telnetd: code shrink suggested by Ralf Friedl <Ralf.Friedl@online.de>

1 files changed, 36 insertions, 31 deletions

diff --git a/networking/telnetd.c b/networking/telnetd.c
index eb3701133..f06bff8b9 100644
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -203,7 +203,7 @@ getpty(char *line, int size)
 
 static struct tsession *
 make_new_session(
-                USE_FEATURE_TELNETD_STANDALONE(int sock_r, int sock_w)
+                USE_FEATURE_TELNETD_STANDALONE(int sock)
                 SKIP_FEATURE_TELNETD_STANDALONE(void)
 ) {
         const char *login_argv[2];
@@ -221,19 +221,22 @@ make_new_session(
                 bb_error_msg("can't create pty");
                 return NULL;
         }
-        if (fd > maxfd) maxfd = fd;
+        if (fd > maxfd)
+                maxfd = fd;
         ts->ptyfd = fd;
         ndelay_on(fd);
 #if ENABLE_FEATURE_TELNETD_STANDALONE
-        if (sock_w > maxfd) maxfd = sock_w;
-        ts->sockfd_write = sock_w;
-        ndelay_on(sock_w);
-        if (sock_r > maxfd) maxfd = sock_r;
-        ts->sockfd_read = sock_r;
-        ndelay_on(sock_r);
+        ts->sockfd_read = sock;
+        ndelay_on(sock);
+        if (!sock) /* We are called with fd 0 - we are in inetd mode */
+                sock++;
+        ts->sockfd_write = sock;
+        ndelay_on(sock);
+        if (sock > maxfd)
+                maxfd = sock;
 #else
-        ts->sockfd_write = 1;
         /* ts->sockfd_read = 0; - done by xzalloc */
+        ts->sockfd_write = 1;
         ndelay_on(0);
         ndelay_on(1);
 #endif
@@ -326,27 +329,33 @@ free_session(struct tsession *ts)
                 t->next = ts->next;
         }
 
+#if 0
         /* It was said that "normal" telnetd just closes ptyfd,
          * doesn't send SIGKILL. When we close ptyfd,
          * kernel sends SIGHUP to processes having slave side opened. */
-        /*kill(ts->shell_pid, SIGKILL);
-        wait4(ts->shell_pid, NULL, 0, NULL);*/
+        kill(ts->shell_pid, SIGKILL);
+        wait4(ts->shell_pid, NULL, 0, NULL);
+#endif
         close(ts->ptyfd);
         close(ts->sockfd_read);
-        /* error if ts->sockfd_read == ts->sockfd_write. So what? ;) */
-        close(ts->sockfd_write);
+        /* We do not need to close(ts->sockfd_write), it's the same
+         * as sockfd_read unless we are in inetd mode. But in inetd mode
+         * we do not free_session(), ever */
         free(ts);
 
         /* Scan all sessions and find new maxfd */
-        ts = sessions;
         maxfd = 0;
+        ts = sessions;
         while (ts) {
                 if (maxfd < ts->ptyfd)
                         maxfd = ts->ptyfd;
                 if (maxfd < ts->sockfd_read)
                         maxfd = ts->sockfd_read;
+#if 0
+                /* Again, sockfd_write == sockfd_read here */
                 if (maxfd < ts->sockfd_write)
                         maxfd = ts->sockfd_write;
+#endif
                 ts = ts->next;
         }
 }
@@ -434,7 +443,7 @@ int telnetd_main(int argc, char **argv)
 
 #if ENABLE_FEATURE_TELNETD_STANDALONE
         if (IS_INETD) {
-                sessions = make_new_session(0, 1);
+                sessions = make_new_session(0);
                 if (!sessions) /* pty opening or vfork problem, exit */
                         return 1; /* make_new_session prints error message */
         } else {
@@ -519,7 +528,7 @@ int telnetd_main(int argc, char **argv)
                 if (fd < 0)
                         goto again;
                 /* Create a new session and link it into our active list */
-                new_ts = make_new_session(fd, fd);
+                new_ts = make_new_session(fd);
                 if (new_ts) {
                         new_ts->next = sessions;
                         sessions = new_ts;
@@ -545,9 +554,7 @@ int telnetd_main(int argc, char **argv)
                                         goto skip1;
                                 if (IS_INETD)
                                         return 0;
-                                free_session(ts);
-                                ts = next;
-                                continue;
+                                goto kill_session;
                         }
                         ts->size1 -= count;
                         ts->wridx1 += count;
@@ -564,9 +571,7 @@ int telnetd_main(int argc, char **argv)
                                         goto skip2;
                                 if (IS_INETD)
                                         return 0;
-                                free_session(ts);
-                                ts = next;
-                                continue;
+                                goto kill_session;
                         }
                         ts->size2 -= count;
                         ts->wridx2 += count;
@@ -577,7 +582,7 @@ int telnetd_main(int argc, char **argv)
                 /* Should not be needed, but... remove_iacs is actually buggy
                  * (it cannot process iacs which wrap around buffer's end)!
                  * Since properly fixing it requires writing bigger code,
-                 * we will rely instead on this code making it virtually impossible
+                 * we rely instead on this code making it virtually impossible
                  * to have wrapped iac (people don't type at 2k/second).
                  * It also allows for bigger reads in common case. */
                 if (ts->size1 == 0) {
@@ -598,14 +603,11 @@ int telnetd_main(int argc, char **argv)
                                         goto skip3;
                                 if (IS_INETD)
                                         return 0;
-                                free_session(ts);
-                                ts = next;
-                                continue;
+                                goto kill_session;
                         }
                         /* Ignore trailing NUL if it is there */
                         if (!TS_BUF1[ts->rdidx1 + count - 1]) {
-                                if (!--count)
-                                        goto skip3;
+                                --count;
                         }
                         ts->size1 += count;
                         ts->rdidx1 += count;
@@ -622,9 +624,7 @@ int telnetd_main(int argc, char **argv)
                                         goto skip4;
                                 if (IS_INETD)
                                         return 0;
-                                free_session(ts);
-                                ts = next;
-                                continue;
+                                goto kill_session;
                         }
                         ts->size2 += count;
                         ts->rdidx2 += count;
@@ -633,6 +633,11 @@ int telnetd_main(int argc, char **argv)
                 }
  skip4:
                 ts = next;
+                continue;
+ kill_session:
+                free_session(ts);
+                ts = next;
         }
+
         goto again;
 }