--- /dev/null
+/* dhcpd.c
+ *
+ * udhcp DHCP client
+ *
+ * Russ Dill <Russ.Dill@asu.edu> July 2001
+ *
+ * Converted to busybox by Glenn McGrath August 2002
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/file.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <signal.h>
+#include <time.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <errno.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#if __GLIBC__ >=2 && __GLIBC_MINOR >= 1
+#include <netpacket/packet.h>
+#include <net/ethernet.h>
+#else
+#include <asm/types.h>
+#include <linux/if_packet.h>
+#include <linux/if_ether.h>
+#endif
+#include "libbb.h"
+
+static int state;
+static unsigned long requested_ip; /* = 0 */
+static unsigned long server_addr;
+static unsigned long timeout;
+static int packet_num; /* = 0 */
+static int fd_main;
+#define DEBUG
+
+#define VERSION "0.9.7"
+
+#define LISTEN_NONE 0
+#define LISTEN_KERNEL 1
+#define LISTEN_RAW 2
+static int listen_mode;
+
+#define DEFAULT_SCRIPT "/usr/share/udhcpc/default.script"
+
+#define DHCP_END 0xFF
+#define TYPE_MASK 0x0F
+#define BROADCAST_FLAG 0x8000
+
+#define SERVER_PORT 67
+
+#define DHCP_MAGIC 0x63825363
+
+#define BOOTREQUEST 1
+#define BOOTREPLY 2
+
+#define ETH_10MB 1
+#define ETH_10MB_LEN 6
+
+#define OPTION_FIELD 0
+#define FILE_FIELD 1
+#define SNAME_FIELD 2
+
+#define INIT_SELECTING 0
+#define REQUESTING 1
+#define BOUND 2
+#define RENEWING 3
+#define REBINDING 4
+#define INIT_REBOOT 5
+#define RENEW_REQUESTED 6
+#define RELEASED 7
+
+#define CLIENT_PORT 68
+
+#define DHCPDISCOVER 1
+#define DHCPOFFER 2
+#define DHCPREQUEST 3
+#define DHCPDECLINE 4
+#define DHCPACK 5
+#define DHCPNAK 6
+#define DHCPRELEASE 7
+#define DHCPINFORM 8
+
+/* DHCP option codes (partial list) */
+#define DHCP_PADDING 0x00
+#define DHCP_SUBNET 0x01
+#define DHCP_TIME_OFFSET 0x02
+#define DHCP_ROUTER 0x03
+#define DHCP_TIME_SERVER 0x04
+#define DHCP_NAME_SERVER 0x05
+#define DHCP_DNS_SERVER 0x06
+#define DHCP_LOG_SERVER 0x07
+#define DHCP_COOKIE_SERVER 0x08
+#define DHCP_LPR_SERVER 0x09
+#define DHCP_HOST_NAME 0x0c
+#define DHCP_BOOT_SIZE 0x0d
+#define DHCP_DOMAIN_NAME 0x0f
+#define DHCP_SWAP_SERVER 0x10
+#define DHCP_ROOT_PATH 0x11
+#define DHCP_IP_TTL 0x17
+#define DHCP_MTU 0x1a
+#define DHCP_BROADCAST 0x1c
+#define DHCP_NTP_SERVER 0x2a
+#define DHCP_WINS_SERVER 0x2c
+#define DHCP_REQUESTED_IP 0x32
+#define DHCP_LEASE_TIME 0x33
+#define DHCP_OPTION_OVER 0x34
+#define DHCP_MESSAGE_TYPE 0x35
+#define DHCP_SERVER_ID 0x36
+#define DHCP_PARAM_REQ 0x37
+#define DHCP_MESSAGE 0x38
+#define DHCP_MAX_SIZE 0x39
+#define DHCP_T1 0x3a
+#define DHCP_T2 0x3b
+#define DHCP_VENDOR 0x3c
+#define DHCP_CLIENT_ID 0x3d
+
+/* miscellaneous defines */
+#define MAC_BCAST_ADDR (unsigned char *) "\xff\xff\xff\xff\xff\xff"
+#define OPT_CODE 0
+#define OPT_LEN 1
+#define OPT_DATA 2
+
+enum {
+ OPTION_IP=1,
+ OPTION_IP_PAIR,
+ OPTION_STRING,
+ OPTION_BOOLEAN,
+ OPTION_U8,
+ OPTION_U16,
+ OPTION_S16,
+ OPTION_U32,
+ OPTION_S32
+};
+
+#define OPTION_REQ 0x10 /* have the client request this option */
+#define OPTION_LIST 0x20 /* There can be a list of 1 or more of these */
+
+#ifdef SYSLOG
+# define LOG(level, str, args...) do { printf(str, ## args); \
+ printf("\n"); \
+ syslog(level, str, ## args); } while(0)
+# define OPEN_LOG(name) openlog(name, 0, 0)
+#define CLOSE_LOG() closelog()
+#else
+# define LOG_EMERG "EMERGENCY!"
+# define LOG_ALERT "ALERT!"
+# define LOG_CRIT "critical!"
