udhcpc: simplify manual renew (make it more similar to automatic one)

function                                             old     new   delta
udhcp_run_script                                     669     673      +4
udhcpc_main                                         2414    2401     -13
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 4/-13)              Total: -9 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 077098f..8b6019b 100644 (file)
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -7,9 +7,7 @@
  *
  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
-
 #include <syslog.h>
-
 /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
 #define WANT_PIDFILE 1
 #include "common.h"
@@ -25,14 +23,20 @@ static int sockfd = -1;
 #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 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
-#define INIT_REBOOT     5
-#define RENEW_REQUESTED 6
-#define RELEASED        7
+/* 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 */
@@ -42,7 +46,10 @@ static smallint state;
 static void change_listen_mode(int new_mode)
 {
        log1("Entering listen mode: %s",
-               new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
+               new_mode != LISTEN_NONE
+                       ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
+                       : "none"
+       );
 
        listen_mode = new_mode;
        if (sockfd >= 0) {
@@ -349,14 +356,16 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                tv.tv_sec = timeout - already_waited_sec;
                tv.tv_usec = 0;
                retval = 0; /* If we already timed out, fall through, else... */
-               if (tv.tv_sec > 0) {
+               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);
                        if (retval < 0) {
                                /* EINTR? A signal was caught, don't panic */
-                               if (errno == EINTR)
+                               if (errno == EINTR) {
+                                       already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
                                        continue;
+                               }
                                /* Else: an error occured, panic! */
                                bb_perror_msg_and_die("select");
                        }
@@ -374,9 +383,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                if (packet_num < discover_retries) {
                                        if (packet_num == 0)
                                                xid = random_xid();
-
-                                       send_discover(xid, requested_ip); /* broadcast */
-
+                                       /* broadcast */
+                                       send_discover(xid, requested_ip);
                                        timeout = discover_timeout;
                                        packet_num++;
                                        continue;
@@ -400,44 +408,33 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                timeout = tryagain_timeout;
                                packet_num = 0;
                                continue;
-                       case RENEW_REQUESTED:
                        case REQUESTING:
                                if (packet_num < discover_retries) {
-                                       /* send request packet */
-                                       if (state == RENEW_REQUESTED) /* unicast */
-                                               send_renew(xid, server_addr, requested_ip);
-                                       else /* broadcast */
-                                               send_select(xid, server_addr, requested_ip);
-
+                                       /* send broadcast select packet */
+                                       send_select(xid, server_addr, requested_ip);
                                        timeout = discover_timeout;
                                        packet_num++;
                                        continue;
                                }
-                               /* timed out, go back to init state */
-                               if (state == RENEW_REQUESTED)
-                                       udhcp_run_script(NULL, "deconfig");
-                               change_listen_mode(LISTEN_RAW);
-                               /* "discover...select...discover..." loops
+                               /* 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 */
-                               if (state == REQUESTING) {
-                                       state = INIT_SELECTING;
-                                       goto leasefail;
-                               }
+                               change_listen_mode(LISTEN_RAW);
                                state = INIT_SELECTING;
-                               timeout = 0;
-                               packet_num = 0;
-                               continue;
+                               goto leasefail;
                        case BOUND:
                                /* Half of the lease passed, time to enter renewing state */
+                               state = RENEWING;
                                change_listen_mode(LISTEN_KERNEL);
                                log1("Entering renew state");
-                               state = RENEWING;
                                /* fall right through */
+                       case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
+                       case_RENEW_REQUESTED:
                        case RENEWING:
                                if (timeout > 60) {
-                                       /* send a request packet */
-                                       send_renew(xid, server_addr, requested_ip); /* unicast */
+                                       /* send an unicast renew request packet */
+                                       send_renew(xid, server_addr, requested_ip);
                                        timeout >>= 1;
                                        continue;
                                }
@@ -449,8 +446,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                /* 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 /*INADDR_ANY*/, requested_ip); /* broadcast */
+                                       /* send a broadcast renew request packet */
+                                       send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
                                        timeout >>= 1;
                                        continue;
                                }
@@ -476,6 +473,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                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 */
@@ -562,9 +561,9 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                already_waited_sec = 0;
                        }
                        continue;
-               case RENEW_REQUESTED:
                case REQUESTING:
                case RENEWING:
+               case RENEW_REQUESTED:
                case REBINDING:
                        if (*message == DHCPACK) {
                                temp = get_option(&packet, DHCP_LEASE_TIME);
@@ -622,7 +621,9 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                }
                                requested_ip = packet.yiaddr;
                                udhcp_run_script(&packet,
-                                               ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
+                                       ((state >= RENEWING && state <= RENEW_REQUESTED)
+                                       ? "renew" : "bound")
+                               );
 
                                state = BOUND;
                                change_listen_mode(LISTEN_NONE);