2005-02-23 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
* buffer.h: Make the struct buffer and struct buffer_data structures
private by moving them inside buffer.c. Add comments for all
functions. Rename buffer_write as buffer_put (to be more consistent
with the buffer_putc and buffer_putstr functions). Declare a new
buffer_write function that is used to write data to a file descriptor
and/or add it to the buffer queue. Remove unused function
buffer_flush_vty_all. Create a new enum typedef buffer_status_t
to be used as the return code for all buffer_flush* functions
and buffer_write.
* buffer.c: The struct buffer and struct buffer_data declarations
are now private to this file. In conjunction with that, remove
some unnecessary fields: struct buffer (alloc, unused_head,
unused_tail, length), struct buffer_data (prev).
(buffer_data_new) Removed: functionality incorporated into buffer_add.
(buffer_data_free) Removed: use a macro BUFFER_DATA_FREE instead.
(buffer_new) Use calloc instead of malloc + memset(zero).
Supply an appropriate default size if the specified size is 0.
(buffer_free) Eliminate code duplication by calling buffer_reset to
free the contents of the buffer (and remove unused code related
to unused_head).
(buffer_empty,buffer_putc,buffer_putstr) Aesthetic change (make more
compact).
(buffer_reset) Use macro BUFFER_DATA_FREE. No need to set
alloc and length to 0 (these fields have been removed).
(buffer_add) Fix scope to be static. Call XMALLOC directly instead
of calling removed buffer_data_new function. Simplify the logic
(since it's now a singly-linked list instead of doubly-linked).
(buffer_write) Renamed to buffer_put. Change to void, since return
code of 1 was meaningless. No need to adjust length field, since
it has been removed.
(buffer_putw,buffer_flush,buffer_flush_vty_all,buffer_flush_vty)
Remove unused functions.
(buffer_flush_all) Rewrite using buffer_flush_available to eliminate
a possible failure mode if IOV_MAX is less than the number of buffers
on the queue.
(buffer_flush_window) Incorporate logic from buffer_flush_vty.
Log an error message if there is a writev error.
(buffer_flush_available) Be more paranoid: check for case where
buffer is already empty. Use new ERRNO_IO_RETRY macro, and use
new enum for return codes. Simplify deletion logic (since it's
now a singly-linked list).
(buffer_write) New function for use with non-blocking I/O.
* vty.h: Replace the struct vty sb_buffer field with a fixed-size
(5-character) sb_buf field and an sb_len field, since using
a struct buffer was inappropriate for this task. Add some useful
comments about telnet window size negotiation.
* vty.c: Include <arpa/telnet.h> (no longer included by zebra.h).
Remove VTY_OBUF_SIZE (instead use buffer_new default size).
Make telnet_backward_char and telnet_space_char static const.
(vty_out) Replace buffer_write with buffer_put.
(vty_log_out) Check for I/O errors. If fatal, close the vty session.
Consolidate 3 separate writes into a single write call.
(vty_will_echo,vty_command,vty_next_line,vty_previous_line,
vty_end_config,vty_describe_fold,vty_clear_buf,vty_serv_sock_addrinfo,
vty_serv_sock_family,vty_serv_un,vty_use_backup_config,exec_timeout,
vty_config_write,vty_save_cwd) Fix scope to static.
(vty_new) Let buffer_new use its default buffer size.
(vty_write) Fix signature: 2nd arg should be const char *.
Replaced buffer_write with buffer_put.
(vty_telnet_option) Fix minor bug (window height or width greater than
255 was broken). Use sb_buf and sb_len instead of removed sb_buffer
(which was being used improperly).
(vty_read) On error, use ERRNO_IO_RETRY to decide whether it's fatal.
If the error is fatal, call buffer_reset so vty_close does not attempt
to flush the data. Use new sb_buf and sb_len instead of sb_buffer
to store the SB negotiation string.
(vty_flush) When vty->lines is 0, call buffer_flush_available instead
of buffer_flush_window. Look at the return code from buffer_flush
to detect I/O errors (and in that case, log an error message and
close the vty).
(vty_create) Fix scope to static. Initialize sb_len to 0 instead
of creating sb_buffer.
(vty_accept) Set socket nonblocking.
(vtysh_accept) Use new set_nonblocking function instead of calling
fcntl directly.
(vtysh_flush) New function called from vtysh_read (after command
execution) and from vtysh_write. This flushes the buffer
and reacts appropriately to the return code (by closing the vty
or scheduling further flushes).
(vtysh_read) Check whether error is fatal using ERRNO_IO_RETRY.
If not, just try again later. Otherwise, call buffer_reset before
calling vty_close (to avoid trying to flush the buffer in vty_close).
Fix logic to allow case where a command does not arrive atomically
in a single read call by checking for the terminating NUL char.
(vtysh_write) Use new vtysh_flush helper function.
(vty_close) No need to call buffer_empty, just call buffer_flush_all
in any case (it will check whether the buffer is empty).
Do not free sb_buffer (since it has been removed).
(vty_log_fixed) Use writev instead of write.
* zebra.h: Do not include <arpa/telnet.h>, since this is used only
by lib/vty.c.
diff --git a/lib/vty.h b/lib/vty.h
index 8cd2b4e..0290a83 100644
--- a/lib/vty.h
+++ b/lib/vty.h
@@ -81,12 +81,21 @@
/* Current vty status. */
enum {VTY_NORMAL, VTY_CLOSE, VTY_MORE, VTY_MORELINE} status;
- /* IAC handling */
+ /* IAC handling: was the last character received the
+ IAC (interpret-as-command) escape character (and therefore the next
+ character will be the command code)? Refer to Telnet RFC 854. */
unsigned char iac;
- /* IAC SB handling */
+ /* IAC SB (option subnegotiation) handling */
unsigned char iac_sb_in_progress;
- struct buffer *sb_buffer;
+ /* At the moment, we care only about the NAWS (window size) negotiation,
+ and that requires just a 5-character buffer (RFC 1073):
+ <NAWS char> <16-bit width> <16-bit height> */
+#define TELNET_NAWS_SB_LEN 5
+ unsigned char sb_buf[TELNET_NAWS_SB_LEN];
+ /* How many subnegotiation characters have we received? We just drop
+ those that do not fit in the buffer. */
+ size_t sb_len;
/* Window width/height. */
int width;