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-rw-r--r--src/vnet/ip/ip_frag.c581
1 files changed, 581 insertions, 0 deletions
diff --git a/src/vnet/ip/ip_frag.c b/src/vnet/ip/ip_frag.c
new file mode 100644
index 00000000000..ca062bfd5e8
--- /dev/null
+++ b/src/vnet/ip/ip_frag.c
@@ -0,0 +1,581 @@
+/*---------------------------------------------------------------------------
+ * Copyright (c) 2009-2014 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *---------------------------------------------------------------------------
+ */
+/*
+ * IPv4 Fragmentation Node
+ *
+ *
+ */
+
+#include "ip_frag.h"
+
+#include <vnet/ip/ip.h>
+
+
+typedef struct
+{
+ u8 ipv6;
+ u16 header_offset;
+ u16 mtu;
+ u8 next;
+ u16 n_fragments;
+} ip_frag_trace_t;
+
+static u8 *
+format_ip_frag_trace (u8 * s, va_list * args)
+{
+ CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+ CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+ ip_frag_trace_t *t = va_arg (*args, ip_frag_trace_t *);
+ s = format (s, "IPv%s offset: %u mtu: %u fragments: %u",
+ t->ipv6 ? "6" : "4", t->header_offset, t->mtu, t->n_fragments);
+ return s;
+}
+
+static u32 running_fragment_id;
+
+static void
+ip4_frag_do_fragment (vlib_main_t * vm, u32 pi, u32 ** buffer,
+ ip_frag_error_t * error)
+{
+ vlib_buffer_t *p;
+ 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)))
+ {
+ *error = IP_FRAG_ERROR_MALFORMED;
+ return;
+ }
+
+ if (mtu < sizeof (*ip4))
+ {
+ *error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
+ return;
+ }
+
+ if (ip4->flags_and_fragment_offset &
+ clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT))
+ {
+ *error = IP_FRAG_ERROR_DONT_FRAGMENT_SET;
+ return;
+ }
+
+ if (ip4_is_fragment (ip4))
+ {
+ ip_frag_id = ip4->fragment_id;
+ ip_frag_offset = ip4_get_fragment_offset (ip4);
+ more =
+ ! !(ip4->flags_and_fragment_offset &
+ clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS));
+ }
+ else
+ {
+ ip_frag_id = (++running_fragment_id);
+ ip_frag_offset = 0;
+ more = 0;
+ }
+
+ //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)
+ {
+ bi = pi;
+ b = p;
+ fip4 = (ip4_header_t *) (vlib_buffer_get_current (b) + offset);
+ }
+ else
+ {
+ if (!vlib_buffer_alloc (vm, &bi, 1))
+ {
+ *error = IP_FRAG_ERROR_MEMORY;
+ 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];
+ 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);
+ }
+ b->current_length = offset + len + sizeof (*fip4);
+
+ 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 |=
+ 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);
+
+ if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP4_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);
+ encap_header4->checksum = ip4_header_checksum (encap_header4);
+ }
+ else if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
+ {
+ //Encapsulating ipv6 header
+ ip6_header_t *encap_header6 =
+ (ip6_header_t *) vlib_buffer_get_current (b);
+ encap_header6->payload_length =
+ clib_host_to_net_u16 (b->current_length -
+ sizeof (*encap_header6));
+ }
+
+ rem -= len;
+ ptr += len;
+ }
+}
+
+void
+ip_frag_set_vnet_buffer (vlib_buffer_t * b, u16 offset, u16 mtu,
+ u8 next_index, u8 flags)
+{
+ vnet_buffer (b)->ip_frag.header_offset = offset;
+ vnet_buffer (b)->ip_frag.mtu = mtu;
+ vnet_buffer (b)->ip_frag.next_index = next_index;
+ vnet_buffer (b)->ip_frag.flags = flags;
+}
+
+static uword
+ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+ u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
+ vlib_node_runtime_t *error_node =
+ vlib_node_get_runtime (vm, ip4_frag_node.index);
+ from = vlib_frame_vector_args (frame);
+ n_left_from = frame->n_vectors;
+ next_index = node->cached_next_index;
+ u32 frag_sent = 0, small_packets = 0;
+ u32 *buffer = 0;
+
+ while (n_left_from > 0)
+ {
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ u32 pi0, *frag_from, frag_left;
+ vlib_buffer_t *p0;
+ ip_frag_error_t error0;
+ ip4_frag_next_t next0;
+
+ //Note: The packet is not enqueued now.
