From: Jason Wang <jasowang@redhat.com>
To: qemu-devel@nongnu.org, peter.maydell@linaro.org
Cc: Akihiko Odaki <akihiko.odaki@daynix.com>,
Jason Wang <jasowang@redhat.com>
Subject: [PULL 03/50] hw/net/net_tx_pkt: Decouple interface from PCI
Date: Tue, 23 May 2023 15:31:51 +0800 [thread overview]
Message-ID: <20230523073238.54236-4-jasowang@redhat.com> (raw)
In-Reply-To: <20230523073238.54236-1-jasowang@redhat.com>
From: Akihiko Odaki <akihiko.odaki@daynix.com>
This allows to use the network packet abstractions even if PCI is not
used.
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
hw/net/e1000e_core.c | 13 ++++++++-----
hw/net/igb_core.c | 13 ++++++-------
hw/net/net_tx_pkt.c | 36 +++++++++++++-----------------------
hw/net/net_tx_pkt.h | 31 ++++++++++++++++++++-----------
hw/net/vmxnet3.c | 14 +++++++-------
5 files changed, 54 insertions(+), 53 deletions(-)
diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c
index cfa3f55..15821a7 100644
--- a/hw/net/e1000e_core.c
+++ b/hw/net/e1000e_core.c
@@ -746,7 +746,8 @@ e1000e_process_tx_desc(E1000ECore *core,
addr = le64_to_cpu(dp->buffer_addr);
if (!tx->skip_cp) {
- if (!net_tx_pkt_add_raw_fragment(tx->tx_pkt, addr, split_size)) {
+ if (!net_tx_pkt_add_raw_fragment_pci(tx->tx_pkt, core->owner,
+ addr, split_size)) {
tx->skip_cp = true;
}
}
@@ -764,7 +765,7 @@ e1000e_process_tx_desc(E1000ECore *core,
}
tx->skip_cp = false;
- net_tx_pkt_reset(tx->tx_pkt, core->owner);
+ net_tx_pkt_reset(tx->tx_pkt, net_tx_pkt_unmap_frag_pci, core->owner);
tx->sum_needed = 0;
tx->cptse = 0;
@@ -3421,7 +3422,7 @@ e1000e_core_pci_realize(E1000ECore *core,
qemu_add_vm_change_state_handler(e1000e_vm_state_change, core);
for (i = 0; i < E1000E_NUM_QUEUES; i++) {
- net_tx_pkt_init(&core->tx[i].tx_pkt, core->owner, E1000E_MAX_TX_FRAGS);
+ net_tx_pkt_init(&core->tx[i].tx_pkt, E1000E_MAX_TX_FRAGS);
}
net_rx_pkt_init(&core->rx_pkt);
@@ -3446,7 +3447,8 @@ e1000e_core_pci_uninit(E1000ECore *core)
qemu_del_vm_change_state_handler(core->vmstate);
for (i = 0; i < E1000E_NUM_QUEUES; i++) {
- net_tx_pkt_reset(core->tx[i].tx_pkt, core->owner);
+ net_tx_pkt_reset(core->tx[i].tx_pkt,
+ net_tx_pkt_unmap_frag_pci, core->owner);
net_tx_pkt_uninit(core->tx[i].tx_pkt);
}
@@ -3571,7 +3573,8 @@ static void e1000e_reset(E1000ECore *core, bool sw)
e1000x_reset_mac_addr(core->owner_nic, core->mac, core->permanent_mac);
for (i = 0; i < ARRAY_SIZE(core->tx); i++) {
- net_tx_pkt_reset(core->tx[i].tx_pkt, core->owner);
+ net_tx_pkt_reset(core->tx[i].tx_pkt,
+ net_tx_pkt_unmap_frag_pci, core->owner);
memset(&core->tx[i].props, 0, sizeof(core->tx[i].props));
core->tx[i].skip_cp = false;
}
diff --git a/hw/net/igb_core.c b/hw/net/igb_core.c
index 826e7a6..abfdce9 100644
--- a/hw/net/igb_core.c
+++ b/hw/net/igb_core.c
@@ -597,7 +597,8 @@ igb_process_tx_desc(IGBCore *core,
