diff options
| -rw-r--r-- | net/core/Makefile | 1 | ||||
| -rw-r--r-- | net/core/netfilter.c | 737 | ||||
| -rw-r--r-- | net/netfilter/Makefile | 4 | ||||
| -rw-r--r-- | net/netfilter/core.c | 216 | ||||
| -rw-r--r-- | net/netfilter/nf_internals.h | 39 | ||||
| -rw-r--r-- | net/netfilter/nf_log.c | 165 | ||||
| -rw-r--r-- | net/netfilter/nf_queue.c | 273 | ||||
| -rw-r--r-- | net/netfilter/nf_sockopt.c | 132 |
8 files changed, 829 insertions, 738 deletions
diff --git a/net/core/Makefile b/net/core/Makefile index f5f5e58943e..630da0f0579 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -12,7 +12,6 @@ obj-y += dev.o ethtool.o dev_mcast.o dst.o \ obj-$(CONFIG_XFRM) += flow.o obj-$(CONFIG_SYSFS) += net-sysfs.o -obj-$(CONFIG_NETFILTER) += netfilter.o obj-$(CONFIG_NET_DIVERT) += dv.o obj-$(CONFIG_NET_PKTGEN) += pktgen.o obj-$(CONFIG_NET_RADIO) += wireless.o diff --git a/net/core/netfilter.c b/net/core/netfilter.c deleted file mode 100644 index 98cc61e79fe..00000000000 --- a/net/core/netfilter.c +++ /dev/null @@ -1,737 +0,0 @@ -/* netfilter.c: look after the filters for various protocols. - * Heavily influenced by the old firewall.c by David Bonn and Alan Cox. - * - * Thanks to Rob `CmdrTaco' Malda for not influencing this code in any - * way. - * - * Rusty Russell (C)2000 -- This code is GPL. - * - * February 2000: Modified by James Morris to have 1 queue per protocol. - * 15-Mar-2000: Added NF_REPEAT --RR. - * 08-May-2003: Internal logging interface added by Jozsef Kadlecsik. - */ -#include <linux/config.h> -#include <linux/kernel.h> -#include <linux/netfilter.h> -#include <net/protocol.h> -#include <linux/init.h> -#include <linux/skbuff.h> -#include <linux/wait.h> -#include <linux/module.h> -#include <linux/interrupt.h> -#include <linux/if.h> -#include <linux/netdevice.h> -#include <linux/inetdevice.h> -#include <linux/proc_fs.h> -#include <net/sock.h> - -/* In this code, we can be waiting indefinitely for userspace to - * service a packet if a hook returns NF_QUEUE. We could keep a count - * of skbuffs queued for userspace, and not deregister a hook unless - * this is zero, but that sucks. Now, we simply check when the - * packets come back: if the hook is gone, the packet is discarded. */ -#ifdef CONFIG_NETFILTER_DEBUG -#define NFDEBUG(format, args...) printk(format , ## args) -#else -#define NFDEBUG(format, args...) -#endif - -/* Sockopts only registered and called from user context, so - net locking would be overkill. Also, [gs]etsockopt calls may - sleep. */ -static DECLARE_MUTEX(nf_sockopt_mutex); - -struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS]; -static LIST_HEAD(nf_sockopts); -static DEFINE_SPINLOCK(nf_hook_lock); - -/* - * A queue handler may be registered for each protocol. Each is protected by - * long term mutex. The handler must provide an an outfn() to accept packets - * for queueing and must reinject all packets it receives, no matter what. - */ -static struct nf_queue_handler_t { - nf_queue_outfn_t outfn; - void *data; -} queue_handler[NPROTO]; - -static struct nf_queue_rerouter *queue_rerouter; - -static DEFINE_RWLOCK(queue_handler_lock); - -int nf_register_hook(struct nf_hook_ops *reg) -{ - struct list_head *i; - - spin_lock_bh(&nf_hook_lock); - list_for_each(i, &nf_hooks[reg->pf][reg->hooknum]) { - if (reg->priority < ((struct nf_hook_ops *)i)->priority) - break; - } - list_add_rcu(®->list, i->prev); - spin_unlock_bh(&nf_hook_lock); - - synchronize_net(); - return 0; -} - -void nf_unregister_hook(struct nf_hook_ops *reg) -{ - spin_lock_bh(&nf_hook_lock); - list_del_rcu(®->list); - spin_unlock_bh(&nf_hook_lock); - - synchronize_net(); -} - -/* Do exclusive ranges overlap? */ -static inline int overlap(int min1, int max1, int min2, int max2) -{ - return max1 > min2 && min1 < max2; -} - -/* Functions to register sockopt ranges (exclusive). */ -int nf_register_sockopt(struct nf_sockopt_ops *reg) -{ - struct list_head *i; - int ret = 0; - - if (down_interruptible(&nf_sockopt_mutex) != 0) - return -EINTR; - - list_for_each(i, &nf_sockopts) { - struct nf_sockopt_ops *ops = (struct nf_sockopt_ops *)i; - if (ops->pf == reg->pf - && (overlap(ops->set_optmin, ops->set_optmax, - reg->set_optmin, reg->set_optmax) - || overlap(ops->get_optmin, ops->get_optmax, - reg->get_optmin, reg->get_optmax))) { - NFDEBUG("nf_sock overlap: %u-%u/%u-%u v %u-%u/%u-%u\n", - ops->set_optmin, ops->set_optmax, - ops->get_optmin, ops->get_optmax, - reg->set_optmin, reg->set_optmax, - reg->get_optmin, reg->get_optmax); - ret = -EBUSY; - goto out; - } - } - - list_add(®->list, &nf_sockopts); -out: - up(&nf_sockopt_mutex); - return ret; -} - -void nf_unregister_sockopt(struct nf_sockopt_ops *reg) -{ - /* No point being interruptible: we're probably in cleanup_module() */ - restart: - down(&nf_sockopt_mutex); - if (reg->use != 0) { - /* To be woken by nf_sockopt call... */ - /* FIXME: Stuart Young's name appears gratuitously. */ - set_current_state(TASK_UNINTERRUPTIBLE); - reg->cleanup_task = current; - up(&nf_sockopt_mutex); - schedule(); - goto restart; - } - list_del(®->list); - up(&nf_sockopt_mutex); -} - -/* Call get/setsockopt() */ -static int nf_sockopt(struct sock *sk, int pf, int val, - char __user *opt, int *len, int get) -{ - struct list_head *i; - struct nf_sockopt_ops *ops; - int ret; - - if (down_interruptible(&nf_sockopt_mutex) != 0) - return -EINTR; - - list_for_each(i, &nf_sockopts) { - ops = (struct nf_sockopt_ops *)i; - if (ops->pf == pf) { - if (get) { - if (val >= ops->get_optmin - && val < ops->get_optmax) { - ops->use++; - up(&nf_sockopt_mutex); - ret = ops->get(sk, val, opt, len); - goto out; - } - } else { - if (val >= ops->set_optmin - && val < ops->set_optmax) { - ops->use++; - up(&nf_sockopt_mutex); - ret = ops->set(sk, val, opt, *len); - goto out; - } - } - } - } - up(&nf_sockopt_mutex); - return -ENOPROTOOPT; - - out: - down(&nf_sockopt_mutex); - ops->use--; - if (ops->cleanup_task) - wake_up_process(ops->cleanup_task); - up(&nf_sockopt_mutex); - return ret; -} - -int nf_setsockopt(struct sock *sk, int pf, int val, char __user *opt, - int len) -{ - return nf_sockopt(sk, pf, val, opt, &len, 0); -} - -int nf_getsockopt(struct sock *sk, int pf, int val, char __user *opt, int *len) -{ - return nf_sockopt(sk, pf, val, opt, len, 1); -} - -static unsigned int nf_iterate(struct list_head *head, - struct sk_buff **skb, - int hook, - const struct net_device *indev, - const struct net_device *outdev, - struct list_head **i, - int (*okfn)(struct sk_buff *), - int hook_thresh) -{ - unsigned int verdict; - - /* - * The caller must not block between calls to this - * function because of risk of continuing from deleted element. - */ - list_for_each_continue_rcu(*i, head) { - struct nf_hook_ops *elem = (struct nf_hook_ops *)*i; - - if (hook_thresh > elem->priority) - continue; - - /* Optimization: we don't need to hold module - reference here, since function can't sleep. --RR */ - verdict = elem->hook(hook, skb, indev, outdev, okfn); - if (verdict != NF_ACCEPT) { -#ifdef CONFIG_NETFILTER_DEBUG - if (unlikely((verdict & NF_VERDICT_MASK) - > NF_MAX_VERDICT)) { - NFDEBUG("Evil return from %p(%u).\n", - elem->hook, hook); - continue; - } -#endif - if (verdict != NF_REPEAT) - return verdict; - *i = (*i)->prev; - } - } - return NF_ACCEPT; -} - -int nf_register_queue_handler(int pf, nf_queue_outfn_t outfn, void *data) -{ - int ret; - - if (pf >= NPROTO) - return -EINVAL; - - write_lock_bh(&queue_handler_lock); - if (queue_handler[pf].outfn) - ret = -EBUSY; - else { - queue_handler[pf].outfn = outfn; - queue_handler[pf].data = data; - ret = 0; - } - write_unlock_bh(&queue_handler_lock); - - return ret; -} - -/* The caller must flush their queue before this */ -int nf_unregister_queue_handler(int pf) -{ - if (pf >= NPROTO) - return -EINVAL; - - write_lock_bh(&queue_handler_lock); - queue_handler[pf].outfn = NULL; - queue_handler[pf].data = NULL; - write_unlock_bh(&queue_handler_lock); - - return 0; -} - -int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer) -{ - if (pf >= NPROTO) - return -EINVAL; - - write_lock_bh(&queue_handler_lock); - memcpy(&queue_rerouter[pf], rer, sizeof(queue_rerouter[pf])); - write_unlock_bh(&queue_handler_lock); - - return 0; -} - -int nf_unregister_queue_rerouter(int pf) -{ - if (pf >= NPROTO) - return -EINVAL; - - write_lock_bh(&queue_handler_lock); - memset(&queue_rerouter[pf], 0, sizeof(queue_rerouter[pf])); - write_unlock_bh(&queue_handler_lock); - return 0; -} - -void nf_unregister_queue_handlers(nf_queue_outfn_t outfn) -{ - int pf; - - write_lock_bh(&queue_handler_lock); - for (pf = 0; pf < NPROTO; pf++) { - if (queue_handler[pf].outfn == outfn) { - queue_handler[pf].outfn = NULL; - queue_handler[pf].data = NULL; - } - } - write_unlock_bh(&queue_handler_lock); -} - -/* - * Any packet that leaves via this function must come back - * through nf_reinject(). - */ -static int nf_queue(struct sk_buff **skb, - struct list_head *elem, - int pf, unsigned int hook, - struct net_device *indev, - struct net_device *outdev, - int (*okfn)(struct sk_buff *), - unsigned int queuenum) -{ - int status; - struct nf_info *info; -#ifdef CONFIG_BRIDGE_NETFILTER - struct net_device *physindev = NULL; - struct net_device *physoutdev = NULL; -#endif - - /* QUEUE == DROP if noone is waiting, to be safe. */ - read_lock(&queue_handler_lock); - if (!queue_handler[pf].outfn) { - read_unlock(&queue_handler_lock); - kfree_skb(*skb); - return 1; - } - - info = kmalloc(sizeof(*info)+queue_rerouter[pf].rer_size, GFP_ATOMIC); - if (!info) { - if (net_ratelimit()) - printk(KERN_ERR "OOM queueing packet %p\n", - *skb); - read_unlock(&queue_handler_lock); - kfree_skb(*skb); - return 1; - } - - *info = (struct nf_info) { - (struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn }; - - /* If it's going away, ignore hook. */ - if (!try_module_get(info->elem->owner)) { - read_unlock(&queue_handler_lock); - kfree(info); - return 0; - } - - /* Bump dev