+ //It is instead put in a vector where other fragments
+ //will be put as well.
+ pi0 = from[0];
+ from += 1;
+ n_left_from -= 1;
+ error0 = IP_FRAG_ERROR_NONE;
+
+ p0 = vlib_get_buffer (vm, pi0);
+ ip4_frag_do_fragment (vm, pi0, &buffer, &error0);
+
+ if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ ip_frag_trace_t *tr =
+ vlib_add_trace (vm, node, p0, sizeof (*tr));
+ tr->header_offset = vnet_buffer (p0)->ip_frag.header_offset;
+ tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
+ tr->ipv6 = 0;
+ tr->n_fragments = vec_len (buffer);
+ tr->next = vnet_buffer (p0)->ip_frag.next_index;
+ }
+
+ if (error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
+ {
+ icmp4_error_set_vnet_buffer (p0, ICMP4_destination_unreachable,
+ ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
+ vnet_buffer (p0)->ip_frag.mtu);
+ vlib_buffer_advance (p0,
+ vnet_buffer (p0)->ip_frag.header_offset);
+ next0 = IP4_FRAG_NEXT_ICMP_ERROR;
+ }
+ else
+ next0 =
+ (error0 ==
+ IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
+ ip_frag.next_index : IP4_FRAG_NEXT_DROP;
+
+ if (error0 == IP_FRAG_ERROR_NONE)
+ {
+ frag_sent += vec_len (buffer);
+ small_packets += (vec_len (buffer) == 1);
+ }
+ else
+ vlib_error_count (vm, ip4_frag_node.index, error0, 1);
+
+ //Send fragments that were added in the frame
+ frag_from = buffer;
+ frag_left = vec_len (buffer);
+
+ while (frag_left > 0)
+ {
+ while (frag_left > 0 && n_left_to_next > 0)
+ {
+ u32 i;
+ i = to_next[0] = frag_from[0];
+ frag_from += 1;
+ frag_left -= 1;
+ to_next += 1;
+ n_left_to_next -= 1;
+
+ vlib_get_buffer (vm, i)->error = error_node->errors[error0];
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+ to_next, n_left_to_next, i,
+ next0);
+ }
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ vlib_get_next_frame (vm, node, next_index, to_next,
+ n_left_to_next);
+ }
+ vec_reset_length (buffer);
+ }
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+ vec_free (buffer);
+
+ vlib_node_increment_counter (vm, ip4_frag_node.index,
+ IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
+ vlib_node_increment_counter (vm, ip4_frag_node.index,
+ IP_FRAG_ERROR_SMALL_PACKET, small_packets);
+
+ return frame->n_vectors;
+}
+
+
+static void
+ip6_frag_do_fragment (vlib_main_t * vm, u32 pi, u32 ** buffer,
+ ip_frag_error_t * error)
+{
+ vlib_buffer_t *p;
+ ip6_header_t *ip6_hdr;
+ ip6_frag_hdr_t *frag_hdr;
+ u8 *payload, *next_header;
+
+ p = vlib_get_buffer (vm, pi);
+
+ //Parsing the IPv6 headers
+ ip6_hdr =
+ vlib_buffer_get_current (p) + vnet_buffer (p)->ip_frag.header_offset;
+ payload = (u8 *) (ip6_hdr + 1);
+ next_header = &ip6_hdr->protocol;
+ if (*next_header == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS)
+ {
+ next_header = payload;
+ payload += payload[1] * 8;
+ }
+
+ if (*next_header == IP_PROTOCOL_IP6_DESTINATION_OPTIONS)
+ {
+ next_header = payload;
+ payload += payload[1] * 8;
+ }
+
+ if (*next_header == IP_PROTOCOL_IPV6_ROUTE)
+ {
+ next_header = payload;
+ payload += payload[1] * 8;
+ }
+
+ if (PREDICT_FALSE
+ (payload >= (u8 *) vlib_buffer_get_current (p) + p->current_length))
+ {
+ //A malicious packet could set an extension header with a too big size
