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bird/lib/cbor.c
2024-10-05 15:54:15 +02:00

256 lines
6.6 KiB
C

#include <stdint.h>
#include <string.h>
#include "lib/cbor.h"
static const char *cbor_type_str_a[] = {
"POSINT",
"NEGINT",
"BYTES",
"TEXT",
"ARRAY",
"MAP",
"TAG",
"SPECIAL",
};
const char *
cbor_type_str(enum cbor_basic_type t)
{
return (t < ARRAY_SIZE(cbor_type_str_a)) ?
cbor_type_str_a[t] :
tmp_sprintf("(unknown: %u)", t);
}
void write_item(struct cbor_writer *writer, uint8_t major, uint64_t num);
void check_memory(struct cbor_writer *writer, int add_size);
struct cbor_writer *cbor_init(uint8_t *buff, uint32_t capacity, struct linpool *lp)
{
struct cbor_writer *writer = (struct cbor_writer*)lp_alloc(lp, sizeof(struct cbor_writer));
writer->cbor = buff;
writer->capacity = capacity;
writer->pt = 0;
writer->lp = lp;
return writer;
}
void cbor_open_block(struct cbor_writer *writer) { // We will need to close the block later manualy
check_memory(writer, 2);
writer->cbor[writer->pt] = 0xbf;
writer->pt++;
}
void cbor_open_list(struct cbor_writer *writer)
{
check_memory(writer, 2);
writer->cbor[writer->pt] = 0x9f;
writer->pt++;
}
void cbor_close_block_or_list(struct cbor_writer *writer)
{
check_memory(writer, 2);
writer->cbor[writer->pt] = 0xff;
writer->pt++;
}
void cbor_open_block_with_length(struct cbor_writer *writer, uint32_t length)
{
write_item(writer, 5, length);
}
void cbor_open_list_with_length(struct cbor_writer *writer, uint32_t length)
{
write_item(writer, 4, length);
}
void cbor_add_int(struct cbor_writer *writer, int64_t item)
{
if (item >= 0)
{
write_item(writer, 0, item); // 0 is the "major" (three bits) introducing positive int, 1 is for negative
}
else
{
write_item(writer, 1, -item - 1);
}
}
void cbor_epoch_time(struct cbor_writer *writer, int64_t time, int shift)
{
write_item(writer, 6, 1); // 6 is TAG, 1 is tag number for epoch time
cbor_relativ_time(writer, time, shift);
}
void cbor_relativ_time(struct cbor_writer *writer, int64_t time, int shift)
{
write_item(writer, 6, 4); // 6 is TAG, 4 is tag number for decimal fraction
cbor_open_list_with_length(writer, 2);
cbor_add_int(writer, shift);
cbor_add_int(writer, time);
}
void cbor_add_ipv4(struct cbor_writer *writer, ip4_addr addr)
{
write_item(writer, 6, 52); // 6 is TAG, 52 is tag number for ipv4
write_item(writer, 2, 4); // bytestring of length 4
put_ip4(&writer->cbor[writer->pt], addr);
writer->pt += 4;
}
void cbor_add_ipv6(struct cbor_writer *writer, ip6_addr addr)
{
write_item(writer, 6, 54); // 6 is TAG, 54 is tag number for ipv6
write_item(writer, 2, 16); // bytestring of length 16
put_ip6(&writer->cbor[writer->pt], addr);
writer->pt += 16;
}
void cbor_add_ipv4_prefix(struct cbor_writer *writer, net_addr_ip4 *n)
{
write_item(writer, 6, 52); // 6 is TAG, 52 is tag number for ipv4
cbor_open_block_with_length(writer, 2);
cbor_add_int(writer, n->pxlen);
write_item(writer, 2, 4); // bytestring of length 4
put_ip4(&writer->cbor[writer->pt], n->prefix);
writer->pt += 4;
}
void cbor_add_ipv6_prefix(struct cbor_writer *writer, net_addr_ip6 *n)
{
write_item(writer, 6, 54); // 6 is TAG, 54 is tag number for ipv6
cbor_open_block_with_length(writer, 2);
cbor_add_int(writer, n->pxlen);
