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qemu/hw/net/net_tx_pkt.c
Akihiko Odaki 4b52d63249 tap: Remove qemu_using_vnet_hdr() 
Since qemu_set_vnet_hdr_len() is always called when
qemu_using_vnet_hdr() is called, we can merge them and save some code.

For consistency, express that the virtio-net header is not in use by
returning 0 with qemu_get_vnet_hdr_len() instead of having a dedicated
function, qemu_get_using_vnet_hdr().

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-06-04 15:14:25 +08:00

877 lines
26 KiB
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/*
* QEMU TX packets abstractions
*
* Copyright (c) 2012 Ravello Systems LTD (http://ravellosystems.com)
*
* Developed by Daynix Computing LTD (http://www.daynix.com)
*
* Authors:
* Dmitry Fleytman <dmitry@daynix.com>
* Tamir Shomer <tamirs@daynix.com>
* Yan Vugenfirer <yan@daynix.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qemu/crc32c.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,
NET_TX_PKT_L2HDR_FRAG,
NET_TX_PKT_L3HDR_FRAG,
NET_TX_PKT_PL_START_FRAG
};
/* TX packet private context */
struct NetTxPkt {
struct virtio_net_hdr virt_hdr;
struct iovec *raw;
uint32_t raw_frags;
uint32_t max_raw_frags;
struct iovec *vec;
struct {
struct eth_header eth;
struct vlan_header vlan[3];
} l2_hdr;
union {
struct ip_header ip;
struct ip6_header ip6;
uint8_t octets[ETH_MAX_IP_DGRAM_LEN];
} l3_hdr;
uint32_t payload_len;
uint32_t payload_frags;
uint32_t max_payload_frags;
uint16_t hdr_len;
eth_pkt_types_e packet_type;
uint8_t l4proto;
};
void net_tx_pkt_init(struct NetTxPkt **pkt, uint32_t max_frags)
{
struct NetTxPkt *p = g_malloc0(sizeof *p);
p->vec = g_new(struct iovec, max_frags + NET_TX_PKT_PL_START_FRAG);
p->raw = g_new(struct iovec, max_frags);
p->max_payload_frags = max_frags;
p->max_raw_frags = max_frags;
p->vec[NET_TX_PKT_VHDR_FRAG].iov_base = &p->virt_hdr;
p->vec[NET_TX_PKT_VHDR_FRAG].iov_len = sizeof p->virt_hdr;
p->vec[NET_TX_PKT_L2HDR_FRAG].iov_base = &p->l2_hdr;
p->vec[NET_TX_PKT_L3HDR_FRAG].iov_base = &p->l3_hdr;
*pkt = p;
}
void net_tx_pkt_uninit(struct NetTxPkt *pkt)
{
if (pkt) {
g_free(pkt->vec);
g_free(pkt->raw);
g_free(pkt);
}
}
void net_tx_pkt_update_ip_hdr_checksum(struct NetTxPkt *pkt)
{
uint16_t csum;
assert(pkt);
pkt->l3_hdr.ip.ip_len = cpu_to_be16(pkt->payload_len +
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len);
pkt->l3_hdr.ip.ip_sum = 0;
csum = net_raw_checksum(pkt->l3_hdr.octets,
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len);
pkt->l3_hdr.ip.ip_sum = cpu_to_be16(csum);
}
void net_tx_pkt_update_ip_checksums(struct NetTxPkt *pkt)
{
uint16_t csum;
uint32_t cntr, cso;
assert(pkt);
uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN;
void *ip_hdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base;
if (pkt->payload_len + pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len >
ETH_MAX_IP_DGRAM_LEN) {
return;
}
if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4 ||
