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Diffstat (limited to 'src/vnet/lisp-cp/packets.c')
| -rw-r--r-- | src/vnet/lisp-cp/packets.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/src/vnet/lisp-cp/packets.c b/src/vnet/lisp-cp/packets.c new file mode 100644 index 00000000..25086b8e --- /dev/null +++ b/src/vnet/lisp-cp/packets.c @@ -0,0 +1,226 @@ +/* + * Copyright (c) 2016 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. + */ + +#include <vnet/lisp-cp/packets.h> +#include <vnet/lisp-cp/lisp_cp_messages.h> +#include <vnet/udp/udp_packet.h> + +/* Returns IP ID for the packet */ +/* static u16 ip_id = 0; +static inline u16 +get_IP_ID() +{ + ip_id++; + return (ip_id); +} */ + +u16 +udp_ip4_checksum (const void *b, u32 len, u8 * src, u8 * dst) +{ + const u16 *buf = b; + u16 *ip_src = (u16 *) src; + u16 *ip_dst = (u16 *) dst; + u32 length = len; + u32 sum = 0; + + while (len > 1) + { + sum += *buf++; + if (sum & 0x80000000) + sum = (sum & 0xFFFF) + (sum >> 16); + len -= 2; + } + + /* Add the padding if the packet length is odd */ + if (len & 1) + sum += *((u8 *) buf); + + /* Add the pseudo-header */ + sum += *(ip_src++); + sum += *ip_src; + + sum += *(ip_dst++); + sum += *ip_dst; + + sum += clib_host_to_net_u16 (IP_PROTOCOL_UDP); + sum += clib_host_to_net_u16 (length); + + /* Add the carries */ + while (sum >> 16) + sum = (sum & 0xFFFF) + (sum >> 16); + + /* Return the one's complement of sum */ + return ((u16) (~sum)); +} + +u16 +udp_ip6_checksum (ip6_header_t * ip6, udp_header_t * up, u32 len) +{ + size_t i; + register const u16 *sp; + u32 sum; + union + { + struct + { + ip6_address_t ph_src; + ip6_address_t ph_dst; + u32 ph_len; + u8 ph_zero[3]; + u8 ph_nxt; + } ph; + u16 pa[20]; + } phu; + + /* pseudo-header */ + memset (&phu, 0, sizeof (phu)); + phu.ph.ph_src = ip6->src_address; + phu.ph.ph_dst = ip6->dst_address; + phu.ph.ph_len = clib_host_to_net_u32 (len); + phu.ph.ph_nxt = IP_PROTOCOL_UDP; + + sum = 0; + for (i = 0; i < sizeof (phu.pa) / sizeof (phu.pa[0]); i++) + sum += phu.pa[i]; + + sp = (const u16 *) up; + + for (i = 0; i < (len & ~1); i += 2) + sum += *sp++; + + if (len & 1) + sum += clib_host_to_net_u16 ((*(const u8 *) sp) << 8); + + while (sum > 0xffff) + sum = (sum & 0xffff) + (sum >> 16); + sum = ~sum & 0xffff; + + return (sum); +} + +u16 +udp_checksum (udp_header_t * uh, u32 udp_len, void *ih, u8 version) +{ + switch (version) + { + case IP4: + return (udp_ip4_checksum (uh, udp_len, + ((ip4_header_t *) ih)->src_address.as_u8, + ((ip4_header_t *) ih)->dst_address.as_u8)); + case IP6: + return (udp_ip6_checksum (ih, uh, udp_len)); + default: + return ~0; + } +} + +void * +pkt_push_udp (vlib_main_t * vm, vlib_buffer_t * b, u16 sp, u16 dp) +{ + udp_header_t *uh; + u16 udp_len = sizeof (udp_header_t) + vlib_buffer_length_in_chain (vm, b); + + uh = vlib_buffer_push_uninit (b, sizeof (*uh)); + + uh->src_port = clib_host_to_net_u16 (sp); + uh->dst_port = clib_host_to_net_u16 (dp); + uh->length = clib_host_to_net_u16 (udp_len); + uh->checksum = 0; + return uh; +} + +void * +pkt_push_ip (vlib_main_t * vm, vlib_buffer_t * b, ip_address_t * src, + ip_address_t * dst, u32 proto, u8 csum_offload) +{ + if (ip_addr_version (src) != ip_addr_version (dst)) + { + clib_warning ("src %U and dst %U IP have different AFI! Discarding!", + format_ip_address, src, format_ip_address, dst); + return 0; + } + + switch (ip_addr_version (src)) + { + case IP4: + return vlib_buffer_push_ip4 (vm, b, &ip_addr_v4 (src), + &ip_addr_v4 (dst), proto, csum_offload); + break; + case IP6: + return vlib_buffer_push_ip6 (vm, b, &ip_addr_v6 (src), + &ip_addr_v6 (dst), proto); + break; + } + + return 0; +} + +void * +pkt_push_udp_and_ip (vlib_main_t * vm, vlib_buffer_t * b, u16 sp, u16 dp, + ip_address_t * sip, ip_address_t * dip, u8 csum_offload) +{ + u16 udpsum; + udp_header_t *uh; + void *ih; + + uh = pkt_push_udp (vm, b, sp, dp); + + if (csum_offload) + { + ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP, 1); + b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM; + vnet_buffer (b)->l3_hdr_offset = (u8 *) ih - b->data; + vnet_buffer (b)->l4_hdr_offset = (u8 *) uh - b->data; + uh->checksum = 0; + } + else + { + ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP, 0); + udpsum = udp_checksum (uh, clib_net_to_host_u16 (uh->length), ih, + ip_addr_version (sip)); + if (udpsum == (u16) ~ 0) + { + clib_warning ("Failed UDP checksum! Discarding"); + return 0; + } + /* clear flags used for csum since we're not offloading */ + b->flags &= ~(VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_IS_IP6); + uh->checksum = udpsum; + } + return ih; +} + +void * +pkt_push_ecm_hdr (vlib_buffer_t * b) +{ + ecm_hdr_t *h; + h = vlib_buffer_push_uninit (b, sizeof (h[0])); + + memset (h, 0, sizeof (h[0])); + h->type = LISP_ENCAP_CONTROL_TYPE; + memset (h->reserved2, 0, sizeof (h->reserved2)); + + return h; +} + +/* *INDENT-ON* */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |