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udhcp: merge clientpacket.c into dhcpc.c

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function                                             old     new   delta
udhcpc_main                                         2569    2855    +286
perform_release                                      122     124      +2
client_background                                     31      32      +1
init_packet                                          156      88     -68
send_decline                                         114       -    -114
send_discover                                        121       -    -121
send_select                                          130       -    -130
------------------------------------------------------------------------------
(add/remove: 0/4 grow/shrink: 3/1 up/down: 289/-433)         Total: -144 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2010-03-22 13:43:12 +01:00
parent 6b24d5354b
commit 501e35c474
5 changed files with 240 additions and 295 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
networking/udhcp/Kbuild
View File

@ -10,7 +10,7 @@ lib-y:=
lib-$(CONFIG_UDHCPC) += common.o options.o packet.o signalpipe.o socket.o
lib-$(CONFIG_UDHCPD) += common.o options.o packet.o signalpipe.o socket.o
lib-$(CONFIG_UDHCPC) += dhcpc.o clientpacket.o script.o
lib-$(CONFIG_UDHCPC) += dhcpc.o script.o
lib-$(CONFIG_UDHCPD) += dhcpd.o arpping.o files.o leases.o static_leases.o
lib-$(CONFIG_DUMPLEASES) += dumpleases.o
lib-$(CONFIG_DHCPRELAY) += dhcprelay.o

