/*
* Copyright (c) 2015, Juniper Networks, Inc.
* All rights reserved.
* This SOFTWARE is licensed under the LICENSE provided in the
* ../Copyright file. By downloading, installing, copying, or otherwise
* using the SOFTWARE, you agree to be bound by the terms of that
* LICENSE.
* Phil Shafer, August 2015
*/
/*
* CBOR (RFC 7049) mades a suitable test case for libxo's external
* encoder API. It's simple, streaming, well documented, and an
* IETF standard.
*
* This encoder uses the "pretty" flag for diagnostics, which isn't
* really kosher, but it's example code.
*/
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdint.h>
#include <ctype.h>
#include <stdlib.h>
#include <limits.h>
#include "xo.h"
#include "xo_encoder.h"
#include "xo_buf.h"
/*
* memdump(): dump memory contents in hex/ascii
0 1 2 3 4 5 6 7
0123456789012345678901234567890123456789012345678901234567890123456789012345
XX XX XX XX XX XX XX XX - XX XX XX XX XX XX XX XX abcdefghijklmnop
*/
static void
cbor_memdump (FILE *fp, const char *title, const char *data,
size_t len, const char *tag, int indent)
{
enum { MAX_PER_LINE = 16 };
char buf[ 80 ];
char text[ 80 ];
char *bp, *tp;
size_t i;
#if 0
static const int ends[ MAX_PER_LINE ] = { 2, 5, 8, 11, 15, 18, 21, 24,
29, 32, 35, 38, 42, 45, 48, 51 };
#endif
if (fp == NULL)
fp = stdout;
if (tag == NULL)
tag = "";
fprintf(fp, "%*s[%s] @ %p (%lx/%lu)\n", indent + 1, tag,
title, data, (unsigned long) len, (unsigned long) len);
while (len > 0) {
bp = buf;
tp = text;
for (i = 0; i < MAX_PER_LINE && i < len; i++) {
if (i && (i % 4) == 0) *bp++ = ' ';
if (i == 8) {
*bp++ = '-';
*bp++ = ' ';
}
sprintf(bp, "%02x ", (unsigned char) *data);
bp += strlen(bp);
*tp++ = (isprint((int) *data) && *data >= ' ') ? *data : '.';
data += 1;
}
*tp = 0;
*bp = 0;
fprintf(fp, "%*s%-54s%s\n", indent + 1, tag, buf, text);
len -= i;
}
}
/*
* CBOR breaks the first byte into two pieces, the major type in the
* top 3 bits and the minor value in the low 5 bits. The value can be
* a small value (0 .. 23), an 8-bit value (24), a 16-bit value (25),
* a 32-bit value (26), or a 64-bit value (27). A value of 31
* represents an unknown length, which we'll use extensively for
* streaming our content.
*/
#define CBOR_MAJOR_MASK 0xE0
#define CBOR_MINOR_MASK 0x1F
#define CBOR_MAJOR_SHIFT 5
#define CBOR_MAJOR(_x) ((_x) & CBOR_MAJOR_MASK)
#define CBOR_MAJOR_VAL(_x) ((_x) << CBOR_MAJOR_SHIFT)
#define CBOR_MINOR_VAL(_x) ((_x) & CBOR_MINOR_MASK)
/* Major type codes */
#define CBOR_UNSIGNED CBOR_MAJOR_VAL(0) /* 0x00 */
#define CBOR_NEGATIVE CBOR_MAJOR_VAL(1) /* 0x20 */
#define CBOR_BYTES CBOR_MAJOR_VAL(2) /* 0x40 */
#define CBOR_STRING CBOR_MAJOR_VAL(3) /* 0x60 */
#define CBOR_ARRAY CBOR_MAJOR_VAL(4) /* 0x80 */
#define CBOR_MAP CBOR_MAJOR_VAL(5) /* 0xa0 */
#define CBOR_SEMANTIC CBOR_MAJOR_VAL(6) /* 0xc0 */
#define CBOR_SPECIAL CBOR_MAJOR_VAL(7) /* 0xe0 */
