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/*
* Copyright (c) 2015-16 David Lamparter, for NetDEF, Inc.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef _FRR_FERR_H
#define _FRR_FERR_H
/***********************************************************
* scroll down to the end of this file for a full example! *
***********************************************************/
#include <stdint.h>
#include <limits.h>
#include <errno.h>
/* return type when this error indication stuff is used.
*
* guaranteed to have boolean evaluation to "false" when OK, "true" when error
* (i.e. can be changed to pointer in the future if neccessary)
*
* For checking, always use "if (value)", nothing else.
* Do _NOT_ use any integer constant (!= 0), or sign check (< 0).
*/
typedef int ferr_r;
/* rough category of error indication */
enum ferr_kind {
/* no error */
FERR_OK = 0,
/* something isn't the way it's supposed to be.
* (things that might otherwise be asserts, really)
*/
FERR_CODE_BUG,
/* user-supplied parameters don't make sense or is inconsistent
* if you can express a rule for it (e.g. "holdtime > 2 * keepalive"),
* it's this category.
*/
FERR_CONFIG_INVALID,
/* user-supplied parameters don't line up with reality
* (IP address or interface not available, etc.)
* NB: these are really TODOs where the code needs to be fixed to
* respond to future changes!
*/
FERR_CONFIG_REALITY,
/* out of some system resource (probably memory)
* aka "you didn't spend enough money error" */
FERR_RESOURCE,
/* system error (permission denied, etc.) */
FERR_SYSTEM,
/* error return from some external library
* (FERR_SYSTEM and FERR_LIBRARY are not strongly distinct) */
FERR_LIBRARY,
};
struct ferr {
/* code location */
const char *file;
const char *func;
int line;
enum ferr_kind kind;
/* unique_id is calculated as a checksum of source filename and error
* message format (*before* calling vsnprintf). Line number and
* function name are not used; this keeps the number reasonably static
* across changes.
*/
uint32_t unique_id;
char message[384];
/* valid if != 0. note "errno" might be preprocessor foobar. */
int errno_val;
/* valid if pathname[0] != '\0' */
char pathname[PATH_MAX];
};
/* get error details.
*
* NB: errval/ferr_r does NOT carry the full error information. It's only
* passed around for future API flexibility. ferr_get_last always returns
* the last error set in the current thread.
*/
const struct ferr *ferr_get_last(ferr_r errval);
/* can optionally be called at strategic locations.
* always returns 0. */
ferr_r ferr_clear(void);
/* do NOT call these functions directly. only for macro use! */
ferr_r ferr_set_internal(const char *file, int line, const char *func,
enum ferr_kind kind, const char *text, ...);
ferr_r ferr_set_internal_ext(const char *file, int line, const char *func,
enum ferr_kind kind, const char *pathname, int errno_val,
const char *text, ...);
#define ferr_ok() \
0
/* Report an error.
*
* If you need to do cleanup (free memory, etc.), save the return value in a
* variable of type ferr_r.
*
* Don't put a \n at the end of the error message.
*/
#define ferr_code_bug(...) \
ferr_set_internal(__FILE__, __LINE__, __func__, FERR_CODE_BUG, \
__VA_ARGS__)
#define ferr_cfg_invalid(...) \
ferr_set_internal(__FILE__, __LINE__, __func__, FERR_CONFIG_INVALID, \
__VA_ARGS__)
#define ferr_cfg_reality(...) \
ferr_set_internal(__FILE__, __LINE__, __func__, FERR_CONFIG_REALITY, \
__VA_ARGS__)
#define ferr_cfg_resource(...) \
ferr_set_internal(__FILE__, __LINE__, __func__, FERR_RESOURCE, \
__VA_ARGS__)
#define ferr_system(...) \
ferr_set_internal(__FILE__, __LINE__, __func__, FERR_SYSTEM, \
__VA_ARGS__)
#define ferr_library(...) \
ferr_set_internal(__FILE__, __LINE__, __func__, FERR_LIBRARY, \
__VA_ARGS__)
/* extended information variants */
#define ferr_system_errno(...) \
ferr_set_internal_ext(__FILE__, __LINE__, __func__, FERR_SYSTEM, \
NULL, errno, __VA_ARGS__)
#define ferr_system_path_errno(path, ...) \
ferr_set_internal_ext(__FILE__, __LINE__, __func__, FERR_SYSTEM, \
path, errno, __VA_ARGS__)
#include "vty.h"
/* print error message to vty; $ERR is replaced by the error's message */
void vty_print_error(struct vty *vty, ferr_r err, const char *msg, ...);
#define CMD_FERR_DO(func, action, ...) \
do { ferr_r cmd_retval = func; \
if (cmd_retval) { \
vty_print_error(vty, cmd_retval, __VA_ARGS__); \
action; \
} \
} while (0)
#define CMD_FERR_RETURN(func, ...) \
CMD_FERR_DO(func, return CMD_WARNING_CONFIG_FAILED, __VA_ARGS__)
#define CMD_FERR_GOTO(func, label, ...) \
CMD_FERR_DO(func, goto label, __VA_ARGS__)
/* example:
ferr_r foo_bar_set(struct object *obj, int bar)
{
if (bar < 1 || bar >= 100)
return ferr_config_invalid("bar setting (%d) must be 0<x<100", bar);
obj->bar = bar;
if (ioctl (obj->fd, bar))
return ferr_system_errno("couldn't set bar to %d", bar);
return ferr_ok();
}
DEFUN("bla")
{
CMD_FERR_RETURN(foo_bar_set(obj, atoi(argv[1])),
"command failed: $ERR\n");
return CMD_SUCCESS;
}
*/
#endif /* _FERR_H */
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