nc: switch to using poll(2)

Upstream started using poll(2) rather than select(2) in `nc` some
time ago, in commit 5b3b468ec (nc: use poll() instead of select()).

Now that poll(2) in busybox-w32 has been updated to work with `nc`
switch to using the same code as upstream.

As a result of this change nothing in busybox-w32 now uses the
select(2) implementation.  This reduces the size of the binaries
by about 3.4KB.

1 files changed, 2 insertions, 49 deletions

diff --git a/networking/nc.c b/networking/nc.c
index d039e2055..ee008595d 100644
--- a/networking/nc.c
+++ b/networking/nc.c
@@ -30,7 +30,7 @@
 //config:config NC_EXTRA
 //config:       bool "Netcat extensions (-eiw and -f FILE)"
 //config:       default y
-//config:       depends on NC || NETCAT
+//config:       depends on (NC || NETCAT) && PLATFORM_POSIX
 //config:       help
 //config:       Add -e (support for executing the rest of the command line after
 //config:       making or receiving a successful connection), -i (delay interval for
@@ -127,13 +127,11 @@ int nc_main(int argc, char **argv)
         IF_NOT_NC_SERVER(const) unsigned do_listen = 0;
 #if !ENABLE_PLATFORM_MINGW32
         IF_NOT_NC_EXTRA (const) unsigned wsecs = 0;
+#endif
         IF_NOT_NC_EXTRA (const) unsigned delay = 0;
         IF_NOT_NC_EXTRA (const int execparam = 0;)
         IF_NC_EXTRA     (char **execparam = NULL;)
         struct pollfd pfds[2];
-#else
-        fd_set readfds, testfds;
-#endif
         int opt; /* must be signed (getopt returns -1) */
 
         if (ENABLE_NC_SERVER || ENABLE_NC_EXTRA) {
@@ -220,9 +218,7 @@ int nc_main(int argc, char **argv)
                         cfd = accept(sfd, NULL, 0);
                         if (cfd < 0)
                                 bb_simple_perror_msg_and_die("accept");
-#if !ENABLE_PLATFORM_MINGW32
                         if (!execparam)
-#endif
                                 close(sfd);
                 } else {
                         cfd = create_and_connect_stream_or_die(argv[0],
@@ -259,20 +255,13 @@ int nc_main(int argc, char **argv)
 
         /* loop copying stdin to cfd, and cfd to stdout */
 
-#if !ENABLE_PLATFORM_MINGW32
         pfds[0].fd = STDIN_FILENO;
         pfds[0].events = POLLIN;
         pfds[1].fd = cfd;
         pfds[1].events = POLLIN;
-#else
-        FD_ZERO(&readfds);
-        FD_SET(cfd, &readfds);
-        FD_SET(STDIN_FILENO, &readfds);
-#endif
 
 #define iobuf bb_common_bufsiz1
         setup_common_bufsiz();
-#if !ENABLE_PLATFORM_MINGW32
         for (;;) {
                 int fdidx;
                 int ofd;
@@ -307,41 +296,5 @@ int nc_main(int argc, char **argv)
                         fdidx++;
                 }
         }
-#else
-        for (;;) {
-                int fd;
-                int ofd;
-                int nread;
-
-                testfds = readfds;
-
-                if (select(cfd + 1, &testfds, NULL, NULL, NULL) < 0)
-                        bb_simple_perror_msg_and_die("select");
-
-                fd = STDIN_FILENO;
-                while (1) {
-                        if (FD_ISSET(fd, &testfds)) {
-                                nread = safe_read(fd, iobuf, COMMON_BUFSIZE);
-                                if (fd == cfd) {
-                                        if (nread < 1)
-                                                exit_SUCCESS();
-                                        ofd = STDOUT_FILENO;
-                                } else {
-                                        if (nread < 1) {
-                                                /* Close outgoing half-connection so they get EOF,
-                                                 * but leave incoming alone so we can see response */
-                                                shutdown(cfd, SHUT_WR);
-                                                FD_CLR(STDIN_FILENO, &readfds);
-                                        }
-                                        ofd = cfd;
-                                }
-                                xwrite(ofd, iobuf, nread);
-                        }
-                        if (fd == cfd)
-                                break;
-                        fd = cfd;
-                }
-        }
-#endif
 }
 #endif