gso_type == VIRTIO_NET_HDR_GSO_UDP) {
/* Calculate IP header checksum */
net_tx_pkt_update_ip_hdr_checksum(pkt);
/* Calculate IP pseudo header checksum */
cntr = eth_calc_ip4_pseudo_hdr_csum(ip_hdr, pkt->payload_len, &cso);
csum = cpu_to_be16(~net_checksum_finish(cntr));
} else if (gso_type == VIRTIO_NET_HDR_GSO_TCPV6) {
/* Calculate IP pseudo header checksum */
cntr = eth_calc_ip6_pseudo_hdr_csum(ip_hdr, pkt->payload_len,
IP_PROTO_TCP, &cso);
csum = cpu_to_be16(~net_checksum_finish(cntr));
} else {
return;
}
iov_from_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG], pkt->payload_frags,
pkt->virt_hdr.csum_offset, &csum, sizeof(csum));
}
bool net_tx_pkt_update_sctp_checksum(struct NetTxPkt *pkt)
{
uint32_t csum = 0;
struct iovec *pl_start_frag = pkt->vec + NET_TX_PKT_PL_START_FRAG;
if (iov_size(pl_start_frag, pkt->payload_frags) < 8 + sizeof(csum)) {
return false;
}
if (iov_from_buf(pl_start_frag, pkt->payload_frags, 8, &csum, sizeof(csum)) < sizeof(csum)) {
return false;
}
csum = cpu_to_le32(iov_crc32c(0xffffffff, pl_start_frag, pkt->payload_frags));
if (iov_from_buf(pl_start_frag, pkt->payload_frags, 8, &csum, sizeof(csum)) < sizeof(csum)) {
return false;
}
return true;
}
static void net_tx_pkt_calculate_hdr_len(struct NetTxPkt *pkt)
{
pkt->hdr_len = pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len +
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len;
}
static bool net_tx_pkt_parse_headers(struct NetTxPkt *pkt)
{
struct iovec *l2_hdr, *l3_hdr;
size_t bytes_read;
size_t full_ip6hdr_len;
uint16_t l3_proto;
assert(pkt);
l2_hdr = &pkt->vec[NET_TX_PKT_L2HDR_FRAG];
l3_hdr = &pkt->vec[NET_TX_PKT_L3HDR_FRAG];
bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, 0, l2_hdr->iov_base,
ETH_MAX_L2_HDR_LEN);
if (bytes_read < sizeof(struct eth_header)) {
l2_hdr->iov_len = 0;
return false;
}
l2_hdr->iov_len = sizeof(struct eth_header);
switch (be16_to_cpu(PKT_GET_ETH_HDR(l2_hdr->iov_base)->h_proto)) {
case ETH_P_VLAN:
l2_hdr->iov_len += sizeof(struct vlan_header);
break;
case ETH_P_DVLAN:
l2_hdr->iov_len += 2 * sizeof(struct vlan_header);
break;
}
if (bytes_read < l2_hdr->iov_len) {
l2_hdr->iov_len = 0;
l3_hdr->iov_len = 0;
pkt->packet_type = ETH_PKT_UCAST;
return false;
} else {
l2_hdr->iov_len = ETH_MAX_L2_HDR_LEN;
l2_hdr->iov_len = eth_get_l2_hdr_length(l2_hdr->iov_base);
pkt->packet_type = get_eth_packet_type(l2_hdr->iov_base);
}
l3_proto = eth_get_l3_proto(l2_hdr, 1, l2_hdr->iov_len);
switch (l3_proto) {
case ETH_P_IP:
bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, l2_hdr->iov_len,
l3_hdr->iov_base, sizeof(struct ip_header));
if (bytes_read < sizeof(struct ip_header)) {
l3_hdr->iov_len = 0;
return false;
}
l3_hdr->iov_len = IP_HDR_GET_LEN(l3_hdr->iov_base);
if (l3_hdr->iov_len < sizeof(struct ip_header)) {
l3_hdr->iov_len = 0;
return false;
}
pkt->l4proto = IP_HDR_GET_P(l3_hdr->iov_base);
if (IP_HDR_GET_LEN(l3_hdr->iov_base) != sizeof(struct ip_header)) {