+# define LOG_WARNING "warning"
+# define LOG_ERR "error"
+# define LOG_INFO "info"
+# define LOG_DEBUG "debug"
+# define LOG(level, str, args...) do { printf("%s, ", level); printf(str, ## args); printf("\n"); } while(0)
+# define OPEN_LOG(name) do {;} while(0)
+#define CLOSE_LOG() do {;} while(0)
+#endif
+
+#ifdef DEBUG
+# undef DEBUG
+# define DEBUG(level, str, args...) LOG(level, str, ## args)
+# define DEBUGGING
+#else
+# define DEBUG(level, str, args...) do {;} while(0)
+#endif
+
+struct client_config_t {
+ char foreground; /* Do not fork */
+ char quit_after_lease; /* Quit after obtaining lease */
+ char abort_if_no_lease; /* Abort if no lease */
+ char *interface; /* The name of the interface to use */
+ char *pidfile; /* Optionally store the process ID */
+ char *script; /* User script to run at dhcp events */
+ unsigned char *clientid; /* Optional client id to use */
+ unsigned char *hostname; /* Optional hostname to use */
+ int ifindex; /* Index number of the interface to use */
+ unsigned char arp[6]; /* Our arp address */
+};
+extern struct client_config_t client_config;
+
+struct dhcpMessage {
+ u_int8_t op;
+ u_int8_t htype;
+ u_int8_t hlen;
+ u_int8_t hops;
+ u_int32_t xid;
+ u_int16_t secs;
+ u_int16_t flags;
+ u_int32_t ciaddr;
+ u_int32_t yiaddr;
+ u_int32_t siaddr;
+ u_int32_t giaddr;
+ u_int8_t chaddr[16];
+ u_int8_t sname[64];
+ u_int8_t file[128];
+ u_int32_t cookie;
+ u_int8_t options[308]; /* 312 - cookie */
+};
+
+struct client_config_t client_config = {
+ /* Default options. */
+ abort_if_no_lease: 0,
+ foreground: 0,
+ quit_after_lease: 0,
+ interface: "eth0",
+ pidfile: NULL,
+ script: DEFAULT_SCRIPT,
+ clientid: NULL,
+ hostname: NULL,
+ ifindex: 0,
+ arp: "\0\0\0\0\0\0", /* appease gcc-3.0 */
+};
+
+struct dhcp_option {
+ char name[10];
+ char flags;
+ unsigned char code;
+};
+
+struct udp_dhcp_packet {
+ struct iphdr ip;
+ struct udphdr udp;
+ struct dhcpMessage data;
+};
+
+struct dhcp_option options[] = {
+ /* name[10] flags code */
+ {"subnet", OPTION_IP | OPTION_REQ, 0x01},
+ {"timezone", OPTION_S32, 0x02},
+ {"router", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x03},
+ {"timesvr", OPTION_IP | OPTION_LIST, 0x04},
+ {"namesvr", OPTION_IP | OPTION_LIST, 0x05},
+ {"dns", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x06},
+ {"logsvr", OPTION_IP | OPTION_LIST, 0x07},
+ {"cookiesvr", OPTION_IP | OPTION_LIST, 0x08},
+ {"lprsvr", OPTION_IP | OPTION_LIST, 0x09},
+ {"hostname", OPTION_STRING | OPTION_REQ, 0x0c},
+ {"bootsize", OPTION_U16, 0x0d},
+ {"domain", OPTION_STRING | OPTION_REQ, 0x0f},
+ {"swapsvr", OPTION_IP, 0x10},
+ {"rootpath", OPTION_STRING, 0x11},
+ {"ipttl", OPTION_U8, 0x17},
+ {"mtu", OPTION_U16, 0x1a},
+ {"broadcast", OPTION_IP | OPTION_REQ, 0x1c},
+ {"ntpsrv", OPTION_IP | OPTION_LIST, 0x2a},
+ {"wins", OPTION_IP | OPTION_LIST, 0x2c},
+ {"requestip", OPTION_IP, 0x32},
+ {"lease", OPTION_U32, 0x33},
+ {"dhcptype", OPTION_U8, 0x35},
+ {"serverid", OPTION_IP, 0x36},
+ {"message", OPTION_STRING, 0x38},
+ {"tftp", OPTION_STRING, 0x42},
+ {"bootfile", OPTION_STRING, 0x43},
+ {"", 0x00, 0x00}
+};
+
+/* Lengths of the different option types */
+int option_lengths[] = {
+ [OPTION_IP] = 4,
+ [OPTION_IP_PAIR] = 8,
+ [OPTION_BOOLEAN] = 1,
+ [OPTION_STRING] = 1,
+ [OPTION_U8] = 1,
+ [OPTION_U16] = 2,
+ [OPTION_S16] = 2,
+ [OPTION_U32] = 4,
+ [OPTION_S32] = 4
+};
+
+/* get a rough idea of how long an option will be (rounding up...) */
+static int max_option_length[] = {
+ [OPTION_IP] = sizeof("255.255.255.255 "),
+ [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
+ [OPTION_STRING] = 1,
+ [OPTION_BOOLEAN] = sizeof("yes "),
+ [OPTION_U8] = sizeof("255 "),
+ [OPTION_U16] = sizeof("65535 "),
+ [OPTION_S16] = sizeof("-32768 "),
+ [OPTION_U32] = sizeof("4294967295 "),
+ [OPTION_S32] = sizeof("-2147483684 "),
+};
+
+static void print_usage(void)
+{
+ printf(
+"Usage: udhcpcd [OPTIONS]\n\n"
+" -c, --clientid=CLIENTID Client identifier\n"
+" -H, --hostname=HOSTNAME Client hostname\n"
+" -f, --foreground Do not fork after getting lease\n"
+" -i, --interface=INTERFACE Interface to use (default: eth0)\n"
+" -n, --now Exit with failure if lease cannot be\n"
+" immediately negotiated.\n"
+" -p, --pidfile=file Store process ID of daemon in file\n"
+" -q, --quit Quit after obtaining lease\n"
+" -r, --request=IP IP address to request (default: none)\n"
+" -s, --script=file Run file at dhcp events (default:\n"
+" " DEFAULT_SCRIPT ")\n"
+" -v, --version Display version\n"
+ );
+}
+/* return the position of the 'end' option (no bounds checking) */
+int end_option(unsigned char *optionptr)
+{
+ int i = 0;
+
+ while (optionptr[i] != DHCP_END) {
+ if (optionptr[i] == DHCP_PADDING) i++;
+ else i += optionptr[i + OPT_LEN] + 2;
+ }
+ return i;
+}
+
+/* add an option string to the options (an option string contains an option code,
+ * length, then data) */
+int add_option_string(unsigned char *optionptr, unsigned char *string)
+{
+ int end = end_option(optionptr);
+
+ /* end position + string length + option code/length + end option */
+ if (end + string[OPT_LEN] + 2 + 1 >= 308) {
+ LOG(LOG_ERR, "Option 0x%02x did not fit into the packet!", string[OPT_CODE]);
+ return 0;
+ }
+ DEBUG(LOG_INFO, "adding option 0x%02x", string[OPT_CODE]);
+ memcpy(optionptr + end, string, string[OPT_LEN] + 2);
+ optionptr[end + string[OPT_LEN] + 2] = DHCP_END;
+ return string[OPT_LEN] + 2;
+}
+
+/* add a one to four byte option to a packet */
+int add_simple_option(unsigned char *optionptr, unsigned char code, u_int32_t data)
+{
+ char length = 0;
+ int i;
+ unsigned char option[2 + 4];
+ unsigned char *u8;
+ u_int16_t *u16;
+ u_int32_t *u32;
+ u_int32_t aligned;
+ u8 = (unsigned char *) &aligned;
+ u16 = (u_int16_t *) &aligned;
+ u32 = &aligned;
+
+ for (i = 0; options[i].code; i++)
+ if (options[i].code == code) {
+ length = option_lengths[options[i].flags & TYPE_MASK];
+ }
+
+ if (!length) {
+ DEBUG(LOG_ERR, "Could not add option 0x%02x", code);
+ return 0;
+ }
+
+ option[OPT_CODE] = code;
+ option[OPT_LEN] = length;
+
+ switch (length) {
+ case 1: *u8 = data; break;
+ case 2: *u16 = data; break;
+ case 4: *u32 = data; break;
+ }
+
+ memcpy(option + 2, &aligned, length);
+ return add_option_string(optionptr, option);
+}
+#if 0
+void init_header(struct dhcpMessage *packet, char type)
+{
+ memset(packet, 0, sizeof(struct dhcpMessage));
+ switch (type) {
+ case DHCPDISCOVER:
+ case DHCPREQUEST:
+ case DHCPRELEASE:
+ case DHCPINFORM:
+ packet->op = BOOTREQUEST;
+ break;
+ case DHCPOFFER:
+ case DHCPACK:
+ case DHCPNAK:
+ packet->op = BOOTREPLY;
+ }
+ packet->htype = ETH_10MB;
+ packet->hlen = ETH_10MB_LEN;
+ packet->cookie = htonl(DHCP_MAGIC);
+ packet->options[0] = DHCP_END;
+ add_simple_option(packet->options, DHCP_MESSAGE_TYPE, type);
+}
+#endif
+u_int16_t checksum(void *addr, int count)
+{
+ /* Compute Internet Checksum for "count" bytes
+ * beginning at location "addr".
