Root/net/packet/af_packet.c

1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * PACKET - implements raw packet sockets.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 *
12 * Fixes:
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
41 * and packet_mreq.
42 * Johann Baudy : Added TX RING.
43 *
44 * This program is free software; you can redistribute it and/or
45 * modify it under the terms of the GNU General Public License
46 * as published by the Free Software Foundation; either version
47 * 2 of the License, or (at your option) any later version.
48 *
49 */
50
51#include <linux/types.h>
52#include <linux/mm.h>
53#include <linux/capability.h>
54#include <linux/fcntl.h>
55#include <linux/socket.h>
56#include <linux/in.h>
57#include <linux/inet.h>
58#include <linux/netdevice.h>
59#include <linux/if_packet.h>
60#include <linux/wireless.h>
61#include <linux/kernel.h>
62#include <linux/kmod.h>
63#include <linux/slab.h>
64#include <net/net_namespace.h>
65#include <net/ip.h>
66#include <net/protocol.h>
67#include <linux/skbuff.h>
68#include <net/sock.h>
69#include <linux/errno.h>
70#include <linux/timer.h>
71#include <asm/system.h>
72#include <asm/uaccess.h>
73#include <asm/ioctls.h>
74#include <asm/page.h>
75#include <asm/cacheflush.h>
76#include <asm/io.h>
77#include <linux/proc_fs.h>
78#include <linux/seq_file.h>
79#include <linux/poll.h>
80#include <linux/module.h>
81#include <linux/init.h>
82#include <linux/mutex.h>
83#include <linux/if_vlan.h>
84#include <linux/virtio_net.h>
85
86#ifdef CONFIG_INET
87#include <net/inet_common.h>
88#endif
89
90/*
91   Assumptions:
92   - if device has no dev->hard_header routine, it adds and removes ll header
93     inside itself. In this case ll header is invisible outside of device,
94     but higher levels still should reserve dev->hard_header_len.
95     Some devices are enough clever to reallocate skb, when header
96     will not fit to reserved space (tunnel), another ones are silly
97     (PPP).
98   - packet socket receives packets with pulled ll header,
99     so that SOCK_RAW should push it back.
100
101On receive:
102-----------
103
104Incoming, dev->hard_header!=NULL
105   mac_header -> ll header
106   data -> data
107
108Outgoing, dev->hard_header!=NULL
109   mac_header -> ll header
110   data -> ll header
111
112Incoming, dev->hard_header==NULL
113   mac_header -> UNKNOWN position. It is very likely, that it points to ll
114         header. PPP makes it, that is wrong, because introduce
115         assymetry between rx and tx paths.
116   data -> data
117
118Outgoing, dev->hard_header==NULL
119   mac_header -> data. ll header is still not built!
120   data -> data
121
122Resume
123  If dev->hard_header==NULL we are unlikely to restore sensible ll header.
124
125
126On transmit:
127------------
128
129dev->hard_header != NULL
130   mac_header -> ll header
131   data -> ll header
132
133dev->hard_header == NULL (ll header is added by device, we cannot control it)
134   mac_header -> data
135   data -> data
136
137   We should set nh.raw on output to correct posistion,
138   packet classifier depends on it.
139 */
140
141/* Private packet socket structures. */
142
143struct packet_mclist {
144    struct packet_mclist *next;
145    int ifindex;
146    int count;
147    unsigned short type;
148    unsigned short alen;
149    unsigned char addr[MAX_ADDR_LEN];
150};
151/* identical to struct packet_mreq except it has
152 * a longer address field.
153 */
154struct packet_mreq_max {
155    int mr_ifindex;
156    unsigned short mr_type;
157    unsigned short mr_alen;
158    unsigned char mr_address[MAX_ADDR_LEN];
159};
160
161static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
162        int closing, int tx_ring);
163
164struct packet_ring_buffer {
165    char **pg_vec;
166    unsigned int head;
167    unsigned int frames_per_block;
168    unsigned int frame_size;
169    unsigned int frame_max;
170
171    unsigned int pg_vec_order;
172    unsigned int pg_vec_pages;
173    unsigned int pg_vec_len;
174
175    atomic_t pending;
176};
177
178struct packet_sock;
179static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
180
181static void packet_flush_mclist(struct sock *sk);
182
183struct packet_sock {
184    /* struct sock has to be the first member of packet_sock */
185    struct sock sk;
186    struct tpacket_stats stats;
187    struct packet_ring_buffer rx_ring;
188    struct packet_ring_buffer tx_ring;
189    int copy_thresh;
190    spinlock_t bind_lock;
191    struct mutex pg_vec_lock;
192    unsigned int running:1, /* prot_hook is attached*/
193                auxdata:1,
194                origdev:1,
195                has_vnet_hdr:1;
196    int ifindex; /* bound device */
197    __be16 num;
198    struct packet_mclist *mclist;
199    atomic_t mapped;
200    enum tpacket_versions tp_version;
201    unsigned int tp_hdrlen;
202    unsigned int tp_reserve;
203    unsigned int tp_loss:1;
204    struct packet_type prot_hook ____cacheline_aligned_in_smp;
205};
206
207struct packet_skb_cb {
208    unsigned int origlen;
209    union {
210        struct sockaddr_pkt pkt;
211        struct sockaddr_ll ll;
212    } sa;
213};
214
215#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
216
217static void __packet_set_status(struct packet_sock *po, void *frame, int status)
218{
219    union {
220        struct tpacket_hdr *h1;
221        struct tpacket2_hdr *h2;
222        void *raw;
223    } h;
224
225    h.raw = frame;
226    switch (po->tp_version) {
227    case TPACKET_V1:
228        h.h1->tp_status = status;
229        flush_dcache_page(virt_to_page(&h.h1->tp_status));
230        break;
231    case TPACKET_V2:
232        h.h2->tp_status = status;
233        flush_dcache_page(virt_to_page(&h.h2->tp_status));
234        break;
235    default:
236        pr_err("TPACKET version not supported\n");
237        BUG();
238    }
239
240    smp_wmb();
241}
242
243static int __packet_get_status(struct packet_sock *po, void *frame)
244{
245    union {
246        struct tpacket_hdr *h1;
247        struct tpacket2_hdr *h2;
248        void *raw;
249    } h;
250
251    smp_rmb();
252
253    h.raw = frame;
254    switch (po->tp_version) {
255    case TPACKET_V1:
256        flush_dcache_page(virt_to_page(&h.h1->tp_status));
257        return h.h1->tp_status;
258    case TPACKET_V2:
259        flush_dcache_page(virt_to_page(&h.h2->tp_status));
260        return h.h2->tp_status;
261    default:
262        pr_err("TPACKET version not supported\n");
263        BUG();
264        return 0;
265    }
266}
267
268static void *packet_lookup_frame(struct packet_sock *po,
269        struct packet_ring_buffer *rb,
270        unsigned int position,
271        int status)
272{
273    unsigned int pg_vec_pos, frame_offset;
274    union {
275        struct tpacket_hdr *h1;
276        struct tpacket2_hdr *h2;
277        void *raw;
278    } h;
279
280    pg_vec_pos = position / rb->frames_per_block;
281    frame_offset = position % rb->frames_per_block;
282
283    h.raw = rb->pg_vec[pg_vec_pos] + (frame_offset * rb->frame_size);
284
285    if (status != __packet_get_status(po, h.raw))
286        return NULL;
287
288    return h.raw;
289}
290
291static inline void *packet_current_frame(struct packet_sock *po,
292        struct packet_ring_buffer *rb,
293        int status)
294{
295    return packet_lookup_frame(po, rb, rb->head, status);
296}
297
298static inline void *packet_previous_frame(struct packet_sock *po,
299        struct packet_ring_buffer *rb,
300        int status)
301{
302    unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
303    return packet_lookup_frame(po, rb, previous, status);
304}
305
306static inline void packet_increment_head(struct packet_ring_buffer *buff)
307{
308    buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
309}
310
311static inline struct packet_sock *pkt_sk(struct sock *sk)
312{
313    return (struct packet_sock *)sk;
314}
315
316static void packet_sock_destruct(struct sock *sk)
317{
318    WARN_ON(atomic_read(&sk->sk_rmem_alloc));
319    WARN_ON(atomic_read(&sk->sk_wmem_alloc));
320
321    if (!sock_flag(sk, SOCK_DEAD)) {
322        pr_err("Attempt to release alive packet socket: %p\n", sk);
323        return;
324    }
325
326    sk_refcnt_debug_dec(sk);
327}
328
329
330static const struct proto_ops packet_ops;
331
332static const struct proto_ops packet_ops_spkt;
333
334static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
335               struct packet_type *pt, struct net_device *orig_dev)
336{
337    struct sock *sk;
338    struct sockaddr_pkt *spkt;
339
340    /*
341     * When we registered the protocol we saved the socket in the data
342     * field for just this event.
343     */
344
345    sk = pt->af_packet_priv;
346
347    /*
348     * Yank back the headers [hope the device set this
349     * right or kerboom...]
350     *
351     * Incoming packets have ll header pulled,
352     * push it back.
353     *
354     * For outgoing ones skb->data == skb_mac_header(skb)
355     * so that this procedure is noop.
356     */
357
358    if (skb->pkt_type == PACKET_LOOPBACK)
359        goto out;
360
361    if (!net_eq(dev_net(dev), sock_net(sk)))
362        goto out;
363
364    skb = skb_share_check(skb, GFP_ATOMIC);
365    if (skb == NULL)
366        goto oom;
367
368    /* drop any routing info */
369    skb_dst_drop(skb);
370
371    /* drop conntrack reference */
372    nf_reset(skb);
373
374    spkt = &PACKET_SKB_CB(skb)->sa.pkt;
375
376    skb_push(skb, skb->data - skb_mac_header(skb));
377
378    /*
379     * The SOCK_PACKET socket receives _all_ frames.