/* copy optional IPv4 header data if any*/
bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags,
l2_hdr->iov_len + sizeof(struct ip_header),
l3_hdr->iov_base + sizeof(struct ip_header),
l3_hdr->iov_len - sizeof(struct ip_header));
if (bytes_read < l3_hdr->iov_len - sizeof(struct ip_header)) {
l3_hdr->iov_len = 0;
return false;
}
}
break;
case ETH_P_IPV6:
{
eth_ip6_hdr_info hdrinfo;
if (!eth_parse_ipv6_hdr(pkt->raw, pkt->raw_frags, l2_hdr->iov_len,
&hdrinfo)) {
l3_hdr->iov_len = 0;
return false;
}
pkt->l4proto = hdrinfo.l4proto;
full_ip6hdr_len = hdrinfo.full_hdr_len;
if (full_ip6hdr_len > ETH_MAX_IP_DGRAM_LEN) {
l3_hdr->iov_len = 0;
return false;
}
bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, l2_hdr->iov_len,
l3_hdr->iov_base, full_ip6hdr_len);
if (bytes_read < full_ip6hdr_len) {
l3_hdr->iov_len = 0;
return false;
} else {
l3_hdr->iov_len = full_ip6hdr_len;
}
break;
}
default:
l3_hdr->iov_len = 0;
break;
}
net_tx_pkt_calculate_hdr_len(pkt);
return true;
}
static void net_tx_pkt_rebuild_payload(struct NetTxPkt *pkt)
{
pkt->payload_len = iov_size(pkt->raw, pkt->raw_frags) - pkt->hdr_len;
pkt->payload_frags = iov_copy(&pkt->vec[NET_TX_PKT_PL_START_FRAG],
pkt->max_payload_frags,
pkt->raw, pkt->raw_frags,
pkt->hdr_len, pkt->payload_len);
}
bool net_tx_pkt_parse(struct NetTxPkt *pkt)
{
if (net_tx_pkt_parse_headers(pkt)) {
net_tx_pkt_rebuild_payload(pkt);
return true;
} else {
return false;
}
}
struct virtio_net_hdr *net_tx_pkt_get_vhdr(struct NetTxPkt *pkt)
{
assert(pkt);
return &pkt->virt_hdr;
}
static uint8_t net_tx_pkt_get_gso_type(struct NetTxPkt *pkt,
bool tso_enable)
{
uint8_t rc = VIRTIO_NET_HDR_GSO_NONE;
uint16_t l3_proto;
l3_proto = eth_get_l3_proto(&pkt->vec[NET_TX_PKT_L2HDR_FRAG], 1,
pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len);
if (!tso_enable) {
goto func_exit;
}
rc = eth_get_gso_type(l3_proto, pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base,
pkt->l4proto);
func_exit:
return rc;
}
bool net_tx_pkt_build_vheader(struct NetTxPkt *pkt, bool tso_enable,
bool csum_enable, uint32_t gso_size)
{
struct tcp_hdr l4hdr;
size_t bytes_read;
assert(pkt);
/* csum has to be enabled if tso is. */
assert(csum_enable || !tso_enable);
pkt->virt_hdr.gso_type = net_tx_pkt_get_gso_type(pkt, tso_enable);
switch (pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_NONE:
pkt->virt_hdr.hdr_len = 0;
pkt->virt_hdr.gso_size = 0;
break;
case VIRTIO_NET_HDR_GSO_UDP:
pkt->virt_hdr.gso_size = gso_size;
pkt->virt_hdr.hdr_len = pkt->hdr_len + sizeof(struct udp_header);
break;
case VIRTIO_NET_HDR_GSO_TCPV4:
case VIRTIO_NET_HDR_GSO_TCPV6:
bytes_read = iov_to_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG],
pkt->payload_frags, 0, &l4hdr, sizeof(l4hdr));
if (bytes_read < sizeof(l4hdr) ||
l4hdr.th_off * sizeof(uint32_t) < sizeof(l4hdr)) {
return false;
}
pkt->virt_hdr.hdr_len = pkt->hdr_len + l4hdr.th_off * sizeof(uint32_t);
pkt->virt_hdr.gso_size = gso_size;
