+/*
+ * sys-linux.c - System-dependent procedures for setting up
+ * PPP interfaces on Linux systems
+ *
+ * Copyright (c) 1989 Carnegie Mellon University.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by Carnegie Mellon University. The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/*
+ * TODO:
+ */
+
+#include <stdio.h>
+#include <syslog.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/errno.h>
+#include <mntent.h>
+
+#include <net/if.h>
+#include <linux/ppp.h>
+#include <linux/route.h>
+#include <linux/if_ether.h>
+#include <netinet/in.h>
+#include <net/if_ppp.h>
+
+#include "pppd.h"
+#include "ppp.h"
+#include "fsm.h"
+#include "ipcp.h"
+
+static int initdisc = -1; /* Initial TTY discipline */
+static int prev_kdebugflag = 0;
+extern int kdebugflag;
+extern u_long netmask;
+
+#define MAX_IFS 32
+
+/* prototypes */
+void die __ARGS((int));
+
+/*
+ * SET_SA_FAMILY - set the sa_family field of a struct sockaddr,
+ * if it exists.
+ */
+
+#define SET_SA_FAMILY(addr, family) \
+ memset ((char *) &(addr), '\0', sizeof(addr)); \
+ addr.sa_family = (family);
+
+/*
+ * set_kdebugflag - Define the debugging level for the kernel
+ */
+
+int set_kdebugflag (int requested_level)
+{
+ if (ioctl(fd, PPPIOCGDEBUG, &prev_kdebugflag) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCGDEBUG): %m");
+ return (0);
+ }
+
+ if (prev_kdebugflag != requested_level) {
+ if (ioctl(fd, PPPIOCSDEBUG, &requested_level) < 0) {
+ syslog (LOG_ERR, "ioctl(PPPIOCSDEBUG): %m");
+ return (0);
+ }
+ syslog(LOG_INFO, "set kernel debugging level to %d", requested_level);
+ }
+ return (1);
+}
+
+/*
+ * establish_ppp - Turn the serial port into a ppp interface.
+ */
+
+void establish_ppp (void)
+{
+ int pppdisc = N_PPP;
+
+ if (ioctl(fd, TIOCEXCL, 0) < 0) {
+ syslog (LOG_WARNING, "ioctl(TIOCEXCL): %m");
+ }
+
+ if (ioctl(fd, TIOCGETD, &initdisc) < 0) {
+ syslog(LOG_ERR, "ioctl(TIOCGETD): %m");
+ die (1);
+ }
+
+ if (ioctl(fd, TIOCSETD, &pppdisc) < 0) {
+ syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
+ die (1);
+ }
+
+ if (ioctl(fd, PPPIOCGUNIT, &ifunit) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCGUNIT): %m");
+ die (1);
+ }
+
+ set_kdebugflag (kdebugflag);
+}
+
+/*
+ * disestablish_ppp - Restore the serial port to normal operation.
+ * This shouldn't call die() because it's called from die().
+ */
+
+void disestablish_ppp(void)
+{
+ int x;
+ char *s;
+
+ if (initdisc >= 0) {
+ set_kdebugflag (prev_kdebugflag);
+ /*
+ * Check whether the link seems not to be 8-bit clean.
+ */
+ if (ioctl(fd, PPPIOCGFLAGS, (caddr_t) &x) == 0) {
+ s = NULL;
+ switch (~x & (SC_RCV_B7_0|SC_RCV_B7_1|SC_RCV_EVNP|SC_RCV_ODDP)) {
+ case SC_RCV_B7_0:
+ s = "bit 7 set to 1";
+ break;
+ case SC_RCV_B7_1:
+ s = "bit 7 set to 0";
+ break;
+ case SC_RCV_EVNP:
+ s = "odd parity";
+ break;
+ case SC_RCV_ODDP:
+ s = "even parity";
+ break;
+ }
+ if (s != NULL) {
+ syslog(LOG_WARNING, "Serial link is not 8-bit clean:");
+ syslog(LOG_WARNING, "All received characters had %s", s);
+ }
+ }
+
+ if (ioctl(fd, TIOCSETD, &initdisc) < 0)
+ syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
+
+ if (ioctl(fd, TIOCNXCL, 0) < 0)
+ syslog (LOG_WARNING, "ioctl(TIOCNXCL): %m");
+
+ initdisc = -1;
+ }
+}
+
+/*
+ * output - Output PPP packet.