length = cmd_type_len & 0xFFFF;
if (!tx->skip_cp) {
- if (!net_tx_pkt_add_raw_fragment(tx->tx_pkt, buffer_addr, length)) {
+ if (!net_tx_pkt_add_raw_fragment_pci(tx->tx_pkt, dev,
+ buffer_addr, length)) {
tx->skip_cp = true;
}
}
@@ -616,7 +617,7 @@ igb_process_tx_desc(IGBCore *core,
tx->first = true;
tx->skip_cp = false;
- net_tx_pkt_reset(tx->tx_pkt, dev);
+ net_tx_pkt_reset(tx->tx_pkt, net_tx_pkt_unmap_frag_pci, dev);
}
}
@@ -842,8 +843,6 @@ igb_start_xmit(IGBCore *core, const IGB_TxRing *txr)
d = core->owner;
}
- net_tx_pkt_reset(txr->tx->tx_pkt, d);
-
while (!igb_ring_empty(core, txi)) {
base = igb_ring_head_descr(core, txi);
@@ -861,6 +860,8 @@ igb_start_xmit(IGBCore *core, const IGB_TxRing *txr)
core->mac[EICR] |= eic;
igb_set_interrupt_cause(core, E1000_ICR_TXDW);
}
+
+ net_tx_pkt_reset(txr->tx->tx_pkt, net_tx_pkt_unmap_frag_pci, d);
}
static uint32_t
@@ -3954,7 +3955,7 @@ igb_core_pci_realize(IGBCore *core,
core->vmstate = qemu_add_vm_change_state_handler(igb_vm_state_change, core);
for (i = 0; i < IGB_NUM_QUEUES; i++) {
- net_tx_pkt_init(&core->tx[i].tx_pkt, NULL, E1000E_MAX_TX_FRAGS);
+ net_tx_pkt_init(&core->tx[i].tx_pkt, E1000E_MAX_TX_FRAGS);
}
net_rx_pkt_init(&core->rx_pkt);
@@ -3979,7 +3980,6 @@ igb_core_pci_uninit(IGBCore *core)
qemu_del_vm_change_state_handler(core->vmstate);
for (i = 0; i < IGB_NUM_QUEUES; i++) {
- net_tx_pkt_reset(core->tx[i].tx_pkt, NULL);
net_tx_pkt_uninit(core->tx[i].tx_pkt);
}
@@ -4158,7 +4158,6 @@ static void igb_reset(IGBCore *core, bool sw)
for (i = 0; i < ARRAY_SIZE(core->tx); i++) {
tx = &core->tx[i];
- net_tx_pkt_reset(tx->tx_pkt, NULL);
memset(tx->ctx, 0, sizeof(tx->ctx));
tx->first = true;
tx->skip_cp = false;
diff --git a/hw/net/net_tx_pkt.c b/hw/net/net_tx_pkt.c
index aca12ff..cc36750 100644
--- a/hw/net/net_tx_pkt.c
+++ b/hw/net/net_tx_pkt.c
@@ -16,12 +16,12 @@
*/
#include "qemu/osdep.h"
-#include "net_tx_pkt.h"
#include "net/eth.h"
#include "net/checksum.h"
#include "net/tap.h"
#include "net/net.h"
#include "hw/pci/pci_device.h"
+#include "net_tx_pkt.h"
enum {
NET_TX_PKT_VHDR_FRAG = 0,
@@ -32,8 +32,6 @@ enum {
/* TX packet private context */
struct NetTxPkt {
- PCIDevice *pci_dev;
-
struct virtio_net_hdr virt_hdr;
struct iovec *raw;
@@ -59,13 +57,10 @@ struct NetTxPkt {
uint8_t l4proto;
};
-void net_tx_pkt_init(struct NetTxPkt **pkt, PCIDevice *pci_dev,
- uint32_t max_frags)
+void net_tx_pkt_init(struct NetTxPkt **pkt, uint32_t max_frags)
{
struct NetTxPkt *p = g_malloc0(sizeof *p);
- p->pci_dev = pci_dev;
-
p->vec = g_new(struct iovec, max_frags + NET_TX_PKT_PL_START_FRAG);
p->raw = g_new(struct iovec, max_frags);
@@ -384,8 +379,7 @@ void net_tx_pkt_setup_vlan_header_ex(struct NetTxPkt *pkt,
}
}
-static bool net_tx_pkt_add_raw_fragment_common(struct NetTxPkt *pkt,
- void *base, size_t len)
+bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, void *base, size_t len)
{
struct iovec *ventry;
assert(pkt);
@@ -433,7 +427,8 @@ void net_tx_pkt_dump(struct NetTxPkt *pkt)
#endif
}
-void net_tx_pkt_reset(struct NetTxPkt *pkt, PCIDevice *pci_dev)
+void net_tx_pkt_reset(struct NetTxPkt *pkt,
+ NetTxPktFreeFrag callback, void *context)
{
int i;
@@ -453,12 +448,9 @@ void net_tx_pkt_reset(struct NetTxPkt *pkt, PCIDevice *pci_dev)
assert(pkt->raw);
for (i = 0; i < pkt->raw_frags; i++) {
assert(pkt->raw[i].iov_base);
- net_tx_pkt_unmap_frag_pci(pkt->pci_dev,
- pkt->raw[i].iov_base,
- pkt->raw[i].iov_len);
+ callback(context, pkt->raw[i].iov_base, pkt->raw[i].iov_len);
}
}
- pkt->pci_dev = pci_dev;
pkt->raw_frags = 0;
pkt->hdr_len = 0;
@@ -470,19 +462,17 @@ void net_tx_pkt_unmap_frag_pci(void *context, void *base, size_t len)
pci_dma_unmap(context, base, len, DMA_DIRECTION_TO_DEVICE, 0);
}
-bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa,
- size_t len)
+bool net_tx_pkt_add_raw_fragment_pci(struct NetTxPkt *pkt, PCIDevice *pci_dev,
+ dma_addr_t pa, size_t len)
{
dma_addr_t mapped_len = len;
- void *base = pci_dma_map(pkt->pci_dev, pa, &mapped_len,
- DMA_DIRECTION_TO_DEVICE);
+ void *base = pci_dma_map(pci_dev, pa, &mapped_len, DMA_DIRECTION_TO_DEVICE);
if (!base) {
return false;
}
- if (mapped_len != len ||
- !net_tx_pkt_add_raw_fragment_common(pkt, base, len)) {
- net_tx_pkt_unmap_frag_pci(pkt->pci_dev, base, mapped_len);
+ if (mapped_len != len || !net_tx_pkt_add_raw_fragment(pkt, base, len)) {
+ net_tx_pkt_unmap_frag_pci(pci_dev, base, mapped_len);
return false;
}
@@ -710,7 +700,7 @@ static void net_tx_pkt_udp_fragment_fix(struct NetTxPkt *pkt,
}
static bool net_tx_pkt_do_sw_fragmentation(struct NetTxPkt *pkt,
- NetTxPktCallback callback,
+ NetTxPktSend callback,
void *context)
{
uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN;
@@ -807,7 +797,7 @@ bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc)
}
bool net_tx_pkt_send_custom(struct NetTxPkt *pkt, bool offload,
- NetTxPktCallback callback, void *context)
+ NetTxPktSend callback, void *context)
{
assert(pkt);
diff --git a/hw/net/net_tx_pkt.h b/hw/net/net_tx_pkt.h
index 5eb123e..4d7233e 100644
--- a/hw/net/net_tx_pkt.h
+++ b/hw/net/net_tx_pkt.h
@@ -26,17 +26,16 @@
struct NetTxPkt;
-typedef void (* NetTxPktCallback)(void *, const struct iovec *, int, const struct iovec *, int);
+typedef void (*NetTxPktFreeFrag)(void *, void *, size_t);
+typedef void (*NetTxPktSend)(void *, const struct iovec *, int, const struct iovec *, int);
/**
* Init function for tx packet functionality
*
* @pkt: packet pointer
- * @pci_dev: PCI device processing this packet
* @max_frags: max tx ip fragments
*/
-void net_tx_pkt_init(struct NetTxPkt **pkt, PCIDevice *pci_dev,
- uint32_t max_frags);
+void net_tx_pkt_init(struct NetTxPkt **pkt, uint32_t max_frags);
/**
* Clean all tx packet resources.