+ */
+ register int32_t sum = 0;
+ u_int16_t *source = (u_int16_t *) addr;
+
+ while( count > 1 ) {
+ /* This is the inner loop */
+ sum += *source++;
+ count -= 2;
+ }
+
+ /* Add left-over byte, if any */
+ if( count > 0 )
+ sum += * (unsigned char *) source;
+
+ /* Fold 32-bit sum to 16 bits */
+ while (sum>>16)
+ sum = (sum & 0xffff) + (sum >> 16);
+
+ return ~sum;
+}
+
+/* Constuct a ip/udp header for a packet, and specify the source and dest hardware address */
+int raw_packet(struct dhcpMessage *payload, u_int32_t source_ip, int source_port,
+ u_int32_t dest_ip, int dest_port, unsigned char *dest_arp, int ifindex)
+{
+ int l_fd;
+ int result;
+ struct sockaddr_ll dest;
+ struct udp_dhcp_packet packet;
+
+ if ((l_fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP))) < 0) {
+ DEBUG(LOG_ERR, "socket call failed: %s", sys_errlist[errno]);
+ return -1;
+ }
+
+ memset(&dest, 0, sizeof(dest));
+ memset(&packet, 0, sizeof(packet));
+
+ dest.sll_family = AF_PACKET;
+ dest.sll_protocol = htons(ETH_P_IP);
+ dest.sll_ifindex = ifindex;
+ dest.sll_halen = 6;
+ memcpy(dest.sll_addr, dest_arp, 6);
+ if (bind(l_fd, (struct sockaddr *)&dest, sizeof(struct sockaddr_ll)) < 0) {
+ DEBUG(LOG_ERR, "bind call failed: %s", sys_errlist[errno]);
+ close(l_fd);
+ return -1;
+ }
+
+ packet.ip.protocol = IPPROTO_UDP;
+ packet.ip.saddr = source_ip;
+ packet.ip.daddr = dest_ip;
+ packet.udp.source = htons(source_port);
+ packet.udp.dest = htons(dest_port);
+ packet.udp.len = htons(sizeof(packet.udp) + sizeof(struct dhcpMessage)); /* cheat on the psuedo-header */
+ packet.ip.tot_len = packet.udp.len;
+ memcpy(&(packet.data), payload, sizeof(struct dhcpMessage));
+ packet.udp.check = checksum(&packet, sizeof(struct udp_dhcp_packet));
+
+ packet.ip.tot_len = htons(sizeof(struct udp_dhcp_packet));
+ packet.ip.ihl = sizeof(packet.ip) >> 2;
+ packet.ip.version = IPVERSION;
+ packet.ip.ttl = IPDEFTTL;
+ packet.ip.check = checksum(&(packet.ip), sizeof(packet.ip));
+
+ result = sendto(l_fd, &packet, sizeof(struct udp_dhcp_packet), 0, (struct sockaddr *) &dest, sizeof(dest));
+ if (result <= 0) {
+ DEBUG(LOG_ERR, "write on socket failed: %s", sys_errlist[errno]);
+ }
+ close(l_fd);
+ return result;
+}
+
+/* Let the kernel do all the work for packet generation */
+int kernel_packet(struct dhcpMessage *payload, u_int32_t source_ip, int source_port,
+ u_int32_t dest_ip, int dest_port)
+{
+ int n = 1;
+ int l_fd, result;
+ struct sockaddr_in client;
+
+ if ((l_fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
+ return -1;
+
+ if (setsockopt(l_fd, SOL_SOCKET, SO_REUSEADDR, (char *) &n, sizeof(n)) == -1)
+ return -1;
+
+ memset(&client, 0, sizeof(client));
+ client.sin_family = AF_INET;
+ client.sin_port = htons(source_port);
+ client.sin_addr.s_addr = source_ip;
+
+ if (bind(l_fd, (struct sockaddr *)&client, sizeof(struct sockaddr)) == -1)
+ return -1;
+
+ memset(&client, 0, sizeof(client));
+ client.sin_family = AF_INET;
+ client.sin_port = htons(dest_port);
+ client.sin_addr.s_addr = dest_ip;
+
+ if (connect(l_fd, (struct sockaddr *)&client, sizeof(struct sockaddr)) == -1)
+ return -1;
+
+ result = write(l_fd, payload, sizeof(struct dhcpMessage));
+ close(l_fd);
+ return result;
+}
+
+/* initialize a packet with the proper defaults */
+static void init_packet(struct dhcpMessage *packet, char type)
+{
+ struct vendor {
+ char vendor, length;
+ char str[sizeof("udhcp "VERSION)];
+ } vendor_id = { DHCP_VENDOR, sizeof("udhcp "VERSION) - 1, "udhcp "VERSION};
+
+// init_header(packet, type);
+ memset(packet, 0, sizeof(struct dhcpMessage));
+ switch (type) {
+ case DHCPDISCOVER:
+ case DHCPREQUEST:
+ case DHCPRELEASE:
+ case DHCPINFORM:
+ packet->op = BOOTREQUEST;
+ break;
+ case DHCPOFFER:
+ case DHCPACK:
+ case DHCPNAK:
+ packet->op = BOOTREPLY;
+ }
+ packet->htype = ETH_10MB;
+ packet->hlen = ETH_10MB_LEN;
+ packet->cookie = htonl(DHCP_MAGIC);
+ packet->options[0] = DHCP_END;
+ add_simple_option(packet->options, DHCP_MESSAGE_TYPE, type);
+
+ memcpy(packet->chaddr, client_config.arp, 6);
+ add_option_string(packet->options, client_config.clientid);
+ if (client_config.hostname) add_option_string(packet->options, client_config.hostname);
+ add_option_string(packet->options, (unsigned char *) &vendor_id);
+}
+
+
+/* Add a paramater 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_requests(struct dhcpMessage *packet)
+{
+ int end = end_option(packet->options);
+ int i, len = 0;
+
+ packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
+ for (i = 0; options[i].code; i++)
+ if (options[i].flags & OPTION_REQ)
+ packet->options[end + OPT_DATA + len++] = options[i].code;
+ packet->options[end + OPT_LEN] = len;
+ packet->options[end + OPT_DATA + len] = DHCP_END;
+
+}
+
+/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
+int send_discover(unsigned long xid, unsigned long requested)
+{
+ struct dhcpMessage packet;
+
+ init_packet(&packet, DHCPDISCOVER);
+ packet.xid = xid;
+ if (requested)
+ add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
+
+ add_requests(&packet);
