diff options
| -rw-r--r-- | gatmux/gsm0710.c | 951 | ||||
| -rw-r--r-- | gatmux/gsm0710_p.h | 82 |
2 files changed, 529 insertions, 504 deletions
diff --git a/gatmux/gsm0710.c b/gatmux/gsm0710.c index 17a48937..279a9a22 100644 --- a/gatmux/gsm0710.c +++ b/gatmux/gsm0710.c @@ -30,57 +30,75 @@ #include "gsm0710_p.h" +/* Frame types and subtypes */ +#define GSM0710_OPEN_CHANNEL 0x3F +#define GSM0710_CLOSE_CHANNEL 0x53 +#define GSM0710_DATA 0xEF +#define GSM0710_DATA_ALT 0x03 +#define GSM0710_STATUS_SET 0xE3 +#define GSM0710_STATUS_ACK 0xE1 +#define GSM0710_TERMINATE_BYTE1 0xC3 +#define GSM0710_TERMINATE_BYTE2 0x01 + +/* Status flags */ +#define GSM0710_FC 0x02 +#define GSM0710_DTR 0x04 +#define GSM0710_DSR 0x04 +#define GSM0710_RTS 0x08 +#define GSM0710_CTS 0x08 +#define GSM0710_DCD 0x80 + /* Initialize a GSM 07.10 context, in preparation for startup */ void gsm0710_initialize(struct gsm0710_context *ctx) { - ctx->mode = GSM0710_MODE_BASIC; - ctx->frame_size = GSM0710_DEFAULT_FRAME_SIZE; - ctx->port_speed = 115200; - ctx->server = 0; - ctx->buffer_used = 0; - memset(ctx->used_channels, 0, sizeof(ctx->used_channels)); - ctx->reinit_detect = 0; - ctx->reinit_detect_len = 0; - ctx->user_data = 0; - ctx->fd = -1; - ctx->at_command = 0; - ctx->read = 0; - ctx->write = 0; - ctx->deliver_data = 0; - ctx->deliver_status = 0; - ctx->debug_message = 0; - ctx->open_channel = 0; - ctx->close_channel = 0; - ctx->terminate = 0; - ctx->packet_filter = 0; + ctx->mode = GSM0710_MODE_BASIC; + ctx->frame_size = GSM0710_DEFAULT_FRAME_SIZE; + ctx->port_speed = 115200; + ctx->server = 0; + ctx->buffer_used = 0; + memset(ctx->used_channels, 0, sizeof(ctx->used_channels)); + ctx->reinit_detect = 0; + ctx->reinit_detect_len = 0; + ctx->user_data = 0; + ctx->fd = -1; + ctx->at_command = 0; + ctx->read = 0; + ctx->write = 0; + ctx->deliver_data = 0; + ctx->deliver_status = 0; + ctx->debug_message = 0; + ctx->open_channel = 0; + ctx->close_channel = 0; + ctx->terminate = 0; + ctx->packet_filter = 0; } /* Determine if a channel is in use */ static int is_channel_used(struct gsm0710_context *ctx, int channel) { - int index = channel / 32; - return ((ctx->used_channels[index] & (1L << (channel % 32))) != 0); + int index = channel / 32; + return ((ctx->used_channels[index] & (1L << (channel % 32))) != 0); } /* Mark a channel as used */ static void mark_channel_used(struct gsm0710_context *ctx, int channel) { - int index = channel / 32; - ctx->used_channels[index] |= (1L << (channel % 32)); + int index = channel / 32; + ctx->used_channels[index] |= (1L << (channel % 32)); } /* Mark a channel as unused */ static void mark_channel_unused(struct gsm0710_context *ctx, int channel) { - int index = channel / 32; - ctx->used_channels[index] &= ~(1L << (channel % 32)); + int index = channel / 32; + ctx->used_channels[index] &= ~(1L << (channel % 32)); } /* Write a debug message */ static void gsm0710_debug(struct gsm0710_context *ctx, const char *msg) { - if (ctx->debug_message) - ctx->debug_message(ctx, msg); + if (ctx->debug_message) + ctx->debug_message(ctx, msg); } /* Set the "reinitialize detect" string to "str". When "str" is @@ -90,117 +108,117 @@ static void gsm0710_debug(struct gsm0710_context *ctx, const char *msg) The data at "str" must persist until the context is destroyed */ void gsm0710_set_reinit_detect(struct gsm0710_context *ctx, const char *str) { - ctx->reinit_detect = str; - ctx->reinit_detect_len = (str ? strlen(str) : 0); + ctx->reinit_detect = 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 + 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 unsigned char gsm0710_compute_crc(const unsigned char *data, int len) { - int sum = 0xFF; - while ( len > 0 ) { - sum = crc_table[ ( sum ^ *data++ ) & 0xFF ]; - --len; - } - return (~sum & 0xFF); + 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 unsigned char *data, int len) + int type, const unsigned char *data, int len) { - unsigned char *frame = 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] = 0x7E; - frame[1] = ((channel << 2) | 0x03); - frame[2] = 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] = 0x7D; - frame[3] = (type ^ 0x20); - size = 4; - } else { - size = 3; - } - while ( len > 0 ) { - temp = *data++ & 0xFF; - --len; - if ( temp != 0x7E && temp != 0x7D ) { - frame[size++] = temp; - } else { - frame[size++] = 0x7D; - frame[size++] = (temp ^ 0x20); - } - } - if ( crc != 0x7E && crc != 0x7D ) { - frame[size++] = crc; - } else { - frame[size++] = 0x7D; - frame[size++] = (crc ^ 0x20); - } - frame[size++] = 0x7E; - } else { - int header_size; - frame[0] = 0xF9; - frame[1] = ((channel << 2) | 0x03); - frame[2] = type; - if (len <= 127) { - frame[3] = ((len << 1) | 0x01); - header_size = size = 4; - } else { - frame[3] = (len << 1); - frame[4] = (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++] = gsm0710_compute_crc(frame + 1, header_size - 1); - frame[size++] = 0xF9; - } - if (ctx->write) - ctx->write(ctx, frame, size); + unsigned char *frame = 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] = 0x7E; + frame[1] = ((channel << 2) | 0x03); + frame[2] = 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] = 0x7D; + frame[3] = (type ^ 0x20); + size = 4; + } else { + size = 3; + } + while (len > 0) { + temp = *data++ & 0xFF; + --len; + if (temp != 0x7E && temp != 0x7D) { + frame[size++] = temp; + } else { + frame[size++] = 0x7D; + frame[size++] = (temp ^ 0x20); + } + } + if (crc != 0x7E && crc != 0x7D) { + frame[size++] = crc; + } else { + frame[size++] = 0x7D; + frame[size++] = (crc ^ 0x20); + } + frame[size++] = 0x7E; + } else { + int header_size; + frame[0] = 0xF9; + frame[1] = ((channel << 2) | 0x03); + frame[2] = type; + if (len <= 127) { + frame[3] = ((len << 1) | 0x01); + header_size = size = 4; + } else { + frame[3] = (len << 1); + frame[4] = (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++] = gsm0710_compute_crc(frame + 1, header_size - 1); + frame[size++] = 0xF9; + } + if (ctx->write) + ctx->write(ctx, frame, size); } /* Start up the GSM 07.10 session on the underlying device. @@ -209,372 +227,397 @@ static void gsm0710_write_frame(struct gsm0710_context *ctx, int channel, in multiplexing mode. Returns zero if the AT+CMUX failed */ int gsm0710_startup(struct gsm0710_context *ctx, int send_cmux) { - int channel; - char command[64]; - - /* Discard any data in the buffer, in case of restart */ - ctx->buffer_used = 0; - - /* Send the appropriate AT+CMUX command */ - if (send_cmux) { - int speed; - switch (ctx->port_speed) { - case 9600: speed = 1; break; - case 19200: speed = 2; break; - case 38400: speed = 3; break; - case 57600: speed = 4; break; - case 115200: speed = 5; break; - case 230400: speed = 6; break; - default: speed = 5; break; - } - sprintf(command, "AT+CMUX=%d,0,%d,%d", - ctx->mode, speed, ctx->frame_size); - if (!ctx->at_command || !ctx->at_command(ctx, command)) { - gsm0710_debug - (ctx, "could not initialize multiplexing with AT+CMUX"); - return 0; - } - } - - /* Open the control channel */ - gsm0710_write_frame(ctx, 0, GSM0710_OPEN_CHANNEL, 0, 0); - - /* Open previously-used channels if this is a reinit. - Send "ERROR" on re-opened channels, to cause higher - layers to abort pending AT commands */ - for (channel = 1; channel <= GSM0710_MAX_CHANNELS; ++channel) { - if (is_channel_used(ctx, channel)) { - gsm0710_write_frame(ctx, channel, GSM0710_OPEN_CHANNEL, 0, 0); - if (ctx->deliver_data) - ctx->deliver_data(ctx, channel, "\r\nERROR\r\n", 9); - } - } - return 1; + int channel; + char command[64]; + + /* Discard