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Merge branch 'TPACKET_V3-TX_RING-support'
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Sowmini Varadhan says:

====================
TPACKET_V3 TX_RING support

This patch series allows an application to use a single PF_PACKET
descriptor and leverage the best implementations of TX_RING
and RX_RING that exist today.

Patch 1 adds the kernel/Documentation changes for TX_RING
support and patch2 adds the associated test case in selftests.

Changes since v2: additional sanity checks for setsockopt
input for TX_RING/TPACKET_V3. Refactored psock_tpacket.c
test code to avoid code duplication from V2.
====================

Signed-off-by: David S. Miller <[email protected]>
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@davem330
davem330 committed Jan 3, 2017
2 parents e7072f6 + fe878ca commit aa276dd
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Showing 3 changed files with 111 additions and 28 deletions.
9 changes: 7 additions & 2 deletions Documentation/networking/packet_mmap.txt
View file
Original file line number Diff line number Diff line change
Expand Up @@ -565,7 +565,7 @@ TPACKET_V1 --> TPACKET_V2:
(void *)hdr + TPACKET_ALIGN(sizeof(struct tpacket_hdr))

TPACKET_V2 --> TPACKET_V3:
- Flexible buffer implementation:
- Flexible buffer implementation for RX_RING:
1. Blocks can be configured with non-static frame-size
2. Read/poll is at a block-level (as opposed to packet-level)
3. Added poll timeout to avoid indefinite user-space wait
Expand All @@ -574,7 +574,12 @@ TPACKET_V2 --> TPACKET_V3:
4.1 block::timeout
4.2 tpkt_hdr::sk_rxhash
- RX Hash data available in user space
- Currently only RX_RING available
- TX_RING semantics are conceptually similar to TPACKET_V2;
use tpacket3_hdr instead of tpacket2_hdr, and TPACKET3_HDRLEN
instead of TPACKET2_HDRLEN. In the current implementation,
the tp_next_offset field in the tpacket3_hdr MUST be set to
zero, indicating that the ring does not hold variable sized frames.
Packets with non-zero values of tp_next_offset will be dropped.

-------------------------------------------------------------------------------
+ AF_PACKET fanout mode
Expand Down
39 changes: 30 additions & 9 deletions net/packet/af_packet.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -409,6 +409,9 @@ static void __packet_set_status(struct packet_sock *po, void *frame, int status)
flush_dcache_page(pgv_to_page(&h.h2->tp_status));
break;
case TPACKET_V3:
h.h3->tp_status = status;
flush_dcache_page(pgv_to_page(&h.h3->tp_status));
break;
default:
WARN(1, "TPACKET version not supported.\n");
BUG();
Expand All @@ -432,6 +435,8 @@ static int __packet_get_status(struct packet_sock *po, void *frame)
flush_dcache_page(pgv_to_page(&h.h2->tp_status));
return h.h2->tp_status;
case TPACKET_V3:
flush_dcache_page(pgv_to_page(&h.h3->tp_status));
return h.h3->tp_status;
default:
WARN(1, "TPACKET version not supported.\n");
BUG();
Expand Down Expand Up @@ -2497,6 +2502,13 @@ static int tpacket_parse_header(struct packet_sock *po, void *frame,
ph.raw = frame;

switch (po->tp_version) {
case TPACKET_V3:
if (ph.h3->tp_next_offset != 0) {
pr_warn_once("variable sized slot not supported");
return -EINVAL;
}
tp_len = ph.h3->tp_len;
break;
case TPACKET_V2:
tp_len = ph.h2->tp_len;
break;
Expand All @@ -2516,6 +2528,9 @@ static int tpacket_parse_header(struct packet_sock *po, void *frame,
off_max = po->tx_ring.frame_size - tp_len;
if (po->sk.sk_type == SOCK_DGRAM) {
switch (po->tp_version) {
case TPACKET_V3:
off = ph.h3->tp_net;
break;
case TPACKET_V2:
off = ph.h2->tp_net;
break;
Expand All @@ -2525,6 +2540,9 @@ static int tpacket_parse_header(struct packet_sock *po, void *frame,
}
} else {
switch (po->tp_version) {
case TPACKET_V3:
off = ph.h3->tp_mac;
break;
case TPACKET_V2:
off = ph.h2->tp_mac;
break;
Expand Down Expand Up @@ -4113,11 +4131,6 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
struct tpacket_req *req = &req_u->req;