+ */
+
+void output (int unit, unsigned char *p, int len)
+{
+ if (unit != 0)
+ MAINDEBUG((LOG_WARNING, "output: unit != 0!"));
+
+ if (debug)
+ log_packet(p, len, "sent ");
+
+ if (write(fd, p, len) < 0) {
+ syslog(LOG_ERR, "write: %m");
+ die(1);
+ }
+}
+
+/*
+ * read_packet - get a PPP packet from the serial device.
+ */
+
+int read_packet (unsigned char *buf)
+{
+ int len;
+
+ len = read(fd, buf, MTU + DLLHEADERLEN);
+ if (len < 0) {
+ if (errno == EWOULDBLOCK) {
+#if 0
+ MAINDEBUG((LOG_DEBUG, "read(fd): EWOULDBLOCK"));
+#endif
+ return -1;
+ }
+ syslog(LOG_ERR, "read(fd): %m");
+ die(1);
+ }
+ return len;
+}
+
+/*
+ * ppp_send_config - configure the transmit characteristics of
+ * the ppp interface.
+ */
+void ppp_send_config (int unit,int mtu,u_long asyncmap,int pcomp,int accomp)
+{
+ u_int x;
+ struct ifreq ifr;
+
+ MAINDEBUG ((LOG_DEBUG, "send_config: mtu = %d\n", mtu));
+ strncpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+ ifr.ifr_mtu = mtu;
+ if (ioctl(s, SIOCSIFMTU, (caddr_t) &ifr) < 0) {
+ syslog(LOG_ERR, "ioctl(SIOCSIFMTU): %m");
+ quit();
+ }
+
+ MAINDEBUG ((LOG_DEBUG, "send_config: asyncmap = %lx\n", asyncmap));
+ if (ioctl(fd, PPPIOCSASYNCMAP, (caddr_t) &asyncmap) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCSASYNCMAP): %m");
+ quit();
+ }
+
+ if (ioctl(fd, PPPIOCGFLAGS, (caddr_t) &x) < 0) {
+ syslog(LOG_ERR, "ioctl (PPPIOCGFLAGS): %m");
+ quit();
+ }
+
+ x = pcomp ? x | SC_COMP_PROT : x & ~SC_COMP_PROT;
+ x = accomp ? x | SC_COMP_AC : x & ~SC_COMP_AC;
+
+ MAINDEBUG ((LOG_DEBUG, "send_config: flags = %x\n", x));
+ if (ioctl(fd, PPPIOCSFLAGS, (caddr_t) &x) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
+ quit();
+ }
+}
+
+/*
+ * ppp_set_xaccm - set the extended transmit ACCM for the interface.
+ */
+void
+ppp_set_xaccm(unit, accm)
+ int unit;
+ ext_accm accm;
+{
+ MAINDEBUG ((LOG_DEBUG, "set_xaccm: %08lx %08lx %08lx %08lx\n",
+ accm[0], accm[1], accm[2], accm[3]));
+ if (ioctl(fd, PPPIOCSXASYNCMAP, accm) < 0 && errno != ENOTTY)
+ syslog(LOG_WARNING, "ioctl(set extended ACCM): %m");
+}
+
+/*
+ * ppp_recv_config - configure the receive-side characteristics of
+ * the ppp interface.