any data in the buffer, in case of restart */ + ctx->buffer_used = 0; + + /* Send the appropriate AT+CMUX command */ + if (send_cmux) { + int speed; + switch (ctx->port_speed) { + case 9600: + speed = 1; + break; + case 19200: + speed = 2; + break; + case 38400: + speed = 3; + break; + case 57600: + speed = 4; + break; + case 115200: + speed = 5; + break; + case 230400: + speed = 6; + break; + default: + speed = 5; + break; + } + sprintf(command, "AT+CMUX=%d,0,%d,%d", + ctx->mode, speed, ctx->frame_size); + if (!ctx->at_command || !ctx->at_command(ctx, command)) { + gsm0710_debug(ctx, + "could not initialize multiplexing with AT+CMUX"); + return 0; + } + } + + /* Open the control channel */ + gsm0710_write_frame(ctx, 0, GSM0710_OPEN_CHANNEL, 0, 0); + + /* Open previously-used channels if this is a reinit. + Send "ERROR" on re-opened channels, to cause higher + layers to abort pending AT commands */ + for (channel = 1; channel <= GSM0710_MAX_CHANNELS; ++channel) { + if (is_channel_used(ctx, channel)) { + gsm0710_write_frame(ctx, channel, + GSM0710_OPEN_CHANNEL, 0, 0); + if (ctx->deliver_data) + ctx->deliver_data(ctx, channel, + "\r\nERROR\r\n", 9); + } + } + return 1; } /* Shut down the GSM 07.10 session, closing all channels */ void gsm0710_shutdown(struct gsm0710_context *ctx) { - static const unsigned char terminate[2] = - {GSM0710_TERMINATE_BYTE1, GSM0710_TERMINATE_BYTE2}; - if (!ctx->server) { - int channel; - for (channel = 1; channel <= GSM0710_MAX_CHANNELS; ++channel) { - if(is_channel_used(ctx, channel)) { - gsm0710_write_frame(ctx, channel, GSM0710_CLOSE_CHANNEL, 0, 0); - } - } - gsm0710_write_frame(ctx, 0, GSM0710_DATA, terminate, 2); - } - memset(ctx->used_channels, 0, sizeof(ctx->used_channels)); + static const unsigned char terminate[2] = { GSM0710_TERMINATE_BYTE1, + GSM0710_TERMINATE_BYTE2 }; + if (!ctx->server) { + int channel; + for (channel = 1; channel <= GSM0710_MAX_CHANNELS; ++channel) { + if (is_channel_used(ctx, channel)) { + gsm0710_write_frame(ctx, channel, + GSM0710_CLOSE_CHANNEL, 0, 0); + } + } + gsm0710_write_frame(ctx, 0, GSM0710_DATA, terminate, 2); + } + memset(ctx->used_channels, 0, sizeof(ctx->used_channels)); } /* Open a specific channel. Returns non-zero if successful */ int gsm0710_open_channel(struct gsm0710_context *ctx, int channel) { - if (channel <= 0 || channel > GSM0710_MAX_CHANNELS) - return 0; /* Invalid channel number */ - if (is_channel_used(ctx, channel)) - return 1; /* Channel is already open */ - mark_channel_used(ctx, channel); - if (!ctx->server) - gsm0710_write_frame(ctx, channel, GSM0710_OPEN_CHANNEL, 0, 0); - return 1; + if (channel <= 0 || channel > GSM0710_MAX_CHANNELS) + return 0; /* Invalid channel number */ + if (is_channel_used(ctx, channel)) + return 1; /* Channel is already open */ + mark_channel_used(ctx, channel); + if (!ctx->server) + gsm0710_write_frame(ctx, channel, GSM0710_OPEN_CHANNEL, 0, 0); + return 1; } /* Close a specific channel */ void gsm0710_close_channel(struct gsm0710_context *ctx, int channel) { - if (channel <= 0 || channel > GSM0710_MAX_CHANNELS) - return; /* Invalid channel number */ - if (!is_channel_used(ctx, channel)) - return; /* Channel is already closed */ - mark_channel_unused(ctx, channel); - if (!ctx->server) - gsm0710_write_frame(ctx, channel, GSM0710_CLOSE_CHANNEL, 0, 0); + if (channel <= 0 || channel > GSM0710_MAX_CHANNELS) + return; /* Invalid channel number */ + if (!is_channel_used(ctx, channel)) + return; /* Channel is already closed */ + mark_channel_unused(ctx, channel); + if (!ctx->server) + gsm0710_write_frame(ctx, channel, GSM0710_CLOSE_CHANNEL, 0, 0); } /* Determine if a specific channel is open */ int gsm0710_is_channel_open(struct gsm0710_context *ctx, int channel) { - if (channel <= 0 || channel > GSM0710_MAX_CHANNELS) - return 0; /* Invalid channel number */ - return is_channel_used(ctx, channel); + if (channel <= 0 || channel > GSM0710_MAX_CHANNELS) + return 0; /* Invalid channel number */ + return is_channel_used(ctx, channel); } /* Process an incoming GSM 07.10 packet */ -static int gsm0710_packet( struct gsm0710_context *ctx, int channel, int type, - const unsigned char *data, int len ) +static int gsm0710_packet(struct gsm0710_context *ctx, int channel, int type, + const unsigned char *data, int len) { - if (ctx->packet_filter && - ctx->packet_filter(ctx, channel, type, data, len)) { - /* The filter has extracted and processed the packet */ - return 1; - } - if (type == 0xEF || type == 0x03) { - - if (channel >= 1 && channel <= GSM0710_MAX_CHANNELS && - is_channel_used(ctx, channel)) { - /* Ordinary data packet */ - if (ctx->deliver_data) - ctx->deliver_data(ctx, channel, data, len); - } else if (channel == 0) { - /* An embedded command or response on channel 0 */ - if (len >= 2 && data[0] == GSM0710_STATUS_SET) { - return gsm0710_packet(ctx, channel, GSM0710_STATUS_ACK, - data + 2, len - 2); - } else if (len >= 2 && data[0] == 0xC3 && ctx->server) { - /* Incoming terminate request on server side */ - for (channel = 1; channel <= GSM0710_MAX_CHANNELS; ++channel) { - if (is_channel_used(ctx, channel)) { - if (ctx->close_channel) - ctx->close_channel(ctx, channel); - } - } - memset(ctx->used_channels, 0, sizeof(ctx->used_channels)); - if (ctx->terminate) - ctx->terminate(ctx); - return 0; - } else if (len >= 2 && data[0] == 0x43) { - /* Test command from other side - send the same bytes back */ - unsigned char *resp = alloca(len); - memcpy(resp, data, len); - resp[0] = 0x41; /* Clear the C/R bit in the response */ - gsm0710_write_frame(ctx, 0, GSM0710_DATA, resp, len); - } - } - - } else if (type == GSM0710_STATUS_ACK && channel == 0) { - - unsigned char resp[33]; - - /* Status change message */ - if (len >= 2) { - /* Handle status changes on other channels */ - channel = ((data[0] & 0xFC) >> 2); - if (channel >= 1 && channel <= GSM0710_MAX_CHANNELS && - is_channel_used(ctx, channel)) { - if (ctx->deliver_status) - ctx->deliver_status(ctx, channel, data[1] & 0xFF); - } - } - - /* Send the response to the status change request to ACK it */ - gsm0710_debug(ctx, "received status line signal, sending response"); - if ( len > 31 ) - len = 31; - resp[0] = GSM0710_STATUS_ACK; - resp[1] = ((len << 1) | 0x01); - memcpy(resp + 2, data, len); - gsm0710_write_frame(ctx, 0, GSM0710_DATA, resp, len + 2); - - } else if (type == (0x3F & 0xEF) && ctx->server) { - - /* Incoming channel open request on server side */ - if (channel >= 1 && channel <= GSM0710_MAX_CHANNELS) { - if (!is_channel_used(ctx, channel)) { - mark_channel_used(ctx, channel); - if (ctx->open_channel) - ctx->open_channel(ctx, channel); - } - } - - } else if (type == (0x53 & 0xEF) && ctx->server) { - - /* Incoming channel close request on server side */ - if (channel >= 1 && channel <= GSM0710_MAX_CHANNELS) { - if (is_channel_used(ctx, channel)) { - mark_channel_unused(ctx, channel); - if (ctx->close_channel) - ctx->close_channel(ctx, channel); - } - } - - } - return 1; + if (ctx->packet_filter && + ctx->packet_filter(ctx, channel, type, data, len)) { + /* The filter has extracted and processed the packet */ + return 1; + } + if (type == 0xEF || type == 0x03) { + + if (channel >= 1 && channel <= GSM0710_MAX_CHANNELS && + is_channel_used(ctx, channel)) { + /* Ordinary data packet */ + if (ctx->deliver_data) + ctx->deliver_data(ctx, channel, data, len); + } else if (channel == 0) { + /* An embedded command or response on channel 0 */ + if (len >= 2 && data[0] == GSM0710_STATUS_SET) { + return gsm0710_packet(ctx, channel, + GSM0710_STATUS_ACK, + data + 2, len - 2); + } else if (len >= 2 && data[0] == 0xC3 && ctx->server) { + /* Incoming terminate request on server side */ + for (channel = 1; channel <= GSM0710_MAX_CHANNELS; ++channel) { + if (is_channel_used(ctx, channel)) { + if (ctx->close_channel) + ctx->close_channel(ctx, channel); + } + } + memset(ctx->used_channels, 0, + sizeof(ctx->used_channels)); + if (ctx->terminate) + ctx->terminate(ctx); + return 0; + } else if (len >= 2 && data[0] == 0x43) { + /* Test command from other side - send the same bytes back */ + unsigned char *resp = alloca(len); + memcpy(resp, data, len); + resp[0] = 0x41; /* Clear the C/R bit in the response */ + gsm0710_write_frame(ctx, 0, GSM0710_DATA, + resp, len); + } + } + + } else if (type == GSM0710_STATUS_ACK && channel == 0) { + + unsigned char resp[33]; + + /* Status change message */ + if (len >= 2) { + /* Handle status changes on other channels */ + channel = ((data[0] & 0xFC) >> 2); + if (channel >= 1 && channel <= GSM0710_MAX_CHANNELS && + is_channel_used(ctx, channel)) { + if (ctx->deliver_status) + ctx->deliver_status(ctx, channel, + data[1] & 0xFF); + } + } + + /* Send the response to the status change request to ACK it */ + gsm0710_debug(ctx, + "received status line signal, sending response"); + if (len > 31) + len = 31; + resp[0] = GSM0710_STATUS_ACK; + resp[1] = ((len << 1) | 0x01); + memcpy(resp + 2, data, len); + gsm0710_write_frame(ctx, 0, GSM0710_DATA, resp, len + 2); + + } else if (type == (0x3F & 0xEF) && ctx->server) { + + /* Incoming channel open request on server side */ + if (channel >= 1 && channel <= GSM0710_MAX_CHANNELS) { + if (!is_channel_used(ctx, channel)) { + mark_channel_used(ctx, channel); + if (ctx->open_channel) + ctx->open_channel(ctx, channel); + } + } + + } else if (type == (0x53 & 0xEF) && ctx->server) { + + /* Incoming channel close request on server side */ + if (channel >= 1 && channel <= GSM0710_MAX_CHANNELS) { + if (is_channel_used(ctx, channel)) { + mark_channel_unused(ctx, channel); + if (ctx->close_channel) + ctx->close_channel(ctx, channel); + } + } + + } + return 1; } /* Function that is called when the underlying device is ready to be read. A callback will be made to ctx->read to get the data for processing */ void gsm0710_ready_read(struct gsm0710_context *ctx) { - int len, posn, posn2, header_size, channel, type; - - /* Read more data from the underlying serial device */ - if (!ctx->read) - return; - len = ctx->read(ctx, ctx->buffer + ctx->buffer_used, - sizeof(ctx->buffer) - ctx->buffer_used); - if ( len <= 0 ) - return; - - /* Update the buffer size */ - ctx->buffer_used += len; - - /* Check for the re-initialization detection string */ - if (!ctx->server && ctx->reinit_detect_len && - len >= ctx->reinit_detect_len && - !memcmp(ctx->buffer, ctx->reinit_detect, ctx->reinit_detect_len)) { - gsm0710_startup(ctx, 1); - return; - } - - /* Break the incoming data up into packets */ - posn = 0; - while (posn < ctx->buffer_used) { - if (ctx->buffer[posn] == 0xF9) { - - /* Basic format: skip additional 0xF9 bytes between frames */ - while ((posn + 1) < ctx->buffer_used && - ctx->buffer[posn + 1] == 0xF9) { - ++posn; - } - - /* We need at least 4 bytes for the header */ - if ((posn + 4) > ctx->buffer_used) - break; - - /* The low bit of the second byte should be 1, - which indicates a short channel number */ - if ((ctx->buffer[posn + 1] & 0x01 ) == 0) { - ++posn; - continue; - } - - /* Get the packet length and validate it */ - len = (ctx->buffer[posn + 3] >> 1) & 0x7F; - if ((ctx->buffer[posn + 3] & 0x01) != 0) { - /* Single-byte length indication */ - header_size = 3; - } else { - /* Double-byte length indication */ - if ((posn + 5) > ctx->buffer_used) - break; - len |= ((int)(ctx->buffer[posn + 4])) << 7; - header_size = 4; - } - if ((posn + header_size + 2 + len) > ctx->buffer_used ) - break; - - /* Verify the packet header checksum */ - if (((gsm0710_compute_crc(ctx->buffer + posn + 1, header_size) ^ - ctx->buffer[posn + len + header_size + 1]) & 0xFF) - != 0) { - gsm0710_debug(ctx, "*** GSM 07.10 checksum check failed ***"); - posn += len + header_size + 2; - continue; - } - - /* Get the channel number and packet type from the header */ - channel = (ctx->buffer[posn + 1] >> 2) & 0x3F; - type = ctx->buffer[posn + 2] & 0xEF; /* Strip "PF" bit */ - - /* Dispatch data packets to the appropriate channel */ - if (!gsm0710_packet(ctx, channel, type, - ctx->buffer + posn + header_size + 1, len)) { - /* Session has been terminated */ - ctx->buffer_used = 0; - return; - } - posn += len + header_size + 2; - - } else if (ctx->buffer[posn] == 0x7E) { - - /* Advanced format: skip additional 0x7E bytes between frames */ - while ((posn + 1) < ctx->buffer_used && - ctx->buffer[posn + 1] == 0x7E) { - ++posn; - } - - /* Search for the end of the packet (the next 0x7E byte) */ - len = posn + 1; - while (len < ctx->buffer_used && - ctx->buffer[len] != 0x7E) { - ++len; - } - if (len >= ctx->buffer_used) { - /* There are insufficient bytes for a packet at present */ - if ( posn == 0 && len >= (int)sizeof( ctx->buffer ) ) { - /* The buffer is full and we were unable to find a - legitimate packet. Discard the buffer and restart */ - posn = len; - } - break; - } - - /* Undo control byte quoting in the packet */ - posn2 = 0; - ++posn; - while (posn < len) { - if (ctx->buffer[posn] == 0x7D) { - ++posn; - if ( posn >= len) - break; - ctx->buffer[posn2++] = (ctx->buffer[posn++] ^ 0x20); - } else { - ctx->buffer[posn2++] = ctx->buffer[posn++]; - } - } - - /* Validate the checksum on the packet header */ - if (posn2 >= 3) { - if (((gsm0710_compute_crc(ctx->buffer, 2) ^ - ctx->buffer[posn2 - 1]) & 0xFF) != 0 ) { - gsm0710_debug(ctx, "*** GSM 07.10 advanced checksum " - "check failed ***"); - continue; - } - } else { - gsm0710_debug(ctx, "*** GSM 07.10 advanced packet " - "is too small ***"); - continue; - } - - /* Decode and dispatch the packet */ - channel = (ctx->buffer[0] >> 2) & 0x3F; - type = ctx->buffer[1] & 0xEF; /* Strip "PF" bit */ - if (!gsm0710_packet(ctx, channel, type, - ctx->buffer + 2, posn2 - 3)) { - /* Session has been terminated */ - ctx->buffer_used = 0; - return; - } - - } else { - ++posn; - } - } - if ( posn < ctx->buffer_used ) { - memmove( ctx->buffer, ctx->buffer + posn, ctx->buffer_used - posn ); - ctx->buffer_used -= posn; - } else { - ctx->buffer_used = 0; - } + int len, posn, posn2, header_size, channel, type; + + /* Read more data from the underlying serial device */ + if (!ctx->read) + return; + len = ctx->read(ctx, ctx->buffer + ctx->buffer_used, + sizeof(ctx->buffer) - ctx->buffer_used); + if (len <= 0) + return; + + /* Update the buffer size */ + ctx->buffer_used += len; + + /* Check for the re-initialization detection string */ + if (!ctx->server && ctx->reinit_detect_len && + len >= ctx->reinit_detect_len && + !memcmp(ctx->buffer, ctx->reinit_detect, ctx->reinit_detect_len)) { + gsm0710_startup(ctx, 1); + return; + } + + /* Break the incoming data up into packets */ + posn = 0; + while (posn < ctx->buffer_used) { + if (ctx->buffer[posn] == 0xF9) { + + /* Basic format: skip additional 0xF9 bytes between frames */ + while ((posn + 1) < ctx->buffer_used && + ctx->buffer[posn + 1] == 0xF9) { + ++posn; + } + + /* We need at least 4 bytes for the header */ + if ((posn + 4) > ctx->buffer_used) + break; + + /* The low bit of the second byte should be 1, + which indicates a short channel number */ + if ((ctx->buffer[posn + 1] & 0x01) == 0) { + ++posn; + continue; + } + + /* Get the packet