// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2023 Red Hat
*/
#include "errors.h"
#include <linux/compiler.h>
#include <linux/errno.h>
#include "logger.h"
#include "permassert.h"
#include "string-utils.h"
static const struct error_info successful = { "UDS_SUCCESS", "Success" };
static const char *const message_table[] = {
[EPERM] = "Operation not permitted",
[ENOENT] = "No such file or directory",
[ESRCH] = "No such process",
[EINTR] = "Interrupted system call",
[EIO] = "Input/output error",
[ENXIO] = "No such device or address",
[E2BIG] = "Argument list too long",
[ENOEXEC] = "Exec format error",
[EBADF] = "Bad file descriptor",
[ECHILD] = "No child processes",
[EAGAIN] = "Resource temporarily unavailable",
[ENOMEM] = "Cannot allocate memory",
[EACCES] = "Permission denied",
[EFAULT] = "Bad address",
[ENOTBLK] = "Block device required",
[EBUSY] = "Device or resource busy",
[EEXIST] = "File exists",
[EXDEV] = "Invalid cross-device link",
[ENODEV] = "No such device",
[ENOTDIR] = "Not a directory",
[EISDIR] = "Is a directory",
[EINVAL] = "Invalid argument",
[ENFILE] = "Too many open files in system",
[EMFILE] = "Too many open files",
[ENOTTY] = "Inappropriate ioctl for device",
[ETXTBSY] = "Text file busy",
[EFBIG] = "File too large",
[ENOSPC] = "No space left on device",
[ESPIPE] = "Illegal seek",
[EROFS] = "Read-only file system",
[EMLINK] = "Too many links",
[EPIPE] = "Broken pipe",
[EDOM] = "Numerical argument out of domain",
[ERANGE] = "Numerical result out of range"
};
static const struct error_info error_list[] = {
{ "UDS_OVERFLOW", "Index overflow" },
{ "UDS_INVALID_ARGUMENT", "Invalid argument passed to internal routine" },
{ "UDS_BAD_STATE", "UDS data structures are in an invalid state" },
{ "UDS_DUPLICATE_NAME", "Attempt to enter the same name into a delta index twice" },
{ "UDS_ASSERTION_FAILED", "Assertion failed" },
{ "UDS_QUEUED", "Request queued" },
{ "UDS_ALREADY_REGISTERED", "Error range already registered" },
{ "UDS_OUT_OF_RANGE", "Cannot access data outside specified limits" },
{ "UDS_DISABLED", "UDS library context is disabled" },
{ "UDS_UNSUPPORTED_VERSION", "Unsupported version" },
{ "UDS_CORRUPT_DATA", "Some index structure is corrupt" },
{ "UDS_NO_INDEX", "No index found" },
{ "UDS_INDEX_NOT_SAVED_CLEANLY", "Index not saved cleanly" },
};
struct error_block {
const char *name;
int base;
int last;
int max;
const struct error_info *infos;
};
#define MAX_ERROR_BLOCKS 6
static struct {
int allocated;
int count;
struct error_block blocks[MAX_ERROR_BLOCKS];
} registered_errors = {
.allocated = MAX_ERROR_BLOCKS,
.count = 1,
.blocks = { {
.name = "UDS Error",
.base = UDS_ERROR_CODE_BASE,
.last = UDS_ERROR_CODE_LAST,
.max = UDS_ERROR_CODE_BLOCK_END,
.infos = error_list,
} },
};
/* Get the error info for an error number. Also returns the name of the error block, if known. */
static const char *get_error_info(int errnum, const struct error_info **info_ptr)
{
struct error_block *block;
if (errnum == UDS_SUCCESS) {
*info_ptr = &successful;
return NULL;
}
for (block = registered_errors.blocks;
block < registered_errors.blocks + registered_errors.count;
block++) {
if ((errnum >= block->base) && (errnum < block->last)) {
*info_ptr = block->infos + (errnum - block->base);
return block->name;
} else if ((errnum >= block->last) && (errnum < block->max)) {
*info_ptr = NULL;
return block->name;
}
}
return NULL;
}
/* Return a string describing a system error message. */
static const char *system_string_error(int errnum, char *buf, size_t buflen)
{
size_t len;
const char *error_string = NULL;
if ((errnum > 0) && (errnum < ARRAY_SIZE(message_table)))
error_string = message_table[errnum];
len = ((error_string == NULL) ?
