diff options
Diffstat (limited to 'drivers/net/ppp/pppoe.c')
| -rw-r--r-- | drivers/net/ppp/pppoe.c | 1208 |
1 files changed, 1208 insertions, 0 deletions
diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c new file mode 100644 index 000000000000..bc9a4bb31980 --- /dev/null +++ b/drivers/net/ppp/pppoe.c @@ -0,0 +1,1208 @@ +/** -*- linux-c -*- *********************************************************** + * Linux PPP over Ethernet (PPPoX/PPPoE) Sockets + * + * PPPoX --- Generic PPP encapsulation socket family + * PPPoE --- PPP over Ethernet (RFC 2516) + * + * + * Version: 0.7.0 + * + * 070228 : Fix to allow multiple sessions with same remote MAC and same + * session id by including the local device ifindex in the + * tuple identifying a session. This also ensures packets can't + * be injected into a session from interfaces other than the one + * specified by userspace. Florian Zumbiehl <florz@florz.de> + * (Oh, BTW, this one is YYMMDD, in case you were wondering ...) + * 220102 : Fix module use count on failure in pppoe_create, pppox_sk -acme + * 030700 : Fixed connect logic to allow for disconnect. + * 270700 : Fixed potential SMP problems; we must protect against + * simultaneous invocation of ppp_input + * and ppp_unregister_channel. + * 040800 : Respect reference count mechanisms on net-devices. + * 200800 : fix kfree(skb) in pppoe_rcv (acme) + * Module reference count is decremented in the right spot now, + * guards against sock_put not actually freeing the sk + * in pppoe_release. + * 051000 : Initialization cleanup. + * 111100 : Fix recvmsg. + * 050101 : Fix PADT procesing. + * 140501 : Use pppoe_rcv_core to handle all backlog. (Alexey) + * 170701 : Do not lock_sock with rwlock held. (DaveM) + * Ignore discovery frames if user has socket + * locked. (DaveM) + * Ignore return value of dev_queue_xmit in __pppoe_xmit + * or else we may kfree an SKB twice. (DaveM) + * 190701 : When doing copies of skb's in __pppoe_xmit, always delete + * the original skb that was passed in on success, never on + * failure. Delete the copy of the skb on failure to avoid + * a memory leak. + * 081001 : Misc. cleanup (licence string, non-blocking, prevent + * reference of device on close). + * 121301 : New ppp channels interface; cannot unregister a channel + * from interrupts. Thus, we mark the socket as a ZOMBIE + * and do the unregistration later. + * 081002 : seq_file support for proc stuff -acme + * 111602 : Merge all 2.4 fixes into 2.5/2.6 tree. Label 2.5/2.6 + * as version 0.7. Spacing cleanup. + * Author: Michal Ostrowski <mostrows@speakeasy.net> + * Contributors: + * Arnaldo Carvalho de Melo <acme@conectiva.com.br> + * David S. Miller (davem@redhat.com) + * + * License: + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +#include <linux/string.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/netdevice.h> +#include <linux/net.h> +#include <linux/inetdevice.h> +#include <linux/etherdevice.h> +#include <linux/skbuff.h> +#include <linux/init.h> +#include <linux/if_ether.h> +#include <linux/if_pppox.h> +#include <linux/ppp_channel.h> +#include <linux/ppp_defs.h> +#include <linux/if_ppp.h> +#include <linux/notifier.h> +#include <linux/file.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> + +#include <linux/nsproxy.