lock_sock(sk);
/* Opening a Tx-ring is NOT supported in TPACKET_V3 */
if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
net_warn_ratelimited("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;
Expand Down Expand Up @@ -4177,11 +4190,19 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
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)
/* Block transmit is not supported yet */
if (!tx_ring) {
init_prb_bdqc(po, rb, pg_vec, req_u);
} else {
struct tpacket_req3 *req3 = &req_u->req3;

if (req3->tp_retire_blk_tov ||
req3->tp_sizeof_priv ||
req3->tp_feature_req_word) {
err = -EINVAL;
goto out;
}
}
break;
default:
break;
Expand Down
91 changes: 74 additions & 17 deletions tools/testing/selftests/net/psock_tpacket.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -311,20 +311,33 @@ static inline void __v2_tx_user_ready(struct tpacket2_hdr *hdr)
__sync_synchronize();
}

static inline int __v1_v2_tx_kernel_ready(void *base, int version)
static inline int __v3_tx_kernel_ready(struct tpacket3_hdr *hdr)
{
return !(hdr->tp_status & (TP_STATUS_SEND_REQUEST | TP_STATUS_SENDING));
}

static inline void __v3_tx_user_ready(struct tpacket3_hdr *hdr)
{
hdr->tp_status = TP_STATUS_SEND_REQUEST;
__sync_synchronize();
}

static inline int __tx_kernel_ready(void *base, int version)
{
switch (version) {
case TPACKET_V1:
return __v1_tx_kernel_ready(base);
case TPACKET_V2:
return __v2_tx_kernel_ready(base);
case TPACKET_V3:
return __v3_tx_kernel_ready(base);
default:
bug_on(1);
return 0;
}
}

static inline void __v1_v2_tx_user_ready(void *base, int version)
static inline void __tx_user_ready(void *base, int version)
{
switch (version) {
case TPACKET_V1:
Expand All @@ -333,6 +346,9 @@ static inline void __v1_v2_tx_user_ready(void *base, int version)
case TPACKET_V2:
__v2_tx_user_ready(base);
break;
case TPACKET_V3:
__v3_tx_user_ready(base);
break;
}
}

Expand All @@ -348,7 +364,22 @@ static void __v1_v2_set_packet_loss_discard(int sock)
}
}

static void walk_v1_v2_tx(int sock, struct ring *ring)
static inline void *get_next_frame(struct ring *ring, int n)
{
uint8_t *f0 = ring->rd[0].iov_base;

switch (ring->version) {
case TPACKET_V1:
case TPACKET_V2:
return ring->rd[n].iov_base;
case TPACKET_V3:
return f0 + (n * ring->req3.tp_frame_size);
default:
bug_on(1);
}
}

static void walk_tx(int sock, struct ring *ring)
{
struct pollfd pfd;
int rcv_sock, ret;
Expand All @@ -360,9 +391,19 @@ static void walk_v1_v2_tx(int sock, struct ring *ring)
.sll_family = PF_PACKET,
.sll_halen = ETH_ALEN,
};
int nframes;

