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afe62c68cd
linux/net/packet/af_packet.c
Eric Dumazet afe62c68cd af_packet: lock imbalance 
fanout_add() might return with fanout_mutex held.

Reduce indentation level while we are at it

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-07 06:41:29 -07:00

3113 lines
69 KiB
C
Raw Blame History

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* PACKET - implements raw packet sockets.
*
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Alan Cox, <gw4pts@gw4pts.ampr.org>
*
* Fixes:
* Alan Cox : verify_area() now used correctly
* Alan Cox : new skbuff lists, look ma no backlogs!
* Alan Cox : tidied skbuff lists.
* Alan Cox : Now uses generic datagram routines I
* added. Also fixed the peek/read crash
* from all old Linux datagram code.
* Alan Cox : Uses the improved datagram code.
* Alan Cox : Added NULL's for socket options.
* Alan Cox : Re-commented the code.
* Alan Cox : Use new kernel side addressing
* Rob Janssen : Correct MTU usage.
* Dave Platt : Counter leaks caused by incorrect
* interrupt locking and some slightly
* dubious gcc output. Can you read
* compiler: it said _VOLATILE_
* Richard Kooijman : Timestamp fixes.
* Alan Cox : New buffers. Use sk->mac.raw.
* Alan Cox : sendmsg/recvmsg support.
* Alan Cox : Protocol setting support
* Alexey Kuznetsov : Untied from IPv4 stack.
* Cyrus Durgin : Fixed kerneld for kmod.
* Michal Ostrowski : Module initialization cleanup.
* Ulises Alonso : Frame number limit removal and
* packet_set_ring memory leak.
* Eric Biederman : Allow for > 8 byte hardware addresses.
* The convention is that longer addresses
* will simply extend the hardware address
* byte arrays at the end of sockaddr_ll
* and packet_mreq.
* Johann Baudy : Added TX RING.
*
* 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/types.h>
#include <linux/mm.h>
#include <linux/capability.h>
#include <linux/fcntl.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_packet.h>
#include <linux/wireless.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <net/net_namespace.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <asm/io.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/if_vlan.h>
#include <linux/virtio_net.h>
#include <linux/errqueue.h>
#include <linux/net_tstamp.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
#endif
/*
Assumptions:
- if device has no dev->hard_header routine, it adds and removes ll header
inside itself. In this case ll header is invisible outside of device,
but higher levels still should reserve dev->hard_header_len.
Some devices are enough clever to reallocate skb, when header
will not fit to reserved space (tunnel), another ones are silly
(PPP).
- packet socket receives packets with pulled ll header,
so that SOCK_RAW should push it back.
On receive:
-----------
Incoming, dev->hard_header!=NULL
mac_header -> ll header
data -> data
Outgoing, dev->hard_header!=NULL
mac_header -> ll header
data -> ll header
Incoming, dev->hard_header==NULL
mac_header -> UNKNOWN position. It is very likely, that it points to ll
header. PPP makes it, that is wrong, because introduce
assymetry between rx and tx paths.
data -> data
Outgoing, dev->hard_header==NULL
mac_header -> data. ll header is still not built!
data -> data
Resume
If dev->hard_header==NULL we are unlikely to restore sensible ll header.
On transmit:
------------
dev->hard_header != NULL
mac_header -> ll header
data -> ll header
dev->hard_header == NULL (ll header is added by device, we cannot control it)
mac_header -> data
data -> data
We should set nh.raw on output to correct posistion,
packet classifier depends on it.
*/
/* Private packet socket structures. */
struct packet_mclist {
struct packet_mclist *next;
int ifindex;
int count;
unsigned short type;
unsigned short alen;
unsigned char addr[MAX_ADDR_LEN];
};
/* identical to struct packet_mreq except it has
* a longer address field.
*/
struct packet_mreq_max {
int mr_ifindex;
unsigned short mr_type;
unsigned short mr_alen;
unsigned char mr_address[MAX_ADDR_LEN];
};
static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
int closing, int tx_ring);
struct pgv {
char *buffer;
};
struct packet_ring_buffer {
struct pgv *pg_vec;
unsigned int head;
unsigned int frames_per_block;
unsigned int frame_size;
unsigned int frame_max;
unsigned int pg_vec_order;
unsigned int pg_vec_pages;
unsigned int pg_vec_len;
atomic_t pending;
};
struct packet_sock;
static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
static void packet_flush_mclist(struct sock *sk);
struct packet_fanout;
struct packet_sock {
/* struct sock has to be the first member of packet_sock */
struct sock sk;
struct packet_fanout *fanout;
struct tpacket_stats stats;
struct packet_ring_buffer rx_ring;
struct packet_ring_buffer tx_ring;
int copy_thresh;
spinlock_t bind_lock;
struct mutex pg_vec_lock;
unsigned int running:1, /* prot_hook is attached*/
auxdata:1,
origdev:1,
has_vnet_hdr:1;
int ifindex; /* bound device */
__be16 num;
struct packet_mclist *mclist;
atomic_t mapped;
enum tpacket_versions tp_version;
unsigned int tp_hdrlen;
unsigned int tp_reserve;
unsigned int tp_loss:1;
unsigned int tp_tstamp;
struct packet_type prot_hook ____cacheline_aligned_in_smp;
};
#define PACKET_FANOUT_MAX 256
struct packet_fanout {
#ifdef CONFIG_NET_NS
struct net *net;
#endif
unsigned int num_members;
u16 id;
u8 type;
u8 defrag;
atomic_t rr_cur;
struct list_head list;
struct sock *arr[PACKET_FANOUT_MAX];
spinlock_t lock;
atomic_t sk_ref;
struct packet_type prot_hook ____cacheline_aligned_in_smp;
};
struct packet_skb_cb {
unsigned int origlen;
union {
struct sockaddr_pkt pkt;
struct sockaddr_ll ll;
} sa;
};
#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
static inline struct packet_sock *pkt_sk(struct sock *sk)
{
return (struct packet_sock *)sk;
}
static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
static void __fanout_link(struct sock *sk, struct packet_sock *po);
/* register_prot_hook must be invoked with the po->bind_lock held,
* or from a context in which asynchronous accesses to the packet
* socket is not possible (packet_create()).
*/
static void register_prot_hook(struct sock *sk)
{
struct packet_sock *po = pkt_sk(sk);
if (!po->running) {
if (po->fanout)
__fanout_link(sk, po);
else
dev_add_pack(&po->prot_hook);
sock_hold(sk);
po->running = 1;
}
}
/* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
* held. If the sync parameter is true, we will temporarily drop
* the po->bind_lock and do a synchronize_net to make sure no
* asynchronous packet processing paths still refer to the elements
* of po->prot_hook. If the sync parameter is false, it is the
* callers responsibility to take care of this.
