X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fudhcp%2Fdhcpc.c;h=fb328cb030e796158cf0473ff7d463fb72930f99;hb=32dcc53b7162406148203b8222c3f5c5056f70f2;hp=8009bec041a2785a9f4624b6ceece60578fc9cf0;hpb=3cc01a80a33f659bb6ff42f0fd618d6d3059b4c8;p=oweals%2Fbusybox.git diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c index 8009bec04..fb328cb03 100644 --- a/networking/udhcp/dhcpc.c +++ b/networking/udhcp/dhcpc.c @@ -1,114 +1,47 @@ +/* vi: set sw=4 ts=4: */ /* dhcpc.c * * udhcp DHCP client * * Russ Dill July 2001 * - * 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. + * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include +#include +/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */ +#define WANT_PIDFILE 1 +#include "common.h" #include "dhcpd.h" #include "dhcpc.h" #include "options.h" -#include "clientpacket.h" -#include "clientsocket.h" -#include "script.h" -#include "socket.h" -#include "common.h" -#include "signalpipe.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 = -1; + +static int timeout; /* = 0. Must be signed */ +static uint32_t requested_ip; /* = 0 */ +static uint32_t server_addr; +static int sockfd = -1; #define LISTEN_NONE 0 #define LISTEN_KERNEL 1 #define LISTEN_RAW 2 -static int listen_mode; +static smallint listen_mode; -struct client_config_t client_config = { - /* Default options. */ - .abort_if_no_lease = 0, - .foreground = 0, - .quit_after_lease = 0, - .background_if_no_lease = 0, - .interface = "eth0", - .pidfile = NULL, - .script = DEFAULT_SCRIPT, - .clientid = NULL, - .hostname = NULL, - .fqdn = NULL, - .ifindex = 0, - .arp = "\0\0\0\0\0\0", /* appease gcc-3.0 */ -}; - -#ifndef IN_BUSYBOX -static void __attribute__ ((noreturn)) show_usage(void) -{ - printf( -"Usage: udhcpc [OPTIONS]\n\n" -" -c, --clientid=CLIENTID Client identifier\n" -" -H, --hostname=HOSTNAME Client hostname\n" -" -h Alias for -H\n" -" -F, --fqdn=FQDN Client fully qualified domain name\n" -" -f, --foreground Do not fork after getting lease\n" -" -b, --background Fork to background if lease cannot be\n" -" immediately negotiated.\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" - ); - exit(0); -} -#else -#define show_usage bb_show_usage -extern void show_usage(void) __attribute__ ((noreturn)); -#endif +static smallint state; + +/* struct client_config_t client_config is in bb_common_bufsiz1 */ /* just a little helper */ -static void change_mode(int new_mode) +static void change_listen_mode(int new_mode) { - DEBUG(LOG_INFO, "entering %s listen mode", + DEBUG("entering %s listen mode", new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none"); - if (fd >= 0) close(fd); - fd = -1; + if (sockfd >= 0) { + close(sockfd); + sockfd = -1; + } listen_mode = new_mode; } @@ -116,332 +49,452 @@ static void change_mode(int new_mode) /* perform a renew */ static void perform_renew(void) { - LOG(LOG_INFO, "Performing a DHCP renew"); + bb_info_msg("Performing a DHCP renew"); switch (state) { case BOUND: - change_mode(LISTEN_KERNEL); + change_listen_mode(LISTEN_KERNEL); case RENEWING: case REBINDING: state = RENEW_REQUESTED; break; case RENEW_REQUESTED: /* impatient are we? fine, square 1 */ - run_script(NULL, "deconfig"); + udhcp_run_script(NULL, "deconfig"); case REQUESTING: case RELEASED: - change_mode(LISTEN_RAW); + change_listen_mode(LISTEN_RAW); state = INIT_SELECTING; break; case INIT_SELECTING: break; } - - /* start