1 files changed, 168 insertions, 154 deletions

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 6666cbce6..4e3d8ca5e 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -55,8 +55,7 @@ struct tpacket_auxdata {
 #if ENABLE_LONG_OPTS
 static const char udhcpc_longopts[] ALIGN1 =
         "clientid-none\0"  No_argument       "C"
-        "vendorclass\0"    Required_argument "V"
-        "hostname\0"       Required_argument "H"
+        "vendorclass\0"    Required_argument "V" //deprecated
         "fqdn\0"           Required_argument "F"
         "interface\0"      Required_argument "i"
         "now\0"            No_argument       "n"
@@ -84,27 +83,25 @@ static const char udhcpc_longopts[] ALIGN1 =
 enum {
         OPT_C = 1 << 0,
         OPT_V = 1 << 1,
-        OPT_H = 1 << 2,
-        OPT_h = 1 << 3,
-        OPT_F = 1 << 4,
-        OPT_i = 1 << 5,
-        OPT_n = 1 << 6,
-        OPT_p = 1 << 7,
-        OPT_q = 1 << 8,
-        OPT_R = 1 << 9,
-        OPT_r = 1 << 10,
-        OPT_s = 1 << 11,
-        OPT_T = 1 << 12,
-        OPT_t = 1 << 13,
-        OPT_S = 1 << 14,
-        OPT_A = 1 << 15,
-        OPT_O = 1 << 16,
-        OPT_o = 1 << 17,
-        OPT_x = 1 << 18,
-        OPT_f = 1 << 19,
-        OPT_B = 1 << 20,
+        OPT_F = 1 << 2,
+        OPT_i = 1 << 3,
+        OPT_n = 1 << 4,
+        OPT_p = 1 << 5,
+        OPT_q = 1 << 6,
+        OPT_R = 1 << 7,
+        OPT_r = 1 << 8,
+        OPT_s = 1 << 9,
+        OPT_T = 1 << 10,
+        OPT_t = 1 << 11,
+        OPT_S = 1 << 12,
+        OPT_A = 1 << 13,
+        OPT_O = 1 << 14,
+        OPT_o = 1 << 15,
+        OPT_x = 1 << 16,
+        OPT_f = 1 << 17,
+        OPT_B = 1 << 18,
 /* The rest has variable bit positions, need to be clever */
-        OPTBIT_B = 20,
+        OPTBIT_B = 18,
         USE_FOR_MMU(             OPTBIT_b,)
         IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
         IF_FEATURE_UDHCP_PORT(   OPTBIT_P,)
@@ -569,8 +566,8 @@ static void fill_envp(struct dhcp_packet *packet)
         }
 }
 
-/* Call a script with a par file and env vars */
-static void udhcp_run_script(struct dhcp_packet *packet, const char *name)
+/* Call a script with env vars */
+static void d4_run_script(struct dhcp_packet *packet, const char *name)
 {
         char *argv[3];
 
@@ -588,6 +585,10 @@ static void udhcp_run_script(struct dhcp_packet *packet, const char *name)
         client_data.envp = NULL;
 }
 
+static void d4_run_script_deconfig(void)
+{
+        d4_run_script(NULL, "deconfig");
+}
 
 /*** Sending/receiving packets ***/
 
@@ -613,8 +614,6 @@ static void init_packet(struct dhcp_packet *packet, char type)
         packet->secs = (secs < 0xffff) ? htons(secs) : 0xffff;
 
         memcpy(packet->chaddr, client_data.client_mac, 6);
-        if (client_data.clientid)
-                udhcp_add_binary_option(packet, client_data.clientid);
 }
 
 static void add_client_options(struct dhcp_packet *packet)
@@ -640,13 +639,6 @@ static void add_client_options(struct dhcp_packet *packet)
                 packet->options[end + OPT_DATA + len] = DHCP_END;
         }
 