+ LOG(LOG_DEBUG, "Sending discover...");
+ return raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
+ SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
+}
+
+/* Broadcasts a DHCP request message */
+int send_selecting(unsigned long xid, unsigned long server, unsigned long requested)
+{
+ struct dhcpMessage 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_requests(&packet);
+ addr.s_addr = requested;
+ LOG(LOG_DEBUG, "Sending select for %s...", inet_ntoa(addr));
+ return raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
+ SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
+}
+
+
+/* Unicasts or broadcasts a DHCP renew message */
+int send_renew(unsigned long xid, unsigned long server, unsigned long ciaddr)
+{
+ struct dhcpMessage packet;
+ int ret = 0;
+
+ init_packet(&packet, DHCPREQUEST);
+ packet.xid = xid;
+ packet.ciaddr = ciaddr;
+
+ add_requests(&packet);
+ LOG(LOG_DEBUG, "Sending renew...");
+ if (server)
+ ret = kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
+ else ret = raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
+ SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
+ return ret;
+}
+
+/* Create a random xid */
+unsigned long random_xid(void)
+{
+ static int initialized;
+ if (!initialized) {
+ srand(time(0));
+ initialized++;
+ }
+ return rand();
+}
+#if 0
+/* Unicasts a DHCP release message */
+int send_release(unsigned long server, unsigned long ciaddr)
+{
+ struct dhcpMessage packet;
+
+ init_packet(&packet, DHCPRELEASE);
+ packet.xid = random_xid();
+ packet.ciaddr = ciaddr;
+
+ add_simple_option(packet.options, DHCP_REQUESTED_IP, ciaddr);
+ add_simple_option(packet.options, DHCP_SERVER_ID, server);
+
+ LOG(LOG_DEBUG, "Sending release...");
+ return kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
+}
+#endif
+
+/* just a little helper */
+static void change_mode(int new_mode)
+{
+ DEBUG(LOG_INFO, "entering %s listen mode",
+ new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
+ close(fd_main);
+ fd_main = -1;
+ listen_mode = new_mode;
+}
+
+
+/* SIGUSR1 handler (renew) */
+static void renew_requested(int sig)
+{
+ sig = 0;
+ LOG(LOG_INFO, "Received SIGUSR1");
+ if (state == BOUND || state == RENEWING || state == REBINDING ||
+ state == RELEASED) {
+ change_mode(LISTEN_KERNEL);
+ packet_num = 0;
+ state = RENEW_REQUESTED;
+ }
+
+ if (state == RELEASED) {
+ change_mode(LISTEN_RAW);
+ state = INIT_SELECTING;
+ }
+
+ /* Kill any timeouts because the user wants this to hurry along */
+ timeout = 0;
+}
+
+/* get an option with bounds checking (warning, not aligned). */
+unsigned char *get_option(struct dhcpMessage *packet, int code)
+{
+ int i, length;
+ unsigned char *optionptr;
+ int over = 0, done = 0, curr = OPTION_FIELD;
+
+ optionptr = packet->options;
+ i = 0;
+ length = 308;
+ while (!done) {
+ if (i >= length) {
+ LOG(LOG_WARNING, "bogus packet, option fields too long.");
+ return NULL;
+ }
+ if (optionptr[i + OPT_CODE] == code) {
+ if (i + 1 + optionptr[i + OPT_LEN] >= length) {
+ LOG(LOG_WARNING, "bogus packet, option fields too long.");
+ return NULL;
+ }
+ return optionptr + i + 2;
+ }
+ switch (optionptr[i + OPT_CODE]) {
+ case DHCP_PADDING:
+ i++;
+ break;
+ case DHCP_OPTION_OVER:
+ if (i + 1 + optionptr[i + OPT_LEN] >= length) {
+ LOG(LOG_WARNING, "bogus packet, option fields too long.");
+ return NULL;
+ }
+ over = optionptr[i + 3];
+ i += optionptr[OPT_LEN] + 2;
+ break;
+ case DHCP_END:
+ if (curr == OPTION_FIELD && over & FILE_FIELD) {
+ optionptr = packet->file;
+ i = 0;
+ length = 128;
+ curr = FILE_FIELD;
+ } else if (curr == FILE_FIELD && over & SNAME_FIELD) {
+ optionptr = packet->sname;
+ i = 0;
+ length = 64;
+ curr = SNAME_FIELD;
+ } else done = 1;
+ break;
+ default:
+ i += optionptr[OPT_LEN + i] + 2;
+ }
+ }
+ return NULL;
+}
+#if 0
+static int upper_length(int length, struct dhcp_option *option)
+{
+ return max_option_length[option->flags & TYPE_MASK] *
+ (length / option_lengths[option->flags & TYPE_MASK]);
+}
+#endif
+
+static int sprintip(char *dest, char *pre, unsigned char *ip) {
+ return sprintf(dest, "%s%d.%d.%d.%d ", pre, ip[0], ip[1], ip[2], ip[3]);
+}
+
+
+/* Fill dest with the text of option 'option'. */
+static void fill_options(char *dest, unsigned char *option, struct dhcp_option *type_p)
+{
+ int type, optlen;
+ u_int16_t val_u16;
+ int16_t val_s16;
+ u_int32_t val_u32;
+ int32_t val_s32;
+ int len = option[OPT_LEN - 2];
+
+ dest += sprintf(dest, "%s=", type_p->name);
+
+ type = type_p->flags & TYPE_MASK;
+ optlen = option_lengths[type];
+ for(;;) {
+ switch (type) {
+ case OPTION_IP_PAIR:
+ dest += sprintip(dest, "", option);
+ *(dest++) = '/';
+ option += 4;
+ optlen = 4;
+ case OPTION_IP: /* Works regardless of host byte order. */
+ dest += sprintip(dest, "", option);
+ break;
+ case OPTION_BOOLEAN:
+ dest += sprintf(dest, *option ? "yes " : "no ");
+ break;
+ case OPTION_U8:
+ dest += sprintf(dest, "%u ", *option);
+ break;
+ case OPTION_U16:
+ memcpy(&val_u16, option, 2);
+ dest += sprintf(dest, "%u ", ntohs(val_u16));
