*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
-
-#include <getopt.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"
-static int state;
-/* 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 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_NONE 0
#define LISTEN_KERNEL 1
-#define LISTEN_RAW 2
-static int listen_mode;
+#define LISTEN_RAW 2
+static smallint listen_mode;
+
+/* 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 to 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,
- .release_on_quit = 0,
- .background_if_no_lease = 0,
- .interface = "eth0",
- .pidfile = NULL,
- .script = DEFAULT_SCRIPT,
- .clientid = NULL,
- .vendorclass = NULL,
- .hostname = NULL,
- .fqdn = NULL,
- .ifindex = 0,
- .retries = 3,
- .timeout = 3,
- .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("entering %s listen mode",
- new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
- if (fd >= 0) close(fd);
- fd = -1;
+ log1("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 */
}
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;
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;
bb_info_msg("Unicasting a release of %s to %s",
inet_ntoa(temp_addr), buffer);
}
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)
{
- udhcp_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
+
+
+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[])
+int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int udhcpc_main(int argc UNUSED_PARAM, char **argv)
{
uint8_t *temp, *message;
- unsigned long t1 = 0, t2 = 0, xid = 0;
- unsigned long start = 0, lease = 0;
- fd_set rfds;
+ char *str_c, *str_V, *str_h, *str_F, *str_r;
+ IF_FEATURE_UDHCP_PORT(char *str_P;)
+ llist_t *list_O = NULL;
+ int tryagain_timeout = 20;
+ int discover_timeout = 3;
+ int discover_retries = 3;
+ 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;
- long now;
- int max_fd;
- int sig;
- int no_clientid = 0;
-
- 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}
+ struct dhcp_packet packet;
+ fd_set rfds;
+
+#if ENABLE_LONG_OPTS
+ 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"
+ IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
+ IF_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_S = 1 << 15,
+ OPT_A = 1 << 16,
+ OPT_O = 1 << 17,
+ OPT_o = 1 << 18,
+ OPT_f = 1 << 19,
+/* The rest has variable bit positions, need to be clever */
+ OPTBIT_f = 19,
+ USE_FOR_MMU( OPTBIT_b,)
+ IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
+ IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
+ USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
+ IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
+ IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
};
- /* get options */
- while (1) {
- int option_index = 0;
- c = getopt_long(argc, argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:v", arg_options, &option_index);
- if (c == -1) break;
-
- switch (c) {
- case 'c':
- if (no_clientid) bb_show_usage();
- len = strlen(optarg) > 255 ? 255 : strlen(optarg);
- 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((char*)client_config.clientid + OPT_DATA, optarg, len);
- break;
- case 'C':
- if (client_config.clientid) bb_show_usage();
- no_clientid = 1;
- break;
- case 'V':
- len = strlen(optarg) > 255 ? 255 : strlen(optarg);
- free(client_config.vendorclass);
- client_config.vendorclass = xmalloc(len + 2);
- client_config.vendorclass[OPT_CODE] = DHCP_VENDOR;
- client_config.vendorclass[OPT_LEN] = len;
- strncpy((char*)client_config.vendorclass + 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);
- 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((char*)client_config.hostname + 2, optarg, len);
- break;
- case 'F':
- len = strlen(optarg) > 255 ? 255 : strlen(optarg);
- 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((char*)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':
- client_config.release_on_quit = 1;
- break;
- case 'r':
- requested_ip = inet_addr(optarg);
- break;
- case 's':
- client_config.script = optarg;
- break;
- case 'T':
- client_config.timeout = xatoi_u(optarg);
- break;
- case 't':
- client_config.retries = xatoi_u(optarg);
- break;
- case 'v':
- printf("version %s\n\n", BB_VER);
- return 0;
- break;
- default:
- bb_show_usage();
- }
+ /* Default options. */
+ IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
+ IF_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+"
+#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
+ ":vv"
+#endif
+ ;
+ IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
+ opt = getopt32(argv, "c:CV:H:h:F:i:np:qRr:s:T:t:SA:O:of"
+ USE_FOR_MMU("b")
+ IF_FEATURE_UDHCPC_ARPING("a")
+ IF_FEATURE_UDHCP_PORT("P:")
+ "v"
+ , &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
+ IF_FEATURE_UDHCP_PORT(, &str_P)
+#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
+ , &dhcp_verbose
+#endif
+ );
+ 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 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);
}
- /* Start the log, sanitize fd's, and write a pid file */
- udhcp_start_log_and_pid(client_config.pidfile);
-
- if (read_interface(client_config.interface, &client_config.ifindex,
- NULL, client_config.arp) < 0)
+ if (udhcp_read_interface(client_config.interface,
+ &client_config.ifindex,
+ NULL,
+ client_config.client_mac)
+ ) {
return 1;
+ }
- /* if not set, and not suppressed, setup the default client ID */
- if (!client_config.clientid && !no_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);
+#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;
+ }
+
+ /* 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 (!client_config.vendorclass) {
- client_config.vendorclass = xmalloc(sizeof("udhcp "BB_VER) + 2);
- client_config.vendorclass[OPT_CODE] = DHCP_VENDOR;
- client_config.vendorclass[OPT_LEN] = sizeof("udhcp "BB_VER) - 1;
- client_config.vendorclass[OPT_DATA] = 1;
- memcpy(&client_config.vendorclass[OPT_DATA],
- "udhcp "BB_VER, sizeof("udhcp "BB_VER) - 1);
+ /* Goes to stdout (unless NOMMU) and possibly syslog */
+ bb_info_msg("%s (v"BB_VER") started", applet_name);
+
+ /* If not set, and not suppressed, set up 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 + OPT_DATA+1, client_config.client_mac, 6);
}
+ if (!client_config.vendorclass)
+ client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, "udhcp "BB_VER, 0);
- /* setup the signal pipe */
+ /* Set up the signal pipe */
udhcp_sp_setup();
state = INIT_SELECTING;
udhcp_run_script(NULL, "deconfig");
- change_mode(LISTEN_RAW);
+ 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 - uptime();
- tv.tv_usec = 0;
+ //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) {
- bb_perror_msg("FATAL: cannot listen on socket");
- return 0;
- }
- }
- max_fd = udhcp_sp_fd_set(&rfds, fd);
+ /* 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:"). */
- if (tv.tv_sec > 0) {
- DEBUG("Waiting on select...");
+ max_fd = udhcp_sp_fd_set(&rfds, sockfd);
+
+ 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();
+ log1("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 = uptime();
+ /* 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 < 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;
+ /* broadcast */
+ send_discover(xid, requested_ip);
+ 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");
- return 1;
- }
- /* wait to try again */
- packet_num = 0;
- timeout = now + 60;
+ continue;
+ }
+ 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;
}
- break;
- case RENEW_REQUESTED:
+ /* wait before trying again */
+ timeout = tryagain_timeout;
+ packet_num = 0;
+ continue;
case REQUESTING:
- if (packet_num < client_config.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);
+ 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) 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.