+ //and make us modify another vlib_buffer
+ *error = IP_FRAG_ERROR_MALFORMED;
+ return;
+ }
+
+ u8 has_more;
+ u16 initial_offset;
+ if (*next_header == IP_PROTOCOL_IPV6_FRAGMENTATION)
+ {
+ //The fragmentation header is already there
+ frag_hdr = (ip6_frag_hdr_t *) payload;
+ has_more = ip6_frag_hdr_more (frag_hdr);
+ initial_offset = ip6_frag_hdr_offset (frag_hdr);
+ }
+ else
+ {
+ //Insert a fragmentation header in the packet
+ u8 nh = *next_header;
+ *next_header = IP_PROTOCOL_IPV6_FRAGMENTATION;
+ vlib_buffer_advance (p, -sizeof (*frag_hdr));
+ u8 *start = vlib_buffer_get_current (p);
+ memmove (start, start + sizeof (*frag_hdr),
+ payload - (start + sizeof (*frag_hdr)));
+ frag_hdr = (ip6_frag_hdr_t *) (payload - sizeof (*frag_hdr));
+ frag_hdr->identification = ++running_fragment_id;
+ frag_hdr->next_hdr = nh;
+ frag_hdr->rsv = 0;
+ has_more = 0;
+ initial_offset = 0;
+ }
+ payload = (u8 *) (frag_hdr + 1);
+
+ u16 headers_len = payload - (u8 *) vlib_buffer_get_current (p);
+ u16 max_payload = vnet_buffer (p)->ip_frag.mtu - headers_len;
+ u16 rem = p->current_length - headers_len;
+ u16 ptr = 0;
+
+ if (max_payload < 8)
+ {
+ *error = IP_FRAG_ERROR_CANT_FRAGMENT_HEADER;
+ return;
+ }
+
+ while (rem)
+ {
+ u32 bi;
+ vlib_buffer_t *b;
+ u16 len = (rem > max_payload) ? (max_payload & ~0x7) : rem;
+ rem -= len;
+
+ if (ptr != 0)
+ {
+ if (!vlib_buffer_alloc (vm, &bi, 1))
+ {
+ *error = IP_FRAG_ERROR_MEMORY;
+ return;
+ }
+ 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];
+ clib_memcpy (vlib_buffer_get_current (b),
+ vlib_buffer_get_current (p), headers_len);
+ clib_memcpy (vlib_buffer_get_current (b) + headers_len,
+ payload + ptr, len);
+ frag_hdr =
+ vlib_buffer_get_current (b) + headers_len - sizeof (*frag_hdr);
+ }
+ else
+ {
+ bi = pi;
+ b = vlib_get_buffer (vm, bi);
+ //frag_hdr already set here
+ }
+
+ ip6_hdr =
+ vlib_buffer_get_current (b) + vnet_buffer (p)->ip_frag.header_offset;
+ frag_hdr->fragment_offset_and_more =
+ ip6_frag_hdr_offset_and_more (initial_offset + (ptr >> 3),
+ (rem || has_more));
+ b->current_length = headers_len + len;
+ ip6_hdr->payload_length =
+ clib_host_to_net_u16 (b->current_length -
+ vnet_buffer (p)->ip_frag.header_offset -
+ sizeof (*ip6_hdr));
+
+ if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP4_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);
+ encap_header4->checksum = ip4_header_checksum (encap_header4);
+ }
+ else if (vnet_buffer (p)->ip_frag.flags & IP_FRAG_FLAG_IP6_HEADER)
+ {
+ //Encapsulating ipv6 header
+ ip6_header_t *encap_header6 =
+ (ip6_header_t *) vlib_buffer_get_current (b);
+ encap_header6->payload_length =
+ clib_host_to_net_u16 (b->current_length -
+ sizeof (*encap_header6));
+ }
+
+ vec_add1 (*buffer, bi);
+
+ ptr += len;
+ }
+}
+
+static uword
+ip6_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+ u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
+ vlib_node_runtime_t *error_node =
+ vlib_node_get_runtime (vm, ip6_frag_node.index);
+ from = vlib_frame_vector_args (frame);
+ n_left_from = frame->n_vectors;
+ next_index = node->cached_next_index;
