mirror of
https://github.com/rsmarples/dhcpcd.git
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Minimum message size is now 300 bytes for crappy DHCP servers :/
This commit is contained in:
Roy Marples
parent
378dcbd5d5
commit
750bc1d4f8
@ -1,3 +1,4 @@
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Minimum message size is now 300 bytes for crappy DHCP servers :/
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Compile ok on OpenBSD (thanks to icezimm and reb in #gentoo-bsd for testing)
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We check gcc supports -Wextra and friends before using them.
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We now restore the starting MTU value when we exit OR we don't receive a
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8
dhcp.c
8
dhcp.c
@ -38,8 +38,6 @@
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#include "logger.h"
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#include "socket.h"
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#define BROADCAST_FLAG 0x8000
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static const char *dhcp_message[] = {
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[DHCP_DISCOVER] = "DHCP_DISCOVER",
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[DHCP_OFFER] = "DHCP_OFFER",
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@ -248,7 +246,13 @@ size_t send_message (const interface_t *iface, const dhcp_t *dhcp,
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*p++ = DHCP_END;
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#ifdef DHCP_MESSAGE_LENTH_MIN
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while (p - m < DHCP_MESSAGE_LENTH_MIN)
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*p++ = DHCP_PAD;
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#endif
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message_length = p - m;
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logger (LOG_DEBUG, "xx %d\n", message_length);
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memset (&packet, 0, sizeof (struct udp_dhcp_packet));
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make_dhcp_packet (&packet, (unsigned char *) &message, message_length,
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90
dhcp.h
90
dhcp.h
@ -31,15 +31,17 @@
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#include "dhcpcd.h"
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#include "interface.h"
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/* Max MTU - defines dhcp option length */
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#define MTU_MAX 1500
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#define MTU_MIN 576
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#define MTU_MAX 1500
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#define MTU_MIN 576
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/* UDP port numbers for DHCP */
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#define DHCP_SERVER_PORT 67
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#define DHCP_CLIENT_PORT 68
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#define DHCP_SERVER_PORT 67
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#define DHCP_CLIENT_PORT 68
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#define MAGIC_COOKIE 0x63825363
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#define MAGIC_COOKIE 0x63825363
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#define BROADCAST_FLAG 0x8000
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/* DHCP message OP code */
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#define DHCP_BOOTREQUEST 1
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@ -47,55 +49,54 @@
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/* DHCP message type */
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#define DHCP_DISCOVER 1
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#define DHCP_OFFER 2
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#define DHCP_OFFER 2
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#define DHCP_REQUEST 3
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#define DHCP_DECLINE 4
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#define DHCP_ACK 5
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#define DHCP_NAK 6
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#define DHCP_ACK 5
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#define DHCP_NAK 6
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#define DHCP_RELEASE 7
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#define DHCP_INFORM 8
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#define DHCP_INFORM 8
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/* DHCP options */
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enum DHCP_OPTIONS
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{
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DHCP_PAD = 0,
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DHCP_PAD = 0,
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DHCP_NETMASK = 1,
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DHCP_TIMEROFFSET = 2,
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DHCP_ROUTERS = 3,
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DHCP_TIMESERVER = 4,
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DHCP_NAMESERVER = 5,
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DHCP_DNSSERVER = 6,
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DHCP_LOGSERVER = 7,
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DHCP_TIMESERVER = 4,
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DHCP_NAMESERVER = 5,
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DHCP_DNSSERVER = 6,
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DHCP_LOGSERVER = 7,
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DHCP_COOKIESERVER = 8,
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DHCP_HOSTNAME = 12,
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DHCP_DNSDOMAIN = 15,
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DHCP_DNSDOMAIN = 15,
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DHCP_ROOTPATH = 17,
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DHCP_DEFAULTIPTTL = 23,
