diff options
Diffstat (limited to 'release/src/router/busybox/networking/udhcp/dhcpc.c')
| -rw-r--r-- | release/src/router/busybox/networking/udhcp/dhcpc.c | 924 |
1 files changed, 549 insertions, 375 deletions
diff --git a/release/src/router/busybox/networking/udhcp/dhcpc.c b/release/src/router/busybox/networking/udhcp/dhcpc.c index d18cb423..37a26a46 100644 --- a/release/src/router/busybox/networking/udhcp/dhcpc.c +++ b/release/src/router/busybox/networking/udhcp/dhcpc.c @@ -1,492 +1,666 @@ +/* vi: set sw=4 ts=4: */ /* dhcpc.c * * udhcp DHCP client * * Russ Dill <Russ.Dill@asu.edu> 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 <sys/time.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 <syslog.h> + +/* 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 "script.h" -#include "socket.h" -#include "common.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 sockfd = -1; #define LISTEN_NONE 0 #define LISTEN_KERNEL 1 #define LISTEN_RAW 2 -static int listen_mode; +static smallint listen_mode; -#ifdef CONFIG_INSTALL_NO_USR -#define DEFAULT_SCRIPT "/share/udhcpc/default.script" -#else -#define DEFAULT_SCRIPT "/usr/share/udhcpc/default.script" -#endif +/* initial state: (re)start DHCP negotiation */ +#define INIT_SELECTING 0 +/* discover was sent, DHCPOFFER reply received */ +#define REQUESTING 1 +/* select/renew was sent, DHCPACK reply received */ +#define BOUND 2 +/* half of lease passed, want renew it by sending unicast renew requests */ +#define RENEWING 3 +/* renew requests were not answered, lease is almost over, send broadcast renew */ +#define REBINDING 4 +/* manually requested renew (SIGUSR1) */ +#define RENEW_REQUESTED 5 +/* release, possibly manually requested (SIGUSR2) */ +#define RELEASED 6 +static smallint state; + +/* struct client_config_t client_config is in bb_common_bufsiz1 */ -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, - ifindex: 0, - arp: "\0\0\0\0\0\0", /* appease gcc-3.0 */ -}; /* 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", - new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none"); - if (fd >= 0) close(fd); - fd = -1; + DEBUG("Entering listen mode: %s", + new_mode != LISTEN_NONE + ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw") + : "none" + ); + listen_mode = new_mode; + if (sockfd >= 0) { + close(sockfd); + sockfd = -1; + } + if (new_mode == LISTEN_KERNEL) + sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface); + else if (new_mode != LISTEN_NONE) + sockfd = udhcp_raw_socket(client_config.ifindex); + /* else LISTEN_NONE: sockfd stay closed */ } /* 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_RAW); // zzz case RENEWING: case REBINDING: - state = RENEW_REQUESTED; - break; +// state = RENEW_REQUESTED; // zzz +// 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) +static void perform_release(uint32_t requested_ip, uint32_t server_addr) { - 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; } +#if BB_MMU static void client_background(void) { - background(client_config.pidfile); - client_config.foreground = 1; /* Do not fork again. */ - client_config.background_if_no_lease = 0; + bb_daemonize(0); + logmode &= ~LOGMODE_STDIO; + /* rewrite pidfile, as our pid is different now */ + write_pidfile(client_config.pidfile); } +#endif -int udhcpc_main(int argc, char *argv[]) +static uint8_t* alloc_dhcp_option(int code, const char *str, int extra) { - unsigned char *temp, *message; - unsigned long t1 = 0, t2 = 0, xid = 0; - unsigned long start = 0, lease; - fd_set rfds; + 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 UNUSED_PARAM, char **argv) +{ + uint8_t *temp, *message; + char *str_c, *str_V, *str_h, *str_F, *str_r; + USE_FEATURE_UDHCP_PORT(char *str_P;) + llist_t *list_O = NULL; + int tryagain_timeout = 20; + int discover_timeout = 3; + int discover_retries = 5; + uint32_t server_addr = server_addr; /* for compiler */ + uint32_t requested_ip = 0; + uint32_t xid = 0; + uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */ + int packet_num; + int timeout; /* must be signed */ + unsigned already_waited_sec; + unsigned opt; + int max_fd; int retval; struct timeval tv; - int c, len; struct dhcpMessage packet; - struct in_addr temp_addr; - time_t 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'}, - {"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} + fd_set rfds; + +#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" + "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" + "request-option\0" Required_argument "O" + "no-default-options\0" No_argument "o" + "foreground\0" No_argument "f" + "background\0" No_argument "b" + USE_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a") + USE_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P") + ; +#endif + enum { + OPT_c = 1 << 0, + OPT_C = 1 << 1, + OPT_V = 1 << 2, + OPT_H = 1 << 3, + OPT_h = 1 << 4, + OPT_F = 1 << 5, + OPT_i = 1 << 6, + OPT_n = 1 << 7, + OPT_p = 1 << 8, + OPT_q = 1 << 9, + OPT_R = 1 << 10, + OPT_r = 1 << 11, + OPT_s = 1 << 12, + OPT_T = 1 << 13, + OPT_t = 1 << 14, + OPT_v = 1 << 15, + OPT_S = 1 << 16, + OPT_A = 1 << 17, + OPT_O = 1 << 18, + OPT_o = 1 << 19, + OPT_f = 1 << 20, + OPT_m = 1 << 21, // zzz +/* The rest has variable bit positions, need to be clever */ + OPTBIT_LAST = 21, + USE_FOR_MMU( OPTBIT_b,) + USE_FEATURE_UDHCPC_ARPING(OPTBIT_a,) + USE_FEATURE_UDHCP_PORT( OPTBIT_P,) + USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,) + USE_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,) + USE_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,) }; - /* get options */ - while (1) { - int option_index = 0; - c = getopt_long(argc, argv, "c:fbH:h: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 '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': - bb_error_msg("version %s\n", VERSION); - return(0); - break; - default: - bb_show_usage(); - } + /* Default options. */ + USE_FEATURE_UDHCP_PORT(SERVER_PORT = 67;) + USE_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;) + 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+"; + USE_GETOPT_LONG(applet_long_options = udhcpc_longopts;) + opt = getopt32(argv, "c:CV:H:h:F:i:np:qRr:s:T:t:vSA:O:of" + "m" // zzz + USE_FOR_MMU("b") + USE_FEATURE_UDHCPC_ARPING("a") + USE_FEATURE_UDHCP_PORT("P:") + , &str_c, &str_V, &str_h, &str_h, &str_F + , &client_config.interface, &client_config.pidfile, &str_r /* i,p */ + , &client_config.script /* s */ + , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */ + , &list_O + USE_FEATURE_UDHCP_PORT(, &str_P) + ); + if (opt & OPT_c) + client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, str_c, 0); + if (opt & OPT_V) + client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0); + 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<3>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_r) + requested_ip = inet_addr(str_r); + if (opt & OPT_v) { + puts("version "BB_VER); + return 0; + } +#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) { + char *optstr = llist_pop(&list_O); + int n = index_in_strings(dhcp_option_strings, optstr); + if (n < 0) + bb_error_msg_and_die("unknown option '%s'", optstr); + n = dhcp_options[n].code; + client_config.opt_mask[n >> 3] |= 1 << (n & 7); + } + if (opt & OPT_m) minpkt = 1; // zzz + + if (udhcp_read_interface(client_config.interface, &client_config.ifindex, + NULL, client_config.arp)) + return 1; +#if !BB_MMU + /* on NOMMU reexec (i.e., background) early */ + if (!(opt & OPT_f)) { + bb_daemonize_or_rexec(0 /* flags */, argv); + logmode = LOGMODE_NONE; + } +#endif + if (opt & OPT_S) { + openlog(applet_name, LOG_PID, LOG_DAEMON); + logmode |= LOGMODE_SYSLOG; } - start_log("client"); - if (read_interface(client_config.interface, &client_config.ifindex, - NULL, client_config.arp) < 0) - 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); + + /* Goes to stdout (unless NOMMU) 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); } - /* setup signal handlers */ - udhcp_set_signal_pipe(SIGUSR2); - + 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; + timeout = 0; + already_waited_sec = 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 (;;) { + /* silence "uninitialized!" warning */ + unsigned timestamp_before_wait = timestamp_before_wait; - tv.tv_sec = timeout - time(0); - tv.tv_usec = 0; - FD_ZERO(&rfds); + //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode); - if (listen_mode != LISTEN_NONE && fd < 0) { - if (listen_mode == LISTEN_KERNEL) - fd = 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); - } - } - if (fd >= 0) FD_SET(fd, &rfds); - FD_SET(udhcp_signal_pipe[0], &rfds); + /* Was opening raw or udp socket here + * if (listen_mode != LISTEN_NONE && sockfd < 0), + * but on fast network renew responses return faster + * than we open sockets. Thus this code is moved + * to change_listen_mode(). Thus we open listen socket + * BEFORE we send renew request (see "case BOUND:"). */ + + max_fd = udhcp_sp_fd_set(&rfds, sockfd); - if (tv.tv_sec > 0) { - DEBUG(LOG_INFO, "Waiting on select...