380     */
381
382    spkt->spkt_family = dev->type;
383    strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
384    spkt->spkt_protocol = skb->protocol;
385
386    /*
387     * Charge the memory to the socket. This is done specifically
388     * to prevent sockets using all the memory up.
389     */
390
391    if (sock_queue_rcv_skb(sk, skb) == 0)
392        return 0;
393
394out:
395    kfree_skb(skb);
396oom:
397    return 0;
398}
399
400
401/*
402 * Output a raw packet to a device layer. This bypasses all the other
403 * protocol layers and you must therefore supply it with a complete frame
404 */
405
406static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
407                   struct msghdr *msg, size_t len)
408{
409    struct sock *sk = sock->sk;
410    struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
411    struct sk_buff *skb = NULL;
412    struct net_device *dev;
413    __be16 proto = 0;
414    int err;
415
416    /*
417     * Get and verify the address.
418     */
419
420    if (saddr) {
421        if (msg->msg_namelen < sizeof(struct sockaddr))
422            return -EINVAL;
423        if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
424            proto = saddr->spkt_protocol;
425    } else
426        return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
427
428    /*
429     * Find the device first to size check it
430     */
431
432    saddr->spkt_device[13] = 0;
433retry:
434    rcu_read_lock();
435    dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
436    err = -ENODEV;
437    if (dev == NULL)
438        goto out_unlock;
439
440    err = -ENETDOWN;
441    if (!(dev->flags & IFF_UP))
442        goto out_unlock;
443
444    /*
445     * You may not queue a frame bigger than the mtu. This is the lowest level
446     * raw protocol and you must do your own fragmentation at this level.
447     */
448
449    err = -EMSGSIZE;
450    if (len > dev->mtu + dev->hard_header_len)
451        goto out_unlock;
452
453    if (!skb) {
454        size_t reserved = LL_RESERVED_SPACE(dev);
455        unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
456
457        rcu_read_unlock();
458        skb = sock_wmalloc(sk, len + reserved, 0, GFP_KERNEL);
459        if (skb == NULL)
460            return -ENOBUFS;
461        /* FIXME: Save some space for broken drivers that write a hard
462         * header at transmission time by themselves. PPP is the notable
463         * one here. This should really be fixed at the driver level.
464         */
465        skb_reserve(skb, reserved);
466        skb_reset_network_header(skb);
467
468        /* Try to align data part correctly */
469        if (hhlen) {
470            skb->data -= hhlen;
471            skb->tail -= hhlen;
472            if (len < hhlen)
473                skb_reset_network_header(skb);
474        }
475        err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
476        if (err)
477            goto out_free;
478        goto retry;
479    }
480
481
482    skb->protocol = proto;
483    skb->dev = dev;
484    skb->priority = sk->sk_priority;
485    skb->mark = sk->sk_mark;
486
487    dev_queue_xmit(skb);
488    rcu_read_unlock();
489    return len;
490
491out_unlock:
492    rcu_read_unlock();
493out_free:
494    kfree_skb(skb);
495    return err;
496}
497
498static inline unsigned int run_filter(struct sk_buff *skb, struct sock *sk,
499                      unsigned int res)
500{
501    struct sk_filter *filter;
502
503    rcu_read_lock_bh();
504    filter = rcu_dereference_bh(sk->sk_filter);
505    if (filter != NULL)
506        res = sk_run_filter(skb, filter->insns, filter->len);
507    rcu_read_unlock_bh();
508
509    return res;
510}
511
512/*
513   This function makes lazy skb cloning in hope that most of packets
514   are discarded by BPF.
515
516   Note tricky part: we DO mangle shared skb! skb->data, skb->len
517   and skb->cb are mangled. It works because (and until) packets
518   falling here are owned by current CPU. Output packets are cloned
519   by dev_queue_xmit_nit(), input packets are processed by net_bh
520   sequencially, so that if we return skb to original state on exit,
521   we will not harm anyone.
522 */
523
524static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
525              struct packet_type *pt, struct net_device *orig_dev)
526{
527    struct sock *sk;
528    struct sockaddr_ll *sll;
529    struct packet_sock *po;
530    u8 *skb_head = skb->data;
531    int skb_len = skb->len;
532    unsigned int snaplen, res;
533
534    if (skb->pkt_type == PACKET_LOOPBACK)
535        goto drop;
536
537    sk = pt->af_packet_priv;
538    po = pkt_sk(sk);
539
540    if (!net_eq(dev_net(dev), sock_net(sk)))
541        goto drop;
542
543    skb->dev = dev;
544
545    if (dev->header_ops) {
546        /* The device has an explicit notion of ll header,
547           exported to higher levels.
548
549           Otherwise, the device hides datails of it frame
550           structure, so that corresponding packet head
551           never delivered to user.
552         */
553        if (sk->sk_type != SOCK_DGRAM)
554            skb_push(skb, skb->data - skb_mac_header(skb));
555        else if (skb->pkt_type == PACKET_OUTGOING) {
556            /* Special case: outgoing packets have ll header at head */
557            skb_pull(skb, skb_network_offset(skb));
558        }
559    }
560
561    snaplen = skb->len;
562
563    res = run_filter(skb, sk, snaplen);
564    if (!res)
565        goto drop_n_restore;
566    if (snaplen > res)
567        snaplen = res;
568
569    if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
570        (unsigned)sk->sk_rcvbuf)
571        goto drop_n_acct;
572
573    if (skb_shared(skb)) {
574        struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
575        if (nskb == NULL)
576            goto drop_n_acct;
577
578        if (skb_head != skb->data) {
579            skb->data = skb_head;
580            skb->len = skb_len;
581        }
582        kfree_skb(skb);
583        skb = nskb;
584    }
585
586    BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
587             sizeof(skb->cb));
588
589    sll = &PACKET_SKB_CB(skb)->sa.ll;
590    sll->sll_family = AF_PACKET;
591    sll->sll_hatype = dev->type;
592    sll->sll_protocol = skb->protocol;
593    sll->sll_pkttype = skb->pkt_type;
594    if (unlikely(po->origdev))
595        sll->sll_ifindex = orig_dev->ifindex;
596    else
597        sll->sll_ifindex = dev->ifindex;
598
599    sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
600
601    PACKET_SKB_CB(skb)->origlen = skb->len;
602
603    if (pskb_trim(skb, snaplen))
604        goto drop_n_acct;
605
606    skb_set_owner_r(skb, sk);
607    skb->dev = NULL;
608    skb_dst_drop(skb);
609
610    /* drop conntrack reference */
611    nf_reset(skb);
612
613    spin_lock(&sk->sk_receive_queue.lock);
614    po->stats.tp_packets++;
615    skb->dropcount = atomic_read(&sk->sk_drops);
616    __skb_queue_tail(&sk->sk_receive_queue, skb);
617    spin_unlock(&sk->sk_receive_queue.lock);
618    sk->sk_data_ready(sk, skb->len);
619    return 0;
620
621drop_n_acct:
622    po->stats.tp_drops = atomic_inc_return(&sk->sk_drops);
623
624drop_n_restore:
625    if (skb_head != skb->data && skb_shared(skb)) {
626        skb->data = skb_head;
627        skb->len = skb_len;
628    }
629drop:
630    consume_skb(skb);
631    return 0;
632}
633
634static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
635               struct packet_type *pt, struct net_device *orig_dev)
636{
637    struct sock *sk;
638    struct packet_sock *po;
639    struct sockaddr_ll *sll;
640    union {
641        struct tpacket_hdr *h1;
642        struct tpacket2_hdr *h2;
643        void *raw;
644    } h;
645    u8 *skb_head = skb->data;
646    int skb_len = skb->len;
647    unsigned int snaplen, res;
648    unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER;
649    unsigned short macoff, netoff, hdrlen;
650    struct sk_buff *copy_skb = NULL;
651    struct timeval tv;
652    struct timespec ts;
653
654    if (skb->pkt_type == PACKET_LOOPBACK)
655        goto drop;
656
657    sk = pt->af_packet_priv;
658    po = pkt_sk(sk);
659
660    if (!net_eq(dev_net(dev), sock_net(sk)))
661        goto drop;
662
663    if (dev->header_ops) {
664        if (sk->sk_type != SOCK_DGRAM)
665            skb_push(skb, skb->data - skb_mac_header(skb));
666        else if (skb->pkt_type == PACKET_OUTGOING) {
667            /* Special case: outgoing packets have ll header at head */
668            skb_pull(skb, skb_network_offset(skb));
669        }
670    }
671
672    if (skb->ip_summed == CHECKSUM_PARTIAL)
673        status |= TP_STATUS_CSUMNOTREADY;
674
675    snaplen = skb->len;
676
677    res = run_filter(skb, sk, snaplen);
678    if (!res)
679        goto drop_n_restore;
680    if (snaplen > res)
681        snaplen = res;
682
683    if (sk->sk_type == SOCK_DGRAM) {
684        macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
685                  po->tp_reserve;
686    } else {
687        unsigned maclen = skb_network_offset(skb);
688        netoff = TPACKET_ALIGN(po->tp_hdrlen +
689                       (maclen < 16 ? 16 : maclen)) +
690            po->tp_reserve;
691        macoff = netoff - maclen;
692    }
693
694    if (macoff + snaplen > po->rx_ring.frame_size) {
695        if (po->copy_thresh &&
696            atomic_read(&sk->sk_rmem_alloc) + skb->truesize <
697            (unsigned)sk->sk_rcvbuf) {
698            if (skb_shared(skb)) {
699                copy_skb = skb_clone(skb, GFP_ATOMIC);
700            } else {
701                copy_skb = skb_get(skb);
702                skb_head = skb->data;
703            }
704            if (copy_skb)
705                skb_set_owner_r(copy_skb, sk);
706        }
707        snaplen = po->rx_ring.frame_size - macoff;
708        if ((int)snaplen < 0)
709            snaplen = 0;
710    }
711
712    spin_lock(&sk->sk_receive_queue.lock);
713    h.raw = packet_current_frame(po, &po->rx_ring, TP_STATUS_KERNEL);
714    if (!h.raw)
715        goto ring_is_full;
716    packet_increment_head(&po->rx_ring);
717    po->stats.tp_packets++;
718    if (copy_skb) {
719        status |= TP_STATUS_COPY;
720        __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
721    }
722    if (!po->stats.tp_drops)
723        status &= ~TP_STATUS_LOSING;
724    spin_unlock(&sk->sk_receive_queue.lock);
725
726    skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
727
728    switch (po->tp_version) {
729    case TPACKET_V1:
730        h.h1->tp_len = skb->len;
731        h.h1->tp_snaplen = snaplen;
732        h.h1->tp_mac = macoff;
733        h.h1->tp_net = netoff;
734        if (skb->tstamp.tv64)
