// ****** PRELIMINARY - needs work ****** #define DEBUG 1 // // This file is part of Dire Wolf, an amateur radio packet TNC. // #include "direwolf.h" #include #include #include #include #include #include #include #include #include #include "ax25_pad.h" #include "textcolor.h" #include "agwlib.h" // Network TNC interface. /*------------------------------------------------------------------ * * Module: appserver.c * * Purpose: Simple application server for connected mode AX.25. * * This demonstrates how you can write a application that will wait for * a connection from another station and respond to commands. * It can be used as a starting point for developing your own applications. * * Description: This attaches to an instance of Dire Wolf via the AGW network interface. * It processes commands from other radio stations and responds. * *---------------------------------------------------------------*/ static void usage() { text_color_set(DW_COLOR_ERROR); dw_printf ("Usage: \n"); dw_printf (" \n"); dw_printf ("appserver [ -h hostname ] [ -p port ] mycall \n"); dw_printf (" \n"); dw_printf (" -h hostname for TNC. Default is localhost. \n"); dw_printf (" \n"); dw_printf (" -p tcp port for TNC. Default is 8000. \n"); dw_printf (" \n"); dw_printf (" mycall is required because that is the callsign for \n"); dw_printf (" which the TNC will accept connections. \n"); dw_printf (" \n"); exit (EXIT_FAILURE); } static char mycall[AX25_MAX_ADDR_LEN]; /* Callsign, with SSID, for the application. */ /* Future? Could have multiple applications, on the same */ /* radio channel, each with its own SSID. */ static char tnc_hostname[80]; /* DNS host name or IPv4 address. */ /* Some of the code is there for IPv6 but */ /* needs more work. */ /* Defaults to "localhost" if not specified. */ static char tnc_port[8]; /* a TCP port number. Default 8000. */ /* * Maintain information about connections from users which we will call "sessions." * It should be possible to have multiple users connected at the same time. * * This allows a "who" command to see who is currently connected and a place to keep * possible state information for each user. * * Each combination of channel & callsign is a separate session. * The same user (callsign), on a different channel, is a different session. */ struct session_s { char client_addr[AX25_MAX_ADDR_LEN]; // Callsign of other station. // Clear to mean this table entry is not in use. int channel; // Radio channel. time_t login_time; // Time when connection established. // For the timing test. // Send specified number of frames, optional length. // When finished summarize with statistics. time_t tt_start_time; volatile int tt_count; // Number to send. int tt_length; // Bytes in info part. int tt_next; // Next sequence to send. volatile int tx_queue_len; // Number in transmit queue. For flow control. }; #define MAX_SESSIONS 12 static struct session_s session[MAX_SESSIONS]; static int find_session (int chan, char *addr, int create); static void poll_timing_test (void); /*------------------------------------------------------------------ * * Name: main * * Purpose: Attach to Dire Wolf TNC, wait for requests from users. * * Usage: Described above. * *---------------------------------------------------------------*/ int main (int argc, char *argv[]) { int c; char *p; #if __WIN32__ setvbuf(stdout, NULL, _IONBF, 0); #else setlinebuf (stdout); #endif memset (session, 0, sizeof(session)); strlcpy (tnc_hostname, "localhost", sizeof(tnc_hostname)); strlcpy (tnc_port, "8000", sizeof(tnc_port)); /* * Extract command line args. */ while ((c = getopt (argc, argv, "h:p:")) != -1) { switch (c) { case 'h': strlcpy (tnc_hostname, optarg, sizeof(tnc_hostname)); break; case 'p': strlcpy (tnc_port, optarg, sizeof(tnc_port)); break; default: usage (); } } if (argv[optind] == NULL) { usage (); } strlcpy (mycall, argv[optind], sizeof(mycall)); // Force to upper case. for (p = mycall; *p != '\0'; p++) { if (islower(*p)) { *p = toupper(*p); } } /* * Establish a TCP socket to the network TNC. * It starts up a thread, which listens for messages from the TNC, * and calls the corresponding agw_cb_... callback functions. * * After attaching to the TNC, the specified init function is called. * We pass it to the library, rather than doing it here, so it can * repeated automatically if the TNC goes away and comes back again. * We need to reestablish what it knows about the application. */ if (agwlib_init (tnc_hostname, tnc_port, agwlib_G_ask_port_information) != 0) { text_color_set(DW_COLOR_ERROR); dw_printf ("Could not attach to network TNC %s:%s.