things over */ - packet_num = 0; - - /* Kill any timeouts because the user wants this to hurry along */ - timeout = 0; } /* perform a release */ static void perform_release(void) { - char buffer[16]; + char buffer[sizeof("255.255.255.255")]; struct in_addr temp_addr; /* send release packet */ if (state == BOUND || state == RENEWING || state == REBINDING) { temp_addr.s_addr = server_addr; - sprintf(buffer, "%s", inet_ntoa(temp_addr)); + strcpy(buffer, inet_ntoa(temp_addr)); temp_addr.s_addr = requested_ip; - LOG(LOG_INFO, "Unicasting a release of %s to %s", + bb_info_msg("Unicasting a release of %s to %s", inet_ntoa(temp_addr), buffer); send_release(server_addr, requested_ip); /* unicast */ - run_script(NULL, "deconfig"); + udhcp_run_script(NULL, "deconfig"); } - LOG(LOG_INFO, "Entering released state"); + bb_info_msg("Entering released state"); - change_mode(LISTEN_NONE); + change_listen_mode(LISTEN_NONE); state = RELEASED; - timeout = 0x7fffffff; + timeout = INT_MAX; } static void client_background(void) { - background(client_config.pidfile); - client_config.foreground = 1; /* Do not fork again. */ +#if !BB_MMU + bb_error_msg("cannot background in uclinux (yet)"); +/* ... mainly because udhcpc calls client_background() + * in _the _middle _of _udhcpc _run_, not at the start! + * If that will be properly disabled for NOMMU, client_background() + * will work on NOMMU too */ +#else + bb_daemonize(0); + logmode &= ~LOGMODE_STDIO; + /* rewrite pidfile, as our pid is different now */ + write_pidfile(client_config.pidfile); +#endif + /* Do not fork again. */ + client_config.foreground = 1; client_config.background_if_no_lease = 0; } -#ifdef COMBINED_BINARY -int udhcpc_main(int argc, char *argv[]) -#else -int main(int argc, char *argv[]) -#endif +static uint8_t* alloc_dhcp_option(int code, const char *str, int extra) +{ + uint8_t *storage; + int len = strlen(str); + if (len > 255) len = 255; + storage = xzalloc(len + extra + OPT_DATA); + storage[OPT_CODE] = code; + storage[OPT_LEN] = len + extra; + memcpy(storage + extra + OPT_DATA, str, len); + return storage; +} + + +int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv) { uint8_t *temp, *message; - unsigned long t1 = 0, t2 = 0, xid = 0; - unsigned long start = 0, lease; - fd_set rfds; + char *str_c, *str_V, *str_h, *str_F, *str_r; + USE_FEATURE_UDHCP_PORT(char *str_P;) + llist_t *list_O = NULL; +#if ENABLE_FEATURE_UDHCPC_ARPING + char *str_W; +#endif + int tryagain_timeout = 20; + int discover_timeout = 3; + int discover_retries = 3; + uint32_t xid = 0; + uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */ + int packet_num; + /* t1, t2... what a wonderful names... */ + unsigned t1 = t1; /* for gcc */ + unsigned t2 = t2; + unsigned timestamp_got_lease = timestamp_got_lease; + unsigned opt; + int max_fd; int retval; + int len; struct timeval tv; - int c, len; - struct dhcpMessage packet; struct in_addr temp_addr; - long now; - int max_fd; - int sig; - - static const struct option arg_options[] = { - {"clientid", required_argument, 0, 'c'}, - {"foreground", no_argument, 0, 'f'}, - {"background", no_argument, 0, 'b'}, - {"hostname", required_argument, 0, 'H'}, - {"hostname", required_argument, 0, 'h'}, - {"fqdn", required_argument, 0, 'F'}, - {"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} - }; + struct dhcpMessage packet; + fd_set rfds; - /* get options */ - while (1) { - int option_index = 0; - c = getopt_long(argc, argv, "c:fbH:h:F:i:np:qr:s:v", arg_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 + OPT_DATA, optarg, len); - break; - case 'f': - client_config.foreground = 1; - break; - case 'b': - client_config.background_if_no_lease = 1; - break; - case 'h': - 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 'F': - len = strlen(optarg) > 255 ? 