-        if (client_data.vendorclass)
-                udhcp_add_binary_option(packet, client_data.vendorclass);
-        if (client_data.hostname)
-                udhcp_add_binary_option(packet, client_data.hostname);
-        if (client_data.fqdn)
-                udhcp_add_binary_option(packet, client_data.fqdn);
-
         /* Request broadcast replies if we have no IP addr */
         if ((option_mask32 & OPT_B) && packet->ciaddr == 0)
                 packet->flags |= htons(BROADCAST_FLAG);
@@ -715,7 +707,7 @@ static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
 
         /* Fill in: op, htype, hlen, cookie, chaddr fields,
          * random xid field (we override it below),
-         * client-id option (unless -C), message type option:
+         * message type option:
          */
         init_packet(&packet, DHCPDISCOVER);
 
@@ -724,7 +716,6 @@ static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
                 udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
 
         /* Add options: maxsize,
-         * optionally: hostname, fqdn, vendorclass,
          * "param req" option according to -O, options specified with -x
          */
         add_client_options(&packet);
@@ -758,7 +749,7 @@ static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requeste
  */
         /* Fill in: op, htype, hlen, cookie, chaddr fields,
          * random xid field (we override it below),
-         * client-id option (unless -C), message type option:
+         * message type option:
          */
         init_packet(&packet, DHCPREQUEST);
 
@@ -768,7 +759,6 @@ static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requeste
         udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 
         /* Add options: maxsize,
-         * optionally: hostname, fqdn, vendorclass,
          * "param req" option according to -O, and options specified with -x
          */
         add_client_options(&packet);
@@ -805,7 +795,7 @@ static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
  */
         /* Fill in: op, htype, hlen, cookie, chaddr fields,
          * random xid field (we override it below),
-         * client-id option (unless -C), message type option:
+         * message type option:
          */
         init_packet(&packet, DHCPREQUEST);
 
@@ -813,7 +803,6 @@ static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
         packet.ciaddr = ciaddr;
 
         /* Add options: maxsize,
-         * optionally: hostname, fqdn, vendorclass,
          * "param req" option according to -O, and options specified with -x
          */
         add_client_options(&packet);
@@ -837,7 +826,7 @@ static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t req
         struct dhcp_packet packet;
 
         /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
-         * client-id option (unless -C), message type option:
+         * message type option:
          */
         init_packet(&packet, DHCPDECLINE);
 
@@ -854,6 +843,8 @@ static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t req
 
         udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 
+//TODO: add client-id opt?
+
         bb_simple_info_msg("broadcasting decline");
         return raw_bcast_from_client_data_ifindex(&packet, INADDR_ANY);
 }
@@ -865,9 +856,10 @@ ALWAYS_INLINE /* one caller, help compiler to use this fact */
 int send_release(uint32_t server, uint32_t ciaddr)
 {
         struct dhcp_packet packet;
+        struct option_set *ci;
 
         /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
-         * client-id option (unless -C), message type option:
+         * message type option:
          */
         init_packet(&packet, DHCPRELEASE);
 
@@ -876,6 +868,14 @@ int send_release(uint32_t server, uint32_t ciaddr)
 
         udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 
+        /* RFC 2131 section 3.1.6:
+         * If the client used a 'client identifier' when it obtained the lease,
+         * it MUST use the same 'client identifier' in the DHCPRELEASE message.
+         */
+        ci = udhcp_find_option(client_data.options, DHCP_CLIENT_ID);
+        if (ci)
+                udhcp_add_binary_option(&packet, ci->data);
+
         bb_info_msg("sending %s", "release");
         /* Note: normally we unicast here since "server" is not zero.
          * However, there _are_ people who run "address-less" DHCP servers,
@@ -886,7 +886,7 @@ int send_release(uint32_t server, uint32_t ciaddr)
 
 /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
 /* NOINLINE: limit stack usage in caller */
-static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
+static NOINLINE int d4_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
 {
         int bytes;
         struct ip_udp_dhcp_packet packet;
@@ -979,11 +979,12 @@ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
  skip_udp_sum_check:
 
         if (packet.data.cookie != htonl(DHCP_MAGIC)) {
-                bb_simple_info_msg("packet with bad magic, ignoring");
+                log1s("packet with bad magic, ignoring");
                 return -2;
         }
 