+ u32 frag_sent = 0, small_packets = 0;
+ u32 *buffer = 0;
+
+ while (n_left_from > 0)
+ {
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ u32 pi0, *frag_from, frag_left;
+ vlib_buffer_t *p0;
+ ip_frag_error_t error0;
+ ip6_frag_next_t next0;
+
+ pi0 = from[0];
+ from += 1;
+ n_left_from -= 1;
+ error0 = IP_FRAG_ERROR_NONE;
+
+ p0 = vlib_get_buffer (vm, pi0);
+ ip6_frag_do_fragment (vm, pi0, &buffer, &error0);
+
+ if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ ip_frag_trace_t *tr =
+ vlib_add_trace (vm, node, p0, sizeof (*tr));
+ tr->header_offset = vnet_buffer (p0)->ip_frag.header_offset;
+ tr->mtu = vnet_buffer (p0)->ip_frag.mtu;
+ tr->ipv6 = 1;
+ tr->n_fragments = vec_len (buffer);
+ tr->next = vnet_buffer (p0)->ip_frag.next_index;
+ }
+
+ next0 =
+ (error0 ==
+ IP_FRAG_ERROR_NONE) ? vnet_buffer (p0)->
+ ip_frag.next_index : IP6_FRAG_NEXT_DROP;
+ frag_sent += vec_len (buffer);
+ small_packets += (vec_len (buffer) == 1);
+
+ //Send fragments that were added in the frame
+ frag_from = buffer;
+ frag_left = vec_len (buffer);
+ while (frag_left > 0)
+ {
+ while (frag_left > 0 && n_left_to_next > 0)
+ {
+ u32 i;
+ i = to_next[0] = frag_from[0];
+ frag_from += 1;
+ frag_left -= 1;
+ to_next += 1;
+ n_left_to_next -= 1;
+
+ vlib_get_buffer (vm, i)->error = error_node->errors[error0];
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+ to_next, n_left_to_next, i,
+ next0);
+ }
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ vlib_get_next_frame (vm, node, next_index, to_next,
+ n_left_to_next);
+ }
+ vec_reset_length (buffer);
+ }
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+ vec_free (buffer);
+ vlib_node_increment_counter (vm, ip6_frag_node.index,
+ IP_FRAG_ERROR_FRAGMENT_SENT, frag_sent);
+ vlib_node_increment_counter (vm, ip6_frag_node.index,
+ IP_FRAG_ERROR_SMALL_PACKET, small_packets);
+
+ return frame->n_vectors;
+}
+
+static char *ip4_frag_error_strings[] = {
+#define _(sym,string) string,
+ foreach_ip_frag_error
+#undef _
+};
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ip4_frag_node) = {
+ .function = ip4_frag,
+ .name = IP4_FRAG_NODE_NAME,
+ .vector_size = sizeof (u32),
+ .format_trace = format_ip_frag_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+
+ .n_errors = IP_FRAG_N_ERROR,
+ .error_strings = ip4_frag_error_strings,
+
+ .n_next_nodes = IP4_FRAG_N_NEXT,
+ .next_nodes = {
+ [IP4_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
+ [IP4_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
+ [IP4_FRAG_NEXT_ICMP_ERROR] = "ip4-icmp-error",
+ [IP4_FRAG_NEXT_DROP] = "error-drop"
+ },
+};
+/* *INDENT-ON* */
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ip6_frag_node) = {
+ .function = ip6_frag,
+ .name = IP6_FRAG_NODE_NAME,
+ .vector_size = sizeof (u32),
+ .format_trace = format_ip_frag_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+
+ .n_errors = IP_FRAG_N_ERROR,
+ .error_strings = ip4_frag_error_strings,
+
+ .n_next_nodes = IP6_FRAG_N_NEXT,
+ .next_nodes = {
+ [IP6_FRAG_NEXT_IP4_LOOKUP] = "ip4-lookup",
+ [IP6_FRAG_NEXT_IP6_LOOKUP] = "ip6-lookup",
+ [IP6_FRAG_NEXT_DROP] = "error-drop"
+ },
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */