From 25f18053feac88f6f7251f5f64630f39bdca423b Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Tue, 24 May 1994 05:59:03 +0000 Subject: [PATCH] Initial revision --- pppd/sys-linux.c | 801 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 801 insertions(+) create mode 100644 pppd/sys-linux.c diff --git a/pppd/sys-linux.c b/pppd/sys-linux.c new file mode 100644 index 0000000..42fadaa --- /dev/null +++ b/pppd/sys-linux.c @@ -0,0 +1,801 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#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; +} -- 2.39.2