+
+/*
+ * lcp_printpkt - print the contents of an LCP packet.
+ */
+static char *lcp_codenames[] = {
+ "ConfReq", "ConfAck", "ConfNak", "ConfRej",
+ "TermReq", "TermAck", "CodeRej", "ProtRej",
+ "EchoReq", "EchoRep", "DiscReq"
+};
+
+static int
+lcp_printpkt(p, plen, printer, arg)
+ u_char *p;
+ int plen;
+ void (*printer) __P((void *, char *, ...));
+ void *arg;
+{
+ int code, id, len, olen;
+ u_char *pstart, *optend;
+ u_short cishort;
+ u_int32_t cilong;
+
+ if (plen < HEADERLEN)
+ return 0;
+ pstart = p;
+ GETCHAR(code, p);
+ GETCHAR(id, p);
+ GETSHORT(len, p);
+ if (len < HEADERLEN || len > plen)
+ return 0;
+
+ if (code >= 1 && code <= sizeof(lcp_codenames) / sizeof(char *))
+ printer(arg, " %s", lcp_codenames[code-1]);
+ else
+ printer(arg, " code=0x%x", code);
+ printer(arg, " id=0x%x", id);
+ len -= HEADERLEN;
+ switch (code) {
+ case CONFREQ:
+ case CONFACK:
+ case CONFNAK:
+ case CONFREJ:
+ /* print option list */
+ while (len >= 2) {
+ GETCHAR(code, p);
+ GETCHAR(olen, p);
+ p -= 2;
+ if (olen < 2 || olen > len) {
+ break;
+ }
+ printer(arg, " <");
+ len -= olen;
+ optend = p + olen;
+ switch (code) {
+ case CI_MRU:
+ if (olen == CILEN_SHORT) {
+ p += 2;
+ GETSHORT(cishort, p);
+ printer(arg, "mru %d", cishort);
+ }
+ break;
+ case CI_ASYNCMAP:
+ if (olen == CILEN_LONG) {
+ p += 2;
+ GETLONG(cilong, p);
+ printer(arg, "asyncmap 0x%x", cilong);
+ }
+ break;
+ case CI_AUTHTYPE:
+ if (olen >= CILEN_SHORT) {
+ p += 2;
+ printer(arg, "auth ");
+ GETSHORT(cishort, p);
+ switch (cishort) {
+ case PPP_PAP:
+ printer(arg, "pap");
+ break;
+ case PPP_CHAP:
+ printer(arg, "chap");
+ break;
+ default:
+ printer(arg, "0x%x", cishort);
+ }
+ }
+ break;
+ case CI_QUALITY:
+ if (olen >= CILEN_SHORT) {
+ p += 2;
+ printer(arg, "quality ");
+ GETSHORT(cishort, p);
+ switch (cishort) {
+ case PPP_LQR:
+ printer(arg, "lqr");
+ break;
+ default:
+ printer(arg, "0x%x", cishort);
+ }
+ }
+ break;
+ case CI_CALLBACK:
+ if (olen >= CILEN_CHAR) {
+ p += 2;
+ printer(arg, "callback ");
+ GETSHORT(cishort, p);
+ switch (cishort) {
+ case CBCP_OPT:
+ printer(arg, "CBCP");
+ break;
+ default:
+ printer(arg, "0x%x", cishort);
+ }
+ }
+ break;
+ case CI_MAGICNUMBER:
+ if (olen == CILEN_LONG) {
+ p += 2;
+ GETLONG(cilong, p);
+ printer(arg, "magic 0x%x", cilong);
+ }
+ break;
+ case CI_PCOMPRESSION:
+ if (olen == CILEN_VOID) {
+ p += 2;
+ printer(arg, "pcomp");
+ }
+ break;
+ case CI_ACCOMPRESSION:
+ if (olen == CILEN_VOID) {
+ p += 2;
+ printer(arg, "accomp");
+ }
+ break;
+ }
+ while (p < optend) {
+ GETCHAR(code, p);
+ printer(arg, " %.2x", code);
+ }
+ printer(arg, ">");
+ }
+ break;
+
+ case TERMACK:
+ case TERMREQ:
+ if (len > 0 && *p >= ' ' && *p < 0x7f) {
+ printer(arg, " ");
+ print_string(p, len, printer, arg);
+ p += len;
+ len = 0;
+ }
+ break;
+
+ case ECHOREQ:
+ case ECHOREP:
+ case DISCREQ:
+ if (len >= 4) {
+ GETLONG(cilong, p);
+ printer(arg, " magic=0x%x", cilong);
+ p += 4;
+ len -= 4;
+ }
+ break;
+ }
+
+ /* print the rest of the bytes in the packet */
+ for (; len > 0; --len) {
+ GETCHAR(code, p);
+ printer(arg, " %.2x", code);
+ }
+
+ return p - pstart;
+}
+
+/*
+ * Time to shut down the link because there is nothing out there.
