TMXR: Added option to use UDP transport for packet transport

README.md

@@ -68,6 +68,7 @@ A remote console session will close when an EOF character is entered (i.e. ^D or
     Serial Console Support
     Separate TCP listening ports per line
     Outgoing connections per line (virtual Null Modem cable).
+    Packet sending and reception semantics for simulated network device support using either TCP or UDP transport.
 
 #### Asynchronous I/O
     * Disk and Tape I/O can be asynchronous.  Asynchronous support exists 

sim_sock.c

@@ -69,6 +69,8 @@
 /* OS dependent routines
 
    sim_master_sock      create master socket
+   sim_connect_sock     connect a socket to a remote destination
+   sim_connect_sock_ex  connect a socket to a remote destination
    sim_accept_conn      accept connection
    sim_read_sock        read from socket
    sim_write_sock       write from socket
@@ -99,6 +101,11 @@ SOCKET sim_connect_sock (const char *hostport, const char *default_host, const c
 return INVALID_SOCKET;
 }
 
+SOCKET sim_connect_sock_ex (const char *sourcehostport, const char *hostport, const char *default_host, const char *default_port, t_bool datagram)
+{
+return INVALID_SOCKET;
+}
+
 SOCKET sim_accept_conn (SOCKET master, char **connectaddr);
 {
 return INVALID_SOCKET;
@@ -710,12 +717,12 @@ return 0;
 
 #endif                                                  /* endif !Win32 && !VMS */
 
-static SOCKET sim_create_sock (int af)
+static SOCKET sim_create_sock_ex (int af, t_bool datagram)
 {
 SOCKET newsock;
 int32 err;
 
-newsock = socket (af, SOCK_STREAM, 0);                  /* create socket */
+newsock = socket (af, (datagram ? SOCK_DGRAM : SOCK_STREAM), 0);/* create socket */
 if (newsock == INVALID_SOCKET) {                        /* socket error? */
     err = WSAGetLastError ();
 #if defined(WSAEAFNOSUPPORT)
@@ -727,6 +734,11 @@ if (newsock == INVALID_SOCKET) {                        /* socket error? */
 return newsock;
 }
 
+static SOCKET sim_create_sock (int af)
+{
+return sim_create_sock_ex (af, FALSE);
+}
+
 /*
    Some platforms and/or network stacks have varying support for listening on 
    an IPv6 socket and receiving connections from both IPv4 and IPv6 client 
@@ -823,28 +835,71 @@ return newsock;                                         /* got it! */
 
 SOCKET sim_connect_sock (const char *hostport, const char *default_host, const char *default_port)
 {
+return sim_connect_sock_ex (NULL, hostport, default_host, default_port, FALSE);
+}
+
+SOCKET sim_connect_sock_ex (const char *sourcehostport, const char *hostport, const char *default_host, const char *default_port, t_bool datagram)
+{
 SOCKET newsock = INVALID_SOCKET;
 int32 sta;
 char host[CBUFSIZE], port[CBUFSIZE];
 t_stat r;
 struct addrinfo hints;
-struct addrinfo *result = NULL;
+struct addrinfo *result = NULL, *source = NULL;
 
 r = sim_parse_addr (hostport, host, sizeof(host), default_host, port, sizeof(port), default_port, NULL);
 if (r != SCPE_OK)
-    return newsock;
+    return INVALID_SOCKET;
 
 memset(&hints, 0, sizeof(hints));
 hints.ai_family = AF_UNSPEC;
-hints.ai_protocol = IPPROTO_TCP;
+hints.ai_protocol = (datagram ? IPPROTO_UDP : IPPROTO_TCP);
-hints.ai_socktype = SOCK_STREAM;
+hints.ai_socktype = (datagram ? SOCK_DGRAM : SOCK_STREAM);
 if (p_getaddrinfo(host[0] ? host : NULL, port[0] ? port : NULL, &hints, &result))
+    return INVALID_SOCKET;
+
+if (sourcehostport) {
+
+    /* Validate the local/source side address which we'll bind to */
+    r = sim_parse_addr (sourcehostport, host, sizeof(host), NULL, port, sizeof(port), NULL, NULL);
+    if (r != SCPE_OK) {
+        p_freeaddrinfo (result);
+        return INVALID_SOCKET;
+        }
+
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_flags = AI_PASSIVE;
+    hints.ai_family = result->ai_family;                /* Same family as connect destination */
+    hints.ai_protocol = (datagram ? IPPROTO_UDP : IPPROTO_TCP);
+    hints.ai_socktype = (datagram ? SOCK_DGRAM : SOCK_STREAM);
+    if (p_getaddrinfo(host[0] ? host : NULL, port[0] ? port : NULL, &hints, &source)) {
+        p_freeaddrinfo (result);
+        return INVALID_SOCKET;
+        }
+
+    newsock = sim_create_sock_ex (result->ai_family, datagram);/* create socket */
+    if (newsock == INVALID_SOCKET) {                    /* socket error? */
+        p_freeaddrinfo (result);
+        p_freeaddrinfo (source);
         return newsock;
-newsock = sim_create_sock (result->ai_family);          /* create socket */
+        }
+
+    sta = bind (newsock, source->ai_addr, source->ai_addrlen);
+    p_freeaddrinfo(source);
+    source = NULL;
+    if (sta == SOCKET_ERROR) {                          /* bind error? */
+        p_freeaddrinfo (result);
+        return sim_err_sock (newsock, "bind", 1);
+        }
+    }
+
 if (newsock == INVALID_SOCKET) {                        /* socket error? */
+    newsock = sim_create_sock_ex (result->ai_family, datagram);/* create socket */
+    if (newsock == INVALID_SOCKET) {                    /* socket error? */
         p_freeaddrinfo (result);
         return newsock;
         }
+    }
 