-        log1("received %s", "a packet");
+        log2("received %s", "a packet");
+        /* log2 because more informative msg for valid packets is printed later at log1 level */
         udhcp_dump_packet(&packet.data);
 
         bytes -= sizeof(packet.ip) + sizeof(packet.udp);
@@ -1096,8 +1097,6 @@ static int udhcp_raw_socket(int ifindex)
                         log1s("can't set PACKET_AUXDATA on raw socket");
         }
 
-        log1s("created raw socket");
-
         return fd;
 }
 
@@ -1126,6 +1125,8 @@ static void perform_release(uint32_t server_addr, uint32_t requested_ip)
         char buffer[sizeof("255.255.255.255")];
         struct in_addr temp_addr;
 
+        change_listen_mode(LISTEN_NONE);
+
         /* send release packet */
         if (client_data.state == BOUND
          || client_data.state == RENEWING
@@ -1146,23 +1147,10 @@ static void perform_release(uint32_t server_addr, uint32_t requested_ip)
  * Users requested to be notified in all cases, even if not in one
  * of the states above.
  */
-        udhcp_run_script(NULL, "deconfig");
-
-        change_listen_mode(LISTEN_NONE);
+        d4_run_script_deconfig();
         client_data.state = RELEASED;
 }
 
-static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
-{
-        uint8_t *storage;
-        int len = strnlen(str, 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;
-}
-
 #if BB_MMU
 static void client_background(void)
 {
@@ -1227,10 +1215,10 @@ int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 {
         uint8_t *message;
-        const char *str_V, *str_h, *str_F, *str_r;
+        const char *str_V, *str_F, *str_r;
         IF_FEATURE_UDHCPC_ARPING(const char *str_a = "2000";)
         IF_FEATURE_UDHCP_PORT(char *str_P;)
-        void *clientid_mac_ptr;
+        uint8_t *clientid_mac_ptr;
         llist_t *list_O = NULL;
         llist_t *list_x = NULL;
         int tryagain_timeout = 20;
@@ -1263,14 +1251,14 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
         /* Parse command line */
         opt = getopt32long(argv, "^"
                 /* O,x: list; -T,-t,-A take numeric param */
-                "CV:H:h:F:i:np:qRr:s:T:+t:+SA:+O:*ox:*fB"
+                "CV:F:i:np:qRr:s:T:+t:+SA:+O:*ox:*fB"
                 USE_FOR_MMU("b")
                 IF_FEATURE_UDHCPC_ARPING("a::")
                 IF_FEATURE_UDHCP_PORT("P:")
                 "v"
                 "\0" IF_UDHCP_VERBOSE("vv") /* -v is a counter */
                 , udhcpc_longopts
-                , &str_V, &str_h, &str_h, &str_F
+                , &str_V, &str_F
                 , &client_data.interface, &client_data.pidfile /* i,p */
                 , &str_r /* r */
                 , &client_data.script /* s */
@@ -1281,14 +1269,14 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 IF_FEATURE_UDHCP_PORT(, &str_P)
                 IF_UDHCP_VERBOSE(, &dhcp_verbose)
         );
-        if (opt & (OPT_h|OPT_H)) {
-                //msg added 2011-11
-                bb_simple_error_msg("option -h NAME is deprecated, use -x hostname:NAME");
-                client_data.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
-        }
         if (opt & OPT_F) {
+                char *p;
+                unsigned len;
                 /* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
-                client_data.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
+                len = strlen(str_F);
+                p = udhcp_insert_new_option(
+                                &client_data.options, DHCP_FQDN,
+                                len + 3, /*dhcp6:*/ 0);
                 /* Flag bits: 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
@@ -1297,9 +1285,10 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                  * N: 1 = Client requests server to not update DNS (S must be 0 then)
                  * Two [0] bytes which follow are deprecated and must be 0.
                  */
-                client_data.fqdn[OPT_DATA + 0] = 0x1;
-                /*client_data.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
-                /*client_data.fqdn[OPT_DATA + 2] = 0; */
+                p[OPT_DATA + 0] = 0x1;
+                /*p[OPT_DATA + 1] = 0; - xzalloc did it */
+                /*p[OPT_DATA + 2] = 0; */
+                memcpy(p + OPT_DATA + 3, str_F, len); /* do not store NUL byte */
         }
         if (opt & OPT_r)
                 requested_ip = inet_addr(str_r);
@@ -1335,7 +1324,29 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 );
                 free(optstr);
         }
+        if (str_V[0] != '\0') {
+                char *p;
+                unsigned len = strnlen(str_V, 254);
+                p = udhcp_insert_new_option(
+                                &client_data.options, DHCP_VENDOR,
+                                len, /*dhcp6:*/ 0);
+                memcpy(p + OPT_DATA, str_V, len); /* do not store NUL byte */
+        }
+
+        clientid_mac_ptr = NULL;
+        if (!(opt & OPT_C) && !udhcp_find_option(client_data.options, DHCP_CLIENT_ID)) {
+                /* not suppressed and not set, create default client ID */
+                clientid_mac_ptr = udhcp_insert_new_option(
+                                &client_data.options, DHCP_CLIENT_ID,
+                                1 + 6, /*dhcp6:*/ 0);
+                clientid_mac_ptr[OPT_DATA] = 1; /* type: ethernet */
+                clientid_mac_ptr += OPT_DATA + 1; /* skip option code, len, ethernet */
+        }
 
