ce); } spin_unlock(&compressor_list_lock); } /* Find a compressor. */ static struct compressor * find_compressor(int type) { struct compressor_entry *ce; struct compressor *cp = 0; spin_lock(&compressor_list_lock); ce = find_comp_entry(type); if (ce != 0) cp = ce->comp; spin_unlock(&compressor_list_lock); return cp; } /* * Miscelleneous stuff. */ static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) { struct slcompress *vj = ppp->vj; memset(st, 0, sizeof(*st)); st->p.ppp_ipackets = ppp->stats.rx_packets; st->p.ppp_ierrors = ppp->stats.rx_errors; st->p.ppp_ibytes = ppp->stats.rx_bytes; st->p.ppp_opackets = ppp->stats.tx_packets; st->p.ppp_oerrors = ppp->stats.tx_errors; st->p.ppp_obytes = ppp->stats.tx_bytes; if (vj == 0) return; st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; st->vj.vjs_compressed = vj->sls_o_compressed; st->vj.vjs_searches = vj->sls_o_searches; st->vj.vjs_misses = vj->sls_o_misses; st->vj.vjs_errorin = vj->sls_i_error; st->vj.vjs_tossed = vj->sls_i_tossed; st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; st->vj.vjs_compressedin = vj->sls_i_compressed; } /* * Stuff for handling the lists of ppp units and channels * and for initialization. */ /* * Create a new ppp interface unit. Fails if it can't allocate memory * or if there is already a unit with the requested number. * unit == -1 means allocate a new number. */ static struct ppp * ppp_create_interface(int unit, int *retp) { struct ppp *ppp; struct net_device *dev; struct list_head *list; int last_unit = -1; int ret = -EEXIST; int i; spin_lock(&all_ppp_lock); list = &all_ppp_units; while ((list = list->next) != &all_ppp_units) { ppp = list_entry(list, struct ppp, file.list); if ((unit < 0 && ppp->file.index > last_unit + 1) || (unit >= 0 && unit < ppp->file.index)) break; if (unit == ppp->file.index) goto out; /* unit already exists */ last_unit = ppp->file.index; } if (unit < 0) unit = last_unit + 1; /* Create a new ppp structure and link it before `list'. */ ret = -ENOMEM; ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL); if (ppp == 0) goto out; memset(ppp, 0, sizeof(struct ppp)); dev = kmalloc(sizeof(struct net_device), GFP_KERNEL); if (dev == 0) { kfree(ppp); goto out; } memset(dev, 0, sizeof(struct net_device)); ppp->file.index = unit; ppp->mru = PPP_MRU; init_ppp_file(&ppp->file, INTERFACE); for (i = 0; i < NUM_NP; ++i) ppp->npmode[i] = NPMODE_PASS; INIT_LIST_HEAD(&ppp->channels); spin_lock_init(&ppp->rlock); spin_lock_init(&ppp->wlock); #ifdef CONFIG_PPP_MULTILINK ppp->minseq = -1; skb_queue_head_init(&ppp->mrq); #endif /* CONFIG_PPP_MULTILINK */ ppp->dev = dev; dev->init = ppp_net_init; sprintf(dev->name, "ppp%d", unit); dev->priv = ppp; dev->new_style = 1; rtnl_lock(); ret = register_netdevice(dev); rtnl_unlock(); if (ret != 0) { printk(KERN_ERR "PPP: couldn't register device (%d)\n", ret); kfree(dev); kfree(ppp); goto out; } list_add(&ppp->file.list, list->prev); out: spin_unlock(&all_ppp_lock); *retp = ret; if (ret != 0) ppp = 0; return ppp; } /* * Initialize a ppp_file structure. */ static void init_ppp_file(struct ppp_file *pf, int kind) { pf->kind = kind; skb_queue_head_init(&pf->xq); skb_queue_head_init(&pf->rq); atomic_set(&pf->refcnt, 1); init_waitqueue_head(&pf->rwait); } /* * Free up all the resources used by a ppp interface unit. */ static void ppp_destroy_interface(struct ppp *ppp) { struct net_device *dev; spin_lock(&all_ppp_lock); list_del(&ppp->file.list); /* Last fd open to this ppp unit is being closed or detached: mark the interface down, free the ppp unit */ ppp_lock(ppp); ppp_ccp_closed(ppp); if (ppp->vj) { slhc_free(ppp->vj); ppp->vj = 0; } skb_queue_purge(&ppp->file.xq); skb_queue_purge(&ppp->file.rq); #ifdef