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qemu-e2k/hw/net/net_tx_pkt.c

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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 "net_tx_pkt.h"
#include "net/eth.h"
#include "net/checksum.h"
#include "net/tap.h"
#include "net/net.h"
#include "hw/pci/pci.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 {
PCIDevice *pci_dev;
struct virtio_net_hdr virt_hdr;
bool has_virt_hdr;
struct iovec *raw;
uint32_t raw_frags;
uint32_t max_raw_frags;
struct iovec *vec;
uint8_t l2_hdr[ETH_MAX_L2_HDR_LEN];
uint8_t l3_hdr[ETH_MAX_IP_DGRAM_LEN];
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;
bool is_loopback;
};
void net_tx_pkt_init(struct NetTxPkt **pkt, PCIDevice *pci_dev,
uint32_t max_frags, bool has_virt_hdr)
{
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);
p->max_payload_frags = max_frags;
p->max_raw_frags = max_frags;
p->has_virt_hdr = has_virt_hdr;
p->vec[NET_TX_PKT_VHDR_FRAG].iov_base = &p->virt_hdr;
p->vec[NET_TX_PKT_VHDR_FRAG].iov_len =
p->has_virt_hdr ? sizeof p->virt_hdr : 0;
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);
struct ip_header *ip_hdr;
ip_hdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base;
ip_hdr->ip_len = cpu_to_be16(pkt->payload_len +
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len);
ip_hdr->ip_sum = 0;
csum = net_raw_checksum((uint8_t *)ip_hdr,
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len);
ip_hdr->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));
}
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;
}
void net_tx_pkt_build_vheader(struct NetTxPkt *pkt, bool tso_enable,
bool csum_enable, uint32_t gso_size)
{
struct tcp_hdr l4hdr;
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:
iov_to_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG], pkt->payload_frags,
0, &l4hdr, sizeof(l4hdr));
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:
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:
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;
}
}
}
void net_tx_pkt_setup_vlan_header_ex(struct NetTxPkt *pkt,
uint16_t vlan, uint16_t vlan_ethtype)
{
bool is_new;
assert(pkt);
eth_setup_vlan_headers_ex(pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base,
vlan, vlan_ethtype, &is_new);
/* update l2hdrlen */
if (is_new) {
pkt->hdr_len += sizeof(struct vlan_header);
pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len +=
sizeof(struct vlan_header);
}
}
bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa,
size_t len)
{
hwaddr mapped_len = 0;
struct iovec *ventry;
assert(pkt);
if (pkt->raw_frags >= pkt->max_raw_frags) {
return false;
}
if (!len) {
return true;
}
ventry = &pkt->raw[pkt->raw_frags];
mapped_len = len;
ventry->iov_base = pci_dma_map(pkt->pci_dev, pa,
&mapped_len, DMA_DIRECTION_TO_DEVICE);
if ((ventry->iov_base != NULL) && (len == mapped_len)) {
ventry->iov_len = mapped_len;
pkt->raw_frags++;
return true;
} else {
return false;
}
}
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)
{
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);
pci_dma_unmap(pkt->pci_dev, pkt->raw[i].iov_base,
pkt->raw[i].iov_len, DMA_DIRECTION_TO_DEVICE, 0);
}
}
pkt->raw_frags = 0;
pkt->hdr_len = 0;
pkt->l4proto = 0;
}
static void net_tx_pkt_do_sw_csum(struct NetTxPkt *pkt)
{
struct iovec *iov = &pkt->vec[NET_TX_PKT_L2HDR_FRAG];
uint32_t csum_cntr;
uint16_t csum = 0;
uint32_t cso;
/* num of iovec without vhdr */
uint32_t iov_len = pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1;
uint16_t csl;
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 */