+        /* Not really necessary (we redo it on every iteration)
+         * but allows early (before daemonization) detection
+         * of bad interface name.
+         */
         if (udhcp_read_interface(client_data.interface,
                         &client_data.ifindex,
                         NULL,
@@ -1344,24 +1355,6 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 return 1;
         }
 
-        clientid_mac_ptr = NULL;
-        if (!(opt & OPT_C) && !udhcp_find_option(client_data.options, DHCP_CLIENT_ID)) {
-                /* not suppressed and not set, set the default client ID */
-                client_data.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
-                client_data.clientid[OPT_DATA] = 1; /* type: ethernet */
-                clientid_mac_ptr = client_data.clientid + OPT_DATA+1;
-                memcpy(clientid_mac_ptr, client_data.client_mac, 6);
-        }
-        if (str_V[0] != '\0') {
-                // can drop -V, str_V, client_data.vendorclass,
-                // but need to add "vendor" to the list of recognized
-                // string opts for this to work;
-                // and need to tweak add_client_options() too...
-                // ...so the question is, should we?
-                //bb_error_msg("option -V VENDOR is deprecated, use -x vendor:VENDOR");
-                client_data.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
-        }
-
 #if !BB_MMU
         /* on NOMMU reexec (i.e., background) early */
         if (!(opt & OPT_f)) {
@@ -1382,8 +1375,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
         srand(monotonic_us());
 
