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packet: support extensible, 64 bit clean mmaped ring structure
The tpacket_hdr is not 64 bit clean due to use of an unsigned long and can't be extended because the following struct sockaddr_ll needs to be at a fixed offset. Add support for a version 2 tpacket protocol that removes these limitations. Userspace can query the header size through a new getsockopt option and change the protocol version through a setsockopt option. The changes needed to switch to the new protocol version are: 1. replace struct tpacket_hdr by struct tpacket2_hdr 2. query header len and save 3. set protocol version to 2 - set up ring as usual 4. for getting the sockaddr_ll, use (void *)hdr + TPACKET_ALIGN(hdrlen) instead of (void *)hdr + TPACKET_ALIGN(sizeof(struct tpacket_hdr)) Steps 2 and 4 can be omitted if the struct sockaddr_ll isn't needed. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy
David S. Miller
parent
bc1d0411b8
commit
bbd6ef87c5
@ -43,6 +43,8 @@ struct sockaddr_ll
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#define PACKET_COPY_THRESH 7
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#define PACKET_AUXDATA 8
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#define PACKET_ORIGDEV 9
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#define PACKET_VERSION 10
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#define PACKET_HDRLEN 11
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struct tpacket_stats
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{
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@ -79,6 +81,25 @@ struct tpacket_hdr
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#define TPACKET_ALIGN(x) (((x)+TPACKET_ALIGNMENT-1)&~(TPACKET_ALIGNMENT-1))
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#define TPACKET_HDRLEN (TPACKET_ALIGN(sizeof(struct tpacket_hdr)) + sizeof(struct sockaddr_ll))
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struct tpacket2_hdr
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{
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__u32 tp_status;
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__u32 tp_len;
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__u32 tp_snaplen;
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__u16 tp_mac;
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__u16 tp_net;
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__u32 tp_sec;
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__u32 tp_nsec;
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};
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#define TPACKET2_HDRLEN (TPACKET_ALIGN(sizeof(struct tpacket2_hdr)) + sizeof(struct sockaddr_ll))
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enum tpacket_versions
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{
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TPACKET_V1,
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TPACKET_V2,
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};
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/*
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Frame structure:
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@ -186,6 +186,8 @@ struct packet_sock {
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unsigned int pg_vec_order;
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unsigned int pg_vec_pages;
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unsigned int pg_vec_len;
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enum tpacket_versions tp_version;
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unsigned int tp_hdrlen;
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#endif
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};
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@ -201,14 +203,52 @@ struct packet_skb_cb {
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#ifdef CONFIG_PACKET_MMAP
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static inline struct tpacket_hdr *packet_lookup_frame(struct packet_sock *po, unsigned int position)
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static void *packet_lookup_frame(struct packet_sock *po, unsigned int position,
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int status)
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{
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unsigned int pg_vec_pos, frame_offset;
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union {
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struct tpacket_hdr *h1;
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struct tpacket2_hdr *h2;
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void *raw;
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} h;
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pg_vec_pos = position / po->frames_per_block;
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frame_offset = position % po->frames_per_block;
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return (struct tpacket_hdr *)(po->pg_vec[pg_vec_pos] + (frame_offset * po->frame_size));
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h.raw = po->pg_vec[pg_vec_pos] + (frame_offset * po->frame_size);
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switch (po->tp_version) {
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case TPACKET_V1:
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if (status != h.h1->tp_status ? TP_STATUS_USER :
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TP_STATUS_KERNEL)
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return NULL;
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break;
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case TPACKET_V2:
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if (status != h.h2->tp_status ? TP_STATUS_USER :
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TP_STATUS_KERNEL)
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return NULL;
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break;
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}
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return h.raw;
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}
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static void __packet_set_status(struct packet_sock *po, void *frame, int status)
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{
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union {
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struct tpacket_hdr *h1;
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struct tpacket2_hdr *h2;
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void *raw;
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} h;
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h.raw = frame;
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switch (po->tp_version) {
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case TPACKET_V1:
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h.h1->tp_status = status;
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break;
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case TPACKET_V2:
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h.h2->tp_status = status;
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break;
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}
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}
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#endif
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@ -551,14 +591,19 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
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struct sock *sk;
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struct packet_sock *po;
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struct sockaddr_ll *sll;
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struct tpacket_hdr *h;
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union {