csl = pkt->payload_len;
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);
}
enum {
NET_TX_PKT_FRAGMENT_L2_HDR_POS = 0,
NET_TX_PKT_FRAGMENT_L3_HDR_POS,
NET_TX_PKT_FRAGMENT_HEADER_NUM
};
#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, struct iovec *dst, int *dst_idx)
{
size_t fetched = 0;
struct iovec *src = pkt->vec;
*dst_idx = NET_TX_PKT_FRAGMENT_HEADER_NUM;
while (fetched < IP_FRAG_ALIGN_SIZE(pkt->virt_hdr.gso_size)) {
/* 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,
IP_FRAG_ALIGN_SIZE(pkt->virt_hdr.gso_size) - 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 inline void net_tx_pkt_sendv(struct NetTxPkt *pkt,
NetClientState *nc, const struct iovec *iov, int iov_cnt)
{
if (pkt->is_loopback) {
qemu_receive_packet_iov(nc, iov, iov_cnt);
} else {
qemu_sendv_packet(nc, iov, iov_cnt);
}
}
static bool net_tx_pkt_do_sw_fragmentation(struct NetTxPkt *pkt,
NetClientState *nc)
{
struct iovec fragment[NET_MAX_FRAG_SG_LIST];
size_t fragment_len = 0;
bool more_frags = false;
/* some pointers for shorter code */
void *l2_iov_base, *l3_iov_base;
size_t l2_iov_len, l3_iov_len;
int src_idx = NET_TX_PKT_PL_START_FRAG, dst_idx;
size_t src_offset = 0;
size_t fragment_offset = 0;
l2_iov_base = pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base;
l2_iov_len = pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len;
l3_iov_base = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base;
l3_iov_len = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len;
/* Copy headers */
fragment[NET_TX_PKT_FRAGMENT_L2_HDR_POS].iov_base = l2_iov_base;
fragment[NET_TX_PKT_FRAGMENT_L2_HDR_POS].iov_len = l2_iov_len;
fragment[NET_TX_PKT_FRAGMENT_L3_HDR_POS].iov_base = l3_iov_base;
fragment[NET_TX_PKT_FRAGMENT_L3_HDR_POS].iov_len = l3_iov_len;
/* Put as much data as possible and send */
do {
fragment_len = net_tx_pkt_fetch_fragment(pkt, &src_idx, &src_offset,
fragment, &dst_idx);
more_frags = (fragment_offset + fragment_len < pkt->payload_len);
eth_setup_ip4_fragmentation(l2_iov_base, l2_iov_len, l3_iov_base,
l3_iov_len, fragment_len, fragment_offset, more_frags);
eth_fix_ip4_checksum(l3_iov_base, l3_iov_len);
net_tx_pkt_sendv(pkt, nc, fragment, dst_idx);
fragment_offset += fragment_len;
} while (fragment_len && more_frags);
return true;
}
bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc)
{
assert(pkt);
if (!pkt->has_virt_hdr &&
pkt->virt_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
net_tx_pkt_do_sw_csum(pkt);
}
/*
* 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 != pkt->virt_hdr.gso_type) {
if (pkt->payload_len >
ETH_MAX_IP_DGRAM_LEN -
pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len) {
return false;
}
}
if (pkt->has_virt_hdr ||
pkt->virt_hdr.gso_type == VIRTIO_NET_HDR_GSO_NONE) {
net_tx_pkt_fix_ip6_payload_len(pkt);
net_tx_pkt_sendv(pkt, nc, pkt->vec,
pkt->payload_frags + NET_TX_PKT_PL_START_FRAG);
return true;
}
return net_tx_pkt_do_sw_fragmentation(pkt, nc);
}
bool net_tx_pkt_send_loopback(struct NetTxPkt *pkt, NetClientState *nc)
{
bool res;
pkt->is_loopback = true;
res = net_tx_pkt_send(pkt, nc);
pkt->is_loopback = false;
return res;
}
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) {
struct ip6_header *ip6 = (struct ip6_header *) pkt->l3_hdr;
/*
* TODO: if qemu would support >64K packets - add jumbo option check
* something like that:
* 'if (ip6->ip6_plen == 0 && !has_jumbo_option(ip6)) {'
*/
if (ip6->ip6_plen == 0) {
if (pkt->payload_len <= ETH_MAX_IP_DGRAM_LEN) {
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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