#define CBOR_ULIMIT 24 /* Largest unsigned value */
#define CBOR_NLIMIT 23 /* Largest negative value */
#define CBOR_BREAK 0xFF
#define CBOR_INDEF 0x1F
#define CBOR_FALSE 0xF4
#define CBOR_TRUE 0xF5
#define CBOR_NULL 0xF6
#define CBOR_UNDEF 0xF7
#define CBOR_LEN8 0x18 /* 24 - 8-bit value */
#define CBOR_LEN16 0x19 /* 25 - 16-bit value */
#define CBOR_LEN32 0x1a /* 26 - 32-bit value */
#define CBOR_LEN64 0x1b /* 27 - 64-bit value */
#define CBOR_LEN128 0x1c /* 28 - 128-bit value */
typedef struct cbor_private_s {
xo_buffer_t c_data; /* Our data buffer */
unsigned c_indent; /* Indent level */
unsigned c_open_leaf_list; /* Open leaf list construct? */
} cbor_private_t;
static void
cbor_encode_uint (xo_buffer_t *xbp, uint64_t minor, unsigned limit)
{
char *bp = xbp->xb_curp;
int i, m;
if (minor > (1ULL << 32)) {
*bp++ |= CBOR_LEN64;
m = 64;
} else if (minor > (1<<16)) {
*bp++ |= CBOR_LEN32;
m = 32;
} else if (minor > (1<<8)) {
*bp++ |= CBOR_LEN16;
m = 16;
} else if (minor > limit) {
*bp++ |= CBOR_LEN8;
m = 8;
} else {
*bp++ |= minor & CBOR_MINOR_MASK;
m = 0;
}
if (m) {
for (i = m - 8; i >= 0; i -= 8)
*bp++ = minor >> i;
}
xbp->xb_curp = bp;
}
static void
cbor_append (xo_handle_t *xop, cbor_private_t *cbor, xo_buffer_t *xbp,
unsigned major, unsigned minor, const char *data)
{
if (!xo_buf_has_room(xbp, minor + 2))
return;
unsigned offset = xo_buf_offset(xbp);
*xbp->xb_curp = major;
cbor_encode_uint(xbp, minor, CBOR_ULIMIT);
if (data)
xo_buf_append(xbp, data, minor);
if (xo_get_flags(xop) & XOF_PRETTY)
cbor_memdump(stdout, "append", xo_buf_data(xbp, offset),
xbp->xb_curp - xbp->xb_bufp - offset, "",
cbor->c_indent * 2);
}
static int
cbor_create (xo_handle_t *xop)
{
cbor_private_t *cbor = xo_realloc(NULL, sizeof(*cbor));
if (cbor == NULL)
return -1;
bzero(cbor, sizeof(*cbor));
xo_buf_init(&cbor->c_data);
xo_set_private(xop, cbor);
cbor_append(xop, cbor, &cbor->c_data, CBOR_MAP | CBOR_INDEF, 0, NULL);
return 0;
}
static int
cbor_content (xo_handle_t *xop, cbor_private_t *cbor, xo_buffer_t *xbp,
const char *value)
{
int rc = 0;
unsigned offset = xo_buf_offset(xbp);
if (value == NULL || *value == '\0' || xo_streq(value, "true"))
cbor_append(xop, cbor, &cbor->c_data, CBOR_TRUE, 0, NULL);
else if (xo_streq(value, "false"))
cbor_append(xop, cbor, &cbor->c_data, CBOR_FALSE, 0, NULL);
else {
int negative = 0;
if (*value == '-') {
value += 1;
negative = 1;
}
char *ep;
unsigned long long ival;
ival = strtoull(value, &ep, 0);
if (ival == ULLONG_MAX) /* Sometimes a string is just a string */
cbor_append(xop, cbor, xbp, CBOR_STRING, strlen(value), value);
else {
*xbp->xb_curp = negative ? CBOR_NEGATIVE : CBOR_UNSIGNED;
if (negative)
ival -= 1; /* Don't waste a negative zero */
cbor_encode_uint(xbp, ival, negative ? CBOR_NLIMIT : CBOR_ULIMIT);
}
}
if (xo_get_flags(xop) & XOF_PRETTY)
cbor_memdump(stdout, "content", xo_buf_data(xbp, offset),
xbp->xb_curp - xbp->xb_bufp - offset, "",
