diff options
Diffstat (limited to 'drivers/net/ppp/ppp_generic.c')
| -rw-r--r-- | drivers/net/ppp/ppp_generic.c | 3435 |
1 files changed, 3435 insertions, 0 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c new file mode 100644 index 000000000..b825c6a9b --- /dev/null +++ b/drivers/net/ppp/ppp_generic.c @@ -0,0 +1,3435 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Generic PPP layer for Linux. + * + * Copyright 1999-2002 Paul Mackerras. + * + * 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/module.h> +#include <linux/kernel.h> +#include <linux/sched/signal.h> +#include <linux/kmod.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/idr.h> +#include <linux/netdevice.h> +#include <linux/poll.h> +#include <linux/ppp_defs.h> +#include <linux/filter.h> +#include <linux/ppp-ioctl.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/rwsem.h> +#include <linux/stddef.h> +#include <linux/device.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/file.h> +#include <asm/unaligned.h> +#include <net/slhc_vj.h> +#include <linux/atomic.h> +#include <linux/refcount.h> + +#include <linux/nsproxy.h> +#include <net/net_namespace.h> +#include <net/netns/generic.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 PPP_PROTO_LEN 2 + +/* + * 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 */ + refcount_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) container_of(pf, X, file) + +#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) +#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) + +/* + * Data structure to hold primary network stats for which + * we want to use 64 bit storage. Other network stats + * are stored in dev->stats of the ppp strucute. + */ +struct ppp_link_stats { + u64 rx_packets; + u64 tx_packets; + u64 rx_bytes; + u64 tx_bytes; +}; + +/* + * 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 __percpu *xmit_recursion; /* xmit recursion detect */ + 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 */ + int closing; /* is device closing down? a8 */ +#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 */ +#ifdef CONFIG_PPP_FILTER + struct bpf_prog *pass_filter; /* filter for packets to pass */ + struct bpf_prog *active_filter; /* filter for pkts to reset idle */ +#endif /* CONFIG_PPP_FILTER */ + struct net *ppp_net; /* the net we belong to */ + struct ppp_link_stats stats64; /* 64 bit network stats */ +}; + +/* + * 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, + * SC_MUST_COMP + * 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|SC_MUST_COMP) + +/* + * 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 net *chan_net; /* the net channel belongs 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 */ + int speed; /* speed of the corresponding ppp channel*/ +#endif /* CONFIG_PPP_MULTILINK */ +}; + +struct ppp_config { + struct file *file; + s32 unit; + bool ifname_is_set; +}; + +/* + * 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. + */ + +static DEFINE_MUTEX(ppp_mutex); +static atomic_t ppp_unit_count = ATOMIC_INIT(0); +static atomic_t channel_count = ATOMIC_INIT(0); + +/* per-net private data for this module */ +static unsigned int ppp_net_id __read_mostly; +struct ppp_net { + /* units to ppp mapping */ + struct idr units_idr; + + /* + * all_ppp_mutex protects the units_idr mapping. + * It also ensures that finding a ppp unit in the units_idr + * map and updating its file.refcnt field is atomic. + */ + struct mutex all_ppp_mutex; + + /* channels */ + struct list_head all_channels; + struct list_head new_channels; + int last_channel_index; + + /* + * all_channels_lock protects all_channels and + * last_channel_index, and the atomicity of find + * a channel and updating its file.refcnt field. + */ + spinlock_t all_channels_lock; +}; + +/* Get the PPP protocol number from a skb */ +#define PPP_PROTO(skb) get_unaligned_be16((skb)->data) + +/* 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 net *net, struct ppp_file *pf, + struct file *file, unsigned int cmd, unsigned long arg); +static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); +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, struct ppp_option_data *data); +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 int ppp_create_interface(struct net *net, struct file *file, int *unit); +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(struct ppp_net *pn, int unit); +static struct channel *ppp_find_channel(struct ppp_net *pn, 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 int unit_get(struct idr *p, void *ptr, int min); +static int unit_set(struct idr *p, void *ptr, int n); +static void unit_put(struct idr *p, int n); +static void *unit_find(struct idr *p, int n); +static void ppp_setup(struct net_device *dev); + +static const struct net_device_ops ppp_netdev_ops; + +static struct class *ppp_class; + +/* per net-namespace data */ +static inline struct ppp_net *ppp_pernet(struct net *net) +{ + return net_generic(net, ppp_net_id); +} + +/* 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 (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) + return -EPERM; + return 0; +} + +static int ppp_release(struct inode *unused, struct file *file) +{ + struct ppp_file *pf = file->private_data; + struct ppp *ppp; + + if (pf) { + file->private_data = NULL; + if (pf->kind == INTERFACE) { + ppp = PF_TO_PPP(pf); + rtnl_lock(); + if (file == ppp->owner) + unregister_netdevice(ppp->dev); + rtnl_unlock(); + } + if (refcount_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; + struct iovec iov; + struct iov_iter to; + + ret = count; + + if (!pf) + 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); + + ppp_recv_lock(ppp); + if (ppp->n_channels == 0 && + (ppp->flags & SC_LOOP_TRAFFIC) == 0) { + ppp_recv_unlock(ppp); + break; + } + ppp_recv_unlock(ppp); + } + 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) + goto out; + + ret = -EOVERFLOW; + if (skb->len > count) + goto outf; + ret = -EFAULT; + iov.iov_base = buf; + iov.iov_len = count; + iov_iter_init(&to, READ, &iov, 1, count); + if (skb_copy_datagram_iter(skb, 0, &to, 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) + return -ENXIO; + /* All PPP packets should start with the 2-byte protocol */ + if (count < PPP_PROTO_LEN) + return -EINVAL; + ret = -ENOMEM; + skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); + if (!skb) + goto out; + skb_reserve(skb, pf->hdrlen); + ret = -EFAULT; + if (copy_from_user(skb_put(skb, count), buf, count)) { + kfree_skb(skb); + goto out; + } + + switch (pf->kind) { + case