[PATCH v2 net-next af-packet 2/2] Enhance af-packet to provide (near zero)lossless packet capture functionality.
From: Chetan Loke
Date: Tue Jun 21 2011 - 22:12:08 EST
1) Blocks can now be configured with non-static frame format.
Non-static frame format provides following benefits:
1.1) Increases packet density by a factor of 2x.
1.2) Ability to capture entire packet.
1.3) Captures 99% 64-byte traffic as seen by the kernel.
2) Read/poll is now at a block-level rather than at packet level.
3) Added user-configurable timeout knob for timing out blocks on slow/bursty links.
4) Block level processing now allows monitoring multiple links as a single
logical pipe.
Changes:
C1) tpacket_rcv()
C1.1) packet_current_frame() is replaced by packet_current_rx_frame()
The bulk of the processing is then moved in the following chain:
packet_current_rx_frame()
__packet_lookup_frame_in_block
fill_curr_block()
or
retire_current_block
dispatch_next_block
or
return NULL(queue is plugged/paused)
Signed-off-by: Chetan Loke <loke.chetan@xxxxxxxxx>
---
net/packet/af_packet.c | 881 +++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 836 insertions(+), 45 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index b54ec41..bcbe6ec 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -40,6 +40,9 @@
* byte arrays at the end of sockaddr_ll
* and packet_mreq.
* Johann Baudy : Added TX RING.
+ * Chetan Loke : Implemented TPACKET_V3 block abstraction
+ * layer. Copyright (C) 2011, <lokec@xxxxxxxxxxx>
+ *
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -161,9 +164,55 @@ struct packet_mreq_max {
unsigned char mr_address[MAX_ADDR_LEN];
};
-static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
+static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
int closing, int tx_ring);
+
+#define V3_ALIGNMENT (4)
+#define ALIGN_4(x) (((x)+V3_ALIGNMENT-1)&~(V3_ALIGNMENT-1))
+
+#define BLK_HDR_LEN (ALIGN_4(sizeof(struct block_desc)))
+
+#define BLK_PLUS_PRIV(sz_of_priv) \
+ (BLK_HDR_LEN + ALIGN_4((sz_of_priv)))
+
+/* kbdq - kernel block descriptor queue */
+struct kbdq_core {
+ struct pgv *pkbdq;
+ unsigned int hdrlen;
+ unsigned char reset_pending_on_curr_blk;
+ unsigned char delete_blk_timer;
+ unsigned short kactive_blk_num;
+ unsigned short blk_sizeof_priv;
+
+ /* last_kactive_blk_num:
+ * trick to see if user-space has caught up
+ * in order to avoid refreshing timer when every single pkt arrives.
+ */
+ unsigned short last_kactive_blk_num;
+
+ char *pkblk_start;
+ char *pkblk_end;
+ int kblk_size;
+ unsigned int knum_blocks;
+ uint64_t knxt_seq_num;
+ char *prev;
+ char *nxt_offset;
+
+
+ atomic_t blk_fill_in_prog;
+
+ /* Default is set to 8ms */
+#define DEFAULT_PRB_RETIRE_TOV (8)
+
+ unsigned short retire_blk_tov;
+ unsigned short version;
+ unsigned long tov_in_jiffies;
+
+ /* timer to retire an outstanding block */
+ struct timer_list retire_blk_timer;
+};
+
struct pgv {
char *buffer;
};
@@ -179,18 +228,36 @@ struct packet_ring_buffer {
unsigned int pg_vec_pages;
unsigned int pg_vec_len;
+ struct kbdq_core prb_bdqc;
atomic_t pending;
};
struct packet_sock;
static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
+static void *packet_previous_frame(struct packet_sock *po,
+ struct packet_ring_buffer *rb,
+ int status);
+static void packet_increment_head(struct packet_ring_buffer *buff);
+static int prb_curr_blk_in_use(struct kbdq_core *,
+ struct block_desc *);
+static void *prb_dispatch_next_block(struct kbdq_core *,
+ struct packet_sock *);
+static void prb_retire_current_block(struct kbdq_core *,
+ struct packet_sock *, unsigned int status);
+static int prb_queue_frozen(struct kbdq_core *);
+static void prb_open_block(struct kbdq_core *, struct block_desc *);
+static void prb_retire_rx_blk_timer_expired(unsigned long);
+static void _prb_refresh_rx_retire_blk_timer(struct kbdq_core *);
+static void prb_init_blk_timer(struct packet_sock *, struct kbdq_core *,
+ void (*func) (unsigned long));
static void packet_flush_mclist(struct sock *sk);
struct packet_sock {
/* struct sock has to be the first member of packet_sock */
struct sock sk;
struct tpacket_stats stats;
+ union tpacket_stats_u stats_u;
struct packet_ring_buffer rx_ring;
struct packet_ring_buffer tx_ring;
