static u32 running_fragment_id;
+/*
+ * Limitation: Does follow buffer chains in the packet to fragment,
+ * but does not generate buffer chains. I.e. a fragment is always
+ * contained with in a single buffer and limited to the max buffer
+ * size.
+ */
void
-ip4_frag_do_fragment (vlib_main_t * vm, u32 pi, u32 ** buffer,
+ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
ip_frag_error_t * error)
{
- vlib_buffer_t *p;
+ vlib_buffer_t *from_b;
ip4_header_t *ip4;
- u16 mtu, ptr, len, max, rem, offset, ip_frag_id, ip_frag_offset;
- u8 *packet, more;
-
- vec_add1 (*buffer, pi);
- p = vlib_get_buffer (vm, pi);
- offset = vnet_buffer (p)->ip_frag.header_offset;
- mtu = vnet_buffer (p)->ip_frag.mtu;
- packet = (u8 *) vlib_buffer_get_current (p);
- ip4 = (ip4_header_t *) (packet + offset);
-
- rem = clib_net_to_host_u16 (ip4->length) - sizeof (*ip4);
- ptr = 0;
- max = (mtu - sizeof (*ip4) - vnet_buffer (p)->ip_frag.header_offset) & ~0x7;
-
- if (rem > (p->current_length - offset - sizeof (*ip4)))
+ u16 mtu, len, max, rem, offset, ip_frag_id, ip_frag_offset;
+ u8 *org_from_packet, more;
+
+ from_b = vlib_get_buffer (vm, from_bi);
+ offset = vnet_buffer (from_b)->ip_frag.header_offset;
+ mtu = vnet_buffer (from_b)->ip_frag.mtu;
+ org_from_packet = vlib_buffer_get_current (from_b);
+ ip4 = (ip4_header_t *) vlib_buffer_get_current (from_b) + offset;
+
+ rem = clib_net_to_host_u16 (ip4->length) - sizeof (ip4_header_t);
+ max =
+ (mtu - sizeof (ip4_header_t) -
+ vnet_buffer (from_b)->ip_frag.header_offset) & ~0x7;
+
+ if (rem >
+ (vlib_buffer_length_in_chain (vm, from_b) - offset -
+ sizeof (ip4_header_t)))
{
*error = IP_FRAG_ERROR_MALFORMED;
return;
}
- if (mtu < sizeof (*ip4))
+ if (mtu < sizeof (ip4_header_t))
{
*error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
return;
return;
}
- if (p->flags & VLIB_BUFFER_NEXT_PRESENT)
- {
- *error = IP_FRAG_ERROR_MALFORMED;
- return;
- }
-
if (ip4_is_fragment (ip4))
{
ip_frag_id = ip4->fragment_id;
more = 0;
}
- //Do the actual fragmentation
+ u8 *from_data = (void *) (ip4 + 1);
+ vlib_buffer_t *org_from_b = from_b;
+ u16 ptr = 0, fo = 0;
+ u16 left_in_from_buffer =
+ from_b->current_length - offset - sizeof (ip4_header_t);
+
+ /* Do the actual fragmentation */
while (rem)
{
- u32 bi;
- vlib_buffer_t *b;
- ip4_header_t *fip4;
-
- len =
- (rem >
- (mtu - sizeof (*ip4) -
- vnet_buffer (p)->ip_frag.header_offset)) ? max : rem;
-
- if (ptr == 0)
+ u32 to_bi;
+ vlib_buffer_t *to_b;
+ ip4_header_t *to_ip4;
+ u8 *to_data;
+
+ len = (rem > (mtu - sizeof (ip4_header_t) - offset) ? max : rem);
+ if (len != rem) /* Last fragment does not need to divisible by 8 */
+ len &= ~0x7;
+ if (!vlib_buffer_alloc (vm, &to_bi, 1))
{
- bi = pi;
- b = p;
- fip4 = (ip4_header_t *) (vlib_buffer_get_current (b) + offset);
+ *error = IP_FRAG_ERROR_MEMORY;
+ /* XXX: Free already allocated buffers? */
+ return;
}
- else
+ vec_add1 (*buffer, to_bi);
+ to_b = vlib_get_buffer (vm, to_bi);
+ vnet_buffer (to_b)->sw_if_index[VLIB_RX] =
+ vnet_buffer (org_from_b)->sw_if_index[VLIB_RX];
+ vnet_buffer (to_b)->sw_if_index[VLIB_TX] =
+ vnet_buffer (org_from_b)->sw_if_index[VLIB_TX];
+ /* Copy adj_index in case DPO based node is sending for the
+ * fragmentation, the packet would be sent back to the proper
+ * DPO next node and Index
+ */
+ vnet_buffer (to_b)->ip.adj_index[VLIB_RX] =
+ vnet_buffer (org_from_b)->ip.adj_index[VLIB_RX];
+ vnet_buffer (to_b)->ip.adj_index[VLIB_TX] =
+ vnet_buffer (org_from_b)->ip.adj_index[VLIB_TX];
+
+ /* Copy offset and ip4 header */
+ clib_memcpy (to_b->data, org_from_packet,
+ offset + sizeof (ip4_header_t));
+ to_ip4 = vlib_buffer_get_current (to_b) + offset;
+ to_data = (void *) (to_ip4 + 1);
+
+ /* Spin through buffer chain copying data */
+ // XXX: Make sure we don't overflow source buffer!!!
