diff options
Diffstat (limited to 'networking')
| -rw-r--r-- | networking/Makefile.in | 1 | ||||
| -rw-r--r-- | networking/config.in | 1 | ||||
| -rw-r--r-- | networking/udhcpc.c | 1571 |
3 files changed, 1573 insertions, 0 deletions
diff --git a/networking/Makefile.in b/networking/Makefile.in index be4b53b..425b5d3 100644 --- a/networking/Makefile.in +++ b/networking/Makefile.in @@ -34,6 +34,7 @@ NETWORKING-$(CONFIG_ROUTE) += route.o NETWORKING-$(CONFIG_TELNET) += telnet.o NETWORKING-$(CONFIG_TFTP) += tftp.o NETWORKING-$(CONFIG_TRACEROUTE) += traceroute.o +NETWORKING-$(CONFIG_UDHCPC) += udhcpc.o NETWORKING-$(CONFIG_WGET) += wget.o libraries-y+=$(NETWORKING_DIR)$(NETWORKING_AR) diff --git a/networking/config.in b/networking/config.in index 1edc1de..bc11d83 100644 --- a/networking/config.in +++ b/networking/config.in @@ -46,6 +46,7 @@ if [ "$CONFIG_TRACEROUTE" = "y" ]; then bool ' Enable verbose output' CONFIG_FEATURE_TRACEROUTE_VERBOSE bool ' Enable SO_DEBUG option' CONFIG_FEATURE_TRACEROUTE_SO_DEBUG fi +bool 'udhcpc' CONFIG_UDHCPC bool 'wget' CONFIG_WGET if [ "$CONFIG_WGET" = "y" ]; then bool ' Enable a nifty process meter (+2k)' CONFIG_FEATURE_WGET_STATUSBAR diff --git a/networking/udhcpc.c b/networking/udhcpc.c new file mode 100644 index 0000000..f13d44d --- /dev/null +++ b/networking/udhcpc.c @@ -0,0 +1,1571 @@ +/* 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; +} |