+ break;
+ case OPTION_S16:
+ memcpy(&val_s16, option, 2);
+ dest += sprintf(dest, "%d ", ntohs(val_s16));
+ break;
+ case OPTION_U32:
+ memcpy(&val_u32, option, 4);
+ dest += sprintf(dest, "%lu ", (unsigned long) ntohl(val_u32));
+ break;
+ case OPTION_S32:
+ memcpy(&val_s32, option, 4);
+ dest += sprintf(dest, "%ld ", (long) ntohl(val_s32));
+ break;
+ case OPTION_STRING:
+ memcpy(dest, option, len);
+ dest[len] = '\0';
+ return; /* Short circuit this case */
+ }
+ option += optlen;
+ len -= optlen;
+ if (len <= 0) break;
+ }
+}
+
+static char *find_env(const char *prefix, char *defaultstr)
+{
+ extern char **environ;
+ char **ptr;
+ const int len = strlen(prefix);
+
+ for (ptr = environ; *ptr != NULL; ptr++) {
+ if (strncmp(prefix, *ptr, len) == 0)
+ return *ptr;
+ }
+ return defaultstr;
+}
+
+/* put all the paramaters into an environment */
+static char **fill_envp(struct dhcpMessage *packet)
+{
+ /* supported options are easily added here */
+ int num_options = 0;
+ int i, j;
+ char **envp;
+ unsigned char *temp;
+ char over = 0;
+
+ if (packet == NULL)
+ num_options = 0;
+ else {
+ for (i = 0; options[i].code; i++)
+ if (get_option(packet, options[i].code))
+ num_options++;
+ if (packet->siaddr) num_options++;
+ if ((temp = get_option(packet, DHCP_OPTION_OVER)))
+ over = *temp;
+ if (!(over & FILE_FIELD) && packet->file[0]) num_options++;
+ if (!(over & SNAME_FIELD) && packet->sname[0]) num_options++;
+ }
+
+ envp = xmalloc((num_options + 5) * sizeof(char *));
+ envp[0] = xmalloc(sizeof("interface=") + strlen(client_config.interface));
+ sprintf(envp[0], "interface=%s", client_config.interface);
+ envp[1] = find_env("PATH", "PATH=/bin:/usr/bin:/sbin:/usr/sbin");
+ envp[2] = find_env("HOME", "HOME=/");
+
+ if (packet == NULL) {
+ envp[3] = NULL;
+ return envp;
+ }
+
+ envp[3] = xmalloc(sizeof("ip=255.255.255.255"));
+ sprintip(envp[3], "ip=", (unsigned char *) &packet->yiaddr);
+ for (i = 0, j = 4; options[i].code; i++) {
+ if ((temp = get_option(packet, options[i].code))) {
+ envp[j] = xmalloc(max_option_length[(&options[i])->flags & TYPE_MASK] * (temp[OPT_LEN - 2] / option_lengths[(&options[i])->flags & TYPE_MASK]) + strlen((&options[i])->name) + 2);
+// envp[j] = xmalloc(upper_length(temp[OPT_LEN - 2], &options[i]) + strlen(options[i].name) + 2);
+ fill_options(envp[j], temp, &options[i]);
+ j++;
+ }
+ }
+ if (packet->siaddr) {
+ envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
+ sprintip(envp[j++], "siaddr=", (unsigned char *) &packet->yiaddr);
+ }
+ if (!(over & FILE_FIELD) && packet->file[0]) {
+ /* watch out for invalid packets */
+ packet->file[sizeof(packet->file) - 1] = '\0';
+ envp[j] = xmalloc(sizeof("boot_file=") + strlen(packet->file));
+ sprintf(envp[j++], "boot_file=%s", packet->file);
+ }
+ if (!(over & SNAME_FIELD) && packet->sname[0]) {
+ /* watch out for invalid packets */
+ packet->sname[sizeof(packet->sname) - 1] = '\0';
+ envp[j] = xmalloc(sizeof("sname=") + strlen(packet->sname));
+ sprintf(envp[j++], "sname=%s", packet->sname);
+ }
+ envp[j] = NULL;
+ return envp;
+}
+
+/* Call a script with a par file and env vars */
+void run_script(struct dhcpMessage *packet, const char *name)
+{
+ int pid;
+ char **envp;
+
+ if (client_config.script == NULL)
+ return;
+
+ /* call script */
+ pid = fork();
+ if (pid) {
+ waitpid(pid, NULL, 0);
+ return;
+ } else if (pid == 0) {
+ envp = fill_envp(packet);
+
+ /* close fd's? */
+
+ /* exec script */
+ DEBUG(LOG_INFO, "execle'ing %s", client_config.script);
+ execle(client_config.script, client_config.script,
+ name, NULL, envp);
+ LOG(LOG_ERR, "script %s failed: %s",
+ client_config.script, sys_errlist[errno]);
+ exit(1);
+ }
+}
+
+/* SIGUSR2 handler (release) */
+static void release_requested(int sig)
+{
+ sig = 0;
+ LOG(LOG_INFO, "Received SIGUSR2");
+ /* send release packet */
+ if (state == BOUND || state == RENEWING || state == REBINDING) {
+ struct dhcpMessage packet;
+
+ init_packet(&packet, DHCPRELEASE);
+ packet.xid = random_xid();
+ packet.ciaddr = requested_ip;
+
+ add_simple_option(packet.options, DHCP_REQUESTED_IP, requested_ip);
+ add_simple_option(packet.options, DHCP_SERVER_ID, server_addr);
+
+ LOG(LOG_DEBUG, "Sending release...");
+ kernel_packet(&packet, requested_ip, CLIENT_PORT, server_addr, SERVER_PORT);
+ run_script(NULL, "deconfig");
+ }
+
+ change_mode(LISTEN_NONE);
+ state = RELEASED;
+ timeout = 0x7fffffff;
+}
+
+
+int pidfile_acquire(char *pidfile)
+{
+ int pid_fd;
+ if (pidfile == NULL) return -1;
+
+ pid_fd = open(pidfile, O_CREAT | O_WRONLY, 0644);
+ if (pid_fd < 0) {
+ LOG(LOG_ERR, "Unable to open pidfile %s: %s\n",
+ pidfile, strerror(errno));
+ } else {
+ lockf(pid_fd, F_LOCK, 0);
+ }
+
+ return pid_fd;
+}
+
+
+void pidfile_write_release(int pid_fd)
+{
+ FILE *out;
+
+ if (pid_fd < 0) return;
+
+ if ((out = fdopen(pid_fd, "w")) != NULL) {
+ fprintf(out, "%d\n", getpid());
+ fclose(out);
+ }
+ lockf(pid_fd, F_UNLCK, 0);
+ close(pid_fd);
+}
+
+
+void pidfile_delete(char *pidfile)
+{
+ if (pidfile) unlink(pidfile);
+}
+