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/sock.h> + +#include <asm/uaccess.h> + +#define PPPOE_HASH_BITS 4 +#define PPPOE_HASH_SIZE (1 << PPPOE_HASH_BITS) +#define PPPOE_HASH_MASK (PPPOE_HASH_SIZE - 1) + +static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb); + +static const struct proto_ops pppoe_ops; +static const struct ppp_channel_ops pppoe_chan_ops; + +/* per-net private data for this module */ +static int pppoe_net_id __read_mostly; +struct pppoe_net { + /* + * we could use _single_ hash table for all + * nets by injecting net id into the hash but + * it would increase hash chains and add + * a few additional math comparations messy + * as well, moreover in case of SMP less locking + * controversy here + */ + struct pppox_sock *hash_table[PPPOE_HASH_SIZE]; + rwlock_t hash_lock; +}; + +/* + * PPPoE could be in the following stages: + * 1) Discovery stage (to obtain remote MAC and Session ID) + * 2) Session stage (MAC and SID are known) + * + * Ethernet frames have a special tag for this but + * we use simpler approach based on session id + */ +static inline bool stage_session(__be16 sid) +{ + return sid != 0; +} + +static inline struct pppoe_net *pppoe_pernet(struct net *net) +{ + BUG_ON(!net); + + return net_generic(net, pppoe_net_id); +} + +static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b) +{ + return a->sid == b->sid && !memcmp(a->remote, b->remote, ETH_ALEN); +} + +static inline int cmp_addr(struct pppoe_addr *a, __be16 sid, char *addr) +{ + return a->sid == sid && !memcmp(a->remote, addr, ETH_ALEN); +} + +#if 8 % PPPOE_HASH_BITS +#error 8 must be a multiple of PPPOE_HASH_BITS +#endif + +static int hash_item(__be16 sid, unsigned char *addr) +{ + unsigned char hash = 0; + unsigned int i; + + for (i = 0; i < ETH_ALEN; i++) + hash ^= addr[i]; + for (i = 0; i < sizeof(sid_t) * 8; i += 8) + hash ^= (__force __u32)sid >> i; + for (i = 8; (i >>= 1) >= PPPOE_HASH_BITS;) + hash ^= hash >> i; + + return hash & PPPOE_HASH_MASK; +} + +/********************************************************************** + * + * Set/get/delete/rehash items (internal versions) + * + **********************************************************************/ +static struct pppox_sock *__get_item(struct pppoe_net *pn, __be16 sid, + unsigned char *addr, int ifindex) +{ + int hash = hash_item(sid, addr); + struct pppox_sock *ret; + + ret = pn->hash_table[hash]; + while (ret) { + if (cmp_addr(&ret->pppoe_pa, sid, addr) && + ret->pppoe_ifindex == ifindex) + return ret; + + ret = ret->next; + } + + return NULL; +} + +static int __set_item(struct pppoe_net *pn, struct pppox_sock *po) +{ + int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); + struct pppox_sock *ret; + + ret = pn->hash_table[hash]; + while (ret) { + if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) && + ret->pppoe_ifindex == po->pppoe_ifindex) + return -EALREADY; + + ret = ret->next; + } + + po->next = pn->hash_table[hash]; + pn->hash_table[hash] = po; + + return 0; +} + +static struct pppox_sock *__delete_item(struct pppoe_net *pn, __be16 sid, + char *addr, int ifindex) +{ + int hash = hash_item(sid, addr); + struct pppox_sock *ret, **src; + + ret = pn->hash_table[hash]; + src = &pn->hash_table[hash]; + + while (ret) { + if (cmp_addr(&ret->pppoe_pa, sid, addr) && + ret->pppoe_ifindex == ifindex) { + *src = ret->next; + break; + } + + src = &ret->next; + ret = ret->next; + } + + return ret; +} + +/********************************************************************** + * + * Set/get/delete/rehash items + * + **********************************************************************/ +static inline struct pppox_sock *get_item(struct pppoe_net *pn, __be16 sid, + unsigned char *addr, int ifindex) +{ + struct pppox_sock *po; + + read_lock_bh(&pn->hash_lock); + po = __get_item(pn, sid, addr, ifindex); + if (po) + sock_hold(sk_pppox(po)); + read_unlock_bh(&pn->hash_lock); + + return po; +} + +static inline struct pppox_sock *get_item_by_addr(struct net *net, + struct sockaddr_pppox *sp) +{ + struct net_device *dev; + struct pppoe_net *pn; + struct pppox_sock *pppox_sock = NULL; + + int ifindex; + + rcu_read_lock(); + dev = dev_get_by_name_rcu(net, sp->sa_addr.pppoe.dev); + if (dev) { + ifindex = dev->ifindex; + pn = pppoe_pernet(net); + pppox_sock = get_item(pn, sp->sa_addr.pppoe.sid, + sp->sa_addr.pppoe.remote, ifindex); + } + rcu_read_unlock(); + return pppox_sock; +} + +static inline struct pppox_sock *delete_item(struct pppoe_net *pn, __be16 sid, + char *addr, int ifindex) +{ + struct pppox_sock *ret; + + write_lock_bh(&pn->hash_lock); + ret = __delete_item(pn, sid, addr, ifindex); + write_unlock_bh(&pn->hash_lock); + + return ret; +} + +/*************************************************************************** + * + * Handler for device events. + * Certain device events require that sockets be unconnected. + * + **************************************************************************/ + +static void pppoe_flush_dev(struct net_device *dev) +{ + struct pppoe_net *pn; + int i; + + pn = pppoe_pernet(dev_net(dev)); + write_lock_bh(&pn->hash_lock); + for (i = 0; i < PPPOE_HASH_SIZE; i++) { + struct pppox_sock *po = pn->hash_table[i]; + struct sock *sk; + + while (po) { + while (po && po->pppoe_dev != dev) { + po = po->next; + } + + if (!po) + break; + + sk = sk_pppox(po); + + /* We always grab the socket lock, followed by the + * hash_lock, in that order. Since we should hold the + * sock lock while doing any unbinding, we need to + * release the lock we're holding. Hold a reference to + * the sock so it doesn't disappear as we're jumping + * between locks. + */ + + sock_hold(sk); + write_unlock_bh(&pn->hash_lock); + lock_sock(sk); + + if (po->pppoe_dev == dev && + sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND | PPPOX_ZOMBIE)) { + pppox_unbind_sock(sk); + sk->sk_state = PPPOX_ZOMBIE; + sk->sk_state_change(sk); + po->pppoe_dev = NULL; + dev_put(dev); + } + + release_sock(sk); + sock_put(sk); + + /* Restart the process from the start of the current + * hash chain. We dropped locks so the world may have + * change from underneath us. + */ + + BUG_ON(pppoe_pernet(dev_net(dev)) == NULL); + write_lock_bh(&pn->hash_lock); + po = pn->hash_table[i]; + } + } + write_unlock_bh(&pn->hash_lock); +} + +static int pppoe_device_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = (struct net_device *)ptr; + + /* Only look at sockets that are using this specific device. */ + switch (event) { + case NETDEV_CHANGEADDR: + case NETDEV_CHANGEMTU: + /* A change in mtu or address is a bad thing, requiring + * LCP re-negotiation. + */ + + case NETDEV_GOING_DOWN: + case NETDEV_DOWN: + /* Find every socket on this device and kill it. */ + pppoe_flush_dev(dev); + break; + + default: + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block pppoe_notifier = { + .notifier_call = pppoe_device_event, +}; + +/************************************************************************ + * + * Do the real work of receiving a PPPoE Session frame. + * + ***********************************************************************/ +static int pppoe_rcv_core(struct sock *sk, struct sk_buff *skb) +{ + struct pppox_sock *po = pppox_sk(sk); + struct pppox_sock *relay_po; + + /* Backlog receive. Semantics of backlog rcv preclude any code from + * executing in lock_sock()/release_sock() bounds; meaning sk->sk_state + * can't change. + */ + + if (sk->sk_state & PPPOX_BOUND) { + ppp_input(&po->chan, skb); + } else if (sk->sk_state & PPPOX_RELAY) { + relay_po = get_item_by_addr(sock_net(sk), + &po->pppoe_relay); + if (relay_po == NULL) + goto abort_kfree; + + if ((sk_pppox(relay_po)->sk_state & PPPOX_CONNECTED) == 0) + goto abort_put; + + if (!__pppoe_xmit(sk_pppox(relay_po), skb)) + goto abort_put; + } else { + if (sock_queue_rcv_skb(sk, skb)) + goto abort_kfree; + } + + return NET_RX_SUCCESS; + +abort_put: + sock_put(sk_pppox(relay_po)); + +abort_kfree: + kfree_skb(skb); + return NET_RX_DROP; +} + +/************************************************************************ + * + * Receive wrapper called in BH context. + * + ***********************************************************************/ +static int pppoe_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct pppoe_hdr *ph; + struct pppox_sock *po; + struct pppoe_net *pn; + int len; + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + goto out; + + if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr))) + goto drop; + + ph = pppoe_hdr(skb); + len = ntohs(ph->length); + + skb_pull_rcsum(skb, sizeof(*ph)); + if (skb->len < len) + goto drop; + + if (pskb_trim_rcsum(skb, len)) + goto drop; + + pn = pppoe_pernet(dev_net(dev)); + + /* Note that get_item does a sock_hold(), so sk_pppox(po) + * is known to be safe. + */ + po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex); + if (!po) + goto drop; + + return sk_receive_skb(sk_pppox(po), skb, 0); + +drop: + kfree_skb(skb); +out: + return NET_RX_DROP; +} + +/************************************************************************ + * + * Receive a PPPoE Discovery frame. + * This is solely for detection of PADT frames + * + ***********************************************************************/ +static int pppoe_disc_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) + +{ + struct pppoe_hdr *ph; + struct pppox_sock *po; + struct pppoe_net *pn; + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + goto out; + + if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr))) + goto abort; + + ph = pppoe_hdr(skb); + if (ph->code != PADT_CODE) + goto abort; + + pn = pppoe_pernet(dev_net(dev)); + po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex); + if (po) { + struct sock *sk = sk_pppox(po); + + bh_lock_sock(sk); + + /* If the user has locked the socket, just ignore + * the packet. With the way two rcv protocols hook into + * one socket family type, we cannot (easily) distinguish + * what kind of SKB it is during backlog rcv. + */ + if (sock_owned_by_user(sk) == 0) { + /* We're no longer connect at the PPPOE layer, + * and must wait for ppp channel to disconnect us. + */ + sk->sk_state = PPPOX_ZOMBIE; + } + + bh_unlock_sock(sk); + sock_put(sk); + } + +abort: + kfree_skb(skb); +out: + return NET_RX_SUCCESS; /* Lies... :-) */ +} + +static struct packet_type pppoes_ptype __read_mostly = { + .type = cpu_to_be16(ETH_P_PPP_SES), + .func = pppoe_rcv, +}; + +static struct packet_type pppoed_ptype __read_mostly = { + .type = cpu_to_be16(ETH_P_PPP_DISC), + .func = pppoe_disc_rcv, +}; + +static struct proto pppoe_sk_proto __read_mostly = { + .name = "PPPOE", + .owner = THIS_MODULE, + .obj_size = sizeof(struct pppox_sock), +}; + +/*********************************************************************** + * + * Initialize a new struct sock. + * + **********************************************************************/ +static int pppoe_create(struct