*/
static void __unregister_prot_hook(struct sock *sk, bool sync)
{
struct packet_sock *po = pkt_sk(sk);
po->running = 0;
if (po->fanout)
__fanout_unlink(sk, po);
else
__dev_remove_pack(&po->prot_hook);
__sock_put(sk);
if (sync) {
spin_unlock(&po->bind_lock);
synchronize_net();
spin_lock(&po->bind_lock);
}
}
static void unregister_prot_hook(struct sock *sk, bool sync)
{
struct packet_sock *po = pkt_sk(sk);
if (po->running)
__unregister_prot_hook(sk, sync);
}
static inline __pure struct page *pgv_to_page(void *addr)
{
if (is_vmalloc_addr(addr))
return vmalloc_to_page(addr);
return virt_to_page(addr);
}
static void __packet_set_status(struct packet_sock *po, void *frame, int status)
{
union {
struct tpacket_hdr *h1;
struct tpacket2_hdr *h2;
void *raw;
} h;
h.raw = frame;
switch (po->tp_version) {
case TPACKET_V1:
h.h1->tp_status = status;
flush_dcache_page(pgv_to_page(&h.h1->tp_status));
break;
case TPACKET_V2:
h.h2->tp_status = status;
flush_dcache_page(pgv_to_page(&h.h2->tp_status));
break;
default:
pr_err("TPACKET version not supported\n");
BUG();
}
smp_wmb();
}
static int __packet_get_status(struct packet_sock *po, void *frame)
{
union {
struct tpacket_hdr *h1;
struct tpacket2_hdr *h2;
void *raw;
} h;
smp_rmb();
h.raw = frame;
switch (po->tp_version) {
case TPACKET_V1:
flush_dcache_page(pgv_to_page(&h.h1->tp_status));
return h.h1->tp_status;
case TPACKET_V2:
flush_dcache_page(pgv_to_page(&h.h2->tp_status));
return h.h2->tp_status;
default:
pr_err("TPACKET version not supported\n");
BUG();
return 0;
}
}
static void *packet_lookup_frame(struct packet_sock *po,
struct packet_ring_buffer *rb,
unsigned int position,
int status)
{
unsigned int pg_vec_pos, frame_offset;
union {
struct tpacket_hdr *h1;
struct tpacket2_hdr *h2;
void *raw;
} h;
pg_vec_pos = position / rb->frames_per_block;
frame_offset = position % rb->frames_per_block;
h.raw = rb->pg_vec[pg_vec_pos].buffer +
(frame_offset * rb->frame_size);
if (status != __packet_get_status(po, h.raw))
return NULL;
return h.raw;
}
static inline void *packet_current_frame(struct packet_sock *po,
struct packet_ring_buffer *rb,
int status)
{
return packet_lookup_frame(po, rb, rb->head, status);
}
static inline void *packet_previous_frame(struct packet_sock *po,
struct packet_ring_buffer *rb,
int status)
{
unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
return packet_lookup_frame(po, rb, previous, status);
}
static inline void packet_increment_head(struct packet_ring_buffer *buff)
{
buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
}
static void packet_sock_destruct(struct sock *sk)
{
skb_queue_purge(&sk->sk_error_queue);
WARN_ON(atomic_read(&sk->sk_rmem_alloc));
WARN_ON(atomic_read(&sk->sk_wmem_alloc));
if (!sock_flag(sk, SOCK_DEAD)) {
pr_err("Attempt to release alive packet socket: %p\n", sk);
return;
}
sk_refcnt_debug_dec(sk);
}
static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
{
int x = atomic_read(&f->rr_cur) + 1;
if (x >= num)
x = 0;
return x;
}
static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
{
u32 idx, hash = skb->rxhash;
idx = ((u64)hash * num) >> 32;
return f->arr[idx];
}
static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
{
int cur, old;
cur = atomic_read(&f->rr_cur);
while ((old = atomic_cmpxchg(&f->rr_cur, cur,
fanout_rr_next(f, num))) != cur)
cur = old;
return f->arr[cur];
}
static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
{
unsigned int cpu = smp_processor_id();
return f->arr[cpu % num];
}
static struct sk_buff *fanout_check_defrag(struct sk_buff *skb)
{
const struct iphdr *iph;
u32 len;
if (skb->protocol != htons(ETH_P_IP))
return skb;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
return skb;
iph = ip_hdr(skb);
if (iph->ihl < 5 || iph->version != 4)
return skb;
if (!pskb_may_pull(skb, iph->ihl*4))
return skb;
iph = ip_hdr(skb);
len = ntohs(iph->tot_len);
if (skb->len < len || len < (iph->ihl * 4))
return skb;
if (ip_is_fragment(ip_hdr(skb))) {
skb = skb_share_check(skb, GFP_ATOMIC);
if (skb) {
if (pskb_trim_rcsum(skb, len))
return skb;
memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
if (ip_defrag(skb, IP_DEFRAG_AF_PACKET))
return NULL;
skb->rxhash = 0;
}
}
return skb;
}
static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct packet_fanout *f = pt->af_packet_priv;
unsigned int num = f->num_members;
struct packet_sock *po;
struct sock *sk;
if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
!num) {
kfree_skb(skb);
return 0;
}
switch (f->type) {
case PACKET_FANOUT_HASH:
default:
if (f->defrag) {
skb = fanout_check_defrag(skb);
if (!skb)
return 0;
}
skb_get_rxhash(skb);
sk = fanout_demux_hash(f, skb, num);
break;
case PACKET_FANOUT_LB:
sk = fanout_demux_lb(f, skb, num);
break;
case PACKET_FANOUT_CPU:
sk = fanout_demux_cpu(f, skb, num);
break;
}
po = pkt_sk(sk);
return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
}
static DEFINE_MUTEX(fanout_mutex);
static LIST_HEAD(fanout_list);
static void __fanout_link(struct sock *sk, struct packet_sock *po)
{
struct packet_fanout *f = po->fanout;
spin_lock(&f->lock);
f->arr[f->num_members] = sk;
smp_wmb();
f->num_members++;
spin_unlock(&f->lock);
}
static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
{
struct packet_fanout *f = po->fanout;
int i;
spin_lock(&f->lock);
for (i = 0; i < f->num_members; i++) {
if (f->arr[i] == sk)
break;
}
BUG_ON(i >= f->num_members);
f->arr[i] = f->arr[f->num_members - 1];
f->num_members--;
spin_unlock(&f->lock);
}
static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
{
struct packet_sock *po = pkt_sk(sk);
struct packet_fanout *f, *match;
u8 type = type_flags & 0xff;
u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
int err;
switch (type) {
case PACKET_FANOUT_HASH:
case PACKET_FANOUT_LB:
case PACKET_FANOUT_CPU:
break;
default:
return -EINVAL;
}
if (!po->running)
return -EINVAL;
if (po->fanout)
return -EALREADY;
mutex_lock(&fanout_mutex);
match = NULL;
list_for_each_entry(f, &fanout_list, list) {
if (f->id == id &&
read_pnet(&f->net) == sock_net(sk)) {
match = f;
break;
}
}
err = -EINVAL;
if (match && match->defrag != defrag)
goto out;
if (!match) {
err = -ENOMEM;
match = kzalloc(sizeof(*match), GFP_KERNEL);
if (!match)
goto out;
write_pnet(&match->net, sock_net(sk));
match->id = id;
match->type = type;
match->defrag = defrag;
atomic_set(&match->rr_cur, 0);
INIT_LIST_HEAD(&match->list);
spin_lock_init(&match->lock);
atomic_set(&match->sk_ref, 0);
match->prot_hook.type = po->prot_hook.type;
match->prot_hook.dev = po->prot_hook.dev;
match->prot_hook.func = packet_rcv_fanout;
match->prot_hook.af_packet_priv = match;
dev_add_pack(&match->prot_hook);
list_add(&match->list, &fanout_list);
}
err = -EINVAL;
if (match->type == type &&
match->prot_hook.type == po->prot_hook.type &&
match->prot_hook.dev == po->prot_hook.dev) {
err = -ENOSPC;
if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
__dev_remove_pack(&po->prot_hook);
po->fanout = match;
atomic_inc(&match->sk_ref);
__fanout_link(sk, po);
err = 0;
}
}
out:
mutex_unlock(&fanout_mutex);
return err;
}
static void fanout_release(struct sock *sk)
{
struct packet_sock *po = pkt_sk(sk);
struct packet_fanout *f;
f = po->fanout;
if (!f)
return;
po->fanout = NULL;
mutex_lock(&fanout_mutex);
if (atomic_dec_and_test(&f->sk_ref)) {
list_del(&f->list);
dev_remove_pack(&f->prot_hook);
kfree(f);
}
mutex_unlock(&fanout_mutex);
}
static const struct proto_ops packet_ops;
static const struct proto_ops packet_ops_spkt;
static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct sock *sk;
struct sockaddr_pkt *spkt;
/*
* When we registered the protocol we saved the socket in the data
* field for just this event.
*/
sk = pt->af_packet_priv;
/*
* Yank back the headers [hope the device set this
* right or kerboom...]
*
* Incoming packets have ll header pulled,
* push it back.
*
* For outgoing ones skb->data == skb_mac_header(skb)
* so that this procedure is noop.
*/
if (skb->pkt_type == PACKET_LOOPBACK)
goto out;
if (!net_eq(dev_net(dev), sock_net(sk)))
goto out;
skb = skb_share_check(skb, GFP_ATOMIC);
if (skb == NULL)
goto oom;
/* drop any routing info */
skb_dst_drop(skb);
/* drop conntrack reference */
nf_reset(skb);
spkt = &PACKET_SKB_CB(skb)->sa.pkt;
skb_push(skb, skb->data - skb_mac_header(skb));
/*
* The SOCK_PACKET socket receives _all_ frames.
*/
spkt->spkt_family = dev->type;
strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
spkt->spkt_protocol = skb->protocol;
/*
* Charge the memory to the socket. This is done specifically
* to prevent sockets using all the memory up.
*/
if (sock_queue_rcv_skb(sk, skb) == 0)
return 0;
out:
kfree_skb(skb);
oom:
return 0;
}
/*
* Output a raw packet to a device layer. This bypasses all the other
* protocol layers and you must therefore supply it with a complete frame
*/
static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
struct sk_buff *skb = NULL;
struct net_device *dev;
__be16 proto = 0;
int err;
/*
* Get and verify the address.
*/
if (saddr) {
if (msg->msg_namelen < sizeof(struct sockaddr))
return -EINVAL;
if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
proto = saddr->spkt_protocol;
} else
return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
/*
* Find the device first to size check it
*/
saddr->spkt_device[13] = 0;
retry:
rcu_read_lock();
dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
err = -ENODEV;
if (dev == NULL)
goto out_unlock;
err = -ENETDOWN;
if (!(dev->flags & IFF_UP))
goto out_unlock;
/*
* You may not queue a frame bigger than the mtu. This is the lowest level
* raw protocol and you must do your own fragmentation at this level.