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DHCP_MTU = 26,
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DHCP_BROADCAST = 28,
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DHCP_MTU = 26,
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DHCP_BROADCAST = 28,
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DHCP_MASKDISCOVERY = 29,
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DHCP_ROUTERDISCOVERY = 31,
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DHCP_ROUTERDISCOVERY = 31,
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DHCP_STATICROUTE = 33,
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DHCP_NISDOMAIN = 40,
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DHCP_NISSERVER = 41,
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DHCP_NTPSERVER = 42,
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DHCP_NISDOMAIN = 40,
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DHCP_NISSERVER = 41,
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DHCP_NTPSERVER = 42,
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DHCP_ADDRESS = 50,
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DHCP_LEASETIME = 51,
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DHCP_LEASETIME = 51,
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DHCP_MESSAGETYPE = 53,
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DHCP_SERVERIDENTIFIER = 54,
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DHCP_PARAMETERREQUESTLIST = 55,
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DHCP_SERVERIDENTIFIER = 54,
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DHCP_PARAMETERREQUESTLIST = 55,
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DHCP_MESSAGE = 56,
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DHCP_MAXMESSAGESIZE = 57,
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DHCP_RENEWALTIME = 58,
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DHCP_REBINDTIME = 59,
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DHCP_REBINDTIME = 59,
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DHCP_CLASSID = 60,
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DHCP_CLIENTID = 61,
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DHCP_USERCLASS = 77, /* RFC 3004 */
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DHCP_FQDN = 81,
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DHCP_DNSSEARCH = 119, /* RFC 3397 */
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DHCP_CSR = 121, /* RFC 3442 */
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DHCP_END = 255
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DHCP_USERCLASS = 77, /* RFC 3004 */
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DHCP_FQDN = 81,
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DHCP_DNSSEARCH = 119, /* RFC 3397 */
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DHCP_CSR = 121, /* RFC 3442 */
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DHCP_END = 255
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};
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/* SetFQDNHostName values - lsnybble used in flags
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@ -103,7 +104,7 @@ enum DHCP_OPTIONS
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* and to allow 0x00 to mean disable
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*/
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enum FQQN {
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FQDN_DISABLE = 0x00,
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FQDN_DISABLE = 0x00,
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FQDN_NONE = 0x18,
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FQDN_PTR = 0x20,
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FQDN_BOTH = 0x31
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@ -152,17 +153,22 @@ typedef struct dhcp_t
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char *rootpath;
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} dhcp_t;
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/* Sizes for DHCP options */
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#define DHCP_CHADDR_LEN 16
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#define SERVERNAME_LEN 64
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#define BOOTFILE_LEN 128
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#define DHCP_UDP_LEN (20 + 8)
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#define DHCP_BASE_LEN (4 + 4 + 2 + 2 + 4 + 4 + 4 + 4 + 4)
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#define DHCP_RESERVE_LEN (4 + 4 + 4 + 4 + 2)
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#define DHCP_FIXED_LEN (DHCP_BASE_LEN + DHCP_CHADDR_LEN + \
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+ SERVERNAME_LEN + BOOTFILE_LEN)
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#define DHCP_OPTION_LEN (MTU_MAX - DHCP_FIXED_LEN - DHCP_UDP_LEN \
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- DHCP_RESERVE_LEN)
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#define DHCP_CHADDR_LEN 16
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#define SERVERNAME_LEN 64
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#define BOOTFILE_LEN 128
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#define DHCP_UDP_LEN (20 + 8)
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#define DHCP_BASE_LEN (4 + 4 + 2 + 2 + 4 + 4 + 4 + 4 + 4)
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#define DHCP_RESERVE_LEN (4 + 4 + 4 + 4 + 2)
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#define DHCP_FIXED_LEN (DHCP_BASE_LEN + DHCP_CHADDR_LEN + \
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+ SERVERNAME_LEN + BOOTFILE_LEN)
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#define DHCP_OPTION_LEN (MTU_MAX - DHCP_FIXED_LEN - DHCP_UDP_LEN \
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- DHCP_RESERVE_LEN)
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/* Some crappy DHCP servers require the BOOTP minimum length */
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#define DHCP_MESSAGE_LENTH_MIN 300
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typedef struct dhcpmessage_t
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{
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