/*
* Reassemble fragments into one packet.
*/
struct rte_mbuf *
ipv4_frag_reassemble(struct ip_frag_pkt *fp)
{
struct ipv4_hdr *ip_hdr;
struct rte_mbuf *m, *prev;
uint32_t i, n, ofs, first_len;
uint32_t curr_idx = 0;
first_len = fp->frags[IP_FIRST_FRAG_IDX].len;
n = fp->last_idx - 1;
/*start from the last fragment. */
m = fp->frags[IP_LAST_FRAG_IDX].mb;
ofs = fp->frags[IP_LAST_FRAG_IDX].ofs;
curr_idx = IP_LAST_FRAG_IDX;
while (ofs != first_len) {
prev = m;
for (i = n; i != IP_FIRST_FRAG_IDX && ofs != first_len; i--) {
/* previous fragment found. */
if(fp->frags[i].ofs + fp->frags[i].len == ofs) {
/* adjust start of the last fragment data. */
rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len));
rte_pktmbuf_chain(fp->frags[i].mb, m);
/* this mbuf should not be accessed directly */
fp->frags[curr_idx].mb = NULL;
curr_idx = i;
/* update our last fragment and offset. */
m = fp->frags[i].mb;
ofs = fp->frags[i].ofs;
}
}
/* error - hole in the packet. */
if (m == prev) {
return NULL;
}
}
/* chain with the first fragment. */
rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len));
rte_pktmbuf_chain(fp->frags[IP_FIRST_FRAG_IDX].mb, m);
m = fp->frags[IP_FIRST_FRAG_IDX].mb;
/* update mbuf fields for reassembled packet. */
m->ol_flags |= PKT_TX_IP_CKSUM;
/* update ipv4 header for the reassmebled packet */
ip_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *, m->l2_len);
ip_hdr->total_length = rte_cpu_to_be_16((uint16_t)(fp->total_size +
m->l3_len));
ip_hdr->fragment_offset = (uint16_t)(ip_hdr->fragment_offset &
rte_cpu_to_be_16(IPV4_HDR_DF_FLAG));
ip_hdr->hdr_checksum = 0;
return m;
}
/*
* Reassemble fragments into one packet.
*/
struct rte_mbuf *
ipv6_frag_reassemble(struct ip_frag_pkt *fp)
{
struct ipv6_hdr *ip_hdr;
struct ipv6_extension_fragment *frag_hdr;
struct rte_mbuf *m, *prev;
uint32_t i, n, ofs, first_len;
uint32_t last_len, move_len, payload_len;
uint32_t curr_idx = 0;
first_len = fp->frags[IP_FIRST_FRAG_IDX].len;
n = fp->last_idx - 1;
/*start from the last fragment. */
m = fp->frags[IP_LAST_FRAG_IDX].mb;
ofs = fp->frags[IP_LAST_FRAG_IDX].ofs;
last_len = fp->frags[IP_LAST_FRAG_IDX].len;
curr_idx = IP_LAST_FRAG_IDX;
payload_len = ofs + last_len;
while (ofs != first_len) {
prev = m;
for (i = n; i != IP_FIRST_FRAG_IDX && ofs != first_len; i--) {
/* previous fragment found. */
if (fp->frags[i].ofs + fp->frags[i].len == ofs) {
/* adjust start of the last fragment data. */
rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len));
rte_pktmbuf_chain(fp->frags[i].mb, m);
/* this mbuf should not be accessed directly */
fp->frags[curr_idx].mb = NULL;
curr_idx = i;
/* update our last fragment and offset. */
m = fp->frags[i].mb;
ofs = fp->frags[i].ofs;
}
}
/* error - hole in the packet. */
if (m == prev) {
return NULL;
}
}
/* chain with the first fragment. */
rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len));
rte_pktmbuf_chain(fp->frags[IP_FIRST_FRAG_IDX].mb, m);
m = fp->frags[IP_FIRST_FRAG_IDX].mb;
/* update mbuf fields for reassembled packet. */
m->ol_flags |= PKT_TX_IP_CKSUM;
/* update ipv6 header for the reassembled datagram */
ip_hdr = rte_pktmbuf_mtod_offset(m, struct ipv6_hdr *, m->l2_len);
ip_hdr->payload_len = rte_cpu_to_be_16(payload_len);
/*
* remove fragmentation header. note that per RFC2460, we need to update
* the last non-fragmentable header with the "next header" field to contain
* type of the first fragmentable header, but we currently don't support
* other headers, so we assume there are no other headers and thus update
* the main IPv6 header instead.
*/
move_len = m->l2_len + m->l3_len - sizeof(*frag_hdr);
frag_hdr = (struct ipv6_extension_fragment *) (ip_hdr + 1);
ip_hdr->proto = frag_hdr->next_header;
ip_frag_memmove(rte_pktmbuf_mtod_offset(m, char *, sizeof(*frag_hdr)),
rte_pktmbuf_mtod(m, char*), move_len);
rte_pktmbuf_adj(m, sizeof(*frag_hdr));
return m;
}