735            tv = ktime_to_timeval(skb->tstamp);
736        else
737            do_gettimeofday(&tv);
738        h.h1->tp_sec = tv.tv_sec;
739        h.h1->tp_usec = tv.tv_usec;
740        hdrlen = sizeof(*h.h1);
741        break;
742    case TPACKET_V2:
743        h.h2->tp_len = skb->len;
744        h.h2->tp_snaplen = snaplen;
745        h.h2->tp_mac = macoff;
746        h.h2->tp_net = netoff;
747        if (skb->tstamp.tv64)
748            ts = ktime_to_timespec(skb->tstamp);
749        else
750            getnstimeofday(&ts);
751        h.h2->tp_sec = ts.tv_sec;
752        h.h2->tp_nsec = ts.tv_nsec;
753        h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
754        hdrlen = sizeof(*h.h2);
755        break;
756    default:
757        BUG();
758    }
759
760    sll = h.raw + TPACKET_ALIGN(hdrlen);
761    sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
762    sll->sll_family = AF_PACKET;
763    sll->sll_hatype = dev->type;
764    sll->sll_protocol = skb->protocol;
765    sll->sll_pkttype = skb->pkt_type;
766    if (unlikely(po->origdev))
767        sll->sll_ifindex = orig_dev->ifindex;
768    else
769        sll->sll_ifindex = dev->ifindex;
770
771    __packet_set_status(po, h.raw, status);
772    smp_mb();
773    {
774        struct page *p_start, *p_end;
775        u8 *h_end = h.raw + macoff + snaplen - 1;
776
777        p_start = virt_to_page(h.raw);
778        p_end = virt_to_page(h_end);
779        while (p_start <= p_end) {
780            flush_dcache_page(p_start);
781            p_start++;
782        }
783    }
784
785    sk->sk_data_ready(sk, 0);
786
787drop_n_restore:
788    if (skb_head != skb->data && skb_shared(skb)) {
789        skb->data = skb_head;
790        skb->len = skb_len;
791    }
792drop:
793    kfree_skb(skb);
794    return 0;
795
796ring_is_full:
797    po->stats.tp_drops++;
798    spin_unlock(&sk->sk_receive_queue.lock);
799
800    sk->sk_data_ready(sk, 0);
801    kfree_skb(copy_skb);
802    goto drop_n_restore;
803}
804
805static void tpacket_destruct_skb(struct sk_buff *skb)
806{
807    struct packet_sock *po = pkt_sk(skb->sk);
808    void *ph;
809
810    BUG_ON(skb == NULL);
811
812    if (likely(po->tx_ring.pg_vec)) {
813        ph = skb_shinfo(skb)->destructor_arg;
814        BUG_ON(__packet_get_status(po, ph) != TP_STATUS_SENDING);
815        BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
816        atomic_dec(&po->tx_ring.pending);
817        __packet_set_status(po, ph, TP_STATUS_AVAILABLE);
818    }
819
820    sock_wfree(skb);
821}
822
823static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
824        void *frame, struct net_device *dev, int size_max,
825        __be16 proto, unsigned char *addr)
826{
827    union {
828        struct tpacket_hdr *h1;
829        struct tpacket2_hdr *h2;
830        void *raw;
831    } ph;
832    int to_write, offset, len, tp_len, nr_frags, len_max;
833    struct socket *sock = po->sk.sk_socket;
834    struct page *page;
835    void *data;
836    int err;
837
838    ph.raw = frame;
839
840    skb->protocol = proto;
841    skb->dev = dev;
842    skb->priority = po->sk.sk_priority;
843    skb->mark = po->sk.sk_mark;
844    skb_shinfo(skb)->destructor_arg = ph.raw;
845
846    switch (po->tp_version) {
847    case TPACKET_V2:
848        tp_len = ph.h2->tp_len;
849        break;
850    default:
851        tp_len = ph.h1->tp_len;
852        break;
853    }
854    if (unlikely(tp_len > size_max)) {
855        pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
856        return -EMSGSIZE;
857    }
858
859    skb_reserve(skb, LL_RESERVED_SPACE(dev));
860    skb_reset_network_header(skb);
861
862    data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
863    to_write = tp_len;
864
865    if (sock->type == SOCK_DGRAM) {
866        err = dev_hard_header(skb, dev, ntohs(proto), addr,
867                NULL, tp_len);
868        if (unlikely(err < 0))
869            return -EINVAL;
870    } else if (dev->hard_header_len) {
871        /* net device doesn't like empty head */
872        if (unlikely(tp_len <= dev->hard_header_len)) {
873            pr_err("packet size is too short (%d < %d)\n",
874                   tp_len, dev->hard_header_len);
875            return -EINVAL;
876        }
877
878        skb_push(skb, dev->hard_header_len);
879        err = skb_store_bits(skb, 0, data,
880                dev->hard_header_len);
881        if (unlikely(err))
882            return err;
883
884        data += dev->hard_header_len;
885        to_write -= dev->hard_header_len;
886    }
887
888    err = -EFAULT;
889    page = virt_to_page(data);
890    offset = offset_in_page(data);
891    len_max = PAGE_SIZE - offset;
892    len = ((to_write > len_max) ? len_max : to_write);
893
894    skb->data_len = to_write;
895    skb->len += to_write;
896    skb->truesize += to_write;
897    atomic_add(to_write, &po->sk.sk_wmem_alloc);
898
899    while (likely(to_write)) {
900        nr_frags = skb_shinfo(skb)->nr_frags;
901
902        if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
903            pr_err("Packet exceed the number of skb frags(%lu)\n",
904                   MAX_SKB_FRAGS);
905            return -EFAULT;
906        }
907
908        flush_dcache_page(page);
909        get_page(page);
910        skb_fill_page_desc(skb,
911                nr_frags,
912                page++, offset, len);
913        to_write -= len;
914        offset = 0;
915        len_max = PAGE_SIZE;
916        len = ((to_write > len_max) ? len_max : to_write);
917    }
918
919    return tp_len;
920}
921
922static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
923{
924    struct socket *sock;
925    struct sk_buff *skb;
926    struct net_device *dev;
927    __be16 proto;
928    int ifindex, err, reserve = 0;
929    void *ph;
930    struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
931    int tp_len, size_max;
932    unsigned char *addr;
933    int len_sum = 0;
934    int status = 0;
935
936    sock = po->sk.sk_socket;
937
938    mutex_lock(&po->pg_vec_lock);
939
940    err = -EBUSY;
941    if (saddr == NULL) {
942        ifindex = po->ifindex;
943        proto = po->num;
944        addr = NULL;
945    } else {
946        err = -EINVAL;
947        if (msg->msg_namelen < sizeof(struct sockaddr_ll))
948            goto out;
949        if (msg->msg_namelen < (saddr->sll_halen
950                    + offsetof(struct sockaddr_ll,
951                        sll_addr)))
952            goto out;
953        ifindex = saddr->sll_ifindex;
954        proto = saddr->sll_protocol;
955        addr = saddr->sll_addr;
956    }
957
958    dev = dev_get_by_index(sock_net(&po->sk), ifindex);
959    err = -ENXIO;
960    if (unlikely(dev == NULL))
961        goto out;
962
963    reserve = dev->hard_header_len;
964
965    err = -ENETDOWN;
966    if (unlikely(!(dev->flags & IFF_UP)))
967        goto out_put;
968
969    size_max = po->tx_ring.frame_size
970        - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
971
972    if (size_max > dev->mtu + reserve)
973        size_max = dev->mtu + reserve;
974
975    do {
976        ph = packet_current_frame(po, &po->tx_ring,
977                TP_STATUS_SEND_REQUEST);
978
979        if (unlikely(ph == NULL)) {
980            schedule();
981            continue;
982        }
983
984        status = TP_STATUS_SEND_REQUEST;
985        skb = sock_alloc_send_skb(&po->sk,
986                LL_ALLOCATED_SPACE(dev)
987                + sizeof(struct sockaddr_ll),
988                0, &err);
989
990        if (unlikely(skb == NULL))
991            goto out_status;
992
993        tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
994                addr);
995
996        if (unlikely(tp_len < 0)) {
997            if (po->tp_loss) {
998                __packet_set_status(po, ph,
999                        TP_STATUS_AVAILABLE);
1000                packet_increment_head(&po->tx_ring);
1001                kfree_skb(skb);
1002                continue;
1003            } else {
1004                status = TP_STATUS_WRONG_FORMAT;
1005                err = tp_len;
1006                goto out_status;
1007            }
1008        }
1009
1010        skb->destructor = tpacket_destruct_skb;
1011        __packet_set_status(po, ph, TP_STATUS_SENDING);
1012        atomic_inc(&po->tx_ring.pending);
1013
1014        status = TP_STATUS_SEND_REQUEST;
1015        err = dev_queue_xmit(skb);
1016        if (unlikely(err > 0)) {
1017            err = net_xmit_errno(err);
1018            if (err && __packet_get_status(po, ph) ==
1019                   TP_STATUS_AVAILABLE) {
1020                /* skb was destructed already */
1021                skb = NULL;
1022                goto out_status;
1023            }
1024            /*
1025             * skb was dropped but not destructed yet;
1026             * let's treat it like congestion or err < 0
1027             */
1028            err = 0;
1029        }
1030        packet_increment_head(&po->tx_ring);
1031        len_sum += tp_len;
1032    } while (likely((ph != NULL) ||
1033            ((!(msg->msg_flags & MSG_DONTWAIT)) &&
1034             (atomic_read(&po->tx_ring.pending))))
1035        );
1036
1037    err = len_sum;
1038    goto out_put;
1039
1040out_status:
1041    __packet_set_status(po, ph, status);
1042    kfree_skb(skb);
1043out_put:
1044    dev_put(dev);
1045out:
1046    mutex_unlock(&po->pg_vec_lock);
1047    return err;
1048}
1049
1050static inline struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
1051                           size_t reserve, size_t len,
1052                           size_t linear, int noblock,
1053                           int *err)
1054{
1055    struct sk_buff *skb;
1056
1057    /* Under a page? Don't bother with paged skb. */
1058    if (prepad + len < PAGE_SIZE || !linear)
1059        linear = len;
1060
1061    skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1062                   err);
1063    if (!skb)
1064        return NULL;
1065
1066    skb_reserve(skb, reserve);
1067    skb_put(skb, linear);
1068    skb->data_len = len - linear;
1069    skb->len += len - linear;
1070
1071    return skb;
1072}
1073
1074static int packet_snd(struct socket *sock,
1075              struct msghdr *msg, size_t len)
1076{
1077    struct sock *sk = sock->sk;
1078    struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
1079    struct sk_buff *skb;
1080    struct net_device *dev;
1081    __be16 proto;
1082    unsigned char *addr;
1083    int ifindex, err, reserve = 0;
1084    struct virtio_net_hdr vnet_hdr = { 0 };
1085    int offset = 0;
1086    int vnet_hdr_len;
1087    struct packet_sock *po = pkt_sk(sk);
1088    unsigned short gso_type = 0;
1089
1090    /*
1091     * Get and verify the address.