int copy_thresh;
@@ -222,6 +289,19 @@ struct packet_skb_cb {
#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
+#define GET_PBDQC_FROM_RB(x) ((struct kbdq_core *)(&(x)->prb_bdqc))
+
+#define GET_PBLOCK_DESC(x, bid) ((struct block_desc *)((x)->pkbdq[(bid)].buffer))
+
+#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
+ ((struct block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
+
+
+#define GET_NEXT_PRB_BLK_NUM(x) \
+ (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
+ ((x)->kactive_blk_num+1) : 0)
+
+
static inline __pure struct page *pgv_to_page(void *addr)
{
if (is_vmalloc_addr(addr))
@@ -247,6 +327,7 @@ static void __packet_set_status(struct packet_sock *po, void *frame, int status)
h.h2->tp_status = status;
flush_dcache_page(pgv_to_page(&h.h2->tp_status));
break;
+ case TPACKET_V3:
default:
pr_err("TPACKET version not supported\n");
BUG();
@@ -273,6 +354,7 @@ static int __packet_get_status(struct packet_sock *po, void *frame)
case TPACKET_V2:
flush_dcache_page(pgv_to_page(&h.h2->tp_status));
return h.h2->tp_status;
+ case TPACKET_V3:
default:
pr_err("TPACKET version not supported\n");
BUG();
@@ -311,6 +393,618 @@ static inline void *packet_current_frame(struct packet_sock *po,
return packet_lookup_frame(po, rb, rb->head, status);
}
+static void prb_del_retire_blk_timer(struct kbdq_core *pkc)
+{
+ del_timer_sync(&pkc->retire_blk_timer);
+}
+
+static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
+ int tx_ring,
+ struct sk_buff_head *rb_queue)
+{
+ struct kbdq_core *pkc;
+
+ pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
+
+ spin_lock(&rb_queue->lock);
+ pkc->delete_blk_timer = 1;
+ spin_unlock(&rb_queue->lock);
+
+ prb_del_retire_blk_timer(pkc);
+}
+
+static void prb_init_blk_timer(struct packet_sock *po,
+ struct kbdq_core *pkc,
+ void (*func) (unsigned long))
+{
+ init_timer(&pkc->retire_blk_timer);
+ pkc->retire_blk_timer.data = (long)po;
+ pkc->retire_blk_timer.function = func;
+ pkc->retire_blk_timer.expires = jiffies;
+}
+
+static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
+{
+ struct kbdq_core *pkc;
+
+ if (tx_ring)
+ BUG();
+
+ pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
+ prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
+}
+
+static int prb_calc_retire_blk_tmo(struct packet_sock *po,
+ int blk_size_in_bytes)
+{
+ struct net_device *dev;
+ unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
+
+ dev = dev_get_by_index(sock_net(&po->sk), po->ifindex);
+ if (unlikely(dev == NULL))
+ return DEFAULT_PRB_RETIRE_TOV;
+
+ if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
+ struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
+
+ if (!dev->ethtool_ops->get_settings(dev, &ecmd)) {
+ switch (ecmd.speed) {
+ case SPEED_10000:
+ msec = 1;
+ div = 10000/1000;
+ break;
+ case SPEED_1000:
+ msec = 1;
+ div = 1000/1000;
+ break;
+ /*
+ * If the link speed is so slow you don't really
+ * need to worry about perf anyways
+ */
+ case SPEED_100:
+ case SPEED_10:
+ default:
+ return DEFAULT_PRB_RETIRE_TOV;
+ }
+ }
+ }
+
+ mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
+
+ if (div)
+ mbits /= div;
+
+ tmo = mbits * msec;
+
+ if (div)
+ return tmo+1;
+ return tmo;
+}
+
+static void init_prb_bdqc(struct packet_sock *po,
+ struct packet_ring_buffer *rb,
+ struct pgv *pg_vec,
+ union tpacket_req_u *req_u, int tx_ring)
+{
+ struct kbdq_core *p1 = &rb->prb_bdqc;
+ struct block_desc *pbd;
+
+ memset(p1, 0x0, sizeof(*p1));
+ p1->knxt_seq_num = 1;
+ p1->pkbdq = pg_vec;
+ pbd = (struct block_desc *)pg_vec[0].buffer;
+ p1->pkblk_start = (char *)pg_vec[0].buffer;
+ p1->kblk_size = req_u->req3.tp_block_size;
+ p1->knum_blocks = req_u->req3.tp_block_nr;
+ p1->hdrlen = po->tp_hdrlen;
+ p1->version = po->tp_version;
+ p1->last_kactive_blk_num = 0;
+ po->stats_u.stats3.tp_freeze_q_cnt = 0;
+ if (req_u->req3.tp_retire_blk_tov)
+ p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
+ else
+ p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
+ req_u->req3.tp_block_size);
+ p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
+ p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
+ prb_setup_retire_blk_timer(po, tx_ring);
+ prb_open_block(p1, pbd);
+}
+
+/* Do NOT update the last_blk_num first.