+ */
+
+static
+void LcpLinkFailure (f)
+ fsm *f;
+{
+ if (f->state == OPENED) {
+ syslog(LOG_INFO, "No response to %d echo-requests", lcp_echos_pending);
+ syslog(LOG_NOTICE, "Serial link appears to be disconnected.");
+ lcp_close(f->unit, "Peer not responding");
+ }
+}
+
+/*
+ * Timer expired for the LCP echo requests from this process.
+ */
+
+static void
+LcpEchoCheck (f)
+ fsm *f;
+{
+ LcpSendEchoRequest (f);
+
+ /*
+ * Start the timer for the next interval.
+ */
+ assert (lcp_echo_timer_running==0);
+ TIMEOUT (LcpEchoTimeout, f, lcp_echo_interval);
+ lcp_echo_timer_running = 1;
+}
+
+/*
+ * LcpEchoTimeout - Timer expired on the LCP echo
+ */
+
+static void
+LcpEchoTimeout (arg)
+ void *arg;
+{
+ if (lcp_echo_timer_running != 0) {
+ lcp_echo_timer_running = 0;
+ LcpEchoCheck ((fsm *) arg);
+ }
+}
+
+/*
+ * LcpEchoReply - LCP has received a reply to the echo
+ */
+
+static void
+lcp_received_echo_reply (f, id, inp, len)
+ fsm *f;
+ int id; u_char *inp; int len;
+{
+ u_int32_t magic;
+
+ /* Check the magic number - don't count replies from ourselves. */
+ if (len < 4) {
+ syslog(LOG_DEBUG, "lcp: received short Echo-Reply, length %d", len);
+ return;
+ }
+ GETLONG(magic, inp);
+ if (lcp_gotoptions[f->unit].neg_magicnumber
+ && magic == lcp_gotoptions[f->unit].magicnumber) {
+ syslog(LOG_WARNING, "appear to have received our own echo-reply!");
+ return;
+ }
+
+ /* Reset the number of outstanding echo frames */
+ lcp_echos_pending = 0;
+}
+
+/*
+ * LcpSendEchoRequest - Send an echo request frame to the peer
+ */
+
+static void
+LcpSendEchoRequest (f)
+ fsm *f;
+{
+ u_int32_t lcp_magic;
+ u_char pkt[4], *pktp;
+
+ /*
+ * Detect the failure of the peer at this point.
+ */
+ if (lcp_echo_fails != 0) {
+ if (lcp_echos_pending >= lcp_echo_fails) {
+ LcpLinkFailure(f);
+ lcp_echos_pending = 0;
+ }
+ }
+
+ /*
+ * Make and send the echo request frame.
+ */
+ if (f->state == OPENED) {
+ lcp_magic = lcp_gotoptions[f->unit].magicnumber;
+ pktp = pkt;
+ PUTLONG(lcp_magic, pktp);
+ fsm_sdata(f, ECHOREQ, lcp_echo_number++ & 0xFF, pkt, pktp - pkt);
+ ++lcp_echos_pending;
+ }
+}
+
+/*
+ * lcp_echo_lowerup - Start the timer for the LCP frame
+ */
+
+static void
+lcp_echo_lowerup (unit)
+ int unit;
+{
+ fsm *f = &lcp_fsm[unit];
+
+ /* Clear the parameters for generating echo frames */
+ lcp_echos_pending = 0;
+ lcp_echo_number = 0;
+ lcp_echo_timer_running = 0;
+
+ /* If a timeout interval is specified then start the timer */
+ if (lcp_echo_interval != 0)
+ LcpEchoCheck (f);
+}
+
+/*
+ * lcp_echo_lowerdown - Stop the timer for the LCP frame
+ */
+
+static void
+lcp_echo_lowerdown (unit)
+ int unit;
+{
+ fsm *f = &lcp_fsm[unit];
+
+ if (lcp_echo_timer_running != 0) {
+ UNTIMEOUT (LcpEchoTimeout, f);
+ lcp_echo_timer_running = 0;
+ }
+}