\n", tnc_hostname, tnc_port); exit (EXIT_FAILURE); } /* * Send command to ask what channels are available. * The response will be handled by agw_cb_G_port_information. */ // FIXME: Need to do this again if we lose TNC and reattach to it. /// should happen automatically now. agwlib_G_ask_port_information (); while (1) { SLEEP_SEC(1); // other places based on 1 second assumption. poll_timing_test (); } } /* end main */ static void poll_timing_test (void) { int s; for (s = 0; s < MAX_SESSIONS; s++) { if (session[s].tt_count == 0) { continue; // nothing to do } else if (session[s].tt_next <= session[s].tt_count) { int rem = session[s].tt_count - session[s].tt_next + 1; // remaining to send. agwlib_Y_outstanding_frames_for_station (session[s].channel, mycall, session[s].client_addr); SLEEP_MS(10); if (session[s].tx_queue_len > 128) continue; // enough queued up for now. if (rem > 64) rem = 64; // add no more than 64 at a time. int i; for (i = 0; i < rem; i++) { char c = 'a'; char stuff[AX25_MAX_INFO_LEN+2]; snprintf (stuff, sizeof(stuff), "%06d ", session[s].tt_next); int k; for (k = strlen(stuff); k < session[s].tt_length - 1; k++) { stuff[k] = c; c++; if (c == 'z' + 1) c = 'A'; if (c == 'Z' + 1) c = '0'; if (c == '9' + 1) c = 'a'; } stuff[k++] = '\r'; stuff[k++] = '\0'; agwlib_D_send_connected_data (session[s].channel, 0xF0, mycall, session[s].client_addr, strlen(stuff), stuff); session[s].tt_next++; } } else { // All done queuing up the packets. // Wait until they have all been sent and ack'ed by other end. agwlib_Y_outstanding_frames_for_station (session[s].channel, mycall, session[s].client_addr); SLEEP_MS(10); if (session[s].tx_queue_len > 0) continue; // not done yet. int elapsed = time(NULL) - session[s].tt_start_time; if (elapsed <= 0) elapsed = 1; // avoid divide by 0 int byte_count = session[s].tt_count * session[s].tt_length; char summary[100]; snprintf (summary, sizeof(summary), "%d bytes in %d seconds, %d bytes/sec, efficiency %d%% at 1200, %d%% at 9600.\r", byte_count, elapsed, byte_count/elapsed, byte_count * 8 * 100 / elapsed / 1200, byte_count * 8 * 100 / elapsed / 9600); agwlib_D_send_connected_data (session[s].channel, 0xF0, mycall, session[s].client_addr, strlen(summary), summary); session[s].tt_count = 0; // all done. } } } // end poll_timing_test /*------------------------------------------------------------------- * * Name: agw_cb_C_connection_received * * Purpose: Callback for the "connection received" command from the TNC. * * Inputs: chan - Radio channel, first is 0. * * call_from - Address of other station. * * call_to - Callsign I responded to. (could be an alias.) * * data_len - Length of data field. * * data - Should look something like this for incoming: * *** CONNECTED to Station xxx\r * * Description: Add to the sessions table. * *--------------------------------------------------------------------*/ /*------------------------------------------------------------------- * * Name: on_C_connection_received * * Purpose: Callback for the "connection received" command from the TNC. * * Inputs: chan - Radio channel, first is 0. * * call_from - Address of other station. * * call_to - My call. * In the case of an incoming connect request (i.e. to * a server) this is the callsign I responded to. * It is possible to define additional aliases and respond * to any one of them. It would be possible to have a server * that responds to multiple names and behaves differently * depending on the name. * * incoming - true(1) if other station made connect request. * false(0) if I made request and other statio accepted. * * data - Should look something like this for incoming: * *** CONNECTED to Station xxx\r * and this for my request being accepted: * *** CONNECTED With Station xxx\r * * session_id - Session id to be used in data transfer and * other control functions related to this connection. * Think of it like a file handle. Once it is open * we usually don't care about the name anymore and * and just refer to the handle. This is used to * keep track of multiple connections at the same * time. e.g. a server could be handling multiple * clients at once on the same or different channels. * * Description: Add to the table of clients. * *--------------------------------------------------------------------*/ // old void agw_cb_C_connection_received (int chan, char *call_from, char *call_to, int data_len, char *data) void on_C_connection_received (int chan, char *call_from, char *call_to, int incoming, char *data) { int s; char *p; char greeting[256]; for (p = data; *p != '\0'; p++) { if (! isprint(*p)) *p = '\0'; // Remove any \r character at end. } s = find_session (chan, call_from, 1); if (s >= 0) { text_color_set(DW_COLOR_INFO); dw_printf ("Begin session %d: %s\n", s, data); // Send greeting. snprintf (greeting, sizeof(greeting), "Welcome! Type ? for list of commands or HELP for details.