CONFIG_PPP_MULTILINK skb_queue_purge(&ppp->mrq); #endif /* CONFIG_PPP_MULTILINK */ dev = ppp->dev; ppp->dev = 0; ppp_unlock(ppp); if (dev) { rtnl_lock(); dev_close(dev); unregister_netdevice(dev); rtnl_unlock(); } /* * We can't acquire any new channels (since we have the * all_ppp_lock) so if n_channels is 0, we can free the * ppp structure. Otherwise we leave it around until the * last channel disconnects from it. */ if (ppp->n_channels == 0) kfree(ppp); spin_unlock(&all_ppp_lock); } /* * Locate an existing ppp unit. * The caller should have locked the all_ppp_lock. */ static struct ppp * ppp_find_unit(int unit) { struct ppp *ppp; struct list_head *list; list = &all_ppp_units; while ((list = list->next) != &all_ppp_units) { ppp = list_entry(list, struct ppp, file.list); if (ppp->file.index == unit) return ppp; } return 0; } /* * Locate an existing ppp channel. * The caller should have locked the all_channels_lock. */ static struct channel * ppp_find_channel(int unit) { struct channel *pch; struct list_head *list; list = &all_channels; while ((list = list->next) != &all_channels) { pch = list_entry(list, struct channel, file.list); if (pch->file.index == unit) return pch; } return 0; } /* * Connect a PPP channel to a PPP interface unit. */ static int ppp_connect_channel(struct channel *pch, int unit) { struct ppp *ppp; int ret = -ENXIO; int hdrlen; spin_lock(&all_ppp_lock); ppp = ppp_find_unit(unit); if (ppp == 0) goto out; write_lock_bh(&pch->upl); ret = -EINVAL; if (pch->ppp != 0) goto outw; ppp_lock(ppp); spin_lock_bh(&pch->downl); if (pch->chan == 0) /* need to check this?? */ goto outr; if (pch->file.hdrlen > ppp->file.hdrlen) ppp->file.hdrlen = pch->file.hdrlen; hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ if (ppp->dev && hdrlen > ppp->dev->hard_header_len) ppp->dev->hard_header_len = hdrlen; list_add_tail(&pch->clist, &ppp->channels); ++ppp->n_channels; pch->ppp = ppp; ret = 0; outr: spin_unlock_bh(&pch->downl); ppp_unlock(ppp); outw: write_unlock_bh(&pch->upl); out: spin_unlock(&all_ppp_lock); return ret; } /* * Disconnect a channel from its ppp unit. */ static int ppp_disconnect_channel(struct channel *pch) { struct ppp *ppp; int err = -EINVAL; int dead; write_lock_bh(&pch->upl); ppp = pch->ppp; if (ppp != 0) { /* remove it from the ppp unit's list */ pch->ppp = NULL; ppp_lock(ppp); list_del(&pch->clist); --ppp->n_channels; dead = ppp->dev == 0 && ppp->n_channels == 0; ppp_unlock(ppp); if (dead) /* Last disconnect from a ppp unit that is already dead: free it. */ kfree(ppp); err = 0; } write_unlock_bh(&pch->upl); return err; } /* * Free up the resources used by a ppp channel. */ static void ppp_destroy_channel(struct channel *pch) { skb_queue_purge(&pch->file.xq); skb_queue_purge(&pch->file.rq); kfree(pch); } void __exit ppp_cleanup(void) { /* should never happen */ if (!list_empty(&all_ppp_units) || !list_empty(&all_channels)) printk(KERN_ERR "PPP: removing module but units remain!\n"); if (devfs_unregister_chrdev(PPP_MAJOR, "ppp") != 0) printk(KERN_ERR "PPP: failed to unregister PPP device\n"); devfs_unregister(devfs_handle); } module_init(ppp_init); module_exit(ppp_cleanup); EXPORT_SYMBOL(ppp_register_channel); EXPORT_SYMBOL(ppp_unregister_channel); EXPORT_SYMBOL(ppp_channel_index); EXPORT_SYMBOL(ppp_unit_number); EXPORT_SYMBOL(ppp_input); EXPORT_SYMBOL(ppp_input_error); EXPORT_SYMBOL(ppp_output_wakeup); EXPORT_SYMBOL(ppp_register_compressor); EXPORT_SYMBOL(ppp_unregister_compressor); EXPORT_SYMBOL(ppp_channel_read); EXPORT_SYMBOL(ppp_channel_write); EXPORT_SYMBOL(ppp_channel_poll); EXPORT_SYMBOL(ppp_channel_ioctl); EXPORT_SYMBOL(all_ppp_units); /* for debugging */ EXPORT_SYMBOL(all_channels); /* for debugging */