272
networking/udhcp/clientpacket.c
View File

@ -1,272 +0,0 @@
/* vi: set sw=4 ts=4: */
/* clientpacket.c
*
* Packet generation and dispatching functions for the DHCP client.
*
* Russ Dill <Russ.Dill@asu.edu> July 2001
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "common.h"
#include "dhcpd.h"
#include "dhcpc.h"
#include "options.h"
//#include <features.h>
#if (defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1) || defined _NEWLIB_VERSION
#include <netpacket/packet.h>
#include <net/ethernet.h>
#else
#include <asm/types.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h>
#endif
/* Create a random xid */
uint32_t FAST_FUNC random_xid(void)
{
static smallint initialized;
if (!initialized) {
srand(monotonic_us());
initialized = 1;
}
return rand();
}
/* Initialize the packet with the proper defaults */
static void init_packet(struct dhcp_packet *packet, char type)
{
udhcp_init_header(packet, type);
memcpy(packet->chaddr, client_config.client_mac, 6);
if (client_config.clientid)
add_option_string(packet->options, client_config.clientid);
if (client_config.hostname)
add_option_string(packet->options, client_config.hostname);
if (client_config.fqdn)
add_option_string(packet->options, client_config.fqdn);
if (type != DHCPDECLINE
&& type != DHCPRELEASE
&& client_config.vendorclass
) {
add_option_string(packet->options, client_config.vendorclass);
}
}
/* Add a parameter request list for stubborn DHCP servers. Pull the data
* from the struct in options.c. Don't do bounds checking here because it
* goes towards the head of the packet. */
static void add_param_req_option(struct dhcp_packet *packet)
{
uint8_t c;
int end = end_option(packet->options);
int i, len = 0;
for (i = 0; (c = dhcp_options[i].code) != 0; i++) {
if (( (dhcp_options[i].flags & OPTION_REQ)
&& !client_config.no_default_options
)
|| (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
) {
packet->options[end + OPT_DATA + len] = c;
len++;
}
}
if (len) {
packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
packet->options[end + OPT_LEN] = len;
packet->options[end + OPT_DATA + len] = DHCP_END;
}
}
/* RFC 2131
* 4.4.4 Use of broadcast and unicast
*
* The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
* messages, unless the client knows the address of a DHCP server.
* The client unicasts DHCPRELEASE messages to the server. Because
* the client is declining the use of the IP address supplied by the server,
* the client broadcasts DHCPDECLINE messages.
*
* When the DHCP client knows the address of a DHCP server, in either
* INIT or REBOOTING state, the client may use that address
* in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
* The client may also use unicast to send DHCPINFORM messages
* to a known DHCP server. If the client receives no response to DHCP
* messages sent to the IP address of a known DHCP server, the DHCP
* client reverts to using the IP broadcast address.
*/
static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
{
return udhcp_send_raw_packet(packet,
/*src*/ INADDR_ANY, CLIENT_PORT,
/*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
client_config.ifindex);
}
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
int FAST_FUNC send_discover(uint32_t xid, uint32_t requested)
{
struct dhcp_packet packet;
init_packet(&packet, DHCPDISCOVER);
packet.xid = xid;
if (requested)
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
/* Explicitly saying that we want RFC-compliant packets helps
* some buggy DHCP servers to NOT send bigger packets */
add_simple_option(packet.options, DHCP_MAX_SIZE, htons(576));
add_param_req_option(&packet);
bb_info_msg("Sending discover...");
return raw_bcast_from_client_config_ifindex(&packet);
}
/* Broadcast a DHCP request message */
/* RFC 2131 3.1 paragraph 3:
* "The client _broadcasts_ a DHCPREQUEST message..."
*/
int FAST_FUNC send_select(uint32_t xid, uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
struct in_addr addr;
init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
add_simple_option(packet.options, DHCP_SERVER_ID, server);
add_param_req_option(&packet);
addr.s_addr = requested;
bb_info_msg("Sending select for %s...", inet_ntoa(addr));
return raw_bcast_from_client_config_ifindex(&packet);
}
/* Unicast or broadcast a DHCP renew message */
int FAST_FUNC send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
packet.ciaddr = ciaddr;
add_param_req_option(&packet);
bb_info_msg("Sending renew...");
if (server)
return udhcp_send_kernel_packet(&packet,
ciaddr, CLIENT_PORT,
server, SERVER_PORT);
return raw_bcast_from_client_config_ifindex(&packet);
}
#if ENABLE_FEATURE_UDHCPC_ARPING
/* Broadcast a DHCP decline message */
int FAST_FUNC send_decline(uint32_t xid, uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
init_packet(&packet, DHCPDECLINE);
packet.xid = xid;
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
add_simple_option(packet.options, DHCP_SERVER_ID, server);
bb_info_msg("Sending decline...");
return raw_bcast_from_client_config_ifindex(&packet);
}
#endif
/* Unicast a DHCP release message */
int FAST_FUNC send_release(uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
init_packet(&packet, DHCPRELEASE);
packet.xid = random_xid();
packet.ciaddr = ciaddr;
add_simple_option(packet.options, DHCP_SERVER_ID, server);
bb_info_msg("Sending release...");
return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
}
/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
int FAST_FUNC udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
{
int bytes;
struct ip_udp_dhcp_packet packet;
uint16_t check;
memset(&packet, 0, sizeof(packet));
bytes = safe_read(fd, &packet, sizeof(packet));
if (bytes < 0) {
log1("Packet read error, ignoring");
/* NB: possible down interface, etc. Caller should pause. */
return bytes; /* returns -1 */
}
if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
log1("Packet is too short, ignoring");
return -2;
}
if (bytes < ntohs(packet.ip.tot_len)) {
/* packet is bigger than sizeof(packet), we did partial read */
log1("Oversized packet, ignoring");
return -2;
}
/* ignore any extra garbage bytes */
bytes = ntohs(packet.ip.tot_len);
/* make sure its the right packet for us, and that it passes sanity checks */
if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
|| packet.ip.ihl != (sizeof(packet.ip) >> 2)
|| packet.udp.dest != htons(CLIENT_PORT)
/* || bytes > (int) sizeof(packet) - can't happen */
|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
) {
log1("Unrelated/bogus packet, ignoring");
return -2;
}
/* verify IP checksum */
check = packet.ip.check;
packet.ip.check = 0;
if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) {
log1("Bad IP header checksum, ignoring");
return -2;
}
/* verify UDP checksum. IP header has to be modified for this */
memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
/* ip.xx fields which are not memset: protocol, check, saddr, daddr */
packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
check = packet.udp.check;
packet.udp.check = 0;
if (check && check != udhcp_checksum(&packet, bytes)) {
log1("Packet with bad UDP checksum received, ignoring");
return -2;
}
memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
if (dhcp_pkt->cookie != htonl(DHCP_MAGIC)) {
bb_info_msg("Packet with bad magic, ignoring");
return -2;
}
log1("Got valid DHCP packet");
udhcp_dump_packet(dhcp_pkt);
return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
}

1
networking/udhcp/common.h
View File

@ -136,7 +136,6 @@ uint16_t udhcp_checksum(void *addr, int count) FAST_FUNC;
void udhcp_init_header(struct dhcp_packet *packet, char type) FAST_FUNC;
/*int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd); - in dhcpc.h */
int udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) FAST_FUNC;
int udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,

