+/********************************************************************
+ *
+ * get_loop_output - get outgoing packets from the ppp device,
+ * and detect when we want to bring the real link up.
+ * Return value is 1 if we need to bring up the link, 0 otherwise.
+ */
+int
+get_loop_output(void)
+{
+ int rv = 0;
+ int n;
+
+ if (new_style_driver) {
+ while ((n = read_packet(inpacket_buf)) > 0)
+ if (loop_frame(inpacket_buf, n))
+ rv = 1;
+ return rv;
+ }
+
+ while ((n = read(master_fd, inbuf, sizeof(inbuf))) > 0)
+ if (loop_chars(inbuf, n))
+ rv = 1;
+
+ if (n == 0)
+ fatal("eof on loopback");
+
+ if (errno != EWOULDBLOCK)
+ fatal("read from loopback: %m(%d)", errno);
+
+ return rv;
+}
+
+/********************************************************************
+ *
+ * ppp_send_config - configure the transmit characteristics of
+ * the ppp interface.
+ */
+
+void ppp_send_config (int unit,int mtu,u_int32_t asyncmap,int pcomp,int accomp)
+{
+ u_int x;
+ struct ifreq ifr;
+
+ SYSDEBUG ((LOG_DEBUG, "send_config: mtu = %d\n", mtu));
+/*
+ * Set the MTU and other parameters for the ppp device
+ */
+ memset (&ifr, '\0', sizeof (ifr));
+ strlcpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+ ifr.ifr_mtu = mtu;
+
+ if (ioctl(sock_fd, SIOCSIFMTU, (caddr_t) &ifr) < 0)
+ fatal("ioctl(SIOCSIFMTU): %m(%d)", errno);
+
+ if (!still_ppp())
+ return;
+ SYSDEBUG ((LOG_DEBUG, "send_config: asyncmap = %lx\n", asyncmap));
+ if (ioctl(ppp_fd, PPPIOCSASYNCMAP, (caddr_t) &asyncmap) < 0) {
+ if (!ok_error(errno))
+ fatal("ioctl(PPPIOCSASYNCMAP): %m(%d)", errno);
+ return;
+ }
+
+ x = get_flags(ppp_fd);
+ x = pcomp ? x | SC_COMP_PROT : x & ~SC_COMP_PROT;
+ x = accomp ? x | SC_COMP_AC : x & ~SC_COMP_AC;
+ x = sync_serial ? x | SC_SYNC : x & ~SC_SYNC;
+ set_flags(ppp_fd, x);
+}
+
+/********************************************************************
+ *
+ * ppp_set_xaccm - set the extended transmit ACCM for the interface.
+ */
+
+void ppp_set_xaccm (int unit, ext_accm accm)
+{
+ SYSDEBUG ((LOG_DEBUG, "set_xaccm: %08lx %08lx %08lx %08lx\n",
+ accm[0], accm[1], accm[2], accm[3]));
+
+ if (!still_ppp())
+ return;
+ if (ioctl(ppp_fd, PPPIOCSXASYNCMAP, accm) < 0 && errno != ENOTTY) {
+ if ( ! ok_error (errno))
+ warn("ioctl(set extended ACCM): %m(%d)", errno);
+ }
+}
+
+/********************************************************************
+ *
+ * ppp_recv_config - configure the receive-side characteristics of
+ * the ppp interface.
+ */
+
+void ppp_recv_config (int unit,int mru,u_int32_t asyncmap,int pcomp,int accomp)
+{
+ SYSDEBUG ((LOG_DEBUG, "recv_config: mru = %d\n", mru));
+/*
+ * If we were called because the link has gone down then there is nothing
+ * which may be done. Just return without incident.
+ */
+ if (!still_ppp())
+ return;
+/*
+ * Set the receiver parameters
+ */
+ if (ioctl(ppp_fd, PPPIOCSMRU, (caddr_t) &mru) < 0) {
+ if ( ! ok_error (errno))
+ error("ioctl(PPPIOCSMRU): %m(%d)", errno);
+ }
+ if (new_style_driver && ioctl(ppp_dev_fd, PPPIOCSMRU, (caddr_t) &mru) < 0)
+ error("Couldn't set MRU in generic PPP layer: %m");
+
+ SYSDEBUG ((LOG_DEBUG, "recv_config: asyncmap = %lx\n", asyncmap));
+ if (ioctl(ppp_fd, PPPIOCSRASYNCMAP, (caddr_t) &asyncmap) < 0) {
+ if (!ok_error(errno))
+ error("ioctl(PPPIOCSRASYNCMAP): %m(%d)", errno);
+ }
+}
+
+/********************************************************************
+ *
+ * ccp_test - ask kernel whether a given compression method
+ * is acceptable for use.
