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Diffstat (limited to 'lib/src/base.h')
| -rwxr-xr-x | lib/src/base.h | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/lib/src/base.h b/lib/src/base.h new file mode 100755 index 000000000..c1bd23aeb --- /dev/null +++ b/lib/src/base.h @@ -0,0 +1,136 @@ +/* + * Copyright (c) 2017-2019 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. + */ + +/** + * @file base.h + * @brief Base hICN definitions. + */ + +#ifndef HICN_BASE_H +#define HICN_BASE_H + +#include "common.h" + +/* Default header fields */ +#define HICN_DEFAULT_TTL 254 + +typedef u32 hicn_faceid_t; +typedef u8 hicn_pathlabel_t; +typedef u32 hicn_lifetime_t; + +#define HICN_MAX_LIFETIME HICN_MAX_LIFETIME_SCALED << HICN_MAX_LIFETIME_MULTIPLIER +#define HICN_MAX_LIFETIME_SCALED 0xFFFF +#define HICN_MAX_LIFETIME_MULTIPLIER 0xF /* 4 bits */ + +/** + * @brief hICN packet format type + * + * The hICN type represents the sequence of protocols that we can find in packet + * headers. They are represented as a quartet of u8 values, correponding to + * IANA protocol assignment, and read from right to left. This is done to + * faciliate decapsulation of packet header by simple shift/mask operations. + * + * For instance, an IPv6/TCP packet will be identified as : + * [IPPROTO_NONE, IPPROTO_NONE, IPPROTO_TCP, IPPROTO_IPV6] + * + * We expect four elements to be sufficient for most uses, the max being + * currently used by an hypothetical signed MAP-Me update : + * [IPPROTO_ICMPRD, IPPROTO_AH, IPPROTO_ICMP, IPPROTO_IPV6] + */ +typedef union +{ + /** protocol layers representation */ + struct + { +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + u8 l1; /**< First layer */ + u8 l2; /**< Second layer */ + u8 l3; /**< Third layer */ + u8 l4; /**< Fourth layer */ +#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + u8 l4; /**< Fourth layer */ + u8 l3; /**< Third layer */ + u8 l2; /**< Second layer */ + u8 l1; /**< First layer */ +#else +#error "Unsupported endianness" +#endif + }; + /** u32 representation */ + u32 as_u32; +} hicn_type_t; + +/* Common protocol layers */ +#define HICN_TYPE_IPV4_TCP (hicn_type_t) {{ .l4 = IPPROTO_NONE, .l3 = IPPROTO_NONE, .l2 = IPPROTO_TCP, .l1 = IPPROTO_IP }} +#define HICN_TYPE_IPV4_ICMP (hicn_type_t) {{ .l4 = IPPROTO_NONE, .l3 = IPPROTO_NONE, .l2 = IPPROTO_ICMP, .l1 = IPPROTO_IP }} +#define HICN_TYPE_IPV6_TCP (hicn_type_t) {{ .l4 = IPPROTO_NONE, .l3 = IPPROTO_NONE, .l2 = IPPROTO_TCP, .l1 = IPPROTO_IPV6 }} +#define HICN_TYPE_IPV6_ICMP (hicn_type_t) {{ .l4 = IPPROTO_NONE, .l3 = IPPROTO_NONE, .l2 = IPPROTO_ICMPV6, .l1 = IPPROTO_IPV6 }} + + +/** + * @brief hICN Payload type + * + * This type distinguishes several types of data packet, which can either carry + * content data, or Manifest + */ +typedef enum +{ + HPT_DATA = 0, + HPT_MANIFEST = 1, + HPT_UNSPEC = 999 +} hicn_payload_type_t; + +/** + * @brief Path label computations + * + * Path label is computed by accumulating the identifiers of successive output + * faces as a Data packet is traveling from its producer back to the consumer + * originating the Interest. + * + * NOTE: this computation is not (yet) part of the hICN specification. + */ + +#define HICN_PATH_LABEL_MASK 0xF000 /* 1000 0000 0000 0000 */ +#define HICN_PATH_LABEL_SIZE 8 + +/** + * @brief Path label update + * @param [in] current_label Current pathlabel + * @param [in] face_id The face identifier to combine into the path label + * @param [out] new_label Computed pathlabel + * + * This function updates the current_label based on the new face_id, and returns + */ +always_inline void +update_pathlabel (hicn_pathlabel_t current_label, hicn_faceid_t face_id, + hicn_pathlabel_t * new_label) +{ + hicn_pathlabel_t pl_face_id = + (hicn_pathlabel_t) ((face_id & HICN_PATH_LABEL_MASK) >> + (16 - HICN_PATH_LABEL_SIZE)); + *new_label = + ((current_label << 1) | (current_label >> (HICN_PATH_LABEL_SIZE - 1))) ^ + pl_face_id; +} + +#endif /* HICN_BASE_H */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |