gso: fix segmentation when gso_size greater than vlib buffer size

[vpp.git] / src / vnet / interface_output.c

diff --git a/src/vnet/interface_output.c b/src/vnet/interface_output.c
index 28f44c3..92cbaac 100644 (file)
--- a/src/vnet/interface_output.c
+++ b/src/vnet/interface_output.c
@@ -224,7 +224,6 @@ calc_checksums (vlib_main_t * vm, vlib_buffer_t * b)
            ip6_tcp_udp_icmp_compute_checksum (vm, b, ip6, &bogus);
        }
     }
-
   b->flags &= ~VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
   b->flags &= ~VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
   b->flags &= ~VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
@@ -233,13 +232,14 @@ calc_checksums (vlib_main_t * vm, vlib_buffer_t * b)
 static_always_inline u16
 tso_alloc_tx_bufs (vlib_main_t * vm,
                   vnet_interface_per_thread_data_t * ptd,
-                  vlib_buffer_t * b0, u16 l4_hdr_sz)
+                  vlib_buffer_t * b0, u32 n_bytes_b0, u16 l234_sz,
+                  u16 gso_size)
 {
-  u32 n_bytes_b0 = vlib_buffer_length_in_chain (vm, b0);
-  u16 gso_size = vnet_buffer2 (b0)->gso_size;
-  u16 l234_sz = vnet_buffer (b0)->l4_hdr_offset + l4_hdr_sz;
+  u16 size =
+    clib_min (gso_size, vlib_buffer_get_default_data_size (vm) - l234_sz);
+
   /* rounded-up division */
-  u16 n_bufs = (n_bytes_b0 - l234_sz + (gso_size - 1)) / gso_size;
+  u16 n_bufs = (n_bytes_b0 - l234_sz + (size - 1)) / size;
   u16 n_alloc;
 
   ASSERT (n_bufs > 0);
@@ -251,18 +251,19 @@ tso_alloc_tx_bufs (vlib_main_t * vm,
       vlib_buffer_free (vm, ptd->split_buffers, n_alloc);
       return 0;
     }
-  return 1;
+  return n_alloc;
 }
 
 static_always_inline void
 tso_init_buf_from_template_base (vlib_buffer_t * nb0, vlib_buffer_t * b0,
                                 u32 flags, u16 length)
 {
-  nb0->current_data = 0;
+  nb0->current_data = b0->current_data;
   nb0->total_length_not_including_first_buffer = 0;
   nb0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID | flags;
   clib_memcpy_fast (&nb0->opaque, &b0->opaque, sizeof (nb0->opaque));
-  clib_memcpy_fast (nb0->data, b0->data, length);
+  clib_memcpy_fast (vlib_buffer_get_current (nb0),
+                   vlib_buffer_get_current (b0), length);
   nb0->current_length = length;
 }
 
@@ -276,8 +277,9 @@ tso_init_buf_from_template (vlib_main_t * vm, vlib_buffer_t * nb0,
 
   *p_dst_left =
     clib_min (gso_size,
-             vlib_buffer_get_default_data_size (vm) - template_data_sz);
-  *p_dst_ptr = nb0->data + template_data_sz;
+             vlib_buffer_get_default_data_size (vm) - (template_data_sz +
+                                                       nb0->current_data));
+  *p_dst_ptr = vlib_buffer_get_current (nb0) + template_data_sz;
 
   tcp_header_t *tcp =
     (tcp_header_t *) (nb0->data + vnet_buffer (nb0)->l4_hdr_offset);
@@ -298,11 +300,11 @@ tso_fixup_segmented_buf (vlib_buffer_t * b0, u8 tcp_flags, int is_ip6)
   if (is_ip6)
     ip6->payload_length =
       clib_host_to_net_u16 (b0->current_length -
-                           vnet_buffer (b0)->l4_hdr_offset);
+                           (l4_hdr_offset - b0->current_data));
   else
     ip4->length =
       clib_host_to_net_u16 (b0->current_length -
-                           vnet_buffer (b0)->l3_hdr_offset);
+                           (l3_hdr_offset - b0->current_data));
 }
 
 /**
@@ -343,16 +345,18 @@ tso_segment_buffer (vlib_main_t * vm, vnet_interface_per_thread_data_t * ptd,
 
   u32 default_bflags =
     sb0->flags & ~(VNET_BUFFER_F_GSO | VLIB_BUFFER_NEXT_PRESENT);
-  u16 l234_sz = vnet_buffer (sb0)->l4_hdr_offset + l4_hdr_sz;
+  u16 l234_sz = vnet_buffer (sb0)->l4_hdr_offset + l4_hdr_sz
+    - sb0->current_data;
   int first_data_size = clib_min (gso_size, sb0->current_length - l234_sz);
   next_tcp_seq += first_data_size;
 
