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Make gsm0710_compute_crc and gsm0710_send_frame private functions

This commit is contained in:
Marcel Holtmann 2009-09-05 07:09:46 +02:00
parent 15e1c3f0d5
commit 4d781ae6e5
2 changed files with 109 additions and 112 deletions
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218
gatmux/gsm0710.c
View File

@ -86,6 +86,115 @@ void gsm0710_set_reinit_detect(struct gsm0710_context *ctx, const char *str)
ctx->reinit_detect_len = (str ? strlen(str) : 0);
}
static const unsigned char crc_table[256] = {
0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75,
0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69,
0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D,
0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51,
0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05,
0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19,
0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D,
0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21,
0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95,
0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89,
0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD,
0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1,
0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5,
0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9,
0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD,
0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1,
0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
};
static int gsm0710_compute_crc(const char *data, int len)
{
int sum = 0xFF;
while ( len > 0 ) {
sum = crc_table[ ( sum ^ *data++ ) & 0xFF ];
--len;
}
return (~sum & 0xFF);
}
/* Write a raw GSM 07.10 frame to the underlying device */
static void gsm0710_write_frame(struct gsm0710_context *ctx, int channel,
int type, const char *data, int len)
{
char *frame = (char *)alloca(ctx->frame_size * 2 + 8);
int size;
if (len > ctx->frame_size)
len = ctx->frame_size;
if (ctx->mode) {
int temp, crc;
frame[0] = (char)0x7E;
frame[1] = (char)((channel << 2) | 0x03);
frame[2] = (char)type;
crc = gsm0710_compute_crc(frame + 1, 2);
if ( type == 0x7E || type == 0x7D ) {
/* Need to quote the type field now that crc has been computed */
frame[2] = (char)0x7D;
frame[3] = (char)(type ^ 0x20);
size = 4;
} else {
size = 3;
}
while ( len > 0 ) {
temp = *data++ & 0xFF;
--len;
if ( temp != 0x7E && temp != 0x7D ) {
frame[size++] = (char)temp;
} else {
frame[size++] = (char)0x7D;
frame[size++] = (char)(temp ^ 0x20);
}
}
if ( crc != 0x7E && crc != 0x7D ) {
frame[size++] = (char)crc;
} else {
frame[size++] = (char)0x7D;
frame[size++] = (char)(crc ^ 0x20);
}
frame[size++] = (char)0x7E;
} else {
int header_size;
frame[0] = (char)0xF9;
frame[1] = (char)((channel << 2) | 0x03);
frame[2] = (char)type;
if (len <= 127) {
frame[3] = (char)((len << 1) | 0x01);
header_size = size = 4;
} else {
frame[3] = (char)(len << 1);
frame[4] = (char)(len >> 7);
header_size = size = 5;
}
if (len > 0) {
memcpy(frame + size, data, len);
size += len;
}
/* Note: GSM 07.10 says that the CRC is only computed over the header */
frame[size++] = (char)gsm0710_compute_crc(frame + 1, header_size - 1);
frame[size++] = (char)0xF9;
}
if (ctx->write)
ctx->write(ctx, frame, size);
}
/* Start up the GSM 07.10 session on the underlying device.
If "send_cmux" is non-zero, then send the AT+CMUX command.
Otherwise the underlying device is assumed to already be
@ -185,51 +294,6 @@ int gsm0710_is_channel_open(struct gsm0710_context *ctx, int channel)
return is_channel_used(ctx, channel);
}
static const unsigned char crc_table[256] = {
0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75,
0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69,
0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D,
0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51,
0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05,
0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19,
0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D,
0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21,
0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95,
0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89,
0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD,
0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1,
0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5,
0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9,
0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD,
0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1,
0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
};
int gsm0710_compute_crc(const char *data, int len)
{
int sum = 0xFF;
while ( len > 0 ) {
sum = crc_table[ ( sum ^ *data++ ) & 0xFF ];
--len;
}
return (~sum & 0xFF);
}
/* Process an incoming GSM 07.10 packet */
static int gsm0710_packet( struct gsm0710_context *ctx, int channel, int type,
const char *data, int len )
@ -480,70 +544,6 @@ void gsm0710_ready_read(struct gsm0710_context *ctx)
}
}
/* Write a raw GSM 07.10 frame to the underlying device */
void gsm0710_write_frame(struct gsm0710_context *ctx, int channel, int type,
const char *data, int len)
{
char *frame = (char *)alloca(ctx->frame_size * 2 + 8);
int size;
if (len > ctx->frame_size)
len = ctx->frame_size;
if (ctx->mode) {
int temp, crc;
frame[0] = (char)0x7E;
frame[1] = (char)((channel << 2) | 0x03);
frame[2] = (char)type;
crc = gsm0710_compute_crc(frame + 1, 2);
if ( type == 0x7E || type == 0x7D ) {
/* Need to quote the type field now that crc has been computed */
frame[2] = (char)0x7D;
frame[3] = (char)(type ^ 0x20);
size = 4;
} else {
size = 3;
}
while ( len > 0 ) {
temp = *data++ & 0xFF;
--len;
if ( temp != 0x7E && temp != 0x7D ) {
frame[size++] = (char)temp;
} else {
frame[size++] = (char)0x7D;
frame[size++] = (char)(temp ^ 0x20);
}
}
if ( crc != 0x7E && crc != 0x7D ) {
frame[size++] = (char)crc;
} else {
frame[size++] = (char)0x7D;
frame[size++] = (char)(crc ^ 0x20);
}
frame[size++] = (char)0x7E;
} else {
int header_size;
frame[0] = (char)0xF9;
frame[1] = (char)((channel << 2) | 0x03);
frame[2] = (char)type;
if (len <= 127) {
frame[3] = (char)((len << 1) | 0x01);
header_size = size = 4;
} else {
frame[3] = (char)(len << 1);
frame[4] = (char)(len >> 7);
header_size = size = 5;
}
if (len > 0) {
memcpy(frame + size, data, len);
size += len;
}
/* Note: GSM 07.10 says that the CRC is only computed over the header */
frame[size++] = (char)gsm0710_compute_crc(frame + 1, header_size - 1);
frame[size++] = (char)0xF9;
}
if (ctx->write)
ctx->write(ctx, frame, size);
}
/* Write a block of data to the the underlying device. It will be split
into several frames according to the frame size, if necessary */
void gsm0710_write_data(struct gsm0710_context *ctx, int channel,

3
gatmux/gsm0710_p.h
View File

@ -99,12 +99,9 @@ int gsm0710_open_channel(struct gsm0710_context *ctx, int channel);
void gsm0710_close_channel(struct gsm0710_context *ctx, int channel);
int gsm0710_is_channel_open(struct gsm0710_context *ctx, int channel);
void gsm0710_ready_read(struct gsm0710_context *ctx);
void gsm0710_write_frame(struct gsm0710_context *ctx, int channel, int type,
const char *data, int len);
void gsm0710_write_data(struct gsm0710_context *ctx, int channel,
const void *data, int len);
void gsm0710_set_status(struct gsm0710_context *ctx, int channel, int status);
int gsm0710_compute_crc(const char *data, int len);
#ifdef __cplusplus
};