net *net, struct socket *sock) +{ + struct sock *sk; + + sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto); + if (!sk) + return -ENOMEM; + + sock_init_data(sock, sk); + + sock->state = SS_UNCONNECTED; + sock->ops = &pppoe_ops; + + sk->sk_backlog_rcv = pppoe_rcv_core; + sk->sk_state = PPPOX_NONE; + sk->sk_type = SOCK_STREAM; + sk->sk_family = PF_PPPOX; + sk->sk_protocol = PX_PROTO_OE; + + return 0; +} + +static int pppoe_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct pppox_sock *po; + struct pppoe_net *pn; + struct net *net = NULL; + + if (!sk) + return 0; + + lock_sock(sk); + if (sock_flag(sk, SOCK_DEAD)) { + release_sock(sk); + return -EBADF; + } + + po = pppox_sk(sk); + + if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) { + dev_put(po->pppoe_dev); + po->pppoe_dev = NULL; + } + + pppox_unbind_sock(sk); + + /* Signal the death of the socket. */ + sk->sk_state = PPPOX_DEAD; + + net = sock_net(sk); + pn = pppoe_pernet(net); + + /* + * protect "po" from concurrent updates + * on pppoe_flush_dev + */ + delete_item(pn, po->pppoe_pa.sid, po->pppoe_pa.remote, + po->pppoe_ifindex); + + sock_orphan(sk); + sock->sk = NULL; + + skb_queue_purge(&sk->sk_receive_queue); + release_sock(sk); + sock_put(sk); + + return 0; +} + +static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr, + int sockaddr_len, int flags) +{ + struct sock *sk = sock->sk; + struct sockaddr_pppox *sp = (struct sockaddr_pppox *)uservaddr; + struct pppox_sock *po = pppox_sk(sk); + struct net_device *dev = NULL; + struct pppoe_net *pn; + struct net *net = NULL; + int error; + + lock_sock(sk); + + error = -EINVAL; + if (sp->sa_protocol != PX_PROTO_OE) + goto end; + + /* Check for already bound sockets */ + error = -EBUSY; + if ((sk->sk_state & PPPOX_CONNECTED) && + stage_session(sp->sa_addr.pppoe.sid)) + goto end; + + /* Check for already disconnected sockets, on attempts to disconnect */ + error = -EALREADY; + if ((sk->sk_state & PPPOX_DEAD) && + !stage_session(sp->sa_addr.pppoe.sid)) + goto end; + + error = 0; + + /* Delete the old binding */ + if (stage_session(po->pppoe_pa.sid)) { + pppox_unbind_sock(sk); + pn = pppoe_pernet(sock_net(sk)); + delete_item(pn, po->pppoe_pa.sid, + po->pppoe_pa.remote, po->pppoe_ifindex); + if (po->pppoe_dev) { + dev_put(po->pppoe_dev); + po->pppoe_dev = NULL; + } + + memset(sk_pppox(po) + 1, 0, + sizeof(struct pppox_sock) - sizeof(struct sock)); + sk->sk_state = PPPOX_NONE; + } + + /* Re-bind in session stage only */ + if (stage_session(sp->sa_addr.pppoe.sid)) { + error = -ENODEV; + net = sock_net(sk); + dev = dev_get_by_name(net, sp->sa_addr.pppoe.dev); + if (!dev) + goto err_put; + + po->pppoe_dev = dev; + po->pppoe_ifindex = dev->ifindex; + pn = pppoe_pernet(net); + if (!(dev->flags & IFF_UP)) { + goto err_put; + } + + memcpy(&po->pppoe_pa, + &sp->sa_addr.pppoe, + sizeof(struct pppoe_addr)); + + write_lock_bh(&pn->hash_lock); + error = __set_item(pn, po); + write_unlock_bh(&pn->hash_lock); + if (error < 0) + goto err_put; + + po->chan.hdrlen = (sizeof(struct pppoe_hdr) + + dev->hard_header_len); + + po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr); + po->chan.private = sk; + po->chan.ops = &pppoe_chan_ops; + + error = ppp_register_net_channel(dev_net(dev), &po->chan); + if (error) { + delete_item(pn, po->pppoe_pa.sid, + po->pppoe_pa.remote, po->pppoe_ifindex); + goto err_put; + } + + sk->sk_state = PPPOX_CONNECTED; + } + + po->num = sp->sa_addr.pppoe.sid; + +end: + release_sock(sk); + return error; +err_put: + if (po->pppoe_dev) { + dev_put(po->pppoe_dev); + po->pppoe_dev = NULL; + } + goto end; +} + +static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr, + int *usockaddr_len, int peer) +{ + int len = sizeof(struct sockaddr_pppox); + struct sockaddr_pppox sp; + + sp.sa_family = AF_PPPOX; + sp.sa_protocol = PX_PROTO_OE; + memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa, + sizeof(struct pppoe_addr)); + + memcpy(uaddr, &sp, len); + + *usockaddr_len = len; + + return 0; +} + +static int pppoe_ioctl(struct socket *sock, unsigned int cmd, + unsigned long arg) +{ + struct sock *sk = sock->sk; + struct pppox_sock *po = pppox_sk(sk); + int val; + int err; + + switch (cmd) { + case PPPIOCGMRU: + err = -ENXIO; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + err = -EFAULT; + if (put_user(po->pppoe_dev->mtu - + sizeof(struct pppoe_hdr) - + PPP_HDRLEN, + (int __user *)arg)) + break; + err = 0; + break; + + case PPPIOCSMRU: + err = -ENXIO; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + err = -EFAULT; + if (get_user(val, (int __user *)arg)) + break; + + if (val < (po->pppoe_dev->mtu + - sizeof(struct pppoe_hdr) + - PPP_HDRLEN)) + err = 0; + else + err = -EINVAL; + break; + + case PPPIOCSFLAGS: + err = -EFAULT; + if (get_user(val, (int __user *)arg)) + break; + err = 0; + break; + + case PPPOEIOCSFWD: + { + struct pppox_sock *relay_po; + + err = -EBUSY; + if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD)) + break; + + err = -ENOTCONN; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + /* PPPoE address from the user specifies an outbound + PPPoE address which frames are forwarded to */ + err = -EFAULT; + if (copy_from_user(&po->pppoe_relay, + (void __user *)arg, + sizeof(struct sockaddr_pppox))) + break; + + err = -EINVAL; + if (po->pppoe_relay.sa_family != AF_PPPOX || + po->pppoe_relay.sa_protocol != PX_PROTO_OE) + break; + + /* Check that the socket referenced by the address + actually exists. */ + relay_po = get_item_by_addr(sock_net(sk), &po->pppoe_relay); + if (!relay_po) + break; + + sock_put(sk_pppox(relay_po)); + sk->sk_state |= PPPOX_RELAY; + err = 0; + break; + } + + case PPPOEIOCDFWD: + err = -EALREADY; + if (!(sk->sk_state & PPPOX_RELAY)) + break; + + sk->sk_state &= ~PPPOX_RELAY; + err = 0; + break; + + default: + err = -ENOTTY; + } + + return err; +} + +static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock, + struct msghdr *m, size_t total_len) +{ + struct sk_buff *skb; + struct sock *sk = sock->sk; + struct pppox_sock *po = pppox_sk(sk); + int error; + struct pppoe_hdr hdr; + struct pppoe_hdr *ph; + struct net_device *dev; + char *start; + + lock_sock(sk); + if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) { + error = -ENOTCONN; + goto end; + } + + hdr.ver = 1; + hdr.type = 1; + hdr.code = 0; + hdr.sid = po->num; + + dev = po->pppoe_dev; + + error = -EMSGSIZE; + if (total_len > (dev->mtu + dev->hard_header_len)) + goto end; + + + skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32, + 0, GFP_KERNEL); + if (!skb) { + error = -ENOMEM; + goto end; + } + + /* Reserve space for headers. */ + skb_reserve(skb, dev->hard_header_len); + skb_reset_network_header(skb); + + skb->dev = dev; + + skb->priority = sk->sk_priority; + skb->protocol = cpu_to_be16(ETH_P_PPP_SES); + + ph = (struct pppoe_hdr *)skb_put(skb, total_len + sizeof(struct pppoe_hdr)); + start = (char *)&ph->tag[0]; + + error = memcpy_fromiovec(start, m->msg_iov, total_len); + if (error < 0) { + kfree_skb(skb); + goto end; + } + + error = total_len; + dev_hard_header(skb, dev, ETH_P_PPP_SES, + po->pppoe_pa.remote, NULL, total_len); + + memcpy(ph, &hdr, sizeof(struct