 sta = sim_setnonblock (newsock);                        /* set nonblocking */
 if (sta == SOCKET_ERROR) {                              /* fcntl error? */

sim_sock.h

@@ -104,6 +104,7 @@
 t_stat sim_parse_addr (const char *cptr, char *host, size_t hostlen, const char *default_host, char *port, size_t port_len, const char *default_port, const char *validate_addr);
 SOCKET sim_master_sock (const char *hostport, t_stat *parse_status);
 SOCKET sim_connect_sock (const char *hostport, const char *default_host, const char *default_port);
+SOCKET sim_connect_sock_ex (const char *sourcehostport, const char *hostport, const char *default_host, const char *default_port, t_bool datagram);
 SOCKET sim_accept_conn (SOCKET master, char **connectaddr);
 int32 sim_check_conn (SOCKET sock, t_bool rd);
 int32 sim_read_sock (SOCKET sock, char *buf, int32 nbytes);

sim_tmxr.c

@@ -862,6 +862,10 @@ if (lp->destination || lp->port || lp->txlogname) {
         sprintf (growstring(&tptr, 32), ",Buffered=%d", lp->txbsz);
     if (!lp->txbfd && (lp->mp->buffered > 0))
         sprintf (growstring(&tptr, 32), ",UnBuffered");
+    if (lp->mp->datagram != lp->datagram)
+        sprintf (growstring(&tptr, 8), ",%s", lp->datagram ? "UDP" : "TCP");
+    if (lp->port)
+        sprintf (growstring(&tptr, 12 + strlen (lp->port)), ",%s%s", lp->port, ((lp->mp->notelnet != lp->notelnet) && (!lp->datagram)) ? (lp->notelnet ? ";notelnet" : ";telnet") : "");
     if (lp->destination) {
         if (lp->serport) {
             char portname[CBUFSIZE];
@@ -870,10 +874,8 @@ if (lp->destination || lp->port || lp->txlogname) {
             sprintf (growstring(&tptr, 25 + strlen (lp->destination)), ",Connect=%s%s%s", portname, strcmp("9600-8N1", lp->serconfig) ? ";" : "", strcmp("9600-8N1", lp->serconfig) ? lp->serconfig : "");
             }
         else
-            sprintf (growstring(&tptr, 25 + strlen (lp->destination)), ",Connect=%s%s", lp->destination, (lp->mp->notelnet != lp->notelnet) ? (lp->notelnet ? ";notelnet" : ";telnet") : "");
+            sprintf (growstring(&tptr, 25 + strlen (lp->destination)), ",Connect=%s%s", lp->destination, ((lp->mp->notelnet != lp->notelnet) && (!lp->datagram)) ? (lp->notelnet ? ";notelnet" : ";telnet") : "");
         }
-    if (lp->port)
-        sprintf (growstring(&tptr, 12 + strlen (lp->port)), ",%s%s", lp->port, (lp->mp->notelnet != lp->notelnet) ? (lp->notelnet ? ";notelnet" : ";telnet") : "");
     if (lp->txlogname)
         sprintf (growstring(&tptr, 12 + strlen (lp->txlogname)), ",Log=%s", lp->txlogname);
     if (lp->loopback)
@@ -1136,7 +1138,7 @@ for (i = 0; i < mp->lines; i++) {                       /* check each line in se
         (!lp->modem_control || (lp->modembits & TMXR_MDM_DTR))) {
         sprintf (msg, "tmxr_poll_conn() - establishing outgoing connection to: %s", lp->destination);
         tmxr_debug_connect_line (lp, msg);
-        lp->connecting = sim_connect_sock (lp->destination, "localhost", NULL);
+        lp->connecting = sim_connect_sock_ex (lp->datagram ? lp->port : NULL, lp->destination, "localhost", NULL, lp->datagram);
         }
 