1092     */
1093
1094    if (saddr == NULL) {
1095        ifindex = po->ifindex;
1096        proto = po->num;
1097        addr = NULL;
1098    } else {
1099        err = -EINVAL;
1100        if (msg->msg_namelen < sizeof(struct sockaddr_ll))
1101            goto out;
1102        if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
1103            goto out;
1104        ifindex = saddr->sll_ifindex;
1105        proto = saddr->sll_protocol;
1106        addr = saddr->sll_addr;
1107    }
1108
1109
1110    dev = dev_get_by_index(sock_net(sk), ifindex);
1111    err = -ENXIO;
1112    if (dev == NULL)
1113        goto out_unlock;
1114    if (sock->type == SOCK_RAW)
1115        reserve = dev->hard_header_len;
1116
1117    err = -ENETDOWN;
1118    if (!(dev->flags & IFF_UP))
1119        goto out_unlock;
1120
1121    if (po->has_vnet_hdr) {
1122        vnet_hdr_len = sizeof(vnet_hdr);
1123
1124        err = -EINVAL;
1125        if (len < vnet_hdr_len)
1126            goto out_unlock;
1127
1128        len -= vnet_hdr_len;
1129
1130        err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
1131                       vnet_hdr_len);
1132        if (err < 0)
1133            goto out_unlock;
1134
1135        if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1136            (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
1137              vnet_hdr.hdr_len))
1138            vnet_hdr.hdr_len = vnet_hdr.csum_start +
1139                         vnet_hdr.csum_offset + 2;
1140
1141        err = -EINVAL;
1142        if (vnet_hdr.hdr_len > len)
1143            goto out_unlock;
1144
1145        if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1146            switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1147            case VIRTIO_NET_HDR_GSO_TCPV4:
1148                gso_type = SKB_GSO_TCPV4;
1149                break;
1150            case VIRTIO_NET_HDR_GSO_TCPV6:
1151                gso_type = SKB_GSO_TCPV6;
1152                break;
1153            case VIRTIO_NET_HDR_GSO_UDP:
1154                gso_type = SKB_GSO_UDP;
1155                break;
1156            default:
1157                goto out_unlock;
1158            }
1159
1160            if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1161                gso_type |= SKB_GSO_TCP_ECN;
1162
1163            if (vnet_hdr.gso_size == 0)
1164                goto out_unlock;
1165
1166        }
1167    }
1168
1169    err = -EMSGSIZE;
1170    if (!gso_type && (len > dev->mtu+reserve))
1171        goto out_unlock;
1172
1173    err = -ENOBUFS;
1174    skb = packet_alloc_skb(sk, LL_ALLOCATED_SPACE(dev),
1175                   LL_RESERVED_SPACE(dev), len, vnet_hdr.hdr_len,
1176                   msg->msg_flags & MSG_DONTWAIT, &err);
1177    if (skb == NULL)
1178        goto out_unlock;
1179
1180    skb_set_network_header(skb, reserve);
1181
1182    err = -EINVAL;
1183    if (sock->type == SOCK_DGRAM &&
1184        (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
1185        goto out_free;
1186
1187    /* Returns -EFAULT on error */
1188    err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
1189    if (err)
1190        goto out_free;
1191
1192    skb->protocol = proto;
1193    skb->dev = dev;
1194    skb->priority = sk->sk_priority;
1195    skb->mark = sk->sk_mark;
1196
1197    if (po->has_vnet_hdr) {
1198        if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1199            if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
1200                          vnet_hdr.csum_offset)) {
1201                err = -EINVAL;
1202                goto out_free;
1203            }
1204        }
1205
1206        skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
1207        skb_shinfo(skb)->gso_type = gso_type;
1208
1209        /* Header must be checked, and gso_segs computed. */
1210        skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1211        skb_shinfo(skb)->gso_segs = 0;
1212
1213        len += vnet_hdr_len;
1214    }
1215
1216    /*
1217     * Now send it
1218     */
1219
1220    err = dev_queue_xmit(skb);
1221    if (err > 0 && (err = net_xmit_errno(err)) != 0)
1222        goto out_unlock;
1223
1224    dev_put(dev);
1225
1226    return len;
1227
1228out_free:
1229    kfree_skb(skb);
1230out_unlock:
1231    if (dev)
1232        dev_put(dev);
1233out:
1234    return err;
1235}
1236
1237static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
1238        struct msghdr *msg, size_t len)
1239{
1240    struct sock *sk = sock->sk;
1241    struct packet_sock *po = pkt_sk(sk);
1242    if (po->tx_ring.pg_vec)
1243        return tpacket_snd(po, msg);
1244    else
1245        return packet_snd(sock, msg, len);
1246}
1247
1248/*
1249 * Close a PACKET socket. This is fairly simple. We immediately go
1250 * to 'closed' state and remove our protocol entry in the device list.
1251 */
1252
1253static int packet_release(struct socket *sock)
1254{
1255    struct sock *sk = sock->sk;
1256    struct packet_sock *po;
1257    struct net *net;
1258    struct tpacket_req req;
1259
1260    if (!sk)
1261        return 0;
1262
1263    net = sock_net(sk);
1264    po = pkt_sk(sk);
1265
1266    spin_lock_bh(&net->packet.sklist_lock);
1267    sk_del_node_init_rcu(sk);
1268    sock_prot_inuse_add(net, sk->sk_prot, -1);
1269    spin_unlock_bh(&net->packet.sklist_lock);
1270
1271    spin_lock(&po->bind_lock);
1272    if (po->running) {
1273        /*
1274         * Remove from protocol table
1275         */
1276        po->running = 0;
1277        po->num = 0;
1278        __dev_remove_pack(&po->prot_hook);
1279        __sock_put(sk);
1280    }
1281    spin_unlock(&po->bind_lock);
1282
1283    packet_flush_mclist(sk);
1284
1285    memset(&req, 0, sizeof(req));
1286
1287    if (po->rx_ring.pg_vec)
1288        packet_set_ring(sk, &req, 1, 0);
1289
1290    if (po->tx_ring.pg_vec)
1291        packet_set_ring(sk, &req, 1, 1);
1292
1293    synchronize_net();
1294    /*
1295     * Now the socket is dead. No more input will appear.
1296     */
1297    sock_orphan(sk);
1298    sock->sk = NULL;
1299
1300    /* Purge queues */
1301
1302    skb_queue_purge(&sk->sk_receive_queue);
1303    sk_refcnt_debug_release(sk);
1304
1305    sock_put(sk);
1306    return 0;
1307}
1308
1309/*
1310 * Attach a packet hook.
1311 */
1312
1313static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
1314{
1315    struct packet_sock *po = pkt_sk(sk);
1316    /*
1317     * Detach an existing hook if present.