+ * Assumes sk_buff_head lock is held.
+ */
+static void _prb_refresh_rx_retire_blk_timer(struct kbdq_core *pkc)
+{
+ mod_timer(&pkc->retire_blk_timer,
+ jiffies + pkc->tov_in_jiffies);
+ pkc->last_kactive_blk_num = pkc->kactive_blk_num;
+}
+
+/*
+ * Timer logic:
+ * 1) We refresh the timer only when we open a block.
+ * By doing this we don't waste cycles refreshing the timer
+ * on packet-by-packet basis.
+ *
+ * With a 1MB block-size, on a 1Gbps line, it will take
+ * i) ~8 ms to fill a block + ii) memcpy etc.
+ * In this cut we are not accounting for the memcpy time.
+ *
+ * So, if the user sets the 'tmo' to 10ms then the timer
+ * will never fire while the block is still getting filled
+ * (which is what we want). However, the user could choose
+ * to close a block early and that's fine.
+ *
+ * But when the timer does fire, we check whether or not to refresh it.
+ * Since the tmo granularity is in msecs, it is not too expensive
+ * to refresh the timer, lets say every '8' msecs.
+ * Either the user can set the 'tmo' or we can derive it based on
+ * a) line-speed and b) block-size.
+ * prb_calc_retire_blk_tmo() calculates the tmo.
+ *
+ */
+static void prb_retire_rx_blk_timer_expired(unsigned long data)
+{
+ struct packet_sock *po = (struct packet_sock *)data;
+ struct kbdq_core *pkc = &po->rx_ring.prb_bdqc;
+ unsigned int frozen;
+ struct block_desc *pbd;
+
+ spin_lock(&po->sk.sk_receive_queue.lock);
+
+ frozen = prb_queue_frozen(pkc);
+ pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
+
+ if (unlikely(pkc->delete_blk_timer))
+ goto out;
+
+ /* We only need to plug the race when the block is partially filled.
+ * tpacket_rcv:
+ * lock(); increment BLOCK_NUM_PKTS; unlock()
+ * copy_bits() is in progress ...
+ * timer fires on other cpu:
+ * we can't retire the current block because copy_bits
+ * is in progress.
+ *
+ */
+ if (BLOCK_NUM_PKTS(pbd)) {
+ while (atomic_read(&pkc->blk_fill_in_prog)) {
+ /* Waiting for skb_copy_bits to finish... */
+ cpu_relax();
+ }
+ }
+
+ if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
+ if (!frozen) {
+ prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
+ if (!prb_dispatch_next_block(pkc, po))
+ goto refresh_timer;
+ else
+ goto out;
+ } else {
+ /* Case 1. Queue was frozen because user-space was
+ * lagging behind.
+ */
+ if (prb_curr_blk_in_use(pkc, pbd)) {
+ /*
+ * Ok, user-space is still behind.
+ * So just refresh the timer.
+ */
+ goto refresh_timer;
+ } else {
+ /* Case 2. queue was frozen, user-space caught up,
+ * now the link went idle && the timer fired.
+ * We don't have a block to close. So we open this
+ * block and restart the timer.
+ * opening a block thaws the queue, restarts timer.
+ * Thawing/timer-refresh is a side effect.
+ */
+ prb_open_block(pkc, pbd);
+ goto out;
+ }
+ }
+ }
+
+refresh_timer:
+ _prb_refresh_rx_retire_blk_timer(pkc);
+
+out:
+ spin_unlock(&po->sk.sk_receive_queue.lock);
+}
+
+static inline void prb_flush_block(struct kbdq_core *pkc1, struct block_desc *pbd1,
+ __u32 status)
+{
+ /* Flush everything minus the block header */
+
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
+ u8 *start, *end;
+
+ start = (u8 *)pbd1;
+
+ /* Skip the block header(we know header WILL fit in 4K) */
+ start += PAGE_SIZE;
+
+ end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
+ for (; start < end; start += PAGE_SIZE)
+ flush_dcache_page(pgv_to_page(start));
+
+ smp_wmb();
+#endif
+
+ /* Now update the block status. */
+
+ BLOCK_STATUS(pbd1) = status;
+
+ /* Flush the block header */
+
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
+ start = (u8 *)pbd1;
+ flush_dcache_page(pgv_to_page(start));
+
+ smp_wmb();
+#endif
+}
+
+/*
+ * Side effect:
+ *
+ * 1) flush the block
+ * 2) Increment active_blk_num
+ *
+ * Note:We DONT refresh the timer on purpose.
