X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fnet%2Fax25.c;h=3bd3e75ce2376c3d7220ee056daae962e3e21917;hb=69189320a33089d77c2623698c583a7a0fc48702;hp=19e63a204e9aab09f557493e54adbbc1feca9336;hpb=74e46ae18c19b6f770530adc846dc1b0325f4b40;p=bertos.git diff --git a/bertos/net/ax25.c b/bertos/net/ax25.c index 19e63a20..3bd3e75c 100644 --- a/bertos/net/ax25.c +++ b/bertos/net/ax25.c @@ -34,7 +34,6 @@ * For now, only UI frames without any Layer 3 protocol are handled. * This however is enough to send/receive APRS packets. * - * \version $Id$ * \author Francesco Sacchi * */ @@ -48,13 +47,25 @@ #define LOG_FORMAT AX25_LOG_FORMAT #include -#include //memset +#include //memset, memcmp +#include //isalnum, toupper + +#if CONFIG_AX25_RPT_LST + #define AX25_SET_REPEATED(msg, idx, val) \ + do \ + { \ + if (val) \ + (msg)->rpt_flags |= BV(idx) ; \ + else \ + (msg)->rpt_flags &= ~BV(idx) ; \ + } while(0) +#endif #define DECODE_CALL(buf, addr) \ for (unsigned i = 0; i < sizeof((addr)); i++) \ { \ - ASSERT(!(*(buf) & 0x01)); \ - (addr)[i] = *(buf)++ >> 1; \ + char c = (*(buf)++ >> 1); \ + (addr)[i] = (c == ' ') ? '\x0' : c; \ } static void ax25_decode(AX25Ctx *ctx) @@ -63,7 +74,6 @@ static void ax25_decode(AX25Ctx *ctx) uint8_t *buf = ctx->buf; DECODE_CALL(buf, msg.dst.call); - ASSERT(!(*buf & 0x01)); msg.dst.ssid = (*buf++ >> 1) & 0x0F; DECODE_CALL(buf, msg.src.call); @@ -77,7 +87,12 @@ static void ax25_decode(AX25Ctx *ctx) { DECODE_CALL(buf, msg.rpt_lst[msg.rpt_cnt].call); msg.rpt_lst[msg.rpt_cnt].ssid = (*buf >> 1) & 0x0F; - LOG_INFO("RPT%d[%.6s-%d]\n", msg.rpt_cnt, msg.rpt_lst[msg.rpt_cnt].call, msg.rpt_lst[msg.rpt_cnt].ssid); + AX25_SET_REPEATED(&msg, msg.rpt_cnt, (*buf & 0x80)); + + LOG_INFO("RPT%d[%.6s-%d]%c\n", msg.rpt_cnt, + msg.rpt_lst[msg.rpt_cnt].call, + msg.rpt_lst[msg.rpt_cnt].ssid, + (AX25_REPEATED(&msg, msg.rpt_cnt) ? '*' : ' ')); } #else while (!(*buf++ & 0x01)) @@ -93,25 +108,36 @@ static void ax25_decode(AX25Ctx *ctx) msg.ctrl = *buf++; if (msg.ctrl != AX25_CTRL_UI) { - LOG_INFO("Only UI frames are handled, got [%02X]\n", msg.ctrl); + LOG_WARN("Only UI frames are handled, got [%02X]\n", msg.ctrl); return; } msg.pid = *buf++; if (msg.pid != AX25_PID_NOLAYER3) { - LOG_INFO("Only frames without layer3 protocol are handled, got [%02X]\n", msg.pid); + LOG_WARN("Only frames without layer3 protocol are handled, got [%02X]\n", msg.pid); return; } msg.len = ctx->frm_len - 2 - (buf - ctx->buf); msg.info = buf; - LOG_INFO("DATA[%.*s]\n", msg.len, msg.info); + LOG_INFO("DATA: %.*s\n", msg.len, msg.info); if (ctx->hook) ctx->hook(&msg); } + +/** + * Check if there are any AX25 messages to be processed. + * This function read available characters from the medium and search for + * any AX25 messages. + * If a message is found it is decoded and the linked callback executed. + * This function may be blocking if there are no available chars and the KFile + * used in \a ctx to access the medium is configured in blocking mode. + * + * \param ctx AX25 context to operate on. + */ void ax25_poll(AX25Ctx *ctx) { int c; @@ -120,7 +146,6 @@ void ax25_poll(AX25Ctx *ctx) { if (!ctx->escape && c == HDLC_FLAG) { - LOG_INFO("Frame start, frm_len %d\n", ctx->frm_len); if (ctx->frm_len >= AX25_MIN_FRAME_LEN) { if (ctx->crc_in == AX25_CRC_CORRECT) @@ -175,6 +200,123 @@ void ax25_poll(AX25Ctx *ctx) } } +static void ax25_putchar(AX25Ctx *ctx, uint8_t c) +{ + if (c == HDLC_FLAG || c == HDLC_RESET + || c == AX25_ESC) + kfile_putc(AX25_ESC, ctx->ch); + ctx->crc_out = updcrc_ccitt(c, ctx->crc_out); + kfile_putc(c, ctx->ch); +} + +static void ax25_sendCall(AX25Ctx *ctx, const AX25Call *addr, bool last) +{ + unsigned len = MIN(sizeof(addr->call), strlen(addr->call)); + + for (unsigned i = 0; i < len; i++) + { + uint8_t c = addr->call[i]; + ASSERT(isalnum(c) || c == ' '); + c = toupper(c); + ax25_putchar(ctx, c << 1); + } + + /* Fill with spaces the rest of the CALL if it's shorter */ + if (len < sizeof(addr->call)) + for (unsigned i = 0; i < sizeof(addr->call) - len; i++) + ax25_putchar(ctx, ' ' << 1); + + /* The bit7 "has-been-repeated" flag is not implemented here */ + /* Bits6:5 should be set to 1 for all SSIDs (0x60) */ + /* The bit0 of last call SSID should be set to 1 */ + uint8_t ssid = 0x60 | (addr->ssid << 1) | (last ? 0x01 : 0); + ax25_putchar(ctx, ssid); +} + +/** + * Send an AX25 frame on the channel through a specific path. + * \param ctx AX25 context to operate on. + * \param path An array of callsigns used as path, \see AX25_PATH for + * an handy way to create a path. + * \param path_len callsigns path lenght. + * \param _buf payload buffer. + * \param len length of the payload. + */ +void ax25_sendVia(AX25Ctx *ctx, const AX25Call *path, size_t path_len, const void *_buf, size_t len) +{ + const uint8_t *buf = (const uint8_t *)_buf; + ASSERT(path); + ASSERT(path_len >= 2); + + ctx->crc_out = CRC_CCITT_INIT_VAL; + kfile_putc(HDLC_FLAG, ctx->ch); + + + /* Send call */ + for (size_t i = 0; i < path_len; i++) + ax25_sendCall(ctx, &path[i], (i == path_len - 1)); + + ax25_putchar(ctx, AX25_CTRL_UI); + ax25_putchar(ctx, AX25_PID_NOLAYER3); + + while (len--) + ax25_putchar(ctx, *buf++); + + /* + * According to AX25 protocol, + * CRC is sent in reverse order! + */ + uint8_t crcl = (ctx->crc_out & 0xff) ^ 0xff; + uint8_t crch = (ctx->crc_out >> 8) ^ 0xff; + ax25_putchar(ctx, crcl); + ax25_putchar(ctx, crch); + + ASSERT(ctx->crc_out == AX25_CRC_CORRECT); + + kfile_putc(HDLC_FLAG, ctx->ch); +} + +static void print_call(KFile *ch, const AX25Call *call) +{ + kfile_printf(ch, "%.6s", call->call); + if (call->ssid) + kfile_printf(ch, "-%d", call->ssid); +} + +/** + * Print a AX25 message in TNC-2 packet monitor format. + * \param ch a kfile channel where the message will be printed. + * \param msg the message to be printed. + */ +void ax25_print(KFile *ch, const AX25Msg *msg) +{ + print_call(ch, &msg->src); + kfile_putc('>', ch); + print_call(ch, &msg->dst); + + #if CONFIG_AX25_RPT_LST + for (int i = 0; i < msg->rpt_cnt; i++) + { + kfile_putc(',', ch); + print_call(ch, &msg->rpt_lst[i]); + /* Print a '*' if packet has already been transmitted + * by this repeater */ + if (AX25_REPEATED(msg, i)) + kfile_putc('*', ch); + } + #endif + + kfile_printf(ch, ":%.*s\n", msg->len, msg->info); +} + + +/** + * Init the AX25 protocol decoder. + * + * \param ctx AX25 context to init. + * \param channel Used to gain access to the physical medium + * \param hook Callback function called when a message is received + */ void ax25_init(AX25Ctx *ctx, KFile *channel, ax25_callback_t hook) { ASSERT(ctx);