@@ -95,12 +94,11 @@ net_tx_pkt_setup_vlan_header(struct NetTxPkt *pkt, uint16_t vlan)
* populate data fragment into pkt context.
*
* @pkt: packet
- * @pa: physical address of fragment
+ * @base: pointer to fragment
* @len: length of fragment
*
*/
-bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa,
- size_t len);
+bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, void *base, size_t len);
/**
* Fix ip header fields and calculate IP header and pseudo header checksums.
@@ -148,10 +146,11 @@ void net_tx_pkt_dump(struct NetTxPkt *pkt);
* reset tx packet private context (needed to be called between packets)
*
* @pkt: packet
- * @dev: PCI device processing the next packet
- *
+ * @callback: function to free the fragments
+ * @context: pointer to be passed to the callback
*/
-void net_tx_pkt_reset(struct NetTxPkt *pkt, PCIDevice *dev);
+void net_tx_pkt_reset(struct NetTxPkt *pkt,
+ NetTxPktFreeFrag callback, void *context);
/**
* Unmap a fragment mapped from a PCI device.
@@ -163,6 +162,16 @@ void net_tx_pkt_reset(struct NetTxPkt *pkt, PCIDevice *dev);
void net_tx_pkt_unmap_frag_pci(void *context, void *base, size_t len);
/**
+ * map data fragment from PCI device and populate it into pkt context.
+ *
+ * @pci_dev: PCI device owning fragment
+ * @pa: physical address of fragment
+ * @len: length of fragment
+ */
+bool net_tx_pkt_add_raw_fragment_pci(struct NetTxPkt *pkt, PCIDevice *pci_dev,
+ dma_addr_t pa, size_t len);
+
+/**
* Send packet to qemu. handles sw offloads if vhdr is not supported.
*
* @pkt: packet
@@ -182,7 +191,7 @@ bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc);
* @ret: operation result
*/
bool net_tx_pkt_send_custom(struct NetTxPkt *pkt, bool offload,
- NetTxPktCallback callback, void *context);
+ NetTxPktSend callback, void *context);
/**
* parse raw packet data and analyze offload requirements.
diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
index f7b874c..9acff31 100644
--- a/hw/net/vmxnet3.c
+++ b/hw/net/vmxnet3.c
@@ -651,9 +651,8 @@ static void vmxnet3_process_tx_queue(VMXNET3State *s, int qidx)
data_len = (txd.len > 0) ? txd.len : VMXNET3_MAX_TX_BUF_SIZE;
data_pa = txd.addr;
- if (!net_tx_pkt_add_raw_fragment(s->tx_pkt,
- data_pa,
- data_len)) {
+ if (!net_tx_pkt_add_raw_fragment_pci(s->tx_pkt, PCI_DEVICE(s),
+ data_pa, data_len)) {
s->skip_current_tx_pkt = true;
}
}
@@ -678,7 +677,8 @@ static void vmxnet3_process_tx_queue(VMXNET3State *s, int qidx)
vmxnet3_complete_packet(s, qidx, txd_idx);
s->tx_sop = true;
s->skip_current_tx_pkt = false;
- net_tx_pkt_reset(s->tx_pkt, PCI_DEVICE(s));
+ net_tx_pkt_reset(s->tx_pkt,
+ net_tx_pkt_unmap_frag_pci, PCI_DEVICE(s));
}
}
}
@@ -1159,7 +1159,7 @@ static void vmxnet3_deactivate_device(VMXNET3State *s)
