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Diffstat (limited to 'pimd/pim6_mld_protocol.h')
| -rw-r--r-- | pimd/pim6_mld_protocol.h | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/pimd/pim6_mld_protocol.h b/pimd/pim6_mld_protocol.h new file mode 100644 index 0000000..8e602d3 --- /dev/null +++ b/pimd/pim6_mld_protocol.h @@ -0,0 +1,125 @@ +/* + * MLD protocol definitions + * Copyright (C) 2022 David Lamparter for NetDEF, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; see the file COPYING; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef _PIM6_MLD_PROTOCOL_H +#define _PIM6_MLD_PROTOCOL_H + +#include <stdalign.h> +#include <stdint.h> + +/* There is a struct icmp6_hdr provided by OS, but it includes 4 bytes of data. + * Not helpful for us if we want to put the MLD struct after it. + */ + +struct icmp6_plain_hdr { + uint8_t icmp6_type; + uint8_t icmp6_code; + uint16_t icmp6_cksum; +}; +static_assert(sizeof(struct icmp6_plain_hdr) == 4, "struct mismatch"); +static_assert(alignof(struct icmp6_plain_hdr) <= 4, "struct mismatch"); + +/* for MLDv1 query, report and leave all use the same packet format */ +struct mld_v1_pkt { + uint16_t max_resp_code; + uint16_t rsvd0; + struct in6_addr grp; +}; +static_assert(sizeof(struct mld_v1_pkt) == 20, "struct mismatch"); +static_assert(alignof(struct mld_v1_pkt) <= 4, "struct mismatch"); + + +struct mld_v2_query_hdr { + uint16_t max_resp_code; + uint16_t rsvd0; + struct in6_addr grp; + uint8_t flags; + uint8_t qqic; + uint16_t n_src; + struct in6_addr srcs[0]; +}; +static_assert(sizeof(struct mld_v2_query_hdr) == 24, "struct mismatch"); +static_assert(alignof(struct mld_v2_query_hdr) <= 4, "struct mismatch"); + + +struct mld_v2_report_hdr { + uint16_t rsvd; + uint16_t n_records; +}; +static_assert(sizeof(struct mld_v2_report_hdr) == 4, "struct mismatch"); +static_assert(alignof(struct mld_v2_report_hdr) <= 4, "struct mismatch"); + + +struct mld_v2_rec_hdr { + uint8_t type; + uint8_t aux_len; + uint16_t n_src; + struct in6_addr grp; + struct in6_addr srcs[0]; +}; +static_assert(sizeof(struct mld_v2_rec_hdr) == 20, "struct mismatch"); +static_assert(alignof(struct mld_v2_rec_hdr) <= 4, "struct mismatch"); + +/* clang-format off */ +enum icmp6_mld_type { + ICMP6_MLD_QUERY = 130, + ICMP6_MLD_V1_REPORT = 131, + ICMP6_MLD_V1_DONE = 132, + ICMP6_MLD_V2_REPORT = 143, +}; + +enum mld_v2_rec_type { + MLD_RECTYPE_IS_INCLUDE = 1, + MLD_RECTYPE_IS_EXCLUDE = 2, + MLD_RECTYPE_CHANGE_TO_INCLUDE = 3, + MLD_RECTYPE_CHANGE_TO_EXCLUDE = 4, + MLD_RECTYPE_ALLOW_NEW_SOURCES = 5, + MLD_RECTYPE_BLOCK_OLD_SOURCES = 6, +}; +/* clang-format on */ + +/* helper functions */ + +static inline unsigned int mld_max_resp_decode(uint16_t wire) +{ + uint16_t code = ntohs(wire); + uint8_t exp; + + if (code < 0x8000) + return code; + exp = (code >> 12) & 0x7; + return ((code & 0xfff) | 0x1000) << (exp + 3); +} + +static inline uint16_t mld_max_resp_encode(uint32_t value) +{ + uint16_t code; + uint8_t exp; + + if (value < 0x8000) + code = value; + else { + exp = 16 - __builtin_clz(value); + code = (value >> (exp + 3)) & 0xfff; + code |= 0x8000 | (exp << 12); + } + return htons(code); +} + +#endif /* _PIM6_MLD_PROTOCOL_H */ |