         client_data.state = INIT_SELECTING;
-        udhcp_run_script(NULL, "deconfig");
-        change_listen_mode(LISTEN_RAW);
+        d4_run_script_deconfig();
         packet_num = 0;
         timeout = 0;
         lease_remaining = 0;
@@ -1417,14 +1409,17 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                         log1("waiting %u seconds", timeout);
                         diff = (unsigned)monotonic_sec();
                         retval = poll(pfds, 2, timeout * 1000);
+                        diff = (unsigned)monotonic_sec() - diff;
+                        lease_remaining -= diff;
+                        if (lease_remaining < 0)
+                                lease_remaining = 0;
+                        timeout -= diff;
+                        if (timeout < 0)
+                                timeout = 0;
+
                         if (retval < 0) {
                                 /* EINTR? A signal was caught, don't panic */
                                 if (errno == EINTR) {
-                                        diff = (unsigned)monotonic_sec() - diff;
-                                        lease_remaining -= diff;
-                                        if (lease_remaining < 0)
-                                                lease_remaining = 0;
-                                        timeout -= diff;
                                         continue;
                                 }
                                 /* Else: an error occurred, panic! */
@@ -1454,8 +1449,10 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                         switch (client_data.state) {
                         case INIT_SELECTING:
                                 if (!discover_retries || packet_num < discover_retries) {
-                                        if (packet_num == 0)
+                                        if (packet_num == 0) {
+                                                change_listen_mode(LISTEN_RAW);
                                                 xid = random_xid();
+                                        }
                                         /* broadcast */
                                         send_discover(xid, requested_ip);
                                         timeout = discover_timeout;
@@ -1463,7 +1460,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                         continue;
                                 }
  leasefail:
-                                udhcp_run_script(NULL, "leasefail");
+                                change_listen_mode(LISTEN_NONE);
+                                d4_run_script(NULL, "leasefail");
 #if BB_MMU /* -b is not supported on NOMMU */
                                 if (opt & OPT_b) { /* background if no lease */
                                         bb_simple_info_msg("no lease, forking to background");
@@ -1483,7 +1481,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                         retval = 1;
                                         goto ret;
                                 }
-                                /* wait before trying again */
+                                /* Wait before trying again */
                                 timeout = tryagain_timeout;
                                 packet_num = 0;
                                 continue;
@@ -1499,22 +1497,20 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                  * "discover...select...discover..." loops
                                  * were seen in the wild. Treat them similarly
                                  * to "no response to discover" case */
-                                change_listen_mode(LISTEN_RAW);
                                 client_data.state = INIT_SELECTING;
                                 goto leasefail;
                         case BOUND:
                                 /* 1/2 lease passed, enter renewing state */
                                 client_data.state = RENEWING;
                                 client_data.first_secs = 0; /* make secs field count from 0 */
-                                change_listen_mode(LISTEN_KERNEL);
+                        got_SIGUSR1:
                                 log1s("entering renew state");
+                                change_listen_mode(LISTEN_KERNEL);
                                 /* fall right through */
-                        case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
-                        case_RENEW_REQUESTED:
+                        case RENEW_REQUESTED: /* in manual (SIGUSR1) renew */
                         case RENEWING:
-                                if (packet_num < 3) {
-                                        packet_num++;
-                                        /* send an unicast renew request */
+                                if (packet_num == 0) {
+                                        /* 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
@@ -1525,7 +1521,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                          */
                                         if (send_renew(xid, server_addr, requested_ip) >= 0) {
                                                 timeout = discover_timeout;
-                                                /* ^^^ used to be = lease_remaining / 2 - WAY too long */
+                                                packet_num++;
                                                 continue;
                                         }
                                         /* else: error sending.
@@ -1533,27 +1529,34 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                          * which gave us bogus server ID 1.1.1.1
                                          * which wasn't reachable (and probably did not exist).
                                          */
+                                } /* else: we had sent one packet, but got no reply */
+                                log1s("no response to renew");
+                                if (lease_remaining > 30) {
+                                        /* Some lease time remains, try to renew later */
+                                        change_listen_mode(LISTEN_NONE);
+                                        goto BOUND_for_half_lease;
                                 }
-//TODO: if 3 renew's failed (no reply) but remaining lease is large,
-//it might make sense to make a large pause (~1 hour?) and try later?
-                                /* Timed out or error, enter rebinding state */
-                                log1s("entering rebinding state");
+                                /* Enter rebinding state */
                                 client_data.state = REBINDING;
-                                /* fall right through */
-                        case REBINDING:
+                                log1s("entering rebinding state");
                                 /* Switch to bcast receive */
                                 change_listen_mode(LISTEN_RAW);
+                                packet_num = 0;
+                                /* fall right through */
+                        case REBINDING:
                                 /* Lease is *really* about to run out,
                                  * try to find DHCP server using broadcast */
-                                if (lease_remaining > 0) {
+                                if (lease_remaining > 0 && packet_num < 3) {
                                         /* send a broadcast renew request */
                                         send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
                                         timeout = discover_timeout;
+                                        packet_num++;
                                         continue;
                                 }
                                 /* Timed out, enter init state */
+                                change_listen_mode(LISTEN_NONE);
                                 bb_simple_info_msg("lease lost, entering init state");
-                                udhcp_run_script(NULL, "deconfig");
+                                d4_run_script_deconfig();
                                 client_data.state = INIT_SELECTING;
                                 client_data.first_secs = 0; /* make secs field count from 0 */
                                 timeout = 0;
@@ -1561,7 +1564,9 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                 continue;
                         /* case RELEASED: */
                         }
-                        /* yah, I know, *you* say it would never happen */
+                        /* RELEASED state (when we got SIGUSR2) ends up here.
+                         * (wait for SIGUSR1 to re-init, or for TERM, etc)
+                         */
                         timeout = INT_MAX;
                         continue; /* back to main loop */
                 } /* if poll timed out */
@@ -1571,33 +1576,42 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 /* Is it a signal? */
                 switch (udhcp_sp_read()) {
                 case SIGUSR1:
+                        if (client_data.state <= REQUESTING)
+                                /* Initial negotiations in progress, do not disturb */
+                                break;
+                        if (client_data.state == REBINDING)
+                                /* Do not go back from rebind to renew state */
+                                break;
+
+                        if (lease_remaining > 30) /* if renew fails, do not go back to BOUND */
+                                lease_remaining = 30;
                         client_data.first_secs = 0; /* make secs field count from 0 */
-                        bb_simple_info_msg("performing DHCP renew");
+                        packet_num = 0;
 
