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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/net/ppp_generic.c | |
download | kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/net/ppp_generic.c')
-rw-r--r-- | drivers/net/ppp_generic.c | 2746 |
1 files changed, 2746 insertions, 0 deletions
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c new file mode 100644 index 0000000..c456dc8 --- /dev/null +++ b/drivers/net/ppp_generic.c @@ -0,0 +1,2746 @@ +/* + * Generic PPP layer for Linux. + * + * Copyright 1999-2002 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 20041108== + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/kmod.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/devfs_fs_kernel.h> +#include <linux/netdevice.h> +#include <linux/poll.h> +#include <linux/ppp_defs.h> +#include <linux/filter.h> +#include <linux/if_ppp.h> +#include <linux/ppp_channel.h> +#include <linux/ppp-comp.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <linux/if_arp.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/spinlock.h> +#include <linux/smp_lock.h> +#include <linux/rwsem.h> +#include <linux/stddef.h> +#include <linux/device.h> +#include <net/slhc_vj.h> +#include <asm/atomic.h> + +#define PPP_VERSION "2.4.2" + +/* + * 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 NP_MPLS_UC 4 /* MPLS unicast */ +#define NP_MPLS_MC 5 /* MPLS multicast */ +#define NUM_NP 6 /* 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 */ + int index; /* interface unit / channel number */ + int dead; /* unit/channel has been shut down */ +}; + +#define PF_TO_X(pf, X) ((X *)((char *)(pf) - offsetof(X, 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 0 */ + struct file *owner; /* file that owns this unit 48 */ + struct list_head channels; /* list of attached channels 4c */ + int n_channels; /* how many channels are attached 54 */ + spinlock_t rlock; /* lock for receive side 58 */ + spinlock_t wlock; /* lock for transmit side 5c */ + int mru; /* max receive unit 60 */ + unsigned int flags; /* control bits 64 */ + unsigned int xstate; /* transmit state bits 68 */ + unsigned int rstate; /* receive state bits 6c */ + int debug; /* debug flags 70 */ + struct slcompress *vj; /* state for VJ header compression */ + enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ + struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ + struct compressor *xcomp; /* transmit packet compressor 8c */ + void *xc_state; /* its internal state 90 */ + struct compressor *rcomp; /* receive decompressor 94 */ + void *rc_state; /* its internal state 98 */ + unsigned long last_xmit; /* jiffies when last pkt sent 9c */ + unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ + struct net_device *dev; /* network interface device a4 */ +#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 */ +#ifdef CONFIG_PPP_FILTER + struct sock_filter *pass_filter; /* filter for packets to pass */ + struct sock_filter *active_filter;/* filter for pkts to reset idle */ + unsigned pass_len, active_len; +#endif /* CONFIG_PPP_FILTER */ +}; + +/* + * 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 list_head list; /* link in all/new_channels list */ + struct ppp_channel *chan; /* public channel data structure */ + struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ + 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' */ +#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. + */ + +/* + * A cardmap represents a mapping from unsigned integers to pointers, + * and provides a fast "find lowest unused number" operation. + * It uses a broad (32-way) tree with a bitmap at each level. + * It is designed to be space-efficient for small numbers of entries + * and time-efficient for large numbers of entries. + */ +#define CARDMAP_ORDER 5 +#define CARDMAP_WIDTH (1U << CARDMAP_ORDER) +#define CARDMAP_MASK (CARDMAP_WIDTH - 1) + +struct cardmap { + int shift; + unsigned long inuse; + struct cardmap *parent; + void *ptr[CARDMAP_WIDTH]; +}; +static void *cardmap_get(struct cardmap *map, unsigned int nr); +static void cardmap_set(struct cardmap **map, unsigned int nr, void *ptr); +static unsigned int cardmap_find_first_free(struct cardmap *map); +static void cardmap_destroy(struct cardmap **map); + +/* + * all_ppp_sem protects the all_ppp_units mapping. + * It also ensures that finding a ppp unit in the all_ppp_units map + * and updating its file.refcnt field is atomic. + */ +static DECLARE_MUTEX(all_ppp_sem); +static struct cardmap *all_ppp_units; +static atomic_t ppp_unit_count = ATOMIC_INIT(0); + +/* + * all_channels_lock protects all_channels and last_channel_index, + * and the atomicity of find a channel and updating its file.refcnt + * field. + */ +static DEFINE_SPINLOCK(all_channels_lock); +static LIST_HEAD(all_channels); +static LIST_HEAD(new_channels); +static int last_channel_index; +static atomic_t channel_count = ATOMIC_INIT(0); + +/* 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 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_shutdown_interface(struct ppp *ppp); +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); + +static struct class_simple *ppp_class; + +/* 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; + case PPP_MPLS_UC: + return NP_MPLS_UC; + case PPP_MPLS_MC: + return NP_MPLS_MC; + } + 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, + PPP_MPLS_UC, + PPP_MPLS_MC, +}; + +/* 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; + case ETH_P_MPLS_UC: + return NP_MPLS_UC; + case ETH_P_MPLS_MC: + return NP_MPLS_MC; + } + 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, + ETH_P_MPLS_UC, + ETH_P_MPLS_MC, +}; + +/* + * 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; + return 0; +} + +static int ppp_release(struct inode *inode, struct file *file) +{ + struct ppp_file *pf = file->private_data; + struct ppp *ppp; + + if (pf != 0) { + file->private_data = NULL; + if (pf->kind == INTERFACE) { + ppp = PF_TO_PPP(pf); + if (file == ppp->owner) + ppp_shutdown_interface(ppp); + } + 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; + } + } + } + return 0; +} + +static ssize_t ppp_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct ppp_file *pf = file->private_data; + DECLARE_WAITQUEUE(wait, current); + ssize_t ret; + struct sk_buff *skb = NULL; + + ret = count; + + if (pf == 0) + return -ENXIO; + add_wait_queue(&pf->rwait, &wait); + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + skb = skb_dequeue(&pf->rq); + if (skb) + break; + ret = 0; + if (pf->dead) + break; + if (pf->kind == INTERFACE) { + /* + * Return 0 (EOF) on an interface that has no + * channels connected, unless it is looping + * network traffic (demand mode). + */ + struct ppp *ppp = PF_TO_PPP(pf); + if (ppp->n_channels == 0 + && (ppp->flags & SC_LOOP_TRAFFIC) == 0) + break; + } + ret = -EAGAIN; + if (file->f_flags & O_NONBLOCK) + break; + ret = -ERESTARTSYS; + if (signal_pending(current)) + break; + schedule(); + } + set_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 __user *buf, + size_t count, loff_t *ppos) +{ + struct ppp_file *pf = file->private_data; + struct sk_buff *skb; + ssize_t ret; + + if (pf == 0) + return -ENXIO; + 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 = 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->dead) + mask |= POLLHUP; + else if (pf->kind == INTERFACE) { + /* see comment in ppp_read */ + struct ppp *ppp = PF_TO_PPP(pf); + if (ppp->n_channels == 0 + && (ppp->flags & SC_LOOP_TRAFFIC) == 0) + mask |= POLLIN | POLLRDNORM; + } + + return mask; +} + +#ifdef CONFIG_PPP_FILTER +static int get_filter(void __user *arg, struct sock_filter **p) +{ + struct sock_fprog uprog; + struct sock_filter *code = NULL; + int len, err; + + if (copy_from_user(&uprog, arg, sizeof(uprog))) + return -EFAULT; + + if (uprog.len > BPF_MAXINSNS) + return -EINVAL; + + if (!uprog.len) { + *p = NULL; + return 0; + } + + len = uprog.len * sizeof(struct sock_filter); + code = kmalloc(len, GFP_KERNEL); + if (code == NULL) + return -ENOMEM; + + if (copy_from_user(code, uprog.filter, len)) { + kfree(code); + return -EFAULT; + } + + err = sk_chk_filter(code, uprog.len); + if (err) { + kfree(code); + return err; + } + + *p = code; + return uprog.len; +} +#endif /* CONFIG_PPP_FILTER */ + +static int ppp_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct ppp_file *pf = file->private_data; + struct ppp *ppp; + int err = -EFAULT, val, val2, i; + struct ppp_idle idle; + struct npioctl npi; + int unit, cflags; + struct slcompress *vj; + void __user *argp = (void __user *)arg; + int __user *p = argp; + + if (pf == 0) + return ppp_unattached_ioctl(pf, file, cmd, arg); + + if (cmd == PPPIOCDETACH) { + /* + * We have to be careful here... if the file descriptor + * has been dup'd, we could have another process in the + * middle of a poll using the same file *, so we had + * better not free the interface data structures - + * instead we fail the ioctl. Even in this case, we + * shut down the interface if we are the owner of it. + * Actually, we should get rid of PPPIOCDETACH, userland + * (i.e. pppd) could achieve the same effect by closing + * this fd and reopening /dev/ppp. + */ + err = -EINVAL; + if (pf->kind == INTERFACE) { + ppp = PF_TO_PPP(pf); + if (file == ppp->owner) + ppp_shutdown_interface(ppp); + } + if (atomic_read(&file->f_count) <= 2) { + ppp_release(inode, file); + err = 0; + } else + printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n", + atomic_read(&file->f_count)); + return err; + } + + if (pf->kind == CHANNEL) { + struct channel *pch = PF_TO_CHANNEL(pf); + struct ppp_channel *chan; + + switch (cmd) { + case PPPIOCCONNECT: + if (get_user(unit, p)) + break; + err = ppp_connect_channel(pch, unit); + break; + + case PPPIOCDISCONN: + err = ppp_disconnect_channel(pch); + break; + + default: + down_read(&pch->chan_sem); + chan = pch->chan; + err = -ENOTTY; + if (chan && chan->ops->ioctl) + err = chan->ops->ioctl(chan, cmd, arg); + up_read(&pch->chan_sem); + } + 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 PPPIOCSMRU: + if (get_user(val, p)) + break; + ppp->mru = val; + err = 0; + break; + + case PPPIOCSFLAGS: + if (get_user(val, p)) + break; + ppp_lock(ppp); + cflags = ppp->flags & ~val; + ppp->flags = val & SC_FLAG_BITS; + ppp_unlock(ppp); + if (cflags & SC_CCP_OPEN) + ppp_ccp_closed(ppp); + err = 0; + break; + + case PPPIOCGFLAGS: + val = ppp->flags | ppp->xstate | ppp->rstate; + if (put_user(val, p)) + break; + err = 0; + break; + + case PPPIOCSCOMPRESS: + err = ppp_set_compress(ppp, arg); + break; + + case PPPIOCGUNIT: + if (put_user(ppp->file.index, p)) + break; + err = 0; + break; + + case PPPIOCSDEBUG: + if (get_user(val, p)) + break; + ppp->debug = val; + err = 0; + break; + + case PPPIOCGDEBUG: + if (put_user(ppp->debug, p)) + 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(argp, &idle, sizeof(idle))) + break; + err = 0; + break; + + case PPPIOCSMAXCID: + if (get_user(val, p)) + 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, argp, 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(argp, &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_FILTER + case PPPIOCSPASS: + { + struct sock_filter *code; + err = get_filter(argp, &code); + if (err >= 0) { + ppp_lock(ppp); + kfree(ppp->pass_filter); + ppp->pass_filter = code; + ppp->pass_len = err; + ppp_unlock(ppp); + err = 0; + } + break; + } + case PPPIOCSACTIVE: + { + struct sock_filter *code; + err = get_filter(argp, &code); + if (err >= 0) { + ppp_lock(ppp); + kfree(ppp->active_filter); + ppp->active_filter = code; + ppp->active_len = err; + ppp_unlock(ppp); + err = 0; + } + break; + } +#endif /* CONFIG_PPP_FILTER */ + +#ifdef CONFIG_PPP_MULTILINK + case PPPIOCSMRRU: + if (get_user(val, p)) + 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; + int __user *p = (int __user *)arg; + + switch (cmd) { + case PPPIOCNEWUNIT: + /* Create a new ppp unit */ + if (get_user(unit, p)) + break; + ppp = ppp_create_interface(unit, &err); + if (ppp == 0) + break; + file->private_data = &ppp->file; + ppp->owner = file; + err = -EFAULT; + if (put_user(ppp->file.index, p)) + break; + err = 0; + break; + + case PPPIOCATTACH: + /* Attach to an existing ppp unit */ + if (get_user(unit, p)) + break; + down(&all_ppp_sem); + err = -ENXIO; + ppp = ppp_find_unit(unit); + if (ppp != 0) { + atomic_inc(&ppp->file.refcnt); + file->private_data = &ppp->file; + err = 0; + } + up(&all_ppp_sem); + break; + + case PPPIOCATTCHAN: + if (get_user(unit, p)) + break; + spin_lock_bh(&all_channels_lock); + err = -ENXIO; + chan = ppp_find_channel(unit); + if (chan != 0) { + atomic_inc(&chan->file.refcnt); + file->private_data = &chan->file; + err = 0; + } + spin_unlock_bh(&all_channels_lock); + break; + + default: + err = -ENOTTY; + } + return err; +} + +static struct file_operations ppp_device_fops = { + .owner = THIS_MODULE, + .read = ppp_read, + .write = ppp_write, + .poll = ppp_poll, + .ioctl = ppp_ioctl, + .open = ppp_open, + .release = ppp_release +}; + +#define PPP_MAJOR 108 + +/* Called at boot time if ppp is compiled into the kernel, + or at module load time (from init_module) if compiled as a module. */ +static int __init ppp_init(void) +{ + int err; + + printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n"); + err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); + if (!err) { + ppp_class = class_simple_create(THIS_MODULE, "ppp"); + if (IS_ERR(ppp_class)) { + err = PTR_ERR(ppp_class); + goto out_chrdev; + } + class_simple_device_add(ppp_class, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); + err = devfs_mk_cdev(MKDEV(PPP_MAJOR, 0), + S_IFCHR|S_IRUSR|S_IWUSR, "ppp"); + if (err) + goto out_class; + } + +out: + if (err) + printk(KERN_ERR "failed to register PPP device (%d)\n", err); + return err; + +out_class: + class_simple_device_remove(MKDEV(PPP_MAJOR,0)); + class_simple_destroy(ppp_class); +out_chrdev: + unregister_chrdev(PPP_MAJOR, "ppp"); + goto out; +} + +/* + * 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); + skb_copy_bits(skb, 0, skb_put(ns, skb->len), 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 __user *addr = (void __user *) 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; +} + +static void ppp_setup(struct net_device *dev) +{ + dev->hard_header_len = PPP_HDRLEN; + dev->mtu = PPP_MTU; + dev->addr_len = 0; + dev->tx_queue_len = 3; + dev->type = ARPHRD_PPP; + dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; +} + +/* + * 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); + if (ppp->dev != 0) { + 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) + 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; + + if (proto < 0x8000) { +#ifdef CONFIG_PPP_FILTER + /* check if we should pass this packet */ + /* the filter instructions are constructed assuming + a four-byte PPP header on each packet */ + *skb_push(skb, 2) = 1; + if (ppp->pass_filter + && sk_run_filter(skb, ppp->pass_filter, + ppp->pass_len) == 0) { + if (ppp->debug & 1) + printk(KERN_DEBUG "PPP: outbound frame not passed\n"); + kfree_skb(skb); + return; + } + /* if this packet passes the active filter, record the time */ + if (!