From 61fb48930f45aa536584b2047f9e703186e8f69f Mon Sep 17 00:00:00 2001 From: Russ Dill Date: Mon, 14 Oct 2002 21:41:28 +0000 Subject: added full udhcp integration --- networking/udhcpc.c | 1587 --------------------------------------------------- 1 file changed, 1587 deletions(-) delete mode 100644 networking/udhcpc.c (limited to 'networking/udhcpc.c') diff --git a/networking/udhcpc.c b/networking/udhcpc.c deleted file mode 100644 index c05ca4557..000000000 --- a/networking/udhcpc.c +++ /dev/null @@ -1,1587 +0,0 @@ -/* dhcpd.c - * - * udhcp DHCP client - * - * Russ Dill 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 -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#if __GLIBC__ >=2 && __GLIBC_MINOR >= 1 -#include -#include -#else -#include -#include -#include -#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, " str "\n", level, ## args); } while(0) -# define OPEN_LOG(name) -# define CLOSE_LOG() -#endif - -#ifdef DEBUG -# undef DEBUG -# define DEBUG(level, str, args...) LOG(level, str, ## args) -# define DEBUGGING -#else -# define DEBUG(level, str, args...) -#endif - -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 { - 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 */ -}; - -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; -}; - -static const 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 */ -static const unsigned char 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 const unsigned char 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 "), -}; - -/* return the position of the 'end' option (no bounds checking) */ -static 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) */ -static 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 */ -static 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); -} - -static 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 */ -static 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", strerror(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", strerror(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", strerror(errno)); - } - close(l_fd); - return result; -} - -/* Let the kernel do all the work for packet generation */ -static 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}; - - 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 */ -static inline 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); - DEBUG(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 */ -static inline 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; - DEBUG(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 */ -static int send_renew(unsigned long xid, unsigned long server, - unsigned long ciaddr) -{ - struct dhcpMessage packet; - - init_packet(&packet, DHCPREQUEST); - packet.xid = xid; - packet.ciaddr = ciaddr; - - add_requests(&packet); - DEBUG(LOG_DEBUG, "Sending renew..."); - if (server) { - return kernel_packet(&packet, ciaddr, CLIENT_PORT, server, - SERVER_PORT); - } - return raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST, - SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex); -} - -/* Create a random xid */ -static unsigned long random_xid(void) -{ - static int initialized; - - if (!initialized) { - srand(time(0)); - initialized++; - } - return rand(); -} - -/* 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). */ -static 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; -} - -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 inline void fill_options(char *dest, unsigned char *option, - const 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); - 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 */ -static 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, strerror(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); - - DEBUG(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; -} - - -static 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; -} - - -static 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); -} - -/* Exit and cleanup */ -static void exit_client(int retval) -{ - unlink(client_config.pidfile); - if (client_config.pidfile) { - unlink(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 inline 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", strerror(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", strerror(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", strerror(errno)); - return -1; - } - } else { - LOG(LOG_ERR, "socket failed!: %s", strerror(errno)); - return -1; - } - close(l_fd); - return 0; -} - - -static inline 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", strerror(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; -} - - -static 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", strerror(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", strerror(errno)); - close(l_fd); - return -1; - } - - return l_fd; - -} - -/* read a packet from socket fd, return -1 on read error, -2 on packet error */ -static 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; -} - -static inline 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:i:np:qr:s:v", l_options, - &option_index); - if (c == -1) { - break; - } - - switch (c) { - case 'c': - len = strlen(optarg); - if (len > 255) { - len = 255; - } - 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); - if (len > 255) { - len = 255; - } - 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 '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; - default: - show_usage(); - } - } - - 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", - strerror(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", - strerror(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); - { - int pid_fd2; - - if (client_config.quit_after_lease) { - exit_client(0); - } else if (!client_config.foreground) { - pid_fd2 = 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_fd2); - } - } - } 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; -} -- cgit v1.2.3