-  if (PREDICT_FALSE (!tso_alloc_tx_bufs (vm, ptd, sb0, l4_hdr_sz)))
+  if (PREDICT_FALSE
+      (!tso_alloc_tx_bufs (vm, ptd, sb0, n_bytes_b0, l234_sz, gso_size)))
     return 0;
 
   vlib_buffer_t *b0 = vlib_get_buffer (vm, ptd->split_buffers[0]);
   tso_init_buf_from_template_base (b0, sb0, default_bflags,
-                                  l4_hdr_sz + first_data_size);
+                                  l234_sz + first_data_size);
 
   u32 total_src_left = n_bytes_b0 - l234_sz - first_data_size;
   if (total_src_left)
@@ -367,9 +371,8 @@ tso_segment_buffer (vlib_main_t * vm, vnet_interface_per_thread_data_t * ptd,
       vlib_buffer_t *cdb0;
       u16 dbi = 1;             /* the buffer [0] is b0 */
 
-      src_ptr = sb0->data + l234_sz + first_data_size;
+      src_ptr = vlib_buffer_get_current (sb0) + l234_sz + first_data_size;
       src_left = sb0->current_length - l234_sz - first_data_size;
-      b0->current_length = l234_sz + first_data_size;
 
       tso_fixup_segmented_buf (b0, tcp_flags_no_fin_psh, is_ip6);
       if (do_tx_offloads)
@@ -410,7 +413,7 @@ tso_segment_buffer (vlib_main_t * vm, vnet_interface_per_thread_data_t * ptd,
                  csbi0 = next_bi;
                  csb0 = vlib_get_buffer (vm, csbi0);
                  src_left = csb0->current_length;
-                 src_ptr = csb0->data;
+                 src_ptr = vlib_buffer_get_current (csb0);
                }
              else
                {
@@ -800,7 +803,7 @@ static_always_inline void vnet_interface_pcap_tx_trace
   u32 n_left_from, *from;
   u32 sw_if_index;
 
-  if (PREDICT_TRUE (vm->pcap[VLIB_TX].pcap_enable == 0))
+  if (PREDICT_TRUE (vlib_global_main.pcap[VLIB_TX].pcap_enable == 0))
     return;
 
   if (sw_if_index_from_buffer == 0)
@@ -822,9 +825,10 @@ static_always_inline void vnet_interface_pcap_tx_trace
       if (sw_if_index_from_buffer)
        sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 
-      if (vm->pcap[VLIB_TX].pcap_sw_if_index == 0 ||
-         vm->pcap[VLIB_TX].pcap_sw_if_index == sw_if_index)
-       pcap_add_buffer (&vm->pcap[VLIB_TX].pcap_main, vm, bi0, 512);
+      if (vlib_global_main.pcap[VLIB_TX].pcap_sw_if_index == 0 ||
+         vlib_global_main.pcap[VLIB_TX].pcap_sw_if_index == sw_if_index)
+       pcap_add_buffer (&vlib_global_main.pcap[VLIB_TX].pcap_main, vm, bi0,
+                        512);
       from++;
       n_left_from--;
     }
@@ -1410,7 +1414,7 @@ pcap_drop_trace_command_fn (vlib_main_t * vm,
 
              clib_memset (&im->pcap_main, 0, sizeof (im->pcap_main));
              im->pcap_main.file_name = (char *) im->pcap_filename;
-             im->pcap_main.n_packets_to_capture = 100;
+             im->pcap_main.n_packets_to_capture = PCAP_DEF_PKT_TO_CAPTURE;
              if (im->pcap_pkts_to_capture)
                im->pcap_main.n_packets_to_capture = im->pcap_pkts_to_capture;
 
@@ -1438,6 +1442,8 @@ pcap_drop_trace_command_fn (vlib_main_t * vm,
                  im->pcap_main.n_packets_to_capture =
                    im->pcap_main.n_packets_captured;
                  error = pcap_write (&im->pcap_main);
+                 if (im->pcap_main.file_descriptor >= 0)
+                   pcap_close (&im->pcap_main);
                  if (error)
                    clib_error_report (error);
                  else