From 02833ff3294f4abbd8e3d52b38446e0f8f533ffc Mon Sep 17 00:00:00 2001 From: Srikanth A Date: Wed, 2 Oct 2019 17:48:58 -0700 Subject: tcp: custom checksum calculations for Ipv4/Ipv6 Type: feature Based on the configuration, we can disable checksum offload capability and calculate checksum while pushing the TCP & IP header. This saves some cycles when VPP stack is used in legacy hardware devices. Signed-off-by: Srikanth A Change-Id: Ic1b3fcf3040917e47ee65263694ebf7437ac5668 (cherry picked from commit 3642782a2748503f5b5ccf89d1575c1d489948ef) --- src/vnet/ip/ip.h | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) (limited to 'src/vnet/ip/ip.h') diff --git a/src/vnet/ip/ip.h b/src/vnet/ip/ip.h index 7a82dcf8f2b..65ccaef40c2 100644 --- a/src/vnet/ip/ip.h +++ b/src/vnet/ip/ip.h @@ -195,6 +195,85 @@ ip_incremental_checksum_buffer (vlib_main_t * vm, return sum; } +always_inline u16 +ip_calculate_l4_checksum (vlib_main_t * vm, vlib_buffer_t * p0, + ip_csum_t sum0, u32 payload_length, + u8 * iph, u32 ip_header_size, u8 * l4h) +{ + u16 sum16; + u8 *data_this_buffer, length_odd; + u32 n_bytes_left, n_this_buffer, n_ip_bytes_this_buffer; + + n_bytes_left = payload_length; + + if (l4h) /* packet l4 header and no buffer chain involved */ + { + ASSERT (p0 == NULL); + n_this_buffer = payload_length; + data_this_buffer = l4h; + } + else + { + ASSERT (p0); + if (iph) /* ip header pointer set to packet in buffer */ + { + ASSERT (ip_header_size); + n_this_buffer = payload_length; + data_this_buffer = iph + ip_header_size; /* at l4 header */ + n_ip_bytes_this_buffer = + p0->current_length - (((u8 *) iph - p0->data) - p0->current_data); + if (PREDICT_FALSE (payload_length + ip_header_size > + n_ip_bytes_this_buffer)) + { + n_this_buffer = n_ip_bytes_this_buffer - ip_header_size; + if (PREDICT_FALSE (n_this_buffer >> 31)) + { /* error - ip header don't fit this buffer */ + ASSERT (0); + return 0xfefe; + } + } + } + else /* packet in buffer with no ip header */ + { /* buffer current pointer at l4 header */ + n_this_buffer = p0->current_length; + data_this_buffer = vlib_buffer_get_current (p0); + } + n_this_buffer = clib_min (n_this_buffer, n_bytes_left); + } + + while (1) + { + sum0 = ip_incremental_checksum (sum0, data_this_buffer, n_this_buffer); + n_bytes_left -= n_this_buffer; + if (n_bytes_left == 0) + break; + + if (!(p0->flags & VLIB_BUFFER_NEXT_PRESENT)) + { + ASSERT (0); /* error - more buffer expected */ + return 0xfefe; + } + + length_odd = (n_this_buffer & 1); + + p0 = vlib_get_buffer (vm, p0->next_buffer); + data_this_buffer = vlib_buffer_get_current (p0); + n_this_buffer = clib_min (p0->current_length, n_bytes_left); + + if (PREDICT_FALSE (length_odd)) + { + /* Prepend a 0 byte to maintain 2-byte checksum alignment */ + data_this_buffer--; + n_this_buffer++; + n_bytes_left++; + data_this_buffer[0] = 0; + } + } + + sum16 = ~ip_csum_fold (sum0); + return sum16; +} + void ip_del_all_interface_addresses (vlib_main_t * vm, u32 sw_if_index); extern vlib_node_registration_t ip4_inacl_node; -- cgit 1.2.3-korg