busybox-w32/networking/telnetd.c, branch mount_point

telnetd: if vfork in make_new_session() fails, do close socket.

2026-02-23T23:03:20+00:00

function old new delta telnetd_main 372 385 +13 make_new_session 550 552 +2 xgetpty 81 78 -3 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/1 up/down: 15/-3) Total: 12 bytes Signed-off-by: Denys Vlasenko

telnetd: do not wait for more input after 10-byte NAWS is received

2026-02-22T20:20:59+00:00

If the the screen is resized to 255 columns without any subsequent data received, the server won't parse and react to the NAWS (until eventually at least one more byte arrives). function old new delta read_byte_unescaping_IAC 28 31 +3 net_to_pty__have_data_to_write 551 552 +1 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/0 up/down: 4/0) Total: 4 bytes Signed-off-by: Denys Vlasenko

telnetd: fix handshake: had one wrong, but harmless element

2026-02-22T19:04:41+00:00

function old new delta static.iacs_to_send 12 9 -3 Signed-off-by: Denys Vlasenko

telnetd: correct handling of screen sizes with any dimension equal to 255

2026-02-22T08:45:03+00:00

IOW: teach NAWS parser how to IAC-unescape. function old new delta net_to_pty__have_data_to_write 429 551 +122 read_byte_unescaping_IAC - 28 +28 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 1/0 up/down: 150/0) Total: 150 bytes Signed-off-by: Denys Vlasenko

telnetd: do close pty when network read returns EOF; try to cause EOF-on-read

2026-02-22T06:11:16+00:00

function old new delta fabricate_ctrl_D_on_pty - 65 +65 net_to_pty__have_data_to_write 368 429 +61 .rodata 107096 107125 +29 telnetd_main 367 372 +5 net_to_pty__have_buffer_to_read_into 164 162 -2 packed_usage 36066 36040 -26 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 3/2 up/down: 160/-28) Total: 132 bytes Signed-off-by: Denys Vlasenko

libbb: add generic "fd polling and I/O" loop, use it in telnetd

2026-02-21T15:54:35+00:00

We do it, badly, in many places. Better to use one robust implementation. Can be buggy yet. Initial use is in a rather old, rarely used tech: telnet. The I/O in telnetd should be fully non-blocking now, including pty delays handling. Several bugs in telnetd handling of IACs are fixed. function old new delta ioloop_run - 411 +411 net_to_pty__have_data_to_write - 368 +368 pty_to_net__write - 318 +318 net_to_pty__write - 180 +180 pty_to_net__read - 171 +171 net_to_pty__have_buffer_to_read_into - 164 +164 pty_to_net__have_buffer_to_read_into - 90 +90 net_to_pty__read - 87 +87 pty_to_net__have_data_to_write - 59 +59 make_new_session 491 550 +59 conn_close_fds - 52 +52 accept_conn__accept - 49 +49 conn_close_fds_remove_and_free - 27 +27 ioloop_remove_conn - 22 +22 remove_and_free_to_pty - 19 +19 ioloop_insert_conn - 10 +10 accept_conn__can_accept - 6 +6 accept_conn__return_zero - 3 +3 static.ayt_response - 2 +2 handle_sigchld 59 61 +2 free_session 130 - -130 telnetd_main 1797 367 -1430 ------------------------------------------------------------------------------ (add/remove: 19/1 grow/shrink: 2/1 up/down: 2099/-1560) Total: 539 bytes Signed-off-by: Denys Vlasenko

telnetd: improve --help

2025-07-27T12:24:23+00:00

function old new delta packed_usage 34996 35021 +25 Signed-off-by: Denys Vlasenko

Update applet size estimates

2023-07-10T15:25:21+00:00

Signed-off-by: Denys Vlasenko

libbb: code shrink: introduce and use [_]exit_FAILURE()

2023-06-15T09:55:56+00:00

function old new delta exit_FAILURE - 7 +7 _exit_FAILURE - 7 +7 run 198 199 +1 restore_state_and_exit 114 115 +1 xbsd_write_bootstrap 399 397 -2 vfork_compressor 209 207 -2 sig_handler 12 10 -2 serial_ctl 154 152 -2 parse_args 1169 1167 -2 onintr 21 19 -2 make_new_session 493 491 -2 login_main 988 986 -2 gotsig 35 33 -2 do_iplink 1315 1313 -2 addgroup_main 397 395 -2 inetd_main 1911 1908 -3 ------------------------------------------------------------------------------ (add/remove: 2/0 grow/shrink: 2/12 up/down: 16/-25) Total: -9 bytes Signed-off-by: Denys Vlasenko

libbb: code shrink: introduce and use [_]exit_SUCCESS()

2022-01-05T21:16:06+00:00

function old new delta exit_SUCCESS - 7 +7 _exit_SUCCESS - 7 +7 run_pipe 1562 1567 +5 pseudo_exec_argv 399 400 +1 finish 86 87 +1 start_stop_daemon_main 1109 1107 -2 shutdown_on_signal 38 36 -2 runsv_main 1662 1660 -2 redirect 1070 1068 -2 read_line 79 77 -2 pause_and_low_level_reboot 54 52 -2 list_i2c_busses_and_exit 483 481 -2 less_exit 12 10 -2 identify 4123 4121 -2 grep_file 1161 1159 -2 getty_main 1519 1517 -2 fsck_minix_main 2681 2679 -2 free_session 132 130 -2 fdisk_main 4739 4737 -2 clean_up_and_exit 53 51 -2 bsd_select 1566 1564 -2 bb_daemonize_or_rexec 198 196 -2 ------------------------------------------------------------------------------ (add/remove: 2/0 grow/shrink: 3/17 up/down: 21/-34) Total: -13 bytes Signed-off-by: Denys Vlasenko