break;
default:
g_assert_not_reached();
}
if (csum_enable) {
switch (pkt->l4proto) {
case IP_PROTO_TCP:
if (pkt->payload_len < sizeof(struct tcp_hdr)) {
return false;
}
pkt->virt_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
pkt->virt_hdr.csum_start = pkt->hdr_len;
pkt->virt_hdr.csum_offset = offsetof(struct tcp_hdr, th_sum);
break;
case IP_PROTO_UDP:
if (pkt->payload_len < sizeof(struct udp_hdr)) {
return false;
}
pkt->virt_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
pkt->virt_hdr.csum_start = pkt->hdr_len;
pkt->virt_hdr.csum_offset = offsetof(struct udp_hdr, uh_sum);
break;
default:
break;
}
}
return true;
}
void net_tx_pkt_setup_vlan_header_ex(struct NetTxPkt *pkt,
uint16_t vlan, uint16_t vlan_ethtype)
{
assert(pkt);
eth_setup_vlan_headers(pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base,
&pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len,
vlan, vlan_ethtype);
pkt->hdr_len += sizeof(struct vlan_header);
}
bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, void *base, size_t len)
{
struct iovec *ventry;
assert(pkt);
if (pkt->raw_frags >= pkt->max_raw_frags) {
return false;
}
ventry = &pkt->raw[pkt->raw_frags];
ventry->iov_base = base;
ventry->iov_len = len;
pkt->raw_frags++;
return true;
}
bool net_tx_pkt_has_fragments(struct NetTxPkt *pkt)
{
return pkt->raw_frags > 0;
}
eth_pkt_types_e net_tx_pkt_get_packet_type(struct NetTxPkt *pkt)
{
assert(pkt);
return pkt->packet_type;
}
size_t net_tx_pkt_get_total_len(struct NetTxPkt *pkt)
{
assert(pkt);
return pkt->hdr_len + pkt->payload_len;
}
void net_tx_pkt_dump(struct NetTxPkt *pkt)
{
#ifdef NET_TX_PKT_DEBUG
assert(pkt);
printf("TX PKT: hdr_len: %d, pkt_type: 0x%X, l2hdr_len: %lu, "
"l3hdr_len: %lu, payload_len: %u\n", pkt->hdr_len, pkt->packet_type,
pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len,
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len, pkt->payload_len);
#endif
}
void net_tx_pkt_reset(struct NetTxPkt *pkt,
NetTxPktFreeFrag callback, void *context)
{
int i;
/* no assert, as reset can be called before tx_pkt_init */
if (!pkt) {
return;
}
memset(&pkt->virt_hdr, 0, sizeof(pkt->virt_hdr));
assert(pkt->vec);
pkt->payload_len = 0;
pkt->payload_frags = 0;
if (pkt->max_raw_frags > 0) {
assert(pkt->raw);
for (i = 0; i < pkt->raw_frags; i++) {
assert(pkt->raw[i].iov_base);
callback(context, pkt->raw[i].iov_base, pkt->raw[i].iov_len);
}
}
pkt->raw_frags = 0;
pkt->hdr_len = 0;
pkt->l4proto = 0;
}
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_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(pci_dev, pa, &mapped_len, DMA_DIRECTION_TO_DEVICE);
if (!base) {
return false;
}
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;
}
return true;
}
static void net_tx_pkt_do_sw_csum(struct NetTxPkt *pkt,
struct iovec *iov, uint32_t iov_len,
uint16_t csl)
{
uint32_t csum_cntr;
uint16_t csum = 0;
uint32_t cso;
/* num of iovec without vhdr */