*/
err = -EMSGSIZE;
if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN)
goto out_unlock;
if (!skb) {
size_t reserved = LL_RESERVED_SPACE(dev);
unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
rcu_read_unlock();
skb = sock_wmalloc(sk, len + reserved, 0, GFP_KERNEL);
if (skb == NULL)
return -ENOBUFS;
/* FIXME: Save some space for broken drivers that write a hard
* header at transmission time by themselves. PPP is the notable
* one here. This should really be fixed at the driver level.
*/
skb_reserve(skb, reserved);
skb_reset_network_header(skb);
/* Try to align data part correctly */
if (hhlen) {
skb->data -= hhlen;
skb->tail -= hhlen;
if (len < hhlen)
skb_reset_network_header(skb);
}
err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
if (err)
goto out_free;
goto retry;
}
if (len > (dev->mtu + dev->hard_header_len)) {
/* Earlier code assumed this would be a VLAN pkt,
* double-check this now that we have the actual
* packet in hand.
*/
struct ethhdr *ehdr;
skb_reset_mac_header(skb);
ehdr = eth_hdr(skb);
if (ehdr->h_proto != htons(ETH_P_8021Q)) {
err = -EMSGSIZE;
goto out_unlock;
}
}
skb->protocol = proto;
skb->dev = dev;
skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;
err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
if (err < 0)
goto out_unlock;
dev_queue_xmit(skb);
rcu_read_unlock();
return len;
out_unlock:
rcu_read_unlock();
out_free:
kfree_skb(skb);
return err;
}
static inline unsigned int run_filter(const struct sk_buff *skb,
const struct sock *sk,
unsigned int res)
{
struct sk_filter *filter;
rcu_read_lock();
filter = rcu_dereference(sk->sk_filter);
if (filter != NULL)
res = SK_RUN_FILTER(filter, skb);
rcu_read_unlock();
return res;
}
/*
* This function makes lazy skb cloning in hope that most of packets
* are discarded by BPF.
*
* Note tricky part: we DO mangle shared skb! skb->data, skb->len
* and skb->cb are mangled. It works because (and until) packets
* falling here are owned by current CPU. Output packets are cloned
* by dev_queue_xmit_nit(), input packets are processed by net_bh
* sequencially, so that if we return skb to original state on exit,
* we will not harm anyone.
*/
static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct sock *sk;
struct sockaddr_ll *sll;
struct packet_sock *po;
u8 *skb_head = skb->data;
int skb_len = skb->len;
unsigned int snaplen, res;
if (skb->pkt_type == PACKET_LOOPBACK)
goto drop;
sk = pt->af_packet_priv;
po = pkt_sk(sk);
if (!net_eq(dev_net(dev), sock_net(sk)))
goto drop;
skb->dev = dev;
if (dev->header_ops) {
/* The device has an explicit notion of ll header,
* exported to higher levels.
*
* Otherwise, the device hides details of its frame
* structure, so that corresponding packet head is
* never delivered to user.
*/
if (sk->sk_type != SOCK_DGRAM)
skb_push(skb, skb->data - skb_mac_header(skb));
else if (skb->pkt_type == PACKET_OUTGOING) {
/* Special case: outgoing packets have ll header at head */
skb_pull(skb, skb_network_offset(skb));
}
}
snaplen = skb->len;
res = run_filter(skb, sk, snaplen);
if (!res)
goto drop_n_restore;
if (snaplen > res)
snaplen = res;
if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
(unsigned)sk->sk_rcvbuf)
goto drop_n_acct;
if (skb_shared(skb)) {
struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
if (nskb == NULL)
goto drop_n_acct;
if (skb_head != skb->data) {
skb->data = skb_head;
skb->len = skb_len;
}
kfree_skb(skb);
skb = nskb;
}
BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
sizeof(skb->cb));
sll = &PACKET_SKB_CB(skb)->sa.ll;
sll->sll_family = AF_PACKET;
sll->sll_hatype = dev->type;
sll->sll_protocol = skb->protocol;
sll->sll_pkttype = skb->pkt_type;
if (unlikely(po->origdev))
sll->sll_ifindex = orig_dev->ifindex;
else
sll->sll_ifindex = dev->ifindex;
sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
PACKET_SKB_CB(skb)->origlen = skb->len;
if (pskb_trim(skb, snaplen))
goto drop_n_acct;
skb_set_owner_r(skb, sk);
skb->dev = NULL;
skb_dst_drop(skb);
/* drop conntrack reference */
nf_reset(skb);
spin_lock(&sk->sk_receive_queue.lock);
po->stats.tp_packets++;
skb->dropcount = atomic_read(&sk->sk_drops);
__skb_queue_tail(&sk->sk_receive_queue, skb);
spin_unlock(&sk->sk_receive_queue.lock);
sk->sk_data_ready(sk, skb->len);
return 0;
drop_n_acct:
po->stats.tp_drops = atomic_inc_return(&sk->sk_drops);
drop_n_restore:
if (skb_head != skb->data && skb_shared(skb)) {
skb->data = skb_head;
skb->len = skb_len;
}
drop:
consume_skb(skb);
return 0;
}
static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct sock *sk;
struct packet_sock *po;
struct sockaddr_ll *sll;
union {
struct tpacket_hdr *h1;
struct tpacket2_hdr *h2;
void *raw;
} h;
u8 *skb_head = skb->data;
int skb_len = skb->len;
unsigned int snaplen, res;
unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER;
unsigned short macoff, netoff, hdrlen;
struct sk_buff *copy_skb = NULL;
struct timeval tv;
struct timespec ts;
struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
if (skb->pkt_type == PACKET_LOOPBACK)
goto drop;
sk = pt->af_packet_priv;
po = pkt_sk(sk);
if (!net_eq(dev_net(dev), sock_net(sk)))
goto drop;
if (dev->header_ops) {
if (sk->sk_type != SOCK_DGRAM)
skb_push(skb, skb->data - skb_mac_header(skb));
else if (skb->pkt_type == PACKET_OUTGOING) {
/* Special case: outgoing packets have ll header at head */
skb_pull(skb, skb_network_offset(skb));
}
}
if (skb->ip_summed == CHECKSUM_PARTIAL)
status |= TP_STATUS_CSUMNOTREADY;
snaplen = skb->len;
res = run_filter(skb, sk, snaplen);
if (!res)
goto drop_n_restore;
if (snaplen > res)
snaplen = res;
if (sk->sk_type == SOCK_DGRAM) {
macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
po->tp_reserve;
} else {
unsigned maclen = skb_network_offset(skb);
netoff = TPACKET_ALIGN(po->tp_hdrlen +
(maclen < 16 ? 16 : maclen)) +
po->tp_reserve;
macoff = netoff - maclen;
}
if (macoff + snaplen > po->rx_ring.frame_size) {
if (po->copy_thresh &&
atomic_read(&sk->sk_rmem_alloc) + skb->truesize <
(unsigned)sk->sk_rcvbuf) {
if (skb_shared(skb)) {
copy_skb = skb_clone(skb, GFP_ATOMIC);
} else {
copy_skb = skb_get(skb);
skb_head = skb->data;
}
if (copy_skb)
skb_set_owner_r(copy_skb, sk);
}
snaplen = po->rx_ring.frame_size - macoff;
if ((int)snaplen < 0)
snaplen = 0;
}
spin_lock(&sk->sk_receive_queue.lock);
h.raw = packet_current_frame(po, &po->rx_ring, TP_STATUS_KERNEL);
if (!h.raw)
goto ring_is_full;
packet_increment_head(&po->rx_ring);
po->stats.tp_packets++;
if (copy_skb) {
status |= TP_STATUS_COPY;
__skb_queue_tail(&sk->sk_receive_queue, copy_skb);
}
if (!po->stats.tp_drops)
status &= ~TP_STATUS_LOSING;
spin_unlock(&sk->sk_receive_queue.lock);
skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
switch (po->tp_version) {
case TPACKET_V1:
h.h1->tp_len = skb->len;
h.h1->tp_snaplen = snaplen;
h.h1->tp_mac = macoff;
h.h1->tp_net = netoff;
if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
&& shhwtstamps->syststamp.tv64)
tv = ktime_to_timeval(shhwtstamps->syststamp);
else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
&& shhwtstamps->hwtstamp.tv64)
tv = ktime_to_timeval(shhwtstamps->hwtstamp);
else if (skb->tstamp.tv64)
tv = ktime_to_timeval(skb->tstamp);
else
do_gettimeofday(&tv);
h.h1->tp_sec = tv.tv_sec;
h.h1->tp_usec = tv.tv_usec;
hdrlen = sizeof(*h.h1);
break;
case TPACKET_V2:
h.h2->tp_len = skb->len;
h.h2->tp_snaplen = snaplen;
h.h2->tp_mac = macoff;
h.h2->tp_net = netoff;
if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
&& shhwtstamps->syststamp.tv64)
ts = ktime_to_timespec(shhwtstamps->syststamp);
else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
&& shhwtstamps->hwtstamp.tv64)
ts = ktime_to_timespec(shhwtstamps->hwtstamp);
else if (skb->tstamp.tv64)
ts = ktime_to_timespec(skb->tstamp);
else
getnstimeofday(&ts);
h.h2->tp_sec = ts.tv_sec;
h.h2->tp_nsec = ts.tv_nsec;
if (vlan_tx_tag_present(skb)) {
h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
status |= TP_STATUS_VLAN_VALID;
} else {
h.h2->tp_vlan_tci = 0;
}
h.h2->tp_padding = 0;
hdrlen = sizeof(*h.h2);
break;
default:
BUG();
}
sll = h.raw + TPACKET_ALIGN(hdrlen);
sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
sll->sll_family = AF_PACKET;
sll->sll_hatype = dev->type;
sll->sll_protocol = skb->protocol;
sll->sll_pkttype = skb->pkt_type;
if (unlikely(po->origdev))
sll->sll_ifindex = orig_dev->ifindex;
else
sll->sll_ifindex = dev->ifindex;
__packet_set_status(po, h.raw, status);
smp_mb();
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
{
u8 *start, *end;
end = (u8 *)PAGE_ALIGN((unsigned long)h.raw + macoff + snaplen);
for (start = h.raw; start < end; start += PAGE_SIZE)
flush_dcache_page(pgv_to_page(start));
}
#endif
sk->sk_data_ready(sk, 0);
drop_n_restore:
if (skb_head != skb->data && skb_shared(skb)) {
skb->data = skb_head;
skb->len = skb_len;
}
drop:
kfree_skb(skb);
return 0;
ring_is_full:
po->stats.tp_drops++;
spin_unlock(&sk->sk_receive_queue.lock);
sk->sk_data_ready(sk, 0);
kfree_skb(copy_skb);
goto drop_n_restore;
}
static void tpacket_destruct_skb(struct sk_buff *skb)
{
struct packet_sock *po = pkt_sk(skb->sk);
void *ph;
BUG_ON(skb == NULL);
if (likely(po->tx_ring.pg_vec)) {
ph = skb_shinfo(skb)->destructor_arg;
BUG_ON(__packet_get_status(po, ph) != TP_STATUS_SENDING);
BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
atomic_dec(&po->tx_ring.pending);
__packet_set_status(po, ph, TP_STATUS_AVAILABLE);
}
sock_wfree(skb);
}
static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
void *frame, struct net_device *dev, int size_max,
__be16 proto, unsigned char *addr)
{
union {
struct tpacket_hdr *h1;
struct tpacket2_hdr *h2;
void *raw;
} ph;
int to_write, offset, len, tp_len, nr_frags, len_max;
struct socket *sock = po->sk.sk_socket;
struct page *page;
void *data;
int err;
ph.raw = frame;
skb->protocol = proto;
skb->dev = dev;
skb->priority = po->sk.sk_priority;
skb->mark = po->sk.sk_mark;
skb_shinfo(skb)->destructor_arg = ph.raw;
switch (po->tp_version) {
case TPACKET_V2:
tp_len = ph.h2->tp_len;
break;
default:
tp_len = ph.h1->tp_len;
break;
}
if (unlikely(tp_len > size_max)) {
pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
return -EMSGSIZE;
}
skb_reserve(skb, LL_RESERVED_SPACE(dev));
skb_reset_network_header(skb);
data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
to_write = tp_len;
if (sock->type == SOCK_DGRAM) {
err = dev_hard_header(skb, dev, ntohs(proto), addr,
NULL, tp_len);
if (unlikely(err < 0))
return -EINVAL;
} else if (dev->hard_header_len) {
/* net device doesn't like empty head */
if (unlikely(tp_len <= dev->hard_header_len)) {
pr_err("packet size is too short (%d < %d)\n",
tp_len, dev->hard_header_len);
return -EINVAL;
}
skb_push(skb, dev->hard_header_len);
err = skb_store_bits(skb, 0, data,
dev->hard_header_len);
if (unlikely(err))
return err;
data += dev->hard_header_len;
to_write -= dev->hard_header_len;
}
err = -EFAULT;
offset = offset_in_page(data);
len_max = PAGE_SIZE - offset;
len = ((to_write > len_max) ? len_max : to_write);
skb->data_len = to_write;
skb->len += to_write;
skb->truesize += to_write;
atomic_add(to_write, &po->sk.sk_wmem_alloc);
while (likely(to_write)) {
nr_frags = skb_shinfo(skb)->nr_frags;
if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
pr_err("Packet exceed the number of skb frags(%lu)\n",
MAX_SKB_FRAGS);
return -EFAULT;
}
page = pgv_to_page(data);
data += len;
flush_dcache_page(page);
get_page(page);
skb_fill_page_desc(skb, nr_frags, page, offset, len);
to_write -= len;
offset = 0;
len_max = PAGE_SIZE;
len = ((to_write > len_max) ? len_max : to_write);
}
return tp_len;
}
static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
{
struct sk_buff *skb;
struct net_device *dev;
__be16 proto;
bool need_rls_dev = false;
int err, reserve = 0;
void *ph;
struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
int tp_len, size_max;
unsigned char *addr;
int len_sum = 0;
int status = 0;
mutex_lock(&po->pg_vec_lock);
err = -EBUSY;
if (saddr == NULL) {
dev = po->prot_hook.dev;
proto = po->num;
addr = NULL;
} else {
err = -EINVAL;
if (msg->msg_namelen < sizeof(struct sockaddr_ll))
goto out;
if (msg->msg_namelen < (saddr->sll_halen
+ offsetof(struct sockaddr_ll,
sll_addr)))
goto out;
proto = saddr->sll_protocol;
addr = saddr->sll_addr;
dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
need_rls_dev = true;
}
err = -ENXIO;
if (unlikely(dev == NULL))
goto out;
reserve = dev->hard_header_len;
err = -ENETDOWN;
if (unlikely(!(dev->flags & IFF_UP)))
goto out_put;
size_max = po->tx_ring.frame_size
- (po->tp_hdrlen - sizeof(struct sockaddr_ll));
if (size_max > dev->mtu + reserve)
size_max = dev->mtu + reserve;
do {
ph = packet_current_frame(po, &po->tx_ring,
TP_STATUS_SEND_REQUEST);
if (unlikely(ph == NULL)) {
schedule();
continue;
}
status = TP_STATUS_SEND_REQUEST;
skb = sock_alloc_send_skb(&po->sk,
LL_ALLOCATED_SPACE(dev)
+ sizeof(struct sockaddr_ll),
0, &err);
if (unlikely(skb == NULL))
goto out_status;
tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
addr);
if (unlikely(tp_len < 0)) {
if (po->tp_loss) {
__packet_set_status(po, ph,
TP_STATUS_AVAILABLE);
packet_increment_head(&po->tx_ring);
kfree_skb(skb);
continue;
} else {
status = TP_STATUS_WRONG_FORMAT;
err = tp_len;
goto out_status;
}
}
skb->destructor = tpacket_destruct_skb;
__packet_set_status(po, ph, TP_STATUS_SENDING);
atomic_inc(&po->tx_ring.pending);
status = TP_STATUS_SEND_REQUEST;
err = dev_queue_xmit(skb);
if (unlikely(err > 0)) {
err = net_xmit_errno(err);
if (err && __packet_get_status(po, ph) ==
TP_STATUS_AVAILABLE) {
/* skb was destructed already */
skb = NULL;
goto out_status;
}
/*
* skb was dropped but not destructed yet;
* let's treat it like congestion or err < 0
*/
err = 0;
}
packet_increment_head(&po->tx_ring);
len_sum += tp_len;
} while (likely((ph != NULL) ||
((!(msg->msg_flags & MSG_DONTWAIT)) &&
(atomic_read(&po->tx_ring.pending))))
);
err = len_sum;
goto out_put;
out_status:
__packet_set_status(po, ph, status);
kfree_skb(skb);
out_put:
if (need_rls_dev)
dev_put(dev);
out:
mutex_unlock(&po->pg_vec_lock);
return err;
}
static inline struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
size_t reserve, size_t len,
size_t linear, int noblock,
int *err)
{
struct sk_buff *skb;
/* Under a page? Don't bother with paged skb. */
if (prepad + len < PAGE_SIZE || !linear)
linear = len;
skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
err);
if (!skb)
return NULL;
skb_reserve(skb, reserve);
skb_put(skb, linear);
skb->data_len = len - linear;
skb->len += len - linear;
return skb;
}
static int packet_snd(struct socket *sock,
struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
struct sk_buff *skb;
struct net_device *dev;
__be16 proto;
bool need_rls_dev = false;
unsigned char *addr;
int err, reserve = 0;
struct virtio_net_hdr vnet_hdr = { 0 };
int offset = 0;
int vnet_hdr_len;
struct packet_sock *po = pkt_sk(sk);
unsigned short gso_type = 0;
/*
* Get and verify the address.