+/* Exit and cleanup */
+static void exit_client(int retval)
+{
+ pidfile_delete(client_config.pidfile);
+ CLOSE_LOG();
+ exit(retval);
+}
+
+
+/* SIGTERM handler */
+static void terminate(int sig)
+{
+ sig = 0;
+ LOG(LOG_INFO, "Received SIGTERM");
+ exit_client(0);
+}
+
+
+static void background(void)
+{
+ int pid_fd;
+ if (client_config.quit_after_lease) {
+ exit_client(0);
+ } else if (!client_config.foreground) {
+ pid_fd = pidfile_acquire(client_config.pidfile); /* hold lock during fork. */
+ if (daemon(0, 0) == -1) {
+ perror("fork");
+ exit_client(1);
+ }
+ client_config.foreground = 1; /* Do not fork again. */
+ pidfile_write_release(pid_fd);
+ }
+}
+
+int read_interface(char *interface, int *ifindex, u_int32_t *addr, unsigned char *arp)
+{
+ int l_fd;
+ struct ifreq ifr;
+ struct sockaddr_in *s_in;
+
+ memset(&ifr, 0, sizeof(struct ifreq));
+ if((l_fd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) >= 0) {
+ ifr.ifr_addr.sa_family = AF_INET;
+ strcpy(ifr.ifr_name, interface);
+
+ if (addr) {
+ if (ioctl(l_fd, SIOCGIFADDR, &ifr) == 0) {
+ s_in = (struct sockaddr_in *) &ifr.ifr_addr;
+ *addr = s_in->sin_addr.s_addr;
+ DEBUG(LOG_INFO, "%s (our ip) = %s", ifr.ifr_name, inet_ntoa(s_in->sin_addr));
+ } else {
+ LOG(LOG_ERR, "SIOCGIFADDR failed!: %s", sys_errlist[errno]);
+ return -1;
+ }
+ }
+
+ if (ioctl(l_fd, SIOCGIFINDEX, &ifr) == 0) {
+ DEBUG(LOG_INFO, "adapter index %d", ifr.ifr_ifindex);
+ *ifindex = ifr.ifr_ifindex;
+ } else {
+ LOG(LOG_ERR, "SIOCGIFINDEX failed!: %s", sys_errlist[errno]);
+ return -1;
+ }
+ if (ioctl(l_fd, SIOCGIFHWADDR, &ifr) == 0) {
+ memcpy(arp, ifr.ifr_hwaddr.sa_data, 6);
+ DEBUG(LOG_INFO, "adapter hardware address %02x:%02x:%02x:%02x:%02x:%02x",
+ arp[0], arp[1], arp[2], arp[3], arp[4], arp[5]);
+ } else {
+ LOG(LOG_ERR, "SIOCGIFHWADDR failed!: %s", sys_errlist[errno]);
+ return -1;
+ }
+ } else {
+ LOG(LOG_ERR, "socket failed!: %s", sys_errlist[errno]);
+ return -1;
+ }
+ close(l_fd);
+ return 0;
+}
+
+
+int listen_socket(unsigned int ip, int port, char *inf)
+{
+ struct ifreq interface;
+ int l_fd;
+ struct sockaddr_in addr;
+ int n = 1;
+
+ DEBUG(LOG_INFO, "Opening listen socket on 0x%08x:%d %s\n", ip, port, inf);
+ if ((l_fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
+ DEBUG(LOG_ERR, "socket call failed: %s", sys_errlist[errno]);
+ return -1;
+ }
+
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ addr.sin_port = htons(port);
+ addr.sin_addr.s_addr = ip;
+
+ if (setsockopt(l_fd, SOL_SOCKET, SO_REUSEADDR, (char *) &n, sizeof(n)) == -1) {
+ close(l_fd);
+ return -1;
+ }
+ if (setsockopt(l_fd, SOL_SOCKET, SO_BROADCAST, (char *) &n, sizeof(n)) == -1) {
+ close(l_fd);
+ return -1;
+ }
+
+ strncpy(interface.ifr_ifrn.ifrn_name, inf, IFNAMSIZ);
+ if (setsockopt(l_fd, SOL_SOCKET, SO_BINDTODEVICE,(char *)&interface, sizeof(interface)) < 0) {
+ close(l_fd);
+ return -1;
+ }
+
+ if (bind(l_fd, (struct sockaddr *)&addr, sizeof(struct sockaddr)) == -1) {
+ close(l_fd);
+ return -1;
+ }
+
+ return l_fd;
+}
+
+
+int raw_socket(int ifindex)
+{
+ int l_fd;
+ struct sockaddr_ll sock;
+
+ DEBUG(LOG_INFO, "Opening raw socket on ifindex %d\n", ifindex);
+ if ((l_fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP))) < 0) {
+ DEBUG(LOG_ERR, "socket call failed: %s", sys_errlist[errno]);
+ return -1;
+ }
+
+ sock.sll_family = AF_PACKET;
+ sock.sll_protocol = htons(ETH_P_IP);
+ sock.sll_ifindex = ifindex;
+ if (bind(l_fd, (struct sockaddr *) &sock, sizeof(sock)) < 0) {
+ DEBUG(LOG_ERR, "bind call failed: %s", sys_errlist[errno]);
+ close(l_fd);
+ return -1;
+ }
+
+ return l_fd;
+
+}
+
+/* read a packet from socket fd, return -1 on read error, -2 on packet error */
+int get_packet(struct dhcpMessage *packet, int l_fd)
+{
+ int bytes;
+ int i;
+ const char broken_vendors[][8] = {
+ "MSFT 98",
+ ""
+ };
+ char unsigned *vendor;
+
+ memset(packet, 0, sizeof(struct dhcpMessage));
+ bytes = read(l_fd, packet, sizeof(struct dhcpMessage));
+ if (bytes < 0) {
+ DEBUG(LOG_INFO, "couldn't read on listening socket, ignoring");
+ return -1;
+ }
+
+ if (ntohl(packet->cookie) != DHCP_MAGIC) {
+ LOG(LOG_ERR, "received bogus message, ignoring");
+ return -2;
+ }
+ DEBUG(LOG_INFO, "Received a packet");
+
+ if (packet->op == BOOTREQUEST && (vendor = get_option(packet, DHCP_VENDOR))) {
+ for (i = 0; broken_vendors[i][0]; i++) {
+ if (vendor[OPT_LEN - 2] == (unsigned char) strlen(broken_vendors[i]) &&
+ !strncmp(vendor, broken_vendors[i], vendor[OPT_LEN - 2])) {
+ DEBUG(LOG_INFO, "broken client (%s), forcing broadcast",
+ broken_vendors[i]);
+ packet->flags |= htons(BROADCAST_FLAG);
+ }
+ }
+ }
+
+
+ return bytes;
+}
+
+int get_raw_packet(struct dhcpMessage *payload, int l_fd)
+{
+ int bytes;
+ struct udp_dhcp_packet packet;
+ u_int32_t source, dest;
+ u_int16_t check;
+
+ memset(&packet, 0, sizeof(struct udp_dhcp_packet));
+ bytes = read(l_fd, &packet, sizeof(struct udp_dhcp_packet));
+ if (bytes < 0) {
+ DEBUG(LOG_INFO, "couldn't read on raw listening socket -- ignoring");
+ usleep(500000); /* possible down interface, looping condition */