size_t csum_offset = pkt->virt_hdr.csum_start + pkt->virt_hdr.csum_offset;
uint16_t l3_proto = eth_get_l3_proto(iov, 1, iov->iov_len);
/* Put zero to checksum field */
iov_from_buf(iov, iov_len, csum_offset, &csum, sizeof csum);
/* Calculate L4 TCP/UDP checksum */
csum_cntr = 0;
cso = 0;
/* add pseudo header to csum */
if (l3_proto == ETH_P_IP) {
csum_cntr = eth_calc_ip4_pseudo_hdr_csum(
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base,
csl, &cso);
} else if (l3_proto == ETH_P_IPV6) {
csum_cntr = eth_calc_ip6_pseudo_hdr_csum(
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base,
csl, pkt->l4proto, &cso);
}
/* data checksum */
csum_cntr +=
net_checksum_add_iov(iov, iov_len, pkt->virt_hdr.csum_start, csl, cso);
/* Put the checksum obtained into the packet */
csum = cpu_to_be16(net_checksum_finish_nozero(csum_cntr));
iov_from_buf(iov, iov_len, csum_offset, &csum, sizeof csum);
}
#define NET_MAX_FRAG_SG_LIST (64)
static size_t net_tx_pkt_fetch_fragment(struct NetTxPkt *pkt,
int *src_idx, size_t *src_offset, size_t src_len,
struct iovec *dst, int *dst_idx)
{
size_t fetched = 0;
struct iovec *src = pkt->vec;
while (fetched < src_len) {
/* no more place in fragment iov */
if (*dst_idx == NET_MAX_FRAG_SG_LIST) {
break;
}
/* no more data in iovec */
if (*src_idx == (pkt->payload_frags + NET_TX_PKT_PL_START_FRAG)) {
break;
}
dst[*dst_idx].iov_base = src[*src_idx].iov_base + *src_offset;
dst[*dst_idx].iov_len = MIN(src[*src_idx].iov_len - *src_offset,
src_len - fetched);
*src_offset += dst[*dst_idx].iov_len;
fetched += dst[*dst_idx].iov_len;
if (*src_offset == src[*src_idx].iov_len) {
*src_offset = 0;
(*src_idx)++;
}
(*dst_idx)++;
}
return fetched;
}
static void net_tx_pkt_sendv(
void *opaque, const struct iovec *iov, int iov_cnt,
const struct iovec *virt_iov, int virt_iov_cnt)
{
NetClientState *nc = opaque;
if (qemu_get_vnet_hdr_len(nc->peer)) {
qemu_sendv_packet(nc, virt_iov, virt_iov_cnt);
} else {
qemu_sendv_packet(nc, iov, iov_cnt);
}
}
static bool net_tx_pkt_tcp_fragment_init(struct NetTxPkt *pkt,
struct iovec *fragment,
int *pl_idx,
size_t *l4hdr_len,
int *src_idx,
size_t *src_offset,
size_t *src_len)
{
struct iovec *l4 = fragment + NET_TX_PKT_PL_START_FRAG;
size_t bytes_read = 0;
struct tcp_hdr *th;
if (!pkt->payload_frags) {
return false;
}
l4->iov_len = pkt->virt_hdr.hdr_len - pkt->hdr_len;
l4->iov_base = g_malloc(l4->iov_len);
*src_idx = NET_TX_PKT_PL_START_FRAG;
while (pkt->vec[*src_idx].iov_len < l4->iov_len - bytes_read) {
memcpy((char *)l4->iov_base + bytes_read, pkt->vec[*src_idx].iov_base,
pkt->vec[*src_idx].iov_len);
bytes_read += pkt->vec[*src_idx].iov_len;
(*src_idx)++;
if (*src_idx >= pkt->payload_frags + NET_TX_PKT_PL_START_FRAG) {
g_free(l4->iov_base);
return false;
}
}
*src_offset = l4->iov_len - bytes_read;
memcpy((char *)l4->iov_base + bytes_read, pkt->vec[*src_idx].iov_base,
*src_offset);
th = l4->iov_base;
th->th_flags &= ~(TH_FIN | TH_PUSH);
*pl_idx = NET_TX_PKT_PL_START_FRAG + 1;