*/
if (saddr == NULL) {
dev = po->prot_hook.dev;
proto = po->num;
addr = NULL;
} else {
err = -EINVAL;
if (msg->msg_namelen < sizeof(struct sockaddr_ll))
goto out;
if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
goto out;
proto = saddr->sll_protocol;
addr = saddr->sll_addr;
dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
need_rls_dev = true;
}
err = -ENXIO;
if (dev == NULL)
goto out_unlock;
if (sock->type == SOCK_RAW)
reserve = dev->hard_header_len;
err = -ENETDOWN;
if (!(dev->flags & IFF_UP))
goto out_unlock;
if (po->has_vnet_hdr) {
vnet_hdr_len = sizeof(vnet_hdr);
err = -EINVAL;
if (len < vnet_hdr_len)
goto out_unlock;
len -= vnet_hdr_len;
err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
vnet_hdr_len);
if (err < 0)
goto out_unlock;
if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
(vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
vnet_hdr.hdr_len))
vnet_hdr.hdr_len = vnet_hdr.csum_start +
vnet_hdr.csum_offset + 2;
err = -EINVAL;
if (vnet_hdr.hdr_len > len)
goto out_unlock;
if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
gso_type = SKB_GSO_TCPV4;
break;
case VIRTIO_NET_HDR_GSO_TCPV6:
gso_type = SKB_GSO_TCPV6;
break;
case VIRTIO_NET_HDR_GSO_UDP:
gso_type = SKB_GSO_UDP;
break;
default:
goto out_unlock;
}
if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
gso_type |= SKB_GSO_TCP_ECN;
if (vnet_hdr.gso_size == 0)
goto out_unlock;
}
}
err = -EMSGSIZE;
if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN))
goto out_unlock;
err = -ENOBUFS;
skb = packet_alloc_skb(sk, LL_ALLOCATED_SPACE(dev),
LL_RESERVED_SPACE(dev), len, vnet_hdr.hdr_len,
msg->msg_flags & MSG_DONTWAIT, &err);
if (skb == NULL)
goto out_unlock;
skb_set_network_header(skb, reserve);
err = -EINVAL;
if (sock->type == SOCK_DGRAM &&
(offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
goto out_free;
/* Returns -EFAULT on error */
err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
if (err)
goto out_free;
err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
if (err < 0)
goto out_free;
if (!gso_type && (len > dev->mtu + reserve)) {
/* Earlier code assumed this would be a VLAN pkt,
* double-check this now that we have the actual
* packet in hand.
*/
struct ethhdr *ehdr;
skb_reset_mac_header(skb);
ehdr = eth_hdr(skb);
if (ehdr->h_proto != htons(ETH_P_8021Q)) {
err = -EMSGSIZE;
goto out_free;
}
}
skb->protocol = proto;
skb->dev = dev;
skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;
if (po->has_vnet_hdr) {
if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
vnet_hdr.csum_offset)) {
err = -EINVAL;
goto out_free;
}
}
skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
skb_shinfo(skb)->gso_type = gso_type;
/* Header must be checked, and gso_segs computed. */
skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
skb_shinfo(skb)->gso_segs = 0;
len += vnet_hdr_len;
}
/*
* Now send it
*/
err = dev_queue_xmit(skb);
if (err > 0 && (err = net_xmit_errno(err)) != 0)
goto out_unlock;
if (need_rls_dev)
dev_put(dev);
return len;
out_free:
kfree_skb(skb);
out_unlock:
if (dev && need_rls_dev)
dev_put(dev);
out:
return err;
}
static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
struct packet_sock *po = pkt_sk(sk);
if (po->tx_ring.pg_vec)
return tpacket_snd(po, msg);
else
return packet_snd(sock, msg, len);
}
/*
* Close a PACKET socket. This is fairly simple. We immediately go
* to 'closed' state and remove our protocol entry in the device list.
*/
static int packet_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct packet_sock *po;
struct net *net;
struct tpacket_req req;
if (!sk)
return 0;
net = sock_net(sk);
po = pkt_sk(sk);
spin_lock_bh(&net->packet.sklist_lock);
sk_del_node_init_rcu(sk);
sock_prot_inuse_add(net, sk->sk_prot, -1);
spin_unlock_bh(&net->packet.sklist_lock);
spin_lock(&po->bind_lock);
unregister_prot_hook(sk, false);
if (po->prot_hook.dev) {
dev_put(po->prot_hook.dev);
po->prot_hook.dev = NULL;
}
spin_unlock(&po->bind_lock);
packet_flush_mclist(sk);
memset(&req, 0, sizeof(req));
if (po->rx_ring.pg_vec)
packet_set_ring(sk, &req, 1, 0);
if (po->tx_ring.pg_vec)
packet_set_ring(sk, &req, 1, 1);
fanout_release(sk);
synchronize_net();
/*
* Now the socket is dead. No more input will appear.
*/
sock_orphan(sk);
sock->sk = NULL;
/* Purge queues */
skb_queue_purge(&sk->sk_receive_queue);
sk_refcnt_debug_release(sk);
sock_put(sk);
return 0;
}
/*
* Attach a packet hook.
*/
static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
{
struct packet_sock *po = pkt_sk(sk);
if (po->fanout)
return -EINVAL;
lock_sock(sk);
spin_lock(&po->bind_lock);
unregister_prot_hook(sk, true);
po->num = protocol;
po->prot_hook.type = protocol;
if (po->prot_hook.dev)
dev_put(po->prot_hook.dev);
po->prot_hook.dev = dev;
po->ifindex = dev ? dev->ifindex : 0;
if (protocol == 0)
goto out_unlock;
if (!dev || (dev->flags & IFF_UP)) {
register_prot_hook(sk);
} else {
sk->sk_err = ENETDOWN;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
}
out_unlock:
spin_unlock(&po->bind_lock);
release_sock(sk);
return 0;
}
/*
* Bind a packet socket to a device
*/
static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
int addr_len)
{
struct sock *sk = sock->sk;
char name[15];
struct net_device *dev;
int err = -ENODEV;
/*
* Check legality
*/
if (addr_len != sizeof(struct sockaddr))
return -EINVAL;
strlcpy(name, uaddr->sa_data, sizeof(name));
dev = dev_get_by_name(sock_net(sk), name);
if (dev)
err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
return err;
}
static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
struct sock *sk = sock->sk;
struct net_device *dev = NULL;
int err;
/*
* Check legality
*/
if (addr_len < sizeof(struct sockaddr_ll))
return -EINVAL;
if (sll->sll_family != AF_PACKET)
return -EINVAL;
if (sll->sll_ifindex) {
err = -ENODEV;
dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
if (dev == NULL)
goto out;
}
err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
out:
return err;
}
static struct proto packet_proto = {
.name = "PACKET",
.owner = THIS_MODULE,
.obj_size = sizeof(struct packet_sock),
};
/*
* Create a packet of type SOCK_PACKET.
*/
static int packet_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
struct sock *sk;
struct packet_sock *po;
__be16 proto = (__force __be16)protocol; /* weird, but documented */
int err;
if (!capable(CAP_NET_RAW))
return -EPERM;
if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
sock->type != SOCK_PACKET)
return -ESOCKTNOSUPPORT;
sock->state = SS_UNCONNECTED;
err = -ENOBUFS;
sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
if (sk == NULL)
goto out;
sock->ops = &packet_ops;
if (sock->type == SOCK_PACKET)
sock->ops = &packet_ops_spkt;
sock_init_data(sock, sk);
po = pkt_sk(sk);
sk->sk_family = PF_PACKET;
po->num = proto;
sk->sk_destruct = packet_sock_destruct;
sk_refcnt_debug_inc(sk);
/*
* Attach a protocol block
*/
spin_lock_init(&po->bind_lock);
mutex_init(&po->pg_vec_lock);
po->prot_hook.func = packet_rcv;
if (sock->type == SOCK_PACKET)
po->prot_hook.func = packet_rcv_spkt;
po->prot_hook.af_packet_priv = sk;
if (proto) {
po->prot_hook.type = proto;
register_prot_hook(sk);
}
spin_lock_bh(&net->packet.sklist_lock);
sk_add_node_rcu(sk, &net->packet.sklist);
sock_prot_inuse_add(net, &packet_proto, 1);
spin_unlock_bh(&net->packet.sklist_lock);
return 0;
out:
return err;
}
static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
{
struct sock_exterr_skb *serr;
struct sk_buff *skb, *skb2;
int copied, err;
err = -EAGAIN;
skb = skb_dequeue(&sk->sk_error_queue);
if (skb == NULL)
goto out;
copied = skb->len;
if (copied > len) {
msg->msg_flags |= MSG_TRUNC;
copied = len;
}
err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
if (err)
goto out_free_skb;
sock_recv_timestamp(msg, sk, skb);
serr = SKB_EXT_ERR(skb);
put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
sizeof(serr->ee), &serr->ee);
msg->msg_flags |= MSG_ERRQUEUE;
err = copied;
/* Reset and regenerate socket error */
spin_lock_bh(&sk->sk_error_queue.lock);
sk->sk_err = 0;
if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
spin_unlock_bh(&sk->sk_error_queue.lock);
sk->sk_error_report(sk);
} else
spin_unlock_bh(&sk->sk_error_queue.lock);
out_free_skb:
kfree_skb(skb);
out:
return err;
}
/*
* Pull a packet from our receive queue and hand it to the user.
