diff options
| -rw-r--r-- | src/libsystemd-network/dhcp6-internal.h | 2 | ||||
| -rw-r--r-- | src/libsystemd-network/dhcp6-option.c | 181 |
2 files changed, 174 insertions, 9 deletions
diff --git a/src/libsystemd-network/dhcp6-internal.h b/src/libsystemd-network/dhcp6-internal.h index 31f5bd2b9b..ec1d82abee 100644 --- a/src/libsystemd-network/dhcp6-internal.h +++ b/src/libsystemd-network/dhcp6-internal.h @@ -66,6 +66,8 @@ int dhcp6_option_append(uint8_t **buf, size_t *buflen, uint16_t code, int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, DHCP6IA *ia); int dhcp6_option_parse(uint8_t **buf, size_t *buflen, uint16_t *optcode, size_t *optlen, uint8_t **optvalue); +int dhcp6_option_parse_ia(uint8_t **buf, size_t *buflen, uint16_t iatype, + DHCP6IA *ia); int dhcp6_network_bind_udp_socket(int index, struct in6_addr *address); int dhcp6_network_send_udp_socket(int s, struct in6_addr *address, diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c index cc4d261ae7..f488832cf9 100644 --- a/src/libsystemd-network/dhcp6-option.c +++ b/src/libsystemd-network/dhcp6-option.c @@ -129,22 +129,185 @@ int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, DHCP6IA *ia) { return 0; } + +static int option_parse_hdr(uint8_t **buf, size_t *buflen, uint16_t *opt, + size_t *optlen) { + uint16_t len; + + assert_return(buf, -EINVAL); + assert_return(opt, -EINVAL); + assert_return(optlen, -EINVAL); + + if (*buflen < 4) + return -ENOMSG; + + len = (*buf)[2] << 8 | (*buf)[3]; + + if (len > *buflen) + return -ENOMSG; + + *opt = (*buf)[0] << 8 | (*buf)[1]; + *optlen = len; + + *buf += 4; + *buflen -= 4; + + return 0; +} + int dhcp6_option_parse(uint8_t **buf, size_t *buflen, uint16_t *optcode, size_t *optlen, uint8_t **optvalue) { - assert_return(buf && buflen && optcode && optlen && optvalue, -EINVAL); + int r; - if (*buflen == 0) - return -ENOMSG; + assert_return(buf && buflen && optcode && optlen && optvalue, -EINVAL); - *optcode = (*buf)[0] << 8 | (*buf)[1]; - *optlen = (*buf)[2] << 8 | (*buf)[3]; + r = option_parse_hdr(buf, buflen, optcode, optlen); + if (r < 0) + return r; - if (*optlen > *buflen - 4) + if (*optlen > *buflen) return -ENOBUFS; - *optvalue = &(*buf)[4]; - *buflen -= (*optlen + 4); - (*buf) += (*optlen + 4); + *optvalue = *buf; + *buflen -= *optlen; + *buf += *optlen; return 0; } + +int dhcp6_option_parse_ia(uint8_t **buf, size_t *buflen, uint16_t iatype, + DHCP6IA *ia) { + int r; + uint16_t opt, status; + size_t optlen; + size_t iaaddr_offset; + DHCP6Address *addr; + uint32_t lt_t1, lt_t2, lt_valid, lt_pref, lt_min = ~0; + + assert_return(ia, -EINVAL); + assert_return(!ia->addresses, -EINVAL); + + switch (iatype) { + case DHCP6_OPTION_IA_NA: + + if (*buflen < DHCP6_OPTION_IA_NA_LEN + DHCP6_OPTION_HDR_LEN + + DHCP6_OPTION_IAADDR_LEN) { + r = -ENOBUFS; + goto error; + } + + iaaddr_offset = DHCP6_OPTION_IA_NA_LEN; + memcpy(&ia->id, *buf, iaaddr_offset); + + lt_t1 = be32toh(ia->lifetime_t1); + lt_t2 = be32toh(ia->lifetime_t2); + + if (lt_t1 && lt_t2 && lt_t1 > lt_t2) { + log_dhcp6_client(client, "IA T1 %ds > T2 %ds", + lt_t1, lt_t2); + r = -EINVAL; + goto error; + } + + break; + + case DHCP6_OPTION_IA_TA: + if (*buflen < DHCP6_OPTION_IA_TA_LEN + DHCP6_OPTION_HDR_LEN + + DHCP6_OPTION_IAADDR_LEN) { + r = -ENOBUFS; + goto error; + } + + iaaddr_offset = DHCP6_OPTION_IA_TA_LEN; + memcpy(&ia->id, *buf, iaaddr_offset); + + ia->lifetime_t1 = 0; + ia->lifetime_t2 = 0; + + break; + + default: + r = -ENOMSG; + goto error; + } + + ia->type = iatype; + + *buflen -= iaaddr_offset; + *buf += iaaddr_offset; + + while ((r = option_parse_hdr(buf, buflen, &opt, &optlen)) >= 0) { + + switch (opt) { + case DHCP6_OPTION_IAADDR: + + addr = new0(DHCP6Address, 1); + if (!addr) { + r = -ENOMEM; + goto error; + } + + LIST_INIT(addresses, addr); + + memcpy(&addr->address, *buf, DHCP6_OPTION_IAADDR_LEN); + + lt_valid = be32toh(addr->lifetime_valid); + lt_pref = be32toh(addr->lifetime_valid); + + if (!lt_valid || lt_pref > lt_valid) { + log_dhcp6_client(client, "IA preferred %ds > valid %ds", + lt_pref, lt_valid); + free(addr); + } else { + LIST_PREPEND(addresses, ia->addresses, addr); + if (lt_valid < lt_min) + lt_min = lt_valid; + } + + break; + + case DHCP6_OPTION_STATUS_CODE: + if (optlen < sizeof(status)) + break; + + status = (*buf)[0] << 8 | (*buf)[1]; + if (status) { + log_dhcp6_client(client, "IA status %d", + status); + r = -EINVAL; + goto error; + } + + break; + + default: + log_dhcp6_client(client, "Unknown IA option %d", opt); + break; + } + + *buflen -= optlen; + *buf += optlen; + } + + if (r == -ENOMSG) + r = 0; + + if (!ia->lifetime_t1 && !ia->lifetime_t2) { + lt_t1 = lt_min / 2; + lt_t2 = lt_min / 10 * 8; + ia->lifetime_t1 = htobe32(lt_t1); + ia->lifetime_t2 = htobe32(lt_t2); + + log_dhcp6_client(client, "Computed IA T1 %ds and T2 %ds as both were zero", + lt_t1, lt_t2); + } + + if (*buflen) + r = -ENOMSG; + +error: + *buf += *buflen; + *buflen = 0; + + return r; +} |