/* C++ would be better for this. Please don't torture me with this code
* ever again.
*/
static inline unsigned int csum_and_copy_to_dst(struct kvec_dst *dst,
const char *from, int len, unsigned int csum)
{
do {
int cnt = len;
if (dst->space < cnt)
cnt = dst->space;
memcpy(dst->dst, from, cnt);
csum = csum_partial_copy_nocheck(from, dst->dst, cnt, csum);
from += cnt;
dst->space -= cnt;
dst->dst += cnt;
len -= cnt;
if (!dst->space && len) {
kvec_dst_unmap(dst);
dst->let++;
dst->offset = 0;
kvec_dst_map(dst);
if (!dst->space)
BUG();
}
} while (len);
return csum;
}
static int rt_icmp_glue_reply_bits(const void *p, char *to,
unsigned int offset, unsigned int fraglen)
{
struct icmp_bxm *icmp_param = (struct icmp_bxm *)p;
struct icmphdr *icmph;
unsigned long csum;
/* TODO: add support for fragmented ICMP packets */
if (offset != 0)
return -EMSGSIZE;
csum = csum_partial_copy_nocheck((void *)&icmp_param->head, to,
icmp_param->head_len, icmp_param->csum);
csum = rtskb_copy_and_csum_bits(icmp_param->data.skb,
icmp_param->offset,
to + icmp_param->head_len,
fraglen - icmp_param->head_len,
csum);
icmph = (struct icmphdr *)to;
icmph->checksum = csum_fold(csum);
return 0;
}
/***
* rtskb_copy_and_csum_bits
*/
unsigned int rtskb_copy_and_csum_bits(const struct rtskb *skb, int offset,
u8 *to, int len, unsigned int csum)
{
int copy;
/* Copy header. */
if ((copy = skb->len-offset) > 0) {
if (copy > len)
copy = len;
csum = csum_partial_copy_nocheck(skb->data+offset, to, copy, csum);
if ((len -= copy) == 0)
return csum;
offset += copy;
to += copy;
}
RTNET_ASSERT(len == 0, );
return csum;
}
/***
* rtskb_copy_and_csum_bits
*/
unsigned int rtskb_copy_and_csum_bits(const struct rtskb *skb, int offset, u8 *to, int len, unsigned int csum)
{
int copy;
int start = skb->len - skb->data_len;
int pos = 0;
/* Copy header. */
if ((copy = start-offset) > 0) {
if (copy > len)
copy = len;
csum = csum_partial_copy_nocheck(skb->data+offset, to, copy, csum);
if ((len -= copy) == 0)
return csum;
offset += copy;
to += copy;
pos = copy;
}
BUG();
return csum;
}
static int rt_icmp_glue_reply_bits(const void *p, char *to,
unsigned int offset, unsigned int fraglen)
{
struct icmp_bxm *icmp_param = (struct icmp_bxm *)p;
struct icmphdr *icmph;
unsigned long csum;
RTNET_ASSERT(offset == 0,
rtos_print("RTnet: %s() does not support fragmentation.",
__FUNCTION__);
return -1;);
csum = csum_partial_copy_nocheck((void *)&icmp_param->head, to,
icmp_param->head_len, icmp_param->csum);
csum = rtskb_copy_and_csum_bits(icmp_param->data.skb,
icmp_param->offset,
to + icmp_param->head_len,
fraglen - icmp_param->head_len,
csum);
icmph = (struct icmphdr *)to;
icmph->checksum = csum_fold(csum);
return 0;
}