255 : strlen(optarg); - if (client_config.fqdn) free(client_config.fqdn); - client_config.fqdn = xmalloc(len + 5); - client_config.fqdn[OPT_CODE] = DHCP_FQDN; - client_config.fqdn[OPT_LEN] = len + 3; - /* Flags: 0000NEOS - S: 1 => Client requests Server to update A RR in DNS as well as PTR - O: 1 => Server indicates to client that DNS has been updated regardless - E: 1 => Name data is DNS format, i.e. <4>host<6>domain<4>com<0> not "host.domain.com" - N: 1 => Client requests Server to not update DNS - */ - client_config.fqdn[OPT_LEN + 1] = 0x1; - client_config.fqdn[OPT_LEN + 2] = 0; - client_config.fqdn[OPT_LEN + 3] = 0; - strncpy(client_config.fqdn + 5, 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); - return 0; - break; - default: - show_usage(); - } + enum { + OPT_c = 1 << 0, + OPT_C = 1 << 1, + OPT_V = 1 << 2, + OPT_f = 1 << 3, + OPT_b = 1 << 4, + OPT_H = 1 << 5, + OPT_h = 1 << 6, + OPT_F = 1 << 7, + OPT_i = 1 << 8, + OPT_n = 1 << 9, + OPT_p = 1 << 10, + OPT_q = 1 << 11, + OPT_R = 1 << 12, + OPT_r = 1 << 13, + OPT_s = 1 << 14, + OPT_T = 1 << 15, + OPT_t = 1 << 16, + OPT_v = 1 << 17, + OPT_S = 1 << 18, + OPT_A = 1 << 19, +#if ENABLE_FEATURE_UDHCPC_ARPING + OPT_a = 1 << 20, + OPT_W = 1 << 21, +#endif + OPT_P = 1 << 22, + OPT_o = 1 << 23, + }; +#if ENABLE_GETOPT_LONG + static const char udhcpc_longopts[] ALIGN1 = + "clientid\0" Required_argument "c" + "clientid-none\0" No_argument "C" + "vendorclass\0" Required_argument "V" + "foreground\0" No_argument "f" + "background\0" No_argument "b" + "hostname\0" Required_argument "H" + "fqdn\0" Required_argument "F" + "interface\0" Required_argument "i" + "now\0" No_argument "n" + "pidfile\0" Required_argument "p" + "quit\0" No_argument "q" + "release\0" No_argument "R" + "request\0" Required_argument "r" + "script\0" Required_argument "s" + "timeout\0" Required_argument "T" + "version\0" No_argument "v" + "retries\0" Required_argument "t" + "tryagain\0" Required_argument "A" + "syslog\0" No_argument "S" +#if ENABLE_FEATURE_UDHCPC_ARPING + "arping\0" No_argument "a" +#endif + "request-option\0" Required_argument "O" +#if ENABLE_FEATURE_UDHCP_PORT + "client-port\0" Required_argument "P" +#endif + "no-default-options\0" No_argument "o" + ; +#endif + /* Default options. */ +#if ENABLE_FEATURE_UDHCP_PORT + SERVER_PORT = 67; + CLIENT_PORT = 68; +#endif + client_config.interface = "eth0"; + client_config.script = DEFAULT_SCRIPT; + + /* Parse command line */ + /* Cc: mutually exclusive; O: list; -T,-t,-A take numeric param */ + opt_complementary = "c--C:C--c:O::T+:t+:A+"; +#if ENABLE_GETOPT_LONG + applet_long_options = udhcpc_longopts; +#endif + opt = getopt32(argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:vSA:" + USE_FEATURE_UDHCPC_ARPING("aW:") + USE_FEATURE_UDHCP_PORT("P:") + "O:o" + , &str_c, &str_V, &str_h, &str_h, &str_F + , &client_config.interface, &client_config.pidfile, &str_r + , &client_config.script + , &discover_timeout, &discover_retries, &tryagain_timeout + USE_FEATURE_UDHCPC_ARPING(, &str_W) + USE_FEATURE_UDHCP_PORT(, &str_P) + , &list_O + ); + + if (opt & OPT_c) + client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, str_c, 0); + //if (opt & OPT_C) + if (opt & OPT_V) + client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0); + if (opt & OPT_f) + client_config.foreground = 1; + if (opt & OPT_b) + client_config.background_if_no_lease = 1; + if (opt & (OPT_h|OPT_H)) + client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0); + if (opt & OPT_F) { + client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3); + /* Flags: 0000NEOS + S: 1 => Client requests Server to update A RR in DNS as well as PTR + O: 1 => Server indicates to client that DNS has been updated regardless + E: 1 => Name data is DNS format, i.e. <4>host<6>domain<4>com<0> not "host.domain.com" + N: 1 => Client requests Server to not update DNS + */ + client_config.fqdn[OPT_DATA + 0] = 0x1; + /* client_config.fqdn[OPT_DATA + 1] = 0; - redundant */ + /* client_config.fqdn[OPT_DATA + 2] = 0; - redundant */ + } + // if (opt & OPT_i) client_config.interface = ... + if (opt & OPT_n) + client_config.abort_if_no_lease = 1; + // if (opt & OPT_p) client_config.pidfile = ... + if (opt & OPT_q) + client_config.quit_after_lease = 1; + if (opt & OPT_R) + client_config.release_on_quit = 1; + if (opt & OPT_r) + requested_ip = inet_addr(str_r); + // if (opt & OPT_s) client_config.script = ... + // if (opt & OPT_T) discover_timeout = xatoi_u(str_T); + // if (opt & OPT_t) discover_retries = xatoi_u(str_t); + // if (opt & OPT_A) tryagain_timeout = xatoi_u(str_A); + if (opt & OPT_v) { + puts("version "BB_VER); + return 0; + } + if (opt & OPT_S) { + openlog(applet_name, LOG_PID, LOG_LOCAL0); + logmode |= LOGMODE_SYSLOG; + } +#if ENABLE_FEATURE_UDHCP_PORT + if (opt & OPT_P) { + CLIENT_PORT = xatou16(str_P); + SERVER_PORT = CLIENT_PORT - 1; + } +#endif + if (opt & OPT_o) + client_config.no_default_options = 1; + while (list_O) { + int n = index_in_strings(dhcp_option_strings, list_O->data); + if (n < 0) + bb_error_msg_and_die("unknown option '%s'", list_O->data); + n = dhcp_options[n].code; + client_config.opt_mask[n >> 3] |= 1 << (n & 7); + list_O = list_O->link; } - - /* Start the log, sanitize fd's, and write a pid file */ - start_log_and_pid("udhcpc", client_config.pidfile); if (read_interface(client_config.interface, &client_config.ifindex, - NULL, client_config.arp) < 0) + NULL, client_config.arp)) return 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; + /* Make sure fd 0,1,2 are open */ + bb_sanitize_stdio(); + /* Equivalent of doing a fflush after every \n */ + setlinebuf(stdout); + + /* Create pidfile */ + write_pidfile(client_config.pidfile); + /* if (!..) bb_perror_msg("cannot create pidfile %s", pidfile); */ + + /* Goes to stdout and possibly syslog */ + bb_info_msg("%s (v"BB_VER") started", applet_name); + + /* if not set, and not suppressed, setup the default client ID */ + if (!client_config.clientid && !