freebsd-skq/sys/dev/bhnd/nvram/bhnd_nvram_value_prf.c
landonf 55e6f51da0 bhnd(4): support direct conversion of bhnd_nvram_val
This adds support for bhnd_nvram_val_convert_init() and
bhnd_nvram_val_convert_new(), which may be used to perform value
format-aware encoding of an NVRAM value to a new target format/type.

This will be used to simplify converting to/from serialized
format-specific NVRAM value representations to common external
representations.

Approved by:	adrian (mentor)
Differential Revision:	https://reviews.freebsd.org/D8757
2016-12-19 20:20:33 +00:00

883 lines
21 KiB
C

/*-
* Copyright (c) 2015-2016 Landon Fuller <landonf@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
* redistribution must be conditioned upon including a substantially
* similar Disclaimer requirement for further binary redistribution.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGES.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/sbuf.h>
#ifdef _KERNEL
#include <sys/ctype.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <machine/_inttypes.h>
#else /* !_KERNEL */
#include <ctype.h>
#include <inttypes.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#endif /* _KERNEL */
#include "bhnd_nvram_private.h"
#include "bhnd_nvram_valuevar.h"
#ifdef _KERNEL
#define bhnd_nv_hex2ascii(hex) hex2ascii(hex)
#else /* !_KERNEL */
static char const bhnd_nv_hex2ascii[] = "0123456789abcdefghijklmnopqrstuvwxyz";
#define bhnd_nv_hex2ascii(hex) (bhnd_nv_hex2ascii[hex])
#endif /* _KERNEL */
/**
* Maximum size, in bytes, of a string-encoded NVRAM integer value, not
* including any prefix (0x, 0, etc).
*
* We assume the largest possible encoding is the base-2 representation
* of a 64-bit integer.
*/
#define NV_NUMSTR_MAX ((sizeof(uint64_t) * CHAR_BIT) + 1)
/**
* Format a string representation of @p value using @p fmt, with, writing the
* result to @p outp.
*
* @param value The value to be formatted.
* @param fmt The format string.
* @param[out] outp On success, the string will be written to this
* buffer. This argment may be NULL if the value is
* not desired.
* @param[in,out] olen The capacity of @p outp. On success, will be set
* to the actual number of bytes required for the
* requested string encoding (including a trailing
* NUL).
*
* Refer to bhnd_nvram_val_vprintf() for full format string documentation.
*
* @retval 0 success
* @retval EINVAL If @p fmt contains unrecognized format string
* specifiers.
* @retval ENOMEM If the @p outp is non-NULL, and the provided @p olen
* is too small to hold the encoded value.
* @retval EFTYPE If value coercion from @p value to a single string
* value via @p fmt is unsupported.
* @retval ERANGE If value coercion of @p value would overflow (or
* underflow) the representation defined by @p fmt.
*/
int
bhnd_nvram_val_printf(bhnd_nvram_val *value, const char *fmt, char *outp,
size_t *olen, ...)
{
va_list ap;
int error;
va_start(ap, olen);
error = bhnd_nvram_val_vprintf(value, fmt, outp, olen, ap);
va_end(ap);
return (error);
}
/**
* Format a string representation of the elements of @p value using @p fmt,
* writing the result to @p outp.
*
* @param value The value to be formatted.
* @param fmt The format string.
* @param[out] outp On success, the string will be written to this
* buffer. This argment may be NULL if the value is
* not desired.
* @param[in,out] olen The capacity of @p outp. On success, will be set
* to the actual number of bytes required for the
* requested string encoding (including a trailing
* NUL).
* @param ap Argument list.
*
* @par Format Strings
*
* Value format strings are similar, but not identical to, those used
* by printf(3).
*
* Format specifier format:
* %[repeat][flags][width][.precision][length modifier][specifier]
*
* The format specifier is interpreted as an encoding directive for an
* individual value element; each format specifier will fetch the next element
* from the value, encode the element as the appropriate type based on the
* length modifiers and specifier, and then format the result as a string.
*
* For example, given a string value of '0x000F', and a format specifier of
* '%#hhx', the value will be asked to encode its first element as
* BHND_NVRAM_TYPE_UINT8. String formatting will then be applied to the 8-bit
* unsigned integer representation, producing a string value of "0xF".