INTERFACE: + ppp_xmit_process(PF_TO_PPP(pf), skb); + break; + case CHANNEL: + skb_queue_tail(&pf->xq, skb); + ppp_channel_push(PF_TO_CHANNEL(pf)); + break; + } + + ret = count; + + out: + return ret; +} + +/* No kernel lock - fine */ +static __poll_t ppp_poll(struct file *file, poll_table *wait) +{ + struct ppp_file *pf = file->private_data; + __poll_t mask; + + if (!pf) + return 0; + poll_wait(file, &pf->rwait, wait); + mask = EPOLLOUT | EPOLLWRNORM; + if (skb_peek(&pf->rq)) + mask |= EPOLLIN | EPOLLRDNORM; + if (pf->dead) + mask |= EPOLLHUP; + else if (pf->kind == INTERFACE) { + /* see comment in ppp_read */ + struct ppp *ppp = PF_TO_PPP(pf); + + ppp_recv_lock(ppp); + if (ppp->n_channels == 0 && + (ppp->flags & SC_LOOP_TRAFFIC) == 0) + mask |= EPOLLIN | EPOLLRDNORM; + ppp_recv_unlock(ppp); + } + + return mask; +} + +#ifdef CONFIG_PPP_FILTER +static struct bpf_prog *get_filter(struct sock_fprog *uprog) +{ + struct sock_fprog_kern fprog; + struct bpf_prog *res = NULL; + int err; + + if (!uprog->len) + return NULL; + + /* uprog->len is unsigned short, so no overflow here */ + fprog.len = uprog->len; + fprog.filter = memdup_user(uprog->filter, + uprog->len * sizeof(struct sock_filter)); + if (IS_ERR(fprog.filter)) + return ERR_CAST(fprog.filter); + + err = bpf_prog_create(&res, &fprog); + kfree(fprog.filter); + + return err ? ERR_PTR(err) : res; +} + +static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p) +{ + struct sock_fprog uprog; + + if (copy_from_user(&uprog, p, sizeof(struct sock_fprog))) + return ERR_PTR(-EFAULT); + return get_filter(&uprog); +} + +#ifdef CONFIG_COMPAT +struct sock_fprog32 { + unsigned short len; + compat_caddr_t filter; +}; + +#define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32) +#define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32) + +static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p) +{ + struct sock_fprog32 uprog32; + struct sock_fprog uprog; + + if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32))) + return ERR_PTR(-EFAULT); + uprog.len = uprog32.len; + uprog.filter = compat_ptr(uprog32.filter); + return get_filter(&uprog); +} +#endif +#endif + +static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ppp_file *pf; + struct ppp *ppp; + int err = -EFAULT, val, val2, i; + struct ppp_idle32 idle32; + struct ppp_idle64 idle64; + struct npioctl npi; + int unit, cflags; + struct slcompress *vj; + void __user *argp = (void __user *)arg; + int __user *p = argp; + + mutex_lock(&ppp_mutex); + + pf = file->private_data; + if (!pf) { + err = ppp_unattached_ioctl(current->nsproxy->net_ns, + pf, file, cmd, arg); + goto out; + } + + if (cmd == PPPIOCDETACH) { + /* + * PPPIOCDETACH is no longer supported as it was heavily broken, + * and is only known to have been used by pppd older than + * ppp-2.4.2 (released November 2003). + */ + pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", + current->comm, current->pid); + err = -EINVAL; + goto out; + } + + if (pf->kind == CHANNEL) { + struct channel *pch; + struct ppp_channel *chan; + + pch = PF_TO_CHANNEL(pf); + + 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); + } + goto out; + } + + if (pf->kind != INTERFACE) { + /* can't happen */ + pr_err("PPP: not interface or channel??\n"); + err = -EINVAL; + goto out; + } + + 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; +#ifdef CONFIG_PPP_MULTILINK + if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) + ppp->nextseq = 0; +#endif + 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: + { + struct ppp_option_data data; + if (copy_from_user(&data, argp, sizeof(data))) + err = -EFAULT; + else + err = ppp_set_compress(ppp, &data); + 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 PPPIOCGIDLE32: + idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; + idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; + if (copy_to_user(argp, &idle32, sizeof(idle32))) + break; + err = 0; + break; + + case PPPIOCGIDLE64: + idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; + idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; + if (copy_to_user(argp, &idle64, sizeof(idle64))) + 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 (IS_ERR(vj)) { + err = PTR_ERR(vj); + break; + } + ppp_lock(ppp); + if (ppp->vj) + 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: + case PPPIOCSACTIVE: + { + struct bpf_prog *filter = ppp_get_filter(argp); + struct bpf_prog **which; + + if (IS_ERR(filter)) { + err = PTR_ERR(filter); + break; + } + if (cmd == PPPIOCSPASS) + which = &ppp->pass_filter; + else + which = &ppp->active_filter; + ppp_lock(ppp); + if (*which) + bpf_prog_destroy(*which); + *which = filter; + 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; + } + +out: + mutex_unlock(&ppp_mutex); + + return err; +} + +#ifdef CONFIG_COMPAT +struct ppp_option_data32 { + compat_uptr_t ptr; + u32 length; + compat_int_t transmit; +}; +#define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32) + +static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ppp_file *pf; + int err = -ENOIOCTLCMD; + void __user *argp = (void __user *)arg; + + mutex_lock(&ppp_mutex); + + pf = file->private_data; + if (pf && pf->kind == INTERFACE) { + struct ppp *ppp = PF_TO_PPP(pf); + switch (cmd) { +#ifdef CONFIG_PPP_FILTER + case PPPIOCSPASS32: + case PPPIOCSACTIVE32: + { + struct bpf_prog *filter = compat_ppp_get_filter(argp); + struct bpf_prog **which; + + if (IS_ERR(filter)) { + err = PTR_ERR(filter); + break; + } + if (cmd == PPPIOCSPASS32) + which = &ppp->pass_filter; + else + which = &ppp->active_filter; + ppp_lock(ppp); + if (*which) + bpf_prog_destroy(*which); + *which = filter; + ppp_unlock(ppp); + err = 0; + break; + } +#endif /* CONFIG_PPP_FILTER */ + case PPPIOCSCOMPRESS32: + { + struct ppp_option_data32 data32; + if (copy_from_user(&data32, argp, sizeof(data32))) { + err = -EFAULT; + } else { + struct ppp_option_data data = { + .ptr = compat_ptr(data32.ptr), + .length = data32.length, + .transmit = data32.transmit + }; + err = ppp_set_compress(ppp, &data); + } + break; + } + } + } + mutex_unlock(&ppp_mutex); + + /* all other commands have compatible arguments */ + if (err == -ENOIOCTLCMD) + err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); + + return err; +} +#endif + +static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, + struct file *file, unsigned int cmd, unsigned long arg) +{ + int unit, err = -EFAULT; + struct ppp *ppp; + struct channel *chan; + struct ppp_net *pn; + int __user *p = (int __user *)arg; + + switch (cmd) { + case