\r"); agwlib_D_send_connected_data (chan, 0xF0, mycall, call_from, strlen(greeting), greeting); } else { text_color_set(DW_COLOR_INFO); dw_printf ("Too many users already: %s\n", data); // Sorry, too many users already. snprintf (greeting, sizeof(greeting), "Sorry, maximum number of users has been exceeded. Try again later.\r"); agwlib_D_send_connected_data (chan, 0xF0, mycall, call_from, strlen(greeting), greeting); // FIXME: Ideally we'd want to wait until nothing in the outgoing queue // to that station so we know the rejection message was received. SLEEP_SEC (10); agwlib_d_disconnect (chan, mycall, call_from); } } /* end agw_cb_C_connection_received */ /*------------------------------------------------------------------- * * Name: agw_cb_d_disconnected * * Purpose: Process the "disconnected" command from the TNC. * * Inputs: chan - Radio channel. * * call_from - Address of other station. * * call_to - Callsign I responded to. (could be aliases.) * * data_len - Length of data field. * * data - Should look something like one of these: * *** DISCONNECTED RETRYOUT With xxx\r * *** DISCONNECTED From Station xxx\r * * Description: Remove from the sessions table. * *--------------------------------------------------------------------*/ void agw_cb_d_disconnected (int chan, char *call_from, char *call_to, int data_len, char *data) { int s; char *p; s = find_session (chan, call_from, 0); for (p = data; *p != '\0'; p++) { if (! isprint(*p)) *p = '\0'; // Remove any \r character at end. } text_color_set(DW_COLOR_INFO); dw_printf ("End session %d: %s\n", s, data); // Remove from session table. if (s >= 0) { memset (&(session[s]), 0, sizeof(struct session_s)); } } /* end agw_cb_d_disconnected */ /*------------------------------------------------------------------- * * Name: agw_cb_D_connected_data * * Purpose: Process "connected ax.25 data" from the TNC. * * Inputs: chan - Radio channel. * * addr - Address of other station. * * msg - What the user sent us. Probably a command. * * Global In: tnc_sock - Socket for TNC. * * Description: Remove from the session table. * *--------------------------------------------------------------------*/ void agw_cb_D_connected_data (int chan, char *call_from, char *call_to, int data_len, char *data) { int s; char *p; char logit[AX25_MAX_INFO_LEN+100]; char *pcmd; char *save; s = find_session (chan, call_from, 0); for (p = data; *p != '\0'; p++) { if (! isprint(*p)) *p = '\0'; // Remove any \r character at end. } // TODO: Should timestamp to all output. snprintf (logit, sizeof(logit), "%d,%d,%s: %s\n", s, chan, call_from, data); text_color_set(DW_COLOR_INFO); dw_printf ("%s", logit); if (s < 0) { // Uh oh. Data from some station when not connected. text_color_set(DW_COLOR_ERROR); dw_printf ("Internal error. Incoming data, no corresponding session.\n"); return; } // Process the command from user. pcmd = strtok_r (data, " ", &save); if (pcmd == NULL || strlen(pcmd) == 0) { char greeting[80]; strlcpy (greeting, "Type ? for list of commands or HELP for details.\r", sizeof(greeting)); agwlib_D_send_connected_data (chan, 0xF0, mycall, call_from, strlen(greeting), greeting); return; } if (strcasecmp(pcmd, "who") == 0) { // who - list people currently logged in. int n; char greeting[128]; snprintf (greeting, sizeof(greeting), "Session Channel User Since\r"); agwlib_D_send_connected_data (chan, 0xF0, mycall, call_from, strlen(greeting), greeting); for (n = 0; n < MAX_SESSIONS; n++) { if (session[n].client_addr[0]) { // I think compiler is confused. It says up to 520 characters can be written. #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wformat-truncation" snprintf (greeting, sizeof(greeting), " %2d %d %-9s [time later]\r", n, session[n].channel, session[n].client_addr); #pragma GCC diagnostic pop agwlib_D_send_connected_data (chan, 0xF0, mycall, call_from, strlen(greeting), greeting); } } } else if (strcasecmp(pcmd, "test") == 0) { // test - timing test // Send specified number of frames with optional length. char *pcount = strtok_r (NULL, " ", &save); char *plength = strtok_r (NULL, " ", &save); session[s].tt_start_time = time(NULL); session[s].tt_next = 1; session[s].tt_length = 256; session[s].tt_count = 1; if (plength != NULL) { session[s].tt_length = atoi(plength); if (session[s].tt_length < 16) session[s].tt_length = 16; if (session[s].tt_length > AX25_MAX_INFO_LEN) session[s].tt_length = AX25_MAX_INFO_LEN; } if (pcount != NULL) { session[s].tt_count = atoi(pcount); } // The background polling will take it from here. } else if (strcasecmp(pcmd, "bye") == 0) { // bye - disconnect. char greeting[80]; strlcpy (greeting, "Thank you folks for kindly droppin' in. Y'all come on back now, ya hear?