245
networking/udhcp/dhcpc.c
View File

@ -63,6 +63,245 @@ static smallint state;
/* struct client_config_t client_config is in bb_common_bufsiz1 */
/* Create a random xid */
static uint32_t random_xid(void)
{
static smallint initialized;
if (!initialized) {
srand(monotonic_us());
initialized = 1;
}
return rand();
}
/* Initialize the packet with the proper defaults */
static void init_packet(struct dhcp_packet *packet, char type)
{
udhcp_init_header(packet, type);
memcpy(packet->chaddr, client_config.client_mac, 6);
if (client_config.clientid)
add_option_string(packet->options, client_config.clientid);
if (client_config.hostname)
add_option_string(packet->options, client_config.hostname);
if (client_config.fqdn)
add_option_string(packet->options, client_config.fqdn);
if (type != DHCPDECLINE
&& type != DHCPRELEASE
&& client_config.vendorclass
) {
add_option_string(packet->options, client_config.vendorclass);
}
}
/* Add a parameter request list for stubborn DHCP servers. Pull the data
* from the struct in options.c. Don't do bounds checking here because it
* goes towards the head of the packet. */
static void add_param_req_option(struct dhcp_packet *packet)
{
uint8_t c;
int end = end_option(packet->options);
int i, len = 0;
for (i = 0; (c = dhcp_options[i].code) != 0; i++) {
if (( (dhcp_options[i].flags & OPTION_REQ)
&& !client_config.no_default_options
)
|| (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
) {
packet->options[end + OPT_DATA + len] = c;
len++;
}
}
if (len) {
packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
packet->options[end + OPT_LEN] = len;
packet->options[end + OPT_DATA + len] = DHCP_END;
}
}
/* RFC 2131
* 4.4.4 Use of broadcast and unicast
*
* The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
* messages, unless the client knows the address of a DHCP server.
* The client unicasts DHCPRELEASE messages to the server. Because
* the client is declining the use of the IP address supplied by the server,
* the client broadcasts DHCPDECLINE messages.
*
* When the DHCP client knows the address of a DHCP server, in either
* INIT or REBOOTING state, the client may use that address
* in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
* The client may also use unicast to send DHCPINFORM messages
* to a known DHCP server. If the client receives no response to DHCP
* messages sent to the IP address of a known DHCP server, the DHCP
* client reverts to using the IP broadcast address.
*/
static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
{
return udhcp_send_raw_packet(packet,
/*src*/ INADDR_ANY, CLIENT_PORT,
/*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
client_config.ifindex);
}
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
static int send_discover(uint32_t xid, uint32_t requested)
{
struct dhcp_packet packet;
init_packet(&packet, DHCPDISCOVER);
packet.xid = xid;
if (requested)
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
/* Explicitly saying that we want RFC-compliant packets helps
* some buggy DHCP servers to NOT send bigger packets */
add_simple_option(packet.options, DHCP_MAX_SIZE, htons(576));
add_param_req_option(&packet);
bb_info_msg("Sending discover...");
return raw_bcast_from_client_config_ifindex(&packet);
}
/* Broadcast a DHCP request message */
/* RFC 2131 3.1 paragraph 3:
* "The client _broadcasts_ a DHCPREQUEST message..."
*/
static int send_select(uint32_t xid, uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
struct in_addr addr;
init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
add_simple_option(packet.options, DHCP_SERVER_ID, server);
add_param_req_option(&packet);
addr.s_addr = requested;
bb_info_msg("Sending select for %s...", inet_ntoa(addr));
return raw_bcast_from_client_config_ifindex(&packet);
}
/* Unicast or broadcast a DHCP renew message */
static int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
packet.ciaddr = ciaddr;
add_param_req_option(&packet);
bb_info_msg("Sending renew...");
if (server)
return udhcp_send_kernel_packet(&packet,
ciaddr, CLIENT_PORT,
server, SERVER_PORT);
return raw_bcast_from_client_config_ifindex(&packet);
}
#if ENABLE_FEATURE_UDHCPC_ARPING
/* Broadcast a DHCP decline message */
static int send_decline(uint32_t xid, uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
init_packet(&packet, DHCPDECLINE);
packet.xid = xid;