*
* Repeat:
* - [digits] Repeatedly apply the format specifier to the input
* value's elements up to `digits` times. The delimiter
* must be passed as a string in the next variadic
* argument.
* - [] Repeatedly apply the format specifier to the input
* value's elements until all elements have been. The
* processed. The delimiter must be passed as a string in
* the next variadic argument.
* - [*] Repeatedly apply the format specifier to the input
* value's elements. The repeat count is read from the
* next variadic argument as a size_t value
*
* Flags:
* - '#' use alternative form (e.g. 0x/0X prefixing of hex
* strings).
* - '0' zero padding
* - '-' left adjust padding
* - '+' include a sign character
* - ' ' include a space in place of a sign character for
* positive numbers.
*
* Width/Precision:
* - digits minimum field width.
* - * read the minimum field width from the next variadic
* argument as a ssize_t value. A negative value enables
* left adjustment.
* - .digits field precision.
* - .* read the field precision from the next variadic argument
* as a ssize_t value. A negative value enables left
* adjustment.
*
* Length Modifiers:
* - 'hh', 'I8' Convert the value to an 8-bit signed or unsigned
* integer.
* - 'h', 'I16' Convert the value to an 16-bit signed or unsigned
* integer.
* - 'l', 'I32' Convert the value to an 32-bit signed or unsigned
* integer.
* - 'll', 'j', 'I64' Convert the value to an 64-bit signed or unsigned
* integer.
*
* Data Specifiers:
* - 'd', 'i' Convert and format as a signed decimal integer.
* - 'u' Convert and format as an unsigned decimal integer.
* - 'o' Convert and format as an unsigned octal integer.
* - 'x' Convert and format as an unsigned hexadecimal integer,
* using lowercase hex digits.
* - 'X' Convert and format as an unsigned hexadecimal integer,
* using uppercase hex digits.
* - 's' Convert and format as a string.
* - '%' Print a literal '%' character.
*
* @retval 0 success
* @retval EINVAL If @p fmt contains unrecognized format string
* specifiers.
* @retval ENOMEM If the @p outp is non-NULL, and the provided @p olen
* is too small to hold the encoded value.
* @retval EFTYPE If value coercion from @p value to a single string
* value via @p fmt is unsupported.
* @retval ERANGE If value coercion of @p value would overflow (or
* underflow) the representation defined by @p fmt.
*/
int
bhnd_nvram_val_vprintf(bhnd_nvram_val *value, const char *fmt, char *outp,
size_t *olen, va_list ap)
{
const void *elem;
size_t elen;
size_t limit, nbytes;
int error;
elem = NULL;
/* Determine output byte limit */
nbytes = 0;
if (outp != NULL)
limit = *olen;
else
limit = 0;
#define WRITE_CHAR(_c) do { \
if (limit > nbytes) \
*(outp + nbytes) = _c; \
\
if (nbytes == SIZE_MAX) \
return (EFTYPE); \
nbytes++; \
} while (0)
/* Encode string value as per the format string */
for (const char *p = fmt; *p != '\0'; p++) {
const char *delim;
size_t precision, width, delim_len;
u_long repeat, bits;
bool alt_form, ladjust, have_precision;
char padc, signc, lenc;
padc = ' ';
signc = '\0';
lenc = '\0';
delim = "";
delim_len = 0;
ladjust = false;
alt_form = false;
have_precision = false;
precision = 1;
bits = 32;
width = 0;
repeat = 1;
/* Copy all input to output until we hit a format specifier */
if (*p != '%') {
WRITE_CHAR(*p);
continue;
}
/* Hit '%' -- is this followed by an escaped '%' literal? */
p++;
if (*p == '%') {
WRITE_CHAR('%');
p++;
continue;
}
/* Parse repeat specifier */
if (*p == '[') {
p++;
/* Determine repeat count */
if (*p == ']') {
/* Repeat consumes all input */
repeat = bhnd_nvram_val_nelem(value);
} else if (*p == '*') {
/* Repeat is supplied as an argument */
repeat = va_arg(ap, size_t);
p++;
} else {
char *endp;
/* Repeat specified as argument */
repeat = strtoul(p, &endp, 10);
if (p == endp) {
BHND_NV_LOG("error parsing repeat "
"count at '%s'", p);
return (EINVAL);
}