refs so they don't vanish while packet is out */ - if (indev) dev_hold(indev); - if (outdev) dev_hold(outdev); - -#ifdef CONFIG_BRIDGE_NETFILTER - if ((*skb)->nf_bridge) { - physindev = (*skb)->nf_bridge->physindev; - if (physindev) dev_hold(physindev); - physoutdev = (*skb)->nf_bridge->physoutdev; - if (physoutdev) dev_hold(physoutdev); - } -#endif - if (queue_rerouter[pf].save) - queue_rerouter[pf].save(*skb, info); - - status = queue_handler[pf].outfn(*skb, info, queuenum, - queue_handler[pf].data); - - if (status >= 0 && queue_rerouter[pf].reroute) - status = queue_rerouter[pf].reroute(skb, info); - - read_unlock(&queue_handler_lock); - - if (status < 0) { - /* James M doesn't say fuck enough. */ - if (indev) dev_put(indev); - if (outdev) dev_put(outdev); -#ifdef CONFIG_BRIDGE_NETFILTER - if (physindev) dev_put(physindev); - if (physoutdev) dev_put(physoutdev); -#endif - module_put(info->elem->owner); - kfree(info); - kfree_skb(*skb); - - return 1; - } - - return 1; -} - -/* Returns 1 if okfn() needs to be executed by the caller, - * -EPERM for NF_DROP, 0 otherwise. */ -int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb, - struct net_device *indev, - struct net_device *outdev, - int (*okfn)(struct sk_buff *), - int hook_thresh) -{ - struct list_head *elem; - unsigned int verdict; - int ret = 0; - - /* We may already have this, but read-locks nest anyway */ - rcu_read_lock(); - - elem = &nf_hooks[pf][hook]; -next_hook: - verdict = nf_iterate(&nf_hooks[pf][hook], pskb, hook, indev, - outdev, &elem, okfn, hook_thresh); - if (verdict == NF_ACCEPT || verdict == NF_STOP) { - ret = 1; - goto unlock; - } else if (verdict == NF_DROP) { - kfree_skb(*pskb); - ret = -EPERM; - } else if ((verdict & NF_VERDICT_MASK) == NF_QUEUE) { - NFDEBUG("nf_hook: Verdict = QUEUE.\n"); - if (!nf_queue(pskb, elem, pf, hook, indev, outdev, okfn, - verdict >> NF_VERDICT_BITS)) - goto next_hook; - } -unlock: - rcu_read_unlock(); - return ret; -} - -void nf_reinject(struct sk_buff *skb, struct nf_info *info, - unsigned int verdict) -{ - struct list_head *elem = &info->elem->list; - struct list_head *i; - - rcu_read_lock(); - - /* Release those devices we held, or Alexey will kill me. */ - if (info->indev) dev_put(info->indev); - if (info->outdev) dev_put(info->outdev); -#ifdef CONFIG_BRIDGE_NETFILTER - if (skb->nf_bridge) { - if (skb->nf_bridge->physindev) - dev_put(skb->nf_bridge->physindev); - if (skb->nf_bridge->physoutdev) - dev_put(skb->nf_bridge->physoutdev); - } -#endif - - /* Drop reference to owner of hook which queued us. */ - module_put(info->elem->owner); - - list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) { - if (i == elem) - break; - } - - if (elem == &nf_hooks[info->pf][info->hook]) { - /* The module which sent it to userspace is gone. */ - NFDEBUG("%s: module disappeared, dropping packet.\n", - __FUNCTION__); - verdict = NF_DROP; - } - - /* Continue traversal iff userspace said ok... */ - if (verdict == NF_REPEAT) { - elem = elem->prev; - verdict = NF_ACCEPT; - } - - if (verdict == NF_ACCEPT) { - next_hook: - verdict = nf_iterate(&nf_hooks[info->pf][info->hook], - &skb, info->hook, - info->indev, info->outdev, &elem, - info->okfn, INT_MIN); - } - - switch (verdict & NF_VERDICT_MASK) { - case NF_ACCEPT: - info->okfn(skb); - break; - - case NF_QUEUE: - if (!nf_queue(&skb, elem, info->pf, info->hook, - info->indev, info->outdev, info->okfn, - verdict >> NF_VERDICT_BITS)) - goto next_hook; - break; - } - rcu_read_unlock(); - - if (verdict == NF_DROP) - kfree_skb(skb); - - kfree(info); - return; -} - -int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len) -{ - struct sk_buff *nskb; - - if (writable_len > (*pskb)->len) - return 0; - - /* Not exclusive use of packet? Must copy. */ - if (skb_shared(*pskb) || skb_cloned(*pskb)) - goto copy_skb; - - return pskb_may_pull(*pskb, writable_len); - -copy_skb: - nskb = skb_copy(*pskb, GFP_ATOMIC); - if (!nskb) - return 0; - BUG_ON(skb_is_nonlinear(nskb)); - - /* Rest of kernel will get very unhappy if we pass it a - suddenly-orphaned skbuff */ - if ((*pskb)->sk) - skb_set_owner_w(nskb, (*pskb)->sk); - kfree_skb(*pskb); - *pskb = nskb; - return 1; -} -EXPORT_SYMBOL(skb_make_writable); - -/* Internal logging interface, which relies on the real - LOG target modules */ - -#define NF_LOG_PREFIXLEN 128 - -static struct nf_logger *nf_logging[NPROTO]; /* = NULL */ -static DEFINE_SPINLOCK(nf_log_lock); - -int nf_log_register(int pf, struct nf_logger *logger) -{ - int ret = -EBUSY; - - /* Any setup of logging members must be done before - * substituting pointer. */ - spin_lock(&nf_log_lock); - if (!nf_logging[pf]) { - rcu_assign_pointer(nf_logging[pf], logger); - ret = 0; - } - spin_unlock(&nf_log_lock); - return ret; -} - -void nf_log_unregister_pf(int pf) -{ - spin_lock(&nf_log_lock); - nf_logging[pf] = NULL; - spin_unlock(&nf_log_lock); - - /* Give time to concurrent readers. */ - synchronize_net(); -} - -void nf_log_unregister_logger(struct