(opt & OPT_C)) { + client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7); client_config.clientid[OPT_DATA] = 1; - memcpy(client_config.clientid + 3, client_config.arp, 6); + memcpy(client_config.clientid + OPT_DATA+1, client_config.arp, 6); } + if (!client_config.vendorclass) + client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, "udhcp "BB_VER, 0); + /* setup the signal pipe */ udhcp_sp_setup(); state = INIT_SELECTING; - run_script(NULL, "deconfig"); - change_mode(LISTEN_RAW); + udhcp_run_script(NULL, "deconfig"); + change_listen_mode(LISTEN_RAW); + packet_num = 0; + /* Main event loop. select() waits on signal pipe and possibly + * on sockfd. + * "continue" statements in code below jump to the top of the loop. + */ for (;;) { - - tv.tv_sec = timeout - uptime(); + tv.tv_sec = timeout; tv.tv_usec = 0; - if (listen_mode != LISTEN_NONE && fd < 0) { + if (listen_mode != LISTEN_NONE && sockfd < 0) { if (listen_mode == LISTEN_KERNEL) - fd = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface); + sockfd = listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface); else - fd = raw_socket(client_config.ifindex); - if (fd < 0) { - LOG(LOG_ERR, "FATAL: couldn't listen on socket, %m"); - return 0; - } + sockfd = raw_socket(client_config.ifindex); } - max_fd = udhcp_sp_fd_set(&rfds, fd); + max_fd = udhcp_sp_fd_set(&rfds, sockfd); + retval = 0; /* If we already timed out, fall through, else... */ if (tv.tv_sec > 0) { - DEBUG(LOG_INFO, "Waiting on select..."); + DEBUG("Waiting on select..."); retval = select(max_fd + 1, &rfds, NULL, NULL, &tv); - } else retval = 0; /* If we already timed out, fall through */ + } + + if (retval < 0) { + /* EINTR? signal was caught, don't panic */ + if (errno != EINTR) { + /* Else: an error occured, panic! */ + bb_perror_msg_and_die("select"); + } + continue; + } - now = uptime(); + /* If timeout dropped to zero, time to become active: + * resend discover/renew/whatever + */ if (retval == 0) { - /* timeout dropped to zero */ switch (state) { case INIT_SELECTING: - if (packet_num < 3) { + if (packet_num < discover_retries) { if (packet_num == 0) xid = random_xid(); /* send discover packet */ send_discover(xid, requested_ip); /* broadcast */ - timeout = now + ((packet_num == 2) ? 4 : 2); + timeout = discover_timeout; packet_num++; - } else { - run_script(NULL, "leasefail"); - if (client_config.background_if_no_lease) { - LOG(LOG_INFO, "No lease, forking to background."); - client_background(); - } else if (client_config.abort_if_no_lease) { - LOG(LOG_INFO, "No lease, failing."); - return 1; - } - /* wait to try again */ - packet_num = 0; - timeout = now + 60; + continue; } - break; + udhcp_run_script(NULL, "leasefail"); + if (client_config.background_if_no_lease) { + bb_info_msg("No lease, forking to background"); + client_background(); + } else if (client_config.abort_if_no_lease) { + bb_info_msg("No lease, failing"); + retval = 1; + goto ret; + } + /* wait to try again */ + timeout = tryagain_timeout; + packet_num = 0; + continue; case RENEW_REQUESTED: case REQUESTING: - if (packet_num < 3) { + if (packet_num < discover_retries) { /* 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); + timeout = ((packet_num == 2) ? 10 : 2); packet_num++; - } else { - /* timed out, go back to init state */ - if (state == RENEW_REQUESTED) run_script(NULL, "deconfig"); - state = INIT_SELECTING; - timeout = now; - packet_num = 0; - change_mode(LISTEN_RAW); + continue; } - break; + /* timed out, go back to init state */ + if (state == RENEW_REQUESTED) + udhcp_run_script(NULL, "deconfig"); + change_listen_mode(LISTEN_RAW); + state = INIT_SELECTING; + timeout = 0; + packet_num = 0; + continue; case BOUND: /* Lease is starting to run out, time to enter renewing state */ + change_listen_mode(LISTEN_KERNEL); + DEBUG("Entering renew 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 { + if ((t2 - t1) > (lease_seconds / (4*60*60) + 1)) { /* send a request packet */ send_renew(xid, server_addr, requested_ip); /* unicast */ - - t1 = (t2 - t1) / 2 + t1; - timeout = t1 + start; + t1 += (t2 - t1) / 2; + timeout = t1 - ((int)monotonic_sec() - timestamp_got_lease); + continue; } - break; + /* Timed out, enter rebinding state */ + DEBUG("Entering rebinding state"); + state = REBINDING; + timeout = (t2 - t1); + continue; 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 { + /* Lease is *really* about to run out, + * try to find DHCP server using broadcast */ + if ((lease_seconds - t2) > (lease_seconds / (4*60*60) + 1)) { /* send a request packet */ send_renew(xid, 0, requested_ip); /* broadcast */ - - t2 = (lease - t2) / 2 + t2; - timeout = t2 + start; + t2 += (lease_seconds - t2) / 2; + timeout = t2 - ((int)monotonic_sec() - timestamp_got_lease); + continue; } - break; - case RELEASED: - /* yah, I know, *you* say it would never happen */ - timeout = 0x7fffffff; - break; + /* Timed out, enter init state */ + bb_info_msg("Lease lost, entering init state"); + udhcp_run_script(NULL, "deconfig"); + change_listen_mode(LISTEN_RAW); + state = INIT_SELECTING; + timeout = 0; + packet_num = 0; + continue; + /* case RELEASED: */ } - } else if (retval > 0 && listen_mode != LISTEN_NONE && FD_ISSET(fd, &rfds)) { - /* a packet is ready, read it */ + /* yah, I know, *you* say it would never happen */ + timeout = INT_MAX; + continue; /* back to main loop */ + } + + /* select() didn't timeout, something did happen. */ + /* Is is a packet? */ + if (listen_mode != LISTEN_NONE && FD_ISSET(sockfd, &rfds)) { + /* A packet is ready, read it */ if (listen_mode == LISTEN_KERNEL) - len = get_packet(&packet, fd); - else len = get_raw_packet(&packet, fd); + len = udhcp_recv_packet(&packet, sockfd); + else + len = get_raw_packet(&packet, sockfd); - if (len == -1 && errno != EINTR) { - DEBUG(LOG_INFO, "error on read, %m, reopening socket"); - change_mode(listen_mode); /* just close and reopen */ + if (len == -1) { /* error is severe, reopen socket */ + DEBUG("error on read, %s, reopening socket", strerror(errno)); + change_listen_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); + DEBUG("Ignoring XID %x (our xid is %x)", + (unsigned)packet.xid, (unsigned)xid); continue; } - if ((message = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) { - DEBUG(LOG_ERR, "couldnt get option from packet -- ignoring"); + /* Ignore packets that aren't for us */ + if (memcmp(packet.chaddr, client_config.arp, 6)) { + DEBUG("Packet does not have our chaddr - ignoring"); + continue; + } + + message = get_option(&packet, DHCP_MESSAGE_TYPE); + if (message == NULL) { + bb_error_msg("cannot get message type from packet - ignoring"); continue; } @@ -449,89 +502,133 @@ int main(int argc, char *argv[]) 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"); + /* TODO: why we don't just fetch server's IP from IP header? */ + temp = get_option(&packet, DHCP_SERVER_ID); + if (!temp) { + bb_error_msg("no server ID in message"); + continue; + /* still selecting - this server looks bad */ } + /* can be misaligned, thus memcpy */ + memcpy(&server_addr, temp, 4); + xid = packet.xid; + requested_ip = packet.yiaddr; + + /* enter requesting state */ + state = REQUESTING; + timeout = 0; + packet_num = 0; } - break; + continue; 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; + temp = get_option(&packet, DHCP_LEASE_TIME); + if (!temp) { + bb_error_msg("no lease time with ACK, using 1 hour lease"); + lease_seconds = 60 * 60; } else { - memcpy(&lease, temp, 4); - lease = ntohl(lease); + /* can be misaligned, thus memcpy */ + memcpy(&lease_seconds, temp, 4); + lease_seconds = ntohl(lease_seconds); } - +#if ENABLE_FEATURE_UDHCPC_ARPING + if (opt & OPT_a) { + if (!arpping(packet.yiaddr, + (uint32_t) 0, + client_config.arp, + client_config.interface) + ) { + bb_info_msg("offered address is in use " + "(got ARP reply), declining"); + send_decline(xid, server_addr, packet.yiaddr); + + if (state != REQUESTING) + udhcp_run_script(NULL, "deconfig"); + change_listen_mode(LISTEN_RAW); + state = INIT_SELECTING; + requested_ip = 0; + timeout = tryagain_timeout; + packet_num = 0; + continue; /* back to main loop */ + } + } +#endif /* enter bound state */ - t1 = lease / 2; + t1 = lease_seconds / 2; /* little fixed point for n * .875 */ - t2 = (lease * 0x7) >> 3; + t2 = (lease_seconds * 7) >> 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; + bb_info_msg("Lease of %s obtained, lease time %u", + inet_ntoa(temp_addr), (unsigned)lease_seconds); + timestamp_got_lease = monotonic_sec(); + timeout = t1; requested_ip = packet.yiaddr; - run_script(&packet, + udhcp_run_script(&packet, ((state == RENEWING || state == REBINDING) ? "renew" : "bound")); state = BOUND; - change_mode(LISTEN_NONE); - if (client_config.quit_after_lease) - return 0; + change_listen_mode(LISTEN_NONE); + if (client_config.quit_after_lease) { + if (client_config.release_on_quit) + perform_release(); + goto ret0; + } if (!client_config.foreground) client_background(); - } else if (*message == DHCPNAK) { + continue; /* back to main loop */ + } + if (*message == DHCPNAK) { /* return to init state */ - LOG(LOG_INFO, "Received DHCP NAK"); - run_script(&packet, "nak"); + bb_info_msg("Received DHCP NAK"); + udhcp_run_script(&packet, "nak"); if (state != REQUESTING) - run_script(NULL, "deconfig"); + udhcp_run_script(NULL, "deconfig"); + change_listen_mode(LISTEN_RAW); + sleep(3); /* avoid excessive network traffic */ state = INIT_SELECTING; - timeout = now; requested_ip = 0; + timeout = 0; packet_num = 0; - change_mode(LISTEN_RAW); - sleep(3); /* avoid excessive network traffic */ } - break; + continue; /* case BOUND, RELEASED: - ignore all packets */ } - } else if (retval > 0 && (sig = udhcp_sp_read(&rfds))) { - switch (sig) { + continue; /* back to main loop */ + } + + /* select() didn't timeout, something did happen. + * But it wasn't a packet. It's a signal pipe then. */ + { + int signo = udhcp_sp_read(&rfds); + switch (signo) { case SIGUSR1: perform_renew(); + /* start things over */ + packet_num = 0; + /* Kill any timeouts because the user wants this to hurry along */ + timeout = 0; break; case SIGUSR2: perform_release(); break; case SIGTERM: - LOG(LOG_INFO, "Received SIGTERM"); - return 0; + bb_info_msg("Received SIGTERM"); + if (client_config.release_on_quit) + perform_release(); + goto ret0; } - } else if (retval == -1 && errno == EINTR) { - /* a signal was caught */ - } else { - /* An error occured */ - DEBUG(LOG_ERR, "Error on select"); } - - } - return 0; + } /* for (;;) - main loop ends */ + + ret0: + retval = 0; + ret: + /*if (client_config.pidfile) - remove_pidfile has it's own check */ + remove_pidfile(client_config.pidfile); + return retval; }