* If necessary we block.
*/
static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len, int flags)
{
struct sock *sk = sock->sk;
struct sk_buff *skb;
int copied, err;
struct sockaddr_ll *sll;
int vnet_hdr_len = 0;
err = -EINVAL;
if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
goto out;
#if 0
/* What error should we return now? EUNATTACH? */
if (pkt_sk(sk)->ifindex < 0)
return -ENODEV;
#endif
if (flags & MSG_ERRQUEUE) {
err = packet_recv_error(sk, msg, len);
goto out;
}
/*
* Call the generic datagram receiver. This handles all sorts
* of horrible races and re-entrancy so we can forget about it
* in the protocol layers.
*
* Now it will return ENETDOWN, if device have just gone down,
* but then it will block.
*/
skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
/*
* An error occurred so return it. Because skb_recv_datagram()
* handles the blocking we don't see and worry about blocking
* retries.
*/
if (skb == NULL)
goto out;
if (pkt_sk(sk)->has_vnet_hdr) {
struct virtio_net_hdr vnet_hdr = { 0 };
err = -EINVAL;
vnet_hdr_len = sizeof(vnet_hdr);
if (len < vnet_hdr_len)
goto out_free;
len -= vnet_hdr_len;
if (skb_is_gso(skb)) {
struct skb_shared_info *sinfo = skb_shinfo(skb);
/* This is a hint as to how much should be linear. */
vnet_hdr.hdr_len = skb_headlen(skb);
vnet_hdr.gso_size = sinfo->gso_size;
if (sinfo->gso_type & SKB_GSO_TCPV4)
vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
else if (sinfo->gso_type & SKB_GSO_TCPV6)
vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
else if (sinfo->gso_type & SKB_GSO_UDP)
vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
else if (sinfo->gso_type & SKB_GSO_FCOE)
goto out_free;
else
BUG();
if (sinfo->gso_type & SKB_GSO_TCP_ECN)
vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
} else
vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
vnet_hdr.csum_start = skb_checksum_start_offset(skb);
vnet_hdr.csum_offset = skb->csum_offset;
} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
} /* else everything is zero */
err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
vnet_hdr_len);
if (err < 0)
goto out_free;
}
/*
* If the address length field is there to be filled in, we fill
* it in now.
*/
sll = &PACKET_SKB_CB(skb)->sa.ll;
if (sock->type == SOCK_PACKET)
msg->msg_namelen = sizeof(struct sockaddr_pkt);
else
msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
/*
* You lose any data beyond the buffer you gave. If it worries a
* user program they can ask the device for its MTU anyway.
*/
copied = skb->len;
if (copied > len) {
copied = len;
msg->msg_flags |= MSG_TRUNC;
}
err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
if (err)
goto out_free;
sock_recv_ts_and_drops(msg, sk, skb);
if (msg->msg_name)
memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
msg->msg_namelen);
if (pkt_sk(sk)->auxdata) {
struct tpacket_auxdata aux;
aux.tp_status = TP_STATUS_USER;
if (skb->ip_summed == CHECKSUM_PARTIAL)
aux.tp_status |= TP_STATUS_CSUMNOTREADY;
aux.tp_len = PACKET_SKB_CB(skb)->origlen;
aux.tp_snaplen = skb->len;
aux.tp_mac = 0;
aux.tp_net = skb_network_offset(skb);
if (vlan_tx_tag_present(skb)) {
aux.tp_vlan_tci = vlan_tx_tag_get(skb);
aux.tp_status |= TP_STATUS_VLAN_VALID;
} else {
aux.tp_vlan_tci = 0;
}
aux.tp_padding = 0;
put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
}
/*
* Free or return the buffer as appropriate. Again this
* hides all the races and re-entrancy issues from us.
*/
err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
out_free:
skb_free_datagram(sk, skb);
out:
return err;
}
static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
int *uaddr_len, int peer)
{
struct net_device *dev;
struct sock *sk = sock->sk;
if (peer)
return -EOPNOTSUPP;
uaddr->sa_family = AF_PACKET;
rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
if (dev)
strncpy(uaddr->sa_data, dev->name, 14);
else
memset(uaddr->sa_data, 0, 14);
rcu_read_unlock();
*uaddr_len = sizeof(*uaddr);
return 0;
}
static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
int *uaddr_len, int peer)
{
struct net_device *dev;
struct sock *sk = sock->sk;
struct packet_sock *po = pkt_sk(sk);
DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
if (peer)
return -EOPNOTSUPP;
sll->sll_family = AF_PACKET;
sll->sll_ifindex = po->ifindex;
sll->sll_protocol = po->num;
sll->sll_pkttype = 0;
rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
if (dev) {
sll->sll_hatype = dev->type;
sll->sll_halen = dev->addr_len;
memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
} else {
sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
sll->sll_halen = 0;
}
rcu_read_unlock();
*uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
return 0;
}
static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
int what)
{
switch (i->type) {
case PACKET_MR_MULTICAST:
if (i->alen != dev->addr_len)
return -EINVAL;
if (what > 0)
return dev_mc_add(dev, i->addr);
else
return dev_mc_del(dev, i->addr);
break;
case PACKET_MR_PROMISC:
return dev_set_promiscuity(dev, what);
break;
case PACKET_MR_ALLMULTI:
return dev_set_allmulti(dev, what);
break;
case PACKET_MR_UNICAST:
if (i->alen != dev->addr_len)
return -EINVAL;
if (what > 0)
return dev_uc_add(dev, i->addr);
else
return dev_uc_del(dev, i->addr);
break;
default:
break;
}
return 0;
}
static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
{
for ( ; i; i = i->next) {
if (i->ifindex == dev->ifindex)
packet_dev_mc(dev, i, what);
}
}
static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
{
struct packet_sock *po = pkt_sk(sk);
struct packet_mclist *ml, *i;
struct net_device *dev;
int err;
rtnl_lock();
err = -ENODEV;
dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
if (!dev)
goto done;
err = -EINVAL;
if (mreq->mr_alen > dev->addr_len)
goto done;
err = -ENOBUFS;
i = kmalloc(sizeof(*i), GFP_KERNEL);
if (i == NULL)
goto done;
err = 0;
for (ml = po->mclist; ml; ml = ml->next) {
if (ml->ifindex == mreq->mr_ifindex &&
ml->type == mreq->mr_type &&
ml->alen == mreq->mr_alen &&
memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
ml->count++;
/* Free the new element ... */
kfree(i);
goto done;
}
}
i->type = mreq->mr_type;
i->ifindex = mreq->mr_ifindex;
i->alen = mreq->mr_alen;
memcpy(i->addr, mreq->mr_address, i->alen);
i->count = 1;
i->next = po->mclist;
po->mclist = i;
err = packet_dev_mc(dev, i, 1);
if (err) {
po->mclist = i->next;
kfree(i);
}
done:
rtnl_unlock();
return err;
}
static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
{
struct packet_mclist *ml, **mlp;
rtnl_lock();
for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
if (ml->ifindex == mreq->mr_ifindex &&
ml->type == mreq->mr_type &&
ml->alen == mreq->mr_alen &&
memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
if (--ml->count == 0) {
struct net_device *dev;
*mlp = ml->next;
dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
if (dev)
packet_dev_mc(dev, ml, -1);
kfree(ml);
}
rtnl_unlock();
return 0;
}
}
rtnl_unlock();
return -EADDRNOTAVAIL;
}
static void packet_flush_mclist(struct sock *sk)
{
struct packet_sock *po = pkt_sk(sk);
struct packet_mclist *ml;
if (!po->mclist)
return;
rtnl_lock();
while ((ml = po->mclist) != NULL) {
struct net_device *dev;
po->mclist = ml->next;
dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
if (dev != NULL)
packet_dev_mc(dev, ml, -1);
kfree(ml);
}
rtnl_unlock();
}
static int
packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
{
struct sock *sk = sock->sk;
struct packet_sock *po = pkt_sk(sk);