nf_logger *logger) -{ - int i; - - spin_lock(&nf_log_lock); - for (i = 0; i < NPROTO; i++) { - if (nf_logging[i] == logger) - nf_logging[i] = NULL; - } - spin_unlock(&nf_log_lock); - - synchronize_net(); -} - -void nf_log_packet(int pf, - unsigned int hooknum, - const struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - struct nf_loginfo *loginfo, - const char *fmt, ...) -{ - va_list args; - char prefix[NF_LOG_PREFIXLEN]; - struct nf_logger *logger; - - rcu_read_lock(); - logger = rcu_dereference(nf_logging[pf]); - if (logger) { - va_start(args, fmt); - vsnprintf(prefix, sizeof(prefix), fmt, args); - va_end(args); - /* We must read logging before nf_logfn[pf] */ - logger->logfn(pf, hooknum, skb, in, out, loginfo, prefix); - } else if (net_ratelimit()) { - printk(KERN_WARNING "nf_log_packet: can\'t log since " - "no backend logging module loaded in! Please either " - "load one, or disable logging explicitly\n"); - } - rcu_read_unlock(); -} -EXPORT_SYMBOL(nf_log_register); -EXPORT_SYMBOL(nf_log_unregister_pf); -EXPORT_SYMBOL(nf_log_unregister_logger); -EXPORT_SYMBOL(nf_log_packet); - -#ifdef CONFIG_PROC_FS -struct proc_dir_entry *proc_net_netfilter; -EXPORT_SYMBOL(proc_net_netfilter); - -static void *seq_start(struct seq_file *seq, loff_t *pos) -{ - rcu_read_lock(); - - if (*pos >= NPROTO) - return NULL; - - return pos; -} - -static void *seq_next(struct seq_file *s, void *v, loff_t *pos) -{ - (*pos)++; - - if (*pos >= NPROTO) - return NULL; - - return pos; -} - -static void seq_stop(struct seq_file *s, void *v) -{ - rcu_read_unlock(); -} - -static int seq_show(struct seq_file *s, void *v) -{ - loff_t *pos = v; - const struct nf_logger *logger; - - logger = rcu_dereference(nf_logging[*pos]); - - if (!logger) - return seq_printf(s, "%2lld NONE\n", *pos); - - return seq_printf(s, "%2lld %s\n", *pos, logger->name); -} - -static struct seq_operations nflog_seq_ops = { - .start = seq_start, - .next = seq_next, - .stop = seq_stop, - .show = seq_show, -}; - -static int nflog_open(struct inode *inode, struct file *file) -{ - return seq_open(file, &nflog_seq_ops); -} - -static struct file_operations nflog_file_ops = { - .owner = THIS_MODULE, - .open = nflog_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release, -}; - -#endif /* PROC_FS */ - - -/* This does not belong here, but locally generated errors need it if connection - tracking in use: without this, connection may not be in hash table, and hence - manufactured ICMP or RST packets will not be associated with it. */ -void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *); - -void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) -{ - void (*attach)(struct sk_buff *, struct sk_buff *); - - if (skb->nfct && (attach = ip_ct_attach) != NULL) { - mb(); /* Just to be sure: must be read before executing this */ - attach(new, skb); - } -} - -void __init netfilter_init(void) -{ - int i, h; -#ifdef CONFIG_PROC_FS - struct proc_dir_entry *pde; -#endif - - queue_rerouter = kmalloc(NPROTO * sizeof(struct nf_queue_rerouter), - GFP_KERNEL); - if (!queue_rerouter) - panic("netfilter: cannot allocate queue rerouter array\n"); - memset(queue_rerouter, 0, NPROTO * sizeof(struct nf_queue_rerouter)); - - for (i = 0; i < NPROTO; i++) { - for (h = 0; h < NF_MAX_HOOKS; h++) - INIT_LIST_HEAD(&nf_hooks[i][h]); - } - -#ifdef CONFIG_PROC_FS - proc_net_netfilter = proc_mkdir("netfilter", proc_net); - if (!proc_net_netfilter) - panic("cannot create netfilter proc entry"); - pde = create_proc_entry("nf_log", S_IRUGO, proc_net_netfilter); - if (!pde) - panic("cannot create /proc/net/netfilter/nf_log"); - pde->proc_fops = &nflog_file_ops; -#endif -} - -EXPORT_SYMBOL(ip_ct_attach); -EXPORT_SYMBOL(nf_ct_attach); -EXPORT_SYMBOL(nf_getsockopt); -EXPORT_SYMBOL(nf_hook_slow); -EXPORT_SYMBOL(nf_hooks); -EXPORT_SYMBOL(nf_register_hook); -EXPORT_SYMBOL(nf_register_queue_handler); -EXPORT_SYMBOL(nf_register_sockopt); -EXPORT_SYMBOL(nf_reinject); -EXPORT_SYMBOL(nf_setsockopt); -EXPORT_SYMBOL(nf_unregister_hook); -EXPORT_SYMBOL(nf_unregister_queue_handler); -EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers); -EXPORT_SYMBOL_GPL(nf_register_queue_rerouter); -EXPORT_SYMBOL_GPL(nf_unregister_queue_rerouter); -EXPORT_SYMBOL(nf_unregister_sockopt); diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index c41caebc4a7..b3b44f8b415 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -1,3 +1,7 @@ +netfilter-objs := core.o nf_log.o nf_queue.o nf_sockopt.o + +obj-$(CONFIG_NETFILTER) = netfilter.o + obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o diff --git a/net/netfilter/core.c b/net/netfilter/core.c new file mode 100644 index 00000000000..1ceb1a6c254 --- /dev/null +++ b/net/netfilter/core.c @@ -0,0 +1,216 @@ +/* netfilter.c: look after the filters for various protocols. + * Heavily influenced by the old firewall.c by David Bonn and Alan Cox. + * + * Thanks to Rob `CmdrTaco' Malda for not influencing this code in any + * way. + * + * Rusty Russell (C)2000 -- This code is GPL. + * + * February 2000: Modified by James Morris to have 1 queue per protocol. + * 15-Mar-2000: Added NF_REPEAT --RR. + * 08-May-2003: Internal logging interface added by Jozsef Kadlecsik. + */ +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/netfilter.h> +#include <net/protocol.h> +#include <linux/init.h> +#include <linux/skbuff.h> +#include <linux/wait.