From 9fc7ebf10b7bb638ddf6d1b4b2d562dd417866fc Mon Sep 17 00:00:00 2001 From: ajs Date: Wed, 23 Feb 2005 15:12:34 +0000 Subject: 2005-02-23 Andrew J. Schorr * 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 (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 , since this is used only by lib/vty.c. --- lib/vty.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'lib/vty.h') diff --git a/lib/vty.h b/lib/vty.h index 8cd2b4e3..0290a836 100644 --- a/lib/vty.h +++ b/lib/vty.h @@ -81,12 +81,21 @@ struct vty /* 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): + <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; -- cgit v1.2.1