* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
-#include "qemu-common.h"
+#include "qemu/osdep.h"
#include "net/checksum.h"
-
-#define PROTO_TCP 6
-#define PROTO_UDP 17
+#include "net/eth.h"
uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq)
{
- uint32_t sum = 0;
+ uint32_t sum1 = 0, sum2 = 0;
int i;
- for (i = seq; i < seq + len; i++) {
- if (i & 1) {
- sum += (uint32_t)buf[i - seq];
- } else {
- sum += (uint32_t)buf[i - seq] << 8;
- }
+ 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);
}
- return sum;
}
uint16_t net_checksum_finish(uint32_t sum)
{
while (sum>>16)
- sum = (sum & 0xFFFF)+(sum >> 16);
+ sum = (sum & 0xFFFF)+(sum >> 16);
return ~sum;
}
return net_checksum_finish(sum);
}
-void net_checksum_calculate(uint8_t *data, int length)
+void net_checksum_calculate(uint8_t *data, int length, int csum_flag)
{
- int hlen, plen, proto, csum_offset;
+ int mac_hdr_len, ip_len;
+ struct ip_header *ip;
uint16_t csum;
- if ((data[14] & 0xf0) != 0x40)
- return; /* not IPv4 */
- hlen = (data[14] & 0x0f) * 4;
- plen = (data[16] << 8 | data[17]) - hlen;
- proto = data[23];
-
- switch (proto) {
- case PROTO_TCP:
- csum_offset = 16;
- break;
- case PROTO_UDP:
- csum_offset = 6;
- break;
+ /*
+ * 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 optional 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:
- return;
+ mac_hdr_len = sizeof(struct eth_header);
+ break;
}
- if (plen < csum_offset+2)
- return;
+ length -= mac_hdr_len;
- data[14+hlen+csum_offset] = 0;
- data[14+hlen+csum_offset+1] = 0;
- csum = net_checksum_tcpudp(plen, proto, data+14+12, data+14+hlen);
- data[14+hlen+csum_offset] = csum >> 8;
- data[14+hlen+csum_offset+1] = csum & 0xff;
+ /* Now check we have an IP header (with an optional 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 iov_off, uint32_t size, uint32_t csum_offset)
{
- size_t iovec_off, buf_off;
+ size_t iovec_off;
unsigned int i;
uint32_t res = 0;
- uint32_t seq = 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, seq);
- seq += len;
+ res += net_checksum_add_cont(len, chunk_buf, csum_offset);
+ csum_offset += len;
- buf_off += len;
iov_off += len;
size -= len;
}
projects / mirror_qemu.git / blobdiff