length and validate it */ + len = (ctx->buffer[posn + 3] >> 1) & 0x7F; + if ((ctx->buffer[posn + 3] & 0x01) != 0) { + /* Single-byte length indication */ + header_size = 3; + } else { + /* Double-byte length indication */ + if ((posn + 5) > ctx->buffer_used) + break; + len |= ((int)(ctx->buffer[posn + 4])) << 7; + header_size = 4; + } + if ((posn + header_size + 2 + len) > ctx->buffer_used) + break; + + /* Verify the packet header checksum */ + if (((gsm0710_compute_crc(ctx->buffer + posn + 1, + header_size) ^ ctx->buffer[posn + len + header_size + 1]) & 0xFF) != 0) { + gsm0710_debug(ctx, + "*** GSM 07.10 checksum check failed ***"); + posn += len + header_size + 2; + continue; + } + + /* Get the channel number and packet type from the header */ + channel = (ctx->buffer[posn + 1] >> 2) & 0x3F; + type = ctx->buffer[posn + 2] & 0xEF; /* Strip "PF" bit */ + + /* Dispatch data packets to the appropriate channel */ + if (!gsm0710_packet(ctx, channel, type, + ctx->buffer + posn + header_size + 1, len)) { + /* Session has been terminated */ + ctx->buffer_used = 0; + return; + } + posn += len + header_size + 2; + + } else if (ctx->buffer[posn] == 0x7E) { + + /* Advanced format: skip additional 0x7E bytes between frames */ + while ((posn + 1) < ctx->buffer_used && + ctx->buffer[posn + 1] == 0x7E) { + ++posn; + } + + /* Search for the end of the packet (the next 0x7E byte) */ + len = posn + 1; + while (len < ctx->buffer_used && + ctx->buffer[len] != 0x7E) { + ++len; + } + if (len >= ctx->buffer_used) { + /* There are insufficient bytes for a packet at present */ + if (posn == 0 && len >= (int)sizeof(ctx->buffer)) { + /* The buffer is full and we were unable to find a + legitimate packet. Discard the buffer and restart */ + posn = len; + } + break; + } + + /* Undo control byte quoting in the packet */ + posn2 = 0; + ++posn; + while (posn < len) { + if (ctx->buffer[posn] == 0x7D) { + ++posn; + if (posn >= len) + break; + ctx->buffer[posn2++] = (ctx->buffer[posn++] ^ 0x20); + } else { + ctx->buffer[posn2++] = ctx->buffer[posn++]; + } + } + + /* Validate the checksum on the packet header */ + if (posn2 >= 3) { + if (((gsm0710_compute_crc(ctx->buffer, 2) ^ + ctx->buffer[posn2 - 1]) & 0xFF) != 0) { + gsm0710_debug(ctx, + "*** GSM 07.10 advanced checksum " + "check failed ***"); + continue; + } + } else { + gsm0710_debug(ctx, + "*** GSM 07.10 advanced packet " + "is too small ***"); + continue; + } + + /* Decode and dispatch the packet */ + channel = (ctx->buffer[0] >> 2) & 0x3F; + type = ctx->buffer[1] & 0xEF; /* Strip "PF" bit */ + if (!gsm0710_packet(ctx, channel, type, + ctx->buffer + 2, posn2 - 3)) { + /* Session has been terminated */ + ctx->buffer_used = 0; + return; + } + + } else { + ++posn; + } + } + if (posn < ctx->buffer_used) { + memmove(ctx->buffer, ctx->buffer + posn, + ctx->buffer_used - posn); + ctx->buffer_used -= posn; + } else { + ctx->buffer_used = 0; + } } /* 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, - const void *data, int len) + const void *data, int len) { - int temp; - while (len > 0) { - temp = len; - if (temp > ctx->frame_size) - temp = ctx->frame_size; - gsm0710_write_frame(ctx, channel, GSM0710_DATA, data, temp); - data = ((const unsigned char *)data) + temp; - len -= temp; - } + int temp; + while (len > 0) { + temp = len; + if (temp > ctx->frame_size) + temp = ctx->frame_size; + gsm0710_write_frame(ctx, channel, GSM0710_DATA, data, temp); + data = ((const unsigned char *) data) + temp; + len -= temp; + } } /* Set the modem status lines on a channel */ void gsm0710_set_status(struct gsm0710_context *ctx, int channel, int status) { - unsigned char data[4]; - data[0] = GSM0710_STATUS_SET; - data[1] = 0x03; - data[2] = ((channel << 2) | 0x03); - data[3] = status; - gsm0710_write_frame(ctx, 