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struct tpacket_hdr *h1;
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struct tpacket2_hdr *h2;
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void *raw;
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} h;
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u8 * skb_head = skb->data;
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int skb_len = skb->len;
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unsigned int snaplen, res;
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unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER;
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unsigned short macoff, netoff;
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unsigned short macoff, netoff, hdrlen;
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struct sk_buff *copy_skb = NULL;
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struct timeval tv;
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struct timespec ts;
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if (skb->pkt_type == PACKET_LOOPBACK)
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goto drop;
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@ -590,10 +635,11 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
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snaplen = res;
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if (sk->sk_type == SOCK_DGRAM) {
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macoff = netoff = TPACKET_ALIGN(TPACKET_HDRLEN) + 16;
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macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16;
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} else {
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unsigned maclen = skb_network_offset(skb);
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netoff = TPACKET_ALIGN(TPACKET_HDRLEN + (maclen < 16 ? 16 : maclen));
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netoff = TPACKET_ALIGN(po->tp_hdrlen +
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(maclen < 16 ? 16 : maclen));
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macoff = netoff - maclen;
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}
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@ -616,9 +662,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
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}
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spin_lock(&sk->sk_receive_queue.lock);
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h = packet_lookup_frame(po, po->head);
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if (h->tp_status)
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h.raw = packet_lookup_frame(po, po->head, TP_STATUS_KERNEL);
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if (!h.raw)
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goto ring_is_full;
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po->head = po->head != po->frame_max ? po->head+1 : 0;
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po->stats.tp_packets++;
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@ -630,20 +675,40 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
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status &= ~TP_STATUS_LOSING;
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spin_unlock(&sk->sk_receive_queue.lock);
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skb_copy_bits(skb, 0, (u8*)h + macoff, snaplen);
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skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
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h->tp_len = skb->len;
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h->tp_snaplen = snaplen;
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h->tp_mac = macoff;
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h->tp_net = netoff;
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if (skb->tstamp.tv64)
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tv = ktime_to_timeval(skb->tstamp);
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else
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do_gettimeofday(&tv);
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h->tp_sec = tv.tv_sec;
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h->tp_usec = tv.tv_usec;
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switch (po->tp_version) {
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case TPACKET_V1:
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h.h1->tp_len = skb->len;
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h.h1->tp_snaplen = snaplen;
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h.h1->tp_mac = macoff;
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h.h1->tp_net = netoff;
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if (skb->tstamp.tv64)
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tv = ktime_to_timeval(skb->tstamp);
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else
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do_gettimeofday(&tv);
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h.h1->tp_sec = tv.tv_sec;
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h.h1->tp_usec = tv.tv_usec;
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hdrlen = sizeof(*h.h1);
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break;
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case TPACKET_V2:
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h.h2->tp_len = skb->len;
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h.h2->tp_snaplen = snaplen;
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h.h2->tp_mac = macoff;
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h.h2->tp_net = netoff;
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if (skb->tstamp.tv64)
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ts = ktime_to_timespec(skb->tstamp);
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else
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getnstimeofday(&ts);
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h.h2->tp_sec = ts.tv_sec;
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h.h2->tp_nsec = ts.tv_nsec;
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hdrlen = sizeof(*h.h2);
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break;
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default:
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BUG();
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}
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sll = (struct sockaddr_ll*)((u8*)h + TPACKET_ALIGN(sizeof(*h)));
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sll = h.raw + TPACKET_ALIGN(hdrlen);
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sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
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sll->sll_family = AF_PACKET;
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sll->sll_hatype = dev->type;
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@ -654,14 +719,14 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
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else
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sll->sll_ifindex = dev->ifindex;
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h->tp_status = status;
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__packet_set_status(po, h.raw, status);
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smp_mb();
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{
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struct page *p_start, *p_end;
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u8 *h_end = (u8 *)h + macoff + snaplen - 1;
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u8 *h_end = h.raw + macoff + snaplen - 1;
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p_start = virt_to_page(h);
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p_start = virt_to_page(h.raw);