+ * Because almost always the next block will be opened.
+ */
+static void prb_close_block(struct kbdq_core *pkc1, struct block_desc *pbd1,
+ struct packet_sock *po, unsigned int stat)
+{
+ __u32 status = TP_STATUS_USER | stat;
+
+ struct tpacket3_hdr *last_pkt;
+ struct bd_v1 *b1 = &pbd1->bd1;
+
+ if (po->stats.tp_drops)
+ status |= TP_STATUS_LOSING;
+
+ last_pkt = (struct tpacket3_hdr *)pkc1->prev;
+ last_pkt->tp_next_offset = 0;
+
+ /* Get the ts of the last pkt */
+ if (BLOCK_NUM_PKTS(pbd1)) {
+ b1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
+ b1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
+ } else {
+ /* Ok, we tmo'd - so get the current time */
+ struct timespec ts;
+ getnstimeofday(&ts);
+ b1->ts_last_pkt.ts_sec = ts.tv_sec;
+ b1->ts_last_pkt.ts_nsec = ts.tv_nsec;
+ }
+
+ smp_wmb();
+
+ /* Flush the block */
+ prb_flush_block(pkc1, pbd1, status);
+
+ pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
+}
+
+static inline void prb_thaw_queue(struct kbdq_core *pkc)
+{
+ pkc->reset_pending_on_curr_blk = 0;
+}
+
+/*
+ * Side effect of opening a block:
+ *
+ * 1) prb_queue is thawed.
+ * 2) retire_blk_timer is refreshed.
+ *
+ */
+static void prb_open_block(struct kbdq_core *pkc1, struct block_desc *pbd1)
+{
+ struct timespec ts;
+ struct bd_v1 *b1 = &pbd1->bd1;
+
+ smp_rmb();
+
+ if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) {
+
+ /* We could have just memset this but we will lose the flexibility of
+ * making the priv area sticky
+ */
+ BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
+ BLOCK_NUM_PKTS(pbd1) = 0;
+ BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
+ getnstimeofday(&ts);
+ b1->ts_first_pkt.ts_sec = ts.tv_sec;
+ b1->ts_first_pkt.ts_nsec = ts.tv_nsec;
+ pkc1->pkblk_start = (char *)pbd1;
+ pkc1->nxt_offset = (char *)(pkc1->pkblk_start+BLK_PLUS_PRIV(pkc1->blk_sizeof_priv));
+ BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
+ BLOCK_O2PRIV(pbd1) = (__u16)BLK_HDR_LEN;
+ pbd1->version = pkc1->version;
+ pkc1->prev = pkc1->nxt_offset;
+ pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
+ prb_thaw_queue(pkc1);
+ _prb_refresh_rx_retire_blk_timer(pkc1);
+
+ smp_wmb();
+
+ return;
+ }
+
+ WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n",
+ pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num);
+ dump_stack();
+ BUG();
+}
+
+/*
+ * Queue freeze logic:
+ * 1) Assume tp_block_nr = 8 blocks.
+ * 2) At time 't0', user opens Rx ring.
+ * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
+ * 4) user-space is either sleeping or processing block '0'.
+ * 5) tpacket_rcv is currently filling block '7', since there is no space left,
+ * it will close block-7,loop around and try to fill block '0'.
+ * call-flow:
+ * __packet_lookup_frame_in_block
+ * prb_retire_current_block()
+ * prb_dispatch_next_block()
+ * |->(BLOCK_STATUS == USER) evaluates to true
+ * 5.1) Since block-0 is currently in-use, we just freeze the queue.
+ * 6) Now there are two cases:
+ * 6.1) Link goes idle right after the queue is frozen.
+ * But remember, the last open_block() refreshed the timer.
+ * When this timer expires,it will refresh itself so that we can
+ * re-open block-0 in near future.
+ * 6.2) Link is busy and keeps on receiving packets. This is a simple
+ * case and __packet_lookup_frame_in_block will check if block-0
+ * is free and can now be re-used.
+ */
+static inline void prb_freeze_queue(struct kbdq_core *pkc,
+ struct packet_sock *po)
+{
+ pkc->reset_pending_on_curr_blk = 1;
+ po->stats_u.stats3.tp_freeze_q_cnt++;
+}
+
+#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN_4((length)))
+
+/*
+ * If the next block is free then we will dispatch it
+ * and return a good offset.
+ * Else, we will freeze the queue.