     }
@@ -1204,7 +1206,7 @@ if ((lp->destination) && (!lp->serport)) {
     if ((!lp->modem_control) || (lp->modembits & TMXR_MDM_DTR)) {
         sprintf (msg, "tmxr_reset_ln_ex() - connecting to %s", lp->destination);
         tmxr_debug_connect_line (lp, msg);
-        lp->connecting = sim_connect_sock (lp->destination, "localhost", NULL);
+        lp->connecting = sim_connect_sock_ex (lp->datagram ? lp->port : NULL, lp->destination, "localhost", NULL, lp->datagram);
         }
     }
 tmxr_init_line (lp);                                /* initialize line state */
@@ -1382,7 +1384,7 @@ if (lp->mp && lp->modem_control) {                  /* This API ONLY works on mo
 
                 sprintf (msg, "tmxr_set_get_modem_bits() - establishing outgoing connection to: %s", lp->destination);
                 tmxr_debug_connect_line (lp, msg);
-                lp->connecting = sim_connect_sock (lp->destination, "localhost", NULL);
+                lp->connecting = sim_connect_sock_ex (lp->datagram ? lp->port : NULL, lp->destination, "localhost", NULL, lp->datagram);
                 }
             }
         }
@@ -1900,6 +1902,8 @@ if (nbytes) {                                           /* >0? write */
             lp->txbpr = 0;
         lp->txcnt = lp->txcnt + sbytes;                 /* update counts */
         nbytes = nbytes - sbytes;
+        if ((nbytes == 0) && (lp->datagram))            /* if Empty buffer on datagram line */
+            lp->txbpi = lp->txbpr = 0;                  /* Start next packet at beginning of buffer */
         }
     if (sbytes < 0) {                                   /* I/O Error? */
         lp->txbpi = lp->txbpr = 0;                      /* Drop the data we already know we can't send */
@@ -2012,7 +2016,7 @@ char tbuf[CBUFSIZE], listen[CBUFSIZE], destination[CBUFSIZE],
 SOCKET sock;
 SERHANDLE serport;
 char *tptr = cptr;
-t_bool nolog, notelnet, listennotelnet, unbuffered, modem_control, loopback;
+t_bool nolog, notelnet, listennotelnet, unbuffered, modem_control, loopback, datagram;
 TMLN *lp;
 t_stat r = SCPE_ARG;
 