PPPIOCNEWUNIT: + /* Create a new ppp unit */ + if (get_user(unit, p)) + break; + err = ppp_create_interface(net, file, &unit); + if (err < 0) + break; + + err = -EFAULT; + if (put_user(unit, p)) + break; + err = 0; + break; + + case PPPIOCATTACH: + /* Attach to an existing ppp unit */ + if (get_user(unit, p)) + break; + err = -ENXIO; + pn = ppp_pernet(net); + mutex_lock(&pn->all_ppp_mutex); + ppp = ppp_find_unit(pn, unit); + if (ppp) { + refcount_inc(&ppp->file.refcnt); + file->private_data = &ppp->file; + err = 0; + } + mutex_unlock(&pn->all_ppp_mutex); + break; + + case PPPIOCATTCHAN: + if (get_user(unit, p)) + break; + err = -ENXIO; + pn = ppp_pernet(net); + spin_lock_bh(&pn->all_channels_lock); + chan = ppp_find_channel(pn, unit); + if (chan) { + refcount_inc(&chan->file.refcnt); + file->private_data = &chan->file; + err = 0; + } + spin_unlock_bh(&pn->all_channels_lock); + break; + + default: + err = -ENOTTY; + } + + return err; +} + +static const struct file_operations ppp_device_fops = { + .owner = THIS_MODULE, + .read = ppp_read, + .write = ppp_write, + .poll = ppp_poll, + .unlocked_ioctl = ppp_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = ppp_compat_ioctl, +#endif + .open = ppp_open, + .release = ppp_release, + .llseek = noop_llseek, +}; + +static __net_init int ppp_init_net(struct net *net) +{ + struct ppp_net *pn = net_generic(net, ppp_net_id); + + idr_init(&pn->units_idr); + mutex_init(&pn->all_ppp_mutex); + + INIT_LIST_HEAD(&pn->all_channels); + INIT_LIST_HEAD(&pn->new_channels); + + spin_lock_init(&pn->all_channels_lock); + + return 0; +} + +static __net_exit void ppp_exit_net(struct net *net) +{ + struct ppp_net *pn = net_generic(net, ppp_net_id); + struct net_device *dev; + struct net_device *aux; + struct ppp *ppp; + LIST_HEAD(list); + int id; + + rtnl_lock(); + for_each_netdev_safe(net, dev, aux) { + if (dev->netdev_ops == &ppp_netdev_ops) + unregister_netdevice_queue(dev, &list); + } + + idr_for_each_entry(&pn->units_idr, ppp, id) + /* Skip devices already unregistered by previous loop */ + if (!net_eq(dev_net(ppp->dev), net)) + unregister_netdevice_queue(ppp->dev, &list); + + unregister_netdevice_many(&list); + rtnl_unlock(); + + mutex_destroy(&pn->all_ppp_mutex); + idr_destroy(&pn->units_idr); + WARN_ON_ONCE(!list_empty(&pn->all_channels)); + WARN_ON_ONCE(!list_empty(&pn->new_channels)); +} + +static struct pernet_operations ppp_net_ops = { + .init = ppp_init_net, + .exit = ppp_exit_net, + .id = &ppp_net_id, + .size = sizeof(struct ppp_net), +}; + +static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) +{ + struct ppp_net *pn = ppp_pernet(ppp->ppp_net); + int ret; + + mutex_lock(&pn->all_ppp_mutex); + + if (unit < 0) { + ret = unit_get(&pn->units_idr, ppp, 0); + if (ret < 0) + goto err; + if (!ifname_is_set) { + while (1) { + snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret); + if (!__dev_get_by_name(ppp->ppp_net, ppp->dev->name)) + break; + unit_put(&pn->units_idr, ret); + ret = unit_get(&pn->units_idr, ppp, ret + 1); + if (ret < 0) + goto err; + } + } + } else { + /* Caller asked for a specific unit number. Fail with -EEXIST + * if unavailable. For backward compatibility, return -EEXIST + * too if idr allocation fails; this makes pppd retry without + * requesting a specific unit number. + */ + if (unit_find(&pn->units_idr, unit)) { + ret = -EEXIST; + goto err; + } + ret = unit_set(&pn->units_idr, ppp, unit); + if (ret < 0) { + /* Rewrite error for backward compatibility */ + ret = -EEXIST; + goto err; + } + } + ppp->file.index = ret; + + if (!ifname_is_set) + snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); + + mutex_unlock(&pn->all_ppp_mutex); + + ret = register_netdevice(ppp->dev); + if (ret < 0) + goto err_unit; + + atomic_inc(&ppp_unit_count); + + return 0; + +err_unit: + mutex_lock(&pn->all_ppp_mutex); + unit_put(&pn->units_idr, ppp->file.index); +err: + mutex_unlock(&pn->all_ppp_mutex); + + return ret; +} + +static int ppp_dev_configure(struct net *src_net, struct net_device *dev, + const struct ppp_config *conf) +{ + struct ppp *ppp = netdev_priv(dev); + int indx; + int err; + int cpu; + + ppp->dev = dev; + ppp->ppp_net = src_net; + ppp->mru = PPP_MRU; + ppp->owner = conf->file; + + init_ppp_file(&ppp->file, INTERFACE); + ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ + + for (indx = 0; indx < NUM_NP; ++indx) + ppp->npmode[indx] = NPMODE_PASS; + INIT_LIST_HEAD(&ppp->channels); + spin_lock_init(&ppp->rlock); + spin_lock_init(&ppp->wlock); + + ppp->xmit_recursion = alloc_percpu(int); + if (!ppp->xmit_recursion) { + err = -ENOMEM; + goto err1; + } + for_each_possible_cpu(cpu) + (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; + +#ifdef CONFIG_PPP_MULTILINK + ppp->minseq = -1; + skb_queue_head_init(&ppp->mrq); +#endif /* CONFIG_PPP_MULTILINK */ +#ifdef CONFIG_PPP_FILTER + ppp->pass_filter = NULL; + ppp->active_filter = NULL; +#endif /* CONFIG_PPP_FILTER */ + + err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); + if (err < 0) + goto err2; + + conf->file->private_data = &ppp->file; + + return 0; +err2: + free_percpu(ppp->xmit_recursion); +err1: + return err; +} + +static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { + [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, +}; + +static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + if (!data) + return -EINVAL; + + if (!data[IFLA_PPP_DEV_FD]) + return -EINVAL; + if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) + return -EBADF; + + return 0; +} + +static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ppp_config conf = { + .unit = -1, + .ifname_is_set = true, + }; + struct file *file; + int err; + + file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); + if (!file) + return -EBADF; + + /* rtnl_lock is already held here, but ppp_create_interface() locks + * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids + * possible deadlock due to lock order inversion, at the cost of + * pushing the problem back to userspace. + */ + if (!mutex_trylock(&ppp_mutex)) { + err = -EBUSY; + goto out; + } + + if (file->f_op != &ppp_device_fops || file->private_data) { + err = -EBADF; + goto out_unlock; + } + + conf.file = file; + + /* Don't use device name generated by the rtnetlink layer when ifname + * isn't specified. Let ppp_dev_configure() set the device name using + * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows + * userspace to infer the device name using to the PPPIOCGUNIT ioctl. + */ + if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME])) + conf.ifname_is_set = false; + + err = ppp_dev_configure(src_net, dev, &conf); + +out_unlock: + mutex_unlock(&ppp_mutex); +out: + fput(file); + + return err; +} + +static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) +{ + unregister_netdevice_queue(dev, head); +} + +static size_t ppp_nl_get_size(const struct net_device *dev) +{ + return 0; +} + +static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + return 0; +} + +static struct net *ppp_nl_get_link_net(const struct net_device *dev) +{ + struct ppp *ppp = netdev_priv(dev); + + return ppp->ppp_net; +} + +static struct rtnl_link_ops ppp_link_ops __read_mostly = { + .kind = "ppp", + .maxtype = IFLA_PPP_MAX, + .policy = ppp_nl_policy, + .priv_size = sizeof(struct ppp), + .setup = ppp_setup, + .validate = ppp_nl_validate, + .newlink = ppp_nl_newlink, + .dellink = ppp_nl_dellink, + .get_size = ppp_nl_get_size, + .fill_info = ppp_nl_fill_info, + .get_link_net = ppp_nl_get_link_net, +}; + +#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; + + pr_info("PPP generic driver version " PPP_VERSION "\n"); + + err = register_pernet_device(&ppp_net_ops); + if (err) { + pr_err("failed to register PPP pernet device (%d)\n", err); + goto out; + } + + err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); + if (err) { + pr_err("failed to register PPP device (%d)\n", err); + goto out_net; + } + + ppp_class = class_create(THIS_MODULE, "ppp"); + if (IS_ERR(ppp_class)) { + err = PTR_ERR(ppp_class); + goto out_chrdev; + } + + err = rtnl_link_register(&ppp_link_ops); + if (err) { + pr_err("failed to register rtnetlink PPP handler\n"); + goto out_class; + } + + /* not a big deal if we fail here :-) */ + device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); + + return 0; + +out_class: + class_destroy(ppp_class); +out_chrdev: + unregister_chrdev(PPP_MAJOR, "ppp"); +out_net: + unregister_pernet_device(&ppp_net_ops); +out: + return err; +} + +/* + * Network interface unit routines. + */ +static netdev_tx_t +ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ppp *ppp = netdev_priv(dev); + 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_cow_head(skb, PPP_HDRLEN)) + goto outf; + + pp = skb_push(skb, 2); + proto = npindex_to_proto[npi]; + put_unaligned_be16(proto, pp); + + skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); + ppp_xmit_process(ppp, skb); + + return NETDEV_TX_OK; + + outf: + kfree_skb(skb); + ++dev->stats.tx_dropped; + return NETDEV_TX_OK; +} + +static int +ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) +{ + struct ppp *ppp = netdev_priv(dev); + 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) + ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); + if (ppp->rc_state) + 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_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) +{ + struct ppp *ppp = netdev_priv(dev); + + ppp_recv_lock(ppp); + stats64->rx_packets = ppp->stats64.rx_packets; + stats64->rx_bytes = ppp->stats64.rx_bytes; + ppp_recv_unlock(ppp); + + ppp_xmit_lock(ppp); + stats64->tx_packets = ppp->stats64.tx_packets; + stats64->tx_bytes = ppp->stats64.tx_bytes; + ppp_xmit_unlock(ppp); + + stats64->rx_errors = dev->stats.rx_errors; + stats64->tx_errors = dev->stats.tx_errors; + stats64->rx_dropped = dev->stats.rx_dropped; + stats64->tx_dropped = dev->stats.tx_dropped; + stats64->rx_length_errors = dev->stats.rx_length_errors; +} + +static int ppp_dev_init(struct net_device *dev) +{ + struct ppp *ppp; + + netdev_lockdep_set_classes(dev); + + ppp = netdev_priv(dev); + /* Let the netdevice take a reference on the ppp file. This ensures + * that ppp_destroy_interface() won't run before the device gets + * unregistered. + */ + refcount_inc(&ppp->file.refcnt); + + return 0; +} + +static void ppp_dev_uninit(struct net_device *dev) +{ + struct ppp *ppp = netdev_priv(dev); + struct ppp_net *pn = ppp_pernet(ppp->ppp_net); + + ppp_lock(ppp); + ppp->closing = 1; + ppp_unlock(ppp); + + mutex_lock(&pn->all_ppp_mutex); + unit_put(&pn->units_idr, ppp->file.index); + mutex_unlock(&pn->all_ppp_mutex); + + ppp->owner = NULL; + + ppp->file.dead = 1; + wake_up_interruptible(&ppp->file.rwait); +} + +static void ppp_dev_priv_destructor(struct net_device *dev) +{ + struct ppp *ppp; + + ppp = netdev_priv(dev); + if (refcount_dec_and_test(&ppp->file.refcnt)) + ppp_destroy_interface(ppp); +} + +static const struct net_device_ops ppp_netdev_ops = { + .ndo_init = ppp_dev_init, + .ndo_uninit = ppp_dev_uninit, + .ndo_start_xmit = ppp_start_xmit, + .ndo_do_ioctl = ppp_net_ioctl, + .ndo_get_stats64 = ppp_get_stats64, +}; + +static struct device_type ppp_type = { + .name = "ppp", +}; + +static void ppp_setup(struct net_device *dev) +{ + dev->netdev_ops = &ppp_netdev_ops; + SET_NETDEV_DEVTYPE(dev, &ppp_type); + + dev->features |= NETIF_F_LLTX; + + dev->hard_header_len = PPP_HDRLEN; + dev->mtu = PPP_MRU; + dev->addr_len = 0; + dev->tx_queue_len = 3; + dev->type = ARPHRD_PPP; + dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; + dev->priv_destructor = ppp_dev_priv_destructor; + netif_keep_dst(dev); +} + +/* + * 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->closing) { + ppp_push(ppp); + + if (skb) + skb_queue_tail(&ppp->file.xq, skb); + while (!ppp->xmit_pending && + (skb = skb_dequeue(&ppp->file.xq))) + 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 && !skb_peek(&ppp->file.xq)) + netif_wake_queue(ppp->dev); + else + netif_stop_queue(ppp->dev); + } else { + kfree_skb(skb); + } + ppp_xmit_unlock(ppp); +} + +static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) +{ + local_bh_disable(); + + if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) + goto err; + + (*this_cpu_ptr(ppp->xmit_recursion))++; + __ppp_xmit_process(ppp, skb); + (*this_cpu_ptr(ppp->xmit_recursion))--; + + local_bh_enable(); + + return; + +err: + local_bh_enable(); + + kfree_skb(skb); + + if (net_ratelimit()) + netdev_err(ppp->dev, "recursion detected\n"); +} + +static inline struct sk_buff * +pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) +{ + struct sk_buff *new_skb; + int len; + int new_skb_size = ppp->dev->mtu + + ppp->xcomp->comp_extra + ppp->dev->hard_header_len; + int compressor_skb_size = ppp->dev->mtu + + ppp->xcomp->comp_extra + PPP_HDRLEN; + new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); + if (!new_skb) { + if (net_ratelimit()) + netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); + return NULL; + } + 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, + compressor_skb_size); + if (len > 0 && (ppp->flags & SC_CCP_UP)) { + consume_skb(skb); + skb = new_skb; + skb_put(skb, len); + skb_pull(skb, 2); /* pull off A/C bytes */ + } else if (len == 0) { + /* didn't compress, or CCP not up yet */ + consume_skb(new_skb); + new_skb = skb; + } else { + /* + * (len < 0) + * MPPE requires that we do not send unencrypted + * frames. The compressor will return -1 if we + * should drop the frame. We cannot simply test + * the compress_proto because MPPE and MPPC share + * the same number. + */ + if (net_ratelimit()) + netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); + kfree_skb(skb); + consume_skb(new_skb); + new_skb = NULL; + } + return new_skb; +} + +/* + * 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; + + skb->dev = ppp->dev; + + 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 */ + *(u8 *)skb_push(skb, 2) = 1; + if (ppp->pass_filter && + BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { + if (ppp->debug & 1) + netdev_printk(KERN_DEBUG, ppp->dev, + "PPP: outbound frame " + "not passed\n"); + kfree_skb(skb); + return; + } + /* if this packet passes the active filter, record the time */ + if (!(ppp->active_filter && + BPF_PROG_RUN(ppp->active_filter, skb) == 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->stats64.tx_packets; + ppp->stats64.tx_bytes += skb->len - PPP_PROTO_LEN; + + switch (proto) { + case PPP_IP: + if (!ppp->vj || (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) { + netdev_err(ppp->dev, "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 */ + consume_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]; + } + consume_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 && + proto != PPP_LCP && proto != PPP_CCP) { + if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { + if (net_ratelimit()) + netdev_err(ppp->dev, + "ppp: compression required but " + "down - pkt dropped.\n"); + goto drop; + } + skb = pad_compress_skb(ppp, skb); + if (!skb) + goto drop; + } + + /* + * 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->dev->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) + 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(&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(&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 +static bool mp_protocol_compress __read_mostly = true; +module_param(mp_protocol_compress, bool, 0644); +MODULE_PARM_DESC(mp_protocol_compress, + "compress protocol id in multilink fragments"); + +/* + * 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 len, totlen; + int i, bits, hdrlen, mtu; + int flen; + int navail, nfree, nzero; + int nbigger; + int totspeed; + int totfree; + unsigned char *p, *q; + struct list_head *list; + struct channel *pch; + struct sk_buff *frag; + struct ppp_channel *chan; + + totspeed = 0; /*total bitrate of the bundle*/ + nfree = 0; /* # channels which have no packet already queued */ + navail = 0; /* total # of usable channels (not deregistered) */ + nzero = 0; /* number of channels with zero speed associated*/ + totfree = 0; /*total # of channels available and + *having no queued packets before + *starting the fragmentation*/ + + hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; + i = 0; + list_for_each_entry(pch, &ppp->channels, clist) { + if (pch->chan) { + pch->avail = 1; + navail++; + pch->speed = pch->chan->speed; + } else { + pch->avail = 0; + } + if (pch->avail) { + if (skb_queue_empty(&pch->file.xq) || + !pch->had_frag) { + if (pch->speed == 0) + nzero++; + else + totspeed += pch->speed; + + pch->avail = 2; + ++nfree; + ++totfree; + } + if (!pch->had_frag && i < ppp->nxchan) + ppp->nxchan = i; + } + ++i; + } + /* + * Don't start sending this packet unless at least half of + * the channels are free. This gives much better TCP + * performance if we have a lot of channels. + */ + if (nfree == 0 || nfree < navail / 2) + return 0; /* can't take now, leave it in xmit_pending */ + + /* Do protocol field compression */ + p = skb->data; + len = skb->len; + if (*p == 0 && mp_protocol_compress) { + ++p; + --len; + } + + totlen = len; + nbigger = len % nfree; + + /* skip to the channel after the one we last used + and start at that one */ + list = &ppp->channels; + 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; + while (len > 0) { + list = list->next; + if (list == &ppp->channels) { + i = 0; + continue; + } + pch = list_entry(list, struct channel, clist); + ++i; + if (!pch->avail) + continue; + + /* + * Skip this channel if it has a fragment pending already and + * we haven't given a fragment to all of the free channels. + */ + if (pch->avail == 1) { + if (nfree > 0) + continue; + } else { + pch->avail = 1; + } + + /* check the channel's mtu and whether it is still attached. */ + spin_lock(&pch->downl); + if (pch->chan == NULL) { + /* can't use this channel, it's being deregistered */ + if (pch->speed == 0) + nzero--; + else + totspeed -= pch->speed; + + spin_unlock(&pch->downl); + pch->avail = 0; + totlen = len; + totfree--; + nfree--; + if (--navail == 0) + break; + continue; + } + + /* + *if the channel speed is not set divide + *the packet evenly among the free channels; + *otherwise divide it according to the speed + *of the channel we are going to transmit on + */ + flen = len; + if (nfree > 0) { + if (pch->speed == 0) { + flen = len/nfree; + if (nbigger > 0) { + flen++; + nbigger--; + } + } else { + flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / + ((totspeed*totfree)/pch->speed)) - hdrlen; + if (nbigger > 0) { + flen += ((totfree - nzero)*pch->speed)/totspeed; + nbigger -= ((totfree - nzero)*pch->speed)/ + totspeed; + } + } + nfree--; + } + + /* + *check if we are on the last channel or + *we exceded the length of the data to + *fragment + */ + if ((nfree <= 0) || (flen > len)) + flen = len; + /* + *it is not worth to tx on slow channels: + *in that case from the resulting flen according to the + *above formula will be equal or less than zero. + *Skip the channel in this case + */ + if (flen <= 0) { + pch->avail = 2; + spin_unlock(&pch->downl); + continue; + } + + /* + * hdrlen includes the 2-byte PPP protocol field, but the + * MTU counts only the payload excluding the protocol field. + * (RFC1661 Section 2) + */ + mtu = pch->chan->mtu - (hdrlen - 2); + if (mtu < 4) + mtu = 4; + if (flen > mtu) + flen = mtu; + if (flen == len) + bits |= E; + frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); + if (!frag) + goto noskb; + q = skb_put(frag, flen + hdrlen); + + /* make the MP header */ + put_unaligned_be16(PPP_MP, q); + 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; + } + + memcpy(q + hdrlen, p, flen); + + /* try to send it down the channel */ + chan = pch->chan; + if (!skb_queue_empty(&pch->file.xq) || + !chan->ops->start_xmit(chan, frag)) + skb_queue_tail(&pch->file.xq, frag); + pch->had_frag = 1; + p += flen; + len -= flen; + ++ppp->nxseq; + bits = 0; + spin_unlock(&pch->downl); + } + ppp->nxchan = i; + + return 1; + + noskb: + spin_unlock(&pch->downl); + if (ppp->debug & 1) + netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); + ++ppp->dev->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(&pch->downl); + if (pch->chan) { + while (!skb_queue_empty(&pch->file.xq)) { + 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(&pch->downl); + /* see if there is anything from the attached unit to be sent */ + if (skb_queue_empty(&pch->file.xq)) { + ppp = pch->ppp; + if (ppp) + __ppp_xmit_process(ppp, NULL); + } +} + +static void ppp_channel_push(struct channel *pch) +{ + read_lock_bh(&pch->upl); + if (pch->ppp) { + (*this_cpu_ptr(pch->ppp->xmit_recursion))++; + __ppp_channel_push(pch); + (*this_cpu_ptr(pch->ppp->xmit_recursion))--; + } else { + __ppp_channel_push(pch); + } + read_unlock_bh(&pch->upl); +} + +/* + * Receive-side routines. + */ + +struct ppp_mp_skb_parm { + u32 sequence; + u8 BEbits; +}; +#define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) + +static inline void +ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) +{ + ppp_recv_lock(ppp); + if (!ppp->closing) + ppp_receive_frame(ppp, skb, pch); + else + kfree_skb(skb); + ppp_recv_unlock(ppp); +} + +/** + * __ppp_decompress_proto - Decompress protocol field, slim version. + * @skb: Socket buffer where protocol field should be decompressed. It must have + * at least 1 byte of head room and 1 byte of linear data. First byte of + * data must be a protocol field byte. + * + * Decompress protocol field in PPP header if it's compressed, e.g. when + * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data + * length are done in this function. + */ +static void __ppp_decompress_proto(struct sk_buff *skb) +{ + if (skb->data[0] & 0x01) + *(u8 *)skb_push(skb, 1) = 0x00; +} + +/** + * ppp_decompress_proto - Check skb data room and decompress protocol field. + * @skb: Socket buffer where protocol field should be decompressed. First byte + * of data must be a protocol field byte. + * + * Decompress protocol field in PPP header if it's compressed, e.g. when + * Protocol-Field-Compression (PFC) was negotiated. This function also makes + * sure that skb data room is sufficient for Protocol field, before and after + * decompression. + * + * Return: true - decompressed successfully, false - not enough room in skb. + */ +static bool ppp_decompress_proto(struct sk_buff *skb) +{ + /* At least one byte should be present (if protocol is compressed) */ + if (!pskb_may_pull(skb, 1)) + return false; + + __ppp_decompress_proto(skb); + + /* Protocol field should occupy 2 bytes when not compressed */ + return pskb_may_pull(skb, 2); +} + +void +ppp_input(struct ppp_channel *chan, struct sk_buff *skb) +{ + struct channel *pch = chan->ppp; + int proto; + + if (!pch) { + kfree_skb(skb); + return; + } + + read_lock_bh(&pch->upl); + if (!ppp_decompress_proto(skb)) { + kfree_skb(skb); + if (pch->ppp) { + ++pch->ppp->dev->stats.rx_length_errors; + ppp_receive_error(pch->ppp); + } + goto done; + } + + proto = PPP_PROTO(skb); + if (!pch->ppp || 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))) + kfree_skb(skb); + wake_up_interruptible(&pch->file.rwait); + } else { + ppp_do_recv(pch->ppp, skb, pch); + } + +done: + 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) + return; + + read_lock_bh(&pch->upl); + if (pch->ppp) { + skb = alloc_skb(0, GFP_ATOMIC); + if (skb) { + 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) +{ + /* note: a 0-length skb is used as an error indication */ + if (skb->len > 0) { + skb_checksum_complete_unset(skb); +#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); + } else { + kfree_skb(skb); + ppp_receive_error(ppp); + } +} + +static void +ppp_receive_error(struct ppp *ppp) +{ + ++ppp->dev->stats.rx_errors; + if (ppp->vj) + 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 && (ppp->rstate & SC_DECOMP_RUN) && + (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) + skb = ppp_decompress_frame(ppp, skb); + + if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) + goto err; + + /* At this point the "Protocol" field MUST be decompressed, either in + * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). + */ + proto = PPP_PROTO(skb); + switch (proto) { + case PPP_VJC_COMP: + /* decompress VJ compressed packets */ + if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) + goto err; + + if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { + /* copy to a new sk_buff with more tailroom */ + ns = dev_alloc_skb(skb->len + 128); + if (!ns) { + netdev_err(ppp->dev, "PPP: no memory " + "(VJ decomp)\n"); + goto err; + } + skb_reserve(ns, 2); + skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); + consume_skb(skb); + skb = ns; + } + else + skb->ip_summed = CHECKSUM_NONE; + + len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); + if (len <= 0) { + netdev_printk(KERN_DEBUG, ppp->dev, + "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 || (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) { + netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); + goto err; + } + proto = PPP_IP; + break; + + case PPP_CCP: + ppp_ccp_peek(ppp, skb, 1); + break; + } + + ++ppp->stats64.rx_packets; + ppp->stats64.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))) + 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 */ + if (ppp->pass_filter || ppp->active_filter) { + if (skb_unclone(skb, GFP_ATOMIC)) + goto err; + + *(u8 *)skb_push(skb, 2) = 0; + if (ppp->pass_filter && + BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { + if (ppp->debug & 1) + netdev_printk(KERN_DEBUG, ppp->dev, + "PPP: inbound frame " + "not passed\n"); + kfree_skb(skb); + return; + } + if (!