X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fudhcp%2Fdhcpc.c;h=fb328cb030e796158cf0473ff7d463fb72930f99;hb=32dcc53b7162406148203b8222c3f5c5056f70f2;hp=6909e8489d4339ad5ea57a205dbd151907881beb;hpb=42b3dea9bfb8ac595c71089ee23012f44dd43eb2;p=oweals%2Fbusybox.git diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c index 6909e8489..fb328cb03 100644 --- a/networking/udhcp/dhcpc.c +++ b/networking/udhcp/dhcpc.c @@ -8,24 +8,19 @@ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. */ -#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" -/* Something is definitely wrong here. IPv4 addresses - * in variables of type long?? BTW, we use inet_ntoa() - * in the code. Manpage says that struct in_addr has a member of type long (!) - * which holds IPv4 address, and the struct is passed by value (!!) - */ -static unsigned timeout; +static int timeout; /* = 0. Must be signed */ static uint32_t requested_ip; /* = 0 */ static uint32_t server_addr; -static int packet_num; /* = 0 */ static int sockfd = -1; #define LISTEN_NONE 0 @@ -35,11 +30,11 @@ static smallint listen_mode; static smallint state; -struct client_config_t client_config; +/* 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("entering %s listen mode", new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none"); @@ -57,7 +52,7 @@ static void perform_renew(void) 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; @@ -66,18 +61,12 @@ static void perform_renew(void) 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; } @@ -99,7 +88,7 @@ static void perform_release(void) } bb_info_msg("Entering released state"); - change_mode(LISTEN_NONE); + change_listen_mode(LISTEN_NONE); state = RELEASED; timeout = INT_MAX; } @@ -107,7 +96,7 @@ static void perform_release(void) static void client_background(void) { -#ifdef __uClinux__ +#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! @@ -117,8 +106,7 @@ static void client_background(void) bb_daemonize(0); logmode &= ~LOGMODE_STDIO; /* rewrite pidfile, as our pid is different now */ - if (client_config.pidfile) - write_pidfile(client_config.pidfile); + write_pidfile(client_config.pidfile); #endif /* Do not fork again. */ client_config.foreground = 1; @@ -139,26 +127,34 @@ static uint8_t* alloc_dhcp_option(int code, const char *str, int extra) } -int udhcpc_main(int argc, char **argv); -int udhcpc_main(int argc, char **argv) +int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv) { uint8_t *temp, *message; - char *str_c, *str_V, *str_h, *str_F, *str_r, *str_T, *str_t; + 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 = 0; /* can be given as 32-bit quantity */ - unsigned t1 = 0, t2 = 0; - unsigned start = 0; - unsigned now; + 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 sig; int retval; int len; - int no_clientid = 0; - fd_set rfds; struct timeval tv; - struct dhcpMessage packet; struct in_addr temp_addr; + struct dhcpMessage packet; + fd_set rfds; enum { OPT_c = 1 << 0, @@ -179,59 +175,83 @@ int udhcpc_main(int argc, char **argv) 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 struct option arg_options[] = { - { "clientid", required_argument, 0, 'c' }, - { "clientid-none", no_argument, 0, 'C' }, - { "vendorclass", required_argument, 0, 'V' }, - { "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' }, - { "release", no_argument, 0, 'R' }, - { "request", required_argument, 0, 'r' }, - { "script", required_argument, 0, 's' }, - { "timeout", required_argument, 0, 'T' }, - { "version", no_argument, 0, 'v' }, - { "retries", required_argument, 0, 't' }, - { 0, 0, 0, 0 } - }; + 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; - client_config.retries = 3; - client_config.timeout = 3; /* Parse command line */ - opt_complementary = "?:c--C:C--c" // mutually exclusive - ":hH:Hh"; // -h and -H are the same + /* 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 = arg_options; + applet_long_options = udhcpc_longopts; #endif - opt = getopt32(argc, argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:v", - &str_c, &str_V, &str_h, &str_h, &str_F, - &client_config.interface, &client_config.pidfile, &str_r, - &client_config.script, &str_T, &str_t + 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) - no_clientid = 1; + //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) + 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); @@ -256,29 +276,52 @@ int udhcpc_main(int argc, char **argv) if (opt & OPT_r) requested_ip = inet_addr(str_r); // if (opt & OPT_s) client_config.script = ... - if (opt & OPT_T) - client_config.timeout = xatoi_u(str_T); - if (opt & OPT_t) - client_config.retries = xatoi_u(str_t); + // 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) { - printf("version %s\n\n", BB_VER); + puts("version "BB_VER); return 0; } - - if (ENABLE_FEATURE_UDHCP_SYSLOG) { + 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; + } if (read_interface(client_config.interface, &client_config.ifindex, - NULL, client_config.arp) < 0) + NULL, client_config.arp)) return 1; - /* Sanitize fd's and write pidfile */ - udhcp_make_pidfile(client_config.pidfile); + /* 