+ */
+
+int ccp_test (int unit, u_char *opt_ptr, int opt_len, int for_transmit)
+{
+ struct ppp_option_data data;
+
+ memset (&data, '\0', sizeof (data));
+ data.ptr = opt_ptr;
+ data.length = opt_len;
+ data.transmit = for_transmit;
+
+ if (ioctl(ppp_dev_fd, PPPIOCSCOMPRESS, (caddr_t) &data) >= 0)
+ return 1;
+
+ return (errno == ENOBUFS)? 0: -1;
+}
+
+/********************************************************************
+ *
+ * ccp_flags_set - inform kernel about the current state of CCP.
+ */
+
+void ccp_flags_set (int unit, int isopen, int isup)
+{
+ if (still_ppp()) {
+ int x = get_flags(ppp_dev_fd);
+ x = isopen? x | SC_CCP_OPEN : x &~ SC_CCP_OPEN;
+ x = isup? x | SC_CCP_UP : x &~ SC_CCP_UP;
+ set_flags (ppp_dev_fd, x);
+ }
+}
+
+/********************************************************************
+ *
+ * get_idle_time - return how long the link has been idle.
+ */
+int
+get_idle_time(u, ip)
+ int u;
+ struct ppp_idle *ip;
+{
+ return ioctl(ppp_dev_fd, PPPIOCGIDLE, ip) >= 0;
+}
+
+/********************************************************************
+ *
+ * get_ppp_stats - return statistics for the link.
+ */
+int
+get_ppp_stats(u, stats)
+ int u;
+ struct pppd_stats *stats;
+{
+ struct ifpppstatsreq req;
+
+ memset (&req, 0, sizeof (req));
+
+ req.stats_ptr = (caddr_t) &req.stats;
+ strlcpy(req.ifr__name, ifname, sizeof(req.ifr__name));
+ if (ioctl(sock_fd, SIOCGPPPSTATS, &req) < 0) {
+ error("Couldn't get PPP statistics: %m");
+ return 0;
+ }
+ stats->bytes_in = req.stats.p.ppp_ibytes;
+ stats->bytes_out = req.stats.p.ppp_obytes;
+ return 1;
+}
+
+/********************************************************************
+ *
+ * ccp_fatal_error - returns 1 if decompression was disabled as a
+ * result of an error detected after decompression of a packet,
+ * 0 otherwise. This is necessary because of patent nonsense.
+ */
+
+int ccp_fatal_error (int unit)
+{
+ int x = get_flags(ppp_dev_fd);
+
+ return x & SC_DC_FERROR;
+}
+
+/*
+ * path_to_route - determine the path to the proc file system data
+ */
+#define ROUTE_MAX_COLS 12
+FILE *route_fd = (FILE *) 0;
+static char route_buffer [512];
+static int route_dev_col, route_dest_col, route_gw_col;
+static int route_flags_col, route_mask_col;
+static int route_num_cols;
+
+static char *path_to_route (void);
+static int open_route_table (void);
+static void close_route_table (void);
+static int read_route_table (struct rtentry *rt);
+
+/********************************************************************
+ *
+ * path_to_procfs - find the path to the proc file system mount point
+ */
+
+static int path_to_procfs (const char *tail)
+{
+ struct mntent *mntent;
+ FILE *fp;
+
+ fp = fopen(MOUNTED, "r");
+ if (fp == NULL) {
+ /* Default the mount location of /proc */
+ strlcpy (route_buffer, "/proc", sizeof (route_buffer));
+ strlcat (route_buffer, tail, sizeof(route_buffer));
+ return 1;
+ }
+
+ while ((mntent = getmntent(fp)) != NULL) {
+ if (strcmp(mntent->mnt_type, MNTTYPE_IGNORE) == 0)
+ continue;
+ if (strcmp(mntent->mnt_type, "proc") == 0)
+ break;
+ }
+ fclose (fp);
+ if (mntent == 0)
+ return 0;
+
+ strlcpy(route_buffer, mntent->mnt_dir, sizeof (route_buffer));
+ strlcat (route_buffer, tail, sizeof(route_buffer));
+ return 1;
+}
+
+/********************************************************************
+ *
+ * path_to_route - find the path to the route tables in the proc file system
+ */
+