pppoe_hdr)); + + ph->length = htons(total_len); + + dev_queue_xmit(skb); + +end: + release_sock(sk); + return error; +} + +/************************************************************************ + * + * xmit function for internal use. + * + ***********************************************************************/ +static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb) +{ + struct pppox_sock *po = pppox_sk(sk); + struct net_device *dev = po->pppoe_dev; + struct pppoe_hdr *ph; + int data_len = skb->len; + + /* The higher-level PPP code (ppp_unregister_channel()) ensures the PPP + * xmit operations conclude prior to an unregistration call. Thus + * sk->sk_state cannot change, so we don't need to do lock_sock(). + * But, we also can't do a lock_sock since that introduces a potential + * deadlock as we'd reverse the lock ordering used when calling + * ppp_unregister_channel(). + */ + + if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) + goto abort; + + if (!dev) + goto abort; + + /* Copy the data if there is no space for the header or if it's + * read-only. + */ + if (skb_cow_head(skb, sizeof(*ph) + dev->hard_header_len)) + goto abort; + + __skb_push(skb, sizeof(*ph)); + skb_reset_network_header(skb); + + ph = pppoe_hdr(skb); + ph->ver = 1; + ph->type = 1; + ph->code = 0; + ph->sid = po->num; + ph->length = htons(data_len); + + skb->protocol = cpu_to_be16(ETH_P_PPP_SES); + skb->dev = dev; + + dev_hard_header(skb, dev, ETH_P_PPP_SES, + po->pppoe_pa.remote, NULL, data_len); + + dev_queue_xmit(skb); + return 1; + +abort: + kfree_skb(skb); + return 1; +} + +/************************************************************************ + * + * xmit function called by generic PPP driver + * sends PPP frame over PPPoE socket + * + ***********************************************************************/ +static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb) +{ + struct sock *sk = (struct sock *)chan->private; + return __pppoe_xmit(sk, skb); +} + +static const struct ppp_channel_ops pppoe_chan_ops = { + .start_xmit = pppoe_xmit, +}; + +static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock, + struct msghdr *m, size_t total_len, int flags) +{ + struct sock *sk = sock->sk; + struct sk_buff *skb; + int error = 0; + + if (sk->sk_state & PPPOX_BOUND) { + error = -EIO; + goto end; + } + + skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, + flags & MSG_DONTWAIT, &error); + if (error < 0) + goto end; + + m->msg_namelen = 0; + + if (skb) { + total_len = min_t(size_t, total_len, skb->len); + error = skb_copy_datagram_iovec(skb, 0, m->msg_iov, total_len); + if (error == 0) + error = total_len; + } + + kfree_skb(skb); +end: + return error; +} + +#ifdef CONFIG_PROC_FS +static int pppoe_seq_show(struct seq_file *seq, void *v) +{ + struct pppox_sock *po; + char *dev_name; + + if (v == SEQ_START_TOKEN) { + seq_puts(seq, "Id Address Device\n"); + goto out; + } + + po = v; + dev_name = po->pppoe_pa.dev; + + seq_printf(seq, "%08X %pM %8s\n", + po->pppoe_pa.sid, po->pppoe_pa.remote, dev_name); +out: + return 0; +} + +static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos) +{ + struct pppox_sock *po; + int i; + + for (i = 0; i < PPPOE_HASH_SIZE; i++) { + po = pn->hash_table[i]; + while (po) { + if (!pos--) + goto out; + po = po->next; + } + } + +out: + return po; +} + +static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(pn->hash_lock) +{ + struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); + loff_t l = *pos; + + read_lock_bh(&pn->hash_lock); + return l ? pppoe_get_idx(pn, --l) : SEQ_START_TOKEN; +} + +static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); + struct pppox_sock *po; + + ++*pos; + if (v == SEQ_START_TOKEN) { + po = pppoe_get_idx(pn, 0); + goto out; + } + po = v; + if (po->next) + po = po->next; + else { + int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); + + po = NULL; + while (++hash < PPPOE_HASH_SIZE) { + po = pn->hash_table[hash]; + if (po) + break; + } + } + +out: + return po; +} + +static void pppoe_seq_stop(struct seq_file *seq, void *v) + __releases(pn->hash_lock) +{ + struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); + read_unlock_bh(&pn->hash_lock); +} + +static const struct seq_operations pppoe_seq_ops = { + .start = pppoe_seq_start, + .next = pppoe_seq_next, + .stop = pppoe_seq_stop, + .show = pppoe_seq_show, +}; + +static int pppoe_seq_open(struct inode *inode, struct file *file) +{ + return seq_open_net(inode, file, &pppoe_seq_ops, + sizeof(struct seq_net_private)); +} + +static const struct file_operations pppoe_seq_fops = { + .owner = THIS_MODULE, + .open = pppoe_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_net, +}; + +#endif /* CONFIG_PROC_FS */ + +static const struct proto_ops pppoe_ops = { + .family = AF_PPPOX, + .owner = THIS_MODULE, + .release = pppoe_release, + .bind = sock_no_bind, + .connect = pppoe_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = pppoe_getname, + .poll = datagram_poll, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = sock_no_setsockopt, + .getsockopt = sock_no_getsockopt, + .sendmsg = pppoe_sendmsg, + .recvmsg = pppoe_recvmsg, + .mmap = sock_no_mmap, + .ioctl = pppox_ioctl, +}; + +static const struct pppox_proto pppoe_proto = { + .create = pppoe_create, + .ioctl = pppoe_ioctl, + .owner = THIS_MODULE, +}; + +static __net_init int pppoe_init_net(struct net *net) +{ + struct pppoe_net *pn = pppoe_pernet(net); + struct proc_dir_entry *pde; + + rwlock_init(&pn->hash_lock); + + pde = proc_net_fops_create(net, "pppoe", S_IRUGO, &pppoe_seq_fops); +#ifdef CONFIG_PROC_FS + if (!pde) + return -ENOMEM; +#endif + + return 0; +} + +static __net_exit void pppoe_exit_net(struct net *net) +{ + proc_net_remove(net, "pppoe"); +} + +static struct pernet_operations pppoe_net_ops = { + .init = pppoe_init_net, + .exit = pppoe_exit_net, + .id = &pppoe_net_id, + .size = sizeof(struct pppoe_net), +}; + +static int __init pppoe_init(void) +{ + int err; + + err = register_pernet_device(&pppoe_net_ops); + if (err) + goto out; + + err = proto_register(&pppoe_sk_proto, 0); + if (err) + goto out_unregister_net_ops; + + err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto); + if (err) + goto out_unregister_pppoe_proto; + + dev_add_pack(&pppoes_ptype); + dev_add_pack(&pppoed_ptype); + register_netdevice_notifier(&pppoe_notifier); + + return 0; + +out_unregister_pppoe_proto: + proto_unregister(&pppoe_sk_proto); +out_unregister_net_ops: + unregister_pernet_device(&pppoe_net_ops); +out: + return err; +} + +static void __exit pppoe_exit(void) +{ + unregister_netdevice_notifier(&pppoe_notifier); + dev_remove_pack(&pppoed_ptype); + dev_remove_pack(&pppoes_ptype); + unregister_pppox_proto(PX_PROTO_OE); + proto_unregister(&pppoe_sk_proto); + unregister_pernet_device(&pppoe_net_ops); +} + +module_init(pppoe_init); +module_exit(pppoe_exit); + +MODULE_AUTHOR("Michal Ostrowski <mostrows@speakeasy.net>"); +MODULE_DESCRIPTION("PPP over Ethernet driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NETPROTO(PF_PPPOX); |