write_item(writer, 2, 16);
put_ip6(&writer->cbor[writer->pt], n->prefix);
writer->pt += 16;
}
void cbor_add_uint(struct cbor_writer *writer, uint64_t item)
{
write_item(writer, 0, item);
}
void cbor_add_tag(struct cbor_writer *writer, int item)
{
write_item(writer, 6, item);
}
void cbor_add_string(struct cbor_writer *writer, const char *string)
{
int length = strlen(string);
write_item(writer, 3, length); // 3 is major, then goes length of string and string
check_memory(writer, length);
memcpy(writer->cbor+writer->pt, string, length);
writer->pt+=length;
}
void cbor_nonterminated_string(struct cbor_writer *writer, const char *string, uint32_t length)
{
write_item(writer, 3, length); // 3 is major, then goes length of string and string
check_memory(writer, length);
memcpy(writer->cbor+writer->pt, string, length);
writer->pt+=length;
}
void write_item(struct cbor_writer *writer, uint8_t major, uint64_t num)
{
//log("write major %i %li", major, num);
major = major<<5;
check_memory(writer, 10);
if (num > ((uint64_t)1<<(4*8))-1)
{ // We need 8 bytes to encode the num
major += 0x1b; // reserving those bytes
writer->cbor[writer->pt] = major;
writer->pt++;
for (int i = 7; i>=0; i--)
{ // write n-th byte of num
uint8_t to_write = (num>>(i*8)) & 0xff;
writer->cbor[writer->pt] = to_write;
writer->pt++;
}
return;
}
if (num > (1<<(2*8))-1)
{ // We need 4 bytes to encode the num
major += 0x1a; // reserving those bytes
writer->cbor[writer->pt] = major;
writer->pt++;
for (int i = 3; i>=0; i--)
{ // write n-th byte of num
uint8_t to_write = (num>>(i*8)) & 0xff;
writer->cbor[writer->pt] = to_write;
writer->pt++;
}
return;
}
if (num > (1<<(8))-1)
{ // We need 2 bytes to encode the num
major += 0x19; // reserving those bytes
writer->cbor[writer->pt] = major;
writer->pt++;
for (int i = 1; i>=0; i--)
{ // write n-th byte of num
uint8_t to_write = (num>>(i*8)) & 0xff;
writer->cbor[writer->pt] = to_write;
writer->pt++;
}
return;
}
if (num > 23)
{ // byte is enough, but aditional value would be too big
major += 0x18; // reserving that byte
writer->cbor[writer->pt] = major;
writer->pt++;
uint8_t to_write = num & 0xff;
writer->cbor[writer->pt] = to_write;
writer->pt++;
return;
}
//log("write item major %i num %i writer->pt %i writer->capacity %i writer %i", major, num, writer->pt, writer->capacity, writer);
major += num; // we can store the num as additional value
writer->cbor[writer->pt] = major;
writer->pt++;
}
void cbor_write_item_with_constant_val_length_4(struct cbor_writer *writer, uint8_t major, uint64_t num)
{
// this is only for headers which should be constantly long.
major = major<<5;
check_memory(writer, 10);
major += 0x1a; // reserving those bytes
writer->cbor[writer->pt] = major;
writer->pt++;
for (int i = 3; i>=0; i--)
{ // write n-th byte of num
uint8_t to_write = (num>>(i*8)) & 0xff;
writer->cbor[writer->pt] = to_write;
writer->pt++;
}
}
void rewrite_4bytes_int(struct cbor_writer *writer, int pt, int num)
{
for (int i = 3; i>=0; i--)
{
uint8_t to_write = (num>>(i*8)) & 0xff;
writer->cbor[pt] = to_write;
pt++;
}
}
void check_memory(struct cbor_writer *writer, int add_size)
{
if (writer->capacity - writer->pt-add_size < 0)
{
bug("There is not enough space for cbor response in given buffer");
}
}