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
+++ /dev/null
-/* 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));
-}
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,
/* 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)
{
return fd;
}
-
/* just a little helper */
static void change_listen_mode(int new_mode)
{
/* else LISTEN_NONE: sockfd stays closed */
}
-
/* perform a renew */
static void perform_renew(void)
{
}
}
-
/* perform a release */
static void perform_release(uint32_t requested_ip, uint32_t server_addr)
{
state = RELEASED;
}
-
#if BB_MMU
static void client_background(void)
{
}
#endif
-
static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
{
uint8_t *storage;
return storage;
}
-
int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int udhcpc_main(int argc UNUSED_PARAM, char **argv)
{
/* vi: set sw=4 ts=4: */
-/* dhcpc.h */
#ifndef UDHCP_DHCPC_H
#define UDHCP_DHCPC_H 1
#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