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/if.h> +#include <linux/netdevice.h> +#include <linux/inetdevice.h> +#include <linux/proc_fs.h> +#include <net/sock.h> + +#include "nf_internals.h" + +/* In this code, we can be waiting indefinitely for userspace to + * service a packet if a hook returns NF_QUEUE. We could keep a count + * of skbuffs queued for userspace, and not deregister a hook unless + * this is zero, but that sucks. Now, we simply check when the + * packets come back: if the hook is gone, the packet is discarded. */ +struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS]; +EXPORT_SYMBOL(nf_hooks); +static DEFINE_SPINLOCK(nf_hook_lock); + +int nf_register_hook(struct nf_hook_ops *reg) +{ + struct list_head *i; + + spin_lock_bh(&nf_hook_lock); + list_for_each(i, &nf_hooks[reg->pf][reg->hooknum]) { + if (reg->priority < ((struct nf_hook_ops *)i)->priority) + break; + } + list_add_rcu(®->list, i->prev); + spin_unlock_bh(&nf_hook_lock); + + synchronize_net(); + return 0; +} +EXPORT_SYMBOL(nf_register_hook); + +void nf_unregister_hook(struct nf_hook_ops *reg) +{ + spin_lock_bh(&nf_hook_lock); + list_del_rcu(®->list); + spin_unlock_bh(&nf_hook_lock); + + synchronize_net(); +} +EXPORT_SYMBOL(nf_unregister_hook); + +unsigned int nf_iterate(struct list_head *head, + struct sk_buff **skb, + int hook, + const struct net_device *indev, + const struct net_device *outdev, + struct list_head **i, + int (*okfn)(struct sk_buff *), + int hook_thresh) +{ + unsigned int verdict; + + /* + * The caller must not block between calls to this + * function because of risk of continuing from deleted element. + */ + list_for_each_continue_rcu(*i, head) { + struct nf_hook_ops *elem = (struct nf_hook_ops *)*i; + + if (hook_thresh > elem->priority) + continue; + + /* Optimization: we don't need to hold module + reference here, since function can't sleep. --RR */ + verdict = elem->hook(hook, skb, indev, outdev, okfn); + if (verdict != NF_ACCEPT) { +#ifdef CONFIG_NETFILTER_DEBUG + if (unlikely((verdict & NF_VERDICT_MASK) + > NF_MAX_VERDICT)) { + NFDEBUG("Evil return from %p(%u).\n", + elem->hook, hook); + continue; + } +#endif + if (verdict != NF_REPEAT) + return verdict; + *i = (*i)->prev; + } + } + return NF_ACCEPT; +} + + +/* Returns 1 if okfn() needs to be executed by the caller, + * -EPERM for NF_DROP, 0 otherwise. */ +int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb, + struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct sk_buff *), + int hook_thresh) +{ + struct list_head *elem; + unsigned int verdict; + int ret = 0; + + /* We may already have this, but read-locks nest anyway */ + rcu_read_lock(); + + elem = &nf_hooks[pf][hook]; +next_hook: + verdict = nf_iterate(&nf_hooks[pf][hook], pskb, hook, indev, + outdev, &elem, okfn, hook_thresh); + if (verdict == NF_ACCEPT || verdict == NF_STOP) { + ret = 1; + goto unlock; + } else if (verdict == NF_DROP) { + kfree_skb(*pskb); + ret = -EPERM; + } else if ((verdict & NF_VERDICT_MASK) == NF_QUEUE) { + NFDEBUG("nf_hook: Verdict = QUEUE.\n"); + if (!nf_queue(pskb, elem, pf, hook, indev, outdev, okfn, + verdict >> NF_VERDICT_BITS)) + goto next_hook; + } +unlock: + rcu_read_unlock(); + return ret; +} +EXPORT_SYMBOL(nf_hook_slow); + + +int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len) +{ + struct sk_buff *nskb; + + if (writable_len > (*pskb)->len) + return 0; + + /* Not exclusive use of packet? Must copy. */ + if (skb_shared(*pskb) || skb_cloned(*pskb)) + goto copy_skb; + + return pskb_may_pull(*pskb, writable_len); + +copy_skb: + nskb = skb_copy(*pskb, GFP_ATOMIC); + if (!nskb) + return 0; + BUG_ON(skb_is_nonlinear(nskb)); + + /* Rest of kernel will get very unhappy if we pass it a + suddenly-orphaned skbuff */ + if ((*pskb)->sk) + skb_set_owner_w(nskb, (*pskb)->sk); + kfree_skb(*pskb); + *pskb = nskb; + return 1; +} +EXPORT_SYMBOL(skb_make_writable); + + +/* This does not belong here, but locally generated errors need it if connection + tracking in use: without this, connection may not be in hash table, and hence + manufactured ICMP or RST packets will not be associated with it. */ +void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *); +EXPORT_SYMBOL(ip_ct_attach); + +void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) +{ + void (*attach)(struct sk_buff *, struct sk_buff *); + + if (skb->nfct && (attach = ip_ct_attach) != NULL) { + mb(); /* Just to be sure: must be read before executing this */ + attach(new, skb); + } +} +EXPORT_SYMBOL(nf_ct_attach); + +#ifdef CONFIG_PROC_FS +struct proc_dir_entry *proc_net_netfilter; +EXPORT_SYMBOL(proc_net_netfilter); +#endif + +void __init netfilter_init(void) +{ + int i, h; + for (i = 0; i < NPROTO; i++) { + for (h = 0; h < NF_MAX_HOOKS; h++) + INIT_LIST_HEAD(&nf_hooks[i][h]); + } + +#ifdef CONFIG_PROC_FS + proc_net_netfilter = proc_mkdir("netfilter", proc_net); + if (!proc_net_netfilter) + panic("cannot create netfilter proc entry"); +#endif + + if (netfilter_queue_init() < 0) + panic("cannot initialize nf_queue"); + if (netfilter_log_init() < 0) + panic("cannot initialize nf_log"); +} diff --git a/net/netfilter/nf_internals.h b/net/netfilter/nf_internals.h new file mode 100644 index 00000000000..6bdee291061 --- /dev/null +++ b/net/netfilter/nf_internals.h @@ -0,0 +1,39 @@ +#ifndef _NF_INTERNALS_H +#define _NF_INTERNALS_H + +#include <linux/config.h> +#include <linux/list.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> + +#ifdef CONFIG_NETFILTER_DEBUG +#define NFDEBUG(format, args...) printk(format , ## args) +#else +#define NFDEBUG(format, args...) +#endif + + +/* core.c */ +extern unsigned int nf_iterate(struct list_head *head, + struct sk_buff **skb, + int hook, + const struct net_device *indev, + const struct net_device *outdev, + struct list_head **i, + int (*okfn)(struct sk_buff *), + int hook_thresh); + +/* nf_queue.c */ +extern int nf_queue(struct sk_buff **skb, + struct list_head *elem, + int pf, unsigned int hook, + struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct sk_buff *), + unsigned int queuenum); +extern int __init netfilter_queue_init(void); + +/* nf_log.c */ +extern int __init netfilter_log_init(void); + +#endif diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c new file mode 100644 index 00000000000..ec58c4d2c66 --- /dev/null +++ b/net/netfilter/nf_log.c @@ -0,0 +1,165 @@ +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/skbuff.h> +#include <linux/netfilter.h> +#include <net/protocol.h> + +#include "nf_internals.h" + +/* Internal logging interface, which relies on the real + LOG target modules */ + +#define NF_LOG_PREFIXLEN 128 + +static struct nf_logger *nf_logging[NPROTO]; /* = NULL */ +static DEFINE_SPINLOCK(nf_log_lock); + +int nf_log_register(int pf, struct nf_logger *logger) +{ + int ret = -EBUSY; + + /* Any setup of logging members must be done before + * substituting pointer. */ + spin_lock(&nf_log_lock); + if (!nf_logging[pf]) { + rcu_assign_pointer(nf_logging[pf], logger); + ret = 0; + } + spin_unlock(&nf_log_lock); + return ret; +} +EXPORT_SYMBOL(nf_log_register); + +void nf_log_unregister_pf(int pf) +{ + spin_lock(&nf_log_lock); + nf_logging[pf] = NULL; + spin_unlock(&nf_log_lock); + + /* Give time to concurrent readers. */ + synchronize_net(); +} +EXPORT_SYMBOL(nf_log_unregister_pf); + +void nf_log_unregister_logger(struct nf_logger *logger) +{ + int i; + + spin_lock(&nf_log_lock); + for (i = 0; i < NPROTO; i++) { + if (nf_logging[i] == logger) + nf_logging[i] = NULL; + } + spin_unlock(&nf_log_lock); + + synchronize_net(); +} +EXPORT_SYMBOL(nf_log_unregister_logger); + +void nf_log_packet(int pf, + unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_loginfo *loginfo, + const char *fmt, ...) +{ + va_list args; + char prefix[NF_LOG_PREFIXLEN]; + struct nf_logger *logger; + + rcu_read_lock(); + logger = rcu_dereference(nf_logging[pf]); + if (logger) { + va_start(args, fmt); + vsnprintf(prefix, sizeof(prefix), fmt, args); + va_end(args); + /* We must read logging before nf_logfn[pf] */ + logger->logfn(pf, hooknum, skb, in, out, loginfo, prefix); + } else if (net_ratelimit()) { + printk(KERN_WARNING "nf_log_packet: can\'t log since " + "no backend logging module loaded in! Please either " + "load one, or disable logging explicitly\n"); + } + rcu_read_unlock(); +} +EXPORT_SYMBOL(nf_log_packet); + +#ifdef CONFIG_PROC_FS +static void *seq_start(struct seq_file *seq, loff_t *pos) +{ + rcu_read_lock(); + + if (*pos >= NPROTO) + return NULL; + + return pos; +} + +static void *seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + (*pos)++; + + if (*pos >= NPROTO) + return NULL; + + return pos; +} + +static void seq_stop(struct seq_file *s, void *v) +{ + rcu_read_unlock(); +} + +static int seq_show(struct seq_file *s, void *v) +{ + loff_t *pos = v; + const struct nf_logger *logger; + + logger = rcu_dereference(nf_logging[*pos]); + + if (!logger) + return seq_printf(s, "%2lld NONE\n", *pos); + + return seq_printf(s, "%2lld %s\n", *pos, logger->name); +} + +static struct seq_operations nflog_seq_ops = { + .start = seq_start, + .next = seq_next, + .stop = seq_stop, + .show = seq_show, +}; + +static int nflog_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &nflog_seq_ops); +} + +static struct file_operations nflog_file_ops = { + .owner = THIS_MODULE, + .open = nflog_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +#endif /* PROC_FS */ + + +int __init netfilter_log_init(void) +{ +#ifdef CONFIG_PROC_FS + struct proc_dir_entry *pde; + pde = create_proc_entry("nf_log", S_IRUGO, proc_net_netfilter); +#endif + if (!pde) + return -1; + + pde->proc_fops = &nflog_file_ops; + + return 0; +} diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c new file mode 100644 index 00000000000..5586f843ed4 --- /dev/null +++ b/net/netfilter/nf_queue.c @@ -0,0 +1,273 @@ +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/skbuff.h> +#include <linux/netfilter.h> +#include <net/protocol.h> + +#include "nf_internals.h" + +/* + * A queue handler may be registered for each protocol. Each is protected by + * long term mutex. The handler must provide an an outfn() to accept packets + * for queueing and must reinject all packets it receives, no matter what. + */ +static struct nf_queue_handler_t { + nf_queue_outfn_t outfn; + void *data; +} queue_handler[NPROTO]; + +static struct nf_queue_rerouter *queue_rerouter; + +static DEFINE_RWLOCK(queue_handler_lock); + + +int nf_register_queue_handler(int pf, nf_queue_outfn_t outfn, void *data) +{ + int ret; + + if (pf >= NPROTO) + return -EINVAL; + + write_lock_bh(&queue_handler_lock); + if (queue_handler[pf].outfn) + ret = -EBUSY; + else { + queue_handler[pf].outfn = outfn; + queue_handler[pf].data = data; + ret = 0; + } + write_unlock_bh(&queue_handler_lock); + + return ret; +} +EXPORT_SYMBOL(nf_register_queue_handler); + +/* The caller must flush their queue before this */ +int nf_unregister_queue_handler(int pf) +{ + if (pf >= NPROTO) + return -EINVAL; + + write_lock_bh(&queue_handler_lock); + queue_handler[pf].outfn = NULL; + queue_handler[pf].data = NULL; + write_unlock_bh(&queue_handler_lock); + + return 0; +} +EXPORT_SYMBOL(nf_unregister_queue_handler); + +int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer) +{ + if (pf >= NPROTO) + return -EINVAL; + + write_lock_bh(&queue_handler_lock); + memcpy(&queue_rerouter[pf], rer, sizeof(queue_rerouter[pf])); + write_unlock_bh(&queue_handler_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(nf_register_queue_rerouter); + +int nf_unregister_queue_rerouter(int pf) +{ + if (pf >= NPROTO) + return -EINVAL; + + write_lock_bh(&queue_handler_lock); + memset(&queue_rerouter[pf], 0, sizeof(queue_rerouter[pf])); + write_unlock_bh(&queue_handler_lock); + return 0; +} +EXPORT_SYMBOL_GPL(nf_unregister_queue_rerouter); + +void nf_unregister_queue_handlers(nf_queue_outfn_t outfn) +{ + int pf; + + write_lock_bh(&queue_handler_lock); + for (pf = 0; pf < NPROTO; pf++) { + if (queue_handler[pf].outfn == outfn) { + queue_handler[pf].outfn = NULL; + queue_handler[pf].data = NULL; + } + } + write_unlock_bh(&queue_handler_lock); +} +EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers); + +/* + * Any packet that leaves via this function must come back + * through nf_reinject(). + */ +int nf_queue(struct sk_buff **skb, + struct list_head *elem, + int pf, unsigned int hook, + struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct sk_buff *), + unsigned int queuenum) +{ + int status; + struct nf_info *info; +#ifdef CONFIG_BRIDGE_NETFILTER + struct net_device *physindev = NULL; + struct net_device *physoutdev = NULL; +#endif + + /* QUEUE == DROP if noone is waiting, to be safe. */ + read_lock(&queue_handler_lock); + if (!queue_handler[pf].outfn) { + read_unlock(&queue_handler_lock); + kfree_skb(*skb); + return 1; + } + + info = kmalloc(sizeof(*info)+queue_rerouter[pf].rer_size, GFP_ATOMIC); + if (!info) { + if (net_ratelimit()) + printk(KERN_ERR "OOM queueing packet %p\n", + *skb); + read_unlock(&queue_handler_lock); + kfree_skb(*skb); + return 1; + } + + *info = (struct nf_info) { + (struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn }; + + /* If it's going away, ignore hook. */ + if (!try_module_get(info->elem->owner)) { + read_unlock(&queue_handler_lock); + kfree(info); + return 0; + } + + /* Bump dev refs so they don't vanish while packet is out */ + if (indev) dev_hold(indev); + if (outdev) dev_hold(outdev); + +#ifdef CONFIG_BRIDGE_NETFILTER + if ((*skb)->nf_bridge) { + physindev = (*skb)->nf_bridge->physindev; + if (physindev) dev_hold(physindev); + physoutdev = (*skb)->nf_bridge->physoutdev; + if (physoutdev) dev_hold(physoutdev); + } +#endif + if (queue_rerouter[pf].save) + queue_rerouter[pf].save(*skb, info); + + status = queue_handler[pf].outfn(*skb, info, queuenum, + queue_handler[pf].data); + + if (status >= 0 && queue_rerouter[pf].reroute) + status = queue_rerouter[pf].reroute(skb, info); + + read_unlock(&queue_handler_lock); + + if (status < 0) { + /* James M doesn't say fuck enough. */ + if (indev) dev_put(indev); + if (outdev) dev_put(outdev); +#ifdef CONFIG_BRIDGE_NETFILTER + if (physindev) dev_put(physindev); + if (physoutdev) dev_put(physoutdev); +#endif + module_put(info->elem->owner); + kfree(info); + kfree_skb(*skb); + + return 1; + } + + return 1; +} + +void nf_reinject(struct sk_buff *skb, struct nf_info *info, + unsigned int verdict) +{ + struct list_head *elem = &info->elem->list; + struct list_head *i; + + rcu_read_lock(); + + /* Release those devices we held, or Alexey will kill me. */ + if (info->indev) dev_put(info->indev); + if (info->outdev) dev_put(info->outdev); +#ifdef CONFIG_BRIDGE_NETFILTER + if (skb->nf_bridge) { + if (skb->nf_bridge->physindev) + dev_put(skb->nf_bridge->physindev); + if (skb->nf_bridge->physoutdev) + dev_put(skb->nf_bridge->physoutdev); + } +#endif + + /* Drop reference to owner of hook which queued us. */ + module_put(info->elem->owner); + + list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) { + if (i == elem) + break; + } + + if (elem == &nf_hooks[info->pf][info->hook]) { + /* The module which sent it to userspace is gone. */ + NFDEBUG("%s: module disappeared, dropping packet.