+ */
+void ppp_recv_config (int unit,int mru,u_long asyncmap,int pcomp,int accomp)
+{
+ u_int x;
+
+ MAINDEBUG ((LOG_DEBUG, "recv_config: mru = %d\n", mru));
+ if (ioctl(fd, PPPIOCSMRU, (caddr_t) &mru) < 0)
+ syslog(LOG_ERR, "ioctl(PPPIOCSMRU): %m");
+
+ MAINDEBUG ((LOG_DEBUG, "recv_config: asyncmap = %lx\n", asyncmap));
+ if (ioctl(fd, PPPIOCRASYNCMAP, (caddr_t) &asyncmap) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCRASYNCMAP): %m");
+ quit();
+ }
+
+ if (ioctl(fd, PPPIOCGFLAGS, (caddr_t) &x) < 0) {
+ syslog(LOG_ERR, "ioctl (PPPIOCGFLAGS): %m");
+ quit();
+ }
+
+ x = !accomp? x | SC_REJ_COMP_AC: x &~ SC_REJ_COMP_AC;
+ MAINDEBUG ((LOG_DEBUG, "recv_config: flags = %x\n", x));
+ if (ioctl(fd, PPPIOCSFLAGS, (caddr_t) &x) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
+ quit();
+ }
+}
+
+/*
+ * sifvjcomp - config tcp header compression
+ */
+
+int sifvjcomp (int u, int vjcomp, int cidcomp, int maxcid)
+{
+ u_int x;
+
+ if (ioctl(fd, PPPIOCGFLAGS, (caddr_t) &x) < 0) {
+ syslog(LOG_ERR, "ioctl (PPPIOCGFLAGS): %m");
+ return 0;
+ }
+
+ x = vjcomp ? x | SC_COMP_TCP : x &~ SC_COMP_TCP;
+ x = cidcomp ? x & ~SC_NO_TCP_CCID : x | SC_NO_TCP_CCID;
+
+ if(ioctl(fd, PPPIOCSFLAGS, (caddr_t) &x) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
+ return 0;
+ }
+
+ if (vjcomp) {
+ if (ioctl (fd, PPPIOCSMAXCID, (caddr_t) &maxcid) < 0) {
+ syslog (LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+/*
+ * sifup - Config the interface up and enable IP packets to pass.
+ */
+
+int sifup (int u)
+{
+ struct ifreq ifr;
+
+ strncpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+ if (ioctl(s, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
+ syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
+ return 0;
+ }
+
+ ifr.ifr_flags |= (IFF_UP | IFF_POINTOPOINT);
+ if (ioctl(s, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
+ syslog(LOG_ERR, "ioctl(SIOCSIFFLAGS): %m");
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * sifdown - Config the interface down and disable IP.
+ */
+
+int sifdown (int u)
+{
+ struct ifreq ifr;
+
+ strncpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+ if (ioctl(s, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
+ syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
+ return 0;
+ }
+
+ ifr.ifr_flags &= ~IFF_UP;
+ ifr.ifr_flags |= IFF_POINTOPOINT;
+ if (ioctl(s, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
+ syslog(LOG_ERR, "ioctl(SIOCSIFFLAGS): %m");
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * sifaddr - Config the interface IP addresses and netmask.
+ */
+
+int sifaddr (int unit, int our_adr, int his_adr, int net_mask)
+{
+ struct ifreq ifr;
+ struct rtentry rt;
+
+ SET_SA_FAMILY (ifr.ifr_addr, AF_INET);
+ SET_SA_FAMILY (ifr.ifr_dstaddr, AF_INET);
+ SET_SA_FAMILY (ifr.ifr_netmask, AF_INET);
+
+ strncpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+/*
+ * Set our IP address
+ */
+ ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr.s_addr = our_adr;
+ if (ioctl(s, SIOCSIFADDR, (caddr_t) &ifr) < 0) {
+ if (errno != EEXIST)
+ syslog (LOG_ERR, "ioctl(SIOCAIFADDR): %m");
+ else
+ syslog (LOG_WARNING, "ioctl(SIOCAIFADDR): Address already exists");
+ return (0);
+ }
+/*
+ * Set the gateway address
+ */
+ ((struct sockaddr_in *) &ifr.ifr_dstaddr)->sin_addr.s_addr = his_adr;
+ if (ioctl(s, SIOCSIFDSTADDR, (caddr_t) &ifr) < 0) {
+ syslog (LOG_ERR, "ioctl(SIOCSIFDSTADDR): %m");
+ return (0);
+ }
+/*
+ * Set the netmask
+ */
+ if (net_mask != 0) {
+ ((struct sockaddr_in *) &ifr.ifr_netmask)->sin_addr.s_addr = net_mask;
+ if (ioctl(s, SIOCSIFNETMASK, (caddr_t) &ifr) < 0) {
+ syslog (LOG_ERR, "ioctl(SIOCSIFNETMASK): %m");
+ return (0);
+ }
+ }
+/*
+ * Add the device route
+ */
+ memset (&rt, '\0', sizeof (rt));
+
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+ SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+ rt.rt_dev = ifname; /* MJC */
+
+ ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = 0;
+ ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr = his_adr;
+ rt.rt_flags = RTF_UP | RTF_HOST;
+
+ if (ioctl(s, SIOCADDRT, &rt) < 0) {
+ syslog (LOG_ERR, "ioctl(SIOCADDRT) device route: %m");
+ return (0);
+ }
+ return 1;
+}
+
+/*
+ * cifaddr - Clear the interface IP addresses, and delete routes
+ * through the interface if possible.