int ret;
if (level != SOL_PACKET)
return -ENOPROTOOPT;
switch (optname) {
case PACKET_ADD_MEMBERSHIP:
case PACKET_DROP_MEMBERSHIP:
{
struct packet_mreq_max mreq;
int len = optlen;
memset(&mreq, 0, sizeof(mreq));
if (len < sizeof(struct packet_mreq))
return -EINVAL;
if (len > sizeof(mreq))
len = sizeof(mreq);
if (copy_from_user(&mreq, optval, len))
return -EFAULT;
if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
return -EINVAL;
if (optname == PACKET_ADD_MEMBERSHIP)
ret = packet_mc_add(sk, &mreq);
else
ret = packet_mc_drop(sk, &mreq);
return ret;
}
case PACKET_RX_RING:
case PACKET_TX_RING:
{
struct tpacket_req req;
if (optlen < sizeof(req))
return -EINVAL;
if (pkt_sk(sk)->has_vnet_hdr)
return -EINVAL;
if (copy_from_user(&req, optval, sizeof(req)))
return -EFAULT;
return packet_set_ring(sk, &req, 0, optname == PACKET_TX_RING);
}
case PACKET_COPY_THRESH:
{
int val;
if (optlen != sizeof(val))
return -EINVAL;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
pkt_sk(sk)->copy_thresh = val;
return 0;
}
case PACKET_VERSION:
{
int val;
if (optlen != sizeof(val))
return -EINVAL;
if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
return -EBUSY;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
switch (val) {
case TPACKET_V1:
case TPACKET_V2:
po->tp_version = val;
return 0;
default:
return -EINVAL;
}
}
case PACKET_RESERVE:
{
unsigned int val;
if (optlen != sizeof(val))
return -EINVAL;
if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
return -EBUSY;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
po->tp_reserve = val;
return 0;
}
case PACKET_LOSS:
{
unsigned int val;
if (optlen != sizeof(val))
return -EINVAL;
if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
return -EBUSY;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
po->tp_loss = !!val;
return 0;
}
case PACKET_AUXDATA:
{
int val;
if (optlen < sizeof(val))
return -EINVAL;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
po->auxdata = !!val;
return 0;
}
case PACKET_ORIGDEV:
{
int val;
if (optlen < sizeof(val))
return -EINVAL;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
po->origdev = !!val;
return 0;
}
case PACKET_VNET_HDR:
{
int val;
if (sock->type != SOCK_RAW)
return -EINVAL;
if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
return -EBUSY;
if (optlen < sizeof(val))
return -EINVAL;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
po->has_vnet_hdr = !!val;
return 0;
}
case PACKET_TIMESTAMP:
{
int val;
if (optlen != sizeof(val))
return -EINVAL;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
po->tp_tstamp = val;
return 0;
}
case PACKET_FANOUT:
{
int val;
if (optlen != sizeof(val))
return -EINVAL;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
return fanout_add(sk, val & 0xffff, val >> 16);
}
default:
return -ENOPROTOOPT;
}
}
static int packet_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
int len;
int val;
struct sock *sk = sock->sk;
struct packet_sock *po = pkt_sk(sk);
void *data;
struct tpacket_stats st;
if (level != SOL_PACKET)
return -ENOPROTOOPT;
if (get_user(len, optlen))
return -EFAULT;
if (len < 0)
return -EINVAL;
switch (optname) {
case PACKET_STATISTICS:
if (len > sizeof(struct tpacket_stats))
len = sizeof(struct tpacket_stats);
spin_lock_bh(&sk->sk_receive_queue.lock);
st = po->stats;
memset(&po->stats, 0, sizeof(st));
spin_unlock_bh(&sk->sk_receive_queue.lock);
st.tp_packets += st.tp_drops;
data = &st;
break;
case PACKET_AUXDATA:
if (len > sizeof(int))
len = sizeof(int);
val = po->auxdata;
data = &val;
break;
case PACKET_ORIGDEV:
if (len > sizeof(int))
len = sizeof(int);
val = po->origdev;
data = &val;
break;
case PACKET_VNET_HDR:
if (len > sizeof(int))
len = sizeof(int);
val = po->has_vnet_hdr;
data = &val;
break;
case PACKET_VERSION:
if (len > sizeof(int))
len = sizeof(int);
val = po->tp_version;
data = &val;
break;
case PACKET_HDRLEN:
if (len > sizeof(int))
len = sizeof(int);
if (copy_from_user(&val, optval, len))
return -EFAULT;
switch (val) {
case TPACKET_V1:
val = sizeof(struct tpacket_hdr);
break;
case TPACKET_V2:
val = sizeof(struct tpacket2_hdr);
break;
default:
return -EINVAL;
}
data = &val;
break;
case PACKET_RESERVE:
if (len > sizeof(unsigned int))
len = sizeof(unsigned int);
val = po->tp_reserve;
data = &val;
break;
case PACKET_LOSS:
if (len > sizeof(unsigned int))
len = sizeof(unsigned int);
val = po->tp_loss;
data = &val;
break;
case PACKET_TIMESTAMP:
if (len > sizeof(int))
len = sizeof(int);
val = po->tp_tstamp;
data = &val;
break;
case PACKET_FANOUT:
if (len > sizeof(int))
len = sizeof(int);
val = (po->fanout ?
((u32)po->fanout->id |
((u32)po->fanout->type << 16)) :
0);
data = &val;
break;
default:
return -ENOPROTOOPT;
}
if (put_user(len, optlen))
return -EFAULT;
if (copy_to_user(optval, data, len))
return -EFAULT;
return 0;
}
static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
{
struct sock *sk;
struct hlist_node *node;
struct net_device *dev = data;
struct net *net = dev_net(dev);
rcu_read_lock();
sk_for_each_rcu(sk, node, &net->packet.sklist) {
struct packet_sock *po = pkt_sk(sk);
switch (msg) {
case NETDEV_UNREGISTER:
if (po->mclist)
packet_dev_mclist(dev, po->mclist, -1);
/* fallthrough */
case NETDEV_DOWN:
if (dev->ifindex == po->ifindex) {
spin_lock(&po->bind_lock);
if (po->running) {
__unregister_prot_hook(sk, false);
sk->sk_err = ENETDOWN;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
}
if (msg == NETDEV_UNREGISTER) {
po->ifindex = -1;
if (po->prot_hook.dev)
dev_put(po->prot_hook.dev);
po->prot_hook.dev = NULL;
}
spin_unlock(&po->bind_lock);
}
break;
case NETDEV_UP:
if (dev->ifindex == po->ifindex) {
spin_lock(&po->bind_lock);
if (po->num)
register_prot_hook(sk);
spin_unlock(&po->bind_lock);
}
break;
}
}
rcu_read_unlock();
return NOTIFY_DONE;
}
static int packet_ioctl(struct socket *sock, unsigned int cmd,
unsigned long arg)
{
struct sock *sk = sock->sk;
switch (cmd) {
case SIOCOUTQ:
{
int amount = sk_wmem_alloc_get(sk);
return put_user(amount, (int __user *)arg);
}
case SIOCINQ:
{
struct sk_buff *skb;
int amount = 0;
spin_lock_bh(&sk->sk_receive_queue.lock);
skb = skb_peek(&sk->sk_receive_queue);
if (skb)
amount = skb->len;
spin_unlock_bh(&sk->sk_receive_queue.lock);
return put_user(amount, (int __user *)arg);
}
case SIOCGSTAMP:
return sock_get_timestamp(sk, (struct timeval __user *)arg);
case SIOCGSTAMPNS:
return sock_get_timestampns(sk, (struct timespec __user *)arg);
#ifdef CONFIG_INET
case SIOCADDRT:
case SIOCDELRT:
case SIOCDARP:
case SIOCGARP:
case SIOCSARP:
case SIOCGIFADDR:
case SIOCSIFADDR:
case SIOCGIFBRDADDR:
case SIOCSIFBRDADDR:
case SIOCGIFNETMASK:
case SIOCSIFNETMASK:
case SIOCGIFDSTADDR:
case SIOCSIFDSTADDR:
case SIOCSIFFLAGS:
return inet_dgram_ops.ioctl(sock, cmd, arg);
#endif
default:
return -ENOIOCTLCMD;
}
return 0;
}
static unsigned int packet_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
struct sock *sk = sock->sk;
struct packet_sock *po = pkt_sk(sk);
unsigned int mask = datagram_poll(file, sock, wait);
spin_lock_bh(&sk->sk_receive_queue.lock);
if (po->rx_ring.pg_vec) {
if (!packet_previous_frame(po, &po->rx_ring, TP_STATUS_KERNEL))
mask |= POLLIN | POLLRDNORM;
}
spin_unlock_bh(&sk->sk_receive_queue.lock);
spin_lock_bh(&sk->sk_write_queue.lock);
if (po->tx_ring.pg_vec) {
if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
mask |= POLLOUT | POLLWRNORM;
}
spin_unlock_bh(&sk->sk_write_queue.lock);
return mask;
}
/* Dirty? Well, I still did not learn better way to account
* for user mmaps.