/* TPACKET_V{1,2} sets up the ring->rd* related variables based
* on frames (e.g., rd_num is tp_frame_nr) whereas V3 sets these
* up based on blocks (e.g, rd_num is tp_block_nr)
*/
if (ring->version <= TPACKET_V2)
nframes = ring->rd_num;
else
nframes = ring->req3.tp_frame_nr;

bug_on(ring->type != PACKET_TX_RING);
bug_on(ring->rd_num < NUM_PACKETS);
bug_on(nframes < NUM_PACKETS);

rcv_sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (rcv_sock == -1) {
Expand All @@ -388,10 +429,11 @@ static void walk_v1_v2_tx(int sock, struct ring *ring)
create_payload(packet, &packet_len);

while (total_packets > 0) {
while (__v1_v2_tx_kernel_ready(ring->rd[frame_num].iov_base,
ring->version) &&
void *next = get_next_frame(ring, frame_num);

while (__tx_kernel_ready(next, ring->version) &&
total_packets > 0) {
ppd.raw = ring->rd[frame_num].iov_base;
ppd.raw = next;

switch (ring->version) {
case TPACKET_V1:
Expand All @@ -413,14 +455,27 @@ static void walk_v1_v2_tx(int sock, struct ring *ring)
packet_len);
total_bytes += ppd.v2->tp_h.tp_snaplen;
break;
case TPACKET_V3: {
struct tpacket3_hdr *tx = next;

tx->tp_snaplen = packet_len;
tx->tp_len = packet_len;
tx->tp_next_offset = 0;

memcpy((uint8_t *)tx + TPACKET3_HDRLEN -
sizeof(struct sockaddr_ll), packet,
packet_len);
total_bytes += tx->tp_snaplen;
break;
}
}

status_bar_update();
total_packets--;

__v1_v2_tx_user_ready(ppd.raw, ring->version);
__tx_user_ready(next, ring->version);

frame_num = (frame_num + 1) % ring->rd_num;
frame_num = (frame_num + 1) % nframes;
}

poll(&pfd, 1, 1);
Expand Down Expand Up @@ -460,7 +515,7 @@ static void walk_v1_v2(int sock, struct ring *ring)
if (ring->type == PACKET_RX_RING)
walk_v1_v2_rx(sock, ring);
else
walk_v1_v2_tx(sock, ring);
walk_tx(sock, ring);
}

static uint64_t __v3_prev_block_seq_num = 0;
Expand Down Expand Up @@ -583,7 +638,7 @@ static void walk_v3(int sock, struct ring *ring)
if (ring->type == PACKET_RX_RING)
walk_v3_rx(sock, ring);
else
bug_on(1);
walk_tx(sock, ring);
}

static void __v1_v2_fill(struct ring *ring, unsigned int blocks)
Expand All @@ -602,12 +657,13 @@ static void __v1_v2_fill(struct ring *ring, unsigned int blocks)
ring->flen = ring->req.tp_frame_size;
}

static void __v3_fill(struct ring *ring, unsigned int blocks)
static void __v3_fill(struct ring *ring, unsigned int blocks, int type)
{
ring->req3.tp_retire_blk_tov = 64;
ring->req3.tp_sizeof_priv = 0;
ring->req3.tp_feature_req_word = TP_FT_REQ_FILL_RXHASH;

if (type == PACKET_RX_RING) {
ring->req3.tp_retire_blk_tov = 64;
ring->req3.tp_sizeof_priv = 0;
ring->req3.tp_feature_req_word = TP_FT_REQ_FILL_RXHASH;
}
ring->req3.tp_block_size = getpagesize() << 2;
ring->req3.tp_frame_size = TPACKET_ALIGNMENT << 7;
ring->req3.tp_block_nr = blocks;
Expand Down Expand Up @@ -641,7 +697,7 @@ static void setup_ring(int sock, struct ring *ring, int version, int type)
break;

case TPACKET_V3:
__v3_fill(ring, blocks);
__v3_fill(ring, blocks, type);
ret = setsockopt(sock, SOL_PACKET, type, &ring->req3,
sizeof(ring->req3));
break;
Expand Down Expand Up @@ -796,6 +852,7 @@ int main(void)
ret |= test_tpacket(TPACKET_V2, PACKET_TX_RING);

ret |= test_tpacket(TPACKET_V3, PACKET_RX_RING);
ret |= test_tpacket(TPACKET_V3, PACKET_TX_RING);

if (ret)
return 1;
Expand Down

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