+ */
+
+int cifaddr (int unit, int our_adr, int his_adr)
+{
+ struct rtentry rt;
+/*
+ * Delete the route through the device
+ */
+ memset (&rt, '\0', sizeof (rt));
+
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+ SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+ rt.rt_dev = ifname; /* MJC */
+
+ ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = 0;
+ ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr = his_adr;
+ rt.rt_flags = RTF_UP | RTF_HOST;
+
+ if (ioctl(s, SIOCDELRT, &rt) < 0) {
+ syslog (LOG_ERR, "ioctl(SIOCDELRT) device route: %m");
+ return (0);
+ }
+ return 1;
+}
+
+/*
+ * path_to_route - determine the path to the proc file system data
+ */
+
+FILE *route_fd = (FILE *) 0;
+static char route_buffer [100];
+
+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);
+static int defaultroute_exists (void);
+
+/*
+ * path_to_route - find the path to the route tables in the proc file system
+ */
+
+static char *path_to_route (void)
+{
+ struct mntent *mntent;
+ FILE *fp;
+
+ fp = fopen (MOUNTED, "r");
+ if (fp != 0) {
+ while ((mntent = getmntent (fp)) != 0) {
+ if (strcmp (mntent->mnt_type, MNTTYPE_IGNORE) == 0)
+ continue;
+
+ if (strcmp (mntent->mnt_type, "proc") == 0) {
+ strncpy (route_buffer, mntent->mnt_dir,
+ sizeof (route_buffer)-10);
+ route_buffer [sizeof (route_buffer)-10] = '\0';
+ strcat (route_buffer, "/net/route");
+
+ fclose (fp);
+ return (route_buffer);
+ }
+ }
+ fclose (fp);
+ }
+ syslog (LOG_ERR, "proc file system not mounted");
+ return 0;
+}
+
+/*
+ * open_route_table - open the interface to the route table
+ */
+
+static int open_route_table (void)
+{
+ char *path;
+
+ if (route_fd != (FILE *) 0)
+ close_route_table();
+
+ path = path_to_route();
+ if (path == NULL)
+ return 0;
+
+ route_fd = fopen (path, "r");
+ if (route_fd == (FILE *) 0) {
+ syslog (LOG_ERR, "can not open %s: %m", path);
+ return 0;
+ }
+
+ /* read and discard the header line. */
+ if (fgets (route_buffer, sizeof (route_buffer), route_fd) == (char *) 0) {
+ close_route_table();
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * 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;
+ }
+}
+
+/*
+ * read_route_table - read the next entry from the route table
+ */
+
+static int read_route_table (struct rtentry *rt)
+{
+ static char delims[] = " \t\n";
+ char *dev_ptr, *ptr, *dst_ptr, *gw_ptr, *flag_ptr;
+
+ if (fgets (route_buffer, sizeof (route_buffer), route_fd) == (char *) 0)
+ return 0;
+
+ memset (rt, '\0', sizeof (struct rtentry));
+
+ dev_ptr = strtok (route_buffer, delims); /* interface name */
+ dst_ptr = strtok (NULL, delims); /* destination address */
+ gw_ptr = strtok (NULL, delims); /* gateway */
+ flag_ptr = strtok (NULL, delims); /* flags */
+#if 0
+ ptr = strtok (NULL, delims); /* reference count */
+ ptr = strtok (NULL, delims); /* useage count */