\n"); - max_fd = udhcp_signal_pipe[0] > fd ? udhcp_signal_pipe[0] : fd; + tv.tv_sec = timeout - already_waited_sec; + tv.tv_usec = 0; + retval = 0; /* If we already timed out, fall through, else... */ + if ((int)tv.tv_sec > 0) { + timestamp_before_wait = (unsigned)monotonic_sec(); + 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? A signal was caught, don't panic */ + if (errno == EINTR) { + already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait; + continue; + } + /* Else: an error occured, panic! */ + bb_perror_msg_and_die("select"); + } + } - now = time(0); + /* If timeout dropped to zero, time to become active: + * resend discover/renew/whatever + */ if (retval == 0) { - /* timeout dropped to zero */ + /* We will restart the wait in any case */ + already_waited_sec = 0; + 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 { - 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; - case RENEW_REQUESTED: + leasefail: + udhcp_run_script(NULL, "leasefail"); +#if BB_MMU /* -b is not supported on NOMMU */ + if (opt & OPT_b) { /* background if no lease */ + bb_info_msg("No lease, forking to background"); + client_background(); + /* do not background again! */ + opt = ((opt & ~OPT_b) | OPT_f); + } else +#endif + if (opt & OPT_n) { /* abort if no lease */ + bb_info_msg("No lease, failing"); + retval = 1; + goto ret; + } + /* wait before trying again */ + timeout = tryagain_timeout; + packet_num = 0; + continue; 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); + if (packet_num < discover_retries) { + /* send broadcast select packet */ + send_select(xid, server_addr, requested_ip); + timeout = discover_timeout; 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. + * "discover...select...discover..." loops + * were seen in the wild. Treat them similarly + * to "no response to discover" case */ + change_listen_mode(LISTEN_RAW); + state = INIT_SELECTING; + goto leasefail; case BOUND: - /* Lease is starting to run out, time to enter renewing state */ + /* Half of the lease passed, time to enter renewing state */ state = RENEWING; - change_mode(LISTEN_KERNEL); - DEBUG(LOG_INFO, "Entering renew state"); + change_listen_mode(LISTEN_RAW); // was: LISTEN_KERNEL -- zzz + DEBUG("Entering renew state"); /* fall right through */ + case RENEW_REQUESTED: /* manual (SIGUSR1) renew */ + case_RENEW_REQUESTED: 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; + if (timeout > 60) { + /* send an unicast renew request packet */ + send_renew(xid, server_addr, requested_ip); + timeout >>= 1; + continue; } - break; + /* Timed out, enter rebinding state */ + DEBUG("Entering rebinding state"); + state = REBINDING; + /* fall right through */ 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 { + /* Switch to bcast receive */ + change_listen_mode(LISTEN_RAW); + /* Lease is *really* about to run out, + * try to find DHCP server using broadcast */ + if (timeout > 0) { /* send a request packet */ - send_renew(xid, 0, requested_ip); /* broadcast */ - - t2 = (lease - t2) / 2 + t2; - timeout = t2 + start; + send_renew(xid, 0 /*INADDR_ANY*/, requested_ip); /* broadcast */ + timeout >>= 1; + 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"); + state = INIT_SELECTING; + /*timeout = 0; - already is */ + 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 */ + } /* if select timed out */ + + /* select() didn't timeout, something happened */ + + /* Is it a signal? */ + /* note: udhcp_sp_read checks FD_ISSET before reading */ + switch (udhcp_sp_read(&rfds)) { + case SIGUSR1: + perform_renew(); + if (state == RENEW_REQUESTED) + goto case_RENEW_REQUESTED; + /* Start things over */ + packet_num = 0; + /* Kill any timeouts because the user wants this to hurry along */ + timeout = 0; + continue; + case SIGUSR2: + perform_release(requested_ip, server_addr); + timeout = INT_MAX; + continue; + case SIGTERM: + bb_info_msg("Received SIGTERM"); + if (opt & OPT_R) /* release on quit */ + perform_release(requested_ip, server_addr); + goto ret0; + } + + /* Is it a packet? */ + if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds)) + continue; /* no */ + + { + int len; + + /* A packet is ready, read it */ if (listen_mode == LISTEN_KERNEL) - len = get_packet(&packet, fd); - else len = get_raw_packet(&packet, fd); - - if (len == -1 && errno != EINTR) { - DEBUG(LOG_INFO, "error on read, %m, reopening socket"); - 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; + len = udhcp_recv_kernel_packet(&packet, sockfd); + else + len = udhcp_recv_raw_packet(&packet, sockfd); + if (len == -1) { + /* Error is severe, reopen socket */ + bb_info_msg("Read error: %s, reopening socket", strerror(errno)); + sleep(discover_timeout); /* 3 seconds by default */ + change_listen_mode(listen_mode); /* just close and reopen */ } - - if ((message = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) { - DEBUG(LOG_ERR, "couldnt get option from packet -- ignoring"); + /* If this packet will turn out to be unrelated/bogus, + * we will go back and wait for next one. + * Be sure timeout is properly decreased. */ + already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait; + if (len < 0) continue; + } + + if (packet.xid != xid) { + DEBUG("xid %x (our is %x), ignoring packet", + (unsigned)packet.xid, (unsigned)xid); + continue; + } + + /* 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("no message type option, ignoring packet"); + continue; + } + + switch (state) { + case INIT_SELECTING: + /* Must be a DHCPOFFER to one of our xid's */ + if (*message == DHCPOFFER) { + /* 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 */ + } + /* it IS unaligned sometimes, don't "optimize" */ + move_from_unaligned32(server_addr, temp); + xid = packet.xid; + requested_ip = packet.yiaddr; + + /* enter requesting state */ + state = REQUESTING; + timeout = 0; + packet_num = 0; + already_waited_sec = 0; } - - 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; + continue; + case REQUESTING: + case RENEWING: + case RENEW_REQUESTED: + case REBINDING: + if (*message == DHCPACK) { + 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 { + /* it IS unaligned sometimes, don't "optimize" */ + move_from_unaligned32(lease_seconds, temp); + lease_seconds = ntohl(lease_seconds); + lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */ + if (lease_seconds < 10) /* and not too small */ + lease_seconds = 10; + } +#if ENABLE_FEATURE_UDHCPC_ARPING + if (opt & OPT_a) { +/* RFC 2131 3.1 paragraph 5: + * "The client receives the DHCPACK message with configuration + * parameters. The client SHOULD perform a final check on the + * parameters (e.g., ARP for allocated network address), and notes + * the duration of the lease specified in the DHCPACK message. At this + * point, the client is configured. If the client detects that the + * address is already in use (e.g., through the use of ARP), + * the client MUST send a DHCPDECLINE message to the server and restarts + * the configuration process..." */ + 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; - } else { - DEBUG(LOG_ERR, "No server ID in message"); + already_waited_sec = 0; + continue; /* back to main loop */ } } - 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; +#endif + /* enter bound state */ + timeout = lease_seconds / 2; + { + struct in_addr temp_addr; 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); - if (client_config.quit_after_lease) - return(0); - if (!client_config.foreground) - client_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 */ + bb_info_msg("Lease of %s obtained, lease time %u", + inet_ntoa(temp_addr), (unsigned)lease_seconds); } - break; - /* case BOUND, RELEASED: - ignore all packets */ - } - } else if (retval > 0 && FD_ISSET(udhcp_signal_pipe[0], &rfds)) { - if (read(udhcp_signal_pipe[0], &sig, sizeof(sig)) < 0) { - DEBUG(LOG_ERR, "Could not read signal: %m"); - continue; /* probably just EINTR */ + requested_ip = packet.yiaddr; + udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew"); + + state = BOUND; + change_listen_mode(LISTEN_NONE); + if (opt & OPT_q) { /* quit after lease */ + if (opt & OPT_R) /* release on quit */ + perform_release(requested_ip, server_addr); + goto ret0; + } + /* future renew failures should not exit (JM) */ + opt &= ~OPT_n; +#if BB_MMU /* NOMMU case backgrounded earlier */ + if (!(opt & OPT_f)) { + client_background(); + /* do not background again! */ + opt = ((opt & ~OPT_b) | OPT_f); + } +#endif + already_waited_sec = 0; + continue; /* back to main loop */ } - switch (sig) { - case SIGUSR1: - perform_renew(); - break; - case SIGUSR2: - perform_release(); - break; - case SIGTERM: - LOG(LOG_INFO, "Received SIGTERM"); - return(0); + if (*message == DHCPNAK) { + /* return to init state */ + bb_info_msg("Received DHCP NAK"); + udhcp_run_script(&packet, "nak"); + if (state != REQUESTING) + udhcp_run_script(NULL, "deconfig"); + change_listen_mode(LISTEN_RAW); + sleep(3); /* avoid excessive network traffic */ + state = INIT_SELECTING; + requested_ip = 0; + timeout = 0; + packet_num = 0; + already_waited_sec = 0; } - } else if (retval == -1 && errno == EINTR) { - /* a signal was caught */ - } else { - /* An error occured */ - DEBUG(LOG_ERR, "Error on select"); + continue; + /* case BOUND: - ignore all packets */ + /* case RELEASED: - ignore all packets */ } - - } - return 0; + /* back to main loop */ + } /* for (;;) - main loop ends */ + + ret0: + retval = 0; + ret: + /*if (client_config.pidfile) - remove_pidfile has its own check */ + remove_pidfile(client_config.pidfile); + return retval; } |