snprintf(buf, buflen, "Unknown error %d", errnum) :
snprintf(buf, buflen, "%s", error_string));
if (len < buflen)
return buf;
buf[0] = '\0';
return "System error";
}
/* Convert an error code to a descriptive string. */
const char *uds_string_error(int errnum, char *buf, size_t buflen)
{
char *buffer = buf;
char *buf_end = buf + buflen;
const struct error_info *info = NULL;
const char *block_name;
if (buf == NULL)
return NULL;
if (errnum < 0)
errnum = -errnum;
block_name = get_error_info(errnum, &info);
if (block_name != NULL) {
if (info != NULL) {
buffer = vdo_append_to_buffer(buffer, buf_end, "%s: %s",
block_name, info->message);
} else {
buffer = vdo_append_to_buffer(buffer, buf_end, "Unknown %s %d",
block_name, errnum);
}
} else if (info != NULL) {
buffer = vdo_append_to_buffer(buffer, buf_end, "%s", info->message);
} else {
const char *tmp = system_string_error(errnum, buffer, buf_end - buffer);
if (tmp != buffer)
buffer = vdo_append_to_buffer(buffer, buf_end, "%s", tmp);
else
buffer += strlen(tmp);
}
return buf;
}
/* Convert an error code to its name. */
const char *uds_string_error_name(int errnum, char *buf, size_t buflen)
{
char *buffer = buf;
char *buf_end = buf + buflen;
const struct error_info *info = NULL;
const char *block_name;
if (errnum < 0)
errnum = -errnum;
block_name = get_error_info(errnum, &info);
if (block_name != NULL) {
if (info != NULL) {
buffer = vdo_append_to_buffer(buffer, buf_end, "%s", info->name);
} else {
buffer = vdo_append_to_buffer(buffer, buf_end, "%s %d",
block_name, errnum);
}
} else if (info != NULL) {
buffer = vdo_append_to_buffer(buffer, buf_end, "%s", info->name);
} else {
const char *tmp;
tmp = system_string_error(errnum, buffer, buf_end - buffer);
if (tmp != buffer)
buffer = vdo_append_to_buffer(buffer, buf_end, "%s", tmp);
else
buffer += strlen(tmp);
}
return buf;
}
/*
* Translate an error code into a value acceptable to the kernel. The input error code may be a
* system-generated value (such as -EIO), or an internal UDS status code. The result will be a
* negative errno value.
*/
int uds_status_to_errno(int error)
{
char error_name[VDO_MAX_ERROR_NAME_SIZE];
char error_message[VDO_MAX_ERROR_MESSAGE_SIZE];
/* 0 is success, and negative values are already system error codes. */
if (likely(error <= 0))
return error;
if (error < 1024) {
/* This is probably an errno from userspace. */
return -error;
}
/* Internal UDS errors */
switch (error) {
case UDS_NO_INDEX:
case UDS_CORRUPT_DATA:
/* The index doesn't exist or can't be recovered. */
return -ENOENT;
case UDS_INDEX_NOT_SAVED_CLEANLY:
case UDS_UNSUPPORTED_VERSION:
/*
* The index exists, but can't be loaded. Tell the client it exists so they don't
* destroy it inadvertently.
*/
return -EEXIST;
case UDS_DISABLED:
/* The session is unusable; only returned by requests. */
return -EIO;
default:
/* Translate an unexpected error into something generic. */
vdo_log_info("%s: mapping status code %d (%s: %s) to -EIO",
__func__, error,
uds_string_error_name(error, error_name,
sizeof(error_name)),
uds_string_error(error, error_message,
sizeof(error_message)));
return -EIO;
}
}
/*
* Register a block of error codes.
*
* @block_name: the name of the block of error codes
* @first_error: the first error code in the block
* @next_free_error: one past the highest possible error in the block
* @infos: a pointer to the error info array for the block
* @info_size: the size of the error info array
*/
int uds_register_error_block(const char *block_name, int first_error,
int next_free_error, const struct error_info *infos,
size_t info_size)
{
int result;
struct error_block *block;
struct error_block new_block = {
.name = block_name,
.base = first_error,
.last = first_error + (info_size / sizeof(struct error_info)),
.max = next_free_error,
.infos = infos,
};
result = VDO_ASSERT(first_error < next_free_error,
"well-defined error block range");
if (result != VDO_SUCCESS)
return result;
if (registered_errors.count == registered_errors.allocated) {
/* This should never happen. */
return UDS_OVERFLOW;
}
for (block = registered_errors.blocks;
block < registered_errors.blocks + registered_errors.count;
block++) {
if (strcmp(block_name, block->name) == 0)
return UDS_DUPLICATE_NAME;
/* Ensure error ranges do not overlap. */
if ((first_error < block->max) && (next_free_error > block->base))
return UDS_ALREADY_REGISTERED;
}
registered_errors.blocks[registered_errors.count++] = new_block;
return UDS_SUCCESS;
}
Codebase Browser
linux