+ ptr = strtok (NULL, delims); /* metric */
+ ptr = strtok (NULL, delims); /* mask */
+#endif
+
+ ((struct sockaddr_in *) &rt->rt_dst)->sin_addr.s_addr =
+ strtoul (dst_ptr, NULL, 16);
+
+ ((struct sockaddr_in *) &rt->rt_gateway)->sin_addr.s_addr =
+ strtoul (gw_ptr, NULL, 16);
+
+ rt->rt_flags = (short) strtoul (flag_ptr, NULL, 16);
+ rt->rt_dev = dev_ptr;
+
+ return 1;
+}
+
+/*
+ * defaultroute_exists - determine if there is a default route
+ */
+
+static int defaultroute_exists (void)
+{
+ 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) {
+ syslog (LOG_ERR,
+ "ppp not replacing existing default route to %s[%s]",
+ rt.rt_dev,
+ inet_ntoa (((struct sockaddr_in *) &rt.rt_gateway)->
+ 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, int gateway)
+{
+ struct rtentry rt;
+
+ if (defaultroute_exists())
+ return 0;
+
+ memset (&rt, '\0', sizeof (rt));
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+ SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+ ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = gateway;
+
+ rt.rt_flags = RTF_UP | RTF_GATEWAY;
+ if (ioctl(s, SIOCADDRT, &rt) < 0) {
+ syslog (LOG_ERR, "default route ioctl(SIOCADDRT): %m");
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * cifdefaultroute - delete a default route through the address given.
+ */
+
+int cifdefaultroute (int unit, int gateway)
+{
+ struct rtentry rt;
+
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+ SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+ ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = gateway;
+
+ rt.rt_flags = RTF_UP | RTF_GATEWAY;
+ if (ioctl(s, SIOCDELRT, &rt) < 0) {
+ syslog (LOG_ERR, "default route ioctl(SIOCDELRT): %m");
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * sifproxyarp - Make a proxy ARP entry for the peer.
+ */
+
+int sifproxyarp (int unit, u_long his_adr)
+{
+ struct arpreq arpreq;
+
+ memset (&arpreq, '\0', sizeof(arpreq));
+/*
+ * Get the hardware address of an interface on the same subnet
+ * as our local address.
+ */
+ if (!get_ether_addr(his_adr, &arpreq.arp_ha)) {
+ syslog(LOG_ERR, "Cannot determine ethernet address for proxy ARP");
+ return 0;
+ }
+
+ 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;
+
+ if (ioctl(s, SIOCSARP, (caddr_t)&arpreq) < 0) {
+ syslog(LOG_ERR, "ioctl(SIOCSARP): %m");
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * cifproxyarp - Delete the proxy ARP entry for the peer.
+ */
+
+int cifproxyarp (int unit, u_long his_adr)
+{
+ struct arpreq arpreq;
+
+ 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;
+ if (ioctl(s, SIOCDARP, (caddr_t)&arpreq) < 0) {
+ syslog(LOG_WARNING, "ioctl(SIOCDARP): %m");
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * get_ether_addr - get the hardware address of an interface on the
+ * the same subnet as ipaddr.
+ */
+
+int get_ether_addr (u_long ipaddr, struct sockaddr *hwaddr)
+{
+ struct ifreq *ifr, *ifend, *ifp;
+ int i;
+ u_long ina, mask;
+ struct sockaddr_dl *dla;
+ struct ifreq ifreq;
+ struct ifconf ifc;
+ struct ifreq ifs[MAX_IFS];
+
+ ifc.ifc_len = sizeof(ifs);
+ ifc.ifc_req = ifs;
+ if (ioctl(s, SIOCGIFCONF, &ifc) < 0) {
+ syslog(LOG_ERR, "ioctl(SIOCGIFCONF): %m");
+ return 0;
+ }
+ MAINDEBUG ((LOG_DEBUG, "proxy arp: scanning %d interfaces for IP %s",
+ ifc.ifc_len / sizeof(struct ifreq), ip_ntoa(ipaddr)));
+/*
+ * Scan through looking for an interface with an Internet
+ * address on the same subnet as `ipaddr'.
+ */
+ ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
+ for (ifr = ifc.ifc_req; ifr < ifend; ifr++) {
+ if (ifr->ifr_addr.sa_family == AF_INET) {
+ ina = ((struct sockaddr_in *) &ifr->ifr_addr)->sin_addr.s_addr;
+ strncpy(ifreq.ifr_name, ifr->ifr_name, sizeof(ifreq.ifr_name));
+ MAINDEBUG ((LOG_DEBUG, "proxy arp: examining interface %s",
+ ifreq.ifr_name));
+/*
+ * Check that the interface is up, and not point-to-point
+ * or loopback.
+ */
+ if (ioctl(s, SIOCGIFFLAGS, &ifreq) < 0)
+ continue;
+ if ((ifreq.ifr_flags &
+ (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT|IFF_LOOPBACK|IFF_NOARP))
+ != (IFF_UP|IFF_BROADCAST))
+ continue;
+/*
+ * Get its netmask and check that it's on the right subnet.
+ */
+ if (ioctl(s, SIOCGIFNETMASK, &ifreq) < 0)
+ continue;
+ mask = ((struct sockaddr_in *) &ifreq.ifr_addr)->sin_addr.s_addr;
+ MAINDEBUG ((LOG_DEBUG, "proxy arp: interface addr %s mask %lx",
+ ip_ntoa(ina), ntohl(mask)));
+ if (((ipaddr ^ ina) & mask) != 0)
+ continue;
+ break;
+ }
+ }
+
+ if (ifr >= ifend)
+ return 0;
+
+ syslog(LOG_INFO, "found interface %s for proxy arp", ifreq.ifr_name);
+/*
+ * Now get the hardware address.
+ */
+ if (ioctl (s, SIOCGIFHWADDR, &ifreq) < 0) {
+ syslog(LOG_ERR, "SIOCGIFHWADDR(%s): %m", ifreq.ifr_name);
+ return 0;
+ }
+
+ hwaddr->sa_family = ARPHRD_ETHER;
+ memcpy (&hwaddr->sa_data, &ifr->ifr_hwaddr, ETH_ALEN);
+
+ MAINDEBUG ((LOG_DEBUG,
+ "proxy arp: found hwaddr %02x:%02x:%02x:%02x:%02x:%02x",
+ (int) ((unsigned char *) &ifr->ifr_hwaddr)[0],
+ (int) ((unsigned char *) &ifr->ifr_hwaddr)[1],
+ (int) ((unsigned char *) &ifr->ifr_hwaddr)[2],
+ (int) ((unsigned char *) &ifr->ifr_hwaddr)[3],
+ (int) ((unsigned char *) &ifr->ifr_hwaddr)[4],
+ (int) ((unsigned char *) &ifr->ifr_hwaddr)[5]));
+ return 1;
+}
+
+/*
+ * ppp_available - check whether the system has any ppp interfaces
+ * (in fact we check whether we can do an ioctl on ppp0).
+ */
+
+int ppp_available(void)
+{
+ int s, ok;
+ struct ifreq ifr;
+
+ s = socket(AF_INET, SOCK_DGRAM, 0);
+ if (s < 0)
+ return 1; /* can't tell - maybe we're not root */
+
+ strncpy(ifr.ifr_name, "ppp0", sizeof (ifr.ifr_name));
+ ok = ioctl(s, SIOCGIFFLAGS, (caddr_t) &ifr) >= 0;
+ close(s);
+
+ return ok;
+}
projects / ppp.git / commitdiff