qemu/net/checksum.c

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/*
* IP checksumming functions.
* (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; under version 2 or later of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "net/checksum.h"
#include "net/eth.h"
uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq)
{
uint32_t sum1 = 0, sum2 = 0;
int i;
for (i = 0; i < len - 1; i += 2) {
sum1 += (uint32_t)buf[i];
sum2 += (uint32_t)buf[i + 1];
}
if (i < len) {
sum1 += (uint32_t)buf[i];
}
if (seq & 1) {
return sum1 + (sum2 << 8);
} else {
return sum2 + (sum1 << 8);
}
}
uint16_t net_checksum_finish(uint32_t sum)
{
while (sum>>16)
avoid TABs in files that only contain a few Most files that have TABs only contain a handful of them. Change them to spaces so that we don't confuse people. disas, standard-headers, linux-headers and libdecnumber are imported from other projects and probably should be exempted from the check. Outside those, after this patch the following files still contain both 8-space and TAB sequences at the beginning of the line. Many of them have a majority of TABs, or were initially committed with all tabs. bsd-user/i386/target_syscall.h bsd-user/x86_64/target_syscall.h crypto/aes.c hw/audio/fmopl.c hw/audio/fmopl.h hw/block/tc58128.c hw/display/cirrus_vga.c hw/display/xenfb.c hw/dma/etraxfs_dma.c hw/intc/sh_intc.c hw/misc/mst_fpga.c hw/net/pcnet.c hw/sh4/sh7750.c hw/timer/m48t59.c hw/timer/sh_timer.c include/crypto/aes.h include/disas/bfd.h include/hw/sh4/sh.h libdecnumber/decNumber.c linux-headers/asm-generic/unistd.h linux-headers/linux/kvm.h linux-user/alpha/target_syscall.h linux-user/arm/nwfpe/double_cpdo.c linux-user/arm/nwfpe/fpa11_cpdt.c linux-user/arm/nwfpe/fpa11_cprt.c linux-user/arm/nwfpe/fpa11.h linux-user/flat.h linux-user/flatload.c linux-user/i386/target_syscall.h linux-user/ppc/target_syscall.h linux-user/sparc/target_syscall.h linux-user/syscall.c linux-user/syscall_defs.h linux-user/x86_64/target_syscall.h slirp/cksum.c slirp/if.c slirp/ip.h slirp/ip_icmp.c slirp/ip_icmp.h slirp/ip_input.c slirp/ip_output.c slirp/mbuf.c slirp/misc.c slirp/sbuf.c slirp/socket.c slirp/socket.h slirp/tcp_input.c slirp/tcpip.h slirp/tcp_output.c slirp/tcp_subr.c slirp/tcp_timer.c slirp/tftp.c slirp/udp.c slirp/udp.h target/cris/cpu.h target/cris/mmu.c target/cris/op_helper.c target/sh4/helper.c target/sh4/op_helper.c target/sh4/translate.c tcg/sparc/tcg-target.inc.c tests/tcg/cris/check_addo.c tests/tcg/cris/check_moveq.c tests/tcg/cris/check_swap.c tests/tcg/multiarch/test-mmap.c ui/vnc-enc-hextile-template.h ui/vnc-enc-zywrle.h util/envlist.c util/readline.c The following have only TABs: bsd-user/i386/target_signal.h bsd-user/sparc64/target_signal.h bsd-user/sparc64/target_syscall.h bsd-user/sparc/target_signal.h bsd-user/sparc/target_syscall.h bsd-user/x86_64/target_signal.h crypto/desrfb.c hw/audio/intel-hda-defs.h hw/core/uboot_image.h hw/sh4/sh7750_regnames.c hw/sh4/sh7750_regs.h include/hw/cris/etraxfs_dma.h linux-user/alpha/termbits.h linux-user/arm/nwfpe/fpopcode.h linux-user/arm/nwfpe/fpsr.h linux-user/arm/syscall_nr.h linux-user/arm/target_signal.h linux-user/cris/target_signal.h linux-user/i386/target_signal.h linux-user/linux_loop.h linux-user/m68k/target_signal.h linux-user/microblaze/target_signal.h linux-user/mips64/target_signal.h linux-user/mips/target_signal.h linux-user/mips/target_syscall.h linux-user/mips/termbits.h linux-user/ppc/target_signal.h linux-user/sh4/target_signal.h linux-user/sh4/termbits.h linux-user/sparc64/target_syscall.h linux-user/sparc/target_signal.h linux-user/x86_64/target_signal.h linux-user/x86_64/termbits.h pc-bios/optionrom/optionrom.h slirp/mbuf.h slirp/misc.h slirp/sbuf.h slirp/tcp.h slirp/tcp_timer.h slirp/tcp_var.h target/i386/svm.h target/sparc/asi.h target/xtensa/core-dc232b/xtensa-modules.inc.c target/xtensa/core-dc233c/xtensa-modules.inc.c target/xtensa/core-de212/core-isa.h target/xtensa/core-de212/xtensa-modules.inc.c target/xtensa/core-fsf/xtensa-modules.inc.c target/xtensa/core-sample_controller/core-isa.h target/xtensa/core-sample_controller/xtensa-modules.inc.c target/xtensa/core-test_kc705_be/core-isa.h target/xtensa/core-test_kc705_be/xtensa-modules.inc.c tests/tcg/cris/check_abs.c tests/tcg/cris/check_addc.c tests/tcg/cris/check_addcm.c tests/tcg/cris/check_addoq.c tests/tcg/cris/check_bound.c tests/tcg/cris/check_ftag.c tests/tcg/cris/check_int64.c tests/tcg/cris/check_lz.c tests/tcg/cris/check_openpf5.c tests/tcg/cris/check_sigalrm.c tests/tcg/cris/crisutils.h tests/tcg/cris/sys.c tests/tcg/i386/test-i386-ssse3.c ui/vgafont.h Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20181213223737.11793-3-pbonzini@redhat.com> Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com> Acked-by: Richard Henderson <richard.henderson@linaro.org> Acked-by: Eric Blake <eblake@redhat.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 01:37:37 +03:00
sum = (sum & 0xFFFF)+(sum >> 16);
return ~sum;
}
uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
uint8_t *addrs, uint8_t *buf)
{
uint32_t sum = 0;
sum += net_checksum_add(length, buf); // payload
sum += net_checksum_add(8, addrs); // src + dst address
sum += proto + length; // protocol & length
return net_checksum_finish(sum);
}
void net_checksum_calculate(uint8_t *data, int length, int csum_flag)
{
int mac_hdr_len, ip_len;
struct ip_header *ip;
uint16_t csum;
/*
* Note: We cannot assume "data" is aligned, so the all code uses
* some macros that take care of possible unaligned access for
* struct members (just in case).
*/
/* Ensure we have at least an Eth header */
if (length < sizeof(struct eth_header)) {
return;
}
/* Handle the optionnal VLAN headers */
switch (lduw_be_p(&PKT_GET_ETH_HDR(data)->h_proto)) {
case ETH_P_VLAN:
mac_hdr_len = sizeof(struct eth_header) +
sizeof(struct vlan_header);
break;
case ETH_P_DVLAN:
if (lduw_be_p(&PKT_GET_VLAN_HDR(data)->h_proto) == ETH_P_VLAN) {
mac_hdr_len = sizeof(struct eth_header) +
2 * sizeof(struct vlan_header);
} else {
mac_hdr_len = sizeof(struct eth_header) +
sizeof(struct vlan_header);
}
break;
default:
mac_hdr_len = sizeof(struct eth_header);
break;
}
length -= mac_hdr_len;
/* Now check we have an IP header (with an optionnal VLAN header) */
if (length < sizeof(struct ip_header)) {
return;
}
ip = (struct ip_header *)(data + mac_hdr_len);
if (IP_HEADER_VERSION(ip) != IP_HEADER_VERSION_4) {
return; /* not IPv4 */
}
/* Calculate IP checksum */
if (csum_flag & CSUM_IP) {
stw_he_p(&ip->ip_sum, 0);
csum = net_raw_checksum((uint8_t *)ip, IP_HDR_GET_LEN(ip));
stw_be_p(&ip->ip_sum, csum);
}
if (IP4_IS_FRAGMENT(ip)) {
return; /* a fragmented IP packet */
}
ip_len = lduw_be_p(&ip->ip_len);
/* Last, check that we have enough data for the all IP frame */
if (length < ip_len) {
return;
}
ip_len -= IP_HDR_GET_LEN(ip);
switch (ip->ip_p) {
case IP_PROTO_TCP:
{
if (!(csum_flag & CSUM_TCP)) {
return;
}
tcp_header *tcp = (tcp_header *)(ip + 1);
if (ip_len < sizeof(tcp_header)) {
return;
}
/* Set csum to 0 */
stw_he_p(&tcp->th_sum, 0);
csum = net_checksum_tcpudp(ip_len, ip->ip_p,
(uint8_t *)&ip->ip_src,
(uint8_t *)tcp);
/* Store computed csum */
stw_be_p(&tcp->th_sum, csum);
break;
}
case IP_PROTO_UDP:
{
if (!(csum_flag & CSUM_UDP)) {
return;
}
udp_header *udp = (udp_header *)(ip + 1);
if (ip_len < sizeof(udp_header)) {
return;
}
/* Set csum to 0 */
stw_he_p(&udp->uh_sum, 0);
csum = net_checksum_tcpudp(ip_len, ip->ip_p,
(uint8_t *)&ip->ip_src,
(uint8_t *)udp);
/* Store computed csum */
stw_be_p(&udp->uh_sum, csum);
break;
}
default:
/* Can't handle any other protocol */
break;
}
}
uint32_t
net_checksum_add_iov(const struct iovec *iov, const unsigned int iov_cnt,
uint32_t iov_off, uint32_t size, uint32_t csum_offset)
{
size_t iovec_off, buf_off;
unsigned int i;
uint32_t res = 0;
iovec_off = 0;
buf_off = 0;
for (i = 0; i < iov_cnt && size; i++) {
if (iov_off < (iovec_off + iov[i].iov_len)) {
size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);
void *chunk_buf = iov[i].iov_base + (iov_off - iovec_off);
res += net_checksum_add_cont(len, chunk_buf, csum_offset);
csum_offset += len;
buf_off += len;
iov_off += len;
size -= len;
}
iovec_off += iov[i].iov_len;
}
return res;
}