@@ -2031,6 +2035,7 @@ while (*tptr) {
     memset(port,        '\0', sizeof(port));
     memset(option,      '\0', sizeof(option));
     nolog = notelnet = listennotelnet = unbuffered = loopback = FALSE;
+    datagram = mp->datagram;
     if (line != -1)
         notelnet = listennotelnet = mp->notelnet;
     modem_control = mp->modem_control;
@@ -2100,6 +2105,18 @@ while (*tptr) {
                 modem_control = TRUE;
                 continue;
                 }
+            if ((0 == MATCH_CMD (gbuf, "DATAGRAM")) || (0 == MATCH_CMD (gbuf, "UDP"))) {
+                if ((NULL != cptr) && ('\0' != *cptr))
+                    return SCPE_2MARG;
+                notelnet = datagram = TRUE;
+                continue;
+                }
+            if ((0 == MATCH_CMD (gbuf, "STREAM")) || (0 == MATCH_CMD (gbuf, "TCP"))) {
+                if ((NULL != cptr) && ('\0' != *cptr))
+                    return SCPE_2MARG;
+                datagram = FALSE;
+                continue;
+                }
             if (0 == MATCH_CMD (gbuf, "CONNECT")) {
                 if ((NULL == cptr) || ('\0' == *cptr))
                     return SCPE_ARG;
@@ -2114,21 +2131,24 @@ while (*tptr) {
                     strncpy (hostport, cptr, sizeof(hostport)-1);
                     if ((cptr = strchr (hostport, ';')))
                         *(cptr++) = '\0';
-                    sock = sim_connect_sock (hostport, "localhost", NULL);
-                    if (sock != INVALID_SOCKET)
-                        sim_close_sock (sock, 0);
-                    else
-                        return SCPE_ARG;
                     if (cptr) {
                         get_glyph (cptr, cptr, 0);          /* upcase this string */
                         if (0 == MATCH_CMD (cptr, "NOTELNET"))
                             notelnet = TRUE;
                         else
                             if (0 == MATCH_CMD (cptr, "TELNET"))
+                                if (datagram)
+                                    return SCPE_ARG;
+                                else
                                     notelnet = FALSE;
                             else
                                 return SCPE_ARG;
                         }
+                    sock = sim_connect_sock_ex (NULL, hostport, "localhost", NULL, datagram);
+                    if (sock != INVALID_SOCKET)
+                        sim_close_sock (sock, 0);
+                    else
+                        return SCPE_ARG;
                     cptr = hostport;
                     }
                 strcpy(destination, cptr);
@@ -2231,7 +2251,7 @@ while (*tptr) {
                     }
                 }
             }
-        if (listen[0]) {
+        if ((listen[0]) && (!datagram)) {
             sock = sim_master_sock (listen, &r);            /* make master socket */
             if (r != SCPE_OK)
                 return r;
@@ -2306,7 +2326,16 @@ while (*tptr) {
                     }
                 }
             else {
-                sock = sim_connect_sock (destination, "localhost", NULL);
+                lp->datagram = datagram;
+                if (datagram) {
+                    if (listen[0]) {
+                        lp->port = (char *)realloc (lp->port, 1 + strlen (listen));
+                        strcpy(lp->port, listen);           /* save port */
+                        }
+                    else
+                        return SCPE_ARG;
+                    }
+                sock = sim_connect_sock_ex (datagram ? listen : NULL, destination, "localhost", NULL, datagram);
                 if (sock != INVALID_SOCKET) {
                     _mux_detach_line (lp, FALSE, TRUE);
                     lp->destination = (char *)malloc(1+strlen(destination));
@@ -2370,7 +2399,7 @@ while (*tptr) {
                 lp->txlog = NULL;
                 }
             }
-        if (listen[0]) {
+        if ((listen[0]) && (!datagram)) {
             if ((mp->lines == 1) && (mp->master))           /* single line mux can have either line specific OR mux listener but NOT both */
                 return SCPE_ARG;
             sock = sim_master_sock (listen, &r);            /* make master socket */
@@ -2409,7 +2438,16 @@ while (*tptr) {
                     }
                 }
             else {
-                sock = sim_connect_sock (destination, "localhost", NULL);
+                lp->datagram = datagram;
+                if (datagram) {
+                    if (listen[0]) {
+                        lp->port = (char *)realloc (lp->port, 1 + strlen (listen));
+                        strcpy(lp->port, listen);           /* save port */
+                        }
+                    else
+                        return SCPE_ARG;
+                    }
+                sock = sim_connect_sock_ex (datagram ? listen : NULL, destination, "localhost", NULL, datagram);
                 if (sock != INVALID_SOCKET) {
                     _mux_detach_line (lp, FALSE, TRUE);
                     lp->destination = (char *)malloc(1+strlen(destination));
@@ -3673,6 +3711,9 @@ if (ln >= 0)
 
 if ((lp->sock) || (lp->connecting)) {                   /* tcp connection? */
     if (lp->destination)                                /* remote connection? */
+        if (lp->datagram)
+            fprintf (st, "Datagram Connection from %s to remote port %s\n", lp->port, lp->destination);/* print port name */
+        else
             fprintf (st, "Connection to remote port %s\n", lp->destination);/* print port name */
     else                                                /* incoming connection */
         fprintf (st, "Connection from IP address %s\n", lp->ipad);
@@ -3689,7 +3730,7 @@ if (lp->sock) {
     free (peername);
     }
 
-if (lp->port)
+if ((lp->port) && (!lp->datagram))
     fprintf (st, "Listening on port %s\n", lp->port);   /* print port name */
 
 if (lp->serport)                                        /* serial connection? */

sim_tmxr.h

@@ -114,7 +114,7 @@ struct tmln {
     int32               tsta;                           /* Telnet state */
     int32               rcve;                           /* rcv enable */
     int32               xmte;                           /* xmt enable */
-    int32               dstb;                           /* disable Tlnt bin */
+    int32               dstb;                           /* disable Telnet binary mode */
     t_bool              notelnet;                       /* raw binary data (no telnet interpretation) */
     int32               rxbpr;                          /* rcv buf remove */
     int32               rxbpi;                          /* rcv buf insert */
@@ -151,6 +151,7 @@ struct tmln {
     char                *destination;                   /* Outgoing destination address:port */
     t_bool              loopback;                       /* Line in loopback mode */
     t_bool              halfduplex;                     /* Line in half-duplex mode */
+    t_bool              datagram;                       /* Line is datagram packet oriented */
     int32               lpbpr;                          /* loopback buf remove */
     int32               lpbpi;                          /* loopback buf insert */
     int32               lpbcnt;                         /* loopback buf used count */
@@ -176,6 +177,7 @@ struct tmxr {
     uint32              last_poll_time;                 /* time of last connection poll */
     t_bool              notelnet;                       /* default telnet capability for incoming connections */
     t_bool              modem_control;                  /* multiplexer supports modem control behaviors */
+    t_bool              datagram;                       /* Lines are datagram packet oriented */
     };
 
 int32 tmxr_poll_conn (TMXR *mp);