From 273ec51dd7ceaa76e038875d85061ec856d8905e Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Wed, 21 Jan 2009 15:55:35 -0800 Subject: [PATCH] net: ppp_generic - introduce net-namespace functionality v2 - Each namespace contains ppp channels and units separately with appropriate locks Signed-off-by: Cyrill Gorcunov Signed-off-by: David S. Miller --- drivers/net/ppp_generic.c | 275 ++++++++++++++++++++++++++---------- include/linux/ppp_channel.h | 4 + 2 files changed, 202 insertions(+), 77 deletions(-) diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index 7b2728b8f1b7..4405a76ed3da 100644 --- a/drivers/net/ppp_generic.c +++ b/drivers/net/ppp_generic.c @@ -49,6 +49,10 @@ #include #include +#include +#include +#include + #define PPP_VERSION "2.4.2" /* @@ -131,6 +135,7 @@ struct ppp { struct sock_filter *active_filter;/* filter for pkts to reset idle */ unsigned pass_len, active_len; #endif /* CONFIG_PPP_FILTER */ + struct net *ppp_net; /* the net we belong to */ }; /* @@ -155,6 +160,7 @@ struct channel { 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 @@ -173,26 +179,35 @@ struct channel { * channel.downl. */ -/* - * all_ppp_mutex 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 DEFINE_MUTEX(all_ppp_mutex); static atomic_t ppp_unit_count = ATOMIC_INIT(0); -static DEFINE_IDR(ppp_units_idr); - -/* - * 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); +/* per-net private data for this module */ +static unsigned int ppp_net_id; +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) (((skb)->data[0] << 8) + (skb)->data[1]) @@ -216,8 +231,8 @@ static atomic_t channel_count = ATOMIC_INIT(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 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); static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); static void ppp_push(struct ppp *ppp); @@ -240,12 +255,12 @@ 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 struct ppp *ppp_create_interface(struct net *net, 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 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); @@ -256,6 +271,14 @@ static void *unit_find(struct idr *p, int n); static struct class *ppp_class; +/* per net-namespace data */ +static inline struct ppp_net *ppp_pernet(struct net *net) +{ + BUG_ON(!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) { @@ -544,7 +567,8 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) int __user *p = argp; if (!pf) - return ppp_unattached_ioctl(pf, file, cmd, arg); + return ppp_unattached_ioctl(current->nsproxy->net_ns, + pf, file, cmd, arg); if (cmd == PPPIOCDETACH) { /* @@ -763,12 +787,13 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return err; } -static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file, - unsigned int cmd, unsigned long arg) +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; lock_kernel(); @@ -777,7 +802,7 @@ static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file, /* Create a new ppp unit */ if (get_user(unit, p)) break; - ppp = ppp_create_interface(unit, &err); + ppp = ppp_create_interface(net, unit, &err); if (!ppp) break; file->private_data = &ppp->file; @@ -792,29 +817,31 @@ static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file, /* Attach to an existing ppp unit */ if (get_user(unit, p)) break; - mutex_lock(&all_ppp_mutex); err = -ENXIO; - ppp = ppp_find_unit(unit); + pn = ppp_pernet(net); + mutex_lock(&pn->all_ppp_mutex); + ppp = ppp_find_unit(pn, unit); if (ppp) { atomic_inc(&ppp->file.refcnt); file->private_data = &ppp->file; err = 0; } - mutex_unlock(&all_ppp_mutex); + mutex_unlock(&pn->all_ppp_mutex); break; case PPPIOCATTCHAN: if (get_user(unit, p)) break; - spin_lock_bh(&all_channels_lock); err = -ENXIO; - chan = ppp_find_channel(unit); + pn = ppp_pernet(net); + spin_lock_bh(&pn->all_channels_lock); + chan = ppp_find_channel(pn, unit); if (chan) { atomic_inc(&chan->file.refcnt); file->private_data = &chan->file; err = 0; } - spin_unlock_bh(&all_channels_lock); + spin_unlock_bh(&pn->all_channels_lock); break; default: @@ -834,6 +861,51 @@ static const struct file_operations ppp_device_fops = { .release = ppp_release }; +static __net_init int ppp_init_net(struct net *net) +{ + struct ppp_net *pn; + int err; + + pn = kzalloc(sizeof(*pn), GFP_KERNEL); + if (!pn) + return -ENOMEM; + + 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); + + err = net_assign_generic(net, ppp_net_id, pn); + if (err) { + kfree(pn); + return err; + } + + return 0; +} + +static __net_exit void ppp_exit_net(struct net *net) +{ + struct ppp_net *pn; + + pn = net_generic(net, ppp_net_id); + idr_destroy(&pn->units_idr); + /* + * if someone has cached our net then + * further net_generic call will return NULL + */ + net_assign_generic(net, ppp_net_id, NULL); + kfree(pn); +} + +static __net_initdata struct pernet_operations ppp_net_ops = { + .init = ppp_init_net, + .exit = ppp_exit_net, +}; + #define PPP_MAJOR 108 /* Called at boot time if ppp is compiled into the kernel, @@ -843,25 +915,36 @@ 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_create(THIS_MODULE, "ppp"); - if (IS_ERR(ppp_class)) { - err = PTR_ERR(ppp_class); - goto out_chrdev; - } - device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, - "ppp"); + + err = register_pernet_gen_device(&ppp_net_id, &ppp_net_ops); + if (err) { + printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err); + goto out; } -out: - if (err) + err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); + if (err) { printk(KERN_ERR "failed to register PPP device (%d)\n", err); - return err; + goto out_net; + } + + ppp_class = class_create(THIS_MODULE, "ppp"); + if (IS_ERR(ppp_class)) { + err = PTR_ERR(ppp_class); + goto out_chrdev; + } + + /* not a big deal if we fail here :-) */ + device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); + + return 0; out_chrdev: unregister_chrdev(PPP_MAJOR, "ppp"); - goto out; +out_net: + unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops); +out: + return err; } /* @@ -969,6 +1052,7 @@ static void ppp_setup(struct net_device *dev) dev->tx_queue_len = 3; dev->type = ARPHRD_PPP; dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; + dev->features |= NETIF_F_NETNS_LOCAL; } /* @@ -1986,19 +2070,27 @@ ppp_mp_reconstruct(struct ppp *ppp) * Channel interface. */ -/* - * Create a new, unattached ppp channel. - */ -int -ppp_register_channel(struct ppp_channel *chan) +/* 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 = net; chan->ppp = pch; init_ppp_file(&pch->file, CHANNEL); pch->file.hdrlen = chan->hdrlen; @@ -2008,11 +2100,13 @@ ppp_register_channel(struct ppp_channel *chan) 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); + + 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(&all_channels_lock); + spin_unlock_bh(&pn->all_channels_lock); + return 0; } @@ -2053,9 +2147,11 @@ 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; /* @@ -2068,9 +2164,12 @@ ppp_unregister_channel(struct ppp_channel *chan) spin_unlock_bh(&pch->downl); up_write(&pch->chan_sem); ppp_disconnect_channel(pch); - spin_lock_bh(&all_channels_lock); + + pn = ppp_pernet(pch->chan_net); + spin_lock_bh(&pn->all_channels_lock); list_del(&pch->list); - spin_unlock_bh(&all_channels_lock); + spin_unlock_bh(&pn->all_channels_lock); + pch->file.dead = 1; wake_up_interruptible(&pch->file.rwait); if (atomic_dec_and_test(&pch->file.refcnt)) @@ -2395,9 +2494,10 @@ ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) * unit == -1 means allocate a new number. */ static struct ppp * -ppp_create_interface(int unit, int *retp) +ppp_create_interface(struct net *net, int unit, int *retp) { struct ppp *ppp; + struct ppp_net *pn; struct net_device *dev = NULL; int ret = -ENOMEM; int i; @@ -2406,6 +2506,8 @@ ppp_create_interface(int unit, int *retp) if (!dev) goto out1; + pn = ppp_pernet(net); + ppp = netdev_priv(dev); ppp->dev = dev; ppp->mru = PPP_MRU; @@ -2421,17 +2523,23 @@ ppp_create_interface(int unit, int *retp) skb_queue_head_init(&ppp->mrq); #endif /* CONFIG_PPP_MULTILINK */ + /* + * drum roll: don't forget to set + * the net device is belong to + */ + dev_net_set(dev, net); + ret = -EEXIST; - mutex_lock(&all_ppp_mutex); + mutex_lock(&pn->all_ppp_mutex); if (unit < 0) { - unit = unit_get(&ppp_units_idr, ppp); + unit = unit_get(&pn->units_idr, ppp); if (unit < 0) { *retp = unit; goto out2; } } else { - if (unit_find(&ppp_units_idr, unit)) + if (unit_find(&pn->units_idr, unit)) goto out2; /* unit already exists */ /* * if caller need a specified unit number @@ -2442,7 +2550,7 @@ ppp_create_interface(int unit, int *retp) * fair but at least pppd will ask us to allocate * new unit in this case so user is happy :) */ - unit = unit_set(&ppp_units_idr, ppp, unit); + unit = unit_set(&pn->units_idr, ppp, unit); if (unit < 0) goto out2; } @@ -2453,20 +2561,22 @@ ppp_create_interface(int unit, int *retp) ret = register_netdev(dev); if (ret != 0) { - unit_put(&ppp_units_idr, unit); + unit_put(&pn->units_idr, unit); printk(KERN_ERR "PPP: couldn't register device %s (%d)\n", dev->name, ret); goto out2; } + ppp->ppp_net = net; + atomic_inc(&ppp_unit_count); - mutex_unlock(&all_ppp_mutex); + mutex_unlock(&pn->all_ppp_mutex); *retp = 0; return ppp; out2: - mutex_unlock(&all_ppp_mutex); + mutex_unlock(&pn->all_ppp_mutex); free_netdev(dev); out1: *retp = ret; @@ -2492,7 +2602,11 @@ init_ppp_file(struct ppp_file *pf, int kind) */ static void ppp_shutdown_interface(struct ppp *ppp) { - mutex_lock(&all_ppp_mutex); + struct ppp_net *pn; + + pn = ppp_pernet(ppp->ppp_net); + mutex_lock(&pn->all_ppp_mutex); + /* This will call dev_close() for us. */ ppp_lock(ppp); if (!ppp->closing) { @@ -2502,11 +2616,12 @@ static void ppp_shutdown_interface(struct ppp *ppp) } else ppp_unlock(ppp); - unit_put(&ppp_units_idr, ppp->file.index); + unit_put(&pn->units_idr, ppp->file.index); ppp->file.dead = 1; ppp->owner = NULL; wake_up_interruptible(&ppp->file.rwait); - mutex_unlock(&all_ppp_mutex); + + mutex_unlock(&pn->all_ppp_mutex); } /* @@ -2554,9 +2669,9 @@ static void ppp_destroy_interface(struct ppp *ppp) * The caller should have locked the all_ppp_mutex. */ static struct ppp * -ppp_find_unit(int unit) +ppp_find_unit(struct ppp_net *pn, int unit) { - return unit_find(&ppp_units_idr, unit); + return unit_find(&pn->units_idr, unit); } /* @@ -2568,20 +2683,22 @@ ppp_find_unit(int unit) * when we have a lot of channels in use. */ static struct channel * -ppp_find_channel(int unit) +ppp_find_channel(struct ppp_net *pn, int unit) { struct channel *pch; - list_for_each_entry(pch, &new_channels, list) { + list_for_each_entry(pch, &pn->new_channels, list) { if (pch->file.index == unit) { - list_move(&pch->list, &all_channels); + list_move(&pch->list, &pn->all_channels); return pch; } } - list_for_each_entry(pch, &all_channels, list) { + + list_for_each_entry(pch, &pn->all_channels, list) { if (pch->file.index == unit) return pch; } + return NULL; } @@ -2592,11 +2709,14 @@ static int ppp_connect_channel(struct channel *pch, int unit) { struct ppp *ppp; + struct ppp_net *pn; int ret = -ENXIO; int hdrlen; - mutex_lock(&all_ppp_mutex); - ppp = ppp_find_unit(unit); + 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); @@ -2620,7 +2740,7 @@ ppp_connect_channel(struct channel *pch, int unit) outl: write_unlock_bh(&pch->upl); out: - mutex_unlock(&all_ppp_mutex); + mutex_unlock(&pn->all_ppp_mutex); return ret; } @@ -2677,7 +2797,7 @@ static void __exit ppp_cleanup(void) unregister_chrdev(PPP_MAJOR, "ppp"); device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); class_destroy(ppp_class); - idr_destroy(&ppp_units_idr); + unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops); } /* @@ -2743,6 +2863,7 @@ static void *unit_find(struct idr *p, int n) 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); diff --git a/include/linux/ppp_channel.h b/include/linux/ppp_channel.h index a942892d6dfe..9d64bdf14770 100644 --- a/include/linux/ppp_channel.h +++ b/include/linux/ppp_channel.h @@ -22,6 +22,7 @@ #include #include #include +#include struct ppp_channel; @@ -56,6 +57,9 @@ extern void ppp_input(struct ppp_channel *, struct sk_buff *); that we may have missed a packet. */ extern void ppp_input_error(struct ppp_channel *, int code); +/* Attach a channel to a given PPP unit in specified net. */ +extern int ppp_register_net_channel(struct net *, struct ppp_channel *); + /* Attach a channel to a given PPP unit. */ extern int ppp_register_channel(struct ppp_channel *); -- GitLab