                         switch (client_data.state) {
-                        /* Try to renew/rebind */
                         case BOUND:
                         case RENEWING:
-                        case REBINDING:
-                                change_listen_mode(LISTEN_KERNEL);
+                                /* Try to renew/rebind */
                                 client_data.state = RENEW_REQUESTED;
-                                goto case_RENEW_REQUESTED;
-
-                        /* Start things over */
-                        case RENEW_REQUESTED: /* two or more SIGUSR1 received */
-                                udhcp_run_script(NULL, "deconfig");
-                        /* case REQUESTING: break; */
-                        /* case RELEASED: break; */
-                        /* case INIT_SELECTING: break; */
+                                goto got_SIGUSR1;
+
+                        case RENEW_REQUESTED:
+                                /* Two SIGUSR1 received, start things over */
+                                change_listen_mode(LISTEN_NONE);
+                                d4_run_script_deconfig();
+
+                        default:
+                        /* case RELEASED: */
+                                /* Wake from SIGUSR2-induced deconfigured state */
+                                change_listen_mode(LISTEN_NONE);
                         }
-                        change_listen_mode(LISTEN_RAW);
                         client_data.state = INIT_SELECTING;
-                        packet_num = 0;
                         /* Kill any timeouts, user wants this to hurry along */
                         timeout = 0;
                         continue;
                 case SIGUSR2:
                         perform_release(server_addr, requested_ip);
+                        /* ^^^ switches to LISTEN_NONE */
                         timeout = INT_MAX;
                         continue;
                 case SIGTERM:
@@ -1616,7 +1630,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                         if (client_data.listen_mode == LISTEN_KERNEL)
                                 len = udhcp_recv_kernel_packet(&packet, client_data.sockfd);
                         else
-                                len = udhcp_recv_raw_packet(&packet, client_data.sockfd);
+                                len = d4_recv_raw_packet(&packet, client_data.sockfd);
                         if (len == -1) {
                                 /* Error is severe, reopen socket */
                                 bb_error_msg("read error: "STRERROR_FMT", reopening socket" STRERROR_ERRNO);
@@ -1640,13 +1654,13 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                  || memcmp(packet.chaddr, client_data.client_mac, 6) != 0
                 ) {
 //FIXME: need to also check that last 10 bytes are zero
-                        log1("chaddr does not match%s", ", ignoring packet"); // log2?
+                        log1("chaddr does not match%s", ", ignoring packet");
                         continue;
                 }
 
                 message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
                 if (message == NULL) {
-                        bb_info_msg("no message type option%s", ", ignoring packet");
+                        log1("no message type option%s", ", ignoring packet");
                         continue;
                 }
 
