docs/logging_and_backgrounding.txt: new mini-doc

[oweals/busybox.git] / networking / udhcp / dhcpc.c

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index e2e5b0a82382f2939e2ad1fbd0a8369004eba2e2..e9f99e39c83e8d18573638cab3f2ec06e70b9831 100644 (file)
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -43,11 +43,17 @@ static void change_listen_mode(int new_mode)
 {
        DEBUG("entering %s listen mode",
                new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
+
+       listen_mode = new_mode;
        if (sockfd >= 0) {
                close(sockfd);
                sockfd = -1;
        }
-       listen_mode = new_mode;
+       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 */
 }
 
 
@@ -274,11 +280,11 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
        /* on NOMMU reexec (i.e., background) early */
        if (!(opt & OPT_f)) {
                bb_daemonize_or_rexec(0 /* flags */, argv);
-               logmode = 0;
+               logmode = LOGMODE_NONE;
        }
 #endif
        if (opt & OPT_S) {
-               openlog(applet_name, LOG_PID, LOG_LOCAL0);
+               openlog(applet_name, LOG_PID, LOG_DAEMON);
                logmode |= LOGMODE_SYSLOG;
        }
 
@@ -318,14 +324,18 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
         * "continue" statements in code below jump to the top of the loop.
         */
        for (;;) {
-               unsigned timestamp_before_wait;
+               /* silence "uninitialized!" warning */
+               unsigned timestamp_before_wait = timestamp_before_wait;
+
+               //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
+
+               /* 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 (listen_mode != LISTEN_NONE && sockfd < 0) {
-                       if (listen_mode == LISTEN_KERNEL)
-                               sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
-                       else
-                               sockfd = udhcp_raw_socket(client_config.ifindex);
-               }
                max_fd = udhcp_sp_fd_set(&rfds, sockfd);
 
                tv.tv_sec = timeout - already_waited_sec;
@@ -432,7 +442,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                 * try to find DHCP server using broadcast */
                                if (timeout > 0) {
                                        /* send a request packet */
-                                       send_renew(xid, 0 /* INADDR_ANY*/, requested_ip); /* broadcast */
+                                       send_renew(xid, 0 /*INADDR_ANY*/, requested_ip); /* broadcast */
                                        timeout >>= 1;
                                        continue;
                                }