1318     */
1319
1320    lock_sock(sk);
1321
1322    spin_lock(&po->bind_lock);
1323    if (po->running) {
1324        __sock_put(sk);
1325        po->running = 0;
1326        po->num = 0;
1327        spin_unlock(&po->bind_lock);
1328        dev_remove_pack(&po->prot_hook);
1329        spin_lock(&po->bind_lock);
1330    }
1331
1332    po->num = protocol;
1333    po->prot_hook.type = protocol;
1334    po->prot_hook.dev = dev;
1335
1336    po->ifindex = dev ? dev->ifindex : 0;
1337
1338    if (protocol == 0)
1339        goto out_unlock;
1340
1341    if (!dev || (dev->flags & IFF_UP)) {
1342        dev_add_pack(&po->prot_hook);
1343        sock_hold(sk);
1344        po->running = 1;
1345    } else {
1346        sk->sk_err = ENETDOWN;
1347        if (!sock_flag(sk, SOCK_DEAD))
1348            sk->sk_error_report(sk);
1349    }
1350
1351out_unlock:
1352    spin_unlock(&po->bind_lock);
1353    release_sock(sk);
1354    return 0;
1355}
1356
1357/*
1358 * Bind a packet socket to a device
1359 */
1360
1361static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
1362                int addr_len)
1363{
1364    struct sock *sk = sock->sk;
1365    char name[15];
1366    struct net_device *dev;
1367    int err = -ENODEV;
1368
1369    /*
1370     * Check legality
1371     */
1372
1373    if (addr_len != sizeof(struct sockaddr))
1374        return -EINVAL;
1375    strlcpy(name, uaddr->sa_data, sizeof(name));
1376
1377    dev = dev_get_by_name(sock_net(sk), name);
1378    if (dev) {
1379        err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
1380        dev_put(dev);
1381    }
1382    return err;
1383}
1384
1385static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1386{
1387    struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
1388    struct sock *sk = sock->sk;
1389    struct net_device *dev = NULL;
1390    int err;
1391
1392
1393    /*
1394     * Check legality
1395     */
1396
1397    if (addr_len < sizeof(struct sockaddr_ll))
1398        return -EINVAL;
1399    if (sll->sll_family != AF_PACKET)
1400        return -EINVAL;
1401
1402    if (sll->sll_ifindex) {
1403        err = -ENODEV;
1404        dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
1405        if (dev == NULL)
1406            goto out;
1407    }
1408    err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
1409    if (dev)
1410        dev_put(dev);
1411
1412out:
1413    return err;
1414}
1415
1416static struct proto packet_proto = {
1417    .name = "PACKET",
1418    .owner = THIS_MODULE,
1419    .obj_size = sizeof(struct packet_sock),
1420};
1421
1422/*
1423 * Create a packet of type SOCK_PACKET.
1424 */
1425
1426static int packet_create(struct net *net, struct socket *sock, int protocol,
1427             int kern)
1428{
1429    struct sock *sk;
1430    struct packet_sock *po;
1431    __be16 proto = (__force __be16)protocol; /* weird, but documented */
1432    int err;
1433
1434    if (!capable(CAP_NET_RAW))
1435        return -EPERM;
1436    if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
1437        sock->type != SOCK_PACKET)
1438        return -ESOCKTNOSUPPORT;
1439
1440    sock->state = SS_UNCONNECTED;
1441
1442    err = -ENOBUFS;
1443    sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
1444    if (sk == NULL)
1445        goto out;
1446
1447    sock->ops = &packet_ops;
1448    if (sock->type == SOCK_PACKET)
1449        sock->ops = &packet_ops_spkt;
1450
1451    sock_init_data(sock, sk);
1452
1453    po = pkt_sk(sk);
1454    sk->sk_family = PF_PACKET;
1455    po->num = proto;
1456
1457    sk->sk_destruct = packet_sock_destruct;
1458    sk_refcnt_debug_inc(sk);
1459
1460    /*
1461     * Attach a protocol block
1462     */
1463
1464    spin_lock_init(&po->bind_lock);
1465    mutex_init(&po->pg_vec_lock);
1466    po->prot_hook.func = packet_rcv;
1467
1468    if (sock->type == SOCK_PACKET)
1469        po->prot_hook.func = packet_rcv_spkt;
1470
1471    po->prot_hook.af_packet_priv = sk;
1472
1473    if (proto) {
1474        po->prot_hook.type = proto;
1475        dev_add_pack(&po->prot_hook);
1476        sock_hold(sk);
1477        po->running = 1;
1478    }
1479
1480    spin_lock_bh(&net->packet.sklist_lock);
1481    sk_add_node_rcu(sk, &net->packet.sklist);
1482    sock_prot_inuse_add(net, &packet_proto, 1);
1483    spin_unlock_bh(&net->packet.sklist_lock);
1484
1485    return 0;
1486out:
1487    return err;
1488}
1489
1490/*
1491 * Pull a packet from our receive queue and hand it to the user.
1492 * If necessary we block.
1493 */
1494
1495static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
1496              struct msghdr *msg, size_t len, int flags)
1497{
1498    struct sock *sk = sock->sk;
1499    struct sk_buff *skb;
1500    int copied, err;
1501    struct sockaddr_ll *sll;
1502    int vnet_hdr_len = 0;
1503
1504    err = -EINVAL;
1505    if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT))
1506        goto out;
1507
1508#if 0
1509    /* What error should we return now? EUNATTACH? */
1510    if (pkt_sk(sk)->ifindex < 0)
1511        return -ENODEV;
1512#endif
1513
1514    /*
1515     * Call the generic datagram receiver. This handles all sorts
1516     * of horrible races and re-entrancy so we can forget about it
1517     * in the protocol layers.
1518     *
1519     * Now it will return ENETDOWN, if device have just gone down,
1520     * but then it will block.
1521     */
1522
1523    skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
1524
1525    /*
1526     * An error occurred so return it. Because skb_recv_datagram()
1527     * handles the blocking we don't see and worry about blocking
1528     * retries.
1529     */
1530
1531    if (skb == NULL)
1532        goto out;
1533
1534    if (pkt_sk(sk)->has_vnet_hdr) {
1535        struct virtio_net_hdr vnet_hdr = { 0 };
1536
1537        err = -EINVAL;
1538        vnet_hdr_len = sizeof(vnet_hdr);
1539        if ((len -= vnet_hdr_len) < 0)
1540            goto out_free;
1541
1542        if (skb_is_gso(skb)) {
1543            struct skb_shared_info *sinfo = skb_shinfo(skb);
1544
1545            /* This is a hint as to how much should be linear. */
1546            vnet_hdr.hdr_len = skb_headlen(skb);
1547            vnet_hdr.gso_size = sinfo->gso_size;
1548            if (sinfo->gso_type & SKB_GSO_TCPV4)
1549                vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1550            else if (sinfo->gso_type & SKB_GSO_TCPV6)
1551                vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1552            else if (sinfo->gso_type & SKB_GSO_UDP)
1553                vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1554            else if (sinfo->gso_type & SKB_GSO_FCOE)
1555                goto out_free;
1556            else
1557                BUG();
1558            if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1559                vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1560        } else
1561            vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1562
1563        if (skb->ip_summed == CHECKSUM_PARTIAL) {
1564            vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1565            vnet_hdr.csum_start = skb->csum_start -
1566                            skb_headroom(skb);
1567            vnet_hdr.csum_offset = skb->csum_offset;
1568        } /* else everything is zero */
1569
1570        err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
1571                     vnet_hdr_len);
1572        if (err < 0)
1573            goto out_free;
1574    }
1575
1576    /*
1577     * If the address length field is there to be filled in, we fill
1578     * it in now.
1579     */
1580
1581    sll = &PACKET_SKB_CB(skb)->sa.ll;
1582    if (sock->type == SOCK_PACKET)
1583        msg->msg_namelen = sizeof(struct sockaddr_pkt);
1584    else
1585        msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
1586
1587    /*
1588     * You lose any data beyond the buffer you gave. If it worries a
1589     * user program they can ask the device for its MTU anyway.
1590     */
1591
1592    copied = skb->len;
1593    if (copied > len) {
1594        copied = len;
1595        msg->msg_flags |= MSG_TRUNC;
1596    }
1597
1598    err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1599    if (err)
1600        goto out_free;
1601
1602    sock_recv_ts_and_drops(msg, sk, skb);
1603
1604    if (msg->msg_name)
1605        memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
1606               msg->msg_namelen);
1607
1608    if (pkt_sk(sk)->auxdata) {
1609        struct tpacket_auxdata aux;
1610
1611        aux.tp_status = TP_STATUS_USER;
1612        if (skb->ip_summed == CHECKSUM_PARTIAL)
1613            aux.tp_status |= TP_STATUS_CSUMNOTREADY;
1614        aux.tp_len = PACKET_SKB_CB(skb)->origlen;
1615        aux.tp_snaplen = skb->len;
1616        aux.tp_mac = 0;
1617        aux.tp_net = skb_network_offset(skb);
1618        aux.tp_vlan_tci = vlan_tx_tag_get(skb);
1619
1620        put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
1621    }
1622
1623    /*
1624     * Free or return the buffer as appropriate. Again this
1625     * hides all the races and re-entrancy issues from us.
1626     */
1627    err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
1628
1629out_free:
1630    skb_free_datagram(sk, skb);
1631out:
1632    return err;
1633}
1634
1635static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
1636                   int *uaddr_len, int peer)
1637{
1638    struct net_device *dev;
1639    struct sock *sk = sock->sk;
1640
1641    if (peer)
1642        return -EOPNOTSUPP;
1643
1644    uaddr->sa_family = AF_PACKET;
1645    rcu_read_lock();
1646    dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
1647    if (dev)
1648        strlcpy(uaddr->sa_data, dev->name, 15);
1649    else
1650        memset(uaddr->sa_data, 0, 14);
1651    rcu_read_unlock();
1652    *uaddr_len = sizeof(*uaddr);
1653
1654    return 0;
1655}
1656
1657static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
1658              int *uaddr_len, int peer)
1659{
1660    struct net_device *dev;
1661    struct sock *sk = sock->sk;
1662    struct packet_sock *po = pkt_sk(sk);
1663    DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
1664
1665    if (peer)
1666        return -EOPNOTSUPP;
1667
1668    sll->sll_family = AF_PACKET;
1669    sll->sll_ifindex = po->ifindex;
1670    sll->sll_protocol = po->num;
1671    rcu_read_lock();
1672    dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
1673    if (dev) {
1674        sll->sll_hatype = dev->type;
1675        sll->sll_halen = dev->addr_len;
1676        memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
1677    } else {
1678        sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
1679        sll->sll_halen = 0;
1680    }
1681    rcu_read_unlock();
1682    *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
1683
1684    return 0;
1685}
1686
1687static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
1688             int what)
1689{
1690    switch (i->type) {
1691    case PACKET_MR_MULTICAST:
1692        if (i->alen != dev->addr_len)
1693            return -EINVAL;
1694        if (what > 0)
1695            return dev_mc_add(dev, i->addr, i->alen, 0);
1696        else
1697            return dev_mc_delete(dev, i->addr, i->alen, 0);
1698        break;
1699    case PACKET_MR_PROMISC:
1700        return dev_set_promiscuity(dev, what);
1701        break;
1702    case PACKET_MR_ALLMULTI:
1703        return dev_set_allmulti(dev, what);
1704        break;
1705    case PACKET_MR_UNICAST:
1706        if (i->alen != dev->addr_len)
1707            return -EINVAL;
1708        if (what > 0)
1709            return dev_unicast_add(dev, i->addr);
1710        else
1711            return dev_unicast_delete(dev, i->addr);
1712        break;
1713    default:
1714        break;
1715    }
1716    return 0;
1717}
1718
1719static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
1720{
1721    for ( ; i; i = i->next) {
1722        if (i->ifindex == dev->ifindex)
1723            packet_dev_mc(dev, i, what);
1724    }
1725}
1726
1727static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
1728{
1729    struct packet_sock *po = pkt_sk(sk);
1730    struct packet_mclist *ml, *i;
1731    struct net_device *dev;
1732    int err;
1733
1734    rtnl_lock();
1735
1736    err = -ENODEV;
1737    dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
1738    if (!dev)
1739        goto done;
1740
1741    err = -EINVAL;
1742    if (mreq->mr_alen > dev->addr_len)
1743        goto done;
1744
1745    err = -ENOBUFS;
1746    i = kmalloc(sizeof(*i), GFP_KERNEL);
1747    if (i == NULL)
1748        goto done;
1749
1750    err = 0;
1751    for (ml = po->mclist; ml; ml = ml->next) {
1752        if (ml->ifindex == mreq->mr_ifindex &&
1753            ml->type == mreq->mr_type &&
1754            ml->alen == mreq->mr_alen &&
1755            memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
1756            ml->count++;
1757            /* Free the new element ... */
1758            kfree(i);
1759            goto done;
1760        }
1761    }
1762
1763    i->type = mreq->mr_type;
1764    i->ifindex = mreq->mr_ifindex;
1765    i->alen = mreq->mr_alen;
1766    memcpy(i->addr, mreq->mr_address, i->alen);
1767    i->count = 1;
1768    i->next = po->mclist;
1769    po->mclist = i;
1770    err = packet_dev_mc(dev, i, 1);
1771    if (err) {
1772        po->mclist = i->next;
1773        kfree(i);
1774    }
1775
1776done:
1777    rtnl_unlock();
1778    return err;
1779}
1780
1781static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
1782{
1783    struct packet_mclist *ml, **mlp;
1784
1785    rtnl_lock();
1786
1787    for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
1788        if (ml->ifindex == mreq->mr_ifindex &&
1789            ml->type == mreq->mr_type &&
1790            ml->alen == mreq->mr_alen &&
1791            memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
1792            if (--ml->count == 0) {
1793                struct net_device *dev;
1794                *mlp = ml->next;
1795                dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
1796                if (dev)
1797                    packet_dev_mc(dev, ml, -1);
1798                kfree(ml);
1799            }
1800            rtnl_unlock();
1801            return 0;
1802        }
1803    }
1804    rtnl_unlock();
1805    return -EADDRNOTAVAIL;
1806}
1807
1808static void packet_flush_mclist(struct sock *sk)
1809{
1810    struct packet_sock *po = pkt_sk(sk);
1811    struct packet_mclist *ml;
1812
1813    if (!po->mclist)
1814        return;
1815
1816    rtnl_lock();
1817    while ((ml = po->mclist) != NULL) {
1818        struct net_device *dev;
1819
1820        po->mclist = ml->next;
1821        dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
1822        if (dev != NULL)
1823            packet_dev_mc(dev, ml, -1);
1824        kfree(ml);
1825    }
1826    rtnl_unlock();
1827}
1828
1829static int
1830packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
1831{
1832    struct sock *sk = sock->sk;
1833    struct packet_sock *po = pkt_sk(sk);
1834    int ret;
1835
1836    if (level != SOL_PACKET)
1837        return -ENOPROTOOPT;
1838
1839    switch (optname) {
1840    case PACKET_ADD_MEMBERSHIP:
1841    case PACKET_DROP_MEMBERSHIP:
1842    {
1843        struct packet_mreq_max mreq;
1844        int len = optlen;
1845        memset(&mreq, 0, sizeof(mreq));
1846        if (len < sizeof(struct packet_mreq))
1847            return -EINVAL;
1848        if (len > sizeof(mreq))
1849            len = sizeof(mreq);
1850        if (copy_from_user(&mreq, optval, len))
1851            return -EFAULT;
1852        if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
1853            return -EINVAL;
1854        if (optname == PACKET_ADD_MEMBERSHIP)
1855            ret = packet_mc_add(sk, &mreq);
1856        else
1857            ret = packet_mc_drop(sk, &mreq);
1858        return ret;
1859    }
1860
1861    case PACKET_RX_RING:
1862    case PACKET_TX_RING:
1863    {
1864        struct tpacket_req req;
1865
1866        if (optlen < sizeof(req))
1867            return -EINVAL;
1868        if (pkt_sk(sk)->has_vnet_hdr)
1869            return -EINVAL;
1870        if (copy_from_user(&req, optval, sizeof(req)))
1871            return -EFAULT;
1872        return packet_set_ring(sk, &req, 0, optname == PACKET_TX_RING);
1873    }
1874    case PACKET_COPY_THRESH:
1875    {
1876        int val;
1877
1878        if (optlen != sizeof(val))
1879            return -EINVAL;
1880        if (copy_from_user(&val, optval, sizeof(val)))
1881            return -EFAULT;
1882
1883        pkt_sk(sk)->copy_thresh = val;
1884        return 0;
1885    }
1886    case PACKET_VERSION:
1887    {
1888        int val;
1889
1890        if (optlen != sizeof(val))
1891            return -EINVAL;
1892        if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
1893            return -EBUSY;
1894        if (copy_from_user(&val, optval, sizeof(val)))
1895            return -EFAULT;
1896        switch (val) {
1897        case TPACKET_V1:
1898        case TPACKET_V2:
1899            po->tp_version = val;
1900            return 0;
1901        default:
1902            return -EINVAL;
1903        }
1904    }
1905    case PACKET_RESERVE:
1906    {
1907        unsigned int val;
1908
1909        if (optlen != sizeof(val))
1910            return -EINVAL;
1911        if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
1912            return -EBUSY;
1913        if (copy_from_user(&val, optval, sizeof(val)))
1914            return -EFAULT;
1915        po->tp_reserve = val;
1916        return 0;
1917    }
1918    case PACKET_LOSS:
1919    {
1920        unsigned int val;
1921
1922        if (optlen != sizeof(val))
1923            return -EINVAL;
1924        if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
1925            return -EBUSY;
1926        if (copy_from_user(&val, optval, sizeof(val)))
1927            return -EFAULT;
1928        po->tp_loss = !!val;
1929        return 0;
1930    }
1931    case PACKET_AUXDATA:
1932    {
1933        int val;
1934
1935        if (optlen < sizeof(val))
1936            return -EINVAL;
1937        if (copy_from_user(&val, optval, sizeof(val)))
1938            return -EFAULT;
1939
1940        po->auxdata = !!val;
1941        return 0;
1942    }
1943    case PACKET_ORIGDEV:
1944    {
1945        int val;
1946
1947        if (optlen < sizeof(val))
1948            return -EINVAL;
1949        if (copy_from_user(&val, optval, sizeof(val)))
1950            return -EFAULT;
1951
1952        po->origdev = !!val;
1953        return 0;
1954    }
1955    case PACKET_VNET_HDR:
1956    {
1957        int val;
1958
1959        if (sock->type != SOCK_RAW)
1960            return -EINVAL;
1961        if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
1962            return -EBUSY;
1963        if (optlen < sizeof(val))
1964            return -EINVAL;
1965        if (copy_from_user(&val, optval, sizeof(val)))
1966            return -EFAULT;
1967
1968        po->has_vnet_hdr = !!val;
1969        return 0;
1970    }
1971    default:
1972        return -ENOPROTOOPT;
1973    }
1974}
1975
1976static int packet_getsockopt(struct socket *sock, int level, int optname,
1977                 char __user *optval, int __user *optlen)
1978{
1979    int len;
1980    int val;
1981    struct sock *sk = sock->sk;
1982    struct packet_sock *po = pkt_sk(sk);
1983    void *data;
1984    struct tpacket_stats st;
1985
1986    if (level != SOL_PACKET)
1987        return -ENOPROTOOPT;
1988
1989    if (get_user(len, optlen))
1990        return -EFAULT;
1991
1992    if (len < 0)
1993        return -EINVAL;
1994
1995    switch (optname) {
1996    case PACKET_STATISTICS:
1997        if (len > sizeof(struct tpacket_stats))
1998            len = sizeof(struct tpacket_stats);
1999        spin_lock_bh(&sk->sk_receive_queue.lock);
2000        st = po->stats;
2001        memset(&po->stats, 0, sizeof(st));
2002        spin_unlock_bh(&sk->sk_receive_queue.lock);
2003        st.tp_packets += st.tp_drops;
2004
2005        data = &st;
2006        break;
2007    case PACKET_AUXDATA:
2008        if (len > sizeof(int))
2009            len = sizeof(int);
2010        val = po->auxdata;
2011
2012        data = &val;
2013        break;
2014    case PACKET_ORIGDEV:
2015        if (len > sizeof(int))
2016            len = sizeof(int);
2017        val = po->origdev;
2018
2019        data = &val;
2020        break;
2021    case PACKET_VNET_HDR:
2022        if (len > sizeof(int))
2023            len = sizeof(int);
2024        val = po->has_vnet_hdr;
2025
2026        data = &val;
2027        break;
2028    case PACKET_VERSION:
2029        if (len > sizeof(int))
2030            len = sizeof(int);
2031        val = po->tp_version;
2032        data = &val;
2033        break;
2034    case PACKET_HDRLEN:
2035        if (len > sizeof(int))
2036            len = sizeof(int);
2037        if (copy_from_user(&val, optval, len))
2038            return -EFAULT;
2039        switch (val) {
2040        case TPACKET_V1:
2041            val = sizeof(struct tpacket_hdr);
2042            break;
2043        case TPACKET_V2:
2044            val = sizeof(struct tpacket2_hdr);
2045            break;
2046        default:
2047            return -EINVAL;
2048        }
2049        data = &val;
2050        break;
2051    case PACKET_RESERVE:
2052        if (len > sizeof(unsigned int))
2053            len = sizeof(unsigned int);
2054        val = po->tp_reserve;
2055        data = &val;
2056        break;
2057    case PACKET_LOSS:
2058        if (len > sizeof(unsigned int))
2059            len = sizeof(unsigned int);
2060        val = po->tp_loss;
2061        data = &val;
2062        break;
2063    default:
2064        return -ENOPROTOOPT;
2065    }
2066
2067    if (put_user(len, optlen))
2068        return -EFAULT;
2069    if (copy_to_user(optval, data, len))
2070        return -EFAULT;
2071    return 0;
2072}
2073
2074
2075static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
2076{
2077    struct sock *sk;
2078    struct hlist_node *node;
2079    struct net_device *dev = data;
2080    struct net *net = dev_net(dev);
2081
2082    rcu_read_lock();
2083    sk_for_each_rcu(sk, node, &net->packet.sklist) {
2084        struct packet_sock *po = pkt_sk(sk);
2085
2086        switch (msg) {
2087        case NETDEV_UNREGISTER:
2088            if (po->mclist)
2089                packet_dev_mclist(dev, po->mclist, -1);
2090            /* fallthrough */
2091
2092        case NETDEV_DOWN:
2093            if (dev->ifindex == po->ifindex) {
2094                spin_lock(&po->bind_lock);
2095                if (po->running) {
2096                    __dev_remove_pack(&po->prot_hook);
2097                    __sock_put(sk);
2098                    po->running = 0;
2099                    sk->sk_err = ENETDOWN;
2100                    if (!sock_flag(sk, SOCK_DEAD))
2101                        sk->sk_error_report(sk);
2102                }
2103                if (msg == NETDEV_UNREGISTER) {
2104                    po->ifindex = -1;
2105                    po->prot_hook.dev = NULL;
2106                }
2107                spin_unlock(&po->bind_lock);
2108            }
2109            break;
2110        case NETDEV_UP:
2111            if (dev->ifindex == po->ifindex) {
2112                spin_lock(&po->bind_lock);
2113                if (po->num && !po->running) {
2114                    dev_add_pack(&po->prot_hook);
2115                    sock_hold(sk);
2116                    po->running = 1;
2117                }
2118                spin_unlock(&po->bind_lock);
2119            }
2120            break;
2121        }
2122    }
2123    rcu_read_unlock();
2124    return NOTIFY_DONE;
2125}
2126
2127
2128static int packet_ioctl(struct socket *sock, unsigned int cmd,
2129            unsigned long arg)
2130{
2131    struct sock *sk = sock->sk;
2132
2133    switch (cmd) {
2134    case SIOCOUTQ:
2135    {
2136        int amount = sk_wmem_alloc_get(sk);
2137
2138        return put_user(amount, (int __user *)arg);
2139    }
2140    case SIOCINQ:
2141    {
2142        struct sk_buff *skb;
2143        int amount = 0;
2144
2145        spin_lock_bh(&sk->sk_receive_queue.lock);
2146        skb = skb_peek(&sk->sk_receive_queue);
2147        if (skb)
2148            amount = skb->len;
2149        spin_unlock_bh(&sk->sk_receive_queue.lock);
2150        return put_user(amount, (int __user *)arg);
2151    }
2152    case SIOCGSTAMP:
2153        return sock_get_timestamp(sk, (struct timeval __user *)arg);
2154    case SIOCGSTAMPNS:
2155        return sock_get_timestampns(sk, (struct timespec __user *)arg);
2156
2157#ifdef CONFIG_INET
2158    case SIOCADDRT:
2159    case SIOCDELRT:
2160    case SIOCDARP:
2161    case SIOCGARP:
2162    case SIOCSARP:
2163    case SIOCGIFADDR:
2164    case SIOCSIFADDR:
2165    case SIOCGIFBRDADDR:
2166    case SIOCSIFBRDADDR:
2167    case SIOCGIFNETMASK:
2168    case SIOCSIFNETMASK:
2169    case SIOCGIFDSTADDR:
2170    case SIOCSIFDSTADDR:
2171    case SIOCSIFFLAGS:
2172        return inet_dgram_ops.ioctl(sock, cmd, arg);
2173#endif
2174
2175    default:
2176        return -ENOIOCTLCMD;
2177    }
2178    return 0;
2179}
2180
2181static unsigned int packet_poll(struct file *file, struct socket *sock,
2182                poll_table *wait)
2183{
2184    struct sock *sk = sock->sk;
2185    struct packet_sock *po = pkt_sk(sk);
2186    unsigned int mask = datagram_poll(file, sock, wait);
2187
2188    spin_lock_bh(&sk->sk_receive_queue.lock);
2189    if (po->rx_ring.pg_vec) {
2190        if (!packet_previous_frame(po, &po->rx_ring, TP_STATUS_KERNEL))
2191            mask |= POLLIN | POLLRDNORM;
2192    }
2193    spin_unlock_bh(&sk->sk_receive_queue.lock);
2194    spin_lock_bh(&sk->sk_write_queue.lock);
2195    if (po->tx_ring.pg_vec) {
2196        if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
2197            mask |= POLLOUT | POLLWRNORM;
2198    }
2199    spin_unlock_bh(&sk->sk_write_queue.lock);
2200    return mask;
2201}
2202
2203
2204/* Dirty? Well, I still did not learn better way to account
2205 * for user mmaps.
2206 */
2207
2208static void packet_mm_open(struct vm_area_struct *vma)
2209{
2210    struct file *file = vma->vm_file;
2211    struct socket *sock = file->private_data;
2212    struct sock *sk = sock->sk;
2213
2214    if (sk)
2215        atomic_inc(&pkt_sk(sk)->mapped);
2216}
2217
2218static void packet_mm_close(struct vm_area_struct *vma)
2219{
2220    struct file *file = vma->vm_file;
2221    struct socket *sock = file->private_data;
2222    struct sock *sk = sock->sk;
2223
2224    if (sk)
2225        atomic_dec(&pkt_sk(sk)->mapped);
2226}
2227
2228static const struct vm_operations_struct packet_mmap_ops = {
2229    .open = packet_mm_open,
2230    .close = packet_mm_close,
2231};
2232
2233static void free_pg_vec(char **pg_vec, unsigned int order, unsigned int len)
2234{
2235    int i;
2236
2237    for (i = 0; i < len; i++) {
2238        if (likely(pg_vec[i]))
2239            free_pages((unsigned long) pg_vec[i], order);
2240    }
2241    kfree(pg_vec);
2242}
2243
2244static inline char *alloc_one_pg_vec_page(unsigned long order)
2245{
2246    gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | __GFP_ZERO | __GFP_NOWARN;
2247
2248    return (char *) __get_free_pages(gfp_flags, order);
2249}
2250
2251static char **alloc_pg_vec(struct tpacket_req *req, int order)
2252{
2253    unsigned int block_nr = req->tp_block_nr;
2254    char **pg_vec;
2255    int i;
2256
2257    pg_vec = kzalloc(block_nr * sizeof(char *), GFP_KERNEL);
2258    if (unlikely(!pg_vec))
2259        goto out;
2260
2261    for (i = 0; i < block_nr; i++) {
2262        pg_vec[i] = alloc_one_pg_vec_page(order);
2263        if (unlikely(!pg_vec[i]))
2264            goto out_free_pgvec;
2265    }
2266
2267out:
2268    return pg_vec;
2269
2270out_free_pgvec:
2271    free_pg_vec(pg_vec, order, block_nr);
2272    pg_vec = NULL;
2273    goto out;
2274}
2275
2276static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
2277        int closing, int tx_ring)
2278{
2279    char **pg_vec = NULL;
2280    struct packet_sock *po = pkt_sk(sk);
2281    int was_running, order = 0;
2282    struct packet_ring_buffer *rb;
2283    struct sk_buff_head *rb_queue;
2284    __be16 num;
2285    int err;
2286
2287    rb = tx_ring ? &po->tx_ring : &po->rx_ring;
2288    rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
2289
2290    err = -EBUSY;
2291    if (!closing) {
2292        if (atomic_read(&po->mapped))
2293            goto out;
2294        if (atomic_read(&rb->pending))
2295            goto out;
2296    }
2297
2298    if (req->tp_block_nr) {
2299        /* Sanity tests and some calculations */
2300        err = -EBUSY;
2301        if (unlikely(rb->pg_vec))
2302            goto out;
2303
2304        switch (po->tp_version) {
2305        case TPACKET_V1:
2306            po->tp_hdrlen = TPACKET_HDRLEN;
2307            break;
2308        case TPACKET_V2:
2309            po->tp_hdrlen = TPACKET2_HDRLEN;
2310            break;
2311        }
2312
2313        err = -EINVAL;
2314        if (unlikely((int)req->tp_block_size <= 0))
2315            goto out;
2316        if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
2317            goto out;
2318        if (unlikely(req->tp_frame_size < po->tp_hdrlen +
2319                    po->tp_reserve))
2320            goto out;
2321        if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
2322            goto out;
2323
2324        rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
2325        if (unlikely(rb->frames_per_block <= 0))
2326            goto out;
2327        if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
2328                    req->tp_frame_nr))
2329            goto out;
2330
2331        err = -ENOMEM;
2332        order = get_order(req->tp_block_size);
2333        pg_vec = alloc_pg_vec(req, order);
2334        if (unlikely(!pg_vec))
2335            goto out;
2336    }
2337    /* Done */
2338    else {
2339        err = -EINVAL;
2340        if (unlikely(req->tp_frame_nr))
2341            goto out;
2342    }
2343
2344    lock_sock(sk);
2345
2346    /* Detach socket from network */
2347    spin_lock(&po->bind_lock);
2348    was_running = po->running;
2349    num = po->num;
2350    if (was_running) {
2351        __dev_remove_pack(&po->prot_hook);
2352        po->num = 0;
2353        po->running = 0;
2354        __sock_put(sk);
2355    }
2356    spin_unlock(&po->bind_lock);
2357
2358    synchronize_net();
2359
2360    err = -EBUSY;
2361    mutex_lock(&po->pg_vec_lock);
2362    if (closing || atomic_read(&po->mapped) == 0) {
2363        err = 0;
2364#define XC(a, b) ({ __typeof__ ((a)) __t; __t = (a); (a) = (b); __t; })
2365        spin_lock_bh(&rb_queue->lock);
2366        pg_vec = XC(rb->pg_vec, pg_vec);
2367        rb->frame_max = (req->tp_frame_nr - 1);
2368        rb->head = 0;
2369        rb->frame_size = req->tp_frame_size;
2370        spin_unlock_bh(&rb_queue->lock);
2371
2372        order = XC(rb->pg_vec_order, order);
2373        req->tp_block_nr = XC(rb->pg_vec_len, req->tp_block_nr);
2374
2375        rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
2376        po->prot_hook.func = (po->rx_ring.pg_vec) ?