+static char *path_to_route (void)
+{
+ if (!path_to_procfs("/net/route")) {
+ error("proc file system not mounted");
+ return 0;
+ }
+ return (route_buffer);
+}
+
+/********************************************************************
+ *
+ * close_route_table - close the interface to the route table
+ */
+
+static void close_route_table (void)
+{
+ if (route_fd != (FILE *) 0) {
+ fclose (route_fd);
+ route_fd = (FILE *) 0;
+ }
+}
+
+/********************************************************************
+ *
+ * open_route_table - open the interface to the route table
+ */
+static char route_delims[] = " \t\n";
+
+static int open_route_table (void)
+{
+ char *path;
+
+ close_route_table();
+
+ path = path_to_route();
+ if (path == NULL)
+ return 0;
+
+ route_fd = fopen (path, "r");
+ if (route_fd == NULL) {
+ error("can't open %s: %m (%d)", path, errno);
+ return 0;
+ }
+
+ route_dev_col = 0; /* default to usual columns */
+ route_dest_col = 1;
+ route_gw_col = 2;
+ route_flags_col = 3;
+ route_mask_col = 7;
+ route_num_cols = 8;
+
+ /* parse header line */
+ if (fgets(route_buffer, sizeof(route_buffer), route_fd) != 0) {
+ char *p = route_buffer, *q;
+ int col;
+ for (col = 0; col < ROUTE_MAX_COLS; ++col) {
+ int used = 1;
+ if ((q = strtok(p, route_delims)) == 0)
+ break;
+ if (strcasecmp(q, "iface") == 0)
+ route_dev_col = col;
+ else if (strcasecmp(q, "destination") == 0)
+ route_dest_col = col;
+ else if (strcasecmp(q, "gateway") == 0)
+ route_gw_col = col;
+ else if (strcasecmp(q, "flags") == 0)
+ route_flags_col = col;
+ else if (strcasecmp(q, "mask") == 0)
+ route_mask_col = col;
+ else
+ used = 0;
+ if (used && col >= route_num_cols)
+ route_num_cols = col + 1;
+ p = NULL;
+ }
+ }
+
+ return 1;
+}
+
+/********************************************************************
+ *
+ * read_route_table - read the next entry from the route table
+ */
+
+static int read_route_table(struct rtentry *rt)
+{
+ char *cols[ROUTE_MAX_COLS], *p;
+ int col;
+
+ memset (rt, '\0', sizeof (struct rtentry));
+
+ if (fgets (route_buffer, sizeof (route_buffer), route_fd) == (char *) 0)
+ return 0;
+
+ p = route_buffer;
+ for (col = 0; col < route_num_cols; ++col) {
+ cols[col] = strtok(p, route_delims);
+ if (cols[col] == NULL)
+ return 0; /* didn't get enough columns */
+ p = NULL;
+ }
+
+ ((struct sockaddr_in *) &rt->rt_dst)->sin_addr.s_addr =
+ strtoul(cols[route_dest_col], NULL, 16);
+
+ ((struct sockaddr_in *) &rt->rt_gateway)->sin_addr.s_addr =
+ strtoul(cols[route_gw_col], NULL, 16);
+
+ ((struct sockaddr_in *) &rt->rt_genmask)->sin_addr.s_addr =
+ strtoul(cols[route_mask_col], NULL, 16);
+
+ rt->rt_flags = (short) strtoul(cols[route_flags_col], NULL, 16);
+ rt->rt_dev = cols[route_dev_col];
+
+ return 1;
+}
+
+/********************************************************************
+ *
+ * defaultroute_exists - determine if there is a default route
+ */
+
+static int defaultroute_exists (struct rtentry *rt)
+{
+ int result = 0;
+
+ if (!open_route_table())
+ return 0;
+
+ while (read_route_table(rt) != 0) {
+ if ((rt->rt_flags & RTF_UP) == 0)
+ continue;
+
+ if (((struct sockaddr_in *) (&rt->rt_dst))->sin_addr.s_addr == 0L) {
+ result = 1;
+ break;
+ }
+ }
+
+ close_route_table();
+ return result;
+}
+
+/*
+ * have_route_to - determine if the system has any route to
+ * a given IP address. `addr' is in network byte order.
+ * Return value is 1 if yes, 0 if no, -1 if don't know.