+ if (len > left_in_from_buffer)
{
- if (!vlib_buffer_alloc (vm, &bi, 1))
+ clib_memcpy (to_data, from_data + ptr, left_in_from_buffer);
+
+ /* Move buffer */
+ if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
{
- *error = IP_FRAG_ERROR_MEMORY;
+ *error = IP_FRAG_ERROR_MALFORMED;
return;
}
- vec_add1 (*buffer, bi);
- b = vlib_get_buffer (vm, bi);
- vnet_buffer (b)->sw_if_index[VLIB_RX] =
- vnet_buffer (p)->sw_if_index[VLIB_RX];
- vnet_buffer (b)->sw_if_index[VLIB_TX] =
- vnet_buffer (p)->sw_if_index[VLIB_TX];
- /* Copy Adj_index in case DPO based node is sending for the fragmentation,
- the packet would be sent back to the proper DPO next node and Index */
- vnet_buffer (b)->ip.adj_index[VLIB_RX] =
- vnet_buffer (p)->ip.adj_index[VLIB_RX];
- vnet_buffer (b)->ip.adj_index[VLIB_TX] =
- vnet_buffer (p)->ip.adj_index[VLIB_TX];
- fip4 = (ip4_header_t *) (vlib_buffer_get_current (b) + offset);
-
- //Copy offset and ip4 header
- clib_memcpy (b->data, packet, offset + sizeof (*ip4));
- //Copy data
- clib_memcpy (((u8 *) (fip4)) + sizeof (*fip4),
- packet + offset + sizeof (*fip4) + ptr, len);
+ from_b = vlib_get_buffer (vm, from_b->next_buffer);
+ from_data = (u8 *) vlib_buffer_get_current (from_b);
+ clib_memcpy (to_data + left_in_from_buffer, from_data,
+ len - left_in_from_buffer);
+ ptr = len - left_in_from_buffer;
+ left_in_from_buffer =
+ from_b->current_length - (len - left_in_from_buffer);
+ }
+ else
+ {
+ clib_memcpy (to_data, from_data + ptr, len);
+ left_in_from_buffer -= len;
+ ptr += len;
}
- b->current_length = offset + len + sizeof (*fip4);
+ to_b->current_length = offset + len + sizeof (ip4_header_t);
- fip4->fragment_id = ip_frag_id;
- fip4->flags_and_fragment_offset =
- clib_host_to_net_u16 ((ptr >> 3) + ip_frag_offset);
- fip4->flags_and_fragment_offset |=
+ to_ip4->fragment_id = ip_frag_id;
+ to_ip4->flags_and_fragment_offset =
+ clib_host_to_net_u16 ((fo >> 3) + ip_frag_offset);
+ to_ip4->flags_and_fragment_offset |=
clib_host_to_net_u16 (((len != rem) || more) << 13);
- // ((len0 != rem0) || more0) << 13 is optimization for
- // ((len0 != rem0) || more0) ? IP4_HEADER_FLAG_MORE_FRAGMENTS : 0
- fip4->length = clib_host_to_net_u16 (len + sizeof (*fip4));
- fip4->checksum = ip4_header_checksum (fip4);
+ to_ip4->length = clib_host_to_net_u16 (len + sizeof (ip4_header_t));
+ to_ip4->checksum = ip4_header_checksum (to_ip4);
- if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
+ if (vnet_buffer (org_from_b)->ip_frag.flags & IP_FRAG_FLAG_IP4_HEADER)
{
- //Encapsulating ipv4 header
+ /* Encapsulating ipv4 header */
ip4_header_t *encap_header4 =
- (ip4_header_t *) vlib_buffer_get_current (b);
- encap_header4->length = clib_host_to_net_u16 (b->current_length);
+ (ip4_header_t *) vlib_buffer_get_current (to_b);
+ encap_header4->length = clib_host_to_net_u16 (to_b->current_length);
encap_header4->checksum = ip4_header_checksum (encap_header4);
}
- else if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
+ else if (vnet_buffer (org_from_b)->
+ ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
{
- //Encapsulating ipv6 header
+ /* Encapsulating ipv6 header */
ip6_header_t *encap_header6 =
- (ip6_header_t *) vlib_buffer_get_current (b);
+ (ip6_header_t *) vlib_buffer_get_current (to_b);
encap_header6->payload_length =
- clib_host_to_net_u16 (b->current_length -
+ clib_host_to_net_u16 (to_b->current_length -
sizeof (*encap_header6));
}
-
rem -= len;
- ptr += len;
+ fo += len;
}
+ /* Free original packet chain */
+ vlib_buffer_free_one (vm, from_bi);
}
void
Code Review / vpp.git / blobdiff