diff options
Diffstat (limited to 'openpicc/application/iso14443a_manchester.c')
| -rw-r--r-- | openpicc/application/iso14443a_manchester.c | 100 |
1 files changed, 57 insertions, 43 deletions
diff --git a/openpicc/application/iso14443a_manchester.c b/openpicc/application/iso14443a_manchester.c index efc4baf..eff5a31 100644 --- a/openpicc/application/iso14443a_manchester.c +++ b/openpicc/application/iso14443a_manchester.c @@ -25,7 +25,7 @@ * MSB first LSB first hex LSB first * Sequence D 1010101000000000 0000000001010101 0x0055 * Sequence E 0000000010101010 0101010100000000 0x5500 - * Sequence F 1010101010101010 0101010101010101 0x5555 + * Sequence F 0000000000000000 0000000000000000 0x0000 * * Logic 1 Sequence D * Logic 0 Sequence E @@ -44,79 +44,93 @@ #define MANCHESTER_SEQ_D 0x0055 #define MANCHESTER_SEQ_E 0x5500 -#define MANCHESTER_SEQ_F 0x5555 +#define MANCHESTER_SEQ_F 0x0000 #include <errno.h> #include <string.h> #include "openpicc.h" +#include "iso14443_layer3a.h" +#include "iso14443a_manchester.h" -static u_int32_t manchester_sample_size(u_int8_t frame_bytelen) __attribute__((unused)); -static u_int32_t manchester_sample_size(u_int8_t frame_bytelen) -{ - /* 16 bits (2 bytes) per bit => 16 bytes samples per data byte, - * plus 16bit (2 bytes) parity per data byte - * plus 16bit (2 bytes) SOF plus 16bit (2 bytes) EOF */ - return (frame_bytelen*18) + 2 + 2; - - /* this results in a maximum samples-per-frame size of 4612 bytes - * for a 256byte frame */ -} - -struct manch_enc_state { - const char *data; - char *samples; - u_int16_t *samples16; +enum parity { + PARITY_NONE, /* Don't add a parity bit */ + ODD_PARITY, EVEN_PARITY, /* Calculate parity */ + PARITY_0, PARITY_1 /* Set fixed parity */ }; -static void manchester_enc_byte(struct manch_enc_state *mencs, u_int8_t data) __attribute__((unused)); -static void manchester_enc_byte(struct manch_enc_state *mencs, u_int8_t data) +static void manchester_enc_byte(u_int16_t **s16, u_int8_t data, enum parity parity) { int i; u_int8_t sum_1 = 0; + u_int16_t *samples16 = *s16; /* append 8 sample blobs, one for each bit */ for (i = 0; i < 8; i++) { if (data & (1 << i)) { - *(mencs->samples16) = MANCHESTER_SEQ_D; + *(samples16) = MANCHESTER_SEQ_D; sum_1++; } else { - *(mencs->samples16) = MANCHESTER_SEQ_E; + *(samples16) = MANCHESTER_SEQ_E; + } + samples16++; + } + if(parity != PARITY_NONE) { + /* Append parity */ + u_int8_t par=0; + switch(parity) { + case PARITY_NONE: break; + case PARITY_0: par = 0; break; + case PARITY_1: par = 1; break; + case ODD_PARITY: par = (sum_1 & 0x1) ? 0 : 1; break; + case EVEN_PARITY: par = (sum_1 & 0x1) ? 1 : 0; break; } - mencs->samples16++; + if (par) + *(samples16) = MANCHESTER_SEQ_D; + else + *(samples16) = MANCHESTER_SEQ_E; + samples16++; } - /* append odd parity */ - if (sum_1 & 0x01) - *(mencs->samples16) = MANCHESTER_SEQ_E; - else - *(mencs->samples16) = MANCHESTER_SEQ_D; - mencs->samples16++; + *s16 = samples16; } -#if 0 -/* Broken? */ -int manchester_encode(char *sample_buf, u_int16_t sample_buf_len, - const char *data, u_int8_t data_len) +int manchester_encode(u_int8_t *sample_buf, u_int16_t sample_buf_len, + const iso14443_frame *frame) { - int i, enc_size; - struct manch_enc_state mencs; - - enc_size = manchester_sample_size(data_len); + unsigned int i, enc_size; + u_int16_t *samples16; + + if(frame->type != TYPE_A) return -EINVAL; + if(frame->parameters.a.format != STANDARD_FRAME) return -EINVAL; /* AC not implemented yet */ + + /* One bit data is 16 bit/2 byte modulation data */ + enc_size = 2*2 /* SOF and EOF */ + + frame->numbytes * 8 * 2 + + ((frame->parameters.a.parity != NO_PARITY) ? 1 : 0)*8*2; if (sample_buf_len < enc_size) return -EINVAL; + + samples16 = (u_int16_t*)sample_buf; /* SOF */ - *(mencs.samples16++) = MANCHESTER_SEQ_D; - - for (i = 0; i < data_len; i++) - manchester_enc_byte(&mencs, data[i]); + *(samples16++) = MANCHESTER_SEQ_D; + + if(frame->parameters.a.parity == NO_PARITY) + for (i = 0; i < frame->numbytes; i++) + manchester_enc_byte(&samples16, frame->data[i], PARITY_NONE); + else if(frame->parameters.a.parity == GIVEN_PARITY) + for (i = 0; i < frame->numbytes; i++) + manchester_enc_byte(&samples16, frame->data[i], frame->parity[i]?PARITY_1:PARITY_0); + else if(frame->parameters.a.parity == PARITY) + for (i = 0; i < frame->numbytes; i++) + manchester_enc_byte(&samples16, frame->data[i], ODD_PARITY); /* EOF */ - *(mencs.samples16++) = MANCHESTER_SEQ_F; + *(samples16++) = MANCHESTER_SEQ_F; return enc_size; } -#endif + #if 0 /* Broken? */ #define BPSK_SPEED_212 |