\r", sizeof(greeting)); agwlib_D_send_connected_data (chan, 0xF0, mycall, call_from, strlen(greeting), greeting); // Ideally we'd want to wait until nothing in the outgoing queue // to that station so we know the message was received. SLEEP_SEC (10); agwlib_d_disconnect (chan, mycall, call_from); } else if (strcasecmp(pcmd, "help") == 0 || strcasecmp(pcmd, "?") == 0) { // help. char greeting[80]; strlcpy (greeting, "Help not yet available.\r", sizeof(greeting)); agwlib_D_send_connected_data (chan, 0xF0, mycall, call_from, strlen(greeting), greeting); } else { // command not recognized. char greeting[80]; strlcpy (greeting, "Invalid command. Type ? for list of commands or HELP for details.\r", sizeof(greeting)); agwlib_D_send_connected_data (chan, 0xF0, mycall, call_from, strlen(greeting), greeting); } } /* end agw_cb_D_connected_data */ /*------------------------------------------------------------------- * * Name: agw_cb_G_port_information * * Purpose: Process the port information "radio channels available" response from the TNC. * * * Inputs: num_chan_avail - Number of radio channels available. * * chan_descriptions - Array of string pointers to form "Port99 description". * Port1 is channel 0. * *--------------------------------------------------------------------*/ void agw_cb_G_port_information (int num_chan_avail, char *chan_descriptions[]) { char *p; int n; text_color_set(DW_COLOR_INFO); dw_printf("TNC has %d radio channel%s available:\n", num_chan_avail, (num_chan_avail != 1) ? "s" : ""); for (n = 0; n < num_chan_avail; n++) { p = chan_descriptions[n]; // Expecting something like this: "Port1 first soundcard mono" if (strncasecmp(p, "Port", 4) == 0 && isdigit(p[4])) { int chan = atoi(p+4) - 1; // "Port1" is our channel 0. if (chan >= 0 && chan < MAX_CHANS) { char *desc = p + 4; while (*desc != '\0' && (*desc == ' ' || isdigit(*desc))) { desc++; } text_color_set(DW_COLOR_INFO); dw_printf(" Channel %d: %s\n", chan, desc); // Later? Use 'g' to get speed and maybe other properties? // Though I'm not sure why we would care here. /* * Send command to register my callsign for incoming connect requests. */ agwlib_X_register_callsign (chan, mycall); } else { text_color_set(DW_COLOR_ERROR); dw_printf("Radio channel number is out of bounds: %s\n", p); } } else { text_color_set(DW_COLOR_ERROR); dw_printf("Radio channel description not in expected format: %s\n", p); } } } /* end agw_cb_G_port_information */ /*------------------------------------------------------------------- * * Name: agw_cb_Y_outstanding_frames_for_station * * Purpose: Process the "disconnected" command from the TNC. * * Inputs: chan - Radio channel. * * call_from - Should be my call. * * call_to - Callsign of other station. * * frame_count * * Description: Remove from the sessions table. * *--------------------------------------------------------------------*/ void agw_cb_Y_outstanding_frames_for_station (int chan, char *call_from, char *call_to, int frame_count) { int s; s = find_session (chan, call_to, 0); text_color_set(DW_COLOR_DEBUG); // FIXME temporary dw_printf ("debug ----------------------> session %d, callback Y outstanding frame_count %d\n", s, frame_count); // Update the transmit queue length if (s >= 0) { session[s].tx_queue_len = frame_count; } else { text_color_set(DW_COLOR_ERROR); dw_printf ("Oops! Did not expect to be here.\n"); } } /* end agw_cb_Y_outstanding_frames_for_station */ /*------------------------------------------------------------------- * * Name: find_session * * Purpose: Given a channel number and address (callsign), find existing * table entry or create a new one. * * Inputs: chan - Radio channel number. * * addr - Address of station contacting us. * * create - If true, try create a new entry if not already there. * * Returns: "session id" which is an index into "session" array or -1 for failure. * *--------------------------------------------------------------------*/ static int find_session (int chan, char *addr, int create) { int i; int s = -1; // Is it there already? //#if DEBUG // // text_color_set(DW_COLOR_DEBUG); // dw_printf("find_session (%d, %s, %d)\n", chan, addr, create); //#endif for (i = 0; i < MAX_SESSIONS; i++) { if (session[i].channel == chan && strcmp(session[i].client_addr, addr) == 0) { s = i; break; } } if (s >= 0) return (s); if (! create) return (-1); // No, and there is a request to add a new entry. // See if we have any available space. s = -1; for (i = 0; i < MAX_SESSIONS; i++) { if (strlen(session[i].client_addr) == 0) { s = i; break; } } if (s < 0) return (-1); strlcpy (session[s].client_addr, addr, sizeof(session[s].client_addr)); session[s].channel = chan; session[s].login_time = time(NULL); return (s); } /* end find_session */ /* end appserver.c */