cbor->c_indent * 2);
return rc;
}
static int
cbor_handler (XO_ENCODER_HANDLER_ARGS)
{
int rc = 0;
cbor_private_t *cbor = private;
xo_buffer_t *xbp = cbor ? &cbor->c_data : NULL;
if (xo_get_flags(xop) & XOF_PRETTY) {
printf("%*sop %s: [%s] [%s]\n", cbor ? cbor->c_indent * 2 + 4 : 0, "",
xo_encoder_op_name(op), name, value);
fflush(stdout);
}
/* If we don't have private data, we're sunk */
if (cbor == NULL && op != XO_OP_CREATE)
return -1;
switch (op) {
case XO_OP_CREATE: /* Called when the handle is init'd */
rc = cbor_create(xop);
break;
case XO_OP_OPEN_CONTAINER:
cbor_append(xop, cbor, xbp, CBOR_STRING, strlen(name), name);
cbor_append(xop, cbor, xbp, CBOR_MAP | CBOR_INDEF, 0, NULL);
cbor->c_indent += 1;
break;
case XO_OP_CLOSE_CONTAINER:
cbor_append(xop, cbor, xbp, CBOR_BREAK, 0, NULL);
cbor->c_indent -= 1;
break;
case XO_OP_OPEN_LIST:
cbor_append(xop, cbor, xbp, CBOR_STRING, strlen(name), name);
cbor_append(xop, cbor, xbp, CBOR_ARRAY | CBOR_INDEF, 0, NULL);
cbor->c_indent += 1;
break;
case XO_OP_CLOSE_LIST:
cbor_append(xop, cbor, xbp, CBOR_BREAK, 0, NULL);
cbor->c_indent -= 1;
break;
case XO_OP_OPEN_LEAF_LIST:
cbor_append(xop, cbor, xbp, CBOR_STRING, strlen(name), name);
cbor_append(xop, cbor, xbp, CBOR_ARRAY | CBOR_INDEF, 0, NULL);
cbor->c_indent += 1;
cbor->c_open_leaf_list = 1;
break;
case XO_OP_CLOSE_LEAF_LIST:
cbor_append(xop, cbor, xbp, CBOR_BREAK, 0, NULL);
cbor->c_indent -= 1;
cbor->c_open_leaf_list = 0;
break;
case XO_OP_OPEN_INSTANCE:
cbor_append(xop, cbor, xbp, CBOR_MAP | CBOR_INDEF, 0, NULL);
cbor->c_indent += 1;
break;
case XO_OP_CLOSE_INSTANCE:
cbor_append(xop, cbor, xbp, CBOR_BREAK, 0, NULL);
cbor->c_indent -= 1;
break;
case XO_OP_STRING: /* Quoted UTF-8 string */
if (!cbor->c_open_leaf_list)
cbor_append(xop, cbor, xbp, CBOR_STRING, strlen(name), name);
cbor_append(xop, cbor, xbp, CBOR_STRING, strlen(value), value);
break;
case XO_OP_CONTENT: /* Other content */
if (!cbor->c_open_leaf_list)
cbor_append(xop, cbor, xbp, CBOR_STRING, strlen(name), name);
/*
* It's content, not string, so we need to look at the
* string and build some content. Turns out we only
* care about true, false, null, and numbers.
*/
cbor_content(xop, cbor, xbp, value);
break;
case XO_OP_FINISH: /* Clean up function */
cbor_append(xop, cbor, xbp, CBOR_BREAK, 0, NULL);
cbor->c_indent -= 1;
break;
case XO_OP_FLUSH: /* Clean up function */
if (xo_get_flags(xop) & XOF_PRETTY)
cbor_memdump(stdout, "cbor",
xbp->xb_bufp, xbp->xb_curp - xbp->xb_bufp,
">", 0);
else {
rc = write(1, xbp->xb_bufp, xbp->xb_curp - xbp->xb_bufp);
if (rc > 0)
rc = 0;
}
break;
case XO_OP_DESTROY: /* Clean up function */
break;
case XO_OP_ATTRIBUTE: /* Attribute name/value */
break;
case XO_OP_VERSION: /* Version string */
break;
}
return rc;
}
int
xo_encoder_library_init (XO_ENCODER_INIT_ARGS)
{
arg->xei_handler = cbor_handler;
arg->xei_version = XO_ENCODER_VERSION;
return 0;
}