(ppp->active_filter + && sk_run_filter(skb, ppp->active_filter, + ppp->active_len) == 0)) + ppp->last_xmit = jiffies; + skb_pull(skb, 2); +#else + /* for data packets, record the time */ + ppp->last_xmit = jiffies; +#endif /* CONFIG_PPP_FILTER */ + } + + ++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); + } + } + + /* + * 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 = NULL; + 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 = NULL; + } else { + /* channel got unregistered */ + kfree_skb(skb); + ppp->xmit_pending = NULL; + } + 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 = NULL; + 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); + skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); + kfree_skb(skb); + skb = ns; + } + else if (!pskb_may_pull(skb, skb->len)) + goto err; + + 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; + + /* Until we fix the decompressor need to make sure + * data portion is linear. + */ + if (!pskb_may_pull(skb, skb->len)) + 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 */ + +#ifdef CONFIG_PPP_FILTER + /* check if the packet passes the pass and active filters */ + /* the filter instructions are constructed assuming + a four-byte PPP header on each packet */ + *skb_push(skb, 2) = 0; + if (ppp->pass_filter + && sk_run_filter(skb, ppp->pass_filter, + ppp->pass_len) == 0) { + if (ppp->debug & 1) + printk(KERN_DEBUG "PPP: inbound frame not passed\n"); + kfree_skb(skb); + return; + } + if (!(ppp->active_filter + && sk_run_filter(skb, ppp->active_filter, + ppp->active_len) == 0)) + ppp->last_recv = jiffies; + skb_pull(skb, 2); +#else + ppp->last_recv = jiffies; +#endif /* CONFIG_PPP_FILTER */ + + 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; + skb->input_dev = ppp->dev; + netif_rx(skb); + ppp->dev->last_rx = jiffies; + } + } + 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; + + /* Until we fix all the decompressor's need to make sure + * data portion is linear. + */ + if (!pskb_may_pull(skb, skb->len)) + goto err; + + 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; + kfree_skb(ns); + 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 (!pskb_may_pull(skb, 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) + skb_copy_bits(p, 0, skb_put(skb, p->len), 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_KERNEL); + 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 */ + init_rwsem(&pch->chan_sem); + spin_lock_init(&pch->downl); + rwlock_init(&pch->upl); + spin_lock_bh(&all_channels_lock); + pch->file.index = ++last_channel_index; + list_add(&pch->list, &new_channels); + atomic_inc(&channel_count); + spin_unlock_bh(&all_channels_lock); + return 0; +} + +/* + * Return the index of a channel. + */ +int ppp_channel_index(struct ppp_channel *chan) +{ + struct channel *pch = chan->ppp; + + if (pch != 0) + return pch->file.index; + return -1; +} + +/* + * 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 must be called in process context. + */ +void +ppp_unregister_channel(struct ppp_channel *chan) +{ + struct channel *pch = chan->ppp; + + if (pch == 0) + return; /* should never happen */ + chan->ppp = NULL; + + /* + * This ensures that we have returned from any calls into the + * the channel's start_xmit or ioctl routine before we proceed. + */ + down_write(&pch->chan_sem); + spin_lock_bh(&pch->downl); + pch->chan = NULL; + spin_unlock_bh(&pch->downl); + up_write(&pch->chan_sem); + ppp_disconnect_channel(pch); + spin_lock_bh(&all_channels_lock); + list_del(&pch->list); + spin_unlock_bh(&all_channels_lock); + pch->file.dead = 1; + wake_up_interruptible(&pch->file.rwait); + if (atomic_dec_and_test(&pch->file.refcnt)) + ppp_destroy_channel(pch); +} + +/* + * 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); +} + +/* + * Compression control. + */ + +/* Process the PPPIOCSCOMPRESS ioctl. */ +static int +ppp_set_compress(struct ppp *ppp, unsigned long arg) +{ + int err; + struct compressor *cp, *ocomp; + struct ppp_option_data data; + void *state, *ostate; + unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; + + err = -EFAULT; + if (copy_from_user(&data, (void __user *) arg, sizeof(data)) + || (data.length <= CCP_MAX_OPTION_LENGTH + && copy_from_user(ccp_option, (void __user *) 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) { + request_module("ppp-compress-%d", ccp_option[0]); + cp = find_compressor(ccp_option[0]); + } +#endif /* CONFIG_KMOD */ + if (cp == 0) + goto out; + + err = -ENOBUFS; + if (data.transmit) { + state = cp->comp_alloc(ccp_option, data.length); + if (state != 0) { + ppp_xmit_lock(ppp); + ppp->xstate &= ~SC_COMP_RUN; + ocomp = ppp->xcomp; + ostate = ppp->xc_state; + ppp->xcomp = cp; + ppp->xc_state = state; + ppp_xmit_unlock(ppp); + if (ostate != 0) { + ocomp->comp_free(ostate); + module_put(ocomp->owner); + } + err = 0; + } else + module_put(cp->owner); + + } else { + state = cp->decomp_alloc(ccp_option, data.length); + if (state != 0) { + ppp_recv_lock(ppp); + ppp->rstate &= ~SC_DECOMP_RUN; + ocomp = ppp->rcomp; + ostate = ppp->rc_state; + ppp->rcomp = cp; + ppp->rc_state = state; + ppp_recv_unlock(ppp); + if (ostate != 0) { + ocomp->decomp_free(ostate); + module_put(ocomp->owner); + } + err = 0; + } else + module_put(cp->owner); + } + + 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; + int len; + + if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) + return; /* no header */ + dp = skb->data + 2; + + switch (CCP_CODE(dp)) { + case CCP_CONFREQ: + + /* A ConfReq starts negotiation of compression + * in one direction of transmission, + * and hence brings it down...but which way? + * + * Remember: + * A ConfReq indicates what the sender would like to receive + */ + if(inbound) + /* He is proposing what I should send */ + ppp->xstate &= ~SC_COMP_RUN; + else + /* I am proposing to what he should send */ + ppp->rstate &= ~SC_DECOMP_RUN; + + break; + + case CCP_TERMREQ: + case CCP_TERMACK: + /* + * CCP is going down, both directions of transmission + */ + ppp->rstate &= ~SC_DECOMP_RUN; + ppp->xstate &= ~SC_COMP_RUN; + break; + + case CCP_CONFACK: + if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) + break; + len = CCP_LENGTH(dp); + if (!pskb_may_pull(skb, len + 2)) + return; /* too short */ + 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) +{ + void *xstate, *rstate; + struct compressor *xcomp, *rcomp; + + ppp_lock(ppp); + ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); + ppp->xstate = 0; + xcomp = ppp->xcomp; + xstate = ppp->xc_state; + ppp->xc_state = NULL; + ppp->rstate = 0; + rcomp = ppp->rcomp; + rstate = ppp->rc_state; + ppp->rc_state = NULL; + ppp_unlock(ppp); + + if (xstate) { + xcomp->comp_free(xstate); + module_put(xcomp->owner); + } + if (rstate) { + rcomp->decomp_free(rstate); + module_put(rcomp->owner); + } +} + +/* List of compressors. */ +static LIST_HEAD(compressor_list); +static DEFINE_SPINLOCK(compressor_list_lock); + +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 NULL; +} + +/* 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_ATOMIC); + 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 = NULL; + + spin_lock(&compressor_list_lock); + ce = find_comp_entry(type); + if (ce != 0) { + cp = ce->comp; + if (!try_module_get(cp->owner)) + cp = NULL; + } + 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 = NULL; + int ret = -ENOMEM; + int i; + + ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL); + if (!ppp) + goto out; + dev = alloc_netdev(0, "", ppp_setup); + if (!dev) + goto out1; + memset(ppp, 0, sizeof(struct ppp)); + + ppp->mru = PPP_MRU; + init_ppp_file(&ppp->file, INTERFACE); + ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ + 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->priv = ppp; + + dev->hard_start_xmit = ppp_start_xmit; + dev->get_stats = ppp_net_stats; + dev->do_ioctl = ppp_net_ioctl; + + ret = -EEXIST; + down(&all_ppp_sem); + if (unit < 0) + unit = cardmap_find_first_free(all_ppp_units); + else if (cardmap_get(all_ppp_units, unit) != NULL) + goto out2; /* unit already exists */ + + /* Initialize the new ppp unit */ + ppp->file.index = unit; + sprintf(dev->name, "ppp%d", unit); + + ret = register_netdev(dev); + if (ret != 0) { + printk(KERN_ERR "PPP: couldn't register device %s (%d)\n", + dev->name, ret); + goto out2; + } + + atomic_inc(&ppp_unit_count); + cardmap_set(&all_ppp_units, unit, ppp); + up(&all_ppp_sem); + *retp = 0; + return ppp; + +out2: + up(&all_ppp_sem); + free_netdev(dev); +out1: + kfree(ppp); +out: + *retp = ret; + return NULL; +} + +/* + * 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); +} + +/* + * Take down a ppp interface unit - called when the owning file + * (the one that created the unit) is closed or detached. + */ +static void ppp_shutdown_interface(struct ppp *ppp) +{ + struct net_device *dev; + + down(&all_ppp_sem); + ppp_lock(ppp); + dev = ppp->dev; + ppp->dev = NULL; + ppp_unlock(ppp); + /* This will call dev_close() for us. */ + if (dev) { + unregister_netdev(dev); + free_netdev(dev); + } + cardmap_set(&all_ppp_units, ppp->file.index, NULL); + ppp->file.dead = 1; + ppp->owner = NULL; + wake_up_interruptible(&ppp->file.rwait); + up(&all_ppp_sem); +} + +/* + * Free the memory used by a ppp unit. This is only called once + * there are no channels connected to the unit and no file structs + * that reference the unit. + */ +static void ppp_destroy_interface(struct ppp *ppp) +{ + atomic_dec(&ppp_unit_count); + + if (!ppp->file.dead || ppp->n_channels) { + /* "can't happen" */ + printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d " + "n_channels=%d !\n", ppp, ppp->file.dead, + ppp->n_channels); + return; + } + + ppp_ccp_closed(ppp); + if (ppp->vj) { + slhc_free(ppp->vj); + ppp->vj = NULL; + } + 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 */ +#ifdef CONFIG_PPP_FILTER + if (ppp->pass_filter) { + kfree(ppp->pass_filter); + ppp->pass_filter = NULL; + } + if (ppp->active_filter) { + kfree(ppp->active_filter); + ppp->active_filter = NULL; + } +#endif /* CONFIG_PPP_FILTER */ + + kfree(ppp); +} + +/* + * Locate an existing ppp unit. + * The caller should have locked the all_ppp_sem. + */ +static struct ppp * +ppp_find_unit(int unit) +{ + return cardmap_get(all_ppp_units, unit); +} + +/* + * Locate an existing ppp channel. + * The caller should have locked the all_channels_lock. + * First we look in the new_channels list, then in the + * all_channels list. If found in the new_channels list, + * we move it to the all_channels list. This is for speed + * when we have a lot of channels in use. + */ +static struct channel * +ppp_find_channel(int unit) +{ + struct channel *pch; + struct list_head *list; + + list = &new_channels; + while ((list = list->next) != &new_channels) { + pch = list_entry(list, struct channel, list); + if (pch->file.index == unit) { + list_del(&pch->list); + list_add(&pch->list, &all_channels); + return pch; + } + } + list = &all_channels; + while ((list = list->next) != &all_channels) { + pch = list_entry(list, struct channel, list); + if (pch->file.index == unit) + return pch; + } + return NULL; +} + +/* + * 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; + + down(&all_ppp_sem); + ppp = ppp_find_unit(unit); + if (ppp == 0) + goto out; + write_lock_bh(&pch->upl); + ret = -EINVAL; + if (pch->ppp != 0) + goto outl; + + ppp_lock(ppp); + 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; + atomic_inc(&ppp->file.refcnt); + ppp_unlock(ppp); + ret = 0; + + outl: + write_unlock_bh(&pch->upl); + out: + up(&all_ppp_sem); + return ret; +} + +/* + * Disconnect a channel from its ppp unit. + */ +static int +ppp_disconnect_channel(struct channel *pch) +{ + struct ppp *ppp; + int err = -EINVAL; + + write_lock_bh(&pch->upl); + ppp = pch->ppp; + pch->ppp = NULL; + write_unlock_bh(&pch->upl); + if (ppp != 0) { + /* remove it from the ppp unit's list */ + ppp_lock(ppp); + list_del(&pch->clist); + if (--ppp->n_channels == 0) + wake_up_interruptible(&ppp->file.rwait); + ppp_unlock(ppp); + if (atomic_dec_and_test(&ppp->file.refcnt)) + ppp_destroy_interface(ppp); + err = 0; + } + return err; +} + +/* + * Free up the resources used by a ppp channel. + */ +static void ppp_destroy_channel(struct channel *pch) +{ + atomic_dec(&channel_count); + + if (!pch->file.dead) { + /* "can't happen" */ + printk(KERN_ERR "ppp: destroying undead channel %p !\n", + pch); + return; + } + skb_queue_purge(&pch->file.xq); + skb_queue_purge(&pch->file.rq); + kfree(pch); +} + +static void __exit ppp_cleanup(void) +{ + /* should never happen */ + if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) + printk(KERN_ERR "PPP: removing module but units remain!\n"); + cardmap_destroy(&all_ppp_units); + if (unregister_chrdev(PPP_MAJOR, "ppp") != 0) + printk(KERN_ERR "PPP: failed to unregister PPP device\n"); + devfs_remove("ppp"); + class_simple_device_remove(MKDEV(PPP_MAJOR, 0)); + class_simple_destroy(ppp_class); +} + +/* + * Cardmap implementation. + */ +static void *cardmap_get(struct cardmap *map, unsigned int nr) +{ + struct cardmap *p; + int i; + + for (p = map; p != NULL; ) { + if ((i = nr >> p->shift) >= CARDMAP_WIDTH) + return NULL; + if (p->shift == 0) + return p->ptr[i]; + nr &= ~(CARDMAP_MASK << p->shift); + p = p->ptr[i]; + } + return NULL; +} + +static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr) +{ + struct cardmap *p; + int i; + + p = *pmap; + if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) { + do { + /* need a new top level */ + struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL); + memset(np, 0, sizeof(*np)); + np->ptr[0] = p; + if (p != NULL) { + np->shift = p->shift + CARDMAP_ORDER; + p->parent = np; + } else + np->shift = 0; + p = np; + } while ((nr >> p->shift) >= CARDMAP_WIDTH); + *pmap = p; + } + while (p->shift > 0) { + i = (nr >> p->shift) & CARDMAP_MASK; + if (p->ptr[i] == NULL) { + struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL); + memset(np, 0, sizeof(*np)); + np->shift = p->shift - CARDMAP_ORDER; + np->parent = p; + p->ptr[i] = np; + } + if (ptr == NULL) + clear_bit(i, &p->inuse); + p = p->ptr[i]; + } + i = nr & CARDMAP_MASK; + p->ptr[i] = ptr; + if (ptr != NULL) + set_bit(i, &p->inuse); + else + clear_bit(i, &p->inuse); +} + +static unsigned int cardmap_find_first_free(struct cardmap *map) +{ + struct cardmap *p; + unsigned int nr = 0; + int i; + + if ((p = map) == NULL) + return 0; + for (;;) { + i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH); + if (i >= CARDMAP_WIDTH) { + if (p->parent == NULL) + return CARDMAP_WIDTH << p->shift; + p = p->parent; + i = (nr >> p->shift) & CARDMAP_MASK; + set_bit(i, &p->inuse); + continue; + } + nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift); + if (p->shift == 0 || p->ptr[i] == NULL) + return nr; + p = p->ptr[i]; + } +} + +static void cardmap_destroy(struct cardmap **pmap) +{ + struct cardmap *p, *np; + int i; + + for (p = *pmap; p != NULL; p = np) { + if (p->shift != 0) { + for (i = 0; i < CARDMAP_WIDTH; ++i) + if (p->ptr[i] != NULL) + break; + if (i < CARDMAP_WIDTH) { + np = p->ptr[i]; + p->ptr[i] = NULL; + continue; + } + } + np = p->parent; + kfree(p); + } + *pmap = NULL; +} + +/* Module/initialization stuff */ + +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); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR); +MODULE_ALIAS("/dev/ppp"); |