diff options
Diffstat (limited to 'networking')
| -rw-r--r-- | networking/udhcp/common.h | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h index ca778da..e374771 100644 --- a/networking/udhcp/common.h +++ b/networking/udhcp/common.h @@ -38,13 +38,27 @@ struct dhcp_packet { #define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */ uint32_t ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */ uint32_t yiaddr; /* 'your' (client) IP address */ - /* IP address of next server to use in bootstrap, returned in DHCPOFFER, DHCPACK by server */ + /* IP address of "next server" (usually meant to be an TFTP server) + * to use in bootstrap, returned in DHCPOFFER, DHCPACK by server: */ uint32_t siaddr_nip; - uint32_t gateway_nip; /* aka 'giaddr': relay agent IP address */ + /* RFC 951 (BOOTP): "place my (server) IP address in the 'siaddr' field" + * (IOW: unconditionally, not just if we are also a TFTP server). + * DHCP servers don't have to do this, they add SERVER_ID option + * to their reply packets to let client identify lease-giving server. + */ + uint32_t gateway_nip; /* aka 'giaddr': relay agent IP address, else 0 */ uint8_t chaddr[16]; /* link-layer client hardware address (MAC) */ uint8_t sname[64]; /* server host name (ASCIZ) */ + /* RFC 951 (BOOTP): "If the client wishes to restrict booting + * to a particular server name, it may place [it] in 'sname'" + */ uint8_t file[128]; /* boot file name (ASCIZ) */ - uint32_t cookie; /* fixed first four option bytes (99,130,83,99 dec) */ + /* RFC 951 (BOOTP): in client requests, "...can be a 'generic' name + * such as 'unix' or 'gateway'; this means 'boot the named program + * configured for my machine'" + */ + /* BOOTP fields end here, BOOTP says optional uint8_t vend[64] follows */ + uint32_t cookie; /* DHCP magic bytes: 99,130,83,99 decimal */ uint8_t options[DHCP_OPTIONS_BUFSIZE + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS]; }; #define DHCP_PKT_SNAME_LEN 64 @@ -142,18 +156,21 @@ struct dhcp_scan_state { //#define DHCP_NTP_SERVER 0x2a //#define DHCP_WINS_SERVER 0x2c #define DHCP_REQUESTED_IP 0x32 /* 50: sent by client if specific IP is wanted */ -#define DHCP_LEASE_TIME 0x33 /* 51: */ -#define DHCP_OPTION_OVERLOAD 0x34 /* 52: */ -#define DHCP_MESSAGE_TYPE 0x35 /* 53: */ +#define DHCP_LEASE_TIME 0x33 /* 51: 32bit big-endian */ +#define DHCP_OPTION_OVERLOAD 0x34 /* 52: 1 byte */ +#define DHCP_MESSAGE_TYPE 0x35 /* 53: 1 byte */ #define DHCP_SERVER_ID 0x36 /* 54: server's IP */ #define DHCP_PARAM_REQ 0x37 /* 55: list of options client wants */ //#define DHCP_ERR_MESSAGE 0x38 /* 56: error message when sending NAK etc */ -#define DHCP_MAX_SIZE 0x39 /* 57: */ +#define DHCP_MAX_SIZE 0x39 /* 57: 16bit big-endian */ +// 0x3a /* 58: from server: renew time, 32bit big-endian */ +// 0x3b /* 59: from server: rebind time, 32bit big-endian */ #define DHCP_VENDOR 0x3c /* 60: client's vendor (a string) */ #define DHCP_CLIENT_ID 0x3d /* 61: by default client's MAC addr, but may be arbitrarily long */ //#define DHCP_TFTP_SERVER_NAME 0x42 /* 66: same as 'sname' field */ //#define DHCP_BOOT_FILE 0x43 /* 67: same as 'file' field */ //#define DHCP_USER_CLASS 0x4d /* 77: RFC 3004. set of LASCII strings. "I am a printer" etc */ +// 0x50 /* 80: rapid commit ("I'm ok with getting immediate ACK, not just OFFER"), 0 bytes */ #define DHCP_FQDN 0x51 /* 81: client asks to update DNS to map its FQDN to its new IP */ //#define DHCP_PCODE 0x64 /* 100: RFC 4833. IEEE 1003.1 TZ string */ //#define DHCP_TCODE 0x65 /* 101: RFC 4833. Reference to the TZ database string */ |