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p_end = virt_to_page(h_end);
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while (p_start <= p_end) {
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flush_dcache_page(p_start);
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@ -1362,6 +1427,25 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
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pkt_sk(sk)->copy_thresh = val;
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return 0;
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}
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case PACKET_VERSION:
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{
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int val;
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if (optlen != sizeof(val))
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return -EINVAL;
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if (po->pg_vec)
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return -EBUSY;
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if (copy_from_user(&val, optval, sizeof(val)))
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return -EFAULT;
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switch (val) {
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case TPACKET_V1:
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case TPACKET_V2:
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po->tp_version = val;
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return 0;
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default:
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return -EINVAL;
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}
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}
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#endif
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case PACKET_AUXDATA:
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{
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@ -1437,6 +1521,31 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
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data = &val;
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break;
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#ifdef CONFIG_PACKET_MMAP
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case PACKET_VERSION:
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if (len > sizeof(int))
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len = sizeof(int);
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val = po->tp_version;
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data = &val;
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break;
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case PACKET_HDRLEN:
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if (len > sizeof(int))
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len = sizeof(int);
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if (copy_from_user(&val, optval, len))
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return -EFAULT;
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switch (val) {
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case TPACKET_V1:
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val = sizeof(struct tpacket_hdr);
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break;
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case TPACKET_V2:
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val = sizeof(struct tpacket2_hdr);
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break;
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default:
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return -EINVAL;
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}
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data = &val;
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break;
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#endif
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default:
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return -ENOPROTOOPT;
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}
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@ -1570,11 +1679,8 @@ static unsigned int packet_poll(struct file * file, struct socket *sock,
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spin_lock_bh(&sk->sk_receive_queue.lock);
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if (po->pg_vec) {
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unsigned last = po->head ? po->head-1 : po->frame_max;
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struct tpacket_hdr *h;
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h = packet_lookup_frame(po, last);
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if (h->tp_status)
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if (packet_lookup_frame(po, last, TP_STATUS_USER))
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mask |= POLLIN | POLLRDNORM;
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}
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spin_unlock_bh(&sk->sk_receive_queue.lock);
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@ -1669,11 +1775,20 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing
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if (unlikely(po->pg_vec))
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return -EBUSY;
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switch (po->tp_version) {
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case TPACKET_V1:
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po->tp_hdrlen = TPACKET_HDRLEN;
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break;
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case TPACKET_V2:
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po->tp_hdrlen = TPACKET2_HDRLEN;
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break;
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}
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if (unlikely((int)req->tp_block_size <= 0))
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return -EINVAL;
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if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
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return -EINVAL;
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if (unlikely(req->tp_frame_size < TPACKET_HDRLEN))
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if (unlikely(req->tp_frame_size < po->tp_hdrlen))
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return -EINVAL;
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if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
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return -EINVAL;
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@ -1692,13 +1807,11 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing
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goto out;
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for (i = 0; i < req->tp_block_nr; i++) {
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char *ptr = pg_vec[i];
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struct tpacket_hdr *header;
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void *ptr = pg_vec[i];
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int k;
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for (k = 0; k < po->frames_per_block; k++) {
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header = (struct tpacket_hdr *) ptr;
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header->tp_status = TP_STATUS_KERNEL;
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__packet_set_status(po, ptr, TP_STATUS_KERNEL);
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ptr += req->tp_frame_size;
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}
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}
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