+ * So, caller must check the return value.
+ */
+static void *prb_dispatch_next_block(struct kbdq_core *pkc,
+ struct packet_sock *po)
+{
+ struct block_desc *pbd;
+
+ smp_rmb();
+
+ /* 1. Get current block num */
+ pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
+
+ /* 2. If this block is currently in_use then freeze the queue */
+ if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
+ prb_freeze_queue(pkc, po);
+ return NULL;
+ }
+
+ /*
+ * 3.
+ * open this block and return the offset where the first packet
+ * needs to get stored.
+ */
+ prb_open_block(pkc, pbd);
+ return (void *)pkc->nxt_offset;
+}
+
+static void prb_retire_current_block(struct kbdq_core *pkc,
+ struct packet_sock *po, unsigned int status)
+{
+ struct block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
+
+ /* retire/close the current block */
+ if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
+ /*
+ * Plug the case where copy_bits() is in progress on
+ * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
+ * have space to copy the pkt in the current block and
+ * called prb_retire_current_block()
+ *
+ * TODO:DURING REVIEW ASK IF THIS IS A VALID RACE.
+ * MAIN CONCERN IS ABOUT r[f/p]s THREADS(?) EXECUTING
+ * IN PARALLEL.
+ *
+ * We don't need to worry about the TMO case because
+ * the timer-handler already handled this case.
+ */
+ if (!(status & TP_STATUS_BLK_TMO)) {
+ while (atomic_read(&pkc->blk_fill_in_prog)) {
+ /* Waiting for skb_copy_bits to finish... */
+ cpu_relax();
+ }
+ }
+ prb_close_block(pkc, pbd, po, status);
+ return;
+ }
+
+ WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd);
+ dump_stack();
+ BUG();
+}
+
+static inline int prb_curr_blk_in_use(struct kbdq_core *pkc,
+ struct block_desc *pbd)
+{
+ return TP_STATUS_USER & BLOCK_STATUS(pbd);
+}
+
+static inline int prb_queue_frozen(struct kbdq_core *pkc)
+{
+ return pkc->reset_pending_on_curr_blk;
+}
+
+static inline void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
+{
+ struct kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
+ atomic_dec(&pkc->blk_fill_in_prog);
+}
+
+static inline void prb_fill_curr_block(char *curr, struct kbdq_core *pkc,
+ struct block_desc *pbd,
+ unsigned int len)
+{
+ struct tpacket3_hdr *ppd;
+
+ ppd = (struct tpacket3_hdr *)curr;
+ ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
+ pkc->prev = curr;
+ pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
+ BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
+ BLOCK_NUM_PKTS(pbd) += 1;
+ atomic_inc(&pkc->blk_fill_in_prog);
+}
+
+/* Assumes caller has the sk->rx_queue.lock */
+static void *__packet_lookup_frame_in_block(struct packet_ring_buffer *rb,
+ int status,
+ unsigned int len,
+ struct packet_sock *po)
+{
+ struct kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
+ struct block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
+ char *curr, *end;
+
+ /* Queue is frozen when user space is lagging behind */
+ if (prb_queue_frozen(pkc)) {
+ /*
+ * Check if that last block which caused the queue to freeze,
+ * is still in_use by user-space.
+ */
+ if (prb_curr_blk_in_use(pkc, pbd)) {
+ /* Can't record this packet */
+ return NULL;
+ } else {
+ /*
+ * Ok, the block was released by user-space.
+ * Now let's open that block.
+ * opening a block also thaws the queue.
+ * Thawing is a side effect.
+ */
+ prb_open_block(pkc, pbd);
+ }
+ }
+
+ smp_mb();
+ curr = pkc->nxt_offset;
+ end = (char *) ((char *)pbd + pkc->kblk_size);
+
+ /* first try the current block */
+ if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
+ prb_fill_curr_block(curr, pkc, pbd, len);
+ return (void *)curr;
+ }
+
+ /* Ok, close the current block */
+ prb_retire_current_block(pkc, po, 0);
+
+ /* Now, try to dispatch the next block */
+ curr = (char *)prb_dispatch_next_block(pkc, po);
+ if (curr) {
+ pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
+ prb_fill_curr_block(curr, pkc, pbd, len);
+ return (void *)curr;
+ }
+
+ /*
+ * No free blocks are available.user_space hasn't caught up yet.
+ * Queue was just frozen and now this packet will get dropped.