@@ -1654,6 +1668,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 case INIT_SELECTING:
                         /* Must be a DHCPOFFER */
                         if (*message == DHCPOFFER) {
+                                struct in_addr temp_addr;
                                 uint8_t *temp;
 
 /* What exactly is server's IP? There are several values.
@@ -1689,7 +1704,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                         move_from_unaligned32(server_addr, temp);
                                 }
                                 /*xid = packet.xid; - already is */
-                                requested_ip = packet.yiaddr;
+                                temp_addr.s_addr = requested_ip = packet.yiaddr;
+                                log1("received offer of %s", inet_ntoa(temp_addr));
 
                                 /* enter requesting state */
                                 client_data.state = REQUESTING;
@@ -1707,14 +1723,15 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                 char server_str[sizeof("255.255.255.255")];
                                 uint8_t *temp;
 
+                                change_listen_mode(LISTEN_NONE);
+
                                 temp_addr.s_addr = server_addr;
                                 strcpy(server_str, inet_ntoa(temp_addr));
                                 temp_addr.s_addr = packet.yiaddr;
 
+                                lease_remaining = 60 * 60;
                                 temp = udhcp_get_option32(&packet, DHCP_LEASE_TIME);
-                                if (!temp) {
-                                        lease_remaining = 60 * 60;
-                                } else {
+                                if (temp) {
                                         uint32_t lease;
                                         /* it IS unaligned sometimes, don't "optimize" */
                                         move_from_unaligned32(lease, temp);
@@ -1758,8 +1775,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                                 send_decline(/*xid,*/ server_addr, packet.yiaddr);
 
                                                 if (client_data.state != REQUESTING)
-                                                        udhcp_run_script(NULL, "deconfig");
-                                                change_listen_mode(LISTEN_RAW);
+                                                        d4_run_script_deconfig();
                                                 client_data.state = INIT_SELECTING;
                                                 client_data.first_secs = 0; /* make secs field count from 0 */
                                                 requested_ip = 0;
@@ -1769,17 +1785,12 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                         }
                                 }
 #endif
-
                                 /* enter bound state */
                                 start = monotonic_sec();
-                                udhcp_run_script(&packet, client_data.state == REQUESTING ? "bound" : "renew");
-                                timeout = (unsigned)lease_remaining / 2;
-//TODO: why / 2?
-                                timeout -= (unsigned)monotonic_sec() - start;
-                                packet_num = 0;
-
-                                client_data.state = BOUND;
-                                change_listen_mode(LISTEN_NONE);
+                                d4_run_script(&packet, client_data.state == REQUESTING ? "bound" : "renew");
+                                lease_remaining -= (unsigned)monotonic_sec() - start;
+                                if (lease_remaining < 0)
+                                        lease_remaining = 0;
                                 if (opt & OPT_q) { /* quit after lease */
                                         goto ret0;
                                 }
@@ -1792,9 +1803,12 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                         opt = ((opt & ~OPT_b) | OPT_f);
                                 }
 #endif
+ BOUND_for_half_lease:
+                                timeout = (unsigned)lease_remaining / 2;
+                                client_data.state = BOUND;
                                 /* make future renew packets use different xid */
                                 /* xid = random_xid(); ...but why bother? */
-
+                                packet_num = 0;
                                 continue; /* back to main loop */
                         }
                         if (*message == DHCPNAK) {
@@ -1818,11 +1832,11 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                                 goto non_matching_svid;
                                 }
                                 /* return to init state */
+                                change_listen_mode(LISTEN_NONE);
                                 bb_info_msg("received %s", "DHCP NAK");
-                                udhcp_run_script(&packet, "nak");
+                                d4_run_script(&packet, "nak");
                                 if (client_data.state != REQUESTING)
-                                        udhcp_run_script(NULL, "deconfig");
-                                change_listen_mode(LISTEN_RAW);
+                                        d4_run_script_deconfig();
                                 sleep(3); /* avoid excessive network traffic */
                                 client_data.state = INIT_SELECTING;
                                 client_data.first_secs = 0; /* make secs field count from 0 */