*l4hdr_len = l4->iov_len;
*src_len = pkt->virt_hdr.gso_size;
return true;
}
static void net_tx_pkt_tcp_fragment_deinit(struct iovec *fragment)
{
g_free(fragment[NET_TX_PKT_PL_START_FRAG].iov_base);
}
static void net_tx_pkt_tcp_fragment_fix(struct NetTxPkt *pkt,
struct iovec *fragment,
size_t fragment_len,
uint8_t gso_type)
{
struct iovec *l3hdr = fragment + NET_TX_PKT_L3HDR_FRAG;
struct iovec *l4hdr = fragment + NET_TX_PKT_PL_START_FRAG;
struct ip_header *ip = l3hdr->iov_base;
struct ip6_header *ip6 = l3hdr->iov_base;
size_t len = l3hdr->iov_len + l4hdr->iov_len + fragment_len;
switch (gso_type) {
case VIRTIO_NET_HDR_GSO_TCPV4:
ip->ip_len = cpu_to_be16(len);
eth_fix_ip4_checksum(l3hdr->iov_base, l3hdr->iov_len);
break;
case VIRTIO_NET_HDR_GSO_TCPV6:
len -= sizeof(struct ip6_header);
ip6->ip6_ctlun.ip6_un1.ip6_un1_plen = cpu_to_be16(len);
break;
}
}
static void net_tx_pkt_tcp_fragment_advance(struct NetTxPkt *pkt,
struct iovec *fragment,
size_t fragment_len,
uint8_t gso_type)
{
struct iovec *l3hdr = fragment + NET_TX_PKT_L3HDR_FRAG;
struct iovec *l4hdr = fragment + NET_TX_PKT_PL_START_FRAG;
struct ip_header *ip = l3hdr->iov_base;
struct tcp_hdr *th = l4hdr->iov_base;
if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4) {
ip->ip_id = cpu_to_be16(be16_to_cpu(ip->ip_id) + 1);
}
th->th_seq = cpu_to_be32(be32_to_cpu(th->th_seq) + fragment_len);
th->th_flags &= ~TH_CWR;
}
static void net_tx_pkt_udp_fragment_init(struct NetTxPkt *pkt,
int *pl_idx,
size_t *l4hdr_len,
int *src_idx, size_t *src_offset,
size_t *src_len)
{
*pl_idx = NET_TX_PKT_PL_START_FRAG;
*l4hdr_len = 0;
*src_idx = NET_TX_PKT_PL_START_FRAG;
*src_offset = 0;
*src_len = IP_FRAG_ALIGN_SIZE(pkt->virt_hdr.gso_size);
}
static void net_tx_pkt_udp_fragment_fix(struct NetTxPkt *pkt,
struct iovec *fragment,
size_t fragment_offset,
size_t fragment_len)
{
bool more_frags = fragment_offset + fragment_len < pkt->payload_len;
uint16_t orig_flags;
struct iovec *l3hdr = fragment + NET_TX_PKT_L3HDR_FRAG;
struct ip_header *ip = l3hdr->iov_base;
uint16_t frag_off_units = fragment_offset / IP_FRAG_UNIT_SIZE;
uint16_t new_ip_off;
assert(fragment_offset % IP_FRAG_UNIT_SIZE == 0);
assert((frag_off_units & ~IP_OFFMASK) == 0);
orig_flags = be16_to_cpu(ip->ip_off) & ~(IP_OFFMASK | IP_MF);
new_ip_off = frag_off_units | orig_flags | (more_frags ? IP_MF : 0);
ip->ip_off = cpu_to_be16(new_ip_off);
ip->ip_len = cpu_to_be16(l3hdr->iov_len + fragment_len);
eth_fix_ip4_checksum(l3hdr->iov_base, l3hdr->iov_len);
}
static bool net_tx_pkt_do_sw_fragmentation(struct NetTxPkt *pkt,
NetTxPktSend callback,
void *context)
{
uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN;
struct iovec fragment[NET_MAX_FRAG_SG_LIST];
size_t fragment_len;
size_t l4hdr_len;
size_t src_len;
int src_idx, dst_idx, pl_idx;
size_t src_offset;
size_t fragment_offset = 0;
struct virtio_net_hdr virt_hdr = {
.flags = pkt->virt_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM ?