+ */
+ return NULL;
+}
+
+static inline void *packet_current_rx_frame(struct packet_sock *po,
+ struct packet_ring_buffer *rb,
+ int status, unsigned int len)
+{
+ char *curr = NULL;
+ switch (po->tp_version) {
+ case TPACKET_V1:
+ case TPACKET_V2:
+ curr = packet_lookup_frame(po, rb, rb->head, status);
+ return curr;
+ case TPACKET_V3:
+ return __packet_lookup_frame_in_block(rb, status, len, po);
+ default:
+ WARN(1, "TPACKET version not supported\n");
+ BUG();
+ return 0;
+ }
+}
+
+static inline void *prb_lookup_block(struct packet_sock *po,
+ struct packet_ring_buffer *rb,
+ unsigned int previous,
+ int status)
+{
+ struct kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
+ struct block_desc *pbd = GET_PBLOCK_DESC(pkc, previous);
+
+ if (status != BLOCK_STATUS(pbd))
+ return NULL;
+ return pbd;
+}
+
+static inline int prb_previous_blk_num(struct packet_ring_buffer *rb)
+{
+ unsigned int prev;
+ if (rb->prb_bdqc.kactive_blk_num)
+ prev = rb->prb_bdqc.kactive_blk_num-1;
+ else
+ prev = rb->prb_bdqc.knum_blocks-1;
+ return prev;
+}
+
+/* Assumes caller has held the rx_queue.lock */
+static inline void *__prb_previous_block(struct packet_sock *po,
+ struct packet_ring_buffer *rb,
+ int status)
+{
+ unsigned int previous = prb_previous_blk_num(rb);
+ return prb_lookup_block(po, rb, previous, status);
+}
+
+static inline void *packet_previous_rx_frame(struct packet_sock *po,
+ struct packet_ring_buffer *rb,
+ int status)
+{
+ if (po->tp_version <= TPACKET_V2)
+ return packet_previous_frame(po, rb, status);
+
+ return __prb_previous_block(po, rb, status);
+}
+
+static inline void packet_increment_rx_head(struct packet_sock *po,
+ struct packet_ring_buffer *rb)
+{
+ switch (po->tp_version) {
+ case TPACKET_V1:
+ case TPACKET_V2:
+ return packet_increment_head(rb);
+ case TPACKET_V3:
+ default:
+ WARN(1, "TPACKET version not supported.\n");
+ BUG();
+ return;
+ }
+}
+
static inline void *packet_previous_frame(struct packet_sock *po,
struct packet_ring_buffer *rb,
int status)
@@ -675,12 +1369,13 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
union {
struct tpacket_hdr *h1;
struct tpacket2_hdr *h2;
+ struct tpacket3_hdr *h3;
void *raw;
} h;
u8 *skb_head = skb->data;
int skb_len = skb->len;
unsigned int snaplen, res;
- unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER;
+ unsigned long status = TP_STATUS_USER;
unsigned short macoff, netoff, hdrlen;
struct sk_buff *copy_skb = NULL;
struct timeval tv;
@@ -726,37 +1421,46 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
po->tp_reserve;
macoff = netoff - maclen;
}
-
- if (macoff + snaplen > po->rx_ring.frame_size) {
- if (po->copy_thresh &&
- atomic_read(&sk->sk_rmem_alloc) + skb->truesize <
- (unsigned)sk->sk_rcvbuf) {
- if (skb_shared(skb)) {
- copy_skb = skb_clone(skb, GFP_ATOMIC);
- } else {
- copy_skb = skb_get(skb);
- skb_head = skb->data;
+ if (po->tp_version <= TPACKET_V2) {
+ if (macoff + snaplen > po->rx_ring.frame_size) {
+ if (po->copy_thresh &&
+ atomic_read(&sk->sk_rmem_alloc) + skb->truesize <
+ (unsigned)sk->sk_rcvbuf) {
+ if (skb_shared(skb)) {
+ copy_skb = skb_clone(skb, GFP_ATOMIC);
+ } else {
+ copy_skb = skb_get(skb);
+ skb_head = skb->data;
+ }
+ if (copy_skb)
+ skb_set_owner_r(copy_skb, sk);
}
- if (copy_skb)
- skb_set_owner_r(copy_skb, sk);
+ snaplen = po->rx_ring.frame_size - macoff;
+ if ((int)snaplen < 0)
+ snaplen = 0;
}
- snaplen = po->rx_ring.frame_size - macoff;
- if ((int)snaplen < 0)
- snaplen = 0;
}
-
spin_lock(&sk->sk_receive_queue.lock);
- h.raw = packet_current_frame(po, &po->rx_ring, TP_STATUS_KERNEL);
+ h.raw = packet_current_rx_frame(po, &po->rx_ring,
+ TP_STATUS_KERNEL, (macoff+snaplen));
if (!h.raw)
goto ring_is_full;
- packet_increment_head(&po->rx_ring);
+ if (po->tp_version <= TPACKET_V2) {
+ packet_increment_rx_head(po, &po->rx_ring);
+ /*
+ * LOSING will be reported till you read the stats,
+ * because it's COR - Clear On Read.