*/
static void packet_mm_open(struct vm_area_struct *vma)
{
struct file *file = vma->vm_file;
struct socket *sock = file->private_data;
struct sock *sk = sock->sk;
if (sk)
atomic_inc(&pkt_sk(sk)->mapped);
}
static void packet_mm_close(struct vm_area_struct *vma)
{
struct file *file = vma->vm_file;
struct socket *sock = file->private_data;
struct sock *sk = sock->sk;
if (sk)
atomic_dec(&pkt_sk(sk)->mapped);
}
static const struct vm_operations_struct packet_mmap_ops = {
.open = packet_mm_open,
.close = packet_mm_close,
};
static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
unsigned int len)
{
int i;
for (i = 0; i < len; i++) {
if (likely(pg_vec[i].buffer)) {
if (is_vmalloc_addr(pg_vec[i].buffer))
vfree(pg_vec[i].buffer);
else
free_pages((unsigned long)pg_vec[i].buffer,
order);
pg_vec[i].buffer = NULL;
}
}
kfree(pg_vec);
}
static inline char *alloc_one_pg_vec_page(unsigned long order)
{
char *buffer = NULL;
gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
__GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
buffer = (char *) __get_free_pages(gfp_flags, order);
if (buffer)
return buffer;
/*
* __get_free_pages failed, fall back to vmalloc
*/
buffer = vzalloc((1 << order) * PAGE_SIZE);
if (buffer)
return buffer;
/*
* vmalloc failed, lets dig into swap here
*/
gfp_flags &= ~__GFP_NORETRY;
buffer = (char *)__get_free_pages(gfp_flags, order);
if (buffer)
return buffer;
/*
* complete and utter failure
*/
return NULL;
}
static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
{
unsigned int block_nr = req->tp_block_nr;
struct pgv *pg_vec;
int i;
pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
if (unlikely(!pg_vec))
goto out;
for (i = 0; i < block_nr; i++) {
pg_vec[i].buffer = alloc_one_pg_vec_page(order);
if (unlikely(!pg_vec[i].buffer))
goto out_free_pgvec;
}
out:
return pg_vec;
out_free_pgvec:
free_pg_vec(pg_vec, order, block_nr);
pg_vec = NULL;
goto out;
}
static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
int closing, int tx_ring)
{
struct pgv *pg_vec = NULL;
struct packet_sock *po = pkt_sk(sk);
int was_running, order = 0;
struct packet_ring_buffer *rb;
struct sk_buff_head *rb_queue;
__be16 num;
int err;
rb = tx_ring ? &po->tx_ring : &po->rx_ring;
rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
err = -EBUSY;
if (!closing) {
if (atomic_read(&po->mapped))
goto out;
if (atomic_read(&rb->pending))
goto out;
}
if (req->tp_block_nr) {
/* Sanity tests and some calculations */
err = -EBUSY;
if (unlikely(rb->pg_vec))
goto out;
switch (po->tp_version) {
case TPACKET_V1:
po->tp_hdrlen = TPACKET_HDRLEN;
break;
case TPACKET_V2:
po->tp_hdrlen = TPACKET2_HDRLEN;
break;
}
err = -EINVAL;
if (unlikely((int)req->tp_block_size <= 0))
goto out;
if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
goto out;
if (unlikely(req->tp_frame_size < po->tp_hdrlen +
po->tp_reserve))
goto out;
if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
goto out;
rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
if (unlikely(rb->frames_per_block <= 0))
goto out;
if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
req->tp_frame_nr))
goto out;
err = -ENOMEM;
order = get_order(req->tp_block_size);
pg_vec = alloc_pg_vec(req, order);
if (unlikely(!pg_vec))
goto out;
}
/* Done */
else {
err = -EINVAL;
if (unlikely(req->tp_frame_nr))
goto out;
}
lock_sock(sk);
/* Detach socket from network */
spin_lock(&po->bind_lock);
was_running = po->running;
num = po->num;
if (was_running) {
po->num = 0;
__unregister_prot_hook(sk, false);
}
spin_unlock(&po->bind_lock);
synchronize_net();
err = -EBUSY;
mutex_lock(&po->pg_vec_lock);
if (closing || atomic_read(&po->mapped) == 0) {
err = 0;
spin_lock_bh(&rb_queue->lock);
swap(rb->pg_vec, pg_vec);
rb->frame_max = (req->tp_frame_nr - 1);
rb->head = 0;
rb->frame_size = req->tp_frame_size;
spin_unlock_bh(&rb_queue->lock);
swap(rb->pg_vec_order, order);
swap(rb->pg_vec_len, req->tp_block_nr);
rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
po->prot_hook.func = (po->rx_ring.pg_vec) ?
tpacket_rcv : packet_rcv;
skb_queue_purge(rb_queue);
if (atomic_read(&po->mapped))
pr_err("packet_mmap: vma is busy: %d\n",
atomic_read(&po->mapped));
}
mutex_unlock(&po->pg_vec_lock);
spin_lock(&po->bind_lock);
if (was_running) {
po->num = num;
register_prot_hook(sk);
}
spin_unlock(&po->bind_lock);
release_sock(sk);
if (pg_vec)
free_pg_vec(pg_vec, order, req->tp_block_nr);
out:
return err;
}
static int packet_mmap(struct file *file, struct socket *sock,
struct vm_area_struct *vma)
{
struct sock *sk = sock->sk;
struct packet_sock *po = pkt_sk(sk);
unsigned long size, expected_size;
struct packet_ring_buffer *rb;
unsigned long start;
int err = -EINVAL;
int i;
if (vma->vm_pgoff)
return -EINVAL;
mutex_lock(&po->pg_vec_lock);
expected_size = 0;
for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
if (rb->pg_vec) {
expected_size += rb->pg_vec_len
* rb->pg_vec_pages
* PAGE_SIZE;
}
}
if (expected_size == 0)
goto out;
size = vma->vm_end - vma->vm_start;
if (size != expected_size)
goto out;
start = vma->vm_start;
for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
if (rb->pg_vec == NULL)
continue;
for (i = 0; i < rb->pg_vec_len; i++) {
struct page *page;
void *kaddr = rb->pg_vec[i].buffer;
int pg_num;
for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
page = pgv_to_page(kaddr);
err = vm_insert_page(vma, start, page);
if (unlikely(err))
goto out;
start += PAGE_SIZE;
kaddr += PAGE_SIZE;
}
}
}
atomic_inc(&po->mapped);
vma->vm_ops = &packet_mmap_ops;
err = 0;
out:
mutex_unlock(&po->pg_vec_lock);
return err;
}
static const struct proto_ops packet_ops_spkt = {
.family = PF_PACKET,
.owner = THIS_MODULE,
.release = packet_release,
.bind = packet_bind_spkt,
.connect = sock_no_connect,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = packet_getname_spkt,
.poll = datagram_poll,
.ioctl = packet_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.setsockopt = sock_no_setsockopt,
.getsockopt = sock_no_getsockopt,
.sendmsg = packet_sendmsg_spkt,
.recvmsg = packet_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static const struct proto_ops packet_ops = {
.family = PF_PACKET,
.owner = THIS_MODULE,
.release = packet_release,
.bind = packet_bind,
.connect = sock_no_connect,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = packet_getname,
.poll = packet_poll,
.ioctl = packet_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.setsockopt = packet_setsockopt,
.getsockopt = packet_getsockopt,
.sendmsg = packet_sendmsg,
.recvmsg = packet_recvmsg,
.mmap = packet_mmap,
.sendpage = sock_no_sendpage,
};
static const struct net_proto_family packet_family_ops = {
.family = PF_PACKET,
.create = packet_create,
.owner = THIS_MODULE,
};
static struct notifier_block packet_netdev_notifier = {
.notifier_call = packet_notifier,
};
#ifdef CONFIG_PROC_FS
static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(RCU)
{
struct net *net = seq_file_net(seq);
rcu_read_lock();
return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
}
static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct net *net = seq_file_net(seq);
return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
}
static void packet_seq_stop(struct seq_file *seq, void *v)
__releases(RCU)
{
rcu_read_unlock();
}
static int packet_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
else {
struct sock *s = sk_entry(v);
const struct packet_sock *po = pkt_sk(s);
seq_printf(seq,
"%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
s,
atomic_read(&s->sk_refcnt),
s->sk_type,
ntohs(po->num),
po->ifindex,
po->running,
atomic_read(&s->sk_rmem_alloc),
sock_i_uid(s),
sock_i_ino(s));
}
return 0;
}
static const struct seq_operations packet_seq_ops = {
.start = packet_seq_start,
.next = packet_seq_next,
.stop = packet_seq_stop,
.show = packet_seq_show,
};
static int packet_seq_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &packet_seq_ops,
sizeof(struct seq_net_private));
}
static const struct file_operations packet_seq_fops = {
.owner = THIS_MODULE,
.open = packet_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
#endif
static int __net_init packet_net_init(struct net *net)
{
spin_lock_init(&net->packet.sklist_lock);
INIT_HLIST_HEAD(&net->packet.sklist);
if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
return -ENOMEM;
return 0;
}
static void __net_exit packet_net_exit(struct net *net)
{
proc_net_remove(net, "packet");
}
static struct pernet_operations packet_net_ops = {
.init = packet_net_init,
.exit = packet_net_exit,
};
static void __exit packet_exit(void)
{
unregister_netdevice_notifier(&packet_netdev_notifier);
unregister_pernet_subsys(&packet_net_ops);
sock_unregister(PF_PACKET);
proto_unregister(&packet_proto);
}
static int __init packet_init(void)
{
int rc = proto_register(&packet_proto, 0);
if (rc != 0)
goto out;
sock_register(&packet_family_ops);
register_pernet_subsys(&packet_net_ops);
register_netdevice_notifier(&packet_netdev_notifier);
out:
return rc;
}
module_init(packet_init);
module_exit(packet_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_PACKET);
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