/* Advance past repeat count */
p = endp;
}
/* Advance past terminating ']' */
if (*p != ']') {
BHND_NV_LOG("error parsing repeat count at "
"'%s'", p);
return (EINVAL);
}
p++;
delim = va_arg(ap, const char *);
delim_len = strlen(delim);
}
/* Parse flags */
while (*p != '\0') {
const char *np;
bool stop;
stop = false;
np = p+1;
switch (*p) {
case '#':
alt_form = true;
break;
case '0':
padc = '0';
break;
case '-':
ladjust = true;
break;
case ' ':
/* Must not override '+' */
if (signc != '+')
signc = ' ';
break;
case '+':
signc = '+';
break;
default:
/* Non-flag character */
stop = true;
break;
}
if (stop)
break;
else
p = np;
}
/* Parse minimum width */
if (*p == '*') {
ssize_t arg;
/* Width is supplied as an argument */
arg = va_arg(ap, int);
/* Negative width argument is interpreted as
* '-' flag followed by positive width */
if (arg < 0) {
ladjust = true;
arg = -arg;
}
width = arg;
p++;
} else if (bhnd_nv_isdigit(*p)) {
uint32_t v;
size_t len, parsed;
/* Parse width value */
len = sizeof(v);
error = bhnd_nvram_parse_int(p, strlen(p), 10, &parsed,
&v, &len, BHND_NVRAM_TYPE_UINT32);
if (error) {
BHND_NV_LOG("error parsing width %s: %d\n", p,
error);
return (EINVAL);
}
/* Save width and advance input */
width = v;
p += parsed;
}
/* Parse precision */
if (*p == '.') {
uint32_t v;
size_t len, parsed;
p++;
have_precision = true;
if (*p == '*') {
ssize_t arg;
/* Precision is specified as an argument */
arg = va_arg(ap, int);
/* Negative precision argument is interpreted
* as '-' flag followed by positive
* precision */
if (arg < 0) {
ladjust = true;
arg = -arg;
}
precision = arg;
} else if (!bhnd_nv_isdigit(*p)) {
/* Implicit precision of 0 */
precision = 0;
} else {
/* Parse precision value */
len = sizeof(v);
error = bhnd_nvram_parse_int(p, strlen(p), 10,
&parsed, &v, &len,
BHND_NVRAM_TYPE_UINT32);
if (error) {
BHND_NV_LOG("error parsing width %s: "
"%d\n", p, error);
return (EINVAL);
}
/* Save precision and advance input */
precision = v;
p += parsed;
}
}
/* Parse length modifiers */
while (*p != '\0') {
const char *np;
bool stop;
stop = false;
np = p+1;
switch (*p) {
case 'h':
if (lenc == '\0') {
/* Set initial length value */
lenc = *p;
bits = 16;
} else if (lenc == *p && bits == 16) {
/* Modify previous length value */
bits = 8;
} else {
BHND_NV_LOG("invalid length modifier "
"%c\n", *p);
return (EINVAL);
}
break;
case 'l':
if (lenc == '\0') {
/* Set initial length value */
lenc = *p;
bits = 32;
} else if (lenc == *p && bits == 32) {
/* Modify previous length value */
bits = 64;
} else {
BHND_NV_LOG("invalid length modifier "
"%c\n", *p);
return (EINVAL);
}
break;
case 'j':
/* Conflicts with all other length
* specifications, and may only occur once */
if (lenc != '\0') {
BHND_NV_LOG("invalid length modifier "
"%c\n", *p);
return (EINVAL);
}
lenc = *p;
bits = 64;
break;
case 'I': {
char *endp;
/* Conflicts with all other length
* specifications, and may only occur once */
if (lenc != '\0') {
BHND_NV_LOG("invalid length modifier "
"%c\n", *p);
return (EINVAL);
}
lenc = *p;
/* Parse the length specifier value */
p++;
bits = strtoul(p, &endp, 10);
if (p == endp) {
BHND_NV_LOG("invalid size specifier: "
"%s\n", p);
return (EINVAL);
}
/* Advance input past the parsed integer */
np = endp;
break;
}
default:
/* Non-length modifier character */
stop = true;
break;
}
if (stop)
break;
else
p = np;
}
/* Parse conversion specifier and format the value(s) */
for (u_long n = 0; n < repeat; n++) {
bhnd_nvram_type arg_type;
size_t arg_size;
size_t i;
u_long base;
bool is_signed, is_upper;
is_signed = false;
is_upper = false;
base = 0;
/* Fetch next element */
elem = bhnd_nvram_val_next(value, elem, &elen);
if (elem == NULL) {
BHND_NV_LOG("format string references more "
"than %zu available value elements\n",
bhnd_nvram_val_nelem(value));
return (EINVAL);
}
/*
* If this is not the first value, append the delimiter.
