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Diffstat (limited to 'libdhcp/dhcp_common.c')
| -rw-r--r-- | libdhcp/dhcp_common.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/libdhcp/dhcp_common.c b/libdhcp/dhcp_common.c new file mode 100644 index 0000000..d691836 --- /dev/null +++ b/libdhcp/dhcp_common.c @@ -0,0 +1,104 @@ +/* libdhcp/dhcp_common.c - Base definitions for the DHCP protocol + * + * Copyright (C) 2025 Luke T. Shumaker <lukeshu@lukeshu.com> + * SPDX-License-Identifier: AGPL-3.0-or-later + */ + +#include "dhcp_common.h" + +/** + * DHCP Options + * https://www.iana.org/assignments/bootp-dhcp-parameters/bootp-dhcp-parameters.xhtml#options + */ +bool dhcp_opt_length_is_valid(uint8_t opt, uint16_t len) { + switch (opt) { + /* RFC 2132 */ + case DHCP_OPT_PAD: return len == 0; + case DHCP_OPT_SUBNET_MASK: return len == 4; + case DHCP_OPT_TIME_OFFSET: return len == 4; + case DHCP_OPT_ROUTER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_TIME_SERVER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_NAME_SERVER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_DOMAIN_SERVER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_LOG_SERVER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_QUOTES_SERVER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_LPR_SERVER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_IMPRESS_SERVER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_RLP_SERVER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_HOSTNAME: return len >= 1; + case DHCP_OPT_BOOT_FILE_SIZE: return len == 2; + case DHCP_OPT_MERIT_DUMP_FILE: return len >= 1; + case DHCP_OPT_DOMAIN_NAME: return len >= 1; + case DHCP_OPT_SWAP_SERVER: return len == 4; /* IANA says length is "N", but RFC 2132 says "length is 4"; likely releated to errata ID 487 */ + case DHCP_OPT_ROOT_PATH: return len >= 1; + case DHCP_OPT_EXTENSION_FILE: return len >= 1; + case DHCP_OPT_FORWARD_ONOFF: return len == 1; + case DHCP_OPT_SRCRTE_ONOFF: return len == 1; + case DHCP_OPT_POLICY_FILTER: return len >= 8 && len % 8 == 0; + case DHCP_OPT_MAX_DG_ASSEMBLY: return len == 2; + case DHCP_OPT_DEFAULT_IP_TTL: return len == 1; + case DHCP_OPT_MTU_TIMEOUT: return len == 4; + case DHCP_OPT_MTU_PLATEAU: return len >= 2 && len % 2 == 0; + case DHCP_OPT_MTU_INTERFACE: return len == 2; + case DHCP_OPT_MTU_SUBNET: return len == 1; + case DHCP_OPT_BROADCAST_ADDRESS: return len == 4; + case DHCP_OPT_MASK_DISCOVERY: return len == 1; + case DHCP_OPT_MASK_SUPPLIER: return len == 1; + case DHCP_OPT_ROUTER_DISCOVERY: return len == 1; + case DHCP_OPT_ROUTER_REQUEST: return len == 4; + case DHCP_OPT_STATIC_ROUTE: return len >= 8 && len % 8 == 0; + case DHCP_OPT_TRAILERS: return len == 1; + case DHCP_OPT_ARP_TIMEOUT: return len == 4; + case DHCP_OPT_ETHERNET: return len == 1; + case DHCP_OPT_DEFAULT_TCP_TTL: return len == 1; + case DHCP_OPT_KEEPALIVE_TIME: return len == 4; + case DHCP_OPT_KEEPALIVE_DATA: return len == 1; + case DHCP_OPT_NIS_DOMAIN: return len >= 1; + case DHCP_OPT_NIS_SERVERS: return len >= 4 && len % 4 == 0; + case DHCP_OPT_NTP_SERVERS: return len >= 4 && len % 4 == 0; + case DHCP_OPT_VENDOR_SPECIFIC: return len >= 1; + case DHCP_OPT_NETBIOS_NAME_SRV: return len >= 4 && len % 4 == 0; + case DHCP_OPT_NETBIOS_DIST_SRV: return len >= 4 && len % 4 == 0; + case DHCP_OPT_NETBIOS_NODE_TYPE: return len == 1; + case DHCP_OPT_NETBIOS_SCOPE: return len >= 1; + case DHCP_OPT_X_WINDOW_FONT: return len >= 4 && len % 4 == 0; + case DHCP_OPT_X_WINDOW_MANAGER: return len >= 4 && len % 4 == 0; + case DHCP_OPT_ADDRESS_REQUEST: return len == 4; + case DHCP_OPT_ADDRESS_TIME: return len == 4; + case DHCP_OPT_OVERLOAD: return len == 1; + case DHCP_OPT_DHCP_MSG_TYPE: return len == 1; + case DHCP_OPT_DHCP_SERVER_ID: return len == 4; + case DHCP_OPT_PARAMETER_LIST: return len >= 1; + case DHCP_OPT_DHCP_MESSAGE: return len >= 1; + case DHCP_OPT_DHCP_MAX_MSG_SIZE: return len == 2; + case DHCP_OPT_RENEWAL_TIME: return len == 4; + case DHCP_OPT_REBINDING_TIME: return len == 4; + case DHCP_OPT_CLASS_ID: return len >= 1; + case DHCP_OPT_CLIENT_ID: return len >= 2; + + /* RFC 2132 */ + case DHCP_OPT_END: return len == 0; + + /* Unrecognized */ + default: + return true; + } +} + +/** + * DHCP Message Type 53 Values + * https://www.iana.org/assignments/bootp-dhcp-parameters/bootp-dhcp-parameters.xhtml#message-type-53 + */ +const char *dhcp_msgtyp_str(uint8_t typ) { + switch (typ) { + case DHCP_MSGTYP_DISCOVER: return "DHCP_MSGTYP_DISCOVER"; + case DHCP_MSGTYP_OFFER: return "DHCP_MSGTYP_OFFER"; + case DHCP_MSGTYP_REQUEST: return "DHCP_MSGTYP_REQUEST"; + case DHCP_MSGTYP_DECLINE: return "DHCP_MSGTYP_DECLINE"; + case DHCP_MSGTYP_ACK: return "DHCP_MSGTYP_ACK"; + case DHCP_MSGTYP_NAK: return "DHCP_MSGTYP_NAK"; + case DHCP_MSGTYP_RELEASE: return "DHCP_MSGTYP_RELEASE"; + case DHCP_MSGTYP_INFORM: return "DHCP_MSGTYP_INFORM"; + default: return const_byte_str(typ); + } +} |