/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (C) 2014-2015 Vincenzo Maffione
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(__FreeBSD__)
#include <sys/cdefs.h> /* prerequisite */
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/param.h> /* defines used in kernel.h */
#include <sys/kernel.h> /* types used in module initialization */
#include <sys/sockio.h>
#include <sys/malloc.h>
#include <sys/socketvar.h> /* struct socket */
#include <sys/socket.h> /* sockaddrs */
#include <net/if.h>
#include <net/if_var.h>
#include <machine/bus.h> /* bus_dmamap_* */
#include <sys/endian.h>
#elif defined(linux)
#include "bsd_glue.h"
#elif defined(__APPLE__)
#warning OSX support is only partial
#include "osx_glue.h"
#else
#error Unsupported platform
#endif /* unsupported */
#include <net/netmap.h>
#include <dev/netmap/netmap_kern.h>
/* This routine is called by bdg_mismatch_datapath() when it finishes
* accumulating bytes for a segment, in order to fix some fields in the
* segment headers (which still contain the same content as the header
* of the original GSO packet). 'pkt' points to the beginning of the IP
* header of the segment, while 'len' is the length of the IP packet.
*/
static void
gso_fix_segment(uint8_t *pkt, size_t len, u_int ipv4, u_int iphlen, u_int tcp,
u_int idx, u_int segmented_bytes, u_int last_segment)
{
struct nm_iphdr *iph = (struct nm_iphdr *)(pkt);
struct nm_ipv6hdr *ip6h = (struct nm_ipv6hdr *)(pkt);
uint16_t *check = NULL;
uint8_t *check_data = NULL;
if (ipv4) {
/* Set the IPv4 "Total Length" field. */
iph->tot_len = htobe16(len);
nm_prdis("ip total length %u", be16toh(ip->tot_len));
/* Set the IPv4 "Identification" field. */
iph->id = htobe16(be16toh(iph->id) + idx);
nm_prdis("ip identification %u", be16toh(iph->id));
/* Compute and insert the IPv4 header checksum. */
iph->check = 0;
iph->check = nm_os_csum_ipv4(iph);
nm_prdis("IP csum %x", be16toh(iph->check));
} else {
/* Set the IPv6 "Payload Len" field. */
ip6h->payload_len = htobe16(len-iphlen);
}
if (tcp) {
struct nm_tcphdr *tcph = (struct nm_tcphdr *)(pkt + iphlen);
/* Set the TCP sequence number. */
tcph->seq = htobe32(be32toh(tcph->seq) + segmented_bytes);
nm_prdis("tcp seq %u", be32toh(tcph->seq));
/* Zero the PSH and FIN TCP flags if this is not the last
segment. */
if (!last_segment)
tcph->flags &= ~(0x8 | 0x1);
nm_prdis("last_segment %u", last_segment);
check = &tcph->check;
check_data = (uint8_t *)tcph;
} else { /* UDP */
struct nm_udphdr *udph = (struct nm_udphdr *)(pkt + iphlen);
/* Set the UDP 'Length' field. */
udph->len = htobe16(len-iphlen);
check = &udph->check;
check_data = (uint8_t *)udph;
}
/* Compute and insert TCP/UDP checksum. */
*check = 0;
if (ipv4)
nm_os_csum_tcpudp_ipv4(iph, check_data, len-iphlen, check);
else
nm_os_csum_tcpudp_ipv6(ip6h, check_data, len-iphlen, check);
nm_prdis("TCP/UDP csum %x", be16toh(*check));
}
static inline int
vnet_hdr_is_bad(struct nm_vnet_hdr *vh)
{
uint8_t gso_type = vh->gso_type & ~VIRTIO_NET_HDR_GSO_ECN;
return (
(gso_type != VIRTIO_NET_HDR_GSO_NONE &&
gso_type != VIRTIO_NET_HDR_GSO_TCPV4 &&
gso_type != VIRTIO_NET_HDR_GSO_UDP &&
gso_type != VIRTIO_NET_HDR_GSO_TCPV6)
||
(vh->flags & ~(VIRTIO_NET_HDR_F_NEEDS_CSUM
| VIRTIO_NET_HDR_F_DATA_VALID))
);
}
/* The VALE mismatch datapath implementation. */
void
bdg_mismatch_datapath(struct netmap_vp_adapter *na,
struct netmap_vp_adapter *dst_na,
const struct nm_bdg_fwd *ft_p,
struct netmap_ring *dst_ring,
u_int *j, u_int lim, u_int *howmany)
{
struct netmap_slot *dst_slot = NULL;
struct nm_vnet_hdr *vh = NULL;
const struct nm_bdg_fwd *ft_end = ft_p + ft_p->ft_frags;
/* Source and destination pointers. */
uint8_t *dst, *src;
size_t src_len, dst_len;
/* Indices and counters for the destination ring. */
u_int j_start = *j;
u_int j_cur = j_start;
u_int dst_slots = 0;
if (unlikely(ft_p == ft_end)) {
nm_prlim(1, "No source slots to process");
return;
}
/* Init source and dest pointers. */
src = ft_p->ft_buf;
src_len = ft_p->ft_len;
dst_slot = &dst_ring->slot[j_cur];
dst = NMB(&dst_na->up, dst_slot);
dst_len = src_len;
/* If the source port uses the offloadings, while destination doesn't,
* we grab the source virtio-net header and do the offloadings here.