+ return -1;
+ }
+
+ if (bytes < (int) (sizeof(struct iphdr) + sizeof(struct udphdr))) {
+ DEBUG(LOG_INFO, "message too short, ignoring");
+ return -1;
+ }
+
+ if (bytes < ntohs(packet.ip.tot_len)) {
+ DEBUG(LOG_INFO, "Truncated packet");
+ return -1;
+ }
+
+ /* 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(struct udp_dhcp_packet) ||
+ ntohs(packet.udp.len) != (short) (bytes - sizeof(packet.ip))) {
+ DEBUG(LOG_INFO, "unrelated/bogus packet");
+ return -1;
+ }
+
+ /* check IP checksum */
+ check = packet.ip.check;
+ packet.ip.check = 0;
+ if (check != checksum(&(packet.ip), sizeof(packet.ip))) {
+ DEBUG(LOG_INFO, "bad IP header checksum, ignoring");
+ return -1;
+ }
+
+ /* verify the UDP checksum by replacing the header with a psuedo header */
+ source = packet.ip.saddr;
+ dest = packet.ip.daddr;
+ check = packet.udp.check;
+ packet.udp.check = 0;
+ memset(&packet.ip, 0, sizeof(packet.ip));
+
+ packet.ip.protocol = IPPROTO_UDP;
+ packet.ip.saddr = source;
+ packet.ip.daddr = dest;
+ packet.ip.tot_len = packet.udp.len; /* cheat on the psuedo-header */
+ if (check && check != checksum(&packet, bytes)) {
+ DEBUG(LOG_ERR, "packet with bad UDP checksum received, ignoring");
+ return -1;
+ }
+
+ memcpy(payload, &(packet.data), bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
+
+ if (ntohl(payload->cookie) != DHCP_MAGIC) {
+ LOG(LOG_ERR, "received bogus message (bad magic) -- ignoring");
+ return -1;
+ }
+ DEBUG(LOG_INFO, "oooooh!!! got some!");
+ return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
+
+}
+
+
+int udhcpc_main(int argc, char *argv[])
+{
+ unsigned char *temp, *message;
+ unsigned long t1 = 0, t2 = 0, xid = 0;
+ unsigned long start = 0, lease;
+ fd_set rfds;
+ int retval;
+ struct timeval tv;
+ int c, len;
+ struct dhcpMessage packet;
+ struct in_addr temp_addr;
+ int pid_fd;
+ time_t now;
+
+ static struct option l_options[] = {
+ {"clientid", required_argument, 0, 'c'},
+ {"foreground", no_argument, 0, 'f'},
+ {"hostname", required_argument, 0, 'H'},
+ {"help", no_argument, 0, 'h'},
+ {"interface", required_argument, 0, 'i'},
+ {"now", no_argument, 0, 'n'},
+ {"pidfile", required_argument, 0, 'p'},
+ {"quit", no_argument, 0, 'q'},
+ {"request", required_argument, 0, 'r'},
+ {"script", required_argument, 0, 's'},
+ {"version", no_argument, 0, 'v'},
+ {0, 0, 0, 0}
+ };
+
+ /* get options */
+ while (1) {
+ int option_index = 0;
+ c = getopt_long(argc, argv, "c:fH:hi:np:qr:s:v", l_options, &option_index);
+ if (c == -1) break;
+
+ switch (c) {
+ case 'c':
+ len = strlen(optarg) > 255 ? 255 : strlen(optarg);
+ if (client_config.clientid) free(client_config.clientid);
+ client_config.clientid = xmalloc(len + 2);
+ client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
+ client_config.clientid[OPT_LEN] = len;
+ client_config.clientid[OPT_DATA] = '\0';
+ strncpy(client_config.clientid + 3, optarg, len - 1);
+ break;
+ case 'f':
+ client_config.foreground = 1;
+ break;
+ case 'H':
+ len = strlen(optarg) > 255 ? 255 : strlen(optarg);
+ if (client_config.hostname) free(client_config.hostname);
+ client_config.hostname = xmalloc(len + 2);
+ client_config.hostname[OPT_CODE] = DHCP_HOST_NAME;
+ client_config.hostname[OPT_LEN] = len;
+ strncpy(client_config.hostname + 2, optarg, len);
+ break;
+ case 'h':
+ print_usage();
+ return 0;
+ case 'i':
+ client_config.interface = optarg;
+ break;
+ case 'n':
+ client_config.abort_if_no_lease = 1;
+ break;
+ case 'p':
+ client_config.pidfile = optarg;
+ break;
+ case 'q':
+ client_config.quit_after_lease = 1;
+ break;
+ case 'r':
+ requested_ip = inet_addr(optarg);
+ break;
+ case 's':
+ client_config.script = optarg;
+ break;
+ case 'v':
+ printf("udhcpcd, version %s\n\n", VERSION);
+ exit_client(0);
+ break;
+ }
+ }
+
+ OPEN_LOG("udhcpc");
+ LOG(LOG_INFO, "udhcp client (v%s) started", VERSION);
+
+ pid_fd = pidfile_acquire(client_config.pidfile);
+ pidfile_write_release(pid_fd);
+
+ if (read_interface(client_config.interface, &client_config.ifindex, NULL, client_config.arp) < 0) {
+ exit_client(1);
+ }
+
+ if (!client_config.clientid) {
+ client_config.clientid = xmalloc(6 + 3);
+ client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
+ client_config.clientid[OPT_LEN] = 7;
+ client_config.clientid[OPT_DATA] = 1;
+ memcpy(client_config.clientid + 3, client_config.arp, 6);
+ }
+
+ /* setup signal handlers */
+ signal(SIGUSR1, renew_requested);
+ signal(SIGUSR2, release_requested);
+ signal(SIGTERM, terminate);
+
+ state = INIT_SELECTING;
+ run_script(NULL, "deconfig");
+ change_mode(LISTEN_RAW);
+
+ for (;;) {
+ tv.tv_sec = timeout - time(0);
+ tv.tv_usec = 0;
+ FD_ZERO(&rfds);
+
+ if (listen_mode != LISTEN_NONE && fd_main < 0) {
+ if (listen_mode == LISTEN_KERNEL) {
+ fd_main = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface);
+ } else {
+ fd_main = raw_socket(client_config.ifindex);
+ }
+ if (fd_main < 0) {
+ LOG(LOG_ERR, "FATAL: couldn't listen on socket, %s", sys_errlist[errno]);
+ exit_client(0);
+ }
+ }
+ if (fd_main >= 0) {
+ FD_SET(fd_main, &rfds);