2377                        tpacket_rcv : packet_rcv;
2378        skb_queue_purge(rb_queue);
2379#undef XC
2380        if (atomic_read(&po->mapped))
2381            pr_err("packet_mmap: vma is busy: %d\n",
2382                   atomic_read(&po->mapped));
2383    }
2384    mutex_unlock(&po->pg_vec_lock);
2385
2386    spin_lock(&po->bind_lock);
2387    if (was_running && !po->running) {
2388        sock_hold(sk);
2389        po->running = 1;
2390        po->num = num;
2391        dev_add_pack(&po->prot_hook);
2392    }
2393    spin_unlock(&po->bind_lock);
2394
2395    release_sock(sk);
2396
2397    if (pg_vec)
2398        free_pg_vec(pg_vec, order, req->tp_block_nr);
2399out:
2400    return err;
2401}
2402
2403static int packet_mmap(struct file *file, struct socket *sock,
2404        struct vm_area_struct *vma)
2405{
2406    struct sock *sk = sock->sk;
2407    struct packet_sock *po = pkt_sk(sk);
2408    unsigned long size, expected_size;
2409    struct packet_ring_buffer *rb;
2410    unsigned long start;
2411    int err = -EINVAL;
2412    int i;
2413
2414    if (vma->vm_pgoff)
2415        return -EINVAL;
2416
2417    mutex_lock(&po->pg_vec_lock);
2418
2419    expected_size = 0;
2420    for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
2421        if (rb->pg_vec) {
2422            expected_size += rb->pg_vec_len
2423                        * rb->pg_vec_pages
2424                        * PAGE_SIZE;
2425        }
2426    }
2427
2428    if (expected_size == 0)
2429        goto out;
2430
2431    size = vma->vm_end - vma->vm_start;
2432    if (size != expected_size)
2433        goto out;
2434
2435    start = vma->vm_start;
2436    for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
2437        if (rb->pg_vec == NULL)
2438            continue;
2439
2440        for (i = 0; i < rb->pg_vec_len; i++) {
2441            struct page *page = virt_to_page(rb->pg_vec[i]);
2442            int pg_num;
2443
2444            for (pg_num = 0; pg_num < rb->pg_vec_pages;
2445                    pg_num++, page++) {
2446                err = vm_insert_page(vma, start, page);
2447                if (unlikely(err))
2448                    goto out;
2449                start += PAGE_SIZE;
2450            }
2451        }
2452    }
2453
2454    atomic_inc(&po->mapped);
2455    vma->vm_ops = &packet_mmap_ops;
2456    err = 0;
2457
2458out:
2459    mutex_unlock(&po->pg_vec_lock);
2460    return err;
2461}
2462
2463static const struct proto_ops packet_ops_spkt = {
2464    .family = PF_PACKET,
2465    .owner = THIS_MODULE,
2466    .release = packet_release,
2467    .bind = packet_bind_spkt,
2468    .connect = sock_no_connect,
2469    .socketpair = sock_no_socketpair,
2470    .accept = sock_no_accept,
2471    .getname = packet_getname_spkt,
2472    .poll = datagram_poll,
2473    .ioctl = packet_ioctl,
2474    .listen = sock_no_listen,
2475    .shutdown = sock_no_shutdown,
2476    .setsockopt = sock_no_setsockopt,
2477    .getsockopt = sock_no_getsockopt,
2478    .sendmsg = packet_sendmsg_spkt,
2479    .recvmsg = packet_recvmsg,
2480    .mmap = sock_no_mmap,
2481    .sendpage = sock_no_sendpage,
2482};
2483
2484static const struct proto_ops packet_ops = {
2485    .family = PF_PACKET,
2486    .owner = THIS_MODULE,
2487    .release = packet_release,
2488    .bind = packet_bind,
2489    .connect = sock_no_connect,
2490    .socketpair = sock_no_socketpair,
2491    .accept = sock_no_accept,
2492    .getname = packet_getname,
2493    .poll = packet_poll,
2494    .ioctl = packet_ioctl,
2495    .listen = sock_no_listen,
2496    .shutdown = sock_no_shutdown,
2497    .setsockopt = packet_setsockopt,
2498    .getsockopt = packet_getsockopt,
2499    .sendmsg = packet_sendmsg,
2500    .recvmsg = packet_recvmsg,
2501    .mmap = packet_mmap,
2502    .sendpage = sock_no_sendpage,
2503};
2504
2505static const struct net_proto_family packet_family_ops = {
2506    .family = PF_PACKET,
2507    .create = packet_create,
2508    .owner = THIS_MODULE,
2509};
2510
2511static struct notifier_block packet_netdev_notifier = {
2512    .notifier_call = packet_notifier,
2513};
2514
2515#ifdef CONFIG_PROC_FS
2516
2517static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
2518    __acquires(RCU)
2519{
2520    struct net *net = seq_file_net(seq);
2521
2522    rcu_read_lock();
2523    return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
2524}
2525
2526static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2527{
2528    struct net *net = seq_file_net(seq);
2529    return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
2530}
2531
2532static void packet_seq_stop(struct seq_file *seq, void *v)
2533    __releases(RCU)
2534{
2535    rcu_read_unlock();
2536}
2537
2538static int packet_seq_show(struct seq_file *seq, void *v)
2539{
2540    if (v == SEQ_START_TOKEN)
2541        seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
2542    else {
2543        struct sock *s = sk_entry(v);
2544        const struct packet_sock *po = pkt_sk(s);
2545
2546        seq_printf(seq,
2547               "%p %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
2548               s,
2549               atomic_read(&s->sk_refcnt),
2550               s->sk_type,
2551               ntohs(po->num),
2552               po->ifindex,
2553               po->running,
2554               atomic_read(&s->sk_rmem_alloc),
2555               sock_i_uid(s),
2556               sock_i_ino(s));
2557    }
2558
2559    return 0;
2560}
2561
2562static const struct seq_operations packet_seq_ops = {
2563    .start = packet_seq_start,
2564    .next = packet_seq_next,
2565    .stop = packet_seq_stop,
2566    .show = packet_seq_show,
2567};
2568
2569static int packet_seq_open(struct inode *inode, struct file *file)
2570{
2571    return seq_open_net(inode, file, &packet_seq_ops,
2572                sizeof(struct seq_net_private));
2573}
2574
2575static const struct file_operations packet_seq_fops = {
2576    .owner = THIS_MODULE,
2577    .open = packet_seq_open,
2578    .read = seq_read,
2579    .llseek = seq_lseek,
2580    .release = seq_release_net,
2581};
2582
2583#endif
2584
2585static int __net_init packet_net_init(struct net *net)
2586{
2587    spin_lock_init(&net->packet.sklist_lock);
2588    INIT_HLIST_HEAD(&net->packet.sklist);
2589
2590    if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
2591        return -ENOMEM;
2592
2593    return 0;
2594}
2595
2596static void __net_exit packet_net_exit(struct net *net)
2597{
2598    proc_net_remove(net, "packet");
2599}
2600
2601static struct pernet_operations packet_net_ops = {
2602    .init = packet_net_init,
2603    .exit = packet_net_exit,
2604};
2605
2606
2607static void __exit packet_exit(void)
2608{
2609    unregister_netdevice_notifier(&packet_netdev_notifier);
2610    unregister_pernet_subsys(&packet_net_ops);
2611    sock_unregister(PF_PACKET);
2612    proto_unregister(&packet_proto);
2613}
2614
2615static int __init packet_init(void)
2616{
2617    int rc = proto_register(&packet_proto, 0);
2618
2619    if (rc != 0)
2620        goto out;
2621
2622    sock_register(&packet_family_ops);
2623    register_pernet_subsys(&packet_net_ops);
2624    register_netdevice_notifier(&packet_netdev_notifier);
2625out:
2626    return rc;
2627}
2628
2629module_init(packet_init);
2630module_exit(packet_exit);
2631MODULE_LICENSE("GPL");
2632MODULE_ALIAS_NETPROTO(PF_PACKET);
2633

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