*/
if (na->up.virt_hdr_len && !dst_na->up.virt_hdr_len) {
vh = (struct nm_vnet_hdr *)src;
/* Initial sanity check on the source virtio-net header. If
* something seems wrong, just drop the packet. */
if (src_len < na->up.virt_hdr_len) {
nm_prlim(1, "Short src vnet header, dropping");
return;
}
if (unlikely(vnet_hdr_is_bad(vh))) {
nm_prlim(1, "Bad src vnet header, dropping");
return;
}
}
/* We are processing the first input slot and there is a mismatch
* between source and destination virt_hdr_len (SHL and DHL).
* When the a client is using virtio-net headers, the header length
* can be:
* - 10: the header corresponds to the struct nm_vnet_hdr
* - 12: the first 10 bytes correspond to the struct
* virtio_net_hdr, and the last 2 bytes store the
* "mergeable buffers" info, which is an optional
* hint that can be zeroed for compatibility
*
* The destination header is therefore built according to the
* following table:
*
* SHL | DHL | destination header
* -----------------------------
* 0 | 10 | zero
* 0 | 12 | zero
* 10 | 0 | doesn't exist
* 10 | 12 | first 10 bytes are copied from source header, last 2 are zero
* 12 | 0 | doesn't exist
* 12 | 10 | copied from the first 10 bytes of source header
*/
bzero(dst, dst_na->up.virt_hdr_len);
if (na->up.virt_hdr_len && dst_na->up.virt_hdr_len)
memcpy(dst, src, sizeof(struct nm_vnet_hdr));
/* Skip the virtio-net headers. */
src += na->up.virt_hdr_len;
src_len -= na->up.virt_hdr_len;
dst += dst_na->up.virt_hdr_len;
dst_len = dst_na->up.virt_hdr_len + src_len;
/* Here it could be dst_len == 0 (which implies src_len == 0),
* so we avoid passing a zero length fragment.
*/
if (dst_len == 0) {
ft_p++;
src = ft_p->ft_buf;
src_len = ft_p->ft_len;
dst_len = src_len;
}
if (vh && vh->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
u_int gso_bytes = 0;
/* Length of the GSO packet header. */
u_int gso_hdr_len = 0;
/* Pointer to the GSO packet header. Assume it is in a single fragment. */
uint8_t *gso_hdr = NULL;
/* Index of the current segment. */
u_int gso_idx = 0;
/* Payload data bytes segmented so far (e.g. TCP data bytes). */
u_int segmented_bytes = 0;
/* Is this an IPv4 or IPv6 GSO packet? */
u_int ipv4 = 0;
/* Length of the IP header (20 if IPv4, 40 if IPv6). */
u_int iphlen = 0;
/* Length of the Ethernet header (18 if 802.1q, otherwise 14). */
u_int ethhlen = 14;
/* Is this a TCP or an UDP GSO packet? */
u_int tcp = ((vh->gso_type & ~VIRTIO_NET_HDR_GSO_ECN)
== VIRTIO_NET_HDR_GSO_UDP) ? 0 : 1;
/* Segment the GSO packet contained into the input slots (frags). */
for (;;) {
size_t copy;
if (dst_slots >= *howmany) {
/* We still have work to do, but we've run out of
* dst slots, so we have to drop the packet. */
nm_prdis(1, "Not enough slots, dropping GSO packet");
return;
}
/* Grab the GSO header if we don't have it. */
if (!gso_hdr) {
uint16_t ethertype;
gso_hdr = src;
/* Look at the 'Ethertype' field to see if this packet
* is IPv4 or IPv6, taking into account VLAN
* encapsulation. */
for (;;) {
if (src_len < ethhlen) {
nm_prlim(1, "Short GSO fragment [eth], dropping");
return;
}
ethertype = be16toh(*((uint16_t *)
(gso_hdr + ethhlen - 2)));
if (ethertype != 0x8100) /* not 802.1q */
break;
ethhlen += 4;
}
switch (ethertype) {
case 0x0800: /* IPv4 */
{
struct nm_iphdr *iph = (struct nm_iphdr *)
(gso_hdr + ethhlen);
if (src_len < ethhlen + 20) {
nm_prlim(1, "Short GSO fragment "
"[IPv4], dropping");
return;
}
ipv4 = 1;
iphlen = 4 * (iph->version_ihl & 0x0F);
break;
}
case 0x86DD: /* IPv6 */
ipv4 = 0;
iphlen = 40;
break;
default:
nm_prlim(1, "Unsupported ethertype, "
"dropping GSO packet");
return;
}
nm_prdis(3, "type=%04x", ethertype);
if (src_len < ethhlen + iphlen) {
nm_prlim(1, "Short GSO fragment [IP], dropping");
return;
}
/* Compute gso_hdr_len. For TCP we need to read the
* content of the 'Data Offset' field.
*/
if (tcp) {
struct nm_tcphdr *tcph = (struct nm_tcphdr *)
(gso_hdr + ethhlen + iphlen);
if (src_len < ethhlen + iphlen + 20) {
nm_prlim(1, "Short GSO fragment "
"[TCP], dropping");
return;
}
gso_hdr_len = ethhlen + iphlen +
4 * (tcph->doff >> 4);
} else {
gso_hdr_len = ethhlen + iphlen + 8; /* UDP */
}
if (src_len < gso_hdr_len) {
nm_prlim(1, "Short GSO fragment [TCP/UDP], dropping");
return;
}
nm_prdis(3, "gso_hdr_len %u gso_mtu %d", gso_hdr_len,
dst_na->mfs);
/* Advance source pointers. */
src += gso_hdr_len;
src_len -= gso_hdr_len;
if (src_len == 0) {
ft_p++;
if (ft_p == ft_end)
break;
src = ft_p->ft_buf;
src_len = ft_p->ft_len;
}
}
/* Fill in the header of the current segment. */
if (gso_bytes == 0) {
memcpy(dst, gso_hdr, gso_hdr_len);
gso_bytes = gso_hdr_len;
}
/* Fill in data and update source and dest pointers. */
copy = src_len;
if (gso_bytes + copy > dst_na->mfs)
copy = dst_na->mfs - gso_bytes;
memcpy(dst + gso_bytes, src, copy);
gso_bytes += copy;
src += copy;
src_len -= copy;
/* A segment is complete or we have processed all the
the GSO payload bytes. */
if (gso_bytes >= dst_na->mfs ||
(src_len == 0 && ft_p + 1 == ft_end)) {
/* After raw segmentation, we must fix some header
* fields and compute checksums, in a protocol dependent
* way. */
gso_fix_segment(dst + ethhlen, gso_bytes - ethhlen,
ipv4, iphlen, tcp,
gso_idx, segmented_bytes,
src_len == 0 && ft_p + 1 == ft_end);
nm_prdis("frame %u completed with %d bytes", gso_idx, (int)gso_bytes);
dst_slot->len = gso_bytes;
dst_slot->flags = 0;
dst_slots++;
segmented_bytes += gso_bytes - gso_hdr_len;
gso_bytes = 0;
gso_idx++;
/* Next destination slot. */
j_cur = nm_next(j_cur, lim);
dst_slot = &dst_ring->slot[j_cur];
dst = NMB(&dst_na->up, dst_slot);
}
/* Next input slot. */
if (src_len == 0) {
ft_p++;
if (ft_p == ft_end)
break;
src = ft_p->ft_buf;
src_len = ft_p->ft_len;
}
}
nm_prdis(3, "%d bytes segmented", segmented_bytes);
} else {
/* Address of a checksum field into a destination slot. */
uint16_t *check = NULL;
/* Accumulator for an unfolded checksum. */
rawsum_t csum = 0;
/* Process a non-GSO packet. */
/* Init 'check' if necessary. */
if (vh && (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)) {
if (unlikely(vh->csum_offset + vh->csum_start > src_len))
nm_prerr("invalid checksum request");
else
check = (uint16_t *)(dst + vh->csum_start +
vh->csum_offset);
}
while (ft_p != ft_end) {
/* Init/update the packet checksum if needed. */
if (vh && (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)) {
if (!dst_slots)
csum = nm_os_csum_raw(src + vh->csum_start,
src_len - vh->csum_start, 0);
else
csum = nm_os_csum_raw(src, src_len, csum);
}
/* Round to a multiple of 64 */
src_len = (src_len + 63) & ~63;
if (ft_p->ft_flags & NS_INDIRECT) {
if (copyin(src, dst, src_len)) {
/* Invalid user pointer, pretend len is 0. */
dst_len = 0;
}
} else {
memcpy(dst, src, (int)src_len);
}
dst_slot->len = dst_len;
dst_slots++;
/* Next destination slot. */
j_cur = nm_next(j_cur, lim);
dst_slot = &dst_ring->slot[j_cur];
dst = NMB(&dst_na->up, dst_slot);
/* Next source slot. */
ft_p++;
src = ft_p->ft_buf;
dst_len = src_len = ft_p->ft_len;
}
/* Finalize (fold) the checksum if needed. */
if (check && vh && (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)) {
*check = nm_os_csum_fold(csum);
}
nm_prdis(3, "using %u dst_slots", dst_slots);
/* A second pass on the destination slots to set the slot flags,
* using the right number of destination slots.
*/
while (j_start != j_cur) {
dst_slot = &dst_ring->slot[j_start];
dst_slot->flags = (dst_slots << 8)| NS_MOREFRAG;
j_start = nm_next(j_start, lim);
}
/* Clear NS_MOREFRAG flag on last entry. */
dst_slot->flags = (dst_slots << 8);
}
/* Update howmany and j. This is to commit the use of
* those slots in the destination ring. */
if (unlikely(dst_slots > *howmany)) {
nm_prerr("bug: slot allocation error");
}
*j = j_cur;
*howmany -= dst_slots;
}