+ * Anyways, moving it for V1/V2 only as V3 doesn't need this
+ * at packet level.
+ */
+ if (po->stats.tp_drops)
+ status |= TP_STATUS_LOSING;
+ }
po->stats.tp_packets++;
if (copy_skb) {
status |= TP_STATUS_COPY;
__skb_queue_tail(&sk->sk_receive_queue, copy_skb);
}
- if (!po->stats.tp_drops)
- status &= ~TP_STATUS_LOSING;
spin_unlock(&sk->sk_receive_queue.lock);
skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
@@ -806,6 +1510,36 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
}
hdrlen = sizeof(*h.h2);
break;
+ case TPACKET_V3:
+ /* tp_nxt_offset is already populated above.
+ * So DONT clear those fields here
+ */
+ h.h3->tp_status = status;
+ h.h3->tp_len = skb->len;
+ h.h3->tp_snaplen = snaplen;
+ h.h3->tp_mac = macoff;
+ h.h3->tp_net = netoff;
+ if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
+ && shhwtstamps->syststamp.tv64)
+ ts = ktime_to_timespec(shhwtstamps->syststamp);
+ else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
+ && shhwtstamps->hwtstamp.tv64)
+ ts = ktime_to_timespec(shhwtstamps->hwtstamp);
+ else if (skb->tstamp.tv64)
+ ts = ktime_to_timespec(skb->tstamp);
+ else
+ getnstimeofday(&ts);
+ h.h3->tp_sec = ts.tv_sec;
+ h.h3->tp_nsec = ts.tv_nsec;
+ if (vlan_tx_tag_present(skb)) {
+ h.h3->tp_vlan_tci = vlan_tx_tag_get(skb);
+ h.h3->tp_status |= TP_STATUS_VLAN_VALID;
+ } else {
+ h.h3->tp_vlan_tci = 0;
+ }
+ h.h3->tp_padding = 0;
+ hdrlen = sizeof(*h.h3);
+ break;
default:
BUG();
}
@@ -820,18 +1554,22 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
sll->sll_ifindex = orig_dev->ifindex;
else
sll->sll_ifindex = dev->ifindex;
-
- __packet_set_status(po, h.raw, status);
+ if (po->tp_version <= TPACKET_V2)
+ __packet_set_status(po, h.raw, status);
smp_mb();
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
{
u8 *start, *end;
- end = (u8 *)PAGE_ALIGN((unsigned long)h.raw + macoff + snaplen);
- for (start = h.raw; start < end; start += PAGE_SIZE)
- flush_dcache_page(pgv_to_page(start));
+ if (po->tp_version <= TPACKET_V2) {
+ end = (u8 *)PAGE_ALIGN((unsigned long)h.raw + macoff + snaplen);
+ for (start = h.raw; start < end; start += PAGE_SIZE)
+ flush_dcache_page(pgv_to_page(start));
+ }
}
#endif
+ if (po->tp_version > TPACKET_V2)
+ prb_clear_blk_fill_status(&po->rx_ring);
sk->sk_data_ready(sk, 0);
@@ -1322,7 +2060,7 @@ static int packet_release(struct socket *sock)
struct sock *sk = sock->sk;
struct packet_sock *po;
struct net *net;
- struct tpacket_req req;
+ union tpacket_req_u req_u;
if (!sk)
return 0;
@@ -1353,13 +2091,13 @@ static int packet_release(struct socket *sock)
packet_flush_mclist(sk);
- memset(&req, 0, sizeof(req));
+ memset(&req_u, 0, sizeof(req_u));
if (po->rx_ring.pg_vec)
- packet_set_ring(sk, &req, 1, 0);
+ packet_set_ring(sk, &req_u, 1, 0);
if (po->tx_ring.pg_vec)
- packet_set_ring(sk, &req, 1, 1);
+ packet_set_ring(sk, &req_u, 1, 1);
synchronize_net();
/*
@@ -1988,15 +2726,26 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
case PACKET_RX_RING:
case PACKET_TX_RING:
{
- struct tpacket_req req;
+ union tpacket_req_u req_u;
+ int len;
- if (optlen < sizeof(req))
+ switch (po->tp_version) {
+ case TPACKET_V1:
+ case TPACKET_V2:
+ len = sizeof(req_u.req);
+ break;
+ case TPACKET_V3:
+ default:
+ len = sizeof(req_u.req3);
+ break;
+ }
+ if (optlen < len)
return -EINVAL;
if (pkt_sk(sk)->has_vnet_hdr)
return -EINVAL;
- if (copy_from_user(&req, optval, sizeof(req)))
+ if (copy_from_user(&req_u.req, optval, len))
return -EFAULT;
- return packet_set_ring(sk, &req, 0, optname == PACKET_TX_RING);
+ return packet_set_ring(sk, &req_u, 0, optname == PACKET_TX_RING);
}
case PACKET_COPY_THRESH:
{
@@ -2023,6 +2772,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