+ * "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 */
+ /* 1/2 lease passed, enter renewing state */
state = RENEWING;
- change_mode(LISTEN_KERNEL);
- DEBUG("Entering renew state");
+ change_listen_mode(LISTEN_KERNEL);
+ log1("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("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 */
+ /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
+ * a new UDP socket for sending inside send_renew.
+ * I hazard to guess existing listening socket
+ * is somehow conflicting with it, but why is it
+ * not deterministic then?! Strange.
+ * Anyway, it does recover by eventually failing through
+ * into INIT_SELECTING state.
+ */
+ send_renew(xid, server_addr, requested_ip);
+ timeout >>= 1;
+ continue;
}
- break;
+ /* Timed out, enter rebinding state */
+ log1("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;
- bb_info_msg("Lease lost, entering init state");
- udhcp_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;
+ /* 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 broadcast renew request */
+ send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
+ 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, 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;
+ }
- if (listen_mode == LISTEN_KERNEL)
- len = udhcp_get_packet(&packet, fd);
- else len = get_raw_packet(&packet, fd);
+ /* Is it a packet? */
+ if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
+ continue; /* no */
- if (len == -1 && errno != EINTR) {
- DEBUG("error on read, %s, reopening socket", strerror(errno));
- change_mode(listen_mode); /* just close and reopen */
- }
- if (len < 0) continue;
+ {
+ int len;
- if (packet.xid != xid) {
- DEBUG("Ignoring XID %lx (our xid is %lx)",
- (unsigned long) packet.xid, xid);
- continue;
+ /* A packet is ready, read it */
+ if (listen_mode == LISTEN_KERNEL)
+ 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 */
}
-
- /* Ignore packets that aren't for us */
- if (memcmp(packet.chaddr, client_config.arp, 6)) {
- DEBUG("Packet does not have our chaddr - 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 ((message = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
- bb_error_msg("cannot get option from packet - ignoring");
- continue;
- }
+ if (packet.xid != xid) {
+ log1("xid %x (our is %x), ignoring packet",
+ (unsigned)packet.xid, (unsigned)xid);
+ continue;
+ }
- switch (state) {
- case INIT_SELECTING:
- /* Must be a DHCPOFFER to one of our xid's */
- if (*message == DHCPOFFER) {
- temp = get_option(&packet, DHCP_SERVER_ID);
- if (temp) {
- server_addr = *(uint32_t*)temp;
- xid = packet.xid;
- requested_ip = packet.yiaddr;
-
- /* enter requesting state */
- state = REQUESTING;
- timeout = now;
+ /* Ignore packets that aren't for us */
+ if (packet.hlen != 6
+ || memcmp(packet.chaddr, client_config.client_mac, 6)
+ ) {
+//FIXME: need to also check that last 10 bytes are zero
+ log1("chaddr does not match, ignoring packet"); // log2?
+ 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;
+ }
+ 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,
+ NULL,
+ (uint32_t) 0,
+ client_config.client_mac,
+ 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 {
- bb_error_msg("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) {
- temp = get_option(&packet, DHCP_LEASE_TIME);
- if (!temp) {
- bb_error_msg("no lease time with ACK, using 1 hour lease");
- lease = 60 * 60;
- } else {
- lease = ntohl(*(uint32_t*)temp);
- }
-
- /* 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;
- bb_info_msg("Lease of %s obtained, lease time %ld",
- inet_ntoa(temp_addr), lease);
- start = now;
- timeout = t1 + start;
- requested_ip = packet.yiaddr;
- udhcp_run_script(&packet,
- ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
-
- state = BOUND;
- change_mode(LISTEN_NONE);
- if (client_config.quit_after_lease) {
- if (client_config.release_on_quit)
- perform_release();
- return 0;
- }
- if (!client_config.foreground)
- client_background();
-
- } else 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");
- 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 */
+ 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 */
}
- } else if (retval > 0 && (sig = udhcp_sp_read(&rfds))) {
- switch (sig) {
- case SIGUSR1:
- perform_renew();
- break;
- case SIGUSR2:
- perform_release();
- break;
- case SIGTERM:
- bb_info_msg("Received SIGTERM");
- if (client_config.release_on_quit)
- perform_release();
- 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 */
- bb_perror_msg("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;
}
projects / oweals / busybox.git / blobdiff