*/
if (n > 0) {
size_t nremain = 0;
if (limit > nbytes)
nremain = limit - nbytes;
if (nremain >= delim_len)
memcpy(outp + nbytes, delim, delim_len);
/* Add delimiter length to the total byte count */
if (SIZE_MAX - nbytes < delim_len)
return (EFTYPE); /* overflows size_t */
nbytes += delim_len;
}
/* Parse integer conversion specifiers */
switch (*p) {
case 'd':
case 'i':
base = 10;
is_signed = true;
break;
case 'u':
base = 10;
break;
case 'o':
base = 8;
break;
case 'x':
base = 16;
break;
case 'X':
base = 16;
is_upper = true;
break;
}
/* Format argument */
switch (*p) {
#define NV_ENCODE_INT(_width) do { \
arg_type = (is_signed) ? BHND_NVRAM_TYPE_INT ## _width : \
BHND_NVRAM_TYPE_UINT ## _width; \
arg_size = sizeof(v.u ## _width); \
error = bhnd_nvram_val_encode_elem(value, elem, elen, \
&v.u ## _width, &arg_size, arg_type); \
if (error) { \
BHND_NV_LOG("error encoding argument as %s: %d\n", \
bhnd_nvram_type_name(arg_type), error); \
return (error); \
} \
\
if (is_signed) { \
if (v.i ## _width < 0) { \
add_neg = true; \
numval = (int64_t)-(v.i ## _width); \
} else { \
numval = (int64_t) (v.i ## _width); \
} \
} else { \
numval = v.u ## _width; \
} \
} while(0)
case 'd':
case 'i':
case 'u':
case 'o':
case 'x':
case 'X': {
char numbuf[NV_NUMSTR_MAX];
char *sptr;
uint64_t numval;
size_t slen;
bool add_neg;
union {
uint8_t u8;
uint16_t u16;
uint32_t u32;
uint64_t u64;
int8_t i8;
int16_t i16;
int32_t i32;
int64_t i64;
} v;
add_neg = false;
/* If precision is specified, it overrides
* (and behaves identically) to a zero-prefixed
* minimum width */
if (have_precision) {
padc = '0';
width = precision;
ladjust = false;
}
/* If zero-padding is used, value must be right
* adjusted */
if (padc == '0')
ladjust = false;
/* Request encode to the appropriate integer
* type, and then promote to common 64-bit
* representation */
switch (bits) {
case 8:
NV_ENCODE_INT(8);
break;
case 16:
NV_ENCODE_INT(16);
break;
case 32:
NV_ENCODE_INT(32);
break;
case 64:
NV_ENCODE_INT(64);
break;
default:
BHND_NV_LOG("invalid length specifier: "
"%lu\n", bits);
return (EINVAL);
}
#undef NV_ENCODE_INT
/* If a precision of 0 is specified and the
* value is also zero, no characters should
* be produced */
if (have_precision && precision == 0 &&
numval == 0)
{
break;
}
/* Emit string representation to local buffer */
BHND_NV_ASSERT(base <= 16, ("invalid base"));
sptr = numbuf + nitems(numbuf) - 1;
for (slen = 0; slen < sizeof(numbuf); slen++) {
char c;
uint64_t n;
n = numval % base;
c = bhnd_nv_hex2ascii(n);
if (is_upper)
c = bhnd_nv_toupper(c);
sptr--;
*sptr = c;
numval /= (uint64_t)base;
if (numval == 0) {
slen++;
break;
}
}
arg_size = slen;
/* Reserve space for 0/0x prefix? */
if (alt_form) {
if (numval == 0) {
/* If 0, no prefix */
alt_form = false;
} else if (base == 8) {
arg_size += 1; /* 0 */
} else if (base == 16) {
arg_size += 2; /* 0x/0X */
}
}