switch (val) {
case TPACKET_V1:
case TPACKET_V2:
+ case TPACKET_V3:
po->tp_version = val;
return 0;
default:
@@ -2121,6 +2871,7 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
struct packet_sock *po = pkt_sk(sk);
void *data;
struct tpacket_stats st;
+ union tpacket_stats_u st_u;
if (level != SOL_PACKET)
return -ENOPROTOOPT;
@@ -2133,15 +2884,26 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
switch (optname) {
case PACKET_STATISTICS:
- if (len > sizeof(struct tpacket_stats))
- len = sizeof(struct tpacket_stats);
+ if (po->tp_version == TPACKET_V3) {
+ len = sizeof(struct tpacket_stats_v3);
+ } else {
+ if (len > sizeof(struct tpacket_stats))
+ len = sizeof(struct tpacket_stats);
+ }
spin_lock_bh(&sk->sk_receive_queue.lock);
- st = po->stats;
+ if (po->tp_version == TPACKET_V3) {
+ memcpy(&st_u.stats3, &po->stats,
+ sizeof(struct tpacket_stats));
+ st_u.stats3.tp_freeze_q_cnt = po->stats_u.stats3.tp_freeze_q_cnt;
+ st_u.stats3.tp_packets += po->stats.tp_drops;
+ data = &st_u.stats3;
+ } else {
+ st = po->stats;
+ st.tp_packets += st.tp_drops;
+ data = &st;
+ }
memset(&po->stats, 0, sizeof(st));
spin_unlock_bh(&sk->sk_receive_queue.lock);
- st.tp_packets += st.tp_drops;
-
- data = &st;
break;
case PACKET_AUXDATA:
if (len > sizeof(int))
@@ -2182,6 +2944,9 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
case TPACKET_V2:
val = sizeof(struct tpacket2_hdr);
break;
+ case TPACKET_V3:
+ val = sizeof(struct tpacket3_hdr);
+ break;
default:
return -EINVAL;
}
@@ -2334,7 +3099,7 @@ static unsigned int packet_poll(struct file *file, struct socket *sock,
spin_lock_bh(&sk->sk_receive_queue.lock);
if (po->rx_ring.pg_vec) {
- if (!packet_previous_frame(po, &po->rx_ring, TP_STATUS_KERNEL))
+ if (!packet_previous_rx_frame(po, &po->rx_ring, TP_STATUS_KERNEL))
mask |= POLLIN | POLLRDNORM;
}
spin_unlock_bh(&sk->sk_receive_queue.lock);
@@ -2453,7 +3218,7 @@ out_free_pgvec:
goto out;
}
-static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
+static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
int closing, int tx_ring)
{
struct pgv *pg_vec = NULL;
@@ -2462,7 +3227,15 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
struct packet_ring_buffer *rb;
struct sk_buff_head *rb_queue;
__be16 num;
- int err;
+ int err = -EINVAL;
+ /* Added to avoid minimal code churn */
+ struct tpacket_req *req = &req_u->req;
+
+ /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
+ if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
+ WARN(1, "Tx-ring is not supported.\n");
+ goto out;
+ }
rb = tx_ring ? &po->tx_ring : &po->rx_ring;
rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
@@ -2488,6 +3261,9 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
case TPACKET_V2:
po->tp_hdrlen = TPACKET2_HDRLEN;
break;
+ case TPACKET_V3:
+ po->tp_hdrlen = TPACKET3_HDRLEN;
+ break;
}
err = -EINVAL;
@@ -2513,6 +3289,17 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
pg_vec = alloc_pg_vec(req, order);
if (unlikely(!pg_vec))
goto out;
+ switch (po->tp_version) {
+ case TPACKET_V3:
+ /* Transmit path is not supported. We checked
+ * it above but just being paranoid
+ */
+ if (!tx_ring)
+ init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
+ break;
+ default:
+ break;
+ }
}
/* Done */
else {
@@ -2569,7 +3356,11 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
dev_add_pack(&po->prot_hook);
}
spin_unlock(&po->bind_lock);
-
+ if (closing && (po->tp_version > TPACKET_V2)) {
+ /* Because we don't support block-based V3 on tx-ring */
+ if (!tx_ring)
+ prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
+ }
release_sock(sk);
if (pg_vec)
--
1.7.5.2
--
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