\n", + __FUNCTION__); + verdict = NF_DROP; + } + + /* Continue traversal iff userspace said ok... */ + if (verdict == NF_REPEAT) { + elem = elem->prev; + verdict = NF_ACCEPT; + } + + if (verdict == NF_ACCEPT) { + next_hook: + verdict = nf_iterate(&nf_hooks[info->pf][info->hook], + &skb, info->hook, + info->indev, info->outdev, &elem, + info->okfn, INT_MIN); + } + + switch (verdict & NF_VERDICT_MASK) { + case NF_ACCEPT: + info->okfn(skb); + break; + + case NF_QUEUE: + if (!nf_queue(&skb, elem, info->pf, info->hook, + info->indev, info->outdev, info->okfn, + verdict >> NF_VERDICT_BITS)) + goto next_hook; + break; + } + rcu_read_unlock(); + + if (verdict == NF_DROP) + kfree_skb(skb); + + kfree(info); + return; +} +EXPORT_SYMBOL(nf_reinject); + +int __init netfilter_queue_init(void) +{ + queue_rerouter = kmalloc(NPROTO * sizeof(struct nf_queue_rerouter), + GFP_KERNEL); + if (!queue_rerouter) + return -ENOMEM; + + memset(queue_rerouter, 0, NPROTO * sizeof(struct nf_queue_rerouter)); + + return 0; +} + diff --git a/net/netfilter/nf_sockopt.c b/net/netfilter/nf_sockopt.c new file mode 100644 index 00000000000..61a833a9caa --- /dev/null +++ b/net/netfilter/nf_sockopt.c @@ -0,0 +1,132 @@ +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/netfilter.h> +#include <net/sock.h> + +#include "nf_internals.h" + +/* Sockopts only registered and called from user context, so + net locking would be overkill. Also, [gs]etsockopt calls may + sleep. */ +static DECLARE_MUTEX(nf_sockopt_mutex); +static LIST_HEAD(nf_sockopts); + +/* Do exclusive ranges overlap? */ +static inline int overlap(int min1, int max1, int min2, int max2) +{ + return max1 > min2 && min1 < max2; +} + +/* Functions to register sockopt ranges (exclusive). */ +int nf_register_sockopt(struct nf_sockopt_ops *reg) +{ + struct list_head *i; + int ret = 0; + + if (down_interruptible(&nf_sockopt_mutex) != 0) + return -EINTR; + + list_for_each(i, &nf_sockopts) { + struct nf_sockopt_ops *ops = (struct nf_sockopt_ops *)i; + if (ops->pf == reg->pf + && (overlap(ops->set_optmin, ops->set_optmax, + reg->set_optmin, reg->set_optmax) + || overlap(ops->get_optmin, ops->get_optmax, + reg->get_optmin, reg->get_optmax))) { + NFDEBUG("nf_sock overlap: %u-%u/%u-%u v %u-%u/%u-%u\n", + ops->set_optmin, ops->set_optmax, + ops->get_optmin, ops->get_optmax, + reg->set_optmin, reg->set_optmax, + reg->get_optmin, reg->get_optmax); + ret = -EBUSY; + goto out; + } + } + + list_add(®->list, &nf_sockopts); +out: + up(&nf_sockopt_mutex); + return ret; +} +EXPORT_SYMBOL(nf_register_sockopt); + +void nf_unregister_sockopt(struct nf_sockopt_ops *reg) +{ + /* No point being interruptible: we're probably in cleanup_module() */ + restart: + down(&nf_sockopt_mutex); + if (reg->use != 0) { + /* To be woken by nf_sockopt call... */ + /* FIXME: Stuart Young's name appears gratuitously. */ + set_current_state(TASK_UNINTERRUPTIBLE); + reg->cleanup_task = current; + up(&nf_sockopt_mutex); + schedule(); + goto restart; + } + list_del(®->list); + up(&nf_sockopt_mutex); +} +EXPORT_SYMBOL(nf_unregister_sockopt); + +/* Call get/setsockopt() */ +static int nf_sockopt(struct sock *sk, int pf, int val, + char __user *opt, int *len, int get) +{ + struct list_head *i; + struct nf_sockopt_ops *ops; + int ret; + + if (down_interruptible(&nf_sockopt_mutex) != 0) + return -EINTR; + + list_for_each(i, &nf_sockopts) { + ops = (struct nf_sockopt_ops *)i; + if (ops->pf == pf) { + if (get) { + if (val >= ops->get_optmin + && val < ops->get_optmax) { + ops->use++; + up(&nf_sockopt_mutex); + ret = ops->get(sk, val, opt, len); + goto out; + } + } else { + if (val >= ops->set_optmin + && val < ops->set_optmax) { + ops->use++; + up(&nf_sockopt_mutex); + ret = ops->set(sk, val, opt, *len); + goto out; + } + } + } + } + up(&nf_sockopt_mutex); + return -ENOPROTOOPT; + + out: + down(&nf_sockopt_mutex); + ops->use--; + if (ops->cleanup_task) + wake_up_process(ops->cleanup_task); + up(&nf_sockopt_mutex); + return ret; +} + +int nf_setsockopt(struct sock *sk, int pf, int val, char __user *opt, + int len) +{ + return nf_sockopt(sk, pf, val, opt, &len, 0); +} +EXPORT_SYMBOL(nf_setsockopt); + +int nf_getsockopt(struct sock *sk, int pf, int val, char __user *opt, int *len) +{ + return nf_sockopt(sk, pf, val, opt, len, 1); +} +EXPORT_SYMBOL(nf_getsockopt); + |