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 && !no_clientid) { + 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 + OPT_DATA+1, client_config.arp, 6); @@ -292,128 +335,148 @@ int udhcpc_main(int argc, char **argv) state = INIT_SELECTING; udhcp_run_script(NULL, "deconfig"); - change_mode(LISTEN_RAW); + 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 - monotonic_sec(); + tv.tv_sec = timeout; tv.tv_usec = 0; if (listen_mode != LISTEN_NONE && sockfd < 0) { if (listen_mode == LISTEN_KERNEL) - sockfd = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface); + sockfd = listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface); else sockfd = raw_socket(client_config.ifindex); } max_fd = udhcp_sp_fd_set(&rfds, sockfd); + retval = 0; /* If we already timed out, fall through, else... */ if (tv.tv_sec > 0) { DEBUG("Waiting on select..."); retval = select(max_fd + 1, &rfds, NULL, NULL, &tv); - } else retval = 0; /* If we already timed out, fall through */ + } - now = monotonic_sec(); + 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; + } + + /* 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 < client_config.retries) { + if (packet_num < discover_retries) { if (packet_num == 0) xid = random_xid(); /* send discover packet */ send_discover(xid, requested_ip); /* broadcast */ - timeout = now + client_config.timeout; + timeout = discover_timeout; packet_num++; - } else { - 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 */ - 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 < client_config.retries) { + 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) - udhcp_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 */ - state = RENEWING; - change_mode(LISTEN_KERNEL); + change_listen_mode(LISTEN_KERNEL); DEBUG("Entering renew state"); + state = RENEWING; /* 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("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; - bb_info_msg("Lease lost, entering init state"); - udhcp_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 = INT_MAX; - 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(sockfd, &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 = udhcp_get_packet(&packet, sockfd); - else len = get_raw_packet(&packet, sockfd); + len = udhcp_recv_packet(&packet, sockfd); + else + len = get_raw_packet(&packet, sockfd); - if (len == -1 && errno != EINTR) { + if (len == -1) { /* error is severe, reopen socket */ DEBUG("error on read, %s, reopening socket", strerror(errno)); - change_mode(listen_mode); /* just close and reopen */ + change_listen_mode(listen_mode); /* just close and reopen */ } if (len < 0) continue; @@ -431,7 +494,7 @@ int udhcpc_main(int argc, char **argv) message = get_option(&packet, DHCP_MESSAGE_TYPE); if (message == NULL) { - bb_error_msg("cannot get option from packet - ignoring"); + bb_error_msg("cannot get message type from packet - ignoring"); continue; } @@ -439,22 +502,24 @@ int udhcpc_main(int argc, char **argv) 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) { - /* can be misaligned, thus memcpy */ - memcpy(&server_addr, temp, 4); - xid = packet.xid; - requested_ip = packet.yiaddr; - - /* enter requesting state */ - state = REQUESTING; - timeout = now; - packet_num = 0; - } else { + 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: @@ -463,29 +528,50 @@ int udhcpc_main(int argc, char **argv) temp = get_option(&packet, DHCP_LEASE_TIME); if (!temp) { bb_error_msg("no lease time with ACK, using 1 hour lease"); - lease = 60 * 60; + lease_seconds = 60 * 60; } else { /* can be misaligned, thus memcpy */ - memcpy(&lease, temp, 4); - lease = ntohl(lease); + 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 * 7) >> 3; + t2 = (lease_seconds * 7) >> 3; temp_addr.s_addr = packet.yiaddr; bb_info_msg("Lease of %s obtained, lease time %u", - inet_ntoa(temp_addr), (unsigned)lease); - start = now; - timeout = t1 + start; + inet_ntoa(temp_addr), (unsigned)lease_seconds); + timestamp_got_lease = monotonic_sec(); + timeout = t1; requested_ip = packet.yiaddr; udhcp_run_script(&packet, ((state == RENEWING || state == REBINDING) ? "renew" : "bound")); state = BOUND; - change_mode(LISTEN_NONE); + change_listen_mode(LISTEN_NONE); if (client_config.quit_after_lease) { if (client_config.release_on_quit) perform_release(); @@ -494,26 +580,38 @@ int udhcpc_main(int argc, char **argv) if (!client_config.foreground) client_background(); - } else if (*message == DHCPNAK) { + continue; /* back to main loop */ + } + 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; - 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(); @@ -524,17 +622,13 @@ int udhcpc_main(int argc, char **argv) perform_release(); goto ret0; } - } else if (retval == -1 && errno == EINTR) { - /* a signal was caught */ - } else { - /* An error occured */ - bb_perror_msg("select"); } - } /* for (;;) */ + } /* for (;;) - main loop ends */ + ret0: retval = 0; ret: - if (client_config.pidfile) + /*if (client_config.pidfile) - remove_pidfile has it's own check */ remove_pidfile(client_config.pidfile); return retval; }