{
if (s->device_active) {
VMW_CBPRN("Deactivating vmxnet3...");
- net_tx_pkt_reset(s->tx_pkt, PCI_DEVICE(s));
+ net_tx_pkt_reset(s->tx_pkt, net_tx_pkt_unmap_frag_pci, PCI_DEVICE(s));
net_tx_pkt_uninit(s->tx_pkt);
net_rx_pkt_uninit(s->rx_pkt);
s->device_active = false;
@@ -1519,7 +1519,7 @@ static void vmxnet3_activate_device(VMXNET3State *s)
/* Preallocate TX packet wrapper */
VMW_CFPRN("Max TX fragments is %u", s->max_tx_frags);
- net_tx_pkt_init(&s->tx_pkt, PCI_DEVICE(s), s->max_tx_frags);
+ net_tx_pkt_init(&s->tx_pkt, s->max_tx_frags);
net_rx_pkt_init(&s->rx_pkt);
/* Read rings memory locations for RX queues */
@@ -2399,7 +2399,7 @@ static int vmxnet3_post_load(void *opaque, int version_id)
{
VMXNET3State *s = opaque;
- net_tx_pkt_init(&s->tx_pkt, PCI_DEVICE(s), s->max_tx_frags);
+ net_tx_pkt_init(&s->tx_pkt, s->max_tx_frags);
net_rx_pkt_init(&s->rx_pkt);
if (s->msix_used) {
--
2.7.4
next prev parent reply other threads:[~2023-05-23 7:36 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-23 7:31 [PULL 00/50] Net patches Jason Wang
2023-05-23 7:31 ` [PULL 01/50] e1000e: Fix tx/rx counters Jason Wang
2023-05-23 7:31 ` [PULL 02/50] hw/net/net_tx_pkt: Decouple implementation from PCI Jason Wang
2023-05-23 7:31 ` Jason Wang [this message]
2023-05-23 7:31 ` [PULL 04/50] e1000x: Fix BPRC and MPRC Jason Wang
2023-05-23 7:31 ` [PULL 05/50] igb: Fix Rx packet type encoding Jason Wang
2023-05-23 7:31 ` [PULL 06/50] igb: Do not require CTRL.VME for tx VLAN tagging Jason Wang
2023-05-23 7:31 ` [PULL 07/50] igb: Clear IMS bits when committing ICR access Jason Wang
2023-05-23 7:31 ` [PULL 08/50] net/net_rx_pkt: Use iovec for net_rx_pkt_set_protocols() Jason Wang
2023-05-23 7:31 ` [PULL 09/50] e1000e: Always copy ethernet header Jason Wang
2023-05-23 7:31 ` [PULL 10/50] igb: " Jason Wang
2023-05-23 7:31 ` [PULL 11/50] Fix references to igb Avocado test Jason Wang
2023-05-23 7:32 ` [PULL 12/50] tests/avocado: Remove unused imports Jason Wang
2023-05-23 7:32 ` [PULL 13/50] tests/avocado: Remove test_igb_nomsi_kvm Jason Wang
2023-05-23 7:32 ` [PULL 14/50] hw/net/net_tx_pkt: Remove net_rx_pkt_get_l4_info Jason Wang
2023-05-23 7:32 ` [PULL 15/50] net/eth: Rename eth_setup_vlan_headers_ex Jason Wang
2023-05-23 7:32 ` [PULL 16/50] e1000x: Share more Rx filtering logic Jason Wang
2023-05-23 7:32 ` [PULL 17/50] e1000x: Take CRC into consideration for size check Jason Wang
2023-05-23 7:32 ` [PULL 18/50] e1000x: Rename TcpIpv6 into TcpIpv6Ex Jason Wang
2023-05-23 7:32 ` [PULL 19/50] e1000e: Always log status after building rx metadata Jason Wang
2023-05-23 7:32 ` [PULL 20/50] igb: " Jason Wang
2023-05-23 7:32 ` [PULL 21/50] igb: Remove goto Jason Wang