+ }
+
+ if (tv.tv_sec > 0) {
+ DEBUG(LOG_INFO, "Waiting on select...\n");
+ retval = select(fd_main + 1, &rfds, NULL, NULL, &tv);
+ } else {
+ retval = 0; /* If we already timed out, fall through */
+ }
+
+ now = time(0);
+ if (retval == 0) {
+ /* timeout dropped to zero */
+ switch (state) {
+ case INIT_SELECTING:
+ if (packet_num < 3) {
+ if (packet_num == 0) {
+ xid = random_xid();
+ }
+ /* send discover packet */
+ send_discover(xid, requested_ip); /* broadcast */
+
+ timeout = now + ((packet_num == 2) ? 10 : 2);
+ packet_num++;
+ } else {
+ if (client_config.abort_if_no_lease) {
+ LOG(LOG_INFO, "No lease, failing.");
+ exit_client(1);
+ }
+ /* wait to try again */
+ packet_num = 0;
+ timeout = now + 60;
+ }
+ break;
+ case RENEW_REQUESTED:
+ case REQUESTING:
+ if (packet_num < 3) {
+ /* send request packet */
+ if (state == RENEW_REQUESTED) {
+ send_renew(xid, server_addr, requested_ip); /* unicast */
+ } else {
+ send_selecting(xid, server_addr, requested_ip); /* broadcast */
+ }
+ timeout = now + ((packet_num == 2) ? 10 : 2);
+ packet_num++;
+ } else {
+ /* timed out, go back to init state */
+ state = INIT_SELECTING;
+ timeout = now;
+ packet_num = 0;
+ change_mode(LISTEN_RAW);
+ }
+ break;
+ case BOUND:
+ /* Lease is starting to run out, time to enter renewing state */
+ state = RENEWING;
+ change_mode(LISTEN_KERNEL);
+ DEBUG(LOG_INFO, "Entering renew state");
+ /* fall right through */
+ case RENEWING:
+ /* Either set a new T1, or enter REBINDING state */
+ if ((t2 - t1) <= (lease / 14400 + 1)) {
+ /* timed out, enter rebinding state */
+ state = REBINDING;
+ timeout = now + (t2 - t1);
+ DEBUG(LOG_INFO, "Entering rebinding state");
+ } else {
+ /* send a request packet */
+ send_renew(xid, server_addr, requested_ip); /* unicast */
+
+ t1 = (t2 - t1) / 2 + t1;
+ timeout = t1 + start;
+ }
+ break;
+ case REBINDING:
+ /* Either set a new T2, or enter INIT state */
+ if ((lease - t2) <= (lease / 14400 + 1)) {
+ /* timed out, enter init state */
+ state = INIT_SELECTING;
+ LOG(LOG_INFO, "Lease lost, entering init state");
+ run_script(NULL, "deconfig");
+ timeout = now;
+ packet_num = 0;
+ change_mode(LISTEN_RAW);
+ } else {
+ /* send a request packet */
+ send_renew(xid, 0, requested_ip); /* broadcast */
+
+ t2 = (lease - t2) / 2 + t2;
+ timeout = t2 + start;
+ }
+ break;
+ case RELEASED:
+ /* yah, I know, *you* say it would never happen */
+ timeout = 0x7fffffff;
+ break;
+ }
+ } else if (retval > 0 && listen_mode != LISTEN_NONE && FD_ISSET(fd_main, &rfds)) {
+ /* a packet is ready, read it */
+
+ if (listen_mode == LISTEN_KERNEL) {
+ len = get_packet(&packet, fd_main);
+ } else {
+ len = get_raw_packet(&packet, fd_main);
+ }
+ if (len == -1 && errno != EINTR) {
+ DEBUG(LOG_INFO, "error on read, %s, reopening socket", sys_errlist[errno]);
+ change_mode(listen_mode); /* just close and reopen */
+ }
+ if (len < 0) {
+ continue;
+ }
+
+ if (packet.xid != xid) {
+ DEBUG(LOG_INFO, "Ignoring XID %lx (our xid is %lx)",
+ (unsigned long) packet.xid, xid);
+ continue;
+ }
+
+ if ((message = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
+ DEBUG(LOG_ERR, "couldnt get option from packet -- ignoring");
+ continue;
+ }
+
+ switch (state) {
+ case INIT_SELECTING:
+ /* Must be a DHCPOFFER to one of our xid's */
+ if (*message == DHCPOFFER) {
+ if ((temp = get_option(&packet, DHCP_SERVER_ID))) {
+ memcpy(&server_addr, temp, 4);
+ xid = packet.xid;
+ requested_ip = packet.yiaddr;
+
+ /* enter requesting state */
+ state = REQUESTING;
+ timeout = now;
+ packet_num = 0;
+ } else {
+ DEBUG(LOG_ERR, "No server ID in message");
+ }
+ }
+ break;
+ case RENEW_REQUESTED:
+ case REQUESTING:
+ case RENEWING:
+ case REBINDING:
+ if (*message == DHCPACK) {
+ if (!(temp = get_option(&packet, DHCP_LEASE_TIME))) {
+ LOG(LOG_ERR, "No lease time with ACK, using 1 hour lease");
+ lease = 60 * 60;
+ } else {
+ memcpy(&lease, temp, 4);
+ lease = ntohl(lease);
+ }
+
+ /* enter bound state */
+ t1 = lease / 2;
+
+ /* little fixed point for n * .875 */
+ t2 = (lease * 0x7) >> 3;
+ temp_addr.s_addr = packet.yiaddr;
+ LOG(LOG_INFO, "Lease of %s obtained, lease time %ld", inet_ntoa(temp_addr), lease);
+ start = now;
+ timeout = t1 + start;
+ requested_ip = packet.yiaddr;
+ run_script(&packet, ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
+
+ state = BOUND;
+ change_mode(LISTEN_NONE);
+ background();
+ }
+ else if (*message == DHCPNAK) {
+ /* return to init state */
+ LOG(LOG_INFO, "Received DHCP NAK");
+ run_script(&packet, "nak");
+ if (state != REQUESTING) {
+ run_script(NULL, "deconfig");
+ }
+ state = INIT_SELECTING;
+ timeout = now;
+ requested_ip = 0;
+ packet_num = 0;
+ change_mode(LISTEN_RAW);
+ sleep(3); /* avoid excessive network traffic */
+ }
+ break;
+ /* case BOUND, RELEASED: - ignore all packets */
+ }
+ }
+ else if (retval == -1 && errno == EINTR) {
+ /* a signal was caught */
+
+ } else {
+ /* An error occured */
+ DEBUG(LOG_ERR, "Error on select");
+ }
+
+ }
+ return 0;
+}
projects / platform / upstream / busybox.git / commitdiff