(ppp->active_filter && + BPF_PROG_RUN(ppp->active_filter, skb) == 0)) + ppp->last_recv = jiffies; + __skb_pull(skb, 2); + } else +#endif /* CONFIG_PPP_FILTER */ + ppp->last_recv = jiffies; + + if ((ppp->dev->flags & IFF_UP) == 0 || + ppp->npmode[npi] != NPMODE_PASS) { + kfree_skb(skb); + } else { + /* chop off protocol */ + skb_pull_rcsum(skb, 2); + skb->dev = ppp->dev; + skb->protocol = htons(npindex_to_ethertype[npi]); + skb_reset_mac_header(skb); + skb_scrub_packet(skb, !net_eq(ppp->ppp_net, + dev_net(ppp->dev))); + 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; + + /* 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) { + int obuff_size; + + switch(ppp->rcomp->compress_proto) { + case CI_MPPE: + obuff_size = ppp->mru + PPP_HDRLEN + 1; + break; + default: + obuff_size = ppp->mru + PPP_HDRLEN; + break; + } + + ns = dev_alloc_skb(obuff_size); + if (!ns) { + netdev_err(ppp->dev, "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, obuff_size); + 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; + } + + consume_skb(skb); + skb = ns; + skb_put(skb, len); + skb_pull(skb, 2); /* pull off the A/C bytes */ + + /* Don't call __ppp_decompress_proto() here, but instead rely on + * corresponding algo (mppe/bsd/deflate) to decompress it. + */ + } 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 channel *ch; + 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; + } + PPP_MP_CB(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. + * We have to do that here, because ppp_receive_nonmp_frame() expects + * decompressed protocol field. + */ + if (PPP_MP_CB(skb)->BEbits & B) + __ppp_decompress_proto(skb); + + /* + * 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 */ + PPP_MP_CB(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->dev->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. + */ + list_for_each_entry(ch, &ppp->channels, 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) { + struct sk_buff *mskb = skb_peek(&ppp->mrq); + if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) + ppp->minseq = PPP_MP_CB(mskb)->sequence; + } + + /* Pull completed packets off the queue and receive them. */ + while ((skb = ppp_mp_reconstruct(ppp))) { + if (pskb_may_pull(skb, 2)) + ppp_receive_nonmp_frame(ppp, skb); + else { + ++ppp->dev->stats.rx_length_errors; + kfree_skb(skb); + ppp_receive_error(ppp); + } + } + + 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 = PPP_MP_CB(skb)->sequence; + + /* N.B. we don't need to lock the list lock because we have the + ppp unit receive-side lock. */ + skb_queue_walk(list, p) { + if (seq_before(seq, PPP_MP_CB(p)->sequence)) + break; + } + __skb_queue_before(list, p, skb); +} + +/* + * 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. + */ +static 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, *tmp; + 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 = __skb_peek(list); + tail = NULL; + skb_queue_walk_safe(list, p, tmp) { + again: + if (seq_before(PPP_MP_CB(p)->sequence, seq)) { + /* this can't happen, anyway ignore the skb */ + netdev_err(ppp->dev, "ppp_mp_reconstruct bad " + "seq %u < %u\n", + PPP_MP_CB(p)->sequence, seq); + __skb_unlink(p, list); + kfree_skb(p); + continue; + } + if (PPP_MP_CB(p)->sequence != seq) { + u32 oldseq; + /* 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; + oldseq = seq; + seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? + minseq + 1: PPP_MP_CB(p)->sequence; + + if (ppp->debug & 1) + netdev_printk(KERN_DEBUG, ppp->dev, + "lost frag %u..%u\n", + oldseq, seq-1); + + goto again; + } + + /* + * 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 (PPP_MP_CB(p)->BEbits & B) { + head = p; + lost = 0; + len = 0; + } + + len += p->len; + + /* Got a complete packet yet? */ + if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && + (PPP_MP_CB(head)->BEbits & B)) { + if (len > ppp->mrru + 2) { + ++ppp->dev->stats.rx_length_errors; + netdev_printk(KERN_DEBUG, ppp->dev, + "PPP: reconstructed packet" + " is too long (%d)\n", len); + } 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 (PPP_MP_CB(p)->BEbits & E) { + struct sk_buff *tmp2; + + skb_queue_reverse_walk_from_safe(list, p, tmp2) { + if (ppp->debug & 1) + netdev_printk(KERN_DEBUG, ppp->dev, + "discarding frag %u\n", + PPP_MP_CB(p)->sequence); + __skb_unlink(p, list); + kfree_skb(p); + } + head = skb_peek(list); + if (!head) + break; + } + ++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 (PPP_MP_CB(head)->sequence != ppp->nextseq) { + skb_queue_walk_safe(list, p, tmp) { + if (p == head) + break; + if (ppp->debug & 1) + netdev_printk(KERN_DEBUG, ppp->dev, + "discarding frag %u\n", + PPP_MP_CB(p)->sequence); + __skb_unlink(p, list); + kfree_skb(p); + } + + if (ppp->debug & 1) + netdev_printk(KERN_DEBUG, ppp->dev, + " missed pkts %u..%u\n", + ppp->nextseq, + PPP_MP_CB(head)->sequence-1); + ++ppp->dev->stats.rx_dropped; + ppp_receive_error(ppp); + } + + skb = head; + if (head != tail) { + struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; + p = skb_queue_next(list, head); + __skb_unlink(skb, list); + skb_queue_walk_from_safe(list, p, tmp) { + __skb_unlink(p, list); + *fragpp = p; + p->next = NULL; + fragpp = &p->next; + + skb->len += p->len; + skb->data_len += p->len; + skb->truesize += p->truesize; + + if (p == tail) + break; + } + } else { + __skb_unlink(skb, list); + } + + ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; + } + + return skb; +} +#endif /* CONFIG_PPP_MULTILINK */ + +/* + * Channel interface. + */ + +/* Create a new, unattached ppp channel. */ +int ppp_register_channel(struct ppp_channel *chan) +{ + return ppp_register_net_channel(current->nsproxy->net_ns, chan); +} + +/* Create a new, unattached ppp channel for specified net. */ +int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) +{ + struct channel *pch; + struct ppp_net *pn; + + pch = kzalloc(sizeof(struct channel), GFP_KERNEL); + if (!pch) + return -ENOMEM; + + pn = ppp_pernet(net); + + pch->ppp = NULL; + pch->chan = chan; + pch->chan_net = get_net(net); + 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(&pn->all_channels_lock); + pch->file.index = ++pn->last_channel_index; + list_add(&pch->list, &pn->new_channels); + atomic_inc(&channel_count); + spin_unlock_bh(&pn->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) + 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) { + read_lock_bh(&pch->upl); + if (pch->ppp) + unit = pch->ppp->file.index; + read_unlock_bh(&pch->upl); + } + return unit; +} + +/* + * Return the PPP device interface name of a channel. + */ +char *ppp_dev_name(struct ppp_channel *chan) +{ + struct channel *pch = chan->ppp; + char *name = NULL; + + if (pch) { + read_lock_bh(&pch->upl); + if (pch->ppp && pch->ppp->dev) + name = pch->ppp->dev->name; + read_unlock_bh(&pch->upl); + } + return name; +} + + +/* + * 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; + struct ppp_net *pn; + + if (!pch) + 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); + + pn = ppp_pernet(pch->chan_net); + spin_lock_bh(&pn->all_channels_lock); + list_del(&pch->list); + spin_unlock_bh(&pn->all_channels_lock); + + pch->file.dead = 1; + wake_up_interruptible(&pch->file.rwait); + if (refcount_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) + return; + ppp_channel_push(pch); +} + +/* + * Compression control. + */ + +/* Process the PPPIOCSCOMPRESS ioctl. */ +static int +ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) +{ + int err = -EFAULT; + struct compressor *cp, *ocomp; + void *state, *ostate; + unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; + + if (data->length > CCP_MAX_OPTION_LENGTH) + goto out; + if (copy_from_user(ccp_option, data->ptr, data->length)) + goto out; + + err = -EINVAL; + if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) + goto out; + + cp = try_then_request_module( + find_compressor(ccp_option[0]), + "ppp-compress-%d", ccp_option[0]); + if (!cp) + goto out; + + err = -ENOBUFS; + if (data->transmit) { + state = cp->comp_alloc(ccp_option, data->length); + if (state) { + 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) { + 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) { + 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) { + 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) + 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) + 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; + + list_for_each_entry(ce, &compressor_list, 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)) + goto out; + ret = -ENOMEM; + ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); + if (!ce) + 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 && 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) { + 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->stats64.rx_packets; + st->p.ppp_ierrors = ppp->dev->stats.rx_errors; + st->p.ppp_ibytes = ppp->stats64.rx_bytes; + st->p.ppp_opackets = ppp->stats64.tx_packets; + st->p.ppp_oerrors = ppp->dev->stats.tx_errors; + st->p.ppp_obytes = ppp->stats64.tx_bytes; + if (!vj) + 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 int ppp_create_interface(struct net *net, struct file *file, int *unit) +{ + struct ppp_config conf = { + .file = file, + .unit = *unit, + .ifname_is_set = false, + }; + struct net_device *dev; + struct ppp *ppp; + int err; + + dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); + if (!dev) { + err = -ENOMEM; + goto err; + } + dev_net_set(dev, net); + dev->rtnl_link_ops = &ppp_link_ops; + + rtnl_lock(); + + err = ppp_dev_configure(net, dev, &conf); + if (err < 0) + goto err_dev; + ppp = netdev_priv(dev); + *unit = ppp->file.index; + + rtnl_unlock(); + + return 0; + +err_dev: + rtnl_unlock(); + free_netdev(dev); +err: + return err; +} + +/* + * 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); + refcount_set(&pf->refcnt, 1); + init_waitqueue_head(&pf->rwait); +} + +/* + * 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" */ + netdev_err(ppp->dev, "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) { + bpf_prog_destroy(ppp->pass_filter); + ppp->pass_filter = NULL; + } + + if (ppp->active_filter) { + bpf_prog_destroy(ppp->active_filter); + ppp->active_filter = NULL; + } +#endif /* CONFIG_PPP_FILTER */ + + kfree_skb(ppp->xmit_pending); + free_percpu(ppp->xmit_recursion); + + free_netdev(ppp->dev); +} + +/* + * Locate an existing ppp unit. + * The caller should have locked the all_ppp_mutex. + */ +static struct ppp * +ppp_find_unit(struct ppp_net *pn, int unit) +{ + return unit_find(&pn->units_idr, 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(struct ppp_net *pn, int unit) +{ + struct channel *pch; + + list_for_each_entry(pch, &pn->new_channels, list) { + if (pch->file.index == unit) { + list_move(&pch->list, &pn->all_channels); + return pch; + } + } + + list_for_each_entry(pch, &pn->all_channels, 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; + struct ppp_net *pn; + int ret = -ENXIO; + int hdrlen; + + pn = ppp_pernet(pch->chan_net); + + mutex_lock(&pn->all_ppp_mutex); + ppp = ppp_find_unit(pn, unit); + if (!ppp) + goto out; + write_lock_bh(&pch->upl); + ret = -EINVAL; + if (pch->ppp) + goto outl; + + ppp_lock(ppp); + spin_lock_bh(&pch->downl); + if (!pch->chan) { + /* Don't connect unregistered channels */ + spin_unlock_bh(&pch->downl); + ppp_unlock(ppp); + ret = -ENOTCONN; + goto outl; + } + spin_unlock_bh(&pch->downl); + if (pch->file.hdrlen > ppp->file.hdrlen) + ppp->file.hdrlen = pch->file.hdrlen; + hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ + if (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; + refcount_inc(&ppp->file.refcnt); + ppp_unlock(ppp); + ret = 0; + + outl: + write_unlock_bh(&pch->upl); + out: + mutex_unlock(&pn->all_ppp_mutex); + 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) { + /* 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 (refcount_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) +{ + put_net(pch->chan_net); + pch->chan_net = NULL; + + atomic_dec(&channel_count); + + if (!pch->file.dead) { + /* "can't happen" */ + pr_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)) + pr_err("PPP: removing module but units remain!\n"); + rtnl_link_unregister(&ppp_link_ops); + unregister_chrdev(PPP_MAJOR, "ppp"); + device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); + class_destroy(ppp_class); + unregister_pernet_device(&ppp_net_ops); +} + +/* + * Units handling. Caller must protect concurrent access + * by holding all_ppp_mutex + */ + +/* associate pointer with specified number */ +static int unit_set(struct idr *p, void *ptr, int n) +{ + int unit; + + unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); + if (unit == -ENOSPC) + unit = -EINVAL; + return unit; +} + +/* get new free unit number and associate pointer with it */ +static int unit_get(struct idr *p, void *ptr, int min) +{ + return idr_alloc(p, ptr, min, 0, GFP_KERNEL); +} + +/* put unit number back to a pool */ +static void unit_put(struct idr *p, int n) +{ + idr_remove(p, n); +} + +/* get pointer associated with the number */ +static void *unit_find(struct idr *p, int n) +{ + return idr_find(p, n); +} + +/* Module/initialization stuff */ + +module_init(ppp_init); +module_exit(ppp_cleanup); + +EXPORT_SYMBOL(ppp_register_net_channel); +EXPORT_SYMBOL(ppp_register_channel); +EXPORT_SYMBOL(ppp_unregister_channel); +EXPORT_SYMBOL(ppp_channel_index); +EXPORT_SYMBOL(ppp_unit_number); +EXPORT_SYMBOL(ppp_dev_name); +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(PPP_MAJOR, 0); +MODULE_ALIAS_RTNL_LINK("ppp"); +MODULE_ALIAS("devname:ppp"); |