2023-05-23 7:32 ` [PULL 22/50] igb: Read DCMD.VLE of the first Tx descriptor Jason Wang
2023-05-23 7:32 ` [PULL 23/50] e1000e: Reset packet state after emptying Tx queue Jason Wang
2023-05-23 7:32 ` [PULL 24/50] vmxnet3: " Jason Wang
2023-05-23 7:32 ` [PULL 25/50] igb: Add more definitions for Tx descriptor Jason Wang
2023-05-23 7:32 ` [PULL 26/50] igb: Share common VF constants Jason Wang
2023-05-23 7:32 ` [PULL 27/50] igb: Fix igb_mac_reg_init coding style alignment Jason Wang
2023-05-23 7:32 ` [PULL 28/50] igb: Clear EICR bits for delayed MSI-X interrupts Jason Wang
2023-05-23 7:32 ` [PULL 29/50] e1000e: Rename a variable in e1000e_receive_internal() Jason Wang
2023-05-23 7:32 ` [PULL 30/50] igb: Rename a variable in igb_receive_internal() Jason Wang
2023-05-23 7:32 ` [PULL 31/50] net/eth: Use void pointers Jason Wang
2023-05-23 7:32 ` [PULL 32/50] net/eth: Always add VLAN tag Jason Wang
2023-05-23 7:32 ` [PULL 33/50] hw/net/net_rx_pkt: Enforce alignment for eth_header Jason Wang
2023-05-23 7:32 ` [PULL 34/50] tests/qtest/libqos/igb: Set GPIE.Multiple_MSIX Jason Wang
2023-05-23 7:32 ` [PULL 35/50] igb: Implement MSI-X single vector mode Jason Wang
2023-05-23 7:32 ` [PULL 36/50] igb: Use UDP for RSS hash Jason Wang
2023-05-23 7:32 ` [PULL 37/50] igb: Implement Rx SCTP CSO Jason Wang
2023-05-23 7:32 ` [PULL 38/50] igb: Implement Tx " Jason Wang
2023-05-23 7:32 ` [PULL 39/50] igb: Strip the second VLAN tag for extended VLAN Jason Wang
2023-05-23 7:32 ` [PULL 40/50] igb: Filter with " Jason Wang
2023-05-23 7:32 ` [PULL 41/50] igb: Implement igb-specific oversize check Jason Wang
2023-05-23 7:32 ` [PULL 42/50] igb: Implement Rx PTP2 timestamp Jason Wang
2023-05-23 7:32 ` [PULL 43/50] igb: Implement Tx timestamp Jason Wang
2023-05-23 7:32 ` [PULL 44/50] e1000e: Notify only new interrupts Jason Wang
2023-05-23 7:32 ` [PULL 45/50] igb: " Jason Wang
2023-05-23 7:32 ` [PULL 46/50] igb: Clear-on-read ICR when ICR.INTA is set Jason Wang
2023-05-23 7:32 ` [PULL 47/50] vmxnet3: Do not depend on PC Jason Wang
2023-05-23 7:32 ` [PULL 48/50] MAINTAINERS: Add a reviewer for network packet abstractions Jason Wang
2023-05-23 7:32 ` [PULL 49/50] docs/system/devices/igb: Note igb is tested for DPDK Jason Wang
2023-05-23 7:32 ` [PULL 50/50] rtl8139: fix large_send_mss divide-by-zero Jason Wang
2023-05-23 17:56 ` [PULL 00/50] Net patches Richard Henderson
2023-05-23 19:53 ` Michael Tokarev
2023-05-24 4:06 ` Jason Wang
2023-05-24 4:21 ` Akihiko Odaki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230523073238.54236-4-jasowang@redhat.com \
--to=jasowang@redhat.com \
--cc=akihiko.odaki@daynix.com \
--cc=peter.maydell@linaro.org \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).