VIRTIO_NET_HDR_F_DATA_VALID : 0
};
/* Copy headers */
fragment[NET_TX_PKT_VHDR_FRAG].iov_base = &virt_hdr;
fragment[NET_TX_PKT_VHDR_FRAG].iov_len = sizeof(virt_hdr);
fragment[NET_TX_PKT_L2HDR_FRAG] = pkt->vec[NET_TX_PKT_L2HDR_FRAG];
fragment[NET_TX_PKT_L3HDR_FRAG] = pkt->vec[NET_TX_PKT_L3HDR_FRAG];
switch (gso_type) {
case VIRTIO_NET_HDR_GSO_TCPV4:
case VIRTIO_NET_HDR_GSO_TCPV6:
if (!net_tx_pkt_tcp_fragment_init(pkt, fragment, &pl_idx, &l4hdr_len,
&src_idx, &src_offset, &src_len)) {
return false;
}
break;
case VIRTIO_NET_HDR_GSO_UDP:
net_tx_pkt_do_sw_csum(pkt, &pkt->vec[NET_TX_PKT_L2HDR_FRAG],
pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1,
pkt->payload_len);
net_tx_pkt_udp_fragment_init(pkt, &pl_idx, &l4hdr_len,
&src_idx, &src_offset, &src_len);
break;
default:
abort();
}
/* Put as much data as possible and send */
while (true) {
dst_idx = pl_idx;
fragment_len = net_tx_pkt_fetch_fragment(pkt,
&src_idx, &src_offset, src_len, fragment, &dst_idx);
if (!fragment_len) {
break;
}
switch (gso_type) {
case VIRTIO_NET_HDR_GSO_TCPV4:
case VIRTIO_NET_HDR_GSO_TCPV6:
net_tx_pkt_tcp_fragment_fix(pkt, fragment, fragment_len, gso_type);
net_tx_pkt_do_sw_csum(pkt, fragment + NET_TX_PKT_L2HDR_FRAG,
dst_idx - NET_TX_PKT_L2HDR_FRAG,
l4hdr_len + fragment_len);
break;
case VIRTIO_NET_HDR_GSO_UDP:
net_tx_pkt_udp_fragment_fix(pkt, fragment, fragment_offset,
fragment_len);
break;
}
callback(context,
fragment + NET_TX_PKT_L2HDR_FRAG, dst_idx - NET_TX_PKT_L2HDR_FRAG,
fragment + NET_TX_PKT_VHDR_FRAG, dst_idx - NET_TX_PKT_VHDR_FRAG);
if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4 ||
gso_type == VIRTIO_NET_HDR_GSO_TCPV6) {
net_tx_pkt_tcp_fragment_advance(pkt, fragment, fragment_len,
gso_type);
}
fragment_offset += fragment_len;
}
if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4 ||
gso_type == VIRTIO_NET_HDR_GSO_TCPV6) {
net_tx_pkt_tcp_fragment_deinit(fragment);
}
return true;
}
bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc)
{
bool offload = qemu_get_vnet_hdr_len(nc->peer);
return net_tx_pkt_send_custom(pkt, offload, net_tx_pkt_sendv, nc);
}
bool net_tx_pkt_send_custom(struct NetTxPkt *pkt, bool offload,
NetTxPktSend callback, void *context)
{
assert(pkt);
uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN;
/*
* Since underlying infrastructure does not support IP datagrams longer
* than 64K we should drop such packets and don't even try to send
*/
if (VIRTIO_NET_HDR_GSO_NONE != gso_type) {
if (pkt->payload_len >
ETH_MAX_IP_DGRAM_LEN -
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len) {
return false;
}
}
if (offload || gso_type == VIRTIO_NET_HDR_GSO_NONE) {
if (!offload && pkt->virt_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
pkt->virt_hdr.flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
net_tx_pkt_do_sw_csum(pkt, &pkt->vec[NET_TX_PKT_L2HDR_FRAG],
pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1,
pkt->payload_len);
}
net_tx_pkt_fix_ip6_payload_len(pkt);
callback(context, pkt->vec + NET_TX_PKT_L2HDR_FRAG,
pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - NET_TX_PKT_L2HDR_FRAG,
pkt->vec + NET_TX_PKT_VHDR_FRAG,
pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - NET_TX_PKT_VHDR_FRAG);
return true;
}
return net_tx_pkt_do_sw_fragmentation(pkt, callback, context);
}
void net_tx_pkt_fix_ip6_payload_len(struct NetTxPkt *pkt)
{
struct iovec *l2 = &pkt->vec[NET_TX_PKT_L2HDR_FRAG];
if (eth_get_l3_proto(l2, 1, l2->iov_len) == ETH_P_IPV6) {
/*
* TODO: if qemu would support >64K packets - add jumbo option check
* something like that:
* 'if (ip6->ip6_plen == 0 && !has_jumbo_option(ip6)) {'
*/
if (pkt->l3_hdr.ip6.ip6_plen == 0) {
if (pkt->payload_len <= ETH_MAX_IP_DGRAM_LEN) {
pkt->l3_hdr.ip6.ip6_plen = htons(pkt->payload_len);
}
/*
* TODO: if qemu would support >64K packets
* add jumbo option for packets greater then 65,535 bytes
*/
}
}
}
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