/* Reserve space for ' ', '+', or '-' prefix? */
if (add_neg || signc != '\0') {
if (add_neg)
signc = '-';
arg_size++;
}
/* Right adjust (if using spaces) */
if (!ladjust && padc != '0') {
for (i = arg_size; i < width; i++)
WRITE_CHAR(padc);
}
if (signc != '\0')
WRITE_CHAR(signc);
if (alt_form) {
if (base == 8) {
WRITE_CHAR('0');
} else if (base == 16) {
WRITE_CHAR('0');
if (is_upper)
WRITE_CHAR('X');
else
WRITE_CHAR('x');
}
}
/* Right adjust (if using zeros) */
if (!ladjust && padc == '0') {
for (i = slen; i < width; i++)
WRITE_CHAR(padc);
}
/* Write the string to our output buffer */
if (limit > nbytes && limit - nbytes >= slen)
memcpy(outp + nbytes, sptr, slen);
/* Update the total byte count */
if (SIZE_MAX - nbytes < arg_size)
return (EFTYPE); /* overflows size_t */
nbytes += arg_size;
/* Left adjust */
for (i = arg_size; ladjust && i < width; i++)
WRITE_CHAR(padc);
break;
}
case 's': {
char *s;
size_t slen;
/* Query the total length of the element when
* converted to a string */
arg_type = BHND_NVRAM_TYPE_STRING;
error = bhnd_nvram_val_encode_elem(value, elem,
elen, NULL, &arg_size, arg_type);
if (error) {
BHND_NV_LOG("error encoding argument "
"as %s: %d\n",
bhnd_nvram_type_name(arg_type),
error);
return (error);
}
/* Do not include trailing NUL in the string
* length */
if (arg_size > 0)
arg_size--;
/* Right adjust */
for (i = arg_size; !ladjust && i < width; i++)
WRITE_CHAR(padc);
/* Determine output positition and remaining
* buffer space */
if (limit > nbytes) {
s = outp + nbytes;
slen = limit - nbytes;
} else {
s = NULL;
slen = 0;
}
/* Encode the string to our output buffer */
error = bhnd_nvram_val_encode_elem(value, elem,
elen, s, &slen, arg_type);
if (error && error != ENOMEM) {
BHND_NV_LOG("error encoding argument "
"as %s: %d\n",
bhnd_nvram_type_name(arg_type),
error);
return (error);
}
/* Update the total byte count */
if (SIZE_MAX - nbytes < arg_size)
return (EFTYPE); /* overflows size_t */
nbytes += arg_size;
/* Left adjust */
for (i = arg_size; ladjust && i < width; i++)
WRITE_CHAR(padc);
break;
}
case 'c': {
char c;
arg_type = BHND_NVRAM_TYPE_CHAR;
arg_size = bhnd_nvram_type_width(arg_type);
/* Encode as single character */
error = bhnd_nvram_val_encode_elem(value, elem,
elen, &c, &arg_size, arg_type);
if (error) {
BHND_NV_LOG("error encoding argument "
"as %s: %d\n",
bhnd_nvram_type_name(arg_type),
error);
return (error);
}
BHND_NV_ASSERT(arg_size == sizeof(c),
("invalid encoded size"));
/* Right adjust */
for (i = arg_size; !ladjust && i < width; i++)
WRITE_CHAR(padc);
WRITE_CHAR(padc);
/* Left adjust */
for (i = arg_size; ladjust && i < width; i++)
WRITE_CHAR(padc);
break;
}
}
}
}
/* Append terminating NUL */
if (limit > nbytes)
*(outp + nbytes) = '\0';
if (nbytes < SIZE_MAX)
nbytes++;
else
return (EFTYPE);
/* Report required space */
*olen = nbytes;
if (limit < nbytes) {
if (outp != NULL)
return (ENOMEM);
}
return (0);
}