+ * For demand mode to work properly, we have to ignore routes
+ * through our own interface.
+ */
+int have_route_to(u_int32_t addr)
+{
+ struct rtentry rt;
+ int result = 0;
+
+ if (!open_route_table())
+ return -1; /* don't know */
+
+ while (read_route_table(&rt)) {
+ if ((rt.rt_flags & RTF_UP) == 0 || strcmp(rt.rt_dev, ifname) == 0)
+ continue;
+ if ((addr & ((struct sockaddr_in *)&rt.rt_genmask)->sin_addr.s_addr)
+ == ((struct sockaddr_in *)&rt.rt_dst)->sin_addr.s_addr) {
+ result = 1;
+ break;
+ }
+ }
+
+ close_route_table();
+ return result;
+}
+
+/********************************************************************
+ *
+ * sifdefaultroute - assign a default route through the address given.
+ */
+
+int sifdefaultroute (int unit, u_int32_t ouraddr, u_int32_t gateway)
+{
+ struct rtentry rt;
+
+ if (defaultroute_exists(&rt) && strcmp(rt.rt_dev, ifname) != 0) {
+ struct in_addr old_gateway =
+ ((struct sockaddr_in *) (&rt.rt_gateway))-> sin_addr;
+
+ if (old_gateway.s_addr != gateway)
+ error("not replacing existing default route to %s [%I]",
+ rt.rt_dev, old_gateway);
+ return 0;
+ }
+
+ memset (&rt, '\0', sizeof (rt));
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+ SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+
+ if (kernel_version > KVERSION(2,1,0)) {
+ SET_SA_FAMILY (rt.rt_genmask, AF_INET);
+ ((struct sockaddr_in *) &rt.rt_genmask)->sin_addr.s_addr = 0L;
+ }
+
+ ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = gateway;
+
+ rt.rt_flags = RTF_UP | RTF_GATEWAY | RTF_DEFAULT;
+ if (ioctl(sock_fd, SIOCADDRT, &rt) < 0) {
+ if ( ! ok_error ( errno ))
+ error("default route ioctl(SIOCADDRT): %m(%d)", errno);
+ return 0;
+ }
+
+ default_route_gateway = gateway;
+ return 1;
+}
+
+/********************************************************************
+ *
+ * cifdefaultroute - delete a default route through the address given.
+ */
+
+int cifdefaultroute (int unit, u_int32_t ouraddr, u_int32_t gateway)
+{
+ struct rtentry rt;
+
+ default_route_gateway = 0;
+
+ memset (&rt, '\0', sizeof (rt));
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+ SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+
+ if (kernel_version > KVERSION(2,1,0)) {
+ SET_SA_FAMILY (rt.rt_genmask, AF_INET);
+ ((struct sockaddr_in *) &rt.rt_genmask)->sin_addr.s_addr = 0L;
+ }
+
+ ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = gateway;
+
+ rt.rt_flags = RTF_UP | RTF_GATEWAY | RTF_DEFAULT;
+ if (ioctl(sock_fd, SIOCDELRT, &rt) < 0 && errno != ESRCH) {
+ if (still_ppp()) {
+ if ( ! ok_error ( errno ))
+ error("default route ioctl(SIOCDELRT): %m (%d)", errno);
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+/********************************************************************
+ *
+ * sifproxyarp - Make a proxy ARP entry for the peer.
+ */
+
+int sifproxyarp (int unit, u_int32_t his_adr)
+{
+ struct arpreq arpreq;
+
+ if (has_proxy_arp == 0) {
+ memset (&arpreq, '\0', sizeof(arpreq));
+
+ SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
+ ((struct sockaddr_in *) &arpreq.arp_pa)->sin_addr.s_addr = his_adr;
+ arpreq.arp_flags = ATF_PERM | ATF_PUBL;
+/*
+ * Get the hardware address of an interface on the same subnet
+ * as our local address.
+ */
+ if (!get_ether_addr(his_adr, &arpreq.arp_ha, proxy_arp_dev,
+ sizeof(proxy_arp_dev))) {
+ error("Cannot determine ethernet address for proxy ARP");
+ return 0;
+ }
+ strlcpy(arpreq.arp_dev, proxy_arp_dev, sizeof(arpreq.arp_dev));
+
+ if (ioctl(sock_fd, SIOCSARP, (caddr_t)&arpreq) < 0) {
+ if ( ! ok_error ( errno ))
+ error("ioctl(SIOCSARP): %m(%d)", errno);