telnetd: correctly output 0xff char. ~100 bytes.

telnet: fix some atrocious names and style. no code changes

1 files changed, 51 insertions, 7 deletions

diff --git a/networking/telnetd.c b/networking/telnetd.c
index 46dfb318f..f04b32f9e 100644
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -74,9 +74,6 @@ static const char *issuefile = "/etc/issue.net";
    past (bf + len) then that IAC will be left unprocessed and *processed
    will be less than len.
 
-   FIXME - if we mean to send 0xFF to the terminal then it will be escaped,
-   what is the escape character?  We aren't handling that situation here.
-
    CR-LF ->'s CR mapping is also done here, for convenience.
 
    NB: may fail to remove iacs which wrap around buffer!
@@ -159,6 +156,47 @@ remove_iacs(struct tsession *ts, int *pnum_totty)
         return memmove(ptr - num_totty, ptr0, num_totty);
 }
 
+/*
+ * Converting single 0xff into double on output
+ */
+static size_t iac_safe_write(int fd, const char *buf, size_t count)
+{
+        const char *oxff;
+        size_t wr, rc, total;
+
+        total = 0;
+        while (1) {
+                if (count == 0)
+                        return total;
+                if (*buf == (char)0xff) {
+                        rc = safe_write(fd, "\xff\xff", 2);
+                        if (rc != 2)
+                                break;
+                        buf++;
+                        total++;
+                        count--;
+                        continue;
+                }
+                /* count != 0, *buf != 0xff */
+                oxff = memchr(buf, 0xff, count);
+                wr = count;
+                if (oxff)
+                        wr = oxff - buf;
+                rc = safe_write(fd, buf, wr);
+                if (rc != wr)
+                        break;
+                buf += rc;
+                total += rc;
+                count -= rc;
+        }
+        /* here: rc - result of last short write */
+        if ((ssize_t)rc < 0) { /* error? */
+                if (total == 0)
+                        return rc;
+                rc = 0;
+        }
+        return total + rc;
+}
 
 static struct tsession *
 make_new_session(
@@ -212,9 +250,15 @@ make_new_session(
                         IAC, WILL, TELOPT_ECHO,
                         IAC, WILL, TELOPT_SGA
                 };
-                memcpy(TS_BUF2, iacs_to_send, sizeof(iacs_to_send));
-                ts->rdidx2 = sizeof(iacs_to_send);
-                ts->size2 = sizeof(iacs_to_send);
+                /* This confuses iac_safe_write(), it will try to duplicate
+                 * each IAC... */
+                //memcpy(TS_BUF2, iacs_to_send, sizeof(iacs_to_send));
+                //ts->rdidx2 = sizeof(iacs_to_send);
+                //ts->size2 = sizeof(iacs_to_send);
+                /* So just stuff it into TCP buffer! */
+                safe_write(sock, iacs_to_send, sizeof(iacs_to_send));
+                /*ts->rdidx2 = 0; - xzalloc did it! */
+                /*ts->size2 = 0;*/
         }
 
         fflush(NULL); /* flush all streams */
@@ -538,7 +582,7 @@ int telnetd_main(int argc UNUSED_PARAM, char **argv)
                 if (/*ts->size2 &&*/ FD_ISSET(ts->sockfd_write, &wrfdset)) {
                         /* Write to socket from buffer 2. */
                         count = MIN(BUFSIZE - ts->wridx2, ts->size2);
-                        count = safe_write(ts->sockfd_write, TS_BUF2 + ts->wridx2, count);
+                        count = iac_safe_write(ts->sockfd_write, (void*)(TS_BUF2 + ts->wridx2), count);
                         if (count < 0) {
                                 if (errno == EAGAIN)
                                         goto skip2;