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
add_simple_option(packet.options, DHCP_SERVER_ID, server);
bb_info_msg("Sending decline...");
return raw_bcast_from_client_config_ifindex(&packet);
}
#endif
/* Unicast a DHCP release message */
static int send_release(uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
init_packet(&packet, DHCPRELEASE);
packet.xid = random_xid();
packet.ciaddr = ciaddr;
add_simple_option(packet.options, DHCP_SERVER_ID, server);
bb_info_msg("Sending release...");
return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
}
/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
{
int bytes;
struct ip_udp_dhcp_packet packet;
uint16_t check;
memset(&packet, 0, sizeof(packet));
bytes = safe_read(fd, &packet, sizeof(packet));
if (bytes < 0) {
log1("Packet read error, ignoring");
/* NB: possible down interface, etc. Caller should pause. */
return bytes; /* returns -1 */
}
if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
log1("Packet is too short, ignoring");
return -2;
}
if (bytes < ntohs(packet.ip.tot_len)) {
/* packet is bigger than sizeof(packet), we did partial read */
log1("Oversized packet, ignoring");
return -2;
}
/* ignore any extra garbage bytes */
bytes = ntohs(packet.ip.tot_len);
/* make sure its the right packet for us, and that it passes sanity checks */
if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
|| packet.ip.ihl != (sizeof(packet.ip) >> 2)
|| packet.udp.dest != htons(CLIENT_PORT)
/* || bytes > (int) sizeof(packet) - can't happen */
|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
) {
log1("Unrelated/bogus packet, ignoring");
return -2;
}
/* verify IP checksum */
check = packet.ip.check;
packet.ip.check = 0;
if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) {
log1("Bad IP header checksum, ignoring");
return -2;
}
/* verify UDP checksum. IP header has to be modified for this */
memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
/* ip.xx fields which are not memset: protocol, check, saddr, daddr */
packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
check = packet.udp.check;
packet.udp.check = 0;
if (check && check != udhcp_checksum(&packet, bytes)) {
log1("Packet with bad UDP checksum received, ignoring");
return -2;
}
memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
if (dhcp_pkt->cookie != htonl(DHCP_MAGIC)) {
bb_info_msg("Packet with bad magic, ignoring");
return -2;
}
log1("Got valid DHCP packet");
udhcp_dump_packet(dhcp_pkt);
return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
}
static int udhcp_raw_socket(int ifindex)
{
@ -135,7 +374,6 @@ static int udhcp_raw_socket(int ifindex)
return fd;
}
/* just a little helper */
static void change_listen_mode(int new_mode)
{
@ -157,7 +395,6 @@ static void change_listen_mode(int new_mode)
/* else LISTEN_NONE: sockfd stays closed */
}
/* perform a renew */
static void perform_renew(void)
{
@ -181,7 +418,6 @@ static void perform_renew(void)
}
}
/* perform a release */
static void perform_release(uint32_t requested_ip, uint32_t server_addr)
{
@ -204,7 +440,6 @@ static void perform_release(uint32_t requested_ip, uint32_t server_addr)
state = RELEASED;
}
#if BB_MMU
static void client_background(void)
{
@ -215,7 +450,6 @@ static void client_background(void)
}
#endif
static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
{
uint8_t *storage;
@ -227,7 +461,6 @@ static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
return storage;
}
int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int udhcpc_main(int argc UNUSED_PARAM, char **argv)
{

15
networking/udhcp/dhcpc.h
View File

@ -1,5 +1,4 @@
/* vi: set sw=4 ts=4: */
/* dhcpc.h */
#ifndef UDHCP_DHCPC_H
#define UDHCP_DHCPC_H 1
@ -30,20 +29,6 @@ struct client_config_t {
#define CLIENT_PORT 68
#endif
/*** clientpacket.h ***/
uint32_t random_xid(void) FAST_FUNC;
int send_discover(uint32_t xid, uint32_t requested) FAST_FUNC;
int send_select(uint32_t xid, uint32_t server, uint32_t requested) FAST_FUNC;
#if ENABLE_FEATURE_UDHCPC_ARPING
int send_decline(uint32_t xid, uint32_t server, uint32_t requested) FAST_FUNC;
#endif
int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr) FAST_FUNC;
int send_release(uint32_t server, uint32_t ciaddr) FAST_FUNC;
int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) FAST_FUNC;
POP_SAVED_FUNCTION_VISIBILITY
#endif