diff options
Diffstat (limited to 'src/libsystemd-network/ndisc-protocol.c')
| -rw-r--r-- | src/libsystemd-network/ndisc-protocol.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/libsystemd-network/ndisc-protocol.c b/src/libsystemd-network/ndisc-protocol.c index fae4a583ad..d1f0819e14 100644 --- a/src/libsystemd-network/ndisc-protocol.c +++ b/src/libsystemd-network/ndisc-protocol.c @@ -1,7 +1,46 @@ /* SPDX-License-Identifier: LGPL-2.1-or-later */ +#include <netinet/icmp6.h> + #include "ndisc-protocol.h" +int ndisc_option_parse( + ICMP6Packet *p, + size_t offset, + uint8_t *ret_type, + size_t *ret_len, + const uint8_t **ret_opt) { + + assert(p); + + if (offset == p->raw_size) + return -ESPIPE; /* end of the packet */ + + if (offset > p->raw_size) + return -EBADMSG; + + if (p->raw_size - offset < sizeof(struct nd_opt_hdr)) + return -EBADMSG; + + assert_cc(alignof(struct nd_opt_hdr) == 1); + const struct nd_opt_hdr *hdr = (const struct nd_opt_hdr*) (p->raw_packet + offset); + if (hdr->nd_opt_len == 0) + return -EBADMSG; + + size_t len = hdr->nd_opt_len * 8; + if (p->raw_size - offset < len) + return -EBADMSG; + + if (ret_type) + *ret_type = hdr->nd_opt_type; + if (ret_len) + *ret_len = len; + if (ret_opt) + *ret_opt = p->raw_packet + offset; + + return 0; +} + static const uint8_t prefix_length_code_to_prefix_length[_PREFIX_LENGTH_CODE_MAX] = { [PREFIX_LENGTH_CODE_96] = 96, [PREFIX_LENGTH_CODE_64] = 64, |