/*
* Copyright (C) 2014 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.
*/
/* $FreeBSD$ */
#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/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). 'buf' points to the beginning (e.g.
* the ethernet header) of the segment, and 'len' is its length.
*/
static void gso_fix_segment(uint8_t *buf, size_t len, u_int idx,
u_int segmented_bytes, u_int last_segment,
u_int tcp, u_int iphlen)
{
struct nm_iphdr *iph = (struct nm_iphdr *)(buf + 14);
struct nm_ipv6hdr *ip6h = (struct nm_ipv6hdr *)(buf + 14);
uint16_t *check = NULL;
uint8_t *check_data = NULL;
if (iphlen == 20) {
/* Set the IPv4 "Total Length" field. */
iph->tot_len = htobe16(len-14);
ND("ip total length %u", be16toh(ip->tot_len));
/* Set the IPv4 "Identification" field. */
iph->id = htobe16(be16toh(iph->id) + idx);
ND("ip identification %u", be16toh(iph->id));
/* Compute and insert the IPv4 header checksum. */
iph->check = 0;
iph->check = nm_csum_ipv4(iph);
ND("IP csum %x", be16toh(iph->check));
} else {/* if (iphlen == 40) */
/* Set the IPv6 "Payload Len" field. */
ip6h->payload_len = htobe16(len-14-iphlen);
}
if (tcp) {
struct nm_tcphdr *tcph = (struct nm_tcphdr *)(buf + 14 + iphlen);
/* Set the TCP sequence number. */
tcph->seq = htobe32(be32toh(tcph->seq) + segmented_bytes);
ND("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);
ND("last_segment %u", last_segment);
check = &tcph->check;
check_data = (uint8_t *)tcph;
} else { /* UDP */
struct nm_udphdr *udph = (struct nm_udphdr *)(buf + 14 + iphlen);
/* Set the UDP 'Length' field. */
udph->len = htobe16(len-14-iphlen);
check = &udph->check;
check_data = (uint8_t *)udph;
}
/* Compute and insert TCP/UDP checksum. */
*check = 0;
if (iphlen == 20)
nm_csum_tcpudp_ipv4(iph, check_data, len-14-iphlen, check);
else
nm_csum_tcpudp_ipv6(ip6h, check_data, len-14-iphlen, check);
ND("TCP/UDP csum %x", be16toh(*check));
}
/* The VALE mismatch datapath implementation. */
void bdg_mismatch_datapath(struct netmap_vp_adapter *na,
struct netmap_vp_adapter *dst_na,
struct nm_bdg_fwd *ft_p, struct netmap_ring *ring,
u_int *j, u_int lim, u_int *howmany)
{
struct netmap_slot *slot = NULL;
struct nm_vnet_hdr *vh = NULL;
/* Number of source slots to process. */
u_int frags = ft_p->ft_frags;
struct nm_bdg_fwd *ft_end = ft_p + frags;
/* Source and destination pointers. */
uint8_t *dst, *src;
size_t src_len, dst_len;
u_int j_start = *j;
u_int dst_slots = 0;
/* 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->virt_hdr_len && !dst_na->virt_hdr_len) {
vh = (struct nm_vnet_hdr *)ft_p->ft_buf;
}
/* Init source and dest pointers. */
src = ft_p->ft_buf;
src_len = ft_p->ft_len;
slot = &ring->slot[*j];
dst = NMB(&dst_na->up, slot);
dst_len = src_len;
/* 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 compability
*
* 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->virt_hdr_len);
if (na->virt_hdr_len && dst_na->virt_hdr_len)
memcpy(dst, src, sizeof(struct nm_vnet_hdr));
/* Skip the virtio-net headers. */
src += na->virt_hdr_len;
src_len -= na->virt_hdr_len;
dst += dst_na->virt_hdr_len;
dst_len = dst_na->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;
/* Length of the IP header (20 if IPv4, 40 if IPv6). */
u_int iphlen = 0;
/* 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). */
while (ft_p != ft_end) {
size_t copy;
/* 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.
*/
ethertype = be16toh(*((uint16_t *)(gso_hdr + 12)));
if (ethertype == 0x0800)
iphlen = 20;
else /* if (ethertype == 0x86DD) */
iphlen = 40;
ND(3, "type=%04x", ethertype);
/* 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[14+iphlen];
gso_hdr_len = 14 + iphlen + 4*(tcph->doff >> 4);
} else
gso_hdr_len = 14 + iphlen + 8; /* UDP */
ND(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;
continue;
}
}
/* 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, gso_bytes, gso_idx,
segmented_bytes,
src_len == 0 && ft_p + 1 == ft_end,
tcp, iphlen);
ND("frame %u completed with %d bytes", gso_idx, (int)gso_bytes);
slot->len = gso_bytes;
slot->flags = 0;
segmented_bytes += gso_bytes - gso_hdr_len;
dst_slots++;
/* Next destination slot. */
*j = nm_next(*j, lim);
slot = &ring->slot[*j];
dst = NMB(&dst_na->up, slot);
gso_bytes = 0;
gso_idx++;
}
/* 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;
}
}
ND(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))
D("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_csum_raw(src + vh->csum_start,
src_len - vh->csum_start, 0);
else
csum = nm_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);
}
slot->len = dst_len;
dst_slots++;
/* Next destination slot. */
*j = nm_next(*j, lim);
slot = &ring->slot[*j];
dst = NMB(&dst_na->up, 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_csum_fold(csum);
}
ND(3, "using %u dst_slots", dst_slots);
/* A second pass on the desitations slots to set the slot flags,
* using the right number of destination slots.
*/
while (j_start != *j) {
slot = &ring->slot[j_start];
slot->flags = (dst_slots << 8)| NS_MOREFRAG;
j_start = nm_next(j_start, lim);
}
/* Clear NS_MOREFRAG flag on last entry. */
slot->flags = (dst_slots << 8);
}
/* Update howmany. */
if (unlikely(dst_slots > *howmany)) {
dst_slots = *howmany;
D("Slot allocation error: Should never happen");
}
*howmany -= dst_slots;
}