0, GSM0710_DATA, data, 4); + unsigned char data[4]; + data[0] = GSM0710_STATUS_SET; + data[1] = 0x03; + data[2] = ((channel << 2) | 0x03); + data[3] = status; + gsm0710_write_frame(ctx, 0, GSM0710_DATA, data, 4); } diff --git a/gatmux/gsm0710_p.h b/gatmux/gsm0710_p.h index 11246aba..4961dabc 100644 --- a/gatmux/gsm0710_p.h +++ b/gatmux/gsm0710_p.h @@ -27,60 +27,42 @@ extern "C" { #endif -#define GSM0710_BUFFER_SIZE 4096 -#define GSM0710_DEFAULT_FRAME_SIZE 31 -#define GSM0710_MAX_CHANNELS 63 +#define GSM0710_BUFFER_SIZE 4096 +#define GSM0710_DEFAULT_FRAME_SIZE 31 +#define GSM0710_MAX_CHANNELS 63 -#define GSM0710_MODE_BASIC 0 -#define GSM0710_MODE_ADVANCED 1 - -/* Frame types and subtypes */ -#define GSM0710_OPEN_CHANNEL 0x3F -#define GSM0710_CLOSE_CHANNEL 0x53 -#define GSM0710_DATA 0xEF -#define GSM0710_DATA_ALT 0x03 -#define GSM0710_STATUS_SET 0xE3 -#define GSM0710_STATUS_ACK 0xE1 -#define GSM0710_TERMINATE_BYTE1 0xC3 -#define GSM0710_TERMINATE_BYTE2 0x01 - -/* Status flags */ -#define GSM0710_FC 0x02 -#define GSM0710_DTR 0x04 -#define GSM0710_DSR 0x04 -#define GSM0710_RTS 0x08 -#define GSM0710_CTS 0x08 -#define GSM0710_DCD 0x80 +#define GSM0710_MODE_BASIC 0 +#define GSM0710_MODE_ADVANCED 1 struct gsm0710_context { - /* GSM 07.10 implementation details */ - int mode; - int frame_size; - int port_speed; - int server; - unsigned char buffer[GSM0710_BUFFER_SIZE]; - int buffer_used; - unsigned long used_channels[(GSM0710_MAX_CHANNELS + 31) / 32]; - const char *reinit_detect; - int reinit_detect_len; + /* GSM 07.10 implementation details */ + int mode; + int frame_size; + int port_speed; + int server; + unsigned char buffer[GSM0710_BUFFER_SIZE]; + int buffer_used; + unsigned long used_channels[(GSM0710_MAX_CHANNELS + 31) / 32]; + const char *reinit_detect; + int reinit_detect_len; - /* Hooks to other levels */ - void *user_data; - int fd; - int (*at_command)(struct gsm0710_context *ctx, const char *cmd); - int (*read)(struct gsm0710_context *ctx, void *data, int len); - int (*write)(struct gsm0710_context *ctx, const void *data, int len); - void (*deliver_data)(struct gsm0710_context *ctx, int channel, - const void *data, int len); - void (*deliver_status)(struct gsm0710_context *ctx, - int channel, int status); - void (*debug_message)(struct gsm0710_context *ctx, const char *msg); - void (*open_channel)(struct gsm0710_context *ctx, int channel); - void (*close_channel)(struct gsm0710_context *ctx, int channel); - void (*terminate)(struct gsm0710_context *ctx); - int (*packet_filter)(struct gsm0710_context *ctx, int channel, - int type, const unsigned char *data, int len); + /* Hooks to other levels */ + void *user_data; + int fd; + int (*at_command)(struct gsm0710_context *ctx, const char *cmd); + int (*read)(struct gsm0710_context *ctx, void *data, int len); + int (*write)(struct gsm0710_context *ctx, const void *data, int len); + void (*deliver_data)(struct gsm0710_context *ctx, int channel, + const void *data, int len); + void (*deliver_status)(struct gsm0710_context *ctx, + int channel, int status); + void (*debug_message)(struct gsm0710_context *ctx, const char *msg); + void (*open_channel)(struct gsm0710_context *ctx, int channel); + void (*close_channel)(struct gsm0710_context *ctx, int channel); + void (*terminate)(struct gsm0710_context *ctx); + int (*packet_filter)(struct gsm0710_context *ctx, int channel, + int type, const unsigned char *data, int len); }; void gsm0710_initialize(struct gsm0710_context *ctx); @@ -92,7 +74,7 @@ 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_data(struct gsm0710_context *ctx, int channel, - const void *data, int len); + const void *data, int len); void gsm0710_set_status(struct gsm0710_context *ctx, int channel, int status); #ifdef __cplusplus |