include/osmocom/vty/vty.h

#pragma once

#include <stdio.h>
#include <stdarg.h>
#include <stdbool.h>

#include <osmocom/core/linuxlist.h>
#include <osmocom/core/defs.h>

/*! \defgroup vty VTY (Virtual TTY) interface
 *  @{
 * \file vty.h */

/* GCC have printf type attribute check.  */
#ifdef __GNUC__
#define VTY_PRINTF_ATTRIBUTE(a,b) __attribute__ ((__format__ (__printf__, a, b)))
#else
#define VTY_PRINTF_ATTRIBUTE(a,b)
#endif				/* __GNUC__ */

/* Does the I/O error indicate that the operation should be retried later? */
#define ERRNO_IO_RETRY(EN) \
	(((EN) == EAGAIN) || ((EN) == EWOULDBLOCK) || ((EN) == EINTR))

/* Vty read buffer size. */
#define VTY_READ_BUFSIZ 512

#define VTY_BUFSIZ 512
#define VTY_MAXHIST 20

/* Number of application / library specific VTY attributes */
#define VTY_CMD_USR_ATTR_NUM 32
/* Flag characters reserved for global VTY attributes */
#define VTY_CMD_ATTR_FLAGS_RESERVED \
	{ '.', '!', '@', '^' }

/*! VTY events */
enum event {
	VTY_SERV,
	VTY_READ,
	VTY_WRITE,
	VTY_CLOSED,
	VTY_TIMEOUT_RESET,
#ifdef VTYSH
	VTYSH_SERV,
	VTYSH_READ,
	VTYSH_WRITE
#endif				/* VTYSH */
};

enum vty_type {
	VTY_TERM,
	VTY_FILE,
	VTY_SHELL,
	VTY_SHELL_SERV
};

struct vty_parent_node {
	struct llist_head entry;

	/*! private data, specified by creator */
	void *priv;

	/*! Node status of this vty */
	int node;

	/*! When reading from a config file, these are the indenting characters expected for children of
	 * this VTY node. */
	char *indent;
};

/*! Internal representation of a single VTY */
struct vty {
	/*! underlying file (if any) */
	FILE *file;

	/*! private data, specified by creator */
	void *priv;

	/*! File descripter of this vty. */
	int fd;

	/*! Is this vty connect to file or not */
	enum vty_type type;

	/*! Node status of this vty */
	int node;

	/*! Failure count */
	int fail;

	/*! Output buffer. */
	struct buffer *obuf;

	/*! Command input buffer */
	char *buf;

	/*! Command cursor point */
	int cp;

	/*! Command length */
	int length;

	/*! Command max length. */
	int max;

	/*! Histry of command */
	char *hist[VTY_MAXHIST];

	/*! History lookup current point */
	int hp;

	/*! History insert end point */
	int hindex;

	/*! For current referencing point of interface, route-map,
	   access-list etc... */
	void *index;

	/*! For multiple level index treatment such as key chain and key. */
	void *index_sub;

	/*! For escape character. */
	unsigned char escape;

	/*! 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 (option subnegotiation) handling */
	unsigned char iac_sb_in_progress;
	/* 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
	/*! sub-negotiation buffer */
	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 */
	int width;
	/*! Widnow height */
	int height;

	/*! Configure lines. */
	int lines;

	int monitor;

	/*! In configure mode. */
	int config;

	/*! List of parent nodes, last item is the outermost parent. */
	struct llist_head parent_nodes;

	/*! When reading from a config file, these are the indenting characters expected for children of
	 * the current VTY node. */
	char *indent;

	/*! Whether the expert mode is enabled. */
	bool expert_mode;
};

/* Small macro to determine newline is newline only or linefeed needed. */
#define VTY_NEWLINE  ((vty->type == VTY_TERM) ? "\r\n" : "\n")

static inline const char *vty_newline(struct vty *vty)
{
	return VTY_NEWLINE;
}

/*! Information an application registers with the VTY */
struct vty_app_info {
	/*! name of the application */
	const char *name;
	/*! version string of the application */
	const char *version;
	/*! copyright string of the application */
	const char *copyright;
	/*! \ref talloc context */
	void *tall_ctx;
	/*! Call-back for taking actions upon exiting a node.
	 * The return value is ignored, and changes to vty->node and vty->index made in this callback are ignored.
	 * Implicit parent node tracking always sets the correct parent node and vty->index after this callback exits,
	 * so this callback can handle only those nodes that should take specific actions upon node exit, or can be left
	 * NULL entirely. */
	int (*go_parent_cb)(struct vty *vty);
	/*! OBSOLETED: Implicit parent node tracking has replaced the use of this callback. This callback is no longer
	 * called, ever, and can be left NULL. */
	int (*is_config_node)(struct vty *vty, int node)
		OSMO_DEPRECATED("Implicit parent node tracking has replaced the use of this callback. This callback is"
				" no longer called, ever, and can be left NULL.");
	/*! Check if the config is consistent before write */
	int (*config_is_consistent)(struct vty *vty);
	/*! Description of the application specific VTY attributes (optional). */
	const char * usr_attr_desc[VTY_CMD_USR_ATTR_NUM];
	/*! Flag letters of the application specific VTY attributes (optional). */
	char usr_attr_letters[VTY_CMD_USR_ATTR_NUM];
};

/* Prototypes. */
void vty_init(struct vty_app_info *app_info);
int vty_read_config_file(const char *file_name, void *priv);
void vty_init_vtysh (void);
void vty_reset (void);
struct vty *vty_new (void);
struct vty *vty_create (int vty_sock, void *priv);
bool vty_is_active(struct vty *vty);
int vty_out (struct vty *, const char *, ...) VTY_PRINTF_ATTRIBUTE(2, 3);
int vty_out_va(struct vty *vty, const char *format, va_list ap);
int vty_out_newline(struct vty *);
int vty_read(struct vty *vty);
//void vty_time_print (struct vty *, int);
void vty_close (struct vty *);
char *vty_get_cwd (void);
void vty_log (const char *level, const char *proto, const char *fmt, va_list);
int vty_config_lock (struct vty *);
int vty_config_unlock (struct vty *);
int vty_shell (struct vty *);
int vty_shell_serv (struct vty *);
void vty_hello (struct vty *);
void *vty_current_index(struct vty *);
int vty_current_node(struct vty *vty);
int vty_go_parent(struct vty *vty);

/* Return IP address passed to the 'line vty'/'bind' command, or "127.0.0.1" */
const char *vty_get_bind_addr(void);
/** Returns configured port passed to the 'line vty'/'bind' command or default_port. */
int vty_get_bind_port(int default_port);

extern void *tall_vty_ctx;

extern struct cmd_element cfg_description_cmd;
extern struct cmd_element cfg_no_description_cmd;


/**
 * signal handling
 */
enum signal_vty {
	S_VTY_EVENT,
};

struct vty_signal_data {
	enum event event;
	int sock;
	struct vty *vty;
};

/*! @} */